The invention relates to a connection piece which is suitable in particular for fastening an elastic nozzle in a casting machine.
Document DE 34 10 302 C2 shows the nozzles fastened in a nozzle plate of a casting machine. The nozzles consist of an inelastic material, for example steel, and are produced by machining. The nozzles are pressed into the nozzle plate or are welded thereto. The mounted nozzles can then be replaced only to a limited degree and with great effort.
The present invention is based on the object of being able to arrange or fasten an elastic nozzle by way of structurally simple means in a device, in particular in a casting machine, and at the same time of allowing the nozzle to be replaced rapidly in the device by way of simple mounting steps.
This object is achieved according to the invention by a connection piece having the features of claim 1.
The connection piece is arranged, in particular can be screw-mounted, in a nozzle plate of a casting machine. The casting machine can cast for example liquids, and in particular a chocolate mass. The connection piece preferably has a hollow cylindrical form in order that the liquid can pass through the connection piece into the nozzle and from there to a casting point. A first end of the connection piece has a fastening device, which is in particular a thread. This thread is screwed into the nozzle plate so that the connection piece is connected firmly to the nozzle plate. The nozzle is arranged in the connection piece preferably even before the connection piece is mounted in the nozzle plate. In order that the nozzle is held securely in the connection piece, there is provided a clamping unit which can be connected to the second end of the connection piece. The connection piece and/or the clamping unit can have a holder for the nozzle so that the nozzle can be connected to the connection piece. The nozzle is then mounted in the nozzle plate with the aid of the connection piece. A defective elastic nozzle can be replaced easily in that the nozzle connected to the connection piece is removed from the nozzle plate and is replaced by a connection piece which has a new nozzle.
The connection piece and the clamping unit are structurally simple components which can be produced cost-effectively, for example on an automatic lathe or as injection-molded parts.
Advantageously, the inside diameter of the connection piece is smaller than an outside diameter of the nozzle, in order that the nozzle is compressed in the radial direction. This influences the casting properties of the nozzles and allows clean casting of the mass by way of a casting machine.
It is favorable for an internal cylinder of the hollow cylinder to have a conical region at the end having the fastening device of the connection piece, in order that the mass to be cast can run into the connection piece and the nozzle through this funnel shape.
Advantageously, the connection piece has a surface for holding a flange surface of the nozzle, so that the nozzle butts against this surface during mounting and can be fixed precisely.
The connection piece according to the invention has particular advantages when the connection piece has a groove for holding a flange of the nozzle. The nozzle sits in the groove and the clamping unit can ensure that the nozzle is fastened securely.
It is conceivable that one surface of the connection piece, preferably the outer surface, can be connected to the nozzle in order to fix the nozzle in the connection piece by way of the clamping force that occurs between the nozzle and the connection piece. This has the advantage that the additional clamping unit can be dispensed with if there is a sufficiently large clamping force.
In a particularly advantageous embodiment of the invention, the outer surface of the connection piece can have a mounting device, in particular a width across flats or a knurl. This mounting device makes it easier to fasten the connection piece, in particular in a nozzle plate of a casting machine, since the width across flats or a knurl represents an optimal engagement surface for a mounting tool or enables the connection piece to be screwed in by hand.
It is particularly favorable for the nozzle to be arranged in a recessed manner in the connection piece in order that the nozzle can be fastened securely in the connection piece. Furthermore, the connection piece can support the nozzle against an inner surface of the connection piece and facilitate the use of the nozzle in a casting machine.
Advantageously, the connection piece can have a fastening device, in particular a thread, at both ends, so that the connection piece can be fastened in a device in a casting machine and furthermore the nozzle can be fastened to the connection piece by way of a device which can be formed for example as a union nut.
It is particularly favorable for the connection piece to consist of metal, in particular a corrosion-resistant steel or stainless steel, or of aluminum or of plastic, in particular POM 6, since these materials are food-compatible.
In an advantageous embodiment of the invention, it is possible that the connection piece can be connected, in particular welded, to the nozzle and/or the clamping unit, in order to improve the fastening of the nozzle and to provide the replacement part in a more customer-friendly manner.
It is conceivable that a sleeve can be arranged in the connection piece, in order thereby to improve the stability of the connection piece.
In a further embodiment of the invention, at least one securing element can be arranged perpendicularly to the center axis in the connection piece and the clamping unit in order in this way to allow particularly reliable connection of the parts. These securing elements may be pins or splint pins or threaded pins having a securing means.
The object is furthermore achieved by a connection piece, which is suitable in particular for fastening an elastic nozzle in a casting machine, wherein the connection piece preferably has a hollow cylindrical form and has a fastening device, in particular a thread, at one end, and a clamping unit which can be connected to the connection piece. The connection piece and/or the clamping unit have/has a holder for the nozzle and the nozzle can be connected to the connection piece. The connection piece has a fastening device, in particular a thread, at both ends, wherein the nozzle can be fastened to the connection piece by way of a device which is formed for example as a union nut.
The object mentioned at the beginning is also achieved by a clamping unit having the features of claim 14.
The clamping unit facilitates the fastening of the nozzle to a connection piece, wherein the clamping unit is preferably a structurally particularly simple element in the form of a hollow cylinder. One surface of the clamping unit can be connected to the nozzle. The clamping unit allows the nozzle to be replaced rapidly in the device, in particular in the casting machine, by way of simple mounting steps, since only the clamping unit has to be released from the nozzle and/or the connection piece in order to replace the nozzle.
The clamping unit and the seat of the clamping unit on the connection piece can be embodied such that, in order to replace the nozzle, the nozzle and/or the clamping unit have to be destroyed, that is to say the nozzle and/or the clamping unit cannot be removed without being destroyed and in the event of a replacement being made both the nozzle and the clamping unit are renewed.
Alternatively, the clamping unit can be embodied such that, in order to replace the nozzle, said clamping unit has to be removed and reattached using a special tool provided for that purpose. The clamping unit can have for this purpose, for example, recesses which have a particular profile and into which an appropriate tool can be inserted.
The nozzle can be exchanged while the connection part remains on the casting machine or after the connection part has been released from the casting machine.
It is favorable for the clamping unit to be able to fasten the nozzle in or to the connection piece, since the nozzle is exposed primarily to a force along the center axis while it is used in a casting machine and the nozzle can thus be secured optimally in the connection piece.
In an advantageous embodiment, the clamping unit is arranged in the connection piece so that the connection piece forms a closed component in which only the nozzle protrudes beyond the edges of the connection piece. This embodiment affords considerable advantages not only for the absorption of force but also for the cleaning of the connection piece.
In a particularly advantageous embodiment of the invention, the outer surface of the clamping unit can have a mounting device, in particular a thread or a width across flats or a knurl, as a result of which it is possible to accelerate the mounting of the clamping unit with the nozzle on the connection piece.
Advantageously, the clamping unit consists of metal, in particular a corrosion-resistant steel or stainless steel, or of aluminum or of plastic, in particular POM 6, since these materials are food-compatible.
The object is furthermore achieved by a casting machine having a connection piece as described above.
Further advantageous developments of the invention are defined in the dependent claims.
A number of exemplary embodiments are described in more detail in the following text with reference to the appended figures, in which:
Identical components are designated by the same references throughout the figures.
Furthermore, a clamping unit 2 is present, said clamping unit 2 likewise consisting of a plastics material, for example POM 6, and being connected to the connection piece 1. The two components 1, 2 are welded together, for example ultrasonically welded or laser welded. The outside diameter of the clamping unit 2 corresponds to the maximum outside diameter of the connection piece 1. Furthermore, the clamping unit 2 has a shoulder 15, which is suitable for pushing the flange 5 of the nozzle 3 against the surface 7 of the connection piece 1. Once the components 1, 2 and 3 have been connected, the shoulder 15 of the clamping unit 2 axially fixes the nozzle 3.
The outer lateral surface of the clamping unit 2 has surfaces 14 which correspond to the width across flats SW of the connection piece 1 and its surfaces 13, so that, following the mounting of the components 1, 2 and 3, four surfaces 13, 14 are formed jointly on the outside diameters of the connection piece 1 and of the clamping unit 2, on which a mounting tool is positioned for fastening the connection plate in a nozzle plate of a casting machine. In this case, the connection piece 1 has in the region of the tool engagement surface four grooves 17a, into which four corresponding claws 17b of the clamping unit 2 engage axially and act in a radially form-fitting manner, in order to introduce the torque of the mounting tool into the thread 4 on the connection piece 1. The clamping unit 2 extends axially beyond the connection piece 1 and supports the nozzle 3 by way of the inside diameter.
The nozzle 3 consists of an elastic material, for example NBR, and has two openings. One opening 18 is surrounded by a flange 5. The other opening 19 is closed by at least three elastic nozzle flaps. The nozzle 3 is mounted in a machine, i.e. a casting machine, as follows. The flange 5 of the nozzle 3 is pushed against the surface 7 in the form of a circular ring of the connection piece 1 and is pressed with the clamping unit 2 against the connection piece 1. The flange 5 of the nozzle 3 is arranged between the connection piece 1 and the clamping unit 2 and is fixed between the two components by the connection of the clamping unit 2 to the connection piece 1. In the process, the flange 5 is received by a chamber 21 which is formed on the inside and at the top by the connection piece 1 and on the outside and at the bottom by the clamping unit 2.
The clamping unit 2 has a cylindrical form with an outside diameter which corresponds to the outside diameter of the connection piece 1. The inside diameter of the clamping unit 2 is smaller than the outside diameter of the nozzle 3. As a result, in the mounted state the inside diameter of the clamping unit 2 exerts a pressure on the nozzle flaps 3a and closes the opening 19 in the nozzle 3. The clamping unit 2 furthermore has a shoulder 26 in the form of an L, which holds the cylindrical nozzle flange 5.
The nozzle 3 is pressed against the surface 7 of the connection piece 1 and is fixed by the clamping unit 2. The components are connected together by welding. Then, the connection piece 1 is fastened, for example screwed, by way of the fastening device 4 in a device, for example a nozzle plate, of a casting machine. The material to be cast first of all flows through the conical opening 6 or the countersink in the connection piece 1 and through the hole into the nozzle 3. The nozzle has nozzle flaps 3a, which are opened by the pressure of the mass and are bounded and stabilized by the connection piece 1 and/or clamping unit 2 during the open state.
In order that the nozzle 3 can be mounted in the casting machine, it is first of all inserted by way of the flange 5 into the groove 8 in the connection piece 1 and subsequently the clamping unit 2 is inserted into the hole 28 in the connection piece 1 until the terminating flange 31 of the clamping unit 2 sits in the flat countersink 29 in the connection piece 1. The clamping unit 2 presses by way of its outer lateral surface 32 against the inner lateral surface 33 of nozzle 3 and braces it to the connection piece 1. In addition, the connection piece 1 is connected, in particular adhesively bonded or welded, to the clamping unit 2. The connection piece 1, which is formed here from metal, has a knurl 9 in its outside diameter region.
The clamping unit 2 consists of a hollow cylinder having two different inside diameters. A sub-region of the clamping unit 2 has an inside diameter which is adapted to the connection piece 1. The adjoining smaller inside diameter is adapted to the diameter of the nozzle 3. In order to mount the nozzle 3 in the casting device, first of all the nozzle 3 is inserted into the groove 8 in the connection piece 1. The clamping unit 2 is pushed over the nozzle 3 and a region of the connection piece 1 so that an inner flange of the clamping unit 2 pushes against the nozzle flange 5 and fixes the latter. Then, the securing elements 11 are attached, said securing elements 11 preventing axial displacement of the clamping unit 2 against the connection piece 1. The securing elements 11 are firmly connected, for example adhesively bonded, to the connection piece 1. When the mass to be cast enters the connection piece 1 and passes through the internal cylinder of the connection piece 1 into the nozzle 3, a pressure is exerted on the nozzle 3 and would decouple the latter from the connection piece 1 without countermeasures being taken. Since the flange of the nozzle 3 is pressed by the clamping unit 2 against the groove 8 in the connection piece 1 and is held in this position by the securing elements 11, the pressure of the mass to be cast cannot remove the nozzle 3 from its position.
The clamping unit 2 has an internal thread 43, a holder 44 for a nozzle flange 5 and also a conical outlet opening 45. The nozzle 3 is mounted in the device in such a way that it is first of all inserted into the clamping unit 2 and is fastened to the clamping unit 2 on the connection piece 1. On account of the axial thread movement of the clamping unit 2 on the connection piece 1, the flange 5 of the nozzle 3 is pressed against the holder 44 for the nozzle flange 5 in the clamping unit 2 and the nozzle 3 is securely fixed.
Number | Date | Country | Kind |
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10 2008 055 518.5 | Dec 2008 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP09/67116 | 12/14/2009 | WO | 00 | 6/9/2011 |