JP2018158376A - Casting device and method for manufacturing casting - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a casting device that allows for increasing as many as possible the number of times of casting per unit time in making castings continuously.SOLUTION: A casting device 10 has, for example, a stationary mold 20, a movable mold 22 displaceable for the stationary mold 20, and an intermediate mold 24 interposed between the stationary mold 20 and the movable mold 22. The intermediate mold 24 is provided with a cutting mechanism 32 including a cutter 34 for cutting a casting plan part 14 from a casting 16. At a tip end of the cutter 34, a second recess 42 is formed on an end face facing the intermediate mold 24, subsiding from the end face toward an end face facing the stationary mold 20. A bottom surface of the second recess 42 is orthogonal to a first recess 40 (cutting part) for cutting the casting plan part 14.SELECTED DRAWING: Figure 1

Description

  The present invention provides a casting apparatus in which a cavity is formed when a fixed mold that is positioned and fixed and a movable mold that can be displaced toward or away from the fixed mold are clamped, and the cavity. The present invention relates to a method for manufacturing a cast product to obtain a cast product.

  As is well known, a cast product is obtained by filling a cavity formed in a casting apparatus with a molten metal. Here, as described in Patent Document 1, for example, the casting apparatus includes a fixed mold that is positioned and fixed, a movable mold that moves in a direction approaching or separating from the fixed mold, and the fixed mold and the movable mold. And an intermediate mold interposed between the molds. The fixed mold is provided with a sprue and a runner, and the intermediate mold and the movable mold are formed with a product cavity that is a main part of the cavity and forms a product shape. Of course, the product part communicates with the gate via the runner.

  The cast product includes a portion where the molten metal remaining in the sprue and the runner is solidified (hereinafter referred to as “plan portion”) and a product portion formed by a product cavity. Conventionally, the plan part has been cut out by a shearing device as described in Patent Document 2 after releasing the cast product. However, as described in Patent Document 1, a cutter is provided in the intermediate mold. It is also known to cut.

  That is, in this case, the cutter is provided on the end face of the intermediate mold facing the fixed mold so as to be displaceable along the vertical vertical direction. The cutter cuts the design portion exposed when the fixed die and the intermediate die are separated from the product portion.

JP 2008-178896 A JP-A-6-63727

  Recently, attempts have been made to increase the number of castings per unit time to produce a large number of castings in order to reduce the unit price of the castings. For this reason, it can be considered to shorten the casting time from the completion of injection after pouring to mold opening.

  However, in this case, although the surface of the casting is solidified to some extent, the inside may not be sufficiently solidified. When the cast in such a state is cut, the liquid phase flows out from the inside. When this liquid phase enters between the cutter and the intermediate mold and solidifies, the mold clamping becomes difficult. For this reason, in the casting apparatus according to the prior art, it is difficult to shorten the casting time, and thus increase the number of castings per unit time.

  The present invention has been made to solve the above-mentioned problems, and since it can be easily clamped to prevent the liquid phase from entering between the cutter and the intermediate mold, casting per unit time. It is an object of the present invention to provide a casting apparatus capable of increasing the number of times and a method for producing a cast product.

In order to achieve the above object, the present invention includes a fixed mold that is positioned and fixed, a movable mold that is displaceable in a direction approaching or separating from the fixed mold, and a gap between the fixed mold and the movable mold. In a casting apparatus having an intermediate mold interposed and a cutting mechanism including a cutter for cutting a plan part from a cast product obtained in a cavity formed when the mold is clamped,
A recess of the cutter facing the intermediate mold is recessed from the end face toward the end face facing the fixed mold, and a bottom surface of the cutter is perpendicular to a blade portion that cuts the plan portion. It is characterized by being.

Further, according to the present invention, a fixed mold that is positioned and fixed, a movable mold that can be displaced in a direction approaching or separating from the fixed mold, and an intermediate mold that is interposed between the fixed mold and the movable mold. In a method for manufacturing a cast product, after obtaining a cast product in a cavity formed when tightened, and cutting a plan part from the cast product by a cutter,
As the cutter, a concave portion is formed on an end surface facing the intermediate mold, which is recessed from the end surface toward an end surface facing the fixed mold, and whose bottom surface is orthogonal to a blade portion that cuts the plan portion. It is characterized by using what is.

  As described above, in the present invention, the concave portion is formed on the end face of the cutter facing the intermediate mold. The recess captures the unsolidified molten metal (liquid phase) that has flowed out of the interior of the design portion when the design portion is cut. For this reason, it is avoided that the liquid phase enters between the end face of the cutter facing the intermediate mold and the intermediate mold and is solidified at the location.

  For this reason, it is prevented that mold clamping becomes difficult with the solidified substance adhering to the said location. In other words, smooth mold clamping can be continued. This means that cutting can be performed even when the interior of the plan part is not sufficiently solidified, that is, the so-called curing time can be shortened and the number of castings per unit time can be increased.

  Thus, by providing the recess for capturing the liquid phase, smooth mold opening can be repeated. As a result, the number of castings per unit time can be increased.

  In addition, since the cross-sectional shape of a runner is substantially circular, it is preferable to make a blade part into a curved shape. In this case, when cutting the portion where the molten metal in the runner has solidified, the blade portion comes into contact with the design portion substantially equally and substantially simultaneously. For this reason, the occurrence of local stress concentration is avoided, so that uneven wear and chipping are prevented. As a result, the life of the cutter can be extended, and the maintenance frequency for the cutter can be reduced.

  In addition, if the plan part is cut when the surface temperature of the molten metal (cast product) is excessively high, a large amount of liquid phase flows out, so there is a concern that it is not easy to capture the entire amount of the liquid phase in the recess. . On the other hand, when the temperature of the surface is excessively lowered, the solidification of the design part proceeds excessively and the strength is increased, so that it tends to be difficult to cut. Therefore, it is preferable to perform the cutting when the amount of the liquid phase flowing out from the inside of the design part is sufficiently small and is soft enough to be cut easily. Specifically, when obtaining a cast product made of an aluminum alloy, it is preferable to cut the plan portion when the surface temperature of the molten metal is within a range of 390 to 490 ° C.

  According to the present invention, since the concave portion is formed on the end face of the cutter facing the intermediate mold, when the plan portion is cut, the unsolidified molten metal (liquid phase) that has flowed out from the inside of the plan portion is obtained. It is captured by the recess. For this reason, smooth mold opening can be continued and repeated. As a result, the number of castings per unit time can be increased, and a large number of castings can be obtained.

It is a principal part schematic side view of the casting apparatus which concerns on embodiment of this invention. It is a schematic perspective view of the front-end | tip of the cutter which comprises the casting apparatus of FIG. It is a schematic side view which shows the state which has cut | disconnected the plan part with the cutter of FIG. It is a graph which shows the relationship between the pressurization holding time (cure time) from the completion of injection of a molten metal to mold opening, and the surface temperature of a molten metal (casting product).

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for producing a cast product according to the present invention will be described in detail with reference to the accompanying drawings by giving preferred embodiments in relation to a casting apparatus for carrying out the method. The arrow X directions shown in FIGS. 1 to 3 indicate the same direction. The same applies to the arrow Z direction. Moreover, the arrow Y direction in FIG. 2 is a direction orthogonal to a paper surface in FIG.1 and FIG.3.

  FIG. 1 is a schematic side view of a main part of a casting apparatus 10 according to the present embodiment. This casting apparatus 10 is for obtaining a cast product 16 in which a design part 14 is connected to a vehicle wheel 12 (product part), and a fixed mold 20 positioned and fixed, It has a movable mold 22 that is displaced in a separating direction, and an intermediate mold 24 that is interposed between the fixed mold 20 and the movable mold 22. The fixed mold 20, the movable mold 22 and the intermediate mold 24 are all molds.

  The fixed die 20 has a substantially flat plate shape, and a guide bar 26 is provided at the four corners of the end surface facing the intermediate die 24. A first hydraulic cylinder 28 is installed on the side surface. Although not shown in order to facilitate the visual recognition of the shape of the casting 16, the first rod constituting the first hydraulic cylinder 28 is connected to the intermediate mold 24. In other words, the intermediate die 24 is displaced in a direction (arrow X direction) away from or approaching the fixed die 20 as the first rod moves forward or backward.

  The intermediate die 24 also has a substantially flat plate shape, and an insertion hole (not shown) through which the guide bar 26 enters is provided at a position corresponding to the position where the guide bar 26 is provided. On the other hand, an alignment pin 30 for performing alignment with the movable mold 22 is provided on the end face facing the movable mold 22 at a position that does not overlap with the position where the insertion hole is formed.

  A cutting mechanism 32 is provided on the end surface of the intermediate die 24 facing the fixed die 20. The cutting mechanism 32 includes a cutter 34 and a second hydraulic cylinder 36 for displacing the cutter 34 in the vertical vertical direction (arrow Z direction).

  The cutter 34 has a substantially flat plate shape, and the lower end of the long body portion is a blade portion, while the upper end is connected to a second rod (not shown) of the second hydraulic cylinder 36. Further, guide rails (not shown) that sandwich the cutter 34 are provided on both sides of the cutter 34. Accordingly, the cutter 34 descends linearly along the guide rail when the second rod advances, and ascends linearly along the guide rail when retracted.

  As shown in FIG. 2, the blade portion that is the lower end of the cutter 34 is depressed from the flat tip, and extends from the end surface facing the fixed die 20 to the end surface facing the intermediate die 24 and the movable die 22. 1 recess 40 is formed. Hereinafter, in the cutter 34, the direction (arrow X direction) from the side facing the fixed mold 20 toward the intermediate mold 24 and the movable mold 22 is referred to as "depth direction", and the direction orthogonal to the depth direction (arrow Y direction). It is called “width direction”. “Depth” and “width” refer to a dimension along the depth direction and a dimension along the width direction, respectively.

  In this case, the 1st recessed part 40 sinks in the direction away from the design part 14, and the inner wall is formed as a curved surface. That is, the inner wall of the first recess 40 has an arc shape. Moreover, the width | variety of the 1st recessed part 40 becomes large gradually along the depth direction. Therefore, the width of the first recess 40 is the largest at the end facing the intermediate mold 24 and the movable mold 22 and the smallest at the end facing the fixed mold 20.

  A second concave portion 42 (concave portion) recessed from the end surface toward the end surface facing the fixed die 20 (that is, along the depth direction) is provided on the end surface of the cutter 34 facing the intermediate die 24 and the movable die 22. It is formed. The bottom surface of the second recess 42 is continuous so as to be orthogonal to the curved top surface of the first recess 40. In addition, the curved top surface of the second recess 42 is located further vertically above the curved top surface of the first recess 40.

  The second recess 42 has an end face facing the intermediate mold 24 as a start point and an end point midway toward the end face facing the fixed mold 20. For this reason, the depth of the second recess 42 is smaller than that of the first recess 40. The width of the second recess 42 is also smaller than that of the first recess 40.

  An alignment hole (not shown) through which the alignment pin 30 enters is formed on the end surface of the movable mold 22 facing the intermediate mold 24. The movable mold 22 is separated from the fixed mold 20 by the mold opening operation under the action of a mold opening / closing mechanism (not shown), and is displaced so as to approach the fixed mold 20 by the mold clamping operation.

  In the above configuration, the gate 20 and the vertical runner (not shown) are provided in the fixed mold 20, the horizontal runner 44 and a part of the product cavity are provided in the intermediate mold 24, and the remainder of the product cavity and the overflow part are provided in the movable mold 22. (Both not shown) are formed. In the present embodiment, these gates, vertical runners, horizontal runners 44, product cavities, and overflow portions are referred to as cavities. The horizontal runner 44 is shaped like a cylinder cut out.

  The fixed mold 20, the intermediate mold 24, and the movable mold 22 are provided on a base (not shown). Such a configuration is known, for example, as described in Patent Document 1, and thus detailed description thereof is omitted in this specification.

  The casting apparatus 10 according to the present embodiment is basically configured as described above. Next, regarding the function and effect thereof, the relationship with the method for manufacturing the cast product 16 according to the present embodiment. explain. Although not specifically described, the following steps are performed based on sequence control under the action of the control unit constituting the casting apparatus 10.

  First, mold clamping is performed in order to perform casting. That is, the first hydraulic cylinder 28 and the mold opening / closing mechanism are energized to bring the intermediate mold 24 into close contact with the fixed mold 20 and the movable mold 22 into close contact with the intermediate mold 24. At this time, the second rod of the second hydraulic cylinder 36 is retracted, so that the cutter 34 is located at the top dead center.

  By the mold clamping, the gate is communicated with the product cavity via the vertical runner and the horizontal runner 44. In this state, a molten metal such as an aluminum alloy is pushed out toward the gate by an injection machine (not shown) and injected. The molten metal flows from the gate to the vertical runner and is further introduced into the product cavity via the horizontal runner 44. While the molten metal flows into the product cavity, the air in the cavity is discharged into the atmosphere from a vent vent (not shown) connected to the overflow portion.

  When a predetermined time elapses after the supply of the molten metal is started, the product cavity is filled with the molten metal. Excess molten metal enters the overflow section.

  Next, it waits until the surface of a molten metal becomes predetermined temperature. During this time, the temperature of the molten metal in the cavity decreases and the molten metal begins to solidify. That is, the plan portion 14 is formed in the gate, the vertical runner, and the horizontal runner 44, and the vehicle wheel 12 is formed in the product cavity, and the plan portion 14 and the vehicle wheel 12 are integrally connected. A cast product 16 is obtained. In addition, although the excessive molten metal which entered the overflow part is also solidified and continuously connected to the vehicle wheel 12, this portion is not shown in FIG. 1 in order to simplify the drawing and facilitate visual recognition and understanding.

  When the molten metal falls to a predetermined temperature, the surface begins to solidify. In the present embodiment, the plan portion 14 of the cast product 16 is cut when the surface is sufficiently solidified and the inside is not solidified.

  For this reason, the first rod of the first hydraulic cylinder 28 moves forward, and the mold opening / closing mechanism operates in synchronization with the first hydraulic cylinder 28. As a result, the intermediate mold 24 is separated from the fixed mold 20. Along with this, the design part 14 of the casting 16 (excluding the part formed in the horizontal runner 44) is exposed. At this time, since the portion formed in the horizontal runner 44 is inserted into the horizontal runner 44, the casting 16 is supported by the intermediate mold 24.

  Next, the second hydraulic cylinder 36 is energized and the second rod descends, and the cutter 34 sandwiched between the two guide rails descends following this. As shown in FIG. 3, the blade portion (first concave portion 40) at the lower end of the lowered cutter 34 comes into contact with the end portion of the portion solidified by the vertical runner, and further descends, so that the vertical portion in the plan portion 14. The part formed by the directional runner and the gate is cut off from the part formed by the horizontal runner 44.

  Here, the end portion of the vertical runner has a substantially arc shape. On the other hand, as described above, the first concave portion 40 is depressed vertically upward, and the inner wall is curved. Therefore, the inner wall of the first recess 40 abuts the upper side wall of the portion solidified by the vertical runner substantially simultaneously and further cuts.

  As a result, stress acts on the inner wall of the first recess 40 substantially evenly. For this reason, it is avoided that the partial wear and the defect resulting from local stress concentration occur on the inner wall of the first recess 40. Therefore, the maintenance frequency for the cutter 34 can be reduced. Further, since the life of the cutter 34 is extended, the cost required for the cutter 34 can be reduced.

  Next, the mold opening / closing mechanism is activated, and as a result, the movable mold 22 is separated from the intermediate mold 24. That is, the mold is opened and the casting 16 is taken out from the casting apparatus 10.

  In addition, a liquid phase flows out when the inside which is not solidified is exposed. This liquid phase is captured in the second recess 42. Here, the second recess 42 is opened facing the intermediate mold 24. Therefore, the liquid phase flowing toward the intermediate mold 24 can be easily captured. For this reason, it is avoided that the liquid phase leaks to the end face of the cutter 34 facing the intermediate mold 24.

  Therefore, for example, it is effectively avoided that the liquid phase enters between the cutter 34 and the intermediate mold 24. For this reason, even when the curing time is shortened, it is prevented that the mold clamping becomes difficult due to the solidified material solidified between the cutter 34 and the intermediate mold 24. As a result, the number of castings per unit time can be increased.

  FIG. 4 is a graph showing the result of measuring the temperature of the surface of the melt when a predetermined time has elapsed since the start of the supply of the melt as a relationship between the elapsed time (cure time) and the temperature. The fixed mold 20 has a thermocouple insertion hole formed in advance. The surface temperature was measured through a thermocouple inserted into the thermocouple insertion hole.

  It can be seen from FIG. 4 that if the curing time is too short, the surface temperature may exceed 490 ° C., and conversely if too long, the temperature may be below 390 ° C. In the case of the shape of the plan part 14 in the present embodiment and the molten metal is an aluminum alloy, when the surface is at a temperature higher than 490 ° C., a large amount of liquid phase still exists inside. Therefore, when cutting is performed, a large amount of liquid phase flows out from the inside. For this reason, there is a concern that the liquid phase leaks to the end face of the cutter 34 facing the intermediate mold 24. On the other hand, when the temperature is lower than 390 ° C., the inside is excessively solidified, so that cutting may not be easy.

  For the reasons as described above, it is preferable to perform cutting at a timing when the surface temperature falls within the range of 390 to 490 ° C. In this case, in combination with the configuration of the blade part described above, it is possible to effectively avoid leakage of the liquid phase and to easily cut the casting 16.

  The present invention is not particularly limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention.

    For example, the casting 16 is not particularly limited to one including a portion that becomes the vehicle wheel 12, and may be other. The molten metal may also be, for example, a light alloy such as a magnesium alloy or a zinc alloy. Also at this time, the cutting is performed when the temperature of the surface of the casting 16 falls within a range where the liquid phase can be prevented from leaking to the end face of the cutter 34 facing the intermediate mold 24 and can be easily cut. Just do it.

DESCRIPTION OF SYMBOLS 10 ... Casting apparatus 12 ... Vehicle wheel 14 ... Plan part 16 ... Casting product 20 ... Fixed mold 22 ... Movable mold 24 ... Intermediate mold 32 ... Cutting mechanism 34 ... Cutter 36 ... 2nd hydraulic cylinder 40 ... 1st recessed part 42 ... 1st 2 recesses 44 ... horizontal runner

Claims (4)

Formed when the mold is clamped, a fixed mold that is positioned and fixed, a movable mold that can be displaced in a direction approaching or separating from the fixed mold, an intermediate mold that is interposed between the fixed mold and the movable mold In a casting apparatus having a cutting mechanism including a cutter for cutting a plan part from a cast product obtained in a cavity to be manufactured,
A recess of the cutter facing the intermediate mold is recessed from the end face toward the end face facing the fixed mold, and a bottom surface of the cutter is perpendicular to a blade portion that cuts the plan portion. A casting apparatus characterized by comprising:   The casting apparatus according to claim 1, wherein the blade portion has a curved shape. Formed when a fixed mold that is positioned and fixed, a movable mold that can be displaced in a direction approaching or separating from the fixed mold, and an intermediate mold that is interposed between the fixed mold and the movable mold are clamped In the manufacturing method of the cast product, after obtaining the cast product in the cavity to be cut, the plan part is cut from the cast product by the cutter,
As the cutter, a concave portion is formed on an end surface facing the intermediate mold, which is recessed from the end surface toward an end surface facing the fixed mold, and whose bottom surface is orthogonal to a blade portion that cuts the plan portion. What is claimed is: 1. A method for producing a cast product, comprising:   4. The method according to claim 3, wherein when the casting made of an aluminum alloy is obtained, the plan portion is cut when the surface temperature of the molten metal is within a temperature range of 390 to 490 ° C. Manufacturing method.

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