JP2003050065A - Method of manufacturing pipe for freezing cycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a pipe for a freezing cycle, which dispenses with lead soldering for contact. SOLUTION: This manufacturing method for a pipe for a freezing cycle includes a process of processing a groove which is continuous in the longitudinal direction of the periphery of the pipe and a process of processing it so that the opening dimension of the groove may be smaller than the outside diameter dimension of a thin-diameter pipe and fixing both after arranging the pipe thinner in diameter than the above pipe in the groove made in the above pipe.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a refrigerating cycle pipe used in a refrigerating apparatus such as a refrigerator, a freezer, and a dehumidifier that compresses a refrigerant to cool it, and particularly to a small diameter pipe ( (Capillary tube; capillary tube, etc.) and a method for producing a pipe with a small diameter tube.

[0002]

2. Description of the Related Art A conventional refrigeration cycle for a refrigerator or the like is described in, for example, "Refrigeration and Air Conditioning Technology", Vol. 23, No. 264, page 25, and an outline of the conventional refrigeration cycle configuration is shown in FIG. 13 is used for the explanation. FIG. 13 is a transverse cross-sectional view of the heat exchange section of the suction pipe and the capillary tube (thin diameter tube for depressurizing the refrigerant) in FIG.

In FIG. 12, 21 is a compressor, 22 is a condenser, 23 is a capillary tube (a small diameter tube for depressurizing the refrigerant), 24 is an evaporator, and 25 is a suction pipe, which is compressed by the compressor 21. The high-temperature and high-pressure gas becomes a high-pressure liquid in the condenser 22, is decompressed by the capillary tube 23 to become a low-temperature and low-pressure gas-liquid refrigerant, absorbs heat in the evaporator 24 to be gasified, and is stored in the storage by a storage fan (not shown). Exchange heat with the air. After that, the gas constitutes a cycle of returning to the compressor 21 again through the suction pipe 25.

Here, the suction pipe 25 and the capillary pipe 23 are joined by lead solder 26 for heat exchange, which improves the effective refrigerating capacity of the refrigeration cycle and realizes energy saving of a refrigerator or the like. This is because This effect is
Evaporation temperature like in a home refrigerator or freezer
Looking at the low refrigeration cycle around 30 ℃,
It has become an important means for improving efficiency by about 15%.

Next, the cross-sectional structure of the conventional suction pipe 25 and the capillary tube 23 will be described with reference to FIG. 13. 26 is lead solder, and the capillary tube 23 and suction pipe 25 are in contact with each other via the lead solder 26 to perform heat exchange. .

Next, an explanation of the construction of a conventional assembly of a suction pipe and a capillary tube is shown in FIG. FIG. 15 is an explanatory view of a refrigeration cycle piping configuration when the assembly of the suction pipe is incorporated in the refrigerator side. In FIG. 12, 25 is a suction pipe used between the compressor and the evaporator, and its diameter is 8 to 8.5 m.
As shown in FIG. 14, relay pipes 25a and 25b for connecting cycle components on the refrigerator side are connected to both ends of the pipe, which is thicker than other pipes.

When the suction pipe 25 is set to have a large diameter in this way, it cannot be directly connected to the cycle parts on the refrigerator side. Therefore, as shown in FIG. 14, normally, both ends of the suction pipe 25 (large-diameter pipe) are connected. To relay pipe 25
It is necessary to interpose a and 25b. Therefore, before the assembly of the suction pipe 25, the intermediate pipes 25a and 25b are assembled together with the capillaries 23 on the suction pipe 25 side before being assembled on the product side. C and D in the figure are welding points that connect the suction pipe and the relay pipe.

Reference numeral 23 is a capillary tube, which is joined to the outer peripheral surface of the suction pipe 25 by a lead solder 26 as shown in FIGS. 13 and 14 so as to perform heat exchange. The soldering length L should be about 2000 to 3000 mm,
As mentioned above, it is a means for improving the effective refrigerating capacity of the refrigerating cycle.

Here, the diameter of the suction pipe 25 is 8.5.
Although it is as large as mm, this is intended to improve the refrigerating capacity by suppressing the flow resistance in the refrigeration cycle pipe as much as possible during the cooling operation of the refrigerator, thereby suppressing the output value of the compressor. ing. Therefore, the refrigerating capacity of a refrigerator or the like is a synergistic effect due to the combination of the heat exchange length L by soldering the capillary tube 23 and the suction pipe 25 and the inner diameter dimension of the suction pipe 25 (the size of the pipe inner cross-sectional area) to achieve the refrigeration cycle. The necessary refrigerating capacity is secured.

Next, the refrigerating cycle connection structure in which the suction pipe assembly is incorporated in the refrigerator is as shown in FIG. 15, and the suction pipe 25 and the capillary tube 23 are the inner box 29 and the box body 30.
It is embedded in the urethane foam heat insulating material 31 filled in between. Therefore, the welding points of the intermediate pipe section are C, D
The two locations are embedded in the urethane foam heat insulating material 31. The pipe connection to the refrigerator side is the relay pipe 25 from inside the heat insulating material to the evaporator side arranged in the refrigerator.
a is connected to the evaporator side pipe 24a (point A).

On the other hand, a compressor 21, a condenser 22 and the like are provided in the machine room below the box body 30. The pipe 21a on the compressor 21 side is connected (point B) with a relay pipe 25b extending from the heat insulating material 31. In such a conventional suction pipe structure,
In addition to the increase in the unit price of the suction pipe assembly due to the intermediary of the relay pipe component, there is a problem in terms of reliability against refrigerant leakage and the like on the refrigeration cycle side due to an increase in the number of welding points.

[0012]

In the refrigeration cycle having the above-mentioned structure, the conventional product has been soldered with lead as a joining material in order to bring two pipes into contact with each other. However, in such a structure, lead solder is used. It is in an unfavorable situation in terms of hygiene and environmental use.

Further, in order to integrate the two pipes with a joining material, a device for melting lead solder, a device for heating / cooling two parts, and the like are complicated in terms of equipment. It was a factor of increasing the unit price of the product. In addition, since lead solder parts will be added, the cost will increase accordingly.

Further, since the suction pipe and the capillary tube are integrated in a complicated facility, the degree of contact between the soldering of the two pipes tends to vary, which causes a reduction in the refrigerating capacity of the product. Was there. Also,
In the conventional suction pipe, the pipe diameter is set larger than other pipe diameters in order to improve the refrigerating capacity. Therefore, when assembled into a product, both ends of the suction pipe cannot be connected to the refrigeration cycle. Therefore, intermediate pipes are added to both ends of the suction pipe to perform cycle connection with the product side. Such a method has increased the unit price of the suction pipe assembly due to an increase in the number of relay pipe parts. Furthermore, the addition of the intermediate pipe increases the number of welded parts, resulting in a decrease in reliability. The present invention solves the above-mentioned problems of the prior art, can be manufactured at low cost with fewer processing steps, structurally has improved strength, and facilitates reuse of used materials. It is an object of the present invention to provide a method for manufacturing a pipe for a refrigeration cycle having an improved refrigeration function.

[0015]

In order to solve the above-mentioned problems, the present inventor has conducted extensive studies and, as a result, formed a groove in the longitudinal direction of the suction pipe, and after disposing a capillary tube in this groove, the groove is formed. The inventors have found that an excellent heat transfer function can be exerted by processing the opening smaller than the outer diameter of the capillary and closely adhering to each other, and completed the present invention.

The present invention made on the basis of the above-mentioned findings includes a step of processing a groove continuous in the longitudinal direction of the outer periphery of the pipe, and after disposing a tube having a diameter smaller than that of the pipe in the groove formed in the pipe. The gist is a method for manufacturing a pipe for a refrigeration cycle, which is characterized in that the opening size of the groove is processed so as to be smaller than the outer diameter size of the small diameter pipe, and both are fixed.

Further, according to the present invention, prior to the step of processing a groove continuous in the longitudinal direction of the outer circumference of the pipe, both end portions of the pipe where the groove is formed have an outer diameter smaller than that of the portion where the groove is formed. Forming, further, after accommodating and fixing the small-diameter pipe in the groove formed in the longitudinal direction of the pipe outer periphery, bending and forming both into a predetermined shape, or in the groove formed in the longitudinal direction of the pipe outer periphery After accommodating and fixing the small-diameter tube, bend and shape both to be parallel to the horizontal plane to form a predetermined shape, with the center of the small-diameter tube housed in the groove and the small-diameter tube A gist of the method for producing a pipe for a refrigerating cycle is to add a step of bending the pipe with a small diameter pipe into a predetermined shape so that a line connecting the center of the pipe is orthogonal to the horizontal plane.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION The structure and operation of the present invention will be described.
In the present invention, the step of processing a continuous groove in the longitudinal direction of the outer circumference of the pipe, and arranging a pipe having a diameter smaller than that of the pipe in the groove formed in the pipe, and then setting the opening dimension of the groove to that of the small diameter pipe. Refrigeration cycle pipes are manufactured by processing them so that they are smaller than the outer diameter and fixing them together, so that two parts can be integrated and heat exchange equivalent to that of conventional products without using a joining material. Is possible and is environmentally preferable.

Further, it becomes unnecessary to use complicated equipment for integrating the two parts through the joining material as in the conventional case,
The cost can be reduced. Furthermore, the configuration of the present invention is
Since the capillaries are installed in the grooves formed in the thick pipe so that the diameter of the thick pipe falls within the circle, the capillary inside the groove makes good heat exchange by the surface contact with the outer peripheral surface made by the thick pipe. Can be done.

Further, both ends of the thick pipe are subjected to a drawing process or the like, and a continuous groove is provided except for this portion. By doing so, it becomes possible to connect the small diameter pipe parts at both ends of the thick pipe to the compressor side pipe and the evaporator side pipe on the product side, and the refrigeration cycle can be configured without the conventional relay pipe. Can be cheaper.

Further, a pipe with a capillary tube, in which the capillary tube is housed and fixed in a groove formed on the outer circumference of the thick pipe, is bent and formed into a predetermined shape. By doing so, the degree of adhesion between the pipe and the capillary does not change even if bending is performed, and there is no variation in the degree of adhesion.

Further, in a refrigerating apparatus for forming a predetermined shape by bending a pipe with a capillary in which a capillary is housed and fixed in a groove formed on the outer peripheral portion of a thick pipe so as to be parallel to a horizontal plane, The pipe with a capillary tube was bent and formed into a predetermined shape so that a line connecting the center of the capillary tube and the center of the pipe with a capillary tube was orthogonal to the horizontal plane. By doing so, the adhesion between the pipe and the capillaries does not change even if bending is performed as described above, and there is no variation in the adhesion. in this case,
The bending stress of the capillaries in the groove can be minimized. In the present invention, since the capillaries are closely arranged in the circle of the suction pipe, the handling in the bending process is improved, and the efficiency of the manufacturing process can be improved.

[0023]

Embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited thereto. Figure 1
FIG. 4 is an explanatory view showing the main points of a refrigeration cycle configured using the refrigeration cycle pipe manufactured according to the present invention. In the figure, 1 is a compressor, 2 is a condenser, 3 is a capillary tube, 4 is an evaporator, and 5 is a suction pipe. The high-temperature and high-pressure gas compressed by the compressor 1 is the same as that of the conventional example (FIG. 12). ) The same as the refrigeration cycle explained in), each refrigeration cycle part 1 → 2 →
Refrigerant circulates in the order of 3 → 4 → 5 and returns to 1 again.

The component construction of the suction pipe 5 and the capillary tube 3 will be described with reference to FIGS. 2, 3, 4 and 5. FIG. 2 is an explanatory view of an assembly structure of the suction pipe 5 and the capillary tube 3 of FIG. 1, and FIG. 3 is a sectional view of a main part before crimping and fixing the capillary tube 3 in the groove of the large diameter pipe 5a. FIG. 4 is an explanatory view showing a contact situation in the YY cross section of FIG. 2, and FIG.
It is a transverse cross-sectional view showing an intermediate step before the capillary tube is fitted into the groove of FIG.

The diameter of the central portion 5a of the suction pipe in FIG.
A thick pipe of about 8.5 mm is used. here,
The reason for increasing the diameter of the suction pipe 5a is to reduce the flow path resistance in the refrigeration cycle during operation of the refrigerator to reduce the output value of the compressor and save energy in the refrigerator.

Small-diameter pipe portions 8a and 8b are formed at both ends of the thick pipe 5a used between the compressor 1 and the evaporator 4 with a taper portion 9 interposed therebetween. The pipe diameter at the end of the material is formed to have a diameter of about 6 mm through the tapered portion. The small-diameter pipe portions 8a and 8b are connected to the compressor-side pipe 1a and the evaporator-side pipe 4a on the refrigerator side as shown in FIG. 6 showing the refrigeration cycle configuration. The size of the small diameter pipe portion can be changed according to the size of the connection pipe on the product side, and is not limited to the above 6 mm. In other words, the small-diameter pipe portion can be formed into a desired diameter through the tapered portion 9.

Further, the tapered portion 9 of the large diameter pipe 5a
Since the different diameters have a tapered shape, the refrigerating cycle structure can smoothly circulate without obstructing the flow path resistance of the refrigerant flowing inside the pipe.
Further, a continuous groove 6 is formed in the longitudinal direction of the large-diameter pipe 5a as shown in FIGS. 3 to 5, and 2/3 or more of the diameter of the capillary tube 3 is provided in the groove 6 of the large-diameter pipe 5. The length of the L dimension is continuously fitted. With such a configuration, the large-diameter pipe 5a and the capillary tube 3 are in close contact with each other so that heat is exchanged. Therefore, these heat exchanges enable heat exchange between the two parts without using a joining material (solder material).

Next, a description will be given of a construction in which the groove 6 of the large diameter pipe 5 and the capillary tube 3 are assembled. The large diameter pipe 5a shown in FIG.
The depth h1 of the groove 6 formed in the portion is set to the depth to the outer circumference of the small diameter pipe portions 8a and 8b formed at both ends, so that 2/3 or more of the diameter of the capillary tube 3 is fitted in the groove 6. It has become. By doing so, the small-diameter pipe portions 8a, 8 are provided on the extension line of the depth h1 bottom edge ridge of the groove 6 continuous in the longitudinal direction.
Since the outer peripheral surfaces of b are formed so as to coincide with each other, the groove 6 of the suction large-diameter pipe 5a can be easily drawn and molded, and the capillaries can be closely fitted.

FIG. 6 shows a refrigeration cycle configuration when the above-mentioned suction pipe assembly is incorporated in the refrigerator. Figure 6
In FIG. 5, reference numeral 5 is a suction pipe connected between the compressor 1 and the evaporator 4, and a large diameter pipe 5 a is embedded in the center of the suction pipe 5 together with the capillary tube 3. The diameter of the large-diameter pipe 5a is about 8 to 8.5 mm as described above, and a thick pipe is used. Small-diameter pipe portions 8a and 8b formed by drawing are arranged at the upper and lower ends thereof as shown in the drawing. .

The diameter of these small-diameter pipe portions is preferably about 6 mm. The reason is that the pipe diameter of a cycle component such as a refrigerator is about 6 to 6.5 mm. Therefore, the pipe diameter at both ends of the large-diameter pipe used between the compressor 1 and the evaporator 4 is molded to about 6 mm so that it can be directly connected to each recycled part from the product side. Reference characters A and B in the figure respectively indicate welding points of the small-diameter pipe portions 8a, 8b and the pipe 4a on the evaporator 4 side and the pipe 1a on the compressor 1 side in the refrigerator.

Next, FIG. 4 is a cross-sectional view of the construction of an assembly of the large diameter pipe 5a and the capillary tube 3, in which the capillary tube 3 having a diameter of the depth h1 of the groove 6 is arranged in the groove 6. . The dimension of the opening h3 of the groove 6 is smaller than the diameter d1 of the capillary tube by pressure bonding so that the capillary tube 3 arranged in the groove 6 does not protrude from the groove 6 of the large diameter pipe 5a.

To explain further, 1 / of the depth h1 in the groove
There is the center 3b of the capillary at the height h0 at the 2 position.
The lower side of the horizontal plane is a shape of a semicircle of a capillary tube. The inner surface 6a of the groove 6 having the same semi-circular shape is formed so as to match. Therefore, the groove inner surface 6a
Means that at least when the capillary tube 3 is fitted, the capillary tube 3 is in surface contact for a half circumference of the capillary tube 3.

Next, above the center 3b of the capillary tube 3 above the horizontal surface, the ridge line of the opening of the groove after crimp molding of the large diameter pipe is in the height direction, and the contact point between the capillary center 3b, the outer circumference of the capillary and the outer circumference of the large diameter pipe. It is located between 3c and 6 in the figure.
The size of the groove opening (h3) is between d and 6d. Therefore, the dimension h3 of the opening of the groove 6 is press-molded so as to be smaller than the dimension d1 of the capillary tube.

Next, the shape of these capillaries before crimping will be described with reference to FIG. 5. The opening ridgeline of the groove 6 before crimp molding has an opening width h2 (same as the capillary tube diameter d1) and a height position. Forms ridge lines 6c and 6c between the center 3b of the capillary tube and the outer peripheral contact 3c at the height position of h4 in FIG.

By fitting the capillary tube 3 in the groove at such a position and then subjecting the capillary tube 3 to the large-diameter pipe 5a by crimping and drawing, the opening ridge lines 6c, 6c of the groove 6 are formed on the outer peripheral surface 3a of the capillary tube. It is pressed against and crimped. Then, as shown in FIG. 3A, the opening ridge lines 6c, 6c move to the outer peripheral surfaces of the capillaries above the horizontal plane of the center 3b of the capillaries 3 and become 6d, 6d, and the capillaries are fixed so as to be wrapped in the groove 6. be able to. Therefore, with reference to the horizontal plane of the capillary tube 3b, the upper side comes into surface contact with the inner circumferential surface of the groove 6 up to the outer peripheries 6d and 6d of the capillary tube (2/3 or more of the capillary tube diameter).
At this time, the height positions of 6d and 6d are h5 (FIG. 4), which is lower than h4 before pressure bonding. That is, almost the entire peripheral surface (2/3 or more of the tube diameter) of the capillary tube can be continuously crimped into the groove of the large diameter pipe in the groove in the longitudinal direction, so that good heat exchange between the large diameter pipe and the capillary tube can be achieved. Can be done.

Here, in FIG. 3, the shape (FIG. 2) after the capillary tube is crimped from the state where the capillary tube 3 is fitted in the groove 6 of the large diameter pipe 5a will be described. In FIG. 3, the lowermost surface of the groove 6 of the large diameter pipe 5a is a small diameter pipe portion 8 at both ends.
The outer peripheral surfaces of a and 8b are flush with each other, and the capillary tube 3 is inserted into the groove 6, and then the capillary tube is subjected to compression drawing in the groove of the large-diameter pipe to obtain the shape as shown in FIG.

In FIG. 2, both ends of the capillary tube 3 are inclined with the taper portion 9 as a boundary and separated from the outer peripheral surface of the suction pipe. This is because when the groove 6 presses the capillary tube between the L dimensions of the groove 6, a phenomenon occurs in which the leading end of the capillary tube at both ends is lifted at the boundary (tapered portion 9) between the groove 6 and the groove. Therefore, the tapered portion 9 is used as a boundary to gradually incline toward the most distal capillary 3.

According to the conventional method, the both end portions of the capillary tube are inclined in such a manner that both end portions of the capillary tube are separated from the suction pipe in the state of the suction pipe assembly in order to connect with the connecting pipe on the refrigeration cycle side when the refrigerator is assembled. It was performing the work process of the state. However, in the present invention, as described above, since both ends of the capillary tube have an inclined shape in the step of crimping and withdrawing the capillary tube as described above, these steps are not necessary in the configuration of the present invention, and the manufacturing process of the suction pipe part This will improve efficiency and reduce the manufacturing unit price.

FIG. 5 shows the large-diameter pipe 5 as described above.
The cross-sectional shape before the capillary tube 3 is pressure-fixed in the groove of a is shown. As illustrated, the opening size h2 of the groove 6 of the large diameter pipe 5a is equal to the diameter of the capillary tube 3. Therefore, when the capillary tube 3 enters the groove 6, the inner peripheral surface 6a in the groove 6
Means that the surface of the capillary tube 3 and the outer peripheral surface 3a of the capillary tube 3 coincide with each other.

Then, from the state shown in FIG.
By fitting the inside of the inside of the groove 6 and then, as described above, by press-fitting and drawing the opening dimension h2 of the groove 6 to h3 smaller than the diameter d1 of the capillary tube 3 (FIG. 4), almost the entire peripheral surface (of the tube diameter The inner peripheral surface 6a of the groove 6 of the large-diameter pipe 5a is so tightly enclosed that it covers 2/3 or more). Therefore, the suction large diameter pipe and the capillary tube can exchange heat by surface contact with each other's outer peripheral surfaces (3a and 6a).

On the inner surface of the groove 6 with a capillary tube, a large-diameter pipe is wrapped around almost the entire peripheral surface of the capillary tube, so that the refrigerant flowing in the large-diameter pipe has a long length through the thickness of the large-diameter pipe. The heat can be exchanged over substantially the entire circumferential surface of the capillary tube in the direction. In such a heat exchange system, a necessary refrigerating capacity of a refrigerating cycle such as a refrigerator can be secured without using a conventional joining material (solder material), and at the same time energy saving can be realized.

In the heat exchange system as described above,
Since the two parts can be joined without a joining material, it is hygienic and environmentally preferable. Further, by eliminating the bonding material, it is possible to reduce the cost of the product because a complicated device or equipment can be eliminated. In addition, fitting the fitting parts (capillary tubes) in the pipe groove having a fixed shape and integrally molding the parts makes it possible to make the degree of contact or adhesion of the two parts uniform, improving the refrigerating capacity of the product,
We can provide customers with highly reliable products.

Further, FIG. 7 shows an embodiment in which another groove 66 having the same shape as the groove 6 is provided on the opposite side (the symmetrical position of the groove 6) of the groove 6 formed in the large diameter pipe. The manufacturing method of this embodiment is performed in the process procedure as shown in FIG.

That is, jigs for forming a small diameter pipe portion are provided at both ends of the suction large diameter pipe 5a except for the L dimension (processing procedure 2). Then, in the large diameter pipe part, the grooves 6, 6
6 is formed by drawing (processing procedure 3). After that, the capillaries 3 and 33 are fitted in the grooves, and the capillaries are pressed and drawn into the large diameter pipe (processing procedure 4).

Further, the inside of the groove 66 of the present embodiment has the same configuration (same shape) as that of FIG. 4, and the depth h1 of the groove 66 is the depth to the outer circumference of the small diameter pipe portion formed at both ends. The capillary tube 33 is fitted therein. The surface contact area between the outer peripheral surface of the capillary and the outer peripheral surface of the large-diameter pipe is such that the capillary is installed in the groove of the large-diameter pipe so that it enters the circle formed by the large-diameter pipe. Can be secured over most of the capillaries and over the entire length of the grooved pipe in the longitudinal direction.

Further, since the heat transfer area on the inner peripheral surface side of the large diameter pipe can be increased by forming the large diameter pipe with a groove, the refrigerant flowing in the large diameter pipe between them (capillary tube and large diameter pipe) is thick. Since heat can be exchanged with almost the entire circumference of the capillary tube through the wall thickness of the diameter pipe, the amount of heat exchange can be large and efficient. Furthermore, by integrating the capillaries within the circle of the large-diameter pipe, the finished appearance of the suction pipe assembly will be simple and it will be easy to incorporate it into the product. Further, since the two parts are integrated without using a joining material, the weight of the assembly itself can be reduced.

Next, a method of manufacturing the suction pipe and the capillary tube of the present invention will be described with reference to FIG. In the figure, the numbers on the left side indicate the machining procedure, the lower side of the number indicates the shape viewed from the left side surface, and the right side thereof indicates the overall shape diagram of each machining procedure. First, the drawing shown at the top shows the material (copper tube) part of the refrigerating cycle pipe used in the method of the present invention. The upper part is the part of the suction pipe 5 and the diameter of this pipe is 12 to 13 mm and it is a thick material The length is 2500 to 3000 mm. The diameter and length vary depending on the size (capacity) of the product or the specifications (output) of the compressor that constitutes the refrigeration cycle.

The lower part is a part of the capillary tube 3 having an outer diameter of 1.8 to
The length is 2.0 mm, and the length thereof is, for example, about 3000 mm. The length of the capillary tube also varies depending on the size (capacity) of the product or the specifications (output) of the compressor that constitutes the refrigeration cycle, as described above. Here, the diameter of the suction pipe is set larger than the diameter of the pipe described in the prior art, but this is a thick material in advance in order to form a continuous groove in the longitudinal direction of the pipe outer circumference. Is.

Next, the processing procedure 1 is a step of attaching both ends of the suction pipe. When forming the suction pipe, the parts that secure the necessary press allowances at both ends of the pipe are first made. At this time, a pre-fixing jig (processed by a swaging machine or the like) as shown in the drawing is used to reduce the diameter of the tube.

Processing procedure 2 is a double-end drawing process in which both ends of the suction pipe 5 are, for example, about 6 mm in diameter and 250 to 250 mm in length.
It is molded into 500 mm, and both ends thereof correspond to the small diameter pipe portion 8a (8b) in FIG. In the manufacturing method of this step, as shown in the drawing, a drawing jig for forming an outer diameter smaller than the outer diameter of the previous large-diameter pipe 5a is attached to both ends of the large-diameter pipe 5a of the suction pipe 5 excluding the L dimension. Both ends are drawn by this drawing jig to form the small diameter pipe portion 8a (8b).

Therefore, in order to make different outer diameters with one pipe, the large-diameter pipe 5a and the small-diameter pipe portions 8a at both ends are formed.
As shown in the figure, there is a taper (slope) between (8b) and
9 will intervene. With such a shape, the circulation of the refrigerant flowing on the inner surface of the suction pipe can be made smooth.

Next, the processing procedure 3 is a grooved drawing step (first time) of the suction pipe, in which the central portion (5
This is a manufacturing process in which the groove 6 is formed over the entire length of (a) (L dimension portion in FIG. 3). In this machining procedure 3, the suction pipe has two grooves.
In the case where one is provided, it corresponds to the suction pipe shown in FIG. By this grooved drawing process, a groove 6 is formed in the longitudinal direction of the central portion 5a of the suction pipe, and the outer diameter dimension of this large diameter pipe 5a is molded to a size of 8 to 8.5 mm.

The processing procedure 4 is the second drawing step in which the capillary tube 3 is fitted in the groove 6 of the suction pipe 5a and then crimp drawing is performed. This step is a processing step in which the capillary tube 3 is fitted in the longitudinal groove 6 of the suction pipe 5 formed in the processing procedure 3, and the compression drawing is performed so as to wrap the capillary tube in this groove. At the time of this crimping and drawing, as shown in the drawing, the opening size of the openings of the two grooves 6 is formed smaller than the outer diameter of the capillary tube by a dedicated crimping and drawing jig. Through this processing step, the two capillaries are fixed in the suction pipe groove 6. This fixed state corresponds to the cross-sectional view shown in FIG.

Further, after the crimping and drawing step for fixing the capillary tube 3, both end portions of the capillary tube 3 have an inclined shape in which the taper portion 9 is gradually separated from the outer peripheral surfaces of the small-diameter pipe portions 8a and 8b as described above. This is the small-diameter pipe portion 8 where the opening portion of the groove does not crimp the portion where the capillary is crimped.
This is because, due to the presence of a and 8b, stress deformation due to pressure bonding occurs in the capillary tube 3 at the tapered portion 9. This shape corresponds to the assembly block diagram of FIG.

The processing procedure 5 is a cutting step, in which the small-diameter pipe portions 8a and 8b at both ends of the suction pipe 5 are left and the both ends are cut off and both ends of the capillary tube are cut off. This completes the entire shape of the assembly.

After that, in a cleaning process (not shown) of the suction pipe assembly, dirt, dust and the like of the suction pipe assembly are removed, and after the inspection process of the suction pipe assembly, the suction pipe assembly is finally carried out. Completed in the product packaging process.

According to the present invention, in the manufacturing process of the above-described embodiment, the groove for inserting the capillary tube is formed in the suction pipe, and the capillary tube is fitted and crimped into this groove to be integrated. It is possible to produce an assembly by a simple manufacturing process without requiring a complicated manufacturing facility that integrates the bonding material. Therefore, it is possible to provide the customer with a product that is inexpensive in terms of cost.

Next, an embodiment in which the suction pipe assembly 5 completed in the previous processing procedure 5 is bent and molded will be described with reference to FIG. 10, where (A) is a top view of the bent molded product, and (B) is (A).
7 is an enlarged view of the cross-sectional shape as seen from XX in FIG. 1 and is an example in which a pipe with a capillary tube in which a capillary tube is housed in a groove 6 formed on the outer circumference of the pipe is bent and formed into a predetermined shape.

In FIG. 10B, the capillary tube 3 in the groove 6
Is an example in which the capillary tube 3 is arranged in the groove 6 on the horizontal plane of the center 6b of the large diameter pipe 5a. The position of the capillary tube 3 is any position within the circle formed by the diameter of the large diameter pipe. However, it can be bent and formed into a predetermined shape, and is not limited to this embodiment.

Further, in the embodiment of FIG. 11, a pipe with a capillary tube, in which the capillary tube is housed in a groove formed in the outer peripheral portion of the pipe,
When bending and forming so as to be parallel to the horizontal plane to form a predetermined shape, the center 3b of the capillary tube housed in the groove is formed.
This is an example of bending and forming so that a line connecting the center of the pipe with the capillary 6b is orthogonal to the horizontal plane. FIG. 11B is an enlarged view of the cross-sectional shape of FIG. 11A viewed from ZZ.

In this embodiment, as shown in FIG. 11B, the bending center 6b of the grooved pipe and the bending center 3b of the capillary tube are concentric axes. In this method, the capillary tube 3 and the groove 6 are surrounded. This is a molding method that minimizes stress (elongation, shrinkage). Therefore, the degree of adhesion between the inner surface of the groove and the entire peripheral surface of the capillary can be made uniform. Although this embodiment has a single capillary tube, it is needless to say that the present invention can be applied to the case where another capillary tube is provided at a position opposite to the capillary tube 3b.

It is needless to say that the lengths of the W dimension and the P1 dimension in FIGS. 10A and 11A can be freely changed by the length of the grooved suction pipe. Further, the shape of this embodiment has a bending pitch P1 at one bending point, but a combination of different bending pitches at a plurality of bending points may be used. Further, in the present embodiment, the arrangement positions of the small diameter pipe portions 8a and 8b are in different directions, but the arrangement positions of these small diameter pipe portions are not limited.

As described above, since the suction pipe with a capillary tube has the capillary tube housed in the groove, the appearance is simple, the bending process is easy, and the assembling work on the product side is easy.

The suction pipe and the capillary tube manufactured according to the present invention are, for example, as shown in FIG.
/ 3 or more is in close contact with the suction pipe, and the close contact portion performs heat transfer which is almost the same as the heat conductivity of metallic copper. On the other hand, in the suction pipe and the capillary tube in the conventional example, as shown in FIG. 13, for example, the pipes are in line contact with each other and the solder alloy is bonded between them.
Most of the heat is transmitted through a solder alloy having a lower thermal conductivity than copper, and the heat transfer surface area is about 1/2 of the outer circumference of the capillary tube, and sufficient heat transfer as in the product of the present invention cannot be expected.

[0065]

As described above, according to the first aspect of the present invention, the step of forming a continuous groove in the longitudinal direction of the outer circumference of the pipe and the pipe having a diameter smaller than that of the pipe are formed in the groove formed in the pipe. After arranging, the groove opening dimension is processed to be smaller than the outer diameter dimension of the small-diameter pipe, and the two are fixed together. The degree of adhesion of the pipes can be made uniform, which will improve the refrigerating capacity of the product. Further, since the two parts are adhered to each other so that heat can be exchanged between the large diameter pipe and the capillary tube without using lead solder, it is preferable from the environmental and sanitary point of view.

According to the present invention, the size of the small-diameter pipe portion suitable for the connecting pipe to the product side can be obtained by subjecting both ends of the large-diameter pipe to drawing, so that the intermediate pipe can be eliminated and the number of parts can be increased. Can be reduced. Also, reducing the number of welded points will improve the reliability of the refrigeration cycle. Furthermore, by drawing both ends of the pipe, seamless parts with different diameters can be made with one pipe.

Further, since the capillary tube is installed in the groove of the large diameter pipe so that it falls within the circle formed by the diameter of the large diameter pipe, it is possible to secure a large contact area between the outer peripheral surface of the capillary tube and the large diameter pipe. The heat transfer area in the large-diameter pipe can be increased, and the refrigerant that flows in the large-diameter pipe is wrapped around the entire peripheral surface of the capillary so that the refrigerant flowing through the large-diameter pipe is almost the entire peripheral surface of the capillary. Heat can be exchanged.

In the third aspect of the present invention, the capillary position in the groove can be bent and formed into a predetermined shape at any position within the circle formed by the large diameter pipe, and after the bending, the large diameter pipe and the capillary tube are closely attached. The temperature does not change, and the heat exchange between the two can be performed well.

Further, in claim 4, since the line connecting the center 3b of the capillary tube and the center 6b of the pipe with a capillary tube is formed by bending so as to be orthogonal to the horizontal plane,
Bending stress around the capillaries in the groove and around the groove can be minimized. Further, since the entire peripheral surface of the capillary tube is pressure-molded so as to be wrapped with the large-diameter pipe, the efficiency of the bending manufacturing process is also improved.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a refrigeration cycle using an assembly manufactured by the present invention.

FIG. 2 is a schematic diagram of an assembly of a suction pipe and a capillary tube manufactured by the present invention.

FIG. 3 is a cross-sectional view of the main part of the groove portion before the capillary tube is inserted into the groove of the suction pipe manufactured according to the present invention.

FIG. 4 is an explanatory view showing a contact state of a pipe cross-section of a suction large-diameter pipe and a capillary pipe manufactured by the present invention.

5 is a cross-sectional view showing an intermediate step of the suction pipe and the capillary before the capillary is fitted into the groove of FIG.

6 is a refrigeration cycle piping configuration diagram when the suction pipe assembly of FIG. 3 is incorporated in a refrigerator.

FIG. 7 is an explanatory view showing a contact state of a cross section of a large-diameter suction pipe manufactured by the present invention and two capillaries.

8 is a cross-sectional view showing an intermediate step of the suction pipe and the capillary before the capillary is fitted into the groove of FIG.

FIG. 9 is a manufacturing process explanatory diagram of an assembly of a suction pipe and a capillary tube manufactured by the present invention.

FIG. 10 is an explanatory view of an example in which a suction pipe with a capillary tube is bent and formed into a predetermined shape.

FIG. 11 is an explanatory view of another embodiment in which a suction pipe with a capillary is bent and formed into a predetermined shape.

FIG. 12 is an explanatory diagram showing a conventional refrigeration cycle.

FIG. 13 is an explanatory view showing a contact state of a pipe cross section of a conventional suction pipe and a capillary tube.

FIG. 14 is a configuration diagram of a conventional assembly of a suction pipe and a capillary tube.

15 is a refrigeration cycle piping configuration diagram when the suction pipe assembly of FIG. 14 is incorporated in a refrigerator.

[Explanation of symbols]

1 Compressor 7 Groove opening 1a Compressor connecting pipe 8a, 8b Small diameter pipe 2 Condenser 9 Taper 3 ...... Capillary tube (small diameter tube) 29 ………… Inner box 3a ………… Capillary outer peripheral surface 30 ………… Outer box 33 ………… Other capillaries 31 ………… Insulation material (urethane foam material) 4) Evaporator 4a Evaporator connection pipe 5 Suction pipe 5a Large diameter pipe 6 Groove 6a Groove inner peripheral surface 66 Groove 66a ..... Inner peripheral surface of the other groove

Claims (4)

[Claims] 1. A step of processing a continuous groove on the outer circumference of a pipe in a longitudinal direction, and a pipe having a diameter smaller than that of the pipe is disposed in the groove formed in the pipe, and then the opening dimension of the groove is reduced. A process for producing a pipe for a refrigeration cycle, characterized in that it is processed so as to be smaller than the outer diameter of the above, and both are fixed. 2. Prior to the step of machining a continuous groove in the longitudinal direction on the outer circumference of the pipe, both end portions of the pipe where the groove is formed are formed into a smaller outer diameter than the portion where the groove is formed. The method for manufacturing a refrigeration cycle pipe according to claim 1. 3. The method for producing a pipe for a refrigeration cycle according to claim 1, wherein the small diameter pipe is housed and fixed in a groove formed in a longitudinal direction of the outer periphery of the pipe, and both are bent and formed into a predetermined shape. 4. A small-diameter pipe is housed and fixed in a groove formed in the longitudinal direction of the outer circumference of the pipe, and then both are bent and formed parallel to a horizontal plane to form a predetermined shape. A step of bending the pipe with the small diameter pipe into a predetermined shape so that a line connecting the center of the small diameter pipe and the center of the pipe with the small diameter pipe is orthogonal to the horizontal plane. Item 4. A method for manufacturing a refrigeration cycle pipe according to Item 1, 2 or 3.