Die casting manufacturing apparatus and orifice for die-casting

Abstract

To improve the connection point between a biscuit and a die-cast product section, which was prone to breaking and could not be made strong enough.SOLUTION: A refrigerant passage is formed in an orifice component, and a cooling medium is supplied to this refrigerant passage. Additionally, a refrigerant passage is formed in a pressurizing pin of second pressurizing means passing through the orifice, and a cooling medium is supplied to this refrigerant passage.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a die-casting manufacturing apparatus and a die-casting orifice, and more particularly to a die-casting manufacturing apparatus equipped with a cooling structure for a portion where a runner pressurization method or a local pressurization method is used, and to cooling of a die-casting mold. [Background technology]

[0002] The casting method for die-cast products involves filling a cavity made in a mold with molten metal such as aluminum using a plunger, and then removing the product that has solidified to a shape that matches the cavity. In addition, a pressure boosting mechanism is installed at the rear of the plunger to further increase the pressure on the plunger to prevent porosity when molding the product. The plunger applies pressure to fill the cavity, producing a product that matches the cavity shape.

[0003] In recent years, a structure has been proposed in which, in order to further remove porosity from a product pressurized by a plunger, a separate pressure pin is placed in the runner section leading to the product to press the product with a secondary high pressure after the primary pressure is applied by the plunger. An orifice is provided at the sliding point of the pressure pin to prevent the molten metal from flowing back when high pressure is applied, and pressure is applied at a high pressure (Patent Document 1). In order to apply high pressure, the pressure pin of the secondary pressure means has a smaller diameter than the plunger and is set to apply a pressure of 300 MPa, exceeding the pressure limit of the plunger (80 MPa).

[0004] However, conventional pressure pins have a small sliding gap with the runner, and the sliding part, which is an orifice, becomes very hot during continuous production, reducing the backflow prevention function, increasing backflow in the molten metal, and worsening the pressure application effect. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 7090254 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention addresses the above-mentioned problems and aims to provide a die-casting apparatus and manufacturing method that allows cooling of the orifice portion and the pressure pin portion when pressurizing the runner as a second injection after molten metal is injected by the plunger. [Means for solving the problem]

[0007] In order to achieve the above object, the present invention is configured as follows: In a die-casting manufacturing apparatus provided with a first pressurizing means for injecting molten metal into a die-casting mold and a second pressurizing means having a pin for pressurizing a passage directly connected to a cavity, an orifice is provided in the pressurizing path of the second pressurizing means, the orifice portion is configured to shield the molten metal, and a refrigerant passage is formed in a component of the orifice, and a cooling medium is supplied to this refrigerant passage.

[0008] In this case, the orifice is an annular projection, and is formed as a semicircular ring attached to the movable mold and the fixed mold, and a refrigerant passage is provided in each semicircular ring, and an inlet and an outlet are provided.

[0009] In addition, in a die-casting manufacturing apparatus that is provided with a second pressurizing means having a pin that pressurizes a passage directly connected to the cavity in addition to a first pressurizing means that injects molten metal into the die-casting mold, an orifice is provided in the pressurizing path of the second pressurizing means, and the molten metal is shielded at the orifice portion.A refrigerant passage is formed inside the pressurizing pin of the second pressurizing means that passes through the orifice, and a cooling medium is supplied to this refrigerant passage.

[0010] The refrigerant passage is a double passage in which a pipe is inserted inside a passage hole formed in the pressure pin, and the cooling effect is enhanced by connecting the inlet to the internal pipe and the outlet to the external passage hole.

[0011] In addition, in a die-casting manufacturing apparatus that is provided with a second pressurizing means having a pin that pressurizes a passage directly connected to the cavity in addition to a first pressurizing means that injects molten metal into a die-casting mold, an orifice is provided in the pressurizing path of the second pressurizing means, and the molten metal is shielded at the orifice portion.A refrigerant passage is formed in a component of the orifice, and a cooling medium is supplied to this refrigerant passage, and a refrigerant passage is formed inside the pressurizing pin of the second pressurizing means that passes through the orifice, and a cooling medium is supplied to this refrigerant passage.

[0012] The die-casting orifice of the present invention is an orifice that shields molten metal and is installed in a die-casting manufacturing device that has, in addition to a first pressurizing means that injects molten metal into a die-casting mold, a second pressurizing means with a pin that pressurizes a passage directly connected to the cavity, and it forms a refrigerant passage in the orifice component, making it possible to supply a cooling medium to this refrigerant passage.

[0013] In this configuration, the orifice is a semicircular ring attached to each of the fixed mold and the movable mold, and each of the orifices is composed of an inner refrigerant passage and an outer return passage.

[0014] The orifice is divided into upper and lower parts in the direction in which the pressure pin passes, and a refrigerant passage and a return passage are formed on the mating surfaces, and the two are bonded together. Furthermore, drilled holes may be provided to form a refrigerant passage and a return passage above and below, with the two passages connected by a communication passage at one end and an inlet and an outlet of the refrigerant passage at the other end.

[0015] Furthermore, the present invention relates to a die-casting manufacturing apparatus that includes, in addition to a first pressurizing means for injecting molten metal into a die-casting mold, a second pressurizing means having a pin for pressurizing a passage directly connected to the cavity, wherein an orifice is provided in the pressurizing path of the second pressurizing means, and the orifice portion is configured to shield the molten metal, and the components of the orifice may be made of a material having a higher thermal conductivity than the surrounding materials.

[0016] Specifically, the orifice components can be configured to be cooled using a tungsten-based high specific gravity alloy as a material for cooling purposes, or a material with high thermal conductivity, high cooling effect, and wear resistance. [Effects of the Invention]

[0017] With the above configuration, the molten metal is prevented from flowing back by the injection of the molten metal, but the orifice is cooled, which increases the cooling effect on the thin-walled annular portion formed by the orifice, i.e., the portion connecting the product portion and the pressure pin portion. This reduces the fluidity of the molten metal in this portion, causing it to solidify. In addition, by adopting a cooling structure for the pressure pin portion of the second pressure means, the thin portion is cooled from the inside and outside, forming a metal seal. This metal seal therefore prevents backflow from the pressure portion to the tip side. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a cross-sectional view of a main part of a die-casting manufacturing apparatus according to an embodiment. [Figure 2] 3A and 3B are a plan view and a front cross-sectional view of a main part of an orifice portion in a second pressurizing means of the die-casting production apparatus. [Figure 3] 5A to 5C are explanatory views of the operation of the pressure pin of the die-casting manufacturing apparatus according to the embodiment. [Figure 4] 3A and 3B are a plan view and a front view of the orifice portion. [Figure 5] 10A and 10B are a left side view, a plan view, and a front view of another embodiment of the orifice portion. [Figure 6] FIG. DETAILED DESCRIPTION OF THE INVENTION

[0019] Figure 1 shows a cross-sectional view of the main parts of a die-casting production apparatus according to this embodiment. The die-casting production apparatus 10 comprises a movable die 14 attached to a movable platen 12 and a fixed die 18 attached to a fixed platen 16. Molten metal is injected into a cavity 20 formed by bringing the two dies 14, 18 into contact, resulting in a product having a shape that conforms to the cavity 20. The product can be removed from the cavity 20 by separating the dies 14, 18 and operating an ejector pin 22 attached to the back surface of the movable die 14.

[0020] A molten metal supply means 24 is disposed below the cavity 20 as an injection section for supplying molten metal to the cavity 20 of the die-casting manufacturing apparatus 10. This is composed of a first pressure means 30 consisting of an injection sleeve 26 that is attached by penetrating horizontally through the fixed platen 16 and reaches the fixed mold 18, a plunger 28 disposed within the injection sleeve 26, and a pressure device (not shown) that is located behind the plunger 28 and can push and pull the plunger 28.

[0021] A runner 32 is formed at the front end of the injection sleeve 26, serving as a passageway leading to the cavity 20. This runner 32 is composed of a diverter runner portion 34 that extends almost horizontally from the injection sleeve 26 and a rising runner portion 36 that turns upward so as to connect directly to the bottom of the cavity 20. The molten metal pushed out by the plunger 28 passes through the diverter runner portion 34, is turned upward by the rising runner portion 36, and is injected and sprayed into the cavity 20.

[0022] The rising runner portion 36 of the runner 32 is provided with a second pressurizing means 38 that secondarily pressurizes the molten metal in the cavity 20. This second pressurizing means 38 is composed of an actuator 40 attached to the bottom of the molds 14, 18, and a pressurizing pin 42 attached so as to move in and out from the bottom to the top of the rising runner portion 36 by the actuator. As shown in Figure 2, the diameter d of the pressurizing pin 42 is smaller than the inner diameter D of the rising runner portion 36, allowing the pressurizing pin 42 to slide up and down in the rising runner portion 36. Therefore, the amount by which the pressurizing pin 42 is pressed into the rising runner portion 36 improves the density of the product produced by the cavity 20.

[0023] In this embodiment, an orifice 44 that narrows the inner diameter is formed on the rising runner portion 36 side (part B in FIG. 2) above the intersection (section AB in FIG. 2) between the rising runner portion 36 and the diverter runner portion 34. This is an annular protrusion 46 with a rectangular cross section formed on the inner diameter portion of the rising runner portion 36, and the height of the protrusion 46 (i.e., the inner diameter dimension of the rising runner portion 36) is matched as closely as possible to the outer diameter d of the pressure pin 42 so that a metal seal can be formed here. Specifically, although this depends on the size of the cavity 20, the gap dimension Δ is 1 / 2 of the difference between the inner diameter D of the rising runner portion 36 and the outer diameter d of the pressure pin 42, and the height of the annular protrusion 46 is determined so that the gap dimension Δ is 1 / 2 to 1 / 3 or less. That is, the gap dimension δ of the metal seal portion is 1 / 2 of the difference between the inner diameter of the annular protrusion 46 and the outer diameter d of the pressure pin 42, where δ = Δ × 1 / 2, and preferably δ = Δ × 1 / 3, with the lower limit being the value at which the metal seal breaks. Also, the axial length L of the annular protrusion 46 is set to about 10 mm to ensure a reliable metal seal.

[0024] The second pressurizing means 38 configured in this manner starts pressurizing from the position shown in Figure 3(1) after injection by the plunger 28 of the first pressurizing means 30 is completed, and when the pressurizing pin 42 reaches the annular protrusion 46 (Figure 3(2)), the molten metal from above enters the orifice 44 portion, forming a metal seal, which performs a shielding function at that portion. Therefore, the metal seal at this orifice 44 portion increases the amount of molten metal filled into the cavity 20, and the pushing action of the pressurizing pin 42 lengthens the stroke, completing the operation (Figure 3(3)).

[0025] A cooling means is arranged on the annular protrusion 46 that forms the orifice 44. This can be a horizontal water-cooling type or an oil-cooling type, and it is advisable to cool it when injection by the first pressurizing means 30 is completed and pressure is applied to the annular protrusion 46 by the second pressurizing means 38 (Fig. 3(2)). This makes it easier to form a metal seal.

[0026] In the above embodiment, the annular protrusion 46 that forms the orifice 44 is formed as a separate part, and is attached using a fitting structure when forming the runner 32. This is because the runner 32 is structured to split at the parting line of the mold, and the semicircular structure can be easily attached to the rising runner portion 36.

[0027] The specific configuration is shown in Figures 4 to 6. This structure has a central insertion hole 48 through which the pressure pin 42 is inserted, and is split in half at the center of the insertion hole 48. The split block 50A is attached to one of the movable molds 14, and the other is attached to the fixed mold 18. The two halves are molded together to form a ring shape. The split block 50A is further divided into an upper block 52a and a lower block 52b. The mating surface on the lower block 52b side has a water channel 54 carved into a roughly semicircular shape. A water channel wall 56 is provided in the center of the water channel 54, separating it into an inner circumferential side and an outer circumferential side. One end of the water channel wall 56 is cut to connect the separated water channels 54, and the other end forms an inner water supply port 58 and an outer drain port 60 for each passage, which can be connected to a water supply source and a drain source, respectively. The upper block 52a functions as a lid for the lower block 52b, and the two are joined by welding 59 to maintain the configuration shown in FIG.

[0028] The half block 50B attached to the fixed mold 18 has a similar structure. As a result, the coolant introduced from the inlet passes through the inner water passage 54, mainly cooling the inside of the insertion hole 48, passes through the outer water passage 54 and is discharged from the outlet.

[0029] In Figure 5, the annular protrusion 46 that forms the orifice 44 is not divided into upper and lower halves but is formed as a single unit (naturally, the structure is divided into the movable mold 14 and the fixed mold 18). A refrigerant passage is formed from the side by drilling holes. Specifically, a through-hole 48 is formed in the center, through which the pressure pin 42 passes. The block 61A is split in half at the center of the through-hole 48, and the other half, a block 61B, is attached to the movable mold 14 and the other half, a block 61B, is attached to the fixed mold 18. The two halves are molded together to form a ring shape. A refrigerant passage 63 and a return passage 65 are drilled parallel to each other, passing alongside the through-hole 48, within block 61A. A water stop valve is formed at a corresponding position on the outer surface. Furthermore, as shown in Figure 5(3), a water supply port 67 is drilled slightly above the dividing line on the outer surface of block 61A, located at one end of the passages 63 and 65. This water supply port 67 is connected to the refrigerant passage 63 by a horizontal drilling hole. In addition, a drain outlet 69 is opened on the outer surface of the block 61 near the water supply port 67, slightly below the dividing line, and is connected to the return passage 65. Furthermore, a vertical drilled hole is formed at the other end of the passages 63, 65 via a horizontal drilled hole, connecting the passages 63, 65 to each other.

[0030] As a result, the refrigerant supplied from the water supply port 67 cools the area around the insertion hole 48 as shown by the solid arrows in Figures 5(1) and (2), then flows downward in the thickness direction of the block 61A, and as shown by the white arrow in Figure 5(1), passes through the return passage 65 and is discharged from the drain port 69, cooling the area around the insertion hole. Block 61B is configured in a similar manner.

[0031] Furthermore, the orifice can be made of a material with higher thermal conductivity than its surrounding components. For example, the orifice components can be made of a tungsten-based high specific gravity alloy for cooling purposes, or can be made of a material with high thermal conductivity, high cooling effect, and wear resistance.

[0032] Meanwhile, cooling means is also provided on the pressure pin 42 side of the second pressure means 38. The pin 42, which applies pressure to the molten metal discharged into the die-casting mold, is usually solid and cylindrical, but the cylindrical portion is hollow to form a cavity inside, a cylindrical pipe 62 is arranged along the centerline, and a return passage 64 is located a short distance from the tip, with a refrigerant passage 66 formed inside. A water supply port 68 leading to the cylindrical pipe 62 and a drain port 70 leading to the refrigerant passage 66 outside the cylindrical pipe 62 are formed at the bottom of the pressure pin 42, and the inlet is connected to the water supply port 68 and the outlet is connected to the drain port 70 to allow the refrigerant to flow. As a result, the refrigerant flows from the water supply port 68 through the internal cylindrical pipe 62, via the return passage 64, through the refrigerant passage 66, and out through the drain port 70.

[0033] As a result, the molten metal pushed by the pressure pin 42 is cooled by the cooling action of the outer surface of the pressure pin 42, and combined with the action of the half blocks 50A and 50B described above, the cooling effect at the orifice 44 is enhanced, and solidification of the thin-walled portion is promoted.

[0034] As described above, according to this embodiment, injection into cavity 20 is performed by first pressurizing means 30, and second pressurizing means 38 is activated when runner 32 is filled with molten metal. Pressurizing pin 42 performs a normal extrusion action while reaching the intersection (FIGS. 3A-3B) of flow-diverter runner portion 34 and rising runner portion 36. However, as soon as flow-diverter runner portion 34 breaks and reaches rising runner portion 36, it reaches annular protrusion 46, where the molten metal solidifies in gap δ due to the metal seal, interrupting the pressure (FIG. 3(2)). Therefore, the unsolidified molten metal on the cavity 20 side, located above pressurizing pin 62, is pushed toward cavity 20 against the backdrop of the interrupted pressure.

[0035] At this time, when the diverter runner portion 34 is blocked by the pressurizing action of the pressurizing pin 42 and the molten metal reaches the rising runner portion 36, it is inserted between the outer peripheral surface of the pressurizing pin 42 and the inner surface of the orifice 44 in the rising runner portion 36, and solidifies due to the cooling action of the half blocks 50A, 50B (or 61A, 61B) that form the orifice 44, combined with the cooling action from the internal refrigerant passage 66 of the pressurizing pin 42, and the molten metal in the center of the cavity 20, just before solidification, is pressurized under high pressure and densified. In this way, cooling action occurs simultaneously in the orifice 44 portion and the pressurizing pin 42 portion, and cooling begins early due to the actions of both, thereby enhancing the molten metal shielding effect in the portion that solidifies early.

[0036] Furthermore, this technique is not limited to the configuration shown in the figure, but can also be applied to devices that apply local pressure. [Industrial Applicability]

[0037] In the present invention, the die-casting manufacturing apparatus extrudes and molds molten metal into a cavity by the plunger pressure action of the first pressure means, and then subsequently pressurizes the runner by the second pressure means, and the molten metal already formed in the cavity can be cooled by the orifice portion and the pressure pin of the second pressure means. [Explanation of symbols]

[0038] 10... Die-casting manufacturing apparatus, 12... Moving platen, 14... Movable mold, 16... Fixed platen, 18... Fixed mold, 20... Cavity, 22... Ejector pin, 24... Melt supply means, 26... Injection sleeve, 28... Plunger, 30... First pressure means, 32... Runner, 34... Diverter runner portion, 36... Rising runner portion, 38... Second pressure means, 40... Actuator, 42... Pressure pin, 44... ...Orifice, 46...Annular protrusion, 48...Through hole, 50A...Half block, 50B...Half block, 52a...Upper block, 52b...Lower block, 54...Water channel, 56...Water channel wall, 58...Water supply port, 59...Welding, 63...Refrigerant passage, 65...Return passage, 67...Water supply port, 69...Drain port, 60...Drain port, 62...Cylindrical tube, 64...Return passage, 66...Refrigerant passage, 68...Water supply port, 70...Drain port.

Claims

1. In a die casting manufacturing apparatus provided with a first pressurizing means for injecting molten metal into a die casting mold and a second pressurizing means having a pin for pressurizing a passage directly connected to a cavity, An orifice is provided in the pressurizing path of the second pressurizing means, and the molten metal is shielded at the orifice portion, A die-casting manufacturing apparatus characterized in that a refrigerant passage is formed in the orifice component, and a cooling medium is supplied to this refrigerant passage.

2. 2. The die-casting manufacturing apparatus according to claim 1, wherein the orifice is a semicircular annular protrusion attached to the movable mold and the fixed mold, and each semicircular annulus is provided with a refrigerant passage and an inlet and an outlet.

3. In a die casting manufacturing apparatus provided with a first pressurizing means for injecting molten metal into a die casting mold and a second pressurizing means having a pin for pressurizing a passage directly connected to a cavity, An orifice is provided in the pressurizing path of the second pressurizing means, and the molten metal is shielded at the orifice portion, A die-casting manufacturing apparatus characterized in that a pressure pin of the second pressure means that passes through the orifice has a refrigerant passage formed therein, and a cooling medium is supplied to this refrigerant passage.

4. 4. The die-casting manufacturing apparatus according to claim 3, wherein the refrigerant passage is a double passage in which a pipe is inserted into a passage hole formed in the pressure pin, and the cooling effect is enhanced by connecting an inlet to the inner pipe and an outlet to the outer passage hole.

5. In a die casting manufacturing apparatus provided with a first pressurizing means for injecting molten metal into a die casting mold and a second pressurizing means having a pin for pressurizing a passage directly connected to a cavity, An orifice is provided in the pressurizing path of the second pressurizing means, and the molten metal is shielded at the orifice portion, A refrigerant passage is formed in the orifice component, and a cooling medium is supplied to the refrigerant passage; A die-casting manufacturing apparatus characterized in that a pressure pin of the second pressure means that passes through the orifice has a refrigerant passage formed therein, and a cooling medium is supplied to this refrigerant passage.

6. This orifice for die casting is an orifice that shields molten metal and is installed in a die casting manufacturing device that has, in addition to a first pressurizing means that injects molten metal into a die casting mold, a second pressurizing means having a pin that pressurizes a passage directly connected to a cavity, and in which a refrigerant passage is formed in the orifice component, making it possible to supply a cooling medium to this refrigerant passage.

7. 7. The die-casting orifice according to claim 6, wherein the orifice is semi-annular and attached to the fixed mold and the movable mold, respectively, and each of the orifices is composed of an inner refrigerant passage and an outer return passage.

8. 8. The die-cast orifice according to claim 7, wherein the orifice is divided into upper and lower parts in the direction in which the pressure pin passes, and a refrigerant passage and a return passage are formed on the mating surfaces of the upper and lower parts, and the two passages are bonded together.

9. 8. The die-cast orifice according to claim 7, wherein drilled holes are provided to form a refrigerant passage and a return passage above and below, the two passages are connected by a communication passage at one end, and an inlet and an outlet of the refrigerant passage are provided at the other end.

10. In a die casting manufacturing apparatus provided with a first pressurizing means for injecting molten metal into a die casting mold and a second pressurizing means having a pin for pressurizing a passage directly connected to a cavity, An orifice is provided in the pressurizing path of the second pressurizing means, and the molten metal is shielded at the orifice portion, A die-casting manufacturing apparatus characterized in that the components of the orifice are made of a material having higher thermal conductivity than the surrounding members.

11. 11. The die-casting manufacturing apparatus according to claim 10, wherein the orifice components are cooled by a tungsten-based high specific gravity alloy, which has high thermal conductivity, a high cooling effect, and is wear-resistant.

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