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CN-122015729-A - Precise positioning method for detecting turbine blade of aero-engine

CN122015729ACN 122015729 ACN122015729 ACN 122015729ACN-122015729-A

Abstract

The invention discloses a precise positioning method for detecting turbine blades of an aero-engine, and particularly relates to the technical field of detection of parts of the aero-engine. The method adopts a mechanical arm, an electric claw, a shifting clamp, a positioning clamp, a bidirectional linear module and an ultrasonic thickness measuring system to cooperatively operate. The method comprises the core steps of pre-clamping blade mortises by a shifting clamp and moving the blade mortises to a positioning station, elastically attaching and locking the positioning clamp driven by a bidirectional linear module by an independent elastic telescopic plane array elastic thimble, accurately shaping and fixing blade bodies, locking the shifting clamp to fix the mortises, and finally moving the blade to a thickness measuring station to finish ultrasonic detection. According to the invention, the blade body with stable size is used as a positioning reference, the influence of the manufacturing error of the mortise is effectively eliminated through the cooperative locking strategy of the double flexible clamps, the high-precision and high-repeatability positioning of the blade measuring point is realized, and the accuracy and reliability of the ultrasonic thickness measuring result are ensured.

Inventors

  • YANG LIANG
  • CAI GUIXI
  • CUI XINYU
  • LI JINGMING
  • YANG YANG

Assignees

  • 中国科学院金属研究所

Dates

Publication Date
20260512
Application Date
20260123

Claims (9)

  1. 1. A method for detecting the precise positioning of a turbine blade of an aeroengine, characterized in that it is carried out with the following means: The mechanical arm comprises a mechanical arm tail end (1), an electric claw (3) fixedly arranged at the mechanical arm tail end (1), two shifting clamps (5) which are arranged in pairs and driven to open and close by the electric claw (3), wherein the shifting clamps (5) are flexible clamps of which the front ends are provided with plane array elastic ejector pins capable of independently and elastically stretching, each plane array elastic ejector pin can independently and elastically stretch, and the shifting clamps (5) are provided with locking mechanisms for simultaneously locking all the plane array elastic ejector pins; the ultrasonic thickness measuring device comprises two positioning clamps (8) which are arranged in pairs and driven to open and close by a bidirectional linear module (10), wherein the positioning clamps (8) are flexible clamps of which the front ends are provided with plane array elastic thimbles which can be independently elastically stretched, each plane array elastic thimble can be independently elastically stretched, and the positioning clamps (8) are provided with a locking mechanism for simultaneously locking all the plane array elastic thimbles; the locking mechanism of the shifting clamp (5) and the locking mechanism of the positioning clamp (8) are controlled independently; The method sequentially comprises the following steps: S1, material taking and pre-clamping, namely, after the two shifting clamps (5) are driven by the electric claws (3) to open, the shifting clamps are moved to the position above a blade (6) to be detected, which is borne by a blade material frame (7), and move downwards, so that the plane array elastic ejector pins of the shifting clamps (5) are contacted with two sides of a tongue groove of the blade (6); S2, blade body accurate positioning and cooperative locking are performed, namely, at a positioning station, driving two positioning clamps (8) to open by the bidirectional linear module (10), then driving the shifting clamp (5) carrying the blade (6) to move downwards, placing the blade body of the blade (6) between the two open positioning clamps (8), then driving the two positioning clamps (8) to move towards each other by the bidirectional linear module (10), enabling the planar array elastic ejector pins of the positioning clamps (8) to contact the surface of the blade body, enabling each ejector pin to passively attach to the curved surface of the blade body through elastic expansion and contraction of the ejector pins, and then triggering a locking mechanism of the positioning clamps (8) to lock all the planar array elastic ejector pins of the positioning clamps, so as to compound and fix the blade body, and then triggering a locking mechanism of the shifting clamp (5) to lock all the planar array elastic ejector pins of the shifting clamp, so as to fix the tenon groove; S3, moving and thickness measuring, namely driving the two positioning fixtures (8) to move oppositely by the two-way linear module (10) so as to separate from the blade body, driving the blade (6) fixed by the locked moving fixture (5) to move to a thickness measuring station by the mechanical arm, and sequentially moving each preset measuring point on the blade (6) to the position below a probe of the ultrasonic thickness measuring system (12) by the mechanical arm according to a motion track taught in advance at the thickness measuring station.
  2. 2. The method for precisely positioning a turbine blade for detecting an aeroengine according to claim 1, characterized in that in step S2, the position and attitude of the mechanical arm tip (1) and the electric claw (3) in space remain unchanged from the start of the contact of the planar array elastic ejector pins of the positioning jig (8) with the blade body surface until the locking mechanism of the displacement jig (5) is triggered to complete locking.
  3. 3. The precise positioning method for detecting turbine blades of an aeroengine according to claim 1, wherein the electric claw (3) is fixed to the mechanical arm end (1) by a mechanical arm and electric claw connection (2).
  4. 4. The precise positioning method for detecting aircraft engine turbine blades according to claim 1, characterized in that the displacement clamp (5) is fixed to the slider of the electrical jaw (3) by means of an electrical jaw and displacement clamp connection (4).
  5. 5. The precise positioning method for detecting turbine blades of an aeroengine according to claim 1, wherein the positioning clamp (8) is fixed to the slider of the bidirectional linear module (10) by means of a positioning clamp and module connector (9).
  6. 6. The precise positioning method for detecting turbine blades of an aeroengine according to claim 1, wherein the bidirectional linear module (10) comprises a module driving motor (11), and the module driving motor (11) drives a positive and negative screw to rotate so as to drive the two sliding blocks to do synchronous opposite or opposite linear movements.
  7. 7. The method for precisely positioning a turbine blade for detecting an aeroengine according to claim 1, characterized in that in step S2, the locking mechanism of the positioning clamp (8) is triggered during the actuation of the bidirectional linear module (10) to continue clamping the blade body.
  8. 8. The precise positioning method for detecting turbine blades of an aeroengine according to claim 1, wherein in step S3, by controlling the mechanical arm to change the posture of the blade (6), measuring points located in different spatial directions of the blade (6) are sequentially aligned with probes of the ultrasonic thickness measuring system (12).
  9. 9. The method for precisely positioning a turbine blade for an aeroengine according to claim 1, for cyclically operating a plurality of said blades (6) of the same batch.

Description

Precise positioning method for detecting turbine blade of aero-engine Technical Field The invention belongs to the technical field of detection of aero-engine parts, and particularly relates to a precise positioning method for detecting turbine blades of an aero-engine. Background After the turbine blade of the aeroengine is manufactured, the wall thickness of the turbine blade of the aeroengine needs to be detected, and ultrasonic thickness measurement is a common nondestructive detection method. When the ultrasonic probe is detected, the blade is required to be positioned so that a preset measuring point can be accurately aligned with the ultrasonic probe. The turbine blade has a free-form blade body of complex shape and a precision tenon for assembly. The existing automatic positioning modes mainly comprise two types. One type is to carry out moving and positioning by clamping tenons through a manipulator. This approach has the problems that, firstly, the rigid clamping may cause damage to the precise joint face of the tenon, and secondly, it is difficult to compensate for manufacturing tolerances of the blade body itself based on the tenon alone, resulting in poor positional repeatability of the blade body relative to the measurement probe. The other is to use a special fixture matched with the profile of the blade body for positioning. The mode needs to customize the clamp for different blade models, the cost is high, and the rigid clamping can cause the thin-wall blade body to elastically deform, so that the thickness measurement authenticity is affected. In addition, if clamping is required to be switched between the moving clamp and the measuring station clamp in the detection process, a secondary clamping error is introduced, and the overall positioning accuracy is affected. Therefore, there is a need for a positioning method for turbine blades of an aeroengine, which can avoid damage to the blades during the detection process, adapt to individual differences of the blade profiles, achieve high repeatability of positioning, and reduce or eliminate errors caused by reference conversion. Disclosure of Invention The invention aims to provide a precise positioning method for detecting turbine blades of an aeroengine. In order to achieve the above object, the present invention provides the following technical solutions: A precise positioning method for detecting turbine blades of an aeroengine is implemented by adopting the following devices: A robotic arm including a robotic arm tip; an electric claw fixedly arranged at the tail end of the mechanical arm; the two shifting clamps are arranged in pairs and driven to open and close by the electric claws, the front ends of the shifting clamps are flexible clamps with plane array elastic ejector pins capable of independently and elastically stretching, each plane array elastic ejector pin can independently and elastically stretch, and the shifting clamps are provided with locking mechanisms for simultaneously locking all the plane array elastic ejector pins; The ultrasonic thickness measuring device comprises two positioning clamps which are arranged in pairs and driven to open and close by a bidirectional linear module, wherein the positioning clamps are flexible clamps of which the front ends are provided with plane array elastic ejector pins capable of independently and elastically stretching, each plane array elastic ejector pin can independently and elastically stretch, and the positioning clamps are provided with locking mechanisms for simultaneously locking all the plane array elastic ejector pins; The locking mechanism of the shifting clamp and the locking mechanism of the positioning clamp are controlled independently; The method sequentially comprises the following steps: S1, material taking and pre-clamping, namely driving two shifting clamps to open by the electric claw, moving the shifting clamps to the position above a blade to be detected loaded on a blade material frame and moving the shifting clamps downwards to enable the area array elastic thimble of the shifting clamps to contact two sides of a mortise of the blade; S2, in a positioning station, driving two positioning clamps to open by the bidirectional linear module, driving the shifting clamp carrying the blade to move downwards to place the blade body of the blade between the two opened positioning clamps, driving the two positioning clamps to move in opposite directions by the bidirectional linear module to enable the planar array elastic ejector pins of the positioning clamps to contact the surface of the blade body, enabling each ejector pin to passively attach to the curved surface of the blade body through elastic expansion and contraction of the ejector pins, triggering a locking mechanism of the positioning clamps to lock all the planar array elastic ejector pins of the positioning clamps so as to reshape and fix the blade body, and triggering a locking mechanism of the shifti