Casting die

Abstract

The present invention provides a casting/hot forging die having a forming surface and an opposing rear surface. The rear surface has a plurality of cavities spaced by a plurality of walls. Each of the plurality of walls has a substantially equal width. At least one transverse wall may also be provided such that the walls define a grid spacing a series of rectangular or triangular cavities.

Claims

1. A casting/hot forging die comprising: a forming surface, and an opposing rear surface, the rear surface having a plurality of cavities spaced by a plurality of walls such that the plurality of walls all have a substantially equal width, wherein a cavity base surface in at least one of the cavities of the plurality of cavities includes a projection, the projection being positioned in a center of the cavity and extending away from the cavity base surface towards the rear surface.

2. The die according to claim 1 wherein each of the plurality of walls has an axial extension coincident with a width dimension of the die.

3. The die according to claim 1 further comprising one or more transverse walls that further define the cavities on the rear surface.

4. The die according to claim 3 wherein the one or more transverse walls each has a width substantially matching the width of each of the plurality of walls.

5. The die according to claim 1 wherein the transverse walls each has an axial extension perpendicular to the axial extension of the plurality of walls, and each cavity has a substantially square or rectangular cross-sectional profile.

6. The die according to claim 1 wherein the opposing rear surface further includes one or more transverse walls that each has an axial extension extending at substantially 60 degrees to an axial extension of the plurality of walls, and each cavity has a substantially triangular cross-sectional profile.

7. The die according to claim 1 further comprising opposing lateral edge walls such that at least one of the opposing lateral edge walls has a width substantially matching the width of each of the plurality of walls.

8. The die according to claim 1 further comprising opposing transverse edge walls such that at least one of the opposing transverse edges walls has a width substantially matching the width of each of the plurality of walls.

9. The die according to claim 1 wherein a distance through the die between the forming surface and the cavity base surface is uniform within each cavity.

10. The die according to claim 3, wherein a distance through the die between the forming surface and the cavity base surface is uniform within all cavities.

11. The die according to claim 9 wherein the distance through the die between the forming surface and the cavity base surface within each cavity substantially matches the width of each of the plurality of walls.

12. The die according to claim 1 wherein the projection is positioned in the center of the respective cavity base surface such that it is equally spaced from the walls defining the respective cavity.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which:

(2) FIG. 1a shows a perspective view of the forming surface of a prior art die;

(3) FIG. 1b shows a perspective view of the rear surface of the prior art die;

(4) FIG. 1c shows a cross-sectional view along line AA of the prior art die;

(5) FIG. 1d shows a cross-sectional view along line BB of the prior art die;

(6) FIG. 2a shows a perspective view of the forming surface of a die according to a first embodiment of the present invention;

(7) FIG. 2b shows a perspective view of the rear surface of the die according to the first embodiment of the present invention;

(8) FIG. 2c shows a cross-sectional view along line AA of the die according to the first embodiment of the present invention; and

(9) FIG. 2d shows a cross-sectional view along line BB of the die according to the first embodiment of the present invention.

(10) FIG. 3 shows a plan view of the rear surface of a die according to a second aspect of the present invention.

DETAILED DESCRIPTION AND FURTHER OPTIONAL FEATURES OF THE INVENTION

(11) As shown in FIGS. 2a-d, a first embodiment of the present invention provides a casting die having a forming surface 1 and an opposing rear surface 2.

(12) In use, the forming surface 1 is used to define one half of a mould cavity and to form superplastic or liquid material e.g. molten metal or metal in its plastic form into the shape desired for cast, forged, or superplastically formed component.

(13) The rear surface has a width dimension (extending in the direction of line CC) and a longer length dimension (extending in the direction of line DD).

(14) The rear surface has a plurality of rectangular cavities 3 defined and mutually spaced by walls 4 having an axial extension coincident with the width dimension of the die and a transverse wall 6 having an axial extension coincident with the length dimension of the die.

(15) The die further comprises opposing lateral edge walls 7 (having an axial extension coincident with the width of the die) and opposing transverse edge walls 8 (having an axial extension coincident with the length of the die).

(16) As shown in FIGS. 2c and 2d, the walls 4, lateral edge walls 7 and transverse edge walls 8 all have an equal width x (the dimension perpendicular to the axial extension (length) of the walls 4 in the plane of the rear surface). The transverse wall 6 has a reduced width y which is about 75% of the width x. However, in other embodiments, the transverse wall 6 may have the same width x as the walls, 4, lateral edge walls 7 and transverse edge walls 8.

(17) By providing walls having an equal/uniform width x and thus an equal spacing between each cavity 3 and its adjacent cavity, thermal and contraction stresses are reduced thus allowing the cast component to be manufactured nearer to net-shape such that material usage is reduced and the cast component requires less machining.

(18) Each cavity 3 in the rear face 2 extends to a respective cavity base surface 5. As shown in FIGS. 2c and d, the distance through the die between the forming surface and the cavity base surface is uniform within all cavities and substantially matches the width x of each of the plurality of walls 4.

(19) The cavity base surface 5 in two of the cavities 3 comprises a respective projection 9, 9 extending away from the respective cavity base surface 5 towards the rear surface 2 (in a direction coincident with the height of the plurality of walls 4). The projections are positioned in the centre of the respective cavity base surface 5 such that they are equally spaced from the walls 4/transverse wall 6/transverse edge walls 8/lateral edge walls 7 defining the respective cavity 3.

(20) These projections are for assisting easy location of the die within the furnace during the casting or forging process.

(21) FIG. 3 shows a plan view of the rear surface of a casting die according to a second preferred embodiment.

(22) The rear surface has a plurality of triangular cavities 3 defined and mutually spaced by walls 4 having an axial extension coincident with the width dimension of the die and transverse walls 6 having an axial extension at 60 degrees to the axial extension of the walls 4.

(23) Two pairs of transverse walls 6a/6b and 6c/6d diverge from a respective wall 4, angled at 60 degrees to the wall 4 to form an isogrid pattern defining the triangular cavities 3.

(24) The walls 4 and transverse walls 6a-6d all have substantially the same width.

(25) By providing walls having an equal/uniform width and thus an equal spacing between each cavity 3 and its adjacent cavity, thermal and contraction stresses are reduced thus allowing the component to be manufactured nearer to net-shape such that material usage is reduced and the component requires less machining.

(26) While the invention has been described in conjunction with the exemplary embodiments described above, many equivalent modifications and variations will be apparent to those skilled in the art when given this disclosure. Accordingly, the exemplary embodiments of the invention set forth above are considered to be illustrative and not limiting. Various changes to the described embodiments may be made without departing from the spirit and scope of the invention.

(27) All references referred to above are hereby incorporated by reference.