JP2015054349A - Casting method with no feeder used - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a casting method capable of obtaining a casting product which has good quality with a high casting yield without using a feeder, or without using the feeder and a runner.SOLUTION: A coagulation modulus of a casting plan system is properly set for supplying coagulation shrinkage of a product from the casting plan system.

Description

Detailed Description of the Invention

Industrial application fields

  The present invention relates to a casting method for obtaining a sound casting product with a high casting yield by a casting method that does not use a feeder or a feeder and a runner in sand mold casting of a cast iron casting.

  In casting, in order to improve the soundness of the product part, a hot water is provided at an appropriate part of the product, and the solidification shrinkage of the product is replenished from the hot water. A side hot water or a side hot water provided on the side is used. However, in any case, the ratio of the feeder to the casting weight is usually 20 to 30%. As a result, there is a problem that the casting yield indicated by the product weight / casting weight is low. Casting yield is an important indicator that affects the cost of casting.

  In the case of cast iron castings, it is known that graphite crystallizes or precipitates during the solidification process, so-called expansion due to graphite occurs, and self-compensates for solidification shrinkage of the product. However, this is usually insufficient for replenishment of the solidification shrinkage of the product, and the conventional technique is using a feeder.

  Examples of the prior art are shown in FIGS. FIG. 17 shows a state of a mold in which a fried hot water 5A is provided on the upper part of the product 1. FIG. 18 shows a state of the mold in which the side feeder 5B is provided on the side surface of the product 1. It is generally performed to ensure the soundness of the product by replenishing the solidification and shrinkage of the product from the hot water provided in this way.

  Attempts to reduce hot water have been made in terms of chemical composition, inoculation, pouring temperature, hot water shape, etc., but little progress has been made in the last 40 years. There are cases where normal cast iron is used, but there are cases in which some parts of the product can be sound enough to be practically used without using a feeder, but no clear guideline or standard is proposed. Moreover, since spheroidal graphite cast iron has a solidification form different from that of ordinary cast iron, in most cases, a healthy product cannot be obtained without a feeder.

  In addition, the runner is a necessary element for casting the molten metal, and this is an element that the prior art wants to reduce like a feeder.

Regarding the prior art, an example of a main casting method using a feeder is shown below from the results of searching the patent literature with the keyword "casting x feeder".
JP2008-212285A JP2007-111741 JP-A-2005-144461 JP-A-10-221333 JP 10-43836 A JP 9-314308 A JP-A-8-290254 JP-A-8-93204 JP-A-5-104195 JP-A-5-69108

Problems that the Invention is to Solve

  The problems of the prior art as described above can be summarized as follows. One reason for the low casting yield, which is an important indicator that affects the cost of casting, is to reinforce the solidification shrinkage of the cast product using a feeder that occupies 20-30% of the casting weight to ensure its soundness. This is because. Another reason is that the runner required for casting the molten metal accounts for 20 to 25% of the casting weight.

  In view of the above problems, in the present invention, a healthy casting product is obtained by replenishing the solidification shrinkage of the product from the design element in the mold without using a feeder or using a feeder and a runner. A casting method is provided. As a result, the casting yield is greatly improved, and the cost of casting products can be greatly reduced.

  In addition, as shown in the patent document of the prior art, the method of using the feeder and the runner is basically the same in both sand casting and die casting. It is also applicable to molds and castings.

Means for solving the problem

(Means 1)
In sand mold casting of cast iron castings, a design system consisting of design elements of products, runners, gates, and gate cups is used without using a feeder, and the solidification moduli of the design elements of the system are M1, M2, M3, M4 in order. In this case, the casting method is characterized in that the solidification shrinkage of the product is replenished from the runner, the gate and the gate cup by making all of M2, M3 and M4 larger than M1.

  As shown in FIG. 17 and FIG. 18 of the prior art, when a cast product is generally cast, a design system including design elements of a product, a hot water, a runway, a gate, and a gate cup is used. . Explaining the function of the plan elements other than the product, first, the function of the feeder is to replenish the solidification shrinkage of the product. The runway, the sprue, and the spout cup have a function of guiding the molten metal poured into the hot water and the product. The runner is usually provided horizontally on the parting surface that is the mating surface of the upper and lower molds, the sprue is provided perpendicular to the upper mold, and the spout cup receives the molten metal so that the poured molten metal does not spill. It is provided on the upper upper surface of the upper mold.

  In the means 1, a design system consisting of design elements of a product, a runway, a gate, and a gate is used without using a feeder. The solidification moduli of the respective plan elements are sequentially designated as M1, M2, M3, and M4. Here, the solidification modulus is a general index for evaluating the slowing of solidification of each design element, and is expressed by volume / surface area. The unit is length. It is known that those with a large solidification modulus are slow to solidify and those with a small solidification modulus are fast. In sand casting, the solidification time is said to be proportional to the square of the solidification modulus.

  The solidification modulus relationship of each plan element is a plan system in which all of M2, M3, and M4 are larger than M1. As a result, the solidification of the runner, gate and cup is slower than the product. In other words, unsolidified melt remains in the design elements of the runner, gate, and spout cup until the product is completely solidified, and it is possible to replenish the solidification shrinkage of the product from these design elements. is there. The pressure for replenishing the solidification shrinkage is given by the pressure by the molten metal head corresponding to the total height of the gate and the gate cup (usually equal to the height of the upper mold).

  By this means, in the prior art, products that had been supplied with solidification shrinkage from the hot water can be replenished from the design elements of the runner, gate and cup, and a healthy product can be obtained without using the hot water. Can be obtained. As a result, the casting yield is greatly improved. Although this means does not use hot water, it is possible to provide a hot water reservoir of an appropriate size between the product and the runway or in the middle of the runway to keep warm as needed. It can be regarded as a part of the road.

  In addition, as for the solidification modulus of each plan element, when a local minimum exists locally, the value is regarded as the solidification modulus of the design element.

(Means 2)
In sand mold casting of cast iron castings, a design system consisting of design elements of products, runners, gates, and gate cups is used without using a feeder, and the solidification moduli of the design elements of the system are M1, M2, M3, M4 in order. When M2, M3, and M4 are smaller than M1 and all of M2, M3, and M4 are larger than 0.6M1, a part of the solidification shrinkage of the product is made into a runner, a gate. The casting method is characterized by replenishing from the gate cup.

  The means 2 uses a design system consisting of design elements of a product, a runway, a pouring gate, and a pouring cup without using a feeder, and at least one of M2, M3, and M4 has a relationship of solidification moduli from M1. The design system was small and all of M2, M3, and M4 were larger than 0.6M1 (0.6 times M1). This is used when the solidification modulus of the plan system cannot be made larger than that of the product due to reasons such as frame size, product size, and number of packs.

  In this case, when at least one of M2, M3, and M4 is smaller than M1, at least one of the runner, the gate, and the gate cup is solidified faster than the product. However, since all of M2, M3, and M4 are larger than 0.6M1, the solidification time of the runner, gate and cup is about 36% of the solidification time of the product (because the solidification time is proportional to the square of the solidification modulus) Longer. In other words, until the product is solidified by about 36%, unsolidified melt remains in the design elements of the runner, gate and cup, and some of the solidification shrinkage of the product from these design elements. It is possible to replenish. The pressure for replenishing the solidification shrinkage is given by the pressure from the molten metal head corresponding to the total height of the gate and the gate cup.

  The reason why all of M2, M3, and M4 are set to be larger than 0.6M1 will be described. The amount of molten metal replenishment necessary for obtaining a healthy product is a small amount of about 4% of the product volume when calculated in consideration of liquid shrinkage, transformation shrinkage, expansion due to graphite, expansion of the mold, and the like. Since liquid contraction occurs quickly during solidification, about 25% of the required amount of molten metal replenishment in this system is used as replenishment during the liquid contraction period within 36% of the above-mentioned product solidification time. Can be replenished from the design elements of the gate and the cup.

  About 1.5% of the shortage is after the solidification of the design elements other than the product, and the product solidifies independently with no molten metal replenished. Minutes can be compensated. As a result, replenishment of the solidification shrinkage of the product from the plan system is a part of the necessary amount of molten metal replenishment, but it is combined with the self-expansion due to graphite precipitation of the product to prevent shrinkage nests and obtain a healthy product. . Of course, if the minimum solidification modulus of the plan system changes, the form of molten metal supply (such as the ratio of liquid shrinkage supply) changes accordingly.

  The reason why at least one of M2, M3, and M4 is made smaller than M1 is to improve the yield with a system system as small as possible. That is, if all of M2, M3, and M4 are larger than 0.6M1, the above-described replenishment is possible, so there is no need to make M2, M3, and M4 unnecessarily large, so each plan element is made as small as possible. It is. Of course, by making all of M2, M3, and M4 smaller than M1, the highest yield can be obtained. However, because there are restrictions due to the product shape, its solidification modulus, the number of packs, etc. To do.

  Even with this means, in the prior art, the product solidified and contracted from the hot water supply can now be partially replenished from the design elements of the runner, pouring gate and pouring cup, and no hot water is used. You can get a healthy product. In this means, since the method system was made smaller, the casting yield was improved than that of means 1.

  In this means, the solidification of any of the runners, gates and cups is faster than the product, so the solidification shrinkage of the product cannot be completely replenished from these design elements. Depends on expansion by. Therefore, it is not necessarily applicable to all products, and there are restrictions due to the shape of the product, the size of the solidification modulus, and the like. For this reason, this means has restrictions on the products applicable from means 1. Usually, this means can be applied when the solidification modulus of the product is 0.5 cm or more. Even when the solidification modulus is 0.5 cm or less, it is possible if the product shape is simple and the molten metal can be easily replenished.

(Means 3)
In cast iron casting sand mold casting, a design system consisting of product elements of a product, a sprue, and a sprue cup is used without using a feeder and a runner, and the solidification moduli of the design elements of the plan system are M1, M3, and M4 in order. When M3 and M4 are larger than M1, the solidification shrinkage of the product is replenished from the gate and the gate cup.

  In the means 3, a design system consisting of design elements of products, a sprue, and a sprue cup is used without using a feeder and a runner, and a plan system in which M3 and M4 are larger than M1. Thereby, the solidification rate of the gate and the gate cup becomes slower than the product. That is, until the product is completely solidified, unsolidified melt remains in the design elements of the gate and the gate cup, and the solidification shrinkage of the product can be supplied from these design elements.

  Even with this means, in the prior art, the product that has been supplied with solidification shrinkage from the hot water can be replenished from the design elements of the pouring gate and pouring cup. Can be obtained. As a result, a higher casting yield than that of the means 1 and 2 can be obtained. However, this means may not be applicable due to restrictions such as product size and number of packs. At that time, means 1 or 2 are used.

(Means 4)
In cast iron casting sand mold casting, a design system consisting of product elements of a product, a sprue, and a sprue cup is used without using a feeder and a runner, and the solidification moduli of the design elements of the plan system are M1, M3, and M4 in order. When at least one of M3 and M4 is smaller than M1 and M3 and M4 are larger than 0.6M1, a part of the solidification shrinkage of the product is replenished from the gate and the gate cup. It is a casting method.

  In the means 4, the design system comprising the design elements of the product, the pouring gate, and the pouring cup without using the tapping hot water and the runner cup, at least one of M3 and M4 is smaller than M1, and M3 and M4 are larger than 0.6M1. Was used. When at least one of M3 and M4 is smaller than M1, at least one solidification of the gate and the gate cup becomes faster than the product. However, since M3 and M4 are greater than 0.6M1, the solidification time of the gate and the cup is about 36% of the solidification time of the product. In other words, unsolidified melt remains in the design elements of the gate and the gate cup until the product is solidified by about 36%, and a part of the solidification shrinkage of the product is replenished from these design elements. Is possible. The reason why at least one of M3 and M4 is smaller than M1 is to improve the yield, and the reason why M3 and M4 are larger than 0.6M1 is the same as that described in the means 2.

  Even with this means, in the prior art, the solidification shrinkage of the product was replenished from the feeder, but a part of it can be replenished from the design elements of the sprue and sprue cup, and the feeder and the runner are not used. I was able to get a healthy product. In this means, since the plan system smaller than the means 3 was used, the casting yield was further improved as compared with the means 3.

  In this means, since the solidification of either the sprue or the spout cup is faster than the product, the solidification shrinkage of the product cannot be completely replenished from these design elements. It depends. Therefore, it is not necessarily applicable to all products, and there are restrictions due to the size and shape of the solidification modulus of the product. Usually, this is possible when the solidification modulus of the product is 0.5 cm or more. Even when the solidification modulus is 0.5 cm or less, it is possible if the product shape is simple and the molten metal can be easily replenished.

  When the means 1 to 4 are summarized, as for the cast products that can be applied, the means 1 has the widest scope of application, and the means 2, means 3, and means 4 are in this order. Further, in terms of the effect of improving the casting yield to be obtained, the means 4 is the most effective, and the means 3, means 2, and means 1 below. Which means is used is determined in consideration of the product shape, the solidification modulus, the number of containers, the frame size, the material, and the like.

(Means 5)
In the case of casting a plurality of products in one frame using the casting method according to any one of means 1 and 2, the length of the runner from the center of the gate to the product is a plan of the runner, the gate, and the gate cup Applying the casting method to products placed at a position within 40 times the minimum value of the element solidification moduli M2, M3, and M4, without using a feeder, A casting method characterized by using hot water.

  The means 5 presents a more practical casting method when the casting method described in any one of the means 1 and 2 is applied to casting a plurality of products in one frame. In such a case, a problem may occur when the means 1 or 2 that does not use the hot water is applied to all products. For example, in a product that is located at a position where the length of the runner from the sprue to the product is long among multiple products, there may be a place where local cooling is fast in the middle of the runway and the molten metal supply may be cut off. It tends to happen. Moreover, since the distance of molten metal replenishment becomes long, replenishment resistance increases by the solidified layer of the runner in the middle increasing.

  Therefore, in such a case, the means 1 or 2 is applied to a product arranged at a position close to the gate rather than applying the means 1 or 2 to all of the plurality of products to make a system that does not use a feeder. The molten metal was replenished from the system such as the runway, the sprue, and the sprue cup without using the feeder, and the molten metal was replenished to the product far from the spout using the conventional hot water. This is superior when considering the stability of the quality of the entire product within one frame.

  Based on the results obtained from various casting examples, the minimum value of the solidification moduli M2, M3, M4 of the design elements of the runner, the gate, and the gate cup is used as the reference value for whether or not the feeder is used. The runner length is 40 times the modulus and has a unit of length. In other words, for the product arranged at a position where the runner length from the center of the gate to the product is within 40 times the minimum solidification modulus, the means 1 or 2 is applied and the hot water is not used, and the position exceeding 40 times. Means 1 or 2 are not applied to the placed product, and a conventional feeder is used. This makes it possible to apply the means 1 or 2 more widely and stably in casting with a plurality of holes.

(Means 6)
The casting method according to any one of means 1 to 5, characterized in that solidification of the molten metal on the top of the gate cup is delayed by keeping and / or heating the molten metal on the upper surface of the gate cup.

  In means 6, in the casting method according to any one of means 1 to 5, since the molten metal on the upper surface of the spout cup is exposed to air, an oxide film is easily formed, and as a result, solidification is promoted and atmospheric pressure is increased. In some cases, it is difficult to act, so a means for keeping warm and / or heating the molten metal on the upper surface of the gate cup was used. As a result, the molten metal on the upper surface of the spout cup maintains a molten state without generating a solidified layer for a long time, and the atmospheric pressure is effectively applied from the upper surface of the spout cup so that the solidification shrinkage of the product can be stably performed. Become.

  Here, the action of atmospheric pressure, which is the main point of this means, will be described. At the time when pouring is completed, atmospheric pressure is applied equally to each design element, so the pressure to replenish the product from the design element is the total height of the gate and the cup (the height of the upper mold) It is a molten metal head corresponding to (equal to). However, after a certain time, solidification of the surface layer proceeds in each plan element, and even if atmospheric pressure acts, the pressure is not transmitted to the melt inside.

  At this time, the molten metal on the upper surface of the spout cup is solidified on the surface layer while forming an oxide film with the air in contact therewith. If this solidified layer is in a state where the pressure is not transmitted to the melt inside even if atmospheric pressure is applied, as with the other design elements, the pressure to replenish the solidification shrinkage of the product is the same as when the pouring is completed. And a molten metal head corresponding to the total height of the spout cup.

  In this means, this general state is improved. In other words, by maintaining and / or heating the molten metal on the top of the gate, the molten state is maintained without generating a solidified layer for a long time, and the time for applying atmospheric pressure for a long time from the top of the gate cup is extended as much as possible. . As a result, atmospheric pressure can be applied to the unsolidified melt in the design system for a long time, and the solidification shrinkage of the product from the design system can be more reliably performed. The atmospheric pressure of 1 atm is a pressure that is five times or more larger than that of the molten metal head (generally 0.1 to 0.2 atm) corresponding to the total height of the gate and the gate, and the effect is extremely large. .

  Heat insulation and / or heating methods include covering the molten metal on the top of the spout cup with sand, covering with resin-coated sand or mold piece, covering with heat insulating material, covering with refractory material, covering with heat generating material, fuel gas. Any one or more methods of heating using a high frequency heating coil are used.

Action

  With the means 1, it is possible to replenish the solidification shrinkage of the product from the design elements of the runner, the gate and the gate cup without using the feeder, so that the feeder is unnecessary. As a result, the casting yield was greatly improved.

  With the means 2, a part of the solidification and shrinkage of the product can be replenished from the design elements of the runner, the gate and the gate cup without using the feeder, and the feeder is not required. In this means, since a small system was used, the casting yield was further improved as compared with the means 1. However, this means may be limited in comparison with means 1 due to restrictions such as the solidification modulus and shape of the product.

  With the means 3, the coagulation shrinkage of the product can be replenished from the design elements of the pouring gate and the pouring cup without using the pouring hot water and the runner, and the pushing hot water and the runner become unnecessary. As a result, the casting yield was further improved than the means 1 and 2.

  With the means 4, part of the solidification and shrinkage of the product can be replenished from the design elements of the gate and the cup without using the feeder and the runner, and the feeder and the runner become unnecessary. In this means, since a method system having a small solidification modulus was used, the casting yield was further improved as compared with the means 3. However, compared with the means 3, this means is limited in the solidification modulus and shape of the product, and its application range may be limited.

  In the means 5, when applying the means 1 or the means 2 when casting a plurality of products in one frame, a more practical casting method is presented. As a result, the means 1 or the means 2 can be applied more stably in casting with a plurality of holes.

  In means 6, in the casting method according to any one of means 1 to 5, solidification of the molten metal on the top surface of the sprue cup can be delayed by keeping and / or heating the molten metal on the top surface of the sprue cup, and replenishment of solidification shrinkage. Atmospheric pressure can be effectively applied for a long time. As a result, the means 1 to 5 can be implemented more stably.

  The present invention will be described in detail below, but the present invention is not limited to these examples.

  FIG. 1 shows a first embodiment using the means 1. In this example, an example of flat casting is shown. This figure is a longitudinal sectional view of the mold, and a hot water supply 2, a gate 3, and a gate 4 are provided as a system in the product 1 without using a feeder. The solidification moduli M1, M2, M3, and M4 of each part are product M1 = 1.6 cm, runner M2 = 1.7 cm, sprue M3 = 1.75 cm, sprue cup M4 = 1.9 cm. The molten metal is poured into the product 1 from the spout cup 4 through the spout 3 and the runner 2.

  Solidification then proceeds, but all the solidification moduli of runner 2, spout 3 and spout cup 4 are larger than the solidification modulus of product 1, so runner 2, spout 3, and spout until solidification of product 1 is complete. The melt state is maintained inside the cup 4. Accordingly, the solidification shrinkage of the product 1 is supplied from the runner 2, the gate 3, and the gate cup 4. As a result, the problem of the internal shrinkage nest that is likely to occur inside the product 1 is solved. Note that the amount of coagulation shrinkage about 4% to be replenished to the product is a slight amount of shrinkage that can be sufficiently replenished with the volume of the plan system corresponding to the coagulation modulus of this example. The same applies to the following embodiments.

  Further, the weir 7 which is a joint portion between the runner 2 and the product 1 is appropriately sized in consideration of casting time and hot water supply. Generally, the solidification modulus of the weir 7 is recommended to be about 0.5 to 0.7 times the solidification modulus M1 of the product 1. In this example, 1.1 cm was used.

  As a result, in the prior art, as shown in FIG. 17 or FIG. 18, the one using the raised feeder 5A or the side feeder 5B can obtain a healthy product without the feeder. Comparing the weight of the system required for casting of this product in the prior art and this example, in this example, there is no feeder, and instead, the solidification modulus of the runner, gate and cup is compared to the solidification modulus of the product. Since it was made larger, it increased slightly. Usually, the hot water is as large as 45 to 70% with respect to the product. Therefore, the casting yield is improved.

  Further, another effect that a healthy product can be cast without using a feeder is that the operation of removing the feeder after casting can be omitted. Thereby, simplification of the post-process was obtained.

  FIG. 2 shows a second embodiment using the means 2. In this example, the hot water is not used, and the product 1 is provided with a runway 2, a gate 3 and a gate 4 as a system. The solidification moduli M1, M2, M3, and M4 of each part are a product M1 = 1.5 cm, a runner M2 = 0.92 cm, a spout M3 = 1.2 cm, and a spout cup M4 = 1.9 cm. The molten metal is poured into the product from the spout cup 4 through the spout 3 and the runner 2. In addition, the weir 7 which is a junction part of the gate 2 and the product 1 was appropriately sized in consideration of casting time and hot water supply in the same manner as in Example 1, and was 1.1 cm in this example.

In this embodiment, the solidification modulus M4 of the spout cup 4 is larger than the solidification modulus M1 of the product, but the solidification moduli M2 and M3 of the runner 2 and the spout 3 are smaller than the solidification modulus M1 of the product and 0.6 times. Bigger than. As a result, replenishment from the runner 2, the sprue 3, and the spout cup 4, which is a system for coagulation shrinkage of the product 1, has a minimum solidification modulus, the runner M2 = 0.92 cm (M2 / M1 = 0.61). Can be replenished only for a period of about 38% of the coagulation contraction period of product 1 (which is calculated by the square of the ratio of coagulation coagulation modulus = (M2 / M1) ² ).

  In this case, since liquid contraction occurs quickly, about 2.5% of the solidification contraction of about 4% of the product 1 is supplied as liquid contraction replenishment. The remaining 1.5% deficiency is replenished by the expansion of the graphite that occurs during the solidification process of the product 1 because the shape of the product 1 is simpler than in the case of Example 1, so A healthy product without shrinkage can be obtained. Of course, if the minimum solidification modulus of the plan system changes, the form of molten metal replenishment (such as the ratio of liquid shrinkage replenishment) will change accordingly, but the minimum solidification modulus of the plan system will be 0.6 times the solidification modulus of the product. If so, the soundness of the product is ensured.

  Thus, even if one or more of the coagulation moduli of the system consisting of the runner 2, the sluice 3 and the sluice cup 4 is smaller than the sag of the product 1, the coagulation moduli are all If it is larger than 0.6 times the solidification modulus of one product, depending on the product shape, a healthy product can be obtained without using a feeder.

  As a result, even in the present example, it was possible to cast a sound product without using a feeder. However, depending on the casting conditions such as the product shape, material, pouring temperature, mold, etc., it may be necessary to adjust the sizes of the runner 2, the pouring gate 3, and the pouring cup 4.

  In this example, since the size of the runner and the gate is smaller than that in Example 1, the casting yield was further improved. However, this is a method in which the application range is limited because application may be difficult depending on the above casting conditions. In addition, since the hot water has been removed, the post-process of removing the hot water has been simplified.

  FIG. 3 shows a third embodiment using the means 3. In this example, the hot water and the runner are not used, and the product 1 is provided with a gate 3 and a gate 4 as a system. The solidification moduli M1, M3, and M4 of the respective parts are the product M1 = 1.8 cm, the gate M3 = 1.9 cm, and the gate cup M4 = 1.9 cm. The molten metal is poured into the product from the gate cup 4 through the gate 3.

  Thereafter, solidification proceeds, but all of the solidification moduli of the spout 3 and the spout cup 4 are larger than the solidification modulus of the product 1, so that the inside of the spout 3 and the spout cup 4 is in a molten state until the solidification of the product 1 is completed. Is preserved. Therefore, the solidification shrinkage of the product 1 is supplied from the gate 3 and the gate cup 4. As a result, the problem of the internal shrinkage nest that is likely to occur inside the product 1 is solved.

  In addition, the weir 7 which is a junction part of the gate 3 and the product 1 is appropriately sized in consideration of casting time and hot water supply as in the first and second embodiments. In this example, 1.2 cm was used. In the following examples, approximately 0.7 times that of the product M1 is set in a similar manner.

  As a result, a healthy product can be obtained by supplying molten metal from the sprue and the spout cup without using a feeder or a runner. Comparing the weight of the system required for casting this product in the prior art and this example, in this example, there are no feeders and runners. Instead, the solidification modulus of the sprue and the spout cup is compared to the solidification modulus of the product. Since it was made larger, it increased slightly. Normally, the hot water is so large that it accounts for 20 to 30% of the total cast weight and the runner accounts for about 20 to 25%. Therefore, the casting yield is improved.

  In addition, another effect that a healthy product can be cast without using a feeder and a runner is that the operation of removing the feeder and the runner after casting can be omitted. Thereby, the simplification of the post-process was obtained.

  FIG. 4 shows a fourth embodiment in which the means 4 is used. In this example, the pouring gate and the runner are not used, and the pouring gate 3 and the pouring cup 4 are provided in the product 1 as a plan system. The solidification moduli M1, M3, and M4 of the respective parts are the product M1 = 1.55 cm, the gate M3 = 0.94 cm, and the gate M4 = 1.9 cm. The molten metal is poured into the product from the gate cup 4 through the gate 3.

In this embodiment, the coagulation modulus M4 of the spout cup 4 is larger than the coagulation modulus M1 of the product, but the coagulation modulus M3 of the pouring gate 3 is smaller than the coagulation modulus M1 of the product and larger than 0.6 times. As a result, for the replenishment from the spout 3 and the spout cup 4 which is a plan system for the solidification shrinkage of the product 1, the runner M3 = 0.94 cm (M3 / M1 = 0.61) which is the minimum solidification modulus is first solidified. Therefore, only the period of about 37% of the coagulation contraction period of the product 1 (this is calculated by the square of the coagulation coagulation modulus ratio = (M3 / M1) ² ) can be supplied.

  In this case as well, liquid contraction occurs rapidly, and about 2.5% of the solidification contraction of about 4% of the product 1 is supplied as liquid contraction replenishment during this period. The remaining about 1.5% of the shortage is replenished by the expansion of the graphite that occurs in the solidification process of the product 1 because the shape of the product 1 is simpler than in the case of Example 3, so A healthy product without shrinkage can be obtained. In this case as well, if the minimum solidification modulus changes, the form of molten metal replenishment will change accordingly, but if the minimum solidification modulus of the plan system is 0.6 times or more of the solidification modulus of the product, the soundness of the product is ensured. .

  Thus, even if any one or more of the coagulation moduli of the system consisting of the pouring gate 3 and the pouring cup 4 is smaller than the coagulation modulus of the product 1, the coagulation modulus of the product 1 is all solidified. If the modulus is larger than 0.6 times, a healthy product can be obtained without using a feeder depending on the product shape.

  As a result, even in this example, it was possible to cast a sound product without using a hot water and a runner. However, the size of the gate 3 and the gate 4 may need to be adjusted depending on the casting conditions such as the product shape, material, pouring temperature, and mold.

  In this example, the size of the gate was smaller than that in Example 3, so that the casting yield was further improved. However, this is a method in which the application range is limited because application may be difficult depending on the above casting conditions. In addition, since the hot water has been removed, the post-process of removing the hot water has been simplified.

  FIG. 5 shows a fifth embodiment using the means 3. This figure is a plan view of a flat mold. In this example, a plurality of products are arranged in one frame, and the pouring gates 3 and the pouring cups 4 are provided as a system in the product 1 without using a feeder and a runner. The solidification moduli M1, M3, and M4 of each part are the product M1 = 1.8 cm, the gate M3 = 1.9 cm, and the gate cup M4 = 2.0 cm (not shown). The molten metal is poured into the product 1 from the gate cup 4 through the gate 3.

  The present embodiment is an example in which a plurality of products are cast in one frame. Thus, depending on the product shape, size, etc., an extremely efficient casting method can be employed for the casting yield. Moreover, since there is no runner, the molten metal can be replenished stably at a short distance from the gate and the cup.

  FIG. 6 shows a sixth embodiment in which the means 1 and 2 are used. In this example, a plurality of products are arranged in one frame, and a runner 2, a gate 3 and a gate 4 are provided as a system in the product 1 without using a feeder. The solidification moduli M1, M2, M3, and M4 of the respective parts are product M1 = 1.2 cm, runner M2 = 1.1 cm for runner 2A for product A, 1.3 cm for runner 2B for product B, and spout M3 = 1. .3 cm and the spout cup M4 = 1.4 cm. The molten metal is poured into the product 1 from the spout cup 4 through the spout 3 and the runner 2.

  The present embodiment is an example in which a plurality of products 1 are cast in one frame. In this case, four of the eight products labeled A are close to the gate center 3C and are located at a position within 40 times the minimum solidification modulus 1.1 cm of the plan system. Although the runner 2A having a solidification modulus of 4 is used, the four labeled B are far from the gate center 3C and are located at a position more than 40 times, so that solidification progresses in the middle of a long runway. In order to prevent this, a larger runner 2B was used using means 1.

  When a plurality of products are arranged in one frame as described above, it is necessary to change the solidification modulus of the runner, that is, the runner size for each product in consideration of the product shape and size. is there.

  FIG. 7 shows a seventh embodiment in which the means 5 is used. In this example, the product number and arrangement are the same as those in the sixth embodiment. In this example, four of the eight products indicated as A are close to the gate center 3C and are located at a position within 40 times the minimum solidification modulus 1.1 cm. Although the runner 2 having a modulus is used, the four labeled B are far from the gate center 3C and are located at a position more than 40 times the minimum solidification modulus 1.1 cm. The conventional feeder 5 was used on the assumption that the solidification progress was rapid. That is, the means 2 was used in combination with the conventional feeder. Alternatively, the combination of the means 1 and the prior art is also the means 5.

  As a result, the product A is replenished with molten metal from the design system of the runner, the sprue, and the spout cup, and the product B is replenished with molten metal from the hot water without relying on the replenishment of molten metal from this system. A sound product will be obtained. Also by this method, compared with the case where all the conventional products were provided with a feeder, the feeder was reduced by half, and a significant improvement in casting yield was obtained.

  FIG. 8 shows an eighth embodiment using the means 5. In this example, the number of products and the arrangement are similar to those in Example 7, but in this example, the case where the runner 2 has a part in common with respect to the products A and B is shown. As in Example 7, four of the eight products labeled A are close to the gate center 3C (within 40 times the minimum coagulation modulus), so that the runner 2 having a small coagulation modulus using the means 2 is used. However, since the four indicated by B are far from the gate center 3C (more than 40 times the minimum solidification modulus), it is assumed that the solidification progress in the middle of the long runner 2 is fast. The hot water 5 was used.

  As a result, the product A is replenished with the molten metal from the design system of the runner, the sprue, and the sprue cup, and the product B does not depend on the replenishment of the melt from the system such as the runway 2 and the spout 3 as in Example 7. The molten metal is replenished from the feeder 5 and a healthy product is obtained for both A and B as a whole. Also by this method, compared with the case where all the conventional products were provided with a feeder, the feeder was reduced by half, and a significant improvement in casting yield was obtained.

  In the first to fourth embodiments, a basic case where one product is cast in one simple frame is shown. However, in actual mass production casting, a plurality of products are arranged in one frame. Multiple packages are common. In this case, as shown in this example, considering the product shape, size, arrangement, etc., the solidification modulus of the runner is changed for each product, that is, the runner size is changed, and the conventional feeder is used together. To do. That is, in order to comprehensively improve the quality and the casting yield in general mass production of multiple-fill castings, the means 1 to 4 and means 5 appropriately using the conventional feeder are used.

  FIG. 9 shows an embodiment 9 using the means 5. In this example, an example of vertical casting is shown. This figure shows a vertical cross-sectional view of the mold 6, in which eight products 1 are placed, and is composed of a design system of a runner 2, a gate 3 and a feeder 5. In vertical casting, the gate and the gate cup are usually commonly used, and therefore, the gate 3 and the gate center 3C are simply indicated here.

  Among the eight products 1, A having a short runner length from the gate center 3 </ b> C to the product 1 (within 40 times the coagulation modulus M <b> 3 of the gate 3) is indicated as A. In addition, the length of the runner from the gate center 3C to the product 1 is long (more than 40 times the solidification modulus M3 of the gate 3).

  As for the four products A, since the length of the runner from the gate center 3C to the product 1 is short, it is possible to replenish the coagulation contraction through the gate 3 and the runner 2, so no feeder is used. For the four products B, since the length of the runner from the gate center 3C to the product 1 is short, it is difficult to replenish the coagulation shrinkage through the gate 3 and the runner 2, so the feeder 5 is used.

  As described above, the means 1 to 5 can be applied to the vertical casting of this example as well as the flat casting shown in the first to eighth embodiments. Depending on the shape of the product, the number of containers, the location of the runners and the gates, etc., the solidification and shrinkage of all products may be replenished through the gates 3 and 2. Use hot water in the mold, or use it appropriately considering the various conditions of the mold.

  In Examples 1 to 9, an example in which a sand mold is mainly used as the mold is shown, but means 1 to 5 can be similarly applied even if a mold is used.

  FIG. 10 shows a tenth embodiment using the means 6. In this example, in order to delay the solidification of the molten metal on the top surface of the sprue cup by keeping the molten metal on the top surface of the sprue cup after pouring, the molten metal on the top surface of the sprue cup was covered with sand. Sand is desirable because it does not affect the mold even if the same type as the mold is mixed.

  In normal pouring, since the molten metal on the top of the spout cup is exposed to air after pouring, an oxide film is formed at an early stage and solidification tends to proceed. For this reason, when the whole solidification progresses to some extent, the action of atmospheric pressure from the molten metal on the upper surface of the spout cup becomes ineffective. In this example, in order to reduce the phenomenon, the air is blocked by sand to delay the solidification and extend the time during which atmospheric pressure is applied. Examples 10 to 15 show similar heat retention / heating methods, but all have the same basic effects.

  FIG. 11 shows an eleventh embodiment using the means 6. In this example, in order to keep the molten metal on the upper surface of the pouring cup after pouring, the molten metal on the upper surface of the pouring cup was covered with a mold piece coated with a resin. The effect is the same even if sand covered with resin is covered.

  FIG. 12 shows a twelfth embodiment using the means 6. In this example, in order to keep the molten metal on the top surface of the spout cup after pouring, a heat insulating material was put on the molten metal on the top surface of the spout cup.

  FIG. 13 shows a thirteenth embodiment using the means 6. In this example, in order to keep the molten metal on the top of the spout cup after pouring, the molten metal on the top of the spout cup was covered with a refractory material.

  FIG. 14 shows an embodiment 14 using the means 6. In this example, in order to keep the molten metal on the top of the spout cup after pouring, the molten metal on the top of the spout cup was covered with a heating agent and heated.

  FIG. 15 shows a fifteenth embodiment using the means 6. In this example, in order to keep the molten metal on the upper surface of the spout cup after pouring, the molten metal on the upper surface of the sprue cup was heated with fuel gas.

  FIG. 16 shows a sixteenth embodiment using the means 6. In this example, in order to keep the molten metal on the upper surface of the spout cup after pouring, the molten metal on the upper surface of the spout cup was heated using a high-frequency heating coil. Examples 10 to 16 are applicable to sand casting and die casting.

Effect of the invention

As described above, the present invention provides a casting method for producing a healthy product with a high casting yield by supplying molten metal from a plan system without using a feeder or using a feeder and a runner. In addition, a method using these basic methods and a conventional technique was also presented for more general multi-casting. As a result, the following effects were obtained.
(1) The molten metal replenishment method for new products using the plan system significantly improved casting yields while preventing shrinkage defects in the products.
(2) Since the hot water or the hot water and the runway were reduced, the design system was simplified and the brushing work after pouring was simplified.

  It is a figure which shows Example 1 of this invention.   It is a figure which shows Example 2 of this invention.   It is a figure which shows Example 3 of this invention.   It is a figure which shows Example 4 of this invention.   It is a figure which shows Example 5 of this invention.   It is a figure which shows Example 6 of this invention.   It is a figure which shows Example 7 of this invention.   It is a figure which shows Example 8 of this invention.   It is a figure which shows Example 9 of this invention.   It is a figure which shows Example 10 of this invention.   It is a figure which shows Example 11 of this invention.   It is a figure which shows Example 12 of this invention.   It is a figure which shows Example 13 of this invention.   It is a figure which shows Example 14 of this invention.   It is a figure which shows Example 15 of this invention.   It is a figure which shows Example 16 of this invention.   It is a figure which shows an example of the feeder of a prior art.   It is a figure which shows another example of the feeder of a prior art.

DESCRIPTION OF SYMBOLS 1 Product 2 Runway 2A Runway 2B Runway 3 Cup 3C Cup center 4 Cup cup 5 Press hot water 5A Lifting hot water 5B Side hot water 6 Mold 7 Weir 8 Sand 9 Resin-coated sand mold 10 Thermal insulation 11 Refractory Material 12 Heating Material 13 Heating with Fuel Gas 14 Heating with High Frequency Heating Coil

Claims (6)

  In sand mold casting of cast iron castings, a design system consisting of design elements of products, runners, gates, and gate cups is used without using a feeder, and the solidification moduli of the design elements of the system are M1, M2, M3, M4 in order. In this case, the casting method is characterized in that the solidification shrinkage of the product is replenished from the runner, the gate, and the gate cup by making all of M2, M3, and M4 larger than M1.   In sand mold casting of cast iron castings, a design system consisting of design elements of products, runners, gates, and gate cups is used without using a feeder, and the solidification moduli of the design elements of the system are M1, M2, M3, M4 in order. When M2, M3, and M4 are smaller than M1 and all of M2, M3, and M4 are larger than 0.6M1, a part of the solidification shrinkage of the product is made into a runner, a gate. A casting method characterized by replenishing from a spout cup.   In cast iron casting sand mold casting, a design system consisting of product elements of a product, a sprue, and a sprue cup is used without using a feeder and a runner, and the solidification moduli of the design elements of the plan system are M1, M3, and M4 in order. When M3 and M4 are larger than M1, the casting method is characterized in that the solidification shrinkage of the product is replenished from the gate and the gate cup.   In cast iron casting sand mold casting, a design system consisting of product elements, pouring gates, and pouring cup cups is used without using a feeder and a runner, and the solidification moduli of the design elements of the design system are M1, M3, and M4 in order. When at least one of M3 and M4 is smaller than M1 and M3 and M4 are larger than 0.6M1, a part of the solidification shrinkage of the product is replenished from the gate and the gate cup. Casting method.   When casting a plurality of products in one frame using the casting method according to any one of claims 1 and 2, the length of the runner from the gate center to the product is the length of the runner, the gate, and the gate cup. For products placed in positions exceeding 40 times the minimum value of the solidification moduli M2, M3, M4 of the design element, using the casting method without using a feeder, A casting method characterized by using a feeder.   The casting method according to any one of claims 1 to 5, wherein solidification of the molten metal on the upper surface of the pouring cup is delayed by keeping and / or heating the molten metal on the upper surface of the pouring cup after pouring. Method.

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