Ultrasonic wand inspection system with improved centering assembly

Abstract

The invention discloses an ultrasonic wand or tube inspection assembly comprising two centering assemblies and two inspection boxes. The centering assemblies are designed to guide the inspected wand by rollers provided on symmetrically arranged pivot arms activated by a single centering ring. The pressure plate is designed to push the probe boxes onto the centering assemblies in a tightly stacked and concentric manner. The inspection probe boxes with the accompanying design of the engaging grooves and ridges and the pressure plate can be easily removed from the wand inspection assembly for maintenance operations.

Description

Technical Field

[0001] Exemplary embodiments of the present disclosure relate to non-destructive testing and inspection (NDT / NDI) of metal rods, and more particularly to a system having improved alignment accuracy between an ultrasonic probe and a rod held by a centering assembly. Background Art

[0002] Ultrasonic methods are commonly used to test solid bars for cracks, voids, and inclusions. Manual inspection is often impractical for 100% inspection of such products due to the time required for a full volumetric inspection. High-throughput automated ultrasonic testing can be performed using one or more transducers, which are typically immersed in a water tank to maintain acoustic coupling. By using multiple probes at once and moving the product relative to the probes, the speed of inspection and the likelihood of defect detection can be increased. Additional advantages can be obtained by using an automated phased array system (PA), which utilizes multiple-element probes and electronic beam steering technology to guide and focus the acoustic beam. Summary of the invention

[0003] In an exemplary embodiment of the present disclosure, a non-destructive inspection system is provided, which is configured to inspect a test object having a longitudinal shape passing through the inspection system in an axial direction. The inspection system includes a pair of centering assemblies, the pair of centering assemblies including a circular centering frame centered on the system axis. The centering frame has at least three pivot arms, the at least three pivot arms having corresponding first ends, which are pivotally attached to the centering frame at corresponding pivot joints that are substantially equally spaced around the centering frame. The pivot arms also have corresponding second ends, which are configured to engage the test object tangentially when the inspection system is running. The inspection system also includes at least one circular probe box, which is configured to carry an inspection probe. The inspection system also includes a pair of locking components, the pair of locking components being configured to be located on the centering frame and the probe box, respectively, to align the probe box to center along the system axis when the locking components are in an engaged position.

[0004] The centering frame and the probe box are mounted in two independent radial planes perpendicular to the axial direction.

[0005] The inspection system also includes a pressure plate, which is clamped between the centering frame and the probe box and is constructed with a pushing mechanism. When the pushing mechanism is actuated, it pushes the probe box and the centering frame into a coupling position so that the central axis of the probe box is concentric with the central axis of the centering frame (system axis). BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1is a perspective view of a rod inspection system according to an exemplary embodiment of the present disclosure.

[0007] Figure 2 is based on Figure 1 An exploded view of a rod inspection system according to an exemplary embodiment of the present disclosure is shown.

[0008] Figure 3A is a perspective view of a press plate according to an exemplary embodiment of the present disclosure.

[0009] Figure 3B and Figure 3C 1 and 2 are rear and side views, respectively, of a press plate according to an exemplary embodiment of the present disclosure.

[0010] Figure 4 is a cross-sectional view illustrating the operation of a platen of a rod inspection system according to an exemplary embodiment of the present disclosure.

[0011] Figure 5 is a perspective view of a centering assembly of a rod inspection system according to an exemplary embodiment of the present disclosure.

[0012] Fig. 6A and Figure 6B are views of the centering assembly when the pivot arm is in a fully open position and a closed position, respectively.

[0013] Fig. 7A and Figure 7B 2 are perspective views of a first side and a second side, respectively, of an inspection cassette of a rod inspection system according to the present disclosure. DETAILED DESCRIPTION

[0014] Conventional inspection systems may have a mechanical tolerance stack-up between the position of the probe and the position of the wand. For example, the wand may not be straight and the cross-section of the wand may not be uniform, but the centering mechanism must maintain a constant relationship between the centerline of the wand and the probe. Therefore, in order to move the wand at high speeds relative to the probe, conventional ultrasonic wand inspection systems use a centering mechanism to guide and center the passage of the wand.

[0015] However, such conventional ultrasonic wand inspection systems have several drawbacks. For example, the centering mechanism may be subject to tolerance errors, resulting in misalignment of the center axis of the centering assembly and the center axis of the probe. In addition, as disclosed in Faucher et al. (U.S. Pat. No. 8,264,221), there is a lack of radial symmetry in the components of the centering mechanism or their arrangement, which may result in positioning errors of the wand relative to the desired center of the centering mechanism and may produce different forces to be applied to those components. This asymmetric distribution of forces may result in asymmetric wear of the components, resulting in further miscentering of the wand, and may cause the wand to strike various parts of the ultrasonic wand inspection system, resulting in premature failure of the system or its components. Another problem with conventional ultrasonic wand inspection systems is the ease of assembly and maintenance.

[0016] Thus, exemplary embodiments of the present disclosure provide a rod inspection assembly having improved alignment accuracy between a centering assembly and a probe assembly, improved accuracy of the centering mechanism, and improved immunity to alignment errors due to uneven forces and uneven wear of components.

[0017] Figure 1 A perspective view of a rod or tube inspection system 1 according to an exemplary embodiment of the present disclosure is shown. The inspection system 1 is shown inspecting a rod 34 (shown in phantom) fed in an axial direction along a system axis 35 which is ideally concentric with the rod axis 34a. Figure 2 An exploded view of the rod inspection system 1 is shown. Figure 1 and Figure 2 The inspection system 1 includes two centering assemblies 2a and 2b, which are integrated with two inspection boxes 4a and 4b and a pressure plate 12. The centering assemblies 2a and 2b include centering assembly main boards 20a and 20b, respectively. A portion of the centering actuators 6a and 6b is partially attached to the main boards 20a and 20b, respectively. This may be discussed later in conjunction with the present disclosure. Figure 5 The centering components 2a and 2b are described in more detail in the description of FIG.

[0018] In operation, the centering assemblies 2a and 2b, the inspection boxes 4a and 4b and the pressure plate 12 are rigidly held together in part by three rigid links 8a, 8b and 8c located at the periphery of the rod inspection system 1. The rod inspection system 1 is supported by suspension supports 10a and 10b located at the bottom of the system 1. This allows the rod inspection system 1 to be limited in freedom of movement in response to forces applied to the centering assemblies 2a and 2b by the rod 34, for example due to the nonlinearity or inhomogeneity of the rod 34. The centering assemblies 2a and 2b and the inspection boxes 4a and 4b each have their own centers, which are intended to be concentric along the system axis 35 during inspection. It can be noted that the system axis 35 is defined by the centers of the centering assemblies 2a and 2b.

[0019] It should be noted that the orientation of the inspection system 1 shown in the figures is the same as how an operator operates the system 1. Figure 1 In FIG. 1 , the “upward” arrow indicates the “upward” direction. As an example, the actuators 6a and 6b are located at the “upward” part of the centering assembly to make it easy for the operator to access.

[0020] It should also be noted that the centering assemblies 2a and 2b, the inspection boxes 4a and 4b and the pressure plate 12 are mounted in their respective radial planes.

[0021] Reference Figure 3A and Figure 4 And continue to refer to Figure 2 The pressure plate 12 is designed to provide a pushing mechanism to ensure that the centering assemblies 2a and 2b and the inspection boxes 4a and 4b are closely stacked together, so that the rigid links 8a, 8b and 8c are all in a tensioned state, thereby minimizing misalignment or tolerance errors. The pressure plate 12 includes a pressure plate body 45 and a toggle clamp 40, and the toggle clamp 40 has a handle 42, a toggle clamp mechanism 44 and a toggle clamp shaft 46.

[0022] The toggle clamp 40 is located at the upper portion of the pressure plate 12 so that it is easily accessible to the operator. The handle 42 has an actuated position, in which the toggle clamp shaft 46 extends outward from the toggle clamp 42, and a non-actuated position, in which the toggle clamp shaft 46 is retracted from the extended position. When the handle 42 is manually actuated, the toggle clamp shaft 46 applies a toggle clamp force 43 that pushes onto the upper portion of the centering assembly main plate 20b.

[0023] like Figure 3B and Figure 3CAs shown, a pair of pivot brackets 48a and 48b are symmetrically mounted on the edge of the pressure plate body 45. The line connecting the pair of pivot brackets 48a and 48b forms an axis 47. The toggle clamping force 43 causes a slight rotation 41 of the body 45 about the axis 47. The stopper 37 located on the bottom of the pressure plate 12 acts to prevent the slight rotation 41, and the resulting compression forces 49a and 49b are transmitted to the inspection box 4b via the pair of pivot brackets 48a and 48b, respectively.

[0024] If the pressure plate 12 is regarded as a lever (in Figure 3C ), the clamping shaft 40 and the stopper 37 respectively located at the top and bottom of the pressure plate 12 generate the force 43 and the resistance 39 respectively, and the pivot brackets 48a and 48b act as a fulcrum at the middle portion of the pressure plate 12, thereby applying compressive forces 49a and 49b on the box 4b.

[0025] Reference Figure 4 , the compressive forces 49a and 49b are transmitted to the inspection box 4b, and then from the inspection box 4b to the inspection box 4a, and push the inspection box 4a against the main board 20a of the centering assembly. Thus, the inspection boxes 4b and 4a are displaced until all the components of the rod inspection system 1 are tightly stacked and nested together, at which time, the application of further clamping force 43 is used to generate tension in the rigid links 8a, 8b and 8c.

[0026] Reference Figure 3A and Figure 4 , when the toggle clamp 40 is not activated, the toggle clamp shaft 46 is pulled apart so as not to press on the main plate 20b. As a result, the resistance 39 is released and the pivot bracket moves away from pushing the probe box 4b back to the intermediate position. This allows the plate 12 to move freely out, thereby allowing the box 4b to be removed. It should be noted that when the handle 42 is in the inactive position, that is, when the toggle clamp shaft 46 is retracted, the assembly is constructed so that there is space between the pressure plate 12 and the inspection box 4b and between the pressure plate 12 and the centering assembly 2b, so that the pressure plate 12 can be lifted out of the assembly. Referring again to Figure 2 One or both of the inspection boxes 4a and 4b can then be lifted out of the assembly for maintenance or readjustment purposes without disengaging the rigid links 8a, 8b and 8c.

[0027] Figure 4 A cross-sectional view of the platen 12 in the context of the inspection system 1 is provided, illustrating the operation of the platen 12 when the components of the rod inspection system 1 are closely stacked and nested together. It should be noted that the pivot brackets 48a and 48b are susceptible to wear during repeated operation of the platen 12, and therefore, the pivot brackets are preferably replaceable components that may be made of stainless steel or a low friction plastic such as nylon.

[0028] like Figure 3A and Figure 4 As shown, it can be noted that the pressure plate body 45 is preferably configured to take the shape of a generally circular ring plate, the size of which is compatible with the size of the centering boxes 4a and 4b and the size of the main plates 20b and 20a. The size and shape of the pressure plate body 45 are also configured so that after assembly, the center line 34d is aligned with the center line 34d. Figure 1 . The pair of pivot brackets 48a and 48b are preferably configured to be located near or on the periphery of the body 45, symmetrically positioned along the geometric centerline 34d of the plate body 45. The connecting line 47 is substantially in the same plane as the centerline 34d, and when the system 1 is assembled, the connecting line 47 is substantially in the same plane as the system axis 35. This is the following mechanism: when the pressure plate 12 pushes the boxes 4a, 4b into concentric engagement with the main board 20a, the combined force 49 is applied in the same plane as the system axis 35, thereby ensuring that the pushing force does not deviate from the centrally defined system axis 35.

[0029] It should be understood that the positions of the toggle clamp 40, the pivot brackets 48a and 48b, and the stop 37 need not be exactly as shown. Figure 3A and Figure 4 As shown in the exemplary embodiment of . As long as the toggle clamping shaft and the stopper are respectively arranged on the first side but opposite edges of the pressure plate in such a way that the line connecting the toggle clamping shaft and the stopper is orthogonal to the line connecting the pair of pivot brackets, and the pair of pivot brackets are arranged on the second side but opposite edges of the pressure plate, so that when the pushing mechanism is actuated, the toggle clamping shaft and the stopper respectively generate a force and a resistance, and the pair of pivot brackets act as a fulcrum for pushing the locking parts together. All these alternative embodiments are within the scope of the present disclosure.

[0030] Reference Figure 5 , Figure 52 is a more detailed stereoscopic view of a centering assembly 2a according to an exemplary embodiment of the present disclosure. It should be noted that the construction of the centering assembly 2b can be the same as that of the centering assembly 2a. The centering assembly 2a includes a main board 20a and a centering annular plate 22. The combination of the main board 20a and the centering annular plate 22 is referred to as a centering frame 21a. Centering arms such as pivot arms 16-1, 16-2 and 16-3 have respective first ends, such as first ends 16a-3, which are attached to the centering annular plate 22 at arm joints, such as slots 26-1, 26-2 and 26-3, respectively, thereby allowing the first ends of the pivot arms 16-1, 16-2 and 16-3 to move linearly, radially and rotationally in their respective slots. The centering assembly 2a also includes six rollers, which are configured to contact the rod 34 tangentially during inspection and guide the rod 34 through the centering assembly 2a. The six rollers are arranged in three pairs: rollers 14-1.1 and 14-1.2 are rotatably attached to respective second ends of the pivot arm 16-1, rollers 14-2.1 and 14-2.2 are rotatably attached to the second end of the pivot arm 16-2, and rollers 14-3.1 and 14-3.2 are rotatably attached to the second end of the pivot arm 16-3. The pivot arms 16-1, 16-2, and 16-3 are pivotally attached to the centering assembly main plate 20a (also shown in FIG. 1 ) at pivot points 18-1, 18-2, and 18-3, respectively. Figure 1 as well as Fig. 6A and Figure 6B ), each of the pivot points 18-1, 18-2 and 18-3 is located at an intermediate position between the first end and the second end of the corresponding pivot arm.

[0031] It should be noted that the slots 26-1, 26-2 and 26-3 are subject to wear due to the forces applied when the rod 34 passes through the centering assembly 2a. Such wear may result in alignment errors in the alignment of the rod with the system axis 35. Preferably, the annular plate 22 is configured with three spare slots 28-1, 28-2 and 28-3 so that when the wear on one or more of the slots 26-1, 26-2 and 26-3 has become unacceptable, the centering assembly 2a can be reassembled with the second ends of the pivot arms 16-1, 16-2 and 16-3 attached to the spare slots 28-1, 28-2 and 28-3, respectively. Thus, the useful life of the annular plate 22 is effectively doubled.

[0032] Reference Figure 5 , Fig. 6A and Figure 6BAs shown, the centering actuator 6a is preferably a long short stick with three parts, which are the top part 6a-1, the middle part 6a-2 and the bottom part 6a-3. The middle part 6a-2 is enclosed in the housing actuator barrel 80. The housing actuator barrel 80 is rotatably attached to the centering assembly main board 20a at the attachment bearing 31. The top part of the centering actuator 6a is configured for the operator to manipulate by pressing or pulling the actuator 6a upward or downward relative to the housing barrel 80. The bottom part 6a-3 of the centering actuator 6a is attached to the annular plate 22 at the attachment point 29. The centering actuator 6a is configured to cause relative rotational movement between the annular plate 22 and the centering assembly main board 20a when it is actuated by up and down movement, which further causes the consistent movement of the pivot arms 16-1, 16-2 and 16-3. This is because the movement of the pivot arms 16-1, 16-2 and 16-3 is generally caused by the same source of the common relative movement between the annular plate 22 and the main plate 20a. Therefore, the linear actuation of the centering actuator 6a in the direction of the indicated linear extension of the centering actuator 6a causes the clockwise rotation of the annular plate 22, and the linear retraction of the centering actuator 6a causes the counterclockwise rotation of the annular plate 22. The annular plate 22 is held and its rotation is guided by the annular plate guide wheels 24-1, 24-2 and 24-3, which are rotatably attached to the centering assembly main plate 20a. The rotation of the annular plate 22 causes each of the pivot arms 16-1, 16-2 and 16-3 to rotate around its corresponding pivot point. Extension of the linear length of the centering actuator 6a causes clockwise rotation of the annular plate 22, which causes rotation of the pivot arms 16-1, 16-2, and 16-3, which further causes the corresponding second ends of the pivot arms to move symmetrically closer to the central axis of the annular plate 22, so that the centering assembly 2a can accommodate a rod with a smaller diameter. Similarly, contraction of the linear length of the centering actuator 6a causes counterclockwise rotation of the annular plate 22, which causes the pivot arms 16-1, 16-2, and 16-3 to rotate, so that the rollers 14-1.1, 14-1.2, 14-2.1, 14-2.2, 14-3.1, and 14-3.2 all move together further from the central axis of the annular plate 22, so that the centering assembly 2a can accommodate a rod with a larger diameter.

[0033] It should be noted that the teachings disclosed in the exemplary embodiments described herein can be used for other alternative uses and embodiments that are contemplated to fall within the scope of the present disclosure. For example, the centering assembly can be designed to accommodate other elongated test objects, such as square bars, polygonal bars, and tubes, simply by designing other numbers of pivot arms with equivalent configurations.

[0034] Now refer to Fig. 6A , Fig. 6A3 is a view of the centering assembly 2a with the pivot arm in the fully open position, wherein the centering actuator 6a is maximally retracted as indicated by arrow 36-1 and the annular plate 22 is maximally rotated in the counterclockwise direction as indicated by arrow 38-1. In the fully open position, the centering assembly 2a can receive a rod 34-1 having a maximum rod diameter. In one embodiment, the maximum rod diameter is 65 mm.

[0035] Still refer to Fig. 6A And refer to Figure 1 , it should be that the tangential contact between the rod 34-1 and the corresponding roller forms tangential contact points 66-1, 66-2 and 66-3. The contact points 66-1, 66-2 and 66-3 form a geometric circle defining the contact point axis 33a. Fig. 6A Also illustrated is a contact point axis 33a, which corresponds to the center of the contact point of the roller with the rod 34-1.

[0036] It should be noted that in the exemplary embodiment, the pivot arms 16-1, 16-2 and 16-3 and the associated rollers are mechanically identical. This enhances the symmetry of the centering assembly 2a, thereby increasing the accuracy of defining the contact point axis 33a of the centering assembly 2a. It should be noted that the centering assembly 2b has a contact point axis 33b (not shown) defined in a similar manner.

[0037] Figure 6B 3 is a view of the centering assembly 2a in the fully closed position, wherein the centering actuator 6a is maximally extended as indicated by arrow 36-2, and the annular plate 22 is maximally rotated in the clockwise direction as indicated by arrow 38-2. In the fully closed position, the centering assembly 2a can receive a rod 34-2 having a minimum rod diameter. In the exemplary embodiment, the minimum rod diameter is 8 mm.

[0038] It should be noted that in the exemplary embodiment, the centering actuator 6a is only operated to change the opening between the rollers so as to check rods with different diameters. In order to check rods with a given diameter, the centering actuator 6a is adjusted to set the opening between the rollers to be slightly smaller than the rod diameter. Then, the opening between the rollers is increased by the impact of the rod entering the centering assembly 2a. The centering actuator 6a is spring-loaded so that after the rod enters, there is an elastic force in the centering actuator 6a in the direction of the arrow 36-2, and therefore the roller is spring-loaded and contacts the rod. The spring inside the actuator 6a is not shown because spring-loaded actuators are generally known to those skilled in the art. The spring load in the centering actuator 6a keeps the roller on the rod, thereby minimizing the alignment error. The important part of the present disclosure is to use a single force source when the retaining force is applied to the annular plate 22, and the retaining force in this case is an elastic force applied by the spring load of the centering actuator 6a. Then, the single force is symmetrically distributed to each of the pivot arms 16-1, 16-2 and 16-3. Thus, unlike systems in prior practice, the holding force on the rod is always consistent between the pivot arms, thereby improving the accuracy of centering the rod.

[0039] It is understood that the spring load of the centering actuator can be designed to manufacture the actuator and hydraulic actuator instead by hydraulic force. When actuated, the hydraulic actuator transmits the hydraulic force to the annular plate and thus to the pivot arm, so that a holding force is generated on the test object. Hydraulic actuators themselves are well known. Although not shown, this alternative design is within the scope of the present disclosure.

[0040] Fig. 7A is a perspective view of a first side of the inspection box 4a, and Figure 7B 4 is a perspective view of the second side of the inspection box 4a. The inspection box 4a includes ultrasonic array probes 50-a1 and 50-a2 located on the first side, and ultrasonic array probes 50-a3 and 50-a4 located on the second side. Probes 50-a1, 50-a2, 50-a3 and 50-a4 are configured to transmit ultrasonic energy to the inspected rod and receive echo signals from defects in the rod. Each of the probes 50-a1, 50-a2, 50-a3 and 50-a4 is connected to a control and acquisition unit (not shown) via cables 52-a1, 52-a2, 52-a3 and 52-a4, respectively.

[0041] The transmitting and receiving surfaces of the probes 50-a1, 50-a2, 50-a3, and 50-a4 may be curved so that the center of curvature is aligned with the probe axis 65a. In one embodiment, the probes 50-a1 and 50-a3 may have a radius of curvature of 61 mm for inspecting rods having a diameter of 30 mm to 65 mm, and the probes 50-a2 and 50-a4 may have a radius of curvature of 40 mm for inspecting rods having a diameter of 8 mm to 40 mm.

[0042] Similarly, the construction of the inspection box 4b can be substantially the same as that of the inspection box 4a. The inspection box 4b having a probe axis 65b (not shown) can include ultrasonic array probes 50-b1 and 50-b2 (not shown) located on a first side and ultrasonic array probes 50-b3 and 50-b4 (not shown) located on a second side. Therefore, the rod inspection assembly 1 can include a total of eight probes, which are configured to inspect rods with different diameters. In one embodiment, four active probes are used to inspect a rod with a given diameter in a pulse echo mode, with one active probe on each side of the inspection box 4a and one active probe on each side of the inspection box 4b.

[0043] Still refer to Fig. 7A and Figure 7B , illustrating features of an exemplary embodiment of the present disclosure, which is designed to include a pair of locking components to facilitate precise alignment of the components of the wand inspection assembly 1 . Fig. 7A An exemplary embodiment is shown in which the inspection box 4a has a concave groove 59a as a first locking member on the first side, and Figure 7B The inspection box 4a is shown to have a convex ridge 60a as a second locking member on the second side. The concave groove 59a is configured to align and cooperate with the convex ridge 60b (not shown) on the inspection box 4b. The convex ridge 60a is configured to align with the convex groove 61a (see FIG. 20 ) on the centering assembly main plate 20a. Figure 2 ) are aligned and matched. The pivot brackets 48a and 48b on the pressure plate 12 are configured to align with two corresponding reference notches 63-1 and 63-2 on the surface of the inspection box 4b (see Fig. 7A ) are aligned and matched. Therefore, the matching features described herein ensure that the probe axes 65a and 65b of the inspection boxes 4a, 4b and the contact point axes 33a and 33b of the centering components 2a and 2b are aligned with each other and correspond to the system axis 35.

[0044] It will be appreciated that the groove and ridge configuration shown above in FIG. 7 may be configured in other embodiments to have a locking assembly having corresponding male and female components configured to be located on the annular plate and the probe box, respectively. The locking components serve the same purpose as the grooves 59a and ridges 60b, i.e., when the locking components are in an engaged position (e.g., Figure 1 As shown), it is used to lock the probe box to be concentric with the annular plate.

[0045] It should be noted that the center point of the midpoint between the reference notch 63-1 and the reference notch 63-2 accurately defines the probe axis 65a of the inspection box 4a. The reference notches 63-1 and 63-2 are used to ensure that the ultrasonic array probes 50-a1, 50-a2, 50-a3 and 50-a4 are accurately aligned by an alignment fixture (not shown) before use. The alignment fixture is composed of a single metal piece that is accurately machined so that the fixture is centered by contacting the reference notches 63-1 and 63-2. Then, the accurately centered fixture is used to align each of the arcuate surfaces of the ultrasonic array probes 50-a1, 50-a2, 50-a3 and 50-a4 so that the center of curvature of each of the arcuate surfaces is accurately aligned with the probe axis 65a of the inspection box 4a.

[0046] In summary, the main purpose of the rod inspection assembly 1 is to align the contact point axes 33a and 33b of the centering assemblies 2a and 2b with the probe axes 65a and 65b of the inspection boxes 4a and 4b, respectively.

[0047] By completely stacking and nesting the probe boxes and centering assemblies by means of the pressure plate 12, the probe axes 65a, 65b should all be aligned and concentric with the system center axis 35, which is defined by the centers of the centering assemblies 2a and 2b.

[0048] Furthermore, in the centering assemblies 2a and 2b, the mechanical configuration of the plurality of pivoting arms is identical, and the movement of the pivoting arms is caused by a single common displacement of the actuator 6a or 6b, respectively. This guarantees to the greatest extent possible that the position of the contact point axes 33a and 33b of the centering arms coincides with the system axis 35, which is defined by the center of the centering assemblies 2a and 2b, respectively.

[0049] The centering assemblies 2a and 2b according to the exemplary embodiments of the present disclosure have the following advantages over the centering mechanisms in conventional ultrasonic wand inspection systems:

[0050] - The use of an annular plate 22 with rotation by means of annular plate guide wheels 24-1, 24-2 and 24-3 provides a symmetrical mechanism in which equal forces are applied to each of the pivot arms and the forces are reduced by up to 50% relative to the forces on the pivot arms in other prior art designs.

[0051] - The symmetrical mechanism ensures that corresponding components of the mechanism experience uniform wear.

[0052] - The positioning accuracy of the contact point axes 33a and 33b is greatly improved, allowing better alignment accuracy with the system center axis 35.

[0053] The probe boxes 4a and 4b can be easily installed into or removed from the wand inspection assembly 1 .

[0054] It should be noted that the centering component 6a is Fig. 6A and Figure 6B Depicted as being used for a rod having a circular cross-section. However, according to other exemplary embodiments of the present disclosure, the centering assembly 6a can be used for a rod having a hexagonal or triangular cross-section, and further, the centering assembly 6a can be configured to receive a rod having a square or rectangular cross-section, and all of these uses or configurations fall within the scope of the present disclosure. In order to receive a rod having a square or rectangular cross-section, in yet another exemplary embodiment of the present disclosure, the centering assembly 6a can be configured to have three sets of pivot arms, each pivot arm having a pair of rollers at a second end, each pivot arm being slidably and rotatably attached to the annular plate 22 at a first end, and each pivot arm being rotatably attached to the centering assembly main plate 20a at a pivot point between the first end and the second end. In another embodiment of the present disclosure, each of the three pivot arms can be slidably and pivotably attached to the assembly main plate 20a at its respective pivot point, so that rotation of the annular plate 22 causes each pair of rollers to move in a radial direction toward or away from the contact point axis 33a.

[0055] Reference Fig. 7A and Figure 7B In use, the rod inspection assembly 1 is immersed in a water tank (not shown) to maintain acoustic coupling. The rod passing through the rod inspection assembly 1 first enters the water tank through a properly sealed hole in the water tank. When passing from air to water, bubbles may be entrained on the surface of the rod, and such bubbles may be transferred to the transmitting and receiving surfaces of the array probe, thereby causing artifacts in the ultrasound image of the rod. The entrained bubbles are removed by bubble removers 56-a1, 56-a2, 56-a3 and 56-a4, wherein each of the bubble removers generates a water jet 58 in the water tank, which is directed to the surfaces of the probes 50-a1, 50-a2, 50-a3 and 50-a4, respectively.

[0056] The inspection box 4a is provided with a handle 54 to facilitate removal of the box from the rod inspection assembly 1. Using the handle 54, the inspection box 4a can be lifted out of the assembly for maintenance or readjustment without disengaging the rigid links 8a, 8b and 8c.

[0057] It should be noted that the teachings disclosed in the exemplary embodiments can be used to contemplate other alternative uses and embodiments that are within the scope of the present disclosure. For example, the centering assembly can be designed to accommodate other kinds of elongated test objects, such as various types of tubes or pipes.

[0058] Although the present invention has been described with respect to specific embodiments thereof, it will be appreciated that a variety of designs may be conceived based on the teachings of this disclosure and all such designs fall within the scope of this disclosure.

Claims

1. A non-destructive inspection system, the non-destructive inspection system being configured to inspect a test object having a longitudinal shape passing through the inspection system in an axial direction, the inspection system comprising: at least one centering assembly, the at least one centering assembly comprising a centering frame centered about the system axis, positioned along a first radial plane and having at least three centering arms having respective first ends attached to the centering frame at respective arm joints equally spaced about the centering frame, the centering arms having respective second ends configured to hold and feed the test object when the inspection system is in operation, at least one probe box positioned along the second radial plane and configured to carry an inspection probe, a pair of locking members configured to be located on the centering frame and the probe box, respectively, to align the probe box to be centered along the system axis when the locking members are in an engaged position, At least one pressing plate is sandwiched between the centering frame and the probe box and is configured with a pushing mechanism that pushes the probe box and the centering frame into the engaged position when actuated.

2. The inspection system according to claim 1, wherein: The centering frame also includes a main board and a centering annular plate, and the centering frame is configured to enable relative and circular motion between the main board and the centering annular plate, and wherein the main board has at least three annular guide wheels, and the at least three annular guide wheels are configured to hold the centering annular plate and guide the centering annular plate.

3. The inspection system according to claim 2, wherein: The at least three centering arms are pivot arms pivotally attached to the centering annular plate at the corresponding first ends, the arm joints are corresponding slots on the centering annular plate configured to allow the first ends to slidably pivot therein, and the pivot arms also include corresponding arm pivot points between the corresponding first ends and the second ends of the arms, the pivot points pivotally attaching the corresponding arms to the main board.

4. The inspection system according to claim 3, wherein: The centering assembly further includes a centering actuator which, when actuated, causes relative rotational movement between the centering annular plate and the main plate.

5. The inspection system according to claim 4, wherein: The centering actuator has a top portion, a middle portion, and a bottom portion, the middle portion being surrounded by a housing actuator barrel, the housing actuator barrel being rotatably anchored on the main plate, and the bottom portion being attached to the centering annular plate.

6. The inspection system according to claim 5, wherein: The pivot arms have the same mechanical configuration, and the relative rotational movement causes a consistent rotation of each of the pivot arms around its corresponding arm pivot point located at the main plate, and causes a translation of the corresponding first end of each of the pivot arms at its corresponding arm joint located at the centering annular plate.

7. The inspection system according to claim 6, wherein: The rotating in unison includes swinging the centering arms more open or more closed in unison.

8. The inspection system according to claim 4, wherein: The centering actuator is spring loaded and configured to apply a spring force to the centering annular plate, which in turn causes the pivoting arm to apply a retaining force to the test object.

9. The inspection system according to claim 2, wherein: The pair of locking components are a pair of corresponding matching concave grooves and convex ridges, and are correspondingly configured on the corresponding opposite edges of the main board and the probe box.

10. The inspection system according to claim 9, wherein: The urging mechanism is configured to urge the probe box and the centering annular plate together so that the ridge engages the groove during inspection.

11. The inspection system according to claim 10, wherein: The driving mechanism comprises: a toggle clamping shaft disposed on a first side of the pressure plate at a first edge; a stopper disposed on a first side of the pressure plate at a second edge; and A pair of pivot brackets are configured to be located on two opposite edges of the second side of the pressure plate in a manner such that a line connecting the toggle clamping shaft and the stop member is orthogonal to a line connecting the pair of pivot brackets, so that when the pushing mechanism is actuated, the toggle clamping shaft and the stop member will respectively generate a force and a resistance, and the pair of pivot brackets serve as a fulcrum for pushing the locking components together.

12. The inspection system according to claim 11, wherein: The pivot brackets are mounted on the peripheral edge of the pressure plate symmetrically with respect to the system axis, and the connection line connecting the pivot brackets is in the same plane as the system axis.

13. The inspection system of claim 9, further comprising two or more rigid links to hold the system in the engaged position wherein the convex ridge is urged into the concave groove.

14. The inspection system according to claim 1, wherein: The probe is configured to be attached to the probe box to at least partially surround the test object.

15. The inspection system according to claim 1, wherein: The second end of the centering arm includes a roller configured to facilitate feeding of the test object past the inspection probe.

16. The inspection system according to claim 1, wherein: The at least one centering assembly includes two or more centering assemblies configured to enclose the probe box therein.

17. The inspection system according to claim 1, wherein: The at least one probe box includes two or more probe boxes sandwiched between one of the at least one centering assembly and the pressure plate.

18. The inspection system of claim 1, configured to receive a round rod as the test object.

19. The inspection system of claim 1, configured to accommodate a square bar as the test object.

20. The inspection system of claim 1, configured to accommodate a polygonal rod as the test object.

21. The inspection system of claim 1, configured to accommodate a tube as the test object.

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