Electrophoresis process and inspection method for plate-fin cooler

Abstract

The invention discloses a plate-fin cooler electrophoresis process and an inspection method, and relates to the technical field of traffic vehicle accessory manufacturing, and the plate-fin cooler electrophoresis process comprises the following steps: cleaning the surface of a product, mounting an auxiliary anode on the product, keeping a preset distance between the auxiliary anode and the product, soaking the product into a cleaning water tank, and cleaning the surface of the product; cleaning by controlling the product to float up and down, soaking the product in an electrophoresis tank, applying a plurality of sections of voltage to an auxiliary anode to realize electrophoresis of the product, placing the product subjected to electrophoresis in a clean water tank for preset time, and controlling the product to float up and down; the method comprises the following steps: cleaning residual electrophoretic paint in a product, conveying the cleaned product into a baking furnace for baking and curing, and adopting an auxiliary anode and sectional voltage, so that the electrophoretic paint on the surface of the product is more uniform, the heat dissipation effect of the product is ensured, and comprehensive electrophoresis of the product can be ensured; the situation that the corrosion resistance of the product is reduced due to insufficient electrophoresis depth is avoided, and the service life of the product is greatly prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle accessories manufacturing, and more specifically, to an electrophoresis process for a plate-fin cooler. In addition, the present invention also relates to an inspection method for inspecting the electrophoresis process cooler. Background Art

[0002] Plate-fin coolers have the characteristics of high heat dissipation efficiency, compact structure and light weight. They are widely used in the cooling system of traction transformers and converters of rail transit EMUs. The coolers are installed at the bottom or top of the vehicle. The external air enters the cooler core through natural convection or forced convection and exchanges heat with the high-temperature coolant inside the cooler that absorbs the heat generated by the system operation, thereby transferring the heat to the external environment. Due to the high speed of EMUs, the wide geographical coverage and complex geographical environment factors, since the introduction of foreign high-speed EMUs, the coolers have been corroded to varying degrees after 3 to 5 years of use, resulting in leakage failure, which seriously affects the reliability and operation stability of the EMUs.

[0003] In order to solve the above problems, the electrophoretic surface treatment process is currently applied to the cooler anti-corrosion. However, due to the small gap in the air duct of the EMU cooler core and the long channel, the electrophoretic depth can only cover 80 to 100 mm. There are still relatively long channels that cannot be anti-corroded by the electrophoretic layer. During operation, corrosion still exists, resulting in leakage and failure, which has seriously affected the operation of the EMU.

[0004] In summary, how to provide a process that can fully perform electrophoresis on a long-depth plate-fin cooler is an urgent problem to be solved by those skilled in the art. Summary of the invention

[0005] In view of this, the object of the present invention is to provide a plate-fin cooler electrophoresis process to ensure uniform electrophoresis film thickness of the product and achieve full electrophoresis permeability of the plate-fin cooler.

[0006] Another object of the present invention is to provide an inspection method for the electrophoresis process cooler.

[0007] In order to achieve the above object, the present invention provides the following technical solutions: A plate-fin cooler electrophoresis process, comprising: Clean the product surface; Install the auxiliary anode on the product and keep a preset distance between the auxiliary anode and the product; Immerse the product in the cleaning pool and clean it by controlling the product to float up and down; Immerse the product in the electrophoresis tank and apply several voltages to the auxiliary anode to achieve electrophoresis of the product; Place the electrophoretic finished product in a clean water pool for a preset time and control the product to float up and down to clean the residual electrophoretic paint inside the product; The cleaned products are sent to the baking oven for baking and curing.

[0008] In the present invention, the step of cleaning the surface of the product further comprises: It uses chemical oxidation to form micropores on the surface of the product.

[0009] In the present invention, the step of installing the auxiliary anode on the product and maintaining a preset distance between the auxiliary anode and the product comprises: The preset gap is 200-300 mm.

[0010] In the present invention, the step of immersing the product in a cleaning pool and cleaning the product by controlling the product to float up and down comprises: The cleaning pool uses pure water, and the cleaning is repeated multiple times.

[0011] The present invention further includes, after the step of immersing the product in cleaning water and cleaning by controlling the product to float up and down: Clean up any accumulated water inside the product after cleaning.

[0012] The present invention further includes immersing the product in an electrophoresis tank and applying several voltages to the auxiliary anode to achieve the electrophoresis of the product; The plurality of voltage segments are five voltage segments, and the voltage values ​​and time periods of the five voltage segments are all different.

[0013] The present invention further provides that the voltage value of the first section of the five voltage sections is 100V and the duration is 30s; The voltage value of the second section of the five voltage sections is 160V, and the duration is 1min; The voltage value of the third section of the five voltage sections is 220V, and the duration is 3 minutes; The voltage value of the fourth section of the five voltage sections is 270V, and the duration is 10 minutes; The voltage value of the fifth voltage segment among the five voltage segments is 320V, and the duration is 20min.

[0014] The present invention further includes placing the electrophoresis finished product in a clean water tank for a preset time, and controlling the product to float up and down to clean the residual electrophoresis paint inside the product; The residual electrophoretic paint in the clear water tank is filtered and recycled for reuse.

[0015] The present invention further provides that in the step of sending the cleaned product into a baking oven for baking and curing; The baking and curing includes heat preservation and curing, the temperature of the heat preservation and curing is 120 degrees, the time is 10 minutes, and the temperature of the heat preservation and curing is 200 degrees, and the time is 60 minutes.

[0016] A method for inspecting a cooler produced by electrophoresis process, comprising: The auxiliary anode is installed on the product, and a preset distance is maintained between the auxiliary anode and the product, and a plurality of detection wires are inserted into the product; After the step of sending the cleaned product into a baking oven for baking and curing, the detection wire is pulled out from the inside of the product, and the electrophoresis state of the detection wire is observed to determine the electrophoresis depth inside the product.

[0017] Furthermore, in the present invention, the detection wire is made of a metal material capable of electrophoresis.

[0018] According to a further aspect of the present invention, the diameter of the detection wire is less than 2 mm.

[0019] The present invention further provides that the 40 cm surface of the product 2 Insert at least one test wire within the range.

[0020] The plate-fin cooler electrophoresis process provided by the present invention, when in use, first cleans the surface of the product to keep the surface to be attached clean to facilitate the electrophoretic attachment of the product, installs the auxiliary anode on the product, and keeps a preset distance between the auxiliary anode and the product, provides a main anode and a cathode in the electrophoresis pool, and the auxiliary anode can apply a segmented voltage to the product to enable the product to be electrophoresed in segments, immerses the product in a cleaning water pool, and cleans it by controlling the product to float up and down, then immerses the product in the electrophoresis pool, and applies several segments of voltage to the auxiliary anode to achieve electrophoresis of the product, then places the electrophoresed product in a clean water pool for a preset time, and controls the product to float up and down to clean the residual electrophoretic paint inside the product, which is beneficial to improving the smooth effect of the product surface, then sends the cleaned product to a baking furnace for baking and curing, so that the paint film of the product is cured and formed, and by facilitating the auxiliary anode and adopting a segmented voltage, the electrophoretic paint on the surface of the product is more uniform, thereby ensuring the heat dissipation effect of the product, and ensuring that the product can be fully electrophoresed, thereby avoiding the problem of insufficient electrophoresis depth leading to reduced corrosion resistance of the product, and greatly improving the service life of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0022] Figure 1 It is a structural schematic diagram of the overall process flow of the process provided by the present invention; Figure 2 This is a schematic diagram of the structure of the product provided by the present invention after installing the auxiliary anode on the axle side; Figure 3 This is a schematic structural diagram of the product provided by the present invention when the auxiliary anode is installed and the side of the upward-looking axis is shown; Figure 4 This is a schematic diagram of the structure of the product provided by the present invention located in an electrothermal pool; Figure 5 This is a structural schematic diagram of the partial axial side of the heat sink of the product provided by the present invention; Figure 6 A schematic diagram of a structure of a specific heat sink provided by the present invention from a partial top view; Figure 7 It is a structural schematic diagram of a partial front side of a specific heat sink provided by the present invention.

[0023] Figure 1-Figure 7 , the reference numerals include: 1. Product, 2. Auxiliary anode, 3. Electrochemical tank. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] The core of the present invention is to provide a plate-fin cooler electrophoresis process, which ensures that the electrophoresis film thickness of product 1 is uniform and can achieve full electrophoresis penetration of the plate-fin cooler.

[0026] Another core of the present invention is to provide an inspection method applied to the above electrophoresis process cooler.

[0027] Please refer to Figure 1-Figure 7 , a plate-fin cooler electrophoresis process, comprising: Step S1, cleaning the surface of product 1; Step S2, installing the auxiliary anode 2 on the product 1, and keeping a preset distance between the auxiliary anode 2 and the product 1; Step S3, immersing the product 1 in a cleaning pool, and cleaning the product 1 by controlling the product 1 to float up and down; Step S4, immersing the product 1 in the electrophoresis tank 3, and applying several voltages to the auxiliary anode 2 to achieve electrophoresis of the product 1; Step S5: Place the electrophoresis finished product 1 in a clean water pool for a preset time, and control the product 1 to float up and down to clean the residual electrophoresis paint inside the product 1; and recycle Step S6: sending the cleaned product 1 into a baking oven for baking and curing.

[0028] When in use, first clean the surface of product 1 to keep the surface to be attached clean to facilitate electrophoretic attachment of product 1, install auxiliary anode 2 on product 1, and keep a preset distance between auxiliary anode 2 and product 1, and provide main anode and cathode in electrophoretic tank 3, and auxiliary anode 2 can apply segmented voltage to product 1, so that product 1 can obtain segmented electrophoresis, immerse product 1 in cleaning water tank, clean by controlling product 1 to float up and down, then immerse product 1 in electrophoretic tank 3, and apply several segments of voltage to auxiliary anode 2 to realize electrophoresis of product 1, and then Afterwards, the electrophoretic product 1 is placed in a clean water pool for a preset time, and the product 1 is controlled to float up and down to clean the residual electrophoretic paint inside the product 1, which is beneficial to improving the smooth effect of the surface of the product 1. The cleaned product 1 is then sent to a baking furnace for baking and curing to solidify the paint film of the product 1. By facilitating the auxiliary anode 2 and adopting a segmented voltage, the electrophoretic paint on the surface of the product 1 is made more uniform, ensuring the heat dissipation effect of the product 1, and ensuring that the product 1 can be fully electrophoresed, avoiding insufficient electrophoresis depth that leads to reduced corrosion resistance of the product 1, and greatly improving the service life of the product 1.

[0029] At the same time, this electrophoresis process ensures that Product 1 can eventually achieve full penetration (i.e., the electrophoresis depth can reach more than 500mm), and can effectively ensure the depth of electrophoresis, as well as the uniformity and adhesion of the film thickness. It can meet the surface corrosion protection requirements of the cooler (neutral salt spray test for more than 1000h without any corrosion marks) without affecting the heat dissipation performance of the cooler, greatly improving the reliability and service life of Product 1, which can reach more than 8 to 10 years.

[0030] It should be noted that, in the embodiment of the present invention, the surface of the product 1 can be cleaned by first using an air gun to blow away the floating and sediment on the surface of the product 1.

[0031] In addition, the thickness of the electrophoretic paint film of product 1 in the embodiment of the present invention is 15 to 40 μm.

[0032] In addition, the thermal conductivity of the electrophoretic paint in the embodiment of the present invention is 0.1 to 1 W / ㎡K, and the thermal conductivity of the material of product 1 is 150 to 200 W / ㎡K.

[0033] In addition, in the embodiment of the present invention, the control of the product 1 floating up and down can be achieved by using an overhead crane or a mechanical structure. Specifically, a mechanical arm can be used to control the product 1 floating up and down, or a spring structure can be used, that is, the product 1 is connected by a spring, and the elastic deformation of the spring is used to make the product 1 float up and down quickly.

[0034] In addition, in the embodiment of the present invention, the auxiliary anode 2 can be fixed by bolts or by magnets.

[0035] In addition, in the embodiment of the present invention, product 1 includes a heat sink and a frame. The heat sink is distributed in an S shape, and the minimum spacing between the heat sinks is 1.8 mm. The heat sink is installed on the frame, and a coolant inlet and a coolant outlet are provided on the frame. When electrophoresis is performed on product 1, the coolant inlet and the coolant outlet are closed.

[0036] In the above embodiment, programmed automatic control is used to apply several voltage levels during the electrophoresis of the product 1.

[0037] Several voltage levels can effectively increase the depth of electrophoresis, control the film thickness and appearance of the paint on product 1, and due to the special structure of the cooler product 1, if a high voltage is used at the beginning, the film thickness near the auxiliary anode will be too thick and the inner part will be very thin and uneven, and bridging, blockage or non-penetration may occur. It is even possible that high voltage will break through the fins and cause surface damage. Several voltage levels can also avoid damage to the rectifier caused by high current during production, effectively extending the service life of the electrophoresis equipment.

[0038] Optionally, in some embodiments, chemical oxidation is used to clean the surface of product 1, which can effectively achieve the cleaning purpose and deeply clean the stains on the surface of product 1. Micropores are formed on the surface of product 1 during cleaning, which is beneficial to increase the adhesion of electrophoretic paint and enhance the electrophoretic effect of product 1.

[0039] It should be noted that the micropores in the embodiment of the present invention are formed by chemical oxidation, specifically, using Cr 3+ As a chemical agent, it forms an oxidation reaction with the product, causing micro-pores of micron size to form on the surface of the product.

[0040] Optionally, in some embodiments, the auxiliary anode 2 is installed on the product 1, and a preset distance is maintained between the auxiliary anode 2 and the product 1, wherein the preset gap is 200-300 mm, and different distances can be selected and controlled according to the actual size of the product 1 and the electrophoretic paint material.

[0041] Optionally, in some embodiments, during the process of immersing product 1 in a cleaning pool and cleaning by controlling product 1 to float up and down, pure water is used in the cleaning pool and the cleaning is repeated multiple times. Specifically, a filtration system is provided in the cleaning pool to filter impurities in the cleaning process to avoid secondary contamination of product 1 by impurities. For more efficient cleaning, multiple cleaning pools can be used to perform cleaning in sequence to ensure that impurities on product 1 are thoroughly cleaned.

[0042] Optionally, in some embodiments, after the step of immersing the product 1 in cleaning water and cleaning it by controlling the product 1 to float up and down, step S31 is also included, cleaning the accumulated water inside the product 1 after cleaning, that is, cleaning the accumulated water remaining between the heat sinks inside the product 1 before electrophoresis to avoid affecting the subsequent electrophoresis.

[0043] Optionally, in some embodiments, the accumulated water may be cleaned by blowing with an air gun, and the high-pressure airflow may effectively clean the accumulated water inside the product 1.

[0044] Optionally, in some embodiments, in the step of immersing the product 1 in the electrophoresis tank 3 and applying several voltage segments to the auxiliary anode 2 to realize the electrophoresis of the product 1, the several voltage segments are five voltage segments with different voltage values ​​and times. That is to say, a multi-segment voltage is used in the electrophoresis process, and the time and voltage of each voltage application are different. The segmented voltage can effectively increase the depth of electrophoresis, control the film thickness and appearance effect of the paint on the product 1, and due to the special structure of the cooler, if a high voltage is used at the beginning, the film thickness near the auxiliary anode will be too thick and the inner part will be very thin and uneven, and bridging, blockage or non-penetration will occur. It is even possible that the high voltage will break through the fins, causing surface damage. The segmented voltage can also avoid damage to the rectifier caused by large current during production, effectively extending the service life of the equipment.

[0045] In the above embodiment, the voltage value of the first section of the five voltage sections is 100V, and the duration is 30s; The voltage value of the second section of the five-section voltage is 160v, and the time is 1min; The voltage value of the third section of the five-section voltage is 220v, and the time is 3min; The voltage value of the fourth section of the five voltage sections is 270V, and the duration is 10 minutes; The voltage value of the fifth section of the five-section voltage is 320v, and the duration is 20min; Through the above five different voltages, the duration of electrophoresis is increased on and off, which can avoid the use of high voltage at the beginning, which will cause the film thickness near the auxiliary anode to be too thick and the inner part to be very thin and uneven, and may also cause bridging, blockage or non-penetration. It is even possible that the high voltage will break through the fins and cause surface damage, thereby improving product production quality and reducing the defective rate.

[0046] In other embodiments, products 1 of different sizes can select other voltage levels according to actual conditions, and the voltage value and electrophoresis time can also be adjusted. Specifically, the voltage is related to the size and structure of the product. Electrophoresis relies on the penetration and adsorption of ions in the bath liquid on the surface of the workpiece. The higher the voltage, the stronger its penetration will be and the deeper it can penetrate. However, if such a high voltage is turned on at the beginning, the film thickness near the auxiliary anode will be too thick and uneven, and bridging may even cause high voltage to break through the fins and cause surface damage. Therefore, a segmented voltage is used, and different product sizes can use different voltage values ​​and voltage times obtained through experiments.

[0047] Optionally, in some embodiments, the electrophoretic paint is placed in a clean water tank for a preset time, and the product 1 is controlled to float up and down to clean the residual electrophoretic paint inside the product 1. The residual electrophoretic paint in the clean water tank is filtered and recovered for reuse. In other words, the production cost is reduced by recycling the electrophoretic paint.

[0048] Optionally, in some embodiments, in the step of sending the cleaned product 1 into a baking oven for baking and curing, the baking and curing includes heat preservation and baking water and heat preservation and curing, the temperature of the heat preservation and baking water is 120 degrees, the time is 10 minutes, and the temperature of the heat preservation and curing is 200 degrees, and the time is 60 minutes.

[0049] Comparison of some cooler experiments: Product Name Product Model Core thickness Traditional electrophoresis depth The electrophoresis depth of this process CRH2 Cooler BCG0.44-100 / 5 390mm 80~90mm on one side, total depth 160~180mm 195mm on one side, total depth 390mm CRH380 Cooler BCG0.46-130 420mm 90~100mm on one side, total depth 180~200mm 210mm on one side, total depth 420mm CR400AF Cooler BCG1.6-298 / 5 320mm 90~100mm on one side, total depth 180~200mm 160mm on one side, total depth 320mm CR400BF Cooler BCG1.6-260 / 6 280mm 90~100mm on one side, total depth 180~200mm 140mm on one side, total depth 280mm Experimental conclusion: The electrophoresis depth using the above process fully meets the thickness of the current product core.

[0050] A method for inspecting a cooler produced by electrophoresis process, comprising: Install the auxiliary anode 2 on the product 1, and while keeping a preset distance between the auxiliary anode 2 and the product 1, insert a plurality of detection wires into the product 1; After the product 1 is cleaned and sent to a baking oven for baking and curing, the detection wire is pulled out from the inside of the product 1 and the electrophoresis state of the detection wire is observed to determine the electrophoresis depth inside the product 1.

[0051] When in use, the detection wire is inserted into the interior of the product 1, and the detection wire is electrophoresed together with the product 1. After the product 1 is electrophoresed and solidified, the detection wire is pulled out from the interior of the product 1 and the electrophoresis state of the detection wire is observed to determine the electrophoresis depth inside the product 1.

[0052] Optionally, in some embodiments, the detection wire is made of a metal material that can be electrophoresed, such as the same stainless steel material as product 1, or an iron material, specifically Q235B material.

[0053] Optionally, in some embodiments, the diameter of the detection wire is less than 2 mm. Specifically, the diameter of the detection wire is smaller than the minimum diameter of the heat sink of product 1. By reducing the diameter of the detection wire, the detection wire can move more smoothly in the gap of the heat sink, thereby facilitating the insertion of the detection wire.

[0054] Optionally, in some embodiments, 40 cm of the surface of the product 1 2 At least one detection wire is inserted within the range, that is, the number of detection wires inserted into the product 1 is limited so that it can effectively detect the electrophoresis degree.

[0055] At the same time, traditional inspection methods can only inspect the electrophoresis depth by dissecting the product, and the product cannot be restored and used after dissection, so only a certain proportion of random inspections can be carried out. The quality of each product cannot be guaranteed, and the product cannot be restored and used after dissection, resulting in a lot of cost waste. The invention of the inspection method of the present invention has greatly improved the quality assurance capability of the product, improved production efficiency and reduced costs.

[0056] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0057] The above is a detailed introduction to the electrophoresis process and inspection method of a plate-fin cooler provided by the present invention. This article uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A plate-fin cooler electrophoresis process, characterized in that: include: Clean the surface of the product (1); Installing the auxiliary anode (2) on the product (1), and maintaining a preset distance between the auxiliary anode (2) and the product (1); Immersing the product (1) in a cleaning water pool, and cleaning the product (1) by controlling the product (1) to float up and down; Immersing the product (1) in an electrophoresis tank (3), and applying a plurality of voltage levels to the auxiliary anode (2) to achieve electrophoresis of the product (1); Placing the electrophoretic product (1) in a clean water pool for a preset time, and controlling the product (1) to float up and down, so as to clean the residual electrophoretic paint inside the product (1); The product (1) that has been cleaned is sent to a baking oven for baking and curing.

2. The plate-fin cooler electrophoresis process according to claim 1, characterized in that: The steps of cleaning the surface of the product (1) include: A chemical oxidation method is adopted to form micropores on the surface of the product (1).

3. The plate-fin cooler electrophoresis process according to claim 1, characterized in that: The step of installing the auxiliary anode (2) on the product (1) and maintaining a preset distance between the auxiliary anode (2) and the product (1) comprises: The preset gap is 200-300 mm.

4. The plate-fin cooler electrophoresis process according to claim 1, characterized in that: In the step of immersing the product (1) in a cleaning water pool and cleaning the product (1) by controlling the product (1) to float up and down, The cleaning pool uses pure water, and the cleaning is repeated multiple times.

5. The plate-fin cooler electrophoresis process according to claim 4, characterized in that: After the step of immersing the product (1) in cleaning water and washing the product (1) by controlling the product (1) to float up and down, the method further comprises: After cleaning, the accumulated water inside the product (1) is cleaned.

6. The plate-fin cooler electrophoresis process according to claim 1, characterized in that: The step of immersing the product (1) in the electrophoresis tank (3) and applying a plurality of voltage levels to the auxiliary anode (2) to implement electrophoresis of the product (1); The plurality of voltage segments are five voltage segments, and the voltage values ​​and time periods of the five voltage segments are all different.

7. A plate-fin cooler electrophoresis process according to claim 6, characterized in that: The voltage value of the first voltage segment of the five voltage segments is 100V, and the duration is 30s; The voltage value of the second section of the five voltage sections is 160V, and the duration is 1min; The voltage value of the third section of the five voltage sections is 220V, and the duration is 3 minutes; The voltage value of the fourth section of the five voltage sections is 270V, and the duration is 10 minutes; The voltage value of the fifth voltage segment among the five voltage segments is 320V, and the duration is 20min.

8. The plate-fin cooler electrophoresis process according to claim 1, characterized in that: The step of placing the electrophoretic product (1) in a clean water tank for a preset time and controlling the product (1) to float up and down to clean the residual electrophoretic paint inside the product (1); The residual electrophoretic paint in the clear water tank is filtered and recycled for reuse.

9. A plate-fin cooler electrophoresis process according to any one of claims 1 to 8, characterized in that: The step of sending the product (1) after cleaning into a baking oven for baking and curing; The baking and curing includes heat preservation and curing, the temperature of the heat preservation and curing is 120 degrees, the time is 10 minutes, and the temperature of the heat preservation and curing is 200 degrees, and the time is 60 minutes.

10. A method for inspecting a cooler produced by electrophoresis process, characterized in that: include: The auxiliary anode (2) is installed on the product (1), and a preset distance is maintained between the auxiliary anode (2) and the product (1), while a plurality of detection wires are inserted into the product (1); After the step of sending the product (1) after cleaning into a baking oven for baking and curing, the detection wire is pulled out from the inside of the product (1) and the electrophoresis state of the detection wire is observed to determine the electrophoresis depth inside the product (1).

11. A testing method according to claim 10, characterized in that: The detection wire is made of a metal material capable of electrophoresis.

12. A testing method according to claim 11, characterized in that: The diameter of the detection wire is less than 2 mm.

13. A testing method according to claim 12, characterized in that: 40 cm from the surface of the product (1) 2 Insert at least one test wire into the range.

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