Tool and device for measuring symmetry degree of centrifugal counterweight of aero-engine

Abstract

In order to solve the problem that when a counterweight assembly on a centrifugal mechanism shaft in an aero-engine centrifugal sensor is repaired, the symmetry degree of two end faces of the counterweight assembly relative to a center line of a surface A cannot be accurately measured by a traditional method, the utility model provides a tool and a device for measuring the symmetry degree of an aero-engine centrifugal counterweight. The tool comprises a platform, a centrifugal mechanism shaft positioning unit, a counterweight assembly positioning unit, an auxiliary measuring unit and a supporting unit. The centrifugal mechanism shaft positioning unit is used for positioning and clamping a centrifugal mechanism shaft; the counterweight assembly positioning unit is used for positioning two counterweight assemblies on the two sides of the centrifugal mechanism shaft; the auxiliary measuring unit is used for supporting and clamping a distance measuring instrument and selecting a measuring point; the supporting unit is used for supporting and installing the measuring unit on the platform in a lifting and rotating mode. According to the utility model, spatial position positioning of the centrifugal mechanism shaft and the counterweight assemblies during measurement can be realized, two end faces of the two counterweight assemblies which rotate indefinitely can be measured at the same time after positioning, and the accuracy of measured values is high.

Description

Technical Field

[0001] This utility model relates to a measuring fixture, and more particularly to a fixture and device used for measuring the symmetry of centrifugal counterweights in aero engines. Background Technology

[0002] When repairing the counterweight assembly on the centrifugal mechanism shaft of the centrifugal sensor in an aero-engine, it is required to measure the symmetry of the counterweight relative to the center line of the counterweight fork, that is, to measure the symmetry of the two end faces E and F of the counterweight assembly (e.g., Figure 1 As shown, surfaces E and F are the two end faces of the counterweight assembly. Because bearings are installed at both ends of the shaft, the counterweight assembly can rotate freely along its own axis. Its symmetry relative to the centerline of surface ØA does not exceed 0.1 mm. Previously, shims were adjusted between the centrifugal counterweight and the counterweight fork of the centrifugal mechanism shaft to ensure symmetry. However, the measurement was often inaccurate, leading to unstable centrifugal sensor speed, which in turn caused unstable venting belt speed and flashing indicator lights. Therefore, a fixture capable of accurately measuring the symmetry of the two end faces E and F of the counterweight assembly relative to the centerline of surface ØA is urgently needed. Summary of the Invention

[0003] To address the technical problem of unstable centrifugal sensor rotation speed caused by the inability to accurately measure the symmetry of the two end faces of the counterweight assembly relative to the center line of the ØA surface when repairing the counterweight assembly on the centrifugal mechanism shaft using traditional methods, this invention provides a tooling and device for measuring the symmetry of centrifugal counterweights in aero-engines, which has the advantages of simple operation and accurate measurement.

[0004] The technical solution adopted in this utility model is:

[0005] A fixture for measuring the symmetry of centrifugal counterweights in an aero-engine is characterized by comprising a platform and a centrifugal mechanism shaft positioning unit, a counterweight component positioning unit, an auxiliary measurement unit, and a support unit mounted on the platform.

[0006] The centrifuge mechanism shaft positioning unit is used to position and clamp the centrifuge mechanism shaft in the centrifuge sensor.

[0007] The counterweight assembly positioning unit is coaxially and spaced apart from the centrifugal mechanism shaft positioning unit, and is used to simultaneously position one of the E-surface and F-surface of the two counterweight assemblies located on both sides of the centrifugal mechanism shaft;

[0008] The auxiliary measuring unit is used to support and clamp the distance measuring instrument, and to select measuring points on the E and F surfaces of the two counterweight assemblies.

[0009] The support unit is used to support and install the auxiliary measuring unit on the platform, and the support unit can be raised, lowered and rotated within a certain range.

[0010] Furthermore, the centrifugal mechanism shaft positioning unit includes a V-block and a pressure plate; the pressure plate is disposed on the upper part of the V-block, one end of the pressure plate is hinged to one side of the upper part of the V-block, and the other end of the pressure plate is detachably connected to the other side of the upper part of the V-block; by cooperating with the V-block and the pressure plate, the centrifugal mechanism shaft can be positioned and clamped.

[0011] Furthermore, a strip is provided between the V-shaped block and the pressure plate to prevent scratches on the shaft of the centrifugal mechanism.

[0012] Furthermore, the counterweight assembly positioning unit includes a positioning base, two end face positioning plates spaced apart on the same side of the upper end face of the positioning base and extending upward, a connecting lug on the other side of the positioning base, and a first spring disposed between the positioning base and the platform;

[0013] The upper surfaces of the two end-face positioning plates are respectively used to position the detection surfaces of the two counterweight assemblies on both sides of the centrifugal mechanism shaft;

[0014] The connecting lug is hinged to the support unit by a pin, and the clearance between the lug and the pin is no greater than 0.01mm.

[0015] The first spring is in a compressed state to provide an upward preload so that the two end face positioning plates can better press against the surface being tested.

[0016] Furthermore, the end face positioning plate is a wedge-shaped block that is narrow at the top and wide at the bottom.

[0017] Furthermore, the auxiliary measuring unit includes a frame and a measuring rod; the measuring rod 5 is installed at one bottom end of the frame, and the other bottom end of the frame is provided with a mounting hole; the upper part of the frame is provided with a clamping mechanism for mounting the distance measuring instrument.

[0018] Furthermore, the support unit includes a column and a ball joint assembly that are spaced apart and fixedly installed on the platform; the upper end of the column is used to support the middle part of the table frame; the ball joint assembly includes a ball joint pin, a sleeve, a nut, a second spring, and a ball washer; the sleeve is sleeved on the ball head of the ball joint pin, the lower part of the nut is connected to the upper part of the sleeve, the second spring is located between the nut and the ball joint pin, and the ball washer is located between the second spring and the ball joint pin;

[0019] The sleeve is fitted into the mounting hole at the other end of the bottom of the instrument frame and is an interference fit, thereby connecting the instrument frame and the ball head pin assembly.

[0020] After assembly, the watch frame is supported by the support column and the ball head pin assembly. The watch frame can be lifted relative to the ball head pin together with the sleeve to compress the second spring and rotate around the spherical surface.

[0021] Furthermore, before assembling the first spring in the counterweight assembly positioning unit, the parallelism error between the upper end face of the end face positioning plate, the lower surface of the table frame, and the platform is less than or equal to 0.01 mm; the perpendicularity error between the symmetry center plane of the V-block and the upper end face of the end face positioning plate is less than or equal to 0.05 mm.

[0022] This utility model also provides a device for measuring the symmetry of centrifugal counterweights of an aircraft engine, which is characterized in that it includes a distance measuring instrument and the aforementioned measuring fixture for measuring the symmetry of centrifugal counterweights of an aircraft engine; the distance measuring instrument is mounted on the frame of the measuring fixture for measuring the symmetry of centrifugal counterweights of an aircraft engine, and the measuring head of the distance measuring instrument is aligned with the measuring rod of the measuring fixture for measuring the symmetry of centrifugal counterweights of an aircraft engine.

[0023] Furthermore, the ranging instrument is a dial indicator, a micrometer, or a depth gauge.

[0024] The beneficial effects of this utility model are:

[0025] This invention uses a V-block, end face positioning plate, support column, and ball head pin assembly to achieve spatial positioning of the centrifugal mechanism shaft and counterweight assembly during measurement. After positioning, the two end faces of the two rotating counterweight assemblies can be measured simultaneously by the cooperation of a distance measuring instrument and a measuring rod. Then, after flipping, the other two end faces of the two counterweight assemblies can be measured simultaneously. The obtained measurement values ​​are highly accurate and the measurement operation is simple. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the counterweight assembly on the shaft of the centrifugal sensor of a certain type of aircraft engine.

[0027] Figure 2 This is a perspective view of the tooling of this utility model.

[0028] Figure 3 This is the front view of the present invention.

[0029] Figure 4 This is a top view of the tooling of this utility model.

[0030] Figure 5 This is a side view of the tooling of this utility model.

[0031] Figure 6 This is a cross-sectional view of section AA of the tooling of this utility model.

[0032] Explanation of reference numerals in the attached figures:

[0033] 1. Platform, 2. V-block, 3. Hinged bolt, 4. End face positioning plate, 5. Measuring rod, 6. Table holder, 7. Support column, 8. Pressure plate, 9. Slat, 10. Ball head pin, 11. Sleeve, 12. Ball washer, 13. Nut, 14. Screw, 15. First spring, 16. Second spring, 17. Screw, 18. Positioning pin, 19. Screw, 20 and 21. Pin, 22. Wing nut, 23. Positioning base, 24. Connecting lug. Detailed Implementation

[0034] The present invention will now be described in detail with reference to the accompanying drawings.

[0035] like Figure 2-3 As shown, the aero-engine centrifugal counterweight symmetry measuring fixture provided by this utility model includes a platform 1 and a centrifugal mechanism shaft positioning unit, a counterweight component positioning unit, an auxiliary measuring unit, and a support unit disposed on the platform 1.

[0036] The centrifuge mechanism shaft positioning unit is used for positioning and clamping the centrifuge mechanism shaft in the centrifuge sensor of the aero-engine. It includes a V-block 2 and a pressure plate 8. The bottom of the V-block 2 extends outward to form a mounting base. The mounting base has pin holes and threaded holes. The V-block 2 is positioned on the platform 1 by installing a positioning pin 18 in the pin hole, and the V-block 2 is fixedly installed on the platform 1 by installing screws 17 in the threaded holes. The pressure plate 8 is located on the upper part of the V-block 2. One end of the pressure plate 8 is hinged to one side of the upper part of the V-block 2, and the other end of the pressure plate 8 is fixedly connected to the other side of the upper part of the V-block 2 by a hinge bolt 3 and a wing nut 22. The V-block 2 and the pressure plate 8 cooperate to position and clamp the centrifuge mechanism shaft. In order to prevent the centrifuge mechanism shaft from being scratched during clamping and fixing, a strip 9 is also provided between the V-block 2 and the pressure plate 8. The strip 9 is made of aluminum or flexible material. The strip 9 is fixedly installed on the lower end face of the pressure plate 8 by opening multiple threaded holes and installing screws 19 in the threaded holes.

[0037] The counterweight assembly positioning unit and the centrifuge mechanism shaft positioning unit are coaxially spaced apart and used to simultaneously position the two counterweight assemblies on both sides of the centrifuge mechanism shaft. The unit includes a positioning base 23, two end-face positioning plates 4 spaced apart on the same side of the upper surface of the positioning base 23 and extending upwards, a connecting lug 24 on the other side of the positioning base 23, and a first spring 15 positioned between the positioning base 23 and the platform 1. The upper surfaces of the two end-face positioning plates 4 on the positioning base 23 are used to position the detection surfaces of the two counterweight assemblies on both sides of the centrifuge mechanism shaft (simultaneously positioning surface E or surface F). The connecting lug 24 on the positioning base 23 is hinged to the support column 7 in the support unit through the pin 20, and the gap between the lug 24 and the pin 20 is no more than 0.01mm to ensure the positioning accuracy of the counterweight assembly; the first spring 15 is in a compressed state and can provide an upward preload so that the end face positioning plate 4 can better abut against the E or F face of the two counterweight assemblies being tested; considering the narrow space at the positioning end face of the counterweight assembly, and taking into account the strength and processing convenience of the end face positioning plate 4 itself, preferably, the end face positioning plate 4 is designed as a wedge block that is narrow at the top and wide at the bottom.

[0038] The auxiliary measuring unit includes a dial indicator frame 6 and a measuring rod 5; the measuring rod 5 is installed at one bottom end of the dial indicator frame 6, and the other bottom end of the dial indicator frame 6 is provided with a mounting hole; the upper part of the dial indicator frame 6 is provided with a clamping mechanism for mounting a dial indicator.

[0039] The lower surface of the frame 6 is defined as surface M, and the upper surface of the end face positioning plate 4 is defined as surface N. Before assembling the first spring 15 in the counterweight assembly positioning unit, the parallelism error between surface M and surface N and platform 1 is no greater than 0.01 mm, and the perpendicularity error between the symmetrical center plane of V-block 2 and surface M and surface N is no greater than 0.05 mm, so as to improve the positional accuracy of the centrifugal mechanism shaft clamped on the tooling and the counterweight assembly under test during measurement.

[0040] The support unit is used to support and install the auxiliary measuring unit on the platform 1, including a support column 7 and a ball head pin assembly; the support column 7 and the ball head pin assembly are spaced apart and fixedly installed on the platform 1, and the upper ends of the support column 7 and the ball head pin assembly jointly support the instrument frame 6; a limiting groove is provided on the upper part of the support column 7; the ball head pin assembly includes a ball head pin 10, a sleeve 11, a nut 13 and a second spring 16; the lower part of the ball head pin 10 is installed on the platform 1 and is interference-fitted with the platform 1; the sleeve 11 is sleeved on the ball head of the upper part of the ball head pin 10, the lower part of the nut 13 is connected to the upper part of the sleeve 11, a second spring 16 is provided between the nut 13 and the ball head pin 10, and a ball pad 12 is provided between the second spring 16 and the ball head pin 10, the lower part of the ball pad 12 is a spherical surface that matches the ball head of the ball head pin 10. The sleeve 11 is fitted into the mounting hole at the other end of the bottom of the meter holder 6, and is interference-fitted with the meter holder 6. The connection between the meter holder 6 and the ball head pin assembly is achieved through the sleeve 11.

[0041] After assembly, the dial indicator 6 is supported by the support column 7 and the ball head pin assembly. The bottom middle section of the dial indicator 6 is located in the limiting groove on the upper part of the support column 7 and can slide left and right in the limiting groove. One bottom end of the dial indicator 6 is engaged with the sleeve 11 in the ball head pin assembly, and can lift and compress the second spring 16 relative to the ball head pin 10 together with the sleeve 11, and rotate around the spherical surface. Thus, when fixing and clamping the centrifugal mechanism shaft, the dial indicator 6 can be lifted and rotated to make mechanical clearance for it.

[0042] The measurement principle of this utility model is:

[0043] Leveling before measurement:

[0044] First, place the centrifuge shaft on the V-block 2. Adjust the position of the centrifuge shaft and the position of the counterweight assembly on it so that the upper surfaces of the two end face positioning plates 4 of the fixture contact the E-surfaces of the two counterweight assemblies on both sides of the centrifuge shaft (at this time, the E-surfaces face down). Then, fix the centrifuge shaft with the pressure plate 8. Mount a dial indicator on the fixture's frame 6 (in other embodiments, a micrometer or depth gauge or other distance measuring instruments that can measure length or depth can also be used). Adjust the dial indicator so that its measuring head is aligned with the measuring rod 5. Lift and rotate the frame 6 so that the measuring rod mounted on the frame 6 is aligned with the measuring rod 5. With the lower end face of rod 5 against the F-surface of the counterweight assembly, read the dial indicator value as the initial value. Then, adjust the position of rod 5 multiple times so that its lower end face is against different positions on the F-surface of the counterweight assembly (generally, measuring three or four points is sufficient). During this period, if the difference between the dial indicator reading and the initial value is less than 0.1mm, it indicates that the levelness of the F-surface of the current counterweight assembly meets the requirements, and the counterweight assembly is properly installed and adjusted. Otherwise, the position of the centrifugal mechanism shaft and the position of the counterweight assembly should be adjusted until the difference between the dial indicator reading and the initial value is less than 0.1mm.

[0045] Measuring surface F:

[0046] Align the measuring head of the dial indicator with the measuring rod 5, and place the lower end of the measuring rod 5 against a point on the two F surfaces of the two counterweight assemblies respectively, and read the measured values ​​A1 and A2 of the dial indicator at this time respectively;

[0047] Measure surface E:

[0048] Lift the dial indicator 6 along the ball head pin 10 and rotate it to mechanically reposition it. Release the pressure plate 8, then detach the end face positioning plate 4 from the counterweight assembly. Flip the centrifugal mechanism shaft so that the E-side of the counterweight assembly faces upward. Then, make the upper end faces of the two end face positioning plates 4 contact the F-side of the counterweight assembly respectively. Using the same leveling and measurement methods as described above, read the dial indicator values ​​B1 and B2 when the lower end of the measuring rod touches a certain point on the E-side of the counterweight assembly respectively.

[0049] Symmetry judgment:

[0050] Calculate the difference △1 between the measured values ​​A1 and B1 belonging to the same counterweight assembly. This difference △1 can reflect the symmetry of the E and F surfaces of the corresponding counterweight assembly relative to the center line of the ØA surface. If the difference △1 is less than 0.1mm, then the symmetry of the E and F surfaces of the corresponding counterweight assembly relative to the center line of the ØA surface meets the requirements.

[0051] Similarly, calculate the difference △2 between the measured values ​​A2 and B2 belonging to the same counterweight assembly. This difference △2 can reflect the symmetry of the E and F surfaces of the corresponding counterweight assembly relative to the center line of the ØA surface. If the difference △2 is less than 0.1mm, then the symmetry of the E and F surfaces of the corresponding counterweight assembly relative to the center line of the ØA surface meets the requirements.

[0052] In addition to the aforementioned tooling, this utility model also provides a centrifugal counterweight symmetry measuring device for an aero-engine, including the aforementioned tooling and a distance measuring instrument mounted on the gauge frame 6 of the aforementioned tooling, wherein the distance measuring instrument can be a dial indicator, a micrometer, or a depth gauge.

Claims

1. An aircraft engine centrifugal counterweight symmetry measurement tool, characterized by: The platform is provided with a centrifugal mechanism shaft positioning unit, a counterweight assembly positioning unit, an auxiliary measurement unit and a support unit; The centrifugal mechanism shaft positioning unit is used for positioning and clamping a centrifugal mechanism shaft in a centrifugal sensor; The counterweight assembly positioning unit is coaxial with the centrifugal mechanism shaft positioning unit and is arranged in a spaced manner, and is used for positioning one of the E face and the F face of two counterweight assemblies respectively located on two sides of the centrifugal mechanism shaft; The auxiliary measurement unit is used for supporting and clamping a distance measuring instrument, and is used for selecting a measurement point on the E face and the F face of the two counterweight assemblies; The support unit is used for supporting and mounting the auxiliary measurement unit on the platform, and can realize lifting and rotating of the support unit within a certain range.

2. The aircraft engine centrifugal counterweight symmetry measurement tool of claim 1, wherein: The centrifugal mechanism shaft positioning unit comprises a V-shaped block and a pressing plate; the pressing plate is arranged on the upper part of the V-shaped block, one end of the pressing plate is hinged to one side of the upper part of the V-shaped block, and the other end of the pressing plate is detachably connected to the other side of the upper part of the V-shaped block; the centrifugal mechanism shaft can be positioned and clamped through cooperation of the V-shaped block and the pressing plate.

3. The aircraft engine centrifugal counterweight symmetry measurement tool of claim 2, wherein: A baffle is further arranged between the V-shaped block and the pressing plate to prevent the centrifugal mechanism shaft from being scratched.

4. The aircraft engine centrifugal counterweight symmetry measurement tool of claim 3, wherein: The counterweight assembly positioning unit comprises a positioning base, two end face positioning plates arranged in a spaced manner on the same side of the upper end face of the positioning base and extending upward, a connecting lug seat arranged on the other side of the positioning base, and a first spring arranged between the positioning base and the platform; The upper end faces of the two end face positioning plates are respectively used for positioning the detected faces of the two counterweight assemblies on the two sides of the centrifugal mechanism shaft; The connecting lug seat is hinged to the support unit through a pin, and the cooperation gap of the pin is not greater than 0.01 mm; The first spring is in a compressed state, and is used for providing an upward pre-tightening force so that the two end face positioning plates can better abut against the detected faces.

5. The aircraft engine centrifugal counterweight symmetry measurement tool of claim 4, wherein: The end face positioning plate is a wedge block with a narrow upper part and a wide lower part.

6. The aircraft engine centrifugal counterweight symmetry measurement tool of claim 4, wherein: The auxiliary measurement unit comprises a table frame and a measurement rod; the measurement rod is mounted at one end of the bottom of the table frame, the other end of the bottom of the table frame is provided with a mounting hole, and the upper part of the table frame is provided with a clamping mechanism for mounting the distance measuring instrument.

7. The aircraft engine centrifugal counterweight symmetry measurement tool of claim 6, wherein: The support unit comprises support columns and a ball head pin assembly arranged in a spaced manner and fixedly mounted on the platform; the upper end of the support column is used for supporting the middle part of the table frame; the ball head pin assembly comprises a ball head pin, a sleeve, a nut, a second spring and a ball pad; the sleeve is sleeved outside the ball head of the upper part of the ball head pin, the lower part of the nut is butted against the upper part of the sleeve, the second spring is located between the nut and the ball head pin, and the ball pad is located between the second spring and the ball head pin; The sleeve is sleeved in the mounting hole on the other end of the bottom of the table frame in an interference fit, thereby realizing connection of the table frame and the ball head pin assembly; After assembly, the table frame is jointly supported by the support columns and the ball head pin assembly, the table frame can be lifted together with the sleeve relative to the ball head pin to compress the second spring, and the table frame can rotate around the spherical surface.

8. The aircraft engine centrifugal counterweight symmetry measurement tool of claim 7, wherein: Before assembling the first spring in the counterweight assembly positioning unit, parallelism error between the upper end face of the end face positioning plate, the lower surface of the table frame and the platform is less than or equal to 0.01mm; perpendicularity error between the symmetric center face of the V-shaped block and the upper end face of the end face positioning plate is less than or equal to 0.05mm.

9. An aircraft engine centrifugal counterweight symmetry measuring device characterized by: The aero-engine centrifugal counterweight symmetry measurement tooling device according to any one of claims 1-8, and a distance measuring instrument; the distance measuring instrument is installed on the table frame of the aero-engine centrifugal counterweight symmetry measurement tooling device, and a measuring head of the distance measuring instrument is aligned with the measuring rod of the aero-engine centrifugal counterweight symmetry measurement tooling device.

10. The aircraft engine centrifugal balance symmetry measuring device of claim 9, wherein: The distance measuring instrument is a dial gauge, a micrometer or a depth gauge.

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