JP6068930B2 - Die casting mold equipment - Google Patents

Description

  The present invention relates to a die casting die apparatus.

  Conventionally, die casting is known as a metal casting method. In die casting, a product is manufactured (cast) by introducing a molten metal into a cavity formed in a mold at high pressure and solidifying it. A mold used in die casting is generally formed of steel having excellent strength resistance (for example, steel for die casting mold). As the molten metal, for example, aluminum is used.

  The mold may have a gas vent hole for venting the gas in the cavity to the outside (see, for example, Patent Document 1). In this case, when the molten metal is injected into the cavity, the gas in the cavity is discharged to the outside of the cavity through the gas vent hole, so that the molten metal entrains the gas in the cavity and solidifies in a state containing the gas. Can be prevented. Thereby, it is possible to prevent a cast hole from being formed inside the product.

Japanese Patent Laid-Open No. 9-300058

  By the way, the molten metal is introduced into the mold (cavity) at a high temperature, and has a high affinity with the mold (steel) which is the same metal, so when the molten metal is introduced into the mold, The mold may be melted and the vent hole may be clogged. In particular, since the hole diameter of the vent hole is set to a very small size so that the molten metal does not leak outside the cavity, the vent hole is clogged even if the mold is slightly melted. There is a risk that. In this case, the work of repairing the clogged portion to the original state by repairing the mold or exchanging parts frequently occurs, resulting in a great effort.

  The present invention has been made in view of the above circumstances, and a main object of the present invention is to provide a die casting mold apparatus capable of venting gas from a cavity over a long period of time.

  In order to solve the above-described problems, a die casting die apparatus according to a first aspect of the present invention includes a die having a cavity in which a molten metal is introduced and a product is cast, and the die is exposed to the cavity. And a built-in insert piece, wherein the insert piece is formed of ceramics and has a gas vent hole for discharging the gas in the cavity to the outside.

  According to the present invention, the insert piece is formed of ceramics, and the vent hole is formed in the insert piece. Ceramics are excellent in heat resistance and have low affinity with the molten metal compared to the mold, so that the molten metal introduced into the cavity can be prevented from damaging the insertion piece, and clogging of the vent hole can be prevented. Can be suppressed. Thereby, degassing in the cavity can be performed over a long period of time.

  Also, ceramics are inferior to molds (metals) in terms of formability, but the insert piece only needs to be incorporated locally in a part of the mold, so that the above effect can be obtained while suppressing deterioration of formability Can do.

  In a die casting die apparatus according to a second aspect of the present invention, in the first aspect of the invention, the gas vent hole is formed in a direction extending in the same direction as a take-out direction when taking out a product cast in the cavity from the cavity. It is characterized by being.

  By the way, when the molten metal is introduced into the cavity, it is assumed that the molten metal enters the gas vent hole. In that case, when the molten metal is solidified, the portion that has entered the gas vent hole (hereinafter referred to as the “entrance portion”) is also solidified. Therefore, when taking out the solidified product from the cavity, it is necessary to remove the above-mentioned entrance portion from the gas vent hole. There is. Here, since the direction in which the product is taken out from the cavity is normally determined in a predetermined direction, when the gas vent hole extends in a direction different from the predetermined direction, the entry portion is degassed when the product is taken out from the cavity. There is a risk that the product will be caught by the hole and the product may be damaged around the entry portion. In this regard, in the present invention, since the gas vent hole extends in the same direction as the product removal direction, it is possible to avoid the entrance portion from being caught by the gas vent hole when the product is taken out. It can be avoided.

  A die casting mold apparatus according to a third aspect of the present invention is the first or second aspect of the present invention, wherein the insertion piece is formed with a plurality of the gas vent holes, and each of the gas vent holes has a cross-sectional area of the flow path. However, it is characterized in that it is small on one side and large on the other side with reference to the midway position of the gas vent hole in the length direction.

  By the way, in order to prevent the molten metal introduced into the cavity from leaking outside through the vent hole, it is necessary to reduce the flow passage cross-sectional area of the vent hole. On the other hand, since the ceramic forming the insert piece is inferior in workability as compared with a mold (for example, steel), it is difficult to process a hole with a small flow path cross-sectional area. Therefore, in the present invention, in view of this point, the flow passage cross-sectional area of the gas vent hole is small on one side and large on the other side with respect to the middle position in the length direction of the gas vent hole. In this case, it is possible to prevent the molten metal from leaking at a portion where the flow passage cross-sectional area is small in the vent hole, and shorten the length of the portion where the flow passage cross-sectional area is small (the length of the portion where the flow passage cross-sectional area is large). Can be made easier to process the vent hole.

  Moreover, if the thickness of the insert piece is set small, the vent hole can be formed in the insert piece with a small cross-sectional area over the entire length direction (thickness direction of the insert piece). It is possible to obtain both the effects of the ease of processing the vent hole. However, in that case, it is difficult to ensure sufficient strength resistance of the insert piece, and there is a possibility that problems such as breakage of the insert piece when the molten metal is introduced into the cavity may occur. In this respect, according to the present invention, since the thickness of the insert piece can be set large, the above-described effect can be obtained while ensuring the strength of the insert piece.

  According to a fourth aspect of the present invention, there is provided a die casting mold apparatus according to the third aspect, wherein the gas vent hole has a flow passage cross-sectional area on the cavity side, which is the one side with respect to the midway position in the length direction. It is small, and is large on the opposite side to the cavity which is the other side.

  In the third aspect of the invention, when the portion of the gas vent hole having a large channel cross-sectional area is set on the cavity side and the portion of the small channel cross-sectional area is set on the side opposite to the cavity side, the molten metal is injected into the cavity. However, it is easy to enter a portion where the flow passage cross-sectional area of the vent hole is large. Therefore, after the molten metal has solidified, an operation such as removing a portion that has entered the gas vent hole from the hole is likely to occur. In this respect, in the present invention, the small channel cross-sectional area is set on the cavity side, and the large channel cross-sectional area is set on the opposite side of the cavity, so that the molten metal is difficult to enter the vent hole. Generation of work can be suppressed.

  A die casting mold apparatus according to a fifth aspect of the present invention is the die casting apparatus according to any one of the first to fourth aspects, wherein the mold has two mold parts, and the mold parts are combined to form the cavity. And the cavity is formed in an opposing space formed between the opposing portions of the two mold portions, and is formed in one mold portion, and the other mold portion extends from the opposing space portion. A bag-like space portion extending in the opposite direction to form a bag shape, and the gas vent hole communicates with the bag-like space portion.

  When a bag-like space is provided in a part of the cavity, gas tends to accumulate in the bag-like space when the molten metal is introduced into the cavity. In this respect, in the present invention, since the gas vent hole communicates with the bag-like space portion, the gas can be efficiently discharged from the bag-like space portion to the outside.

  A die casting mold apparatus according to a sixth aspect of the present invention is the method according to any one of the first to fifth aspects, wherein the mold communicates with the cavity through the gas vent and sucks the gas in the cavity. A suction passage is provided for the purpose.

  According to the present invention, when the molten metal is introduced into the cavity, the gas in the cavity can be discharged while being sucked through the suction passage. Thereby, compared with the case where the gas in a cavity is only discharged | emitted outside through a vent hole (when open | released to air | atmosphere), the degassing in a cavity can be accelerated | stimulated.

  A die casting die apparatus according to a seventh aspect of the present invention includes, in the sixth aspect of the invention, a water supply passage for supplying cooling water for cooling the insertion piece to the space facing the insertion piece in the suction passage, The cooling water is drawn into the space through the water supply passage as the gas in the cavity is sucked through the suction passage.

  According to the present invention, when the molten metal is introduced into the cavity, the gas in the cavity is sucked so that the cooling water is drawn into the space facing the insertion piece in the suction passage. As a result, the insert piece can be cooled by the cooling water, and the molten metal can be cooled via the insert piece, so that the solidification of the melt can be promoted while promoting the degassing in the cavity. .

  Further, since the cooling water is drawn into the space by suction, the cooling water can flow along the outer periphery of the space in the space unlike the case where the cooling water is pumped to the space. Can flow along the piece. For this reason, the insert piece can be effectively cooled by the cooling water.

Sectional drawing of a die-casting apparatus. Sectional drawing which shows a movable side nest | insert and its periphery structure. (A) is a top view which shows a part of movable side nest | insert and its periphery structure, (b) is a bottom view. (A) is a top view which shows the structure of an insertion piece, (b) is sectional drawing which shows the structure. Sectional drawing which shows the movable side nest | insert in other embodiment, and its periphery structure. The figure which shows the insertion piece in other embodiment. The figure which shows the insertion piece in other embodiment.

  Hereinafter, an embodiment of a mold apparatus will be described. In this embodiment, the mold apparatus is embodied as a die casting apparatus, and it is assumed that the die casting apparatus produces an aluminum casting product.

  As shown in FIG. 1, the die casting apparatus 10 includes a fixed mold 11 and a movable mold 12. The movable mold 12 is provided so as to be movable in a direction approaching and separating from the fixed mold 11 (mold opening / closing direction). The fixed mold 11 and the movable mold 12 are integrally combined to be in a mold closed state, whereby a cavity 13 is formed as a casting space into which molten metal is poured.

  The fixed mold 11 includes a fixed mother mold 15 and a fixed side insert 16. The fixed mother die 15 is made of a steel block, and is attached to a fixed die attachment portion (not shown) provided in the die casting apparatus 10. A nesting receiving groove 18 is formed in a portion of the fixed mother die 15 facing the movable die 12 side. The receiving side insert 16 is fixed in a state in which the receiving side insert 16 is fitted in the receiving groove 18. Note that the fixed mother die 15 is not necessarily made of steel, and may be formed of ductile cast iron. Moreover, in FIG. 1, the die-cast apparatus 10 in a mold closed state is shown.

  The fixed mold 11 is formed with a gate 22 for pouring (casting) a molten aluminum into the cavity 13, and a sleeve 23 is connected to the gate 22. When the molten metal is pushed out from the sleeve 23, the molten metal is guided into the mold through the gate 22.

  The movable mold 12 includes a movable mother mold 25 and a movable side insert 26. The movable mother die 25 is made of a steel block. The movable mother die 25 is attached to a movable attachment portion (not shown) provided in the die casting apparatus 10. The movable mother die 25 can be moved in a direction approaching and separating from the fixed die 11 (die opening / closing direction) by driving the movable die attaching portion. The mold opening is performed by moving the movable mold 25 away from the fixed mold 11, and the mold closing operation is performed by moving the movable mold 25 toward the side approaching the fixed mold 11. Note that the movable mother die 25 is not necessarily made of steel, and may be formed of ductile cast iron.

  The movable mold 12 is formed with a runner 21 for injecting (casting) molten aluminum into the cavity 13. The molten metal is introduced into the runway 21 from the gate 22, and the introduced molten metal is injected into the cavity 13 from the runway 21. In addition, the movable mold 12 is provided with an overflow portion for receiving the molten metal overflowing from the cavity 13.

  The movable die 12 (specifically, the movable mother die 25 and the movable side insert 26) is provided with an extrusion pin (not shown) for extruding the product cast (solidified) in the cavity 13 to take out the product from the cavity 13. It has been. Further, the push-out direction of the push-out pin (in other words, the product take-out direction) is the same as the mold opening / closing direction.

  A nesting receiving groove 28 is formed in a portion of the movable mother die 25 facing the fixed die 11. A movable side insert 26 that is paired with the fixed insert 16 is fixed in the accommodation groove 28 in a state in which it is fitted. A surface of the fixed side insert 16 facing the movable mold 12 (hereinafter referred to as a mating surface 32) is formed with a raised portion 29 that protrudes toward the movable mold 12 side. On the other hand, an accommodation recess 30 for accommodating the raised portion 29 is formed on a surface (hereinafter referred to as a mating surface 33) facing the fixed mold 11 side in the movable side insert 26.

  In the mold closed state, the peripheral portion of the accommodating recess 30 on the mating surface 33 of the movable side insert 26 and the peripheral portion of the raised portion 29 on the mating surface 32 of the fixed side insert 16 are in contact with each other. Both the nestings 16 and 26 are formed so that the raised portion 29 and the accommodating recess 30 face each other with a gap in a state where the mating surfaces 32 and 33 are in contact with each other as described above. Most of the cavity 13 is constituted by the gap 35 formed in this way. The gap 35 corresponds to the facing space portion.

  Next, the movable side insert 26 and the configuration around it will be described with reference to FIGS. FIG. 2 is a cross-sectional view showing the movable side insert 26 and its peripheral configuration. 3A is a plan view showing a part of the same configuration, and FIG. 3B is a bottom view.

  As shown in FIGS. 2 and 3, the movable side insert 26 is made of a block body made of heat-resistant steel (die casting mold steel). As described above, the accommodating recess 30 is formed in the movable side insert 26. The housing recess 30 has a disk shape opened to the fixed mold 11 side.

  A bag-like recess 36 is formed on the bottom surface 30 a of the accommodation recess 30 in the movable side insert 26. The bag-shaped recess 36 has a bag shape extending from the bottom surface 30a of the housing recess 30 to the side opposite to the fixed mold 11, and the bag-shaped recess 36 corresponds to a bag-shaped space portion. The bag-like recess 36 is a narrow space, and its cross section has a substantially rectangular shape, and more specifically, has an oval shape. Further, the bag-shaped recess 36 is disposed at a substantially central portion of the bottom surface 30 a of the housing recess 30, and the depth dimension thereof is deeper (larger) than that of the housing recess 30. And the cavity 13 is comprised by the bag-shaped recessed part 36 and the said clearance gap 35 (more specifically including the recessed part 45 of the insertion piece 40 so that it may mention later).

  In addition, a cross section means the cross section of the direction orthogonal to the type | mold opening / closing direction of the die-cast apparatus 10. As shown in FIG. In the following description, the longitudinal direction in the cross section of the bag-shaped recess 36 is referred to as the length direction of the bag-shaped recess 36, and the short direction is referred to as the width direction of the bag-shaped recess 36.

  An accommodation recess 38 for accommodating a pressing member 41 (described later) is formed on the surface of the movable side insert 26 opposite to the fixed mold 11, and an accommodation space for accommodating an insertion piece 40 (described later) is formed on the bottom surface of the accommodation recess 38. A recess 39 is formed. The housing recess 38 is open toward the side opposite to the fixed mold 11 and has a column shape extending in the length direction of the bag-like recess 36 (see FIG. 3B). The housing recess 39 extends from the bottom surface of the housing recess 38 toward the fixed mold 11 and communicates with the bag-like recess 36. The housing recess 39 has a long shape (oval shape) extending in the length direction of the bag-like recess 36 and is continuous with the entire bottom surface of the bag-like recess 36.

  A slot 40 is accommodated in the accommodating recess 39. Hereinafter, the insert piece 40 will be described with reference to FIG. 4 in addition to FIGS. 4A is a plan view showing the configuration of the insert piece 40, and FIG. 4B is a cross-sectional view showing the same configuration.

  The insert piece 40 is formed of ceramics having excellent heat resistance, and specifically is formed of silicon nitride (silicon nitride). As shown in FIGS. 2 to 4, the insert piece 40 is formed to have a predetermined thickness and has a long shape (oval shape) extending in the length direction of the bag-like recess 36. Specifically, the insert piece 40 is formed to have the same shape as the housing recess 39 and is fixed in a state of being fitted into the housing recess 39.

  The insertion piece 40 is arranged in a state where the surface on the fixed mold 11 side faces the bag-like recess 36 in the accommodation recess 39. In this case, the insert piece 40 is arranged over the entire bottom of the bag-like recess 36.

  A recess 45 is formed on the surface of the insert piece 40 on the fixed mold 11 side so as to be continuous with the bag-like recess 36. The dent 45 has the same shape as the cross-sectional shape (that is, an oval shape) of the bag-like recess 36 and is arranged in alignment with the bag-like recess 36. In this case, the recess 45 constitutes the cavity 13 together with the bag-like recess 36 and the gap 35. In detail, the dent 45 has an arcuate surface in the entire periphery.

  The insertion piece 40 is formed with a plurality (specifically, four) gas vent holes 47 for extracting (discharging) the gas in the cavity 13 to the outside. The gas vent hole 47 is formed so as to penetrate the insertion piece 40 in the thickness direction, and extends in the same direction as the mold opening / closing direction of the die casting apparatus 10 (in other words, the extrusion direction of the extrusion pin). Each vent hole 47 is arranged at a predetermined interval (specifically, an equal interval) along the longitudinal direction of the insert piece 40, and all extend from the recessed portion 45 to a fluid passage portion 53 described later.

  Each of the vent holes 47 has a hole diameter that changes in size from the middle position in the length direction. Specifically, the gas vent hole 47 is a small-diameter portion 47a having a smaller hole diameter on the cavity 13 side than the midway position in the length direction, and is opposite to the cavity 13 from the midway position (in other words, On the side opposite to the fixed die 11, a large-diameter portion 47 b having a large hole diameter is formed.

  Specifically, the hole diameter of the small diameter portion 47a is set to 0.1 mm. This prevents the molten metal injected into the cavity 13 from leaking outside through the small diameter portion 47a (the gas vent hole 47). In addition, the hole diameter of the small diameter part 47a does not necessarily need to be 0.1 mm, and if it is 0.2 mm or less, the leakage of the molten metal can be prevented. In order to reliably prevent the molten metal from leaking out, it is desirable that the hole diameter of the small diameter portion 47a is 0.05 to 0.1 mm.

  In the gas vent hole 47, the length dimension of the small diameter part 47a is made smaller than the length dimension of the large diameter part 47b. Specifically, the length of the small diameter portion 47a is set to 1 mm. In general, ceramics are inferior in workability compared to steel, so it is difficult to drill holes with a small diameter in the insert piece 40. In this regard, in the present embodiment, by making the length of the small diameter portion 47a of the vent hole 47 as short as possible, the small diameter portion 47a can be drilled.

  A holding member 41 for holding the insertion piece 40 is accommodated in the accommodation recess 38 of the movable side insert 26. The pressing member 41 is formed of a steel block material, and is fixed to the movable side insert 26 with a bolt 48 while being accommodated in the accommodating recess 38. Specifically, the holding member 41 is formed with a pair of insertion hole portions 49 for inserting the bolts 48, and the movable side insert 26 has fixed hole portions 51 at positions corresponding to the respective insertion hole portions 49. Is formed. Then, bolts 48 are inserted into the respective insertion hole portions 49 of the pressing member 41, and these bolts 48 are respectively screwed into the respective fixed hole portions 51 of the movable side insert 26.

  A concave fluid passage portion 53 is formed on a surface 41 a of the pressing member 41 facing the insertion piece 40. The fluid passage portion 53 has an elongated shape extending over each gas vent hole 47 and communicates with each gas vent hole 47. The fluid passage portion 53 corresponds to a space portion facing the insertion piece 40 in the suction passage.

  An annular groove portion 54 is formed on the facing surface 41 a of the pressing member 41 so as to surround the fluid passage portion 53. An O-ring 55 as a seal member is disposed in the groove portion 54. The O-ring 55 is provided in a state of being sandwiched between the facing surface 41 a of the pressing member 41 and the movable side insert 26. Thereby, the airtightness of the fluid passage part 53 is maintained.

  A fluid passage 57 communicating with the fluid passage portion 53 is formed in the pressing member 41. The fluid passage 57 is opened on the surface of the pressing member 41 opposite to the fixed mold 11, and the open portion serves as a connection port 58. A gas vent pipe 61 is connected to the connection port 58. The degassing pipe 61, the fluid passage 57, and the fluid passage portion 53 constitute a suction passage.

  The degassing pipe 61 is connected to a vacuum pump (not shown) as a suction device, and the fluid passage portion 53 can be set to a negative pressure via the degassing pipe 61 by driving the vacuum pump. It has become. Thereby, the gas in the cavity 13 can be drawn into the fluid passage portion 53 through the gas vent hole 47 and then discharged to the outside through the gas vent pipe 61.

  A water supply pipe 62 for supplying cooling water to the fluid passage portion 53 is disposed inside the gas vent pipe 61. In this case, the gas venting pipe 61 and the water supply pipe 62 are configured as double pipes arranged in an inner and outer double. One end side of the water supply pipe 62 extends from the end opening of the gas vent pipe 61 and extends to the fluid passage portion 53. The water supply pipe 62 is drawn out of the gas vent pipe 61 in the middle of the other end, and the other end is connected to a water tank (not shown) in which cooling water is stored. These pipes 62 and 63 are drawn out of the die casting apparatus 10 through an insertion hole 59 formed in the movable mother die 25.

  In such a configuration, when the fluid passage portion 53 is set to a negative pressure by driving the vacuum pump, accordingly, cooling water is drawn from the water tank into the fluid passage portion 53 through the water supply pipe 62. Thereby, the insertion piece 40 is cooled by the cooling water, and the molten metal introduced into the cavity 13 via the insertion piece 40 is thereby cooled. That is, in this embodiment, the degassing in the cavity 13 and the cooling of the molten metal introduced into the cavity 13 are performed together by driving the vacuum pump. The cooling water is supplied to the fluid passage portion 53 and then discharged to the outside through the gas vent pipe 61 together with the gas.

  Next, the effect | action at the time of casting an aluminum product using the die-casting apparatus 10 mentioned above is demonstrated.

  At the time of casting, the cavity 13 is formed with the die casting apparatus 10 in the mold closed state. Then, in the mold closed state, the molten metal is pushed out from the sleeve 23 to the gate 22 and injected into the cavity 13 from the runner 21.

  When injecting the molten metal into the cavity 13, the vacuum pump is driven. As a result, the gas in the cavity 13 is drawn into the fluid passage portion 53 through the gas vent hole 47, and then discharged to the outside of the die casting apparatus 10 through the gas vent pipe 61. In this case, it is possible to prevent the molten metal from entraining the gas in the cavity 13 at the time of pouring the molten metal, and as a result, it is possible to prevent a cast hole from being generated inside the solidified molten metal (product).

  Further, as the vacuum pump is driven, cooling water is introduced from the water tank into the fluid passage portion 53. Thereby, the molten metal is cooled via the insertion piece 40 by the introduced cooling water, and solidification of the molten metal is promoted. Further, since the cooling water is drawn into the passage portion 53 by setting the fluid passage portion 53 to a negative pressure, unlike the case where the cooling water is pumped to the fluid passage portion 53, the cooling water is supplied to the fluid passage portion 53. , Along the outside of the passage, that is, along the insert piece 40 (exposed surface to the fluid passage portion 53 in the insert piece 40). Therefore, the insert piece 40 can be effectively cooled by the cooling water.

  When a predetermined cooling period elapses after the molten metal is injected into the cavity 13, the molten metal is solidified and the product X is cast. Thereafter, the movable mold 12 is separated from the fixed mold 11, and the die casting apparatus 10 is brought into the mold open state. At this time, as the movable mold 12 moves, the product X moves to the side away from the fixed mold 11 in a state where it enters the receiving recess 30 and the bag-shaped recess 36 of the movable insert 26. Thereafter, the product X is pushed out to the fixed die 11 side by push pins (not shown) provided on the movable die 12. Thereby, the product X is taken out from the accommodation recess 30 of the movable side insert 26 or the like.

  By the way, when the molten metal is introduced into the cavity 13, it is assumed that the molten metal enters the gas vent hole 47. In that case, when the molten metal is solidified, the portion where the molten metal has entered (hereinafter referred to as the “entry portion”) is also solidified. Therefore, when the solidified product X is taken out, it is necessary to pull out the portion from the gas vent hole 47. Here, in the present embodiment, the gas vent hole 47 extends in the same direction as the push-out direction of the push-out pin (not shown) (product X take-out direction). In other words, it is possible to avoid the occurrence of troubles such as the breakage of the product X around the entering portion due to the catch.

  In addition, after casting, the product X is smoothly finished by cutting the bottom surface (seal surface) of the rib portion formed by the bag-shaped recess 36.

  As mentioned above, according to the structure of this embodiment explained in full detail, the following outstanding effects are acquired.

  A ceramic insert piece 40 is incorporated in the movable mold 12 (specifically, the movable side insert 26) in a state of facing the cavity 13, and a gas vent hole for discharging the gas in the cavity 13 to the insert piece 40 to the outside. 47 was formed. Ceramics are excellent in heat resistance and have a lower affinity with the molten metal than that of the mold (steel), so that the molten metal introduced into the cavity 13 can be prevented from being melted by the molten metal, and thus degassing. The clogging of the holes 47 can be suppressed. Thereby, degassing in the cavity 13 can be performed over a long period of time.

  Ceramics are inferior to molds (metals) in terms of formability. However, since the insert piece 40 only needs to be incorporated locally in a part of the movable mold 12, the above-described effects can be obtained while suppressing deterioration in formability. Can be obtained.

  With respect to the gas vent hole 47, the hole diameter (in other words, the cross-sectional area of the flow path) is small (small) on the cavity 13 side with respect to the midway position in the length direction of the gas vent hole 47, and large on the opposite side of the cavity 13. The diameter was set (larger). Thereby, the leakage of the molten metal can be prevented at the small diameter portion 47a, and the gas vent hole 47 can be processed by shortening the length of the small diameter portion 47a (in other words, increasing the length of the large diameter portion 47b). Can be made easier.

  Further, if the thickness of the insert piece 40 is set to be small, the gas vent hole 47 can be formed in the insert piece 40 with a small hole diameter in the entire length direction (thickness direction of the insert piece), thereby preventing leakage of the molten metal. It is possible to achieve both the ease of processing of the vent hole 47. However, in that case, it is difficult to sufficiently secure the strength of the insertion piece 40, and there is a possibility that problems such as breakage of the insertion piece 40 when the molten metal is introduced into the cavity 13 may occur. In this regard, according to the above-described configuration, the thickness of the insert piece 40 can be increased, so that both the above-described effects can be obtained while ensuring the strength of the insert piece 40.

  Of the large-diameter portion 47b and the small-diameter portion 47a, the small-diameter portion 47a is disposed on the cavity 13 side, so that the molten metal can be made difficult to enter the gas vent hole 47. Accordingly, it is possible to prevent troublesome operations such as removing the solidified portion from the product after entering the gas vent hole 47 after the molten metal is solidified (the product is cast).

  The movable mold 12 (specifically, the movable side insert 26) is formed into a bag shape extending from the gap 35 between the opposed portions of the cavity 13 where the fixed mold 11 and the movable mold 12 face each other to the opposite side of the fixed mold 11. A concave portion 36 was formed, and a gas vent hole 47 was passed through the bag-shaped concave portion 36. In this case, since the gas vent hole 47 communicates with the bag-like recess 36 where gas tends to accumulate, the gas can be efficiently discharged from the bag-like recess 36 to the outside. Further, in the above-described configuration in which the bag-shaped recess 36 is formed narrow, it is particularly significant that gas easily accumulates in the bag-shaped recess 36 and the gas vent hole 47 is made to pass through the bag-shaped recess 36.

  Furthermore, in the above embodiment, after casting the product X, the bottom surface of the rib portion formed in the bag-like recess 36 is smoothly finished by cutting or the like, so that the molten metal introduced into the bag-like recess 36 is When gas is entrained and solidified, there is a risk that the cast hole inside the rib portion is exposed to the processed surface (seal surface) and becomes a defective product during cutting or the like. In this regard, by causing the bag-like recess 36 to pass through the gas vent hole 47, it is possible to suppress the occurrence of such defective products.

  A suction passage (specifically, the fluid passage 57 and the gas venting) for sucking the gas in the cavity 13 through the gas vent hole 47 to the movable die 12 (specifically, the pressing member 41). Since the pipe 61) is provided, the gas in the cavity 13 can be discharged while being sucked through the suction passage when the molten metal is introduced into the cavity 13. Thereby, compared with the case where the gas in the cavity 13 is simply discharged to the outside through the vent hole 47 (that is, when the atmosphere is opened to the atmosphere), the degassing in the cavity 13 can be promoted.

  A water supply pipe 62 for supplying cooling water to the fluid passage portion 53 facing the insertion piece 40 is provided, and cooling water is supplied to the fluid passage portion 53 through the water supply pipe 62 as the gas in the cavity 13 is sucked through the gas vent pipe 61. I tried to pull it in. As a result, the insert piece 40 can be cooled by the cooling water, and the molten metal can be cooled via the insert piece 40, so that the solidification of the melt is promoted while promoting the degassing of the cavity 13. be able to.

  The present invention is not limited to the above embodiment, and may be implemented as follows, for example.

  (1) In the above-described embodiment, gas suction by driving the vacuum pump is performed when the gas in the cavity 13 is discharged through the gas vent hole 47. However, the gas may be discharged without performing such suction. That is, as shown in FIG. 5, the movable mold 12 may be configured such that the cavity 13 is opened to the outside through the gas vent hole 47. In FIG. 5, unlike the above embodiment, the holding member 65 is not provided with the fluid passage portion 53, and instead, a plurality of hole portions 66 are provided corresponding to the respective gas vent holes 47. . Each of these hole portions 66 is formed so as to penetrate the pressing member 65, and each corresponding gas vent hole 47 is opened to the outside of the die casting apparatus 10.

  In such a configuration, when the molten metal is injected into the cavity 13, the gas in the cavity 13 is discharged to the outside through the gas vent hole 47 and the hole portion 66 so as to be pushed by the molten metal. For this reason, even in such a configuration, it is possible to prevent the gas in the cavity 13 from being caught in the molten metal when the molten metal is injected into the cavity 13, and it is possible to prevent the formation of a cast hole inside the product.

  (2) In the above embodiment, the insert piece 40 is formed in a long shape, but the form (shape) of the insert piece is not necessarily limited to this. FIG. 6 shows another form of the insert piece. The insert piece 71 shown in FIGS. 6A and 6B is formed in a columnar shape, and specifically has a large diameter portion 71a and a small diameter portion 71b having different outer diameters.

  The insertion piece 71 is formed with a gas vent hole 72 so as to penetrate in the axial direction. The gas vent hole 72 has a large diameter portion 72a opened on one end side (large diameter portion 71a side) in the axial direction of the insert piece 71, and a plurality of gas vent holes 72 extending from the large diameter portion 72a to the other end in the axial direction of the insert piece 71. And a small diameter portion 72b. That is, in the gas vent hole 72 of this example, a plurality of small diameter portions 72b are provided for one large diameter portion 72a.

  The large diameter portion 72 a extends over substantially the entire area in the axial direction of the insert piece 71. Thereby, in this embodiment, about the part 73 from the hole bottom of the large diameter part 72a in the insertion piece 71 (in other words, the other end of the large diameter part 72a in the axial direction) to the other end of the insertion piece 71 in the axial direction, The thickness is 1 mm.

  The portion 73 of the insertion piece 71 is formed with the plurality of (specifically, eight) small diameter portions 72b. Each small diameter portion 72b is formed so as to penetrate the portion 73 in the thickness direction. Each small-diameter portion 72b has a hole diameter set to 0.1 mm. Each small diameter portion 72 b is arranged side by side on two large and small concentric circles C <b> 1 and C <b> 2 centering on the central axis of the insert piece 71. Specifically, the small diameter portions 72b are arranged on the concentric circles C1 and C2 at four intervals of 90 °, and the four small diameter portions 72b on the concentric circles C1 and C2 are arranged so as to be shifted from each other by 45 °. Yes. In this case, it is easy to arrange a plurality of small diameter portions 72b in a predetermined range.

  Here, the small diameter portion 72b has to have a small hole diameter in order to prevent the molten metal from leaking out from the cavity 13, while in order to sufficiently vent the gas in the cavity 13, the flow of the gas vent hole 72 is reduced. Some road cross-sectional area must be secured. Therefore, in this example, the insertion piece 71 is provided with a plurality of small diameter portions 72b. In providing a plurality of small diameter portions 72b as described above, if the small diameter portions 72b are arranged densely as described above, the insert piece 71 can be reduced in size, so that the molten metal into the cavity 13 (high pressure) is provided. It is possible to suppress an excessive load from being applied to the insert piece 71 at the time of injection, and to prevent problems such as breakage of the insert piece 71.

  For example, as shown in FIG. 6C, the insertion piece 71 can be used for degassing a cavity 75 having a flat bottom. In FIG. 6C, an insertion hole 77 that penetrates the mold 76 is formed in the mold 76 that forms the bottom surface of the cavity 75, and the insertion piece 71 is inserted into the insertion hole 77. . In this case, the insert piece 71 is fixed by being fitted into the insertion hole 77. The insert piece 71 is arranged with the small diameter portion 72b facing the cavity 75 side. Also in this case, the gas in the cavity 75 can be discharged through the gas vent hole 72. Further, the insert pieces 71 may be provided at a plurality of locations in the mold 76.

  Further, as shown in FIG. 7, the insert piece 81 may be formed in a short cylindrical shape. Similarly to the insert piece 71, the insert piece 81 has a gas vent hole 82 penetrating in the axial direction, and the gas vent hole 82 has a large diameter portion 82a and a plurality of small diameter portions 82b. .

  (3) In the above embodiment, the hole diameter of the gas vent hole 47 is changed from the middle position in the length direction of the gas vent hole 47. However, the hole diameter of the gas vent hole 47 extends over the entire length direction. It may be the same. For example, it is conceivable that the hole diameter of the gas vent hole 47 is 0.1 mm over the entire length direction. In the above embodiment, a plurality of gas vent holes 47 are provided in one insert piece 40, but only one gas vent hole 47 may be provided in one insert piece 40.

  (4) In the above-described embodiment, the small-diameter portion 47a is disposed on the cavity 13 side among the large-diameter portion 47b and the small-diameter portion 47a of the gas vent hole 47. However, the large-diameter portion 47b may be disposed on the cavity 13 side. . Even in this case, it is possible to achieve both the prevention of the leakage of the molten metal from the cavity 13 and the ease of processing the gas vent hole 47.

  (5) In the above embodiment, the gas vent hole 47 is formed in a circular shape, but may be formed in other shapes such as a long hole shape or a square shape.

  (6) In the above embodiment, silicon nitride is used as the ceramic for forming the insert piece 40, but other ceramics such as cordierite and unit price silicon may be used.

  (7) Although the case where aluminum was used as the molten metal was described in the above embodiment, a metal other than aluminum (for example, zinc, magnesium, copper, lead, tin, or an alloy thereof) may be used as the molten metal.

  DESCRIPTION OF SYMBOLS 10 ... Die casting apparatus, 11 ... Fixed mold as mold part, 12 ... Movable mold as mold part, 13 ... Cavity, 35 ... Gap as opposed space part, 36 ... Bag-like recessed part as bag-like space part, 40 ... Insertion piece, 47 ... Gas vent hole, 53 ... Fluid passage part as a space part, 61 ... Pipe for gas vent, 62 ... Water supply pipe.

Claims (5)

A mold having a cavity in which molten metal is introduced and casting of the product is performed;
A slot built into the mold in a state facing the cavity;
With
The insert piece is formed of ceramics and has a plurality of gas vent holes for discharging the gas in the cavity to the outside .
Each of the gas vent holes is a small diameter portion having a smaller hole diameter on the cavity side than the midway position in the length direction of the gas vent hole, and the hole diameter is on the opposite side of the cavity from the midway position. It is considered to be a large diameter part,
2. The die casting die apparatus according to claim 1, wherein a length dimension of the small diameter portion is smaller than a length dimension of the large diameter portion . 2. The die casting die apparatus according to claim 1, wherein each of the gas vent holes extends in the same direction as a take-out direction when a product cast in the cavity is taken out from the cavity. The mold has two mold parts, and the cavity is formed by combining the mold parts,
The cavity is formed in an opposing space formed between the opposing parts of the two mold parts, and is formed in one mold part and extends from the opposing space part to the opposite side to the other mold part. And a bag-like space portion that forms a bag shape,
3. The die casting die apparatus according to claim 1, wherein each of the gas vent holes communicates with the bag-like space portion. The suction path for sucking the gas in the said cavity is provided in the said metal mold | die through the said each vent hole for sucking the gas in the said cavity, The Claim 1 thru | or 3 characterized by the above-mentioned. The die-casting die apparatus according to one item. A water supply passage for supplying cooling water for cooling the insert piece to the space facing the insert piece in the suction passage;
5. The die casting die apparatus according to claim 4 , wherein the cooling water is drawn into the space through the water supply passage as the gas in the cavity is sucked through the suction passage.

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