Forging apparatus

Abstract

A forging apparatus and method is disclosed in which a punch 260 is held in a press 210, 220 and propelled towards a billet 250 by a ram 240. The ram 240 is separate from the punch 260. Thus, any axial misalignment between the ram 240 and the press 210, 220 in which the billet is held, for example due to the extremely high loads involved, has no affect on the direction and position of the impact force the punch 260 transmits to the billet 250. This helps to prevent unwanted forces and bending moments in the punch 260, thereby preventing breakage of the punch 260.

Claims

1. A method of forging a shaped component comprising: positioning a billet in a first cavity defined by an upper press and a lower press of a forging machine; positioning a punch between the upper press and the lower press of the forging machine, the billet and the punch being aligned in a forging direction and striking the punch with a separate ram, such that the punch moves along the forging direction (A) and forces the billet into a second cavity formed by the upper press and the lower press, the second cavity defining the shape of the shaped component, the first cavity being separate from the second cavity and the first cavity having a different shape than the second cavity.

2. The method of forging a shaped component according to claim 1, further comprising applying a gripping load to the billet through the upper press and the lower press, the gripping load being perpendicular to the forging direction.

3. The method of forging a shaped component according to claim 1, wherein the second cavity defines an aerofoil shape.

4. A shaped component manufactured using a process comprising the method of claim 1.

5. The method of forging a shaped component according to claim 1, further comprising holding the punch in a position between the upper press and the lower press using a punch holder.

6. The method of forging a shaped component according to claim 5, wherein the punch holder is a third cavity defined by the upper press and the lower press when they are in contact.

7. The method of forging a shaped component according to claim 5, wherein the first cavity and the punch holder have centrelines that are aligned.

8. The method of forging a shaped component according to claim 1, further comprising striking a header punch portion of the punch with the ram, which causes an extrusion punch portion of the punch to strike the billet.

9. The method of forging a shaped component according to claim 8, wherein the header punch has a cross sectional area perpendicular to the direction in which the ram strikes the header punch, and the extrusion punch has a cross sectional area perpendicular to the direction in which the extrusion punch strikes the billet, the cross sectional area of the header punch being greater than the cross sectional area of the extrusion punch.

10. The method of forging a shaped component according to claim 1, wherein: the punch includes an impact portion; the ram includes a striking portion; and the method further comprises striking the impact portion of the punch with the striking portion of the ram.

11. The method of forging a shaped component according to claim 1, further comprising: moving the upper press and the lower press relative to each other in a first direction (B) in order to define the first cavity and the second cavity, and striking the punch with the ram in the forging direction (A), which is perpendicular to the first direction.

12. The method of forging a shaped component according to claim 11, wherein the first cavity and the second cavity are offset from each other in a direction that is aligned with the second direction (B).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) For a better understanding of the present disclosure, reference will now be made, by way of non-limitative example only, to the accompanying drawings, in which:

(2) FIG. 1 shows a forging apparatus;

(3) FIG. 2 shows a forging apparatus according to an aspect of the invention;

(4) FIG. 3 shows a schematic of a cross-section through a ram, punch and billet of a forging apparatus according to an aspect of the invention; and

(5) FIG. 4 shoes the ram, punch and billet of FIG. 3, but with the centrelines of the ram and punch offset from each other.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(6) The operation of an example of a forging apparatus 100 has been described above in relation to FIG. 1. As explained above, a problem of the striking portion 142 breaking off from the rest of the punch 140 exists with the FIG. 1 arrangement. This may occur if, for example, there is variation in the position of the dies 110, 120, and thus the billet 150, between forging operations.

(7) FIG. 2 shows a forging apparatus 200 according to an aspect of the invention. The forging apparatus 200 has an upper press 210 and a lower press 220. The upper press 210 and the lower press 220 are shown spaced apart, but during use they move together, such that the upper press 210 moves in the direction of arrow B relative to the lower press 220, thereby receiving (which, optionally, may include clamping, or holding) a billet 250.

(8) The forging apparatus 200 also comprises a ram 240 and a separate punch 260. The punch 260 is held in a punch holder 270, which may be defined by the upper and lower presses 210, 220, as in the FIG. 2 example.

(9) In operation, the ram 240 is propelled towards the punch 260 using a suitable motive force in the direction of arrow A, which may be referred to as the forging direction. As shown in the FIG. 2 example, the direction of arrow A may be perpendicular to the direction of arrow B. The direction of arrow A may be substantially horizontal, for example.

(10) The ram 240 has a striking portion 242 that strikes an impact portion 262 (which may be part of a header portion 264) of the punch 260. This causes the punch 260 to be propelled in the forging direction towards the billet 250. In turn, this causes the punch 260 (for example an extrusion punch portion 266 of the punch 260) to strike the billet 250, thereby forcing it from a first cavity 280 in which it is shown in FIG. 2, into a second cavity 290. The second cavity 290 may have the shape of the shaped component that is desired to be output from the forging apparatus 200. This may be any suitable shape, for example an aerofoil shape.

(11) The first and second cavities 280, 290 may be offset from each other in the same direction as the forging direction A, as shown in the FIG. 2 example. Also as illustrated in FIG. 2, the first and/or second cavities may be formed by the upper and lower presses 210, 220, for example when the upper and lower presses 210, 220 are moved together. For example, the upper and lower presses 210, 220 may have respective die portions that come together to form the first and/or second cavities 280, 290. Such die portions may be integral parts of the upper and lower presses 210, 220, or may be removable/replaceable parts that are fixed to the respective upper and lower press 210, 220.

(12) The punch 260 and the billet 250 are both placed and held between the upper press 210 and the lower press 220 during forging. This means that their relative position, or at least the relative position of their longitudinal axes, is defined by the same piece of apparatus (i.e. the presses 210, 220), and thus cannot vary between forging operations. This arrangement ensures that the punch 260 always strikes the billet 250 in the same direction and at the same position. As such, regardless of any variability in alignment of the punch 260 and the ram 240 (and thus of the billet 250 and the ram 240) no unknown or variable force or bending moment is passed into the punch 260, and so it is not susceptible to breakage.

(13) FIG. 3 shows a schematic of a scenario in which the centrelines, or longitudinal axes, of the ram 240, punch 260, and billet 250 of the FIG. 2 example are all aligned. In this situation, when the ram 240 is propelled towards the punch 260 in the direction of arrow A, the force path is directly through the punch 260 and billet 250 in the forging direction of arrow A, thereby providing a forging force to the billet without any unwanted forces or bending moments in the punch 260.

(14) However, as noted herein, the precise position of upper and lower presses 210, 220 may vary slightly between forging operations and/or over time, for example due to the extremely high loads involved. This may result in the ram 240 moving relative to the punch 260 (and thus the billet 250) in a direction C that is substantially perpendicular to the forging direction A. This may result in the scenario shown in FIG. 4, in which the longitudinal axis of the ram 240 is offset by a distance 1 with respect to the longitudinal axes of the punch 260 and the billet 250. However, in contrast to the arrangement shown in and described in relation to FIG. 1, the punch 260, and thus the portion 266 of the punch 260 that strikes the billet 250, is still axially aligned with the billet 250. This means that even if the ram 240 strikes the punch 260 along a skewed or offset path, the punch 260 still provides a forging force to the billet 250 that is aligned with the billet 250, for example collinear with the longitudinal axis of the billet 250.

(15) This arrangement shown in FIGS. 2 to 4 prevents damage to the components of the forging apparatus 200 because no unknown or unwanted force or bending moment is passed through the interface 267 between the relatively narrow extrusion portion 266 of the punch 260 and the rest of the punch 260. Any unwanted force or bending moments that result from an unwanted offset of the ram 240, punch 260 and billet 250 passes through the much bulkier and stronger parts of the ram 240 and punch 260 which are not subject to the same dimensional constraints, and thus can be engineered to resist such unwanted forces/bending moments.

(16) It will be appreciated that the forging apparatus 200 described and claimed herein may be a part of a larger apparatus and/or process. For example, the shaped component generated after the billet 250 has been forged by being forced into the second cavity (or die) 290 may required further processing, such as finishing and/or further shaping in order to become a finished part. By way of further example, the billet 250 may be heated before being transferred to the first cavity 280. The various processes may be automated, including the transportation of the billet 250 and/or shaped components between the various processes.

(17) Any component and/or feature described herein may be combined with any other compatible component and/or feature. Furthermore, it will be appreciated that various alternative and/or complimentary arrangements and/or components not explicitly described herein are in accordance with the invention.