A composite material pipe shaft balance block bonding pressure monitoring tool and bonding method

Abstract

The application discloses a kind of composite material pipe shaft counterweight bonding pressure monitoring tool and bonding method, it is related to tubular rotating component assembly and cementing manufacturing field, solve the problems such as that counterweight bonding tool cannot measure and adjust actual bonding pressure etc..The sensor assembly of the present application includes support, driving device and force sensor;The lower end of support and counterweight pressing assembly are connected, and the upper end is provided with driving device;Driving device and force sensor are detachably connected;Counterweight pressing assembly includes elastic pressing assembly and pressing assembly platform, and pressing assembly platform is connected with positioning clamping assembly and support respectively, and the upper end of elastic pressing assembly and the lower end of force sensor pass through pressing assembly platform to press counterweight on pipe shaft.The present application can be installed at any position of large-size composite material pipe shaft, can be adapted to certain outer diameter and counterweight size variation, can quantitatively apply and monitor bonding pressure, has elastic compensation and mechanical locking function, and sensor assembly can be detached.

Description

Technical Field

[0001] This invention relates to the field of composite material tubular rotating component assembly and bonding manufacturing technology, specifically a composite material tubular shaft balance block bonding pressure monitoring tooling and bonding method. Background Technology

[0002] Large-sized composite material tail drive shafts require high uniformity of mass distribution during high-speed rotation. Typically, based on dynamic balancing test results, metal balance blocks, such as aluminum alloy, are bonded to specific locations on the outer wall of the shaft to correct for imbalance. Compared to mechanical connections such as drilling and riveting, adhesive bonding avoids hole damage to the composite material tube wall and offers advantages such as good sealing and minimal mass increase. However, the bonding quality between the balance blocks and the composite material tube shaft directly impacts the long-term reliability of the tail drive shaft.

[0003] (1) Existing ring-type or clamp-type tooling can usually only press the balance block onto the surface of the tube shaft, and cannot directly measure the actual normal pressure at the bonding surface of the balance block, nor can it determine whether the pressure changes during the process of normal temperature storage, heating and heat preservation curing.

[0004] (2) If the bonding pressure is too low, the adhesive will not be able to fully fill the micro-unevenness of the bonded surface, which will easily lead to air gaps, local missing adhesive, and uneven adhesive layer thickness; if the bonding pressure is too high, the adhesive may be over-extruded, the adhesive layer may be too thin, or even cause local deformation of the thin-walled composite material tube shaft. The existing tooling lacks quantifiable adjustment methods, and the consistency of bonding quality mainly depends on the operator's experience.

[0005] (3) The tail drive shaft of the large size is relatively long, and the bonding position of the balance block is determined by the dynamic balance result, which may be located in different axial and circumferential positions of the tube shaft; the outer diameter of the tube shaft and the size of the balance block also vary for different models. The existing fixed size fixture has poor versatility and it is difficult to quickly install it at any position and keep the loading direction consistent with the normal of the curved bonding surface.

[0006] (4) The balance block usually needs to be put into the high-temperature equipment along with the tooling to complete the curing. If only a rigid screw is used to directly press it, the difference in thermal expansion of the tube shaft, balance block, adhesive and tooling during the heating process will cause the pressure to relax or increase abnormally; if the sensor is permanently installed on the tooling, the tooling size will be increased, and the sensor and display device will be exposed to the high-temperature environment for a long time, which will accelerate aging.

[0007] (5) The existing technology lacks a structure that separates "pressure detection and regulation" and "locking and holding pressure": it can accurately set the pressure using a sensor during initial assembly, and maintain the pre-tight state through a mechanical structure after the target pressure is reached, and can choose to remove the sensor assembly or continuously monitor the pressure during the curing process as needed. Summary of the Invention

[0008] To address the aforementioned problems of existing balance block bonding fixtures, such as their inability to measure and adjust actual bonding pressure, unclear pressure changes during curing, difficulty in adapting to different bonding positions and outer diameters of large-sized pipes and shafts, inconvenience of sensors for long-term high-temperature use, and pressure fluctuations caused by rigid loading, this invention proposes a composite material pipe and shaft balance block bonding pressure monitoring fixture and bonding method. This invention can be installed at any position on large-sized composite material pipes and shafts, can adapt to changes in outer diameter and balance block size, can quantitatively apply and monitor bonding pressure, has elastic compensation and mechanical locking functions, and the sensor assembly is detachable.

[0009] This invention proposes a tooling for monitoring the bonding pressure of a composite material tube shaft balance block, specifically comprising a positioning and clamping assembly, a balance block clamping assembly, and a sensor assembly. The positioning and clamping assembly is sleeved on the tube shaft, and the balance block clamping assembly is connected to the positioning and clamping assembly. The sensor assembly is disposed on the balance block clamping assembly. The sensor assembly includes a bracket, a driving device, and a force sensor. The lower end of the bracket is connected to the balance block clamping assembly, and the upper end is provided with the driving device. The driving device and the force sensor are detachably connected. The balance block clamping assembly includes an elastic clamping component and a clamping component platform. The clamping component platform is connected to the positioning and clamping assembly and the bracket, respectively. The upper end of the elastic clamping component and the lower end of the force sensor pass through the clamping component platform to clamp the balance block onto the tube shaft.

[0010] Furthermore, the elastic clamping assembly includes a lower spring block, an elastic element, and an upper spring block connected in sequence, with the upper spring block connected to a force sensor; the lower spring block presses the balance block against the tube shaft.

[0011] Furthermore, the elastic clamping assembly also includes several guide screws, which are disposed on the clamping assembly platform, and the spring upper pressure block and the guide screws are slidably connected; a locking nut is provided at the upper end of the guide screw.

[0012] Furthermore, the elastic element is a spring.

[0013] Furthermore, the driving device includes a screw slider and an adjusting screw, the upper end of the adjusting screw is rotatably connected to the bracket, and the screw slider is disposed on the adjusting screw and threadedly connected to the adjusting screw.

[0014] Furthermore, a sensor mounting bracket is detachably provided at the lower end of the screw slider, and a force sensor is installed on the sensor mounting bracket.

[0015] Furthermore, the force sensor is a force sensor.

[0016] Furthermore, the bracket includes two slider guide rods and a screw mounting platform; the upper end of the slider guide rod is connected to the screw mounting platform, and the lower end is connected to the clamping assembly platform; the screw mounting platform is rotatably connected to the adjusting screw.

[0017] Furthermore, the positioning and clamping assembly includes a positioning frame one and a positioning frame two, which are arc-shaped structures; one end of positioning frame one and one end of positioning frame two are hinged together, and the other end is connected to the clamping assembly platform; the other end of positioning frame two is connected to the clamping assembly platform; and a number of clamping bolts are provided on positioning frame one and positioning frame two.

[0018] A method for bonding balance blocks using the aforementioned composite material tube shaft balance block bonding pressure monitoring fixture includes the following steps: S1. Determine the specifications, axial and circumferential positions of the balancing block through dynamic balancing of the tube shaft, and mark the bonding area. S2. Perform surface treatment on the surfaces to be bonded on the tube shaft and the bonding surfaces of the balance block. Prepare the adhesive according to the adhesive process requirements and apply the adhesive evenly on at least one bonding surface while controlling the thickness of the adhesive layer. S3. Place the balance block at the marked position, install the positioning clamping assembly on the outer circumference of the tube shaft, and adjust the positioning clamping assembly so that the loading axis of the clamping assembly is aligned with the balance block. S4. Install the sensor assembly and zero the force sensor. Calculate the target reading based on the actual bonding area of ​​the balance block, the target bonding pressure, and the weight of the loaded component. S5. Start the drive device to move the force sensor and gradually compress the elastic clamping component; read the force in real time on the display device until the target reading is reached and remains stable. S6. Fix the compression state of the elastic clamping assembly; depending on the process requirements, choose to remove the sensor assembly and then cure the tube shaft and the balance block clamping assembly together, or retain the sensor assembly and continuously collect pressure during the curing process; S7. Perform room temperature pre-curing and / or heat curing according to the adhesive curing regime. After curing is completed and cooled, release the lock and remove the sensor assembly, clamping assembly and positioning clamping assembly in sequence. Check the bonding position of the balance block, the appearance of the adhesive layer and the bonding quality.

[0019] Furthermore, the target reading in step S4 is calculated using the following formula: F=p·S-G1-G2 In the formula: F is the target reading of the force sensor; p is the target bonding pressure; S is the actual bonding area of ​​the balance block; G1 is the gravity of the component involved in the loading; G2 is the gravity of the balance block.

[0020] The beneficial effects of the composite material tube shaft balance block bonding pressure monitoring fixture and bonding method described in this invention are as follows: (1) The composite material tube shaft balance block bonding pressure monitoring fixture and bonding method described in this invention realizes the transformation of bonding pressure from experience control to quantitative control. Through force sensor and pressure conversion relationship, corresponding target force values ​​can be set for balance blocks of different sizes, so that the bonding pressure is stably within the process requirements range.

[0021] (2) The composite material tube shaft balance block bonding pressure monitoring fixture and bonding method described in this invention can observe pressure changes in real time. The sensor assembly can continuously monitor the pressure during the room temperature storage, heating and heat preservation stages, providing data to determine the impact of thermal expansion differences, adhesive layer curing and fixture loosening on the pressure.

[0022] (3) The composite material tube shaft balance block bonding pressure monitoring fixture and bonding method described in this invention have both elastic compensation and mechanical locking capabilities. The elastic element can absorb small thermal deformation and curing shrinkage displacement, and the locking element can prevent the threads from loosening and maintain the pre-tightened state, reducing pressure sudden changes caused by rigid loading.

[0023] (4) The composite material tube shaft balance block bonding pressure monitoring fixture and bonding method described in this invention have a detachable sensor assembly. After the target pressure is reached, the locking structure can independently maintain the pressure and remove the sensor assembly, reducing the fixture volume when the tube shaft enters the high-temperature equipment and avoiding long-term heating of the sensor and display; when it is necessary to study pressure changes, the sensor can be retained to implement full-process monitoring.

[0024] (5) The composite material tube shaft balance block bonding pressure monitoring fixture and bonding method described in this invention have a wide range of applicable positions and specifications. The circumferential positioning frame and multiple radial clamping bolts enable the fixture to be installed at different positions on the long tube shaft, and can adapt to certain outer diameter changes by adjusting the clamping bolts; the replaceable lower pressure block can be adapted to different balance block sizes and curvatures.

[0025] (6) The composite material tube shaft balance block bonding pressure monitoring fixture and bonding method described in this invention avoids drilling damage to the composite material tube shaft. The fixture completes the positioning through peripheral clamping and normal pressing, eliminating the need to machine mounting holes on the tube shaft, which helps maintain the integrity of the composite material tube wall.

[0026] (7) The composite material tube shaft balance block bonding pressure monitoring fixture and bonding method described in this invention have been experimentally verified to have good high-temperature curing pressure retention capability. When the target initial force is 9.22 N, the lowest force in the adhesive test during the heating and 70 ℃ heat preservation process is 9.12 N, with a pressure fluctuation of about 1.08%; the lowest force in the adhesive-free control group is 8.92 N, with a pressure fluctuation of about 3.25%.

[0027] (8) The composite material tube shaft balance block bonding pressure monitoring tooling and bonding method of the present invention, single lap tensile shear test shows that, under the material and adhesive system used, the shear strength of the 0.01 MPa and 0.02 MPa bonding pressure groups is about 14.7±0.67 MPa and 13.2±0.57 MPa, respectively, while the shear strength of the 0.05 MPa group drops to about 6.6±0.88 MPa, indicating that it is necessary to accurately control the bonding pressure. Attached Figure Description

[0028] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0029] In the attached diagram: Figure 1 This is a schematic diagram of the overall structure of a composite material tube shaft balance block bonding pressure monitoring tool according to the present invention; Figure 2 This is a schematic diagram of the positioning and clamping assembly of a composite material tube shaft balance block bonding pressure monitoring fixture according to the present invention; Figure 3 This is a schematic diagram of the balance block clamping assembly of a composite material tube shaft balance block bonding pressure monitoring tool according to the present invention; Figure 4 This is a schematic diagram of the sensor assembly of a composite material tube shaft balance block bonding pressure monitoring fixture according to the present invention; Figure 5 This is a schematic diagram of the force analysis at the bonding position of the balance block of a composite material tube shaft balance block bonding pressure monitoring tool described in this invention; Figure 6 This invention relates to a pressure change curve of a composite material tube shaft balance block bonding pressure monitoring tool under high temperature curing conditions with adhesive. Wherein: 1-tube shaft, 2-positioning frame one, 3-balance block, 4-spring lower pressure block, 5-slider guide rod, 6-sensor mounting bracket, 7-screw slider, 8-screw mounting platform, 9-clamping bolt, 10-positioning frame two, 11-pressing component platform, 12-guide screw, 13-spring, 14-spring upper pressure block, 15-locking nut, 16-force sensor, 17-adjusting screw. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of the present invention can be combined with each other. The described embodiments are merely some embodiments of the present invention, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0031] See Figures 1-6 This embodiment is described in detail. The composite material tube shaft balance block bonding pressure monitoring fixture described in this embodiment specifically includes a positioning clamping assembly, a balance block pressing assembly, and a sensor assembly. The positioning clamping assembly is sleeved on the tube shaft 1, the balance block pressing assembly and the positioning clamping assembly are connected, and the sensor assembly is disposed on the balance block pressing assembly.

[0032] The balance block clamping assembly includes an elastic clamping component and a clamping component platform 11. The clamping component platform 11 is connected to the positioning clamping component and the bracket, respectively. The clamping component platform 11 has a through hole in the center for the pressure transmission component to pass through, and connection holes around it for installing guide components and sensor components. The upper end of the elastic clamping component and the lower end of the force sensor 16 pass through the clamping component platform 11 to clamp the balance block 3 onto the tube shaft 1. The elastic clamping component includes a lower spring pressure block 4, an elastic element, and an upper spring pressure block 14 connected in sequence. The upper spring pressure block 14 is connected to the force sensor 16 and can move along the bracket in the loading direction. The elastic element can be a cylindrical helical compression spring, a disc spring group, a wave spring, or an elastic body pad. In this embodiment, the elastic element is a spring 13, which passes through the through hole in the center of the clamping component platform 11. The lower spring pressure block 4 is located below the clamping component platform 11 and is correspondingly arranged with the balance block 3 to be bonded, clamping the balance block 3 onto the tube shaft 1. The pressing surface of the spring-loaded pressure block 4 is preferably made into a flat or arc-shaped surface that matches the outer surface of the balance block 3. The spring-loaded pressure block 4 can be made into a detachable pressure head that can be replaced according to the size and curvature of the balance block 3; the pressing surface can also be equipped with a universal ball head or a floating pressure plate to make the pressure act more evenly on the curved balance block.

[0033] Spring 13 is positioned on the pressure transmission path to convert the displacement applied by the sensor assembly into the normal pressure of the balance block 3, and to compensate for pressure changes caused by thermal expansion of components, shrinkage of the adhesive layer, and minute assembly displacements during curing. Depending on the specific structure, elements with axial elastic deformation capabilities, such as disc springs, wave springs, and elastic pads, can also be used.

[0034] Four guide screws 12 are provided on the clamping assembly platform 11, and the upper spring pressure block 14 and the guide screws 13 are slidably connected; a locking nut 15 is provided at the upper end of the guide screw 12. The locking nut 15 cooperates with the guide screw 12. When the force displayed by the force sensor 16 reaches the target value, the locking nut 15 is tightened to limit the relative position of the upper spring pressure block 14, the pressure transmission rod or the lower spring pressure block 4, and maintain the compression of the elastic element. This allows pressure on the balance block 3 to be maintained after the sensor assembly is removed, and also prevents the threads from loosening during the high-temperature curing process. The mechanical locking structure composed of the guide screws 12 and the locking nut 15, combined with the elastic clamping assembly, can buffer and compensate for displacement changes caused by thermal deformation and adhesive layer curing shrinkage, and can maintain the compressed state of the elastic element after the target pressure is reached. The mechanical locking structure can also adopt a double nut, a stop nut, a ratchet lock or a pin limiting structure.

[0035] The sensor assembly includes a bracket, a drive unit, and a force sensor 16. The bracket includes two slider guide rods 5 and a screw mounting platform 8; the two slider guide rods 5 are symmetrically arranged, with their upper ends connected to the screw mounting platform 8 and their lower ends connected to the clamping assembly platform 11; the screw mounting platform 8 is rotatably connected to an adjusting screw 17. The drive unit includes a screw slider 7 and an adjusting screw 17; the upper end of the adjusting screw 17 is rotatably connected to the screw mounting platform 8, and the screw slider 7 is mounted on and threadedly connected to the adjusting screw 17; a knob is located at the upper end of the screw mounting platform 8, connected to the adjusting screw 17; rotating the knob rotates the adjusting screw 17, causing the adjusting screw 17 to move the screw slider 7 up and down. A sensor mounting bracket 6 is mounted at the lower end of the screw slider 7 via bolts, a plug-in structure, or other detachable connection method, and the force sensor 16 is mounted on the sensor mounting bracket 6. The screw slider 7 moves along the slider guide rod 5, which is set parallel to the loading direction. The slider guide rod 5 is used to limit the rotation of the screw slider 7 and ensure the stability of the loading direction of the force sensor 16. By adjusting the screw 17, the screw slider 7, and the force sensor 16, quantitative loading is achieved along the normal direction of the bonding surface of the balance block 3, avoiding uneven loading and skewed loading direction of the force sensor 16. The force sensor 16 can be a column-type, spoke-type, thin-film type, or button-type pressure sensor, and the display device can be a handheld push-pull gauge, a digital display, or a computer data acquisition module.

[0036] When the operator rotates the adjusting screw 17, the screw slider 7 and the force sensor 16 move along the loading direction. The lower end of the force sensor 16 acts on the upper spring pressure block 14, compressing the spring 13 and applying pressure to the balance block 3 through the lower spring pressure block 4. The force sensor 16 is connected to a handheld push-pull gauge, digital display instrument, or data acquisition system, which can display and record the applied force in real time. After the target pressure is reached, the pressure can be maintained by locking the nut 15, and the sensor assembly can be removed. When it is necessary to monitor the curing process, the sensor assembly can be retained, and the signal line can be led out from the reserved hole of the high-temperature chamber, so that the display and acquisition equipment is located outside the chamber.

[0037] The positioning and clamping assembly includes a first positioning frame 2, a second positioning frame 10, and several clamping bolts 9. The first positioning frame 2 and the second positioning frame 10 are arc-shaped components adapted to the shape of the tube shaft 1, and are joined together circumferentially along the tube shaft 1 to form a ring-shaped frame. One end of the first positioning frame 2 and one end of the second positioning frame 10 can be connected by bolts, pin hinges for quick-release locking, or flexible belt connections, ensuring that they can encircle the tube shaft and withstand the clamping reaction force. The other end of the first positioning frame 2 is connected to the clamping assembly platform 11; the other end of the second positioning frame 10 is also connected to the clamping assembly platform 11. The ends of the two positioning frames are provided with mounting ears, connecting holes, or connecting grooves for connecting to each other and to the clamping assembly platform 11. Multiple radial threaded holes are distributed along the circumference of the positioning frame. Clamping bolts 9 pass through the threaded holes respectively. The ends of clamping bolts 9 abut against the outer wall of the tube shaft 1. By adjusting the extension of each clamping bolt, the circumferential frame can adapt to a certain range of changes in the outer diameter of the tube shaft and fix the tooling stably at the bonding position determined by dynamic balance testing.

[0038] The end of the clamping bolt 9 that contacts the tube shaft 1 is provided with a non-metallic protective pad, a spherical pressure head, or a flexible pad to increase the contact area and avoid scratching or crushing the surface of the composite material. Multiple clamping bolts 9 are distributed at intervals in the circumferential direction, and the tooling posture can be corrected by differential adjustment so that the loading direction of the balance block clamping assembly passes through the center of the tube shaft 1 as much as possible and is consistent with the normal direction of the local curved surface.

[0039] The clamping bolt 9 can be replaced with an adjustable set screw, an eccentric clamping part, or a fine-tuning screw with a soft pressure head; a gasket made of rubber, polytetrafluoroethylene, polyetheretherketone, or other non-damaging composite material surface can also be installed at the position in contact with the tube shaft.

[0040] A method for bonding balance blocks using the aforementioned composite material tube shaft balance block bonding pressure monitoring fixture includes the following steps: S1. Determine the specifications, axial and circumferential positions of the balancing block 3 by dynamic balancing test of the tube shaft 1, and mark the bonding area; S2. Clean and perform necessary surface treatment on the bonding surfaces of the tube shaft 1 and the balance block 3. Prepare the adhesive according to the adhesive process requirements and apply it evenly on at least one bonding surface. The thickness of the adhesive layer can be controlled by metal wire, glass microspheres or thickness limiting gaskets. S3. Place the balance block 3 at the marked position, and install the positioning frame 1 2 and the positioning frame 2 10 around the outer periphery of the tube shaft 1. Adjust the multiple clamping bolts 9 to fix the tooling on the tube shaft 1 and align the loading axis of the balance block clamping assembly with the balance block 3. S4. Install the sensor assembly and zero the force sensor 16. Calculate the target reading based on the actual bonding area of ​​the balance block 3, the target bonding pressure, and the weight of the loaded component. S5. Rotate the adjusting screw 17, drive the force sensor 16 and the screw slider 7 to move along the slider guide rod 5, and gradually compress the elastic element; read the force in real time on the display device until the target reading is reached and remains stable. S6. Tighten the locking nut 15 to fix the compression state of the elastic clamping structure; depending on the process requirements, you can choose to remove the sensor assembly and then cure the tube shaft 1 together with the balance block clamping assembly, or retain the sensor assembly and continuously collect pressure during the curing process. S7. Perform room temperature pre-curing and / or heat curing according to the adhesive curing regime. After curing is completed and cooled, release the lock and remove the sensor assembly, balance block clamping assembly and positioning clamping assembly in sequence. Check the bonding position of balance block 3, the appearance of the adhesive layer and the bonding quality.

[0041] like Figure 5 As shown, the force sensor 16 measures the force along the loading direction, while the process requirements are usually expressed as the pressure per unit bonding area of ​​the balance block 3. Therefore, the theoretical clamping force is first calculated based on the actual bonding area of ​​the balance block 3 and the target bonding pressure. Then, the gravitational components of the balance block 3, the upper spring pressure block 14, the lower spring pressure block 4, and the spring 13 along the loading direction are subtracted to obtain the target reading that the force sensor 16 should achieve. When the fixture is installed vertically, the target reading in step S4 is calculated using the following formula: F=p·S-G1-G2 In the formula: F is the target reading of force sensor 16; p is the target bonding pressure; S is the actual bonding area of ​​balance block 3; G1 is the weight of spring-loaded pressure block 4 and the components involved in loading; G2 is the weight of balance block 3. When the fixture is not in the vertical direction, G1 and G2 can be replaced with their components in the loading direction. For curved balance blocks, the bonding area is preferably calculated based on the actual arc length and the axial width of the balance block, rather than using only the projected area of ​​the chord length and width.

[0042] Example 1: This example uses a pre-designed and manufactured tooling prototype to conduct an adhesive pressure monitoring test on a curved aluminum alloy balance block. This verifies the tooling's pressure setting, locking, and high-temperature curing monitoring functions. The simulated tube shaft 1 has an inner diameter of 79 mm, an outer diameter of 84.5 mm, and an axial length of 50 mm. The balance block is made of aluminum alloy and measures 26 mm × 24 mm × 3 mm. The bonding surface of the balance block 3 is an arc surface adapted to the tube shaft 1. A handheld push-pull gauge is used for pressure testing, and J-349-1 two-component room-temperature curing paste-like structural adhesive is used.

[0043] (1) Tooling assembly: Install the balance block clamping assembly on the positioning and clamping assembly and reliably connect it with bolts; install the positioning frame 1 2 and positioning frame 2 10 around the outside of the tube shaft 1, and adjust and fix the tooling position by multiple radial clamping bolts 9 so that the balance block clamping assembly is located directly above the balance block 3.

[0044] (2) Adhesive preparation and surface treatment: Weigh out 5 g of component A and 1.5 g of component B and mix them thoroughly. The time from adhesive preparation to bonding should not exceed 30 min. Clean the bonding surfaces of tube shaft 1 and balance block 3 with alcohol, and then wipe them with water. Apply adhesive to the two surfaces to be bonded and place a thin iron wire with a diameter of about 0.1 mm as a thickness limiter for the adhesive layer.

[0045] (3) Sensor installation and zeroing: Install the sensor assembly onto the clamping assembly platform 11, check whether the screw slider 7 can move freely along the slider guide rod 5, connect the force sensor 16 to the handheld push-pull gauge and zero it.

[0046] (4) Target force calculation: The radius of the arc of the bonding surface of balance block 3 is 84.6 mm, and the chord length is 26 mm. According to L=2r·arcsin[s / (2r)], the arc length is approximately 26.1 mm, and the actual bonding area is approximately 26.1 mm × 24 mm = 626.4 mm. 2 The target bonding pressure is taken as 0.015 MPa, and the theoretical clamping force is 626.4 × 0.015 = 9.396 N. After deducting the influence of gravity of about 0.18 N from the loading components such as spring 13, upper spring pressure block 14, and lower spring pressure block 4, the target reading of force sensor 16 is about 9.22 N.

[0047] (5) Pressure loading and room temperature curing: Rotate the adjusting screw 17 to make the force sensor 16 push the spring upper pressure block 14 downward and compress the elastic element; when the push-pull gauge reading reaches about 9.22 N and stabilizes, tighten the locking nut 15. The balance block 3 is pre-cured at room temperature for 2 h.

[0048] (6) High-temperature curing and monitoring: The specimen with tooling was placed in a high-temperature forced-air drying oven. The sensor wires were led out from the pre-drilled holes in the equipment and sealed with heat insulation material. The push-pull gauge was connected to the computer via USB to record the pressure. The temperature was raised from about 18 ℃ to 70 ℃, and the heating time was set to about 30 min. Then it was kept at 70 ℃ for 2 h.

[0049] (7) Results: The initial force was 9.22 N. During the heating stage, the force gradually decreased to approximately 9.12 N. During the holding stage, the force did not continue to decrease significantly but instead showed a slight increase, such as... Figure 6 As shown, the force fluctuation during the entire heating and holding process was approximately 1.08%. The lowest force in the adhesive-free control test was approximately 8.92 N, with a fluctuation of approximately 3.25%. The results indicate that the designed fixture can maintain relatively stable bonding pressure during high-temperature curing and can record pressure changes in real time.

[0050] In summary, the composite material tube shaft balance block bonding pressure monitoring fixture and bonding method described in this invention transforms bonding pressure control from experience-based to quantitative control. Through the force sensor 16 and pressure conversion relationship, corresponding target force values ​​can be set for balance blocks of different sizes, ensuring that the bonding pressure remains stable within the process requirements.

[0051] The present invention discloses a composite material tube shaft balance block bonding pressure monitoring fixture and bonding method, which can observe pressure changes in real time. The sensor assembly can continuously monitor the pressure during room temperature storage, heating, and heat preservation stages, providing data to determine the impact of thermal expansion differences, adhesive layer curing, and fixture loosening on the pressure.

[0052] The present invention discloses a composite material tube shaft balance block bonding pressure monitoring fixture and bonding method, which combines elastic compensation and mechanical locking capabilities. The elastic element can absorb minor thermal deformation and curing shrinkage displacement, while the locking element can prevent the threads from loosening and maintain a pre-tightened state, reducing pressure surges caused by rigid loading.

[0053] The present invention discloses a composite material tube shaft balance block bonding pressure monitoring fixture and bonding method, wherein the sensor assembly is detachable. After the target pressure is reached, the locking structure can independently maintain the pressure and remove the sensor assembly, reducing the fixture volume that enters the high-temperature equipment with the tube shaft 1 and avoiding long-term heating of the sensor and display; when it is necessary to study pressure changes, the sensor can be retained to carry out full-process monitoring.

[0054] The composite material tube shaft balance block bonding pressure monitoring fixture and bonding method described in this invention have a wide range of applicable positions and specifications. The circumferential positioning frame and multiple radial clamping bolts 9 allow the fixture to be installed at different positions on the long tube shaft, and can adapt to certain outer diameter changes by adjusting the clamping bolts 9; the replaceable spring pressure block 4 can be adapted to different balance block 3 sizes and curvatures.

[0055] The present invention discloses a composite material tube shaft balance block bonding pressure monitoring fixture and bonding method, which avoids drilling damage to the composite material tube shaft. The fixture achieves positioning through peripheral clamping and normal compression, eliminating the need to machine mounting holes on the tube shaft 1, thus helping to maintain the integrity of the composite material tube wall.

[0056] The present invention discloses a composite material tube shaft balance block bonding pressure monitoring fixture and bonding method. Experimental verification shows that the fixture has good high-temperature curing pressure retention capability. When the target initial force is 9.22 N, the minimum force with adhesive during heating and holding at 70 °C is 9.12 N, with a pressure fluctuation of approximately 1.08%; the minimum force in the control group without adhesive is 8.92 N, with a pressure fluctuation of approximately 3.25%.

[0057] The composite material tube shaft balance block bonding pressure monitoring fixture and bonding method described in this invention, through single lap tensile shear test, shows that under the material and adhesive system used, the shear strength of the 0.01 MPa and 0.02 MPa bonding pressure groups are approximately 14.7±0.67 MPa and 13.2±0.57 MPa, respectively, while the shear strength of the 0.05 MPa group drops to approximately 6.6±0.88 MPa, indicating the necessity of precise control of bonding pressure.

[0058] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the invention. They can also be reasonable combinations of the features described in the above embodiments. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A tooling for monitoring the bonding pressure of a composite material tube shaft balance block, characterized in that: The device includes a positioning clamping assembly, a counterweight clamping assembly, and a sensor assembly. The positioning clamping assembly is sleeved on the tube shaft (1). The counterweight clamping assembly is connected to the positioning clamping assembly. The sensor assembly is set on the counterweight clamping assembly. The sensor assembly includes a bracket, a drive device, and a force sensor (16). The lower end of the bracket is connected to the counterweight clamping assembly, and the upper end is provided with a drive device. The drive device and the force sensor (16) are detachably connected. The counterweight clamping assembly includes an elastic clamping assembly and a clamping assembly platform (11). The clamping assembly platform (11) is connected to the positioning clamping assembly and the bracket, respectively. The upper end of the elastic clamping assembly and the lower end of the force sensor (16) pass through the clamping assembly platform (11) to press the counterweight (3) onto the tube shaft (1).

2. The composite material tube shaft balance block bonding pressure monitoring fixture according to claim 1, characterized in that: The elastic clamping assembly includes a spring lower pressure block (4), an elastic element and a spring upper pressure block (14) connected in sequence. The spring upper pressure block (14) is connected to a force sensor (16). The spring lower pressure block (4) presses the balance block (3) onto the tube shaft (1).

3. The composite material tube shaft balance block bonding pressure monitoring fixture according to claim 2, characterized in that: The elastic clamping assembly also includes several guide screws (12), which are set on the clamping assembly platform (11). The spring upper pressure block (14) and the guide screws (13) are slidably connected; a locking nut (15) is provided at the upper end of the guide screw (12).

4. The composite material tube shaft balance block bonding pressure monitoring fixture according to claim 2, characterized in that: The elastic element is a spring (13).

5. The composite material tube shaft balance block bonding pressure monitoring fixture according to claim 1, characterized in that: The driving device includes a screw slider (7) and an adjusting screw (17). The upper end of the adjusting screw (17) is rotatably connected to the bracket. The screw slider (7) is set on the adjusting screw (17) and threadedly connected to the adjusting screw (17).

6. The composite material tube shaft balance block bonding pressure monitoring fixture according to claim 5, characterized in that: The lower end of the screw slider (7) is detachably provided with a sensor mounting bracket (6), and a force sensor (16) is provided on the sensor mounting bracket (6).

7. The composite material tube shaft balance block bonding pressure monitoring fixture according to claim 5, characterized in that: The bracket includes two slider guide rods (5) and a screw mounting platform (8); the upper end of the slider guide rod (5) is connected to the screw mounting platform (8), and the lower end is connected to the clamping assembly platform (11); the screw mounting platform (8) and the adjusting screw (17) are rotatably connected.

8. The composite material tube shaft balance block bonding pressure monitoring fixture according to claim 1, characterized in that: The positioning and clamping assembly includes a positioning frame one (2) and a positioning frame two (10), which are arc-shaped structures. One end of the positioning frame one (2) is hinged to one end of the positioning frame two (10), and the other end is connected to the clamping assembly platform (11). The other end of the positioning frame two (10) is connected to the clamping assembly platform (11). Several clamping bolts (9) are provided on the positioning frame one (2) and the positioning frame two (10).

9. A method for bonding balance blocks using a composite material tube shaft balance block bonding pressure monitoring fixture according to any one of claims 1-8, characterized in that: Includes the following steps: S1. Determine the specifications, axial and circumferential positions of the balancing block (3) by dynamic balancing test of the tube shaft (1), and mark the bonding area; S2. Perform surface treatment on the surface to be bonded (1) of the tube shaft and the bonding surface of the balance block (3), prepare the adhesive according to the adhesive process requirements, and apply the adhesive evenly on at least one bonding surface and control the thickness of the adhesive layer. S3. Place the balance block (3) at the marked position, install the positioning clamping assembly on the outer periphery of the tube shaft (1), and adjust the positioning clamping assembly so that the loading axis of the clamping assembly is aligned with the balance block (3). S4. Install the sensor assembly and zero the force sensor (16). Calculate the target reading based on the actual bonding area of ​​the balance block (3), the target bonding pressure, and the weight of the loaded component. S5. Start the drive device to move the drive force sensor (16) and gradually compress the elastic clamping component; read the force in real time on the display device until the target reading is reached and remains stable; S6, Fixed elastic clamping component compression state; Depending on the process requirements, you can choose to remove the sensor assembly and then cure the tube shaft (1) together with the balance block clamping assembly, or retain the sensor assembly and continuously collect pressure during the curing process; S7. Pre-cur at room temperature and / or heat curing according to the adhesive curing regime. After curing and cooling, release the lock and remove the sensor assembly, clamping assembly and positioning clamping assembly in sequence. Check the bonding position, adhesive layer appearance and bonding quality of the balance block (3).

10. The method for bonding balance blocks according to claim 9, characterized in that: The target reading in step S4 is calculated using the following formula: F=p·S-G1-G2 In the formula: F is the target reading of the force sensor (16); p is the target bonding pressure; S is the actual bonding area of ​​the balance block (3); G1 is the gravity of the component involved in the loading; G2 is the gravity of the balance block (3).

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