JPH1129895A - Surface treatment method for internal surface of coil-shaped long size pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface treatment method for the internal surface of a coil-shaped long size pipe in which the film thickness distribution and film quality of a plated film in the longitudinal direction and circumferential direction of the internal surface of the coil-shaped long size pipe are uniform. SOLUTION: This method is executed by injecting and hermetically sealing a long size pipe-surface treatment liq. or electroplating liq. into the coil-shaped long size pipe 1, and simultaneously, inserting an electrode wire 4 into the coil-shaped long size pipe 1 and allowing the electric current to flow between the electrode wire 4 and the coil-shaped long size pipe 1 to carry out the surface treatment such as the plating and washing on the internal surface of the coil- shaped long size pipe 1. In such a case, the surface treatment is executed by allowing the electric current to flow while coating the surface section with a prescribed interval, positioning a bent and coated electrode wire 12 in the center of the coil-shaped long size pipe 1, and simultaneously, moving the coated electrode wire 12 within the coil-shaped long size pipe 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for treating the inner surface of a coiled long tube, and more particularly, to the surface of the inner surface of a coiled long tube such as hot water supply pipe, tap water pipe, and optical fiber thin tube. It relates to a processing method.

[0002]

2. Description of the Related Art As a conventional surface treatment method for an inner surface of a long tube, a plating solution is injected and an anode rod is inserted into a heat transfer tube for a heat exchanger of a straight tube. Plating method (JP-A-62-247098)
Publication), an insulating spacer is partially or intermittently and spirally wound around the surface of an electrode wire inserted into a straight tube, thereby preventing a short circuit between the electrode wire and the tube. At the same time, a method of performing electroplating while the anode rod is stationary (Japanese Patent Application Laid-Open No. 55-38949), by sealing specific portions at both ends of the anode rod inserted into the tube when plating the inner surface of a straight tubular tube, A method of making the plating film thickness uniform (Japanese Patent Application Laid-Open No. 55-38970) is exemplified.

[0003]

However, it is difficult to insert a partially covered electrode wire into a tube into which a plating solution has been injected without care and simply to conduct electricity in a fixed (stationary) state. The current density distribution of the tube as a plating material becomes extremely non-uniform, and the film thickness distribution and film quality of the plating film in the longitudinal direction and circumferential direction of the tube also become non-uniform, so that a practical plating film quality cannot be obtained.

[0004] That is, if the electrode wire is simply inserted into the tube, the voltage of the electrode wire on the outlet side is lower than the electrode wire on the inlet side based on the ohmic resistance. As the thickness of the plating film increases, the thickness of the plating film on the inner surface of the tube at the outlet side of the electrode wire decreases,
The film quality also changes in various ways. Similarly, when the electrode wire is not located at the center of the inner diameter of the tube, the circumferential thickness distribution and film quality of the plating film on the inner surface of the tube become uneven.

The present invention solves the above-mentioned problems and provides a surface treatment method for the inner surface of a coiled long tube in which the film thickness distribution and film quality of the plating film in the longitudinal direction and the circumferential direction of the inner surface of the coiled long tube are uniform. To provide.

[0006]

In order to solve the above-mentioned problems, the invention according to claim 1 is to fill and seal a long tube surface treatment solution or an electroplating solution into a coiled long tube and to seal the coiled long tube. In a method in which an electrode wire is inserted through the inside of the long tube, and a current is applied between the electrode wire and the coiled long tube to perform a surface treatment such as washing or plating on the inner surface of the coiled long tube.
The surface portion is coated with a predetermined interval, and the curved coated electrode wire is positioned at the center of the inner diameter of the coiled long tube, and the coated electrode wire is energized while moving in the coiled long tube. To perform a surface treatment.

A second aspect of the present invention is the surface treatment method for the inner surface of the coiled long tube according to the first aspect, wherein the coated electrode wire continuously moves in the coiled long tube.

According to a third aspect of the present invention, in the coiled long tube according to the first aspect, a total lengthwise extension of the exposed portion of the electrode wire is directly proportional to a plating film thickness or inversely proportional to a moving speed of the coated electrode wire. This is the surface treatment method for the surface.

According to a fourth aspect of the present invention, a part of the electrode wire covering portion has a flange having substantially the same diameter as the inner diameter of the coiled long tube so that the coated electrode wire is located at the center of the inner diameter of the coiled long tube. The surface treatment method for an inner surface of a coiled long tube according to claim 1, which is a part.

According to a fifth aspect of the present invention, in order for the covered electrode wire to move in the long coiled tube, the tip of the covered electrode wire is connected to a towed wire having winding means. A surface treatment method for the inner surface of a coiled long tube according to claim 1 or 4.

According to a sixth aspect of the present invention, in order for the covered electrode wire to move within the coiled long tube, the coiled wire having a diameter substantially equal to the inner diameter of the coiled long tube provided at the distal end of the covered electrode wire. The surface treatment method for an inner surface of a coiled long tube according to claim 1 or 4, wherein a fluid force is applied to the body from outside the coiled long tube.

According to a seventh aspect of the present invention, a degreasing solution is injected and sealed in the coiled elongated tube, and a current is supplied to the coiled elongated tube as a cathode, and a dissolved cleaning liquid is injected into the coiled elongated tube. Either sealing, energizing the coiled long tube side as an anode, or injecting and sealing an electroplating solution into the coiled long tube, and energizing the coiled long tube side as a cathode, The method for treating the inner surface of a coiled long tube according to claim 1, wherein the method is carried out by combining them.

The invention according to claim 8 is the surface treatment of the inner surface of the coiled long tube according to claim 7, wherein the degreasing solution is an alkali degreasing solution, the dissolving and cleaning solution is a sulfuric acid solution, and the electroplating solution is an electric Sn plating solution. Is the way.

According to the above construction, the surface treatment liquid or the electroplating solution is injected and sealed in the coiled long tube, and the electrode wire is inserted through the coiled long tube.
In a method of conducting a surface treatment such as washing or plating on the inner surface of the coiled long tube by conducting electricity between the electrode wire and the coiled long tube, the surface portion is coated with a predetermined interval, and In order to perform the surface treatment by energizing while moving the covered electrode wire at the center of the coiled long tube while moving the covered electrode wire in the coiled long tube, the inner surface of the coiled long tube is used. The film thickness distribution and film quality of the plating film in the longitudinal direction and the circumferential direction are uniform.

[0015]

Embodiments of the present invention will be described below.

The present inventors refer to the function of a catheter with a balloon, which is basically known as a medical device, and newly add a unique function necessary for a plating device,
A surface treatment method for the inner surface of a coiled long tube was found.

That is, the surface treatment method for the inner surface of the coiled long tube satisfies the following conditions.

(A) The inner surface of the coiled long tube can be plated.

(B) A dense plating film can be obtained.

(C) The thickness and quality of the plating film in the longitudinal direction of the coiled long tube can be made uniform.

(D) The thickness and quality of the plating film in the circumferential direction of the coiled long tube can be made uniform.

(E) A curved electrode wire can move inside the coiled long tube.

Further, in order to obtain a dense plating film having good adhesion to the inner surface of the coiled long tube, degreasing or acid cleaning is required as a pretreatment for plating. Inside the long tube, the specific liquid volume is small, the convection of the liquid,
Since the flow and the exchange hardly occur, these pretreatments for plating are hardly effective.

The present inventors have found that a good plating film can be obtained by applying a combination of the pretreatment for plating and the plating treatment satisfying the above conditions.

FIG. 1 is a schematic view of an apparatus used for the surface treatment method for the inner surface of the coiled long tube of the present invention.

As shown in FIG. 1, the apparatus used for the surface treatment method for the inner surface of the coiled long tube according to the present invention comprises a tube, a positive electrode wire 12 and a pulling wire winding wire for winding the pulling wire 8. Device 9
And power supply means.

The tube portion includes a coiled long tube 1 and plating solution sealing materials 2 a, provided at both ends of the coiled long tube 1.
2b.

The positive electrode wire 12 is formed by forming a coating material 5 at a predetermined interval on the surface of the curved electrode wire 4, and a leading wire ( A towing wire 8 is connected.

At the tip of the positive electrode wire 12, a plurality (six in the figure) of electrode wire exposed portions 6 having a predetermined length are formed at equal intervals. The surface of No. 6 is plated with an insoluble metal such as Pt, Ti, and Sn. In order to position the positive electrode wire 12 at the center of the inner diameter of the coiled long tube 1, a supporter (flange) having substantially the same diameter as the inner diameter of the coiled long tube 1 is provided on a part of the coating material 2 on the positive electrode wire 12. The supporter 7 and the inner surface of the coiled long tube 1 are in loose contact with each other.

The power supply means comprises a plating power supply 10 for performing electroplating and a lead wire 11 connected to the plating power supply 10. The lead wire 11a is connected to the negative side of the plating power supply 10 and connected to the coiled long tube 1, and the lead wire 11b is connected to the positive side of the plating power supply 10 and Connected to the rear end.

Next, the surface treatment method for the inner surface of the coiled long tube according to the present invention will be described.

First, a pulling wire 8 is inserted from one end of the coiled long tube 1 into the inside thereof, and the leading end of the pulling wire 8 is connected to the plating solution sealing material 2 a provided at the other end of the coiled long tube 1.
And wound around the tow line winding device 9.

Next, the rear end of the traction line 8 is connected to the front end of the positive electrode wire 12, and the plating solution sealing material 2 b is penetrated immediately after the last electrode wire exposed portion 6 of the positive electrode wire 12. Provided.

Next, the plating solution 3 is injected and filled into the coiled long tube 1, and the traction wire winding device 9 is operated so that the other end of the coiled long tube 1 is sealed with the plating solution sealing material. 2
b, and the plating solution 3 is sealed.

Next, the lead wire 11a connected to the negative pole of the plating power source 10 is connected to the coiled long tube 1, and the lead wire 11b connected to the positive pole of the plating power source 10 is connected to the positive electrode wire 12. Connect to the rear end.

Thereafter, the plating power supply 10 is operated to set A-
A voltage is applied between B (between the coiled long tube and the rear end of the positive electrode wire), and the traction line winding device 9 is operated to wind the traction line 8 at a constant speed. Here, it goes without saying that the towing line 8 may be reciprocated as well as wound in one direction.

As a result, a plated film having good (uniform thickness distribution and film quality in the longitudinal and circumferential directions of the inner surface of the coiled long tube) is obtained on the inner surface of the coiled long tube.

Here, by arbitrarily selecting the winding speed of the pulling wire 8 and the applied voltage, the plating process time and the plating film thickness can be arbitrarily set, and the total length of the electrode wire exposed portion 6 in the longitudinal direction can be set. The extension is determined in direct proportion to the plating film thickness or in inverse proportion to the moving speed of the positive electrode wire 12.

That is, according to the surface treatment method for the inner surface of the coiled long tube of the present invention, the positive electrode wire having the coating material formed at a predetermined interval on the surface of the curved electrode wire is connected to the coiled long wire. In order to conduct electricity while moving the positive electrode wire inside the coiled long tube while positioning it at the center of the inner diameter of the long tube,
A dense plating film having a uniform film thickness distribution and film quality in the longitudinal direction and the circumferential direction can be obtained, and the plating film thickness can be freely set.

Further, since a dense plating film having a uniform film thickness distribution and film quality in the longitudinal direction and the circumferential direction can be obtained, the reliability and durability of the inner surface of the coiled long tube can be improved.

Incidentally, it goes without saying that the surface treatment method for the inner surface of the coiled long tube of the present invention may be used as a simple pretreatment method.

Next, another embodiment of the present invention will be described.

In the surface treatment method for the inner surface of the coiled long tube according to the present invention, a traction line is connected to the tip of the positive electrode wire to move the positive electrode wire, and the traction line is wound by a traction line winding device. Was to take.

FIG. 2 is a schematic view of an apparatus used in the surface treatment method for the inner surface of the coiled long tube according to the first embodiment. still,
The same members as those in FIG. 1 are denoted by the same reference numerals.

As shown in FIG. 2, the apparatus used in the surface treatment method for the inner surface of the coiled long tube according to the first embodiment has the same basic structure as the apparatus used in the present invention, but has a different structure. The means for moving the electrode wire is different.

In order for the positive electrode wire 12 to move inside the coiled long tube 1, the distal end of the positive electrode wire 12 is attached to the coiled long tube 1.
A moving body 27 having substantially the same diameter as the inside diameter of the moving body 27 is provided. The moving body 27 has a substantially hemispherical shape, and has a concave portion on the rear side in the traveling direction of the positive electrode wire 12. The moving body 27 pulls the positive electrode wire 12 by applying a fluid force to the hollow portion of the moving body 27 from outside the coiled long tube 1.

Here, the plating solution 3 immediately after the moving direction of the moving body 27 always stays in the recessed portion and is not updated, so that the plating solution 3 gradually deteriorates, and the plating solution 3 in the longitudinal direction of the coiled long tube 1 is degraded. There is a possibility that the film quality of the plating film may deteriorate. For this reason, the plating solution leak hole 2 for allowing the deteriorated plating solution 3 to partially flow out to the front side in the traveling direction of the moving body 27.
8 may be formed to penetrate from the front surface in the traveling direction of the moving body 27 to the rear surface in the traveling direction.

The material of the moving body 27 is not particularly limited, but a soft material such as soft rubber is particularly preferable.

The means for applying the fluid force is a plating solution injection pipe 21 provided near the rear end of the positive electrode wire 12 in the traveling direction.
And a pump 25 connected to the plating solution injection pipe 21 and a surface treatment solution tank (plating solution 3) filled with each surface treatment solution.
And a surface treatment solution suction pipe (only the plating solution suction pipe 24 is shown) connecting the pump 25 and each surface treatment solution tank.

In the surface treatment method for the inner surface of the coiled long tube according to the present embodiment, first, a moving body 27 is provided at one end from the one end of the coiled long tube 1 to the inside of the coiled long tube 1. The positive electrode wire 12 is inserted. At one end of the coiled long tube 1, a positive electrode wire 12 penetrates the vicinity of a central portion of the plating solution sealing material 2.
b, and a plating solution sealing material 2a is provided at the other end. Here, the supporter 17 in the positive electrode wire 12 is formed with a through-hole for efficiently applying a fluid force to the moving body 27.

Next, the lead wire 11a connected to the negative pole of the plating power source 10 is connected to the coiled long tube 1, and the lead wire 11b connected to the positive pole of the plating power source 10 is connected to the positive electrode wire 12. Connect to the rear end.

Thereafter, the plating power supply 10 is operated to set A-
A voltage is applied between B (between the coiled long tube and the rear end of the positive electrode wire), and the pump 25 is operated to put the plating solution 3, various washing liquids, and drying inside the coiled long tube 1. Accelerating liquid,
And dry air is continuously injected and filled with
7 is moved at a constant speed.

Here, by arbitrarily selecting the moving speed of the moving body 27 and the applied voltage, the plating processing time and the plating film thickness can be arbitrarily set, and the total length of the electrode wire exposed portion 6 in the longitudinal direction can be increased. Is determined in direct proportion to the plating film thickness or in inverse proportion to the moving speed of the positive electrode wire 12.

It goes without saying that the surface treatment method for the coiled long tube of the present embodiment also has the same function and effect as the present invention.

Further, the surface treatment method for a coiled long tube according to the present embodiment has the following new effects.

Since the step of removing the plating solution and the step of injecting various washing liquids after the plating treatment can be performed integrally, the time required for all the surface treatment steps can be greatly reduced, and the work efficiency can be improved. In addition, the manufacturing cost can be reduced.

Since the plating solution is injected and filled only in a part of the vicinity of the recess on the rear side in the traveling direction of the moving body, the amount of the plating solution used can be significantly reduced.

[0058] Since the pulling distance of the positive electrode wire is initially small, the frictional resistance of the insert in the coiled long tube becomes small, so that the inner surface of the coiled long tube having a small diameter can be easily subjected to surface treatment. .

FIG. 3 is a schematic view of an apparatus used in the surface treatment method for the inner surface of the coiled long tube according to the second embodiment. still,
The same members as those in FIG. 1 are denoted by the same reference numerals.

As shown in FIG. 3, the device used in the surface treatment method for the inner surface of the coiled long tube of the present embodiment has the same basic configuration as the device used in the first embodiment. The positive electrode wire 12 having the moving body 27 connected to the tip of FIG. 2 is connected in series.

Here, when plating is performed without performing any degreasing treatment or acid cleaning, or when plating is performed after performing only immersion degreasing that is used on a daily basis, the coil-shaped length is reduced. It is difficult to remove grease and scale adhering to the inside of the long tube, and many plating defects occur on the inner surface of the coiled long tube along the adhesion marks of grease and scale, resulting in a plating film that can withstand practical use. I can't.

For this reason, in order to obtain a dense plating film with good adhesion, degreasing and acid cleaning are extremely important as pretreatments for plating. In addition, the inside of the coiled long tube, which is a closed space, has a small specific liquid volume, convection of the liquid,
Since flow and exchange hardly occur, pretreatment with electrolysis such as degreasing or acid washing is required.

The surface treatment method for the inner surface of the coiled long tube according to the present embodiment is the same as the plating solution for the inside of the coiled long tube 1 in the surface treatment method for the inner surface of the coiled long tube according to the first embodiment. Prior to the injection, a degreasing solution, an acid cleaning solution, a water washing solution, and the like are continuously injected, and the plating pretreatment and the plating treatment are integrally performed.

The moving body 27 is provided inside the coiled long tube 1.
From the position a to the rear side in the traveling direction of the positive electrode wire 12,
An alkali degreasing solution part a, a first washing solution part b, an acid washing solution part c,
A second washing liquid part d, a Sn-Pb liquid part e, and a drying accelerating liquid part f are formed, and degreasing, water washing, acid washing, water washing, plating,
And steps such as drying are integrally performed.

Although not shown in the drawing, the drying of the inner surface of the coiled long tube 1 can be performed in a shorter time by forming a dry air portion behind the drying promoting liquid portion f. It goes without saying that you can do it.

The surface treatment method for a coiled long tube according to the present embodiment can, of course, provide the same operation and effect as the present invention, and can also be applied to a coiled long tube having a large amount of grease or scale adhered to the inner surface. On the other hand, a new function and effect is obtained in which the adhesion is good and a dense plating film can be formed.

[0067]

【Example】

(Embodiment 1) First, the inside diameter 1 of which the inside was previously cleaned
A traction line introduced from one end of a coiled long copper tube having a length of 5.8 mm, a thickness of 1 mm, a length of 100 m, and a coil winding radius of 1.2 m is passed through, and the tip of the traction line is inserted into the coiled long copper tube. The plating solution sealing material provided at the other end is made to penetrate and is wound around a traction line winding device.

Next, the surface of the electrode wire made of Cu or Ag is coated with Teflon resin having a small sliding resistance to a thickness of 0.1 mm to form a positive electrode wire, and at the tip of the positive electrode wire, Exposing the electrode wire exposed part of 5cm length at intervals of 20cm to 60
Individually formed. The exposed portion of the electrode wire is plated with Pt, and the total length of the coiled long copper tube in the longitudinal direction is 3 m.

Next, the rear end of the traction wire is connected to the front end of the positive electrode wire, and a plating solution sealing material is provided to penetrate immediately after the last exposed portion of the positive electrode wire.

Next, the inside of the coiled long copper tube was placed at 25 ° C.
Injection and filling of a commercially available electric Sn plating solution (Ronastan EC, manufactured by Nippon Lee Ronal Co., Ltd.), and by operating the traction wire winding device, plug the other end of the coiled long copper tube with a plating solution sealing material. The electric Sn plating solution is sealed.

Next, the lead wire connected to the negative pole of the plating power supply is connected to the coiled long copper tube, and the lead wire connected to the positive pole of the plating power supply is connected to the rear end of the positive electrode wire. .

Thereafter, the plating power supply was operated to apply a voltage between the coiled long copper tube and the rear end of the positive electrode wire, and the traction line winding device was operated to change the traction line to 1 m / s. Wind at speed. At this time, the current density is set to 2 A / dm ² with respect to the apparent plating area. In addition, the support wire formed on a part of the electrode wire coating portion causes the positive electrode wire to always move while being positioned at the center of the coiled long copper tube.

Thereafter, energization is performed for a total of 100 minutes.
The plating energization time at an arbitrary point on the coiled long copper tube is substantially 3 minutes.

(Embodiment 2) Electroplating is carried out in the same manner as in Embodiment 1, except that the positive electrode wire is reciprocated back and forth at a stroke of 1 m, at a speed of 1 m / min for 3 minutes.

(Comparative Example 1) Except for using a positive electrode wire in which the exposed portion of the electrode wire occupies a large part and conducting electroplating in a state where the positive electrode wire is substantially stopped, the electroplating is performed in the same manner as in Example 1. I do.

As a result, the inner surface of the coiled long copper tubes of Examples 1 and 2 had an average thickness of 2 μm, a maximum thickness error of 0.2 μm in the longitudinal direction, and a maximum thickness error in the circumferential direction. Was formed at a maximum of 0.5 μm, which was remarkably denser and smoother (brighter) than the electroless Sn plating film, and no pinhole was observed.

On the other hand, when the applied current density is large, the inner surface of the coil-shaped long copper tube of Comparative Example 1 is remarkably burnt plating on the tube inlet side, and when the applied current density is small, the inner surface is burnt on the tube inlet side. Although plating could be prevented, the electric Sn plating film hardly adhered to the central portion in the longitudinal direction of the tube (around 50 m from the entrance).

When the outer diameter of the positive electrode wire (electrode wire) is set to 10 mm in order to prevent the ohmic effect and to prevent these problems, the thickness and quality of the electric Sn plating film are slightly improved ( Confirmed by experiments using straight pipes)
It became extremely difficult to insert the positive electrode wire into the coiled long copper tube, and it was impossible to insert the positive electrode wire for 10 m or more.

Example 3 First, the surface of an electrode wire made of Cu or Ag was coated with Teflon resin having a small sliding resistance to a thickness of 0.1 mm.
A positive electrode wire is formed by coating to a thickness of 1 mm, and at the tip of the positive electrode wire, 60 electrode wire exposed portions having a length of 5 cm are formed at intervals of 20 cm. The exposed portion of the electrode wire is plated with Pt, and the total length of the coiled long copper tube in the longitudinal direction is 3 m.

Next, a moving member made of a soft rubber is provided at the tip of the positive electrode wire to form a positive electrode wire portion, and the positive electrode wire portion has an inner diameter of 15.8 m, the inside of which has been cleaned in advance.
m, wall thickness 1mm, length 100m, coil winding radius 1.2m
From one end of the coiled long copper tube.

Next, one end of the coil-shaped long copper tube is sealed with a plating solution sealing material in which the positive electrode wire penetrates the vicinity of the center.

Next, the lead wire connected to the negative pole of the plating power supply is connected to the coiled long copper tube, and the lead wire connected to the positive pole of the plating power supply is connected to the rear end of the positive electrode wire portion. I do.

Thereafter, the plating power supply is operated to apply a voltage between the coiled long copper tube and the rear end of the positive electrode wire portion, and the pump is operated to put the inside of the coiled long copper tube into the inside.
An electric Sn plating solution, a weak alkaline washing solution, pure water, methanol, dry air and the like are continuously injected and filled in a volume of 25 ml each, and the moving body is moved at a speed of 1 m / s. At this time, the current density was 2 A / dm with respect to the apparent plating area.
^{To be 2} . Further, the positive electrode wire portion always moves while being positioned at the center of the coiled long copper tube by the supporter formed in a part of the electrode wire coating portion.

Thereafter, energization is performed for a total of 100 minutes.
The plating energization time at an arbitrary point on the coiled long copper tube is substantially 3 minutes.

As a result, in Embodiment 3, Embodiment 1
And the same electric Sn plating film as Example 2 was obtained.

(Example 4) First, the surface of an electrode wire made of Cu or Ag was coated with Teflon resin having a small sliding resistance to a thickness of 0.1 mm.
A positive electrode wire is formed by coating to a thickness of 1 mm, and at the tip of the positive electrode wire, 60 electrode wire exposed portions having a length of 5 cm are formed at intervals of 20 cm. The exposed portion of the electrode wire is plated with Pt, and the total length of the coiled long copper tube in the longitudinal direction is 3 m.

Next, a moving member made of soft rubber is provided at the tip of the positive electrode wire to form a positive electrode wire portion, and the two positive electrode wire portions are connected in series. The connected positive electrode wire portion was cleaned in advance with an inner diameter of 10 mm and a wall thickness of 0.1 mm.
A coiled long copper tube having a length of 8 mm, a length of 200 m, and a coil winding radius of 1.6 m is inserted into one end of a long copper tube.

Next, one end of the coil-shaped long copper tube is sealed with a plating solution sealing material having a positive electrode wire penetrating near the center.

Next, the lead wire connected to the negative pole of the plating power source is connected to the coiled long copper tube, and the lead wire connected to the positive pole of the plating power source is connected to the rear end of the positive electrode wire portion. I do.

Thereafter, the plating power supply is operated to apply a voltage between the coiled long copper tube and the rear end of the positive electrode wire portion, and the pump is operated to put the inside of the coiled long copper tube into the inside.
Electrolytic degreasing solution (2% NaOH + 5% NaCO ₃ + 50pp
m surfactant mixture), first washing solution (pure water), acid washing solution (2% H ₂ SO ₄ + 4% K ₂ S ₂ O ₈ mixed solution), second washing solution (pure water)
A washing liquid (pure water) and a Sn-Pb plating solution (Soldalon MHS-w, manufactured by Nippon Leelonal Co., Ltd.) were continuously injected and filled for a pipe length of 15 m, respectively, and the moving body was set to 1
Move at a speed of m / s. At this time, the current density is set to 10 A / dm ² with respect to the apparent plating area.
In addition, the positive electrode wire portion always moves while being positioned at the center of the coiled long copper tube by the supporter formed in a part of the electrode wire coating portion.

Thereafter, energization is performed for a total of 100 minutes.
The plating energization time at an arbitrary point on the coiled long copper tube is substantially 3 minutes.

As a result, an Sn—Pb plating film that is dense, smooth (has luster), and has no pinholes is formed on the inner surface of the coiled long copper tube of Example 4. Was completed.

The surface treatment method for the inner surface of the coiled long tube of the present invention can be used for a coiled product, needless to say, fixed parts, for example, hot water supply inside a building already constructed and constructed. It can also be applied to piping and various equipment piping.

[0094]

In summary, according to the present invention, the following excellent effects are exhibited.

(1) A positive electrode wire having a coating material formed at a predetermined interval on the surface of a curved electrode wire is positioned at the center of the inner diameter of the coiled long tube, and the positive electrode wire is coiled. By energizing while moving inside the long tube,
A dense plating film having a uniform film thickness distribution and film quality in the longitudinal direction and the circumferential direction can be obtained, and the plating film thickness can be freely set.

(2) Since a dense plating film having a uniform film thickness distribution and film quality in the longitudinal direction and the circumferential direction can be obtained, the reliability and durability of the inner surface of the coiled long copper tube can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic view of an apparatus used for a surface treatment method for an inner surface of a coiled long tube of the present invention.

FIG. 2 is a schematic view of an apparatus used for a surface treatment method for an inner surface of a coiled long tube according to the first embodiment.

FIG. 3 is a schematic diagram of an apparatus used for a surface treatment method for an inner surface of a coiled long tube according to a second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Coiled long tube 4 Electrode wire 6 Electrode wire exposed part 7, 17 Supporter (flange) 8 Towing wire (towing wire material) 9 Towing wire winding device (winding means) 12 Positive electrode wire (coated electrode wire) 27a, 27b Moving body

Claims (8)

[Claims] 1. A long tube surface treatment solution or an electroplating solution is injected and sealed inside a coiled long tube, and an electrode wire is inserted through the inside of the coiled long tube. In the method of performing a surface treatment such as cleaning or plating on the inner surface of the coiled long tube by conducting electricity between the long tube and the surface portion is coated with a predetermined interval, and a curved coated electrode wire is formed. Surface treatment of the inner surface of the coiled long tube, wherein the surface treatment is performed by energizing the coated electrode wire while moving the coated electrode wire in the coiled long tube while being positioned at the center of the inner diameter of the coiled long tube. Method. 2. The surface treatment method for an inner surface of a coiled elongated tube according to claim 1, wherein the coated electrode wire continuously moves in the coiled elongated tube. 3. The method for treating the inner surface of a coiled long tube according to claim 1, wherein the total extension of the exposed portion of the electrode wire in the longitudinal direction is directly proportional to the plating film thickness or inversely proportional to the moving speed of the coated electrode wire. . 4. A part of the electrode wire covering portion is formed as a flange having substantially the same diameter as the inside diameter of the coiled long tube so that the covered electrode wire is located at the center of the inside diameter of the coiled long tube. The surface treatment method for an inner surface of a long coiled tube according to claim 1. 5. An end of the covered electrode wire is connected to a tow wire provided with a winding means so that the covered electrode wire moves in the coiled long tube. 5. The surface treatment method for the inner surface of the coiled long tube according to 4. 6. A moving body having substantially the same diameter as the inner diameter of the coiled long tube provided at the tip of the coated electrode wire so that the coated electrode wire moves in the coiled long tube. The fluid force is applied from the outside of the elongate tube.
A surface treatment method for the inner surface of the coiled long tube described in the above. 7. A degreasing solution is injected into the coiled long tube.
While enclosing, energizing the coiled long tube side as a cathode, pouring and dissolving the dissolved cleaning liquid into the coiled elongated tube, energizing the coiled long tube side as an anode, and energizing the coiled long tube 2. The method according to claim 1, wherein an electroplating solution is injected into the tube, the tube is sealed, and a current is applied to the coiled long tube side as a cathode or a combination thereof.
A surface treatment method for the inner surface of the coiled long tube described in the above. 8. The method of claim 7, wherein the degreasing liquid is an alkaline degreasing liquid, the dissolving and cleaning liquid is a sulfuric acid liquid, and the electroplating liquid is an electric Sn plating liquid.