JP2015150591A - Resistance-welding machine for metallic pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metallic pipe resistance-welding machine capable of simplifying the steps and improving the quality of a metallic pipe resistance-welding apparatus without depending on the level of skill of an operator.SOLUTION: A resistance-welding machine 300 or a resistance-welding device can perform a welding step work smoothly when the flange parts of cylindrical metal pipes are welded at a manufacturing process, because a clamp part 302 having the electrode A304 of the resistance-welding machine 300 is equipped with movable members 307 and 308 which are divided into a semicircular shape made turnable on a support shaft 306, and the welder electrode parts at the resistance-welding time can hold the cylindrical pipeline weld zone more reliably and stably.

Description

  TECHNICAL FIELD The present invention relates to a welding apparatus for flowing a current through a weld when welding a metal pipe and welding the metal pipe by heat generation.

  Conventionally, when connecting a metal pipe, such as a copper pipe, constituting a refrigeration cycle of a cooling device such as a refrigerator, it has been performed by brazing. Brazing work is performed by heating the weld with a flame torch and using copper brazing or silver brazing, so brazing worker skill is required. In the manufacturing process, the process quality is the skill of the brazing worker. It is left to the degree. (For example, see Patent Document 1)

JP 61-49974 A

  However, welding of metal pipes constituting the refrigeration cycle of a cooling device such as a refrigerator requires the skill of a brazing worker in the manufacturing process, and the process quality depends on the skill level of the brazing worker. Had.

  The present invention solves the above-described conventional problems, and provides a resistance welding apparatus for metal piping that can simplify the process and improve the quality of welding of metal piping in the manufacturing process regardless of the skill level of the operator. The purpose is to provide.

  In order to solve the above-described conventional problems, a resistance welding apparatus for metal pipes according to the present invention is a welding apparatus for welding cylindrical pipes, and each end of the cylindrical pipe has a flange part in surface contact, and the flange The electrode part of resistance welding is provided facing the part.

  As a result, the cylindrical pipe can be welded without the process quality being affected by the skill level of the brazing operator as in the conventional case, and the welder electrode section during resistance welding stabilizes the cylindrical pipe weld. And can be securely welded.

  In the resistance welding apparatus for metal pipes of the present invention, the welding machine electrode part at the time of resistance welding can stably hold the cylindrical pipe welded part, and can be welded reliably. Can be increased.

The longitudinal cross-sectional view of the cooling device (refrigerator) in Embodiment 1 of this invention Machine room schematic diagram of cooling device (refrigerator) in the same embodiment The perspective view of the machine room of the cooling device (refrigerator) in the embodiment Sectional drawing of the metal piping welded using the resistance welding of the refrigerating cycle which comprises the refrigerating apparatus in Embodiment 1 Sectional drawing of the other metal piping welded using the resistance welding of the refrigerating cycle which comprises the refrigerating apparatus in the same Embodiment 1. Sectional drawing of the other metal piping welded using the resistance welding of the refrigerating cycle which comprises the refrigerating apparatus in the same Embodiment 1. Sectional drawing of the other metal piping welded using the resistance welding of the refrigerating cycle which comprises the refrigerating apparatus in the same Embodiment 1. Sectional drawing of the other metal piping welded using the resistance welding of the refrigerating cycle which comprises the refrigerating apparatus in the same Embodiment 1. (A) Outline | summary figure of the resistance welding machine which welds the metal piping of the refrigerating cycle which comprises the refrigerating apparatus in the same Embodiment 1, (b) Welding metal piping of the refrigerating cycle which comprises the refrigerating apparatus in the same Embodiment 1. Of the main part of the resistance welding machine (A) The schematic diagram before arrange | positioning the electrode part of a resistance welding machine to the metal piping of the refrigerating cycle which comprises the refrigerating apparatus in the Embodiment 1, (b) The refrigerating cycle which comprises the refrigerating apparatus in the Embodiment 1. Schematic after placing the electrode part of the resistance welder on the metal pipe

  The invention according to claim 1 is a welding apparatus for welding cylindrical pipes to each other, and end portions of the cylindrical pipes have flange portions that are in surface contact with each other, and are arranged so as to face the flange portions to form electrode portions for resistance welding. As a result, the cylindrical pipe can be welded without the process quality being affected by the skill level of the brazing operator as in the prior art. Can be held stably, can be reliably welded, and can improve the welding reliability of metal piping.

  According to a second aspect of the present invention, in the first aspect of the invention, the electrode portion includes a movable portion, and the electrode portion is annularly arranged on the outer periphery of the cylindrical pipe by the movable portion to generate a predetermined current. By pouring and welding the metal pipe, the welder electrode part during resistance welding can hold the cylindrical pipe welded part more reliably and stably.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, a pair of the electrode portions are provided, a predetermined current is applied while pressing the flange portion, and the metal pipe is welded. The welding reliability of piping can be further increased.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments.

(Embodiment 1)
1 is a longitudinal sectional view of a cooling device (refrigerator) according to Embodiment 1 of the present invention, FIG. 2 is a schematic diagram of a machine room of the cooling device (refrigerator) according to the embodiment, and FIG. 3 is cooling according to the embodiment. FIG. 4 is a cross-sectional view of a metal pipe that is welded using resistance welding of a refrigeration cycle that constitutes the refrigeration apparatus according to the first embodiment, and FIGS. Sectional drawing of the other metal piping welded using resistance welding of the refrigeration cycle constituting the refrigeration apparatus in the first embodiment, FIG. 9A is a metal of the refrigeration cycle constituting the refrigeration apparatus in the first embodiment. FIG. 9B is a schematic diagram of a resistance welder that welds pipes. FIG. 9B is a schematic diagram of a main part of the resistance welder that welds metal pipes of a refrigeration cycle that constitutes the refrigeration apparatus according to the first embodiment. ) Is the freezing in the first embodiment. FIG. 10B is a schematic diagram before placing the electrode part of the resistance welder on the metal pipe of the refrigeration cycle constituting the apparatus, and FIG. 10B shows resistance welding to the metal pipe of the refrigeration cycle constituting the refrigeration apparatus in the first embodiment. It is a schematic diagram after arrange | positioning the electrode part of a machine.

In FIG. 1 to FIG. 3, the refrigerator main body 30 includes a heat insulating box 31 that is divided into a plurality of heat insulating sections and a door provided in each heat insulating section. The heat insulating box 31 includes a heat insulating wall formed by injecting a foam heat insulating material 34 into a space formed by an inner box 32 formed by vacuum molding a resin body such as ABS and an outer box 33 using a metal material such as a pre-coated steel plate. ing. For example, rigid urethane foam, phenol foam, styrene foam, or the like is used as the foam heat insulating material 34. Use of hydrocarbon-based cyclopentane as the foaming material is better from the viewpoint of preventing global warming.

  The heat insulation box 31 forms a plurality of storage rooms, and has a refrigeration room 40, an ice making room 41, a vegetable room 42, and a freezing room 43 from the top. A heat insulating door is provided through a gasket (not shown) at the front opening of each heat insulating section. From the top, the refrigerator compartment door 40a, the ice making compartment door 41a, the vegetable compartment door 42a, and the freezer compartment door 43a. Note that the ice making chamber 41 may not be configured with the full width of the heat insulating box 31 but may form a storage chamber in which the adjacent chamber is partitioned by a partition wall (not shown).

  The heat insulation box 31 forms a recess 50 in which the rear part of the top surface is recessed in a stepped shape, and opens above and behind the heat insulation box 31. The concave portion 50 accommodates a precooling condenser 54 serving as a precooling pipe in which a compressor 52, a heat radiating fan 53, and a part of the condenser are directly connected to the discharge side of the compressor 52 as a machine chamber 51. A compressor 52, a heat radiating fan 53, and a precooling condenser 54 are arranged from the left and right ends of 51. A first section 91a that accommodates the compressor 52 with the heat radiating fan 53 interposed therebetween is defined as a discharge section 91b, and a second section 92a that accommodates the precooling condenser 54 is defined as a suction section 92b. The heat radiating fan 53 is disposed at an intermediate position between the compressor 52 and the precooling condenser 54, that is, at an intermediate position in the width direction of the machine chamber 51. The upstream side is a suction section 92b and the downstream side is a discharge section 91b. It is configured to circulate in such a flow as to hit. A condenser pipe following the precooling condenser 54 is disposed on the inner surface of the outer box 33 of the heat insulating box 31 in a heat conductive manner.

  Next, the configuration in the recess 50 will be described.

  The recess 50 is formed by cutting out the rear side of the top surface of the outer box 33 that is the outer shell of the heat insulating box body 31. The resin part 56 formed integrally with the bottom surface is formed so as to be fitted from the rear side of the heat insulating box 31. In addition, since the intensity | strength becomes weak for the recessed part 50 formed by notching, it is common to provide the reinforcement means which is not shown in the periphery. As the reinforcing means, in particular, if the inclined portion 57 is provided at the joint portion of the bottom surface and the side surface of the recess 50 to connect the bottom surface and the side surface, or the foam heat insulating material 34 is injected into both the left and right sides between the side surface and the outer box 33, the effect is obtained. large.

  The recess 50 is provided with a machine room cover so as to cover the internal compressor 52 and the radiating fan 53 precooling condenser 54. The machine room cover is provided with an opening for allowing air to flow in and out of the machine room 51.

  The heat radiating fan 53 is inserted and fixed in the fan cover 90 via a soft cushioning member (not shown) such as polyurethane foam. The fan cover 90 has the resin component 56 substantially perpendicular to the installation bottom surface of the compressor 52. Arranged to be That is, the heat radiating fan 53 is installed below the machine room 51, and the center position of the heat radiating fan 53 is positioned lower than the center position of the compressor 52. Further, the fan cover 90, the resin component 56, and the machine room cover 62 are brought into close contact with the outer periphery of the fan cover 90 via a soft seal member 93 such as polyurethane foam.

  With such a configuration, the discharge side and the suction side of the heat radiating fan 53 are reliably sealed and partitioned, and the discharge section 91b that is the discharge side section and the suction section 92b that is the suction side section are configured in the machine chamber 51. . Here, the compressor 52 is located in the discharge section 91b.

The opening provided in the machine room cover 62 is located in the suction section 92 b in the machine room 51, and is used to suck the air around the refrigerator body 30 into the machine room 51. On the other hand, the opening located in the discharge section 91 b in the machine room 51 is used for exhausting the heat radiated by the compressor 52 to the outside of the machine room 51.

  On the bottom surface of the heat insulating box 31, a condenser 100 of the refrigeration cycle is arranged in front of it, and an evaporating dish 102 for storing water defrosted by the evaporator 101 is arranged in the rear. In order to improve the internal volume of the refrigerator main body 30, both parts are small and highly efficient. A typical condenser 100 is a spall fin tube type, which is provided in a pipe affixed to the inside of the outer box 33 with good heat transfer or a partition between each heat insulating door body to prevent drip-proofing. You may combine piping for. In addition, the capability of the condenser 100 and prevention of dew condensation are more effective by installing a fan (not shown) for circulating the air at the bottom of the heat insulating box 31.

  And the metal piping 200 which comprises the refrigerating cycle in the machine room 51 uses the copper pipe about 0.2-0.5 mm in thickness, and is welded by a manufacturing process. Conventionally, metal pipes are welded by brazing, but in this embodiment, resistance welding is used.

  With resistance welding, a strong current (several tens to tens of thousands of amperes) is applied for a short time (several milliseconds to several hundreds of milliseconds) while applying pressure to the welded part, and an alloy that utilizes the resistance heat generation of the metal. It is a layer that is melt-bonded, and it can be cleaned easily without using auxiliary materials such as brazing material and flux, and there is almost no spatter or UV generation, and the work environment is clean. Furthermore, it has the advantage that it does not require the skill of the operator as compared with arc welding, gas welding and the like.

  However, in order to flow a strong current while applying pressure while applying an electrode to the weld, it is suitable when welding flat plates, but when welding metal pipes constituting a refrigeration cycle, the wall thickness is 0.2 to There is a problem that the pipe itself is deformed by pressurization in a straight pipe state as thin as 0.5 mm.

  In this embodiment, in order to reliably perform thin-walled piping using resistance welding while suppressing deformation of the piping itself due to pressurization, as shown in FIGS. It is a technical feature that resistance welding is used.

  That is, as shown in FIG. 4, the end portions of the metal pipes 200 and 202, which are cylindrical copper pipes, have flange portions 201 and 203 for surface contact respectively over the entire circumference. Are opposed to each other and welded using a resistance welding machine 300.

  The flange portions 201 and 203 at the ends of the metal pipes 200 and 202 are pre-processed by flare processing or the like, and the protrusion allowance dimension H of the flange portions 201 and 203 is set larger than the wall thickness of the metal pipes 200 and 202. doing.

  Specifically, as shown in FIGS. 9A and 9B, the welded portion 204 has a flange portion 201 and a flange portion 203 arranged to face each other, and a clamp portion 302 provided with the electrode A304 of the resistance welder 300; A current is supplied from the power supply 301 between the electrode A304 and the electrode B305 while being sandwiched and pressed between the clamp unit 303 provided with the electrode B305. As a result, the welded portion 204 enters a molten state due to the generation of resistance heat, forms an alloy layer, and is melt-bonded.

At this time, since the flange portions 201 and 203 are in surface contact with each other over the entire circumference, the supplied current flows uniformly between the flange portions 201 and 203, and the generation of resistance heat is also uniformly generated. Therefore, the formation of the alloy layer in the flange portions 201 and 203 is also generated uniformly,
Reliable resistance welding is possible.

  The metal pipes 200 and 202 may each be a copper pipe, or one may be a copper pipe and the other may be an iron pipe. Iron pipes have the advantage of being able to reduce costs compared to copper pipes. Since welding of iron pipes and copper pipes is generally performed by brazing work using silver brazing, there was a problem that the total cost merit was reduced, but resistance welding as in this embodiment By using, it is possible to perform clean joining at low cost without using auxiliary materials such as silver brazing, and the effect of being able to perform welding reliably without requiring the skill of operators compared to gas welding etc. And can improve the welding reliability of metal piping.

  Moreover, the allowance dimension H of the flange parts 201 and 203 is set to be larger than the wall thickness (0.2 to 0.5 mm) of the cylindrical metal pipe and smaller than the inner diameter of the cylindrical metal pipe.

  The dimensions of the flange parts 201 and 203 are such that the clamp part 302 having the electrode A304 of the resistance welder 300 and the clamp part 303 having the electrode B305 can be securely sandwiched, and the flange parts 201 and 203 are flared. The above dimensions are set based on technical factors such as preliminary workability and uniform formation of the alloy layer at the flange portions 201 and 203.

  Further, as shown in FIGS. 10A and 10B, when welding the flange portions of the cylindrical metal pipes by resistance welding in the manufacturing process, the clamp portion 302 including the electrode A304 of the resistance welding machine 300 is , And movable members 307 and 308 that are divided into semicircular shapes that can be rotated with the support shaft 306 as a fulcrum.

  In addition, the clamp part 303 provided with the electrode B305 is similarly provided with the movable members 310 and 311 divided | segmented into the semicircle shape which can be rotated by using the spindle 309 as a fulcrum.

  When welding with the resistance welder 300, as shown in FIG. 10A, the movable members 307 and 308 and the movable members 310 and 311 are opened with the support shafts 306 and 309 as fulcrums, Then, the metal pipes 200 and 202 are pressed in a direction to bring the clamp part 302 and the clamp part 303 closer to each other while being sandwiched between the hollow parts of the inner surfaces of the movable members 307 and 308 and the movable members 310 and 311.

  In addition, although the dimension of the hollow part of the inner surface of the movable members 307 and 308 and the movable members 310 and 311 is formed in accordance with the outer diameter of the target metal pipes 200 and 202, the inner surface is hollow from the viewpoint of sharing. The dimension of the part may be variable.

  Further, in the present embodiment, the description has been made with the pivotable shafts 306 and 309 as pivots. However, if the metal pipes 200 and 202 can be sandwiched from the outside, the clamp portion can be moved in parallel. But you can.

  In addition, the pressure applied by applying an electrode to the welded portion, the current value, the voltage value, the energization time, and the like are experimentally optimal depending on the material of the target metal pipes 200 and 202, the dimensions of the flange portions 201 and 203, etc. The width of the value is set. Especially for metal pipes that make up the refrigeration cycle, it varies depending on the internal refrigerant and application (for low temperature to high temperature). In many cases, this is an important factor because the reliability of welding is directly linked to the reliability of the refrigeration / cooling function.

In this embodiment, cylindrical pipes (metal pipes 200 and 202) are welded to each other, and the end portions of the cylindrical pipes have flange portions 201 and 203 that are in surface contact with each other, and the flange portions 201 and 203 are arranged to face each other. As a result, the process quality is not affected by the skill level of the brazing operator as in the past, and the cylindrical pipe can be welded, and the welder electrode part during resistance welding stabilizes the cylindrical pipe welded part. And can be reliably welded, and the welding reliability of metal piping can be improved.

  Further, another embodiment different from the above embodiment will be described with reference to FIGS. In addition, it is the same as that of the above except about the flange part of metal piping, and only a different part is demonstrated.

  In FIG. 5, the end portions of the metal pipes 200 and 202 have flange portions 205 and 206 for surface contact, respectively, over the entire circumference. The flange portions 205 and 206 include folded portions 205a and 206a, and are characterized in that the flange portions 205 and 206 have a double structure.

  Thereby, the intensity | strength of the flange parts 205 and 206 can be raised, and the welding machine electrode part in the case of resistance welding can hold | maintain the welding part 207 of cylindrical piping more reliably and stably.

  In addition, when forming the flange portions 205 and 206 having a double structure as a preliminary processing, the double-structure flange portions 205 and 206 can be formed by beading once and then compressed.

  Further, as shown in FIG. 6, the end of one metal pipe 200 is a double-structured flange 205 having a folded portion 205a, and the end of the other metal pipe 202 is a single layer without a folded portion. As a combination of the flange portion 203, a welded portion 208 may be used.

  Thereby, the welding part 208 which considered the characteristic of metal piping can be comprised, and the further reliability improvement in resistance welding can be aimed at.

  The combination of the single-layer flange portion and the multi-layer flange portion can be selected in consideration of preliminary workability depending on the material and thickness of the metal pipe.

  Further, as shown in FIG. 7, the end of one metal pipe 200 is a flared flange portion 209, and the other metal pipe 202 is a beaded flange portion 210, and the flared flange portion 209 is formed. And the flange portion 210 subjected to beading processing may be brought into contact with each other to form a welded portion 211.

  As a result, the flange portion 209 that has been flared and the flange portion 210 that has been beaded are brought into contact with each other, so that the welded portions 211 of the respective metal pipes 200 and 202 are shifted (the center line between the metal pipes 200 and 202 is shifted). Can be prevented. Therefore, the displacement of the pipe wall surface that occurs on the inner surface of the welded portion 211 can be prevented, and the pressure loss in the pipe can be reduced without hindering the flow of refrigerant and oil flowing inside.

  Further, as shown in FIG. 8, in addition to the flange portion 209 flared at the end portion of the metal pipe 200, the end portion of the flange portion 210 that has a pipe expanding portion 212 in the middle thereof and the beading processing of the other metal pipe 202 is performed. The extending portion 213 of the metal pipe 202 can be inserted into the expanded portion 212 of the metal pipe 200 at the time of welding.

  Thereby, the shift | offset | difference of the welding part 214 of each metal piping 200 and 202 can be prevented reliably.

As described above, in the present embodiment, the ends of the metal pipes 200 and 202, which are cylindrical copper pipes, have the flange parts 201 and 203 for surface contact respectively over the entire circumference. By arranging the parts 203 facing each other and welding them using the resistance welding machine 300, the process quality is not affected by the skill level of the brazing operator as in the past, and the cylindrical pipe can be welded. Since the welding machine electrode part at the time of resistance welding can hold | maintain a cylindrical pipe welding part stably, it can weld reliably and can improve the welding reliability of metal piping.

  The flange portions 201 and 203 at the ends of the metal pipes 200 and 202 are pre-processed by flare processing or the like, and the allowance dimension H of the flange portions 201 and 203 is based on the thickness of the metal pipes 200 and 202. Since it sets large, the welding machine electrode part in the case of resistance welding can hold | maintain a cylindrical pipe welding part more reliably and stably.

  In addition, since at least one of the flange portions of the metal pipes 200 and 202 has a folded portion and the flange portion has a double structure, the strength of the flange portion can be increased, and the welder electrode portion during resistance welding is cylindrical. The pipe weld can be more reliably and stably held.

  Moreover, the resistance welding machine 300 which is the resistance welding apparatus in the present embodiment is provided with the electrode 201 of the resistance welding machine 300 by disposing the flange portion 201 and the flange portion 203 of the metal pipes 200 and 202 to be welded portions facing each other. A current is supplied from the power supply 301 between the electrode A304 and the electrode B305 while being sandwiched between the clamp unit 302 and the clamp unit 303 provided with the electrode B305, and pressed. It is possible to weld cylindrical pipes without affecting the process quality depending on the skill level of the welding, and the welding machine electrode part during resistance welding can hold the cylindrical pipe welded parts stably, so that welding is ensured It is possible to improve the welding reliability of metal pipes.

  Furthermore, when the resistance welding machine 300 which is a resistance welding apparatus welds the flange portions of the cylindrical metal pipes by resistance welding in the manufacturing process, the clamp portion 302 including the electrode A304 of the resistance welding machine 300 is Since the movable members 307 and 308 that are divided into semicircular shapes that can rotate with the support shaft 306 as a fulcrum are provided, the welding process can be performed smoothly, and the electrode of the welder during resistance welding is cylindrical. The pipe weld can be more reliably and stably held.

  Further, while holding the metal pipes 200 and 202 between the hollow portions of the inner surfaces of the movable members 307 and 308 and the movable members 310 and 311, a predetermined current is applied while pressing the clamp portion 302 and the clamp portion 303 closer to each other. By casting and welding the metal pipe, the welding reliability of the metal pipe can be further increased.

  In addition, although this Embodiment demonstrated the metal piping of the cooling system used for the refrigerating cycle of a refrigerator, it is not limited to this, The metal used for cooling equipment provided with refrigeration apparatuses, such as an air-conditioner and a showcase It can be applied to pipe welding.

  As described above, the metal pipe welded using the resistance welding according to the present invention can stably hold the cylindrical pipe welded portion by the welding machine electrode portion during the resistance welding. It can be applied to equipment that needs to weld cylindrical pipes.

DESCRIPTION OF SYMBOLS 30 Refrigerator main body 31 Heat insulation box 32 Inner box 33 Outer box 34 Foam insulation 40 Cold storage room 41 Ice making room 42 Vegetable room 43 Freezing room 40a Refrigerating room door 41a Ice making room door 42a Vegetable room door 43a Freezing room door 50 Recessed part 51 Machine room 52 Compressor 53 Heat Dissipation Fan 54 Pre-cooling Condenser 56 Resin Component 57 Inclined Part 62 Machine Room Cover 90 Fan Cover 91a First Section 91b Discharge Section 92b Suction Section 93 Seal Member 100 Condenser 101 Evaporator 102 Evaporating Dish 200, 202 Metal Piping 201, 203, 205, 206, 209, 210 Flange part 204, 207, 208, 211, 214 Welding part 205a, 206a Folding part 212 Expanding part 213 Extension part 300 Resistance welding machine 301 Power supply 302, 303 Clamping part 304 Electrode A
305 Electrode B
306, 309 Support shaft 307, 308, 310, 311 Movable member

Claims (3)

In the welding apparatus for welding cylindrical pipes, the end part of the cylindrical pipe has a flange part that makes surface contact with each other, and is a resistance welding apparatus for metal pipes provided with an electrode part for resistance welding arranged opposite to the flange part. The said electrode part is provided with a movable part, The said electrode part is cyclically | annularly arrange | positioned by the said movable part on the outer periphery of the said cylindrical piping, a predetermined electric current is sent, and the said metal piping is welded. Resistance welding equipment for metal piping. 2. The resistance welding apparatus for metal pipe according to claim 1, wherein a pair of the electrode parts are provided, and a predetermined current is passed while pressing the flange part to weld the metal pipe.

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