A ring-shaped composite tool for assisting in positioning of B737 radar cover paint spraying

Abstract

The utility model discloses a kind of annular composite tool for assisting B737 radar cover paint spraying and positioning. The tool is formed by resin glue and glass cloth directly pasting and warming solidification on the outer surface of radar cover, and the inner profile of shell is completely matched with the shape of B737 radar cover;Six conductive strips avoidance grooves are set in the circumference of shell, which can be embedded with six conductive strips of radar cover one by one, to realize circumferential and axial rapid positioning;Radial shielding flanging is provided on the outer edge of front end face, which is used to one-time press and paste shielding tape and form neat paint dividing line;Shell adopts composite material layer, wall thickness is 1.5 mm~3 mm, and two pairs of handles are symmetrically fixed on the outer surface. The utility model replaces traditional wire positioning, and can determine reference by sleeving, which significantly shortens shielding preparation time, eliminates artificial error, and realizes the standardization of B737 radar cover paint spraying operation.

Description

Technical Field

[0001] This utility model relates to the field of annular composite tooling technology for assisting in the positioning of B737 radome painting, and more particularly to annular composite tooling for assisting in the positioning of B737 radome painting. Background Technology

[0002] When performing painting repairs on the B737 radome, it is necessary to spray antistatic paint, primer, and ceramic paint multiple times on the ring area (STA138.6-STA143.6 shaded area) according to the manual requirements, and then repeatedly mask it. Currently, the process relies on two rulers to find reference points, then connecting them with tape. This process is tedious, time-consuming, and prone to quality problems such as boundary misalignment and paint layer defects due to human error in measurement standards. Existing technology lacks a quick-positioning and masking tool that matches the radome's shape; a dedicated tooling solution is urgently needed to improve efficiency and consistency. Utility Model Content

[0003] The purpose of this invention is to provide a ring-shaped composite tooling for assisting in the positioning of B737 radome painting, thereby solving the aforementioned problems existing in the prior art.

[0004] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0005] A ring-shaped composite tooling for assisting in the positioning of B737 radome painting, comprising:

[0006] The ring-shaped shell is integrally solidified and molded, and the inner surface of the ring-shaped shell is perfectly matched with the theoretical aerodynamic shape of the outer surface of the B737 radome.

[0007] Six conductive strip clearance grooves are evenly spaced around the annular outer shell. The conductive strip clearance grooves extend from the front end face of the outer shell to the rear end face. They are used to fit one-to-one with the six conductive strips on the radome, so as to realize the rapid positioning of the tooling relative to the radome in the circumference and axis.

[0008] The front end face of the annular shell is provided with a shielding flange extending radially outward. The shielding flange coincides with the theoretical boundary of the ring strip to be painted on the radar dome, which is used to press the shielding tape on at one time and form a neat paint separation line.

[0009] The annular outer shell is composed of a composite material layer made of multiple layers of glass fiber cloth and epoxy resin adhesive cured by heating, with a wall thickness of 1.5mm to 3mm;

[0010] Two pairs of handles are symmetrically arranged on the outer surface of the annular shell. The handles are fixed to the shell by countersunk rivets, making it easy for the operator to move and place them.

[0011] In this specific embodiment, the width of the conductive strip clearance groove is 0.5mm to 1mm larger than the width of the conductive strip, and the groove depth is equal to the height of the conductive strip protruding from the surface of the radome, ensuring zero-gap positioning after fitting.

[0012] In this specific embodiment, a 0.2mm thick silicone rubber buffer layer is attached to the lower surface of the shielding flange to prevent damage to the radome paint layer.

[0013] In this specific embodiment, the handle is made of carbon fiber tubing with an anti-slip rubber sleeve on the surface, and the overall weight is no more than 5% of the total mass of the tooling.

[0014] In this specific embodiment, the annular shell has several weight-reducing holes between adjacent conductive strip clearance grooves. The weight-reducing holes are elliptical, with their major axis along the generatrix of the shell. The edges of the holes are covered with aluminum-nickel alloy protective rings to prevent the composite material from delaminating.

[0015] In this specific embodiment, the rear end face of the annular shell is engraved with angle scale lines, which are used to check whether the relative angle between the tooling and the radome meets the process requirements.

[0016] The beneficial effects of this utility model are:

[0017] Rapid positioning: The inner surface of the annular shell perfectly matches the shape of the radome, and the six clearance grooves directly fit into the conductive strip. Circumferential and axial zero-gap positioning can be achieved without additional measurement, eliminating the traditional wire-pulling point-finding process.

[0018] One-time masking: The front masking flange coincides with the theoretical boundary of the ring tape, allowing the masking tape to be applied in one go, forming a neat paint separation line and avoiding multiple rework.

[0019] Lightweight and high strength: The composite material layer is only 1.5mm to 3mm thick, lightweight, resistant to paint mist corrosion, and does not deform over a long period of time; the addition of handles makes it easy to move and reduces labor intensity.

[0020] Improve quality consistency: Eliminate errors caused by human error in finding points and marking lines, ensure accurate paint boundaries for each painting session, achieve standardized batch operations, and significantly improve painting efficiency and appearance quality. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of a ring-shaped composite tooling structure for assisting in the positioning of B737 radome painting according to this utility model.

[0022] In the attached diagram, 10 is the annular outer shell; 100 is the outer surface of the B737 radome; and 12 is the conductive strip clearance groove.

[0023] 102. Radar dome ring to be painted. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the scope of the present utility model.

[0025] Reference Figure 1 The ring-shaped composite tooling shown is for assisting in the positioning of B737 radome painting, comprising:

[0026] The annular shell 10 is integrally solidified and molded, and the inner surface of the annular shell 10 is completely fitted with the theoretical aerodynamic shape of the outer surface 100 of the B737 radome.

[0027] Six conductive strip clearance grooves 12 are equally divided in the circumference of the annular outer shell 10. The clearance grooves 12 extend from the front end face of the outer shell to the rear end face and are used to fit one-to-one with the six conductive strips on the radar dome to achieve rapid positioning of the tooling relative to the radar dome in the circumference and axial direction.

[0028] The front end face of the annular outer shell 10 is provided with a shielding flange extending radially outward. The shielding flange coincides with the theoretical boundary of the radar dome to be painted ring 102, which is used to press the shielding tape on at one time and form a neat paint separation line.

[0029] The annular outer shell 10 is composed of a composite material layer made of multiple layers of glass fiber cloth and epoxy resin adhesive cured by heating, with a wall thickness of 1.5mm to 3mm;

[0030] Two pairs of handles are symmetrically arranged on the outer surface of the annular outer shell 10. The handles are fixed to the outer shell 10 by countersunk rivets, making it convenient for the operator to move and place them.

[0031] In this embodiment, as Figure 1 As shown, the annular composite tooling of this invention consists of an integrally cured annular shell 10, which is fitted over the B737 radome in the form of an inner and outer hyperboloid rotating body. Its inner surface is CNC profiled based on the theoretical aerodynamic shape data of the radome's outer surface 100, with normal gaps at each point of the curved surface ≤0.1mm. This ensures that the tooling fits snugly against the radome surface without stress, preventing shaking during handling and positioning, and avoiding localized interference that could compress the composite material of the radome.

[0032] Six conductive strip clearance grooves 12 are evenly spaced circumferentially on the annular outer shell 10. The clearance grooves 12 extend linearly from the front end face of the outer shell to the rear end face. The groove width is 0.5mm to 1mm wider than the maximum measured width of the conductive strip, and the groove depth is equal to the measured height of the conductive strip protruding from the radome surface, with a tolerance zone controlled within ±0.05mm. When the fixture is pushed in along the radome axial direction, the six conductive strips simultaneously slide into their corresponding clearance grooves 12, achieving unique circumferential and angular alignment. The bottom of the groove contacts the top of the conductive strip with zero clearance, forming an axial rigid limit. The fixture can be positioned to its theoretical position in one go without additional scribing or measurement, with a positioning repeatability ≤0.2mm.

[0033] A shielding flange extending radially outward is provided on the front end face of the annular outer shell 10. The outer edge contour of the flange unfolds according to the theoretical boundary of the ring 102 to be painted on the radome, with a flange width of 5mm to 8mm. A 0.2mm silicone rubber buffer layer is left between the lower surface and the surface of the radome. This buffer layer is bonded to the flange with room temperature vulcanizing adhesive, with a Shore A hardness of 35°. It can prevent the sharp edge of the flange from damaging the primer and also provide elastic compensation when pressing the masking tape, so that the tape adheres closely to the curved surface of the radome without wrinkles, thereby forming a neat and continuous paint separation line and preventing paint from seeping into non-painted areas.

[0034] The annular outer shell 10 is directly wet-laid onto the radome body using multiple layers of alkali-free fiberglass cloth and epoxy resin adhesive, followed by curing at stepped temperatures of 80℃ to 120℃. The fiberglass cloth has a single-layer thickness of 0.15mm to 0.20mm, with symmetrical lay-up angles [0° / 45° / 90° / ‐45°]n, n=4~6, resulting in a final wall thickness of 1.5mm to 3mm. After curing, the outer shell has a density of 1.7g / cm³ to 1.9g / cm³, a tensile strength ≥280MPa, and a flexural modulus ≥18GPa. It maintains dimensional stability under cyclic thermal shock at −55℃ to 85℃ and does not swell or crack when exposed to paint mist and thinner environments for extended periods.

[0035] Two pairs of handles are symmetrically arranged on the outer surface of the casing, located at 0° / 180° and 90° / 270° respectively. The handles are made of T300 carbon fiber tubing with a wall thickness of 1.2mm and an outer diameter of 25mm. The surface is knurled and fitted with a silicone rubber anti-slip sleeve. The handle ends are machined into flat bosses and riveted to the pre-embedded aluminum honeycomb reinforcement plates in the casing using φ4 mm countersunk aluminum rivets. The riveting distance is ≥8mm, and the shear strength of a single rivet is ≥5kN. The total mass of the handle assembly does not exceed 5% of the total mass of the tooling, ensuring a stable center of gravity during handling, allowing for placement and removal by a single person.

[0036] Several elliptical weight-reduction holes are also formed on the outer shell wall between two adjacent conductive strip clearance grooves 12. The major axis of the hole is along the generatrix direction, with a length of 40mm to 60mm and a minor axis of 20mm to 30mm. The edge of the hole is covered with a 0.5mm thick aluminum-nickel alloy protective ring. The inner edge of the protective ring is bonded to the composite material wall with epoxy film, and a φ1mm stitching aramid thread is added to the outer edge of the protective ring to prevent delamination expansion at the hole edge. The total area of ​​the weight-reduction holes does not exceed 15% of the outer shell area in the area where they are located, thus maintaining structural rigidity while reducing weight.

[0037] The rear end face of the annular shell 10 is engraved with 360° angle scale lines, with a minimum division of 2° and a scale line depth of 0.1 mm. The interior is filled with white epoxy paint. After aligning with the reference scale lines on the radome, the relative angle of the tooling can be visually checked to ensure that the angular position of the tooling is consistent with the process requirements before each painting, further eliminating human error.

[0038] Through the above structure, this utility model realizes the standardized operation of "sleeving in for positioning and pressing for masking": the operator only needs to hold the handle and push the tool along the conductive strip to the bottom, the front masking flange naturally forms the painting boundary, and then the masking tape can be directly attached along the outer edge of the flange to complete the masking; the entire positioning-masking process takes less than 10 minutes, which is reduced from the traditional 2 hours, and the boundary deviation is ≤0.3 mm, which significantly improves the efficiency and appearance quality of painting B737 radomes.

[0039] In this specific embodiment, the width of the clearance groove 12 is 0.5mm to 1mm larger than the width of the conductive strip, and the groove depth is equal to the height of the conductive strip protruding from the surface of the radome, ensuring zero-gap positioning after fitting.

[0040] In this specific embodiment, a 0.2mm thick silicone rubber buffer layer is attached to the lower surface of the shielding flange to prevent damage to the radome paint layer.

[0041] In this specific embodiment, the handle is made of carbon fiber tubing with an anti-slip rubber sleeve on the surface, and the overall weight is no more than 5% of the total mass of the tooling.

[0042] In this specific embodiment, the annular outer shell 10 has several weight-reducing holes between two adjacent clearance grooves 12. The weight-reducing holes are elliptical, with their major axis along the generatrix of the outer shell. The edges of the holes are covered with aluminum-nickel alloy protective rings to prevent the composite material from delaminating.

[0043] In this specific embodiment, the rear end face of the annular shell 10 is engraved with angle scale lines, which are used to check whether the relative angle between the tooling and the radome meets the process requirements.

[0044] The working principle of this utility model is based on a triple collaborative mechanism of "self-adhesion of shape, self-guidance of conductive strip, and self-masking of edge," which enables rapid positioning and one-time masking of the B737 radome before painting. The specific process is as follows:

[0045] Self-adhesive positioning

[0046] The inner surface of the annular outer shell 10 is manufactured in 1:1 conformation to the theoretical aerodynamic shape of the outer surface 100 of the radome, and the surface geometry of the two is completely consistent. When the operator holds the handle and pushes the fixture along the axis of the radome, the inner curved surface of the outer shell and the outer surface of the radome form a stress-free fit over the entire area; since the normal gap at each point of the curved surface is ≤0.1 mm, the fixture can achieve preliminary self-alignment in the radial and angular directions without additional clamping force, eliminating the reference drift caused by traditional string-based point finding.

[0047] Conductive strip self-guiding precision positioning

[0048] During insertion, the six raised conductive strips on the radome automatically slide into the six circumferentially distributed conductive strip clearance grooves 12. The width of the clearance grooves 12 is only 0.5mm to 1mm larger than the conductive strips, and the groove depth is equal to the protruding height of the conductive strips, forming a precise "guide rail-slider" fit.

[0049] Circumferential: Six conductive strips simultaneously enter the corresponding slots, generating six sets of tangential limits, instantly completing the unique angular alignment to prevent the tooling from rotating around the axis;

[0050] Axial: The bottom of the groove and the top of the conductive strip make zero-gap contact, forming a rigid limit. The tooling is pushed in to the bottom and reaches the theoretical axial position without the need for manual measurement.

[0051] Thus, the tooling can simultaneously achieve high-precision positioning in three directions—circumferential, axial, and angular—with a positioning repeatability of ≤0.2 mm in a single push-in action.

[0052] The flanging self-masking forms the paint separation line.

[0053] After positioning, the front masking flange naturally covers the theoretical boundary of the radome's painting ring 102. The outer edge contour of the flange coincides 1:1 with the painting boundary, and the 0.2mm thick silicone rubber buffer layer on its lower surface undergoes uniform elastic deformation under compression, tightly adhering to the curved surface of the radome. At this point, the operator only needs to press the masking tape along the outer edge of the flange once. The tape adheres tightly to the curved surface under the elastic compensation of the rubber layer, forming a neat, continuous, and wrinkle-free paint separation line, completely preventing paint from penetrating into non-painted areas. After the painting operation is completed, pulling the handle in the opposite direction allows the fixture to slide out along the conductive strip, and the masking tape is simultaneously removed along with the flange, achieving a rapid integrated operation of "positioning-masking-demolding".

[0054] Through the continuous actions of "shape fitting - conductive strip guidance - edge covering", this utility model transforms the traditional discrete process of "multi-point measurement and repeated tape application" into a continuous operation of "fitting in and positioning, pressing and covering", eliminating errors caused by human point finding and line marking, and significantly improving the accuracy of paint boundary and production efficiency.

[0055] By adopting the above-disclosed technical solution of this utility model, the following beneficial effects are obtained: rapid positioning: the inner surface of the annular shell is perfectly matched with the outer shape of the radar dome, and the six clearance grooves are directly fitted into the conductive strip. Circumferential and axial zero-gap positioning can be achieved without additional measurement, eliminating the traditional wire-pulling point-finding process.

[0056] One-time masking: The front masking flange coincides with the theoretical boundary of the ring tape, allowing the masking tape to be applied in one go, forming a neat paint separation line and avoiding multiple rework.

[0057] Lightweight and high strength: The composite material layer is only 1.5mm to 3mm thick, lightweight, resistant to paint mist corrosion, and does not deform over a long period of time; the addition of handles makes it easy to move and reduces labor intensity.

[0058] Improve quality consistency: Eliminate errors caused by human error in finding points and marking lines, ensure accurate paint boundaries for each painting session, achieve standardized batch operations, and significantly improve painting efficiency and appearance quality.

[0059] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A ring-shaped composite tooling for assisting in the positioning of B737 radome painting, characterized in that, include: An integrally solidified annular shell (10) is formed, wherein the inner surface of the annular shell (10) is completely fitted with the theoretical aerodynamic shape of the outer surface (100) of the B737 radome. Six conductive strip clearance grooves (12) are equally spaced around the annular outer shell (10). The clearance grooves (12) extend from the front end face of the outer shell to the rear end face and are used to fit one-to-one with the six conductive strips on the radar dome, so as to realize the rapid positioning of the tooling relative to the radar dome in the circumferential and axial directions. The front end face of the annular shell (10) is provided with a shielding flange extending radially outward. The shielding flange coincides with the theoretical boundary of the radar dome to be painted ring (102), which is used to press the shielding tape on at one time and form a neat paint separation line. The annular outer shell (10) is composed of a composite material layer made of multiple layers of glass fiber cloth and epoxy resin glue cured by heating, with a wall thickness of 1.5mm to 3mm; Two pairs of handles are symmetrically arranged on the outer surface of the annular shell (10). The handles are fixed to the shell (10) by countersunk rivets, which facilitates the operator to move and place them.

2. The annular composite tooling according to claim 1, characterized in that: The width of the clearance groove (12) is 0.5mm to 1mm larger than the width of the conductive strip, and the groove depth is equal to the height of the conductive strip protruding from the surface of the radar dome, ensuring zero-gap positioning after fitting.

3. The annular composite tooling according to claim 2, characterized in that: The lower surface of the shielding flange is covered with a 0.2mm thick silicone rubber buffer layer to prevent damage to the radar dome paint layer.

4. The annular composite tooling according to claim 1, characterized in that: The handle is made of carbon fiber tubing with a non-slip rubber sleeve on the surface, and its overall weight is no more than 5% of the total weight of the tooling.

5. The annular composite tooling according to claim 1, characterized in that: The annular outer shell (10) has several weight-reducing holes between two adjacent clearance grooves (12). The weight-reducing holes are elliptical, with their major axis along the generatrix of the outer shell. The edges of the holes are covered with aluminum-nickel alloy protective rings to prevent the composite material from delaminating.

6. The annular composite tooling according to any one of claims 1-5, characterized in that: The rear end face of the annular shell (10) is engraved with angle scale lines, which are used to check whether the relative angle between the tooling and the radome meets the process requirements.

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