JPH08296084A - Apparatus for especially local electrochemical treatment of electrically conductive base - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the leakage of an electrolyte by closing an opening of a treatment device with a flexible material, which is permeable a liq. and conducting an electrochemical treatment while keeping the pressure of the treatment device negative with pumps.

SOLUTION: The opening 4 of a container 1 is closed with a pad 16. The pad 16 is made of the nonconductive, absorptive and flexible material which is permeable to a gas and the liq. The electrolyte E is supplied into the container 1 with a first pump 19 and is discharged with a second pump 17. The discharge rate of the second pump 17 is set top be larger than the discharge rate of the first pump 19, thereby keeping the pressure of the container 1 negative. A part A to be treated is connected to an anode 8 of a current generator G, the pad 16 is connected to a cathode 7 via an electrode 7 and the voltage is applied. The surface S to be treated of the part A is anodized with the electrolyte exuding from the pad 16. Since the pressure of the container 1 is kept negative and the electrolyte does not flow out to the outside, the device can be transferred and locally surface-treated.

COPYRIGHT: (C)1996,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electro-chemical treatment device for a conductive substrate, particularly a local electrochemical treatment device, which can be used at any position by moving the conductive substrate.

[0002]

2. Description of the Related Art The device is a container having an opening and bounding a space, and an electrode arranged in the space and intended to be connected to one of the current source terminals, and the other of the current source terminals. Comprises an electrode intended to be connected to a conductive substrate, and an electrolyte inlet and outlet, both in communication with the space.

With such a device, it is possible in particular to obtain an electrochemically formed metal coating, and it is possible to achieve local deposition of metal surfaces or to carry out modifications. In the automotive, aircraft, or rail industry, it is often necessary to prepare the surface prior to assembly or prior to another surface treatment. In these and many other industries, including the plastics or machinery industry, metal parts, or surfaces, are subject to wear, linear scratches, scratches, or corrosion where such localized metal modification is warranted. I'm wearing it.

Such an electrochemical treatment apparatus is not limited to, for example, a pad type apparatus, but also as an apparatus using a chamber having a gel or a compartment to prevent circulation of the electrolytic solution or leakage of the electrolytic solution. Already known.

[0005]

However, these devices have the risk of leakage during processing related to the quality of the seal provided by the joint or during post-processing (in the case of gels) cleaning and non-uniform processing. Always show sex-related risks. Therefore, especially when moving the device over the substrate, electrolyte leakage is a reality for adjacent areas that should not be treated and for workers due to the frequent corrosive nature of the electrolyte used. Indicates a potential danger.

[0006]

SUMMARY OF THE INVENTION The present invention is therefore aimed at eliminating the above-mentioned drawbacks, and for this purpose:
The invention is a device as defined at the beginning of the detailed description, which device is further made of a non-conductive, absorbent and flexible material permeable to gases and liquids, A main body that contacts the electrode to close the opening and projects beyond the opening, a first pump attached to the electrolytic solution inflow portion, and a second pump attached to the electrolytic solution outflow portion. The present invention proposes an apparatus comprising a pump, wherein the discharge rate of the second pump is greater than the discharge rate of the first pump in order to generate a negative pressure in the space.

With this arrangement, the electrolytic solution reaching the inner space of the jig is partially retained by the body of absorbent material in contact therewith, and thus the electrical between the electrode and the conductive substrate to be treated. It will be understood that continuity is ensured. Further, due to the negative pressure existing in this space, the excess electrolytic solution is continuously discharged. Thus, the electrolyte is continuously replenished, which also helps to dissipate the heat generated by the electrochemical process. Moreover, and still due to this negative pressure, external air is continuously drawn through the entire volume of the body made of absorbent material, so that no matter what position the device is used, it is not intended to exit the opening. Any outflow is prevented. Furthermore, the intake of this air ensures the cooling of the electrolyte which is overheated under the application of high current. In addition, the device according to the invention not only allows the treatment of flat, concave or convex surfaces, but also the treatment of any edge present on the substrate to be treated.

According to an embodiment of the device of the present invention, the electrolyte inlet is open into the space in close proximity to the body made of absorbent material, and in particular, preferably the electrolyte inlet. Is
In the contact area between the electrode and the body made of absorbent material, which is made in the electrode, it consists of at least one bore opening in this electrode surface and an opening in the electrode surface. In this way, as soon as the electrolyte exits the electrolyte inlet, it reaches the body of absorbent material immediately and consequently spreads uniformly over the entire volume of this body. Furthermore, the electrolyte outflow portion is created in the space, preferably close to the body of absorbent material.

According to another embodiment, the electrolyte inflow portion and the electrolyte outflow portion each include a flexible tube, and the first and second pumps include two rotors provided with peripheral rollers. A more precisely configured peristaltic pump, mounted axially on a rotatable shaft, one roller of the rotor acting on a flexible tube at the electrolyte inlet,
The other roller of the rotor acts on the flexible tube of the electrolyte outlet, the diameter of the rotor and / or the flexible tube being selected to create the negative pressure in the space.

In this way, the discharge amount of the electrolytic solution inflow portion and the circulation of the electrolytic solution outflow portion are associated with each other, and only once set. This allows the device to be used without any control of the discharge rate, no need to make any adjustments, and the device can be used immediately. Furthermore, the input and output of the electrolyte can be terminated instantaneously in a single operation, ie by simply stopping the motor driving the shaft.

The absorbent material constituting the body used in the present invention is made of a material having a chemical resistance characteristic with respect to an electrolytic solution and a thermal resistance characteristic, particularly in an operating temperature range (15 ° C. to 60 ° C.). It The material should also be non-conductive, permeable to gases and liquids, and ultimately selected to not damage the substrate being processed. It is, for example, from polyester cotton,
Alternatively, it is made of a woven or non-woven material made of nylon fiber or felt.

It should also be added that the current source is a pulsed current source or a direct current source.

The device as defined above makes it possible to carry out all types of electrochemical treatments.
Above all, the device of the invention entails performing electrolytic deposition, in which case the substrate to be treated constitutes the cathode and the electrode of the device constitutes the anode, the electrode being a material which is insoluble under the treatment conditions. Made from. Similarly, the device of the present invention involves a metal recovery process using a recovered electrolyte, with the substrate to be processed selected as the anode and the electrode of the device selected as the cathode. Finally, the device of the present invention comprises aluminum, titanium,
And the anodization of any substrate to be processed, consisting of oxidizable materials such as their alloys, in this application the substrate to be processed is selected as the anode and the electrode of the device is selected as the cathode.

[0014]

The method for carrying out the invention will now be described by way of non-limiting example with reference to the accompanying drawings.

FIG. 1 shows a surface S of an aluminum part A,
2 shows in more detail the device according to the invention, which allows an anodizing treatment to be prepared before bonding.

The device according to the invention comprises a side wall (2), a back wall (3) and a front opening (4) facing said back wall (3).
Consisting of a container (1) having The container is made of an insulating material such as polypropylene or PVDF (polyvinylidene fluoride), but has a cathode (6) with an opening (4).
The internal space (5) to be housed is defined. The cathode (6) has a back surface (6a) and a front surface (6b). This same cathode (6) can have, for example, a circular, square or rectangular cross section, and the effective cathode surface area is a few
It can be changed from mm ² to several cm ² .

Further, the cathode (6) can be formed by any means.
In particular, it is retained in the space (5) by attachment of the cathode back surface (6a) to the back wall of the container (1). In addition, the cathode (6), on the one hand, together with the inner surface of the side wall (2) of the container (1) delimits a continuous peripheral chamber, while on the other hand this front surface (6b) is at a distance from the opening (4). Placed.

The cathode (6) is connected to the "negative" terminal (7) of the current generator G, which is, in particular, a pulsed current, the "positive" terminal (8) of which is the point ( 9) is connected. Furthermore, the cathode (6) is provided with a bore (10) which starts at the back surface (6a) and opens at the front surface (6b).

Although a single bore (10) is shown in FIG. 1, it is advantageous to provide several bores so that they open in a uniform manner over the front surface (6b). .

This and these bores are located on the back surface of the electrode (6
In a), the connection part (11) is connected to the inflow pipe (12) of the electrolytic solution. Furthermore, the wall (2) of the container (1) is provided with a bore (13) extending from the inner surface of the wall (2) to the outer surface thereof, and the electrolytic solution storage tank R is provided by the connecting portion (14). It is connected to the electrolyte outflow pipe (15) which terminates with.

According to the invention, the opening (4) is closed by a pad of absorbent material (16), the thickness of the absorbent material (16) on the one hand being the front surface (6b) of the electrode (6). ), And on the other hand, projecting slightly outside the opening (4), in particular, the bore (13), at a point well spaced from the opening (4), An opening is made in the space (5) so that at this point the pad (1
It is manufactured so as not to be covered by 6). As an example,
This thickness can be 5 mm.

Furthermore, the pipe (15) is connected to the suction part of the pump (17), and the discharge part of the pump (17) is
It is connected to the pipe (18) and communicates with the electrolytic solution storage tank (R).

The pipe (12) is connected to the discharge part of the pump (19), and the suction part of the pump (19) is connected to the pipe (2).
0) and the free end of the tube (20) is immersed in the electrolyte in the storage tank (R).

The operation of the above device is as follows.

The pumps (17) and (19) are connected to the container (1).
Inside, i.e., inside the peripheral chamber defined by the inner surface of the side wall (2) and the outer surface of the electrode (6), are selected to have respective discharge rates that allow a negative pressure to be generated.
These discharge amounts are particularly determined by the area of the opening (4), the pad (1
With regard to the properties of 6) and the thickness of the pad, it will be easy for a person skilled in the art to define these discharge rates by means of some preliminary tests.

As a guide, the ratio of the discharge amount of the pump (17) to the discharge amount of the pump (19) is, for example, about 6.

The operation of the above device is as follows.

After optional degreasing of the surface to be treated, the pump (1
Start 7) and (19). As a result, the storage tank (R)
Electrolyte solution (E) is extracted by a pump (19),
Via the pipe (20), the pump (19), the pipe (12) and the bore (10) it is carried to the pad (16) and thus penetrated by the electrolyte. The discharge rate of the pump (19) is chosen so that a sufficient quantity of electrolyte reaches the pad (16) in order to achieve anodization under good conditions. Furthermore, the pump (17) is alternatively selected to have a discharge rate that allows negative pressure to be created in the container (1) without drying the pad (16). Due to the effect of this pump (17), excess electrolyte drawn through the pad (16), and a certain amount of air, are caused by the bore (13), the tube (15),
It is removed to the storage tank (R) via the pump (17) and the pipe (18). This avoids any outflow of electrolyte over the area other than the area to be treated.

Next, the electrode (6) and the component (A) are connected to the current generator (G). The device is then ready for anodizing and it is sufficient to move the device manually or mechanically on the surface to be treated (S) perpendicular to this surface.

The thickness of the oxide layer will depend, among other things, on the number of times the device has passed over the region to be treated and on the electrical parameters of the current generator (G). These parameters are in particular:

-Current: DC-Voltage: 60 V-Current value: 0-15 A-Current density: 250-350 A / dm ² According to the invention, two pumps (17) and (19).
2 is preferably a peristaltic pump shown schematically and partially in FIGS. 2 (front view) and 3 (cross-sectional view taken along line III-III in FIG. 2). These two pumps consist of two rotors (21, 22), both mounted on a common shaft (23) which is rotated by a drive motor (not shown). The rotor (21) carries three rollers (24, 25, 26) equidistantly around its circumference, and the rotor (22) has two rollers (27) diametrically opposed around it. , 28).

The pump further has a first semi-circular bearing surface () having a circular cross-section and applying a flexible tube (30) connecting the tube (12) and the tube (20) shown in FIG. Two
9) with a circular cross section, shown in FIG. 1 (15)
And a second bearing surface to which the flexible tube (32) is applied, connecting the tube (18). The rollers (24, 25, 26) of the rotor (21) compress the tube (30) against the bearing surface (29) and squeeze through its diameter so that the rotor (21) rotates as it rotates. However, the rotor (21) is arranged with a certain diameter so that by moving along the tube (30), the electrolytic solution in the tube (30) can be moved forward. Similarly, the rollers (27, 2) of the rotor (22)
8) compresses the tube (32) against the bearing surface (31) and squeezes it across its diameter so that when the rotor (22) rotates, the roller causes the tube (3) to rotate.
By moving along this tube (3)
The rotor (22) is arranged with a diameter so as to move the electrolyte in 2) forward. The direction of rotation of the shaft (23) is such that the electrolyte is in the tube (30) from the tubes (20) to (12) and the tube (32).
The direction is such as to move forward from tube (15) to tube (18). The diameter of the rotors (21) and (22), and / or the diameter of the flexible tubes (30, 32) may further be reduced by the tube (3) to create a negative pressure in the interior space (5).
The discharge amount at the outflow part from 2) is the tube (30).
Is selected to be larger than the discharge amount that exits. Thus, for example, as shown in FIGS. 2 and 3, the rotor (22)
The diameter of the flexible tube (32) and the diameter of the flexible tube (32) are respectively the diameter of the rotor (21) and the flexible tube (30).
Larger than the diameter of.

The respective discharge amounts from the two pumps are associated with each other and can be set only once, and by stopping the motor for driving the shaft (23), the supply of the electrolytic solution to the electrolytic solution treatment apparatus can be stopped. It will be appreciated that there will be an almost instantaneous interruption and removal of excess electrolyte and aspirated air.

The device according to the invention can be used for parts with a wide variety of shapes and sizes, and is not limited to flat surfaces. Therefore, the device according to the invention is
Can be used on treated surfaces with diameters of ² to a few dm ² , or on seams of flat or "staircase" metal plates, as well as surfaces that are convex or have sharp edges Is. Furthermore, the surface to be treated can be at any angle, and in particular the retouching can be carried out inversion.

These electrochemical retouching operations can be carried out according to the invention either in fixed places in laboratories or factories or in mobile units as field work. In the case of a mobile unit, regardless of the location of the device of the invention, there will be no leakage from the device, so that the benefit would be beneficial (this is produced by two pumps). The effect of negative pressure).

[0036]

As described above, according to the present invention, since the negative pressure is generated in the space of the container, the discharge amount of the second pump is the first.
Since it is configured to be larger than the discharge amount of the pump, the excess electrolytic solution is continuously discharged due to the negative pressure existing in the space. Therefore, the electrolyte is continuously replenished,
It also helps to dissipate the heat generated by the electrochemical process. Moreover, and still due to this negative pressure, external air is continuously drawn through the entire volume of the body made of absorbent material, so that no matter what position the device is used, it is not intended to exit the opening. Any outflow is prevented. Furthermore, the intake of this air ensures the cooling of the electrolyte which is overheated under the application of high current. In addition, the device according to the invention not only allows the treatment of flat, concave or convex surfaces, but also the treatment of any edge present on the substrate to be treated.

Further, the discharge amount of the electrolytic solution inflow part and the circulation of the electrolytic solution outflow part are associated with each other and can be set only once, so that the discharge amount can be controlled without any control when using the device. It is possible, there is no need to make any adjustments and the device is ready for use. Furthermore, the input and output of the electrolytic solution can be instantaneously terminated by a single operation, that is, by simply stopping the motor that drives the shaft.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a processing apparatus associated with the electrical equipment shown schematically.

FIG. 2 is a partial schematic view of a peristaltic pump used in the preferred embodiment.

FIG. 3 is a partial schematic view of a peristaltic pump used in the preferred embodiment.

[Explanation of symbols]

 A Part E Electrolyte G Current generator R Storage tank S Surface to be treated 1 Container 4 Opening 5 Space 6 Electrode 10 Bore at electrolyte inflow part 13 Bore at electrolyte outflow part 16 Pad (main body made of absorbent material) 17 No. Two pumps 19 First pumps 21 First pump rotors 22 Second pump rotors 24,25,26 First pump rotor rollers 27,28 Second pump rotor rollers 30,32 Flexible Sex tube

Claims (7)

[Claims] 1. A device for conducting a conductive substrate, particularly a localized electrochemical treatment device, which can be used at any position by moving on the conductive substrate, the device comprising a container provided with an opening and bounding a space, An electrode arranged in the space and intended to be connected to one of the current source terminals, the other of the current source terminals being intended to be connected to the conductive substrate, and both of which are the space and In communication with an electrolyte inlet and outlet, the device is further made of a non-conductive, absorbent and flexible material that is permeable to gases and liquids and is in contact with the electrodes. A main body that closes the opening and projects beyond the opening; a first pump that is attached to the electrolytic solution inflow portion; and a second pump that is attached to the electrolytic solution outflow portion. To generate negative pressure in the space The discharge amount of the second pump, and wherein greater than the discharge amount of the first pump. 2. The apparatus according to claim 1, wherein the electrolyte inflow portion is open to the space in proximity to the main body made of an absorbent material. 3. The electrolyte inflow portion comprises at least one bore made in the electrode and opening at the electrode surface in the contact area between the electrode and the body made of absorbent material. Device according to claim 1 or 2, characterized in that 4. The device according to claim 1, wherein the electrolyte outflow portion starts in the vicinity of the body made of absorbent material. 5. The electrolytic solution inflow part and the electrolytic solution outflow part are each made of a flexible tube, and the first and second pumps are provided with peripheral rollers, and are rotatable shafts on a shaft. Is a peristaltic pump with two rotors mounted in one direction, one roller of the rotor acting on the flexible tube of the electrolyte inlet and the other roller of the rotor being the electrolyte outlet. Acting on a flexible tube,
The diameter of the rotor and / or the flexible tube is
Device according to any one of claims 1 to 4, characterized in that it is selected to generate the negative pressure in the space. 6. The device according to claim 1, wherein the main body is made of a woven or non-woven material made of nylon fiber or felt. 7. The device according to claim 1, wherein the current source is a pulse current source or a direct current source.