Corrosion testing measuring device

Abstract

To provide a corrosion inspection measurement device which ensures reliable measurement for corrosion inspection of an object under inspection.SOLUTION: A corrosion inspection measurement device 1 for making measurement for corrosion inspection of an object 2 under inspection comprising a metal substrate 21 and surface treatment films 22, 23 provided on the substrate, the measurement device comprising a contact part 3 configured to hold a hydrous electrolyte material and to be in contact with surfaces of the surface treatment films, and a measurement unit 4 provided with an electrode 41 in electrical contact with the surface treatment films via the contact part and configured to apply a voltage across the electrode and the substrate and measure the conduction state between the electrode and the substrate. At least a portion of the contact part is a water-retentive sheet for holding the hydrous electrolyte material, and the contact part is switchable between an expanded state, where the contact part is expanded to be in contact with the surfaces of the surface treatment films during measurement, and a retracted state where the contact part is reduced in size when not making measurement.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The technology disclosed herein relates to a measuring device for corrosion inspection.

Background Art

[0002] Patent Document 1 describes a corrosion resistance evaluation device for a coated metal material. The coated metal material is formed by providing a resin coating film on a metal base material. In the coated metal material, for example, a corrosion factor such as salt water penetrates the coating film and reaches the base material, causing rust, that is, corrosion starts. The corrosion process of the coated metal material can be divided into a process until rust occurs and a process in which the generated rust progresses. The corrosion resistance test device of Patent Document 1 evaluates the corrosion inhibition period until rust occurs.

[0003] Specifically, this corrosion resistance evaluation device includes an electrode disposed on the coating film side and a power supply unit that applies a voltage between the electrode and the base material. An electrolyte material is disposed between the coating film and the electrode so as to contact both of them. The corrosion resistance evaluation device applies a voltage between the electrode and the base material and evaluates the corrosion resistance of the coated metal material based on the voltage value at which the coating film breaks down.

[0004] Patent Document 2 describes a corrosion resistance test device for evaluating the rate at which corrosion progresses. Two artificial scratches that penetrate the coating film and reach the metal base material are added to the coated metal material used in this test. The corrosion resistance test device evaluates the corrosion resistance by advancing the corrosion of the coated metal material.

[0005] Specifically, this corrosion resistance test device includes a container having two holding portions. The container is installed on the surface of the coated metal material. Each of the two holding portions holds a water-containing electrolyte material. Each of the two holding portions corresponds to two artificial scratches. The bottom of the container is open at each holding portion. The water-containing electrolyte material contacts the artificial scratches. Electrodes are accommodated in each of the two holding portions. The corrosion resistance test device advances the corrosion of the coated metal material by energizing the metal base material through the two electrodes.

[0006] This corrosion resistance testing apparatus contains a water-containing electrolyte material and electrodes housed in a container. Testing of painted metal materials using this corrosion resistance testing apparatus can be performed by placing the container on the surface of the painted metal material to be tested. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Patent No. 6436688 [Patent Document 2] Japanese Patent Publication No. 2020-118468 [Overview of the project] [Problems that the invention aims to solve]

[0008] The evaluation target of the aforementioned evaluation device is, for example, a painted metal sheet for automobile parts. The conventional device described in Patent Document 1 or 2 can be suitably used in automobile manufacturing processes, etc., when parts are removed from the production line at each painting step and the quality of the coating is checked.

[0009] Incidentally, the painted metal parts of cars sold to customers may corrode due to aging. Car users have a desire to predict when the painted metal parts will corrode, or to detect corrosion early.

[0010] The rate of deterioration varies depending on the environment in which the vehicle is used. For example, painted metal plates in vehicles used in environments where de-icing agents are spread on roads during winter, or in environments exposed to sea breezes, are relatively more prone to rust. The timing of rust on painted metal plates is not uniform. Since users' vehicles are regularly taken to repair shops, for example, if the corrosion resistance of painted metal plates can be inspected for vehicles brought into repair shops, it will be possible to predict when the painted metal plates will corrode for each user, or to detect corrosion early.

[0011] However, the conventional devices mentioned above do not have a structure that allows repair shops to test the corrosion resistance of painted metal plates on a user's vehicle. A new device is needed that can be used by mechanics in repair shops.

[0012] In particular, when inspecting the corrosion of painted metal plates on a customer's vehicle at a repair shop, it is necessary to ensure the reliability of the inspection. Conventional equipment does not have a structure that can ensure reliability.

[0013] The technology disclosed herein can ensure the reliability of measurements for corrosion testing of objects under inspection. [Means for solving the problem]

[0014] The technology disclosed herein relates to an apparatus for measuring corrosion of an object to be inspected, which has a metal substrate and a surface treatment film on the substrate. This corrosion inspection measuring apparatus is A contact portion that holds the water-containing electrolyte material and contacts the surface of the surface treatment film, The device includes an electrode electrically connected to the surface treatment film via the contact portion, and a measuring unit that measures the current flow state between the electrode and the substrate while applying a voltage between the electrode and the substrate.

[0015] At least a portion of the contact area is a water-retaining sheet for holding the water-containing electrolyte material, and the contact area switches between an expanded state, which is spread out and in contact with the surface of the surface treatment film during measurement, and a retracted state, which is made smaller when not being measured.

[0016] The measuring device measures the current flow between an electrode electrically connected to the surface treatment film and the substrate while applying a voltage between the electrode and the substrate. A contact portion holding a water-containing electrolyte material is interposed between the electrode and the surface treatment film. The measuring unit measures, for example, the current and / or voltage between the electrode and the substrate as the current flow state. Based on these measurements, the corrosion suppression period until corrosion occurs in the object under inspection can be evaluated.

[0017] In measuring the current flow between an electrode and a substrate, it is necessary for accurate measurement that the contact area is not deteriorated and that the contact area maintains a moist state (in other words, that the contact area holds the water-containing electrolyte material).

[0018] In the aforementioned measuring device, the contact area is at least partially a sheet and can switch between an unfolded state and a retracted state. When not measuring, the contact area is in a retracted state. When the operator is about to perform a measurement, they unfold the contact area from the retracted state to the unfolded state. When unfolding the contact area, the operator can confirm that there is no deterioration in the contact area and that the contact area maintains a moist state.

[0019] Using the aforementioned measuring device, measurements can be performed after the operator has confirmed that there is no deterioration at the contact surface and that the contact surface remains moist. The measuring device can perform measurements accurately. For example, if the aforementioned measuring device is used in a repair shop to perform corrosion inspections on automobiles as the object being inspected, the reliability of the measurements can be ensured.

[0020] Furthermore, because the contact area is reduced when not being measured, the surface area of ​​the contact area is small. In the stored state, drying of the contact area that holds the water-containing electrolyte material is suppressed. At the next measurement, the measurer can spread out the contact area, which has been kept moist, and measure the object under inspection using the measuring device. This improves the efficiency of measurements using the measuring device.

[0021] Furthermore, the storage state of the contact portion may be a state in which the contact portion is folded and made smaller, or a state in which the contact portion is rolled up and made smaller.

[0022] The corrosion inspection measuring device may further include a maintenance unit that is located on the opposite side of the contact portion from the object to be inspected, brings the contact portion into contact with the surface of the surface treatment film, and maintains the contact portion in an expanded state.

[0023] While the measuring device is performing measurement, the maintaining unit maintains the contact portion in a state of contacting the surface of the surface treatment film. The measuring device can accurately measure the energization state between the electrode and the base material. The reliability of the measurement using the measuring device can be ensured.

[0024] The maintaining unit may be a magnet that adsorbs to the inspection object through the contact portion.

[0025] Since the inspection object includes a metal base material, the magnet can adsorb to the inspection object through the contact portion by its magnetic force. The use of the magnet can easily bring the contact portion into contact with the surface treatment film and maintain the contact state during measurement. Also, after the measurement is completed, if the measurer removes the magnet, the contact portion is released, so the measurer can easily switch the contact portion from the deployed state to the stored state.

[0026] The contact portion is wound in the stored state and stretched in the deployed state. The contact portion has a spiral spring attached to the contact portion. The spiral spring may be biasing to wind the contact portion.

[0027] During non-measurement, the contact portion is forcibly wound by the biasing force of the spiral spring. Drying of the contact portion during non-measurement is suppressed.

[0028] When attempting to perform measurement, the measurer can spread the contact portion against the biasing force of the spiral spring to the deployed state. The measurer can promptly start measuring the inspection object using the measuring device. Also, when the measurement is completed, the contact portion is forcibly wound again by the biasing force of the spiral spring. Cleaning up the measuring device is easy.

[0029] The corrosion inspection measuring device further includes a housing that houses the contact portion. The contact portion may be housed in the housing in the stored state and spread out to the outside of the housing in the deployed state.

[0030] Because the contact area expands significantly in the deployed state, the operator can easily bring the contact area into contact with the surface treatment film of the object being inspected. This improves the efficiency of measurement work using the measuring device.

[0031] Furthermore, the contact area, which is reduced in size when not in use, is housed within the housing. This prevents the contact area from drying out when not in use.

[0032] The housing has an opening, The contact portion may be widened and narrowed through the opening.

[0033] The operator using the measuring device can easily insert and remove the contact part from the housing.

[0034] The aforementioned corrosion inspection measuring device is further equipped with a cover that is attached to the housing and opens and closes the opening, The cover may close the opening when not being measured.

[0035] When not in use, the cover closes the opening in the housing, sealing the housing. This prevents the contact parts housed in the housing from drying out when not in use.

[0036] The aforementioned device is portable, The aforementioned corrosion inspection measuring device further includes a rechargeable and dischargeable battery for power supply, The device may be connected to a charger that charges the battery when not in use for measurement.

[0037] A portable measuring device equipped with a battery allows for the measurement of objects under inspection without location constraints. The battery is charged when not in use. For example, when measuring a car in a repair shop, a mechanic can disconnect the measuring device from the charger, carry it to the car to be measured, attach the device to the car, and measure the painted metal plates of that car. This measuring device can meet the needs of car users who want to predict when painted metal plates will corrode or detect corrosion early. [Effects of the Invention]

[0038] As explained above, using the aforementioned corrosion inspection measuring device ensures the reliability of measurements for corrosion inspection of the object being inspected. [Brief explanation of the drawing]

[0039] [Figure 1] Figure 1 shows a measuring device for corrosion inspection. [Figure 2] Figure 2 shows the measuring device when no measurements are being taken. [Figure 3] Figure 3 is a block diagram of the inspection system, including the measuring device. [Figure 4] Figure 4 shows the charging status of the measuring device. [Figure 5] Figure 5 shows the change in voltage applied between the electrode and the painted steel sheet substrate (dotted line), and the change in current flowing between the electrode and the substrate as a result of the application of this voltage (solid line). [Figure 6] Figure 6 shows the correlation between insulation voltage and corrosion suppression period. [Figure 7] Figure 7 illustrates the connection points of electrodes to an automobile. [Figure 8] Figure 8 illustrates the connection points of electrodes to an automobile. [Figure 9] Figure 9 is a flowchart of the measurement procedure using the measuring device. [Figure 10] Figure 10 is a flowchart of the corrosion inspection based on measured values. [Figure 11]Figure 11 shows a modified version of the measuring device. [Figure 12] Figure 12 shows a modified version of the measuring device. [Figure 13] Figure 13 shows a modified version of the measuring device. [Modes for carrying out the invention]

[0040] The following describes an embodiment of a corrosion inspection measuring device (hereinafter referred to as the measuring device) with reference to the drawings. The measuring device described here is an example.

[0041] (Configuration of measuring device and inspection system) Figures 1 and 2 show the measuring device 1. The lower part of Figure 1 is a cross-sectional view of the measuring device 1 from the side. The upper part of Figure 1 is a cross-sectional view AA of the lower part. Figure 3 shows the inspection system 10 including the measuring device 1.

[0042] For the purposes of the following explanation, the front / back, left / right, and up / down directions of the measuring device 1 will be defined as follows: In Figure 1, the right side of the paper is the front and the left side is the rear, and the left-right direction on the paper is the front / back direction; in the upper part of Figure 1, the top is the left and the bottom is the right, and the up / down direction on the paper is the left-right direction; and in the lower part of Figure 1, the top is the top and the bottom is the bottom, and the up / down direction on the paper is the up / down direction. These directions are used solely for explanatory purposes and are not used to define the structure of the measuring device 1.

[0043] The measuring device 1 performs measurements to inspect the corrosion of the object under inspection 2. The object under inspection 2 is, for example, a metal sheet for an automobile part. The metal sheet for an automobile part has a metallic base material and a surface treatment film on the base material. The metallic base material is a steel sheet (including high-tensile steel sheets or ultra-high-tensile steel sheets) or an aluminum alloy sheet, and is conductive. The surface treatment film is a resin coating and is insulating. The object under inspection 2 in the figure is a so-called painted steel sheet 2. As shown in the lower diagram of Figure 1, the painted steel sheet 2 has a steel sheet 21 as a base material, a chemical conversion coating 22 on the steel sheet 21, and an electrodeposited coating 23 on top of that. The chemical conversion coating 22 and the electrodeposited coating 23 are surface treatment films. Note that the thickness of the painted steel sheet 2 in Figure 1 is exaggerated.

[0044] The chemical conversion coating 22 prevents corrosive factors from directly contacting the steel plate 21, and also reacts with the surface of the steel plate 21 to create an alkaline environment, thus preventing rust. The chemical conversion coating 22 also improves the adhesion between the electrodeposited coating 23 and the steel plate 21. Specifically, the chemical conversion coating 22 is, for example, a chromate conversion coating or a zinc phosphate coating.

[0045] The electrodeposited coating 23 has high coverage and uniformity, and after the baking process it exhibits high corrosion resistance, thereby protecting the steel plate 21. Specifically, the electrodeposited coating 23 is, for example, an epoxy resin-based paint, an acrylic resin-based paint, etc.

[0046] The measuring device 1 performs measurements to inspect the corrosion of painted steel sheets 2 in a user's automobile, for example, in a repair shop. The measuring device 1 utilizes the evaluation principle of a corrosion resistance evaluation device described in Japanese Patent Publication No. 6436688 (Patent holder: Mazda Motor Corporation). The measuring device 1 measures the corrosion suppression period until corrosion occurs in the painted steel sheets 2. This measuring device 1 can meet the needs of automobile users who want to predict when the painted steel sheets 2 will corrode, or who want to detect corrosion early.

[0047] (Structure of the measuring device) The measuring device 1 is portable. The measuring device 1 is equipped with a housing 11. Each element of the measuring device 1, as described later, is housed inside the housing 11, at least when not measuring. A mechanic can easily carry the measuring device 1.

[0048] The measuring device 1 comprises a contact section 3 and a measuring section 4. The measuring device 1 also comprises an information processing device 5, a camera 61, a wetness sensor 62, a heater 63, a temperature sensor 64, and a battery 6.

[0049] (Contact area) The contact portion 3 contacts the surface of the electrodeposited coating 23 on the painted steel sheet 2. The contact portion 3 is interposed between the electrodeposited coating 23 and the negative electrode 41, which will be described later. As will be described in detail later, the negative electrode 41 is electrically connected to the rear of the contact portion 3.

[0050] The contact portion 3 is a water-retaining sheet. The contact portion 3 holds the water-containing electrolyte material. The contact portion 3, being a sheet, is flexible and easily deformable. The contact portion 3 is also non-conductive. For example, a cloth made of natural fibers (e.g., cotton) can satisfy all the functions required of the contact portion 3. However, the contact portion 3 is not limited to a cloth made of natural fibers.

[0051] The contact portion 3 has an elongated shape, with its length in the front-to-back direction being longer than its length in the left-to-right direction. As shown in Figure 1, when the measuring device 1 performs a measurement, the contact portion 3 is unfolded. In the unfolded state, the contact portion 3 contacts the surface of the electrodeposited coating 23. Also, as shown in Figure 2, when the measuring device 1 is not performing a measurement, the contact portion 3 is retracted into a smaller, stored state. More specifically, the contact portion 3 is made smaller by the front part of the contact portion 3 being wound around an axis extending in the left-to-right direction (see also the dashed line in the lower part of Figure 1).

[0052] As shown in the upper part of Figure 1, a spiral spring 31 is attached to the front surface of the contact portion 3. The spiral spring 31 is made of a thin metal plate with high elasticity. The spiral spring 31 is located at the right end and left end of the front of the contact portion 3, respectively. Figure 1 shows the spiral spring 31 in an extended state, in which case the spiral spring 31 extends in the front-rear direction.

[0053] When not being measured, the contact portion 3 is forcibly retracted by the elastic restoring force of the spiral spring 31. Since the surface area of ​​the contact portion 3 is small in the retracted state, drying of the contact portion 3 when not being measured is suppressed. As will be described in more detail later, when the mechanic starts measuring using the measuring device 1, he extends the front part of the contact portion 3 forward against the elastic restoring force of the spiral spring 31, thereby unfolding the contact portion 3. The mechanic can then quickly start measuring using the measuring device 1.

[0054] Note that the spiral spring 31 is not an essential element of the contact portion 3. The spiral spring 31 can be omitted.

[0055] The hydrated electrolyte material is an electrolyte solution. The electrolyte solution increases conductivity and also acts as a corrosive factor for the object under inspection 2. Various solutions containing a supporting electrolyte can be used as the hydrated electrolyte material. Specifically, for example, aqueous solutions of sodium chloride, potassium chloride, magnesium sulfate, potassium nitrate, calcium phosphate, potassium bitartrate, etc., can be used as the hydrated electrolyte material. In this embodiment, an aqueous sodium chloride solution is used as the hydrated electrolyte material. The water-retaining contact part 3 holds the aqueous sodium chloride solution. In other words, the contact part 3, which is made of cotton cloth, is moist at least during the measurement.

[0056] Furthermore, the measuring device 1 may also include a holding section for holding the aqueous electrolyte material, separate from the contact section 3. The holding section may be made of, for example, a porous material. If the holding section appropriately supplies the aqueous electrolyte material to the contact section 3, the contact section 3 can hold the aqueous electrolyte material during measurement.

[0057] (housing) As shown in Figure 2, the contact portion 3 in its stored state is housed inside the housing 11. This prevents the contact portion 3 from drying out when not in use.

[0058] In the configuration example shown in the figure, the housing 11 is a roughly rectangular box shape, with a length in the front-to-back direction being longer than its width in the left-to-right direction. The shape of the housing 11 is not limited to a specific shape. The housing 11 has a lower opening 12 and a front opening 13. The lower opening 12 opens downwards to the housing 11. The front opening 13 opens forward to the housing 11.

[0059] The mechanic extends the retracted contact portion 3 through the front opening 13 and the lower opening 12, or rolls up the deployed contact portion 3 and puts it into the housing 11. The openings in the housing 11 facilitate the deployment and retraction of the contact portion 3. As shown in Figure 1, when the contact portion 3 is deployed, the front of the contact portion 3 extends outside the housing 11.

[0060] The front opening 13 is opened and closed by the front cover 14, as indicated by the arrow in Figure 2. The front cover 14 is attached to the housing 11 via a hinge 15. The front cover 14 may be made of a transparent material, such as acrylic resin. If the front cover 14 is made of a transparent material, even when the front opening 13 of the housing 11 is closed, the mechanic can see inside the housing 11 through the front cover 14. Also, if the front cover 14 is made of a transparent material, when the camera 61 (described later) photographs the contact area 3 inside the housing 11, the camera 61 (described later) can illuminate the object being photographed. The housing 11 may also be made of a transparent material, such as acrylic resin.

[0061] A magnet 16 is attached to the tip of the front cover 14. When the mechanic starts measuring using the measuring device 1, he opens the front cover 14 to open the front opening 13, extends the contact portion 3 forward, and then closes the front cover 14. As shown in Figure 1, the magnet 16 is positioned on the contact portion 3 in its deployed state. The magnet 16 is attracted to the painted steel plate 2 by magnetic force. The magnet 16 presses down on the front of the contact portion 3, which is trying to return to its stored state by the elastic restoring force of the spiral spring 31, onto the painted steel plate 2. While the measuring device 1 is performing the measurement, the contact portion 3 is maintained in contact with the surface of the electrodeposited coating 23 on the painted steel plate 2. The measuring device 1 can accurately measure the current flow between the negative electrode 41 and the steel plate 21 while maintaining the state in which the contact portion 3 is in contact with the surface treatment films 22 and 23. The magnet 16 is an example of a maintenance part. The use of the magnet 16 allows the contact portion 3 to easily come into contact with the surface treatment films 22 and 23, and to easily maintain that contact state. Furthermore, the use of the magnet 16 allows the contact portion 3, which has been maintained in contact, to be easily released after the measurement is completed.

[0062] A lower cover 17 is attached to the housing 11. The lower cover 17 opens and closes the lower opening 12 of the housing 11. As shown in Figure 1, the lower cover 17 opens the lower opening 12 during measurement, and as shown in Figure 2, closes the lower opening 12 when not measuring. The contact portion 3 can come into contact with the surface treatment films 22 and 23 through the lower opening 12 of the housing 11 during measurement.

[0063] The lower cover 17 has an elongated shape, longer in the front-to-back direction than in the left-to-right direction, to correspond to the shape of the lower opening 12 of the housing 11. The lower cover 17 is a flexible sheet that can be easily deformed. As shown in Figure 1, while the measuring device 1 is performing measurements, the lower cover 17 is rolled up around an axis extending in the left-to-right direction and positioned at the rear of the housing 11. As shown in Figure 2, when the measuring device 1 is not performing measurements, the lower cover 17 is stretched forward to close the lower opening 12 (see arrow in Figure 2).

[0064] The lower cover 17 may be made of a non-permeable material, such as flexible polyvinyl chloride, so that the inside of the housing 11 becomes as airtight as possible when the lower opening 12 is closed. If the inside of the housing 11 is airtight, drying of the contact part 3 housed in the housing 11 is suppressed.

[0065] A magnetic material may be attached to the tip of the lower cover 17. As shown in Figure 2, when the lower cover 17 closes the lower opening 12, the magnetic material at the tip of the lower cover 17 can be attracted to the magnet 16 of the front cover 14. This keeps both the front cover 14 and the lower cover 17 closed.

[0066] (Measurement part) The measuring unit 4 performs electrochemical measurements. The measuring unit 4 has a negative electrode 41 and a positive electrode 42. The negative electrode 41 is electrically connected to the electrodeposited coating 23 via the contact part 3. The positive electrode 42 is electrically connected to the steel plate 21. The measuring unit 4 measures the current flow between the negative electrode 41 and the steel plate 21 while applying a voltage between them. Specifically, a potentiometer / galvanostat can be used in the measuring unit 4.

[0067] As shown in Figure 1, the negative electrode 41 is connected to the rear of the contact portion 3. In this configuration example, the negative electrode 41 has an inverted L-shape when viewed from the side. The negative electrode 41 is placed on top of the contact portion 3. The stacked negative electrode 41 and the contact portion 3 are sandwiched vertically by a pair of magnets 18. The pair of magnets 18 maintain the connection between the negative electrode 41 and the contact portion 3 during measurement by bringing them into close contact. The negative electrode 41 is electrically connected to the electrodeposited coating 23 via the contact portion 3.

[0068] As will be described later, if, for example, the contact part 3 deteriorates, the mechanic will replace the contact part 3. Since the contact part 3 is held in place by a pair of magnets 18, the mechanic can easily replace the contact part 3 by removing the magnets 18.

[0069] Furthermore, the measuring device 1 may have a clamp that holds the negative electrode 41 and the contact portion 3 in place of the pair of magnets 18. The clamp can also maintain the connection between the negative electrode 41 and the contact portion 3 during measurement, and the contact portion 3 can be easily replaced.

[0070] Of the pair of magnets 18, the lower magnet is exposed to the lower side of the housing 11 through the lower opening 12 when the measuring device 1 is taking measurements. In addition to its function of gripping the negative electrode 41 and the contact portion 3, the lower magnet also has the function of fixing the measuring device 1 to the painted steel plate 2 together with the magnet 16 by being attracted to the painted steel plate 2 when the measuring device 1 is taking measurements.

[0071] Of the pair of magnets 18, the upper magnet may be a magnet with relatively strong magnetic force, and the lower magnet may be a magnet with relatively weak magnetic force. In this way, the pair of magnets 18 can grip the negative electrode 41 and the contact portion 3 with strong force. On the other hand, since the lower magnet has a weaker attractive force to the painted steel sheet 2 of the automobile being inspected 2, scratches and other damage to the surface of the painted steel sheet 2 can be suppressed.

[0072] In this configuration example, the positive electrode 42 is made up of an alligator clip. As will be described later, the alligator clip clamps onto the area of ​​the painted steel sheet 2 where the chemical conversion coating 22 and electrodeposited coating 23 have been removed, exposing the steel sheet 21 (see the lower diagram in Figure 1). This electrically connects the positive electrode 42 to the steel sheet 21. Note that the positive electrode 42 is not limited to an alligator clip.

[0073] (Information processing device) The information processing device 5 functions as a control unit that controls the voltage applied between the negative electrode 41 and the steel plate 21 by the measuring unit 4. The information processing device 5 also functions as an output unit that outputs the measured values ​​from the measuring unit 4 to the outside of the device. As shown in Figure 3, the information processing device 5 has a communication unit 51 as an output unit and a storage unit 52 as an output unit.

[0074] The communication unit 51 communicates using short-range wireless communication, such as Wi-Fi or Bluetooth (registered trademark). The communication unit 51 exchanges information directly or indirectly with the inspection center 7 and the management system 8. A relay device may be interposed between the measuring device 1 and the inspection center 7 or the management system 8. The inspection center 7 collects measurement values ​​from the measuring device 1 to determine the corrosion state of the object under inspection 2. The inspection center 7 will be described later.

[0075] The management system 8 manages the maintenance factory. A surveillance camera 81 is connected to the management system 8. The surveillance camera 81 is installed at the location where measurements for vehicle corrosion inspection are performed. As will be described later, based on the images captured by the surveillance camera 81, the management system 8 can determine whether measurements using the measuring device 1 are to be performed.

[0076] The communication unit 51 transmits various information, including the measured values ​​from the measurement unit 4, to the inspection center 7. Details of the information transmitted by the communication unit 51 will be explained later.

[0077] The storage unit 52 has a storage medium 53 that is detachably attached to the information processing device 5. The storage medium 53 may be, for example, a memory card containing non-volatile memory. Preferably, the storage medium 53 is readable by an external device, such as a personal computer.

[0078] The memory unit 52 writes various information, including the measurement values ​​from the measurement unit 4, to the storage medium 53. The information written to the storage medium 53 is the same as, or nearly the same as, the information transmitted by the communication unit 51, which will be described later. When a technician removes the storage medium 53 from the information processing device 5, it is equivalent to outputting the measurement values ​​from the measurement unit 4 to the outside of the device.

[0079] The information processing device 5 also has an operation unit 54. The operation unit 54 is operated by a maintenance worker. Through the operation of the operation unit 54, the maintenance worker starts and ends measurements using the measuring device 1.

[0080] (Camera, humidity sensor, heater, temperature sensor, battery) Camera 61 comprises a lens and an image sensor. Camera 61 captures moving images. As illustrated in Figure 1, camera 61 is installed inside the housing 11. Camera 61 is located above the contact portion 3. Camera 61 captures, for example, the area shown by the dashed line in Figure 1. The shooting range of camera 61 is from the front of the contact portion 3 to the middle in the front-to-back direction. The shooting range of camera 61 includes at least the area where the magnet 16 is pressing against the contact portion 3. The shooting range of camera 61 also includes areas where the magnet 16 is not pressing against the contact portion 3 and where the wetness sensor 62, heater 63, and temperature sensor 64 are not installed; in other words, areas where the contact portion 3 itself is exposed.

[0081] Camera 61 captures images of the state of the contact portion 3, at least during measurement. The state of the contact portion 3 includes the deterioration state of the contact portion 3 itself and the contact state between the contact portion 3 and the electrodeposited coating 23. In this measuring device 1, the area where the contact portion 3 is in contact with the electrodeposited coating 23 and the area where the contact portion 3 is in contact with the negative electrode 41 are separated in the front-to-back direction by the magnet 16. Therefore, camera 61 can capture images of the state of the contact portion 3 during measurement. The images captured by camera 61 are used to confirm that the measurement by the measuring device 1 is being performed correctly, as will be described later.

[0082] Camera 61 is connected to the information processing device 5. Camera 61 outputs the captured video images to the information processing device 5.

[0083] The moisture sensor 62 is installed in the middle of the contact portion 3. The moisture sensor 62 outputs a signal regarding the moisture state of the contact portion 3 to the information processing device 5. The moisture sensor 62 may, for example, detect moisture and output a signal to the information processing device 5 indicating a level corresponding to the amount of moisture, or it may output a signal to the information processing device 5 when the amount of moisture is above a predetermined level. Based on the signal from the moisture sensor 62, it can be determined that the contact portion 3 does not dry out and retains sufficient moisture-containing electrolyte material during measurement by the measuring device 1.

[0084] The heater 63 is also installed in the middle of the contact area 3 in the front-to-back direction. The heater 63 may be, for example, a rubber heater or a film heater. The operation of the heater 63 is controlled by the information processing device 5. The heater 63 has the function of adjusting the temperature of the water-containing electrolyte material and the measurement area of ​​the painted steel plate 2 to a predetermined temperature range. The heater 63 maintains the temperature of the contact area 3 at a temperature at which the water-containing electrolyte material does not freeze. Setting the temperature of the water-containing electrolyte material, etc., to a predetermined temperature range can improve the reliability of the measurement values ​​of the measuring device 1 and increase the accuracy of corrosion inspection.

[0085] The temperature sensor 64 is installed in the middle of the contact portion 3. The temperature sensor 64 outputs a signal regarding the temperature of the contact portion 3 to the information processing device 5. The temperature sensor 64 may output a signal to the information processing device 5 at a level corresponding to the temperature, or it may output a signal to the information processing device 5 when the temperature is above a predetermined level. Based on the signal from the temperature sensor 64, it can be determined that the contact portion 3 holding the water-containing electrolyte material is not frozen during measurement by the measuring device 1.

[0086] Battery 6 is a rechargeable secondary battery. Power supplied from battery 6 allows the measuring unit 4 to apply voltage to the object under inspection 2 during measurement. In addition, battery 6 supplies power to the information processing device 5, camera 61, moisture sensor 62, heater 63, and temperature sensor 64. The measuring device 1 equipped with battery 6 can measure the object under inspection 2 without being restricted by location.

[0087] Battery 6 is charged when the measuring device 1 is not in use for measurements. Figure 4 shows the charger 9 charging battery 6.

[0088] The measuring device 1 is equipped with a charging connector 19. The charging connector 19 is connected to a charger 9. The charger 9 may have a socket 91 into which the rear end of the measuring device 1 is inserted, as illustrated in Figure 4. As described above, when a mechanic inserts the measuring device 1, with the contact portion 3 housed in the housing 11 and the lower opening 12 and front opening 13 of the housing 11 closed, into the socket 91, the battery 6 can be charged by power from the power supply 92 connected to the charger 9.

[0089] (Testing Center) The inspection center 7 collects measurement data from the measuring device 1. The inspection center 7 may be located in a repair shop or in a location away from a repair shop. The inspection center 7 may collect measurement data from each of the multiple measuring devices 1. In addition to collecting measurement data from multiple measuring devices 1 in one repair shop, the inspection center 7 may also collect measurement data from one or more measuring devices 1 in each of multiple repair shops. The repair shops from which the inspection center 7 collects measurement data may be repair shops in a specific region. By doing so, the inspection center 7 can efficiently collect corrosion measurement data for vehicles used by various users in similar operating environments.

[0090] A computer 72 installed in the inspection center 7 determines the corrosion state of the object under inspection 2 based on the collected measurement data. Details of this determination will be described later. The computer 72 also determines the deterioration of the contact part 3 used for measurement based on the images captured by the camera 61. The inspection center 7 transmits the determination results via communication to a terminal 71 held by the mechanic who performed the measurement. The terminal 71 has at least a communication function and a display function. The terminal 71 may be, for example, a smartphone or a tablet. The mechanic can communicate the determination results received by the terminal 71 to the user.

[0091] The inspection center 7 is equipped with a database 73. The database 73 stores information such as collected measurement values. The database 73 also stores information used to determine the deterioration of the contact area 3. The computer 72 determines the deterioration of the contact area 3 based on the information in the database 73.

[0092] (Principles of corrosion testing) As described above, the negative electrode 41 of the measuring device 1 is electrically connected to the surface of the electrodeposited coating 23 of the painted steel sheet 2 via the contact portion 3 which holds the water-containing electrolyte material, and the positive electrode 42 is connected to the steel sheet 21 (see the lower diagram in Figure 1). Under the control of the information processing device 5, the measuring unit 4 applies a voltage between the negative electrode 41 and the steel sheet 21 and measures the current flow between the negative electrode 41 and the steel sheet 21.

[0093] At this time, the measuring unit 4 applies a voltage while gradually increasing it with respect to time, as shown by the dashed line in Figure 5. Specifically, the sweep rate of the applied voltage is in the range of 0.1 to 10 V / s, and more preferably 0.5 to 2 V / s. The measuring unit 4 detects the current flowing between the negative electrode 41 and the steel plate 21 in response to the applied voltage.

[0094] As shown by the solid line in Figure 5, even if the applied voltage is increased, the current between the two hardly flows until the voltage reaches value V1 at time t1. However, once the voltage exceeds value V1, the current increases rapidly, and at voltage value V2 (time t2), the current reaches threshold A1.

[0095] This indicates that, until the voltage value V1 is reached, the barrier performance of the water-containing electrolyte material as a corrosive factor in the surface treatment films 22 and 23 is maintained, and the amount of current is suppressed. However, the amount of current increases sharply because (1) the increase in applied voltage helps the corrosive factor penetrate into the surface treatment films 22 and 23, or (2) the surface treatment films 22 and 23 are gradually destroyed, the corrosive factor gradually penetrates into the interior of the surface treatment films 22 and 23, and eventually reaches the surface of the steel plate 21. In other words, the application of voltage promotes the penetration of the corrosive factor into the surface treatment films 22 and 23, and when the corrosive factor reaches the surface of the steel plate 21, the surface treatment films 22 and 23 undergo dielectric breakdown, and their barrier performance is lost.

[0096] Furthermore, if we define the insulation voltage as the voltage V2 when the current reaches the threshold A1, then the time t2 at which the insulation voltage V2 is reached is considered to correspond to the period until the corrosion factor reaches the steel plate 21, that is, the corrosion suppression period for the steel plate 21.

[0097] Figure 6 shows the correlation between the corrosion inhibition period obtained by a combined cycle test, which is a corrosion acceleration test, and the insulation voltage V2 obtained by the measurement device 1 for a painted steel sheet 2 in which a chemical conversion coating 22 and an electrodeposited coating 23 are formed on the surface of the steel sheet 21.

[0098] The combined cycle test involves applying a salt spray process (8 hours), a drying process (8 hours), and a wetting process (8 hours) to the test specimen, with each process constituting a 24-hour cycle. The corrosion inhibition period is defined as the number of cycles at which blistering (rust) forms on 20% of the test specimen surface.

[0099] In Figure 6, the four points E1 to E4 represent painted steel sheets 2 with electrodeposited coating film thicknesses of 5 μm, 7 μm, 10 μm, and 15 μm, respectively, and a baking condition of 150°C for 20 minutes. The three points E5, E6, and E3 represent painted steel sheets 2 with an electrodeposited coating film thickness of 10 μm, and a baking condition of 140°C for 15 minutes, 140°C for 20 minutes, and 150°C for 20 minutes, respectively. As shown in Figure 6, these points follow the regression line even when the electrodeposited coating film thickness and baking conditions change, and the coefficient of determination R2 Since the value is 0.83, it can be said that there is a high correlation between the corrosion suppression period and the insulation voltage V2.

[0100] Therefore, the corrosion resistance of the painted steel sheet 2 can be evaluated by measuring the insulation voltage V2 of the surface treatment films 22 and 23 of the painted steel sheet 2.

[0101] Here, when inspecting the corrosion of the painted steel plate 2 of a user's automobile at a repair shop, if the voltage is increased to the insulation voltage V2, the surface treatment films 22 and 23 on the painted steel plate 2 of the user's automobile will undergo dielectric breakdown. In other words, the painted steel plate 2 of the user's automobile will be deteriorated for the purpose of inspection. Therefore, the measuring unit 4 of the measuring device 1 pre-determines a maximum voltage less than the insulation voltage V2, preferably less than the voltage value V1 at which the current increases, for painted steel plates 2 where the surface treatment films 22 and 23 are not deteriorated and the steel plate 21 is not corroded, and gradually increases the voltage applied between the negative electrode 41 and the steel plate 21 to this maximum voltage. The measuring unit 4 detects the current flowing between the negative electrode 41 and the steel plate 21 in response to the applied voltage.

[0102] If the surface treatment films 22 and 23 on the painted steel sheet 2 are not deteriorated, the ability to block corrosive factors in the surface treatment films 22 and 23 is maintained, so even if the applied voltage is increased, almost no current flows between the negative electrode 41 and the steel sheet 21. On the other hand, if the surface treatment films 22 and 23 are deteriorated, the ability to block corrosive factors in the surface treatment films 22 and 23 is reduced, so increasing the applied voltage makes it easier for corrosive factors to penetrate. In other words, even with an applied voltage below the maximum voltage mentioned above, current flows easily between the negative electrode 41 and the steel sheet 21. Furthermore, if the surface treatment films 22 and 23 are further deteriorated and the painted steel sheet 2 is already corroded, the surface treatment films 22 and 23 have already undergone dielectric breakdown, or dielectric breakdown of the surface treatment films 22 and 23 may occur even with an applied voltage below the maximum voltage mentioned above, and the amount of current may reach the threshold A1. Therefore, based on the current value measured by the measuring device 1, the deterioration state of the surface treatment films 22 and 23, or the corrosion state of the painted steel sheet 2, can be determined.

[0103] In other words, the measuring device 1 applies an increasing voltage between the steel plate 21 and the surface treatment films 22 and 23 of the painted steel plate 2, and measures the amount of current between the steel plate 21 and the surface treatment films 22 and 23. Based on these measurements, the inspection center 7 can predict when the painted steel plate 2 will corrode or detect corrosion at an early stage.

[0104] In the measurement described above, it is preferable that the temperature of the contact portion 3 and the painted steel sheet 2 be kept constant between 10 and 40°C. More preferably, the temperature is between 20 and 30°C, and particularly preferably between 23 and 27°C. Since the heater 63 is in contact with the painted steel sheet 2 via the contact portion 3, the temperature of the painted steel sheet 2 and the contact portion 3 can be maintained at a specific temperature during the measurement.

[0105] (Installation procedure for measuring device) Next, the procedure for attaching the measuring device 1 to the measurement point on the painted steel plate 2 will be explained. First, the mechanic removes the measuring device 1 from the charger 9, and opens the lower opening 12 by winding up the lower cover 17, and also opens the front opening 13 by rotating the front cover 14. Then, the mechanic manually extends the contact portion 3, which is in its stored position. The contact portion 3 extends outside the housing 11 through the lower opening 12 and / or the front opening 13. Since both the lower opening 12 and the front opening 13 of the housing 11 are open, the mechanic can easily pull out the contact portion 3.

[0106] The mechanic then places the contact part 3 in contact with the electrodeposited coating 23 of the painted steel plate 2 and closes the front cover 14. This causes the magnet 16 to be attracted to the painted steel plate 2. The contact part 3 is sandwiched between the magnet 16 and the electrodeposited coating 23. The pair of magnets 18 are also attracted to the painted steel plate 2. The measuring device 1 is then placed on the painted steel plate 2 in place by the magnets 16 and 18, so as not to move.

[0107] In the deployed state, the contact portion 3 extends significantly outside the housing 11, making it easier for the mechanic to bring the contact portion 3 into contact with the surface treatment films 22 and 23 of the painted steel plate 2. This improves the work efficiency of measurement operations using the measuring device 1.

[0108] Furthermore, since most of the contact area 3 and the negative electrode 41 are covered by the housing 11 during measurement, it is possible to prevent the mechanic from inadvertently touching the contact area 3 or the negative electrode 41.

[0109] The positive electrode 42 is connected to the steel plate 21 of the painted steel plate 2. The mechanic may connect the positive electrode 42 to the exposed steel plate 21 by scraping off a portion of the chemical conversion coating 22 and electrodeposited coating 23 of the painted steel plate 2, for example, as shown in Figure 1.

[0110] (Examples of measurement locations) The measurement device 1 can be used to perform corrosion inspections on painted steel plates 2 at various locations on an automobile.

[0111] As an example, Figure 7 shows an example where the door 201 of an automobile 20 is the object to be inspected. In this case, the negative electrode 41 of the measuring device 1 may be electrically connected to the inner panel 203 on the inside of the door 201. The positive electrode 42 of the measuring device 1 may, for example, be connected to the hood hinge 204. More specifically, a mechanic may peel off the surface treatment films 22 and 23 of the hood hinge 204 to expose the steel plate 21 and connect the alligator clip, which serves as the positive electrode 42, to the hood hinge 204. It is preferable to connect the negative electrode 41 and / or positive electrode 42 to a location that is not easily visible on the exterior of the automobile 20 when performing an inspection on the user's automobile 20. Note that the areas where the surface treatment films 22 and 23 were peeled off for measurement may be repaired after the measurement.

[0112] Figure 8 shows another example in which the object to be inspected is the suspension arm 205 of an automobile 20. The negative electrode 41 of the measuring device 1 may be connected to the lower surface of the suspension arm 205. In this case, the lower surface is the surface that faces downward when the suspension arm 205 is attached to the automobile 20. The measuring device 1 can be attached upside down to the lower surface of the suspension arm 205 by magnets 16 and 18.

[0113] The positive electrode 42 of the measuring device 1 may, for example, be connected to the upper surface of the suspension arm 205. More specifically, the surface treatment films 22 and 23 on the upper surface of the suspension arm 205 may be peeled off to expose the steel plate 21, and an alligator clip serving as the positive electrode 42 may be connected to the upper surface of the suspension arm 205. Since the alligator clip can grip the object, it is easy to attach to the edge 207 of the upper surface of the suspension arm 205. After measurement with the measuring device 1, the area where the surface treatment films 22 and 23 were peeled off should be repaired as described above.

[0114] When performing corrosion inspections on painted steel plates 2 of an automobile 20 at a repair shop, multiple measurement points may be designated for each part, such as the side sill, subframe, and suspension arm, and measurements may be taken at each point. By considering the measurements from multiple points, the corrosion status of each part can be accurately determined.

[0115] Furthermore, measurement points may include, for example, welded areas. Welded areas may be prone to deterioration of the surface treatment films 22 and 23 due to spatter during welding. Including areas where the surface treatment films 22 and 23 are prone to deterioration as measurement points for corrosion inspection is advantageous in preventing corrosion of the painted steel sheet 2.

[0116] (Inspection procedures in the inspection system) Next, the inspection procedure using the inspection system 10 will be explained in detail with reference to the flowcharts in Figures 9 and 10. The flowchart in Figure 9 relates to the procedure for performing measurements for corrosion inspection of the painted steel sheet 2 of an automobile using the measuring device 1. Note that in the flowchart in Figure 9, the order of the steps may be changed, some steps may be omitted, or steps may be added, to the extent possible.

[0117] First, in step S91 after the start, the information processing device 5 of the measuring device 1 determines whether or not the measuring device 1 has been disconnected from the charger 9. The information processing device 5 may also determine whether or not the measuring device 1 has been disconnected from the charger 9 based on the connection status between the charging connector 19 and the charger 9.

[0118] If the determination in step S91 is No, the measuring device 1 charges the battery 6 in step S911. In the following step S912, the measuring device 1 determines whether or not the battery 6 has been fully charged. If the determination in step S912 is No, the process returns to step S91. If the determination in step S912 is Yes, the process returns.

[0119] If the decision in step S91 is Yes, the camera 61 of the measuring device 1 starts taking pictures. The camera 61 continues to take pictures from before the measurement by the measuring device 1 until the measurement is complete. The images taken by the camera 61, which started before the measurement, can be used to confirm that the measurement by the measuring device 1 is being performed correctly, thus ensuring the reliability of the measurement using the measuring device 1.

[0120] Furthermore, after removing the measuring device 1 from the charger 9, the mechanic pulls out the contact portion 3 from its stored state and unfolds it, as described above, and attaches the measuring device 1 to the measurement location of the automobile 20. The mechanic can check the condition of the contact portion 3 before measurement. For example, if the contact portion 3 is discolored or deteriorated, the mechanic replaces the contact portion 3 with a new one. The contact portion 3 may also be replaced each time a predetermined number of measurements are performed. Since the contact portion 3 is held by a pair of magnets 18, the mechanic can easily replace the contact portion 3. Also, if the contact portion 3 is dry, that is, if the contact portion 3 does not sufficiently hold the water-containing electrolyte material, the mechanic makes the contact portion 3 hold the water-containing electrolyte material.

[0121] When the measuring device 1 measures the current flow between the negative electrode 41 and the steel plate 21, it is necessary to ensure that the contact portion 3 holding the water-containing electrolyte material is not deteriorated and that the wet state of the contact portion 3 is maintained in order to ensure measurement accuracy and achieve accurate measurements.

[0122] Before measurement, the mechanic can spread out the contact area 3 in its stored state and check its condition, allowing the measuring device 1 to perform accurate measurements.

[0123] Furthermore, if the mechanic replaces the contact part 3, the mechanic may temporarily connect the measuring device 1 to the charger 9 and then disconnect it from the charger 9 again. This allows the camera 61 to start taking pictures at the appropriate time.

[0124] The mechanic attaches the measuring device 1 to the measurement point on the painted steel plate 2 according to the procedure described above. In step S93, the measuring device 1 determines whether the mechanic has performed the operation to start the measurement by operating the operation unit 54. If the determination in step S93 is No, the process repeats step S93. The measuring device 1 waits for the operation to be performed. If the determination in step S93 is Yes, the measuring unit 4 of the measuring device 1 applies a voltage between the negative electrode 41 and the steel plate 21 as described above, and measures the current and voltage between the negative electrode 41 and the steel plate 21 (step S94).

[0125] In step S95, the measuring device 1 increases the voltage, and in the following step S96, the measuring device 1 determines whether the applied voltage exceeds the maximum voltage. As mentioned above, the maximum voltage is preset to a voltage lower than the insulation voltage. The maximum voltage may be a uniform voltage regardless of the type of part being inspected 2, or it may be a different voltage for each part. If the maximum voltage is different for each part, the mechanic can input the part to be measured through the operating unit 54 before starting the measurement. By doing so, the measuring device 1 can apply the maximum voltage corresponding to the part between the negative electrode 41 and the steel plate 21.

[0126] If the applied voltage does not exceed the maximum voltage in step S96, the process proceeds to step S97. If the applied voltage exceeds the maximum voltage, the process proceeds to step S98 to terminate the measurement.

[0127] In step S97, the measuring device 1 determines, based on the measured current value, whether dielectric breakdown has occurred in the surface treatment films 22 and 23 of the painted steel sheet 2. If the current value reaches threshold A1, the measuring device 1 determines that dielectric breakdown has occurred. If the determination in step S97 is No, the process returns to step S94. The measuring device 1 continues to measure the current value and voltage value while increasing the applied voltage. If the determination in step S97 is Yes, the process proceeds to step 98 to terminate the measurement.

[0128] In step S98, the measuring unit 4 of the measuring device 1 finishes measuring the current and voltage, and the camera 61 finishes taking images. In the following step S99, the information processing device 5 of the measuring device 1 transmits the measured values ​​from the measuring unit 4 and the images captured by the camera 61 to the inspection center 7 in association with each other. During measurement, the applied voltage gradually increases (i.e., changes) over time, so the measuring device 1 transmits the measured values ​​and captured images in association with the passage of time. The measuring device 1 also transmits to the inspection center 7 information regarding the wetness state of the contact part 3 based on the signal from the wetness sensor 62, and information regarding the temperature of the contact part 3 based on the signal from the temperature sensor 64, during measurement.

[0129] After transmitting the measured values ​​and captured images, the mechanic removes the measuring device 1 from the vehicle 20, retracts the contact portion 3, and places it inside the housing 11. Then, the mechanic connects the measuring device 1 to the charger 9. The measuring device 1 determines whether or not it is attached to the charger 9. The measuring device 1 may also determine whether or not it is attached to the charger 9 based on the connection status between the charging connector 19 and the charger 9. If the determination in step 910 is No, the process repeats step S910. If the determination in step S910 is Yes, the process proceeds to step S911. The measuring device 1 charges the battery 6.

[0130] Thus, the measurement using measuring device 1 is completed.

[0131] Furthermore, after the measurement and imaging of current and voltage are completed in step S98, or after the inspection center 7 information is transmitted in step S99, measurements at other measurement points using the measuring device 1 may be continued. If measurements at multiple measurement points are to be continued, the contact part 3 may be replaced at an appropriate timing as needed.

[0132] Figure 10 is a flowchart of the processing at the inspection center 7. The flowchart in Figure 10 may also be modified to the extent possible, with steps rearranged, some steps omitted, or steps added.

[0133] First, in step S101, the computer 72 of the inspection center 7 determines whether or not it has received a measurement value from the measuring device 1. If it has not been received, the process repeats step S101. If it has been received, the process proceeds to step S102.

[0134] In step S102, the computer 72 performs an analysis based on the received information. In this analysis, the computer 72 determines whether the measurement was performed correctly based on the images captured by the camera 61, which are received along with the measured values. When determining whether the measurement was performed correctly, the computer 72 considers information regarding the wetness and temperature of the contact area 3. If the measurement was performed correctly, the computer 72 determines the corrosion state of the painted steel plate 2 based on the measured current value.

[0135] In step S103, the computer 72 transmits the analysis results to the terminal 71 of the mechanic who performed the measurement. Then, in step S104, the computer 72 stores the measurement values ​​received in the database 73.

[0136] At this point, the terminal 71 of the mechanic who receives the analysis results from the inspection center 7 displays screens 711 to 713, as illustrated in Figure 10. Screen 711 is an example of a screen displayed when the painted steel plate 2 has no problems with corrosion. Screen 711 shows "OK" as the analysis result, the reason is "No dielectric breakdown occurs even when the maximum voltage is applied," and the situation is "It is predicted that no rust will occur for ** years from today."

[0137] Screen 712 shows "NG" as the analysis result, with the reason given as "**dielectric breakdown occurs when a bolt is applied**". The mechanic then conveys this information to the car's user.

[0138] Screen 713 shows "Error" as the analysis result, with the reason "Contact area determined to be deteriorated." In this case, since the measurement was not performed accurately, the mechanic will perform the measurement again using measuring device 1.

[0139] The computer 72 can determine the deterioration of the contact area 3 by using known image analysis techniques, for example, based on the image captured by the camera 61. Specifically, the cloth that constitutes the contact area 3 becomes discolored when it deteriorates. The computer 72 may calculate the discolored area of ​​the contact area 3 based on the image captured by the camera 61, and if the proportion of the discolored area is greater than a predetermined value, it may determine that the contact area 3 is deteriorated.

[0140] The computer 72 may also determine that a measurement is faulty in the following cases: (1) For example, if the area ratio of the contact portion 3 on the image is less than a predetermined value based on the image captured by the camera 61, the computer 72 determines that a measurement is faulty because the contact portion 3 is not sufficiently spread out, or the contact state between the contact portion 3 and the electrodeposited coating 23 is poor. (2) If it can be recognized from the image captured by the camera 61 that the contact portion 3 has peeled off from the electrodeposited coating 23 (even for a moment) during measurement, the computer 72 determines that a measurement is faulty. (3) If the date and time data of the image captured by the camera 61 and the date and time data of the measurement value of the measurement unit 4 do not match, the computer 72 determines that a measurement is faulty because the image captured by the camera 61 and the measurement value of the measurement unit 4 do not correspond. (4) If the temperature of the contact portion 3 is low (for example, below 0°C) based on the signal from the temperature sensor 64, the computer 72 determines that the contact portion 3 is frozen and determines that a measurement is faulty. (5) If the contact portion 3 is dry based on the signal from the moisture sensor 62, the computer 72 determines that a measurement is faulty because the water-containing electrolyte material is not present at the time of measurement.

[0141] If the measurement is not performed accurately, the inspection system 10 prompts the mechanic to repeat the measurement, as described above. This inspection system 10 can achieve accurate measurement and accurate inspection.

[0142] (summary) As explained above, the measuring device 1 is equipped with a contact part 3 that switches between an expanded state, which is extended to contact the surface of the surface treatment films 22 and 23 during measurement, and a retracted state, which is reduced in size when not being measured. When measurement is performed, the contact part 3 switches from the retracted state to the expanded state, so that the mechanic can confirm that there is no deterioration in the contact part 3 and that the contact part 3 maintains a moist state. Since the measurement is performed after this confirmation, the measuring device 1 can accurately perform measurements for corrosion inspection.

[0143] Furthermore, since the contact area 3 is reduced in size when not being measured, the surface area of ​​the contact area 3 is small. In the stored state, drying of the contact area 3, which holds the water-containing electrolyte material, is suppressed. When the next measurement is performed, if the mechanic spreads out the contact area 3, which has been kept moist, the measuring device 1 can perform measurements on the painted steel plate 2. This improves the efficiency of measurement work using the measuring device 1.

[0144] Furthermore, the measuring device 1 is equipped with a camera 61. The camera 61 captures images of the contact portion 3 in contact with the surfaces of the surface treatment films 22 and 23. Based on the images captured by the camera 61, it is possible to confirm that there is no deterioration of the contact portion 3 and that the contact portion 3 is in contact with the surfaces of the surface treatment films 22 and 23 during measurement.

[0145] Furthermore, the measuring device 1 is equipped with a communication unit 51 and a storage unit 52 as output units. Since the measured values ​​from the measuring unit 4 and the images captured by the camera 61 are output in correspondence, it is possible to confirm that the measurement was performed accurately at a location other than the measurement site, or at a later time after the measurement, thereby ensuring the reliability of the measurement.

[0146] Furthermore, since the measurement values ​​from the measurement unit 4 and the images captured by the camera 61 correspond in terms of time, it can be confirmed that the measurement was performed correctly.

[0147] As a result, for example, when a repair shop uses the measuring device 1 to perform corrosion inspections on painted steel sheets 2 of an automobile, the reliability of the measurements can be ensured. By using the measuring device 1, it is possible to satisfy the demands of automobile users who want to predict when painted steel sheets 2 will corrode or who want to detect corrosion of painted steel sheets 2 at an early stage.

[0148] (modified version) In the above configuration, the inspection center 7 determines the corrosion state of the object under inspection 2 based on the measurement values ​​from the measuring device 1. However, the information processing device 5 of the measuring device 1 may also determine whether or not there is a measurement error based on the image captured by the camera 61, and determine the corrosion state of the object under inspection 2 based on the measurement values. In this case, the measuring device 1 can simply transmit the analysis results to the mechanic's terminal 71.

[0149] Furthermore, the measuring unit 4 may be equipped with a monitor that displays current and voltage values, and the camera 61 may capture images of the current and voltage values ​​displayed on the monitor along with the condition of the contact unit 3 during measurement.

[0150] Furthermore, in step S91 of Figure 9, the camera 61 starts taking pictures based on the fact that the measuring device 1 has been removed from the charger 9. Alternatively, the management system 8 may determine, based on the images captured by the surveillance camera 81, that a mechanic holding the measuring device 1 has approached the vehicle under inspection, and transmit an approach signal to the measuring device 1. When the measuring device 1 receives the approach signal, the camera 61 may start taking pictures. Alternatively, the mechanic may manually start the camera 61 taking pictures at an appropriate time.

[0151] Figure 11 shows a modified example of the measuring device 1. In the measuring device 1 described above, the negative electrode 41 was electrically connected to the contact portion 3 at the rear of the contact portion 3. In contrast, the negative electrode may be made up of an alligator clip 43. The alligator clip 43 is electrically connected to the L-shaped negative electrode 41. Note that the L-shaped negative electrode 41 is not connected to the contact portion 3.

[0152] The tip of the deployed contact portion 3 is wrapped around the edge of a hole 24 formed in the object under inspection 2. The alligator clip 43 can electrically connect to the surface of the electrodeposited coating 23 by clamping the edge of the hole 24, with the contact portion 3 sandwiched in between. The hole 24 may be, for example, a drain hole 202 formed in the inner panel 203 of the door 201 (see Figure 7). Alternatively, the hole 24 may be a hole 206 formed in the suspension arm 205 (see Figure 8). The use of the alligator clip 43 makes it easier and more appropriate to electrically connect the negative electrode 41 to the surface treatment films 22 and 23 of the object under inspection 2. The use of the alligator clip 43 also allows the contact portion 3 to be fixed to the surface of the surface treatment films 22 and 23. The alligator clip 43 is an example of a maintenance part that brings the contact portion 3 into contact with the surface of the surface treatment films 22 and 23 and maintains the contact portion 3 in the deployed state.

[0153] As mentioned above, the contact portion 3 can be made smaller by being wound around an axis extending in the left-right direction, or it can be made smaller by being folded and folded, as illustrated in Figure 12. The folded contact portion 3 can be stored inside the housing 11, and combined with the reduced surface area, drying of the contact portion 3 can be suppressed.

[0154] The lower cover 17 is not limited to a flexible sheet; for example, as shown in Figure 13, it may be a lid-shaped cover 170 that can be detachably attached to the bottom of the housing 11. [Explanation of symbols]

[0155] 1. Measuring device 11 Housing 12 Lower opening 13 Front opening 14 Front cover 16 Magnet (maintenance part) 17. Bottom cover 2 Painted steel plate (object to be inspected) 21 Steel plate (base material) 22. Chemical conversion coating (surface treatment film) 23 Electrodeposition coating (surface treatment film) 3 Contact area 31. Spiral spring 4 Measuring part 41 Negative electrode 43 Alligator clip (retention part) 51 Communication section (output section) 52. Memory Unit (Output Unit) 53 Storage medium 6 batteries 61 Camera 7. Testing Center (External) 9 charger

Claims

1. An apparatus for measuring the corrosion of an object to be inspected, which has a metal substrate and a surface treatment film on the substrate, A contact portion that holds the water-containing electrolyte material and contacts the surface of the surface treatment film, The surface treatment film has an electrode electrically connected to it via the contact portion, and a measuring unit that measures the current flow state between the electrode and the substrate while applying a voltage between the electrode and the substrate, A corrosion inspection measuring device wherein at least a portion of the contact portion is a water-retaining sheet for holding the water-containing electrolyte material, and the contact portion switches between an expanded state, which is spread out and in contact with the surface of the surface treatment film during measurement, and a retracted state, which is made smaller when not being measured.

2. In the corrosion inspection measuring device according to claim 1, A corrosion inspection measuring device further comprising a maintenance unit positioned on the opposite side of the contact portion from the object to be inspected, which brings the contact portion into contact with the surface of the surface treatment film and maintains the contact portion in an expanded state.

3. In the corrosion inspection measuring device according to claim 2, Corrosion testing measuring device, wherein the maintenance part is a magnet that is attracted to the object to be inspected via the contact part.

4. In the corrosion inspection measuring device according to claim 1, The aforementioned contact portion is rolled up in the stored state and stretched out in the unfolded state. The contact portion has a spiral spring attached to the surface of the contact portion. The aforementioned spiral spring biases the contact portion to wind, and this is a corrosion inspection measuring device.

5. In the corrosion inspection measuring device according to claim 1, The housing further comprises the contact portion, The contact portion is housed inside the housing in the stored state and extends outside the housing in the deployed state, and is a corrosion inspection measuring device.

6. In the corrosion inspection measuring device according to claim 5, The housing has an opening, A corrosion inspection measuring device in which the contact portion is widened and narrowed through the opening.

7. In the corrosion inspection measuring device according to claim 6, The housing is further equipped with a cover that is attached to the housing and opens and closes the opening, The cover is a corrosion inspection measuring device that closes the opening when not taking measurements.

8. In the corrosion inspection measuring device according to claim 1, The aforementioned device is portable, It also features a rechargeable battery for power supply, The device is a corrosion inspection measuring device connected to a charger that charges the battery when not taking measurements.

Images