A multi-aperture non-symmetrical quadrangular pyramid load mask assembling tool and assembling method

Abstract

A multi-aperture asymmetric four-prism load mask assembly tool and assembly method, relating to the field of thin-walled carbon fiber composite material bonding assembly, including base, guide pipe, support column, reference plate, pressure nut and diaphragm positioning device, the support column and the guide pipe are connected to the base, the top end of the support column is used for the installation of the reference plate, and the guide pipe guides the diaphragm positioning device; the diaphragm positioning device includes a profile, a support flange and a lifting rod, the profile cooperates with the inner profile of the body, the outer surface of the profile is connected with the support flange, the support flange is used for placing the diaphragm, the lifting rod is inserted into the middle position of the profile, the inner wall of the profile is connected with the lifting rod, and the bottom end of the lifting rod is inserted into the guide pipe; the reference plate is provided with a through hole matched with the lifting rod, and the pressure nut is threadedly connected to the end of the lifting rod. The problems of long assembly process period, poor bonding effect and machining difficulty of the existing multi-aperture multi-constraint strong coupling structure asymmetric four-prism load mask structure assembly process are solved.

Description

Technical Field

[0001] This invention belongs to the field of adhesive bonding and assembly of thin-walled carbon fiber composite materials and is applied to adhesive bonding and assembly of variable cross-section conical composite material structures in spacecraft. Background Technology

[0002] As a crucial component of satellite imaging systems, load shields reduce stray light directly entering the space remote sensor from outside the field of view and limit sunlight incident at the stray light suppression angle from directly hitting the primary mirror, thereby improving image quality. The multi-aperture, multi-constraint, strongly coupled asymmetric quadrangular pyramid load shield of this invention achieves stray light suppression through optical design. Its body and apertures are constructed from high-modulus carbon fiber thin-walled composite materials, such as... Figure 1 As shown.

[0003] The multi-aperture, multi-constraint, strongly coupled asymmetric quadrangular pyramid load-bearing light shield consists of one main body and 15 apertures, such as... Figure 1 As shown, the main body is made of CCM40J / epoxy carbon fiber composite material. The working surface of the inner surface of the main body is a variable thickness asymmetric quadrangular pyramid box. The inner surfaces of the four sides of the box are flat. The thickness of the sides is divided into a uniform thickness of 1mm from the top to the root and a uniformly variable thickness of 1-2.8mm. The outer wall of the small end of the main body is connected to a connecting flange with a connecting hole. The flange is 4mm thick and the opening size of the small end is only 82.4mm x 67.4mm. The first reference plane and the second reference plane are defined through the center of the connecting flange and perpendicular to the surface of the connecting flange. The first reference plane and the second reference plane are perpendicular to each other. The quadrangular pyramid box-shaped main body has two sets of opposing surfaces. One set of opposing surfaces is symmetrical about the first reference plane, and the other set of opposing surfaces is located on both sides of the second reference plane, but is an asymmetric plane. The aperture is constructed from CCM40J fabric / epoxy carbon fiber composite material, with a uniform "L"-shaped cross-section of 0.8mm wall thickness. The aperture comprises a first side plate and a second side plate forming the "L" shape. The outer plane of the second side plate is bonded to the inner surface of the main body. The inner end of the first side plate is chamfered, forming an edge line. Theoretically, the edge lines of the 15 apertures on the same side should be coplanar. The final accuracy of the load-bearing light shield depends on the relative positions of the 15 apertures and the inner tangent plane of the free edge.

[0004] Currently, similar multi-aperture, multi-constraint, strongly coupled asymmetric quadrangular pyramid load-bearing light shield structures are typically manufactured by molding individual parts with allowances, bonding the apertures to the body piece by piece in stages, applying positive pressure to the bonding surfaces of the apertures and body to cure the bond, and finally assembling and machining to ensure precision. In practice, this method has been found to have the following drawbacks and shortcomings:

[0005] (1) Due to the curing time limitation of the adhesive, the step-by-step bonding process of the aperture piece extends the product production cycle and results in a large number of tooling, which increases management costs.

[0006] (2) Since both the body and the aperture are closed high-modulus composite material structures, the step-by-step bonding process of the aperture and the body will introduce large internal stress by applying positive pressure to the bonding surface of the aperture and the body. The bonding gap cannot be effectively controlled, and local underpressure is likely to occur, resulting in poor bonding effect.

[0007] (3) Due to the thin and narrow walls of the aperture, it is difficult to install and the tool is easily deflected during the machining process, which reduces the machining accuracy. Moreover, the body is an asymmetrical quadrangular pyramid with a deep inner cavity and small space. The tool stroke is insufficient during the combined machining process, making it difficult to complete the machining of all apertures. Summary of the Invention

[0008] The technical problem solved by this application is to overcome the shortcomings of the prior art and provide an assembly fixture and assembly method for a multi-aperture asymmetric quadrangular pyramid load-bearing light shield, which solves the problems of long assembly cycle, poor bonding effect and difficult machining of the existing multi-aperture multi-constraint strong coupling structure asymmetric quadrangular pyramid load-bearing light shield.

[0009] The technical solution provided in this application is as follows:

[0010] Firstly, a multi-aperture asymmetric quadrangular pyramid load-bearing light shield assembly fixture is provided for assembling the apertures and the main body to obtain the light shield. The fixture includes a base, guide tube, support columns, a reference plate, a pressure nut, and an aperture positioning device. The bottom ends of multiple support columns and the guide tube are fixedly connected to the base. The top ends of the support columns are used for mounting the reference plate. The guide tube guides the movement of the aperture positioning device. The aperture positioning device includes a profile, support flanges, and a lifting rod. The profile is a quadrangular pyramid shape that matches the inner profile of the main body. Multiple support flanges are fixedly connected to the outer surface of the profile, and these flanges are used to place the apertures. The lifting rod is inserted into the middle position of the profile. The inner wall of the profile is fixedly connected to the lifting rod via multiple connecting rods. The bottom end of the lifting rod is inserted into the guide tube. The reference plate has a through hole that matches the lifting rod. The pressure nut is threaded to the end of the lifting rod that passes through the through hole. An anti-rotation structure is provided between the lifting rod and the guide tube, so that the lifting rod only has the freedom to move along the axis of the guide tube.

[0011] A boss is provided on one side surface of the reference plate, and a fixing hole is provided at the position of the boss. The connecting flange at the small end of the body fits into the surface of the boss. The body is fixed to the reference plate by bolts passing through the connecting flange and the fixing hole. The coplanarity of the boss surface is not greater than 0.05mm.

[0012] The anti-rotation structure includes an anti-rotation pin, a guide tube with a vertical elongated groove, a lifting rod with a horizontal anti-rotation hole, and the anti-rotation pin passing through the anti-rotation hole and exiting the guide tube from the elongated groove.

[0013] A limit ring is fixedly connected to the outer wall of the lifting rod, and the outer diameter of the limit ring is larger than the inner diameter of the guide tube.

[0014] Secondly, a method for assembling a multi-aperture, multi-constraint, strongly coupled asymmetric quadrangular pyramid load-bearing light shield is provided, comprising assembling using any of the aforementioned multi-aperture, asymmetric quadrangular pyramid load-bearing light shield assembly fixtures, including:

[0015] S1: Insert the lifting rod into the guide tube and install the aperture on the corresponding support flange;

[0016] S2: Grind the adhesive surfaces of the main body and the aperture, apply adhesive to the adhesive surfaces of the main body and the aperture, install the reference plate with the main body on it from top to bottom onto the top of the support column, and at the same time make the lifting rod pass through the through hole. By threading the pressure nut to the top of the lifting rod and tightening it, the lifting rod moves upward along the Z axis by a certain amount Δz.

[0017] The method for determining the predetermined quantity Δz includes: based on the internal cavity size of the main body and the external size of the aperture, the position of the main body is completely constrained by the reference plate during the assembly process. When the aperture is fully installed on the support flange and the limiting ring is attached to the upper end of the guide tube, one inner surface of the main body is the first inner surface. The actual gap Δactual between the first inner surface of the main body and the corresponding surface of the aperture is calculated. There is an optimal bonding gap Δoptimal during the bonding process. The gap adjustment amount between the aperture and the main body is Δadjustment = Δactual - Δoptimal. The movement amount of the aperture along the Z-axis is Δz = Δadjustment / sinα, where α is the angle between the first inner surface of the main body and the Z-axis, and the Z-axis is the axial direction of the guide tube.

[0018] The trial assembly steps between S1 and S2 include: inspecting the sides of the aperture, marking local low and high points, using carbon fiber or carbon cloth to level the low points, marking the high points, and then installing the reference plate with the main body on it from top to bottom onto the top of the support column, while simultaneously allowing the lifting rod to pass through the through hole. If the reference plate and the main body are obstructed during the installation process, remove the reference plate and the main body, grind the sides of the aperture at the local high points until there is no gap between the reference plate and the mounting surface of the support column, then remove the reference plate and the main body, and apply a protective film to the non-adhesive areas of the inner wall of the main body.

[0019] In summary, this application includes at least the following beneficial technical effects:

[0020] This invention solves the problems of long assembly cycles, poor bonding effects, and difficult machining in multi-aperture, multi-constraint, strongly coupled asymmetric pyramidal load-bearing light shield structures with similar configurations. It effectively reduces the number of bonding fixtures and bonding operations, shortening the product bonding cycle. Simultaneously, the fixtures ensure the final product accuracy, eliminating the need for component assembly and machining. Load-bearing light shields assembled using this multi-aperture asymmetric pyramidal load-bearing light shield assembly fixture and method have been tested and found to have good bonding performance and dimensional accuracy that meets design and usage requirements. Attached Figure Description

[0021] Figure 1 A schematic diagram of an asymmetric quadrangular pyramidal load-bearing light shield structure;

[0022] Figure 2 This is a structural diagram of the assembly tooling;

[0023] Figure 3 This is a schematic diagram of the assembly structure of the aperture and the supporting flange in this application.

[0024] Explanation of icon numbers: 01 - Main body; 02 - Aperture;

[0025] 1-1. Base; 1-2. Guide tube; 2. Support column; 3. Reference plate; 4. Pressure nut; 5-1. Profile; 5-2. Support flange; 5-3. Limiting ring; 6. Anti-rotation pin; α- Angle between the inner surface of the body and the Z-axis. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments disclosed in the present invention will be described in further detail below with reference to the accompanying drawings.

[0027] This application discloses an assembly fixture and assembly method for a multi-aperture asymmetric quadrangular pyramid load-bearing light shield, such as... Figure 1 The diagram shows an asymmetric quadrangular pyramid load-bearing light shield structure, which mainly consists of the main body 01, aperture 02 (15 pieces), and other parts.

[0028] like Figure 2 The diagram shows the assembly tooling structure, which mainly consists of a base 1-1, a guide tube 1-2, a support column 2, a reference plate 3, a pressure nut 4, and an aperture positioning device.

[0029] The bottom ends of multiple support columns 2 are fixedly connected to the base 1-1, and the top ends of the support columns 2 are used for the installation of the reference plate 3. A boss is provided on one side surface of the reference plate 3, and a fixing hole is opened at the position of the boss. The connecting flange fits into the surface of the boss, and the body is fixed to the reference plate 3 by bolts passing through the connecting hole and the fixing hole. In order to ensure the positional installation accuracy between the body and the reference plate 3, the surface of the boss is machined with high precision, and the coplanarity does not exceed 0.05mm. The setting of the boss reduces the machining area of ​​the high-precision surface. The guide tube 1-2 is fixedly connected to the base 1-1 and is set vertically.

[0030] like Figure 2 and Figure 3 As shown, the aperture positioning device includes a profile 5-1, a support flange 5-2, a lifting rod, and a limiting ring 5-3. The profile 5-1 is a four-sided pyramid shape that matches the inner profile of the body 01, with the smaller end of the profile 5-1 at the top and the larger end at the bottom. Multiple support flanges 5-2 are fixedly connected to the outer surface of the profile 5-1. The support flanges 5-2 are used to place the aperture 02. A first side plate is placed on the upper surface of the support flange 5-2, and the inner wall of the second side plate matches the outer edge of the support flange 5-2. The accuracy requirement for the support flange 5-2 is that the aperture will not move after being placed on the support flange 5-2, and it should be relatively easy to detach from the support flange 5-2. The lifting rod is inserted into the middle position of the profile 5-1, and the inner wall of the profile 5-1 is fixedly connected to the lifting rod by multiple connecting rods. The limiting ring 5-3 is fixedly connected to the outer wall of the lifting rod. The bottom end of the lifting rod is inserted into the guide tube 1-2, and the limiting ring 5-3 is used to limit the maximum depth of the lifting rod inserted into the guide tube 1-2, thereby positioning the initial position of the aperture.

[0031] The reference plate 3 has a through hole that mates with the lifting rod, so that after the reference plate 3 is fixed to the top of the support column 2, the lifting rod can pass through the through hole. The end of the lifting rod that passes through the reference plate 3 is threadedly connected to a pressure nut 4. The guide tube 1-2 has a vertical elongated groove, and the lifting rod has a horizontal anti-rotation hole. The anti-rotation pin 6 passes into the anti-rotation hole and through the elongated groove. This allows the anti-rotation pin 6 to restrict the rotation of the lifting rod when the pressure nut 4 is rotated, thus restricting the lifting rod's rotation and giving it only a vertical (Z-axis) degree of freedom.

[0032] The reference plate 3 provides an overall reference. The reference plate 3 is connected to the base 1-1 via the support column 2. The aperture positioning device achieves single-degree-of-freedom movement along the Z-axis via the guide tube 1-2 and the anti-rotation pin 6. The main body 01 is mounted on the upper reference plate. The aperture positioning device can simultaneously support and install 15 apertures 02. The entire device moves along the Z-axis within the Z-direction position tolerance range of the aperture 02 via the pressure nut 4. This ensures the Z-direction position of the aperture 02 and controls the bonding gap between the aperture 02 and the main body 01 during the bonding process, ultimately guaranteeing product accuracy without the need for assembly processing.

[0033] The vertically upward direction is the positive Z-axis. After the main body 01 is fixed on the reference plate 3 and the reference plate 3 is fixed on the support column 2, when the limiting ring 5-3 contacts the top of the guide tube 1-2, the relative position between the aperture 02 and the main body 1 is set as the initial installation position. The initial position is the height of the upper surface of the aperture positioning device support flange from the boss surface on the reference plate 3, which is the nominal height plus the upper limit of the design tolerance.

[0034] The assembly of the load-bearing light shield body and the aperture includes the following steps:

[0035] (1) Preliminary preparation: Receive the qualified tooling and the processed body 01 and aperture 02, remove the pressure nut 4 and the reference plate 3, reassemble and measure the tooling dimensions. After meeting the requirements, carry out subsequent work, measure and record the inner cavity dimensions of the body 01 and the outer dimensions of the aperture 02. One inner surface of the body 01 is the first inner surface. Calculate the actual gap Δreal between the first inner surface of the body 01 and the corresponding surface of the aperture 02. There is also an optimal bonding gap Δoptimal in the bonding process. Therefore, the gap adjustment amount Δadjustment required by the product can be obtained as Δreal - Δoptimal. Based on the geometric dimension relationship, determine the amount of movement Δz of the aperture 02 along the Z-axis as Δadjustment / sinα, where α is the angle between the first inner surface of the body and the Z-axis, and the Z-axis is the axial direction of the guide tube 1-2.

[0036] (2) Trial assembly of aperture and body: Insert the lifting rod of the aperture positioning device into the guide tube 1-2, fit the 15 apertures 02 with the inner contour and the profile 5-1, and install them on the 15 layers of support flange 5-1 respectively. Use a high-flatness inspection ruler or inspection plate to inspect the four sides of the aperture 02, mark the local low points and high points, use glued carbon wire or carbon cloth to level the low points, and mark the high points. Then install the reference plate 3 and the body 01 as a whole onto the support column 2 with pin screws. During the installation process, slowly install downwards from +Z to -Z. If the reference plate 3 and the body 01 are obstructed during the installation process, remove the reference plate 3 and the body 01 as a whole, use fine sandpaper to polish the side of the aperture at the local high point until there is no gap between the mounting surface of the reference plate 3 and the support column 2. At this time, the reference plate 3 and the body 01 as a whole can be removed, and Teflon is applied to the non-glued area of ​​the inner wall of the body 01 for protection.

[0037] (3) Bonding of aperture and body: Use fine sandpaper to lightly sand the bonding surfaces of the body and 15 apertures, then apply adhesive. According to the trial assembly sequence in (2), install aperture 02 and body 01 onto the assembly fixture. By tightening the pressure nut 4, the aperture positioning device moves upward along the Z-axis by a certain amount (i.e., Δz) to ensure a reasonable bonding gap for the product. After final curing, clean up any excess material and accurately measure the final dimensions of the product.

[0038] The contents not described in detail in this application specification are common knowledge to those skilled in the art.

[0039] The present application has been described in detail above with reference to specific embodiments and exemplary examples; however, these descriptions should not be construed as limiting the present application. Those skilled in the art will understand that various equivalent substitutions, modifications, or improvements can be made to the technical solutions and implementation methods of the present application without departing from the spirit and scope of the present application, and all such modifications and improvements fall within the scope of the present application. The scope of protection of the present application is determined by the appended claims.

Claims

1. A multi-aperture asymmetric tetrahedral load-bearing light shield assembly fixture, used to assemble an aperture (02) and a body (01) to obtain a light shield, characterized in that: It includes a base (1-1), a guide tube (1-2), a support column (2), a reference plate (3), a pressure nut (4), and an aperture positioning device. The bottom ends of multiple support columns (2) and the guide tube (1-2) are fixedly connected to the base (1-1). The top ends of the support columns (2) are used for the installation of the reference plate (3), and the guide tube (1-2) is used to guide the movement of the aperture positioning device. The aperture positioning device includes a profile (5-1), a support flange (5-2), and a lifting rod. The profile (5-1) is a four-sided pyramid shape that matches the inner profile of the body (01). Multiple support flanges (5-2) are fixedly connected to the outer surface of the profile (5-1). The support flanges (5-2) are used to place the aperture (02). The lifting rod is inserted into the middle position of the profile (5-1). The inner wall of the profile (5-1) is fixedly connected to the lifting rod through multiple connecting rods. The bottom end of the lifting rod is inserted into the guide tube (1-2). The reference plate (3) has a through hole that matches the lifting rod. The pressure nut (4) is threaded to the end of the lifting rod that passes through the through hole. An anti-rotation structure is provided between the lifting rod and the guide tube (1-2) so that the lifting rod has only the freedom to move along the axis of the guide tube (1-2).

2. The assembly fixture according to claim 1, characterized in that: The reference plate (3) has a boss on one side surface, and a fixing hole is provided at the boss position. The connecting flange at the small end of the body (01) fits against the boss surface. The body (01) is fixed on the reference plate (3) by bolts passing through the connecting flange and the fixing hole. The coplanarity of the boss surface is not greater than 0.05mm.

3. The assembly fixture according to claim 1, characterized in that: The anti-rotation structure includes an anti-rotation pin (6), a guide tube (1-2) with a vertical elongated groove, a lifting rod with a horizontal anti-rotation hole, and the anti-rotation pin (6) passing through the anti-rotation hole and exiting the guide tube (1-2) through the elongated groove.

4. The assembly fixture according to claim 1, characterized in that: A limiting ring (5-3) is fixedly connected to the outer wall of the lifting rod. The outer diameter of the limiting ring (5-3) is larger than the inner diameter of the guide tube (1-2).

5. A method for assembling an asymmetric quadrangular pyramidal load-bearing light shield with a multi-aperture, multi-constraint, strongly coupled structure, characterized in that... Assembly is performed using the multi-aperture asymmetric tetrahedral load-bearing light shield assembly fixture as described in any one of claims 1-4, including: S1: Insert the lifting rod into the guide tube (1-2) and install the aperture (02) on the corresponding support flange (5-2); S2: Grind the adhesive surfaces of the body (01) and the aperture (02), apply adhesive to the adhesive surfaces of the body (01) and the aperture (02), install the reference plate (3) with the body (01) on it from top to bottom onto the top of the support column (2), and at the same time make the lifting rod pass through the through hole. By threading the pressure nut (4) to the top of the lifting rod and tightening it, the lifting rod moves upward along the Z axis by a certain amount Δz.

6. The assembly method according to claim 5, characterized in that: The method for determining the predetermined quantity Δz includes: based on the inner cavity size of the body (01) and the outer dimensions of the aperture (02), the position of the body (01) during the assembly process is completely constrained by the reference plate. When the aperture is fully installed on the support flange (5-1) and the limiting ring (5-3) is attached to the upper end of the guide tube (1-2), one inner surface of the body (01) is the first inner surface. The actual gap Δreal between the first inner surface of the body (01) and the corresponding surface of the aperture (02) is calculated. There is an optimal bonding gap Δoptimum during the bonding process. The gap adjustment amount between the aperture (02) and the body (01) is Δadjustment = Δreal - Δoptimum. The movement amount of the aperture (02) along the Z-axis is Δz = Δadjustment / sinα, where α is the angle between the first inner surface of the body and the Z-axis, and the Z-axis is the axial direction of the guide tube (1-2).

7. The assembly method according to claim 5, characterized in that, The trial assembly steps between S1 and S2 include: inspecting the sides of the aperture (02), marking the local low points and high points, using carbon fiber or carbon cloth to level the low points, marking the high points, and then installing the reference plate (3) with the body (01) installed on it from top to bottom onto the top of the support column (2), while making the lifting rod pass through the through hole. If the reference plate (3) and the body (01) are obstructed during the installation process, the reference plate (3) and the body (01) are removed as a whole, and the sides of the aperture at the local high points are polished until there is no gap between the mounting surface of the reference plate (3) and the support column (2). At this time, the reference plate (3) and the body (01) are removed as a whole, and a protective film is applied to the non-adhesive area of ​​the inner wall of the body (01).

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