Tool for inspecting defects in irregular weld bodies

• US 4,368,644 A
• Filed: 05/26/1981
• Issued: 01/18/1983
• Est. Priority Date: 05/26/1981
• Status: Expired due to Fees

• Current Assignee: Combustion Engineering Incorporated (ABB Limited)
• Original Assignee: Combustion Engineering Incorporated (ABB Limited)
• Inventors: Wentzell, Timothy H., Innes, Charles B. Jr.
• Primary Examiner(s): Ciarlante, Anthony V.
• Assistant Examiner(s): Carlson, David V.
• Application Number:
  US06/267,142
• Time in Patent Office: 602 Days
• Field of Search: 73/634, 73/637, 73/638, 73/635, 73/623, 73/633, 376/249, 376/252
• US Class Current: 73/634
• CPC Class Codes: G01N 29/265 by moving the sensor relative to a stationary material

Abstract

A tool for manipulating an ultrasonic inspection transducer is actuated to move the transducer over the surface of an irregular weld body. The weld body disclosed, joins the nozzle of a reactor vessel to its vessel, the irregularity of the weld body defined by the intersection of the two cylinders. The transducer is moved over the surface of the weld body and actuated to scan through a predetermined angle in relation to the changing aspect of the geometry of the weld body by a cam mounted at the pivoting center of the tool.

Claims

1. In a weld body inspection tool which positions an ultrasonic detector from the centerline of a cylindrical nozzle joined to a cylindrical aperture in the side of a nuclear reactor vessel by moving the detector connected to the outer end of an extensible arm over the surface of the weld body,

a cam fixedly mounted at the center of arm rotation,

a hydraulic closed loop power system connected between the cam and the ultrasonic transducer mounted at the outer end of the extensible arm to control the direction of the output of the ultrasonic transducer as the arm pivots to maintain a predetermined relationship of the ultrasonic transducer output to the weld geometric shape,

and means connected to the ultrasonic transducer to manifest the reflection of the transducer output in detection of imperfections in the weld body.

2. The inspection tool of claim 1, including,

a spring member connected to the ultrasonic detector to urge the detector in one direction of movement in opposition to the power of the hydraulic system.

3. An inspection tool for detecting weld integrity, including, an ultrasonic transducer for establishing and sensing reflections of output of ultrasonic energy directed into a weld body,

a sled on which the ultrasonic transducer is mounted,

an arm radially extensible and pivotable about an axis and connected to the sled by its outer end to carry the transducer over the surface of a circular weld body,

power means connected to the sled with which the sled is automatically moved in directing the transducer output through a predetermined angle relative to the geometric shape of the weld body,

a cam fixedly mounted at the axis of arm pivoting and having a profile in contact with the power means to actuate the power means to automatically shift the position of the sled as the arm is pivoted and direct the output of the transducer in a predetermined relationship to the geometric shape of the weld body,

and means for manifesting the output of the ultrasonic transducer in terms of weld integrity.

4. The inspection tool of claim 3, in which,

the power system is a closed loop hydraulic master actuator/slave actuator system controlled at the master actuator by contact with the cam profile about the axis of arm pivoting the contacting the sled by the slave actuator at the outer end of the pivoting arms.

5. Apparatus for carrying an ultrasonic weld flaw detector over the surface of a circular weld body, including,

support structure on which is mounted a mechanical arm radially extensible and pivotable about the normal axis of the circular weld body,

a weld body to be inspected for flaws arranged about the center of arm pivoting,

means for pivoting the mechanical arm,

means for radially extending and retracting the length of the mechanical arm about the pivot axis,

an ultrasonic flaw detecting transducer mounted on the outer end of the pivoted arm and movable to vary the angle of the transducer output relative to the varying aspect of the weld body geometric shape,

power means extending from the axis of rotation into contact with the transducer on the outer end of the arm for moving the transducer,

a cam fixedly mounted at the axis of rotation and in contact with the power means to control the positioning of the transducer by the power means in accordance with the predetermined cam profile as the arm is pivoted,

and means connected to the transducer to manifest flaws sensed by the transducer in its travel over the surface of the weld body as the transducer is actuated by the power means.

6. The carrying apparatus of claim 5 in which the power means includes,

a master actuator contacting the profile of the cam at the axis of rotation,

a slave actuator mounted at the outer end of the arm contacting the transducer,

and a closed conduit of hydraulic fluid connecting the master actuator and the slave actuator.