Clipping tool

Abstract

The present disclosure provides a clipping tool for clipping flash from a component e.g. a gas turbine aerofoil body. The clipping tool includes a riser having a support surface for supporting the component and a punch for gripping the component on the support surface such that the flash projects laterally from the riser and the punch. The clipping tool further comprises a tool body having a clipping aperture opening to a channel within the tool body. The channel is defined by a channel wall. The riser and the punch are translatable to shear the projecting flash from the gripped component. At least a portion of the channel wall within the tool body comprises a broaching surface having at least one projection, said projection reducing the cross sectional area of the channel to less than that of the clipping aperture.

Claims

1. A clipping tool for clipping flash from a component, the clipping tool comprising: a riser having a support surface for supporting the component; a punch for gripping the component between the punch and the support surface such that the flash projects laterally from the riser and the punch; and a tool body comprising a plurality of stacked plates in direct contact with each other and having a clipping aperture opening to a channel within the tool body, the channel being defined by a channel wall, and the riser and the punch being translatable together within the channel while gripping the component therebetween to shear the projecting flash from the gripped component, wherein: at least a portion of the channel wall comprises a broaching surface formed by first and second ones of the plurality of stacked plates; the first plate includes a first edge surface; the second plate is stacked below the first plate so as to be distal the clipping aperture and includes a second edge surface proximal the clipping aperture that forms a second plate cutting edge; and the second plate cutting edge constitutes a projection by extending into the channel beyond the first edge surface to reduce the cross-sectional area of the channel to less than that of the clipping aperture.

2. A clipping tool according to claim 1, wherein there are a plurality of projections on the broaching surface.

3. A clipping tool according to claim 1, wherein the second edge surface is an angled edge surface that extends from the second plate cutting edge proximal the clipping aperture away from the axis of the channel.

4. A clipping tool according to claim 1, wherein the projection is a step, ridge or tooth.

5. A clipping tool according to claim 1, wherein the broaching surface includes an inlet adjacent the projection proximal the clipping aperture.

6. A clipping tool according to claim 5, further comprising a pneumatic flushing mechanism for flushing swarf from the inlet.

7. A clipping tool according to claim 1, wherein: the clipping aperture and the channel have opposing lateral ends; and the broaching surface is provided at one or both of the laterally opposing ends.

8. A clipping tool according to claim 1, wherein the first edge surface is a planar first edge surface.

9. A clipping tool according to claim 1, wherein: the stacked plates include a third plate stacked below the second plate distal the clipping aperture; the third plate includes an angled third edge surface such that a third plate cutting edge is formed on the third edge surface proximal the clipping aperture, the angled third edge surface extending from the third plate cutting edge proximal the clipping aperture away from the axis of the channel; and the third plate cutting edge extends into the channel beyond the first edge surface.

10. A method of manufacturing a component, comprising: forming a desired shape of the component and thereby forming flash; and using the clipping tool of claim 1, removing the flash.

11. A method of manufacturing a component according to claim 10, wherein the component is an aerofoil component of a gas turbine engine.

12. A method of manufacturing a component according to claim 10, wherein the forming comprising forging.

13. A method of manufacturing a component according to claim 12, wherein the forging comprises forcing two dies together, the flash being formed at the interface of the two dies.

14. A method of clipping flash from a formed component using the clipping tool of claim 1.

15. A clipping tool for clipping flash from a component, the clipping tool comprising: a riser having a support surface for supporting the component; a punch for gripping the component between the punch and the support surface such that the flash projects laterally from the riser and the punch; and a tool body comprising a plurality of stacked plates below the component and having a clipping aperture opening to a channel within the tool body, the channel being defined by a channel wall, and the riser and the punch being translatable together within the channel while gripping the component therebetween to shear the projecting flash from the gripped component, wherein: at least a portion of the channel wall comprises a broaching surface formed by first and second ones of the plurality of stacked plates; the first plate includes a first edge surface; the second plate is stacked below the first plate so as to be distal the clipping aperture and includes a second edge surface proximal the clipping aperture that forms a second plate cutting edge; and the second plate cutting edge constitutes a projection by extending into the channel beyond the first edge surface to reduce the cross-sectional area of the channel to less than that of the clipping aperture.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

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

(2) FIG. 1 is a perspective view of a conventional clipping die;

(3) FIG. 2 is a perspective view of the clipping die of FIG. 1 and an associated clipping steel;

(4) FIG. 3 shows a view of clipping tool according to first arrangement that is cut away along the centreline of the tool;

(5) FIGS. 4 and 5 show cross-sectional views through view of the stacked plates of the first embodiment;

(6) FIG. 6A shows a surface clipped using a conventional clipping tool; and

(7) FIG. 6B shows a surface clipped using the first arrangement of the present disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

(8) FIGS. 3 to 5 show features of a first arrangement of the present disclosure.

(9) As shown in the perspective view of FIG. 3, the tool 20 includes a hydraulically cushioned riser 22 having a support surface 23 for an aerofoil blade having tang portions at opposing lateral ends. A modular tool body 24 surrounds the riser and provides a clipping aperture 25 opening to a channel (see FIG. 4 in which the riser is omitted) through which the riser can descend. An upper ram 26 carries a punch 45.

(10) The modular tool body 24 comprises a set of plates 27.

(11) The set of plates comprises a first plate 28 which defines the upper surface 29 of the tool body. The first laterally opposed edge surfaces 40, 40′ of the first plate are substantially planar in the axial direction of the channel and partly form the clipping aperture 25 and the channel wall defining the channel. The cross-sectional area of the channel defined by the first edge surfaces 40, 40′ of the first plates 28 matches that of the clipping aperture. The upper surface 29 defined by the first plate 28 includes laterally opposed troughs 32 allowing accurate positioning of the aerofoil body on the riser 22.

(12) The lower surface of the first plate comprises cut-outs 30, 30′ proximal the first edge surfaces, 40, 40′.

(13) The set of plates 27 further includes a second plate 33.

(14) The second laterally opposed edge surfaces 35, 35′ of the second plate 33 are angled (at 2 degrees from vertical) from a respective second plate cutting edge 39, 39′ away from the axis of the channel. The second plate cutting edges 39, 39′ project into the channel beyond the first edge surfaces 40, 40′ thus decreasing the cross-sectional area of the channel to less than that of the cross-sectional area of the clipping aperture 25.

(15) The second plate 33 has a substantially planar upper surface (proximal the clipping aperture) with laterally opposed troughs 38, 38′ which are angled at 5 degrees from horizontal away from the respective second plate cutting edge 39, 39′ and are aligned with the respective cut-out 30, 30′ on the lower surface of the adjacent first plate 28, to form an inlet for the collection of swarf.

(16) The lower surface of the second plate comprises cut-outs 41, 41′ proximal the second edge surfaces.

(17) The set of plates 27 further includes a third plate 37.

(18) The third edge surfaces 44, 44′ of the third plate 37 are angled (at 2 degrees from vertical) from a respective third plate cutting edge 43, 43′ away from the axis of the channel. The third plate cutting edges 43, 43′ project into the channel by substantially the same amount as the second plate cutting edges 39, 39′.

(19) The third plate has a substantially planar upper surface (proximal the clipping aperture) with laterally opposed troughs 42, 42′ which are angled at 5 degrees from horizontal away from the respective third plate cutting edge and are aligned with the respective cut-out 41, 41′ on the lower surface of the adjacent second plate 33 to form an inlet for the collection of swarf.

(20) The clipping aperture 25 and the cross-sectional profile of the channel are essentially rectangular with the sets of edges surfaces of the plates 28, 33, 37 disposed at the laterally opposed ends for cutting the tang portions of the aerofoil body.

(21) Each plate further comprises two transversally opposed edge surfaces which define a portion of the aperture/channel. Each transversely opposed edge has a planar clipping surface 31 which clips the leading and trailing edges of the aerofoil body.

(22) At least a portion of the channel wall is coated with Diamolith™ coating which increases edge hardness and reduces friction to ensure extending tool life.

(23) In use, a forged aerofoil body is deposited onto the riser 22, e.g. by a robotic arm (not shown). The upper ram 26 descends commencing the clipping stroke.

(24) Firstly, the aerofoil body is gripped between the riser 20 and the punch 45. The riser 22 and the punch 45 descend through the clipping aperture 25 of the tool body 24 to sheer the flash from the aerofoil body. The flash on leading and trailing edges of the aerofoil body is clipped by the transversely opposed edge surfaces of the plates 28, 33, 37, each having a single, planar shearing edge 31.

(25) The flash on the tang portions (which tends to be thicker (around 3.5 mm) than the flash on the leading/trailing edges (which typically has a thickness of around 1 mm)) is clipped by the edge surfaces of the set of plates 27 at opposing lateral ends of the channel.

(26) The first edge surfaces 40, 40′ of the first plate 28 clip the tang portions to the desired geometry.

(27) The second plate cutting edges 39, 39′ which project further into the channel then further clip the tang portions to obtain dimensional accuracy of the tang portions and to semi-finish the surface.

(28) The third plate cutting edges 44, 44′ finally clip any “spring-back” material from the tang portions to achieve the desired surface finish.

(29) A pneumatic flushing system (not shown) forces air through the swell collection inlets formed between the first/second plates and second/third plates between each clipping action to flush the swarf from the tool body 24 to avoid clogging of the clipping tool.

(30) FIGS. 6A and 6B show a comparison between a surface clipped using a conventional clipping tool (FIG. 6A) and a surface clipped by a clipping tool according to the present disclosure (FIG. 6B). The surface clipped by the conventional clipping tool exhibits a plastically deformed region 46, a sheered region 47 and a smeared region 48. The surface clipped by the clipping tool according to the present disclosure exhibits a much reduced plastically deformed region 46 and the sheered and smeared regions are effectively removed.

(31) While the disclosure 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 disclosure 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 disclosure.

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