JPH09105614A - Apparatus and method for evaluation of surface shape - Google Patents

Abstract

PROBLEM TO BE SOLVED: To directly measure a welding bead part for various products without cutting the welding bead part and to judge whether the quality of a welding bead shape is good or no good with good accuracy. SOLUTION: The surface-shape evaluation apparatus is provided with a light source 12a which can be moved in the X-axis direction, a light source 12b which can be moved in the Y-axis direction, a line sensor 13a which is arranged in the X-axis direction, and a line sensor 13b which is arranged in the Y-axis direction. The shape in the three-dimensional direction on the surface of a weldingbead is detected by a detector 4 which can be moved in the Z-axis direction. The output of every line sensor inside the detector 4 is sent to an analytical device 8 via a signal line L and a measurement and computing control device 7. The analytical device 8 measures the shape in the three-dimensional direction on the surface of the welding bead, it finds a stress concentration factor and a fatigue notch factor at a bead stop end part, it evaluates the life of the welding bead, and it outputs an analyzed result to a printer 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface shape evaluation apparatus and a surface shape evaluation method for determining the quality of a weld bead by measuring the surface shape of various weld beads such as a fillet weld bead and a butt weld bead.

[0002]

2. Description of the Related Art In the field of construction machinery structures, various construction machines such as hydraulic excavators tend to increase in size and capacity as a result of recent expansion of construction scale and increase in size of transportation vehicles. Along with this, along with improvements in operability and functionality, as well as various environmental problems that have recently been highlighted, demands for lighter weight and higher reliability are increasing.

A hydraulic excavator is composed of a front front attachment (hereinafter abbreviated as a front part), an upper revolving structure, and a lower traveling structure (underbody), and the front part has a bucket, an arm, a boom, and various types. It consists of a link and each hydraulic cylinder, and they are pin-connected. The bucket, arm and boom have a thin plate welded structure, and the arm and boom have a nearly complete box structure. Although the box structure of the boom differs depending on the model, three boxes are fixed by a butt-welded weld joint with a backing metal, and the bulkheads are fillet-welded for reinforcement. Also, for ease of operation and weight reduction, a construction method is adopted in which the plate thickness is made thinner toward the tip.

In designing a welded structure, in order to evaluate the fatigue strength in consideration of the construction method and the plate thickness, it is necessary to use the SN diagram for each construction method and each plate thickness. However, it takes a considerable amount of labor and time to obtain the SN diagram under each condition. Therefore, it is desirable to be able to evaluate the fatigue strength from existing experimental results without performing a fatigue test.

The fatigue strength of a welded joint is governed by the geometric shape of the weld bead, and it is important to find each parameter such as the flank angle, the bead height, the leg length, and the weld toe radius that represents the geometric shape of the weld bead. The stress concentration factor and the notch factor can be calculated by the finite element method calculation or the empirical formula by obtaining these respective parameters. Further, by using the result of multiplying the stress concentration factor by the nominal stress and the SN diagram of the material, the life of the welded portion can be predicted and calculated. That is, by calculating the stress concentration factor and the notch factor using the measurement results of the weld bead shape, the fatigue strength of the welded portion can be predicted and evaluated.

Conventionally, when measuring the shape of a weld bead, the weld bead is duplicated with a replica kit or the weld is cut at a right angle to the weld line (longitudinal direction of the welded portion), and the cut surface is universally cut. The trace was enlarged about 10 times with a projector, and the flank angle, the bead height, the leg length and the weld toe radius were measured from this trace using a ruler and a protractor.

[0007]

However, the conventional welding bead measuring method has a problem that it requires a considerable amount of labor and time for pre-preparation and post-treatment for making a copy of the welded portion. In addition, depending on the processing method, the copy may be distorted and its shape may differ from the actual shape, and the measurement of the enlarged cut surface is generally performed using a ruler, so there is a large risk of individual differences, etc., increasing accuracy. I can't. Further, the method of cutting out the welded portion and measuring it is rare when it can be cut out from the product, so in many cases the test piece is welded in advance under the same conditions as the product and the test piece is cut and evaluated. , It takes effort and time to obtain the result, and the evaluation cannot directly evaluate the product,
Only temporary evaluation using the test piece was possible.

An object of the present invention is to provide a surface shape evaluation apparatus and an evaluation method which can directly measure the weld bead portion of various products without cutting and can accurately determine the quality of the weld bead shape.

[0009]

[Means for Solving the Problems]

-Principle of Life Evaluation Test of Weld Beads-Hereinafter, an example of performing the life evaluation test of the fillet welded joint of FIG. 14 will be described. The main plate 51 and the sub plate 52 of FIG. 14 are fixed by fillet welding. In FIG. 14, the flank angle of the fillet weld bead 53 is θ, the bead height is h, the bead toe radius (curvature radius of the bead end) of the fillet weld bead is R, the plate thickness of the main plate is t, and the beat width is Is B.

Now, when stress is applied to the main plate 51 in the nominal stress range Δσ, stress concentration occurs at the bead toe 54, and the maximum local stress σloc acts on the bead toe. Therefore, it is particularly important to obtain the stress concentration coefficient and the notch coefficient at the toe of the bead in order to evaluate the life of the welded portion, and the stress concentration coefficient Kt and the notch coefficient Kf are expressed by equations (1) and (2), respectively. It is represented by.

(Equation 1)

Further, as shown in the equation (3), the stress concentration coefficient K
By multiplying t by the nominal stress range Δσ at the bead toe, the local stress σloc at the bead toe is determined.

## EQU2 ## σloc = Δσ × Kt (3)

The local stress σloc obtained by the equation (3) and FIG.
With the S-N diagram of the welding material shown in (1), the life of the welded portion can be evaluated. In order to calculate the stress concentration coefficient Kt and the notch coefficient Kf, it is essential to measure the flank angle θ, the bead height h, the bead width B, and the bead toe radius R related to the weld bead shape. Therefore, the present invention enables the flank angle θ, the bead height h, and the like to be easily and accurately measured by the following configuration.

-Structure of the Invention-The invention will be described with reference to FIGS. 1, 2, 9 and 12 showing an embodiment of the invention. According to the invention, the illumination light having a predetermined beam diameter is formed on the surface of the welding bead. Illumination light source 12 that can illuminate
a, 12b, first scanning means 11a, 11b for scanning illumination light along a predetermined direction of the welding bead surface, and light receiving means for receiving illumination light reflected from the welding bead surface in a direction of a predetermined angle range. 13a, 13b and light receiving means 13
The above object is achieved by including the surface evaluation means 8 for evaluating the two-dimensional shape of the surface of the weld bead based on the illumination light received by a and 13b. In the invention according to claim 1, the illumination light is scanned along a predetermined direction of the welding bead surface, and the illumination light reflected in the direction of the predetermined angle range is received among the illumination light reflected by the welding bead surface. The light is received by the means 13a and 13b. If there are irregularities or defective welding points on the surface of the weld bead, the reflection direction of the illumination light becomes irregular. Therefore, the surface evaluation means 8 measures and evaluates the two-dimensional shape of the surface of the weld bead according to the reflection direction of the illumination light.

According to the second aspect of the present invention, there is provided the second scanning means 6a for scanning the illumination light in a direction different from the predetermined direction of the surface of the welding bead, and the first and second scanning means 11 are provided.
The surface evaluation means 8 is configured to evaluate the three-dimensional shape of the welding bead surface based on the illumination light received by the light receiving means 13a, 13b when the illumination light is scanned by a, 11b, 6a. is there. According to the second aspect of the present invention, the illumination light is scanned in a direction different from the predetermined direction of the welding bead surface to evaluate the three-dimensional shape of the welding bead surface.

The third aspect of the present invention is an illumination light source 12
Illumination light having a predetermined beam diameter is emitted from a and 12b toward the welding bead surface, and the illumination light is scanned along the first direction of the welding bead surface and reflected from the welding bead surface in a predetermined angular range direction. The illuminated light is received by the light receiving means 13a, 13
b, the illumination light is scanned by a predetermined amount along the second direction on the surface of the welding bead, and scanning is performed in the first direction at each scanning position. Based on the results of light reception by the light receiving means 13a, 13b. This is to evaluate the three-dimensional shape of the weld bead surface. In the invention according to claim 3, the illumination light is scanned by a predetermined amount along the second direction of the welding bead surface, and the illumination light is scanned by the first position on the welding bead surface for each scanning position in the second direction. And the illumination light reflected on the surface of the welding bead is received by the light receiving means 13a, 13a.
The light is received by b, and the three-dimensional shape of the welding bead is evaluated based on the light reception result.

According to a fourth aspect of the invention, the illumination light source 12 is capable of irradiating the welding bead surface with illumination light having a predetermined beam diameter.
a, 12b, a first scanning means 11a for scanning the illumination light in the first direction to change the irradiation position of the illumination light on the surface of the welding bead, and a welding bead by scanning the illumination light in the second direction. At least a part of the illumination light reflected by the welding bead surface, which includes the second scanning means 11b for changing the irradiation position of the illumination light on the surface and a plurality of photoelectric conversion elements arranged side by side in at least the first direction. The first imaging device 13a that receives the light and converts it into an electric signal, and the plurality of photoelectric conversion elements that are arranged side by side in at least the second direction, and receives at least a part of the illumination light reflected by the welding bead surface. A second image pickup device 13b for converting into an electric signal, and a surface evaluation means 8 for evaluating the two-dimensional shape of the welding bead surface based on the electric signal output from the first and second image pickup devices 13a, 13b. , By providing the above object is achieved. In the invention described in claim 4, for example, as shown in FIG. 2, the illumination light is scanned in the first and second directions, and the illumination light reflected by the welding bead surface is converted into two different directions by photoelectric conversion elements. The two-dimensional shape of the welding bead is evaluated by receiving light by the first and second imaging devices 13a and 13b arranged.

According to a fifth aspect of the present invention, there is provided a third scanning means 6a for scanning the illumination light in the third direction to change the irradiation position of the illumination light on the surface of the welding bead. And a surface evaluation unit for evaluating the three-dimensional shape of the welding bead surface based on the illumination light received by the first and second imaging devices 13a and 13b when the illumination light is scanned in the third direction. 8 is configured. In the invention according to claim 5, the illumination light is further scanned in the third direction so that the three-dimensional shape of the weld bead can be evaluated.

According to a sixth aspect of the invention, the illumination light source 12 is capable of irradiating the welding bead surface with illumination light having a predetermined beam diameter.
And a first scanning means 11 for scanning illumination light along a predetermined direction of the welding bead surface, and a plurality of photoelectric conversion elements arranged in a curved shape or a curved surface, in a predetermined angle range from the welding bead surface. An imaging device 13 that receives the illumination light reflected in the direction and converts it into an electric signal, and a surface evaluation means 8 that evaluates the two-dimensional shape of the welding bead surface based on the electric signal output from the imaging device 13. Be prepared. In the invention according to claim 6, for example, as shown in FIG. 9, the illumination light is scanned along a predetermined direction of the surface of the welding bead, and the illumination light reflected by the surface of the welding bead is arranged in a curved or curved shape. The two-dimensional shape of the welding bead is evaluated by receiving light by the plurality of photoelectric conversion elements 13 thus formed.

According to a seventh aspect of the present invention, an illumination light source 12 capable of irradiating the surface of the welding bead with illumination light having a predetermined beam diameter.
A first scanning means 11 for changing the irradiation position of the illumination light on the surface of the welding bead by scanning the illumination light in a prescribed direction; and a plurality of photoelectric conversions arranged linearly or in a plane along the prescribed direction. An image pickup device 13 formed of an element, which receives illumination light reflected from the welding bead surface in a direction of a predetermined angle range and converts it into an electric signal; and a welding bead surface of the welding bead surface based on the electric signal output from the image pickup device 13. And a surface evaluation means 8 for evaluating the shape. In the invention according to claim 7, for example, as shown in FIG. 12, the illumination light is scanned in a predetermined direction, and the illumination light reflected by the welding bead surface is
The two-dimensional shape of the welding bead is evaluated by receiving light with a plurality of photoelectric conversion elements arranged linearly or in a plane along a predetermined direction.

The invention according to claim 8 is provided with a second scanning means 6a for scanning the illumination light along a direction different from the predetermined direction of the surface of the welding bead, and the first and second scanning means 11, 6a. The surface evaluation means 8 is configured to evaluate the shape of the surface of the welding bead in the three-dimensional direction based on the illumination light received by the image pickup device 13 when the illumination light is scanned by the scanning. According to the invention of claim 8, in the invention of claim 6 or 7, the illumination light is further scanned along a direction different from the predetermined direction so that the three-dimensional shape of the weld bead can be evaluated. According to a ninth aspect of the present invention, the surface evaluation means 8 is configured to calculate the stress concentration coefficient and the notch coefficient at the weld toe of the weld bead. In the invention described in claims 9 and 11, since the stress concentration coefficient and the notch coefficient at the weld toe portion are calculated, the local stress at the weld toe portion can be calculated from these calculation results, and by calculating the local stress, It is possible to judge the quality of the weld bead. The invention described in claim 10 is
A display device 8 capable of displaying the calculated stress concentration coefficient and notch coefficient is provided. According to the tenth aspect of the present invention, the calculated stress concentration coefficient and notch coefficient are displayed on the display device 8, and the calculation results can be used for various purposes. According to the eleventh aspect of the present invention, the surface evaluation means 8 is configured to evaluate the quality of the weld bead based on the calculated stress concentration coefficient and notch coefficient. The invention described in claim 12 is mainly for the purpose of downsizing, and the illumination light source 12
Is composed of a semiconductor laser.

Incidentally, in the section of means for solving the above-mentioned problems for explaining the constitution of the present invention, the drawings of one embodiment of the present invention are used to make the present invention easy to understand. Is not limited to the one embodiment.

[0022]

DETAILED DESCRIPTION OF THE INVENTION First and second embodiments of the present invention will be described below with reference to FIGS. First Embodiment FIG. 1 is a diagram showing a schematic configuration of a first embodiment of a surface shape evaluation device according to the present invention, which is formed in a fillet portion between a main plate 1 and a sub plate 2. The example which measures and evaluates the surface shape of the fillet weld bead 3 is shown. In FIG. 1, reference numeral 4 is a detector for measuring the surface shape of the fillet weld bead 3 in the two-dimensional directions (the XY directions in the drawing).

FIG. 2 is a diagram showing a specific internal structure of the detector 4. As shown, X along the light source guide 11a
A light source 12a that is movable in the axial direction and a light source guide portion 11b
A light source 12b movable in the Y-axis direction along the line sensor 13a, a line sensor 13a having a plurality of photoelectric conversion elements arranged in the X-axis direction in the inner region of the light source guide portions 12a and 12b, and one end of which is connected to the line sensor 13a. The line sensor 13b includes a plurality of photoelectric conversion elements arranged in the Y-axis direction. In this way, the light sources 12a and 12b can be moved in the XY two-dimensional directions, and the line sensors 13a and 13b can be moved in the two-dimensional directions.
The reason for arranging b is to accurately measure the surface shape in consideration of the fact that the surface of the welding bead 3 to be measured is not necessarily a flat surface.

Returning to FIG. 1, a drive member 5 for moving the detector 4 in the illustrated Z-axis direction is integrally attached to the rear end of the detector 4. The drive member 5 is provided with a magnet stand 6 to prevent the detector 4 from moving carelessly.
Is engaged with an engaging member 6a extending in the Z-axis direction.

By controlling the light sources 12a and 12b and the driving member 5 inside the detector 4, the surface shape of the welding bead 3 in the three-dimensional direction is measured, and the measurement result is measured by the signal line L and the measurement calculation control device 7. It is sent to the analysis device 8 via the.
The analysis device 8 calculates various data relating to the weld bead shape, for example, flank angle, bead height, leg length and weld toe radius, stress concentration coefficient Kt, notch coefficient Kf, and the like, and determines the quality of the weld bead shape. The determination result is output by the printer 9. Further, the analysis device 8 is provided with a display, and the analysis result is displayed.

FIG. 3 is a view for explaining the optical paths of the illumination light emitted from the light sources 12a and 12b of the detector 4. In FIG. 3, the flank angle of the welding bead 3 is θ and the normal direction of the welding bead surface is It is indicated by a dotted line. In FIG. 3, illumination light incident from a direction inclined by an angle θ with respect to the normal direction (direction indicated by a chain line in the figure) is inclined in a direction inclined by an angle 2θ with respect to an incident direction (direction indicated by a chain line in the figure). When reflected, the relationship of the equation (4) is established between the movement amount Δx of the light source 12a in the X-axis direction and the movement amount Δy of the reflected light in the Y-axis direction.

## EQU3 ## Δy / Δx = tan θ (4) Therefore, the flank angle θ is expressed by the equation (5).

[Equation 4] θ = tan ₋₁ (Δy / Δx) (5)

Further, the irradiation position (α, β) of the illumination light on the surface of the weld bead is as shown in the equation (6) from FIG.

[Mathematical formula-see original document] α = x, β = y−l ₂ (6) Therefore, the deviation between the Y-axis coordinate y of the light receiving position of the reflected light on the line sensor and the Y-axis coordinate β of the irradiation position on the welding bead. l ₂ is expressed by equation (7).

[Equation 6] l ₂ = (L ₁ −x) · tan (90−2θ) (7)

The X-axis coordinate x of the light source 12a in FIG. 3 and the Y-axis coordinate y of the light receiving position of the reflected light on the line sensor 13b have the relationship shown in FIG. 4, and this diagram is output to the printer 9. . According to FIG. 4, the surface shape of the welding bead 3 can be detected.

In FIG. 5, the flank angle θ of the weld bead 3 is 45.
It is a figure which shows the optical path of the illumination light in the case of less than degrees. FIG.
In (a), the coordinate position of the light source 12a in the X-axis direction is x ₀ ,
The light receiving position of the reflected light on the line sensor 13a in the X-axis direction is x ₁ , and the opening angle of the illumination light is 2θ. The deviation l _{3 in} the Y-axis direction between the position of the light source 12a and the irradiation position of the illumination light on the surface of the welding bead is given by the formula (8).

## EQU7 ## l ₃ = (x ₁ −x ₀ ) / tan 2θ (8)

Further, the moving distance b of the reflected light on the line sensor 13a when the light source 12a is moved by a predetermined amount a in the X-axis direction is expressed by the equation (9) as shown in FIG. 5B. .

From Equation 8] _{b = a + l 1 = a} + a · tanθ · tan2θ ... (9) (9) formula, by detecting the light receiving position b of the position a and the line sensor 13a of the light source 12a, that flank angle θ is obtained Recognize.

On the other hand, FIG. 6 is a view showing the optical path of the illumination light when the flank angle of the welding bead 3 is 45 degrees or more. In this case, the opening angle of the illumination light from the light source 12a is represented by π−2θ, and the opening angle of the illumination light from the light source 12b is represented by 2θ. Further, the upper limit angle γ of the opening angle for receiving the reflected light of the illumination light from the light source 12a by the line sensor 13b.
6B is obtained when the illumination light reflected by the welding bead 3 travels along the surface of the welding bead (in the direction of the arrow in the figure), and the relationship of the equation (10) is established. The coordinates (x ₀ , y ₀ ) indicate the irradiation position of the illumination light, and L ₀
Indicates the bead width.

Y ₀ · tan (π−2γ) = L ₀ −x ₀ (10) When the equation (10) is transformed, the upper limit angle γ of the opening angle becomes (1
It is calculated by the equation (1).

(Equation 10)

By performing the calculation of each equation described above, various parameters necessary for evaluating the life of the welding bead 3, such as the flank angle and the bead height, can be obtained, and the shape of the welding bead can be determined. It becomes possible to accurately grasp.

FIG. 7 is a flow chart showing the evaluation test process of the surface shape of the welding bead 3 in the first embodiment, and the operation of the first embodiment will be described with reference to FIG. In step S1 of FIG. 7, the detector 4 is aligned with the position where the Z-axis coordinate is zero. In step S2, the light source 12a shown in FIG. 2 is scanned in the X-axis direction, the reflected light from the welding bead 3 is received by the line sensors 13a and 13b, and photoelectric conversion is performed. The result is signal line L and measurement calculation control. It is sent to the analysis device 8 via the device 7. In step S3, the light source 12b shown in FIG. 2 is scanned in the Y-axis direction, the reflected light from the welding bead 3 is converted into an electric signal and sent to the analysis device 8 as in step S2.

In step S4, the analyzer 8 measures the surface shape of the welding bead 3 based on the processing results of steps S2 and S3. Specifically, the irradiation position of the illumination light on the welding bead 3 is obtained based on the equation (6), and the flank angle θ of the welding bead 3 is obtained based on the equation (5). Further, the above equations (7) to (10) are calculated to obtain the bead height, leg length, weld toe radius, etc. of the weld bead 3, and the result is output to the printer 9 or the display of the analyzer 8. .

In step S5, the detector 4 is moved in the Z-axis direction by a predetermined amount, the process returns to step S2, and the light source is again scanned in the X-axis direction and the Y-axis direction to detect the reflected light from the welding bead 3. When the detector 4 is scanned up to the end of the Z axis, the process proceeds to step S6, and the welding bead 3 is comprehensively evaluated.

FIG. 8 is a diagram for explaining the details of the processing in step S6. FIG. 8 (a) shows the case where the welding bead 3 is judged to be a good product, and FIG. 8 (b) shows the case to be a defective product. Shows. As shown in the figure, when the illumination light emitted from the light source 12a is reflected by the surface of the welding bead and is received by the line sensor 13a or 13b, the letters "OK" or the like are displayed on the display. For example, in the case of FIG. 8A, when the light source 12a is located at the position A or the position B, the characters "OK" or the like are displayed on both. However,
When the welding bead 3 has a defective welding portion such as an overhang or a defective penetration, the analyzing device 8 has a defective portion because the illumination light is not reflected from the defective welding portion as shown in FIG. 8B. Judge and display an error.

-Second Embodiment- In the second embodiment, the internal structure of the detector is different from that of the first embodiment, and the configuration excluding the detector is the first embodiment. Since it is common to the above, the following description will be focused on the internal structure of the detector. FIG. 9 shows the detector 4 of the second embodiment.
It is a figure which shows the internal structure of a, and the same code | symbol is attached | subjected to the structural part common to FIG. As shown in the figure, the detector 4a according to the second embodiment allows one light source 12 to move along the light source guide portion 11 having a length of about a quarter circle, and Inside, a line sensor 1 including a plurality of photoelectric conversion elements along a circumference concentric with the light source guide unit 11.
3 are arranged.

FIG. 10 is a diagram for explaining the optical path of the illumination light emitted from the light source 12 shown in FIG. In FIG. 10, the incident angle of the illumination light from the light source 12 is δ, the irradiation position of the illumination light on the welding bead 3 is P, and the reflection angle (opening angle) of the illumination light is 2
η, the receiving position of the reflected light on the line sensor is Q, and the line segment P
The intersection of Q and the light source guide is R, ∠POY = α, ∠PQ
O is β ₁ , ∠PR 0 is β ₂ , and ∠POQ = γ.

In FIG. 10, the incident angle δ is expressed by the equation (12).

Δ = π− (π / 2−α) −θ = π / 2 + α−θ (12) The reflection angle 2η is expressed by the formula (13) using the formula (12).

[Equation 12] 2η = π−2δ = 2 (θ−α) (13) The angle β ₁ is given by the equation (14) when the equation (12) is used.

Β ₁ = π− (γ + 2δ) = 2 (θ−α) −γ (14)

When the sine theorem is applied to the triangle PQO and the triangle PRO of FIG. 10, the relationships of equations (15) and (16) are established.

Sin2σ / L ₁ = sin β ₁ / γ ₀ (15) sin2σ / L ₂ = sin β ₂ / γ ₀ (16) From the expressions (15) and (16), the relationship of the expression (17) is obtained. To be

(15) L ₁ sin β ₁ = L ₂ sin β ₂ (17)

When ∠QOR in FIG. 10 is Δγ, the angle β
_Since the relation of β ₂ ≈β ₁ −Δγ holds between ₁ and β ₂ , the formula (17) is transformed into the formula (18).

L ₁ · sin β ₁ = L ₂ · sin (β ₁ −Δγ) (18) When the right side of the equation (18) is modified, the equation (19) is obtained.

Equation 17] _{L 1 · sinβ 1 = L 2} (sinβ 1 · cosΔγ-COSβ 1 · sinΔγ) = L 2 (sinβ 1 -Δγ · cosβ 1) ... (19) (19) By transforming equation (20) And the angle β ₁ is expressed by equation (21).

Tan β ₁ = L ₂ · Δγ / (L ₂ −L ₁ ) ... (20) β ₁ = tan ₋₁ Δγ · L ₂ / (L ₂ −L ₁ ) ... (21) Since Δγ can be obtained from the scanning amount of the light source 12, the flank angle θ can be obtained by obtaining β ₁ from the equation (21) and substituting it in the equation (14).

FIG. 11 is a flow chart showing the evaluation test process of the surface shape of the welding bead 3 in the second embodiment, and the operation of the second embodiment will be described with reference to FIG. In step S11 of FIG. 11, the detector 4a is aligned with the position where the Z-axis coordinate is zero. Step S12
Then, the light source 12 is caused to scan along the light source guide portion 11. That is, the light source 12 is scanned in the circumferential direction (π direction) when the angle φ in FIG. 10 is between 0 ° and 90 °, and the illumination light is emitted toward the welding bead 3 at each scanning position. Step S1
3, the reflected light from the welding bead 3 is detected by the line sensor 13
The light signal is received by and the electric signal photoelectrically converted by the line sensor 13 is sent to the analyzer 8. In the analysis device 8, the surface shape of the welding bead 3 is analyzed by performing the calculation based on the above equations, and the analysis result is sent to the printer 9 for printing. When the scanning in the π direction is completed, the process proceeds to step S14, the detector is moved in the Z-axis direction by a predetermined amount, and then the processes of steps S12 to S14 are repeated until the detector reaches the end position in the Z-axis direction. When the detector reaches the end position in the Z-axis direction, the process proceeds to step S15, the welding bead 3 is comprehensively evaluated, and the process ends.

The internal structure of the detector 4a is not limited to the first and second embodiments described above, but various modifications can be made. For example, FIG. 12 is a diagram showing the internal structure of the detector 4b mainly for the purpose of measuring and evaluating the fillet weld bead 3. The detector 4b of FIG. 12 is disposed inside the light source guide unit 11, a linear light source guide unit 11 that is bridged between the main plate 1 and the sub plate 2, a light source 12 that is movable along the light source guide unit 11. Linear line sensor 13
It is composed of

In the detector 4b of FIG. 12, while moving the light source 12 along the light source guide portion 11, the illumination light is emitted toward the welding bead 3 and the illumination light reflected by the welding bead 3 is emitted by the line sensor 13. Receive light. Detector 4 of FIG.
Since b has a simpler structure than that of FIG. 2 and it is not necessary to scan and control the light source in two directions, the surface shape of the welding bead 3 can be evaluated at a higher speed than in the first embodiment.

On the other hand, FIG. 13 is a view showing the internal structure of the detector 4c mainly for the purpose of measuring the butt weld bead 3. The detector 4c shown in FIG. 13 is similar to the detector 4 of the first embodiment in that the light source guide portions 11a and 11 extend in two directions.
b, the light sources 12a and 12b are movable along the respective light source guide portions 11a and 11b. In addition, inside the light source guide parts 11a and 11b, the line sensors 13a and 1b are arranged parallel to the light source guide parts 11a and 11b.
3b is arranged. The measuring method using the detector 4c of FIG. 13 is basically the same as that of the first embodiment, and the illumination light is radiated toward the welding bead 3 while moving the light sources along the light source guide portions, The reflected light is received by the line sensor.

While the fillet weld bead 3 is evaluated in the first and second embodiments, the butt weld bead as shown in FIG. 13 is evaluated by changing the direction of the detector 4 or 4a. You can also do Further, in the first embodiment, the two types of line sensors 13a and 13b are arranged in the directions orthogonal to each other, but the two types of line sensors are arranged in two different directions (need not be orthogonal to each other), and If the light source is scanned in two different directions, the same effect as in the first embodiment can be obtained.

In the second embodiment, the total length of the light source guide portion is set to be approximately one quarter of the circumference, but the length is not limited to one quarter and, for example, half the circumference. May be the length of. If the length is half the circumference, the butt weld bead 3 as shown in FIG. 13 can be easily evaluated.

In the first and second embodiments, an example in which the line sensor receives the illumination light reflected by the surface of the welding bead has been described, but an image of a CCD or the like in which photoelectric conversion elements are arranged in a two-dimensional direction is picked up. A device may be used. Also, the light source 12
If it is a semiconductor laser, the whole device can be downsized, which is convenient. The internal configuration of the detector 4 of FIG. 1 is not limited to that of FIGS. 2, 9, 12, and 13. The illumination light can be scanned along the welding bead surface, and the illumination reflected by the welding bead surface can be used. The effect of the present invention can be obtained as long as it is a detector provided with an imaging device capable of receiving the illumination light reflected in a predetermined range of the angle direction. In each of the above embodiments, an example in which the light source is moved along the light source guide part has been described, but instead of fixing the position of the light source, the reflection of the illumination light from the light source between the light source and the welding bead surface. An irradiation position may be changed by providing a mirror whose angle can be changed and rotating the mirror to change the reflection angle of the illumination light. Further, in the second embodiment, the light source guide portion is formed in an annular shape, but it may be formed in an elliptical shape, a convex curve, a convex curved surface, a concave curved surface, or a concave curved surface.

In the embodiment configured as described above, the light sources 12a and 12b serve as illumination light sources, and the light source guide section 1 is used.
1a and 11b are the first scanning means, and the line sensor 13
a and 13b correspond to the light receiving means, the analysis device 88 corresponds to the surface evaluation means, the line sensor 13a corresponds to the first imaging device, and the line sensor 13b corresponds to the second imaging device.

[0050]

As described above in detail, according to the present invention, the illumination light is scanned along the predetermined direction of the welding bead surface, and the illumination light is reflected from the welding bead surface in the direction of the predetermined angle range. Since the light is received to evaluate the two-dimensional shape of the surface of the weld bead, the shape of the surface of the weld bead can be measured in a non-contact manner without cutting the weld bead. Therefore, it is possible to directly inspect the weld bead portion of various products instead of inspecting a dummy test piece as in the conventional case, so that the inspection accuracy is improved. Also, there are irregularities on the welding bead surface,
Focusing on the fact that the reflection angle of the illumination light changes when there is a defective welding point and the reflection direction of the illumination light is detected, the surface shape of the welding bead can be accurately measured. According to the invention described in claim 2, since the illumination light can be scanned in a direction different from the predetermined direction of the surface of the weld bead, the shape of the surface of the weld bead in the three-dimensional direction can be measured and evaluated. According to the invention described in claims 4 and 5, since the photoelectric conversion elements are arranged side by side in two different directions, the reflection direction of the illumination light reflected by the surface of the welding bead can be accurately detected. Further, since the illumination light is scanned substantially parallel to the arrangement direction of the photoelectric conversion elements, the surface shape of the welding bead can be measured accurately. According to the invention described in claim 6, since the photoelectric conversion elements are arranged side by side in a curved shape or a curved surface shape, the illumination light reflected by the surface of the welding bead can be received without leakage. Claim 7
According to the invention described in (1), since the photoelectric conversion elements are arranged side by side in a straight line or in a plane along a predetermined direction and the reflected light from the surface of the welding bead is received, the line sensor or CCD which is generally commercially available is directly used. It can be used and cost can be reduced. According to the invention described in claims 9 and 11, since the stress concentration factor and the notch factor at the weld toe of the weld bead are calculated, the life of the weld bead can be accurately evaluated using these calculation results. . According to the invention described in claim 10, since the display device capable of displaying the stress concentration coefficient and the notch coefficient is provided, the characteristics of the welding bead can be visually grasped. According to the twelfth aspect of the invention, since the illumination light source is composed of the semiconductor laser, the size of the entire apparatus can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of a first embodiment of a surface shape evaluation apparatus according to the present invention.

FIG. 2 is a diagram showing a specific configuration inside a detector.

FIG. 3 is a diagram illustrating an optical path of illumination light emitted from a light source of a detector.

FIG. 4 is an X-axis coordinate x of the light source 12a and a line sensor 13b.
The figure which shows the relationship with the light receiving position y of the upper reflected light.

FIG. 5 is a diagram showing an optical path of illumination light when a flank angle θ of a welding bead is less than 45 degrees.

FIG. 6 is a diagram showing an optical path of illumination light when a flank angle θ of a welding bead is 45 degrees or more.

FIG. 7 is a flowchart showing an evaluation test process of the surface shape of the welding bead according to the first embodiment.

FIG. 8 is a diagram for explaining the details of the processing in step S6.

FIG. 9 is a diagram showing an internal structure of a detector according to a second embodiment.

FIG. 10 is a diagram illustrating an optical path of illumination light emitted from the light source shown in FIG.

FIG. 11 is a flowchart showing an evaluation test process of the surface shape of the welding bead according to the second embodiment.

FIG. 12 is a view showing the internal structure of a detector mainly for the purpose of measuring and evaluating fillet weld beads.

FIG. 13 is a view showing the internal structure of a detector mainly for the purpose of measuring and evaluating butt welded beads.

FIG. 14 is a diagram illustrating an example of performing a life evaluation test of a fillet welded joint.

FIG. 15 is an SN diagram of the welding material.

[Explanation of symbols]

 1 Main Plate 2 Sub Plate 3 Weld Bead 4 Detector 5 Driving Member 6 Magnet Stand 7 Measurement / Operation Control Device 8 Analysis Device 9 Printer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takayuki Shimodaira 650 Kazunachi-cho, Tsuchiura-shi, Ibaraki Hitachi Construction Machinery Co., Ltd.Tsuchiura factory Ceremony Company Tsuchiura Factory

Claims (12)

[Claims] 1. An illumination light source capable of irradiating a welding beam surface with illumination light having a predetermined beam diameter, a first scanning means for scanning the illumination light along a predetermined direction of the welding bead surface, and the welding bead. Light receiving means for receiving the illumination light reflected in the direction of a predetermined angle range from the surface, and surface evaluation means for evaluating the two-dimensional shape of the welding bead surface based on the illumination light received by the light receiving means,
A surface shape evaluation device comprising: 2. A second scanning unit for scanning the illumination light in a direction different from the predetermined direction of the surface of the welding bead, wherein the surface evaluation unit uses the first and second scanning units for the illumination. The surface shape evaluation device according to claim 1, wherein the three-dimensional shape of the welding bead surface is evaluated based on the illumination light received by the light receiving means when scanning light. 3. An illumination light source irradiating the welding bead surface with illumination light having a predetermined beam diameter, and scanning the illumination light along a first direction of the welding bead surface to cause the welding bead surface to have a predetermined distance. The illumination light reflected in the direction of the angle range is received by the light receiving means, the illumination light is scanned by a predetermined amount along the second direction of the welding bead surface, and the first direction is obtained at each scanning position. Surface shape evaluation method, wherein the three-dimensional shape of the surface of the welding bead is evaluated based on the result of light reception by the light receiving means. 4. An illumination light source capable of irradiating the welding bead surface with illumination light having a predetermined beam diameter, and changing the irradiation position of the illumination light on the welding bead surface by scanning the illumination light in a first direction. First scanning means for scanning, and second scanning means for scanning the illumination light in a second direction to change the irradiation position of the illumination light on the surface of the welding bead, and arranging at least in the first direction. A first image pickup device which is composed of a plurality of photoelectric conversion elements arranged and which receives at least a part of the illumination light reflected by the welding bead surface and converts it into an electric signal; and at least in a line in the second direction. A second image pickup device including a plurality of photoelectric conversion elements arranged, which receives at least a part of the illumination light reflected on the surface of the welding bead and converts it into an electric signal; and the first and second image pickup devices. Out of the device Surface shape evaluation apparatus, characterized in that it and a surface evaluating means for evaluating the two-dimensional shape of the weld bead surface based on the electric signal. 5. A third scanning means for changing the irradiation position of the illumination light on the surface of the welding bead by scanning the illumination light in a third direction, wherein the surface evaluation means comprises the first, The three-dimensional shape of the welding bead surface is evaluated based on the illumination light received by the first and second imaging devices when the illumination light is scanned in the second and third directions. The surface shape evaluation device according to claim 4. 6. An illumination light source capable of irradiating a welding bead surface with illumination light having a predetermined beam diameter, a first scanning means for scanning the illumination light along a predetermined direction of the welding bead surface, and a curved shape or An imaging device which is composed of a plurality of photoelectric conversion elements arranged in a curved surface, receives the illumination light reflected from the welding bead surface in a direction of a predetermined angle range, and converts the illumination light into an electric signal, and an output from the imaging device A surface shape evaluation device for evaluating a two-dimensional shape of the surface of the welding bead based on the generated electric signal. 7. An illumination light source capable of irradiating the welding bead surface with illumination light having a predetermined beam diameter, and changing the irradiation position of the illumination light on the welding bead surface by scanning the illumination light in a predetermined direction. 1 scanning means and a plurality of photoelectric conversion elements arranged linearly or in a plane along the predetermined direction, and receives the illumination light reflected from the welding bead surface in the direction of a predetermined angle range. A surface shape evaluation device for evaluating the shape of the welding bead surface based on the electric signal output from the image pickup device. 8. A second scanning means for scanning the illumination light along a direction different from the predetermined direction on the surface of the welding bead, wherein the surface evaluation means is provided for the first and second scanning means. The shape of the welding bead surface in the three-dimensional direction is evaluated based on the illumination light received by the imaging device when the illumination light is scanned for scanning. Surface shape evaluation device. 9. The surface profile according to claim 4, wherein the surface evaluation means calculates a stress concentration coefficient and a notch coefficient at a weld toe portion of the weld bead. Evaluation device. 10. The surface shape evaluation apparatus according to claim 9, further comprising a display device capable of displaying the calculated stress concentration coefficient and cutout coefficient. 11. The surface evaluation means evaluates the quality of the weld bead based on the calculated stress concentration coefficient and notch coefficient.
The surface shape evaluation device described in 1. 12. The surface shape evaluation device according to claim 4, wherein the illumination light source is composed of a semiconductor laser.