A helicopter torque arm square arm assembly bonding apparatus and bonding method

Abstract

The application provides a kind of helicopter torsion arm square arm assembly cementing device and method, the device includes base 1, support plate 2, positioning bushing 3, compression bushing 4, compression nut 5, compression bolt 6, first sealing washer 7, second sealing washer 8, adhesive core rod 9, torsion arm square arm assembly 10, wherein: the shape of base 1 matches the structure of torsion arm square arm assembly, N threaded holes are machined on the bottom plate for installing support column, N light holes and N threaded holes are machined on the side wall plate of base 1, N light holes are used for installing positioning bushing 3, and N threaded holes are used for installing positioning bushing fixing screw to prevent positioning bushing 3 from rotating and moving; support plate 2 is placed on base 1, the shape of support plate 2 is set according to the structure of torsion arm square arm assembly, and rubber pad is bonded on support plate 2; there are N positioning bushings 3, which are installed on base 1 by interference fit.

Description

Technical Field

[0001] This invention belongs to the field of helicopter assembly technology, specifically relating to a bonding device and bonding method for a helicopter torsion arm square arm assembly. Background Technology

[0002] The torsion arm square arm assembly is a key component in the helicopter's automatic swashplate, and its main function is to drive the rotating ring to rotate synchronously with the main shaft.

[0003] like Figure 1 As shown, the torque arm square arm assembly consists of a torque arm square arm and a tungsten carbide shoulder bushing, forming a bore-shaft mating pair. Because the service life of the tungsten carbide shoulder bushing is shorter than that of the torque arm square arm, to facilitate replacement of the tungsten carbide shoulder bushing upon its expiration date, the design uses J-200-1A adhesive to bond the tungsten carbide shoulder bushing to the inner bore of the square arm. After bonding, it is necessary to ensure… Figure 1 The relevant linear dimensions and geometric tolerances are required. Currently, the entire bonding process for the tungsten carbide shoulder bushing is done manually. To ensure dimensional requirements, repeated measurements and adjustments are necessary, resulting in high labor intensity for operators. Furthermore, the process documentation is unclear, the operating methods are not detailed, and the control requirements are ambiguous. Additionally, the bonding process design does not consider the actual situation where adhesive overflows from the bonding surface, and the bonding fixtures used do not take effective measures to prevent adhesive flow. During pre-curing, the adhesive overflows along the bonding surface, and the amount of overflow varies depending on factors such as gel time and operating techniques, resulting in significant dispersion in the actual bonding strength of the adhesive layer. In summary, this leads to large fluctuations in performance indicators between different batches of products, low product quality stability and consistency, poor bonding performance in some products, and actual bonding force failing to meet usage requirements. Ultimately, this results in the detachment of the tungsten carbide shoulder bushing. When the adhesive layer completely detaches and peels off, the tungsten carbide shoulder bushing directly contacts the square arm hole of the torque arm, and repeated wear causes damage, potentially affecting helicopter flight safety. Summary of the Invention

[0004] This application provides a bonding device for a helicopter torsion arm square arm assembly, which can solve the problem of low product quality stability and consistency.

[0005] The first invention, this application provides a bonding device for a helicopter torque arm square arm assembly, the device comprising a base 1, a support plate 2, a positioning bushing 3, a clamping bushing 4, a clamping nut 5, a clamping bolt 6, a first sealing washer 7, a second sealing washer 8, an adhesive core rod 9, and a torque arm square arm assembly 10, wherein:

[0006] The base 1 is matched with the torsion arm square arm assembly structure, N threaded holes are machined on the base plate for installing support columns, N light holes and N threaded holes are machined on the two side wall plates of the base 1, the N light holes are used for installing the positioning bushing 3, and the N threaded holes are used for installing the positioning bushing fixing screw, so as to prevent the positioning bushing 3 from rotating and moving; the support plate 2 is placed on the base 1, the shape of the support plate 2 is arranged according to the torsion arm square arm assembly structure, and the support plate 2 is bonded with a rubber pad; the positioning bushing 3 has N in total and is installed on the base 1 in a manner of interference fit, the outer diameter of the positioning bushing 3 is arranged according to the size of the N light holes on the two side wall plates of the base 1 and the interference amount; the compression bushing 4 is threaded on the glued core rod 9, the small end of the compression bushing 4 is in contact with the non-shoulder of the tungsten carbide shoulder bushing, the large end of the compression bushing 4 is in contact with the compression nut 5, and the inner diameter of the compression bushing 4 is arranged according to the size of the inner hole of the positioning bushing 3; the compression nut 5 is threaded on the glued core rod 9, hexagons are machined on the outer side of the compression nut 5, and stepped holes are machined on the inner side of the compression nut 5, the small end of the compression nut 5 is a light hole, the large end of the compression nut 5 is a threaded hole, the small end is in contact with the positioning bushing 3, and the large end is connected with the compression bolt 6 through threads, and the size of the light hole of the compression nut 5 is arranged according to the size of the inner hole of the positioning bushing 3; the compression bolt 6 is threaded on the glued core rod 9, hexagons are machined on the outer side of the compression bolt 6 for easy rotation, one end of the compression bolt 6 is installed on the compression nut 5 through threads, the one end of the compression bolt 6 is in contact with the non-shoulder of the tungsten carbide shoulder bushing, and the inner diameter size of the compression bolt 6 is arranged according to the size of the inner hole of the positioning bushing 3; the inner hole size of the first sealing washer 7 is arranged according to the size of the outer circle of the non-shoulder part of the tungsten carbide shoulder bushing, so as to ensure that it is tightly in contact with the outer circle, and the inner hole size of the second sealing washer 8 is arranged according to the size of the outer circle of the non-shoulder part of the tungsten carbide shoulder bushing, so as to ensure that it is tightly in contact with the outer circle; the length of the glued core rod 9 is longer than the distance between the two side wall plates of the base 1, and the diameter of the glued core rod 9 is selected according to the inner diameter of the tungsten carbide shoulder bushing.

[0007] Specifically, the inner hole and end face of the positioning bushing 3 are secondarily processed after assembly, and the linear size and shape tolerance after secondary processing are 3 times of the requirements of the torsion arm square arm assembly.

[0008] Specifically, the compression bushing 4 is 0.05-0.1mm larger than the inner hole of the positioning bushing 3.

[0009] Specifically, the light hole size of the compression nut 5 is 0.05-0.1mm larger than the inner hole of the positioning bushing 3.

[0010] Specifically, the inner diameter size of the compression bolt 6 is 0.05-0.1mm larger than the inner hole size of the positioning bushing 3.

[0011] Specifically, the diameter difference between the glued core rod 9 and the inner diameter of the tungsten carbide shoulder bushing is not more than 0.01mm.

[0012] Specifically, the two side walls of the base 1 are processed with four light holes and four threaded holes. The four light holes are used for installing the positioning bush 3, and the positioning bush 3 has four in total.

[0013] The second application provides a gluing method for a helicopter torsion arm square arm assembly.

[0014] Step 1: initially install the tungsten carbide shoulder bushing on the torsion arm square arm;

[0015] Step 2: install the first sealing ring 7 and the second sealing ring 8 on both sides of the tungsten carbide shoulder bushing, and complete the pre-assembly of the torsion arm square arm assembly;

[0016] Step 3: place the pre-assembled torsion arm square arm assembly on the support plate 2, adjust the position of the torsion arm square arm assembly by compressing the rubber pad, ensure that the hole of the torsion arm square arm assembly is aligned with the hole on the positioning bush 3, and then insert the glue core rod 9 into the hole of the torsion arm square arm assembly and the hole on the positioning bush 3;

[0017] Step 4: use a wrench to rotate the compression nut 5 in the compression direction, and the compression nut 5 will drive the compression bushing 4 to compress the torsion arm square arm assembly 10 during rotation until the outer side end face of the tungsten carbide shoulder bushing of the torsion arm square arm assembly 10 is in close contact with the positioning bush 3;

[0018] Step 5: place the torsion arm square arm assembly 10 and the gluing device in a high-temperature box for glue solidification.

[0019] In summary, the application provides a gluing device for a helicopter torsion arm square arm assembly, which is simple to operate, can reduce assembly difficulty, does not need to be adjusted after assembly, can quickly ensure the linear size and shape tolerance of the torsion arm square arm assembly, and seals the gluing surface of the torsion arm square arm assembly through the sealing ring, solves the problem of overflow of J-200-1A glue along the gluing surface during solidification, improves the uniformity of the glue layer thickness, thereby improving the bonding strength and stability, and avoiding the problem of debonding of the tungsten carbide shoulder bushing during flight use. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of a certain helicopter torsion arm square arm assembly;

[0021] Figure 2 It is a front view of a gluing device for a helicopter torsion arm square arm assembly provided by the application;

[0022] Figure 3 It is a top view of a gluing device for a helicopter torsion arm square arm assembly provided by the application;

[0023] Figure 4A top view of the base 1 of a helicopter torsion arm square arm assembly bonding device provided in this application;

[0024] Figure 5 A schematic diagram of the square arm assembly selection for a helicopter torsion arm square arm assembly bonding method provided in this application;

[0025] Figure 6 The installation position of the sealing ring of the square arm assembly in the adhesive bonding method of the square arm assembly of the helicopter torsion arm provided in this application;

[0026] Figure 7 The first step in the installation of the square boom assembly of the helicopter torsion boom square boom assembly provided in this application;

[0027] Figure 8 The second step in the installation of the square boom assembly of the helicopter torsion boom square boom assembly provided in this application;

[0028] Figure 9 The third step in the installation of the square boom assembly of the helicopter torsion boom square boom assembly provided in this application;

[0029] Among them, 1-base, 2-support plate, 3-positioning bushing, 4-pressure bushing, 5-pressure nut, 6-pressure bolt, 7-first sealing washer, 8-second sealing washer, 9-adhesive core rod, 10-torsion arm square arm assembly. Detailed Implementation

[0030] Example 1

[0031] like Figures 2-3 As shown, this application provides a rapid positioning device for bonding a square arm assembly of a helicopter torque arm, which can avoid the overflow problem of J-200-1A adhesive during the curing process. It includes a base 1, a support plate 2, a positioning bushing 3, a clamping bushing 4, a clamping nut 5, a clamping bolt 6, a first sealing washer 7, a second sealing washer 8, an adhesive core rod 9, and a square arm assembly of the torque arm 10, wherein:

[0032] The base 1 is matched with the torsion arm square arm assembly structure, N threaded holes are machined on the base plate for installing support columns, so that the support columns can be disassembled, replaced, and the adhesive device is convenient to carry and maintain, N light holes and N threaded holes are machined on the two side walls of the base 1, the N light holes are used for installing the positioning bushing 3, and the N threaded holes are used for installing the positioning bushing fixing screw, so as to prevent the positioning bushing 3 from rotating and moving; the support plate 2 is placed on the base 1, the shape of the support plate 2 is set according to the torsion arm square arm assembly structure, and the support plate 2 is bonded with a rubber pad to avoid the torsion arm square arm assembly from contacting metal and causing scratches; the positioning bushing 3 has N, which is installed on the base 1 by interference fit, and the outer diameter of the positioning bushing 3 is set according to the size of the N light holes on the two side walls of the base 1 and the interference amount; the compression bushing 4 is threaded on the adhesive core rod 9, the small end of the compression bushing 4 is in contact with the non-shoulder of the tungsten carbide shoulder bushing, the large end of the compression bushing 4 is in contact with the compression nut 5, and the inner diameter of the compression bushing 4 is set according to the size of the inner hole of the positioning bushing 3; the compression nut 5 is threaded on the adhesive core rod 9, hexagons are machined on the outer side of the compression nut 5 for easy rotation, and stepped holes are machined on the inner side, the small end of the compression nut 5 is a light hole, the large end of the compression nut 5 is a threaded hole, the small end is in contact with the positioning bushing 3, and the large end is connected with the compression bolt 6 through threads, and the light hole size of the compression nut 5 is set according to the inner hole size of the positioning bushing 3; the compression bolt 6 is threaded on the adhesive core rod 9, hexagons are machined on the outer side of the compression bolt 6 for easy rotation, one end of the compression bolt 6 is installed on the compression nut 5 through threads, the one end of the compression bolt 6 is in contact with the non-shoulder of the tungsten carbide shoulder bushing, and the inner diameter size of the compression bolt 6 is set according to the inner hole size of the positioning bushing 3; the inner hole size of the first sealing washer 7 is set according to the outer circle size of the non-shoulder part of the tungsten carbide shoulder bushing to ensure close contact with the outer circle, and the inner hole size of the second sealing washer 8 is set according to the outer circle size of the non-shoulder part of the tungsten carbide shoulder bushing to ensure close contact with the outer circle; the length of the adhesive core rod 9 is longer than the distance between the two side walls of the base 1, and the diameter of the adhesive core rod 9 is selected according to the inner diameter of the tungsten carbide shoulder bushing.

[0033] Specifically, the inner hole and end face of the positioning bushing 3 are secondarily processed after assembly, and the linear size and shape tolerance after secondary processing are 3 times the requirements of the torsion arm square arm assembly, as shown in Figure 4 .

[0034] Specifically, the compression bushing 4 is 0.05-0.1mm larger than the inner hole of the positioning bushing 3.

[0035] Specifically, the light hole size of the compression nut 5 is 0.05-0.1mm larger than the inner hole of the positioning bushing 3.

[0036] Specifically, the inner diameter size of the compression bolt 6 is 0.05-0.1mm larger than the inner hole size of the positioning bushing 3.

[0037] Specifically, the difference between the diameter of the adhesive core rod 9 and the inner diameter of the tungsten carbide shoulder bushing is not greater than 0.01 mm.

[0038] Specifically, four light holes and four threaded holes are processed on the two side wall plates of the base 1, and the four light holes are used for mounting the positioning bush 3.

[0039] Specifically, the positioning bush 3 has a total of four.

[0040] In summary, the application provides a helicopter torsion arm square arm assembly gluing device, which is simple to operate, can reduce assembly difficulty, does not need to be adjusted after assembly, can quickly ensure the linear size and shape tolerance requirements of the torsion arm square arm assembly, and seals the gluing surface of the torsion arm square arm assembly through the sealing ring, solves the problem of overflow of J-200-1A glue along the gluing surface during the curing process, improves the uniformity of the glue layer thickness, thereby improving the bonding strength and stability, and avoiding the problem of debonding of the tungsten carbide shoulder bushing during flight use.

[0041] Example two

[0042] The application embodiment provides a gluing method of a helicopter torsion arm square arm assembly gluing device, which comprises the following steps:

[0043] Step 1: initially assemble the tungsten carbide shoulder bushing on the torsion arm square arm;

[0044] Step 2: install the first sealing ring 7 and the second sealing ring 8 on the two sides of the tungsten carbide shoulder bushing, and complete the pre-assembly of the torsion arm square arm assembly;

[0045] Step 3: place the pre-assembled torsion arm square arm assembly on the support plate 2, adjust the position of the torsion arm square arm assembly by compressing the rubber pad, ensure that the holes of the torsion arm square arm assembly and the holes on the positioning bush 3 are aligned, and then insert the adhesive core rod 9 into the holes of the torsion arm square arm assembly and the holes on the positioning bush 3, so as to ensure the requirements of 230±0.2, parallelism φ0.1 and coaxiality φ0.015 in the torsion arm square arm assembly; Figure 1

[0046] Step 4: rotate the compression nut 5 in the compression direction using a wrench, and the compression nut 5 will drive the compression bushing 4 to compress the torsion arm square arm assembly 10 during the rotation process, until the outer side end face of the tungsten carbide shoulder bushing of the torsion arm square arm assembly 10 is attached to the positioning bush 3, so as to ensure the size requirement of 137.50 -0.1 in the torsion arm square arm assembly; Figure 1

[0047] Step 5: place the torsion arm square arm assembly 10 and the gluing device in a high-temperature box for glue curing.

[0048] Example three

[0049] ​​The embodiment of the application provides a kind of torsion arm square arm assembly cementing method of helicopter, is implemented using the cementing device of torsion arm square arm assembly of helicopter provided in the above embodiment, method includes:

[0050] Step 1: the adhesive surface of the bushing mounting hole surface of torsion arm square arm and the surface of tungsten carbide shoulder bushing is checked;

[0051] Specifically, the anodization layer of the torsion arm square arm bushing mounting hole surface should be continuous, smooth and uniform, and should not have scratch lines, deep scratches, burning and missing anodization parts;The surface of tungsten carbide shoulder bushing should not be scratched, scratched and rusted.

[0052] Step 2: group the tungsten carbide shoulder bushing, and select the corresponding adhesive core rod according to the inner diameter of the tungsten carbide shoulder bushing;

[0053] Specifically, step 2 includes:

[0054] Step 21: as shown in Figure 5 , bushing A and bushing B are a group, and the actual hole diameter of the two bushings is not more than 0.005 mm different from each other;

[0055] Step 22: as shown in Figure 5 , bushing C and bushing D are a group, and the actual hole diameter of the two bushings is not more than 0.005 mm different from each other;

[0056] Step 23: after determining the actual A, B, C and D bushings, record the measured value of the inner diameter of the bushing, the mutual difference value of the inner diameter of the bushing and the maximum inner diameter value in Table 1, and mark the grouped bushings with bagged method.

[0057] Table 1: tungsten carbide shoulder bushing and adhesive core rod matching record table

[0058]

[0059] Step 24: according to the maximum value of the inner diameter of bushing A and bushing B, select the adhesive core rod, and the diameter of the adhesive core rod is not more than 0.01 mm different from the maximum value of the inner diameter of A and B bushing. Select the core rod matched with bushing C and bushing D by the same method, and record the measured value of the outer diameter of the core rod and the maximum gap value between the core rod and the inner hole of the shoulder bushing in Table 1.

[0060] Step 25: select the core rod and mark AB and CD with a marker pen according to the matched tungsten carbide shoulder bushing.

[0061] Step 26: compare the selected adhesive core rod with the hole on the cementing device to ensure that the adhesive core rod can pass freely without jamming. Group the tungsten carbide shoulder bushing and the corresponding adhesive core rod as a group, mark them and place them properly, so as to be used for assembly of the same fork two-hole in the subsequent process.

[0062] Step 3: Clean the inner surface of the square arm bushing mounting hole of the torsion arm and the outer circular surface of the tungsten carbide shoulder bushing;

[0063] Specifically, step 3 includes:

[0064] Step 31: Clean the surface of the bonding device with 180# gasoline. After cleaning, use white non-woven fabric to wipe the joint between the device and the workpiece until the white non-woven fabric is free of any color change.

[0065] Step 32: Clean the overall surface of the part with 180# gasoline. After cleaning, use white non-woven fabric to wipe clean and dry for 5 minutes.

[0066] Step 33: Clean the bonding surface with acetone using a cotton swab. Wipe the inner surface of the torsion arm square arm fitting hole until the cotton swab is free of dirt. Dry at room temperature for 15 minutes or more. Use a clean white cloth to wipe the outer surface of the tungsten carbide shoulder bushing with acetone until the cloth is free of any color change. Dry for 5 minutes.

[0067] It should be noted that the work platform should be covered with wax-free and oil-free kraft paper before cleaning. The operator should wear latex gloves during the cleaning process.

[0068] Step 4: Adjust the glue for -200-1A

[0069] Specifically, step 4 includes:

[0070] Step 41: Evaluate the actual production task's demand for glue. According to the ratio requirements in Table 2, take J-200-1A glue. Check that the surface color of the A component and the B component is uniform, there is no caking phenomenon and no foreign matter.

[0071] Table 2 J-200-1A glue color and ratio information

[0072]

[0073] Step 42: Weigh the A component and the B component taken, calculate the ratio of the A component to the B component, and record the results.

[0074] Step 43: Select a clean surface mixing stick and stir the adhesive in the plastic cup uniformly from the outside to the inside in the same direction until the adhesive is mixed evenly and the surface color is consistent. The surface of the mixed glue should be free of obvious bubbles, and the mixing end time is recorded.

[0075] It should be noted that the glue mixing and stirring time should be more than 5 minutes. Since the J-200-1A glue has a relatively fast gelling speed at high temperature, in order to ensure sufficient construction time, the bonding environment temperature is controlled at 15-25℃, and the subsequent glue coating and tungsten carbide shoulder bush installation work should be completed within 30 minutes.

[0076] Step 5: Glue coating on the inner surface of the square arm bush mounting hole of the torsion arm square arm and the outer circular surface of the tungsten carbide shoulder bush

[0077] Use the brush to dip the prepared glue solution and evenly coat it on the inner surface of the square arm bush mounting hole of the torsion arm square arm and the outer circular surface of the tungsten carbide shoulder bush. After the coating is completed, the glue layer should be free of air bubbles.

[0078] Step 6: Install the tungsten carbide shoulder bush on the torsion arm square arm

[0079] Specifically, step 6 includes:

[0080] Step 61: Place the tungsten carbide shoulder bush opposite the square arm mounting hole of the torsion arm square arm, initially into the square arm hole, and then rotate in the same direction to evenly distribute the glue solution in the gap between the square arm and the shoulder bush and to remove air, until the end face of the shoulder bush is in contact with the surface of the square arm. After the shoulder bush is installed, check that there is uniform glue overflow on the shoulder end of the bush and the exposed square arm bottom hole area, and that the surface of the overflowed glue is free of obvious air bubbles.

[0081] Step 62: As shown in the figure, install first sealing gaskets 7 at four places where the shoulder of the bush and the square arm are in contact with the outer circle, and the sealing gaskets should be flat after installation and have no gap with the contact surface of the square arm; after the gasket installation is completed, remove the excess glue layer outside the gasket. Figure 6

[0082] Step 63: As shown in the figure, install second sealing gaskets 8 at four places where the shoulder of the bush and the square arm are in contact with the outer circle, and the sealing gaskets should be flat after installation and have no gap with the contact surface of the square arm; after the gasket installation is completed, remove the excess glue layer outside the gasket. Figure 6

[0083] Step 7: Install the torsion arm square arm assembly on the gluing device and place it in the high-temperature oven for warming and curing.

[0084] Specifically, step 7 includes:

[0085] Step 71: First, place the support plate 2 on the base 1, then place the torsion arm square arm assembly 10 on the support plate 2, adjust the position of the torsion arm square arm assembly 10 on the support plate 2 to ensure that the inner hole of the tungsten carbide shoulder bush at position A in the figure is aligned with the inner hole of the positioning bush 3. Figure 5

[0086] ​​​Step 72: As Figures 7-9 As shown, insert the adhesive core rod 9. Figure 5 The tungsten carbide shoulder bushing inner hole at point A in the middle reaches... Figure 7 State; sequentially insert the clamping bolt 6, clamping nut 5, and clamping bushing 4 onto the adhesive core rod 9 to achieve the desired state. Figure 8 State; Align the inner hole of the tungsten carbide shoulder bushing at point B with the inner hole of the positioning bushing 3, and insert the adhesive core rod into the inner hole of the shoulder bushing at point B to achieve... Figure 9 Once the state is reached, the installation of one side of the torque arm square boom assembly 10 is complete. Following the same steps, the installation of the other side of the torque arm square boom assembly 10 is completed.

[0087] Step 73: Using a wrench, slowly rotate the tightening nut 5 along the direction of tightening the tungsten carbide shoulder bushing so that the outer end face of the tungsten carbide shoulder bushing of the torque arm square arm assembly 10 fits against the positioning bushing 3. After applying force, check whether the first sealing washer 7 and the second sealing washer 8 fit against the contact surface of the torque arm square arm. If there is a gap, fine adjust the first sealing washer 7 and the second sealing washer 8 to ensure that there is no gap with the contact surface of the torque arm square arm.

[0088] Step 74: Place the installed torsion arm square arm assembly 10 and the bonding device into a high-temperature chamber, heat it to 65°C at a heating rate of no more than 4°C / min, and keep it at that temperature for more than 1 hour to cure the adhesive. The curing process is recorded in Table 3.

[0089] Table 3 Curing Process Record Sheet

[0090]

[0091] Step 75: After curing, remove the torque arm square arm assembly 10 and the bonding device from the high temperature chamber, loosen the clamping nut 5, remove the adhesive core rod 9, and take out the clamping bushing 4, clamping bolt 6, and clamping nut 5 in sequence, and remove the torque arm square arm assembly 10 from the bonding device.

[0092] Step 76: Use a scraper to disassemble the first sealing gasket 7 and the second sealing gasket 8 from the torsion arm square arm assembly 10. Visually inspect the adhesive layer at the bonding area. There should be no discoloration, uneven color, cracks, debris, or bubbles.

[0093] It should be noted that during the disassembly of the first sealing gasket 7 and the second sealing gasket 8, the scraper must not come into contact with the tungsten carbide shoulder bushing and the surface of the torsion arm square arm.

[0094] Step 77: Clean the surface of the torque arm square arm assembly 10 and the adhesive device with a clean white non-woven cloth until the white non-woven cloth shows no color change. The adhesive device accessories are strung on the base 1 for later use.

[0095] Step 8: detect the linear size and shape tolerance of the torsion arm square arm assembly, and detect the bonding force of the tungsten carbide shoulder bushing;

[0096] Specifically, step 8 includes:

[0097] Step 81: use the relevant gauge to detect whether the linear size and shape tolerance in the formula meet the requirements. Figure 1

[0098] Step 82: place the torsion square arm assembly on the press, apply a downward load at a speed of 2mm / min, and detect whether the bonding force of the tungsten carbide shoulder bushing meets the design index requirements.

[0099] The application provides a simple operation, which can quickly ensure the linear size and shape tolerance requirements after assembly, effectively solve the problem of J-200-1A glue overflow along the bonding surface during pre-curing, and is stable and reliable in assembly quality, and is suitable for the gluing device of the hole shaft matching pair of the helicopter torsion arm square arm assembly; the operation specification of the torsion arm square arm assembly tungsten carbide shoulder bushing gluing is formulated, the related requirements of the raw material control, process control and quality control in the gluing process of the torsion arm square arm assembly tungsten carbide shoulder bushing are specified, and a helicopter torsion arm square arm assembly tungsten carbide shoulder bushing gluing process method is formed.​

Claims

1. A method for bonding a square arm assembly of a helicopter torsion arm, characterized in that, The methods include: Step 1: Inspect the adhesive surfaces of the bushing mounting holes and the tungsten carbide shoulder bushing of the torque arm square arm. Step 2: Group the tungsten carbide shoulder bushings and select the corresponding adhesive core rod according to the inner diameter of the tungsten carbide shoulder bushing; Step 3: Clean the inner surface of the mounting hole of the square arm bushing of the torque arm and the outer surface of the tungsten carbide shoulder bushing; Step 4: Prepare the J-200-1A adhesive, including: Step 41: Assess the actual production task's demand for adhesive, requisition J-200-1A adhesive, and check that the surfaces of both component A and component B show no clumping or foreign matter. Step 42: Weigh the received component A and component B, calculate the ratio of component A to component B, and record the results; Step 43: Select a clean mixing stick and stir the adhesive in the plastic cup at a uniform speed from the outside to the inside in the same direction until the adhesive is mixed evenly and the surface color is uniform. There should be no obvious bubbles on the surface of the mixed adhesive. Record the time when the mixing is finished. Step 5: Apply adhesive to the inner surface of the mounting hole of the square arm bushing of the torque arm and the outer surface of the tungsten carbide shoulder bushing. Use a brush to apply the prepared adhesive evenly to the inner surface of the square arm bushing of the torque arm and the outer surface of the tungsten carbide shoulder bushing. After the adhesive is applied, there should be no air bubbles in the adhesive layer. Step 6: Install the tungsten carbide shoulder bushing onto the square arm of the torque arm; Step 7: Install the torsion arm square arm assembly onto the bonding device and place it in a high-temperature oven for heating and curing; Step 8: Inspect the linear dimensions and geometric tolerances of the torsion arm square arm assembly, and test the adhesion of the tungsten carbide shoulder bushing; Step 2 includes: Step 21: Bushing A and bushing B are a pair, and the actual bore diameters of the two bushings differ by no more than 0.005 mm; Step 22: Bushing C and bushing D are a pair, and the actual bore diameters of the two bushings differ by no more than 0.005 mm; Step 23: Record the measured value of the bushing inner diameter, the difference between bushing inner diameters, and the maximum inner diameter value, and mark the grouped bushings using the bagging method; Step 24: Select an adhesive mandrel based on the maximum inner diameter of bushing A and bushing B. The diameter of the adhesive mandrel should not differ from the maximum inner diameter of bushings A and B by more than 0.01 mm. Select a mandrel that matches bushings C and D in the same way. After selection, record the measured outer diameter of the mandrel and the maximum gap between the mandrel and the inner hole of the shoulder bushing. Step 25: Select the good mandrel and mark AB and CD respectively with a marker according to the paired tungsten carbide shoulder bushing; Step 26: Compare the selected adhesive core rod with the hole on the bonding device to ensure that the adhesive core rod can pass through freely without jamming. Mark the grouped tungsten carbide shoulder bushings and corresponding adhesive core rods as a group and place them properly for subsequent assembly of the two holes of the same fork.

2. The method according to claim 1, characterized in that, Step 3 includes: Step 31: Clean the surface of the bonding device. Clean the entire surface of the bonding device with gasoline. After cleaning, wipe the mating area between the device and the workpiece with a white non-woven cloth until the white non-woven cloth shows no color change. Step 32: Cleaning the overall surface of the parts. Use gasoline to clean the overall surface of the torque arm square arm and the tungsten carbide shoulder bushing. After cleaning, wipe it clean with a white non-woven cloth and let it air dry for 5 minutes. Step 33: Clean the bonding surface. Use a cotton ball soaked in acetone to wipe the inner surface of the mating hole of the square arm of the torque arm until there is no dirt on the cotton ball, and let it air dry at room temperature for more than 15 minutes. Use a clean white cloth soaked in acetone to wipe the outer surface of the tungsten carbide shoulder bushing until the cloth does not change color, and let it dry for 5 minutes.

3. The method according to claim 1, characterized in that, Step 6 includes: Step 61: Align the tungsten carbide shoulder bushing with the mounting hole of the square arm of the torque arm and initially insert it into the square arm hole. Then rotate it in the same direction to evenly distribute the adhesive in the gap area between the square arm and the shoulder bushing and remove air until the end face of the shoulder bushing is in contact with the surface of the square arm. After the shoulder bushing is installed, check that there is adhesive evenly overflowing from one end of the shoulder bushing and the area of ​​the bushing exposed at the bottom hole of the square arm. There should be no obvious air bubbles on the surface of the overflowing adhesive. Step 62: Install the first sealing gasket (7) at the four bushing shoulders and the outer circle of the square arm respectively. After the sealing gasket is installed, it should be flat and there should be no gap between it and the contact surface of the square arm. After the adhesive gasket is installed, remove the excess adhesive layer outside the adhesive ring. Step 63: Install the second sealing gasket (8) on the outer circle of the bushing shoulder and the square arm respectively. After the sealing gasket is installed, it should be flat and there should be no gap between it and the contact surface of the square arm. After the adhesive gasket is installed, remove the excess adhesive layer outside the adhesive ring.

4. The method according to claim 1, characterized in that, Step 7 includes: Step 71: First place the support plate (2) on the base (1), then place the torque arm square arm assembly (10) on the support plate (2), adjust the position of the torque arm square arm assembly (10) on the support plate (2) to ensure that the inner hole of the tungsten carbide shoulder bushing is aligned with the inner hole of the positioning bushing (3); Step 72: Insert the adhesive core rod (9) into the inner hole of the tungsten carbide shoulder bushing; insert the clamping bolt (6), clamping nut (5), and clamping bushing (4) into the adhesive core rod (9) in sequence; align the inner hole of the tungsten carbide shoulder bushing at point B with the inner hole of the positioning bushing (3), insert the adhesive core rod into the inner hole of the shoulder bushing at point B, and complete the installation of one side of the torque arm square arm assembly (10). Follow the above steps to complete the installation of the other side of the torque arm square arm assembly (10). Step 73: Using a wrench, slowly rotate the tightening nut (5) along the direction of tightening the tungsten carbide shoulder bushing so that the outer end face of the tungsten carbide shoulder bushing of the torque arm square arm assembly (10) fits against the positioning bushing (3). After the force is applied, check whether the first sealing washer (7) and the second sealing washer (8) fit against the contact surface of the torque arm square arm. If there is a gap, fine adjust the first sealing washer (7) and the second sealing washer (8) to ensure that there is no gap with the contact surface of the torque arm square arm. Step 74: Place the installed torsion arm square arm assembly (10) and the bonding device into a high temperature chamber, heat it to 65°C at a heating rate of no more than 4°C / Min, and keep it at that temperature for more than 1 hour to cure the adhesive. Step 75: After curing, remove the torque arm square arm assembly (10) and the bonding device from the high temperature chamber, loosen the clamping nut (5), remove the adhesive core rod (9), and take out the clamping bushing (4), clamping bolt (6), and clamping nut (5) in sequence. Remove the torque arm square arm assembly (10) from the bonding device. Step 76: Use a scraper to remove the first sealing gasket (7) and the second sealing gasket (8) from the torsion arm square arm assembly (10). Visually inspect the adhesive layer at the bonding area. There should be no discoloration, uneven color, cracks, debris, or bubbles. Step 77: Clean the surface of the torque arm square arm assembly (10) and the adhesive device with a clean white non-woven cloth until the white non-woven cloth shows no color change. The adhesive device accessories are strung on the base (1) for later use.

5. The method according to claim 1, characterized in that, Step 8 includes: Step 81: Use relevant inspection tools to check whether the linear dimensions and geometric tolerances meet the requirements; Step 82: Place the torsion square arm assembly on the press and apply a downward load at a speed of 2 mm / min to check whether the adhesion force of the tungsten carbide shoulder bushing meets the design requirements.

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