DE202018102896U1 - casting system - Google Patents

Abstract

A vertically split casting system comprising: a first mold half and a second mold half, the first and second mold halves meeting at a vertical parting line and defining together a casting cavity and a riser cavity; andan exothermic feeder unit disposed in the feeder cavity, the feeder unit having a sprue, a chamber, and a spout in fluid communication with the casting cavity, the spout being separate from the sprue, the system having a molten metal flow path from the casting Gating the feeder unit defined via the chamber and the spout of the feeder unit to the casting cavity.

Description

The present invention relates to a system for casting metals in mold blocks. In particular, the invention relates to a vertically divided casting system with an exothermic feeder unit.

In order to meet the productivity requirements, automated green sand molding plants for mass production and mass production of small iron castings have become increasingly popular. Units for vertically split mold blocks (eg Disamatic boxless molding machines manufactured by DISA Industries A / S) can produce up to 450 to 500 mold blocks per hour and are often used for gray cast iron. In the Disamatic machine, one half of the model is mounted on the end of a hydraulically actuated plunger and the other half on a pivot plate (so-called because of its ability to move away from the mold and to pivot). Hard, rigid, boxless green sand mold blocks can be made with such machines.

In a typical casting process (horizontally or vertically split mold), molten metal is poured into a preformed mold cavity that determines the shape of the casting. Upon solidification, however, the metal shrinks, forming shrink cavities which, in turn, result in unacceptable defects in the finished casting. This problem is remedied by providing an additional (usually closed) volume or cavity connected to the casting cavity such that molten metal also passes into and fills the additional cavity via an opening leading from the casting cavity to form a metal reservoir. During solidification, the molten metal flows out of the reservoir and flows back through the opening into the casting cavity, thus compensating for the shrinkage of the melt. This is referred to as the melt / casting supply and the reservoir is commonly known as the "feeder", "feeder head" or "riser". Importantly, the metal in the feeder cavity remains molten longer than the metal is placed in the mold cavity and near the appropriate portion of the melt.

Feeders formed from the same material that forms the mold for the casting, usually sand, are called "natural feeders". The riser cavities are usually cylindrical or frusto-conical with an opening in their base and are typically completely enclosed in the mold block. They are generally referred to as "closed" feeders or risers or "blind feeders" or "blind risers". The feeder can be positioned vertically on the mold parting line in the case of two separate, interconnected mold halves. Alternatively, it may also be arranged completely in a mold block half and in a horizontal position. The type of feeder is determined by the dimensions and configuration of the casting (s) and running systems.

In certain casting systems, the feeder may be "open" with the top of the feeder being at the top of the mold so that in use the metal at the top of the feeder is exposed to the atmosphere. In the GB 1357410 described pouring device shows such a feeder in which the metal enters under pressure via a gate into the mold cavity, this fills and then flows through an opening upwards into the feeder cavity. As the melt cools and begins to shrink, the metal in the feeder flows back through the same opening into the melt, so that the feeder opening now serves as a spout while previously acting as a gate.

Supported feeders, commonly referred to as feeder systems, are designed to reduce the heat loss of the feeder, thereby slowing the cooling down and maintaining the liquid state for a longer time, allowing the melt to be fed a larger volume of feed metal. This means that the size of the feeder can be reduced (as compared to a nature feeder), resulting in potential benefits of higher casting yield, producing more castings on a single pattern plate and thus a single mold, lower cleaning costs (cleaning costs) and so forth , These feeder systems or feeders are typically chemically bonded refractory shapes and are designed to be highly insulating and / or exothermic. Exothermic inserts ignite upon contact with the molten metal and generate heat to retard solidification of the metal in the riser cavity.

The use of natural sand risers was originally the general approach when feeding castings made in vertically split mold blocks. With the increasing number and complexity of castings produced in vertically split molds and the consequent demands to increase the yield and the number of castings per mold, the use of feeder liners has begun, with inserts typically occurring at the joining seam of the forming block during the casting cycle Help an automatic Kernsetzers be attached. However, attaching the inserts to the seam (or parting line) of the mold block can be problematic if the inserts change position prior to or during the mold closing. This problem can be partially remedied by the use as in GB 2372004 A described modified with an outer flange.

Restricting the placement of feeders on the joining seam of the forming block also complicates the feeding of heavier, thicker sections of the casting. This limitation can be overcome by the use of metal liners or molds to create a feed path to isolated (usually thick) sections of the casting. However, this approach has only limited effectiveness and has several disadvantages that lead to higher cleaning costs and reduced casting yield. Natural sand climbers can also be used together with linings or molds, but this approach is only limited effectiveness, as it significantly reduces the casting yield and on the model plate often only a limited space is available, especially if several castings per form are provided.

The present invention has arisen in view of these problems to provide a method for the efficient production of consistently defect-free castings, especially when multiple castings are manufactured in a single mold.

• eine erste Formhälfte und eine zweite Formhälfte, wobei die erste und die zweite Formhälfte an einer vertikalen Trennfuge zusammentreffen und gemeinsam einen Gussteilhohlraum und einen Speiserhohlraum definieren; und
• eine exotherme Speisereinheit, die in dem Speiserhohlraum angeordnet ist, wobei die Speisereinheit einen Einguss, einen separaten Ausguss, der mit dem Gussteilhohlraum in Fluidverbindung steht, und eine Kammer zwischen dem Einguss und dem Ausguss aufweist,
• wobei das System einen Strömungspfad für geschmolzenes Metall von dem Einguss durch die Kammer und den Ausguss zum Gussteilhohlraum definiert.

According to a first aspect of the invention, there is provided a vertically split casting system comprising:

• a first mold half and a second mold half, wherein the first and second mold halves meet at a vertical parting line and together define a casting cavity and a riser cavity; and
• an exothermic feeder unit disposed in the feeder cavity, the feeder unit having a sprue, a separate spout in fluid communication with the casting cavity, and a chamber between the sprue and the spout,
• the system defining a molten metal flow path from the gate through the chamber and spout to the casting cavity.

It should be noted that the feeder unit is a self-contained element that can be removed from the feeder cavity. The feeder unit is inserted into the feeder cavity, thereby forming the casting system. An "exothermic feeder unit" is to be understood as meaning that the feeder unit is formed (in whole or in part) from an exothermic material.

During use, metal enters the mold during the casting process and flows through a gate into the feeder unit and via a separate spout into the casting cavity. Once the mold is filled, there is a reservoir of molten metal in the chamber of the feeder unit located between the inlet and the spout. Because the feeder unit is exothermic, the metal trapped in the chamber remains molten longer than the metal in the casting cavity, such that the feeder unit supplies the melt with molten metal through the nozzle of the feeder while the metal in the casting cavity is solidified and shrinking. The system thus enables an improved point supply of the melt.

It is therefore understood that the term "gate" as used herein refers to an opening in the feeder unit through which metal enters the chamber in use. The sprue may be separate from or spaced from a surface of the mold. For example, the metal may flow from a sprue or runner system through the gate.

It will also be understood that the term "spout" as used herein refers to an opening in the feeder unit through which metal comes out of the chamber during use. The metal may flow from the chamber through the spout into a casting cavity, runner, or subchamber.

In some embodiments, the spout is not in the same plane as the gate. In some embodiments, the spout is orthogonal with respect to the gate. For example, the sprue in a first wall of the feeder unit and the spout may be arranged in a second wall of the feeder unit. In embodiments with multiple gates and / or spouts, each gate / spout may be disposed in another wall of the feeder unit.

In use, the feeder unit defines a molten metal flow path from the gate to the spout via the chamber.

In addition, in some embodiments, the first and second mold halves define a sprue which is in fluid communication with and upstream of the sprue of the feeder unit. It is known to those skilled in the art that a pouring funnel is essentially a funnel through which molten metal enters the pouring system. The pouring funnel has a sprue and a spout. The sprue is usually much wider than the spout, leaving a large area where metal can be poured. The spout of the sprue opens either directly or via one with the sprue of the feeder unit connected bleed into the sprue of the feeder unit. The pour-in funnel may be located between the sprue of the feeder unit and a surface of the mold. It is therefore taken for granted that the pouring funnel is a separate element from the feeder cavity and the feeder unit.

In some embodiments, the system includes a plurality of casting cavities and optionally a plurality of riser cavities. Of course, a system according to these embodiments may be formed in one of several different ways. For example, the number of casting cavities may correspond to the number of feeder cavities and feeder units. Alternatively, there may be more die cavities than feeder cavities and feeder units such that one or more of the feeder cavities and feeder units are configured to supply more than one casting cavity. However, of course, in all embodiments, a feeder cavity may contain only a single feeder unit.

In some embodiments, the first and second mold halves define two or more mold cavities and two or more riser cavities, with a riser unit disposed in each mold cavity, and each riser unit having a spout in fluid communication with only one of the mold cavities.

In some embodiments, the first and second mold halves define two or more casting cavities and a riser cavity, wherein a riser having two or more spouts is disposed in the riser cavity and wherein each casting cavity is in fluid communication with another spout.

In embodiments where the system has two or more riser cavities, the riser cavities may be arranged in series and each riser cavity may be connected by a mold channel to the next cavity in the series. The casting channel may extend between a spout of a feeder unit located in one of the feeder cavities and the gate of a feeder unit located in the next feeder cavity. Of course, in these embodiments, apart from the last riser cavity of the series, a feeder unit in each feeder cavity has one or more spouts more than the number of casting cavities fed by that feeder unit. For example, if the feeder unit is in fluid communication with two casting cavities, it must have three spouts; two for feeding the casting cavities and a spout in fluid communication with the casting channel. The sprue of a feed unit downstream of the row may have a smaller opening than the sprue of a feeder unit at the beginning of the row to prevent air trapping in the system.

In some embodiments, the first and second mold halves 2n define casting cavities and n feed cavities, where n is an integer between 1 and 5. In some embodiments, n is 1, 2, or 3. In embodiments with n> 1, the riser cavities may be arranged one behind the other and connected by a runner.

In some embodiments, the first and second mold halves define four mold cavities and first and second riser cavities arranged in series and connected by a runner, wherein a first riser is disposed in the first riser cavity and a second riser is disposed in the second riser cavity. The first feeder unit has a sprue and three spouts, two of the spouts each being in fluid communication with a casting cavity and the third spout being in fluid communication with a gate of the second feeder via the casting channel. The second feeder unit has two spouts, each connected to a casting cavity. Thus, each of the four casting cavities is in fluid communication with another of the spouts.

In some embodiments where the system has two or more serially located riser cavities, the riser cavities are vertically aligned.

In some embodiments, the or each casting cavity has a core.

According to a second aspect of the invention, there is provided a feeder unit for use in a casting system according to the first aspect of the invention, wherein the feeder unit comprises a sprue, a separate spout and a chamber between the sprue and the spout.

In use, the feeder unit defines a molten metal flow path from the gate to the spout via the chamber.

In some embodiments, the feeder unit has at least two spouts. The feeder unit can have three, four or even five spouts.

In some embodiments, the sprue and at least one of the spouts are not in the same plane. For some Embodiments, at least one spout is arranged orthogonal to the sprue.

In some embodiments, the feeder unit further includes an outer protrusion for securing the feeder unit in the feeder cavity. The projection may be in the form of a pin (eg, a square or rectangular pin) protruding from an outer surface of the feeder unit. When the feeder unit is within the feeder cavity, the protrusion may be received in a recess located in the first mold half or the second mold half. The shape of the recess may be complementary to the shape of the projection to allow a frictional engagement between the feeder unit and the mold half.

In some embodiments, the feeder unit further includes a filter located in the flow path between the sprue and the spout. The filter may be near the gate so that molten metal flows through the filter before entering the chamber. The filter has two advantages, cleaning the metal by removing inclusions and reducing turbulence in the metal stream. Placing the filter within the feeder unit rather than positioning the filter in an upstream runner system provides a shortened flow path between the filter and the casting cavity, thereby increasing the purity of the molten metal entering the melt and thus improving the quality of the casting.

Of course, not every feeder unit of the casting system must contain a filter. Therefore, in some embodiments, only a portion of the feeder units of the casting system has a filter. In some embodiments, where two or more feeder cavities and the feeder units disposed therein are arranged in series, only the first (upstream) feeder unit of the row comprises a filter.

The feeder unit may be approximately cuboid, having a first end, a second end and four side walls therebetween. The sprue may be formed by an opening in the first end. The spouts may be formed as openings in one or more of the side walls and / or the second end. Thus, the feeder unit may be considered essentially closed or "blind".

To accommodate a filter, the feeder unit may include one or more internal shoulders or walls to place the filter in the desired position. In some embodiments, a plurality of shoulders are spaced around the inner surfaces of the sidewalls of the feeder unit. However, the feeder unit preferably has a single shoulder or wall that extends completely around the inner surfaces of the sidewalls. Not only does this cause the filter to be in the desired position, but all edges of the filter are supported as molten metal entering the feeder unit impacts the filter surface and metal is prevented from flowing past the filter during casting.

In some embodiments, the feeder unit further includes an inner wall having an opening therein, the inner wall being disposed parallel to the first and second ends and closer to the first end than the second end. This creates between the first end and the inner wall, an inner cavity in which the filter can be arranged.

In some embodiments, the feeder unit is formed by two halves that are connected together along a parting line. The two halves can be glued together or connected by means of a plug connection. One half of the feeder unit has the outer projection. Recesses are formed in one or both halves of the feeder unit. When joining the two halves, the recesses define openings that form the inlets and outlets of the feeder unit.

The feeder unit may be formed of any suitable refractory or exothermic material. Feeders are typically made from a mixture of low and high density refractory fillers (e.g., quartz sand, olivine, hollow microspheres, and aluminum silicate, chamotte, alumina, pumice, perlite, vermiculite) and binders. Exothermic feeders additionally contain a fuel (usually aluminum or an aluminum alloy), an oxidizer (usually iron oxide, manganese dioxide or potassium nitrate) and usually initiators / sensitizers (usually cryolite).

• - Bilden einer ersten Formhälfte mit einer ersten vertikalen Fläche, die einen ersten Teil eines Gussteilhohlraums und einen ersten Teil eines Speiserhohlraums definiert;
• - Bilden einer zweiten Formhälfte mit einer zweiten vertikalen Fläche, die einen zweiten Teil des Gussteilhohlraums und einen zweiten Teil der Speiserhohlraums definiert;
• - Bereitstellung einer exothermen Speisereinheit, die einen Einguss, einen separaten Ausguss und zwischen dem Einguss und dem Ausguss eine Kammer aufweist;
• - Einsetzen der Speisereinheit in den ersten oder den zweiten Teil des Speiserhohlraums, sodass der Ausguss mit dem ersten Teil des Gussteilhohlraums in Fluidverbindung steht; und
• - Zusammenfügen der ersten und zweiten vertikalen Fläche der ersten und zweiten Formhälfte, um das vertikal geteilte Gießsystem zu bilden, das den Gussteilhohlraum und den Speiserhohlraum umfasst, wobei sich die Speisereinheit innerhalb des Speiserhohlraums befindet.

A method for producing a vertically divided casting system comprises:

• Forming a first mold half having a first vertical surface defining a first part of a casting cavity and a first part of a feeder cavity;
• Forming a second mold half having a second vertical surface defining a second part of the mold cavity and a second part of the riser cavity;
• - Providing an exothermic feeder unit having a sprue, a separate spout, and a chamber between the sprue and the spout;
• Inserting the feeder unit into the first or the second part of the feeder cavity so that the spout is in fluid communication with the first part of the casting cavity; and
• - assembling the first and second vertical surfaces of the first and second mold halves to form the vertically split molding system comprising the casting cavity and the riser cavity, the riser unit being within the riser cavity.

The method can be at least partially automated.

The first and second mold halves may be manufactured by means of a vertically split mold unit, such as a machine manufactured by DISA Industries A / S (sold under the trade name DISAMATIC).

A DISAMATIC usually consists of a forming machine and a forming conveyor and produces an endless chain of molded parts, one side of the molding forming the first mold half of a molding system and the other side of the same molding forming the second mold half of the next molding system. One model half is mounted on the end of a hydraulically actuated plunger and the other half on a pivot plate so called because of its ability to move away from the finished mold and pivot upwardly. A green sand mixture is blown with compressed air into a rectangular steel chamber and then pressed against the two models located at both ends of the chamber. After pressing, the pivot plate pivots back and up to open the chamber and the opposite plate pushes the finished mold onto a conveyor. Finally, cores are automatically inserted into the mold cavity using an automatic core inserter while the next mold is being prepared. The cycle repeats until a series of finished molds abut each other on the conveyor and ready for pouring. The molds are then filled with molten metal and placed on a cooling conveyor belt which moves at the same speed as the mold conveyor. Solidified castings are released from the molds and the sand is recycled and reused in subsequent cycles of the DISAMATIC molding process.

The step of inserting the feeder unit into the first or second part of the feeder cavity may be automated. The feeder unit can be used with the help of a Kerneinlegers.

The method may also include inserting a core into the first or second part of the casting cavity. A core can be used with the help of a core inserter.

The step of forming the first or second mold halves may include forming a recess in the first or second portion of the riser cavity to receive a protrusion extending from an outer surface of the riser unit, and the step of inserting the riser unit includes inserting the protrusion into the recess. The recess may be formed by making a mold model having a projection corresponding in size and shape to that of the feeder unit which is complementary to the resulting recess.

The embodiments described herein with reference to the first or second aspect of the invention may, of course, also relate to other aspects of the invention, unless otherwise specified.

• 1a eine Draufsicht auf ein Gießsystem nach dem ersten Aspekt der vorliegenden Erfindung zeigt,
• 1b eine Seitenansicht eines Teils einer DISAMATIC-Formmaschine zur Herstellung des in 1a dargestellten Gießsystems zeigt,
• 1c eine Seitenansicht des in 1a dargestellten Gießsystems zeigt,
• 2 eine perspektivische Ansicht einer Speisereinheit gemäß einer Ausführungsform nach dem zweiten Aspekt der Erfindung zeigt,
• 3 eine perspektivische Ansicht einer Speisereinheit gemäß einer anderen Ausführungsform nach dem zweiten Aspekt der Erfindung zeigt,
• 4a eine perspektivische Ansicht eines Teils der in 3 dargestellten Speisereinheit zeigt,
• 4b einen Querschnitt durch die in 3 dargestellte Speisereinheit zeigt, die ferner einen Filter aufweist, und
• 5 eine Draufsicht auf ein Gießsystem des Stands der Technik zur Herstellung des gleichen Gussteils wie in 1a dargestellt zeigt.

Embodiments of the invention will now be described with reference to the accompanying figures, of which:

• 1a shows a plan view of a casting system according to the first aspect of the present invention,
• 1b a side view of a portion of a DISAMATIC molding machine for the production of in 1a shown casting system shows
• 1c a side view of the in 1a shown casting system shows
• 2 shows a perspective view of a feeder unit according to an embodiment according to the second aspect of the invention,
• 3 shows a perspective view of a feeder unit according to another embodiment according to the second aspect of the invention,
• 4a a perspective view of a part of in 3 shown feeder unit shows
• 4b a cross section through the in 3 shown feeder unit, which further comprises a filter, and
• 5 a plan view of a casting system of the prior art for producing the same casting as in 1a shown shows.

The 1a and 1c show a casting system 100 according to the first aspect of the invention, having a first mold half A and a second mold half B, which at a vertical parting line X (see 1c ) meet each other. In 1a is the parting line (not shown) in the plane of the paper. The first mold half A and the second mold half B can be made of any suitable molding material, such. As clay-bound green sand, be formed.

The first mold half A and the second mold half B together define the casting cavities 2 and esophageal cavities 4 where the riser cavities 4 over a casting channel 6 are connected. Every feeder cavity 4 contains an exothermic feeder unit 8a . 8b , The feeder units 8a . 8b each have a gate 10a , 10b for receiving molten metal and a spout 12 on top of each of the casting cavities 2 that attach to the two sides of the esophageal cavity 4 located above secondary cavities 13 is in fluid communication. The upper feeder unit 8a has another lower spout 14 in fluid communication with the casting channel 6 on. The sprue 10a the upper feeder unit 8a stands with a pouring funnel 16 in fluid communication, during the sprue 10b the lower feeder unit 8b in fluid communication with the casting channel 6 stands and thus with the lower spout 14 the upper feeder unit 8a connected is.

In use, molten metal flows from the pouring funnel 16 through the feeder units 8a . 8b and in the casting cavities 2 , Accordingly, in which in the 1a and 1c shown system, the feeder unit 8a downstream of the pouring funnel 16 arranged. The casting cavities 2 have a core 18 which is flowed around by the molten metal, whereby a cavity is formed in the finished casting. The feeder units 8a . 8b serve as reservoirs for molten metal which, as the molten metal cools and shrinks, forms the casting cavities 2 Food.

1b shows a part of the molding machine with which the mold is made. After pressing the molding sand with the help of the two halves of the model 3a and 3b pivots the Schenkplatte 5 90 degrees up in the direction of P and the press plate 7 moves horizontally towards Q and pushes the shape 9 along the conveyor 11 ,

1c shows two forms 9 ' and 9 " made with molding machine and models made in 1b are shown after they have been moved away from the molding machine along the conveyor. After releasing the models, a core inserter (not shown) places the cores 18 and the feeder units 8a and 8b in the mold half B 'before the mold 9 " is advanced so that the mold half A "on the mold half B 'is applied and so the casting system 100 forms.

2 shows a perspective view of a feeder unit 8b according to the second aspect of the invention. The feeder unit 8b is generally cuboid with a first end 20b , a second end 22b and four side walls in between 24 . 26 , The walls and ends of the feeder unit 8b define a chamber. The side walls 24 . 26 are slightly longer than the width of the first and second ends 20b . 22b , The first end 20b has a short neck 27b on, which has a smaller width than the rest of the feeder unit 8b ,

The feeder unit 8b also has an outer projection 28 in the form of a rectangular spigot extending from an outer surface of one of the side walls 24 extends away. The lead 28 is located on the side wall 24 approximately in the middle between the first end 20b and the second end 22b and is formed so that the longitudinal sides of the rectangular pin parallel to the first and second ends 20b . 22b are aligned.

The sprue 10b the feeder unit 8b is from a slot in the first end 20b formed, wherein the slot is centered in the first end 20b lies. The spouts 12 the feeder unit 8b are as generally elongated openings in the side walls 26 on both sides of the sidewall 24 formed, from which the projection 28 protrudes. The spouts 12 are in the middle of the side walls 26 arranged and aligned so that the elongated openings between the first and second ends 20b . 22b extend. The openings that the spouts 12 form, are larger than the opening that the sprue 10b forms. The second end 22b has no opening.

The feeder unit 8b is from two halves 30b . 32b formed, which are joined together along the parting line Y. The first half 30b has the outer projection 28 on while the second half 32b Has recesses that the sprue 10b and the spouts 12 form when the first and second halves 30b, 32b are joined together at the parting line Y. The first half 30b has sloping channels at the edges 31 on top of the side of the sinks 12 form. The first and second half 30b . 32b expand slightly in the direction of the parting line Y, so that the feeder unit 8b at the joint between the two halves seems to bulge slightly.

3 shows a perspective view of a feeder unit 8a according to another embodiment of the second aspect. The feeder unit 8a is largely similar to the one in 2 shown feeder unit 8b made of two halves 30a and 32a is formed, which are joined together at the parting line Y. The feeder unit 8a is generally cuboid and has a first end 20a , a second end 22a and four side walls in between 24 . 26 as well as an outer projection 28 up, extending from one of the side walls 24 extends away. The feeder unit 8a also has an opening in the second end 22a on top of the lower spout 14 forms. The first half 30a includes the outer projection 28 while the second half 32a has the recesses that the sprue 10a and the spouts 12 . 14 define. The openings that the sprue 10a and the lower spout 14 are generally trapezoidal, with the sprue 10a slightly larger and more equilateral than the lower spout 14 is. The neck 27a at the first end 20a the feeder unit 8a is longer than the neck 27b the feeder unit 27b from 2 ,

4a shows a perspective view of the feeder half 32a the feeder unit 8a, which in 3 is shown. The feeder unit 8a has an inner wall 34 with an opening on. The inner wall 34 is parallel to the first and second ends 20a , 22a of the feeder unit 8a but located closer to the first end 20a as at the second end 22a , Between the first end 20a and the inner wall 34 there is an internal cavity 36 ,

4b shows a cross section through the parting line Y in 3 shown feeder unit 8a , being a filter 40 is shown, the inside of the neck 27a in the cavity 36 between the first end 20a and the inner wall 34 is arranged.

5 shows a plan view of a casting system 200 of the prior art, which is designed to be the same casting 2 as in 1a shown created. This in 5 shown system has six natural sand climbers (feeder) 208a . 208b . 208c , 208d, 208e, 208f, each with a bleed 210a . 210b . 210c . 210d . 210e , 210f are connected to supply liquid metal. Each of the two upper natural sand feeders 208a and 208b has a spout that has a secondary cavity 213 each with a casting cavity 212a . 212b is in fluid communication. Every feeder 208a . 208b also has a lower spout in fluid communication with a casting channel 206a of a lower natural sand feeder 208c, 208d via a gate 210c . 210d fed. The lower natural sand feeders 208c, 208d each have a secondary cavity 213 with a lower casting cavity located near the natural sand feeder 212c . 212d in fluid communication. The other two central natural sand feeders 208e . 208f stand above secondary cavities 213 with two to either side of the natural sand feeder 208e , 208f disposed in fluid communication with casting cavities. The upper natural sand feeder 208e has another lower spout which is in fluid communication with a casting channel 206b stands the lower natural sand feeder 208f over a bleed 210f fed.

In use, metal flows from a pour-in funnel 216 in a horizontal cavity or casting channel 205 and over the gates 210a . 210b . 210e in the upper natural sand feeder 208a . 208b and 208e and into the upper casting cavities 212a, 212b. About the casting channels 206a . 206b and the cuts 210c . 210d . 210f Metal flows into the lower natural sand feeder 208c . 208d . 208f and in the lower casting cavities 212c . 212d , The metal in the natural sand risers 208a . 208b , 208c, 208d, 208e, 208f feed the casting cavities 212a . 212b . 212c . 212d when the molten metal cools and shrinks in it.

Examples

Tests were carried out in a European iron foundry producing various castings of gray and ductile cast iron for the automotive industry.

Comparative example - known casting method

An automatic molding line DISAMATIC was equipped with the in 5 shown casting system 200 Brake caliper housing made of ductile cast iron. Four molds were produced per mold, fed by a total of six natural sand feeders. The total casting weight (castings, running system and feeders) was 33 kg and the weight of each casting 3.65 kg, so that the casting yield was 44.2%.

example 1

Using the MAGMASOFT simulation software to predict the flow and solidification of metal, the casting system of Comparative Example ( 5 ) by replacing the six natural sand feeds with two exothermic feed units according to the invention. MAGMASOFT is a leading simulation tool of MAGMA Gießereitechnologie GmbH, which models the molding and the solidification of melts. It is typically used by foundries to predict the mechanical properties of castings to optimize the casting process (design of the runner system and feeders), thereby avoiding costly and time-consuming foundry trials. With the full version of MAGMASOFT, the inventors performed simulations of various process configurations and feeder dimensions and sizes to predict the flow (direction and velocity) and solidification (temperature profiles over time) of metal in the runner systems, feeder units, and melts. After the simulation of over 25 The design was the in 1a shown casting system using each one of the two in the 2 . 3 . 4a and 4b shown feeder units 8a and 8b designed.

The model plate used by the foundry to make the castings according to the comparative example was modified so that the foundry could produce castings using exothermic feeder units on its DISAMATIC production line. The feeder units were placed in the feed cavities of the sand mold simultaneously with the sand cores during the DISAMATIC forming cycle so that there are no delays, i. H. no cycle time extensions and thus no productivity losses came.

The castings were made with the same metal composition and temperature as in the comparative example. The casting time was the same ( 9 Seconds). It was found that the total casting weight was only 20.5 kg, which corresponds to a casting yield of 71.2%, which is well above the comparative example. This is due to the reduction in the number and size of feeders. In addition to improving the yield, a reduction of scrap contents due to shrinkage by 10% was also observed. Even taking into account the costs of the additional exothermic feeder units, the use of the new casting system resulted in a significant cost savings per mold (casting) and an overall reduction in emissions due to the lower metal consumption.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• GB 1357410 [0005]
• GB 2372004 A [0007]

Claims (20)

Vertically split casting system comprising: a first mold half and a second mold half, wherein the first and second mold halves meet at a vertical parting line and together define a casting cavity and a riser cavity; and an exothermic feeder unit located in the feeder cavity, the feeder unit having a sprue, a chamber and a spout in fluid communication with the casting cavity, the spout being separate from the sprue, the system defining a molten metal flow path from the feed unit via the chamber and the spout of the feeder unit to the casting cavity. Casting system after Claim 1 wherein the feeder unit further comprises a filter disposed in the flow path between the sprue and the spout. Casting system after Claim 1 or Claim 2 wherein the first and second mold halves further form a pour-in funnel located upstream of and in fluid communication with the feed unit's gate. Casting system according to one of the Claims 1 to 3 wherein the first and second mold halves form two or more casting cavities. Casting system after Claim 4 wherein the feeder unit has two or more spouts, each die cavity being in fluid communication with only one spout. Casting system after Claim 4 or Claim 5 wherein the first and second mold halves form two or more riser cavities arranged in series and connected by a casting channel, the system further comprising two or more riser units disposed in the respective riser cavities, and wherein each riser unit has a spout is in fluid communication with only one of the casting cavities. Casting system after Claim 6 wherein the first and second mold halves 2n form casting cavities and n feed cavities, where n is an integer between 1 and 5. Casting system after Claim 6 or Claim 7 with the riser cavities aligned vertically. The casting system of any one of the preceding claims, wherein the feeder unit has an outer protrusion extending into a recess formed in the first mold half or the second mold half to secure the feeder unit in the feeder cavity. The casting system of any one of the preceding claims, wherein the casting cavity further comprises a core. A casting system according to any one of the preceding claims, wherein the feeder unit is formed of two halves split along a parting line and one or both halves have recesses defining the sprue and the spout (s) of the feeder unit when the two halves are joined together become. An exothermic feeder unit for use in a casting system according to any one of the preceding claims, wherein the feeder unit has a sprue, one or more spouts, and a chamber between the sprue and the spout (s) and the feeder unit has a flow path from the sprue over the chamber to the spout / the spouts defined. Exothermic feeder unit after Claim 12 that has two or more spouts. Exothermic feeder unit after Claim 12 or Claim 13 , wherein at least one spout is arranged orthogonal to the sprue. Exothermic feeder unit according to one of Claims 12 to 14 further comprising an outer projection for securing the feeder unit in a feeder cavity. Exothermic feeder unit after Claim 15 wherein the projection is in the form of a pin projecting away from an outer surface of the feeder unit. Exothermic feeder unit according to one of Claims 12 to 16 wherein the feeder unit is approximately cuboid and has a first end, a second end and between these four side walls, and wherein an opening in the first end forms the sprue. Exothermic feeder unit after Claim 17 further comprising a filter disposed in the flow path between the gate and the spout. Exothermic feeder unit after Claim 18 further comprising one or more inner shoulders or walls for positioning the filter. Exothermic feeder unit after Claim 18 or 19 comprising an inner wall having an opening formed therein, the inner wall being disposed parallel to the first and second ends, such that an inner cavity is formed between the first end and the inner wall in which the filter is disposed.

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