CN107270809B - Measuring device and method for determining a layer thickness, and corresponding reference body and calibration body - Google Patents
Measuring device and method for determining a layer thickness, and corresponding reference body and calibration body Download PDFInfo
- Publication number
- CN107270809B CN107270809B CN201710202540.1A CN201710202540A CN107270809B CN 107270809 B CN107270809 B CN 107270809B CN 201710202540 A CN201710202540 A CN 201710202540A CN 107270809 B CN107270809 B CN 107270809B
- Authority
- CN
- China
- Prior art keywords
- probe
- eddy current
- reference body
- measuring device
- coating
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B7/00—Measuring arrangements characterised by the use of electric or magnetic techniques
- G01B7/02—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring length, width or thickness
- G01B7/06—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring length, width or thickness for measuring thickness
- G01B7/10—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring length, width or thickness for measuring thickness using magnetic means, e.g. by measuring change of reluctance
- G01B7/105—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring length, width or thickness for measuring thickness using magnetic means, e.g. by measuring change of reluctance for measuring thickness of coating
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B21/00—Measuring arrangements or details thereof, where the measuring technique is not covered by the other groups of this subclass, unspecified or not relevant
- G01B21/02—Measuring arrangements or details thereof, where the measuring technique is not covered by the other groups of this subclass, unspecified or not relevant for measuring length, width, or thickness
- G01B21/04—Measuring arrangements or details thereof, where the measuring technique is not covered by the other groups of this subclass, unspecified or not relevant for measuring length, width, or thickness by measuring coordinates of points
- G01B21/045—Correction of measurements
Abstract
A measuring device and a method for determining the layer thickness of a coating applied to a cylindrical slot or a perforation of a workpiece. The measuring device is formed by an at least partially cylindrical probe having a plurality of eddy current sensors distributed over the outer circumference, the eddy current sensors being formed by at least one transmitting coil and one receiving coil. The transmitting coil and the receiving coil are arranged on the probe in a spaced-apart circumferential coil array, and the transmitting coil and the associated receiving coil forming the respective eddy current sensor are offset from one another in the circumferential direction. The measuring device has at least one reference body arranged between the probe in the rest position and the workpiece to be measured, the reference body having at least one section-wise cylindrical bore. The eddy current sensors measure the layer thickness of the coating in any desired sequence or in succession or simultaneously in the circumferential direction of the probe during the measuring process. Also relates to a reference body and a calibration body.
Description
Technical Field
The invention relates to a measuring device for determining the layer thickness of a coating applied to a cylindrical recess or bore of a workpiece, in particular to a cylinder running surface of an internal combustion engine. The measuring device is formed by an at least partially cylindrical probe having a plurality of eddy current sensors distributed over the outer circumference of the probe, wherein each eddy current sensor is formed by at least one transmitting coil and one receiving coil. The transmitting coils and the receiving coils are arranged separately from one another on the probe in each case in a spaced-apart, circumferential coil array, and the transmitting coils and the associated receiving coils forming the respective eddy current sensors are arranged offset from one another in the circumferential direction.
The invention also relates to a method for measuring the layer thickness of a coating applied to a cylindrical recess or bore of a workpiece, in particular to a cylinder running surface of an internal combustion engine, by means of a probe arranged in a measuring device.
The invention also relates to a corresponding reference body and a calibration body.
Background
Currently, there is a demand in modern automobile manufacturing to significantly reduce fuel consumption and emissions of harmful substances.
Different possible solutions exist here. For example, in addition to the reduction of the working volume and the so-called downsizing with the same power of the internal combustion engine, means for lightweight manufacturing are increasingly used.
In the field of weight reduction, in addition to vehicle body parts, internal combustion engines are also manufactured by weight reduction manufacturing techniques. In the field of lightweight manufacturing technology, cylinder crankcases for internal combustion engines are generally made of aluminum alloys, such as aluminum-silicon alloys.
Hypoeutectic aluminum-silicon alloys are used here, for example, which have significantly poorer tribological properties than cast iron.
To compensate for this tribological disadvantage, one instead joins the working sleeve made of cast iron into the aluminum cylinder block crankcase after casting it or already at the time of casting it.
In addition to the resulting higher weight of the cylinder crankcase, other disadvantages occur due to the different coefficients of expansion, such as cylinder deformation, deformation of the entire crankcase, or disengagement of the cylinder working sleeve from the crankcase.
These disadvantages may be reduced or avoided in the future by eliminating the cylinder working sleeve and incorporating the coating of the cylinder of the aluminum cylinder block crankcase.
Such coatings are generally of the metal type, which significantly improve the tribological properties of the cylinder running rail, firstly with regard to higher wear resistance and higher corrosion resistance, and secondly with regard to reduced friction in the region of the cylinder and the piston group. This also leads in particular to a significant reduction in carbon dioxide emissions.
For the coating, various possible methods are known, such as, inter alia, powder Plasma spraying, Wire spraying methods, such as the Plasma-Transfer-Wire-Arc method or Arc Wire spraying, and also other methods, such as high-speed flame spraying.
In terms of quality reliability, the layers thus applied must first be examined with regard to layer thickness, pore formation, defective regions and inadequate attachment to the aluminum cylinder block crankcase.
Eddy current testing is considered here as a testing method.
In general, a single eddy current sensor is moved in a spiral rotary motion along the cylinder wall or the cylinder path. The aim here is to achieve the shortest possible inspection time with a high positional resolution, which is subject to a high relative speed of the sensor with respect to the cylinder path.
This constitutes a significant disadvantage of this method, since the sensor is thereby subject to high wear due to direct contact with the working rail and at the same time has a mechanical negative effect on the working rail.
Furthermore, a rotary transducer (Rotier ü bergager) is required for transmitting the sensor signal, which is an electromechanical precision device that makes the inspection system very costly and susceptible to disturbances.
Furthermore, the implementation of the indispensable floating bearing of the conveyor is very laborious, since the rotary conveyor is massive.
The inspection by means of such a single sensor system can furthermore only be carried out when the machining of the cylinder work rails is completed, for example after the honing process, so that the inspection is carried out very late in the process chain. Since the sensor needs to be in contact with the cylinder work rail, layer measurement is not possible immediately after coating or after pre-honing. Such a measurement is useless because layer thickness fluctuations necessarily lead to disturbances in the measurement signal.
Eddy current analysis is used in many fields of technology.
In contrast to the single-sensor test system, it is known from other technical fields to use a plurality of eddy current sensors in a measuring head for evaluating heat exchanger tubes. This method or a method for using the measuring head is described in US 6,344,739B 1. The individual sensors used are designed in the form of coils, wherein the coils are distributed over the circumference of the cylindrical measuring head. The measuring head preferably has three rows of coil measuring heads, two rows being aligned with one another in the axial direction of the measuring head and the third row being arranged offset from the two rows. This three-column coil arrangement is used for measurements in two different modes. The first measuring mode is used to detect cracks in the conductive heat exchanger tubes, which are located in the axial direction of the measuring head and thus also in the axial direction of the tubes during their length extension. The measurement is carried out here by means of the middle of the three coil arrays. The transmit coil and the receive coil are derived from the same intermediate column in this mode. While the second measuring mode is used for detecting cracks in the tube which, in their length extension, are in the circumferential direction of the measuring head and thus orthogonal to the longitudinal direction of the tube. In this mode, the coils of the first and third coil arrays are used. In this case, two receiving coils are assigned to a transmitting coil, wherein the transmitting coil and the receiving coil are in different coil arrays, which are separated from one another by an intermediate coil array. This method involves first determining a defect in the heat exchange tube. A differential arrangement is typically used here as described in the cited publication, which is not suitable for determining the layer thickness.
The method shown in US 6,344,739B 1 relates to the inspection of the inner side of heat exchanger tubes, while DE 2746618C 2 describes a method for the external inspection of tubes, wires or the like and a corresponding measuring device. The pipe to be examined is passed through or past a magnetic or magnetically inductive transmitter assembly and is measured by means of leakage-induced or magnetically induced eddy currents. Before the measurement, calibration is carried out with the aid of a test body, wherein the test body is stationary and the transmitter assembly executes an oscillating movement.
Disclosure of Invention
Against this background, the object of the invention is to implement a measuring device of the type mentioned at the outset in such a way that the layer thickness can be measured, wherein at least the probe is virtually not subject to wear and the mechanical effort is kept small. Another task is to provide a method for using such a measuring device or other measuring devices.
In accordance with the invention, a measuring device is provided for determining the layer thickness of a coating applied to a cylindrical recess or a bore of a workpiece, in particular to a cylinder running surface of an internal combustion engine. The measuring device is formed by an at least partially cylindrical probe having a plurality of eddy current sensors distributed over the outer circumference of the probe. Each eddy current sensor is in turn formed by at least one transmitting coil and one receiving coil. The transmitting coil and the receiving coil are arranged separately from one another on the probe in each case in a circumferential coil array at a distance from one another, and the transmitting coil and the associated receiving coil forming the respective eddy current sensor are arranged offset from one another in the circumferential direction. The measuring device also has at least one reference body, which is arranged between the probe head in the rest position and the workpiece to be measured. The reference body furthermore has at least one at least partially cylindrical bore. The probe is thus movable, wherein movement along all three spatial axes is possible. The movement of the probe during the measurement can be initiated from the rest position through the reference body into a cylindrical recess or bore of the workpiece, for example a cylinder of a cylinder crankcase. Correspondingly, movements extending in the opposite direction are possible after the end of the measuring process. The arrangement of the reference body is particularly advantageous in that the probe or the eddy current sensor can be calibrated as required before each measurement. Since no rotation of the probe is required during the measurement, the probe and the reference body as well as the workpiece are virtually not subject to wear, and the mechanical complexity of the probe or of the measuring device is significantly reduced compared to the prior art.
The rest position of the probe may be on the side of the reference body facing away from the workpiece.
Two rows of coils may be distributed around the periphery of the probe, one row containing the transmit coils and the other row containing the receive coils. The coil pairs, i.e. the associated transmitting and receiving coils, which are offset in the circumferential direction of the probe, form an eddy current sensor. On the basis of this arrangement, a centrally located measuring plane (central measuring plane) can be formed in a highly suitable manner, wherein the eddy-current sensor can have its maximum sensitivity at the point where the respective transmitting coil and receiving coil are closest.
By staggering the coil arrays, it is possible to advantageously approximately double the eddy current sensor. One transmitting coil provides the measuring signals for both receiving coils, and one receiving coil can detect the signals of both transmitting coils.
The probe can have 128 coils here, distributed in two rows. There may be 64 transmit coils and 64 receive coils. However, by staggering the coil arrays, 128 eddy-current sensors can be obtained, which have a corresponding number of sensor measuring points, which lie in the middle measuring plane.
The eddy current sensor can thus be designed as a semi-transmission sensor (halbtransmissionsensor).
It is also conceivable for the transmitting coil and the receiving coil forming the eddy current sensor to be retracted radially inward relative to the circumference of the probe. They are thus located inside the probe, whereby contact between the eddy current sensor and the reference body and/or the workpiece can be avoided.
The probe may also be divided into four sections, wherein each section has one quarter of the eddy current sensors distributed over the circumference of the probe. The measurement time can thereby be effectively reduced, since, on the basis of the segmentation, it is possible to read one eddy current sensor per segment and thus to read four eddy current sensors simultaneously.
In addition, these coils, i.e., the transmitting coil and the receiving coil, may be wound around a ferrite core.
Such ferrite cores, which are designed as shell cores, may have a diameter in the range from 1mm to 5mm and/or in particular 3.35 mm.
The pitch of the coil rows and/or the pitch of the coils of the individual rows can be 0.6mm to 3mm and/or in particular 1.75 mm.
A signal processing unit for generating the alternating signals emitted by the individual transmitting coils and for analog signal processing of the measurement signals received by means of the receiving coils can also be arranged on and/or in the probe. Furthermore, at least one analog-to-digital converter is integrated in the signal processing unit, which converts the analog measurement signal into a digital output signal. By arranging the signal processing unit directly on and/or in the probe, the length of the signal lines can be kept short, which reduces the susceptibility to interference effects.
In a particularly advantageous embodiment of the measuring device according to the invention, the outer diameter of the cylindrical probe is smaller than the inner diameter of the bore of the reference body and/or smaller than the inner diameter of the cylindrical recess or bore of the workpiece to be measured. This ensures that the probe does not come into contact with the reference body and/or with the cylindrical recess or bore during the measurement, and thus allows the layer thickness of the coating to be measured without touching it and damage to the reference body can be avoided.
It is furthermore advantageous: the probe is arranged on the probe carrier and the probe is mounted so as to be movable relative to the probe carrier in the radial direction of the probe. Based on this configuration, it is conceivable to compensate for slight misalignments between the probe and the reference body and/or the cylindrical slot or bore of the workpiece. For example, the probe can have a chamfer on the lower side facing the reference body or the workpiece, by means of which the probe enters approximately automatically into the reference body and/or into a cylindrical notch and/or bore of the workpiece.
The probe of the measuring device can thus be supported in a floating manner relative to the probe carrier.
It is possible by this means to compensate for misalignments between the probe and the reference body and/or the cylindrical recess or bore of the workpiece in the range from 0.5mm to 3mm and/or in particular 1 mm.
In a related manner, it is also advantageous to arrange a centering device on or in the region of the probe, which establishes a defined radial direction between the bore of the reference body and/or the cylindrical recess of the workpiece or the bore and the probe. Such a centering device can ensure, for example, that the probe does not come into contact with the reference body and/or with the workpiece when the probe is inserted into the bore of the reference body and/or into the cylindrical recess or bore of the workpiece. Furthermore, a constant distance with small deviations between the bore of the reference body and/or the cylindrical recess or bore of the workpiece and the probe can be ensured.
The centering device can be configured, for example, such that an outlet opening for a gaseous fluid, for example air, is provided on the probe below the eddy current sensor, so that, when the gaseous fluid is discharged, the probe is centered by a corresponding high pressure in the bore of the reference body and/or in the cylindrical slot or bore of the workpiece.
Likewise conceivable is a centering device which comprises an assembly of spheres on the circumference of the probe below the eddy current sensor, wherein the spheres are supported on the probe by means of a counter-force-generating element, for example a spring, and enter partially into the probe.
Furthermore, a brush, in particular an annular brush, which enables centering, is mounted as a centering device below and/or above the probe.
Another possibility for the centering device consists in using supporting webs which are arranged at a distance from one another in the axial direction of the probe and in the circumferential direction of the probe.
A simply designed centering device can be an arrangement of a soft, at least partially circumferential shape on the probe, wherein the outer radius of the shape is greater than the outer radius of the probe.
Soft in this context means that the shape is less hard than the material constituting the reference body and/or the material constituting the coating of the cylindrical notch or perforation of the workpiece. It is conceivable, for example, to use plastic.
Furthermore, according to the invention, a method is provided for measuring the layer thickness of a coating applied to a cylindrical recess or a bore of a workpiece, in particular a coating applied to a cylinder running surface of an internal combustion engine, by means of a probe arranged in a measuring device. The probe of the measuring device has a plurality of eddy current sensors distributed over the circumference, which are formed by at least one transmitting coil and at least one receiving coil. Importantly, the method comprises the following steps: the eddy current sensors measure the layer thickness of the coating in any desired sequence, or sequentially in a circumferential sequence, or simultaneously during the measuring process. It is thus conceivable, for example, to replace the layer thickness measurement by mechanical rotation of a single eddy current sensor with a measurement by eddy current sensors distributed over the circumference of the probe. The layer thickness of the coating of the cylindrical slot or the bore of the workpiece can thus be determined at the corresponding axial position of the probe.
Preferably, eddy current sensor measurements carried out one after the other in the circumferential sequence can be carried out. Thus, the mechanical rotation of a single eddy current sensor is approximately replaced by the electronic rotation of multiple eddy current sensors.
The layer applied to the cylindrical slots or perforations of the workpiece may be composed of a ferromagnetic material having a permeability greater than one, while the workpiece is composed of a non-ferrous metal, such as aluminum or an aluminum alloy.
It is possible here for the frequency of the alternating signal for generating eddy currents in the layer to be detected to be in the range from 1kHz to 100kHz and/or in particular to be 20 kHz. This ensures that the eddy currents penetrate into the preferably ferromagnetic coating to a depth of up to 500 micrometers, in particular up to 200 micrometers.
The method according to the invention can also be designed such that the probe of the measuring device performs a linear movement in the axial direction, i.e. perpendicular to its circumference, during the measurement. The linear movement allows the layer thickness of the coating of the cylindrical slot or hole of the workpiece to be determined over the entire length of the slot or hole and to be shown continuously.
In a particularly advantageous embodiment of the method: the eddy current sensors arranged in the probe of the measuring device, which are each formed by at least one transmitting coil and at least one receiving coil, are calibrated in a two-stage calibration process using a calibration body and a reference body. It can be advantageous here to: parameters which influence the measurement of the layer thickness, such as the different distances of the eddy current sensor from the cylindrical slot or through-hole to be measured, the layer thickness of the coating to be measured, the aging effect and the temperature effect, the behavior of the eddy current sensor in air and the materials used for the coating and the workpiece, are determined.
The first phase of the calibration can be carried out here by means of a calibration body. This is done once. The second phase of the calibration can be performed with the aid of a reference body, wherein this is performed before each measurement.
Furthermore, the quality of the measurement result can be influenced decisively if the probe used for the measurement passes through the reference body before and/or after the layer thickness of the coating is measured. The aging effects occurring during the time in which the eddy-current sensor is used and the influence of the temperature on the measurement signal can thereby be compensated for. That is, an adaptation to the original characteristic curve field of the eddy current sensor can be made.
It is relevant to the reality that: before a measurement is carried out for the first time with a newly manufactured probe or a modified probe, the characteristic curve fields of the individual eddy current sensors arranged in the probe, which are formed by at least one transmitting coil and at least one receiving coil, are received at least once by means of the calibration body. This makes it possible to determine the original characteristic curve field of the eddy current sensor arranged in the probe, which is not influenced by aging effects, for example, and thus to carry out precise measurements.
Furthermore, it is advantageous from a technical point of view that the influence of the parameters influencing the measurement is taken into account by means of the determined characteristic field of the eddy current sensor of the probe. The parameter can be, for example, the behavior of the eddy current sensor in air, the influence of the measured values on the material of the coating and the workpiece, the relationship of the measured signal to the thickness of the coating, or the distance between the probe or eddy current sensor and the cylindrical slot or bore of the workpiece to be measured.
It is of utmost importance in the implementation of the method that the probe of the measuring device does not come into contact with the cylindrical slot or bore of the workpiece during the measuring process.
According to the invention, a reference body of the measuring device is also provided, wherein the reference body has at least two contour rings made of different materials.
The contour rings of the reference body can each have a perforation, which forms at least part of the perforation of the reference body.
The perforations of the individual contour rings can have the same inner diameter over the length of the perforations.
The inner diameters of the perforations of the profile ring can be associated with equal heights.
It is likewise conceivable for the individual profile ring segments to have at least two mutually different inner diameters.
Furthermore, it is possible that the inner diameter of the profile ring differs from profile ring to profile ring.
The different materials may be, in particular, aluminum or aluminum alloys and steel.
The reference body may have a cover plate and a base plate, which are connected by a fixing means.
The contour rings of the reference body can also be arranged between the cover plate and the base plate, wherein the contour rings can be connected to one another and/or to the cover plate and the base plate in a non-positive and/or positive manner.
Furthermore, according to the invention, a calibration body for calibrating an eddy current sensor arranged in a probe of a measuring device is provided, which eddy current sensor is formed by at least one transmitting coil and at least one receiving coil. The calibration body has a slot or a bore for receiving the probe and has at least two, in particular four, sections which are configured in the form of ring segments. By means of this particularly advantageous configuration of the calibration body, the characteristic curves of all eddy current sensors of the probe distributed over the circumference can be received in a simple manner at once. It is possible that this is achieved by a relative rotational movement of the probe and the calibration body, when the probe is surrounded by the calibration body at least in the radial direction.
A particularly advantageous development of the calibration body consists in: the inner sides of the individual segments facing the probe are provided with a coating, wherein the layer thicknesses of the coatings of the individual segments differ from one another. The influence of different layer thicknesses of the coating on the measurement signal can thus be determined.
It is also to be considered extremely expedient for the segments of the calibration body to be arranged in such a way that the spacing of the inner sides of the individual segments facing the probe, which spacing is formed in the radial direction relative to the spacing of the periphery of the probe, changes continuously in the circumferential direction of the probe. The method can advantageously be used to determine the influence of different distances between the eddy current sensor and the cylindrical slot or perforation to be measured.
It is also to be noted that an extremely advantageous configuration is: the calibration body consists of the same material as the coating to be measured.
Drawings
The invention is susceptible of embodiments. For the purpose of illustrating the general principles thereof, one of the embodiments is shown in the drawings and will be described hereinafter. The figures show:
FIG. 1 is a schematic view of a measuring device according to the present invention;
FIG. 2a is a schematic illustration of an embodiment of a reference body according to the invention;
FIG. 2b is a schematic illustration of an additional embodiment of a reference body according to the invention;
FIG. 3 is a schematic view of a calibration body according to the present invention;
FIG. 4 is a schematic partial view of an arrangement of eddy current sensors.
Detailed Description
Fig. 1 schematically shows a measuring device 1 for determining the layer thickness of a coating 4 applied to a cylindrical bore 2 of a workpiece 3, which is embodied in the figure as an internal combustion engine. The measuring device 1 is formed by an at least partially cylindrical probe 5, wherein a plurality of eddy current sensors 7 are distributed on an outer circumference 6 of the probe 5.
Each eddy-current sensor 7 is formed here by a transmitting coil 8 and a receiving coil 9. The transmission coil 8 and the reception coil 9 are arranged on the probe 5 separately from one another, in each case in the form of a circumferential coil array 10 at a distance from one another. The transmitting coils 8 and the associated receiving coils 9 forming the respective eddy current sensors 7 are arranged offset from one another in the circumferential direction (arrow direction) 11.
Fig. 1 furthermore shows a reference body 12 of the measuring device 1, which is located between the probe 5 in the rest position P and the workpiece 3 to be measured. The reference body 12 has a sectionally cylindrical bore 13 and has two contour rings 19.
The outer diameter 14 of the probe 5 is smaller than the inner diameter 15 of the bore 13 of the reference body 12 and smaller than the inner diameter 16 of the cylindrical bore 2 of the workpiece 3 to be measured.
The probe 5 of the measuring device 1 is arranged on a probe carrier 17, wherein the probe 5 is mounted so as to be movable relative to the probe carrier 17 in a radial direction R of the probe 5.
Furthermore, a centering device 24 is arranged on the probe 5, which establishes a defined radial distance between the bore 13 of the reference body 12 and the bore 2 of the workpiece 3 and the probe 5. The centering device 24 is configured here, for example, in such a way that an outlet opening 28 for a gaseous fluid, for example air, is provided on the probe 5 below the eddy current sensor 7, so that the probe 5 is centered by the correspondingly high pressure in the bore 13 of the reference body 12 and in the bore 2 of the workpiece 3 when the gaseous fluid is discharged.
Fig. 2a schematically shows a first embodiment of a reference body 12 according to the invention, wherein the reference body 12 has two profile rings 19 of different materials, for example aluminum or an aluminum alloy and steel. The contour rings 19 each have a perforation 32, which forms part of the perforation 13 of the reference body. The perforations 32 of the individual contour rings 19 have an equal inner diameter 20 over the length of the perforations 32, wherein the inner diameters 20 are of the same height.
Fig. 2b schematically shows a second embodiment of a reference body 12 according to the invention, wherein the reference body 12 has two contour rings 19 made of different materials, for example aluminum or aluminum alloys and steel, and each contour ring 19 has at least two inner diameters 20, 21 that are different from one another in sections.
The reference body also has a cover plate 25 and a base plate 26, which are connected by means of a fixing device 27.
The contour rings 19 of the reference body 12 are arranged between the cover plate 25 and the base plate 26, wherein the contour rings 19 are connected to one another and to the cover plate 25 and the base plate 26 in a non-positive and positive manner by means of fastening means 27.
Furthermore, the calibration body 18 is schematically shown in fig. 3. The calibration body 18 serves for calibrating the eddy-current sensor 7 arranged in the probe 5, wherein the calibration body 18 has a bore 22 for receiving the probe 5 and four sections 23, which are configured in the form of ring segments.
The inner sides 29 of the individual segments 23 facing the probe 5 are provided with the coating 4, wherein the layer thicknesses of the coating 4 of the individual segments 23 differ from one another.
The segments 23 of the calibration body 18 are designed in such a way that the radially formed spacing of the inner sides 29 of the individual segments 23 facing the probe 5 relative to the circumference 6 of the probe 5 changes continuously in the circumferential direction 11 of the probe 5.
Fig. 4 also shows the arrangement of an eddy current sensor 7, which is formed by a transmitting coil 8 and a receiving coil 9. The transmitting and receiving coils are arranged in the form of two coil arrays 10 in such a way that the lower coil array 10 shown contains the transmitting coil 8 and the upper coil array 10 shown contains the receiving coil 9. The coil rows 10 are arranged offset from one another in the circumferential direction (arrow direction) 11, which is shown for simplicity.
This results in one transmitting coil 8 supplying the two receiving coils 9 with the measuring signal, while one receiving coil 9 again detects the signals of the two transmitting coils 8.
By staggering the coil arrays 10, a plurality of sensor measuring points 30 are obtained, which lie in a central measuring plane 31, the number of sensor measuring points corresponding to the number of eddy current sensors 7 present, or the number of transmitting coils 8 and receiving coils 9. The sensor measurement points 30 shown in dashed lines in fig. 4 reflect the same sensor measurement points 30 connected in phantom.
List of reference numerals
1 measuring device 26 base plate
2 notch or perforation 27 securing means
3 workpiece 28 discharge opening
4 coating 29 inside
5 Probe 30 sensor measuring point
6 peripheral 31 measuring plane
7 eddy current sensor 32 perforation
8 sending coil
9 rest position of receiving coil P
10 coil array R radial
11 circumferential direction
12 reference body
13 perforation
14 outer diameter
15 inner diameter
16 inner diameter
17 Probe carrier
18 calibration body
19 profile ring
20, 21 internal diameter
22 perforation
23 section (C)
24 centering device
25 cover plate
Claims (13)
1. A measuring device (1) for determining the layer thickness of a coating (4) applied to a cylindrical slot or a bore (2) of a workpiece (3), comprising an at least partially cylindrical probe (5) having a plurality of eddy current sensors (7) distributed over the outer circumference (6) of the probe (5), wherein each eddy current sensor (7) comprises at least one transmitting coil (8) and one receiving coil (9), wherein the transmitting coil (8) and the receiving coil (9) are arranged separately from one another, in each case in the form of a mutually spaced-apart, circumferential coil array (10), on the probe (5), and wherein the transmitting coil (8) and the associated receiving coil (9) forming each eddy current sensor (7) are offset from one another in the circumferential direction (11), the measuring device (1) has at least one reference body (12) which is arranged between the probe (5) and the workpiece (3) to be measured when the probe (5) is in the rest position, and the reference body (12) has at least one at least partially cylindrical bore (13), and the reference body (12) has two contour rings (19) made of different materials, the two contour rings (19) each having a bore (32) which forms part of the bore (13) of the reference body (12).
2. A measuring device (1) according to claim 1, characterized in that the coating is a coating (4) on a cylinder face of an internal combustion engine.
3. The measuring device (1) according to claim 1, characterized in that the outer diameter (14) of the cylindrical probe (5) is smaller than the inner diameter (15) of the bore (13) of the reference body (12) and smaller than the inner diameter (16) of the cylindrical notch or bore (2) of the workpiece (3) to be measured.
4. Measuring device (1) according to one of claims 1 to 3, characterized in that the probe (5) is arranged on a probe carrier (17) and in that the probe (5) is supported movably relative to the probe carrier (17) in a radial direction R of the probe (5).
5. A method for measuring the layer thickness of a coating (4) applied to a cylindrical slot or a through-hole (2) of a workpiece (3) by means of a probe (5) arranged in a measuring device (1), characterized in that the probe (5) of the measuring device (1) has a plurality of eddy current sensors (7) distributed over an outer circumference (6) and formed by at least one transmitting coil (8) and at least one receiving coil (9), wherein the eddy current sensors (7) perform a measurement of the layer thickness of the coating (4) in any sequence during the measuring process, wherein the measuring device (1) has at least one reference body (12) which is arranged between the probe (5) and the workpiece (3) to be measured when the probe (5) is in a rest position, and the reference body (12) has at least one through-hole (13) which is cylindrical at least in sections, the reference body (12) also has two contour rings (19) made of different materials, wherein the two contour rings (19) each have a perforation (32) that forms part of the perforation (13) of the reference body (12).
6. The method of claim 5, wherein the coating is a coating applied to a cylinder face of an internal combustion engine.
7. Method according to claim 5, characterized in that eddy current sensors (7) arranged in a probe (5) of the measuring device (1) are calibrated in a two-stage calibration process using a calibration body (18) and a reference body (12), which eddy current sensors are each formed by at least one transmitting coil (8) and at least one receiving coil (9).
8. Method according to any of claims 5-7, characterized in that a probe (5) for measuring is passed through the reference body (12) before and/or after measuring the layer thickness of the coating (4).
9. Method according to any one of claims 5 to 7, characterized in that the characteristic curve field of the respective eddy current sensor (7) arranged in the probe (5) is received at least once by means of a calibration body (18) before a measurement is performed for the first time with a newly manufactured probe (5) or a modified probe (5), the eddy current sensor being formed by at least one transmitting coil (8) and at least one receiving coil (9).
10. Method according to claim 9, characterized in that the influence of the parameters influencing the measurement is taken into account by means of the determined characteristic curve field of the eddy current sensor (7) of the probe (5).
11. Method according to any one of claims 5-7, 10, characterized in that during the measuring process the eddy current sensors (7) perform measuring the layer thickness of the coating (4) sequentially or simultaneously in circumferential direction (11).
12. Calibration body (18) for calibrating an eddy current sensor (7) arranged in a probe (5) of a measuring device (1) according to at least one of claims 7 to 11, which eddy current sensor is formed by at least one transmitting coil (8) and at least one receiving coil (9), characterized in that the calibration body (18) has a slot or a bore (22) for receiving the probe (5) and has at least two sections (23), which are configured in the form of ring sections.
13. The calibration body (18) according to claim 12, wherein the at least two sections (23) are four sections (23).
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE102016205495.3A DE102016205495B4 (en) | 2016-04-04 | 2016-04-04 | Measuring device and method for determining layer thickness and associated reference body and calibration body |
| DE102016205495.3 | 2016-04-04 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107270809A CN107270809A (en) | 2017-10-20 |
| CN107270809B true CN107270809B (en) | 2020-08-04 |
Family
ID=59885868
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710202540.1A Active CN107270809B (en) | 2016-04-04 | 2017-03-30 | Measuring device and method for determining a layer thickness, and corresponding reference body and calibration body |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN107270809B (en) |
| DE (1) | DE102016205495B4 (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108317945A (en) * | 2018-03-13 | 2018-07-24 | 卢曼斯 | The method of engine fuel inner product carbon thickness detection |
| DE102019113277A1 (en) * | 2019-05-20 | 2020-11-26 | Tekon-Prüftechnik GmbH | Test adapter |
| CN110307776B (en) * | 2019-08-06 | 2024-03-26 | 无锡市帕尔斯仪器有限公司 | Hole surface copper integrated thickness measuring device and thickness measuring method of five-terminal micro-resistor |
| CN110553616B (en) * | 2019-10-08 | 2021-05-04 | 江西洪都航空工业集团有限责任公司 | Method for measuring thickness of special-shaped surface coating |
| CN111043975A (en) * | 2019-12-30 | 2020-04-21 | 中核北方核燃料元件有限公司 | Eddy current detection device for detecting thickness of inner cladding of tubular fuel element |
| CN115331506A (en) * | 2022-07-19 | 2022-11-11 | 国能大渡河大岗山发电有限公司 | Simulation training method and device for power grid equipment of hydraulic power plant, medium and electronic equipment |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4425545A (en) * | 1981-07-27 | 1984-01-10 | Scalese Joseph J | Eddy current probe calibration standard |
| CN1207493A (en) * | 1998-09-04 | 1999-02-10 | 清华大学 | Method and apparatus for non-contact measuring thickness of non-metal coating on surface of metal matrix |
| US6288537B1 (en) * | 1999-12-22 | 2001-09-11 | General Electric Company | Eddy current probe with foil sensor mounted on flexible probe tip and method of use |
| US6344739B1 (en) * | 1999-02-12 | 2002-02-05 | R/D Tech Inc. | Eddy current probe with multi-use coils and compact configuration |
| CN101460808A (en) * | 2006-05-31 | 2009-06-17 | 西门子公司 | Method for determining the layer thickness of an electrically conductive coating on an electrically conductive substrate |
| CN101788260A (en) * | 2010-03-18 | 2010-07-28 | 清华大学 | Eddy current measuring method of thickness of metal film |
| JP3165804U (en) * | 2010-07-12 | 2011-02-10 | 株式会社検査技研 | Eddy current testing probe for tube end inspection |
| CN101978486A (en) * | 2008-04-17 | 2011-02-16 | 诺发系统股份有限公司 | Methods and apparatuses for determining thickness of a conductive layer |
| CN103411744A (en) * | 2013-07-26 | 2013-11-27 | 浙江大学 | Electric eddy transducer dynamic calibration device |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2746618C2 (en) | 1977-10-15 | 1986-01-30 | Institut Dr. Friedrich Förster Prüfgerätebau GmbH & Co KG, 7410 Reutlingen | Process and device for testing elongated metallic test material for defects |
| EP2864771A1 (en) | 2012-06-21 | 2015-04-29 | Eddyfi NDT Inc. | High resolution eddy current array probe |
-
2016
- 2016-04-04 DE DE102016205495.3A patent/DE102016205495B4/en active Active
-
2017
- 2017-03-30 CN CN201710202540.1A patent/CN107270809B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4425545A (en) * | 1981-07-27 | 1984-01-10 | Scalese Joseph J | Eddy current probe calibration standard |
| CN1207493A (en) * | 1998-09-04 | 1999-02-10 | 清华大学 | Method and apparatus for non-contact measuring thickness of non-metal coating on surface of metal matrix |
| US6344739B1 (en) * | 1999-02-12 | 2002-02-05 | R/D Tech Inc. | Eddy current probe with multi-use coils and compact configuration |
| US6288537B1 (en) * | 1999-12-22 | 2001-09-11 | General Electric Company | Eddy current probe with foil sensor mounted on flexible probe tip and method of use |
| CN101460808A (en) * | 2006-05-31 | 2009-06-17 | 西门子公司 | Method for determining the layer thickness of an electrically conductive coating on an electrically conductive substrate |
| CN101978486A (en) * | 2008-04-17 | 2011-02-16 | 诺发系统股份有限公司 | Methods and apparatuses for determining thickness of a conductive layer |
| CN101788260A (en) * | 2010-03-18 | 2010-07-28 | 清华大学 | Eddy current measuring method of thickness of metal film |
| JP3165804U (en) * | 2010-07-12 | 2011-02-10 | 株式会社検査技研 | Eddy current testing probe for tube end inspection |
| CN103411744A (en) * | 2013-07-26 | 2013-11-27 | 浙江大学 | Electric eddy transducer dynamic calibration device |
Also Published As
| Publication number | Publication date |
|---|---|
| CN107270809A (en) | 2017-10-20 |
| DE102016205495A1 (en) | 2017-10-05 |
| DE102016205495B4 (en) | 2022-06-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107270809B (en) | Measuring device and method for determining a layer thickness, and corresponding reference body and calibration body | |
| EP2524210B1 (en) | Eddy current measuring sensor and inspection method using this eddy current measuring sensor | |
| US8151636B2 (en) | Device for measuring the axial position of a piston rod relative to a cylinder housing | |
| CA2766462C (en) | Apparatus and method for measuring deposits inside a tube | |
| KR101729039B1 (en) | Pipeline Inspection Tool with Double Spiral EMAT Sensor Array | |
| US10823702B2 (en) | Built-in S-typed array eddy current testing probe and method for detecting defects of tubular structure | |
| WO2019232546A1 (en) | An eddy current probe with 3-d excitation coils | |
| US7876096B2 (en) | Detecting failures in flexible multistrand steel structures | |
| EP2098860B1 (en) | Eddy current testing method | |
| JP4101110B2 (en) | Eddy current flaw detection sensor | |
| CN109459488A (en) | Continuous pipe on-line measuring device | |
| JP3682027B2 (en) | Motor core inner diameter measuring apparatus and method | |
| CN112067690B (en) | Inclined axial array annular eccentric eddy current probe and method for small-diameter pipe detection | |
| US6281678B1 (en) | Tri-tip probe | |
| CN100392391C (en) | Inside-through type low frequency electromagnetic detection sensor | |
| US6972560B2 (en) | Method for detecting a change in permeability of a magnetostrictive object | |
| JP4552953B2 (en) | Cylinder block machining method and apparatus used therefor | |
| JPS5818603B2 (en) | Fushiyokusonmodokenshiyutsusouchi | |
| CN108760896B (en) | Circular pipeline internal detection electromagnetic ultrasonic flaw detection transducer structure | |
| CN116399941A (en) | Eddy current detection system and method for conductive spherical structure | |
| CN111879852B (en) | Interpolation type TR probe and method for eddy current testing of tubular structure | |
| JP5145073B2 (en) | Eddy current flaw detection method and eddy current flaw detection apparatus | |
| CN114113298A (en) | Electromagnetic sensor for detecting defects of winding type fiber bottle | |
| CN114754664A (en) | Device and method for measuring dynamic deformation of cylinder sleeve by using eddy current sensor | |
| KR100466122B1 (en) | Cylinder bore roundness measuring method of engine in vehicle |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |