JP7726478B2 - Die-casting manufacturing method and device - Google Patents

Description

The present invention relates to a die-casting manufacturing method and apparatus, and in particular to a die-casting manufacturing method and apparatus that eliminates obstacles when pressurizing the runner portion, which is the entrance for molten metal in the mold, from below.

Conventionally, two methods for casting die-cast products are known: the "normal die-casting method" shown in Figure 13 and the "center gate method" shown in Figure 14.

The most common "normal die-casting method" involves forcing molten metal such as aluminum into a cavity made in a mold with a plunger, and then removing a product that cools and solidifies to match the shape of the cavity. To prevent porosity during cooling and molding and improve product density, a method has been proposed in which the runner is further pressurized in conjunction with the pressure action of the plunger of the die-casting machine.

The runner consists of a branch runner section that runs in the direction of the plunger's extrusion and a rising runner section that runs perpendicular to this and points upward. In order to perform secondary pressurization through the runner, a pressure pin that moves in and out of the rising runner that is directly connected to the cavity is provided, and after plunger pressurization is complete, the pressure pin on the runner is activated to perform further pressurization (Patent Document 1).

When applying pressure from the runner in Patent Document 1, the pressure applying part and the plunger tip surface are connected, and the maximum pressure that can be applied is the casting pressure multiplied by the mold projected area, which must not exceed the mold clamping force. With a typical casting machine, this limit pressure is around 70 MPa, and pressure beyond this cannot be applied. From this perspective, the technology described in Patent Document 2 has been proposed, which sets the gap between the inner diameter of the member forming the rising runner and the outer diameter of the pressure pin to 0.5 to 3.0 mm, thereby preventing backflow and achieving a pushing effect (Patent Document 2).

This method, which focuses solely on the gap, is impractical due to the following drawbacks. Normally, the product is removed from the casting by grasping the biscuit portion. However, when a pressure pin is inserted into a cylinder with a machined runner portion, the product and biscuit portions of the solidified casting are connected by a thin cylindrical gap formed between the cylinder's inner diameter and the pressure pin's outer diameter. Therefore, as the travel length L of the runner pressure pin moving through the rising runner cylinder increases, the strength of the portion connecting the biscuit portion and the product decreases, resulting in breakage during product removal and failure to remove the product, hindering continuous production. Generally, the flow rate Q of the annular gap is proportional to the cube of the annular gap Δ and inversely proportional to its length L. Therefore, reducing the gap Δ is effective in preventing backflow, and the limit at which the pressure pin can apply pressure to the product from the runner portion is determined by this gap Δ and its length L. Meanwhile, the travel distance of the pressure pin is determined by the predicted volume of porosity in the product. The shrinkage rate of molten aluminum is approximately 6%, so to prevent shrinkage cavities, it is necessary to move the pressure pin so that it compresses the molten metal by approximately 2% of the product volume. To enable continuous casting by applying pressure from the runner section, it is necessary to set optimal values for three elements: the value of the gap Δ between the rising runner section and the pressure pin, the amount of movement L of the pressure pin, and the strength required to connect the biscuit and the product, which is necessary to remove the product after casting. However, continuous casting is difficult with only the element of setting the gap Δ between the inner diameter of the rising runner and the outer diameter of the pressure pin to 0.5 to 3.0 mm, and the expected effect cannot be achieved, which is an issue.

In response to this issue, the present inventors have invented a convex groove orifice structure, as shown in Figure 13. After molten metal is injected into the clamped fixed mold 1 and movable mold 2 by the first pressurizing means 3, a cylindrical section is machined and installed on the runner 6 directly connected to the cavity 5 by the second pressurizing means 4, and a pressure pin 7 moves along the runner to apply second pressure. The cylinder of the second pressurizing means 4 is provided with a convex groove orifice 8, and a metal seal at the orifice 8 prevents backflow of molten metal while the second pressurizing means 4 applies cavity pressure. This convex groove orifice 8 prevents backflow and minimizes the length of the thin section connecting the biscuit and product sections after solidification, improving strength. The required stroke of the pressure pin 7 on the runner section correlates with the expected shrinkage cavity generation capacity and is determined by the volume of the product section. However, in the past, the required stroke required a long section connecting the biscuit and product sections, resulting in insufficient strength. By installing a convex groove orifice, both backflow prevention and breakage prevention strength during product removal can be achieved by determining only the gap Δ and the convex groove orifice width, without being affected by the required pressure pin stroke length. Furthermore, in prior art, the gap length where the pressure pin 7 is inserted into the cylinder varies depending on the amount of movement of the pressure pin 7. The flow rate Q of the annular gap is proportional to the cube of the annular gap Δ and inversely proportional to its length L, so the backflow prevention effect increases with the pressure pin stroke length. On the other hand, when a convex groove orifice 8 is installed, assuming that the pressure pin at least passes through the orifice portion, the backflow prevention effect is determined solely by the gap Δ and is not affected by the pressure pin stroke length. In other words, the factors determining the backflow effect change from variable gap length L and gap Δ, which change with stroke movement, to fixed orifice gap length L and gap Δ, making it easier to design an optimal runner pressure pin cylinder to achieve stable backflow prevention.

In the "normal die-casting method," the runner 6 is located at the bottom of the product, and molten aluminum is injected upward from below toward the cavity 5. However, the second pressurizing means 4 applies second pressure to the rising runner section that connects the branch runner section formed by the first pressurizing means 3 to the cavity beyond, so the second pressurizing means 4 has a branch formed by the first pressurizing means. The branch is equipped with a cooling means, but this interferes with the second pressurizing means 4, making it difficult to position the second pressurizing means 4. As a result, a new branch must be manufactured when applying runner pressure.

The "center gate manufacturing method" shown in Figure 14 is applied to conical shaped parts and point-symmetric parts, and is used to fill the molten metal from the center of the cavity 5 to improve filling balance. In Patent Document 3, a second movable mold 9 is installed between the fixed mold 1 and the movable mold 2, and a spool 10 is installed here connecting the cavity 5 and the runner 6, allowing the molten metal to spread throughout the cavity 5. Then, when injection is complete and the product has solidified and is ready to be removed, the runner portion is cut away using a gate-cutting cutter 11, and then the movable molds 2 and 9 are separated from each other, allowing the product with the spool 10 to be removed, as shown in Figure 15.

As described above, the "center gate method," like the "standard die casting method," can apply runner pressurization from below as a second pressurizing means, and achieve some degree of effectiveness in improving the density of die-cast products. However, while the gate, which is the entrance for molten metal, is located at the bottom of the cavity in the "standard die casting method," the "center gate method" moves the gate upward and positions it in the center of the cavity. This means that the gate-cutting cutter 11 cuts and removes the second pressurizing means 4 located at the bottom along with the gate. Furthermore, the pressure pin 7 of the second pressurizing means is positioned away from the cavity gate, making it difficult to transmit high pressure, meaning that the effect is not as great as with the "standard die casting method." Another issue is that, like the "standard die casting method," the cooling means for the shunt and the second pressurizing means interfere with each other.

JP 2000-117411 JP 2011-224650 Patent No. 6134776

The present invention addresses the above-mentioned problems with "normal die casting methods" and "center gate methods," and aims to facilitate mold processing by enabling the installation of a second pressurizing means for "normal die casting methods" and "center gate methods" after molten metal is injected by the plunger to be positioned so that the pressurizing means does not interfere with the cooling means for the diverter, and by increasing the freedom to select the placement location of the runner section pressurizing means and spool section pressurizing means even when there is no interference with cooling means such as biscuits.

In addition, when installing a second pressure means on the rising runner section in the "center gate manufacturing method," the problem of reduced pressure effect due to the longer distance from the pressure pin to the cavity gate is addressed. By applying a spool section pressure means that is closer to the cavity gate, this aims to avoid this reduction in pressure effect.

To achieve the above objectives with the "normal die-casting method," we devised a method of avoiding interference with the biscuit cooling means device by bending the rising runner section into a U-shape or V-shape when it becomes difficult to position the second pressure means due to the biscuit cooling means device. The second pressure means is installed after bending as shown in Figure 2 if it is U-shaped, or as shown in Figure 5 if it is V-shaped. When applying second pressure through a runner directly connected to the cavity, an orifice is installed, which makes it possible to avoid interference with the biscuit cooling means device without reducing the pressure effect of the second pressure pin. In this case, the bent section is characterized by being formed in a U-shape or V-shape.

The die-casting manufacturing apparatus of the present invention, which uses a "normal die-casting method," is characterized by having an injection section consisting of a first pressurizing means for injecting molten metal into a die-casting mold, a second pressurizing means that bends a runner that communicates with the cavity and is located in the runner section directly connected to the cavity at the bend to apply pressure toward the cavity, and an orifice that is located in the pressurizing path of the pressurizing pin of the second pressurizing means and can shield the molten metal from the pressurizing pin. In this case, the bend is characterized by being U-shaped or V-shaped.

The die-casting manufacturing equipment of the present invention for the "center gate manufacturing method" is characterized by having an injection section consisting of a first pressurizing means for injecting molten metal into the die-casting mold, a second pressurizing means for pressurizing the portion bending from the rising runner portion toward the spool portion toward the cavity, and an orifice that is provided in the pressurizing path of the pressurizing pin of the second pressurizing means and can shield the molten metal from the pressurizing pin. In this case, the pressurizing pin of the second pressurizing means is installed in a fixed mold that is relatively easy to install in a three-piece mold, and presses toward the cavity center.

In the "normal die casting method," the runner section is pressurized as described above. After injection by the plunger as the first pressurizing means, the molten metal is pressurized by the pressurizing pin as the second pressurizing means. The second pressurizing means and orifice that pressurize the runner form a metal seal due to their throttling effect, blocking backflow and maintaining pressure, thereby enabling additional pressurization of the product section. The second pressurizing means and orifice are located at the runner bend, which is positioned to avoid the cooling means, allowing the pressure direction of the second pressurizing means to be freely positioned. This prevents interference with the cooling device for the biscuit section, and makes it easy to avoid the mold core. Furthermore, even if there is no interference with the cooling device for the biscuit section, bending the runner to install the second pressurizing device allows for free modification of the installation location of the second pressurizing device, the direction of operation of the pressurizing pin, and other aspects, thereby improving the design flexibility of the second pressurizing device installation.

In addition, in the "center gate manufacturing method," a second pressurizing means installed in the fixed mold pressurizes the molten metal using a pressure pin as the second pressurizing means after injection using a plunger as the first pressurizing means. The second pressurizing means that pressurizes the spool section and the orifice form a metal seal due to their throttling effect, blocking backflow and maintaining pressure, thereby enabling additional pressure to be applied to the product section.

Furthermore, by installing the orifice, it is possible to adjust the thickness of the cylindrical thick-walled section connecting the runner section and the spool section, making it possible to set the thickness to facilitate cutting with a hydraulic cylinder punch. The thickness is proportional to the orifice gap length L, but by determining the orifice gap length L to thin the gap Δ to a strength that makes cutting easy, cutting becomes easy.

1 is a cross-sectional view of a main part of a die-casting manufacturing apparatus according to an embodiment. FIG. 2 is a schematic side view of FIG. 1; FIG. 4 is a cross-sectional view for explaining a runner pressurizing portion. FIG. 10 is a time-series diagram showing a runner pressurization state. FIG. 10 is a side view of a main part of a die-casting manufacturing apparatus according to a second embodiment of the present invention. A cross-sectional view of runner pressurization using the center gate manufacturing method. FIG. 1 is a cross-sectional view of a main part of an apparatus that employs a center gate manufacturing method, showing the state in which hot water is being supplied. FIG. 10 is a diagram showing an injection state by the first pressurizing means. FIG. 10 is a diagram showing a state of pressure applied by the second pressure applying means. FIG. FIG. FIG. FIG. 1 is a cross-sectional view of a main part of a manufacturing device that performs a "normal die-casting method." FIG. 1 is a cross-sectional view of a main part of a manufacturing device that performs the "center gate manufacturing method." FIG. 2 is a cross-sectional view of a main part of a manufacturing device showing a runner cut state according to the same manufacturing method.

The die-casting manufacturing method and apparatus according to an embodiment of the present invention will be described in detail below with reference to the drawings. Please note that the following description is merely one embodiment, and various modifications may be made to the present invention as long as they do not deviate from the spirit of the present invention.

Figures 1 and 2 show a cross-sectional view and a side view of the main parts of the die-casting manufacturing equipment according to this embodiment. The die-casting manufacturing equipment comprises a movable mold 12 attached to a movable platen and a fixed mold 14 attached to a fixed platen. Molten metal is injected into a cavity 16 formed by bringing the two molds 12, 14 into contact, resulting in a product shaped to match the cavity 16. The product can be removed from the cavity 16 by separating the molds 12, 14 and activating an ejector pin attached to the back of the movable mold 12.

The molten metal supply means is positioned below the cavity 16 as an injection section for supplying molten metal to the cavity 16 of this die-casting manufacturing device. This is composed of a first pressure means 22 consisting of an injection sleeve 18 that penetrates horizontally through the fixed platen and reaches the fixed mold 14, a plunger 20 disposed within the injection sleeve 18, and a pressure device located behind the plunger 20 that can push and pull the plunger 20.

A runner 24 is formed at the front end of the injection sleeve 18, serving as a passageway leading to the cavity 16. This runner 24 consists of a diverter runner 26 that extends almost horizontally from the injection sleeve 18 and gradually narrows in cross section, and a rising runner 28 that turns upward to connect directly to the bottom of the cavity 16. The molten metal extruded by the plunger 20 passes through the diverter runner 26, is turned upward by the rising runner 28, and is injected into the cavity 16.

Such a rising runner 28 is provided with a second pressurizing means 30 that secondarily pressurizes the molten metal in the cavity 16. In this embodiment, a bent portion is formed in the rising runner 28, and the second pressurizing means 30 is provided on the runner portion 32 of this bent portion that is directly connected to the cavity.

Specifically, as shown in Figure 2, the rising runner 28 is composed of a lower horizontal runner section 34 into which molten metal flows directly from the diverter runner 26 side; a connecting runner section 36 that rises parallel to the rising runner 28 at its tip; and an upper horizontal runner section, i.e., a cavity-direct runner section 32, that is parallel to the lower horizontal runner section 34 and returns to the original rising runner 28 side at the tip of the connecting runner section 36, and introduces molten metal into the cavity 16. The lower horizontal runner section 34, connecting runner section 36, and cavity-direct runner section 32 form a U-shaped bend section 38. The pressure pin 40 of the second pressure means 30 moves in and out of the cavity-direct runner section 32 to pressurize the molten metal, thereby enabling secondary pressure application.

The second pressure applying means 30 is composed of an actuator (not shown) mounted on the molds 12, 14, and a pressure pin 40 that protrudes from the end face of the connecting runner portion 36 by the actuator and moves horizontally along the cavity-direct runner portion 32. As shown in Figure 3, the diameter d of the pressure pin 40 is smaller than the inner diameter D of the cavity-direct runner portion 32, allowing the pressure pin 40 to slide left and right along the cavity-direct runner portion 32. Therefore, the amount V (see Figure 3) of pressure applied by the pressure pin 40 into the cavity-direct runner portion 32 improves the density of the product formed by the cavity 16.

In this embodiment, an orifice 42 that narrows the inner diameter is formed on the cavity-direct runner section 32 side (section B in Figure 2) to the right of the intersection of the connecting runner section 36 and the cavity-direct runner section 32 at the bend 38 (section A-B in Figure 3). This is an annular protrusion 44 with a rectangular cross section formed on the inner diameter of the cavity-direct runner section 32, and the height of this protrusion 44 (i.e., the inner diameter dimension of the cavity-direct runner section 32) is matched as closely as possible to the outer diameter d of the pressure pin 40, allowing for a metal seal. Specifically, although this depends on the size of the cavity 16, the gap dimension Δ is 1/2 of the difference between the inner diameter D of the cavity-direct runner section 32 and the outer diameter d of the pressure pin 40. The height of the annular protrusion 44 is determined so that this gap dimension Δ is 1/2 to 1/3 or less. In other words, the gap dimension δ of the metal seal portion is 1/2 of the difference between the inner diameter of the annular protrusion 44 and the outer diameter d of the pressure pin 40, where δ = Δ × 1/2, and preferably δ = Δ × 1/3, with the lower limit being the value at which the metal seal breaks. Furthermore, the axial length L of the annular protrusion 44 is set to approximately 10 mm to ensure a reliable metal seal.

The second pressurizing means 30 configured in this manner begins applying pressure from the position shown in Figure 4 (1) after injection by the plunger 20 of the first pressurizing means 22 is complete. When the pressurizing pin 40 reaches the annular protrusion 44, the molten metal from above enters the orifice 42, forming a metal seal (Figure 4 (2)), which performs a shielding function. As a result, the metal seal at the orifice 42 increases the amount of molten metal filled into the cavity 16, and the pushing action of the pressurizing pin 40 lengthens the stroke, completing the operation (Figure 4 (3)).

The annular protrusion 44 that forms the orifice 42 may have a rectangular cross section as in the embodiment, but it can also have a V-shaped or arc-shaped cross section. In this case, if the tip of the V-shaped or arc-shaped protrusion is sharp, it will be difficult to remove the metal seal, so it is desirable to have a shaved tip.

In addition, a cooling means can be placed on the annular protrusion 44 that forms the orifice 42. This can be a horizontal water-cooled system or an oil-cooled system, and it is recommended that cooling be performed when injection by the first pressurizing means 22 is completed and pressure is applied to the annular protrusion 44 by the second pressurizing means 30 (Figure 4 (2)). This makes it easier to form a metal seal.

In the above embodiment, the annular protrusion 44 that forms the orifice 42 may be formed as a separate part and attached by a fitting structure when forming the runner 24. This is because the runner 24 is structured to split at the parting line of the mold, making it easy to attach to the rising runner 28 that has a semicircular structure.
The above embodiment can also be applied to pushing a runner in a hot chamber and when molding plastics.

As described above, according to this embodiment, injection into the cavity 16 is performed by the first pressurizing means 22, and the second pressurizing means 30 is activated once the runner 24 is filled with molten metal. The normal extrusion action occurs while the pressurizing pin 40 reaches the intersection of the connecting runner portion 36 and the cavity-direct runner portion 32 (Figure 3A->B). However, as soon as the connecting runner portion 36 ends and the runner portion 32 is reached, the annular protrusion 44 solidifies the molten metal by the metal seal in the gap δ, and pressure is interrupted (Figure 4 (2)). Therefore, the unsolidified runner molten metal on the cavity 16 side, located above the pressurizing pin 40, is pushed toward the cavity 16 against the backdrop of the interrupted pressure.

This allows the pressure pin to be advanced by a greater stroke than with conventional methods (Figure 4 (3)), and the second pressure means 30 can be used to produce a denser product. The effect of this is that when filling a cavity 16 of the same volume with molten metal, it results in a 1.7% increase in weight, an astonishing value in this industry.

In particular, in this embodiment, a U-shaped bend 38 is provided in the rising runner 28, and the second pressurizing means 30 is attached to the cavity-directly connected runner section 32, which is the passage leading to the cavity 16. This allows the second pressurizing means 30 to be positioned away from the cooling means associated with the thick biscuit 46, core, etc., thereby increasing design flexibility.

Next, Figure 5 shows a second embodiment. While the previous embodiment had a U-shaped bend, this embodiment uses a V-shaped bend. The runner 24, which connects the first pressurizing means 22 and the cavity 16, is bent in a V-shape, particularly the rising runner 28, midway. The runner 24 comprises a first inclined runner section 50 whose base end leads to the first pressurizing means 22, and a second inclined runner section 52 connected to the first inclined runner section 50 and directly connected to the cavity 16. The second inclined runner section 52 is fitted with a second pressurizing means 30 equipped with a pressurizing pin 40 that can slide back and forth along its axis. An orifice 42 is provided on the second inclined runner section 52 side of the intersection of the inclined runner sections 50 and 52 to reduce its inner diameter. A metal seal is formed between the orifice 42 and the pressurizing pin 40 of the second pressurizing means 30, preventing backflow of molten metal while applying pressure from the second pressurizing means 30. The rest of the configuration is the same as in the previous example, so explanations will be omitted.

In this embodiment, the rising runner 28, which serves as the pressure path, has a V-shaped bend 54, which causes it to bend obliquely, but this configuration also makes it possible to avoid the need for a cooling means, increasing design flexibility.

Next, Figure 6 shows an example of application to the "center gate manufacturing method." The "center gate manufacturing method" is applied to circular or conical shaped parts and point-symmetric parts, and is used by filling the molten metal from the center of cavity 5 to improve filling balance.

As shown in Figure 6, the device for implementing this center gate manufacturing method has a second movable mold 64 installed between a fixed mold 60 and a movable mold 62. A circular cavity 66 is formed between the movable mold (hereinafter referred to as the first movable mold) 62 and the second movable mold 64. A spool 70 connecting this cavity 66 to a runner 68 is formed in the second movable mold 64. The spool 70 is formed in a conical shape, with its apex located at the center of the circular cavity 66. By supplying molten metal from this apex, the molten metal is distributed throughout the cavity 66 through the spool 70. The runner 68 is formed on the mating surface of the fixed mold 60, bends at a right angle from the apex of the spool 70, and extends downward. It connects to a horizontally extending plunger sleeve 72 installed below the fixed mold 60. A plunger 74 is inserted into the plunger sleeve 72, and an actuator (not shown) applies primary pressure to inject the molten metal. The pressure applying means including this plunger 74 is the first pressure applying means 76. In addition, a gate cutting hydraulic cylinder 78 facing the runner 68 is provided on the mating surface between the fixed mold 60 and the second movable mold 64, and when the molds are opened, this gate cutting hydraulic cylinder 78 cuts and separates the runner 68 from the spool 70.

A second pressure applying means 80 is provided on the fixed mold 60 side, facing the apex of the spool 70. It consists of a pressure cylinder 82 and a pressure pin 84 that moves in and out of the pressure cylinder 82. The pressure pin 84 moves in and out toward the apex of the spool 70 formed in the second movable mold 64. Specifically, as shown in the enlarged portion of Figure 6, a curved passage 86 provided at the point connecting the runner 68 and the spool 70 serves as the passage for the pressure pin 84. This passage is formed inside the second movable mold 64 and connects to the cavity 66. The pressure pin 84 crosses the runner 68 and pressurizes the cavity 66 upon reaching the curved passage 86. A circular ring 88 is attached to the curved passage 86, forming an orifice 90 that narrows its inner diameter. This is an annular protrusion with a rectangular cross section formed on the inner diameter of the curved passage 86. The height of the protrusion is adjusted as closely as possible to the outer diameter d of the pressure pin 84, allowing a metal seal to be formed here. Therefore, as shown in the enlarged view of Figure 6 (bottom view), the amount of pressure applied by the pressure pin 84 determines the amount of pressure applied to the cavity 66.

Figures 7 through 12 show the actual process of this "center gate manufacturing method." First, with the mold clamped, the first pressurizing device 76, the gate-cutting hydraulic cylinder 78, and the second pressurizing device 80 are also in standby mode. Molten aluminum is first poured through the inlet of the plunger sleeve 72 (Figure 7). After pouring is complete, the first pressurizing device 76 begins operation, moving at high speed while completing the forward thrust for low-speed, high-pressure injection. The molten aluminum enters the runner 68, rises, passes through the curved passage 86, and fills the cavity 66 from the spool 70 (Figure 8). After the first pressurizing device 76 completes injection, the second pressurizing device 80 applies secondary pressure. This occurs when the pressure cylinder 82 pushes the pressure pin 84 from its standby position (top view of the enlarged view in Figure 6) across the runner 68 and into the curved passage 86. The molten aluminum from the upper portion penetrates the orifice 90, forming a metal seal that provides a shielding function. Therefore, the metal seal at this orifice 90 increases the amount of molten metal filled into the cavity 66, and the pushing action of the pressure pin 84 lengthens the stroke, completing the process (Figure 9). Next, the first movable mold 62, including the second movable mold 64, moves back, and one side of the intermediate mold is opened. This leaves the runner 68 in contact with the cavity 66 (Figure 10). In this mold-open state, the gate-cutting hydraulic cylinder 78 is activated, cutting and removing the runner portion (Figure 11). Finally, the first movable mold 62 is moved back further, widening the gap between the second movable mold 64 and the first movable mold 62 of the intermediate mold, and the product is removed from the cavity 66, completing the process (Figure 12).

In this way, with the "center gate manufacturing method," the second pressurizing means 80 and orifice 90, which pressurize the spool 70 located in the center of the cavity 66, form a metal seal due to their throttling effect, blocking backflow and maintaining pressure, thereby enabling additional pressure to be applied to the product portion. This eliminates the need to place the second pressurizing means 80 below the runner 68, and the second pressurizing means 80 does not get in the way. Furthermore, by installing the orifice 90, the thickness of the cylindrical thick-walled portion connecting the runner 68 and spool 70 can be adjusted, allowing for thickness settings that facilitate cutting with a punch using the gate-cutting hydraulic cylinder 78. While the orifice gap length L is proportional to the gap length L of the orifice 90, determining the gap Δ to a strength that allows for easy cutting provides other benefits, such as easier cutting.

This invention is a method and apparatus for die casting production in which, following plunger pressure from the first pressure means, the second pressure means can pressurize the runner portion in "normal die casting methods" and the spool portion in "center gate methods," improving product density. In addition, in "normal die casting methods," the second pressure means can be positioned so as not to interfere with cooling means such as biscuits, and in "center gate methods," it can be installed in a fixed mold, which is easy to install.

1...Fixed mold,
2... Movable mold,
3...first pressurizing means,
4...Second pressurizing means,
5...cavity,
6...Runner,
7...Pressure pin,
8...Orifice,
9...second movable mold,
10...spool,
11...gate cutting cutter,
12... Movable mold,
14...Fixed mold,
16...cavity,
18... injection sleeve,
20... plunger,
22...first pressurizing means,
24...Runner,
26...Divider Runner,
28...Runner standing up,
30...second pressurizing means,
32: Runner section directly connected to cavity (upper horizontal runner section),
34...Lower horizontal runner section,
36...Connecting runner part,
38...U-shaped bent part,
40...Pressure pin,
42...Orifice,
44...annular protrusion,
46...biscuit,
50...first inclined runner portion,
52...second inclined runner portion,
54...V-shaped bent part,
60...Fixed mold,
62...first movable mold,
64...second movable mold,
66...cavity,
68...Runner,
70...spool,
72... plunger sleeve,
74...plunger,
76...first pressurizing means,
78... Hydraulic cylinder for gate cutting,
80: Second pressurizing means,
82...pressurized cylinder,
84...Pressure pin,
86...Bending passage,
88...Circular ring,
90...Orifice.

Claims (9)

A die-casting manufacturing method characterized by the following: after molten metal is injected into a clamped mold by a first pressurizing means, a second pressurizing means applies a second pressurizing force through a runner directly connected to the cavity; the runner is bent, and the second pressurizing means is provided at the bent part of the runner directly connected to the cavity, along with an orifice; and pressure is applied by the second pressurizing means while a metal seal is provided between the orifice and the pressurizing pin of the second pressurizing means to prevent backflow of molten metal. The die casting manufacturing method described in claim 1, characterized in that the bent portion is formed in a U-shape. The die casting manufacturing method described in claim 1, characterized in that the bent portion is formed in a V shape. a first pressurizing means for injecting molten metal into a die-casting mold;
a second pressurizing means for bending the runner communicating with the cavity and for applying pressure in the direction of the cavity, the second pressurizing means being provided at the bent portion of the runner directly connected to the cavity;
an orifice that is provided in a pressurizing path by a pressurizing pin of the second pressurizing means and that can shield the molten metal between the pressurizing pin and the orifice;
A die-casting manufacturing device characterized by having an injection section comprising: 5. The die-casting manufacturing apparatus according to claim 4 , wherein the bent portion is U-shaped. 5. The die-casting manufacturing apparatus according to claim 4 , wherein the bent portion is V-shaped. In a center gate manufacturing method, a first pressurizing means for injecting molten metal into a clamped mold cavity through a runner and a spool;
a second pressurizing means provided in a fixed mold, facing the spool and pressurizing the molten metal after the first pressurizing means pressurizes the molten metal;
A die casting manufacturing apparatus characterized in that an orifice is provided in a passage provided in a bent portion of the runner leading to a spool, and pressurization is performed by the second pressurizing means while preventing backflow of molten metal at the orifice portion by a metal seal between the orifice and the pressurizing pin of the second pressurizing means. The die casting manufacturing apparatus according to claim 7 , characterized in that in the center gate manufacturing method, the spool portion changes from solid to cylindrical by applying pressure to the runner, making it easier to cut with a punch using a hydraulic cylinder. In a center gate manufacturing method, a first pressurizing means for injecting molten metal into a clamped mold cavity via a runner and a spool that communicates with the mold cavity via a bent portion at the tip of the runner;
a second pressurizing means disposed in the fixed mold opposite the spool;
A die casting manufacturing apparatus characterized in that the pressure pin of the second pressure means is capable of moving in and out of a bent portion installed in the spool portion, and a pressure pin is provided between the bent portion and an orifice provided in this bent portion and prevents backflow of molten metal by a metal seal, thereby pressurizing the spool portion.