PHASED SPLIT DIE

Abstract: This invention relates to a device to compact parts with an undercut out of powder metal, including a pair of dies linearly moveable relative to one another and then phased, and an associated linearly displaceable pair of punches to produce said parts with said undercut.

Description: PHASED SPLIT DIE FIELD OF INNENTION This invention relates to dies and particularly split dies for producing compacted parts out of powder material having an undercut, and more specifically relates to a device to compact parts out of powder material which includes a pair of dies linearly moveable relative one another and then phased, and an associated linearly displaceable pair of punches so as to produce said parts which are phased or have an undercut. Background of the Invention Devices to compact parts out of powder material for sintering are well known to those persons skilled in the art. In some cases, the compacted part has an undercut which prevents removal of the part or blank from the dies by linear or axial displacement. Tool sets with split dies are known in powder material compaction to press parts into shapes that have an undercut in the compacting direction. For example, United States Patent No. 3,773,446 teaches a device for moulding parts to be sintered by compressing powdered material held between a fixed die and moveable die. A pair of punches extending through the dies compresses the powder material. A pressure plate operated by the punch extending through the moveable die engages the moveable die and is also locked to the fixed die during the compression so as produce a part having an undercut. Moreover, United States Patent No. 3,752,622 teaches a device for moulding blanks with undercut parts to be sintered by compaction of powder material. The prior art teaches that both parts of the die are tied together while filling with a feed box that moves across the top of the dies for purpose of filling the cavity with powdered material. After compaction the upper part of the die moves away together with the top punch to eject the part. One of the disadvantages of the known systems as referred to above relates to the fact that the upper part of the die has to be tied mechanically to the lower part of the die and the upper punch in an alternating mode, thus making a complicated tool rig necessary. Moreover, gearsets and camsets, for example, are characterized by two levels of the same shape but phased to each other so as to comprise an undercut in the compacting direction. Such parts may be manufactured by known methods as referred to above with the disadvantages noted therein. Another disadvantage of the prior art is that the undercut can only be indirectly filled thereby creating a section of lower density in the compacted part. It is therefore an object of this invention to provide a device that is simpler to construct and more efficient to operate than heretofore known by the prior art. It is another object of this invention to provide a tool system with a split die where both parts of the die remain tied to one part of the rig during the entire cycle. It is a further object of this invention to provide a device and method to produce compact phased parts such as gears, cams and the like with less complicated tooling and more efficient fill of the undercut than presently available. It is an aspect of this invention to provide a device to compact parts out of powder material including a pair of dies linearly moveable relative one another and then phased and an associated linearly displaceable pair of punches to produce said parts. It is a further aspect of this invention to provide a device to compact parts with an undercut out of powder material comprising: an upper die moveable relative a lower die; at least one upper punch associated with said upper die for relative movement therebetween; at least one lower punch associated with said lower die for relative movement therebetween; said lower punch defining a lower cavity with said lower die for filling with said powder material when said dies are in an open position; said upper die adapted to: contact said lower die in said closed position for movement of said upper punch and said upper die and said lower die relative said lower punch so as to transfer said powder material toward said upper die and for phased movement between said upper punch and said upper die relative said lower die; whereby said powder material is compacted between said upper and lower punches with said dies in said closed position so as to produce said part with said undercut; said dies moveable to an eject position for ejection of said compacted part; It is a further aspect of this invention to provide a device to compact parts out of powder material with an undercut comprising: an upper die linearly moveable relative a lower die between an open, closed, and eject position; structure for relative movement between said dies; at least one upper punch associated with said upper die for linear relative movement therebetween; structure for relative movement between said upper die and said upper punch; at least one lower punch associated with said lower die for relative movement therebetween; structure for relative movement between said lower punch relative said lower die; said lower punch defining a lower cavity with said lower die for filling with said powder material when said dies are in said open position; said upper die adapted to: contact said lower die in said closed position for movement of said upper punch, said upper die and said lower die relative said lower punch so as to transfer said powder material toward said upper die, and for relative phased movement between said upper and lower dies; whereby said powder material is compacted between said upper and lower punches with said dies in said closed position so as to produce said compacted part with said undercut; said dies moveable to an eject open position for ejection of said compacted part. It is yet another aspect of this invention to provide a method of producing a compacted part out of powder material with an undercut by utilizing a press having an upper die, a lower die, at least one upper punch associated with said upper die, and at least one lower punch associated with said lower die, comprising the steps of: positioning said upper die in spaced relationship with said lower die in an open position whereby; (i) said upper punch defines an upper cavity; and (ii) said lower punch is disposed to a lowest position relative said lower die so as to define a lower cavity for filling with said powder material when said dies are in said open position; moving said upper die relative said lower die so as to contact said lower die and seal said cavities; moving said upper punch, upper die and lower die relative said lower punch so as to transfer said powder material to said upper cavity; phasing said upper punch and upper die relative said lower die; compacting said powder material between said upper and lower punches in said dies in said closed position to produce said compacted part with an undercut; moving said dies to an eject position so as to eject said compacted part. Drawings of the Invention These and other objects and features of the invention shall now be described in relation to the following drawings. Figure 1 is a top plan view of a phased part such as a cam. Figure 2 is a side elevational view of figure 1. Figure 3 is a top plan view of a laterally phased part. Figure 4 is a representative view of the device showing the upper and lower dies and upper and lower punches. Figure 5 is a schematic view of another embodiment of the invention. Figure 6 is a front elevational view of the press. Description of the Invention Like parts shall be given like numbers throughout the invention. A device 17 is utilized to compact parts 13 out of powder material with an undercut 15 in a press 30. The press 30 is well known to those persons skilled in the art and includes an upper ram 32, lower ram 34 and press table 36 which is fixed relative the frame of the press 30. Figures 1 and 2 illustrate a top and side elevational view of a cam 22 characterized by two levels 24 and 26 which are of the same shape but phased to each other by an angle (a). More particularly, the cam set 22 illustrated in Figures 1 and 2 includes an undercut 28 in the compacting direction. Although a cam set 22 is illustrated in Figures 1 and 2 the invention as described herein can be utilized to manufacture gearsets or any other part which are phased or have an undercut in the compacting direction. Figure 3 illustrates another part which is laterally phased. Figure 4 illustrates the device 17 which includes the top or upper die 1, at least one top or upper punch 2, a bottom or lower die 3, and at least one bottom or lower punch 4. The top die 1 has a drive system 6 which may comprise a pair of hydraulic cylinders mounted to the upper ram 32 of a press 30. Accordingly, the top die is moveable relative the upper ram by means of the drive system 6. The top punch 2 is mounted on the upper ram 32 in a manner which shall be more precisely described below while the bottom die 3 is mounted to the lower ram 34 of the press 30. The upper punch 2 is associated with the upper die 1. In particular, the upper die 1 has a hole 8 for receiving upper punch 2 for slidable relative motion therebetween. The lower punch 4 is mounted for relative linear slidable movement wi h the lower die 3. In particular, lower die 3 includes a hole 9 to receive punches 4 for relative slidable movement therebetween. The upper die 1 and lower die 3 are adapted for linear relative movement between an open position as illustrated in Figure 4a and a closed position as shown in Figure 4b. In the open position, a feed box (not shown) moves over the cavity 7. The cavity 7 is defined by the space between the lower die 3 and the lower punch 4 when the lower punch 4 is in its lowest position relative the lower die 3. The lower punch 4 is moved far enough down or in its lowest position that enough powder 12 can be stored for the compaction of the part 13. After filling of the cavity 7 the upper ram 32 is moved down until the upper die 1 is touching the lower die 3 as shown in Figure 4b for sealing of the cavity 7. As shown in Figure 4b, the upper ram continues to travel downward so as to move the upper die and the upper punch. Simultaneously, the lower ram moves the lower die downward so as to transfer the powder 12 from the lower cavity 7 into the upper cavity 14 in the top die 1. In other words we have movement between the upper punch, upper die and lower die relative the lower punch. The movement of the powder metal into the upper cavity occurs prior to phasing so that the powder metal does not have any obstruction to flow which may result in pre-densification. The upper cavity 14 is defined by the upper die 1 and upper punch 2. Although the lower punch 4 is stationary in Figure 4, the lower punch 4 could also be moved to transfer the powder material into the upper cavity 14. Thereafter the upper punch and upper die is phased relative the lower die as illustrated in figure 3c so as to produce a part 13 having an undercut 15. In particular the phasing can occur by rotation of the dies 1, and 3 relative each other or by laterally displacing the dies. Rotation is particularly advantageous so as to produce a phased part such as the camset 2 illustrated in figures 1 and 2. Moreover, the upper die would be rotated relative the lower die by the same number of degrees so as to correspond to the angle as shown in figure 1. Phased rotation may be accomplished by a variety of means such as, for example, utilizing a worm gear 60 which could be activated so as to engage gears 62 and thereby cause the cylindrical body 64 to rotate about axis 66. The cylindrical body 64 is mounted to the ram 32 and the upper punch 2 and upper die 1 is mounted to the body 64. Phased lateral movement may be accomplished by a variety of means such as utilizing a hydraulic cylinder which could be activated to move the upper punch and upper die laterally the lower die. The compaction step is then shown in Figure 4d and is accomplished by moving the upper ram 32 and both dies 1 and 3 and upper punch with a suitable speed relationship. After compaction the part is ejected by withdrawing the top die 1 upward and the lower die 3 downward as shown in the ejection position figure 4e. Compaction occurs after phasing. The embodiment illustrated in Figure 4 shows the compaction of a single level part 13 with an undercut 15. The invention is not limited thereto but can also be used for multi-level parts with an undercut by introducing necessary additional top and bottom punches. For example, Figure 5 illustrates a device which would produce a part having multiple levels by utilizing several punches. Numeral 51 shows the pitch diameter of the tooth form within the punches and respective dies. In order to conduct all necessary movements during the cycle with suitable precision and speeds and timing, a hydraulic press with closed loop controls is preferably used, although the invention is not limited thereto. The drawings illustrate the withdrawal principal which means that after compaction the lower die is withdrawn to eject the part. However the invention described herein is also applicable for the counteφressing principle in which case the bottom die is stationary relative the press and all the bottom punches are mounted to the lower ram (including the drives to achieve relative movements between the bottom punches, if more than one bottom punch), so that after compaction the bottom punches will be moved further through the bottom die by the lower ram in order to eject the part. Although the preferred embodiment as well as the operation and use have been specifically described in relation to the drawings, it should be understood that variations in the preferred embodiment could be achieved by a person skilled in the trade without departing from the spirit of the invention as claimed herein.

Claims: CLAHVIS The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: 1. A device to compact parts with an undercut out of powder material including a pair of dies linearly moveable relative one another and then phased, and associated linearly displaceable pair of punches to produce said parts with said undercut. 2. A device to compact parts as claimed in claim 1 wherein said dies are phased by rotatably moving said pairs of dies relative one another. 3. A device as claimed in claim 1 wherein said dies are phased by laterally displacing said pair of dies relative one another. 4. A device to compact parts with an undercut out of powder material comprising: (a) an upper die moveable relative a lower die; (b) at least one upper punch associated with said upper die for relative movement therebetween; (c) at least one lower punch associated with said lower die for relative movement therebetween; (d) said lower punch defining a lower cavity with said lower die for filling with said powder material when said dies are in an open position; (e) said upper die adapted: (i) to contact said lower die in said closed position for movement of said upper punch, said upper die and said lower die relative said lower punch so as to transfer said powder material toward said upper die; (ii) for phased movement between said upper punch and said upper die relative said lower die; (f) whereby said powder material is compacted between said upper and lower punches with said dies in said closed position so as to produce said part with said undercut; (g) said dies moveable to an eject position for ejection of said compacted part; 5. A device as claimed in claim 4 wherein said dies are phased by rotatably moving said upper punch and said upper die relative said lower die; 6. A device as claimed in claim 4 where said dies are phased by laterally displacing said pair of dies relative one another; 7. A device as claimed in claim 4 wherein said lower punch is stationary and said upper and lower die and said upper punch move toward said lower punch, so as to transfer said powder material toward said upper die; 8. A device as claimed in claim 4 wherein said lower punch moves toward said upper die to transfer said powder material toward said upper die; 9. A device as claimed in claim 7 or 8 wherein said upper die and said upper punch define an upper cavity for receiving powder material transferred from said lower cavity to said upper cavity by movement of said upper die and upper punch and lower die relative said lower punch in said closed position. 10. A device as claimed in claim 9 wherein said upper die includes an opening for slidably receiving said upper punch for linear relative movement therebetween. 11. A device as claimed in claim 10 wherein said lower die includes an opening for slidably receiving said lower punch for relative movement therebetween. 12. A device to compact parts out of powder material with an undercut in a press having an upper and lower ram comprising: (a) an upper die linearly moveable relative a lower die between an open, closed and eject position; (b) means for relative movement between said dies; (c) at least one upper punch associated with said upper die for linear relative movement therebetween; (d) means for relative movement between said upper die and said upper punch; (e) at least one lower punch associated with said lower die for relative movement therebetween; (f) means for relative movement between said lower punch relative said lower die; (g) said lower punch defining a lower cavity with said lower die for filling with said powder material when said dies are in said open position. (h) said upper die adapted: (i) to contact said lower die in said closed position for movement of said upper punch, said upper die and said lower die relative said lower punch so as to transfer said powder material toward said upper die; (ii) for relative phased movement between said upper and lower dies; (i) whereby said powder material is compacted between said upper and lower punches with said dies in said closed position so as to produce said compacted part with said undercut; (j) said dies moveable to an eject position for ejection of said compacted part. 13. In a device as claimed in claim 12 wherein said upper die and said upper punch define an upper cavity for receiving powder material transferred from said lower cavity to said upper cavity by movement of said upper and lower die and upper punch relative said lower punch in said closed position. 14. In a method of producing a compacted part out of powder material with an undercut by utilizing a press having an upper die, a lower die, at least one upper punch associated with said upper die, and at least one lower punch associated with said lower die, comprising the steps of: (a) positioning said upper die in spaced relationship with said lower die in an open position whereby; (i) said upper punch defines an upper cavity with said upper die, and; (ii) said lower punch is disposed to a lowest position relative said lower die so as to define a lower cavity for filling with said powder material when said dies are in said open position. (b) moving said upper die relative said lower die so as to contact said lower die and seal said cavities; (c) moving said upper punch, upper die and lower die relative said lower punch so as to transfer said powder material to said upper cavity; (d) phasing said upper punch and upper die relative said lower die; (e) compacting said powder material between said upper and lower punches in said dies in said closed position to produce said compacted part with an undercut; (f) moving said dies to an eject position so as to eject said compacted part. 15. In a method as claimed in claim 14 wherein said lower die includes a plurality of lower punches wherein each said lower punches include an end for contacting said powder material in said lower cavity along planes at different levels. 16. In a method as claimed in claim 14 or 15 wherein said upper die includes a plurality of upper punches, each having an end for contacting said powder material in said upper cavity along planes at different levels. 17. In a method as claimed in claim 14 wherein said upper and lower dies move linearly between said open and closed positions. 18. In a method as claimed in claim 18 wherein said upper punch moves linearly said upper die. 19. In a method as claimed in claim 19 wherein said lower punch moves linearly relative said lower die.

Inventors: BUCKLEY-GOLDER KEITH, HAIKO MARK, HINZMANN GERD, MA FRANK, ROUND ROBERT, WILSON ALLAN, BUCKLEY-GOLDER, KEITH, HAIKO, MARK, HINZMANN, GERD, MA, FRANK, ROUND, ROBERT, WILSON, ALLAN
Applicants: BUCKLEY GOLDER KEITH, HAIKO MARK, HINZMANN GERD, MA FRANK, ROUND ROBERT, STACKPOLE LTD, WILSON ALLAN, BUCKLEY-GOLDER, KEITH, HAIKO, MARK, HINZMANN, GERD, MA, FRANK, ROUND, ROBERT, STACKPOLE LIMITED, WILSON, ALLAN
Application year: 1993
Main classification: B30B11
IPC codes: B22F3, B30B11