Assembling angle self-compensation tool for airplane unequal-thickness composite material part and using method of assembling angle self-compensation tool

Abstract

The invention belongs to the technical field of airplane unequal-thickness composite material part assembling, and relates to an airplane unequal-thickness composite material part assembling angle self-compensation tool and a using method. When a conventional bolt is connected to a component with an assembly interlayer uneven in thickness, the component needs to be locally reamed flat or compensated through a bevel washer, a spherical washer and the like, the composite material structure can be damaged, the strength of a machine body can be weakened, and component force of a parallel bevel is increased on the surface of the component. According to the tool, it can be guaranteed that the surface of a part is only pressed by the nut through self-adaptive adjustment of the internal structure, and the surface of a composite component is not damaged due to facing. According to the tool, the parameters of all the bolts can be adjusted through the adjusting cambered surfaces, angle self-adaptive adjusting connection within the maximum range of 30 degrees can be easily achieved, and the application range is wider.

Description

Technical Field

[0001] The invention belongs to the technical field of assembly of composite materials of unequal thickness for aircraft, and relates to an assembly angle self-compensation tool for composite materials of unequal thickness for aircraft and a use method thereof. Background Art

[0002] Composite materials have excellent mechanical properties, such as light weight, high strength, good mechanical properties, high heat resistance and corrosion resistance. For example, the density of T-1000 carbon fiber is less than 2g / cm 2 Under the condition of , it can have a tensile strength of 7000MPa, which is widely used in aerospace products, and gradually improves to form a manufacturing stage dominated by composite materials. Composite materials are formed by stacking prepregs. Their anisotropic characteristics determine that the in-plane strength of the material is greater than the interlayer strength, which makes the components prone to warping and deformation. At the same time, composite materials are affected by manufacturing processes, the number of layers, curing molding pressure and other factors, and the thickness dimensional deviation of composite parts is large. During the assembly of groups / components, problems such as warping deformation and thickness dimensional changes of composite parts cause assembly gaps between the fitting surfaces of composite materials and other parts, and also cause uneven thickness of the assembly interlayer. The assembly gap can be eliminated through measurement and compensation processes, but the uneven thickness of the assembly interlayer causes the fastener to have an angle on the local surface of the connection. The use of conventional fasteners cannot simultaneously ensure that its head and tail are tightly fitted with the two surfaces of the assembly interlayer, which leads to uneven force on the composite parts and the risk of delamination and splitting. Composite materials are expensive. Taking T-1000 carbon fiber as an example, the price of this material may be as high as RMB 4,000 / kg by 2024. With the development of my country's aviation industry, the proportion of composite materials used in my country's aircraft products has gradually increased. The invention of specific tooling can effectively reduce the scrap rate of composite materials during the production process and significantly reduce costs. Summary of the invention

[0003] In order to solve the problem that composite parts of unequal thickness cannot adjust the angles of the head and tail ends by themselves during assembly, resulting in uneven stress on composite parts and resulting in delamination and splitting, an angle self-compensation method was invented to compensate for the structural angle of uneven assembly interlayer thickness. Its core technology is the development of a special tooling, which automatically adjusts the installation angle of the bolt and nut axis in the connection device through the design of the main body structure during the tightening process, directly compensates for the angle deviation of the bolt head and nut fitting surfaces, and then simultaneously ensures the fitting requirements of the bolt head, nut and structural contact surface.

[0004] The technical solution of the present invention is as follows:

[0005] The angle self-compensation fixture for assembling composite parts of aircraft with unequal thickness is a split design. The polished rod section bolts ensure that the fixture has effective shear resistance. The internal thread is measured, and the internal stepped through hole of the threaded section bolt is designed with an arc surface. The two are assembled with adjusting bolts. The length of the polished rod is selected by measuring the thickness of the interlayer of the composite component. The requirement is: |LH|≤1mm, that is, the length of the polished rod shall not exceed the thickness of the interlayer by 1mm and the length of the polished rod shall not be less than the thickness of the interlayer by 1mm.

[0006] The threaded section bolts are tightened with self-locking nuts to ensure reliable connection of the composite material components. The bolt head of the adjusting bolt is an arc surface and matches with the step surface of the threaded section bolt.

[0007] The angle self-compensation tooling comprises a polished rod internal thread bolt, a curved surface adjustable bolt, an internal twelve-angle compensation bolt, a slot cover, a sealing ring, an adjusting washer and a self-locking nut.

[0008] The polished rod internal thread bolt has a countersunk head with a hexagonal groove and a polished rod with a diameter of d, and the tail end of the polished rod has an MJ internal thread with a diameter of d1; the groove at the countersunk head is used to wrench the bolt, and the groove cover is used to cover it after the connection is completed; the selection of d should comply with the hole diameter required by the drawings or other design materials, d1 should be smaller than d, when d≥5mm, d1 is d / 2, when greater than 4mm≤d<5mm, d1 is d-1, and when d<4mm, d1 is d-1. The depth H' of the internal thread hole is H / 2±0.1mm.

[0009] For example, if the hole diameter on the drawing is 6.1mm or 6.2mm, then the diameter of the polished rod should be 6.0mm. If the hole diameter on the drawing is 5.0mm, then the diameter of the polished rod should be 5.0mm, d1 should be 2.5mm, and when the interlayer thickness is 7.3mm, the depth of the internal threaded hole should be 3.6mm.

[0010] The arc surface adjustable bolt has an MJ external thread with a diameter of d1 and a length of L1, and matches with the internal thread bolt of the bare rod and has the same length of the threaded part. Its nail head has an arc surface with a radius of R and a slotted edge. A groove with a diameter of d2 is designed below the bolt head. On the one hand, it realizes the function of the tool backing groove during bolt processing, and on the other hand, it adopts a clearance fit with the through hole of the internal twelve-angle compensation bolt, thereby increasing the rotation range of the connection device and being applicable to a wider range of assembly sandwich angles.

[0011] The internal twelve-angle compensation bolt has an external thread with a diameter of d3 and an internal stepped through hole. The small end of the through hole is a circular hole with a diameter of d4, and the large end of the through hole is an internal twelve-angle hole with a circumscribed circle diameter of d5. The stepped surface of the through hole is designed with an arc surface with a radius R, and cooperates with the adjustable bolt to achieve an adaptive adjustment function; when the bare rod internal thread bolt and the internal twelve-angle compensation bolt are combined through the bolt head of the adjustable bolt, hinge rotation is achieved at the arc surface of radius R;

[0012] The size of d3 should be the same as the diameter of the polished rod d, d5 should be d3-2, and d4<d5.

[0013] The size of the groove diameter d2 should satisfy the formula: d4-d2≥A·sinθ·d5.

[0014] The length of the groove should be equal to the gasket thickness p.

[0015] Where θ is the interlayer angle, A is the formula coefficient, when the pattern aperture D≤4.2mm, A=1.2, when the aperture 4.2mm≤D≤6.2mm, A=1.1,

[0016] When the aperture D ≥ 6.2 mm, A = 1.

[0017] The radius R of the arc surface should satisfy: d4<R≤d5, and R is preferably selected to be the same value as d5.

[0018] Except for d2, other dimensions are integer multiples of 0.5mm, and d2 is an integer multiple of 0.1mm.

[0019] For example, if the hole diameter D on the drawing is 6.0mm, the angle θ is 15°, and the washer thickness p is 2mm, then the external thread diameter d3 of the internal twelve-angle compensation bolt should be 6mm, d1 is 3mm, d5 is 4mm, d4 is 3.5mm, and R is 4mm. After calculation, d2≤2.4mm, d2=2.3mm, and the groove length is 2mm.

[0020] The sealing ring is installed at the bolt head and bolt rod to enhance the sealing function in structural assembly and replace the use of sealant;

[0021] The adjusting washer is installed between the nut and the sandwich to ensure that the connection device can meet the requirements of the protrusion of the threaded rod when the thickness of the sandwich changes greatly, thereby increasing the connection reliability; wherein the inner diameter d' of the washer should meet the relationship with the sandwich angle θ: d'≥dsecθ, and the inner diameter should be the smallest while meeting other assembly requirements, and the thickness p should meet p>dsinθcosθ, that is, p>1 / 2·dsin2θ, and p should be as small as possible while meeting other requirements. For example, d=Ф6.2mm, and θ=20°, then after calculation, d'>6.598mm, at this time d' should be 7mm, and after calculation, p>1.99, then p should be 2mm.

[0022] The self-locking nut adopts a conventional external hexagonal head nut, whose internal thread cooperates with the MJ external thread d3 of the internal twelve-angle compensation bolt to realize the assembly connection function and the self-locking function of the connection device, and ensures that during the tightening process of the self-locking nut, the tooling can adaptively adjust the axis angle of the bare rod section and the threaded section according to the interlayer angle of the composite component, thereby ensuring that the contact surface of the nut, washer and the composite component fits well. Note that after tightening the nut, the protrusion of the bolt end should not be less than 1 pitch, that is, the bolt length h1 and the nut thickness and the self-locking nut pitch δ should satisfy h1-h2>δ. If the nut thickness h2 is 6mm and the pitch δ is 1mm, then h1>7mm after calculation, and 8mm should be taken at this time.

[0023] The auxiliary special tool is used to tighten the internal twelve-angle compensation bolt, and adopts a replaceable cutter head with a twelve-angle screwdriver bit structure. Its main structure consists of a cutter head bevel gear set, a stabilizing bearing, a coupling, a DC motor with a reduction box, an explosion-proof cable, a battery pack, a tool housing, a tool switch and a replaceable cutter head.

[0024] The specific assembly form of the tool is: the power shaft on the cutter head bevel gear set is connected to the motor shaft of the DC motor with a reduction gear box through a coupling, and a stabilizing bearing is arranged in the middle section of the bevel gear power shaft, between the cutter head bevel gear set and the motor shaft. The DC motor is connected to the battery pack and the tool switch through an explosion-proof cable. Except for the switch, these components are placed inside the tool housing. The switch is placed on the surface of the tool housing, and the positions of all components are fixed. The replaceable cutter head is mechanically connected to the tool body through the socket on it and the base on the cutter head bevel gear set.

[0025] The cutter head bevel gear set is mainly composed of a pair of orthogonal bevel gears, a tool shaft with an inner square base, and an orthogonal power shaft, which realizes vertical transmission of power, saves tool usage space and can operate under difficult construction conditions.

[0026] The stabilizing bearing increases the rotation stability of the shaft and is connected to the motor shaft of the DC motor with a reduction box through a coupling to achieve a firm connection and stable output.

[0027] The DC motor with reduction gearbox is connected to the battery pack and the tool switch through an explosion-proof cable. The tool switch adopts a button mode, and the I / O reversing realizes the switch function. When the I end is pressed, the motor starts the tool and starts working, and when the O end is pressed, the motor turns off the tool and stops working.

[0028] The tool housing provides a location for installing and fixing all the above-mentioned tool components. Except for the tool switch, all other parts are placed inside the tool housing. The tool switch is placed at a dedicated position on the surface of the tool housing. When the tool is working, all components are guaranteed to have a stable operating position and space.

[0029] The replaceable cutter head has an external twelve-corner cutter head and a square drive socket. When in use, the square drive socket fits tightly on the inner square base of the tool shaft in the cutter head bevel gear set. The specifications of the cutter head match the through-hole size of the external twelve-corner with a circumscribed circle diameter d5, and different optional accessories are designed according to the through-hole specifications of the internal twelve-corner compensation bolt.

[0030] The method of using the self-compensation tooling for assembling angles of composite parts of unequal thickness on aircraft is as follows:

[0031] Step 1: Measure the interlayer thickness of the composite component where the fasteners are to be installed, and determine the parameters of the required polished rod internal threaded bolts, curved adjustable bolts and internal twelve-angle compensation bolts based on the hole diameter, actual interlayer thickness and angle of the drawing.

[0032] Step 2: Take the internal threaded bolts with bare rods, and use the curved adjustable bolts to pre-assemble the internal twelve-angle compensation bolts into a connecting device. Use a slotted screwdriver to tighten the curved adjustable bolts manually.

[0033] Step 3: Insert the assembled connection device into the sealing ring, and then insert it into the fastener hole of the composite component. Make sure that the tail end of the polished rod of the internal threaded bolt is not lower than the surface of the component.

[0034] Step 4: Install the matching adjustment washers and self-locking nuts, and use tools to tighten the limited internal twelve-angle compensation bolts, and use special tools to twist and rotate the self-locking nuts, and gradually tighten them to clamp the composite material components;

[0035] Step 5: Check whether the internal twelve-angle compensation bolt is in full contact with the surface of the composite component and check the fitting gap; if it does not meet the requirements, loosen the self-locking nut 6 and repeat the operation of step 4 to tighten it again;

[0036] Step 6: After passing the inspection, install the slot cover in the countersunk slot of the internal threaded bolt of the bare rod, and perform anti-corrosion protection on the connection device.

[0037] Beneficial effects of the present invention:

[0038] (1) When conventional bolts are connected to components with uneven interlayer thickness, it is necessary to partially spot-face the components or use inclined washers, spherical washers, etc. to compensate, which will damage the composite material structure, weaken the body strength, and increase the parallel inclined surface force on the component surface. This tooling can ensure that the surface of the part is only subjected to the compression force of the nut through its own internal structure adaptive adjustment, and the surface of the composite component is not damaged by spot-face.

[0039] (2) The use range of conventional threaded connections using washers for compensation is relatively small, generally within a range of 10°. This tooling can adjust the parameters of each bolt by adjusting the arc surface, easily achieving an angle adaptive adjustment connection within a maximum range of 30°, and has a wider range of use.

[0040] (3) It is only necessary to adjust the length of the bare rod of the internally threaded bolt 1 to meet the connection requirements of composite components with different interlayer thicknesses. After summarizing the requirements in the actual production process, the various parameters of the required bolt assembly can be standardized. After standardization is completed, while achieving large-scale production, the demand for manufacturing equipment can be greatly reduced. Only specific manufacturing modules need to be replaced to meet the requirements, and the manufacturing cost is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 The connecting device structure 1;

[0042] Figure 2 It is the second connecting device structure;

[0043] Figure 3 This is a schematic diagram of the working scene when automatically compensating the angle;

[0044] Figure 4 A schematic diagram of a special tool.

[0045] In the figure: 1. Internal threaded bolt with bare rod; 2. Adjustable bolt with curved surface; 3. Internal twelve-angle compensation bolt; 4. Slot cover; 5. Sealing ring; 6. Adjusting washer; 7. Self-locking nut; 8. Cutter head bevel gear set; 9. Stabilizing bearing; 10. Coupling; 11. DC motor with reduction box; 12. Explosion-proof cable; 13. Battery pack; 14. Tool housing; 15. Tool switch; 16. Replaceable cutter head. DETAILED DESCRIPTION

[0046] 1. Measure the interlayer thickness of the composite component where the fastener is to be installed, and determine the parameters of the required polished rod internal threaded bolt 1, curved adjustable bolt 2 and internal twelve-angle compensation bolt 3 according to the hole diameter, actual interlayer thickness and angle of the drawing.

[0047] example:

[0048] The hole diameter on the drawing is 6.0mm, the composite interlayer thickness is measured to be 7.2mm, and the angle is measured to be 15°. The diameter of the polished rod internal threaded bolt 1 is 6mm, the length of the polished rod part is 7mm, the internal thread hole diameter of the polished rod bolt is 3mm, the internal thread pitch is selected to be 0.8mm, and the depth is selected to be 4mm.

[0049] The pitch of the external thread of the curved adjustable bolt 2 matches the pitch of the internal thread of the polished internal thread bolt 1, which is selected as 0.8mm. The length of the threaded part matches the length of the internal thread hole, which is selected as 4mm. The self-locking nut is selected to use HB8235MJ6×1 (plated as required). The washer thickness p>1 / 2·dsin2θ, the washer inner diameter d'≥dsecθ, after calculation p>1.5mm, d'>6.21mm, take p=2mm, d'=7mm.

[0050] The external thread pitch of the internal twelve-angle compensation bolt 3 matches the nut, which is 1mm, and the length is selected as 8mm. The external thread diameter matches the hole diameter of the drawing, which is selected as 6mm. The diameter d5 of the internal twelve-angle square hole outside the large diameter of the through hole is 4mm, the small diameter d4 of the through hole is 3.5mm, and R is 4mm. After calculation, the groove diameter d2 of the arc-shaped adjustable bolt is ≤2.4mm, d2=2.3mm, and the groove length is 2mm. From then on, the parameters of the three bolts and the model of the self-locking nut have been determined.

[0051] 2. Take the internal threaded bolt 1 of the bare rod, and use the curved adjustable bolt 2 to pre-assemble the internal twelve-angle compensation bolt 3 into a connecting device. Use a slotted screwdriver to tighten the curved adjustable bolt 2 manually;

[0052] 3. Insert the assembled connection device into the sealing ring 5, and then insert it into the fastener hole of the composite material component. It should be ensured that the tail end of the polished rod of the polished rod internal thread bolt 1 is not lower than the surface of the component.

[0053] 4. Install the matching adjustment washer 6 and self-locking nut 7, and use a tool to tighten the limited internal twelve-angle compensation bolt 3, and use a special tool to twist and rotate the self-locking nut 7, and gradually tighten it to clamp the composite material component;

[0054] 5. Check whether the internal twelve-angle compensation bolt 3 is in full contact with the surface of the composite component and check the fitting gap; if it does not meet the requirements, loosen the self-locking nut 6 and repeat the operation in 4 to tighten it again;

[0055] 6. After passing the inspection, install the slot cover 4 in the countersunk slot of the internal threaded bolt 1 of the bare rod, and perform anti-corrosion protection on the connecting device.

Claims

1. The self-compensation tooling for assembling angles of aircraft composite parts of unequal thickness is characterized by: It comprises a polished rod internal thread bolt (1), a curved surface adjustable bolt (2), an internal twelve-angle compensation bolt (3), a slot cover (4), a sealing ring (5), an adjustment washer (6) and a self-locking nut (7); The polished rod internal thread bolt (1) has a countersunk head with an internal hexagonal groove and a polished rod with a diameter of d, and the tail end of the polished rod has an MJ internal thread with a diameter of d1; the groove at the countersunk head is used to tighten the bolt, and a groove cover (4) is used to cover it after the connection is completed; The arc-shaped adjustable bolt (2) has an MJ external thread with a diameter of d1 and a length of L1, and matches the internal threaded bolt (1) with a bare rod and has the same threaded portion length. The nail head has an arc surface with a radius of R and a slotted edge; a groove with a diameter of d2 is designed below the bolt head; The internal twelve-angle compensation bolt (3) has an external thread with a diameter of d3 and an internal stepped through hole, the small end of the through hole is a circular hole with a diameter of d4, and the large end of the through hole is an internal twelve-angle hole with a circumscribed circle diameter of d5. The stepped surface of the through hole is designed with an arc surface with a radius R, and cooperates with the arc surface adjustable bolt (2) to achieve a self-adaptive adjustment function; when the bare rod internal thread bolt (1) and the internal twelve-angle compensation bolt (3) are combined through the bolt head of the arc surface adjustable bolt (2), hinge rotation is achieved at the arc surface of the radius R; The sealing ring (5) is installed at the bolt head and bolt rod to enhance the sealing function in structural assembly and replace the use of sealant; The adjusting washer (6) is installed between the nut and the sandwich to ensure that the connection device can meet the requirement of the protrusion of the threaded rod when the thickness of the sandwich changes greatly, thereby increasing the connection reliability; wherein the inner diameter d' of the washer should satisfy the relationship with the sandwich angle θ (acute angle): d'≥dsecθ, and the inner diameter should be the smallest while meeting other assembly requirements, and the thickness p should satisfy p>dsinθcosθ, that is, p>1 / 2·dsin2θ; The self-locking nut (7) is a conventional external hexagonal head nut, and its internal thread cooperates with the MJ external thread d3 of the internal twelve-angle compensation bolt (3).

2. The self-compensating tooling for assembling angles of composite materials of unequal thickness for aircraft as claimed in claim 1, characterized in that: The dimension d3 should be the same as the diameter d of the polished rod, d5 is d3-2, d4<d5; the dimension of the diameter of the groove d2 should satisfy the formula: d4-d2≥A·sinθ·d5.

3. The self-compensating tooling for assembling angles of composite materials of unequal thickness for aircraft as claimed in claim 1 or 2, characterized in that: The length of the groove should be equal to the gasket thickness p.

4. The self-compensating tooling for assembly angles of composite materials of unequal thickness for aircraft as claimed in claim 1 or 2, characterized in that: Also included is an auxiliary special tool, including a cutter head bevel gear set (8), a stabilizing bearing (9), a coupling (10), a DC motor with a reduction gearbox (11), an explosion-proof cable (12), a battery pack (13), a tool housing (14), a tool switch (15) and a replaceable cutter head (16); The power shaft on the cutter head bevel gear set (8) is connected to the motor shaft of the DC motor (11) with a reduction gear box through a coupling (10). A stabilizing bearing (9) is arranged between the cutter head bevel gear set (8) and the motor shaft at the middle section of the bevel gear power shaft. The DC motor is connected to a battery pack (13) and a tool switch (15) through an explosion-proof cable (12). Except for the switch, all of these components are placed inside the tool housing (14). The switch is placed on the surface of the tool housing and the positions of all components are fixed. The replaceable cutter head (16) is mechanically connected to the tool body through the socket on it and the base on the cutter head bevel gear set (8).

5. The self-compensating tooling for assembling angles of composite materials of unequal thickness for aircraft as claimed in claim 4, characterized in that: The cutter head bevel gear set (8) is composed of a pair of orthogonal bevel gears, a tool shaft with an inner square base, and an orthogonal power shaft.

6. The self-compensating tooling for assembling angles of composite materials of unequal thickness for aircraft as claimed in claim 4, characterized in that: The stabilizing bearing (9) increases the rotation stability of the shaft and is connected to the motor shaft of a DC motor (11) with a reduction gearbox through a coupling (10), thereby achieving a secure connection and stable output.

7. The self-compensating tool for assembling angles of composite materials of unequal thickness for aircraft as claimed in claim 4, characterized in that: The DC motor (11) is connected to a battery pack (13) and a tool switch (15) via an explosion-proof cable (12). The tool switch (15) is a button mode, and the I / O switching realizes the switch function. When the I end is pressed, the motor starts the tool and starts working, and when the O end is pressed, the motor turns off the tool and stops working.

8. The self-compensating tooling for assembling angles of composite materials of unequal thickness for aircraft as claimed in claim 4, characterized in that: The replaceable cutter head (16) has an external twelve-corner cutter head and a square drive socket. When in use, the square drive socket is tightly fitted on the inner square base of the tool shaft in the cutter head bevel gear set (8). The specifications of the cutter head match the size of the external twelve-corner through hole with a circumscribed circle diameter d5.

9. The method for using the self-compensation tool for assembling angles of composite materials of unequal thickness on aircraft is characterized by: Here are the steps: Step 1: Measure the sandwich thickness of the composite component where the fastener is to be installed; Step 2: Take the internal threaded bolt (1) with a bare rod, and use the curved adjustable bolt (2) to pre-assemble the internal twelve-angle compensation bolt (3) into a connecting device, and use a slotted screwdriver to turn the curved adjustable bolt (2) to tighten it manually; Step 3: insert the assembled connection device into the sealing ring (5), and then insert it into the fastener hole of the composite material component, and ensure that the polished rod end of the polished rod internal thread bolt (1) is not lower than the surface of the component; Step 4: Install the matching adjustment washer (6) and self-locking nut (7), and use a tool to tighten the limited internal twelve-angle compensation bolt (3), and use a special tool to twist and rotate the self-locking nut (7), and gradually tighten it to clamp the composite material component; Step 5: Check whether the internal twelve-angle compensation bolt (3) is in full contact with the surface of the composite component and check the fitting gap; if it does not meet the requirements, loosen the self-locking nut (7) and repeat the operation of step 4 to tighten it again; Step 6: After passing the inspection, install the slot cover (4) in the countersunk slot of the internal threaded bolt (1) of the polished rod, and perform anti-corrosion protection on the connection device.

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