JPS6326567A - Method and instrument for measuring current density in various positions of electrode in electrolytic cell - Google Patents

Abstract

PURPOSE:To easily detect the current densities in the various positions of a treating object by bringing two voltage detecting parts near to the surface of the treating object during an electrolytic operation and measuring the potential difference therebetween by a voltmeter. CONSTITUTION:The electrodes 2 are hung down on both sides in an electrolytic cell 1 and the treating object 3 is hung down from a cathode bar at approximately the middle thereof. The potential difference corresponding to the voltage drop generated by the electrolytic current and liquid resistance is generated between the two voltage detecting parts A, B when said detecting parts A, B are brought near to the surface of the material 3 under specified conditions during the electrolytic operation. The generated potential difference is indicated by the voltmeter 7. The voltmeter 7 eventually indicates the current density in said position of the material 3. The current densities in the various positions of the material 3 are thus easily known.

Description

[Detailed Description of the Invention] This invention relates to an electrode (%
This invention relates to a method and apparatus for measuring current density at each location (processed object).

(Prior technology) In surface treatments such as electrolysis, plating, alumite, etc., passing a processing current with an average current density to each position of the electrode (processed object) is a quality control method in surface treatment. This is the first step, and its importance is well known. For this reason, numerous attempts have been made to find out the current density to be processed. For example, a method of setting several objects to be treated and measuring the total current at the flat part of the jig, dividing that value by the number of objects to be treated and the surface area, and calculating the current density. Alternatively, in the case of plating, after processing, the plating thickness at each location of the processed object is measured and the current density is estimated by back calculation. Alternatively, a current detection device with a constant surface area is immersed in an electrolytic bath so that the condition is roughly the same as that of the object to be treated, and the value of the psychological current flowing therein is measured with an ammeter, and the current density can be determined from this.

(Problem to be solved by the invention) However, in such conventional methods, the electrode (
In particular, it was not possible to know the current density at each location (particularly the processed material). Therefore, it has not been possible to discover an imbalance in current density due to a difference in the position of the same object to be treated during electrolysis, or to take countermeasures to correct this.

(Means to solve the problem) 2.2 has been lowered. The object to be processed 3 is set in the middle of i1y. During the electrolytic work, the voltage detection section A5 and the voltage detection section B6 are brought close to the surface of the object 3 to be treated, and the potential difference between them is measured with the voltmeter 7.

FIG. 2 shows the voltage detection section A5 and voltage detection section B6 in a holding state during measurement. Voltage detection section A5 and voltage detection section B6
is, the interval, that is, the detection part interval 10 is 2 at a certain constant interval.
It is convenient to hold it together so that it becomes . Both voltage detection sections are connected to a voltmeter 7. Detection direction line 1 connecting voltage detection section A5 and voltage detection section B6
1, avoid being on this line, and connect one voltage detection part (
In the figure, a spacing part 8 in which the approach distance 9 becomes 1 at a certain constant distance is provided outside the voltage detection part A5) if necessary. The space portion 8 may be made of an electrical wire insulating material or a corrosion-resistant material. The holding conditions for both voltage detection sections during measurement are as follows.

(a) The direction of the detection direction line 11 is perpendicular to the surface of the object to be treated.

(b) 1 for the approach distance and 2 for the detection part interval shall be constant during measurement.

(c) Care must be taken to ensure that there is no obstacle other than the electrolyte at positions 1 and 2 on the detection direction line ll. Also, make sure that the voltage detector etc. are made as small as possible so that the flow of processing current is not disturbed by measurement.

(Function) When both voltage detecting parts are brought close to the surface of the workpiece 30 under constant holding conditions (A, A, N) during electrolysis work, a potential difference corresponding to the voltage drop due to liquid resistance is generated between them. This is displayed by the voltmeter 7. In this case, if the voltage of the material of the voltage detection section changes during measurement, the amount of change due to the difference in unit voltage will enter the measurement, so a material with a low influence is selected.

For example, in anodizing aluminum or its alloy, platinum, titanium, or stainless steel plated with platinum is used, copper is used for copper plating, and nickel is used for nickel plating. In the example of plating, when the material is stainless steel, when it is necessary to remove the plating for use in other plating, an electrolytic tool for removing the plating, which is usually installed in a plating factory, is used. By using a foil tank, the purpose can be easily achieved without damaging the cable material.

If the values of 1 for the approach distance 9 and 2 for the detection part interval 10 are appropriately selected depending on the distance between the poles of the electrolytic cell 1 or the size of the object 3 to be processed, the The ratio of detected voltages is the same as the ratio of current densities at the position.

FIG. 3 and Table 1 are actual measurement examples in nickel plating. If the ratio of the plating thickness is the ratio of the current density (because the main purpose of current density measurement is to control the plating thickness in plating), then the ratio of the detection voltage at each position to the plating thickness is It can be seen that they match.

(Embodiment) In FIG. 4, during the processing operation, wires are connected from the processing plate 17 of the processing object 3 to the processing pole via the ammeter 15 and variable resistor 16, respectively.

During the processing operation, a part of the processing current is diverted through the standard plate 17. Orient the surface of the standard plate 17 so that it is perpendicular to the direction of flow of the processing current (direction that indicates the maximum current under the same conditions), and adjust the variable resistor 16 to obtain an appropriate standard current density. Adjust the current to. For example, when processing object 3 is being nickel plated at a total current density of 3.5 A/1 trn, and a detection plate with a surface area of 1-8 is immersed, the current is adjusted to 3 A and the standard current density is 3 A
/ebb, etc.

The voltage detection section A5 and the voltage detection section B6 are held close to each other near the standard plate 17 in this state under predetermined conditions. The voltage detected at this time is input to the voltmeter 7 via the multiplier 18. The multiplier 18 is adjusted to appropriately divide or amplify the detected voltage so that the display on the voltmeter 7 becomes 3.

When the voltage detection section A5 and the voltage detection section B6 are held close to the workpiece 3 under predetermined conditions while the adjustment of the multiplier 18 is left as is, the voltmeter 7 will be at that position on the workpiece 3. This will indicate the current density (A/dyyc") to be applied.

In continuous surface treatment of coil-shaped products, such as hoop material plating equipment or 7-ply material purumite processing equipment, the coil is passed through a fixed location in the electrolytic cell 1 by a guide roller or a power supply roller. ing. In such a case, several or tens of sets of voltage detecting parts A5 and B6 held at a certain regular interval are provided, and these are constantly or as necessary connected to the electrode surface. is maintained under a predetermined constant condition. Wiring from each set of these two electrodes can be done individually or by switching them! Make sure that it is connected to pressure gauge 7. By doing so, it is possible to know the current density ratio or the current density at a specific position in the electrolytic cell 1 during electrolysis work, all the time or as needed, simultaneously or by switching. In this case, care should be taken to ensure that the combination of voltage detection parts can be easily removed and moved, etc. for maintenance purposes.
Further, it is effective when setting the coil in the electrolytic cell, and the workability is improved.

(Effects of the Invention) According to the present invention, it is possible to easily know the current density at each position of the workpiece during work, which has been difficult in the past. As a result, it provides a very powerful control means for various surface treatments, which previously could not be adequately controlled due to the inability to measure current density during electrolytic work.

It is particularly effective in the following applications.

(,1) Alumite treatment and electrolytic coloring treatment of aluminum building materials such as sash that are several meters long.

Φ) Treatments such as plate plating and electrolytic polishing of up to several plates.

(C) Continuous surface treatment of coiled objects. For example, a further noteworthy effect of hoop plating, hoop alumite, etc. is that the state of the processing current changes very little due to measurement, that is, the influence of measurement on surface treatment is extreme. be. This is much more advantageous than the conventional current density measurement method, which detects current. In addition, the detection source is the voltage drop (voltage) caused by liquid resistance.
Therefore, the processing current can be detected with almost no waveform distortion. When electrolysis is performed using a modulated waveform current such as an AC/DC superimposed waveform, an arrow-shaped pulse waveform, a PR pulse waveform, or a phase control waveform, the current waveform,
One of the excellent effects of the present invention is that peak values, true effective values, etc. can be measured.

[Brief explanation of the drawing]

Fig. 1 is a conceptual diagram of the present invention. Fig. 2 is a conceptual diagram of the measurement state. Fig. 3 is a measurement example of 1'-y Kel plating. Fig. 4 is a conceptual diagram of an example. 1: Electrolytic cell
2.2: i-electrode (anode) 3: treated object 4: electrolyte 5: voltage detection section A 6: voltage detection section B7: voltmeter
8 = Interval part 9: Approach distance 10: Detection part interval 11: Detection part direction line 12: Copper plate 13: Nickel plated part 14-a: Measurement point a 14-b: Measurement point B 14-C: Measurement point C 14- d: Measuring point d 14-1: Measuring point e 15: Ammeter 16 = Variable resistor 17: Standard plate 18 Double multiplier.

Claims (1)

[Claims] 1) Measure the amount of voltage drop due to liquid resistance near the electrode surface in the electrolytic cell under certain conditions during electrolysis work, and measure the voltage drop at each electrode position similarly measured under the same conditions. A method for measuring current density at each electrode position in an electrolytic cell, characterized in that the ratio of (voltage) amount is used as the ratio of current density at each electrode position. 2) During electrolysis work, a standard plate with a constant surface area is immersed near the electrode in almost the same state as the electrode, and a current with a standard current density is passed through this standard plate, and in this state, the liquid resistance near the electrode surface is In the electrolytic cell according to claim 1, the voltage drop near the surface of the standard plate is measured under the same conditions as when measuring the voltage drop, and this is regarded as the standard current density. Method for measuring current density at each electrode position. 3) Make sure that voltage detection section A (5) and voltage detection section B (6) are maintained at a certain constant interval K2, and that both voltage detection sections are connected to the voltmeter (7). A device for measuring current density at each electrode position in an electrolytic cell. 4) Claim 3, characterized in that a multiplier (18) is interposed between the voltage detection unit A (5) and the voltage detection unit B (6) to the voltmeter (7). A device for measuring current density at each electrode position in the electrolytic cell described above. 5) Several or tens of sets of voltage detection part A (5) and voltage detection part B (6) held at a certain constant interval K2 are provided in the electrolytic cell (1), and these are constantly Alternatively, the electrodes are maintained on the surface of the electrodes in a constant condition as required, and the wiring from each set is connected to the voltmeter (7) individually or by switching. Or a device for measuring current density at each electrode position in an electrolytic cell according to item 4.