Abstract
A casting device (01) for a vacuum-assisted pressure die casting system includes a casting chamber (10), which has a wall surface (11), and a plunger (20) configured to move longitudinally in the casting chamber (10) and completing the casting chamber (10) at a first end (12), the casting chamber (10) comprising a filling hole (14), the casting chamber (10) having a gate (16) at a second end (13) opposite the first end, the gate (16) being at an end face, wherein at least one suction groove (17) is disposed tangentially in the inner side of the wall surface (11) at least in sections, and at least one suction hole (18) being disposed in the suction groove (17). Furthermore, a vacuum-assisted pressure die casting system including at least one casting device (01) and a method for operating a vacuum-assisted pressure die casting system are disclosed.
Claims
1. A casting device (01) for a vacuum-assisted pressure die casting system, the casting device (01) comprising a casting chamber (10), which has a wall surface (11), and a plunger (20) configured to move longitudinally in the casting chamber (10) and completing the casting chamber (10) at a first end (12), the casting chamber (10) comprising a filling hole (14), the casting chamber (10) comprising a gate (16) at a second end (13) opposite the first end, the gate (16) being preferably at an end face, wherein at least one suction groove (17) is disposed tangentially in the inner side of the wall surface (11) at least in sections, at least one suction hole (18) being disposed in the suction groove (17).
2. The casting device (01) according to claim 1, wherein the suction groove (17) is disposed behind the filling hole (14).
3. The casting device (01) according to claim 1, wherein an underpressure system or a vacuum pump is connected to the suction hole (18).
4. The casting device (01) according to claim 1, wherein the suction groove (17) extends in part of the wall surface (11).
5. The casting device (01) according to claim 1, wherein the suction groove (17) flattens out at the ends.
6. The casting device (01) according to claim 1, wherein the filling hole (14) is disposed in the wall surface (11) of the casting chamber (10) in a third of the wall surface (11) adjacent to the first end.
7. The casting device (01) according to claim 6, wherein the suction groove (17) is disposed in a first third of a section of the wall surface (11), the section extending from a rear edge (15) of the filling hole (14) to the second end (13) of the casting chamber (10).
8. The casting device (01) according to claim 1, wherein the diameter of the filling hole (14) increases from an inner side to an outer side of the wall surface (11), and the suction groove (17) at least partially extends below the filling hole (14).
9. The casting device (01) according to claim 1, wherein the suction groove (17) has a rectangular cross section.
10. The casting device (01) according to claim 1, wherein the suction groove (17) or the suction hole (18) is disposed at a top of the casting chamber (10).
11. The casting device (01) according to claim 1, wherein the casting device (01) comprises two to ten suction grooves (17), the suction grooves (17) being disposed one behind the other in the longitudinal direction.
12. The casting device (01) according to claim 11, wherein the suction grooves (17) are disposed at a distance from each other, the distance between adjacent suction grooves (17) being smaller than a length of the plunger (20).
13. The casting device (01) according to claim 12, wherein the distance is equal to the length of the plunger (20) minus the widths of the adjacent suction grooves (17).
14. A vacuum-assisted pressure die casting system comprising at least one casting device (01) according to claim 1, a drive for driving the plunger (20), at least one pressure die casting tool, and at least one underpressure system or vacuum pump.
15. A method for operating a vacuum-assisted pressure die casting system, the method comprising the following steps: a) providing a casting device (01) according to claim 1; and b) introducing a melt through the filling hole (14); and c) moving the plunger (20) from the first end (12) to the second end (13) of the casting chamber (10), extracting a gas flowing along the sides of the plunger (20), evacuating a gas present in the pressure die casting tool, and introducing the melt into the pressure die casting tool.
16. The method according to claim 14, wherein the extraction of a gas present in the casting chamber (10), a gas flowing into the casting chamber (10) or the gas flowing along the sides of the plunger (20) or the evacuation of the gas present in the pressure die casting tool takes place in step b).
Description
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0035] Further details, features and advantages of the invention are apparent from the following description of the preferred embodiment in conjunction with the dependent claims. The respective features can be realized individually or in combination with one another. The invention is not limited to the embodiment. The embodiment is shown schematically in the figures. Identical reference numbers in the individual figures denote identical or functionally identical elements or elements corresponding to one another in terms of their function.
[0036] FIG. 1 is a longitudinal cross-sectional view of a first embodiment of a casting device according to the invention; and
[0037] FIG. 2 is a transverse cross-sectional view of the first embodiment of the casting device according to the invention; and
[0038] FIG. 3 is a longitudinal cross-sectional view of a second embodiment of a casting device according to the invention; and
[0039] FIG. 4A, FIG. 4B and FIG. 4C show individual steps of a first variation of the method according to the invention; and
[0040] FIG. 5A, FIG. 5B and FIG. 5C show individual steps of a second variation of the method according to the invention.
DETAILED DESCRIPTION
[0041] FIG. 1 is a longitudinal cross-sectional view of a first embodiment of a casting device 01 according to the invention. The casting device 01 comprises a cylindrical casting chamber 10, which is delimited by a wall surface 11. A plunger 20 is disposed at a first end 12 of the casting chamber 10. This creates a receiving space for a melt. The melt (not shown) can be introduced into the receiving space through a filling hole 14 in the wall surface 11, the filling hole 14 being disposed at the top of the casting chamber 10. The filling hole 14 has a rear edge 15. The diameter of the filling hole 14 increases from an inner side of the wall surface 11 to an outer side of the wall surface 11. As a result, the edges, in particular the rear edge 15, are inclined. Directly behind the rear edge 15 and below the inclined rear edge 15 of the filling hole 14, a suction groove 17 is disposed in the inner side of the wall surface 11 at the top of the casting chamber 10. At a second end 13, the casting chamber 10 comprises a gate 16. The plunger 20 additionally comprises a plunger rod 21, by means of which the plunger 10 can be moved from the first end 12 to the second end 13, causing the melt present in the casting chamber 10 to be discharged through the gate 16 by means of pressure.
[0042] FIG. 2 shows a transverse cross-sectional view of the first embodiment of the casting device 01 according to the invention, the section being taken along axis A of FIG. 1. It can be clearly seen that the suction groove 17 is disposed in the inner side of the wall surface 11 of the casting device 10. In addition, two laterally disposed suction holes 18 are disposed in the suction groove 17. The suction groove 17 extends across an angle of approximately 90. In addition, the suction groove has flattened portions 19 at the ends. At least one underpressure system and/or vacuum pump (not shown) by means of which false air can be extracted is preferably connected to the suction holes 18.
[0043] FIG. 3 shows a longitudinal cross section of a second embodiment of a casting device 01 according to the invention. The second embodiment of the casting device 01 largely corresponds to the first embodiment shown in FIG. 1, so the explanations given for the latter basically also apply to the second embodiment. The second embodiment of the casting device 01 differs from the first embodiment in particular in that the plunger 20 is significantly shorter. The shorter design means that the suction time is very limited with only one suction groove 17 since the suctioning can only take place for as long as the plunger 20 closes the suction groove 17. In order to extend the suction time, a second suction groove 17 is disposed in the wall surface 11. The second suction groove 17 is disposed at a distance from the first suction groove 17, the distance together with the respective groove widths being less than the length of the plunger 20. The plunger 20 completely covers the second suction groove 17 before it uncovers the first suction groove 17 again, thereby enabling continuous suctioning.
[0044] FIG. 4A, FIG. 4B and FIG. 4C show individual steps of a first variation of the method according to the invention. The method according to the invention is carried out in a third embodiment of a casting device 01 according to the invention, which largely corresponds to the first embodiment shown in FIG. 1, the gate 16 being disposed at the top end face of the casting chamber 10. In FIG. 4A, the plunger 20 is located at the first end 12 of the casting chamber 10. Step b) of the method according to the invention is carried out, in which a melt 30 is poured into the casting chamber 10 through the filling hole 14.
[0045] In FIG. 4B, the plunger 20 is moved from the first end 12 to the second end 13. This reduces the volume of the casting chamber 10, and the level of the melt 30 rises. The plunger 20 covers the filling hole 14 and the suction groove 17, so the extraction of a gas flowing laterally along the plunger 20, i.e., the false air, and the evacuation of the gas present in a pressure die casting tool (not shown) can begin.
[0046] In FIG. 4C, the plunger 20 is still being moved from the first end 12 to the second end 13. The level of the melt 30 has risen to the extent that the melt fills the remaining volume of the casting chamber 10 and is pressed through the gate 16 under the pressure applied by the plunger 20. The extraction of the false air can be terminated. The evacuation of the pressure die casting tool (not shown) is preferably continued.
[0047] FIG. 5A, FIG. 5B and FIG. 5C show individual steps of a first variation of the method according to the invention. The method according to the invention is carried out in a fourth embodiment of a casting device 01 according to the invention, which largely corresponds to the second embodiment shown in FIG. 2, the gate 16 being disposed at the top end face of the casting chamber 10. In FIG. 5A, the plunger 20 is moved from the first end 12 to the second end 13. This reduces the volume of the casting chamber 10, and the level of the melt 30 rises. The plunger 20 covers the filling hole 14 and the first suction groove 17, so the extraction of the false air at the first suction groove 17 and the evacuation of the gas present in the pressure die casting tool (not shown) begins.
[0048] In FIG. 5B, the plunger 20 is moved further from the first end 12 to the second end 13, and the level of the melt 30 continues to rise. The melt 30 does not yet completely fill the volume of the casting chamber 10. However, the plunger 20 is short enough for the first suction groove 17 to be uncovered. However, the plunger 20 already completely covers the second suction groove 17, so the false air can be suctioned off through the second suction groove 17. The evacuation of the gas present in a pressure die casting tool (not shown) is maintained.
[0049] In FIG. 5C, the plunger 20 is still being moved from the first end 12 to the second end 13. The level of the melt 30 has risen to such an extent that the melt fills the remaining volume of the casting chamber 10 and is pressed through the gate 16 under the pressure applied by the plunger 20. The extraction of the false air can be terminated. The evacuation of the pressure die casting tool (not shown) is preferably continued.
