1 Title of the Invention

Lower Fairing Tool.

2 Field of the Invention

The invention relates to field of moulding in general and more particularly to lower fairing tool.

3 Background of the Invention

The supply of lower fairing part was discontinued from the OEM, to produce lower fairing part in-house, the lower fairing moulding tool was developed for moulding of lower fairing tool using the lower fairing component.

3.1 Prior Art

As per CN1070091C5A; The fairing is generally paraboloid-shaped. The fairing has a small end and a large end. The axial section of the fairing is gradually reduced from the large end to the small end, and the small end is provided with a central hole extending along the axial direction of the fairing. Center hole for mounting other parts, fairing is not provided with a flange for connection, the flange cannot be positioned and clamped as the other parts during installation of the fairing, which makes the fairing more difficult to install. At the same time, as the fairing for the shell parts, shell parts of the wall thickness compared to the length and width of the size is very small, so the clamping process is very prone to deformation, thus affecting the processing accuracy, whereas the present invention relates to development of lower fairing moulding tool for moulding of lower fairing component which is assembled on a center line pylon of an aircraft.

4 Brief Summary of the Invention

The present invention comprises the development of lower fairing moulding tool for moulding of lower fairing component which is assembled on a center line pylon of an aircraft. The tool is made up of three sections
(bottom, Centre, Top) for easy moulding and dismantling the moulded lower fairing. The three sections of the tool are aligned and connected with three dowel pins guiding their positions in a sequential order.

5 Detail Description of the Drawings

Figure 1: detailed construction of the lower fairing moulding tool which shows the bottom section(1), centre section(2) & top section(3) with supporting legs(5) and the three sections of the tool are aligned and connected with three dowel pins(4) guiding the positions in a sequential order.

Figure 2: detailed construction of bottom section of the lower fairing moulding tool which is mainly a support base of the tool on which the moulding components and other section locates. It comprises curved projections(7)(8)(9) and dowels pins(6).

Figure 3: detailed construction of centre section of the lower fairing moulding tool comprising nine support blocks (a-i) providing thickness formation of the component for easily removal of the components after moulding.

Figure 3a: Is the exploded view of the middle section consisting of nine support blocks (a-i) which are positioned on the eighteen dowel pins{6) on the bottom section(1) of the lower fairing moulding tool as per fig 3.

Figure 4: detailed construction of top section of the lower fairing moulding tool has a curved profile(10) to provide the curved section to the top of the component.

Figure 5: Provides the moulding of lower fairing component.
6 Detail Description of the Invention

The present invention comprises the development of Lower fairing moulding tool(figl) for moulding of low fairing component which is assembled on centre line pylon of an aircraft.

The tool comprises three sections viz. Bottom section{1), Centre section (2), Top section(3) for easy moulding and dismantling the moulded lower fairing component. The three sections of the tool are aligned and connected with three dowel pins(4) guiding their positions in a sequential order.

The following specification particularly describes the invention of lower fairing moulding tool.

Referring to fig 1, Bottom section of Moulding tool (fig 2):

Is mainly a support base of the tool on which locates the moulding component and other sections of the tool.

Bottom section comprises three major parts namely:

> Supporting legs(5)

> Baseplate(l)

> Curved projection(7)(8)(9).

Supporting leasfS): The bottom section has two supporting legs(5) to carry the weight of the tool and create the clearance for clamping of the three section of tool. The supporting leg(5) is made with job rock plywood of dimension 200mm x 175mm x 24mm as per drawing. It is machined to dimension on NC machine.

Base Plated): is a huge supporting plate made from Job rock plywood of dimension 655mm x 200mm x 24mm machined and deburred on NC machine.

Curved projection^): is made from FRP (Fiber reinforced plastic) comprising Araldite AW106, hardener HY953, Aluminium metal powder, variety II glass cloth.
The size and shape to be moulded was taken from the section of lower fairing component.

A wooden pattern was made manually as per the component required. A FRP moulding operation was carried to achieve the shape of curved projection(7)(8){9) required for the creating hollow in the component required for reduction of weight and provide strength. Curved projection (7)(8){9) has three individual projections. One is circular section (9) made of Hylem of 20mm thickness of 50 mm diameter tapered as per fairing components 1)and other two sections of intricate curved projections (7)(8) made from araldite to the wooden pattern developed from the component. The three parts of the bottom section are assembled using wooden screws. They comprise eight nos. of 40mm length and 4mm diameter used to assemble the base plate(1) and supporting legs(5) and eight nos. of 25mm length and 4mm diameter is used to assemble the curved projection and base plate.

Referring to fig 1, Centre section of Moulding tool (fig 3& 3a):

Is comprising nine support blocks(a-i) providing the thickness formation of the component, easily removal of the component after moulding and stop the flow of the resin required for the mould.

The nine support blocks made(a-i) up of 24mm hylem sheet. The nine support blocks(a-i) are located to bottom section (1) using 04.5 steel dowel pins (6) of 25mm length at 18 places and fool proof location is achieved. The dowel pins (6) are permanently fixed on bottom section (1) with the projection of 8mm for the supporting blocks (a-i) for easy removal and insertion.

Referring to fig 1, Top Section of Moulding tool (Fig 4):

Is made to provide the curved section of the top of the component which provides the main profile required to suit the aircraft pylon profile.

Top section has made up of two parts:

> Top support plate (3)

> Curved profile (10)
Top support plate (3): is made with job rock plywood of 24mm x 200mm x 660mm trimmed to shape and size on NC machine.

Curved profiled 0): is developed by the wooden pattern of the component. The materials required are LY5052 Araldite, HY5052 hardness, aluminum metal powder. Variety II glass cloth.

Firstly, 5mm thickness of layer is made with the above materials for good adhesion and strength for the profile.

The curved actual profile is then moulded with above similar procedure using the required component wooden pattern.

Three locating T-pins(4) of 8mm diameter of length of 210mm and 60mm T-handle for positioning and locking the three sections of the tool.

Preparation of Lower fairing moulding component (11) comprises:

Clean the lower fairing moulding tool(Fig 1) and apply the wax coating twice to Bottom section(1), Centre section(2) and Top Section(3) of the tool and left to dry for 30 Mins.

The Araldite and Hardener are mixed and apply resin inside of the tool all the sides and soak the resin on the glass cloth layers and lay up glass cloth cut pieces step by step inside the fairing tool up to Center section{2) surface level. Close the top section (3) of the tool with three Dovel pins{4) and curing in room temperature for 12 hrs.

Remove the Dovel Pins(4) and clear the excess materials all over the tool and open the top section of the tool with utmost care and remove Center section(2) i.e. support blocks(a-i). Remove the fairing components 1) and file the excess glass cloth material and scrubbed with emery sheet to smooth finish