JP2008213009A - Die casting device and die casting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a die casting device which can perform high speed casting as a whole, while controlling the casting speed of molten metal in so that the entanglement of a gas to the molten metal is not caused. <P>SOLUTION: Disclosed is a horizontal die casting device provided with: a fixed die 1 and a movable die 2 forming a die cavity C; a casting passage hole 5 formed at the fixed die 1 and communicated with the die cavity C via a side gate C2; a casting means feeding and charging molten metal from the lower part through a casting stoke 9 via a molten metal feed-out opening 51 formed at the casting passage hole 5; and a clogging plunger 6 sliding in the inside of the casting passage 5 and clogging the molten metal feed-out opening 51 of the casting passage hole 5. The casting means comprises: a gas pressurization pouring pan 7; and a pressurized gas introduction means provided with a gas cylinder 32 and a piston 33 for introducing a pressurized gas to the gas pressurization pouring pan 7. By controlling a piston speed, the charging speed of the molten metal into the die cavity C is controlled. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a die-cast casting apparatus capable of casting a cast product such as a light metal alloy, and supplying and filling molten metal from below into a mold cavity through a casting passage hole. The present invention relates to a die casting apparatus that supplies and fills molten metal from below through a casting hole and a die casting method using the same.

  Conventionally, when casting cast products such as aluminum alloy products, especially parts that require strength, it is difficult to prevent gas entrainment when casting molten metal. The die-casting apparatus) cannot be used, and a die-casting casting apparatus (saddle-type die-casting apparatus) is used (for example, see Patent Document 1).

JP-A-2005-125401

  On the other hand, this inventor has proposed the horizontal die-casting apparatus using the casting means which has a pressurized gas pouring pot, and the method using such an apparatus (Japanese Patent Application No. 2006-221199). Although such an apparatus and method can easily produce a high-quality cast product as compared with other methods, since the control of the pressurized gas is performed using a pressure control valve, the control is difficult. The casting speed could not be controlled to a desired speed, and the occurrence of a jet flow sometimes caused the problem of gas entrainment in the molten metal.

  An object of the present invention is to use a die-casting apparatus capable of casting at a high speed as a whole while controlling the casting speed of the molten metal so that gas entrainment does not occur in the molten metal, and such a die-casting apparatus. The object is to provide a die casting method.

  In casting using high quality castings, especially die casting equipment that casts thin and large castings, in order to avoid the cooling and solidification of the molten metal at the casting stage, the molten metal is quickly and quickly placed in the mold cavity. However, due to the generation of a jet, the molten metal entrains gas, which may cause defective products. As a result of diligent research to solve the above-mentioned problems, the present inventors have found that the molten metal has passed through the molten metal delivery opening at the entrance of the casting passage hole having a narrow passage area and the inflow gate at the cavity inlet. When the speed was too high, it became a jet and entrained the remaining gas, resulting in the knowledge that defective products were generated.

  The present inventors tried to perform casting by temporarily lowering the casting speed when the molten metal passes through the molten metal delivery opening and the inflow gate at the inlet of the casting passage hole by using the conventional pressure control valve. Subtle control is extremely difficult, and the entire casting speed is extremely slow.

  As a result of further earnest research, the inventors of the present invention controlled the casting speed of the molten metal very accurately by controlling the piston speed by using a casting means equipped with a gas cylinder and a piston. This can be done without temporarily reducing the overall casting speed by temporarily lowering the casting speed when the molten metal passes through the molten metal delivery opening or inflow gate at the inlet of the casting passage hole. The inventors have found that it is possible to produce a high-quality cast product that does not involve gas, and have completed the present invention.

  That is, the present invention includes (1) a fixed mold and a movable mold that form a mold cavity, a casting passage hole that is formed in the fixed mold and communicates with the mold cavity through a side gate, A casting means for supplying and filling molten metal from below through a casting stalk through a molten metal delivery opening formed in the casting passage hole, and sliding in the casting passage hole, and a molten metal delivery opening of the casting passage hole. A horizontal die casting apparatus having a closing plunger for closing, wherein the casting means has a gas pressurized hot pot, and a gas cylinder and a piston for introducing pressurized gas into the gas pressurized hot pot. A die casting apparatus characterized by comprising a pressurized gas introducing means and controlling the piston speed by controlling the piston speed; and (2) a pressurized gas. Introduction But it relates die casting apparatus according to (1), characterized in that it has a further accumulator tank.

  In the present invention, (3) the die casting apparatus according to (1) or (2) above, wherein the piston of the pressurized gas introducing means is driven by a pulse motor controlled by a program; (2) A die casting apparatus according to any one of (1) to (3) above, and (5) a casting passage characterized by comprising pressurizing means for pressurizing the molten metal in the closed mold cavity. The die-casting apparatus according to any one of the above (1) to (4), wherein the tip of the hole is enlarged in a tapered shape, and (6) the capacity of the gas pressurized hot water pot is one time. The die casting apparatus according to any one of the above (1) to (5), wherein the die casting apparatus has a capacity capable of accommodating a molten metal necessary for casting.

Furthermore, the present invention is (7) a casting method using the die-casting apparatus according to any one of (1) to (6) above, wherein the molten metal tip passes through the molten metal delivery opening and the mold. A die casting method characterized by casting the molten metal by controlling to lower the casting speed when passing through the side gate at the cavity entrance, and (8) the molten metal hot water passes through the side gate at the mold cavity entrance. When the casting is performed, the molten metal is cast by controlling the casting speed to be the lowest, and (9) the pressure in the gas pouring pan at the end of casting is 1 kg / The die casting method according to (7) or (8) above, wherein the molten metal is cast so as to be controlled to be cm ² or more, and (10) without using a closing plunger, Molten metal mold The die casting method according to any one of the above (7) to (9), wherein the entire bite is filled.

  According to the die-casting apparatus and the die-casting method of the present invention, it is possible to cast at a high speed as a whole while controlling the casting speed of the molten metal so that the gas is not entrained in the molten metal. Can be reliably cast.

  As the die casting apparatus of the present invention, a fixed mold and a movable mold that form a mold cavity, a casting passage hole that is formed in the fixed mold and communicates with the mold cavity via a side gate, Casting means for supplying and filling the molten metal from below through the casting stalk through the molten metal delivery opening formed in the casting passage hole, sliding in the casting passage hole, and the molten metal delivery opening of the casting passage hole A horizontal die casting apparatus having a closing plunger, wherein the casting means includes a gas pressurized hot pot, and a gas cylinder and a piston for introducing pressurized gas into the gas pressurized hot pot. The present invention is not particularly limited as long as the apparatus is configured to control the filling speed of the molten metal into the mold cavities by controlling the piston speed by including the pressurized gas introducing means. According to the die casting apparatus, a pressurized gas introduction means having a gas cylinder and a piston is used to accurately control the pressurized gas to control the casting speed of the molten metal. When passing through the molten metal delivery opening or the molten metal inflow gate, the molten metal speed is temporarily reduced to prevent the generation of jets, and if there is no problem even if the casting speed is increased, the casting speed is increased and the overall speed is increased. It is possible to cast, and a high-quality cast product can be more reliably manufactured. The die casting apparatus of the present invention is particularly useful when it is necessary to perform casting through a narrow molten metal inflow gate in view of the shape of the cast product.

  In the die casting apparatus of the present invention, as described above, the pressurized gas introducing means having the gas cylinder and the piston is used, and the filling speed of the molten metal into the mold cavity is controlled by controlling the piston speed. The piston is preferably driven by a pulse motor that is controlled by a program. That is, the advance / retreat of the piston can be accurately controlled by the screw shaft driven by the pulse motor.

  Moreover, it is preferable that the pressurized gas introduction means in the die-casting apparatus of the present invention further has a pressure accumulation tank (accumulator). Accordingly, it is possible to perform pressure filling instantaneously, and by combining with the above piston mechanism, the molten metal can be cast in a shorter time and controlled, and it is possible to deal with thin wall casting.

  As the casting means, it is a means equipped with a gas pressurized pouring pan in which gas is introduced by the pressurized gas introducing means, such gas pressurized pouring pan may be fixed to the apparatus body, From the viewpoint of maintenance and the like, those that can be attached to and detached from the apparatus main body are preferable. The gas pressurized pouring pan that can be attached and detached can be provided with a closed structure by providing a lid on the gas pressurized pouring pan that is open at the top, and can also be formed by mounting on the apparatus main body. As a configuration for forming a sealed structure by mounting on the apparatus main body, when the gas pressurized pouring pan has a cast stalk, the upper end of the cast stalk is closely attached to the apparatus main body to form a sealed structure Specifically, for example, the upper surface of the casting stalk can be pressed below the casting passage hole of the fixed mold to form a sealed structure. When the main body of the apparatus is equipped with cast stalk, the upper end of the gas pressurizing pouring pan can be brought into close contact with the lower surface of the fixed mold to form a sealed structure. A sealing structure can be formed by pushing into the seal packing of the mounting plate. At this time, it is preferable to reduce the width of the upper portion of the gas pressurized hot water pan so that it can be easily sealed in the fixed mold.

  In this way, by using a gas pressurized pouring pan that can be attached to and detached from the apparatus main body, the molten metal can be introduced from, for example, a hot water ladle from above (opened) the gas pressurized pouring pan that has been detached (removed). Can refill the melt very easily. In addition, since the gas pressurized hot pot can be removed and the casting passage hole of the apparatus main body can be cleaned and sprayed for lubrication, it is very easy to perform maintenance.

  In addition, the gas pressurized pouring pan has a capacity that can accommodate the molten metal required for one casting, so that the amount of molten metal in the pouring pan at each casting is always constant, so there is no need for pressure correction and more accuracy. It is possible to control the filling rate of the molten metal well. That is, in the case of the capacity for multiple times, the liquid level at the time of each casting is different, and it is necessary to finely adjust the pressure, but by making the capacity that can accommodate the molten metal necessary for one casting Thus, it is not necessary to make such a fine adjustment, and it is effective when it is particularly necessary to make a fine adjustment as in the present invention.

  In addition, such a gas pressurized pouring pan can be downsized because the surface of the molten metal can be raised to reduce the volume of the gas part, so that the supply amount of the molten metal can be easily adjusted and the gas pressure can be increased easily. The mold cavity can be filled with molten metal, and the molten metal can be supplied to the mold cavity quantitatively, the supply speed can be increased, and the shot time lag can be shortened. It becomes possible to cast a cast product. Furthermore, by using such a pouring pan, the production cycle time is shortened, so that the productivity is improved.

  Such a gas pressurized pouring pan is preferably provided with a pouring pan heating means, which suppresses the generation of a solidified layer, makes it possible to suppress the occurrence of casting product defects as much as possible because the hot water circulation is good.

  Moreover, it is preferable that a casting means has a vacuum suction mechanism which vacuum-sucks the gas in the mold cavity and sucks and fills the molten metal, in addition to the gas pressurized hot water pouring pan. Accordingly, the mold cavity can be filled with the molten metal at a higher speed, and the gas in the mold cavity can be discharged to prevent the gas from being entrained. This vacuum suction is preferably continued until the molten metal in the mold cavities is cooled and solidified, so that generation of defective products can be prevented more reliably.

  The casting passage hole communicates with the mold cavity located above via the side gate, and is not particularly limited as long as it is formed in at least the fixed mold, and preferably has a circular cross section. For example, a substantially horizontal hole formed by combining a hole drilled in the fixed mold substantially horizontally, a hole drilled in the fixed mold and the movable mold, a fixed mold and the movable mold, or the like. A hole formed in a substantially vertical direction in the mating surface portion of the mold can be exemplified. In the die casting apparatus of the present invention, since the casting sleeve (tube) is eliminated and the casting passage hole has a small diameter, the residence time of the molten metal is very short, no solidified layer is generated by cooling, and the flow resistance is also low. Therefore, filling up to the mold cavities can be carried out more smoothly and at a low pressure, and maintenance such as manufacture and cleaning of the apparatus itself is facilitated. The diameter of the cast-in passage hole is, for example, about 50 mmφ to 150 mmφ, preferably 80 mmφ to 120 mmφ, and the length is, for example, about 100 mm to 200 mm, and is 120 mm to 160 mm. Is preferred.

  In addition, it is preferable that the tip end portion of the casting passage hole is tapered so as to gradually increase toward the tip end, thereby facilitating the discharge of gas and the solidified layer generated on the inner wall to be a closed plunger. Can be prevented from being pushed in.

  The combination of the casting means and the casting passage hole allows the casting means to be configured to fill the entire mold cavity without using a plunger, thereby preventing the molten metal from cooling and solidifying. In addition, mixing of the solidified layer can be prevented and the quality can be further improved.

  In addition, the casting passage hole is provided with a molten metal delivery opening which is a communicating portion with the casting stalk. In the case of a horizontal casting hole, it is provided in the lower part, and in the case of a vertical casting passage hole. Is provided on the side. The shape of the molten metal delivery opening is not particularly limited, but from the viewpoint of ease of processing, the cross section is preferably a quadrangle with rounded corners. In this case, the length of one side of the molten metal delivery opening is larger than the inner diameter of the stalk. It is preferable to reduce the size.

  The closing plunger that slides in the casting passage hole and closes the molten metal delivery opening in the casting passage hole mainly serves to prevent the molten metal filled in the mold cavity from flowing backward and the mold cavity. It is means for closing the gate at the entrance. Examples of such a closed plunger include a plunger tip (plunger head) that can slide in an airtight manner in a casting passage hole and a plunger rod that can move the plunger tip forward and backward. As a driving source for the reciprocating motion of the plunger rod, a hydraulic cylinder and a servo motor can be cited. When the casting passage hole is a horizontal hole, the closing plunger is preferably provided through the fixed mold. In the case of a vertical hole, it is preferably provided below the fixed mold and the movable mold, and may be integrated with the apparatus main body, but is configured to be movable together with the pouring pan. Is preferred.

  In addition, when the plunger tip is located at the forward limit of the casting hole, it is preferable that the rear end of the plunger tip advances to the molten metal delivery opening and opens the molten metal delivery opening. It is preferable to form a gas chamber in the plunger rod insertion part on the rear side (for example, between the hydraulic cylinder and the plunger tip). That is, a gas chamber is formed between the plunger tip located at the front and the hydraulic cylinder located at the rear, and gas is fed into the gas chamber using a gas supply means, and the rear end of the plunger tip is melted. It is possible to connect the gas chamber and the stalk by reaching the delivery opening, and to drop the molten metal in the cast stalk into the pouring pan by the gas pressure from the gas chamber. As a result, it is possible to reliably guide all molten metal to the molten metal pan without leaving the molten metal in the cast stalk, and the molten metal is inserted when the plunger tip is retracted, and solidified and fixed in the cast stalk. The occurrence of troubles can be prevented. The gas pressure in the gas chamber is not particularly limited, but is preferably equal to the molten metal pouring pressure, and the gas introduction into the gas chamber may be performed by using pressurized gas introduction means for introducing gas into the pouring pan. it can.

  Moreover, in the die-casting apparatus of this invention, it is preferable to provide the pressurizing means to pressurize the molten metal in the closed mold cavity. That is, it is preferable to provide a pressurizing means for pressurizing the molten metal in the mold cavity together with the closing plunger. An example of such pressurizing means is a pressurizing pin slidably disposed on the movable mold of the hot water pool portion of the cavity at a position away from the casting passage hole via the mold cavity. It is preferable to provide a plurality of pressure pins, and the diameter thereof is preferably about 2/3 to 1 times the depth of the hot water pool of the cavity. In this way, by pressurizing the molten metal with a closed plunger and a plurality of pressure pins at a distant position, the pressure transmission distance to the molten metal in the cavity is shortened, thereby uniformly transmitting the pressure to the cavity product part. Therefore, it is possible to cast a cast product in which no shrinkage occurs during solidification with a small pressure. In addition, by disposing the closing plunger and the pressure pin at an appropriate position according to the form of the product, the pressure transmission distance of the molten metal in the cavity product part is further shortened, and the pressure transmission is made more uniform and sufficient. This can prevent the formation of a shrinkage nest with a small pressure.

  Further, the die casting method of the present invention is a casting method using the above-described die casting apparatus of the present invention, wherein the molten metal tip passes through the molten metal delivery opening and the side gate of the mold cavity entrance. The casting speed is not particularly limited as long as it is controlled so as to reduce the casting speed, and the casting speed is the lowest when the molten metal passes through the side gate of the mold cavity entrance. It is preferable to cast the molten metal under control. Thereby, generation | occurrence | production of a jet flow can be prevented, the entrainment of the gas to a molten metal can be prevented, and an apparatus trouble can be avoided. Note that “controlling the casting speed to be the lowest” means to control the casting speed to be the lowest among the other casting speeds except for the casting speed when the pressure is increased at the start of casting.

Also, it is preferable to cast the melt by controlling the pressure in the gas pouring pan at the end of casting to be 1 kg / cm ² or more, and design and manufacture the size of the gas cylinder so that it can be controlled in this way. It is preferable to keep it. Thereby, the casting time as a whole can be shortened, and complete filling can be performed to produce a high-quality cast product.

  If the gas pressurized pouring pan is detachable, close the molten metal delivery opening with a closing plunger, then immediately retract the piston of the pressurized gas introducing means to lower the gas pressure in the gas pressurized pouring pan and cast It is preferable that the molten metal in the stalk is dropped and detached from the apparatus main body, the necessary molten metal is supplied next time, and is attached to the apparatus main body again to prepare for the next casting. Thereby, continuous casting can be performed very efficiently using one gas pressure pouring pot.

  Hereinafter, the present invention will be described more specifically with a die casting apparatus for producing an aluminum alloy casting, but the technical scope of the present invention is not limited to this example.

  1 is a schematic longitudinal sectional view before casting of a die casting apparatus according to an embodiment of the present invention, FIG. 2 is a schematic longitudinal sectional view after casting of the die casting apparatus shown in FIG. 1, and FIG. FIG. 4 is a view showing a state in which the molten metal is pushed up in the vicinity of the molten metal delivery opening of the die casting apparatus shown in FIG. 1, FIG. 4 is a view showing a state in which the molten metal following FIG. 3 is almost full, and FIG. 4 is a view showing a state where the molten metal following FIG. 4 passes through the side gate of the cavity inlet, and FIG. 6 is a view showing a state where the closing plunger following FIG. 5 is advanced to pressurize the molten metal. These are the figures which show the state of the preferable casting speed of this invention. FIGS. 8A and 8B are views showing the state of the molten metal at the same time as FIGS. 3 and 5 in a conventional apparatus in which the casting speed is not controlled.

  As shown in FIGS. 1 and 2, a die casting apparatus according to an embodiment of the present invention includes a stationary mold 1 attached to a stationary platen 3 of the casting apparatus, and a mold closed mold opening by moving laterally. A movable platen 4 that can be used includes a movable mold 2 attached via a movable mold holder 15, and a gas pressurizing pouring pan 7 disposed below the fixed mold 1. A mold cavity C is formed by the fixed mold 1 and the movable mold 2.

  The fixed mold 1 is provided with a substantially horizontal casting passage hole 5 penetrating the stationary mold 1, and a casting passage hole 5 and a casting stalk 9 are formed below the casting passage hole 5. A molten metal delivery opening 51 having a size smaller than the diameter of the molten metal delivery opening 51 is formed, and the cast passage hole communicates with the cast stalk 9 extending below the molten metal delivery opening 51.

  The casting passage hole is provided with a closing plunger 6 that is driven by a hydraulic cylinder 25 for the closing plunger. After the mold cavity C is completely filled (filled) into the mold cavity C by the casting means, The closing plunger 6 is advanced by the closing plunger hydraulic cylinder 25 to close the molten metal delivery opening 51, and subsequently advanced to press the molten metal in the mold cavity C for the amount of solidification shrinkage from the casting passage hole 5. Replenish.

  The pressurized gas introducing means for supplying the gas to the pressurized gas pouring pan 7 includes a gas cylinder 32 for pressurizing the pouring pan gas and a piston 33 that advances and retreats in the gas cylinder 32. It is controlled by the rotation of the screw shaft 34 driven by an electric pulse motor for driving a gas cylinder for pressurized gas. When the pressurized gas is fed from the pressurized gas passage 81 by the pressurized gas introduction means, the molten metal M in the gas pressurized hot water pouring pan 7 is pushed up in the casting stalk 9 and the molten metal of the fixed mold 1 is sent out. The mold cavity C is filled through the opening 51 and the side gate C2 formed on the mold mating surface. The molten metal casting speed is controlled, for example, as shown in FIG. 7, and details thereof will be described later.

  One or two or more small hot water reservoirs 14 are formed at the end of the mold cavity C, and a pressure pin 11 driven by a hydraulic cylinder 12 is introduced into the hot water reservoir 14. Pressurize the molten metal in the mold cavity C. That is, the pressurizing pins 11 are pushed out together with the closing plunger 6 to pressurize the molten metal in the mold cavity C via the pressurizing pin hot water reservoir 14 of the cavity C. The outer diameter of the pressurizing pin 11 is configured to be slightly smaller than the diameter of the entrance of the hot water reservoir 14 of the cavity. These pressurizing pins 11 are desirably provided near an end portion where the pressurizing pressure by the closing plunger 6 is difficult to reach or a portion requiring strength.

  Next, the operation and casting method of the above-described die casting apparatus will be described. As shown in FIG. 1 and FIG. 2, when the gas pressurization pouring pan 7 that has completed hot water supply at another position is attached and sealed to the apparatus main body, the gas pressure applied to the molten metal surface in the gas pressurization pouring pan 7, By the suction from the gas discharge port 13 by the vacuum suction mechanism, the molten metal in the gas pressurized pouring pan 7 enters the mold cavity C through the casting stalk 9, the molten metal delivery opening 51, the casting passage hole 5, and the side gate C2. Filled.

  At this time, as shown in FIG. 7, the casting speed is controlled to fill the mold cavity C with the molten metal. By introducing the pressurized gas into the gas pressurized hot water pouring pan 7 using a pressurized gas introducing means using a gas cylinder, the casting speed as shown in FIG. 7 can be accurately controlled.

  That is, in the casting stage of the molten metal, it is necessary to complete the filling of the mold cavity C within a short time during which the molten metal M does not cool and solidify, so that the gas pressure in the gas cylinder is adjusted and the gas pressure injection is performed. It is pushed up quickly from the hot pot until the tip surface Ma of the molten metal M reaches the molten metal delivery opening 51, but when the molten metal tip passes through the molten metal delivery opening 51, as shown in FIG. As shown in FIG. 3, the casting speed is slowed down so that the molten metal is filled so as not to leave the bottom surface around the molten metal delivery opening 51 so that the gas is not entrained. Further, when the hot water tip passes through the side gate C2, if it is rapidly filled, as shown in FIG. 8 (b), the molten metal M becomes a jet 20 and collides with various portions of the cavity, so that the gas 18 is entrained. As shown in FIG. 5, the speed is controlled to be low until the molten metal is collected around the outlet of the side gate C2 so that the molten metal does not leave the bottom surface around the side gate C2.

As described above, when the tip hot water surface Ma of the molten metal M rises in the casting stalk 9, it is pushed in as quickly as possible. However, when reaching the front of the molten metal delivery opening 51, the hot water does not jump out due to inertia. As shown in FIG. 3, the molten metal M is allowed to pass through the casting passage so that the lower surface of the molten metal is not lifted from the bottom surface around the molten metal delivery opening 51. When the hot water accumulates a little in the hole 5, gradually increase the speed to a range where the hot water does not jump into the side gate C 2, fills the casting passage hole 5, and slows down again when the hot water passes through the side gate C 2. When filling the cavity C, the casting speed is increased, the entire filling time is shortened, and the filling is completed. In particular, in the case of thin-wall casting, gas is supplied from a pressure accumulating tank and filled at high speed within a short time. When the filling is completed, it is effective for completely filling and preventing the formation of shrinkage cavities that the gas pressure in the gas pressurized pouring pan is 1 kg / cm ² or more to pressurize the molten metal M.

  When the flow of the molten metal in the mold cavity C stops when the filling is completed and the gas pressure at the outlet of the gas cylinder 32 rises, this is detected as a filling completion signal, and the molten metal delivery opening 51 is immediately opened by the closing plunger 6. The molten metal in the blockage and casting passage hole 5 is pressurized. At this time, when the rear end of the closing plunger tip 63 reaches the molten metal delivery opening 51, the pressurized gas flows into the casting stalk 9 and the molten metal in the casting stalk falls into the gas pressurized hot water pouring pan.

  After the molten metal delivery opening 51 is closed with the closing plunger 6, the solidification shrinkage of the molten metal M occurs, so the closing plunger 6 and the pressure pin 11 are advanced to perform replenishment according to the solidification shrinkage volume. The contact between the molten metal and the mold surface is maintained. Further, at this time, as shown in FIG. 6, since the casting passage hole 5 is enlarged in a tapered shape, the solidified layer 19 generated on the inner wall is not pushed out by the closing plunger 6 and is not mixed into the product. There is no decrease in the applied pressure. Since the pressure replenishment according to the solidification contraction volume by the advancement of the closing plunger 6 is difficult to transmit pressure to the opposite end of the mold cavity C, the pressurizing pin 11 around the end is operated to pressurize. As a result, it is possible to obtain a product having a dense structure free from shrinkage due to coagulation shrinkage. Further, after the cooling and solidification of the molten metal in the mold cavity C is completed, the mold is opened, and the product material taken out by the movable mold 2 can be pushed out by the pressure pins and the extrusion pins and taken out.

  Moreover, the apparatus shown by FIG. 9 can be mentioned as a die-casting apparatus which concerns on other embodiment of this invention. In the apparatus shown in FIG. 9, the upper surface of the pan lid 26 of the gas pressurized pouring pan 7 is inclined corresponding to the lower surface of the inclined fixed mold 1, and cast stalk provided on the pan lid 26. 9 is inserted into the cast stalk insertion portion and hermetically fixed. The closing plunger 6 is provided below the fixed mold 1 and the movable mold 2, and the closing plunger hydraulic cylinder 25 is fixed to the moving table 38. The gas pressurizing pouring pot 7 can be placed on the moving table 38, and the gas pressurizing pouring pot 7 can be moved together with the moving table 38. In this apparatus, similarly to the apparatus shown in FIG. 1, by filling the molten metal at the casting speed as shown in FIG. 7, the gas can be prevented from being entrained and the molten metal can be filled at a high speed.

It is a schematic longitudinal cross-sectional view before casting of the die-casting apparatus which concerns on one Embodiment of this invention. It is a schematic longitudinal cross-sectional view after casting of the die-casting apparatus shown in FIG. It is a figure which shows the push-up state of the molten metal near the molten metal delivery opening of the die-casting apparatus shown in FIG. It is a figure which shows the state which the molten metal is filling the casting passage hole following FIG. FIG. 5 is a diagram illustrating a state where the molten metal passes through the side gate following FIG. 4. FIG. 6 is a diagram illustrating a state where the closing plunger advances and pressurizes the molten metal following FIG. 5. It is a figure which shows the state of the preferable casting speed of this invention. (A) (b) is a figure which shows the state of the molten metal at the same time as FIG.3 and FIG.5 in the apparatus with the conventional casting speed not controlled. It is a schematic longitudinal cross-sectional view before casting of the die-casting apparatus which concerns on other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fixed metal mold 2 Movable metal mold 3 Fixed board 4 Movable board 5 Casting passage hole 51 Molten metal delivery opening 6 Closure plunger 63 Plunger tip 7 Gas pressurization pouring pot 8 Packing 81 Gas passage (pressurization gas passage)
82 Gas passage (Pressurized gas passage)
9 Casting stalk 11 Pressurizing pin 12 Pressurizing pin hydraulic cylinder 13 Gas outlet 14 Pressurizing pin reservoir 15 Movable mold holder 16 Pressing plate 17 Extruding plate 18 Gas 19 Solidified layer 20 Jet 25 25 Hydraulic cylinder for closing plunger 26 Pot lid 28 Packing 32 Gas cylinder 33 for pouring hot pot gas pressurization 34 Piston 34 Screw shaft 36 Pressurized gas piping 37 Pressurized gas switching valve 38 Moving table C Mold cavity C2 Side gate M Molten metal Hot water surface

Claims (10)

A fixed mold and a movable mold that form a mold cavity, a casting passage hole that is formed in the stationary mold and communicates with the mold cavity via a side gate, and is formed in the casting passage hole. Casting means for supplying and filling molten metal from below through cast stalk through a molten metal delivery opening, and a closing plunger that slides in the cast passage hole and closes the molten metal delivery opening of the cast passage hole. A horizontal die casting apparatus,
The casting means includes a gas pressurized pouring pot, and a pressurized gas introducing means having a gas cylinder and a piston for introducing the pressurized gas into the gas pressurized pouring pot, and by controlling the piston speed, A die casting apparatus characterized by controlling the filling speed of the mold cavity.   2. The die casting apparatus according to claim 1, wherein the pressurized gas introducing means further includes a pressure accumulating tank.   3. The die casting apparatus according to claim 1, wherein the piston of the pressurized gas introducing means is driven by a pulse motor controlled by a program.   The die-casting apparatus according to any one of claims 1 to 3, further comprising a pressurizing unit that pressurizes the molten metal in the closed mold cavity.   The die casting apparatus according to any one of claims 1 to 4, wherein a tip end portion of the casting passage hole is enlarged in a tapered shape.   The die casting apparatus according to any one of claims 1 to 5, wherein the capacity of the pressurized gas pouring pot is a capacity capable of accommodating a molten metal required for one casting.   It is a casting method using the die-casting apparatus in any one of Claims 1-6, Comprising: When the tip of a molten metal passes through the molten metal delivery opening and the side gate of a mold cavity entrance, it casts A die casting method characterized in that molten metal is cast by controlling to reduce the speed.   8. The die casting method according to claim 7, wherein the molten metal is cast by controlling the casting speed to be the lowest when the molten metal passes through the side gate of the mold cavity entrance. The die casting method according to claim 7 or 8, wherein the molten metal is cast by controlling the pressure in the gas pouring pan at the end of casting to be 1 kg / cm ² or more.   The die-casting method according to any one of claims 7 to 9, wherein the entire mold cavity is filled by the casting means without using a closing plunger.

Images