Aero-engine deep hole bushing installation detection method

Abstract

The invention discloses an aero-engine deep hole bushing installation detection method, which adopts an impact measurement device, applies impact force and pressing force to a bushing through the device, and measures the displacement change before and after the force is applied, so as to judge whether the bushing is installed in place or not. In addition, whether the lining deflects or not can be detected through measurement of a plurality of different sites. According to the invention, a judgment method of in-place installation of the lower bushing is converted into measurement of the installation distance and the plane difference value, the displacement and deflection conditions of the bushing can be rapidly and accurately detected, and the problems of low detection precision and low detection efficiency during in-situ detection of the installation condition of the deep-hole bushing in a use site of a certain aviation piston engine are solved.

Description

Technical Field

[0001] The invention relates to the technical field of engine bushing installation detection, and more specifically, to an aircraft engine deep hole bushing installation detection method. Background Art

[0002] The vertical shaft of a certain aircraft piston engine transmission is supported between the upper bushing and bushing of the accessory transmission, such as Figure 1 There is an outer cylindrical surface below the vertical shaft spline, which is supported on the upper bushing of the rear cover as the upper support of the vertical shaft; there is an outer cylindrical surface below the vertical shaft bevel gear, which cooperates with the bushing on the rear cover as the lower support of the vertical shaft. The bushing is pressed into the hole of the receiver shell and fixed to the rear cover by two screws. Its upper end face is the axial limit surface of the vertical shaft. The mounting holes of the bushing and the receiver shell are transitional fits; during assembly, first install the vertical shaft into the receiver mounting hole, and then press the bushing into the receiver mounting hole. If the bushing is not installed in place and is slightly deflected, it will cause abnormal stress on the bushing during operation and fatigue cracks will occur.

[0003] The bushing is the lower support of the vertical shaft, and the bevel gear is installed on the vertical shaft. If the bushing is disassembled and reinstalled according to the conventional method to confirm whether it is installed in place, it is not feasible when the engine is in the complete state. This installation is very difficult and may damage the assembled gear transmission mechanism. Therefore, the in-situ detection solution is considered. There are two manifestations of the bushing not being installed in place in the mounting hole of the casing:

[0004] (1) The bushing is not fully installed in the mounting hole of the casing;

[0005] (2) The bushing is installed crookedly in the mounting hole of the receiver shell.

[0006] Therefore, it is necessary to measure the depth dimension in the casing housing mounting hole before and after striking the bushing to determine whether the bushing is installed in place, thereby ensuring the normal operation of the engine. In CN202110938132.9, a tool for installing a rigid shaft bushing of an aircraft engine and a method for using the tool, the tool as a whole adopts a cylindrical copper rod, and a fixed-length detection mark is provided on the surface of the cylindrical copper rod; the inner end face of the cylindrical copper rod is in contact with the circular end face of the rigid shaft bushing, and the outer end face of the cylindrical copper rod is used as the striking surface; when the rigid shaft bushing is against the boss of the engine casing, it is determined whether the rigid shaft bushing meets the installation requirements by judging whether the fixed-length detection mark is aligned with the plane of the flying attachment casing. The method of use is: insert the inner end of the cylindrical copper rod into the mounting hole of the attachment rigid shaft until the inner end of the cylindrical copper rod contacts the circular end face of the rigid shaft bushing; use a rubber hammer to knock the outer end of the cylindrical copper rod to move the rigid shaft bushing toward the attachment casing until the rigid shaft bushing presses against the attachment casing boss; check the relative position of the fixed-length detection mark on the cylindrical copper rod and the plane of the attachment casing to determine whether the fixed-length detection mark is aligned with the plane of the attachment casing; if aligned, it means that the installation of the rigid shaft bushing meets the requirements. However, in the transmission device of this aviation piston engine, when the engine is measured in situ, the lower bushing mounting hole is facing downward, the space is limited and is affected by the position of the engine and the surrounding pipelines. There are the following problems when measuring the size with a depth vernier caliper:

[0007] 1. Since the lower bushing mounting hole in the accessory transmission casing is facing downward, it is blocked by the pipeline and the mounting frame during the measurement process. The measurement position cannot be visually observed when measuring from bottom to top. It is basically a blind measurement operation. The installation surface of the lubricating oil pump is narrow, and the depth gauge is difficult to place stably and securely, which has a great impact on the measurement accuracy.

[0008] 2. After the nylon rod impacts the bushing, the bushing quickly returns to its original position due to gravity and the squeezing of other gears. The actual position and size of the bushing cannot be measured, so it is impossible to effectively determine whether the bushing is installed in place.

[0009] 3. There are pipeline interferences around, whether it is impacting or measuring the lower bushing, which has a certain impact on the quality control of the measurement process.

[0010] Therefore, there is a problem of difficulty in installing and inspecting the lower bushing of the vertical shaft support in the accessory transmission device. Summary of the invention

[0011] The main technical problem to be solved by the present invention is to provide an aircraft engine deep hole bushing installation detection method in view of the shortcomings of low detection accuracy and detection efficiency when in-situ detecting the installation condition of a deep hole bushing of a certain aircraft piston engine in the prior art.

[0012] The purpose of the present invention is achieved through the following technical solutions:

[0013] A method for detecting the installation of a deep hole bushing of an aircraft engine, the method is based on an impact measurement device for detection, the impact measurement device comprises a base, an impact device and a meter frame arranged on the base, the base is provided with a mounting hole for installing the impact device, a measuring hole for measuring the meter frame and a fixing hole for fixing the base; the impact device comprises an impact pressure head and a screw rod, the screw rod is sleeved on the rod portion of the impact pressure head, one end of the screw rod is in contact with the head portion of the impact pressure head, and the outer wall of the screw rod is provided with a thread connected with the mounting hole; the meter frame comprises a meter frame body and a meter head, the meter frame body is connected with the measuring hole, and the meter head is installed on the meter frame body;

[0014] The detection steps include:

[0015] S1. Install the base on the lower end surface of the rear cover, and install the impact head and the screw sleeve on the base, while ensuring that the head of the impact head does not contact the bushing;

[0016] S2. Insert the meter stand into the measuring hole, make the end of the meter stand contact the bushing, and record the value H1 of the meter head;

[0017] S3. Strike the rod of the impact head to make the head of the impact head fit with the bushing, and tighten the screw to keep the impact head and the bushing fit;

[0018] S4. Insert the meter stand into the measuring hole again, make the end of the meter stand contact the bushing, and record the value H2 of the meter head;

[0019] S5. Determine whether the bushing is properly installed based on the difference between the value H2 and the value H1.

[0020] Furthermore, the base is provided with more than two measuring holes, and whether the installation of the bushing is skewed can be determined by measuring at multiple different locations.

[0021] Furthermore, a gasket is provided between the screw and the impact head to reduce friction between the screw and the impact head and protect the impact head.

[0022] Furthermore, a groove is provided on the head of the impact pressure head to avoid the protruding part of the vertical axis on the bushing.

[0023] Furthermore, the impact pressure head is made of nylon to avoid damage to the bushing.

[0024] Furthermore, the value H1 and the value H2 are respectively average values ​​of multiple measured values.

[0025] Furthermore, the difference between the multiple measurement values ​​is no more than 0.02 mm.

[0026] Furthermore, when the impact pressure head and the bushing are attached, the impact pressure head applies a force of 4 to 6 N·m to the bushing.

[0027] Furthermore, the meter stand is subjected to a zeroing operation before measurement.

[0028] Furthermore, if the difference between the value H2 and the value H1 is no greater than 0.03 mm, it is determined that the bushing is installed in place.

[0029] Compared with the prior art, the beneficial effects are:

[0030] The present invention utilizes the characteristics of the bushing being tightly fitted and flat with the casing when it is installed in place, utilizes the impact measuring device to have the function of impacting and pressing the bushing, and continuously applies a certain torque to the bushing, so as to accurately measure the initial size and re-measured size of the bushing, and converts the determination method of whether the bushing is installed in place into measuring the installation distance and plane difference through the difference of the measured values ​​of multiple different measuring points and the difference standard of the re-measured value H2-initial value H1, so as to quickly and accurately detect the displacement and deflection of the bushing, thereby judging whether the bushing is installed in place. The present invention realizes the work of efficiently detecting the engine bushing in situ on site, improves the work efficiency, and shortens the detection cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a schematic diagram of the transmission structure;

[0032] Figure 2 is a structural diagram of the impact measurement device;

[0033] Figure 3 is a cross-sectional view of the impact measurement device.

[0034] Among them, 1-vertical shaft gear; 2-upper bushing; 3-lower bushing; 4-vertical shaft, 5-base, 6-impact pressure head, 7-screw, 8-meter frame, 9-gasket. DETAILED DESCRIPTION

[0035] The present invention will be further explained and illustrated below in conjunction with the embodiments, but the specific embodiments do not limit the present invention in any form.

[0036] Example 1

[0037] This embodiment provides an impact measurement device for installation detection of deep hole bushings of aircraft engines, such as Figures 2-3 The impact measuring device includes a base 5, an impact device and a meter frame 8 arranged on the base 5. The base 5 is provided with a mounting hole for mounting the impact device, the inner wall of the mounting hole is provided with a thread, and the mounting hole is opposite to the end of the vertical shaft 4. The base 5 is also provided with a measuring hole. The measuring hole is a through hole and can be used to install the meter frame 8. The base 5 is provided with fixing holes in the circumference, which are used to fix the base 5 on the screw piles of the accessory transmission case lubricating oil pump mounting hole.

[0038] The impact device includes an impact head 6 and a screw 7. The impact head 6 is made of nylon and includes a head and a rod. The rod of the impact head 6 passes through the screw 7. The center of the screw 7 is a through hole, so that the screw 7 can support and press the impact head 6. The outer wall is provided with a thread matching the mounting hole. One end of the screw 7 contacts the head of the impact head 6, and a gasket 9 is provided between the two to reduce the friction between the screw 7 and the impact head 6 and protect the impact head 6.

[0039] The meter frame 8 includes a meter frame body and a meter head. The lower end surface of the meter frame body is used as the measuring mating surface of the dial indicator, and is fitted with the surface of the base 5 for measurement. At the same time, the meter frame body and the meter jacket are matched with the mounting hole and connected, and the dial indicator is fixed by screws. The meter head is installed on the meter frame body and is used to measure and display the distance between the lower bushing 3 and the base 5.

[0040] Example 2

[0041] This embodiment provides an aero-engine deep hole bushing installation detection method based on the impact measurement device described in Embodiment 1, and the steps include:

[0042] S1. Install the base 5 on the lower end surface of the rear cover, extend the rod of the impact ram 6 through the through hole of the screw 7, connect and fix the base 5 to the transmission casing, and the head of the impact ram 6 does not contact the lower bushing 3.

[0043] S2. Insert the zeroed meter stand 8 into the measuring hole, fit the lower end surface of the meter stand body with the surface of the base 5, measure the distance between the lower bushing 3 and the base 5, record the meter header value, and obtain the initial value H1.

[0044] S4. Strike the rod of the impact ram 6 to make the head of the impact ram 6 fit with the lower bushing 3, and tighten the screw 7 to keep the impact ram 6 applying a force of 5 N·m to the lower bushing 3.

[0045] S5. Use the zeroed stand 8 to insert into the measuring holes again, record the value after applying the torque, and calculate the average value to obtain the re-measured value H2;

[0046] S6. Determine whether the lower bushing 3 is installed in place based on the difference between the re-measured value H2 and the initial value H1. If the re-measured value H2-initial value H1≤0.03mm, it means that the lower bushing 3 fits well with the end surface of the receiver hole and the lower bushing 3 is installed in place.

[0047] Example 3

[0048] The present embodiment provides an impact measurement device for the installation inspection of deep hole bushings of aircraft engines, and the impact measurement device includes a base 5, an impact device and a meter frame 8 arranged on the base 5. The base 5 is provided with a mounting hole for mounting the impact device, and the inner wall of the mounting hole is provided with a thread, and the mounting hole is opposite to the end of the vertical axis 4. The base 5 is also provided with three measuring holes at different points, of which the three measuring holes No. 1, No. 2 and No. 3 are located above the lower bushing 3. The measuring holes are through holes and can be used to install the meter frame 8. The base 5 is circumferentially provided with fixing holes for fixing the base 5 on the screw piles of the accessory transmission case lubricating oil pump mounting hole.

[0049] The impact device includes an impact head 6 and a screw 7. The impact head 6 is made of nylon and includes a head and a rod. The head of the impact head 6 is provided with a groove that fits with the vertical shaft 4 to avoid the protruding part of the vertical shaft 4 in the lower bushing 3. The rod of the impact head 6 passes through the screw 7. The center of the screw 7 is a through hole, so that the screw 7 can support and press the impact head 6. The outer wall is provided with a thread that matches the mounting hole. One end of the screw 7 contacts the head of the impact head 6, and a gasket 9 is provided between the two to reduce the friction between the screw 7 and the impact head 6 and protect the impact head 6.

[0050] The meter frame 8 includes a meter frame body and a meter head. The lower end surface of the meter frame body is used as the measuring mating surface of the dial indicator, and is fitted with the surface of the base 5 for measurement. At the same time, the meter frame body and the meter jacket are matched with the mounting hole and connected, and the dial indicator is fixed by screws. The meter head is installed on the meter frame body for measurement.

[0051] Example 4

[0052] This embodiment provides an aircraft engine deep hole bushing installation detection method based on the impact measurement device described in Embodiment 3, and the steps include:

[0053] S1. Install the base 5 on the lower end surface of the rear cover, the head groove of the impact ram 6 is sleeved to the end of the vertical shaft 4, the rod punches the through hole of the screw 7, and the base 5 is connected and fixed to the transmission casing. The head of the impact ram 6 does not contact the lower bushing 3.

[0054] S2. Use the zeroed meter stand 8 to insert it into the No. 1 measuring hole, so that the lower end surface of the meter stand body fits with the surface of the base 5, measure the value of the distance between the lower bushing 3 and the base 5, and record the value of the meter head.

[0055] S3. Use the meter stand 8 to measure the No. 2 and No. 3 measuring holes in turn, and record the values ​​of the lower headers respectively. The difference between the measured values ​​of the three locations is no more than 0.02 mm, indicating that the lower bushing 3 is installed without deviation. Calculate the average value and obtain the initial value H1.

[0056] S4. Strike the rod of the impact ram 6 to make the head of the impact ram 6 fit with the lower bushing 3, and tighten the screw 7 to keep the impact ram 6 applying a force of 5 N·m to the lower bushing 3.

[0057] S5. Use the zeroed stand 8 again to insert into the measuring holes 1, 2 and 3, respectively, record the value after the torque is applied, and obtain the average value to obtain the re-measured value H2;

[0058] S6. Determine whether the lower bushing 3 is installed in place based on the difference between the re-measured value H2 and the initial value H1. If the re-measured value H2-initial value H1≤0.02mm, it means that the lower bushing 3 fits well with the end surface of the receiver hole and the lower bushing 3 is installed in place.

[0059] Example 5

[0060] The present embodiment provides an impact measurement device for installation inspection of deep hole bushings of aircraft engines. The difference between the present embodiment and embodiment 3 is that four measuring holes at different points are further provided on the base 5, of which three measuring holes No. 1, No. 2 and No. 3 are located above the lower bushing 3, and the other measuring hole No. 4 is located above the asbestos pad on the lower bushing 3.

[0061] The detection steps include:

[0062] S1. Install the base 5 on the lower end surface of the rear cover, the head groove of the impact ram 6 is sleeved to the end of the vertical shaft 4, the rod punches the through hole of the screw 7, and the base 5 is connected and fixed to the transmission casing. The head of the impact ram 6 does not contact the lower bushing 3.

[0063] S2. Use the zeroed meter stand 8 to insert it into the No. 1 measuring hole, so that the lower end surface of the meter stand body fits with the surface of the base 5, measure the value of the distance between the lower bushing 3 and the base 5, and record the value of the meter head.

[0064] S3. Use the meter stand 8 to measure the No. 2 and No. 3 measuring holes in turn, and record the values ​​of the lower headers respectively. The difference between the measured values ​​of the three sites is no more than 0.02mm, indicating that the lower bushing 3 is installed without deflection, and calculate the average value to obtain the initial value H1. At the same time, use the meter stand 8 to measure the No. 4 measuring hole to obtain the value H.

[0065] S4. Strike the rod of the impact ram 6 to make the head of the impact ram 6 fit with the lower bushing 3, and tighten the screw 7 to keep the impact ram 6 applying a force of 5 N·m to the lower bushing 3.

[0066] S5. Use the zeroed stand 8 again to insert into the No. 1, No. 2 and No. 3 measuring holes respectively, record the values ​​after the torque is applied, and calculate the average value to obtain the re-measured value H2; at the same time, measure the No. 4 measuring hole to obtain the value H'.

[0067] S6. When the lower bushing 3 is installed in place, under a force of 5 N·m, there is a compression of 0.01 to 0.02 mm between the value H' and the value H. If the difference between the re-measured value H2 and the initial value H1 is ≤ 0.03 mm, it means that the lower bushing 3 fits well with the end surface of the casing hole and the lower bushing 3 is installed in place.

[0068] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A method for installing and detecting a deep hole bushing of an aircraft engine, characterized in that: The method is based on an impact measurement device for detection. The impact measurement device includes a base, an impact device and a meter frame arranged on the base. The base is provided with a mounting hole for mounting the impact device, a measuring hole for measuring the meter frame, and a fixing hole for fixing the base. The impact device includes an impact pressure head and a screw rod. The screw rod is sleeved on the rod of the impact pressure head, and one end of the screw rod is in contact with the head of the impact pressure head. The outer wall of the screw rod is provided with a thread connected with the mounting hole. The meter frame includes a meter frame body and a meter head. The meter frame body is connected with the measuring hole, and the meter head is installed on the meter frame body. The detection steps include: S1. Install the base on the lower end surface of the rear cover, and install the impact head and the screw sleeve on the base, while ensuring that the head of the impact head does not contact the bushing; S2. Insert the meter stand into the measuring hole, make the end of the meter stand contact the bushing, and record the value H1 of the meter head; S3. Strike the rod of the impact head to make the head of the impact head fit with the bushing, and tighten the screw to keep the impact head and the bushing fit; S4. Insert the meter stand into the measuring hole again, make the end of the meter stand contact the bushing, and record the value H2 of the meter head; S5. Determine whether the bushing is properly installed based on the difference between the value H2 and the value H1.

2. The method for installing and detecting deep hole bushings of an aircraft engine according to claim 1, characterized in that: The base is provided with more than two measuring holes.

3. The method for installing and detecting deep hole bushings of an aircraft engine according to claim 1, characterized in that: A gasket is also arranged between the screw and the impact pressure head.

4. The method for installing and detecting deep hole bushings of an aircraft engine according to claim 1, characterized in that: The head of the impact pressure head is provided with a groove for avoiding interference with the end of the vertical shaft.

5. The method for installing and detecting deep hole bushings of an aircraft engine according to claim 1, characterized in that: The impact pressure head is made of nylon.

6. The method for installing and detecting deep hole bushings of an aircraft engine according to claim 1, characterized in that: The numerical value H1 and the numerical value H2 are respectively average values ​​of a plurality of measured values.

7. The method for installing and detecting deep hole bushings of an aircraft engine according to claim 6, characterized in that: The difference between the multiple measurement values ​​is no greater than 0.02 mm.

8. The method for installing and detecting deep hole bushings of an aircraft engine according to claim 1, characterized in that: When the impact pressure head and the bushing are attached, the impact pressure head applies a force of 4 to 6 N·m to the bushing.

9. The method for installing and detecting deep hole bushings of an aircraft engine according to claim 1, characterized in that: The meter stand is subjected to zeroing operation before measurement.

10. The method for installing and detecting deep hole bushings of an aircraft engine according to claim 1, characterized in that: If the difference between the value H2 and the value H1 is not greater than 0.03 mm, it is determined that the bushing is installed in place.

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