KR101658120B1 - Method and apparatus for maintaining acuracy of measured quality in depth measurement of welded sections using ultrasonic waves - Google Patents

Method and apparatus for maintaining acuracy of measured quality in depth measurement of welded sections using ultrasonic waves Download PDF

Info

Publication number
KR101658120B1
KR101658120B1 KR1020150053021A KR20150053021A KR101658120B1 KR 101658120 B1 KR101658120 B1 KR 101658120B1 KR 1020150053021 A KR1020150053021 A KR 1020150053021A KR 20150053021 A KR20150053021 A KR 20150053021A KR 101658120 B1 KR101658120 B1 KR 101658120B1
Authority
KR
South Korea
Prior art keywords
depth
value
probe
welding
welded
Prior art date
Application number
KR1020150053021A
Other languages
Korean (ko)
Inventor
박봉수
Original Assignee
(주)피앤에스
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by (주)피앤에스 filed Critical (주)피앤에스
Priority to KR1020150053021A priority Critical patent/KR101658120B1/en
Application granted granted Critical
Publication of KR101658120B1 publication Critical patent/KR101658120B1/en

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
    • G01N29/04—Analysing solids
    • G01N29/043—Analysing solids in the interior, e.g. by shear waves
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B17/00—Measuring arrangements characterised by the use of infrasonic, sonic or ultrasonic vibrations
    • G01B17/02—Measuring arrangements characterised by the use of infrasonic, sonic or ultrasonic vibrations for measuring thickness
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
    • G01N29/22—Details, e.g. general constructional or apparatus details
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
    • G01N29/22—Details, e.g. general constructional or apparatus details
    • G01N29/26—Arrangements for orientation or scanning by relative movement of the head and the sensor
    • G01N29/265—Arrangements for orientation or scanning by relative movement of the head and the sensor by moving the sensor relative to a stationary material
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
    • G01N29/44—Processing the detected response signal, e.g. electronic circuits specially adapted therefor
    • G01N29/4409—Processing the detected response signal, e.g. electronic circuits specially adapted therefor by comparison
    • G01N29/4427—Processing the detected response signal, e.g. electronic circuits specially adapted therefor by comparison with stored values, e.g. threshold values
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2291/00—Indexing codes associated with group G01N29/00
    • G01N2291/02—Indexing codes associated with the analysed material
    • G01N2291/023—Solids
    • G01N2291/0234—Metals, e.g. steel
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2291/00—Indexing codes associated with group G01N29/00
    • G01N2291/26—Scanned objects
    • G01N2291/267—Welds
    • G01N2291/2675—Seam, butt welding

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Biochemistry (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Health & Medical Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Acoustics & Sound (AREA)
  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)

Abstract

An inspection apparatus using ultrasonic waves, according to the present invention, measures the welded depths from the top ends of the welded surfaces of welded objects in multiple positions, and then calculates the average value of the welded depths to set the calculated individual average value as a reference value. Then, the inspection apparatus measures the welded depths of other objects in multiple positions and calculates the average values of the welded depths to calculate the difference between the value obtained by averaging the calculated average values and the set reference value. If the calculated difference is out of a predetermined limit, the inspection apparatus generates a visual or acoustic signal where a user can recognize to inform the user that the measured welded depths have the possibility of errors.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for maintaining the accuracy of measurement quality in measuring depth of a welded portion using ultrasonic waves,

TECHNICAL FIELD The present invention relates to a method and apparatus for ultrasonic measurement of a welded portion of an article to be used as a part or the like in a mechanical device or an automobile to confirm the welded quality.

Numerous mechanical parts are used in automobiles and mechanical devices. Some of these mechanical parts are made by welding a plurality of cast or processed base materials. It is also common that the base materials are welded together and made into one complete part by automation to reduce the production cost.

However, since the stability and / or reliability of the machine parts produced in this way are also affected by the quality of the welded parts, it is necessary to check the quality of the welded parts by the automatic equipment. Particularly, in the case of parts used for automobiles and the like, the necessity thereof is very high, so that the quality of the welded part is generally checked for the part having the welded part.

As a general method for checking whether there is an abnormality in the weld quality, that is, whether defects such as bubbles or cracks are present in the welded area, it is necessary to periodically measure the parts sampled at, for example, There is a destructive inspection which checks the welding condition of the parts automatically produced in the manufacturing line by confirming the welding quality of the broken parts by destroying them.

However, such destructive inspection has a disadvantage that production cost is increased due to disposal of the manufactured parts, and quality inspection by periodic sampling, so that the welding state can not be confirmed with respect to the whole parts. Furthermore, even if a part produced during the sampling irradiation time is abnormal due to a change in characteristics of the production / production line (for example, temperature, humidity, etc.) or a slight vibration on the production / production line, no method.

The above problems caused by destructive inspection can be solved by using a nondestructive inspection which confirms the quality of a welded part of a produced part or the like by using ultrasonic waves. Such non-destructive inspection by the ultrasonic inspection method can easily and easily check whether there is an abnormality in welding of parts or the like.

A welding quality inspection method using ultrasonic waves will be described in more detail. After an ultrasonic inspection apparatus is installed on a manufacturing line of parts and the like, ultrasonic waves are incident on an object to be inspected having a welded part, for example, a produced part. Then, when a part of ultrasonic waves propagates into the object to be inspected, and there is welding abnormality due to bubbles, cracks, or the like in the welded part, the part of the propagation signal is reflected at that part and returned. The ultrasonic inspection apparatus analyzes the intensity of the reflected signal (hereinafter, referred to as 'echo signal') to check whether there is an abnormality in the welded portion in real time.

However, it is very easy to confirm whether there is an abnormality such as bubbles or cracks in a portion welded through such ultrasonic inspection. However, according to the known technology to date, there is no method of accurately measuring the depth of a welded portion. For example, as illustrated in Fig. 1, a method of precisely measuring the depth 11 of the welded portion 10 using ultrasonic waves when the joint faces of the base materials 1a and 1b are welded is known It is not.

In the case of parts used for mechanical devices and automobiles, up to now, only welding parts of the parts have been required to have a depth greater than a certain level for the bonding force between the two base materials. In recent years, however, it has been found that if the depth exceeds a certain level, the rigidity of the welded portion becomes excessively higher than the rigidity of the welded material itself, which causes a problem in a particular situation. Therefore, it is very important to accurately measure the depth to which the part is welded, in addition to the presence of bubbles or cracks in the welded part of the part using ultrasonic waves It was highlighted. It is also very important to always maintain correct measurement results despite environmental changes (for example, seasonal average temperature changes, etc.) at manufacturing / production sites that inspect welding quality of parts and the like.

An object of the present invention is to provide a method and an apparatus for accurately measuring a depth of a weld to a welded portion of an object to be inspected.

Another object of the present invention is to provide a method and an apparatus for quickly measuring whether or not an object to be inspected has an abnormality in the depth of the welded portion.

It is a further object of the present invention to provide a method and apparatus for adaptively changing measurement conditions so that the accuracy of measurement of the weld depth of an object to be inspected can be maintained.

It is to be understood that the object of the present invention is not limited to the explicitly stated objects, but, of course, it is an object of the present invention to achieve the effect which can be derived from the following specific and exemplary description of the present invention.

According to an aspect of the present invention, there is provided an apparatus for inspecting a welded state of an object formed by welding a joint surface of both materials by using ultrasonic waves, the ultrasonic wave being transmitted to the joint surface of the object at a distance from the object, A moving part for moving the probe part in the space according to a signal to be applied; and a controller for controlling the probe to move the probe in an initial state with respect to the object through the moving part, Position of the object to be inspected is moved to a position where the probe is moved in the vertical direction relative to the object at the initial position and based on the intensity of the reflected signal detected by the detection operation, An inspection operation for measuring the depth of the weld with respect to the positions on the plane and obtaining the average weld depth with respect to the positions , And the other objects having the same shape as the object other than the object are also individually measured to obtain a plurality of average welding depths, and an average value of the plurality of average welding depths is calculated. The difference between the calculated average value and a predetermined reference value And a control unit configured to generate a visual or audible signal that can be perceived by the user if the predetermined limit is exceeded. Here, the reference value may correspond to an average value calculated for a plurality of average weld depths obtained by the controller performing the inspection operation on objects having the same shape as the object before the object and the other objects do.

In an embodiment according to the present invention, in performing the inspection operation, the control unit may determine whether a portion of the joint surface that is deeper than the depth corresponding to the first limit from the top of the joint surface is vertical And the second gap is wider than the first gap. In the present embodiment, the second gap is determined based on the difference between the designated second limit and the first limit. Here, the second limit value is a value used as a criterion to be determined as a weld defect if the weld depth exceeds the value.

In one embodiment of the present invention, each time the inspection operation is sequentially performed one by one on the other objects, or each time the inspection operation is performed on new objects corresponding to a predetermined number, And compares it with the reference value.

In an embodiment according to the present invention, the control unit may reset the reference value as an average value of a plurality of average welding depths obtained from objects for which the inspection operation is performed after a request from the user, if any, do.

In an embodiment according to the present invention, the initial position may be a position that is the same height as the upper end of the bonding surface, or that is higher than the depth corresponding to the designated second limit, It corresponds to a point deeper than the gap. In the present embodiment, the initial position is a position located after the transducer movement corresponding to the values of the horizontal and vertical movement distances set in the control section, and the vertical movement distance value is a position of the third The welding depth determined by the signal intensity detected by the test operation after the test operation is performed in a direction perpendicular to the welded joint surface of the object and the actual depth measured by cutting the joint surface of the third object It is a value that is corrected according to the comparison result after comparing the welding depth. The vertical moving distance value may be a value obtained by dividing the vertical direction moving distance of the test piece with respect to the test sample in which a hole is formed on a side surface of any depth so that the reflection intensity of the ultrasonic wave incident from the probe is different from the adjacent area. And is determined based on the pattern of the signal detected through the above-described flaw detection operation. The initial determination is performed such that the vertical distance from the probe to the groove is equal to the vertical distance to the upper end of the bonding surface when the probe is subjected to the inspection operation with respect to the object, Based on the resultant signal pattern of the test operation with respect to the EUT in the mounted state.

In one embodiment of the present invention, when the probing operation by the probe section along a curve or a straight line at the same depth from the upper end of the joint surface is completed, the control section controls the probe to vertically Down or up.

In an embodiment according to the present invention, if it is determined that the weld depth is less than the first threshold value or the second threshold value is exceeded, the control unit determines that the welding condition is defective for the object And outputs a visual or audible signal indicating that the welding is defective.

According to another aspect of the present invention, there is provided a method of inspecting a welding state of an object formed by welding a joint surface of both materials using ultrasonic waves, comprising the steps of: A step of transmitting an ultrasonic wave to the joint surface and detecting a change in intensity of a reflected signal according to the transmitted ultrasonic wave to obtain weld depths from the upper end of the joint surface and then calculating an average value of the depths; And a second step of setting a value obtained by averaging the average values individually calculated for each of the plurality of objects, as a reference value, at least two or more coplanar positions for each of the other objects, And detects a change in the intensity of a reflected signal according to the transmitted ultrasonic waves to obtain weld depths from the top of the joint surface, A difference between a value obtained by averaging the individually averaged values in the step 3 and the set reference value is obtained and if the difference exceeds the predetermined limit, And generating a visual or auditory signal that is present in the subject.

In the apparatuses, methods and embodiments described above, the abutment surface may have a circumferential surface, a square or any curved shape.

At least one embodiment of the present invention described in detail above with reference to the present invention or the accompanying drawings will be described in detail with reference to the accompanying drawings. In the ultrasonic quality inspection for the conventional welding surface, I will. That is, when welding depth is shorter or deeper than required, ultrasonic waves are used to detect whether or not the welding object is defective with respect to the object to be inspected such as a part used in a mechanical device or automobile. Therefore, the quality of the manufactured or produced parts is further improved as compared with the prior art.

Then, based on the average value of the welding depths obtained by measuring the objects to be inspected at an early stage when the object to be inspected for welding quality is changed or at a certain point during the course of the welding quality inspection for the same object, By allowing the operator to know how much the average value of the welding depths of the objects to be inspected in real time is out of order, it is possible to measure the welding depth constantly by the environmental change (temperature, humidity, continuous vibration, etc.) Thereby preventing the error from being introduced in advance. Thus, by continuously grasping and providing the fluctuation of the average value of the welding depths to the objects to be inspected, the accuracy of the welding depth measurement on the object to be inspected of the ultrasonic inspection apparatus is always Can be maintained.

Further, in one embodiment of the present invention, by checking the accuracy of ultrasonic flaw detection based on the minimum depth required as the welding quality in inspecting whether or not the welding depth is bad for an object to be inspected, Ensure that the weld quality inspection is performed more quickly. As a result, the total time required for the quality inspection of the inspection object manufactured or produced in the industrial field can be shortened, thereby improving the quality of the inspection object such as parts and improving the productivity.

Fig. 1 schematically shows a cross-section of a welded portion to a joint surface of a mother material having a material such as a metal,
2 is a diagram illustrating a configuration of an ultrasonic inspection apparatus according to an embodiment of the present invention for inspecting a welded portion of a base material with ultrasonic waves and checking the abnormality,
Fig. 3 is a perspective view and a cross-sectional view exemplarily showing that a circumferential surface in which two materials abut each other is welded to be a finished part,
4A and 4B show a flow chart of a method of measuring the welding depth of a welded object to be welded using a ultrasonic wave, the welded part forming a circumferential surface, according to an embodiment of the present invention,
5 is a graph showing the relative initial position of a probe relative to an object to be inspected which must be specified in order to accurately measure the welding depth of the object to be inspected and the spatial initial position set for moving the probe to the initial position, It is a graphical representation of the distance,
FIG. 6 is a graph showing the relationship between the actual initial position of the probe and the reference position of the probe in the test ultrasonic measurement environment in order to set the relative initial position of the probe relative to the probe, according to an embodiment of the present invention. FIG. 2 is a view schematically showing the installation according to the same condition as the measurement position condition,
FIG. 7 is a graph showing a relationship between an echo signal pattern obtained by ultrasonic flaw detection in a test ultrasonic measurement environment for a measurement sample prepared according to an embodiment of the present invention, The horizontal and vertical moving distance values for the first, second,
8A and 8B illustrate a vertical / horizontal movement distance set for moving a probe to an initial position for an object to be inspected, through a test ultrasonic measurement on the object to be inspected in an actual production environment, according to an embodiment of the present invention. Values are corrected, respectively,
FIG. 9 is a schematic view of an entire system constructed when an ultrasonic inspection apparatus constructed according to an embodiment of the present invention is installed in a field and an object to be inspected is automatically mounted on a measurement position for inspection of welding quality,
10 illustrates an example of a measurement data table constructed from the intensity of an echo signal obtained by ultrasonic inspection of test points on the same plane for each depth with respect to an object to be inspected according to an embodiment of the present invention,
11 shows an example of a measurement distribution table in which an average of the detected welding depths is recorded for each inspection object in order to determine the accuracy of the depth measurement in the ultrasonic inspection according to an embodiment of the present invention,
FIG. 12 is a graph showing a relationship between an average value of the welding depths obtained by measuring the object to be inspected selected as a sample and an average of the welding depths of the objects to be inspected in real time, FIG. 2 is a view showing an example of displaying an image,
13A and 13B are diagrams illustrating each example showing how to select a group of inspected objects to calculate the weld depth average in real time in accordance with embodiments of the present invention,
FIG. 14 is a graph showing the relationship between the depth and the depth of a welded portion of a test object mounted for inspection according to an embodiment of the present invention; FIG. That is, a measurement interval), and shows an example of a pattern of an echo signal obtained from the welded portion,

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 is a schematic view showing a configuration of an ultrasonic inspection apparatus according to an embodiment of the present invention for inspecting a welded portion of an object to be inspected, such as a mechanical device or an automobile, .

2, the ultrasonic inspection apparatus 200 includes a transducer 21 for receiving ultrasonic waves into an object to be inspected having a welded portion and detecting an echo signal therefrom, A motor drive unit 23 for applying a drive pulse according to the inputted drive amount information to the servo motor 22, A display unit 26 for displaying the arbitrary data on the display unit 26 so that visual characters, shapes and / or patterns corresponding thereto are displayed on the display unit 26, An interface unit 27 provided with a driving unit 25, a touch sensor and / or a keypad for sensing a user's input and / or selection and outputting corresponding input information, The ultrasonic inspection operation according to the input information from the ultrasonic diagnostic apparatus 27 is carried out by appropriately transmitting or receiving the data to or from the corresponding components among the components and transmitting the result or the obtained raw data to the user A control unit 20 for controlling the display driving unit 25 so as to display the necessary information on the display unit 26 and a control unit 20 for controlling the display unit 26 to display raw data obtained from the inspection operation of the control unit 20, And a storage unit 24 in which information is stored.

The control unit 20 includes a central processing unit (CPU) therein. By executing pre-stored instruction codes such as firmware or a program provided to the control unit 20, So that the quality inspection operation and the preliminary operations necessary for the inspection are properly performed. The control unit 20 includes an input terminal receiving a signal is01 corresponding to the rotation amount of the object to be inspected to determine whether the probe 21 should be moved.

For convenience of explanation of the operation of the ultrasonic inspection apparatus 200 according to an embodiment of the present invention having the configuration as illustrated in FIG. 2, an object such as an automobile part produced on a manufacturing line, that is, As exemplified in Fig. 3, it is assumed that the two materials 31a and 31b are joined in such a manner that their circumferential surfaces are mutually abutted and welded along the circumference at the upper portion of the abutment surface 32. [

It is to be noted that the assumption that the welded portion has the shape of a circumferential surface with respect to the object to be inspected is merely for convenience in describing the concept, technical idea and principle of the present invention more concretely and exemplarily, And the like are not limited to the shape of such welds. That is, the principles and concepts of the present invention can be applied to cases where the welded joint surfaces of both base materials form a square plane or an arbitrary curved surface. Of course, in this case, instead of the amount of rotation of the object to be inspected, a linear movement amount of the object or a movement amount along the curve may be applied to the control unit 20, and the control unit 20 performs the ultrasonic inspection operation It will be based on the horizontal movement amount instead of the rotation amount of the inspection object.

Hereinafter, an ultrasonic inspection apparatus 200 having a configuration as illustrated in FIG. 2 is required to accurately measure the depth of a welded portion in a welded part or the like, and to measure the accuracy with respect to the depth to be measured, With reference to the flow charts of FIGS. 4A and 4B illustrating a method of allowing to be maintained despite changes (e.g., mechanical variations caused by temperature changes between day and night or between seasons, shocks, or daily vibrations, etc.) Explain.

First, the operator of the ultrasonic inspection apparatus 200 installs the ultrasonic inspection apparatus 200 at a desired position on a production line where a subject to be inspected is located, for example, a part. When the ultrasonic inspection apparatus 200 is installed at a desired location, the operator can determine the minimum depth (hereinafter referred to as' minimum limit value ') and the maximum allowable depth (hereinafter, referred to as' Maximum value "), and a value for the transducer 21 is a value for an initial position to be initially positioned with respect to the object to be inspected for accurate measurement of the welding depth (this position is referred to as a " (Step S400), the control unit 20 sets the horizontal and vertical movement distances for moving the display unit 20 to the display unit 20 through the interface unit 27. [

A value for the measurement interval (this measurement interval will be described later) for gradually moving the probe 21 downward is also set in the control unit 20 by the operator. The value set at the measurement interval at this time is the value specified by the high-precision gap.

In the other embodiment of the present invention, the value for the high-precision gap is previously set in the controller 20, so that the controller 20 can measure the high- The interval can also be set automatically.

The distance horizontally and / or vertically set in the control unit 20 so that the transducer 21 is located at the observation point with respect to the object to be welded is determined by the distance Is determined by the horizontal position at which the ultrasonic originating point should be located relatively apart from the joining surface of the object to be inspected and the vertical position which is the height corresponding to the same plane with the top surface of the welded joint (or joint surface). 5 is a view for helping this. The horizontal distance req_dis that the ultrasonic transmitting point of the transducer 21 should be spaced apart from the bonding surface 51 of the object to be inspected is referred to as a " the distance subtracted from the horizontal distance x ip to the joining surface 51 when the probe 21 is in the idle position is a distance to horizontally move the transducer 21. The height difference y ip between the upper end 52 of the welded portion (or the bonding surface 51) and the ultrasonic transmission point of the probe at the dormant position is smaller than the distance do.

The control unit 20 applies the information on the spatial distance to move the transducer 21 to the controller 20 according to the setting of the operator so that the controller 20 controls the transducer 21 according to the inputted spatial- The motor driving unit 23 applies driving pulses corresponding to the driving amount information to the servo motor 23 in the horizontal direction and / or vertically, (S401) so that the operator moves the probe 21 spatially and accurately positions the probe 21 at an initial point desired by the operator, that is, a viewing point.

The above-mentioned horizontal separation distance req_dis is determined by the optical characteristics of the transducer 21 and the characteristics of the ultrasonic signal corresponding thereto. The ultrasonic signal emitted by the transducer 21 is gradually converged to a certain distance and gradually diffused beyond the maximum convergence point. Therefore, the horizontal separation distance is set so that the ultrasound signals emitted from the object to be inspected are most focused on the joint surface 51. In a preferred embodiment according to the present invention, the probe 21 has optical characteristics such that the diameter of the ultrasound wave in the fully focused state is 0.8 mm.

(50a, 50b in Fig. 5) to move the transducer 21 to the observation point where the depth of the welded portion of the object to be inspected can be accurately measured, at the production site where inspection objects such as automobile parts are manufactured It is often difficult to grasp. The relative distance between the object to be inspected such as a part in an actual manufacturing line and the dormancy position of the probe 21 of the ultrasonic inspection apparatus 200 installed is measured and based on the measured vertical and horizontal distances, After the probe 21 is moved, the echo signal from the welded portion of the object to be inspected is analyzed, and the spatial movement distance to the accurate point is determined through an iterative process in which the spatial travel distance, This can also be a time-consuming task.

In the case where ultrasonic waves are used to confirm only the abnormality such as bubbles or cracks in the welded portion as in the conventional technique, the point of view on which the probe 21 is to be placed relative to the object to be inspected is not important. This is because the ultrasonic inspection must be performed for an area spatially containing the welding surface of the object to be inspected, so that it is possible to start the ultrasonic inspection at an arbitrary position higher than the upper end of the welding portion. However, as in the technical idea of the present invention, the point of view is very important in order to accurately measure the depth of the welded portion of the object to be inspected. This is because the vertical point of the visual point is a reference point for measuring the depth. That is, it may be a point having a depth of zero.

In an embodiment of the present invention, in order to more easily grasp the amount of spatial movement of the probe 21 to the observation point with respect to the object to be inspected, a measurement sample for the actual measurement object to be inspected for welding quality is produced And distance information to be moved at the dormant position is obtained in order to position the transducer 21 at the observation point with respect to the object to be inspected in the actual production line through ultrasonic inspection for the measurement sample.

The sample for measurement need not be manufactured in the same shape as the object to be inspected by ultrasonic welding the welded portion. However, as illustrated in FIG. 6, the positioning sample 611 should be provided with the positioning groove 611 in the direction of the incident ultrasonic wave. When the test sample 61 is subjected to a test for obtaining distance information for the probe 21 to move to a position at the observation point, The center axis of the confirmation groove 611 is positioned at the ultrasonic transmission point when the probe 21 is at the dormant position and the ultrasonic transmission point of the portion 621 welded to the object to be inspected 62, The measurement sample 61 is mounted in the test space for measurement so that the position of the measurement sample 61 becomes a position (v_dis S = v_dis A ) such that the distance is vertically equal to the upper face. The mounting position of the positioning groove 611 is also horizontally measured on the basis of the ultrasonic transmission point of the transducer 21 so that the distance to the bottom end 612 of the positioning groove 611 The distance to the joining surface 622 of the object 62 becomes equal.

After the measurement sample 61 is mounted at a position relatively spaced relative to the probe 21 of the ultrasonic inspection apparatus 200 according to the method described above, The control unit 20 causes the control unit 20 to determine whether the ultrasonic wave transmitted from the probe 21 to the bottom end 612 of the measurement sample 61 corresponds to a distance Position to the horizontal position. After this horizontal movement, the control unit 20 causes the probe 21 to descend gradually (for example, by 0.1 mm) (63) starting from the height (63), to transmit an ultrasonic wave, Signal is received. Of course, after the transducer 21 is lowered by a predetermined distance (up to an arbitrary height at which the measurement sample 61 does not exist) after the horizontal movement, the ultrasonic transmission / detection operation may be started from that point.

When the measurement sample 61 produced as illustrated in Fig. 6 emits ultrasonic waves while being slightly lowered vertically and detects the echo signal, the measurement depth is reduced to a measurement depth as illustrated in Fig. 7 The pattern 72 of the echo signal is obtained. The signal pattern 72 illustrated in FIG. 7 is a signal pattern that the control unit 20 receives a signal detected by the transducer 21 and extracts a signal component reflected from the bottom end 713, And stores it in the storage unit 24, and then gives the density of black and white in proportion to the data value reflecting the intensity of the extracted echo signal (when the extracted echo signal is absent, its intensity is set to 0) And is displayed on the display unit 26 as an example. Of course, it can also be displayed in various colors to distinguish the intensity, instead of being displayed in black and white.

The ultrasonic signal incident on the inside of an arbitrary object is reflected every time there is a change in the medium on the path. The control unit 20 controls the ultrasonic signal to be transmitted to the transducer 21 in accordance with the characteristics of the transmitted ultrasonic waves of the transducer 21, It is possible to detect and extract the signal reflected from the bottom end portion 713 from the detection time of the reflected signal even if the signal is reflected from a plurality of places with respect to a single ultrasonic wave incident.

Alternatively, if an echo signal having a certain intensity or more is detected, the signal may be regarded as a signal reflected from the lower end portion 713.

Since the controller 20 knows the distance that the probe 21 is vertically lowered through the motor driving unit 23, when the intensity of the echo signal is displayed, the height at which the probe 21 starts measuring 0 and a ruler 73 indicating the depth at which the corresponding signal intensity is detected are displayed on the display unit 26 together. Of course, when the ultrasonic inspection apparatus 200 has a print function, the control unit 20 may cause the displayed content to be displayed on the paper as it is, .

7, the pattern of the echo signal shown in FIG. 7 is displayed in such a manner that the black density increases when the intensity is low and the white density increases when the intensity is high. In this case, the position of the position determining groove 711 Since the echo signal measured by the ultrasonic wave is highest at the depth of the central axis 712, the density of white is displayed at the highest point corresponding to that point. The measurement sample 71 can be detected without any reflected ultrasonic signal (in the case of extracting the reflected signal component from the extended surface 713a of the lower end portion 713) in the remaining portions except for the boundary portion of the point, The intensity of the signal reflected at the right end 714 of the positioning groove 711 is much weaker than that of the signal reflected at the bottom end 713 of the positioning groove 711 ) The darkness of black is displayed according to the above display method. The surface on which the positioning groove 711 is formed reflects the ultrasonic wave incident on the right end 714 due to the change in the medium, but the incident ultrasonic wave is reflected by the horizontal positioning of the transducer 21 as described above The amount of the light reflected from the right end 714 becomes very small because the diameter is diffused from the bottom end 713.

7, when the distribution of the intensity of the echo signal measured for the measurement sample 71 is obtained, the operator can determine from the displayed pattern whether the probe 21 is in a dormant position It is possible to grasp how much to move vertically from the point of detection of the echo signal, that is, the point where the ultrasonic inspection is started, to the center axis 712 of the positioning groove 711. For example, if the distribution of the echo signal as illustrated in Fig. 7 is obtained, the distribution center of the positioning groove 711 is located at a depth of 74 mm from the start height 74 of the ultrasonic probe .

The operator of the ultrasonic inspection apparatus 200 can measure the depth of the welded portion by using the ultrasonic measurement through the measurement sample 71 as described above. In order to position the probe 21 at the observation point, it can be seen how far it should be moved vertically from its resting position. 7, the vertical movement distance required to move the transducer 21 to the actual viewing point with respect to the object to be inspected becomes 20 mm. Therefore, the vertical movement distance is set to the control unit 20 as the vertical movement distance do.

If the start of the ultrasonic probe for the measurement sample 71 is lowered by a certain distance from the height of the dormant position of the probe 21 in the aforementioned test ultrasonic measurement, The vertical distance is set to a distance to be added to the descent distance 741 determined by the test ultrasonic flaw before a certain distance and to place the probe at the sight point.

Of course, the value of the vertical movement distance required for moving the actual inspection object to the visual point is set in the control unit 20 through the interface unit 27, and the horizontal movement distance Is also set in the controller 20.

As described above, the horizontal and vertical movement distances set in this way are used for moving the transducer 21 after the ultrasonic inspection apparatus 200 is installed on an actual manufacturing line or the like, .

In an exemplary embodiment of the present invention, the values of the horizontal and vertical moving distances set in the controller 20 may be corrected through experimental measurements on an actual manufacturing line or the like. Hereinafter, the present embodiment will be described in detail.

After the ultrasonic inspection apparatus 200 is installed on a line on which an object to be inspected is produced, such as a mechanical device or a part of an automobile, the ultrasonic inspection apparatus 200 may be installed at a specific intended position on the production line, such as a jig The control unit 20 controls the transducer 21 via the moving unit (the motor driving unit 23 and the servomotor 22) in accordance with an instruction to start the inspection by the user, Is moved by a set horizontal and vertical movement distance, and is positioned at the intended viewing point for the object to be inspected. The horizontal and vertical moving distances at this time are values determined and set through measurement samples as described with reference to FIGS. 6 and 7, or may be values set by the ultrasonic inspection apparatus 200 ) And the position at which the intended object is to be mounted.

When the transducer 21 is positioned at the observation point, the controller 20 vertically lowers the transducer 21 by the previously set measurement interval starting from the observation point, An ultrasonic inspection operation is performed in which the ultrasonic wave is transmitted to the welded joint surface in a concentrated manner and an echo signal is detected through the probe 21. When the pattern of the echo signal from the joint surface, that is, the distribution of the signal intensity, is obtained through the detection, the data representing the distribution is stored in the storage unit 24 and the pattern / distribution is analyzed. (Or chromatic color) on the display unit 26 or prints on paper or the like in the manner as illustrated in Fig.

Once the pattern / distribution for the intensity of the echo signal is obtained, the ultrasound inspected vertical surface of the inspected object used for the measurement, i.e., the depth of the welded portion is actually measured by cutting along the welded joint surface.

The operator compares the welding depth determined on the displayed signal pattern with the actually measured welding depth on the cutting surface to obtain a value for the vertical movement distance set in the control section 20 for spatial movement to the point of sight with respect to the inspection object . 8A and 8B show examples of correcting the vertical movement distance according to the pattern of the detected echo signal, respectively.

8A shows the result of the ultrasonic inspection according to the fact that the probe point at which the probe is initially located relative to the object to be inspected is set higher than the point at which it should be positioned relative to the object to be inspected 82 for accurate measurement of the weld depth. In other words, the vertical movement distance for movement to the visual point set in the control unit 20 is shorter than the distance to be applied on the actual production line or the like. The result of this measurement shows that the distance (wave_D 1 ) from the pattern 81 of the detected echo signal to the point 811 where the color density (or color) is changed is smaller than the distance (Dif_D 1 = wave_D 1 - act_D) from the upper end face of the welded portion because ultrasonic inspection is longer than the welding depth act_D measured at the welded portion (dif_D 1 = wave_D 1 - act_D).

Therefore, when the ultrasonic measurement result and the actual measurement result of cutting of the welded portion are obtained as illustrated in Fig. 8A, the operator can obtain the vertical movement distance set in the control unit 20 through the interface unit 27 The difference (dif_D 1 ) is further added and corrected. In other words, the reference point (point of depth 0) for measuring the welding depth is corrected to a point lower by the difference (dif_D 1 ).

The reason why the pattern 81 of the echo signal as shown in FIG. 8A is obtained from the object to be inspected 82 having the welded portion as illustrated in FIG. 8A will be briefly described. The ultrasonic wave is focused on the joint surface 821 of the object 82 and the echo signal is detected so that the distance from the height 83 of the observation point to the depth 811 at which the weld is finished is the distance between the joint surface The signal is not reflected because there is no change in the medium in the weld corresponding to the joint surface.) The echo signal in that interval is zero or very weak And the intensity of the ultrasonic waves reflected due to the change in the medium is relatively strong at the junction surface of the non-welded depth, so that a strong echo signal in the corresponding section It is white, indicating that the exported will be displayed. Therefore, the middle line 811 where transition (or change of color) occurs from black to white becomes the starting point of the joint surface that is not welded.

As illustrated in Fig. 8A, from the echo signal pattern 81 obtained by ultrasonic inspection, it is impossible to confirm the horizontal plane 84 where welding actually starts. This is because the ultrasonic inspection on the upper side and the upper side of the upper face 84 where welding starts does not show a signal pattern enabling the horizontal face 94 to be recognized. Therefore, it is very important to accurately set the reference point (position with a depth of 0) as a reference for the depth measurement of the welded portion, as mentioned in the various embodiments of the present invention.

Fig. 8B shows the measurement result according to the fact that the probe point 85 of the probe is set lower than the initial position at which it should be positioned with respect to the object to be inspected 82. Fig. In other words, the vertical movement distance for movement to the set point in the control unit 20 is longer than the required movement distance for the object in the actual production line . The measurement result shows that the distance (wave_D 2 ) from the detected pattern 86 of the echo signal to the point 861 where the color density (or color) is changed is smaller than the distance since the welding depth shorter than (act_D), from the top surface 87 of the welded portion as measured from the short (dif_D 2 = act_D -wave_D 2) located in the lower area can be seen that the ultrasonic flaw detection is started.

Therefore, when the ultrasound measurement result as illustrated in FIG. 8B and the actual measurement result of the cutting of the welded portion are obtained, the operator sets the difference (dif_D 2 ) to the vertical movement distance set in the control unit 20 And is corrected by subtraction. That is, the position of the visual point is corrected to a slightly higher position.

If ultrasonic inspection of the welding quality of the object to be inspected is instructed by the operator through the interface unit 27 after the ultrasonic inspection apparatus 200 is installed on the site where the object to be inspected is manufactured or produced, The motor driver 23 is driven to move the transducer 21 to the observation point for the object to be inspected on the basis of the horizontal and vertical movement distances set for itself, The inspection of the welded portion to the object to be inspected is started according to the procedure as exemplified. Of course, the set vertical movement distance may be a value corrected by a result obtained by ultrasonic measurement on an actual inspected object according to the same conditions on a manufacturing or production line, as described in the foregoing embodiment.

FIG. 9 is a schematic view of an entire system configured when an object to be inspected is automatically mounted on a measurement position for inspection of a welding quality using an ultrasonic wave in the same site as the production line on which the ultrasonic inspection apparatus 200 is installed. As mentioned above, the object to be inspected for the quality of the welded portion may be a part used for a mechanical device, an automobile or the like, having a welded portion along a circumferential surface of a specified radius. Accordingly, in the system illustrated in FIG. 9, the quality of the welded portion is checked while the object to be inspected is rotated 360 degrees.

9 schematically illustrates a structure of the system illustrated in FIG. 9 in which such a three-dimensional welding quality inspection is performed on an object to be inspected. The water tank 90, which is filled with water having a jig in which the object to be inspected 901 is seated and fixed, A servo motor 91 for rotating the jig to which the object to be inspected 901 is fixed by a drive pulse 911 applied thereto and a signal is01 corresponding to the rotation amount of the servo motor 91 An encoder 92 for outputting ultrasonic waves is additionally provided in addition to the ultrasonic inspection apparatus 200 described above.

In the system as illustrated in Fig. 9, when the object to be inspected 901 is placed at the measurement position, that is, in the jig (S402) with the probe 21 positioned at the observation point according to the above- The controller 20 starts the ultrasonic inspection of the welded portion within the inspection object 901 at the same height as the sight point where the probe 21 is located, that is, the joint surface along the circumference of 360 degrees (S403) The height of the starting point of the ultrasonic inspection is defined as the reference point for measuring the depth of the weld, that is, depth 0.

Whether or not the object to be inspected is seated in the jig in the water tank 90 can be known by receiving a signal from a sensor attached to the jig or a separate sensor provided in the water tank 90 for sensing whether the object is seated.

The 360-degree ultrasonic inspection of the joint surface of the object to be inspected 901 at the current height (depth) of the probe 21 proceeds in accordance with the flowchart illustrated in FIG. 4B. Of course, the flowchart illustrated in FIG. 4B is equally applied to the case where the probe 21 is subjected to 360-degree ultrasonic inspection of the junction plane on the plane of the plane at a position corresponding to an arbitrary depth.

When the ultrasonic inspection is started, the controller 20 controls the transducer 21 to cause the ultrasonic wave to be incident on the object to be inspected 901, and thereby, in the echo signal detected by the transducer 21, And extracts the intensity of the component from the current probe point information, that is, the depth of the probe tip and the position of the probe on the horizontal line with respect to the probe, that is, the values of the phase (angle) And stores it as data in the storage unit 24 (SS41). Of course, the information about the depth currently being examined is the same for each of the detected phases, so that one value is typically recorded. The depth information is information indicating that the probe 21 starts from the observation point, It is a street.

In one embodiment of the present invention, it is also possible to store all the detected signal components in the storage unit 24, analyze the stored signal data, and extract components reflected from the bonded surface.

The detection / storage of the echo signal is instantaneously performed. When the operation is completed, it is confirmed whether the object to be inspected 901 is rotated at a predetermined angle, for example, 1/4 of zero (SS42). This predetermined angle corresponds to each resolution at a 360 degree test on the joint surface and is appropriately determined in accordance with the accuracy required in the weld quality inspection and the radius from the rotation center axis of the welded joint surface.

Whether or not the predetermined angle has been rotated can be known from the signal applied from the encoder 92. [ The driving of the servomotor 91 for rotating the inspection object 901 mounted on the jig can be performed by a driving device other than the ultrasonic testing device 200. [ In another embodiment of the present invention, a driving unit for driving the servo motor 91 may be provided in the ultrasonic inspection apparatus 200. In this embodiment, since the control unit 20 directly drives the servomotor 91 through its driving unit, it can recognize the angle of rotation of the servomotor 91 by the drive signal applied by itself, have. Therefore, in the present embodiment, the encoder 92 may not be provided in the system illustrated in FIG.

If the object to be inspected 901 has rotated by a predetermined angle, that is, corresponding to each resolution, the controller 20 additionally checks whether the total rotation amount from the depth where the transducer 21 is currently located is 360 degrees SS43), the ultrasonic inspection of the current phase of the object to be inspected 901 is performed again (SS41) if the object has not been rotated 360 degrees yet.

During the ultrasonic inspection process, if it is confirmed that there is welding abnormality, bubbles or cracks on the joint surface of the object to be inspected 901, at that point, the control unit 20 instructs the operator So that a special visual notification signal is outputted to the unit (26). At this time, it is also possible to simultaneously output auditory notification signals through means such as a speaker. The information indicating that there is an anomaly with respect to the current to-be-visited point is also stored in the storage unit 24 together with data on the intensity of the detected echo signal

If there are bubbles or cracks in the welded portion where the ultrasonic waves are focused, the intensity of the signal reflected by the change of the medium due to the bubbles or cracks becomes relatively high, so that the intensity of the signal due to the normally welded portion (small or no echo signal) 8A and 8B, the white color is displayed at the portion where the black color is to be displayed). Accordingly, the control unit 20 can determine whether the weld is abnormal based on the change in intensity of the echo signal. Of course, the point at which the intensity of the echo signal is changed is determined as a welding abnormality when the transducer 21 is located within the minimum limit mentioned above with reference to the ultrasonic probe starting point, i.e., the viewing point.

In an embodiment of the present invention, when an abnormality of the welded portion is confirmed in the ultrasonic inspection process according to the flowchart illustrated in FIG. 4B, the controller 20 stops the further inspection of the quality of the welded object 901 The probe 21 may be returned to the visual point and the ultrasonic probe may be started again when the new object to be inspected is seated at the measurement position.

When the 360-degree ultrasonic inspection of the object to be inspected 901 is completed, the controller 20 adds information indicating the welding abnormality to the information obtained from the result of the 360-degree flaw detection at the current measurement depth with respect to the object to be inspected 901 (S404). If there is an abnormality, a visual and / or audible signal is generated so that the operator can recognize the signal as described above (S405).

The control unit 20 then feeds the probe 21 downward by a predetermined measurement interval (currently, a high precision gap, for example, set to 0.1 mm) through the motor drive unit 25 (S406). The measurement interval is an interval resolution for inspecting the welding quality of the object to be inspected, and a different value can be designated according to the accuracy of the required quality inspection.

Meanwhile, the object to be inspected 901 is not rotated during the descent of the probe 21 by the measurement interval. For this interlocking operation, the control unit 20 can send and receive a signal for synchronization with a separate driving unit for driving the servo motor 91. [

After lowering the transducer 21 by the measurement interval, the control unit 20 determines whether the total distance of the transducer 21 so far (that is, the current transducer depth when the visual point is set to the depth 0) , It is confirmed whether it exceeds the minimum threshold set for itself (S407). If the depth does not exceed the minimum limit, the controller 20 performs the 360-degree ultrasonic inspection of the object to be inspected 901 at the current depth lowered by the measurement interval in the manner described above (S403 to S406 ). Of course, when the ultrasonic inspection is started, the inspection object 901 is rotated by the servo motor 91 again.

If the total distance that the probe 21 descends exceeds the minimum threshold value, that is, the measurement distance is further below the minimum threshold value, the control unit 20 sets the measurement interval to the value of the low precision gap (S410). The gap for the low precision may have a value larger than the above-mentioned high-precision gap, for example, a value twice (for example, 0.2 mm) or a value larger than the multiple (such as 3 times or 4 times) And may be determined in proportion to the difference between the maximum threshold and the minimum threshold mentioned above. That is, as the difference becomes larger, the gap for the low precision is also set to a large value and may be set to the measurement interval.

After resetting the measurement interval to a gap for a low precision, the controller 20 performs 360-degree ultrasonic inspection on the object to be inspected 901 (S411). At this time, the same process as the flowchart shown in FIG. 4B is performed.

When the ultrasonic inspection of the weld on the flat surface at the depth just after the above-mentioned minimum limit is completed, the controller 20 controls the storage unit 24 to store And checks whether all the positions (phases) of the current depth of the inspection object 901 are welded (S411). For example, it is confirmed that the echo signal intensity measured at each phase is equal to or higher than a specified threshold level (as described above, the intensity of the reflected signal becomes relatively large on the non-welded surface).

If the signal strength indicating a welded value at any one position (phase) is stored, the control unit 20 determines whether the current ultrasonic probe depth, i.e., the cumulative distance at which the probe 21 is lowered (S413). If the current depth is less than the maximum threshold value, the control unit 20 moves the probe 21 downward by a measurement interval set at a gap for a low precision (S414) The ultrasonic inspection operation of FIG. 4B is performed again (S411).

By repeatedly performing the above-described operations S411 to S413, the detection signal scorecard 100 in which the intensity of the echo signal from the joint surface is recorded for each phase, as illustrated in Fig. 10, An entry 101 k is generated and added. The detection signal scorecard 100 illustrated in FIG. 10 shows that the intensity value detected from the time when the depth of the defect exceeds the minimum threshold value is recorded. However, this is only for a simple example, The signal intensity values detected by the ultrasonic inspection can be recorded by the corresponding depths.

In the course of repeatedly performing the operations (S411 to S413) described above, when the signal intensity of each position at which the data (101 L ) recorded in the detection signal scorecard 100 is detected with respect to the current depth is all non- (S412), the controller 20 calculates an average value of the welding depths of the object to be inspected (S415).

In order to calculate the average value of the welding depths for the current inspection object 901, the control unit 20 firstly performs the welding at each position, i.e., each phase q? 0 , q = 0,1, Understand the depth. For this, the controller 20 finds a row in each column of the detection signal scorecard 100 that changes from the signal strength indicating the welded state to the signal strength indicating the non-contact state, And the welding depth for the corresponding position, that is, the phase, is obtained from the recorded depth value for the found row.

For example, when the detection signal scorecard 100 illustrated in FIG. 10 is taken as an example, the welding depths of the four preceding positions (0 0 , 0 , 2α 0 , 3α 0 ) are d k + 1 , d k , d k -1 , and d k + 1 , respectively.

When the depth of the weld at each position to be inspected is measured in this manner, an average value of the weld depths is obtained. That is, a value obtained by dividing the total sum of the weld depths detected at the respective positions by the number of positions (phases) for ultrasonic inspection (N in the example of FIG. 10) is obtained.

After the average value of the welding depths for the current inspection object 901 is obtained, the average value is added as one entry 111 to the sample depth distribution table 110 having the structure as illustrated in Fig. The entry recorded at this time may include information on the current date and time as illustrated in FIG. 11, in addition to the welding depth average value obtained previously.

According to the embodiment of the present invention, as described above, in the case where the welding object is found at a position lower than the depth corresponding to the minimum limit value, that is, a defect is found, the average value of the welding depth is not obtained, No entry is also listed in the sample depth distribution table 110.

The control unit 20 vertically raises the transducer 21 to return to the visual point (S424), and then the new inspection object 901 is inspected And waits until the object is placed at the measurement position.

On the other hand, during the repeated operations of the above-described operations S411 to S413, before the depth is found to be not welded at any position (phase), the depth of the defect corresponds to the above-mentioned maximum limit (S413), the control unit 20 controls the motor driving unit 23 to feed the probe 21 downward. At this time, the distance of the lowered feed is not the currently set low clearance but the high clearance (S420). This is to check precisely whether the welded depth exceeds the maximum allowed. If the current depth of the transducer 21 is deeper than the depth corresponding to the maximum limit, the transducer 21 is not further transported downward.

When the probe 21 is located at a position deeper than the maximum limit value (or at a position deeper by a distance of a high precision gap), the control unit 20 controls the control unit 20 to perform a 360-degree ultrasound (S421). At this time, the same process as the flowchart shown in FIG. 4B is performed.

When the ultrasonic inspection is completed at a depth equal to or greater than the maximum limit value, the controller 20 examines the result data for the corresponding depth stored in the storage unit 24 in accordance with the inspection, and the data indicating that the data is welded to the echo signal (S422).

If there is data indicating that welding has been performed at the current depth, the control unit 20 generates a visual and / or audible signal indicating that the welding depth is bad for the object to be inspected 901 (S423). Then, information indicating that the welding depth is "bad" is stored in the storage unit 24 in association with the detected data. Then, the transducer 21 is vertically raised to return to the visual point (S424), and waits until the new inspected object is placed at the measurement position.

In one embodiment according to the present invention, the intensity close to the reference signal intensity (for example, the reference intensity and the reference intensity), which is a reference for discriminating whether the signal reflected by the welded surface or the signal reflected by the non- Is detected at a position deeper than the maximum limit, the control section (20) judges whether the welded surface is welded or not at the current depth The probe 21 may be lowered further by a high-precision gap, and further ultrasonic inspection may be performed on points of the same phase. Even if ultrasonic inspection is performed again, if the intensity close to the reference intensity is still detected, the controller 20 determines that the corresponding phase of the welding surface is 'welding depth defect'. Otherwise, when the signal strength indicating the non-welded state is obtained, the welded depth is not judged to be 'welded depth defect' with respect to the phase. In the latter case, an average value of the welding depths for the inspection object may be obtained and registered as one entry in the sample depth distribution table 110. [

Every time a new inspection object is placed in the measurement position in the standby state of the inspection object (S402), the control section 20 repeats the above-described operation for confirming whether the welding object is abnormal and the welding depth with respect to the object to be inspected . Each time this operation is repeated, one entry is additionally registered in the sample depth distribution table 110.

If the number of entries to be registered corresponds to the number of samples previously set in the control section 20 (this value can be set by the control section 20 via the interface section 27 as an operator) Thereafter, the average value of the welding depth obtained by measuring the new inspection object is registered as one entry in the real-time depth distribution table.

The controller 20 calculates an average value of the weld depth average values 112 registered in the sample depth distribution table 110, that is, an average value of the sample group, and sets the average value as the average depth reference value.

In another embodiment of the present invention, when a user applies a command 'designate sample' through the interface unit 27 without a predetermined number of samples, the controller 20 controls the sample depth distribution table 110 The average value for the sample group is calculated and set to the average depth reference value. Of course, the welding depth average value of the object to be inspected, which is measured after the command of specifying the sample, is registered as one entry in the real-time depth distribution table as described above.

The real-time depth distribution table may have the same structure as the sample depth distribution table 110 illustrated in FIG. However, as the number of inspection objects measured after setting the average depth reference value increases, the number of entries in the real time depth distribution table also increases accordingly.

When the number of entries in the real-time depth distribution table becomes equal to the number of entries in the sample depth distribution table 110, the controller 20 updates the entry recorded last time with the entry of the newly acquired weld depth average value The number of the real-time depth distribution tables is always kept equal to the number of the sample depth distribution tables 110.

In an embodiment of the present invention, the number of the real-time depth distribution tables may be maintained to a range allowed by the remaining capacity of the storage unit 24. [

The control unit 20 calculates an average value of weld depth average values of the entries registered in the real-time depth distribution table (hereinafter, referred to as 'current group') from a point in time when the number of entries in the real-time depth distribution table becomes equal to or greater than the number of entries in the sample depth distribution table 110 Average value ") to the set weld depth reference value, and compares the comparison information and the comparison result with the set welding depth reference value through the display driver 25 in the manner as illustrated in FIG. 12, And outputs it to the unit 26 so that it can be seen by the operator.

In another embodiment according to the present invention, the number of entries to obtain the current group average value (i.e., the number of objects to be inspected) may not be the same as the number of objects to be inspected to calculate the weld depth reference value.

12, the weld depth reference value dg AVA_Std obtained in the specimen depth distribution table 110 and the period 1201 obtained by obtaining the reference value are displayed, and the obtained string depth reference value dg AVA_Std for the same or different number of currently measured inspected objects The group average value dg AVA_Cur is also displayed together with the period 1202 in which the average value is obtained. In addition, a ratio 1203 indicating how much the deviation is present when the current group average value dg AVA_Cur is based on the weld depth average value dg AVA_Std is also displayed. Of course, a value indicating the difference from the reference value may be displayed instead of the ratio.

The control unit 20 calculates the current group average value dg AVA_Cur and displays it so that the operator can know it in the manner as illustrated in FIG. 12 and compares it with the welding depth reference value dg AVA_Std . It can be performed for each object. 13A is a diagram for schematically explaining one of such schemes, in which the welding depth reference value is the same as the number of samples (for example, N) of the inspected object (or a different designated number, for example, The ultrasonic measurement 1311 for a new object to be inspected is completed in a state in which the current group average value calculated in the measurements 1300 for the object to be inspected is presently displayed, Every time the depth average is obtained, the current group average value is calculated from the latest N (or R) average values 1310 including the latest average value, and the related information is displayed as illustrated in FIG.

According to another embodiment of the present invention, when the welding depth reference value is inspected for the number of samples of the inspected object (for example, N pieces) or for each of a predetermined number of different inspected objects, To display the related information as illustrated in Fig. 12 and compare the weld depth reference value dg AVA_Std with the weld depth reference value dg AVA_Std . Fig. 13B is a diagram showing this method schematically. After comparison with the calculation and comparison of the current group average value by the measurement 1320 for the previous N (or R) inspected objects, When the measurement (1330) for the N (or R) objects to be inspected is completed, the new current group average is calculated from the values obtained by the measurements 1330, and the welding depth reference value dg AVA_Std and .

In the display example of FIG. 12, only one current group average value is shown in addition to the information related to the welding depth reference value. However, in the case of the latest plurality of the current group average values obtained in accordance with any one of the above- And may be displayed in the order of the calculated time.

Meanwhile, the control unit 20 determines whether the latest current group average value calculated according to any one of the above-described methods is within the range (± 5%, ± 10%) of the weld depth reference value dg AVA_Std , Or a threshold value specified by a specific value such as ± 1.0 mm, ± 2.0 mm, or the like), an appropriate warning message is generated and displayed on the display unit 26. Of course, as described above, an appropriate notification signal may be output so that the operator can perceive it audibly.

The operator ignores such visual or audible warning and continues the ultrasonic inspection on the object to be inspected or performs the operation of resetting or correcting the point of sight of the transducer 21.

In the latter operation, the ultrasonic measurement of the actual object to be inspected and the measurement of the welding depth by cutting, which are described with reference to FIGS. 8A and 8B, are performed vertically for moving the probe to the observation point with respect to the object to be inspected / The horizontal movement distance value is corrected.

If the operator ignores the warning of the ultrasonic inspection apparatus 200 or corrects the vertical / horizontal movement distance value for movement to the viewing point in accordance with the warning, And instructs the controller 20 to 'reset the sample' through the controller 27.

If there is such an instruction, the control unit 20 updates the previous entries of the sample depth distribution table 110 with the welding depth average values obtained for the object to be inspected whose welding quality is checked after the command is issued. When all the previous entries are updated to new values, the weld depth average is newly recorded in the real-time depth distribution table for the inspected object to be inspected from that time.

Then, the above-described operations such as the welding depth reference value calculated from the sample depth distribution table 110 in which the values are newly updated, the on-screen display of the current group average value calculated from the real time depth distribution table, (20).

On the other hand, the control unit 20 may be configured to perform the ultrasonic inspection for one inspection object, for example, data obtained as shown in FIG. 10 in the form illustrated in FIG. 14, 26). Of course, this indication may be made only when there is a special request from the operator.

An example of the echo signal pattern illustrated in FIG. 14 is shown by flattening the entire region of the ultrasonic probe with respect to a circumferential joint surface intended to be welded in one object to be inspected. From the observation point taken as a reference point of depth to the minimum limit (P141), the intensity of the echo signal at each of the gaps is shown. At the depth exceeding the minimum limit, the ultrasonic inspection is performed for every gap for the low precision (P142) And the intensity of the echo signal obtained from the ultrasonic inspection in Fig.

14 does not proceed to the depth corresponding to the maximum limit value of the ultrasonic inspection, but when the ultrasonic inspection is performed to the depth only by reaching the depth 1401 which is not welded over the entire phase in the middle Lt; / RTI > That is, the welding state is detected only at the position 1402 in which the phase from the observation point is? 0 at the depth higher than the depth 1401 determined as the non-contact state for all the phases by the gap for the low precision, In the section, the result of the ultrasonic inspection is shown for the condition that no further welding is performed.

As in the above-described method, ultrasonic inspection is carried out for a welded portion of the object to be inspected such as a mechanical device or a part of an automobile by a high-precision gap up to the minimum limit value based on the required value of the weld depth, For example, the presence of bubbles and cracks is detected and at the same time, it is confirmed whether or not the weld is welded to the minimum length, and the welded depth is confirmed by performing ultrasonic inspection with a gap for a low precision for a region deeper than the minimum limit , It is possible to reduce the failure rate (welded to be shallower or deeper than the required depth) to the depth of the welded portion or to the depth of the welded portion, Compared to the ultrasonic inspection method for every high-precision gap over the maximum limit, It is possible to check the welding quality of the object to be inspected.

The longer the time required to inspect the welding quality of the object to be inspected becomes, the lower the productivity of the parts to be inspected becomes. Thus, by inspecting defects to the depth of welds by performing ultrasonic inspection less precisely at depths corresponding to the minimum depth of weld depths to depths no longer welded or to depths corresponding to maximum limits, The inspection time can be shortened as much as possible.

If the welded joint surface of the object to be inspected is welded to an above-mentioned minimum limit value without an abnormal state (bubbles or cracks), even if there is air bubbles or cracks in the welded portion at the depth below the maximum limit, It has little effect on weld quality. Therefore, as described above, in the section deeper than the minimum limit, the accuracy required to detect the bubbles and cracks, and not only the precision required to detect the bubbles and cracks, but the accuracy required to measure the welded depth (the aforementioned gap for low precision) So that the time required for the inspection of the welding quality of the object to be inspected is shortened.

On the other hand, if there is an inspection stop request from the operator during the ultrasonic inspection for the welded portion of the inspection object as described above (S430), the control unit 20 returns the probe 21 to the dormant position and ends the inspection operation do.

The above-described embodiments are based on the premise that the ultrasonic inspection for inspecting the welding quality is started from the upper surface of the welded portion of the object to be inspected. That is, in the above-described embodiments, for any inspection object, starting from a plane (the plane is a reference surface with a depth of 0) which is flush with the upper end of the welding portion, along the circumference of the bonding surface of the inspection object The ultrasonic inspection is carried out in such a manner that the depth of the test is lowered by the distance of the high precision gap and the depth of the weld is measured at a depth deeper than the minimum limit, I was fascinated.

In another embodiment according to the present invention, it is possible to start from a position which is deeper than the maximum limit value of the welding depth by a high precision gap. In this embodiment, the transducer is moved vertically to the vertical movement distance set in the control unit 20 according to the above-described method, corresponding to the sum of the set maximum limit and the high precision gap. After the ultrasonic inspection is performed on the object to be inspected at the initial depth, the depth of the weld at each position (phase) of the object to be inspected is increased to the minimum limit while raising the probe 21 (The welding depth is obtained by subtracting the distance that the probe 21 is lifted to a value obtained by adding the maximum limit value and the high-precision gap), and at a position above the depth corresponding to the minimum limit value, ultrasonic waves The probe 21 is gradually raised while detecting the welding abnormality. Of course, when the height reaches a predetermined height (that is, a plane having a depth of 0) according to the set vertical movement distance and the ultrasonic inspection is finished, the quality inspection of the welded part for the object to be inspected is completed.

In the embodiments of the present invention described above, the gap for the low precision has a larger value than the gap for the high precision, and the ultrasonic inspection is performed with the gap for the low precision for a section deeper than the depth corresponding to the minimum limit. However, in other embodiments according to the present invention, the ultrasonic inspection is performed by applying a single gap, that is, a high-precision gap, to the entire vertical section to be inspected, without dividing the ultrasonic inspection gap into a high precision gap and a low precision gap It is possible. That is, the ultrasonic inspection may be performed at a gap that is the same as the gap (high-precision gap) measured in the upper section rather than the low-precision gap even in a section deeper than the minimum limit.

In the above-described embodiments, it is assumed that the transducer 21 of the ultrasonic testing apparatus 200 moves in the vertical direction with respect to the horizontally moving or rotating object to be inspected. However, when the transducer 21 is moved to the object to be inspected The object to be inspected may be moved in the vertical direction by the measurement interval. That is, if there is only relative vertical movement between the probe 21 and the object to be inspected, the welding quality inspection and the depth measurement of the object to be inspected of the present invention can be accurately performed.

The methods of maintaining the accuracy of the quality of the measurement in the quality inspection and the depth measurement of the weld described as various embodiments according to the present invention are not necessarily mutually incompatible, .

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined in the appended claims. , Alteration, substitution, addition, or the like.

20: control unit 21: probe
22: Servo motor 23: Motor drive part
24: storage unit 25: display driver
26: display unit 27: interface unit
90: water tank 91: servo motor
92: Encoder 200: Ultrasonic testing device
901: object to be inspected

Claims (12)

An apparatus for inspecting a welding state of an object formed by welding a joint surface of both materials by using ultrasonic waves,
A probe for transmitting an ultrasonic wave to a bonding surface of the object at a distance from the object and for detecting a strength of a reflected signal according to the transmitted ultrasonic wave;
A moving unit for moving the probe unit in a space according to an applied signal;
The moving part moves the probe part to an initial position with respect to the object and then moves the probe part in the vertical direction relative to the object at an initial position thereof while changing the intensity of the reflected signal detected by the scanning operation Based on at least two coplanar positions on the joint surface and measuring the welded depth to obtain an average weld depth with respect to the positions, To obtain a plurality of average welding depths and then to calculate an average value of the plurality of average welding depths. If the difference between the calculated average value and the predetermined reference value exceeds the predetermined limit, the user can recognize And a control unit configured to generate a visual or auditory signal,
Wherein the reference value is an average value calculated for a plurality of average weld depths obtained by the controller performing the inspection operation on objects having the same shape as the object ahead of the object and the other objects,
Wherein the initial position is a point which is the same height as the upper end of the joint surface or is deeper than the depth corresponding to the designated second limit by a distance designated by the control unit vertically through the probe unit, The position being located after the movement of the crossover section corresponding to the horizontal and vertical movement distance values set in the control section,
Wherein the vertical movement distance value is obtained by performing the detection operation in a direction perpendicular to a welded joint surface of a third object having the same shape as that of the object and then measuring the welding depth determined by the signal intensity detected by the detection operation And the actual weld depth measured by cutting the joint surface of the third object is compared and then corrected according to the compared result. The method according to claim 1,
Wherein the control unit is configured to perform the inspection operation so that, when the inspection operation is performed, for a section deeper than the depth corresponding to the first limit from the upper end of the bonding surface, 2 < / RTI > 3. The method of claim 2,
Wherein the second gap is determined based on a difference between a specified second limit and the first limit, and the second limit is a value used as a criterion for determining a weld defect if the weld depth exceeds the value. . The method according to claim 1,
The control unit is configured to update the average value each time the inspection operation is sequentially performed one by one on the other objects or whenever the inspection operation is performed on new objects corresponding to a predetermined number and compare the average value with the reference value / RTI > The method according to claim 1,
Wherein the control unit is further configured to reset the reference value as an average of a plurality of average weld depths obtained from objects for which the inspection operation is performed after a request from the user is made. delete delete The method according to claim 1,
Wherein the vertical movement distance value is a value obtained by subtracting the vertical axis of the probe section from the probe section in the vertical direction of the probe section, Is first determined based on the pattern of the signal detected through the operation,
The initial determination is made such that the test piece is mounted such that the vertical distance to the groove is equal to the vertical distance to the upper end of the joint surface when the test operation is performed with respect to the object, And a resultant signal pattern resulting from the flaw detection operation on the EUT in a state where the test object is in a state of being tested. The method according to claim 1,
Wherein the controller is configured to vertically lower or raise the probe portion by a designated measurement interval when the probe operation is completed by the probe portion along a curve or a straight line at the same depth from the upper end of the contact surface . The method according to claim 1,
If it is determined that the welding depth is less than the designated first threshold value or exceeds the specified second threshold value, the control unit determines that the welded state is defective for the object, and the visual or audible And to output a signal. The method according to claim 1,
Wherein the abutment surface has a circular surface, a square or any curved shape. A method of inspecting a welding state of an object formed by welding a joint surface of both materials by using ultrasonic waves,
By performing a flaw detection operation for detecting the change in the intensity of the reflected signal according to the transmitted ultrasonic wave by transmitting the ultrasonic wave to the bonding face through the probe portion at at least two coplanar positions on each of the objects, A first step of obtaining welded depths from the positions and then calculating an average value of the depths,
A second step of setting a value obtained by averaging the average values individually calculated for the objects as a reference value,
Performing a flaw detection operation at at least two coplanar positions on each of the other objects, not the objects, to obtain weld depths from the initial position and then calculating an average value of the depths; ,
A fourth step of obtaining a difference between a value obtained by averaging the individual average values calculated in the step 3 and the set reference value and generating a visual or audible signal that can be perceived by the user when the difference is out of the predefined limit , ≪ / RTI >
The initial position may be a point that is the same height as the upper end of the object or the other objects or a deeper point than the depth corresponding to the designated second limit value, Is located at a position after the corresponding crossover portion has moved,
Wherein the vertical movement distance value is obtained by performing the detection operation in a direction perpendicular to a welded joint surface of a third object having the same shape as that of the object and then measuring the welding depth determined by the signal intensity detected by the detection operation The actual weld depth measured by cutting the abutment surface of the third object is compared and then corrected according to the compared result.
KR1020150053021A 2015-04-15 2015-04-15 Method and apparatus for maintaining acuracy of measured quality in depth measurement of welded sections using ultrasonic waves KR101658120B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
KR1020150053021A KR101658120B1 (en) 2015-04-15 2015-04-15 Method and apparatus for maintaining acuracy of measured quality in depth measurement of welded sections using ultrasonic waves

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
KR1020150053021A KR101658120B1 (en) 2015-04-15 2015-04-15 Method and apparatus for maintaining acuracy of measured quality in depth measurement of welded sections using ultrasonic waves

Publications (1)

Publication Number Publication Date
KR101658120B1 true KR101658120B1 (en) 2016-09-21

Family

ID=57080418

Family Applications (1)

Application Number Title Priority Date Filing Date
KR1020150053021A KR101658120B1 (en) 2015-04-15 2015-04-15 Method and apparatus for maintaining acuracy of measured quality in depth measurement of welded sections using ultrasonic waves

Country Status (1)

Country Link
KR (1) KR101658120B1 (en)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002214204A (en) * 2001-01-19 2002-07-31 Toshiba Corp Ultrasonic flaw detector and method using the same
JP2002214207A (en) * 2001-01-23 2002-07-31 Aisin Aw Co Ltd Method for inspecting welded part and ultrasonic flaw detector
KR20050105623A (en) * 2004-04-30 2005-11-04 안종열 Supersonic waves welding inspection system
US20110296922A1 (en) * 2010-06-07 2011-12-08 Syed Mohamed Ali Emat for inspecting thick-section welds and weld overlays during the welding process

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002214204A (en) * 2001-01-19 2002-07-31 Toshiba Corp Ultrasonic flaw detector and method using the same
JP2002214207A (en) * 2001-01-23 2002-07-31 Aisin Aw Co Ltd Method for inspecting welded part and ultrasonic flaw detector
KR20050105623A (en) * 2004-04-30 2005-11-04 안종열 Supersonic waves welding inspection system
US20110296922A1 (en) * 2010-06-07 2011-12-08 Syed Mohamed Ali Emat for inspecting thick-section welds and weld overlays during the welding process

Similar Documents

Publication Publication Date Title
CN101672829B (en) Method for measuring parameter of omega welding seam defect
KR101478465B1 (en) Mechanized Ultrasonic Testing Method for Curved Pipe Welding Zone
JP5706772B2 (en) Nondestructive inspection method
JP5604738B2 (en) Progress crack detection method, apparatus and program
JP2008122209A (en) Ultrasonic flaw inspection device and method
US11249053B2 (en) Ultrasonic inspection configuration with beam overlap verification
KR101921685B1 (en) Apparatus for inspecting defect and mehtod for inspecting defect using the same
JP2007046913A (en) Welded structure flaw detection testing method, and steel welded structure flaw detector
JP2007285813A (en) Ultrasonic flaw inspection device and ultrasonic flaw inspection method
CN111537615A (en) Phased array ultrasonic weld tracking system and method and control device thereof
US7204147B2 (en) Ultrasonic inspection method for weld zone
KR101677604B1 (en) Method and apparatus for inspecting weld quality including welded depth using ultrasonic waves
KR101799051B1 (en) Method and apparatus for inspecting bead through laser scanning
KR101658120B1 (en) Method and apparatus for maintaining acuracy of measured quality in depth measurement of welded sections using ultrasonic waves
JP2019219179A (en) Ultrasonic inspection device, ultrasonic inspection method, ultrasonic inspection program, and 3D printer device
JP2007322350A (en) Ultrasonic flaw detector and method
KR101658122B1 (en) Method and apparatus for displaying on a screen the state of welded sections measured using ultrasonic waves
JP4870516B2 (en) Piping inspection method and piping inspection support device
JP5610444B2 (en) Ultrasonic inspection method and apparatus for welds
JP2009014513A (en) Ultrasonic flaw detection method
JP4699242B2 (en) Ultrasonic probe coupling check method and computer program
JP2012137464A (en) Ultrasonic flaw detection system and ultrasonic flaw detection method
JP3745628B2 (en) Welded part inspection method and ultrasonic flaw detector
JPH09113492A (en) Ultrasonic inspection unit
JP6109061B2 (en) Inspection method for remaining life of welded parts of heat-resistant materials

Legal Events

Date Code Title Description
E701 Decision to grant or registration of patent right
GRNT Written decision to grant
FPAY Annual fee payment

Payment date: 20190905

Year of fee payment: 4