High-temperature strain gauge pasting device

Abstract

The utility model discloses a high temperature strain gauge pasting device, comprising a fixing unit, the fixing unit comprises a fixing seat and a plurality of vacuum sucker assemblies arranged on the fixing seat, the vacuum sucker assemblies are respectively connected to a vacuum generating device and are used for fixing the fixing seat on a workpiece; the pressurizing unit is arranged on the fixed seat and is used for applying pressure to the strain gauges; and the heating unit is arranged between the pressurizing unit and the strain gauge and is used for heating the strain gauge. The pasting device composed of the fixing unit, the pressurizing unit and the heating unit is adopted for curing the strain gauge, the pasting requirement of the strain gauge of the complex structural part of the airplane is met, the pasting effect is improved, and therefore the accuracy and authenticity of the strength measurement result of the complex structural part of the airplane are improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of strain gauge pasting, and in particular relates to a high-temperature strain gauge pasting device. Background Art

[0002] In strength testing of complex aircraft structures, stress is often measured indirectly using strain. Contact strain measurement requires installing a strain gauge on the surface of the test piece. While strain measurement at room temperature is well established, high-temperature strain measurement requires high-temperature curing of the adhesive after application due to the adhesive's processing characteristics.

[0003] The pasting process of strain gauges includes: first marking the patch lines, then shielding protection and surface treatment, then cleaning, followed by gluing, then installing the strain gauge, then heating and pressurizing for curing, and finally connecting the wires and testing.

[0004] The heating and pressure curing process can reach temperatures as high as 200°C, with curing times ranging from 2 to 5 hours and pressures ranging from 200 to 500 kPa. The specific parameters for these temperatures, times, and pressures vary depending on the process characteristics of the high-temperature adhesive. Due to the high temperatures, long curing times, and high pressures involved, manual pressure alone is not feasible for the curing process, requiring the use of a dedicated high-temperature strain gauge attachment device.

[0005] However, the existing high-temperature strain gauge pasting device has the following shortcomings:

[0006] 1. For the pasting of strain gauges on large-curvature structural parts, there is a problem that the pasting device cannot effectively fit the strain gauges on the surface of the large-curvature structural parts, resulting in the inability to provide sufficient curing pressure, affecting the pasting effect.

[0007] 2. For the bonding of strain gauges on thick-walled structural parts, the curing pressure of the bonding device may be insufficient, so it is only suitable for bonding strain gauges on simple thin-walled structural parts.

[0008] 3. During the curing process, the curing pressure cannot be adjusted in real time, which affects the pasting effect.

[0009] 4. During the curing process, the heating temperature cannot be feedback controlled in real time. When the ambient temperature changes greatly, the bonding quality is likely to decline, resulting in distortion of the strain gauge measurement results.

[0010] In summary, existing technologies cannot provide stable curing pressure control and curing temperature control for the pasting of strain gauges for complex aviation structural parts with large curvature and thick walls. They are only suitable for the pasting of regular thin-walled parts, with a narrow usage scenario and cannot meet the structural strength test requirements of complex aircraft structural parts under high temperature conditions. Utility Model Content

[0011] The purpose of the utility model is to provide a high-temperature strain gauge pasting device to solve the problem of poor pasting effect of strain gauges on complex structural parts.

[0012] The utility model is achieved through the following technical solutions:

[0013] A high-temperature strain gauge pasting device, comprising:

[0014] A fixing unit, comprising a fixing base and a plurality of vacuum suction cup assemblies disposed on the fixing base, wherein the vacuum suction cup assemblies are respectively connected to a vacuum generating device and are used to fix the fixing base on the workpiece;

[0015] A pressurizing unit, which is disposed on a fixing seat and is used to apply pressure to the strain gauge;

[0016] The heating unit is arranged between the pressurizing unit and the strain gauge and is used to heat the strain gauge.

[0017] In some embodiments, the vacuum suction cup assembly is hingedly connected to the fixing base.

[0018] In some embodiments, the pressurizing unit is a gas cylinder.

[0019] In some embodiments, a pressure regulating unit is further included, and the pressure regulating unit is used to regulate the output pressure of the cylinder.

[0020] In some embodiments, the heating unit is disposed at the force output end of the pressurizing unit.

[0021] In some embodiments, the heating unit includes a heating block, and a PTC heating rod is disposed in the heating block.

[0022] In some embodiments, the heating unit includes a pad, which is disposed on the heating block and connected to the force output end of the pressurizing unit, and an insulating pad is disposed between the pad and the heating block.

[0023] In some embodiments, the force output end of the pressurizing unit is connected to the heating unit via a universal ball joint.

[0024] In some embodiments, a temperature sensor is provided on the heating block.

[0025] In some embodiments, a control unit is further included, which is connected to the pressurizing unit and the heating unit and is used to control the pressure applied to the strain gauge by the pressurizing unit and the heating temperature of the strain gauge by the heating unit.

[0026] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0027] 1. The utility model adopts a pasting device consisting of a fixing unit, a pressurizing unit and a heating unit to solidify the strain gauge, which meets the pasting requirements of the strain gauge of the complex structural parts of the aircraft, improves the pasting effect, and thus improves the accuracy and authenticity of the strength measurement results of the complex structural parts of the aircraft.

[0028] 2. A pressure regulating unit is used to adjust the output pressure of the cylinder in real time, so that the curing pressure output by the pasting device can meet the pasting requirements of strain gauges on complex aircraft structures, thereby improving the pasting effect.

[0029] 3. Use temperature sensor to feedback temperature in real time, so as to effectively control the curing temperature, avoid the curing temperature being affected by ambient temperature changes, and improve the pasting quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0031] Figure 1 This is a schematic structural diagram of a high-temperature strain gauge pasting device in an embodiment of the present utility model.

[0032] Figure 2 It is a structural schematic diagram of the pressurizing unit and the heating unit in an embodiment of the present utility model.

[0033] Among them: 1-workpiece, 2-fixing unit, 3-pressurizing unit, 4-heating unit, 5-pressure regulating unit, 201-vacuum suction cup assembly, 202-rotating pin, 203-fixing seat, 204-vacuum hose, 205-vacuum generating device, 301-cylinder body, 302-piston rod, 303-cylinder joint, 401-heating block, 402-PTC heating rod, 403-pad, 404-temperature sensor, 405-thermal insulation pad, 406-temperature control meter, 407-fastening screw, 6-universal ball head, 7-strain gauge. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0035] Example 1

[0036] Reference Figure 1 、 Figure 2 A high-temperature strain gauge pasting device includes: a fixing unit 2, the fixing unit 2 includes a fixing base 203 and a plurality of vacuum suction cup assemblies 201 arranged on the fixing base 203, and the vacuum suction cup assemblies 201 are respectively connected to a vacuum generating device 205, for fixing the fixing base 203 on the workpiece 1; a pressurizing unit 3, the pressurizing unit 3 is arranged on the fixing base 203, and is used to apply pressure to the strain gauge 7; a heating unit 4, the heating unit 4 is arranged between the pressurizing unit 3 and the strain gauge 7, and is used to heat the strain gauge 7.

[0037] The utility model adopts a pasting device composed of a fixing unit 2, a pressurizing unit 3 and a heating unit 4 to solidify the strain gauge 7, which meets the pasting requirements of the strain gauge 7 of the complex structural parts of the aircraft, improves the pasting effect, and thus improves the accuracy and authenticity of the strength measurement results of the complex structural parts of the aircraft.

[0038] Among them, the vacuum generating device 205 is a vacuum pump or a vacuum generator, and the input end of the vacuum generating device is connected to each vacuum suction cup assembly through a vacuum hose 204, which is used to provide a stable vacuum environment for the vacuum suction cup assembly 201 to ensure the fixed connection effect between the fixing unit 2 and the workpiece 1.

[0039] In some embodiments, the vacuum suction cup assembly 201 is hingedly connected to the fixing base 203 .

[0040] The vacuum suction cup assembly 201 includes a suction cup and a suction cup tube. One end of the suction cup is connected to one end of the suction cup tube, and the other end of the suction cup can be connected to the workpiece 1 for adsorption. The other end of the suction cup tube is hingedly connected to one end of the fixed base via a rotating pin 202. The vacuum suction cup assembly 201 rotates around the rotating pin 202 to effectively adjust the adsorption position of the suction cup, ensuring that stable adsorption force can be provided under different curvatures of the workpiece surface. The vacuum suction cup assembly 201 is used to provide a supporting reaction force to prevent the workpiece 1 and the adhering device from shifting due to the force generated when the adhesive device solidifies and adheres the strain gauge 7 to the workpiece 1.

[0041] In some embodiments, the pressurizing unit 3 is a gas cylinder.

[0042] The cylinder comprises a cylinder body 301 and a piston rod 302. A cylinder joint 303 is provided at one end of the cylinder body, and a return element is located within the other end of the cylinder body. This return element is connected to one end of the piston rod, while the other end of the piston rod is connected to the heating unit 4. The return element is a spring. When compressed air enters the cylinder body 301 through the cylinder joint 303, the compressed air pushes the return element to slide along the inner wall of the cylinder body toward the heating unit, thereby pushing the piston rod 302 to slide. When the compressed air supply to the cylinder stops, the piston rod 302 returns to its original position and retracts under the force of the return element.

[0043] In some embodiments, a pressure regulating unit 5 is further included, and the pressure regulating unit 5 is used to regulate the output pressure of the cylinder. The output end of the pressure regulating unit is connected to the cylinder joint 303 through a compressed air hose.

[0044] The pressure regulating unit 5 is used to adjust the output pressure of the cylinder in real time, so that the curing pressure output by the pasting device can meet the pasting requirements of the strain gauge 7 of the complex structural part of the aircraft, thereby improving the pasting effect.

[0045] In some embodiments, the heating unit 4 is disposed at the force output end of the pressurizing unit.

[0046] In some embodiments, the heating unit 4 includes a heating block 401 , and a PTC heating rod 402 is disposed in the heating block 401 .

[0047] The PTC heating rod 402 is fixedly connected to the heating block 401 via a fastening screw 407 .

[0048] The heating block 401 is a Lu heating block, and the end surface of the heating block facing the strain gauge is bonded with high-temperature thermal conductive silicone.

[0049] In some embodiments, the heating unit 4 includes a pad 403 , which is disposed on the heating block and connected to the force output end of the pressurizing unit. A thermal insulation pad 405 is disposed between the pad 403 and the heating block 401 .

[0050] The heat insulation pad 405 is used to prevent high temperature from being transferred to the piston rod during heating.

[0051] In some embodiments, the force output end of the pressurizing unit is connected to the heating unit 4 via a universal ball joint 6 .

[0052] The universal ball joint 6 is used to connect the pressurizing unit 3 and the heating unit 4, which can realize arbitrary adaptive adjustment of the angle of the heating unit, so that the curing pressure and curing temperature of the strain gauge 7 are more uniform.

[0053] In some embodiments, a temperature sensor 404 is provided on the heating block 401 .

[0054] Among them, the heating unit 4 also includes a temperature control meter 406, the input end of the temperature control meter is connected to the temperature sensor 404, and the output end of the temperature control meter is connected to the PTC heating rod 402. The temperature can be measured in real time through the temperature sensor 404, and the PTC heating rod 402 can be controlled to heat the heating block 401, thereby realizing real-time feedback and control of the heating temperature.

[0055] The temperature sensor 404 is used to provide real-time temperature feedback, thereby effectively controlling the curing temperature, preventing the curing temperature from being affected by ambient temperature changes, and improving the pasting quality.

[0056] In some embodiments, a control unit is further included, which is connected to the pressurizing unit 3 and the heating unit 4 and is used to control the pressure applied to the strain gauge by the pressurizing unit 3 and the heating temperature of the strain gauge by the heating unit 4.

[0057] The working process of the above-mentioned high-temperature strain gauge bonding device is as follows:

[0058] According to the strain gauge pasting process, the area on the surface of the workpiece 1 where the strain gauge is to be pasted is polished and cleaned.

[0059] After the surface to be pasted is polished and cleaned, the pasting device is installed, the vacuum hose 204 is connected to the vacuum generating device 205, the compressed air hose is connected to the pressure regulating unit 5, the temperature control meter 406 is connected to the temperature sensor 404, and the temperature control meter 406 is connected to the PTC heating rod 402.

[0060] After the pasting device is installed, apply high-temperature strain glue and install the strain gauge 7.

[0061] Move the sticking device close to the surface of the workpiece 1, align the center of the heating block with the strain gauge 7, adjust the position of the vacuum suction cup assembly so that it sticks to the workpiece surface, start the vacuum generating device 205, and make the sticking device effectively adsorbed on the workpiece surface.

[0062] When the pressure regulating unit 5 is turned on, the piston rod 302 of the cylinder extends, and the cylinder provides curing pressure to the strain gauge 7. The pressure value is set in the control unit, and the gas pressure is adjusted by the pressure regulating unit 5 so that the gas pressure output from the end of the cylinder meets the process requirements for high-temperature adhesive curing pressure.

[0063] At the same time, according to the process requirements of the high-temperature glue curing temperature, the temperature value and heating time are set in the control unit, the heating temperature of the PTC heating rod 402 is controlled by the temperature control table 406, and the power of the PTC heating rod 402 is turned on to heat the heating block 401 and start heating and curing the strain gauge 7.

[0064] After the heating and curing is completed, let it stand for a period of time according to the high-temperature glue pasting process, and then remove the pasting device.

[0065] Among them, the bonding area of ​​the strain gauge is 8mm×6mm.

[0066] The process and process parameters of high temperature curing adhesive are as follows: under a pressurized state of 200-500kPa, first heat and cure at a temperature of 100°C for 1 hour, then heat and cure at a temperature of 200°C for 2 hours, then stop pressurizing, and continue heating at the current temperature for 2 hours.

[0067] The heating temperature of the PTC heating rod 402 is 200° C., the heating power is 50W, and the voltage is 24V.

[0068] The temperature control accuracy of the temperature controller is ±2℃.

[0069] The temperature sensor 404 adopts a PT100 temperature probe with a temperature measurement range of -50-420°C.

[0070] The curing pressure is 200-500kPa, the end diameter of the cylinder piston rod is 30mm, and the gas pressure value of the pressure regulating unit is calculated to be set between 13.58-33.95kPa. The specific calculation process is as follows:

[0071]

[0072] The ultimate vacuum degree of the vacuum generating device is -92kPa, the suction cup diameter is ≥35mm, and the fixing unit 2 provides sufficient support and reaction force.

[0073] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification or equivalent change made to the above embodiment based on the technical essence of the present invention falls within the scope of protection of the present invention.

Claims

1. A high temperature strain gauge pasting device, characterized in that: include: A fixing unit, comprising a fixing base and a plurality of vacuum suction cup assemblies disposed on the fixing base, wherein the vacuum suction cup assemblies are respectively connected to a vacuum generating device and are used to fix the fixing base on the workpiece; A pressurizing unit, which is disposed on a fixing seat and is used to apply pressure to the strain gauge; The heating unit is arranged between the pressurizing unit and the strain gauge and is used to heat the strain gauge.

2. The high temperature strain gauge bonding device according to claim 1, characterized in that: The vacuum suction cup assembly is hingedly connected to the fixing seat.

3. The high temperature strain gauge bonding device according to claim 1, characterized in that: The pressurizing unit adopts a cylinder.

4. The high temperature strain gauge bonding device according to claim 3, characterized in that: It also includes a pressure regulating unit, which is used to adjust the output pressure of the cylinder.

5. The high temperature strain gauge bonding device according to claim 1, characterized in that: The heating unit is arranged at the force output end of the pressurizing unit.

6. The high temperature strain gauge bonding device according to claim 5, characterized in that: The heating unit includes a heating block, and a PTC heating rod is arranged in the heating block.

7. The high temperature strain gauge bonding device according to claim 6, characterized in that: The heating unit includes a pad, which is arranged on the heating block and connected to the force output end of the pressurizing unit, and a heat insulation pad is arranged between the pad and the heating block.

8. The high temperature strain gauge bonding device according to claim 1 or 7, characterized in that: The force output end of the pressurizing unit is connected to the heating unit via a universal ball joint.

9. The high temperature strain gauge bonding device according to claim 6, characterized in that: A temperature sensor is provided on the heating block.

10. The high temperature strain gauge pasting device according to any one of claims 1, 4, 6 or 9, characterized in that: It also includes a control unit, which is connected to the pressurizing unit and the heating unit and is used to control the pressure applied to the strain gauge by the pressurizing unit and the heating temperature of the strain gauge by the heating unit.

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