Patent Application
20130112363
The invention relates to a temperature control device for a diecasting apparatus. The invention relates, furthermore, to a diecasting apparatus.
Temperature control devices for diecasting apparatuses are known from the prior art. The diecasting apparatus serves in this case for diecasting. Diecasting is preferably used for the casting of metal, in particular nonferrous metals or high-strength hot-work steels, or special materials. In diecasting, the molten casting material, the melt, is pressed under high pressure, at relatively high speed, into a casting mold, also designated as a mold insert. In this case, flow velocities of the melt of 20 to 160 m/s and short shoot times for introduction of 10 to 100 ms are achieved. The casting mold or diecasting mold in this case is composed, for example, of metal, preferably of a hot-work steel. For diecasting, a distinction may be made between the hot-chamber method and the cold-chamber method. In the former, the diecasting apparatus and a holding furnace for the melt form a unit. The casting assembly, which feeds the melt to the casting mold, is located in the melt; during each casting operation, a specific volume of the melt is pressed into the casting mold. By contrast, in the cold-chamber method, the diecasting apparatus and the holding furnace for the melt are arranged separately. Only the quantity required for the respective casting is metered into a casting chamber and is introduced from there into the casting mold.
For the temperature control, in particular cooling, of at least one region of the diecasting apparatus, the temperature control device is employed. This may be used, in particular, to control the temperature of a region of the diecasting apparatus which can be acted upon by a casting material. Such a region is, for example, a casting inlet of the diecasting apparatus, along or through which casting inlet the casting material passes in the direction of a diecasting mold of the diecasting apparatus. In this case, however, in temperature control devices known from the prior art the problem arises that reliable and uniform temperature control of the region capable of being acted upon by casting material cannot be implemented. The temperature control or cooling of the region has to be dimensioned in such a way that reliable cooling is afforded and, at the same time, the cooling down of a diecast component to be produced in the diecasting mold or of the casting material which has remained in the region is not impaired by too rapid and/or too uneven cooling. The boundary conditions for the sufficient cooling of the diecasting mold part and the as uniform cooling of the diecast component as possible give rise to comparatively low cycle times in the production of the diecast component, in order thereby to achieve good durability of the diecast component. This means, however, that only a comparatively small number of diecast components can be produced per unit time.
By contrast, the object of the invention is to present, for a diecasting apparatus, a temperature control device which does not have the disadvantages initially mentioned, but at the same time permits a good cooling-down characteristic and a high throughput (diecast components per unit time).
The foregoing object is achieved, according to the invention, by means of a temperature control device. In this case, there is provision whereby this has a first component, a second component and at least one fluid duct formed in the first component and/or the second component, the first component and/or the second component having at least one receptacle for a region, capable of being acted upon with a casting material, of the diecasting apparatus, in particular of a casting inlet, and the fluid duct issuing into at least one heat exchange chamber which is present at least in regions as a marginally open recess in the first component and which can be closed by means of the second component. The temperature control device for the diecasting apparatus is therefore designed at least in two parts. It is composed of the first and of the second component.
The for controlling the temperature of the region of the diecasting apparatus, that is to say, in particular, the region capable of being acted upon by casting material, can be arranged at least partially in the receptacle. That region of the diecasting apparatus which can be acted upon by casting material is, for example, the casting inlet which may be present in the form of a flow duct or also forms this. During the diecasting operation, casting material, that is to say melt, can flow along the flow duct in the direction of the diecasting mold, from which the diecast component can subsequently be removed. The receptacle of the temperature control device may be formed either by the first component or the second component or by both components together.
For temperature control, the temperature control device can be acted upon with a temperature control fluid, in particular cooling fluid. While the temperature control device is in operation, this temperature control fluid flows through the at least one fluid duct which is formed in the first component and/or the second component. The fluid duct issues, for example, into a fluid connection of the temperature control device, via which fluid connection the temperature control fluid can be introduced into the fluid duct or can be extracted from this. In order to increase the temperature control efficiency of the temperature control device, the heat exchange chamber is provided. The heat exchange chamber is present as a marginally open recess in the first component and can be closed with the aid of the second component. This means that the second component can be arranged on the first component in such a way that the marginally open recess is closed and the heat exchange chamber is formed.
The marginally open recess is therefore designed to be open toward the second component, the orifice of the recess being capable of being covered or closed by means of the second component. This ensures, furthermore, that the heat exchange chamber is supplied with temperature control fluid by the fluid duct. It is especially advantageous if the heat exchange chamber is formed solely by the marginally open recess in the first component, that is to say no further depression is provided.
By the temperature control fluid set at a specific temperature being introduced into the heat exchange chamber, the temperature of that region of the diecasting apparatus which can be acted upon with casting material can be set at least approximately by control and/or regulation. For this purpose, on or in the temperature control device, at least one temperature sensor may be provided, by means of which its temperature and/or the temperature of the region capable of being acted upon can be determined at least approximately. On the basis of this specific temperature, the temperature and/or throughput (volume or mass per unit time) of the temperature control fluid can subsequently be selected or set. The temperature control fluid flows through the heat exchange chamber and at the same time flows, for example, over a heat exchange surface. If the latter is assigned thermally or in a heat-transmitting manner to the region capable of being acted upon with casting material, temperature control of the region takes place in this way.
The temperature of the temperature control fluid is in this case usually markedly lower than the temperature of the temperature control device or of the region capable of being acted upon, so that these can be cooled as quickly as possible and the diecast component to be produced can be removed from the diecasting apparatus. In contrast to the temperature control devices known from the prior art, therefore, the heat exchange chamber is formed here at least partially in the first component, thus allowing more reliable action of the temperature control fluid upon the heat exchange surface and consequently a better cooling characteristic or more rapid cooling of the region being capable of being acted upon.
It should be mentioned expressly at this juncture that the temperature control device is provided both for a diecasting apparatus which operates according to the hot-chamber method and for one which implements the cold-chamber method. Any desired material compositions of the melt may also be used.
In a development of the invention, the heat exchange chamber is coformed partially by a fluid guide depression of the second component. The fluid guide depression of the second component is in this case designed to be open toward the first component. It can therefore form, together with the marginally open recess of the first component, the heat exchange chamber. The volume of the marginally open recess of the first component is usually larger than the volume of the fluid guide depression. However, there may also be provision whereby the fluid guide depression has a larger volume than the recess of the first component, that is to say has a larger fraction of the heat exchange chamber.
In a development of the invention, the heat exchange chamber has a larger cross section than the fluid duct. The cross section in this case lies in a sectional plane which is perpendicular to the direction of the greatest extent of the fluid duct. This applies both to the fluid duct and to the heat exchange chamber. The heat exchange chamber therefore has, as seen in cross section, a larger area contributing to the temperature control of the diecasting apparatus. A widening should therefore be present at the point of issue of the fluid duct into the heat exchange chamber. When temperature control fluid flows out of the fluid duct into the heat exchange chamber, a kind of free jet is formed in the heat exchange chamber.
In a development of the invention, a plurality of fluid ducts issue into the heat exchange chamber, at least one of the fluid ducts being a fluid feed duct connected to a fluid feed connection and at least one further fluid duct being a fluid discharge duct connected to a fluid discharge connection. The temperature control fluid can be fed to the heat exchange chamber by means of the fluid feed duct and extracted from the heat exchange chamber via the fluid discharge duct. The fluid feed connection and the fluid discharge connection, to which the fluid feed duct and the fluid discharge duct are respectively connected or fluid-connected, are arranged on the temperature control device in such a way that simple connection to a feed apparatus can be carried out. The feed apparatus serves, for example, for the supply of temperature control fluid and/or for the temperature control of the latter to a specific temperature.
In a development of the invention, the fluid discharge duct issues into the heat exchange chamber so as to be offset with respect to the fluid feed duct, in particular in the axial direction of the temperature control device. This means that the fluid discharge duct and the fluid feed duct, as seen in their axial direction, do not issue into the heat exchange chamber opposite to one another, but instead so as to be offset with respect to one another. Thus, temperature control fluid flowing through the fluid feed duct into the heat exchange chamber does not impinge directly onto the fluid discharge duct or its point of issue into the heat exchange chamber. Circulation of the temperature control fluid in the heat exchange chamber is thereby achieved. It is especially advantageous if a wall, in particular a heat exchange surface, of the heat exchange chamber lies opposite the fluid feed duct.
The temperature control fluid flowing through the fluid feed duct into the heat exchange chamber, upon its entry into the heat exchange chamber, therefore impinges directly onto this wall in the sense of impact cooling. As a result of this impingement, a high heat transfer coefficient is achieved. Only thereafter does the temperature control fluid flow out of the heat exchange chamber again through the fluid discharge duct. In other words, the inflow direction of the temperature control fluid out of the fluid feed duct into the heat exchange chamber is to be arranged so as to be offset in its lateral direction with respect to an outflow direction of the temperature control fluid out of the heat exchange chamber through the fluid discharge duct. Lateral direction is to be understood in this context to mean a direction which is perpendicular to the respective flow direction. For example, this direction may correspond to an axial direction of the temperature control device.
In a development of the invention, the wall of the heat exchange chamber has at least one heat exchange surface which is assigned thermally to a pressure zone which is associated with the acted-upon region of the diecasting apparatus. The pressure zone is therefore a region which either is itself acted upon or capable of being acted upon directly with the casting material or is at least assigned to the acted-upon region of the diecasting apparatus. The heat exchange surface is assigned thermally to the pressure zone, which means that heat can be transmitted or is transmitted between the heat exchange surface and the pressure zone. For example, the pressure zone is present on one side of the wall of the temperature control device and the heat exchange surface is present on the opposite side of the wall.
The wall is in this case preferably composed of a highly heat-conductive material. The pressure zone or that region of the diecasting apparatus which can be acted upon with casting material can therefore be temperature-controlled via the heat exchange surface. This applies particularly when temperature control fluid can flow over or onto the heat exchange surface. It is in this case especially advantageous if the fluid feed duct of the temperature control device is directed onto the heat exchange surface, so that temperature control fluid flowing through the fluid feed duct into the heat exchange chamber flows directly over the heat exchange surface or impinges onto the latter.
In a development of the invention, the contour of the heat exchange surface is approximated at least in regions to an in particular three-dimensional contour of the pressure zone or corresponds thereto. This can be achieved, for example, by means of a uniform wall thickness of the wall to which both the pressure zone and the heat exchange surface are assigned in each case on opposite sides. Alternatively, however, by an appropriate choice of the wall thickness, a desired heat conduction rate can also be achieved in this or can be set in a directed manner for specific regions. For example, there may be provision whereby the wall thickness of the wall decreases in the flow direction of the fluid, since the fluid, when it flows through, heats up and therefore its cooling action on the heat exchange surface or the pressure zone decreases. In order to compensate this, it may be necessary to increase the heat conductivity of the wall, this usually being achievable by means of a smaller wall thickness. The three-dimensional contour is understood in this context to mean that the contour of the heat exchange surface is approximated in all directions of space to the contour of the pressure zone or corresponds thereto.
In a development of the invention, the receptacle is a recess which, in particular, is frustoconical and/or formed centrally in the first component. The receptacle is therefore present in the first component. Said receptacle is designed as a recess and preferably passes through the first component completely, that is to say is designed to be marginally open on both sides. As already described above, that region of the diecasting apparatus which can be acted upon with casting material may be arranged in the recess. Alternatively, the receptacle or recess conforms to the region. For example, the flow duct for the casting material is obtained as a result of an interaction of the receptacle and of a counterelement, in particular a casting material guide extension, of the diecasting apparatus. The recess is preferably of frustoconical design, that is to say has dimensions decreasing or increasing in the longitudinal direction. In this case, there may be provision whereby the recess is formed centrally, that is to say in the middle, in the first component.
In a development of the invention, the second component is of essentially plate-shaped design. The second component therefore serves, for example, as a closing plate for the marginally open recess of the first component. Plate-shaped is to be understood in this context to mean that the second component has only a small thickness in comparison with its lateral extents. There may also be provision whereby that side of the second component which faces the first component is of essentially planar form. In this case, the heat exchange chamber is formed solely by the marginally open recess of the first component. The second component therefore has no fluid guide depression which at least partially coforms the heat exchange chamber.
In a development of the invention, the second component can be arranged in a reception depression of the first component. The first component therefore has a depression which corresponds at least essentially to a shape or outline of the second component. In particular, it is in this case advantageous if the reception depression has a depth which essentially corresponds to or is greater than the thickness of the second component. The second component can thus be arranged on the first component in such a way that a planar surface is formed or the second component does not project above the first component. Easy handling of the temperature control device is thereby achieved.
After the insertion of the second component into the reception depression, said second component is preferably surrounded by the first component in such a way that the former is secured at least in the lateral direction, that is to say no slipping of the second component with respect to the first component in the lateral direction is possible. In the reception depression, a seal may also be provided, by means of which a sealing action is achieved between the first component and the second component, so that the heat exchange chamber is closed off sealingly by means of the second component.
In a development of the invention, the first and/or the second component have/has at least one fluid guide projection projecting into the heat exchange chamber. If the fluid guide projection is provided on the first component, it usually points in the direction of the second component. If, conversely, said fluid guide projection is provided on the second component, it points in the direction of the first component. Contouring of the first or the second component and therefore of a wall of the heat exchange chamber is achieved by means of the fluid guide projection. By means of such contouring, the flow of the temperature control fluid onto the heat exchange surface can be improved or regions of the heat exchange surface can be acted upon in a directed manner with temperature control fluid. The better cooling characteristic or the more rapid cooling can thereby be achieved. By means of a directed arrangement of one or more fluid guide projections on the first and/or the second component, uniform temperature distribution or a uniform cooling action of the temperature control device or upon the heat exchange surface can therefore be achieved.
For example, this is provided for regions of the heat exchange surface which match with thermally especially highly loaded regions of the region capable of being acted upon. The heat exchange surface is preferably contoured in such a way that as uniform cooling as possible is achieved. Stresses in the casting material are thereby avoided and high stability of the diecast component is thus achieved.
In a development of the invention, the first component is releasably connected to the second component, in particular by means of a screw connection. There is therefore provision whereby the second component is formed separately from the first component. The two components are subsequently assembled to form the temperature control device and are connected releasably to one another. The heat exchange chamber is at the same time formed. The releasable connection may basically be made in any desired way. However, a screw connection with at least one screw or with a threaded bolt is preferred.
In a development of the invention, a seal sealing off the heat exchange chamber is provided between the first component and the second component. In order to prevent an unintended escape of temperature control fluid from the heat exchange chamber, the latter is assigned the seal. The seal may in this case be designed, for example, as an O-ring and essentially surround the heat exchange chamber in the circumferential direction. Exchange of the temperature control fluid located in the heat exchange chamber is of course still possible by means of the fluid duct.
The invention relates, furthermore, to a diecasting apparatus, with at least one temperature control device, in particular according to the above statements, the temperature control device having a first component, a second component and at least one fluid duct formed in the first component and/or the second component, the first component and/or the second component having at least one receptacle for a region, capable of being acted upon with a casting material, of the diecasting apparatus, in particular of a casting inlet, and a fluid duct issuing into at least one heat exchange chamber which is present at least in regions as a marginally open recess in the first component and which can be closed by means of the second component. The diecasting apparatus is, for example, a diecasting machine and is accordingly designed for the production of diecast components. It has, in addition to further, generally known elements, at least one temperature control device which is designed or developed according to the above statements.
The invention is explained in more detail below by means of the exemplary embodiments illustrated in the drawing, without the invention being restricted. In the drawing:
The casting mold unit 2 has a casting mold 13. The casting mold 13 has essentially a shape which reproduces a negative of a diecast component to be produced. During the casting operation carried out by means of the diecasting apparatus 1, therefore, casting material or melt is introduced into the casting mold 13 and, after the melt has cooled and solidified, the diecast component is removed from the casting mold 13. For this purpose, the diecasting mold part 8 and/or the diecasting mold part 9 can be displaced in the vertical direction away from the other diecasting mold part 9 or 8 in each case. For this purpose, therefore, a corresponding displacement device is provided.
The heat exchange chamber 15 is present at least in regions as a marginally open recess 23 in the first component 16. Marginally open means in this context that the recess 23 passes at least partially through an outer wall of the cooling ring 14. The marginally open recess 23 or the orifice present as a result of passage through the outer wall can be closed by means of the second component 17. In this case, the first component 16 has a reception depression 24 which has a depth corresponding to the thickness of the second component 17. The second component 17 can therefore be received completely in the reception depression 24. The first component 16 and the second component 17 are connected to one another by means of a screw connection 25. For this purpose, four screws are provided, although these are not illustrated in
A bearing surface 26, which is designed as a bearing web running around the heat exchange chamber 15, is provided for the second component 17 in the reception depression 24. The reception depression 24 is designed in such a way that the first component 16 can receive the second component 17 completely, so that the second component 17 lies at least in regions on the bearing surface 26, with the result that a sealing action is achieved between the first component 16 and the second component 17. In addition, of course, in the bearing surface 26 a seal may be provided which is designed, for example, as an O-ring and further increases the sealing action between the first component 16 and the second component 17.
The designations, fluid feed duct 30 and fluid discharge duct 31, are to be understood here purely by way of example. The temperature control fluid may, of course, be introduced through any one of the fluid ducts 29 into the heat exchange chamber 15 and be extracted again through any one of these. The fluid feed duct 30 is fluid-connected to a fluid feed connection 32 and the fluid discharge duct 31 to a fluid discharge connection 33. These may be connected, for example, to a feed apparatus which feeds temperature-controlled temperature control fluid to the cooling ring 14 via the fluid feed connection 32 and extracts it again through the fluid discharge connection 33.
It can be seen, moreover, that the fluid discharge duct 31 issues into the heat exchange chamber 15 so as to be offset with respect to the fluid feed duct 30. This means that a point of issue of the fluid discharge duct 31 into the heat exchange chamber 15 is not arranged opposite a point of issue of the fluid feed duct 30 into the heat exchange chamber 15. Temperature control fluid flowing through the fluid feed duct 30 into the heat exchange chamber 14 therefore does not flow directly onto the fluid discharge duct 31. Instead, throughflow of the heat exchange chamber 15 and therefore efficient temperature control of the heat exchange surface 28 are achieved. In the exemplary embodiment illustrated in
The diecasting apparatus 1 illustrated in
The melt is subsequently cooled, for which purpose fluid is introduced into heat exchange chambers of the diecasting mold parts 8, 9, 10, 11 and 12 and into the heat exchange chamber 15. The temperature of the fluid or of its mass flow is selected in such a way that the cooling characteristic of the diecast component is as good as possible. For this purpose, in particular, it is necessary to cool this as uniformly as possible, in order to ensure sufficiently high stability of the diecast component. A further aim is as rapid cooling as possible, in order to achieve a high throughput of the diecast components and consequently lower production costs.
After the solidification or cooling of the melt, the diecasting mold parts 8 and 9 and the diecasting mold parts 10 and 11 are in each case displaced away from one another, so that the casting mold 13 and the gate region are released. The cooling ring 14 is likewise removed from the casting inlet unit 4. The diecast component produced, together with the runner which has remained in the gate region and with that casting material of the diecasting apparatus 1 which has remained in the region of the casting inlet unit 4, can subsequently be removed. In the context of subsequent machining, the runner is removed from the diecast component and is preferably melted in once more.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 163 120.8 | May 2010 | EP | regional |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/EP2011/057124 | 5/4/2011 | WO | 00 | 1/25/2013 |
