Method for installing explosion suppression foam in wing integral fuel tank

Abstract

The invention discloses a method for installing explosion suppression foam in a wing integral fuel tank. The method comprises the steps that the explosion suppression foam is designed and manufactured; pre-splicing inspection is carried out before the explosion suppression foam is installed on the wing fuel tank; the foam installation sequence is determined, the front beam, the rear beam and the ribs of the wing serve as the assembly positioning reference, explosion suppression foam is installed through a maintenance covering cap located below the wing and between the front beam and the rear beam, and the installation path is that explosion suppression foam below a pipeline and the bottommost layer of the rear beam is installed; sequentially installing explosion suppression foams in the rest space of the rear beam from bottom to top and from inside to outside; installing foams on the front beam as a reference; and finally installing foams on the maintenance covering cap from top to bottom by taking the upper wall plate as a reference. And the explosion suppression foam is dismounted according to the sequence opposite to the mounting sequence, and whether foam mounting is reasonable or not is verified. The explosion suppression foam installation reliability and the product quality are improved, and technical support is provided for follow-up explosion suppression foam installation control.

Description

Technical Field

[0001] The invention belongs to the field of aircraft assembly and relates to a method for installing explosion-suppressing foam in an integral oil tank of a wing. Background Art

[0002] Explosion suppression foam is a reticular polymer polyurethane material that can effectively suppress the occurrence of explosions. Due to the complex structure of the aircraft wing tank, different internal layouts, and many required installation locations, installation control is difficult. It is necessary to carry out process design of the installation sequence and path of the explosion suppression foam to solve the problem of installation coordination, so as to ensure that there is enough space around the fuel pump, one-way valve and other components after the explosion suppression foam is installed. Summary of the invention

[0003] The invention provides a method for installing explosion suppression foam in an integral wing oil tank, which solves the problems existing in the installation in the existing wing oil tank.

[0004] In order to achieve the above tasks, the present invention adopts the following technical solutions:

[0005] A method for installing explosion suppression foam in an integral fuel tank of a wing comprises the following steps:

[0006] According to the internal space structure of the wing fuel tank, the space structure is segmented according to the rib position, and explosion suppression foam adapted to each rib position structure is manufactured; a group of explosion suppression foam is arranged in each rib position, and the explosion suppression foam should fill the remaining space except for the lines and pipelines;

[0007] Before installing the explosion suppression foam to the wing fuel tank, first combine the explosion suppression foam to be installed in each group of rib positions according to the spatial structure of the rib positions on the ground, and check the installation quantity of the foam and the coordination between the foams;

[0008] Determine the order of foam installation, take the front and rear beams and ribs of the wing as the assembly positioning reference, and install the explosion suppression foam through the maintenance cover located under the wing between the front and rear beams. The installation path is: install the explosion suppression foam under the pipeline and the bottom layer of the rear beam → take the rear beam as the reference, and install the explosion suppression foam in the remaining space of the rear beam from bottom to top and from inside to outside → then use the front beam as the reference to install the foam in the front beam → finally use the upper wall panel as the reference to install the foam in the maintenance cover from top to bottom;

[0009] The explosion suppression foam shall be removed in the reverse order of installation to verify whether the foam installation is reasonable. During the removal process, if there is interference between the explosion suppression foams, or if the gap or step difference between the explosion suppression foam and the pipeline, wall plate, or beam exceeds the design requirements, or it is difficult to remove, the installation is considered reasonable.

[0010] After reinstalling the explosion suppression foam, check again whether the gap and step difference between the explosion suppression foam and the finished product meet the design requirements. If not, adjust the gap between the explosion suppression foam to ensure that the installation gap meets the design requirements.

[0011] Furthermore, the gap between adjacent explosion-suppression foam joint surfaces is no more than 5-10mm; the step difference between the explosion-suppression foams cannot exceed 10mm; there is at least 50mm gap between the explosion-suppression foam and the lines and pipelines, and there is more than 10mm gap between the explosion-suppression foam and the wing wall panels and beams.

[0012] Furthermore, the maximum outer diameter of each piece of explosion suppression foam cannot be greater than the diameter of the fuel tank maintenance cover on the wing.

[0013] Furthermore, for the finished product in the wing fuel tank, multiple pieces of explosion-suppressing foam should be arranged and wrapped in a splicing manner.

[0014] Furthermore, for the finished product in the wing fuel tank, a finished product protective cover is generated by 3D printing, and the explosion-suppressing foam around the finished product should be compatible with the shape of the finished product protective cover, and the finished product protective cover should be wrapped in a spliced ​​form.

[0015] Furthermore, the finished product includes a fuel pump and a one-way valve.

[0016] Furthermore, the explosion suppression foams are connected by face-to-face butting or plug-in connection.

[0017] Furthermore, if there is a lack of coordination between the surfaces of the explosion suppression foam, the explosion suppression foam needs to be trimmed.

[0018] Furthermore, if it is verified that the foam is not installed properly, the installation sequence should be adjusted and then reinstalled.

[0019] Furthermore, the gaps between the explosion suppression foams are adjusted using pads and auxiliary pads.

[0020] Compared with the prior art, the present invention has the following technical features:

[0021] The present invention provides a method for installing explosion-suppressing foam in an integral fuel tank of a wing. Through the process design of the method for installing explosion-suppressing foam in fuel tanks with different structures, the coordination of the installation of the explosion-suppressing foam, a conduit and a finished product is achieved, and sufficient space around the explosion-suppressing foam and components such as a fuel pump, a one-way valve and the like after installation is ensured, so that the explosion-suppressing foam of the aircraft fuel tank that meets the design requirements is installed, and the functional requirements of the explosion-suppressing foam are achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the explosion suppression foam installation; the left side is the finished product, and the right side is the explosion suppression foam designed based on the protective cover of the finished product. DETAILED DESCRIPTION

[0023] The explosion suppression foam is a specially modified interpenetrating network copolymer material of polyurethane and polyurea. It is filled in the internal parts of each integral fuel tank of the wing. During installation, the explosion suppression foam must ensure that there is enough space around the fuel pump, one-way valve and other components. The installation accuracy and gap of each explosion suppression foam are difficult to control during assembly. The following steps are used in the assembly process:

[0024] like Figure 1 As shown, the present application provides a method for installing explosion suppression foam in an integral fuel tank of a wing, comprising the following steps:

[0025] According to the internal space structure of the wing fuel tank, the space structure is segmented according to the rib position, and explosion suppression foams adapted to each rib position structure are made; a group of explosion suppression foams is set in each rib position, and the explosion suppression foams should fill the remaining space except for the lines and pipelines, and the gap between adjacent explosion suppression foam joint surfaces should not be greater than 5-10mm; there should be no obvious step difference between the explosion suppression foams, that is, the step difference should not exceed 10mm; there should be at least 50mm gap between the explosion suppression foam and the lines and pipelines, and the maximum outer diameter of each piece of explosion suppression foam should not be greater than the diameter of the fuel tank maintenance cover on the wing; there should be a gap of more than 10mm between the explosion suppression foam and the wing wall panels and beams; for the finished products in the wing fuel tank, such as fuel pumps and one-way valves, multiple pieces of explosion suppression foams should be set and wrapped in a splicing manner; among them, the explosion suppression foams are connected by face-to-face butt connection or plug-in connection;

[0026] For the finished products in the wing fuel tank, the finished product protective cover is generated by 3D printing. The explosion suppression foam around the finished product should be compatible with the shape of the finished product protective cover. The finished product protective cover is wrapped in a spliced ​​form to solve the gap coordination problem between the explosion suppression foam and the finished fuel system product.

[0027] Before installing the explosion suppression foam to the wing fuel tank, first combine the explosion suppression foam to be installed in each group of rib positions according to the spatial structure of the rib positions on the ground, and check the installation quantity of the foam and the coordination between the foams; if there is an incoordination between the surfaces of the explosion suppression foam, such as the surfaces cannot be properly connected, or the shape does not meet the requirements, etc., the explosion suppression foam needs to be trimmed;

[0028] Determine the order of foam installation, take the front and rear beams and ribs of the wing as the assembly positioning reference, and install the explosion suppression foam through the maintenance cover located under the wing between the front and rear beams. The installation path is: install the explosion suppression foam at the bottom of the rear beam below the pipeline and with more finished products → use the rear beam as the reference, and install the explosion suppression foam in the remaining space of the rear beam from bottom to top and from inside to outside → then use the front beam as the reference to install the foam at the front beam → finally use the upper wall panel as the reference to install the foam at the maintenance cover from top to bottom;

[0029] The explosion suppression foam shall be removed in the reverse order of installation to verify whether the foam installation is reasonable. During the removal process, if there is interference between the explosion suppression foams, or if the gap or step difference between the explosion suppression foam and the pipeline, wall plate, beam exceeds the design requirements or is difficult to remove by checking with tools such as steel rulers, the installation is considered reasonable. Otherwise, the installation sequence should be adjusted and reinstalled.

[0030] After reinstalling the explosion-suppressing foam, check again whether the gap and step difference between the explosion-suppressing foam and the finished product meet the design requirements. If not, use pads, auxiliary pads, etc. to adjust the gap between the explosion-suppressing foam to ensure that the installation gap meets the design requirements.

[0031] The present invention solves the installation incoordination between foams by determining the installation sequence, and realizes the control of the foam installation position. By determining the installation path, the finished product protective cover is added to solve the gap coordination between the explosion suppression foam and the finished fuel system product, improve the reliability of the explosion suppression foam installation and product quality, and provide technical support for the subsequent installation control of the explosion suppression foam.

Claims

1. A method for installing explosion suppression foam in an integral fuel tank of a wing, characterized in that: The following steps are involved: According to the internal space structure of the wing fuel tank, the space structure is segmented according to the rib position, and explosion suppression foam adapted to each rib position structure is manufactured; a group of explosion suppression foam is arranged in each rib position, and the explosion suppression foam should fill the remaining space except for the lines and pipelines; Before installing the explosion suppression foam to the wing fuel tank, first combine the explosion suppression foam to be installed in each group of rib positions according to the spatial structure of the rib positions on the ground, and check the installation quantity of the foam and the coordination between the foams; Determine the order of foam installation, take the front and rear beams and ribs of the wing as the assembly positioning reference, and install the explosion suppression foam through the maintenance cover located under the wing between the front and rear beams. The installation path is: install the explosion suppression foam under the pipeline and the bottom layer of the rear beam → take the rear beam as the reference, and install the explosion suppression foam in the remaining space of the rear beam from bottom to top and from inside to outside → then use the front beam as the reference to install the foam in the front beam → finally use the upper wall panel as the reference to install the foam in the maintenance cover from top to bottom; The explosion suppression foam shall be removed in the reverse order of installation to verify whether the foam installation is reasonable. During the removal process, if there is interference between the explosion suppression foams, or if the gap or step difference between the explosion suppression foam and the pipeline, wall plate, or beam exceeds the design requirements, or it is difficult to remove, the installation is considered reasonable. After reinstalling the explosion suppression foam, check again whether the gap and step difference between the explosion suppression foam and the finished product meet the design requirements. If not, adjust the gap between the explosion suppression foam to ensure that the installation gap meets the design requirements.

2. The method for installing explosion suppression foam in an integral fuel tank of a wing according to claim 1, characterized in that: The gap between adjacent explosion-suppression foam joint surfaces shall not exceed 5-10mm; the step difference between explosion-suppression foams shall not exceed 10mm; there shall be at least 50mm gap between explosion-suppression foam and lines and pipelines, and there shall be more than 10mm gap between explosion-suppression foam and wing wall panels and beams.

3. The method for installing explosion suppression foam in an integral fuel tank of a wing according to claim 1, characterized in that: The maximum outer diameter of each piece of explosion suppression foam cannot be greater than the diameter of the fuel tank maintenance cover on the wing.

4. The method for installing explosion suppression foam in an integral fuel tank of a wing according to claim 1, characterized in that: For the finished products in the wing fuel tank, multiple pieces of explosion-suppressing foam should be arranged and wrapped by splicing.

5. The method for installing explosion suppression foam in an integral fuel tank of a wing according to claim 1, characterized in that: For the finished products in the wing fuel tank, the finished product protective cover is generated by 3D printing. The explosion-suppressing foam around the finished product should be adapted to the shape of the finished product protective cover, and the finished product protective cover should be wrapped by splicing.

6. The method for installing explosion suppression foam in an integral wing fuel tank according to claim 1, characterized in that: The finished product includes a fuel pump and a one-way valve.

7. The method for installing explosion suppression foam in an integral wing fuel tank according to claim 1, characterized in that: The explosion suppression foams are connected by face-to-face butt connection or plug-in connection.

8. The method for installing explosion suppression foam in an integral wing fuel tank according to claim 1, characterized in that: If there is any inconsistency between the surfaces of the explosion suppression foam, the explosion suppression foam needs to be trimmed.

9. The method for installing explosion suppression foam in an integral fuel tank of a wing according to claim 1, characterized in that: If it is verified that the foam installation is unreasonable, the installation sequence should be adjusted and reinstalled.

10. The method for installing explosion suppression foam in an integral fuel tank of a wing according to claim 1, characterized in that: Use pads and auxiliary blocks to adjust the gaps between explosion-suppression foams.

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