A probe assembly and its fabrication method

Abstract

This invention belongs to the field of icing detection, specifically relating to a probe assembly and its processing method. It includes: an icing probe, a probe heater, a support ring, and a heating converter. The probe heater comprises a heater protective sleeve and a heating wire built into the protective sleeve. Two symmetrical oblique holes are provided in the wall of the icing probe cylinder. The probe heater passes through these holes into the probe and is bent into a U-shape by a U-shaped groove on a mounting mandrel built into the icing probe cylinder. The probe heater is fixed to the inner wall of the icing probe cylinder by high-temperature brazing. The outer wall of the icing probe is located within the support ring, and both ends of the probe heater are connected to the heating converter.

Description

Technical Field

[0001] This invention belongs to the field of icing detection, specifically relating to a probe assembly and its processing method. Background Technology

[0002] Most of the icing detectors installed on domestic aircraft are old products from the 1950s and 1960s. They are icing probes that rely on pilots to visually determine whether icing has occurred. They cannot quantitatively determine the severity of icing and do not have de-icing capabilities. Summary of the Invention

[0003] Purpose of the invention: To provide a probe assembly and its processing method, which ensures the function and detection accuracy of the icing probe through structural design, so that icing detection can continue after de-icing is completed.

[0004] Technical solution:

[0005] A probe assembly includes: an icing probe, a probe heater, a retaining ring, and a heating converter, wherein,

[0006] The probe heater includes a heater protective sleeve and a heating wire built into the heater protective sleeve; the icing probe cylinder wall is provided with two symmetrical oblique holes, the probe heater is inserted into the probe through the symmetrical oblique holes, and the probe heater is bent into a U-shaped structure by the U-shaped groove on the mounting mandrel built into the icing probe cylinder, and the probe heater is fixed to the inner wall of the icing probe cylinder by high temperature brazing; the outer wall of the icing probe is set in the fixed support ring, and the two ends of the probe heater are connected to the heating converter.

[0007] Furthermore, the angle of the inclined hole is 45°.

[0008] Furthermore, the heating wire of the probe heater is made of nickel-chromium alloy, and the space between the heating wires is filled with fused magnesium oxide powder.

[0009] Furthermore, the inner diameter of the icing probe cylinder is 5.3 mm.

[0010] Furthermore, the diameter of the built-in portion of the probe heater is 1mm.

[0011] Furthermore, the probe heater is welded to the inner wall of the probe by filling with solder.

[0012] A method for manufacturing a probe assembly, wherein the probe is a probe assembly on a device, the method comprising:

[0013] Two symmetrical 45-degree oblique holes are drilled in the wall of the icing probe cylinder below the fixed support ring.

[0014] The probe heater is inserted into the probe through symmetrical oblique holes and bent into a U-shaped structure by a mandrel;

[0015] Solder is applied to the inner cavity of the icing probe along the edge of the probe heater, and solder is applied to the joint between the support ring and the probe. The solder is evenly distributed, the amount of solder is controlled, and the probe is dried and heated.

[0016] The probe heater is welded to the inside of the icing probe by vacuum brazing, and the fixed support ring is welded to the middle of the probe, and the three are welded into one piece.

[0017] A heating converter is installed at the external end of the heater to switch welding wiring;

[0018] Test the resistance and insulation resistance of the heater;

[0019] Aging and thermal stabilization treatments were carried out in the range of 550℃ to 750℃.

[0020] Furthermore, the fixed support ring needs to be welded to the middle of the probe at a node that does not affect the resonance.

[0021] Beneficial effects:

[0022] The probe assembly of this application features a probe heater inside the icing probe. The heater uses a small-diameter armored heating wire, which is inserted into the probe through the working node in the middle of the probe. Inside, it is bent into a U-shaped tube that fits the probe using a special tool. The U-shaped tube is welded to the inner wall of the probe with filler solder to ensure the function and detection accuracy of the icing probe, so that icing detection can continue after de-icing. Attached Figure Description

[0023] Figure 1 This is a structural diagram of the sensitive components of the icing detector;

[0024] Figure 2 This is the main view of the probe assembly;

[0025] Figure 3 Left view of the probe assembly;

[0026] Figure 4 This is a right view of the heater in the probe assembly before it is bent.

[0027] The components include: 1. Icing probe; 2. Probe heater; 3. Base; 4. Excitation coil; 5. Baffle ring; 6. Vibration pickup coil; 7. Permanent magnet; 8. Windward heater; 9. Spring; 10. Cover plate; 11. Fixed support ring; and 12. Heat exchanger. Detailed Implementation

[0028] The icing detector involved in this invention is used to detect whether an aircraft is icing during flight. Under continuous maximum and intermittent maximum icing conditions, the product should be able to work effectively throughout the entire flight envelope, promptly issuing icing alarm signals and icing rate level signals for aircraft icing, while the detector should also have in-flight de-icing capabilities.

[0029] The working principle of magnetostrictive vibration-type icing detectors has always been challenging due to the relatively long and narrow vibrating probe and the high requirements for heating time and temperature. The realization of the heating and de-icing function and process of such icing detectors has been a difficult point.

[0030] See the structural diagram of the sensitive components of the icing detector. Figure 1 The sensitive component structure of the icing detector includes an icing probe 1, a probe heater 2, a base 3, an excitation coil 4, a retaining ring 5, a pickup coil 6, a permanent magnet 7, a windward heater 8, a spring 9, and a cover plate 10. The icing detection part of the detector adopts a vibrating cylinder detection principle. The vibrating cylinder probe, as the sensitive element for detecting the icing state, can sense the ice thickness. When ice appears on the probe surface, its mass changes, and the probe's natural frequency decreases proportionally with the thickness of the ice layer. Therefore, the ice thickness can be determined by the shift in the resonant frequency. The heating and de-icing function is achieved through a heating tube built into the inner wall of the vibrating cylinder probe and a heating rod built into the windward side. The heating is controlled by a control circuit. It has the advantages of high testing sensitivity, icing alarm, icing level determination, and de-icing function. Because the vibrating cylinder probe is the sensitive element, the heating wire and its connection structure and manufacturing process are important factors affecting the icing detection performance.

[0031] like Figure 2-4 As shown, the probe assembly of this application includes an icing probe 1, a probe heater 2, a retaining ring 11, and a heating converter 12. The probe heater 2 is assembled inside the icing probe 1. The heater 2 uses a small-diameter armored heating wire. The inner wire material of the heater 1 is nickel-chromium alloy, ensuring reliable contact at the diameter change section. The heater's insulating filler material is high-performance fused magnesium oxide powder (between multiple fine wires), and the heater's protective sleeve material is 316 stainless steel. The probe heater 2 can withstand 10 minutes of continuous high-temperature welding at 1050℃ without embrittlement or melting of the inner wire and outer protective sleeve after welding.

[0032] The probe heater 2 is inserted into the icing probe 1 through symmetrical small holes, forming a U-shaped structure and welded to the inner wall. The external heater end is wired via a converter 4, outputting a cable for easy connection. Simultaneously, the support ring 3 is welded to the middle of the icing probe 1. The support ring 3 is securely fitted to the base, and the heating converter is fixed to the base with screws (see...). Figure 1 The probe heater assembly has the function of detecting and de-icing ice.

[0033] The icing probe 1 has an outer diameter of 6.3mm and an inner diameter of only 5.3mm. It has a single-ended opening with a length of 60mm. The heating wire is 1mm in diameter inside and about 1.8mm at both ends, which makes assembly difficult. By controlling the direction of the opening in the cylinder wall and using the internal mounting mandrel fixture, the following measures are taken: The cylinder wall of the icing probe 1 is provided with two symmetrical 45-degree oblique holes, which are drilled using a special drilling jig. The probe heater 2 is inserted into the probe through the symmetrical oblique holes and is bent into a U-shaped structure by special tooling and fixed to the inner wall by high-temperature brazing, forming a whole. Controlling the solder and welding quality ensures that the probe's working performance is stable and reliable.

[0034] During operation, the probe resonates at its natural frequency, which varies with the thickness of the ice layer. The probe's structural design considers the need for a certain sensitivity to changes in ice thickness on the probe's outer surface. Material selection prioritizes the stability of the resonant frequency during operation, employing a precision constant-elastic alloy with stable temperature characteristics. The plate material is processed using vibratory cylinder techniques such as cupping, stretching, and heat treatment to achieve the probe's ability to sense ice thickness, ensuring optimal performance. The stretching process offers high efficiency, good consistency, and meets the ice layer detection accuracy requirement of (0.5±0.2) mm.

[0035] See probe assembly structure Figure 2 See probe heater 2 Figure 3 and 4 The welding of the probe heater 2 and the icing probe 1 is carried out using low-temperature solder for high-frequency welding. The solder is evenly distributed on the inner wall to ensure that it is as little as possible and to reduce the impact on the frequency performance of the probe. The welding temperature is controlled below 700℃ to ensure the cold deformation performance of the probe after stretching.

[0036] After the de-icing control circuit activates the heating function, it can ensure that the ice layer on the outside of the probe melts within 30 seconds.

[0037] This invention is innovative, employing an integrated design of an icing probe and heater for an icing detector. It features icing alarm, provides icing level signals, delays alarm signals after de-icing, and has high sensitivity in icing alarm.

[0038] Product output information is shown in Table 1.

[0039] Table 1

[0040] performance Icing detector with integrated icing probe and heater Icing alarm threshold (0.5±0.2)mm Alarm signals Alarm delay after de-icing (30±5) s Freezing status level The RS422 output shows the icing conditions: weak icing, moderate icing, strong icing, and extremely strong icing.

[0041] Implementation method of probe component:

[0042] The heater is installed inside the probe, and it must not affect the probe's performance while still achieving the heating and de-icing function, and the installation process must not damage the heater. The design and manufacturing process of the probe assembly are crucial. The probe cylinder has an inner diameter of only 5.2mm, with the heating wire portion inside being 1mm and approximately 2mm at both ends, making assembly difficult. This is ensured by controlling the direction of the openings in the cylinder wall and using an internal mounting mandrel clamp.

[0043] ① The fixed support ring needs to be installed in the middle of the probe, at a node that does not affect the resonance;

[0044] ② Two symmetrical 45-degree inclined holes are set on the wall of the icing probe below the fixed support ring, and drilling is carried out using a special drilling jig;

[0045] ③ The probe heater is inserted into the probe through symmetrical oblique holes and fixed to the inner wall by bending it into a U-shaped structure using a special mandrel fixture;

[0046] ④ Apply solder along the edge of the probe heater inside the icing probe cavity, apply solder to the joint between the support ring and the probe, distribute the solder evenly, control the amount of solder, and dry and heat.

[0047] ⑤ The heater is welded to the inside of the probe using vacuum brazing, while the retaining ring is welded to the middle of the probe. All three are welded together as a single unit. Controlling the solder and welding quality ensures stable and reliable probe performance. See the probe assembly structure below. Figure 2 .

[0048] ⑥ The external end of the heater is connected to a heat exchanger ( Figure 2 (As shown) Perform welding wiring conversion to output easy-to-connect cables and wires, ensuring the reliability of heater connection;

[0049] ⑦ Check the resistance and insulation resistance of the heater to ensure they meet the requirements;

[0050] ⑧ Aging and thermal stabilization treatments are performed within the range of 550℃ to 750℃ to ensure the stable performance of the probe assembly.

[0051] This invention uses an icing detector with an integrated design of an icing probe and a heater. It features icing alarm, provides icing level signals, delays alarm signals after de-icing, and has high sensitivity in icing alarm.

[0052] The integrated design and implementation method of the icing probe and heater is scientific, reasonable, easy to operate, and can meet the product usage requirements.

[0053] (1) The probe is made by stretching process and heat treatment to obtain a probe with stable performance. Compared with the existing turning and grinding process, it has high processing efficiency, good consistency, and is more economical, and can meet the performance requirements.

[0054] (2) Small-diameter armored heating wire is used. The inner wire material of the heater is nickel-chromium alloy, the heater insulation filling material is high-performance fused magnesium oxide powder, and the heater protective sleeve material is 316 stainless steel. After welding, the inner wire and the outer protective sleeve will not become brittle or melt.

[0055] (3) Two symmetrical 45-degree oblique holes are set on the wall of the icing probe. The holes are drilled by a special drilling jig. The heater is inserted into the probe through the symmetrical oblique holes and fixed to the inner wall by bending it into a U-shaped structure using a special mandrel clamping fixture. This reduces the difficulty of heater installation, makes the heater less susceptible to damage, and ensures that the installation of the heater does not affect the probe performance while providing efficient heating and de-icing.

[0056] (4) A heating converter is installed at the external end of the heater to improve the reliability of the connection.

Claims

1. A probe assembly, characterized in that, include: Icing probe, probe heater, fixed support ring, heating converter, among which, The probe heater includes a heater protective sleeve and a heating wire built into the heater protective sleeve; the icing probe cylinder wall is provided with two symmetrical oblique holes, the probe heater is inserted into the probe through the symmetrical oblique holes, and the probe heater is bent into a U-shaped structure by the U-shaped groove on the mounting mandrel built into the icing probe cylinder, and the probe heater is fixed to the inner wall of the icing probe cylinder by high temperature brazing; the outer wall of the icing probe is set in the fixed support ring, and the two ends of the probe heater are connected to the heating converter.

2. The probe assembly according to claim 1, characterized in that, The angle of the inclined hole is 45°.

3. The probe assembly according to claim 1, characterized in that, The heating wire of the probe heater is made of nickel-chromium alloy, and the space between the heating wires is filled with fused magnesium oxide powder.

4. The probe assembly according to claim 1, characterized in that, The inner diameter of the icing probe cylinder is 5.3 mm.

5. The probe assembly according to claim 1, characterized in that, The diameter of the built-in part of the probe heater is 1mm.

6. The probe assembly according to claim 1, characterized in that, The probe heater is welded to the inner wall of the probe by filling with solder.

7. A method for fabricating a probe assembly, characterized in that, The probe is the probe assembly according to any one of claims 1-6, and the processing method includes: Two symmetrical 45-degree oblique holes are drilled in the wall of the icing probe cylinder below the fixed support ring. The probe heater is inserted into the probe through symmetrical oblique holes and bent into a U-shaped structure by a mandrel; Solder is applied to the inner cavity of the icing probe along the edge of the probe heater, and solder is applied to the joint between the support ring and the probe. The solder is evenly distributed, the amount of solder is controlled, and the probe is dried and heated. The probe heater is welded to the inside of the icing probe by vacuum brazing, and the fixed support ring is welded to the middle of the probe, and the three are welded into one piece. A heating converter is installed at the external end of the heater to switch welding wiring; Test the resistance and insulation resistance of the heater; Aging and thermal stabilization treatments were carried out in the range of 550℃ to 750℃.

8. The processing method according to claim 7, characterized in that, The fixed support ring needs to be welded to the middle of the probe at a node that does not affect the resonance.

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