JPH021633B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method of aligning the attachment portion of a cylinder and another cylinder attached to the cylinder from the inside using a manipulator having five degrees of freedom.

<Prior Art> An example of a cylinder in which another cylinder is attached so as to protrude from the surface thereof is an attachment part between a cylindrical drum and a nozzle. Since the cross section inside this attachment part changes suddenly, stress concentration may occur. When materials with high stress concentrations are subjected to repeated loads, fatigue cracks develop and they are prone to fracture. Therefore, detecting unsound parts inside or on the inner surface of the mounting part is an extremely important problem in product maintenance.

Conventionally, ultrasonic flaw detection equipment has often been used to detect flaws inside the nozzle attachment part of a cylindrical drum, and the ultrasonic flaw detection has been carried out manually by an inspector who goes close to the area to be inspected.

However, this conventional method has problems in terms of economy and reliability, such as being extremely time-consuming, slow in flaw detection, and potentially causing flaw detection failure. Furthermore, in particular, inspections of equipment within the reactor coolant pressure boundary, such as the reactor pressure vessel, were not possible because inspectors were unable to get close to the areas to be inspected due to radiation.

<Problems to be Solved by the Invention> Therefore, an ultrasonic flaw detection device using a water immersion method under the inner surface of the nozzle attachment part that can perform flaw detection remotely and automatically has been considered; (2) The probe plate and manipulator may come into contact with the surface of the test piece due to its complicated curved shape, so the parallelism and water distance between the probe plate and the surface of the test piece may not be accurate. There is a risk of accidents such as damage, (3)
Furthermore, there were many problems that needed to be resolved, such as the need to consider compatibility in testing various reactor pressure vessels with the same device, which hindered the completion of the device. .

The present invention has been made in view of the above-mentioned technical situation, which is an obstacle to the completion of an ultrasonic flaw detection device using the water immersion method under the inner surface of the nozzle mounting part that can be remotely and automatically detected. The purpose of this study is to provide a tracing method that can solve the above problems (1), (2), and (3).

<Means for Solving the Problems> In order to achieve the above object, in the present invention, the curved surface part inside the attachment part of one cylinder and another cylinder connected to the side surface thereof is used as the test part, and the other cylinder is a centerline moving shaft mounted on the centerline of the cylinder so as to be movable in the direction of the centerline; a rotating shaft that is attached to the tip of the centerline moving shaft and rotates about the center axis of the centerline moving shaft; When aligning the inspection tool of the manipulator, which has three tiltable bending shafts attached in succession to a rotating shaft and an inspection tool is attached to the bending shaft on the distal end side, to the test subject, An inclination angle of the imaginary axis with respect to an axis passing through the center of curvature and parallel to the center line of the other cylinder as an axis imagining the axis of the bending axis of the tip of the manipulator directed toward the center of curvature of the cylinder, and the rotation. The amount of movement of the other four axes is controlled by the rotation angle of the axes, so that the position and orientation of the test tool with respect to the test subject can be maintained appropriately.

<Operation> In the curved surface tracing method described above, based on the inclination angle of the imaginary axis and the angle of the rotation axis, the angle of the bending axis and the axis of movement on the centerline are adjusted so that the inclination angle of the imaginary axis is kept constant. Position is controlled. Therefore, by using the imaginary axis as the step axis and increasing its inclination angle by a certain amount, and rotating the rotation axis for each inclination angle as the scan axis, it is possible to increase the angle of inclination over the entire curved surface of the attachment part between the cylinders. It can be imitated.

<Example> Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a manipulator to which the profiling method of the present invention is applied, as shown in FIG.
FIG. 3 is a cross-sectional view showing a case where the device is used for flaw detection inside the attachment portion.

The manipulator that is the object of the present invention has a horizontal movement axis 1 as a movement axis on the center line that can move horizontally.
, a rotating shaft 2 provided at the tip of the horizontal movement shaft 1 that can rotate ±200°, and three bending shafts 3, 4, 5 that are continuously provided at the tip of the rotating shaft 2 and capable of bending ±100°. It has 5 degrees of freedom consisting of . The probe plate 6 is installed at the tip of the bending shaft 5, and an inspection tool, etc. is attached to the probe plate 6, and the inspection tool is held parallel to the test area (parallel to the tangent line of the test area) and at a constant level. Distance is something that can be smoothed out. The manipulator configured in this way has a carriage 8.
The base end of the horizontally moving shaft 1 is supported by the shaft 1, and the carriage 8 is mounted so as to be able to move up and down along a rail provided on a main column 9 which can rotate 360 degrees.

Next, a tracing method using this manipulator will be specifically explained.

First, the center line of the horizontally movable shaft 1 is made to coincide with the center line N of the nozzle 102, which is another cylinder.

An axis 7 is assumed to be a step axis. As shown in FIGS. 1 and 5, this imaginary axis 7 is an axis along which the axial center line of the probe plate 6 (the axial center line of the bending shaft 5) passes through the center of curvature 10 of the nozzle curved surface. , its angle θ ₇
passes through the center of curvature 10, and the nozzle center line N is determined as an angle (clockwise is positive) with respect to a parallel axis (referred to as reference axis C).

The angle θ ₇ of the virtual axis 7 with respect to the reference axis C is increased in the range of 0° to approximately 90° in certain increments (for example, 5°), and the rotation axis 2 is
Rotate 360° using as the scan axis. thus,
The inspection tool attached to the probe plate 6 performs flaw detection over the entire area of the nozzle attachment part, which is the surface to be inspected.
At this time, the angle signals of the rotation axis 2 and the virtual axis 7 become input signals of the other four axes 1, 3, 4, and 5,
The amount of movement of each axis is controlled.

Next, the amount of movement of the bending axes 3, 4, and 5 and the horizontal movement axis 1 will be described.

Now, a drum 10 with radius R as shown in FIG.
Consider the cross-sectional shape of the attachment portion between the body of Nozzle 1 and the nozzle 102.

As shown in FIGS. 2 and 6, if we take the angle θ ₂ with the longitudinal direction of the drum 101 as θ ₂ =0°, the cross-sectional shape of that part at the angle θ ₂ will be as shown in FIGS. 3 and 8. Ellipse 1 with minor axis = 2R and major axis = 2R/sinθ ₂
01a intersects with the curved surface 102a of the nozzle 102. Therefore, when the rotation axis 2 is rotated from 0° to 90° with the virtual axis 7 fixed (keeping the angle θ ₇ constant), the center of curvature 10 of the nozzle curved surface 102a is When the object moves and θ ₇ is small, the test part P (virtual axis 7
and the curved surface 102a or 101a) is the elliptical curved surface 1 of the drum body from above the nozzle curved surface 102a.
Move to 01a. FIG. 8 shows that P ₁ is located on the nozzle curved surface 102a, and P ₂ is moved onto the elliptical curved surface 101a of the drum body.

Therefore, when controlling the movement amount of the bending shafts 3, 4, and 5 according to the position of the test part P, it is necessary to check whether the test part P is on the nozzle curved surface 102a or the ellipse of the drum body. It is necessary to change the method of determining the amount of movement of the bending shafts 3, 4, and 5 depending on whether the bending shafts 3, 4, and 5 are on the curved surface 101a.

First, a method of determining the amount of movement (movement angle) of the bending shafts 3, 4, and 5 when the test portion P is on the nozzle curved surface 102a will be described.

As shown in Fig. 1, the angle between the bending axis 3 and the nozzle center line N is θ ₃ (counterclockwise is positive), and the angle between the bending axis 4 and the bending axis 3 is θ ₄ (counterclockwise). The angle between the bending axis 5, which is the axis on which the probe plate 6 is attached, and the bending axis 4 is θ ₅ (counterclockwise is positive), and the respective lengths of the bending axes 3, 4, and 5 are The angles of the virtual axis 7 with respect to the reference axis C are θ ₇ as described above, the radius of curvature of the inner curved surface (center of curvature 10 ₎ of the nozzle mounting part is r _, and the probe plate ₆ is Let w _P be the water distance between and the test area.

When the test part P is on the nozzle curved surface 102a (not on the drum body), the origin is the intersection O between the horizontal movement axis 2 and the bending axis 3, and the center of curvature of the nozzle curved surface in FIG. 10's xy coordinates are (x _r , y _r ), and the xy spot of the junction point between bending axis 5 and bending axis 4 is (x _e , y _e ), then x _r , y _r , x _e , y _e is expressed as follows.

y _r = l ₃ cos θ ₃ + l ₄ cos (θ ₃ + θ ₄ ) +
(l ₅ +w _P +r) cosθ ₇ ...(1) x _r = -l ₃ sinθ ₃ -l ₄ sin (θ ₃ +θ ₄ )
+(l ₅ +w _p +r) sinθ ₇ …(2) y _e =y _r −(l ₅ +w _P +r) cosθ ₇ …(3) x _e =−{x _r −(l ₅ +w _P +r) sinθ ₇ }
...(4) Furthermore, if the intersection O' between the drum center line D and the nozzle center line N is taken as the origin, the coordinates of the joining point of the bending shafts 4 and 5 are expressed as follows.

y′ _e =y _e +(R _s +R _p ) ……(5) x′ _e =−x _e ……(6) However, R _p is the value when the horizontal movement axis 1 is retracted the most (travel amount 0 mm). The protrusion of the horizontal movement axis 1 with respect to the drum center line D (distance from the drum center line D to the intersection of the horizontal movement axis 1 and the bending axis 3), R _s is the amount of movement of the horizontal movement axis 1 with respect to R _p It is.

From the above, the angles θ ₃ , θ 4 , and θ ₅ of the bending axes 3, ₄ , and 5 are expressed as follows.

θ ₄ = cos ^-1 (x′ _e ² +y _e ² −l ₃ ² −l ₄ ² /2・l ₃
・l ₄ ) ...(7) θ ₃ =tan ^-1 {x′ _e・l ₃ +l ₄ (x
′ _e cosθ ₄ −y _e sinθ ₄ )/y _e・l ₄ +l ₄ (y _e cosθ ₄ +x′ _e s
inθ ₄ )}……(8) θ ₅ = −(θ ₃ +θ ₄ +θ ₇ )
(9) As mentioned above, in FIG. 1, the rotation direction of the bending shafts 3, 4, and 5 is positive in the counterclockwise direction, and the rotation direction of the virtual axis 7 is positive in the clockwise direction.

Next, the test portion P is the elliptical curved surface 101 of the drum body.
The case where it is on a is shown.

In FIG. 1, the equation of a straight line passing through the center of curvature 10 of the nozzle curved surface 102a and having an angle θ ₇ of the virtual axis 7 as its inclination is _{expressed as}
Then, it is expressed by the following formula.

y'=ax+b...(10) a=tan(90° _-θ7 )...(11) b= _y'r - _axr ...(12) Also, the equation of the ellipse is as follows.

x ² /c ² +y′ ² /R ² =1 (13) c=R/sinθ ₂ (14) From the above, the value of the coordinates (x _e , y′ _e ) is expressed by the following equation.

However, R is the radius of the drum 101 (the distance from the drum axis center D to the inner surface of the drum 1).

As described above, the test portion P is the nozzle curved surface 102a.
Depending on whether the position is above or on the elliptical curved surface 101a of the drum body, (x _e , y _e ) can be set using the above equations (3), (4), or (15) and (16), and the equation ( 7) From (8) and (9), the amount of movement (angles θ ₃ , θ ₄ , θ _{5 ) of the bending shafts 3, 4, and 5} can be immediately obtained. Note that (x _r , y _r ) are determined in advance according to the tilt angle θ ₇ and the rotation angle θ ₂ .

On the other hand, the horizontal movement shaft 1 is moved so that the distance S from the drum wall surface 101b to the tip of the rotation shaft 2 becomes larger in order to facilitate the movement of the bending shafts 3, 4, and 5 (to increase the space in which they can move). need to be controlled.

However, the movable range of horizontal movement axis 1 is
The rotatable angular range of the bending axes 3, 4, and 5 is physically ±100° (in this manipulator);
It is limited by the stroke amount of the horizontal movement axis 1.

The rotatable angle range of the bending shaft 4 is physically ±
100°, so from equation (7) cos100°≦x′ _e ² +y _e ² −l ₃ ² −l ₄ ² /2・l ₃・l ₄ ≦cos0
゜ ...(17) Therefore, x′ _e ² +y _e ² ≦l ₃ ² +l ₄ ² +2・l ₃・l ₄ cos100゜……(18) x′ _e ² +y _e ² ≦(l ₃ +l ₄ ) ² ……(19) √ ₃ ² + ₄ ² +2・₃・₄ 100゜−
′ _e ² ≦y _e ≦√( ₃ + ₄ ) ² −′ _e ² ...(20) Here, from S=y _e + (l ₅ +w _P +r)cosθ ₇ −r, the possible range of S is , Smin≦S≦Smax (21).

However, Smax=√( ₃ + ₄ ) ² − _′e2 ⁾ +( _l5 + _wP
+r) cosθ ₇ −r……(22) Smin=√ ₃ ² + ₄ ² +2 _{3 4} 100゜−
′ _e ² +(l ₅ +w _P +r) cosθ ₇ −r (23).

Note that since x′ _e is a real number from equation (23), |x′ _e |≦√ ₃ ² + ₄ ² +2 _{3 4} 100°, and x′ _e is x′ _e = x Since _r − (l ₅ + w _P + r) sinθ ₇ , becomes.

Then, in order for the above equation (21) to hold,
It is a necessary and sufficient condition that θ ₇ ≧θ _c .

Therefore, the angle θ ₇ of the virtual axis 7 and the drum wall surface 10
As shown in FIG _. 4, which shows the relationship between the distance S from 1b to the tip O of the horizontal movement axis 1, the possible range of S is the value of S (Smax ) and the S value (Smin) when θ ₄ =100° (the area other than the diagonal line on the upper right in FIG. 4).

Further, since the amount of movement R _s ≧0 of the horizontal movement axis 1, from FIG. 1, R _s =R−R _p −S≧0 S≦S _p =R−R _p (26).

Therefore, the possible range S _PP of S is, if S _p ≧ Smax, then S _PP = Smax − Smin
...(27) If S _p < Smax, then S _PP = S _p −Smin ...(28). That is, in FIG. 4, it is a portion other than the diagonally shaded portions at the upper right and upper left (portions without diagonal lines). Furthermore, the center of curvature 1 of the nozzle curved surface 102a due to a change in the rotation angle θ ₂ of the rotation axis 2
Considering the displacement Δr in the drum radial direction of 0 (see FIG. 3), the possible range ΔS of S is ΔS=S _PP −Δr (29).

Therefore, if we take the largest S in the above range, S(θ ₂ , θ ₇ )=Smin(θ ₇ )+ΔS(θ ₂ )...(30) However, θ ₇ ≥θ _c S(θ ₂ , θ ₇ )=Smin(θ _c +ΔS(θ ₂ )...(31) However, 0<θ ₇ <θ _c . In equation (30), Smin(θ ₇ ) is expressed as (23)
It is found by inserting θ ₇ into the equation, and ΔS (θ ₂ ) is found from equations (27) to (29) and (22) (23).
Smin (θ _c ) in equation (31) can also be found in the same way as in equations (25) and (23). Note that in the range of 0 < θ ₇ < θ _c , the condition of equation (24) is not met, so the maximum value of Smin (θ ₇ ) is set to the maximum possible ΔS
(θ ₂ ) is added to S.

In this way, in the method of this embodiment, S can take the maximum size depending on the angle θ ₇ of the virtual axis 7 that is the step axis and the rotation angle θ ₂ of the rotation axis 2 that is the scan axis. While moving the horizontal movement axis 1,
According to θ ₂ and θ ₇ , the bending axis 3,
By determining the angles 4 and 5, the probe plate 6 is controlled to be a certain distance away from the test area P and parallel to the tangent to the test area P.

<Effects of the Invention> As described in detail above, the present invention is capable of controlling the amount of movement of other axes based on the angle signals of the scan axis and step axis when the mounting part of the drum and nozzle is aligned from the inside with a manipulator having 5 degrees of freedom. By controlling the
The probe plate can be kept parallel to the test area and at a constant water distance. Since the axis of the tip bending axis is controlled to pass through the center of curvature, the parallelism between the probe plate attached perpendicularly to the bending axis and the tangent to the test part is maintained. Note that the fact that the bending axis at the tip of the manipulator passes through the center of curvature of the nozzle mounting portion is the basis of all calculation formulas, as described above.

In addition, since the amount of movement of each axis is preset and controlled based on the dimensions, angles, shapes, etc. of the test part and manipulator, there is a risk that the probe plate, manipulator, etc. may come into contact with the test part and be damaged. The test area can be automatically aligned without any hassle. Therefore, by attaching ultrasonic flaw detection equipment, visual inspection equipment, etc. to the probe plate, it is possible to not only improve flaw detection accuracy and flaw detection efficiency, but also to improve the safety of flaw detection by eliminating radiation exposure through remote automatic operation. It is a tracing method that has a wide range of applications, as it can be used to visualize images using a visual inspection device. Furthermore, changes in the target cylinder can be easily accommodated, and compatibility can be ensured.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing a case where a manipulator to which the profiling method of the present invention is applied is used for flaw detection inside the nozzle attachment part of a cylindrical drum, Fig. 2 is an explanatory diagram of the cylindrical drum to which the present invention is applied, and Fig. 3 The figure is an explanatory diagram showing the cross-sectional shape of the connection part between the drum and the nozzle, FIG. 4 is an explanatory diagram of the possible range of the horizontal movement axis in the embodiment, and FIG. 5 is an explanatory diagram of the hypothetical axis,
FIG. 6 and FIG. 7 are explanatory diagrams of a cross section of the connecting portion between the drum and the nozzle. FIG. 8 is an explanatory diagram showing how the test portion moves from the nozzle curved surface to the elliptical curved surface of the drum body. In the drawing, 1 is a horizontal movement axis, 2 is a rotation axis (scan axis), 3, 4, and 5 are bending axes, 6 is a probe plate, and 7
is a virtual axis (step axis) set on the nozzle mounting part, 8 is a carriage, 9 is a main column, and 10 is the center of curvature of the nozzle mounting part.

Claims (1)

[Claims] 1 The curved surface part inside the attachment part of one cylinder and another cylinder connected to its side surface is the test part, and the test part is on the center line of the other cylinder which is attached movably in the direction of the center line. A moving shaft, a rotary shaft that is attached to the tip of this centerline moving shaft and rotates about the center axis of the centerline moving shaft, and three tiltable bending shafts that are successively attached to this rotating shaft. When aligning the test tool of a manipulator, in which the test tool is attached to the bending axis on the tip side, to the test area, imagine the axis of the bend axis of the tip of the manipulator pointing toward the center of curvature of the test part. The amount of movement of the other four axes is controlled by the inclination angle of the imaginary axis with respect to an axis passing through the center of curvature and parallel to the center line of the other cylinder, and the rotation angle of the rotation axis. A method for tracing a curved surface, characterized in that the position and orientation of the test tool relative to the test part are maintained appropriately.