A non-deformable diaphragm disc measuring fixture and measuring method

Abstract

This invention belongs to the field of transmission shaft manufacturing technology for aerospace transmission systems. It discloses a non-deformable diaphragm disc measurement fixture and method, comprising: a base, spring washers, bolts, two support studs, a support plate, and two micro-force clamping mechanisms. The support plate has an L-shaped structure, and its bottom is fixed to the base by spring washers and bolts, with the support plate perpendicular to the base. The diaphragm disc is fixed to the vertical surface of the support plate by the two micro-force clamping mechanisms. The two support studs are located at the lower left and lower right of the diaphragm disc and are fixed to the support plate, supporting the diaphragm disc from the bottom. This not only meets the requirement of symmetrical measurement on both sides of the diaphragm disc web but also effectively avoids measurement deformation and large measurement errors caused by the weak rigidity of the diaphragm disc.

Description

Technical Field

[0001] This invention belongs to the field of manufacturing technology of transmission shafts for aerospace transmission systems, and particularly relates to a non-deformable diaphragm disc measuring fixture and measuring method. Background Technology

[0002] The diaphragm-type power drive shaft for aircraft is one of the key components in helicopter transmission systems. The use of a thin-walled diaphragm structure gives the power drive shaft characteristics of being lightweight, highly flexible, and stable in operation. Therefore, as the most critical component in the power drive shaft, the machining quality of the diaphragm directly affects the shaft's service life.

[0003] The main characteristics of the membrane disc are that the contours of both sides of the web are special curved segments, the thinnest part of the disc is only 0.35mm, and the web has strict requirements for contour accuracy. Contour accuracy measurement must be performed symmetrically at points on the same phase on both sides of the web, with three measurements evenly distributed around the circumference. In addition, because the membrane disc is extremely prone to deformation, the usual three-jaw clamping measurement will cause vibration and deformation of the disc during the measurement process, affecting the measurement results. Summary of the Invention

[0004] The technical problem solved by this invention is that it provides a non-deformable diaphragm plate measuring fixture and method, which can not only meet the requirement of symmetrical measurement on both sides of the web of the diaphragm plate, but also effectively avoid the problems of measurement deformation and large measurement error caused by the weak rigidity of the diaphragm plate.

[0005] The technical solution of the present invention:

[0006] Technical Solution 1:

[0007] A non-deformable diaphragm measuring fixture, the measuring fixture comprising: a base (1), a spring washer (2), a bolt (3), two support studs (4), a support plate (5), and two micro-force clamping mechanisms;

[0008] The support plate (5) has an L-shaped structure. The bottom of the support plate (5) is fixed to the base (1) by spring washers (2) and bolts (3). The support plate (5) and the base (1) are perpendicular.

[0009] The membrane disc is fixed to the vertical surface of the support plate (5) by the two micro-force clamping mechanisms. The two support studs (4) are located at the lower left and lower right of the membrane disc and are fixed on the support plate (5) to support the membrane disc from the bottom.

[0010] The features and further improvements of the technical solution of this invention are as follows:

[0011] (1) The micro-force clamping mechanism consists of a nut 6, a pressure plate 7, a spring 8, a pull stud 9 and a washer 10;

[0012] The pressure plate 7 faces the center hole of the support plate 5, and the center hole of the membrane disc is passed through the pull stud 9 of the micro-force clamping mechanism. The reference side of the membrane disc is brought close to the support plate 5. The pressure plate 7 presses down on the boss on the non-reference side of the membrane disc. The spring 8 is located below the head of the pull stud 9 on the reference side of the membrane disc. The washer 10 is located between the pressure plate 7 and the non-reference side of the membrane disc. The nut 6 is located on the other side of the pressure plate 7 and connected to the pull stud 9. The micro-force clamping mechanism is pressed and rotated to complete the membrane disc clamping.

[0013] (2) The tooling also includes a reinforcing rib, one end of which is set on the support plate 5 and the other end is set on the base 1.

[0014] (3) The support plate 5 is hollowed out, and the support stud 4 has a threaded end and a ball head structure at the other end.

[0015] Technical Solution Two:

[0016] A method for measuring a non-deformable diaphragm disk, comprising using the measuring fixture described in technical solution one to measure the diaphragm disk, the method comprising:

[0017] S1, calibrate the clamping force of the measuring fixture;

[0018] S2, Place the measuring fixture on the worktable of the coordinate measuring machine;

[0019] S3, rotate the micro-force clamping mechanism in the measuring fixture so that the pressure plate faces the center of the support plate center hole, pass the diaphragm center hole through the pull stud of the micro-force clamping mechanism, and make the reference side of the diaphragm close to the support plate, and place the outer circle of the diaphragm on the two support studs;

[0020] S4, press and rotate the micro-force clamping mechanism to make the pressure plate press against the boss on the non-reference side of the film plate, complete the clamping and start the measurement.

[0021] The features and further improvements of the second technical solution of the present invention are as follows:

[0022] (1) S1 is specifically:

[0023] First, align the reference side of the diaphragm plate with the positioning surface of the support plate. Then, attach the dial indicator probe to the measuring points on the edge plane and the central boss plane of the diaphragm plate in sequence. Rotate the plate and press the pressure plate to tighten the diaphragm plate. Observe that the change of the dial indicator pointer is within 0.003mm, which indicates that the clamping force is appropriate.

[0024] The lower limit of the clamping force adjustment is to ensure that the diaphragm does not undergo visually visible deformation when subjected to the measuring force of the coordinate measuring machine probe during the measurement process, and the upper limit is to ensure that the change in the measuring point is less than 0.003mm when the diaphragm is subjected to the measuring force of the coordinate measuring machine probe during the measurement process.

[0025] (2) If the deformation of the measuring point is greater than 0.003mm when the diaphragm is subjected to the measuring force of the coordinate measuring machine probe during the measurement process, it is necessary to add a shim at the pressure plate to reduce the spring pressure; if the diaphragm is not clamped during the measurement process, it is necessary to remove the diaphragm and reduce the shim at the pressure plate to increase the pressure.

[0026] (3) Each time the shims are adjusted or the thickness of the diaphragm-type parts changes, the deformation before and after the diaphragm is pressed needs to be remeasured.

[0027] (4) S2, After placing the measuring fixture on the worktable of the coordinate measuring machine, use the coordinate measuring machine to calibrate the verticality of the vertical surface of the measuring fixture support plate.

[0028] This invention provides a non-deformable diaphragm disc measuring fixture and method, mainly composed of a base plate and a support plate. The bottom surface of the base plate and the positioning surface of the support plate have sufficient perpendicularity accuracy, providing sufficient rigidity support. The hollow design of the support plate can meet the requirement of symmetrical measurement on both sides of the diaphragm disc web, while reducing the weight of the fixture. One end of the support stud is threaded, and the other end is a ball head structure, which can effectively avoid unnecessary bumps and damage to the diaphragm disc parts. The axis of the support stud has a high perpendicularity requirement with the positioning plane of the support plate. The micro-force clamping mechanism consists of a special stud, a pressure plate, a spring, and standard fasteners. The clamping force is calibrated based on the diaphragm disc edge and web not deforming or the deformation amount being less than 0.003mm before and after the pressure plate test. During the calibration process, a dial indicator should be used to evenly measure four locations on the diaphragm disc edge plane and the central boss plane. If the deformation amount is greater than 0.003mm, shims at the pressure plate need to be added to reduce the spring pressure. If the diaphragm disc is not clamped during the measurement process, the shims at the pressure plate should be reduced to increase the pressure. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the structure of a non-deformable diaphragm measuring fixture provided in an embodiment of the present invention;

[0030] Figure 2 This is a schematic diagram of the clamping force calibration measurement position provided in an embodiment of the present invention;

[0031] Figure 3 This is a schematic diagram of the clamping force adjustment of the micro-force clamping mechanism provided in an embodiment of the present invention;

[0032] In the diagram, 1-base, 2-spring washer, 3-bolt, 4-support stud, 5-support plate, 6-nut, 7-pressure plate, 8-spring, 9-pull stud, 10-washer. Detailed Implementation

[0033] The technical solution of the present invention will now be described in detail with reference to the accompanying drawings.

[0034] This invention provides a non-deformable diaphragm disk measuring fixture, such as... Figure 1 As shown, the measuring fixture includes: a base 1, a spring washer 2, a bolt 3, two support studs 4, a support plate 5, and two micro-force clamping mechanisms; the support plate 5 has an L-shaped structure, and the bottom of the support plate 5 is fixed to the base 1 by the spring washer 2 and the bolt 3, and the support plate 5 is perpendicular to the base 1.

[0035] The membrane disc is fixed to the vertical surface of the support plate 5 by the two micro-force clamping mechanisms. The two support studs 4 are located at the lower left and lower right of the membrane disc and are fixed on the support plate 5 to support the membrane disc from the bottom.

[0036] like Figure 2 As shown, the micro-force clamping mechanism consists of a nut 6, a pressure plate 7, a spring 8, a pull stud 9, and a washer 10. The pressure plate 7 faces the center hole of the support plate 5, through which the center hole of the membrane disc passes the pull stud 9 of the micro-force clamping mechanism, and the reference side of the membrane disc is close to the support plate 5. The pressure plate 7 presses down on the boss on the non-reference side of the membrane disc. The spring 8 is located below the head of the pull stud 9 on the reference side of the membrane disc. The washer 10 is located between the pressure plate 7 and the non-reference side of the membrane disc. The nut 6 is located on the other side of the pressure plate 7 and connected to the pull stud 9. The micro-force clamping mechanism is clamped and rotated to complete the membrane disc clamping.

[0037] The tooling also includes reinforcing ribs, one end of which is set on the support plate 5 and the other end is set on the base 1.

[0038] The hollow design of the support plate can meet the requirement of symmetrical measurement on both sides of the diaphragm plate web, while also reducing the weight of the fixture. One end of the support stud is threaded and the other end is a ball head structure, which can effectively avoid unnecessary bumps and damage to the diaphragm plate parts. The axis of the support stud has a high degree of perpendicularity requirement with the positioning plane of the support plate.

[0039] The above-mentioned measurement method for the tooling used to clamp the film tray includes the following steps:

[0040] The first step is to calibrate the clamping force. If the clamping force is too small, the measuring force of the coordinate measuring machine head will cause a slight deformation of the diaphragm, leading to an increase in measurement error; if the clamping force is too large, it will cause the diaphragm itself to deform, leading to an increase in measurement error.

[0041] like Figure 3The diagram shows the calibration and measurement position for the clamping force. First, align the diaphragm plate's positioning surface with the positioning surface of the support plate on the fixture. Then, sequentially attach the dial indicator probe to the measurement points on the edge plane and the central boss plane of the diaphragm plate. Rotate the dial indicator and press it firmly against the clamping plate. Observe the change in the dial indicator pointer; if it is within 0.003mm, the pressure is considered appropriate. The lower limit of the clamping force adjustment is to ensure that the diaphragm plate does not undergo visually visible deformation under the measuring force of the coordinate measuring machine during measurement. The upper limit is to ensure that the change in the measurement point after clamping is less than 0.003mm. If the deformation is greater than 0.003mm, shims at the clamping plate need to be added to reduce the spring pressure. If the diaphragm plate is not clamped during measurement, it indicates that the clamping pressure is too low. In this case, the diaphragm plate needs to be removed, and the shims at the clamping plate reduced to increase the pressure. Each time the shims are adjusted or when measuring diaphragm-type parts with changes in thickness, the deformation of the diaphragm plate before and after clamping needs to be remeasured.

[0042] The second step is to place the fixture on the worktable of the coordinate measuring machine and use the coordinate measuring machine to calibrate the perpendicularity of the fixture's positioning surface, and check that the micro-force clamping mechanism can operate flexibly.

[0043] The third step is to rotate the micro-force clamping mechanism so that the pressure plate faces the center of the support plate's central hole, pass the diaphragm disc's central hole through the micro-force clamping mechanism and bring the reference side close to the support plate, and place the outer circle of the diaphragm disc on the two support studs.

[0044] The fourth step is to press and rotate the micro-pressure mechanism to press the pressure plate against the boss on the non-reference side of the film plate, complete the clamping and start the measurement.

[0045] The beneficial effects of this invention are: it meets the special measurement requirements of diaphragm disc parts, effectively avoids vibration and deformation, and in particular, the calibration method of the micro-force clamping mechanism avoids measurement errors caused by clamping deformation, thereby improving measurement accuracy and the accuracy of measurement results.

[0046] This invention designs a specialized fixture for measuring thin-walled diaphragm discs and its usage method. It satisfies the requirement of symmetrical measurement of both sides of the diaphragm disc web while effectively avoiding measurement deformation and large measurement errors caused by the weak rigidity of the diaphragm disc. This invention belongs to the field of aerospace transmission system drive shaft manufacturing. The fixture includes a base plate, a support plate, support studs, and a micro-force clamping mechanism. The usage method is as follows: Place the fixture on the worktable of a coordinate measuring machine (CMM). Rotate the micro-force clamping mechanism so that the pressure plate faces the center hole of the support plate. Pass the center hole of the diaphragm disc through the micro-force clamping mechanism and bring the reference side close to the support plate. Place the outer circle of the diaphragm disc on the two support studs. Simultaneously, clamp and rotate the micro-force clamping mechanism so that the pressure plate presses against the boss on the non-reference side of the diaphragm disc. The clamping is then complete, and measurement begins. This invention is a fixture designed for a special measuring instrument of diaphragm discs, a key component of aerospace transmission system drive shafts. It effectively eliminates the problems of vibration and deformation of the diaphragm disc during measurement. Simultaneously, the micro-force clamping mechanism both fixes the diaphragm disc and does not introduce deformation, significantly improving measurement accuracy. Its design concept is suitable for the production of single-piece, small-batch parts with high machining precision.

Claims

1. A method for measuring a non-deformable diaphragm disk, characterized in that, A non-deformable diaphragm disc measuring fixture is used to measure the diaphragm disc, characterized in that... The measuring fixture includes: a base (1), a spring washer (2), a bolt (3), two support studs (4), a support plate (5), and two micro-force clamping mechanisms; the support plate (5) has an L-shaped structure, and the bottom of the support plate (5) is fixed to the base (1) by the spring washer (2) and the bolt (3), and the support plate (5) is perpendicular to the base (1); the diaphragm is fixed to the vertical surface of the support plate (5) by the two micro-force clamping mechanisms, and the two support studs (4) are set at the lower left and lower right of the diaphragm and fixed on the support plate (5) to support the diaphragm from the bottom; The method includes: S1, calibrate the clamping force of the measuring fixture; First, align the reference side of the diaphragm plate with the positioning surface of the support plate. Then, attach the dial indicator probe to the measuring points on the edge plane and the central boss plane of the diaphragm plate in sequence. Rotate the plate and press the pressure plate to tighten the diaphragm plate. Observe that the change of the dial indicator pointer is within 0.003mm, which indicates that the clamping force is appropriate. The lower limit of the clamping force adjustment is to ensure that the diaphragm does not undergo visually visible deformation when subjected to the measuring force of the coordinate measuring machine probe during the measurement process, and the upper limit is to ensure that the change in the measuring point is less than 0.003mm when the diaphragm is subjected to the measuring force of the coordinate measuring machine probe during the measurement process. S2, Place the measuring fixture on the worktable of the coordinate measuring machine; S3, rotate the micro-force clamping mechanism in the measuring fixture so that the pressure plate faces the center of the support plate center hole, pass the diaphragm center hole through the pull stud of the micro-force clamping mechanism, and make the reference side of the diaphragm close to the support plate, and place the outer circle of the diaphragm on the two support studs; S4, press and rotate the micro-force clamping mechanism to make the pressure plate press against the boss on the non-reference side of the film plate, complete the clamping and start the measurement.

2. The method for measuring a non-deformable film disk according to claim 1, characterized in that, The micro-force clamping mechanism consists of a nut (6), a pressure plate (7), a spring (8), a pull stud (9), and a washer (10); The pressure plate (7) faces the center hole of the support plate (5), and the center hole of the membrane disc is passed through the pull stud (9) of the micro-force clamping mechanism. The reference side of the membrane disc is brought close to the support plate (5). The pressure plate (7) presses down on the boss on the non-reference side of the membrane disc. The spring (8) is set below the head of the pull stud (9) and is located on the reference side of the membrane disc. The washer (10) is set between the pressure plate (7) and the non-reference side of the membrane disc. The nut (6) is set on the other side of the pressure plate (7) and is connected to the pull stud (9). The micro-force clamping mechanism is pressed and rotated to complete the membrane disc clamping.

3. The method for measuring a non-deformable film disk according to claim 1, characterized in that, The tooling also includes reinforcing ribs, one end of which is set on the support plate (5) and the other end is set on the base (1).

4. The method for measuring a non-deformable film disk according to claim 1, characterized in that, The support plate (5) has a hollow design, and the support stud (4) has a threaded end and a ball head structure at the other end.

5. The method for measuring a non-deformable film disk according to claim 1, characterized in that, If the deformation of the measuring point is greater than 0.003mm when the diaphragm is subjected to the measuring force of the coordinate measuring machine probe during the measurement process, it is necessary to add shims at the pressure plate to reduce the spring pressure; if the diaphragm is not clamped during the measurement process, it is necessary to remove the diaphragm and reduce the shims at the pressure plate to increase the pressure.

6. The method for measuring a non-deformable diaphragm disk according to claim 5, characterized in that, Each time the shims are adjusted or the thickness of a diaphragm-type part changes, the deformation before and after the diaphragm is pressed needs to be remeasured.

7. The method for measuring a non-deformable film disk according to claim 1, characterized in that, S2, After placing the measuring fixture on the worktable of the coordinate measuring machine, the verticality of the vertical plane of the measuring fixture support plate is calibrated using the coordinate measuring machine.

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