JP2013119650A - Partial plating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a partial plating method in which partial plating can be performed which controls cyanogen burn, while reducing time required for processing.SOLUTION: In the partial plating method, a part of copper plating performed over an entire hollow machine element part 1 is detached. The copper plating is performed over the entire machine element part 1, and inside the machine element part 1, at least a part of the surface of a plating layer in the boundary division 80 between the portion 31 from which the copper plating is to be detached and the portion 30 from which the copper plating is not to be detached is smoothed. Then, by immersing the portion 31 from which the copper plating is to be detached of the machine element part 1 in an aqueous solution of a cyanogen compound, the cooper plating performed on the portion 31 to be detached is detached.

Description

  The present invention relates to a partial plating method, and more particularly to a partial plating method in which copper plating is partially peeled and removed with an aqueous solution of a cyanide compound.

  In many cases, a copper pipe is used for refrigerant piping such as a heat exchanger of an air conditioner. However, when an element part connected to the copper pipe is made of a steel material, brazing becomes difficult as it is. In this way, in the connection between pipes, brazing becomes difficult if the metals constituting both pipes are different. Therefore, the same metal plating as that of the other pipe is partially applied to the connection position of one pipe. Techniques have been proposed that allow application and brazing (see, for example, Patent Document 1).

  The technique described in Patent Document 1 is such that after the surface of the stainless steel member 11 (to-be-plated object) is plated with a material that can be easily brazed with, for example, phosphor copper, the copper tube 3 The stainless steel member 11 is brazed.

  Here, there is a plating method in which partial plating is performed by partial peeling by partial masking by masking or partial plating after partial plating on an object to be plated. The “partial plating method by masking” is a method in which plating is performed after masking a portion of the material to be plated exposed, that is, a portion not to be plated, with a cap or the like. This “partial plating method by masking” may not be employed because it is difficult to mask depending on the shape of the object to be plated. In particular, if the object to be plated has a hollow shape, it is difficult to mask a part of the object to be plated.

  Therefore, in such a case, a method called “a plating method in which a part is peeled off after partial plating and partial plating” is adopted. “Plating method that removes part after complete plating and makes partial plating” uses a cyanide aqueous solution as the chemical solution. For example, the plating object is immersed in the cyanide aqueous solution and chemically plated. Is removed and removed. In this “plating method in which a part is peeled after partial plating and partial plating is performed”, the peeling position is managed by the liquid level of the aqueous solution.

JP-A-8-267228 (see, for example, paragraphs [0030] to [0033] and FIG. 1)

  In connecting the copper pipe and the steel pipe, the steel pipe is plated with copper. At this time, if a copper plating method is applied to the steel pipe, a part of the steel pipe is exfoliated and then partially plated, and when the steel pipe is immersed in an aqueous solution of cyanide, Discoloration called “cyan burn” may occur. This discoloration is due to the production of copper carbonate. Thus, if copper carbonate remains in the steel pipe, it may be difficult to braze because the materials of the pipes to be connected are different.

  In addition, copper carbonate due to “cyan burn” is likely to occur inside a cylindrical part having a hollow interior such as a pipe. Therefore, the copper carbonate can be removed by washing with hydrochloric acid, but since the copper plating is carbonized from the surface, the plating thickness is reduced by removing it. When the plating thickness is reduced, brazing may not be ensured.

  Furthermore, in order to ensure the plating thickness even after washing “cyan burn” with hydrochloric acid, in anticipation of the occurrence of copper carbonate, if the copper plating thickness is increased, the piping processing time will be increased accordingly. there is a possibility.

  Note that hydrochloric acid cleaning may be difficult to use depending on the environment in which the object to be plated is used. For example, residual chlorine may adhere to an object to be plated due to insufficient cleaning process after hydrochloric acid cleaning. Thereby, when a to-be-plated object is piping used with a refrigerant circuit, the residual chlorine may deteriorate the refrigerating machine oil which circulates through a refrigerant circuit.

  The present invention has been made in order to solve at least one of the above-described problems, and is a portion that enables partial plating to suppress cyan burn while reducing the time required for processing. The purpose is to provide a plating method.

  The partial plating method according to the present invention is a partial plating method in which a part of copper plating applied to the entire inside of a machine element part having a hollow inside is peeled off. After smoothing at least a part of the surface of the plating layer inside the part and at the boundary between the part where the copper plating is peeled off and the part where the copper plating is not peeled off, the part where the copper plating of the machine element part is peeled off Then, it is immersed in an aqueous solution of a cyanide compound and the copper plating applied to the part to be peeled off is peeled off.

  According to the partial plating method according to the present invention, before the copper plating of the machine element part is partially peeled, the vicinity of the boundary between the part where the copper plating of the machine element part is peeled off and the part where the copper plating is not peeled off is smoothed. Cyan burning can be suppressed while reducing the time required for processing.

It is a schematic block diagram of the compressor with which the piping in which the partial plating method concerning Embodiment 1 of this invention is implemented was brazed. It is explanatory drawing about the discoloration which arises by the structure of piping shown in FIG. 1, and copper plating peeling. It is sectional drawing of the discoloration part which generate | occur | produced in piping shown in FIG.2 (b) and piping shown in FIG.2 (d). It is explanatory drawing of the copper plating process of the partial plating method which concerns on Embodiment 1 of this invention. It is explanatory drawing of the buffing of the partial plating method which concerns on Embodiment 1 of this invention. A plurality of pipes are buffed to show the surface roughness of each pipe. FIG. 7A is a process diagram of the partial plating method, and FIG. 7B is a process diagram when the partial plating method is not adopted. It is a flowchart of the partial plating construction method which concerns on Embodiment 2 of this invention. It is explanatory drawing of the plating process of step S21 shown in FIG. It is explanatory drawing of the buffing of the partial plating method which concerns on Embodiment 3 of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Embodiment 1 FIG.
FIG. 1 is a schematic configuration diagram of a compressor 60 to which a pipe 1 on which a partial plating method according to Embodiment 1 is performed is brazed. In the first embodiment, an example in which an object to be subjected to a partial plating method, that is, a machine element component is a pipe 1 that constitutes a part of the compressor 60 will be described.
The partial plating method according to the first embodiment is used for the pipe 1 (to-be-plated object) through which the refrigerant supplied to the compressor 60 flows, and while reducing the processing time of the pipe 1, cyan The improvement which suppresses burning is added.

[Configuration of piping 1]
The compressor 60 is connected to the muffler 12 that reduces drive sound and vibration sound generated from the compressor 60, the muffler 12, and is connected to the muffler pipe 10 and the muffler pipe 10 that are made of copper. It has the pipe 1 to which the partial plating method of the form 1 is applied, the main body connection pipe 11 connected to the pipe 1 and made of copper, and the cylinder 21 connected to the pipe 1 and made of iron. . In addition to the muffler 12, the muffler pipe 10, the pipe 1, the main body connection pipe 11, and the cylinder 21, the compressor 60 includes a stator, a rotor, and the like, which are not shown in FIG.

The pipe 1 is a pipe that connects the muffler pipe 10 and the cylinder 21. The pipe 1 has a muffler pipe 10 press-fitted and connected to one side, and a cylinder 21 is press-fitted and connected to the other. The pipe 1 is fixed to the main body of the compressor 60 via the main body connection pipe 11.
That is, a muffler pipe 10 made of copper is contacted and connected to one inner surface of the pipe 1, and a cylinder 21 made of iron is contacted and connected to the other outer surface of the pipe 1. ing. The pipe 1 is connected to the main body connection pipe 11 made of copper on the outer surface of the pipe 1 that is not connected to the cylinder 21.

[Piping 1 copper plating]
Here, the pipe 1 does not form copper plating on the outer surface part to which the cylinder 21 is connected outside the pipe 1, but forms copper plating on the outer surface part to which the main body connection pipe 11 is connected. That is, using the “partial plating method”, after the entire pipe 1 is copper plated, the copper plating of the pipe 1 is partially peeled off. More details are as follows.
The pipe 1 is subjected to copper plating on the entire outside and inside of the pipe 1. However, since the pipe 1 is press-fitted into the cylinder 21 and fixed, if the copper plating is formed on the outer surface of the pipe 1 that contacts the cylinder 21, the sealing performance of the pipe 1 and the cylinder 21 is reduced. there is a possibility. Therefore, the copper plating on the outer surface that contacts the cylinder 21 of the outer surface of the pipe 1 is partially peeled off by the cyanide compound. In the first embodiment, the part of the pipe 1 from which the copper plating is peeled is immersed in an aqueous solution of a cyanide and removed.
On the other hand, the copper plating on the outer surface of the outer surface of the pipe 1 that comes into contact with the main body connecting pipe 11 is left without peeling. Thereby, copper brazing of the pipe 1 and the main body connection pipe 11 is possible.

  Further, the pipe 1 is configured such that a muffler pipe 10 made of copper is connected inside the pipe 1, and copper plating is formed on an inner surface portion to which the muffler pipe 10 is connected. That is, when the cylinder 21 is immersed in an aqueous solution of cyanide, not only the outer surface copper plating that contacts the cylinder 21 out of the outer surface of the pipe 1 but also the inner surface copper plating corresponding to the outer surface is peeled off. Is done. However, the inner surface in contact with the muffler pipe 10 is left without peeling off the copper plating. Thereby, copper brazing with piping 1 is attained.

[Partial peeling of copper plating on pipe 1]
FIG. 2 is an explanatory diagram of the configuration of the pipe 1 shown in FIG. 2A shows the outer surface of the pipe 1, and FIG. 2B shows the inner surface of the pipe 1 by dividing the pipe 1 of FIG. 2A by a plane parallel to the paper surface. 2C shows the outer surface of the pipe 1A having a shape different from that of the pipe 1 shown in FIG. 2A, and FIG. 2D shows the pipe 1A shown in FIG. 2C parallel to the paper surface. And the inner surface of the pipe 1A is shown. Note that the pipe 1A is a pipe having a shape different from that of the pipe 1 and has a shape whose diameter is reduced in the longitudinal direction.
3 is a cross-sectional view of the discolored portion 34 generated in the pipe 1 shown in FIG. 2B and the pipe 1A shown in FIG. FIG. 3A shows the pipe 1 before the copper plating is partially peeled off, and FIG. 3B shows the pipe 1 after the copper plating is partially peeled off. 3A and 3B, the pipe 1 is subjected to copper plating, the copper plating is formed on the outer surface of the pipe 1 by about 50 (μm), and the copper plating is applied to the inner surface of the pipe 1. It is sectional drawing at the time of forming 30 (micrometer).
With reference to FIG.2 and FIG.3, the discoloration which generate | occur | produces in the piping 1 is demonstrated.

The piping 1 shown in FIG. 2A and FIG. 2B is obtained by peeling a part of the copper plating after copper plating the whole. That is, the outer surface of the pipe 1 includes a copper plating portion 30 and a copper plating peeling portion 31. Further, the inner surface of the pipe 1 corresponds to the outer surface, and includes a copper plating portion 30 and a copper plating peeling portion 31. The copper plating part 30 and the copper plating peeling part 31 are formed on both the outer surface and the inner surface of the pipe 1 when the copper plating is peeled without masking the pipe 1 or the like. This is because the plating peeling portion 31 side is immersed in an aqueous solution of a cyanide compound.
The partial plating method using masking is a method in which a part to be exposed of the material surface of the object to be plated is masked with a cap or the like to perform plating. Since it is difficult to mask a member having a shape like the hollow pipe 1, the partial plating method according to the first embodiment does not employ the partial plating method by masking.

  Here, as shown in FIG. 2B, a discolored portion 32 called “cyan burn” is formed at a boundary portion 80 between the copper plating portion 30 and the copper plating peeling portion 31. In addition, the boundary part 80 is a surface part of the plating layer of the copper plating part 30, Comprising: The boundary of the copper plating part 30 and the copper plating peeling part 31, and the part of the said boundary vicinity. Further, as shown in FIG. 2 (d), similarly in the pipe 1A in which one of the pipes 1 has a reduced diameter, the boundary portion 80 between the copper plating portion 30A and the copper plating peeling portion 31A. A discolored portion 32A called “cyan burn” is formed.

  The discolored portion 32 called “cyan burn” is caused by partial peeling of the copper plating. Here, when the copper plating of the pipe 1 is partially peeled, it is immersed in an aqueous solution of a cyanide compound with the copper plating peeling part 31 side of the pipe 1 facing downward. At the time of this immersion, the liquid level of the cyanide aqueous solution is located at the boundary surface between the copper plating portion 30 and the copper plating peeling portion 31, but part of the cyanide aqueous solution is sucked up from the boundary surface by capillary action. It is done. As a result of the aqueous solution of the cyanide compound sucked up by this capillary phenomenon adhering to a part of the copper plating part 30, a discolored part 32 is formed.

As shown in FIGS. 2A to 2D, “cyan burn” is easily formed inside a cylindrical part whose inside is hollow. The reason is as follows.
Since the cylindrical part is formed by drawing, for example, the inner side is often rougher (the surface roughness is higher) than the outer side. Moreover, the surface roughness when copper plating is applied to a rough surface and the surface roughness when copper plating is applied to a smooth surface are the same as when copper plating is applied to a rough surface. It becomes rougher. That is, the inside of the cylindrical part with a hollow interior is rougher than the smooth outside compared to the inside, so the surface is rough even after copper plating, and the cyanide aqueous solution is easily sucked up by capillary action. That's what it means.

In addition, this discoloration part 32 originates in the copper plating of the copper plating part 30 carbonizing with the aqueous solution of the cyanide compound, and the copper carbonate was produced | generated.
With this copper carbonate, copper brazing between the muffler pipe 10 made of copper and the inner surface of the copper plated portion 30 of the pipe 1, and the outside of the main body connection pipe 11 made of copper and the copper plated portion 30 of the pipe 1 Copper brazing with the surface may be difficult. That is, since copper and copper carbonate are different materials, they are difficult to braze.

  Further, the copper carbonate in the discolored portion 32 can be removed by, for example, shaking the pipe 1 for about 15 seconds with an acidic aqueous solution having a hydrochloric acid concentration of 7%. However, as shown in FIG. 3B, since the discolored portion 32 is carbonized from the surface to the deep portion, the plating thickness of the copper-plated portion 30 is reduced by removing it. Specifically, as shown in FIG. 3A, the copper plating formed on the inner surface is formed with about 30 (μm), but when the copper plating is partially peeled, as shown in FIG. 3B. Moreover, about 27 (μm) is oxidized from the surface of the peeled portion. Thereby, when this copper carbonate is partially washed with an acidic aqueous solution or the like, the oxidized portion is removed, and the remaining plating portion becomes about 3 (μm). And when brazing is implemented in a state where the copper plating thickness is reduced, the pipes may not be securely fixed.

  In the partial plating method according to the first embodiment, the capillary phenomenon when the copper plating portion 30 is immersed in an aqueous solution of a cyanide compound is suppressed, and cyan burn is not formed in the copper plating portion 30. That is, the partial plating method described below is performed to suppress the capillary phenomenon.

  FIG. 4 is an explanatory diagram of the copper plating process of the partial plating method according to the first embodiment. FIG. 5 is an explanatory diagram of buffing of the partial plating method according to the first embodiment. FIG. 6 shows the surface roughness of each pipe 1 by buffing a plurality of pipes 1. The copper plating process in FIG. 4 corresponds to step S11 in FIG. 7 described later, and the buffing in FIG. 5 corresponds to step S14 in FIG.

[Plating treatment]
A barrel plating apparatus 50 shown in FIG. 5 performs copper plating of the pipe 1. The barrel plating apparatus 50 includes a plating tank 5 in which the copper plating solution 4 is stored, a barrel 2 into which the copper plating solution in the plating tank 5 flows, and a rotating device 3 that rotates the barrel 2 in the plating tank 5. Have. In addition, although illustration is abbreviate | omitted, the barrel plating apparatus 50 is provided with the electrode of the positive electrode and the negative electrode.
The plating tank 5 stores the copper plating solution 4. The barrel 2 is immersed in the plating tank 5 during copper plating.
The barrel 2 accommodates the pipe 1 and the like, and has, for example, a substantially box shape in which a plurality of through holes are formed. And when the barrel 2 is immersed in the plating tank 5, the copper plating solution 4 flows in through the through hole. Further, both sides of the barrel 2 are rotatably supported by the rotating device 3.
The rotating device 3 rotates the barrel 2 and rotatably supports both side surfaces (both left and right side surfaces of the paper) of the barrel 2 so that the copper plating is performed on the pipe 1 without unevenness.

[Buffing]
The buffing shown in FIG. 5 includes a part where the copper plating of the pipe 1 is peeled off (the peeling part 31 shown in FIGS. 2 and 3) and a part where the copper plating of the pipe 1 is not peeled (FIG. 2 and FIG. 2). 3 near the boundary 80 with the copper plating portion 30). Note that the buffing range is the boundary 80. That is, the range to be buffed is the surface portion of the plating layer of the copper plating portion 30, and the boundary between the copper plating portion 30 and the copper plating peeling portion 31 and the portion in the vicinity of the boundary. The buffing is performed by rotating and driving the buffing tool 6 that smoothes the pipe 1 so as to contact the pipe 1. The buff tool 6 is made of, for example, cloth.

  The buffing in the first embodiment smoothes at least a part of the surface of the plating layer at the boundary 80. That is, the boundary portion 80 on the inner side 1b of the pipe 1 in the boundary portion 80 is smoothed, and the boundary portion 80 on the outer side 1a of the pipe 1 in the boundary portion 80 is not smoothed. This is because, as described above, the inside of the cylindrical part having a hollow interior is rough, and the aqueous cyanide solution is more easily sucked up by capillary action than the smooth outside compared to the inside. is there.

How much the inner side 1b of the pipe 1 is smoothed by buffing will be described.
Through experiments, it is confirmed that cyan burn is formed when the surface roughness of the inner side 1b of the pipe 1 after the copper plating process is about Rz = 13 (μm) (Rz.JIS = 9.5 (μm)) or more. doing. When the surface roughness of the inner side 1b of the pipe 1 is Rz = 13 (μm), surface roughness data as shown in FIG.
Further, it has been confirmed that cyan burn is not formed when the surface roughness of the inner side 1b of the pipe 1 is Rz = 6 (μm) (Rz. JIS = 4.5 (μm)) or less. In addition, when the surface roughness of the inner side 1b of the pipe 1 was Rz = 6 (μm) or less, surface roughness data as shown in FIGS. 6B to 6F was obtained.
Thus, the surface roughness of the inner side 1b of the pipe 1 is preferably set to Rz = 6 (μm) (Rz. JIS = 4.5 (μm)) or less by buffing.
The outer side 1a of the pipe 1 was not buffed, but the surface roughness was Rz = 2 (μm) (Rz. JIS = 1 (μm)). There is no cyan burn.

FIG. 7A is a process diagram of the partial plating method. FIG. 7B is a process diagram when the partial plating method is not adopted. Next, with reference to Fig.7 (a), the process of the partial plating method concerning this Embodiment 1 is demonstrated.
(Step S11)
The piping 1 is put into the barrel plating apparatus 50, and the entire piping 1 is plated with copper.

(Step S12)
In step S11, the copper plating solution 4 attached to the pipe 1 is washed and removed.

(Step S13)
In step S12, the water adhering to the pipe 1 is dried.

(Step S14)
Before the copper plating of the pipe 1 formed in step S11 is partially peeled off, the part of the pipe 1 from which the copper plating is peeled off (the peeling part 31 in FIGS. 2 and 3) and the part that is not peeled off (in FIGS. 2 and 3). The vicinity of the boundary 80 with the copper plating portion 30) is buffed and smoothed.

(Step S15)
Washing with water to remove debris and the like produced by buffing in step S14.

(Step S16)
In step S15, the water attached to the pipe 1 is dried.

(Step S17)
The part to be peeled out of the pipe 1 is immersed in an aqueous solution of a cyanide to partially peel off the copper plating.

(Step S18)
In step S17, the cyanide aqueous solution adhering to the pipe 1 is removed by washing with water.

(Step S19)
In step S18, the water attached to the pipe 1 is dried.

Here, steps S11 to 13 and S17 to S19 in FIG. 7A are the same as steps S1 to S3, S4, S5, and S10 in the normal process in FIG. 7B. That is, the normal process does not include steps S14 to S16 in FIG. 7A, but includes steps S6 to S9.
Therefore, description of steps S1 to S3, S4, S5, and S10 in the normal process is omitted, and steps S6 to S9 are described.

(Step S6)
Since buffing is not performed in the normal process, cyan burn is generated by immersing the pipe 1 in an aqueous solution of a cyanide compound in step S4. Therefore, in order to remove the cyan burn formed in step S4, it is removed by washing with an acidic aqueous solution (hydrochloric acid or the like).

(Step S7)
In step S6, the acidic aqueous solution adhering to the pipe 1 is removed by washing with water.

(Step S8)
In step S7, in order to neutralize the hydrochloric acid remaining in the pipe 1, it is neutralized with an alkaline aqueous solution (such as sodium hydroxide).

(Step S9)
In step S8, the alkaline aqueous solution adhering to the pipe 1 is removed by washing with water.

  Thus, the partial plating method which concerns on this Embodiment 1 has the process of step S14-S16 which is not in a normal process. For this reason, it is possible to suppress cyan burn. Moreover, in the partial plating method which concerns on this Embodiment 1, the processing time of the piping 1 can be suppressed by the part which does not have step S6-S9 of a normal process.

[Effect of partial plating method according to Embodiment 1]
In the partial plating method according to the first embodiment, a part of the pipe 1 where the copper plating is peeled off (the peeling part 31 in FIGS. 2 and 3) and a part which is not peeled off (the copper plating part 30 in FIGS. 2 and 3) The step of smoothing the vicinity of the boundary 80 is provided before the step of partially peeling the copper plating of the pipe 1. Thereby, it is possible to suppress the formation of cyan burn at the boundary 80. As a result, reliable brazing can be performed.

Further, since cyan burn is not formed, it is not necessary to wash with an acidic aqueous solution such as hydrochloric acid. That is, the copper plating thickness does not decrease by removing with an acidic aqueous solution. Therefore, reliable brazing can be performed.
Moreover, since the process wash | cleaned with acidic aqueous solutions, such as hydrochloric acid, is unnecessary, it can suppress that the processing time of the piping 1 becomes long.

  Furthermore, since it is not necessary to omit the step of washing with an acidic aqueous solution such as hydrochloric acid, residual chlorine does not adhere to the pipe 1. Thereby, even if the pipe 1 is provided in the compressor 60, it is possible to prevent the refrigerating machine oil circulating in the refrigerant circuit from being deteriorated.

Embodiment 2. FIG.
FIG. 8 is a flowchart of the partial plating method according to the second embodiment. FIG. 9 is an explanatory diagram of the plating process in step S21 shown in FIG. In the second embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and differences from the first embodiment will be mainly described.

In the partial plating method according to the second embodiment, in addition to the pipe 1, the medium 7 capable of smoothing the surface of the pipe 1 during barrel plating is accommodated in the barrel 2 shown in FIG. To do.
The medium 7 smoothes the pipe 1 by rubbing the pipe 1 and the medium 7. The media 7 is stored in the barrel 2 of the barrel plating apparatus 50 during the copper plating process. The media 7 is stirred in the barrel 2 together with the pipe 1 by rotating the barrel 2 by the rotating device 3. The media 7 rubs against the pipe 1 during the stirring process, and the surface of the pipe 1 can be smoothed.

The diameter of the medium 7 is smaller than the inner diameter of the pipe 1 so that the inner side 1b of the pipe 1 can be smoothed. Moreover, if the diameter of the medium 7 is smaller than the through hole formed in the barrel 2, it will come out of the through hole of the barrel 2 during copper plating. Therefore, the diameter of the medium 7 is preferably smaller than the inner diameter of the pipe 1 and larger than the through hole of the barrel 2.
The shape of the medium 7 is not particularly limited, and various shapes such as a sphere and a triangular pyramid can be employed. The medium 7 may be made of, for example, ceramic.

The partial plating method according to the second embodiment is the same as steps S12, S13, and S17 to S19 according to the first embodiment. As shown in FIG. 9, the partial plating method according to the first embodiment can omit the smoothing process, the cleaning and drying after the smoothing (steps S14 to S16) according to the first embodiment.
This is because the smoothing corresponding to the buffing in step S14 of the first embodiment is performed during the copper plating process of the barrel plating apparatus 50 in step S21. That is, by the copper plating process in step S21, the inside 1b of the pipe 1 is smoothed by the action of the medium 7, and the surface roughness is set to 6 (μm) or less.

As described above, the partial plating method according to the second embodiment has a plating process using the medium 7 unlike the plating process of the normal process. For this reason, it is possible to suppress the occurrence of cyan burn. Moreover, in the partial plating method which concerns on this Embodiment 2, the processing time of the piping 1 can be suppressed by the part which does not have step S6-S9 of a normal process.
In the partial plating method according to the second embodiment, the case where steps S14 to S16 of the first embodiment are not described has been described. For example, when the smoothing of the media 7 is insufficient, buffing is performed. Needless to say, it may be implemented.

[Effects of partial plating method according to Embodiment 2]
The partial plating method according to the second embodiment has the following effects in addition to the effects exhibited by the partial plating method according to the first embodiment.
That is, in the partial plating method according to the second embodiment, the medium 7 is accommodated in the barrel 2 and copper plating is performed before the step of partially peeling the copper plating of the pipe 1. And the whole piping 1 can be smooth | blunted before the process which peels copper plating of the piping 1 partially. As a result, the vicinity of the boundary 80 between the portion of the pipe 1 where the copper plating is peeled off (the peeling portion 31 of FIGS. 2 and 3) and the portion where the copper plating is not peeled (the copper plating portion 30 of FIGS. 2 and 3) is also smoothed. it can.
Thereby, it is possible to suppress the formation of cyan burn at the boundary portion 80 on the inner side 1b and the boundary portion 80 on the outer side 1a, and reliable brazing can be performed.

Embodiment 3 FIG.
FIG. 10 is an explanatory diagram of buffing of the partial plating method according to the third embodiment. In the third embodiment, the same reference numerals are used for the same parts as in the first and second embodiments, and differences from the first and second embodiments will be mainly described.

The buffing of the first embodiment is performed on the peeling portion on the inner side 1b of the pipe 1, but the partial plating method according to the third embodiment also performs buffing on the peeling portion on the outer side 1a. Is.
Even on the outer side 1a, the surface may be rough depending on the processing state of the pipe 1, for example. In such a case, as with the inner side 1b, cyan burning is formed by buffing the outer surface 1a of the pipe 1 so that the surface roughness is 6 (μm) or less. This can be suppressed, and reliable brazing can be performed.

  The matters described in the first to third embodiments may be appropriately combined. For example, the second embodiment may be combined with the third embodiment to smooth the pipe 1 with the medium 7 and to buff the inner side 1 b and the outer side 1 a of the pipe 1.

[Effect of partial plating method according to Embodiment 3]
The partial plating method according to the third embodiment has the following effects in addition to the effects exhibited by the partial plating method according to the first embodiment.
That is, in the partial plating method according to the third embodiment, the medium 7 is accommodated in the barrel 2 and the copper plating is performed before the step of partially peeling the copper plating of the pipe 1. Then, before the step of partially peeling the copper plating of the pipe 1, the portion (the peeling portion 31 in FIG. 2 and FIG. 3) where the copper plating on the inner side 1 b of the pipe 1 is peeled off and the portion (FIG. 2 and FIG. 3). The vicinity of the boundary 80 with the copper plating portion 30) is smoothed. Further, before the step of partially peeling the copper plating of the pipe 1, the part (peeling part 31 in FIGS. 2 and 3) where the copper plating on the outer side 1 a of the pipe 1 is peeled off and the part (FIG. 2 and FIG. 3) that does not peel off. The vicinity of the boundary 80 with the copper plating portion 30) is smoothed.
Thereby, it is possible to suppress the formation of cyan burn at the boundary portion 80 on the inner side 1b and the boundary portion 80 on the outer side 1a, and reliable brazing can be performed.

  1 piping, 1A piping, 1a outside, 1b inside, 2 barrel, 3 rotating device, 4 copper plating solution, 5 plating tank, 6 buffing tool, 7 media, 10 muffler piping, 11 main body connection piping, 12 muffler, 21 cylinder, 30 Copper plating part, 30A Copper plating part, 31 Copper plating peeling part, 31A Copper plating peeling part, 32 Color changing part, 32A Color changing part, 34 Color changing part, 50 Barrel plating apparatus, 60 Compressor, 80 Boundary part.

Claims (6)

It is a partial plating method that peels off a part of copper plating applied to the entire machine element part with a hollow interior,
Copper plating is applied to the entire machine element part,
After smoothing at least a part of the surface of the plating layer at the boundary between the portion where the copper plating is peeled off and the portion where the copper plating is not peeled, inside the machine element part,
A partial plating method characterized by immersing a part of the machine element part from which copper plating is peeled off in an aqueous solution of a cyanide compound and peeling off the copper plating applied to the part to be peeled off. By the smoothing,
2. The partial plating method according to claim 1, wherein the surface roughness of the copper plating layer at the boundary portion inside the machine element part is set to Rz = 6 μm or less. The partial plating method according to claim 1, wherein the vicinity of the boundary portion inside the machine element part is polished by buffing and smoothed. In addition to the inner boundary portion of the machine element part plated with copper, the outer boundary portion corresponding to the boundary portion is polished and smoothed by buffing,
4. The partial plating method according to claim 3, wherein the copper plating is peeled off by immersing a portion of the machine element part from which the copper plating is peeled off in an aqueous solution of a cyanide compound. 5. A plating tank in which a copper plating solution is stored;
A plurality of through holes are formed, and a barrel immersed in the plating tank,
A rotating device for rotating the barrel in the plating tank;
The partial plating method according to any one of claims 1 to 4, wherein the copper plating is performed on the machine element component by a barrel plating apparatus having the following. A plurality of media having a diameter smaller than the hollow portion of the machine element part and larger than the through hole of the barrel are accommodated in the barrel, and the copper plating is performed by the barrel plating apparatus,
The partial plating method according to claim 5, wherein the surface of the machine element part is smoothed during the copper plating.

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