JP2010069514A - Casting method with vibration solidification, casting mold for the same method, and casting apparatus with vibration solidification - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a casting method with vibration solidification for casting a cast product, in which generation of casting defects is suppressed by limitedly imparting mechanical vibration only to a required position of a mold or the like. <P>SOLUTION: A mold 1 used for the casting method with vibration solidification includes: a mold body 5 through which a cavity 3 and a rod insertion hole 4 are penetrated; a vibration core 6, which is housed inside the cavity 3 while holding a predetermined clearance between an inner wall face 5a of the cavity 3 and itself; a vibration rod 7, which is formed slidably through the rod insertion hole 4, one end 7a of which is connected to the vibration core 6, and the other end 7b of which is projected in the outside of the mold body 5 from the rod insertion hole 4; and a rod vibration part 8, which vibrates the vibration core 6 connected to one end 7a of the vibration rod 7 by linearly reciprocating the vibration rod 7 along the longitudinal direction. By the above composition, pressing force for transmitting vibration and pressing force for suppressing vibration, which are opposite to each other, are generated, so that mechanical vibration is limitedly imparted only to the position requiring the vibration. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vibration solidification casting method, a casting mold thereof, and a vibration solidification casting apparatus. In particular, the solidification of a molten metal when casting a cast product made of an aluminum alloy or the like is made finer in a metal structure. Vibration solidification casting method and its casting mold, vibration solidification casting equipment (hereinafter referred to as “vibration solidification casting method”, “mold”, “casting equipment” respectively) For example).

  Conventionally, casting of an aluminum alloy has been performed by filling a molten aluminum alloy melted at a high temperature into a cavity of a mold (such as a mold or a sand mold) and solidifying from a liquid phase to a solid phase. It has been broken. Here, when the molten metal melted at high temperature is solidified, a metal consisting of refined macro crystal grains is used to prevent the concentration of defects such as “hot cracks” and “nests” during the cooling process. Attempts have been made to make a cast product with a texture. Such refinement can improve mechanical properties such as strength and pressure resistance of the cast product itself. Furthermore, it is possible to prevent casting defects on the processed surface. Here, the macro crystal grains are generally recognized as grains having a size that can be observed under an optical microscope.

  Here, when casting an aluminum alloy, there are three methods for refining the macro crystal grains of the metal structure: 1) quenching treatment, 2) addition of a finer, and 3) vibration treatment. It has been known for a long time (see Non-Patent Document 1). 1) Although the rapid cooling treatment can be carried out relatively easily, the entire cast product is not uniformly refined due to differences in the thickness of each part with respect to the product shape in each cast product. Sometimes. On the other hand, in the addition process of 2) the micronizing agent, miniaturization can be promoted by introducing the crystal grain micronizing agent into the molten metal.

  However, injecting a predetermined ratio of the fine agent to all casting products increases the cost of the fine agent and complicated processes such as input work. Therefore, 3) a vibration processing technique is expected for a technique for refining macro crystal grains, assuming that the structure is formed with a relatively simple configuration and the increase in manufacturing cost is not so large. Here, a technique for casting a cast product having a relatively simple shape such as an ingot by applying vibration to the mold has already been disclosed. It is described that it has an effect in preventing a casting defect of “crack” due to vibration of (see, for example, Patent Document 1 and Patent Document 2).

  Furthermore, in order to reduce the defects in the cast holes that occur in the casting products, 1) the product shape, the position of the feeder or the weir, the size, etc. are arranged appropriately and the directivity in the solidification direction is considered, or the molten metal is configured It is mentioned to appropriately manage the composition of the alloy or the component ratio of impurities contained in the molten metal. In addition, it has been proved that mechanical vibration is effective in refining crystal grains (see Non-Patent Document 2).

  In order to solve the above-mentioned problems, the applicants of the present application have developed a casting mold and a casting method of a novel vibration solidification casting method in which the mold itself is vibrated in accordance with the progress of solidification of the molten metal to control the solidification of the molten metal. It has been developed and a patent application has already been filed (see Patent Document 3). Thereby, in the solidification process of a molten metal, it becomes possible to refine | miniaturize a macro crystal grain and to reduce a casting hole defect.

Japanese Patent Laid-Open No. 10-156505 JP 2003-136190 A JP 2006-315046 A Edited by Kazuo Katori and Kazunori Kobayashi, “Casting on the spot”, Agne, 1969, p69 Harold W. Kaehler, “KAISER aluminum casting”, KAISER ALUMINUM & CHEMICAL SALES, INC. , Japan Light Metal Association, 1967

  In the case of the above-mentioned vibration solidification casting method, its casting mold, and vibration solidification casting apparatus, it has an excellent effect of being able to remarkably suppress the defects in the cavity as compared with the conventional mold. However, when trying to cast a casting product having a complicated shape, it is sometimes not suitable in terms of the quality of the casting product to give vibration to the entire mold as described above at a uniform frequency. That is, in the process of casting a cast product by pouring the molten metal from the runner into the cavity, cooling the molten metal in the cavity, and solidifying the molten metal, the progress of solidification of the molten metal is different in each part of the cavity. For example, when the molten metal is filled in a narrow and narrow space, the contact area with the outside is large, the temperature is easily affected by the temperature outside the mold, and heat is relatively easily taken away. For this reason, solidification is completed relatively quickly from the completion of the filling of the molten metal. On the other hand, when the molten metal is filled in a relatively wide space, the influence of the ambient temperature is relatively insensitive, and the progress of solidification becomes relatively slow. As a result, even in a single cast product, there is a possibility that a difference occurs in the solidification time depending on each part of the cavity, and the quality of the cast product may be biased. Furthermore, although mechanical vibration has been proved to be effective for crystal grain refinement, the method of applying mechanical vibration mainly due to dimensional limitations, the device itself is expensive and has become very popular. Not in. Therefore, instead of applying vibration to the entire mold and casting device, an inexpensive vibration device is provided in a part of the mold, and the vibrating core is vibrated, thereby enabling the refinement of crystal grains. Was desired.

  Accordingly, in view of the above circumstances, the present invention provides a mold, a casting apparatus, and a vibration solidification casting method using the mold capable of casting a cast product in which macro crystal grains are miniaturized and generation of defects in a cast hole is suppressed. Is an issue.

  In order to solve the above-mentioned problems, the vibration solidification casting method of the present invention is described as follows: “A molten metal melted at a high temperature is poured into a cavity of a mold through a runner and filled, and the filled molten metal is contained in the cavity. A melt solidification step for cooling and solidifying, and a core vibration step for vibrating the vibration core accommodated in the cavity while holding a predetermined clearance at the same timing at which the solidification of the melt proceeds by the melt solidification step. And ".

  Therefore, according to the vibration solidification casting method of the present invention, when the molten metal is filled and cooled and solidified in the cavity, the vibrating core is vibrated to give vibration of the molten metal being solidified. Thereby, refinement | miniaturization of a macrocrystal grain can be achieved.

  On the other hand, the mold according to the present invention is “a mold body in which a cavity filled with a molten metal is formed and a rod insertion hole communicating with the cavity is penetrated, and a predetermined relative to an inner wall surface of the cavity. The vibration core accommodated in the cavity so as to vibrate, and the rod insertion hole is slidably fitted, and one end portion is connected to the vibration core in the cavity, A rod-shaped vibrating rod having the other end projecting from the mold body and the vibrating rod reciprocating linearly along the longitudinal direction, thereby allowing the vibrating core connected to the one end to move within the cavity. It is mainly comprised from what comprises the rod vibration means to vibrate ".

  Here, the rod vibration means is, for example, a vibration transmission plate that comes into contact with the other end of the vibration rod protruding from the mold body, a vibrator for vibrating the vibration transmission plate, and a vibration transmission plate that can vibrate. What is mainly comprised by the vibration-transmission board support part etc. which were formed with elastic materials, such as a spring supported by, etc. can be shown. For the vibrator, for example, a ball vibrator or a high-frequency wave capable of generating vibration accompanied by centrifugal force by rotating a metal ball filled in a circular inner space at high speed using the air pressure of compressed air. A well-known vibration technique such as a vibration device using an electric motor or the like can be used. In view of vibration performance, availability, cost, and the like, it is preferable to use the above-described ball vibrator.

  On the other hand, as the molten metal used in the present invention, a metal or metal alloy melted at a high temperature is used, and the metal species and alloy species of the molten metal are not particularly limited. For example, it is possible to target various metals or alloys that can be conventionally used for casting products, such as pure aluminum, aluminum alloy, magnesium, and aluminum-copper alloy. In the present invention, a crystal grain refining agent such as titanium, boron, zirconium or the like generally added to the molten metal may not be used.

  On the other hand, the vibration core is housed in the cavity of the mold body, receives vibration generated by the rod vibration means via the vibration rod, and vibrates in the cavity. Here, the vibration width (amplitude) of the vibrating core by the rod vibrating means is set to be smaller than the clearance between the vibrating core and the inner wall surface of the cavity. For example, when the clearance between the inner wall surface of the cavity and the outer surface of the vibrating core is set to 2 mm during non-vibration, vibration with an amplitude of less than 2 mm at maximum can be generated. Thereby, the vibration core does not collide with the cavity during vibration, and there is no possibility of damaging the mold. Note that the vibration core does not need to be provided in all the parts of the cavity, and a part that requires vibration and a part that does not require vibration are determined according to the shape thereof, and are arranged appropriately based on the determination. The By this, even if it is not possible to refine the uniform macro crystal grains due to the difference in the time required for solidification in the cavity (solidification time), by giving appropriate vibrations to individual parts during solidification, It is possible to move the casting cavity and refill the molten metal inside the casting by vibration. As a result, it is possible to stably produce a cast product having excellent mechanical properties by suppressing the occurrence of casting hole defects.

  More specifically, when the vibrating core vibrates in the cavity by the rod vibrating means, vibration is given to a molten metal such as metal melted at a high temperature. At this time, the molten metal is still in a liquid state and is directly affected by the vibration. As a result, immediately after the filling of the molten metal is completed, vibration is transmitted to the molten liquid, and convection or mixing of the molten metal occurs in the cavity. Thereby, for example, even when a situation where specific gravity or density differs between the upper and lower sides of the cavity, it is possible to prevent each part from becoming a non-uniform metal structure due to the vibration. Furthermore, even when there is a difference in the solidification time of the molten metal in the cavity, it is possible to advance the refinement of macro crystal grains for each part by giving (or not giving) vibration only to a specific part. . The applied vibration can be adjusted as appropriate according to the type of rod vibration means and vibration performance, and a wide range of frequencies (frequency) from the low frequency region to the high frequency region can be arbitrarily set according to various conditions. It becomes possible to set.

  Furthermore, the mold according to the present invention may further include “a rod urging means for urging the vibration rod in a direction in which the other end portion is separated from the mold body, in addition to the above-described configuration, , Further comprising reverse biasing means for biasing the other end portion of the vibrating rod in a direction approaching the mold body, opposite to the biasing direction of the vibrating rod by the rod biasing means, The other end portion of the rod and the rod vibration means may be held in contact with each other by urging forces facing each other by the rod urging means and the reverse urging means.

  Here, the rod urging means and the reverse urging means are not particularly limited. For example, a well-known “spring” may be used. Accordingly, the other end of the vibration rod is biased in a direction away from the mold main body (a direction close to the rod biasing means) by the elastic repulsive force of the spring, and on the other hand, the mold main body is biased by the reverse biasing means. Can be urged in the direction approaching.

  Therefore, according to the mold of the present invention, the urging directions of the rod urging means and the reverse urging means are set to face each other. For this reason, the other end portion of the vibrating rod and the rod vibrating means are forced to press each other by the opposing forces, and the contact state between the two is maintained at the point where the respective urging forces coincide with each other. . As a result, the contact state is maintained only by the urging force without a fixing member such as a screw interposed between the vibrating rod and the rod vibrating means. Therefore, it is possible to easily perform replacement of the vibration rod or replacement due to a failure of the rod vibration means.

  On the other hand, the casting apparatus according to the present invention has the following features: “A cavity filled with molten metal is formed, and a predetermined clearance is provided with respect to a rod insertion hole portion that is provided in communication with the cavity and an inner wall surface of the cavity. A mold having a vibrating core that is held in the cavity so as to be capable of vibrating, and is slidably fitted into the rod insertion hole, and one end of the mold is connected to the vibrating core in the cavity. The rod-shaped vibrating rod having the other end projecting from the mold and the vibrating rod linearly reciprocated along the longitudinal direction, thereby allowing the vibrating core connected to the one end to move within the cavity. It mainly comprises rod vibrating means for vibrating.

  Therefore, according to the casting apparatus of the present invention, the vibrating core housed in the mold can be vibrated by the rod vibrating means. Here, the casting apparatus of the present invention is configured such that the vibrating rod and the rod vibrating means in the mold described above are configured separately from the mold body, and the basic functions and effects are substantially the same as those of the mold. is there. For this reason, the rod vibration means (vibrator and the like described above) only needs to have one configuration for a plurality of molds. Therefore, the manufacturing cost of the mold does not increase so much. Therefore, when manufacturing various types of cast products, it is particularly effective to separately configure the rod vibration means and the like.

  Further, the casting apparatus of the present invention further includes a rod urging means for urging the oscillating rod in a direction in which the other end portion is separated from the mold body, in addition to the above configuration. , Further comprising reverse biasing means for biasing the other end portion of the vibrating rod in a direction approaching the mold body, opposite to the biasing direction of the vibrating rod by the rod biasing means, The other end portion of the rod and the rod vibration means may be held in contact with each other by urging forces facing each other by the rod urging means and the reverse urging means.

  Therefore, according to the casting apparatus of the present invention, the contact state between the other end portion of the vibrating rod and the rod vibrating means is held by the biasing forces facing each other. Thereby, there exists an effect similar to the above-mentioned metal mold | die.

  Further, the casting apparatus according to the present invention may include, in addition to the above-described configuration, “a plurality of the rod insertion holes communicating with the cavity are provided in the casting mold of the vibration solidification casting method, The other end portions of the plurality of vibrating rods slidably fitted may be connected to the rod vibrating means.

  Therefore, according to the casting apparatus of the present invention, by providing a plurality of rod insertion holes in the casting mold, it becomes possible to apply vibrations to each part of the cavity simultaneously or independently. . Thereby, refinement | miniaturization of a macrocrystal grain will be performed still more efficiently.

  As an effect of the present invention, a vibrating core is accommodated in the cavity, and this is vibrated by an external rod vibrating means or the like, so that the vibration is limited to the molten metal filled in a specific part in the cavity. it can. As a result, it becomes possible to manufacture a cast product having a metal structure having fine macro crystal grains with few defects in the casting hole.

  Hereinafter, an example of a mold 1 according to an embodiment of the present invention and a vibration solidification casting method 2 using the mold 1 will be described with reference to FIGS. 1 and 2. Here, FIG. 1 is an explanatory diagram showing a schematic configuration of the mold 1 of the first embodiment, and FIG. 2 is a flowchart showing an example of the flow of the vibration solidification casting method 2 using the mold 1.

  As shown in FIG. 1 and the like, the mold 1 of the first embodiment has a cavity 3 filled with a molten metal and engraved so as to substantially match the external shape of a cast product. A predetermined clearance C is maintained with respect to the mold body 5 through which the communicating tubular rod insertion hole 4 communicates and the inner wall surface 3a of the cavity 3, and the vibration is accommodated in the cavity 3 so as to vibrate. The rod 6 and the rod insertion hole 4 are slidably fitted along the longitudinal direction, have a rod diameter substantially matching the hole diameter of the rod insertion hole 4, and one end 7 a is accommodated in the cavity 3. A rod-shaped vibrating rod 7 connected to a part of the vibrating core 6 and having the other end 7b protruding from the rod insertion hole 4 to the outside of the mold body 5, and the vibrating rod 7 are linearly reciprocated along the longitudinal direction. By moving, the vibrating core 6 connected to the one end 7a is moved into the cavity 3. In a rod vibration portion 8 to minute vibrations it is composed mainly provided. Here, the rod vibrating portion 8 corresponds to the rod vibrating means of the present invention. Here, the clearance C between the inner wall surface 3a of the cavity 3 and the vibrating core 6 can be adjusted in units of 0.1 mm and can be slid within a range of several mm in the sliding direction. can do. A predetermined clearance C is always maintained in the width direction orthogonal to the sliding direction.

  The rod vibration portion 8 will be described in more detail. A flat plate vibration transmission plate 9 having a contact surface 9a capable of contacting the other end portion 7b of the vibration rod 7 protruding from the mold body 5, and the vibration transmission plate 9 And a pair of vibration transmission plate support portions 12 that support the vibration transmission plate 9 with respect to the apparatus base portion 11. Here, the vibration transmission support portion 12 is formed of a spring member, supports the vibration transmission plate 9, and can freely vibrate by vibration generated by the vibrator 10. Further, the vibration transmission plate 9 is biased in the direction of the mold body 5 (see arrow A in FIG. 1). Here, the vibration transmission plate support 12 corresponds to the reverse biasing means of the present invention.

  On the other hand, the vibration rod 7 is interposed between the mold body 5 and the vibration transmission plate 9, and the other end portion of the vibration rod 7 is disposed around the portion protruding from the mold body 5 to the outside. The rod biasing portion 13 (see FIG. 7) made of an elastic material that biases the vibration transmitting plate 9 in a direction away from the mold body 5, in other words, in a direction away from the mold body 5. 1 arrow B). Here, the rod urging portion 13 corresponds to the rod urging means in the present invention.

  As a result, the urging direction (arrow A) by the vibration transmission plate support 12 and the urging direction (arrow B) by the rod urging unit 13 are opposed to each other, and the balance is achieved in that the urging forces of the two coincide. Kept. That is, the opponents are pressed against each other, and the contact state is maintained. At this time, no fixing means such as a screw is interposed between the other end 7 b of the vibration rod 7 and the contact surface 9 a of the vibration transmission plate 9. Therefore, it is easy to cancel the contact state. In other words, by eliminating the member that generates one of the urging forces, the balance of the urging forces disappears.

  Hereinafter, a specific example of the vibration solidification casting method 2 using the mold 1 will be described mainly based on the flowchart of FIG. The vibration solidification casting method 2 of the present invention can be applied to any known casting method such as an inclined casting method, a vertical casting method, and a horizontal casting method.

  First, a molten molten metal (not shown) melted at a high temperature is poured into the cavity 3 from a runner (not shown) connected to the mold body 5 to fill the molten metal (melt filling step S1). When a prescribed amount of molten metal is charged into the cavity 3 and filling is completed, the molten metal melted at a high temperature gradually releases heat and loses fluidity due to a difference in ambient temperature. Thereby, the solidification from the liquid to the solid proceeds (molten solidification step S2). Here, in the vibration solidification casting method 2 of the present invention, the rod vibrating portion 8 is operated to vibrate the vibrating core 6 accommodated in the mold body 5 (core vibrating step S3). As described above, the vibration of the vibrating core 6 may be performed immediately after the molten metal is poured into the cavity 3 and the filling of the molten metal is completed, or before the molten metal filling step S1. Any one of filling the molten metal with the vibrating core 6 vibrated in advance may be used.

  Further, the core vibration step S3 will be described in detail. A vibration having a predetermined frequency is generated by the vibrator 10 including a high-frequency electric vibration motor. At this time, since the vibrator 10 is installed on the contact back surface 9 b of the vibration transmission plate 9, the vibration generated by the vibrator 10 is directly transmitted to the vibration transmission plate 9. At this time, since the vibration transmission plate 9 is supported by a pair of vibration transmission support portions 12 formed by spring members, vibration transmission of the vibration transmission plate 9 by the vibrator 10 is not absorbed or restricted. The vibration can be continued while being supported by the support portion 12.

  At this time, the other end portion 7 b of the vibration rod 7 is in contact with the contact surface 9 a of the vibration transmission plate 9 and is urged by the rod urging portion 13 so as to be pressed against the contact surface 9 a. Therefore, the vibration of the vibration transmission plate 9 is transmitted to the vibration rod 7. As a result, the vibrating rod 7 reciprocates linearly along the longitudinal direction, and is slidably fitted into the rod insertion hole 4, so that the vibrating core 6 connected to the one end 7 a is connected to the cavity 3. It will vibrate within. Thereby, it becomes possible to transmit vibration to the liquid molten metal. In particular, since the urging forces are opposed to each other, the vibration rod 7 can be repeatedly moved with a predetermined amplitude in the sliding direction (the vertical direction in the drawing in FIG. 1) by the vibration of the vibration transmission plate 9. Thereby, the molten metal can be vibrated by the vibrating core 6, and the molten metal can be vibrated in the process of solidifying from liquid to solid.

  As a result, the molten metal can be solidified in a state where the macro crystal grains of the metal structure are refined. Furthermore, the arrangement of the vibration core 6 makes it possible to distinguish between a portion that gives vibration and a portion that does not give vibration. Compared with the conventional case that gives vibration to the entire mold, the finer crystal grains This makes it possible to control the miniaturization.

  Thereafter, when a preset time has elapsed since the start of vibration (for example, 5 seconds from the start of vibration), a process of stopping vibration by the rod vibration unit 8 is performed (vibration stop step S4). Here, when filling of the molten metal is completed and a certain amount of time has passed, the liquid molten metal becomes almost solid, so that the effect of vibration hardly occurs. Therefore, a predetermined time is measured from the start of vibration, and the vibration is stopped when solidified to such an extent that it is not affected by vibration.

  Thereafter, after confirming that the molten metal has been completely solidified (solidification completion step S5), the mold body 5 that can be divided into two is opened (die opening step S6). Then, the cast product after casting is removed from the mold body 5 (die removal step S7). As a result, the casting of the casting product having a refined metal structure is completed during the solidification.

  Next, the casting apparatus 20 of 2nd embodiment of this invention is demonstrated based on FIG. Here, FIG. 3 is explanatory drawing which shows schematic structure of the casting apparatus 20 of 2nd embodiment. The casting apparatus 20 of the present embodiment has substantially the same function and effect as the mold 1 shown in the first embodiment, and the vibration generation transmission mechanism 22 (rod) that vibrates the vibration core 21. (Corresponding to vibration means) is provided separately from the mold 23.

  As shown in FIG. 3, the casting apparatus 20 of the second embodiment has a cavity 24 filled with a molten metal (not shown) and carved so as to substantially match the external shape of the cast product. A predetermined clearance C is maintained with respect to the mold 23 in which a circular rod insertion hole 25 communicating with the cavity 24 is provided, and the inner wall surface 24a of the cavity 24, and the cavity 24 is accommodated so as to be able to vibrate. The vibrating core 21 and the rod insertion hole 25 are fitted so as to be slidable along the longitudinal direction, have a rod diameter substantially equal to the hole diameter of the rod insertion hole 25, and one end 26 a is accommodated in the cavity 24. The rod-shaped vibrating rod 26 is connected to a part of the vibrating core 21 and the other end 26b protrudes from the rod insertion hole 25 to the outside of the mold 23, and the vibrating rod 26 is straight along the longitudinal direction. By reciprocating, The end 26a and connected to the vibrating core 21 comprises a vibration generating transmission mechanism 22 for finely oscillating in the cavity inside 24 is mainly composed. Here, the vibration generation transmission mechanism 22 corresponds to the rod vibration means of the present invention.

  The vibration generation transmission mechanism 22 will be described in more detail. A flat vibration transmission plate 27 having a contact surface 27a that can contact the other end 26b of the vibration rod 26 protruding from the mold 23, and a vibration core. A pair of vibration transmissions for transmitting the vibration 21 to the vibration transmission plate 27 by connecting the vibrator 28 for vibrating 21 through the vibration transmission plate 27 and the vibration rod 26, the vibration transmission plate 27 and the vibrator 28. It mainly includes rod rods 29a and 29b and a rod reverse biasing portion 30 formed of an elastic material that supports the vibrator 28. Here, the rod reverse biasing portion 30 is supported by the platen 31. Here, the rod reverse biasing portion 30 corresponds to the reverse biasing means in the present invention.

  Furthermore, in the casting apparatus 20 of the second embodiment, the vibration rod 26 having the other end 26b protruding from the mold 23 is moved in the direction in which the other end 26b is separated from the mold 23 (see the broken line arrow in FIG. 3). A rod urging portion 32 (corresponding to the rod urging means of the present invention) formed of a spring member for urging is provided. On the other hand, the rod reverse biasing portion 30 of the vibration generation transmission mechanism portion 22 is opposed to the biasing direction of the rod biasing portion 32, and the direction in which the other end portion 26b of the vibration rod 26 approaches the mold 23 (see FIG. 3 (see solid line arrow). Thereby, the contact state of the other end portion 26b and the vibration transmission plate 27 is maintained by the opposing urging forces.

  With the above configuration, the vibration generated by the vibrator 28 is transmitted to the vibrating core in the cavity 24 through the vibrating rod 26 in the process of solidifying the molten metal filled in the cavity 24, thereby giving vibration to the molten metal. be able to. Thereby, refinement | miniaturization of the macro crystal grain in the metal structure of a cast product can be achieved. Here, casting of a cast product using the casting apparatus 20 of the second embodiment is substantially the same as the case where the mold 1 of the first embodiment is used, and thus description thereof is omitted here.

  Next, the test piece cast using the casting apparatus 20 according to the second embodiment of the present invention is used, and the effect of the vibration of the present invention on the cast product will be described with reference to FIGS. Here, as shown in FIG. 4, the shape of the cast test piece is <1> the tip of the test piece, and <2> the central part is formed in a substantially cylindrical shape with the same diameter. Is slightly larger than <1> and <2>. Here, in the test piece having the shape shown in FIG. 4, vibration is not applied to the portion <3>.

  First, an internal cross-sectional structure of each cast test piece T1, T2 is shown. When no vibration is applied, as shown in FIG. 5 (a), the generated macro crystal grains are relatively large, and it is confirmed that the structure becomes larger particularly as the feeder part is approached. The On the other hand, when the vibration is applied, as shown in FIG. 5B, the internal cross-sectional structure of the test piece is confirmed to have a finer and finer metal structure than that of the test piece that does not give vibration. Is done. Therefore, it is shown that there is an effect on the refinement of the metal structure by vibration.

  Next, FIG. 6 shows the result of measuring the vibration transmitted to the mold when the vibration is applied by the acceleration sensor. As described above, vibration is not applied to the portion <3>. As a result, vibrations of <1> and <2> that are given vibration by the vibrating core are confirmed to have a constant amplitude, and those of <3> that are not given vibration at all have almost no change in waveform. can not see. Thereby, it becomes possible to vibrate only a specific site | part with a vibrating core, and can control the progress of coagulation.

  Furthermore, the specific gravity of each of the above-mentioned portions <1> and <2> of the test piece due to the difference in vibration application and vibration conditions was measured, and the comparison result is shown in FIG. Before measuring the specific gravity, the elements constituting the test piece and the composition thereof are analyzed in advance using a light emission analyzer (manufactured by Shimadzu Corporation), and based on the analysis result, the test piece mixture and The calculated specific gravity (hereinafter referred to as “calculated specific gravity”) is calculated. In the case of this example, the value of the calculated specific gravity was “2.6740”.

  The test piece specific gravity is measured using an electronic balance and a specific gravity measurement kit for the electronic balance, and the weight of the sample in the air and the weight of the sample in the liquid (in water) are measured. 1, the density (= specific gravity) of the sample is calculated based on the Archimedes method of JIS Z8807 standard. Here, ρ: the density of the sample, A: the weight in the air, B: the weight in the liquid, and ρ0: the density of the liquid. Further, as a condition for measuring the specific gravity, the water temperature is kept at 25 ° C., and the specific gravity of water (= liquid density: ρ0) at that time is set as 0.997071.

  In addition, the mold temperature t is set to two temperature conditions of 360 ° C. and 390 ° C. under three types of vibration conditions of no vibration (inverter output frequency = 0 Hz), inverter output frequency = 140 Hz, and inverter output frequency = 208 Hz. In total, six test pieces were cast. And specific gravity was measured about said <1> and <2> of each cast test piece.

  As shown in FIG. 7, it was confirmed that the variation from the calculated specific gravity increases when no vibration is applied (inverter output frequency = 0 Hz). In particular, the value of the part <2> corresponding to the hot water side is far from the calculated specific gravity. On the other hand, when vibration is applied as in the present invention (inverter output frequency = 140 Hz, 208 Hz), a value approximate to the calculated specific gravity (2.6740) is shown in any part, and the part <2> Even so, it was not far from the calculated specific gravity. Accordingly, the defects in the cast holes were reduced by the specific gravity at each part approaching the calculated specific gravity. It was shown that the present invention has a sufficient effect.

  Furthermore, as shown in FIG. 8, it is shown that transferability of the mold surface is improved by application of vibration. Here, FIG. 8 shows values of the surface roughness Rz of the mold surface, the surface roughness Rz of the casting product cast under the condition with vibration, and the surface roughness Rz of the casting product cast under the condition without vibration (μm ) Are shown from the left. The number of measurements under each condition is 4 points. According to this, the surface roughness Rz of the mold surface itself and the condition with vibration shows relatively approximate values. That is, it was confirmed that the product surface of the cast product cast by the mold has almost the same surface roughness Rz as the mold, and the transferability (reproducibility) at the time of casting is good. On the other hand, in the condition of no vibration, the surface roughness Rz of the mold surface itself showed a value far apart. That is, the transferability at the time of casting is not good, and the product surface of the cast product is greatly different from the mold surface. From these results, in conventional casting without vibration (for example, gravity casting), an “air gap” occurs between the mold surface and the molten metal, and the air layer causes a gap between the mold surface and the mold surface. The adhesion of is impaired. Even the slight unevenness of the mold surface cannot be accurately expressed (transferred) on the surface of the casting product, and as a result, it can be estimated that the value of the surface roughness Rz is greatly different. On the other hand, by applying vibration as in the present invention, the air gap becomes small, the adhesion between the mold surface and the molten metal is improved, and even fine irregularities are accurately transferred to the surface of the casting product. It becomes possible to do. That is, according to the present invention, the transferability of the cast product can be improved.

  Here, applying the vibration can make the air gap small (thin) as described above. The air gap is a layer of air, and the presence of such a layer thickly between the molten metal and the mold means that the heat of the high-temperature molten metal is quickly transferred to the metal due to the heat shielding effect of the air layer having a small heat transfer coefficient. It becomes difficult to transmit to the mold. Therefore, by reducing the air gap layer by vibration, the heat of the molten metal can be quickly transmitted to the mold, and the cooling of the molten metal and the solidification rate of the cast product are expected to be accelerated. It is presumed that there are excellent effects in improving the mechanical properties and refining the metal structure. Here, in order to confirm the difference based on the vibration conditions of the mold temperature change and the solidification rate of the casting product, FIG. 9 shows (a) the mold temperature and (b) the temperature change of the casting product due to the application of vibration. The measured graphs (mold temperature curve and cooling temperature curve) are shown respectively.

  Here, the mold temperature is the temperature inside the mold after a thermocouple is installed at a position inside the mold 6.7 mm below the mold surface, and a high temperature molten metal is introduced into the cavity by an oscilloscope (die mold). The result of measuring (temperature) is shown. At this time, the mold is heated and held at about 420 ° C., while the molten metal charged into the cavity is heated to about 720 ° C. Under the condition with vibration (see the graph in FIG. 9A), after a few seconds from the start of filling (filling) the molten metal, the mold temperature maintained at about 420 ° C. is gradually increased by the heat of the molten metal. After about 40 s from the start of charging, a mold temperature of about 454 ° C., which becomes a peak value, was exhibited. On the other hand, in the condition without vibration (see the graph in FIG. 9A), the peak value is shown about 40 s after the start of charging, but the value is about 445 ° C., which is lower than the condition with vibration. The value is shown. In other words, by applying vibration, the air gap generated between the mold surface and the molten metal is reduced and is not significantly affected by the heat shielding effect of the air gap. Will be better transmitted. For this reason, as shown in the graph results, it was shown that the peak value was higher under the condition with vibration.

  On the other hand, the temperature change inside the casting product during casting is shown in FIG. In this case, a thermocouple was set in the cavity filled with the molten metal, and the temperature change from the start of the molten metal was measured. Here, the mold is heated in advance to 360 ° C. before the molten metal is charged, and the molten metal charged in the cavity is heated to 720 ° C. According to this, as shown in FIG. 9B, when the molten metal is started to be introduced and the molten metal comes into contact with the thermocouple, a rapid increase in temperature is confirmed, and it is confirmed that the temperature rises to about 630 ° C. at a stretch. Thereafter, a slight temperature drop is observed, and the solidification of the molten metal starts after about 5 s to 6 s. Then, the heat of the molten metal is gradually transmitted to the mold, and the molten metal reaches the solidification end temperature to complete the solidification. At this time, it was shown that the solidification start earlier in the condition with vibration compared to the condition without vibration. Furthermore, in the condition with vibration, it is confirmed from the cooling curve that solidification is completed in about 18 s from the start of charging, whereas in the condition without vibration, solidification is completed in about 31 s from the start of charging. It has been confirmed. Further, the temperature of the cast product after 40 seconds passed was about 475 ° C. under the condition with vibration, and about 530 ° C. under the condition without vibration, and a temperature difference of 55 ° C. or more was confirmed. That is, from the above graph, it has been clarified that under the condition with vibration, the heat of the molten metal is quickly transferred to the mold, and the molten metal is cooled in a shorter time. That is, it was shown that the influence of the heat shielding effect by the air gap is reduced by applying vibration.

  Further, the other end portion of the vibration rod and the vibration transmission plate are held only by the urging force of each other. Therefore, even when the mold body (or mold) is replaced, or when the vibration transmission plate is replaced, it is possible to easily perform such work. Further, even when a plurality of vibration rods are provided, it is not necessary to connect the vibration transmitting plate and the other end, and the contact state can be easily held and released.

  The present invention has been described with reference to preferred embodiments. However, the present invention is not limited to these embodiments, and various modifications can be made without departing from the spirit of the present invention as described below. Improvements and design changes are possible.

  That is, in the mold 1 or the casting apparatus 20 of this embodiment, the rod urging means and the reverse urging means are shown using a spring member, but the present invention is not limited to this, and a rubber resin or the like is used. Any material that can be elastically deformed and that can bias the vibration rod and the vibration transmission plate in a desired biasing direction may be used.

  Furthermore, although a case where a single vibrating core is accommodated in the cavity is shown, the present invention is not limited to this, and a plurality of vibrating cores are provided, and a vibrating rod connected to each of them is vibrated independently. It doesn't matter. In this case, a rod vibration part (or vibration generation transmission mechanism part) may be provided corresponding to each vibration rod, or only one may be provided. Thereby, an appropriate vibration according to each part can be given, and progress of coagulation can be controlled more finely.

It is explanatory drawing which shows schematic structure of the metal mold | die of 1st embodiment. It is a flowchart which shows an example of the flow of the vibration solidification casting method using a metal mold | die. It is explanatory drawing which shows schematic structure of the casting apparatus of 2nd embodiment. It is explanatory drawing which shows the structure of a test piece. (A) It is a cross-sectional photograph which shows the internal cross-sectional structure | tissue of the test piece which has not given vibration, (b) It is a cross-sectional photograph which shows the internal cross-sectional structure | tissue of the test piece which gave the vibration. It is the waveform graph which measured the vibration transmitted to a metal mold | die with the acceleration sensor. It is a graph which shows the result of having measured the specific gravity of each site | part of the test piece by application of a vibration. It is a graph which shows the difference in the surface roughness by the application of a vibration. It is a graph which shows the temperature change of (a) metal mold | die temperature and (b) casting product by application of a vibration.

Explanation of symbols

1,23 Mold (Casting mold of vibration solidification casting method)
2 Vibrating solidification casting method 3,24 Cavity 3a, 24a Inner wall surface 4,25 Rod insertion part 5 Mold body 6,21 Vibrating core 7,26 Vibrating rod 7a, 26a One end 7b, 26b The other end 8 Rod vibration Part (rod biasing means)
9, 27 Vibration transmission plate 9a Contact surface 9b Contact back surface 10, 28 Vibrator 11 Device base 12 Vibration transmission support (reverse biasing means)
13 Rod urging unit 20 Casting device (vibrating solidification casting device)
22 Vibration transmission mechanism (
30 Rod reverse biasing part (reverse biasing means)
32 Rod urging section S1 Melt filling process S2 Melt solidification process S3 Core vibration process S4 Vibration stop process
S5 Solidification completion process C Clearance

Claims (6)

A molten metal filling process in which molten metal melted at a high temperature is poured into a cavity of a casting mold of a vibration solidification casting method through a runner, and filled,
A molten metal solidification step for cooling and solidifying the filled molten metal in the cavity;
And a core vibration step of vibrating a vibration core accommodated in the cavity while maintaining a predetermined clearance at the same timing at which the molten metal solidifies in the molten metal solidification step. Casting method. A casting mold used in the vibration solidification casting method according to claim 1,
A mold body in which a cavity filled with a molten metal is formed and a rod insertion hole communicating with the cavity is provided,
Holding a predetermined clearance with respect to the inner wall surface of the cavity, and a vibrating core accommodated in the cavity so as to vibrate;
A rod-shaped vibrating rod that is slidably fitted in the rod insertion hole, has one end connected to the vibrating core in the cavity, and the other end protruded from the mold body,
A vibrating solidification casting method comprising: rod vibrating means for vibrating the vibrating core connected to the one end in the cavity by linearly reciprocating the vibrating rod along the longitudinal direction. Casting mold. Rod urging means for urging the vibrating rod in a direction in which the other end portion is separated from the mold body;
The rod vibrating means is
Reversing biasing means for biasing the other end of the vibrating rod in a direction approaching the mold body, opposite to the biasing direction of the vibrating rod by the rod biasing means,
The other end of the vibrating rod and the rod vibrating means are:
3. The casting mold of the vibration solidification casting method according to claim 2, wherein the contact state is maintained by urging forces opposite to each other by the rod urging means and the reverse urging means. A vibration solidification casting apparatus used in the vibration solidification casting method according to claim 1,
A cavity filled with molten metal is formed inside, and a predetermined clearance is maintained with respect to the rod insertion hole portion that is communicated with the cavity and the inner wall surface of the cavity, so that vibration can be generated in the cavity. A casting mold of a vibration solidification casting method having a housed vibrating core;
A rod-shaped vibrating rod that is slidably fitted in the rod insertion hole, has one end connected to the vibrating core in the cavity, and the other end protruded from a casting mold of the vibration solidification casting method. When,
A vibrating solidification casting apparatus comprising rod vibrating means for vibrating the vibrating core connected to the one end in the cavity by linearly reciprocating the vibrating rod along the longitudinal direction. . Rod urging means for urging the vibrating rod in a direction in which the other end portion is separated from the mold body;
The rod vibrating means is
Reversing biasing means for biasing the other end of the vibrating rod in a direction approaching the mold body, opposite to the biasing direction of the vibrating rod by the rod biasing means,
The other end of the vibrating rod and the rod vibrating means are:
5. The vibration solidification casting apparatus according to claim 4, wherein the contact state is maintained by urging forces opposed to each other by the rod urging means and the reverse urging means. The casting mold of the vibration solidification casting method is
A plurality of the rod insertion holes communicating with the cavity are provided,
The said other end part of the said some vibration rod each slidably fitted by the said rod insertion hole part is connected with the said rod vibration means, The Claim 4 or Claim 5 characterized by the above-mentioned. Vibration solidification casting equipment.