Abstract
A module for a die-casting device that includes a base that can be fastened to a mounting plate of the die-casting device, a screw/cylinder unit for producing a thixotropic material, and a filling chamber, wherein the screw/cylinder unit and the filling chamber are arranged indirectly or directly on the base such that thixotropic material produced by the screw/cylinder unit can be conveyed into the filling chamber.
Claims
1. A module for a die-casting device, said module comprising: a base configured to be fastened to a mounting plate of the die-casting device; a screw/cylinder unit for producing a thixotropic material; and a filling chamber; wherein the base comprises a central open space into which the screw/cylinder unit projects; and wherein the screw/cylinder unit and the filling chamber are arranged indirectly or directly on the base such that thixotropic material produced by the screw/cylinder unit can be conveyed into the filling chamber.
2. The module according to claim 1, wherein: a screw of the screw/cylinder unit is axially displaceable.
3. The module according to claim 1, wherein: the filling chamber comprises a sealing seat against which a first end of the screw can be positioned.
4. The module according to claim 1, wherein: the screw/cylinder unit is arranged vertically.
5. The module according to claim 1, wherein: the filling chamber is arranged horizontally.
6. The module according to claim 1, wherein: a first lifting device is provided with which the screw of the screw/cylinder unit can be axially displaced.
7. The module according to claim 1, wherein: the screw/cylinder unit is mounted on a plate at the top end, which plate is fastened to the base.
8. The module according to claim 1, wherein: the screw/cylinder unit-is mounted on the filling chamber.
9. The module according to claim 8, wherein: the screw/cylinder unit is mounted on an outer part of the filling chamber; and the outer part is connected to the base.
10. The module according to claim 9, wherein: an inner part of the filling chamber is connected to the outer part of the filling chamber such that the inner part can be detached by displacement.
11. The module according to claim 9, wherein: a second lifting device is provided with which the screw/cylinder unit can be axially displaced relative to the outer part of the filling chamber.
12. A die-casting device with a module according to claim 1.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) Additional features, advantages and effects of the invention follow from the exemplary embodiments described below. In the drawings which are thereby referenced:
(2) FIG. 1 shows a first version of module;
(3) FIG. 2 shows a side view of the module according to FIG. 1;
(4) FIG. 3 shows a back side of the module according to FIG. 1;
(5) FIG. 4 shows a perspective illustration of the module according to FIG. 1;
(6) FIG. 5 shows a section of the module along the line V-V in FIG. 3;
(7) FIG. 6 shows a further section through the module according to FIG. 1;
(8) FIG. 7 shows a die-casting device with a module according to FIG. 1;
(9) FIGS. 8 through 12 show a process sequence for an injection operation into a mold cavity;
(10) FIG. 13 shows a cross section through a second version of a module;
(11) FIG. 14 shows a further cross section of the module according to FIG. 13.
DETAILED DESCRIPTION
(12) In FIGS. 1 through 6, a first version of a module 1 is shown which can be used to convert a conventional die-casting device D1 (FIG. 7) such that thixotropic material can be injected with this device into one or more mold cavities in order to create corresponding molded parts. However, the module 1 can of course also already be integrated in or delivered with a new die-casting device D1.
(13) The module 1 comprises a base 2. The base 2 can be embodied to be rectangular or, as illustrated, roughly square. Other basic shapes of the base 2 are of course also possible. For the sake of efficiency, however, the base 2 is embodied to be as small as possible, especially since the base 2 primarily serves to provide a substructure for a screw/cylinder unit 3 and a filling chamber 4 and to enable the coupling thereof to a mounting plate D2 of a die-casting device D1.
(14) In addition, the base 2 accommodates a casting mold, for which reason the base 2 is roughly the size of the mounting plate D2 wherever possible. As can be seen from FIG. 4, the base 2 is roughly embodied to have a constant thickness and comprises a central open space 22. In addition, openings 23 are provided which are used to guide suitable fasteners through so that the base 2 can be fastened to a mounting plate D2 of the die-casting device D1 using suitable fasteners.
(15) As can be seen from FIGS. 1 and 4, the base 2, which in principle is embodied with an essentially uniform thickness, comprises a preferably central open space 22 or slot. The screw/cylinder unit 3, which projects downward in a vertical direction, runs in this slot. If injection is performed from a side, the situation illustrated in FIG. 1 would be rotated 90° to the left or right. However, a vertical arrangement is also preferred for a constant material feed from the screw/cylinder unit 3 into the filling chamber 4. After the module 1 is fastened to a mounting plate D2, a plunger D4 of a die-casting device D1 can protrude into the filling chamber 4.
(16) The screw/cylinder unit 3 is mounted on a plate 7 at the top end, which in turn is connected to the base 2. Additionally, a motor 8 is indirectly mounted on the plate 7, namely via an intermediate plate 71 that is axially displaceable.
(17) As can be seen in the cross sections in FIGS. 5 and 6, the screw/cylinder unit 3 comprises an outer cylinder 31 in which a screw 32 is arranged. The screw 32 can be set in rotation by the motor 8. In addition, the screw 32 can be axially displaced in the cylinder 31 by the first lifting device 5 provided, wherein the intermediate plate 71 together with the motor 8 mounted thereon can be displaced in tandem in a corresponding axial displacement.
(18) The filling chamber 4 is mounted on the base 2 and detachably connected to the vertically arranged screw/cylinder unit 3. The filling chamber 4 extends, as can be seen in particular from FIG. 2, past the base and comprises a nozzle 43 at the end, which nozzle 43 opens into a die half during an injection operation. The filling chamber 4 extends from the nozzle 43 to an opposite end of the filling chamber 4, which end serves to accommodate a plunger D4 that is part of a conventional die-casting device D1.
(19) With the aid of FIGS. 5 and 6, the interaction of the screw/cylinder unit 3 with the filling chamber 4 can be further explained. As can be seen in the cross sections, the screw 32 runs inside the cylinder 31 of the screw/cylinder unit 3. At the first end 321, the screw 32 is embodied to be conically tapered, whereas at the opposite end 322 of the screw a roughly horizontal termination can be provided. To accommodate the first end 321 of the screw 32, the filling chamber 4 comprises a corresponding sealing seat 44. The sealing seat 44 is preferably also embodied, as viewed from the screw 32, to be conically tapered. In this manner, it is possible to prevent a backflow of thixotropic material from the filling chamber 4 back into the screw/cylinder unit 3 during an injection operation, which will be explained below. The screw 32 can be moved up and down inside the cylinder 31 by the first lifting device 5. With the motor 8, which is operatively connected to the screw 32, a rotational movement or rotation of the screw 32 can be generated.
(20) In FIG. 7, a die-casting device D1 to which a module 1 is fastened is illustrated. As can be seen, the module 1 is fastened to a first mounting plate D2 of the die-casting device D1, for which the mentioned openings 23 on the base 2 are used. As can be seen, the module 1 is fastened to the stationary mounting plate D2 and is located opposite of a moveably mounted mounting plate D3 of the die-casting device D1. Furthermore, it can be seen that the plunger D4 of the die-casting device D1 engages in the filling chamber 4 of the module 1. For the creation of a molded part, the two necessary die halves are also mounted on the mounting plates D2, D3. Thixotropic material supplied via the screw/cylinder unit 3 can then be injected into a closed mold cavity via the nozzle 43, for which purpose the movable clamping plate D3 with the die half mounted thereon is first positioned against the stationary clamping plate D2 with the die half mounted on the module 1 in that location, in order to produce the mold cavity. The injection operation can then take place. This operation is explained below.
(21) In FIGS. 8 through 12, the injection operation for the creation of a molded part from thixotropic material by means of a conventional die-casting machine D1, having been converted with a module 1, is illustrated by way of example. FIG. 8 shows an initial state in which the screw 32 is locked, which is equivalent to the state at the end of an injection operation. According to FIG. 9, the screw 32 is then unlocked and set in rotational motion by the motor 8. What is not illustrated, yet is self-evident, is that a suitable granular material or powder is fed into the screw/cylinder unit 3 to produce thixotropic material. As a result of the rotational motion of the screw 32 and a temperature set in the screw/cylinder unit 3 via heating elements which are not illustrated, the supplied granular material or powder is placed in the thixotropic state. This still occurs even during a process phase according to FIG. 10, in which the plunger D4 is retracted in order to clear exactly that space in the filling chamber 4 that is necessary for the feed of thixotropic material. Once this has been achieved, the screw 32 is displaced axially downward in the direction of the filling chamber 4 according to FIG. 11. In this manner, the thixotropic material produced is introduced into the filling chamber 4. Finally, the conically tapered first end 321 of the screw 32 moves into contact with the sealing seat 44 of the filling chamber. The screw 32 is then locked. In this manner, an excellent seal between the screw/cylinder unit 3 and filling chamber 4 is present. Then, according to FIG. 12, a forward movement of the plunger D4, and as a result the injection operation, occurs. At the end of the injection operation, the plunger D4 is once again located in the position according to FIG. 8, and the operation begins anew. Here, it should be mentioned that no plug forms between the screw/cylinder unit 3 and the filling chamber 4 during the injection operation, as is typical in thixomolding processes. Instead, the entire region is kept at one temperature so that plug formation does not occur. This has proven advantageous in terms of a precise feed control for, or filling of, the filling chamber 4, as is necessary for the creation of high-quality molded parts.
(22) In FIGS. 13 and 14, cross sections of a version of the module 1 are illustrated. This version of the module 1 is mainly distinguished by the mounting of the screw/cylinder unit 3. In contrast to the previously explained version, the screw/cylinder unit 3 is mounted on the filling chamber 4. For this purpose, the filling chamber 4 comprises an outer part 41 and an inner part 42. The outer part 41 is connected to the base 2, wherein the filling chamber 4 is, as in the first version and also all other alternative versions, guided through a base opening 21 and preferably protrudes out of this opening with the nozzle 43. At the bottom end of the outer part 41, a second lifting device 6 is provided. This can also be a hydraulically or pneumatically operated lifting device 6. Of course, as is also the case for the first lifting device 5, alternative drives are possible, such as a spindle drive. As in the first embodiment, the screw/cylinder unit 3 protrudes vertically into a central open space 22 of the base 2. With the second lifting device 6, which is fastened to the outer part 41 of the filling chamber 4, the entire screw/cylinder unit 3 can be axially displaced as such. If the second lifting device 6 is embodied as a hydraulic lifting device, the plunger is not displaced when a hydraulic medium is applied to the lifting device 6, but rather the housing and therefore a connected support 9 together with guiding means 10 that are connected to the plate 7 at the top end. A corresponding upstroke exposes an inner part 42 of the filling chamber 4. This inner part 42 is that part which is subjected to the greatest wear during operation, since the strongest forces act in the region thereof during injection. With an axial lifting of the screw/cylinder unit 3, this inner part 42 can be easily exposed, and can be removed by being pulled forward. A new wear part or inner part 42 then only needs to be inserted.
