RU175450U1 - SUPPLY SYSTEM - Google Patents

Abstract

The metal casting feed system comprises a profit sleeve having a flat base, a roof above the base and a side wall between the roof and the base, in which the side wall is discontinuous so that the profit sleeve is open on one side. The feed system also comprises a substantially flat jumper rod with a through hole that is mounted on the open side of the profit sleeve perpendicular to the base, and the profit sleeve and jumper rod together define a closed cavity for storing molten metal, with the exception of the hole in the jumper rod . The feed system provides an alternative to the standard side profits used in conjunction with the intake gate.

Description

FIELD OF TECHNOLOGY

This technical solution relates to a feed system for use in metal casting operations in which molds are used.

In a typical casting process, molten metal is poured into a preformed mold cavity that defines the shape of the cast. However, during crystallization, the metal shrinks, which leads to the formation of shrinkage shells, which, in turn, leads to unacceptable defects in the finished casting. This problem is well known in metallurgy and is solved with the help of profit inserts or risers, which are integrated into the mold either during molding (molded bushings) or inserted later (plug bushings). Each profit sleeve provides an additional (usually enclosed) volume or cavity communicating with the mold cavity so that molten metal also enters this profit sleeve. During crystallization, the molten metal in the profit sleeve flows back into the mold cavity to compensate for the shrinkage of the casting. It is important that the metal in the cavity of the sleeve of the profit remains molten longer than the metal in the cavity of the mold, therefore, the sleeve of the sleeve is made insulated or, more often, exothermic, so that additional heat is generated upon contact with the molten metal to delay crystallization.

The profit sleeve may be located above the mold cavity (commonly known as the "profitable extension" or top feeder) or next to the mold cavity (known as the "side feeder"). During the preparation of the mold, the upper feeders can be installed on the upper horizontal surfaces of the model so that they are in direct contact with the surface of the casting. Alternatively, the side feeders can be positioned above the inlet gates that connect the gating system to the mold cavity, or above the area of the base and neck of the feeder, all of which are horizontally connected to the mold cavity. Due to the different crystallization properties and make-up requirements, steel castings essentially require shorter channels leading to profit than cast iron castings, which requires a plurality of sprues distributed over the olive.

After crystallization of the casting and removal of the mold material, the unwanted residual metal from the profit sleeve remains attached to the casting and must be removed. To facilitate removal of residual metal, the cavity of the profit sleeve may taper toward the base (i.e., toward the end of the profit sleeve that is closer to the mold cavity) in a structure commonly referred to as a narrow neck sleeve. When the residual metal is subjected to a sharp impact, it is separated at the weakest point, which is next to the casting (a process called chipping). It is also desirable to create a small base on the casting in order to enable the positioning of the bushings in the areas of the casting where access may be restricted by neighboring elements.

Although the bushings may have come directly to the surface of the mold cavity, they are often used in combination with a feed element (also known as a lintel). The lintel is simply a disk of refractory material (typically a rod of sand bonded with resin, a ceramic rod or a rod of material of a profit sleeve) with a hole, usually located in its center, which is installed between the mold cavity and the profit sleeve. The diameter of the hole in the jumper rod has a size smaller than the diameter of the inner cavity of the profit sleeve (which does not have to taper), so the cut-off occurs on the jumper rod near the surface of the casting. To further facilitate the stubbing, the bore of the web-jumper often has such a profile as to form a V-shaped groove in the metal neck arrived.

In some cases, there may be restrictions on the size of the flask in which the mold is prepared, so that there is not enough height to fit the top profit sleeve. In addition, some models do not have an upper flat surface on which to place the profit hub. Although the use of intake gates or profit side sleeves avoids the need for a flat top surface on the model, such an intake gate increases the distance between the mold cavity and the profit hub and, therefore, increases the amount of metal required.

This solution has been designed with these in mind.

According to a first aspect of the solution, there is provided a feed system for casting a metal, comprising:

a profit sleeve having a flat base, a roof above the base and a side wall between the roof and the base, in which the side wall is discontinuous so that the profit sleeve is open on one side; and,

essentially a flat jumper rod having a through hole mounted on the open side of the sleeve arrived perpendicular to the base, while the profit sleeve and jumper rod together define a closed cavity for molten metal, with the exception of the hole in the jumper rod.

The system according to the present decision is a lateral profit (feeder), and a flat base allows you to install the feeding system next to the model during the preparation of the mold. Essentially, the flat structure of the side-mounted jumper rod means that the feed system can be installed in direct contact with the flat vertical side of the model. When the model is removed, the hole of the web-jumper is in direct contact with the cavity of the mold. The feed system of the present solution, therefore, provides an alternative to the standard side gains used in conjunction with the intake gate. Due to the direct feeding of the casting (instead of feeding through the inlet gate), the volume of metal in the system is reduced. As a result, waste is reduced and the yield of finished products increases.

The profit sleeve may be of any conventional size or shape. In some embodiments, the profit sleeve has a substantially rectangular or square section. The side wall of the hub of the sleeve extends around the periphery of the base. Thus, it should be understood that in embodiments where the section of the profit sleeve is substantially rectangular or square, the base of the profit sleeve is also rectangular or square. The side wall may extend around three sides of a square or rectangle, and the fourth side is formed by a jumper rod. The side wall, thus, may contain two opposite side sections and a rear section located between the side sections, while the rear section is located opposite the jumper rod. The side sections and the rear section can be molded in one piece, or the side wall can be formed by three separate sections connected to each other by their edges.

In some embodiments, the feed system has a substantially D-shaped cross section. In other words, the feed system has three flat sides (one of which is formed by a jumper rod) and one curved side. In some embodiments, the side wall of the bushing arrived has two opposite side sections and a rear section extending between the side sections, with the rear section opposite the bulkhead and the rear section curved (convex).

Typically, the lower corners formed between the side wall and the base, or between the side wall, the jumper rod and the base, may be straight or slightly beveled. Right or chamfered corners are preferred because if the corners are too rounded, sand cannot be effectively packed under the feed system during the preparation of the mold, which can lead to casting defects.

In some embodiments, the roof and side wall are made in one piece. Alternatively, the side wall and the roof may separate, i.e. the roof is designed as a cover. The roof can be flat, sloping, curved (e.g. convex) made in the form of a dome, partial dome, dome with a flat top or have any other suitable shape. The roof of the supply system can be closed so that the cavity is completely closed, with the exception of the hole in the jumper rod.

A wedge insert can be inserted into the sleeve (Williams Wedge wedge). It can be plug-in or, preferably, made in one piece during the manufacture of the sleeve and take the form of a prism located on the inner side of the roof of the sleeve. During casting, when the sleeve is filled with molten metal, the edge of the Williams wedge provides atmospheric piercing of the surface of the molten metal and relieves the vacuum that occurs inside the profit, providing a more streamlined recharge.

The profit sleeve according to the present decision may contain or be made of any suitable refractory insulating and / or exothermic material or composition from which known profits can be formed, and a specialist can select suitable materials for each specific task. The nature of the material of the sleeve of the profit is not specifically limited and may be, for example, insulating, exothermic, or both at the same time. The manufacturing method is also not particularly limited and may be a vacuum molding process or a sandblasting method. Typically, a profit sleeve is made from a mixture of low and high density refractory fillers (e.g., silica sand, olivine, aluminosilicate hollow microspheres and fibers, fireclay, alumina, pumice, perlite, vermiculite) and binders. The exothermic sleeve further requires fuel (usually aluminum or an aluminum alloy), an oxidizing agent (usually iron oxide, manganese dioxide or potassium nitrate) and usually initiators / sensitizers (usually cryolite).

The profit sleeve can be molded by any of the known methods of forming profits, for example by vacuum molding the pulp of the sleeve material around the model and inside the external shape, after which the sleeve is heated to remove water and to harden or dry the material. Alternatively, the profit sleeve can be molded by stuffing or blowing material into a core box (sandblasting method) and curing the sleeve by passing reaction gas or catalyst through the sleeve to harden the binder, or by heat, using a heated core box, or by removing the sleeve and heating it in ovens. Profitable compositions include, for example, compositions sold by Foseco under the trade names KALMIN and KALMINEX, which are suitable for both pulp and sandblasting.

The density of the sleeve of the profit depends on the composition, and on the method of its manufacture. In some embodiments, the profit density does not exceed 1.5 g / cm ³ , does not exceed 1.0 g / cm ³ or does not exceed 0.7 g / cm ³ . In some embodiments, the profit density is from 0.8 to 1.0 g / cm ³ or from 0.5 to 0.7 g / cm ³ .

The lintel is designed to reduce the area of contact between the profit and the casting, and typically it can be based on alumina or, sometimes, on a chromite molding mixture created by blowing sand coated with novolac phenol-formaldehyde resin into a heated core box allowing the resin to melt and then harden (Croning process). Alternatively, the jumper rod may be made of a highly refractory ceramic material or a deformable metal such as a steel plate.

The thickness of the bulkhead depends in part on the size of the profit, and a typical bulkhead of the moldable mixture has a thickness of 8-15 mm, and the more durable ceramic core of the bulkhead typically has a thickness of 5-10 mm. The jumper rod is mounted on the profit sleeve and fastened with glue, typically hot glue.

There is a hole (through channel) in the jumper rod, which in some cases is located next to the base of the supply system. The hole creates a passage for molten metal from the cavity of the feed system into the cavity of the mold for feeding the casting as it cools and shrinks. The position and size of the hole can be selected according to the geometry of the casting and the requirements of the feed. The hole may be located facing or adjacent to the base of the feed system so that molten metal can flow into the mold cavity by gravity. In some embodiments, the hole is located centrally on the longitudinal axis of the jumper rod. Alternatively, the hole may be offset vertically (left or right) with respect to the longitudinal axis of the bridging rod. It should be understood that, in essence, it is desirable to create the highest possible height of the metal for feeding, so that the hole is located as low as possible in the jumper rod. It also minimizes the reservoir of unused metal under the hole.

The diameter of the hole can be compared with the maximum diameter of the cavity (both are measured in a plane perpendicular to the longitudinal axis of the feed system). In one embodiment, the diameter of the hole does not exceed 40, 30, 20, 15, or 10% of the maximum diameter of the cavity.

The jumper rod can form a complete wall of the supply system so that the maximum height of the jumper rod is equal to the maximum height of the profit sleeve.

In some embodiments, the feed system has a length A, measured from the end of the jumper rod for the rear section, opposite the jumper rod, and between two side sections, the length being measured to the maximum point of curvature, while the back section is curved or has a D-shape , and a width measured from the outside between the two side sections of the profit and component from 0.4 × A to 2 × A. In some embodiments, the feed system has a maximum height of 1 × A to 3 × A, depending on the size of the casting and profit requirements, which typically is from 8 cm to 25 cm or more.

A method of preparing a horizontally divided mold for casting metal may include stages in which:

take a model board with an installed casting model for determining the upper part (upper half-mold) of the desired casting cavity, having at least one horizontal flat surface adjacent to the vertical surface of the model;

place the feed system according to the first aspect of the present solution on this horizontal surface so that at least a portion of the jumper rod with the hole is flush with the vertical surface of the model;

surround the model and the feed system with a molding compound;

compacting the molding mixture;

remove the model and model board from the compacted sand to obtain the upper mold;

prepare the lower half-mold in the same way as the upper half-mold, without the use of a feeding system and

place the upper mold half on the lower mold half.

Therefore, it is understood that the mold has a horizontal separation.

In use, the feeding system is placed next to the model on a horizontal surface. The flat base of the feed system allows it to be self-supporting, therefore no additional supporting structures are required and there is no molding sand under the feed system. Removing the model board and model from the compacted molding sand leaves a casting cavity having a shape that is the inverse of the model, with a feed system built into the molding sand. Since the jumper rod is essentially flat, during the preparation of the mold, it rests on the model, and, after removing the model, the hole of the jumper rod is in direct contact with the casting cavity. Reducing the distance between the cavity of the feed system and the casting cavity can reduce metal waste after removal of the feed system from the finished casting.

The molding sand may be molding sand. As is well known in this technical field, foundry sand can be classified into two main categories: chemically bonded (based on organic or inorganic binders) and clay as a binder. Binders in chemically bonded foundry sand are typically self-hardening systems in which a binder and a chemical hardener are mixed with sand and the binder and hardener immediately react, but slow enough to shape the sand around the model board, and then the mixture is allowed to cure sufficiently. to extract the model and cast. In clay-based molding systems, clay and water are used as a binder, and can be used in a “wet” or un-dried state, and this molding mixture is often referred to as “raw”. Raw moldable mixtures do not have high fluidity and are difficult to compress during compression, and therefore, various combinations of shaking, vibration, compression and packing are used to densify the raw moldable mixture around the model and to give the mold sufficient strength to produce molds with uniform strength .

Molding practice is well known and described, for example, in chapters 12 and 13 of Foseco Ferrous Foundryman's Hanbook (ISBN 075064284 X). A typical process known as the cold hardening process is mixing sand with a liquid resin or silicate binder together with an appropriate catalyst, usually in a continuous mixer. The sand mixture is then compacted around the model using a combination of vibrations and packing, after which it is allowed to settle, and at this time, the catalyst reacts with the binder, which leads to hardening of the moldable mixture. When the mold acquires strength that allows it to be manipulated, it is removed from the model and the hardening process continues until the chemical reaction is completed.

The moldable mixture may be sand bound by a cold curing process using a liquid binder, such as an acid curable furan or phenolic resin, or an ether cured alkaline phenolic or silicate binder with an appropriate catalyst. Alternatively, the molding sand is clay bound sand (raw sand) containing a mixture of clay, such as sodium or calcium bentonite, water and other additives, such as coal dust and a starch-based binder.

The following is a description of the options for the present, the solutions are given only as an example, with reference to the attached drawings, where:

FIG. 1 is a perspective view of a power system according to an embodiment of the present solution.

FIG. 2 is a rear perspective view of a power system according to another embodiment of the present solution.

FIG. 3 is a schematic diagram of a power system according to an embodiment of the present solution.

FIG. 4a - feeding system of the present decision, used in the preparation of the mold.

FIG. 4b is a feed system of the present solution used in the process of casting a metal product.

In FIG. 1 shows a feed system 100 according to the first aspect of the present solution, comprising a profit sleeve 102 and a jumper rod 104. The profit sleeve 102 comprises a flat base 106, a roof 108 located above the base 106, and a side wall 110 extending between the roof 108 and the base 106.

The side wall 110 of the profit sleeve 102 extends around the periphery of the base 106 and is discontinuous so that the profit sleeve 102 is open on one side. The base 106 is substantially rectangular or square. The roof 108 is curved and convex. In other embodiments (not shown), the roof 108 may be flat, sloping, domed, partially shaped like a dome, a dome with a flat top, or any other suitable shape.

The side wall 110 extends around the three sides of the base 106. The side wall 110 comprises two opposing side sections 112 and a rear section (not visible) extending between the side sections 112, with the rear section opposite the open side of the hub 102 of the profit. The side sections 112 and the rear section and the roof are made in one piece. In other embodiments, side wall 110 may consist of three separate sections connected to each other by edges, and / or side wall 110 and roof 108 may be separable, in which case roof 108 is in the form of a cover.

The jumper rod 104 is substantially flat and mounted on the glue on the profit sleeve 102 so that the jumper rod 104 forms the fourth side of the profit sleeve 102. A jumper rod 104 is mounted opposite the rear section of the side wall 110 and extends between the base 106 and the roof 108 of the hub 102 of the profit. The maximum height of the jumper rod 104 is equal to the maximum height of the profit sleeve 102 so that the jumper rod 104 and the profit sleeve 102 completely cover the cavity in the feed system 100. The lower angles 116 between the side wall 110 and the base 106 of the feed system 100 or between the side wall 110, jumper rod 104 and base 106 are straight or slightly tapered.

The jumper rod 104 has an opening 118 located adjacent to the base 106 of the supply system 100. The hole 118 is offset from the longitudinal axis of the jumper rod 104. In other embodiments, the hole 118 may be located centrally on the longitudinal axis of the jumper rod 104.

The profit sleeve 102 may be made of any suitable refractory insulating material and / or exothermic material. The bridging rod 104 may be made of any suitable high refractory material, such as bonded siliceous sand.

In FIG. 2 shows an alternative embodiment of the feed system 200, essentially the same as that shown in FIG. 1, but having a D-shaped cross section. The base 202 of the supply system 202 is substantially D-shaped. The rear section 204 of the side wall 206, opposite the jumper rod 206, is curved, convex, and has a centrally concave groove 212. The roof 210 of the supply system 200 is partially domed. The side wall 206 and the roof 210 are integrally formed.

In FIG. 3 is a schematic diagram of a power system according to a first aspect of the solution. In some embodiments, the feed system has a length (L) equal to A measured outside from the end of the jumper rod to the rear section opposite the jumper rod and between two side sections, the length being measured to the maximum point of curvature where the back section is bent or has a D-shape, and a width (W), measured from the outside between the two side sections of the profit and having a value of from 0.4 × A to 2 × A. In some embodiments, the feed system has a maximum height of 1 × A to 3 × A, depending on the size of the casting and the requirements for the sleeve, which typically is from 8 cm to 25 cm or more.

In FIG. 4a shows a half of a mold assembly containing two feeding systems 100 according to the first aspect of the solution, and a model 402, wherein the feeding system 100 and model 402 are mounted on the horizontal model board 404. The base 106 of the feeding system 100 rests flat on the horizontal flat surface of the model board 404 The jumper rod 104 of the supply system 100 is adjacent to the model 402 so that at least a portion of the jumper rod 104 containing the hole 118 is adjacent and is in direct contact with the vertical surface of the model 402. On one or more top feed systems (not shown) may also be installed on the bottom or more horizontal surfaces of the Model 402.

During the metal casting process, model 402 and feed system 100 are surrounded by moldable mixture 408. Mold 408 is compacted and cured around model 402 and feed system 100. Model board 404 and model 402 are removed from the compacted mold 408, leaving a cavity 410a half-molds (see FIG. 4b), which has a form opposite to that of model 402, and feed systems 100 remain embedded in the compacted molding sand 408.

In FIG. 4b shows a mold 412 assembled and ready for casting. Mold 412 comprises an upper half-mold 414a formed from the assembly shown in FIG. 4a, and the lower half-mold 414b, molded in the same manner, but without a feed system. In the upper half-mold 414a and in the lower half-mold 414b, a riser 416, a gate system 418 and inlet gates 420 are formed. The half-cavity cavities 410a and 410b form a mold cavity, where line X-X represents the horizontal dividing plane of the mold. The jumper rod 104 of the supply system 100 is in direct communication with the mold cavity.

In the metal casting process, molten metal is poured into mold 412 through a riser 416, through a system of 418 gate channels and inlet gates 420. Then, the molten metal fills the mold or casting cavity 410 and enters the feed system 100 through hole 118 in the jumper rod 104. When the metal in the casting cavity 410 crystallizes and shrinks, the molten metal located in the profit sleeve 102 flows back into the casting cavity 410 through the hole 418, compensating for the shrinkage and ensuring that the cavity 410 is completely filled with metal after it is cooled . The position of the hole 118 in the jumper rod 104 near the base 106 of the profit sleeve 102 allows a large level of metal to be stored in the profit sleeve 102 above the hole 118. The pressure of the metal above the hole 118 generates sufficient static metal pressure to allow molten metal to flow into the casting cavity 410 when the casting crystallizes. The position of the hole 118 near the base 106 also minimizes the reservoir of unused metal under the hole 118, thereby reducing waste.

Claims (11)

1. A metal casting feed system comprising a profit sleeve having a flat base, a roof over the base and a side wall between the roof and the base, which is interrupted so that the profit sleeve is open on one side, and a substantially flat jumper rod in which a through hole is made and which is mounted on the open side of the sleeve arrived perpendicular to the base, while the profit sleeve and the jumper rod jointly define a closed cavity for holding molten metal, behind and the exception of the hole in the jumper rod. 2. The system of claim 1, wherein the feed system is substantially rectangular or square in cross section. 3. The system of claim 1, wherein the feed system has a substantially D-shaped cross section. 4. The system according to claim 1, in which the hole in the jumper rod is made facing or adjacent to the base of the bushings arrived. 5. The system according to claim 1, in which the hole is located centrally on the longitudinal axis of the jumper rod. 6. The system according to claim 1, in which the hole is offset from the longitudinal axis of the jumper rod. 7. The system of claim 1, wherein the roof is inclined or curved. 8. The system of claim 1, wherein a Williams Wedge wedge insert is located on the roof inside the hub. 9. The system according to claim 1, in which the lower angles between the wall and the base or between the wall, the jumper rod and the base are made essentially straight. 10. The system according to claim 1, in which the maximum height of the jumper rod is equal to the maximum height of the profit sleeve. 11. The system of claim 1, having a length A, a width of 0.4A to 2A, and a height of 1A to 3A.

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