Method and apparatus for measuring shaft-hole fit clearance in closed space

Abstract

A method and apparatus for measuring a shaft-hole fit clearance in a closed space. The apparatus comprises a process shaft module (103) for replacing a product shaft, a hole module (104) mounted on a part II (102), and a detector module (105); the process shaft module (103) comprises a process shaft (304) and a laser generator (303); a mounting cavity and a laser channel for the laser generator (303) are provided inside the process shaft (304); the process shaft module (103) is sequentially mounted on a part I (101) and the part II (102), and sequentially emits a laser beam coaxial with the outer circle of the product shaft and a laser beam coaxial with the inner circle of a hole (401) in the hole module (104); the front end of the process shaft (304) passes through the hole (401) in the hole module (104); and the laser beams are emitted from the front end of the process shaft (304) and are irradiated on a position-sensitive detector (501) of the detector module (105).

Description

A method and device for measuring shaft-hole clearance in a closed space Technical Field

[0001] The present invention relates to the field of measurement technology, and in particular to a method and device for measuring shaft-hole fitting clearance in a closed space. Background Art

[0002] Some movable parts on an aircraft are connected to the fuselage using a shaft-hole matching structure. To ensure the normal opening / closing of the movable parts and the stability of the parts after closing, the shaft and hole of the movable parts have strict matching clearance requirements. During general assembly, process methods can be used to ensure that the axial directions of the shaft and hole are basically parallel, but it is impossible to ensure that the axes of the shaft and hole are coaxial. In addition, the cumulative assembly errors lead to uneven radial clearance between the shaft and hole. After the movable part is closed, it forms a closed space with the fuselage, and the shaft-hole clearance cannot be measured. To ensure the assembly requirements of the shaft-hole clearance, at this stage, the only method that can be used is the contact coloring method of the shaft-hole matching surface to qualitatively determine whether there is a gap between the shaft and the hole. That is, the hole surface is coated with red lead powder or printing ink or other coloring materials, the movable part is closed and opened once, and the shaft surface is checked to see if it is colored. This is used to determine whether the two are in contact, and then the radial position of the hole relative to the shaft is adjusted to ensure that the shaft and hole are assembled without contact.

[0003] The existing method uses the contact coloring method to solve the problem of the inability to measure the clearance between the hole and the shaft in a closed space. However, it can only perform qualitative measurements and can only minimally ensure that the shaft and the hole are assembled without contact. It cannot quantitatively measure the clearance value and cannot further improve the assembly accuracy. Subsequent products will deform due to use, resulting in repeated adjustments of the shaft and hole contact and frequent maintenance. In addition, the coloring method requires applying coloring pigments on the product surface. If it is not removed in time, it is easy to contaminate the product surface and affect the product surface quality.

[0004] Summary of the Invention

[0005] The present invention aims to solve the problem in the prior art that the fitting clearance cannot be directly and quantitatively measured after the shaft and hole mechanisms are in place to form a closed space. A closed space shaft-hole fitting clearance measurement method and device are proposed, which can achieve high-precision and high-efficiency gap value measurement after the mutually cooperating shaft and hole mechanisms are in place to form a gap, thereby improving detection accuracy and ensuring assembly accuracy.

[0006] In order to achieve the above-mentioned object of the invention, the technical solution of the present invention is as follows:

[0007] A device for measuring the clearance between an axis and a hole in a closed space comprises a first part and a second part which are blocked by a structure after being matched to form a closed space, wherein the product axis on the first part is connected to the hole on the second part by an axis-hole fit; the measuring device comprises a process axis module for replacing the product axis, a hole module installed on the second part, and a detector module; the process axis module comprises a process axis and a laser generator, wherein a mounting cavity and a laser channel for the laser generator are provided inside the process axis; the process axis module is used to be installed on the first part and the second part successively, and to emit a laser beam which is coaxial with the outer circle of the product axis and the inner circle of the hole on the hole module successively; the front end of the process axis passes through the hole on the hole module, and the laser beam is emitted from the front end of the process axis and irradiates the position-sensitive detector of the detector module, and the position-sensitive detector is used to detect the position of the laser beam emitted by the laser generator.

[0008] Furthermore, the process shaft is fixedly connected to part one through a nut and a spring washer.

[0009] Furthermore, the hole module includes a hole and an adjustment gasket arranged below the hole. The adjustment gasket is installed to part two through a threaded connection. By changing the thickness of the adjustment gasket, the position of the elliptical mounting hole on the hole can be adjusted, and the radial position of the hole relative to the process axis can be adjusted.

[0010] Furthermore, the detector module includes a position sensitive detector, a positioning block and a fixing block. The position sensitive detector is mounted on the surface of the positioning block through a threaded connection, and the positioning block is fixed to the part one by magnetic attraction through the fixing block.

[0011] Furthermore, the positioning block is internally provided with a power supply, a memory and a processor for the position sensitive detector to operate normally.

[0012] Furthermore, the photosensitive surface of the position sensitive detector is perpendicular to the outer axis of the process axis.

[0013] The present invention also provides a method for measuring the clearance between shafts and holes in a closed space, according to the device according to any one of claims 1 to 6, characterized in that it comprises the following steps:

[0014] S01: Use the first set of process axis No. I with a laser generator to coaxially replace the product axis on part 1 in situ. The laser generator built into process axis No. I emits a laser beam coaxial with the outer circle of the formal product axis;

[0015] S02: Close process axis No. I, so that process axis No. I passes through the hole on the part two-hole module and matches it to form a matching gap. The laser beam emitted by the laser generator built into the process axis irradiates the position sensitive detector of the detector module;

[0016] S03: Then, the axis position of process axis No. 1 is obtained by a position sensitive detector at a fixed position;

[0017] S04: Exit process axis No. I, and then use the second set of process axis No. II with a laser generator, assemble it coaxially to the hole, and the built-in laser generator of process axis No. II emits a laser beam coaxial with the inner circle of the hole;

[0018] S05: Then, the axis position of the hole through which the second group II process axis passes is obtained by the same position sensitive detector;

[0019] S06: using the axis positions of the shaft and the hole measured twice by the position sensitive detector, the axis deviation between the shaft and the hole can be calculated;

[0020] S07: Finally, the clearance between the shaft and the hole is calculated based on the shaft outer diameter and the hole inner diameter.

[0021] In summary, the present invention has the following advantages:

[0022] (1) The present invention solves the problem that after a closed space is formed, the clearance between the shaft and the hole cannot be directly and quantitatively measured and can only be qualitatively measured using the contact coloring method of the mating surface;

[0023] (2) Compared with the contact coloring method for measuring the mating surface, the present invention can automatically measure after the mechanism is closed in place, and the measurement process does not require manual intervention, which makes the operation simpler;

[0024] (3) The present invention uses a position sensitive detector (PSD) for position detection and a digital measurement method to improve measurement accuracy;

[0025] (4) Digital quantitative measurement of the clearance between the shaft and the hole can be used to guide assembly, improve assembly accuracy, make the clearance between the shaft and the hole as uniform as possible, and avoid deformation of the product during use, which may cause contact between the shaft and the hole and require frequent maintenance;

[0026] (5) The method of the present invention is based on non-contact measurement using a position sensitive detector (PSD), which avoids product coloring and is beneficial to improving product surface quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] FIG1 is a schematic flow chart of a method for measuring a fit gap according to the present invention;

[0028] FIG2 is an overall structural diagram of the fit clearance measuring device of the present invention;

[0029] FIG3 is a process axis module of the fit clearance measuring device of the present invention;

[0030] FIG4 is a hole module of the fit clearance measuring device of the present invention;

[0031] FIG5 is a detector module of the fit gap measuring device of the present invention;

[0032] FIG6 is a schematic diagram of the installation of the second set of process shaft modules into the hole according to the present invention;

[0033] 7 is a schematic diagram of the calculation of the clearance between the shaft and the hole of the present invention;

[0034] FIG8 is a schematic diagram of a closed space shaft-hole matching structure of the present invention;

[0035] In the figure, 101, part one, 102, part two, 103, process axis module, 104, hole module, 105, detector module, 301, nut, 302, spring washer, 303, laser generator, 304, process axis, 401, hole, 402, adjusting gasket, 501, position sensitive detector, 502, positioning block, 503, fixing block. DETAILED DESCRIPTION

[0036] The present invention will be further described in detail below with reference to the examples, but the embodiments of the present invention are not limited thereto.

[0037] Example 1

[0038] The present invention provides a device for measuring the clearance between shafts and holes in a closed space. The device, as shown in Figure 2, comprises part 101, part 2 102, a process shaft module 103, a hole module 104, and a detector module 105. Part 101 is used to mount the shaft module (process shaft 304); part 2 102 is used to mount the hole module 104. When parts 101 and 102 are closed, they are shielded by the structure to form a closed space (see Figure 8). The device of the present invention solves the problem of being unable to directly and quantitatively measure the clearance between the shaft and hole 401 after the closed space is formed.

[0039] The process axis module 103 is installed on part one 101 through a threaded connection, the hole module 104 is installed to part two 102 through a threaded connection, and the detector module 105 is fixed on part one 101 through magnetic attraction or the like, and its detection end face is located on the side where the process axis module 103 passes through the hole module 104.

[0040] Referring to Figure 3 , the process shaft module 103 comprises a nut 301, a spring washer 302, a laser generator 303, and a process shaft 304. This module securely connects the threaded process shaft 304 to part 101 via the nut 301 and spring washer 302. The process shaft 304 is a simulated prototype of the final product shaft. It contains a cavity for mounting the laser generator 303 and a laser channel for mounting the laser generator 303. In this embodiment, two sets of process shaft modules 103 are provided, designated I and II. These two sets of process shaft modules 103 have identical structural components, differing in that the laser generator 303 in process shaft module I can emit a laser beam coaxial with the outer diameter of the final product shaft, while the laser generator 303 in process shaft module II can emit a laser beam coaxial with the inner diameter of hole 401 (see Figure 4 ).

[0041] Referring to Figure 4 , hole module 104 includes hole 401 and adjustment washer 402, which are threadedly attached to part 2 102. During initial assembly, the inner diameter of hole 401 is essentially parallel to the axis of the outer diameter of the final product shaft. Adjustment washer 402 is positioned below hole 401. By varying the thickness of adjustment washer 402, the installation position of the elliptical mounting hole in hole 401 can be adjusted, thereby adjusting the radial position of hole 401 relative to the shaft to ensure proper clearance between the shaft and hole.

[0042] Referring to Figure 5 , the detector module 105 comprises a position-sensitive detector 501 (PSD), a positioning block 502, and a fixing block 503. The PSD 501 (PSD) can be threadedly mounted on the positioning block 502. The positioning block 502 can be magnetically secured to the component 101 using the fixing block 503, ensuring that the photosensitive surface of the PSD 501 (PSD) is perpendicular to the outer axis of the process axis 304. The positioning block 502 houses a power supply, memory, and processor, all necessary for the proper operation of the PSD 501 (PSD). The PSD 501 (PSD) detects the position of the laser beam emitted by the laser generator 303 within the process axis module 103.

[0043] The measurement operation of the fit clearance measuring device of the present invention is as follows:

[0044] Referring to Figure 2, process shaft No. 1 304 is mounted to part 101, and hole module 104 is mounted to part 2 102. The detector module 105 is fixed by a fixing block 503. Process shaft module No. 103 is positioned to enter the hole module 104 to form a shaft-hole gap. The position sensitive detector 501 (PSD) can detect the position of the laser beam emitted by the laser generator 303 inside the process shaft module 103 to obtain the axis position of the process shaft 304, thereby obtaining the axis of the outer circle of the formal product shaft.

[0045] Referring to Figure 6, the process shaft module No. I is withdrawn from the hole module 104, and the process shaft module No. II is installed into the hole 401. The position sensitive detector 501 (PSD) can detect the position of the laser beam emitted by the laser generator 303 inside the hole module 104 to obtain the axial position of the hole 401; finally, the outer diameter of the shaft and the inner diameter of the hole are combined to calculate the fitting clearance between the shaft and the hole.

[0046] Example 2

[0047] To improve the accuracy of shaft-hole clearance measurement, achieve quantitative measurement, enhance detection precision, ensure assembly accuracy, and enhance product surface quality, a closed-space shaft-hole clearance measurement method is proposed, as shown in Figure 1. This method uses a process axis and a position-sensitive detector (PSD) to automatically measure and calculate the clearance between the shaft and hole after they are aligned to form a closed space. The main steps are as follows:

[0048] S01: Use the first set of No. I process axis modules 103 with laser generators 303 to perform coaxial in-situ replacement of the product axis. The laser generator 303 built into the No. I process axis module 103 emits a laser beam coaxial with the outer circle of the formal product axis.

[0049] S02: Close the process axis, so that the process axis 304 in the process axis module 103 No. 1 passes through the hole module 104 and fits into the hole 401 to form a fitting gap. The laser generator 303 built into the process axis 304 No. 1 emits a laser beam that irradiates the position sensitive detector 501 (PSD);

[0050] S03: Then, the axis position (x1, z1) of the process axis 304 No. 1 is obtained by a position sensitive detector 501 (PSD) at a fixed position;

[0051] S04: Open (exit) the process axis, and then use the second set of process axis module II 103 with a laser generator 303, which is coaxially assembled to the hole 401. The laser generator 303 built into the process axis II 304 emits a laser beam coaxial with the inner circle of the hole 401, as shown in FIG6 ;

[0052] S05: Then, the axis position (x2, z2) of process axis (hole) No. II is obtained by the same position sensitive detector (PSD) mentioned above;

[0053] S06: Using the two measurements of the axis positions of the shaft and hole by the position sensitive detector (PSD), the axis deviation of the shaft and hole can be calculated, as shown in Figure 7; Δx = x1-x2, Δz = z1-z2

[0054] S07: Finally, the shaft-hole clearance Δd is calculated based on the shaft outer diameter and hole inner diameter:

[0055] Although the specific embodiments of the present invention are described in detail in conjunction with the accompanying drawings, this should not be construed as limiting the scope of protection of this patent. Within the scope described by the claims, various modifications and variations that can be made by those skilled in the art without creative work still fall within the scope of protection of this patent.

Claims

1. A closed space shaft-hole matching clearance measuring device, comprising a first part (101) and a second part (102) which are matched to form a closed space by being shielded by a structure, wherein the product shaft on the first part (101) and the hole (401) on the second part (102) are connected by shaft-hole matching; characterized in that: The measuring device comprises a process axis module (103) for replacing a product axis, a hole module (104) installed on a second part (102), and a detector module (105); the process axis module (103) comprises a process axis (304) and a laser generator (303); a mounting cavity for the laser generator (303) and a laser channel are arranged inside the process axis (304); the process axis module (103) is used to be installed on the first part (101) and the second part (102) successively, and to emit a laser beam coaxial with the outer circle of the product axis and coaxial with the inner circle of the hole (401) on the hole module (104); the front end of the process axis (304) passes through the hole (401) on the hole module (104), and the laser beam is emitted from the front end of the process axis (304) and irradiates the position sensitive detector (501) of the detector module (105); the position sensitive detector (501) is used to detect the position of the laser beam emitted by the laser generator (303).

2. A closed space shaft hole fit clearance measuring device according to claim 1, characterized in that: The process shaft (304) is fixedly connected to the part one (101) via a nut (301) and a spring washer (302).

3. The closed space shaft hole matching clearance measuring device according to claim 1, characterized in that: The hole module (104) comprises a hole (401) and an adjusting gasket (402) arranged below the hole (401); the adjusting gasket (402) is installed to the second part (102) through a threaded connection; by changing the thickness of the adjusting gasket (402), the position of the elliptical installation hole on the hole (401) can be adjusted, thereby adjusting the radial position of the hole (401) relative to the process axis (304).

4. The closed space shaft hole matching clearance measuring device according to claim 1, characterized in that: The detector module (105) comprises a position sensitive detector (501), a positioning block (502) and a fixing block (503); the position sensitive detector (501) is mounted on the surface of the positioning block (502) by means of a threaded connection; the positioning block (502) is fixed to the first component (101) by means of a magnetic attraction through the fixing block (503).

5. The closed space shaft hole matching clearance measuring device according to claim 4, characterized in that: The positioning block (502) is internally provided with a power supply, a memory and a processor which enable the position sensitive detector (501) to operate normally.

6. The closed space shaft hole matching clearance measuring device according to claim 1, characterized in that: The photosensitive surface of the position sensitive detector (501) is perpendicular to the outer circular axis of the process axis (304).

7. A method for measuring the clearance between shafts and holes in a closed space, according to the device described in any one of claims 1 to 6, characterized in that: The steps include: S01: using the first set of process shaft No. I with a laser generator (303), the product shaft on the part 1 is replaced coaxially in situ, and the laser generator built into the process shaft No. I emits a laser beam coaxial with the outer circle of the formal product shaft; S02: closing the process axis No. 1, so that the process axis No. 1 passes through the hole on the part two-hole module (104) and matches with it, forming a matching gap, and the laser beam emitted by the laser generator (303) built into the process axis No. 1 irradiates the position sensitive detector of the detector module (105); S03: Then, the axis position of process axis No. I is obtained by a position sensitive detector (501) at a fixed position; S04: exiting process axis No. I, and then using a second set of process axis No. II with a laser generator (303), coaxially assembled to the hole (401) on the hole module (104), the laser generator built into process axis No. II emits a laser beam coaxial with the inner circle of the hole; S05: Then, the axis position of the hole through which the process axis No. II of the second group passes is obtained by the position sensitive detector (501); S06: using the axis positions of the shaft and the hole measured twice by the position sensitive detector, the axis deviation of the shaft and the hole can be calculated; S07: Finally, the clearance between the shaft and the hole is calculated by combining the shaft outer diameter and the hole inner diameter.

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