Clamping and rotating mechanism for ultrasonic flaw detection

Abstract

The invention relates to the technical field of nondestructive testing equipment, in particular to a clamping and rotating mechanism for ultrasonic flaw detection, and aims to solve the problems that a traditional pneumatic chuck cannot continuously supply air, is easy to leak and is blocked in movement in liquid immersion type detection. The linkage mechanism is driven through relative rotation of the clamping disc and the rotating disc, and rotating motion is converted into radial clamping motion of the sliding blocks. Wherein the arc-shaped guide groove is in rolling fit with the roller to eliminate friction jamming, and the transverse tooth meshing structure restrains clamping deviation. The device has the advantages that stable clamping force is maintained in the underwater environment, and the leakage rate is lower than 0.1 mL / min; and the mechanism runs smoothly without clamping stagnation, and the clamping radial run-out is smaller than 0.05 mm. The device is suitable for automatic flaw detection of large annular workpieces such as bearing rings and gears.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of nondestructive testing equipment, and in particular to a clamping and rotating mechanism for ultrasonic flaw detection. BACKGROUND

[0002] In ultrasonic nondestructive testing of annular metal workpieces (such as bearing rings, gears, etc.), the workpiece needs to be clamped and driven to rotate to achieve omnidirectional scanning of the probe. Currently, a three-jaw pneumatic chuck is widely used as a clamping and rotating mechanism, and its working process is as follows: first, the chuck jaws are driven to clamp the workpiece by pneumatic pressure, then the air supply is cut off to lock the chuck jaws, and finally the chuck is rotated as a whole by a motor to complete the detection.

[0003] However, in the liquid immersion ultrasonic testing scenario (where the workpiece is completely immersed in a coupling water tank), this mechanism has significant defects: Air supply self-locking failure: after the air supply is cut off, the underwater environment cannot maintain the clamping force of the chuck, causing the workpiece to loosen or even fall off; Insufficient rotation sealing: the sealing structure of the traditional rotating shaft gas circuit is simple, and long-term immersion in water can cause rust and leakage, resulting in a drop in air pressure; Motion jamming: the water medium increases the resistance of the mechanism, and the gear or linkage transmission components are prone to jamming due to increased friction, affecting the smoothness of rotation; Poor adaptability: when clamping large workpieces (diameter > 400mm), single-point return springs cannot balance the centrifugal force, causing clamping deviation.

[0004] Although some improvement schemes attempt to improve underwater adaptability by adding sealing rings or waterproof coatings, they do not solve the fundamental contradictions: the conflict between the need for continuous air supply and the reliability of rotation sealing, and the contradiction between complex transmission structures and the increased friction effect of water medium. This results in the existing technology still being unable to meet the dual stringent requirements of liquid immersion testing for clamping stability and motion smoothness. SUMMARY

[0005] To overcome the above-mentioned defects of the prior art, embodiments of the present application provide a clamping and rotating mechanism for ultrasonic flaw detection.

[0006] To achieve the above-mentioned purposes, the present application has the following innovations: its structure includes: a pneumatic rotating cavity, which is provided with an air inlet at the bottom and an air outlet at the top, and a sealed pipeline is arranged in the cavity to communicate the air inlet and the air outlet; a rotating disc and a clamping disc are coaxially arranged, the rotating disc is fixed to the top of the pneumatic rotating cavity, and the clamping disc can rotate relative to the rotating disc; A clamping drive assembly includes: a plurality of radial sliding rails arranged on the rotating disc; a sliding block slidably arranged on the sliding rail; and a clamping block fixed to the sliding block; The motion conversion mechanism comprises: a guide groove arranged on the clamping disc; a linkage penetrating through the rotating disc, one end of which is connected with a sliding block, and the other end of which is provided with a roller matched with the guide groove; and an elastic reset member connecting the clamping disc and the rotating disc. The cylinder body of the cylinder is hinged to the rotating disc, and the output end is hinged to the clamping disc; wherein the gas outlet is connected with the gas source interface of the cylinder.

[0007] Further, the clamping driving assembly further comprises: a U-shaped connecting block A with an opening arranged downward, and the sliding block is fixed in the U-shaped connecting block A; and a U-shaped connecting block B fixed on the top of the U-shaped connecting block A, and the U-shaped connecting block B is arranged with an upward opening.

[0008] Further, the linkage comprises a U-shaped connecting block C and a roller, the U-shaped connecting block C is arranged with an upward opening, and the two ends of the opening are connected with the ends of the U-shaped connecting block A; and the rotating disc is provided with an avoiding groove for the U-shaped connecting block C to pass through.

[0009] Further, the bottom center of the clamping block is provided with a fixed groove, and symmetric upper transverse teeth are arranged on both sides of the fixed groove; the two ends of the opening of the U-shaped connecting block B are provided with lower transverse teeth; and a fixing block is further included, which penetrates through the opening of the U-shaped connecting block B and is fixed in the fixed groove, so that the upper transverse teeth and the lower transverse teeth are meshed with each other.

[0010] Further, the fixing block is provided with a waist-shaped hole, and the upper transverse teeth and the lower transverse teeth are locked by a fastening bolt.

[0011] Further, the guide groove is an arc-shaped groove, the side wall of the guide groove is provided with a wear-resistant layer, and the groove depth is 1 / 2-2 / 3 of the diameter of the roller.

[0012] Further, the diameter of the rotating disc is greater than the diameter of the clamping disc, and the lower surface edge of the rotating disc is provided with a long fixing column and three short fixing columns; the bottom of the short fixing column is aligned with the side surface of the clamping disc.

[0013] Further, the clamping disc is provided with a protrusion, and a shaft rod is arranged on the protrusion; the mounting end of the shaft rod is aligned in height with the mounting end of the long fixing column; the cylinder body is hinged to the long fixing column, and the output end is hinged to the shaft rod.

[0014] Further, the elastic reset member is three tension springs, and the side surface of the clamping disc is provided with three fixing holes, and the two ends of the tension spring are connected with the short fixing column and the fixing hole respectively.

[0015] Further, the number of sliding rails is three, and the sliding rails are evenly distributed on the surface of the rotating disc at an angle of 120°. The end of the clamping block is provided with a clamping column, and the extension direction of the clamping column points to the center position of the rotating disc.

[0016] The beneficial effects of the present application are: Achieve continuous and stable air supply for underwater clamping: Through the sealed pipe and double sealing ring of the pneumatic rotating cavity, the air path is kept continuously open during rotation, ensuring that the cylinder can continuously obtain air supply in an underwater pressure environment of 35MPa. This completely solves the problem of clamping force failure caused by the air source lockout in traditional mechanisms. The leakage rate is ≤0.1mL / min, and the clamping stability is improved by 200%.

[0017] Eliminating motion jamming and clamping offset: The structure adopts an arc-shaped guide groove and a roller rolling fit structure, combined with a polytetrafluoroethylene wear-resistant layer to reduce the friction coefficient to below 0.04. Simultaneously, the upper and lower horizontal teeth mesh to offset the radial offset force, so that the mechanism can run continuously for 100 hours in a liquid immersion environment without jamming, and the radial runout of the clamping block is ≤0.05mm. Attached Figure Description

[0018] Figure 1 This is an isometric view of the front of the invention.

[0019] Figure 2 This is a cross-sectional view of the inner side of the pneumatic rotating cavity of the present invention.

[0020] Figure 3 This is a bottom structural diagram of the linkage component of the present invention connected to the clamping plate.

[0021] Figure 4 This is a structural diagram of the top of the U-shaped connecting block B of the present invention.

[0022] Figure 5 This is a structural diagram of the bottom surface of the clamping block of the present invention. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Example 1: Ultrasonic flaw detection of bearing rings.

[0025] like Figures 1 to 5 As shown, the mechanism is assembled: Pneumatic Rotation Module Installation: Fix the pneumatic rotation chamber 10 to the base of the testing equipment. Its bottom air inlet 11 is connected to an external air source pipeline, and its top air outlet 12 is connected to the air source interface of the cylinder 90 through a stainless steel hose. The internal sealing pipeline 13 of the chamber is sealed with double-layer fluororubber, and a double O-ring seal 14 is installed at the air inlet 11.

[0026] Double-disc structure positioning: the rotating disc 20 (diameter 300 mm) is coaxially fixed on the top of the pneumatic rotating cavity 10; the clamping disc 30 (diameter 200 mm) is installed below the rotating disc 20 through a thrust bearing, so that the clamping disc 30 can rotate relative to the rotating disc 20.

[0027] Clamping drive assembly installation: three radial slide rails 40 are installed on the surface of the rotating disc 20, arranged in a 120° annular pattern; each slide rail 40 is equipped with a slidable sliding block 50, and the top of the sliding block 50 is fixed with a U-shaped connecting block A 61 with an opening facing downward; a U-shaped connecting block B 62 is fixed on the top of the U-shaped connecting block A 61 by bolts, and the opening of the U-shaped connecting block B 62 faces upward; a tapered clamping column 65 is welded at the end of the clamping block 60, and the axis of the clamping column 65 points to the center of the rotating disc 20, and the contact surface is processed with a 0.5 mm deep net-shaped anti-skid pattern.

[0028] Motion conversion mechanism integration: three arc-shaped guide grooves 31 are processed on the surface of the clamping disc 30, the groove sidewalls are sprayed with a 0.2 mm thick polytetrafluoroethylene wear-resistant layer, and the groove depth is 12 mm; the U-shaped connecting block C 72 is provided with an opening facing upward, and the opening of the U-shaped connecting block C 72 is connected to the end of the U-shaped connecting block A 61 through bolts; a roller 71 with a diameter of 20 mm is installed at the bottom of the U-shaped connecting block C 72, the roller 71 is embedded in the guide groove 31, and the embedding depth is 60% (12 mm) of the diameter of the roller; the rotating disc 20 is provided with an avoidance groove 21 for the U-shaped connecting block C 72 to vertically pass through.

[0029] Anti-deviation transmission structure: a fixed groove 66 is processed in the center of the bottom of the clamping block 60, and 15° sawtooth-shaped upper cross teeth 67 are symmetrically arranged on both sides of the fixed groove 66; 30° sawtooth-shaped lower cross teeth 68 are processed on both ends of the opening of the U-shaped connecting block B 62; the fixed block 63 is inserted into the fixed groove 66 through the opening of the U-shaped connecting block B 62, so that the upper cross teeth 67 and the lower cross teeth 68 are meshed with each other; the meshing pre-tightening force is adjusted to 50 N·m through the waist-shaped hole 63a, and locked with M8 fastening bolts.

[0030] Reset and drive module: long fixed columns 23 and three short fixed columns 22 are welded on the lower surface of the rotating disc 20, and the bottom of the short fixed column 22 is aligned with the side surface of the clamping disc 30; three fixed holes 33 are welded on the side surface of the clamping disc 30, and three tension springs 80 are installed, with the two ends respectively hooked to the short fixed column 22 and the fixed hole 33; an axle 34 is welded on the protrusion 32 of the clamping disc 30, and the height difference between the installation end of the axle 34 and the installation end of the long fixed column 23 is ≤0.1 mm; the cylinder body of the air cylinder 90 is hinged to the long fixed column 23, and the output end is hinged to the axle 34.

[0031] Working principle: clamping stage: the external gas source supplies gas to the pneumatic rotating cavity 10 (0.6 MPa) → the gas is delivered to the air cylinder 90 through the sealed pipeline 13; the piston rod of the air cylinder 90 extends, pushing the clamping disc 30 to rotate counterclockwise by 5° relative to the rotating disc 20; the arc-shaped guide groove 31 of the clamping disc 30 pushes the roller 71 → the roller 71 rolls along the wear-resistant layer, and the friction force is reduced by 60%; the U-shaped connecting block C72 drives the sliding block 50 to slide radially inward by 10 mm along the sliding rail 40 through the avoidance groove 21; the clamping block 60 synchronously moves inward to clamp the workpiece, and the upper cross teeth 67 and the lower cross teeth 68 are engaged to offset the radial offset force; when the clamping block 60 slides radially inward, the tapered surface of the clamping column 65 contacts the outer wall of the workpiece, and the anti-skid pattern provides additional friction force to prevent the sleeve ring from rotating and slipping.

[0032] Detection stage: the whole mechanism is immersed in the water tank, and the external motor drives the pneumatic rotating cavity 10 to rotate at 10 r / min; during the rotation, the sealed pipeline 13 continuously supplies gas to the air cylinder 90 to maintain the clamping force; the three tension springs 80 are symmetrically stretched to balance the rotating torque of the clamping disc 30.

[0033] Loosening stage: the air cylinder 90 is depressurized, the tension spring 80 is contracted to pull the clamping disc 30 to reset counterclockwise; the guide groove 31 reversely pushes the roller 71, causing the sliding block 50 to slide radially outward; the clamping block 60 moves away from the surface of the workpiece, completing unloading Technical effect verification: underwater sealing: under 35 MPa water pressure, continuously supply gas for 2 hours, and the gas leakage rate is ≤0.1 mL / min.

[0034] Anti-offset capability: when a 500N radial force is applied, the radial runout of the clamping block 60 is ≤0.05mm.

[0035] Smoothness of movement: after 100 consecutive clamping operations, the roller 71 does not jam in the arc-shaped guide groove 31.

[0036] Example 2, anti-offset structure verification.

[0037] Changes: 1. The angle of the upper cross teeth 67 is changed from 30° to 15°, and the angle of the lower cross teeth 68 is changed from 30° to 45°; 2. The pre-tightening force of the waist-shaped hole 63a is increased from 50N·m to 80N·m; 3. Test workpiece: thin-walled stainless steel sleeve ring (wall thickness 5mm, easy to deform).

[0038] Anti-offset mechanism: 1. The 15° slope of the upper cross teeth 67 and the 45° slope of the lower cross teeth 68 are engaged during clamping → a radial locking component is generated; 2. The waist-shaped hole 63a is adjusted to make the engagement gap ≤0.02mm, and the pre-tightening force 80N·m offsets the workpiece deformation reaction force.

[0039] Verification data:

[0040] Example 3: Anti-jamming and clamping column optimization Changes: 1. The depth of the guide groove 31 is increased to 15 mm (the diameter of the roller is 25 mm, accounting for 60%); 2. The wear-resistant layer is replaced with a laser cladding tungsten carbide layer (thickness 0.3 mm, hardness HRC70); 3. The taper angle of the clamping column 65 is changed from 60° to 45°, and the surface is processed with a 1 mm deep cross anti-skid pattern; 4. Test workpiece: heavy gear (diameter 600 mm, weight 85 kg).

[0041] Optimization effect: Anti-jamming: The friction coefficient of the tungsten carbide wear-resistant layer is reduced to 0.02 (polytetrafluoroethylene is 0.04); the groove depth of 15 mm ensures that the roller 7160% is embedded, and there is no jamming for 120 hours of continuous operation.

[0042] Anti-skid of clamping column: 45° taper angle increases the contact area by 150%; cross anti-skid pattern provides mechanical interlocking effect, anti-skid coefficient reaches 0.4 (smooth clamping column is only 0.1); gear rotation slip rate is reduced from 12% to 0.5%.

[0043] Stress distribution verification

[0044] Industrial applicability: The invention has been applied to bearing production lines: detection efficiency is improved: single piece detection time is shortened from 8 min to 3 min; failure rate is reduced: underwater mechanism failure frequency is reduced from 5 times / month to 0.2 times / month; compatibility: suitable for bearing rings, gears, flanges and other ring-shaped workpieces (ID100-600mm).

[0045] Finally, it should be pointed out that: first of all, in the description of the present application, it should be pointed out that unless otherwise specified and limited, the terms "installation", "connection", "connection" should be understood broadly, which can be mechanical connection or electrical connection, or the communication between two elements, or direct connection, "up", "down", "left", "right" and the like are only used to indicate the relative positional relationship, when the absolute position of the described object changes, the relative positional relationship may change; secondly: the drawings of the disclosed embodiments only involve the structures involved in the disclosed embodiments, other structures can refer to the usual design, and in the case of no conflict, the same embodiment and different embodiments of the present application can be combined with each other; finally: the above only describes the preferred embodiments of the present application and does not limit the present application, any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A clamping and rotating mechanism for ultrasonic flaw detection, characterized in that, Its structure includes: a pneumatic rotating cavity (10), with an air inlet (11) at the bottom and an air outlet (12) at the top, and a sealed pipe (13) connecting the air inlet (11) and the air outlet (12) inside the cavity; a rotating disk (20) and a clamping disk (30) arranged coaxially, wherein the rotating disk (20) is fixed to the top of the pneumatic rotating cavity (10), and the clamping disk (30) can rotate relative to the rotating disk (20); The clamping drive assembly includes: a plurality of radial slide rails (40) disposed on the rotary disk (20); a slider (50) slidably disposed on the slide rails (40); and a clamping block (60) fixed to the slider (50). The motion conversion mechanism includes: a guide groove (31) provided in the clamping plate (30); a linkage (70) passing through the rotating plate (20), one end of which is connected to the slider (50) and the other end is provided with a roller (71) that cooperates with the guide groove (31); and an elastic reset member (80) connecting the clamping plate (30) and the rotating plate (20). The cylinder (90) has its cylinder body hinged to the rotating disk (20) and its output end hinged to the clamping disk (30); wherein the air outlet (12) is connected to the air source interface of the cylinder (90).

2. The clamping and rotating mechanism for ultrasonic flaw detection according to claim 1, characterized in that, The clamping drive assembly further includes: a U-shaped connecting block A (61) with its opening facing downwards, which fixes the slider (50) inside; and a U-shaped connecting block B (62) fixed to the top of the U-shaped connecting block A (61), which has its opening facing upwards.

3. The clamping and rotating mechanism for ultrasonic flaw detection according to claim 2, characterized in that, The linkage (70) includes a U-shaped connecting block C (72) and a roller (71). The U-shaped connecting block C (72) has an opening facing upwards, and the two ends of the opening are connected to the ends of the U-shaped connecting block A (61). The rotating disk (20) is provided with a clearance groove (21) for the U-shaped connecting block C (72) to pass through.

4. The clamping and rotating mechanism for ultrasonic flaw detection according to claim 2, characterized in that, The clamping block (60) has a fixing groove (66) at the center of its bottom, and symmetrical upper transverse teeth (67) are provided on both sides of the fixing groove (66); the U-shaped connecting block B (62) has lower transverse teeth (68) at both ends of its opening; it also includes a fixing block (63), which passes through the opening of the U-shaped connecting block B (62) and is fixed inside the fixing groove (66), so that the upper transverse teeth (67) and the lower transverse teeth (68) mesh with each other.

5. The clamping and rotating mechanism for ultrasonic flaw detection according to claim 4, characterized in that, The fixing block (63) is provided with a waist-shaped hole (63a), and the upper transverse tooth (67) and the lower transverse tooth (68) are locked by fastening bolts.

6. The clamping and rotating mechanism for ultrasonic flaw detection according to claim 1, characterized in that, The guide groove (31) is an arc-shaped groove with a wear-resistant layer on its side wall, and the groove depth is 1 / 2 to 2 / 3 of the diameter of the roller (71).

7. The clamping and rotating mechanism for ultrasonic flaw detection according to claim 1, characterized in that, The diameter of the rotating disk (20) is larger than that of the clamping disk (30), and the lower surface edge of the rotating disk (20) is provided with a long fixing post (23) and three short fixing posts (22); the bottom of the short fixing posts (22) is aligned with the side of the clamping disk (30).

8. A clamping and rotating mechanism for ultrasonic flaw detection according to claim 7, characterized in that, The clamping plate (30) is provided with a protrusion (32), and a shaft (34) is provided on the protrusion (32); the mounting end of the shaft (34) is aligned with the mounting end of the long fixed column (23); the cylinder body (90) is hinged to the long fixed column (23), and the output end is hinged to the shaft (34).

9. A clamping and rotating mechanism for ultrasonic flaw detection according to claim 7, characterized in that, The elastic reset member (80) consists of three tension springs. The clamping plate (30) has three fixing holes (33) on its side. The two ends of the tension springs are respectively connected to the short fixing post (22) and the fixing hole (33).

10. A clamping and rotating mechanism for ultrasonic flaw detection according to claim 1, characterized in that, The number of slide rails (40) is three, which are evenly distributed in a 120° ring on the surface of the rotating disk (20); The clamping block (60) has a clamping post (65) at its end, and the clamping post (65) extends in the direction of the center of the rotating disk (20).

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