Mold Equipment

Abstract

To suppress, in a metal mold device, damages to a plurality of projections for inhibiting foreign matters from coming to be mixed into a cavity.SOLUTION: A die-casting metal mold device having a cavity formed therein, comprises a mold member that forms at least part of a cavity and has a plurality of projections formed in at least part of a surrounding of a gate being an entrance for melt into the cavity. The plurality of projections protrude toward an interior of the cavity. The plurality of projections have an upstream portion positioned upstream of a flow of melt, protruding from a bottom of a depression formed in the mold member and having a depth in a direction intersecting with a direction of flow.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a die apparatus for die casting. [Background technology]

[0002] In die casting, molten metal (molten metal), such as aluminum, is supplied from an injection sleeve to a cavity formed inside a mold assembly. Generally, an initially solidified layer forms on the inner circumferential surface of the injection sleeve. If foreign matter, such as initially solidified pieces or an oxide film formed on the surface of the molten metal, is supplied into the cavity along with the molten metal, these may be mixed into the casting. As a result, defects such as cracks originating from the initially solidified pieces, irregularities on the machined surface, and linear defects may occur. Therefore, a member with multiple protrusions is sometimes provided near the gate (pouring port) of the mold assembly to prevent foreign matter from being mixed into the cavity. Patent Document 1 proposes providing such a member, a comb-shaped blocking member, in a runner (molten metal flow path). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 7-204821 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the blocking member of Patent Document 1, the protruding comb teeth come into contact with high-temperature molten metal, and thermal stress caused by a sudden temperature change can cause the comb teeth to crack from their bases, which can lead to the comb teeth being chipped and contaminating the product. Therefore, a technology is desired that can prevent damage to the multiple protruding parts that prevent foreign matter from entering the cavity in a mold device. [Means for solving the problem]

[0005] The present disclosure can be realized in the following forms.

[0006] (1) According to one aspect of the present disclosure, there is provided a die apparatus for die casting in which a cavity is formed, the die apparatus comprising a die member forming at least a portion of the cavity, the die member having a plurality of protrusions formed at least partially around a gate that is an inlet for molten metal into the cavity, the plurality of protrusions protruding into the cavity, and upstream portions of the plurality of protrusions located upstream of a flow of the molten metal protruding from a bottom of a recess formed in the die member, the recess having a depth direction intersecting with the flow of the molten metal. According to this form of mold apparatus, the upstream portions of the multiple protrusions, which are portions located upstream of the flow of molten metal, protrude from the bottom of a recess formed in the mold member, the recess having a depth direction intersecting the flow of molten metal, thereby preventing the molten metal flowing in from the gate from directly contacting the base portions of the multiple protrusions, thereby preventing damage to the multiple protrusions, such as cracks at the base portions of the multiple protrusions or breakage of the protrusions from the base portions, that would otherwise occur due to such direct contact. (2) In the mold apparatus of the above embodiment, a downstream portion, which is a portion of the plurality of protrusions located downstream in the flow, may protrude from the bottom of the recess together with the upstream portion. According to this form of mold device, the downstream portion, which is the portion of the multiple protrusions located downstream of the flow, protrudes from the bottom of the recess together with the upstream portion, thereby preventing the molten metal from coming into direct contact with the base portion of the downstream portion, thereby further reducing damage to the multiple protrusions. (3) In the mold device of the above aspect, in each of the protruding portions, a surface that intersects with the flow direction may have a tapered shape that gradually becomes narrower along the protruding direction when viewed in the flow direction. According to this form of mold device, in each protrusion, the surface that intersects with the flow direction has a tapered shape that gradually becomes thinner along the protrusion direction when viewed in the flow direction, so damage to multiple protrusions caused by collision of molten metal can be better suppressed compared to a configuration in which the shape gradually becomes thicker along the protrusion direction or a configuration in which the thickness is uniform along the protrusion direction. (4) In the mold device of the above embodiment, a fixed mold, a movable mold, and a cylindrical sprue bushing that functions as the mold member and is fixed to the fixed mold for use, the sprue bushing having the gate facing the cavity and a molten metal flow path communicating with an injection sleeve that supplies the molten metal to the mold device, the gate facing the lowest part of the cavity, and the plurality of protrusions Our Upward and surrounding only the of Our At least one Department They may also be arranged in a circular arc so as to surround the area. According to this form of mold device, the gate and the plurality of protrusions are formed on a sprue bushing that is different from the fixed mold and the movable mold, so that parts that are easily deteriorated by the injection of molten metal or the collision of foreign matter can be easily replaced. Our Upward and surrounding only the of Our At least one Department Since the protrusions are arranged in an arc-shaped arrangement surrounding the sprue bushing, the protrusions are provided in positions that are necessary for removing foreign matter based on the flow of molten metal, and protrusions are not provided in locations where there is little need for protrusions, such as below the gate, so deterioration of the sprue bushing over time can be suppressed, and the manufacture of the sprue bushing can be simplified, reducing manufacturing costs. (5) In the mold device of the above form, the fixed mold may have a general-purpose mold and a dedicated mold located above the general-purpose mold, and the sprue bush may be arranged sandwiched between the general-purpose mold and the dedicated mold in the vertical direction. According to this type of mold device, the sprue bushing is sandwiched vertically between the general-purpose mold and the dedicated mold, so that displacement of the sprue bushing due to the impact of the injection of molten metal, etc., can be suppressed. The present disclosure may be realized in various forms, such as a die-casting apparatus, a die-casting method, and a sprue bushing device. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is an explanatory diagram schematically illustrating a die casting apparatus to which a die apparatus according to an embodiment of the present disclosure is applied; [Figure 2] FIG. 2 is a perspective view showing a sprue bushing. [Figure 3] FIG. 2 is a perspective view showing a sprue bushing. [Figure 4] FIG. 2 is a perspective view showing a sprue bushing. [Figure 5] FIG. 2 is a plan view showing a sprue bushing. [Figure 6] FIG. 2 is a partial cross-sectional view of a sprue bushing. [Figure 7] FIG. 4 is a perspective view schematically illustrating a detailed configuration of a protrusion. [Figure 8] FIG. 10 is an explanatory diagram illustrating the effect of providing a recess. [Figure 9] FIG. 10 is an enlarged schematic view showing a protruding portion of a sprue bushing of a comparative example. [Figure 10] FIG. 10 is an enlarged schematic view showing the vicinity of a protrusion in a sprue bushing according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] A. First embodiment: A1. Overall structure: FIG. 1 is an explanatory diagram schematically illustrating a die casting apparatus 10 to which a die assembly 100 according to an embodiment of the present disclosure is applied. The die casting apparatus 10 is an apparatus for producing a casting by pouring molten metal (molten metal) into a cavity 190 formed by the die assembly 100. In this embodiment, the molten metal used in the die casting apparatus 10 is molten aluminum. Note that the molten metal is not limited to aluminum, and any type of metal may be used. FIG. 1 illustrates an X-axis, a Y-axis, and a Z-axis that are perpendicular to each other. In this embodiment, the -Z direction corresponds to the vertically downward direction. Note that the X-, Y-, and Z-axes in other figures correspond to the X-, Y-, and Z-axes in FIG. 1. In this embodiment, the "X-axis direction" collectively refers to the +X-direction and the -X-direction.

[0009] The die casting apparatus 10 includes a mold device 100, a sprue bushing 150, an injection sleeve 200, a plunger 250, a rod 260, a pressure reducing device 300, and a pressure reducing valve 310.

[0010] The mold assembly 100 includes a movable mold 110 and a fixed mold 120. The movable mold 110 is configured to be movable by a hydraulic device (not shown) during mold clamping and mold opening. An opening is formed in the end face of the movable mold 110 in the -X direction, in other words, the end face facing the fixed mold 120, and a recess is formed continuous with the opening. A cavity 190 is formed inside the mold assembly 100 by closing the opening with the fixed mold 120. A pressure passage 111 is formed inside the movable mold 110 and communicates with the recess that forms part of the cavity 190. In this embodiment, the die casting apparatus 10 performs die casting using a method known as vacuum die casting or reduced-pressure die casting. The pressure passage 111 is used as a passage for discharging air from the cavity 190 when the pressure inside the cavity 190 is reduced.

[0011] The fixed mold 120 includes a dedicated mold 130 and a general-purpose mold 140. The dedicated mold 130 is disposed opposite the movable mold 110 in the X-axis direction and forms part of the cavity 190. The dedicated mold 130 is a mold component provided specifically for each casting to form the cavity 190 shape that matches the shape of the casting. Therefore, it can be replaced whenever the type of casting changes. The dedicated mold 130 is disposed above the general-purpose mold 140. The general-purpose mold 140 is disposed opposite the movable mold 110 in the X-axis direction. However, unlike the dedicated mold 130, it does not form the cavity 190. The general-purpose mold 140 supports the dedicated mold 130 and serves to fix the sprue bushing 150.

[0012] The sprue bushing 150 is a cylindrical member, one end of which has a molten metal flow path 153 that functions as the gate Gt. The sprue bushing 150 has the function of forming the gate Gt and the function of controlling the temperature of the molten metal flow path 153. Such temperature control is achieved, for example, by flowing a cooling medium through a cooling medium flow path formed in the sprue bushing 150. The sprue bushing 150 is sandwiched vertically between the dedicated mold 130 and the general-purpose mold 140. The sprue bushing 150 is removably fixed to the general-purpose mold 140. The detailed configuration of the sprue bushing 150 will be described later. In this embodiment, the sprue bushing 150 corresponds to the "mold member" in this disclosure.

[0013] The injection sleeve 200 is a cylindrical member, and one end (the end in the +X direction) is connected to an opening in the sprue bushing 150 (a central opening in a flange portion 152, which will be described later). The injection sleeve 200 is provided with a pouring port 210. The plunger 250 is disposed within the injection sleeve 200 so as to be movable back and forth in the X-axis direction. By moving forward, the plunger 250 injects the molten metal poured into the injection sleeve 200 into the cavity 190 via the sprue bushing 150. Specifically, the plunger 250 is connected to a hydraulic device (not shown) via a rod 260 connected to the rear end. The plunger 250 moves forward or backward by the driving force of the hydraulic device. FIG. 1 shows the forward direction, which is the direction in which the plunger 250 approaches the mold assembly 100, and the backward direction, which is the opposite direction.

[0014] The pressure reducing device 300 is connected to a pressure path 111 provided in the movable mold 110, and reduces the pressure in the cavity 190 through the pressure path 111. The pressure reducing device 300 may be configured, for example, by a vacuum pump. A pressure reducing valve 310 is provided in the pressure path 111. When the pressure inside the cavity 190 is reduced, the pressure reducing valve 310 is opened and the air inside the cavity 190 is discharged by the pressure reducing device 300. The pressure reducing device 300 and the pressure reducing valve 310 are electrically connected to a control device (not shown), and their operations are controlled by the control device.

[0015] A2.Detailed configuration of Sprue Bush 150: 2, 3, and 4 are perspective views showing sprue bushing 150. Fig. 5 is a plan view showing sprue bushing 150 as viewed in the -X direction. Fig. 6 is a partial cross-sectional view of sprue bushing 150. Fig. 6 shows a cross section taken along line VI-VI shown in Fig. 5.

[0016] 2 to 5, the sprue bushing 150 has a cylindrical external shape with a central axis CX parallel to the X-axis direction. The sprue bushing 150 includes a main body portion 151, a flange portion 152, and a plurality of protrusions 155.

[0017] The main body 151 has a cylindrical external shape and has a molten metal flow path 153 formed therein. The molten metal flow path 153 communicates with the interior of the injection sleeve 200. A coolant flow path (not shown) is formed inside the main body 151. The flange 152 has a larger outer diameter than the main body 151. The flange 152 is connected to the end of the main body 151 in the -X direction. The sprue bushing 150 is fixed to the fixed mold 120 (general-purpose mold 140) at the flange 152 with a pair of bolts 154.

[0018] As shown in FIGS. 3 and 4 , a notch 158 having an arc shape in plan view is provided in an upper portion of an end 157 in the +X direction of the sprue bushing 150. An end surface S1 in the +X direction of the end 157 contacts an end surface in the −X direction of the movable die 110. Therefore, the molten metal flowing through the molten metal flow path 153 moves upward through the notch 158 and is supplied into the cavity 190. In other words, a portion of the notch 158 close to the molten metal flow path 153 functions as the gate Gt. The notch 158 is provided with a plurality of protrusions 155. The protrusions 155 are arranged in a circular arc shape in plan view at predetermined intervals in a portion around the gate Gt, specifically, above the gate Gt. In other words, the protrusions 155 are arranged in a comb-like shape above the gate Gt.

[0019] As is clear from FIG. 6 , the multiple protrusions 155 protrude from the bottom Bt of the recess 156. The depth direction of the recess 156 is parallel to the X-axis direction. In the gate Gt, the direction in which the molten metal flows (hereinafter also referred to as the "flow direction") is upward, i.e., the +Z direction, as described above. Therefore, the depth direction of the recess 156 can be said to be perpendicular to the flow direction. In this embodiment, the depth dimension of the recess 156 is a value that is a ratio in the range of 10% or more and less than 20% of the protrusion height of the protrusion 155, i.e., the dimension in the X-axis direction. Note that the value may be a ratio greater than 0% and less than 10%, or may be a value of 20% or more.

[0020] 7 is a perspective view that schematically illustrates the detailed configuration of the protrusions 155. In FIG. 7, one protrusion 155 is shown enlarged, and the flow direction D1 is indicated by a white arrow. Because the protrusion 155 protrudes from the bottom Bt of the recess 156, a tip portion 161 of the protrusion 155 is exposed within the cavity 190 when viewed in the flow direction D1. On the other hand, because a base portion 162 of the protrusion 155 is contained within the recess 156, it is not exposed within the cavity 190 when viewed in the flow direction D1.

[0021] In the protrusion 155, the surface S2 intersecting with the flow direction D1 has a tapered shape that gradually becomes narrower along the protrusion direction, i.e., the +X direction. The further away from the base portion 162 along the +X direction, the greater the stress that may be applied to the base portion when the supplied molten metal collides. Therefore, by forming the surface S2 of the protrusion 155 in the tapered shape described above, excessive stress is prevented from being applied to the base portion of the protrusion 155 when the molten metal collides, thereby preventing damage to the protrusion 155.

[0022] FIG. 8 is an explanatory diagram illustrating the effect of providing the recess 156. FIG. 8 schematically illustrates an enlarged view of the protrusion 155 and the recess 156 as viewed in the −Y-axis direction. The molten metal flowing from the gate Gt into the cavity 190, i.e., the molten metal flowing in the flow direction D1, collides with the upstream portion UP of the protrusion 155, which is located upstream of the flow direction D1. As described above, the base portion 162 of the protrusion 155 is not exposed from the cavity 190 when viewed in the flow direction D1. Therefore, the molten metal flowing from the gate Gt into the cavity 190 collides with the tip portion 161 of the upstream portion UP, and collision with the root portion 162 is suppressed. The tip portion 161 has a similar shape that continues along both the X-axis and the Z-axis. Therefore, when the molten metal collides, stress concentration at any one location is suppressed, and damage such as cracking of the protrusion 155 is suppressed. In this embodiment, the base portion of the downstream portion DP of the protruding portion 155 is also housed in the recess 156. Therefore, even if a downward flow of molten metal occurs, damage to the protruding portion 155 is suppressed.

[0023] FIG. 9 is an enlarged schematic diagram of a protrusion 955 in a sprue bushing of a comparative example. Like the protrusion 155 of the embodiment, the protrusion 955 of the comparative example protrudes in the +X direction and is disposed within the cavity 990. The sprue bushing of the comparative example does not have a recess. Therefore, both a tip portion 961 and a base portion 962 of the protrusion 955 are exposed within the cavity 990 when viewed in the molten metal flow direction D9. Therefore, the molten metal supplied from the gate Gt impinges not only on the tip portion 961 but also on the base portion 962. Because the base portion 962 is perpendicular to the plane of the notch 958, impingement of the molten metal on the base portion 962 may result in a crack CK occurring at the boundary between the base portion 962 and the notch 958.

[0024] On the other hand, in the sprue bushing 150 of this embodiment, as described above, the root portion 162 is not exposed within the cavity 190 when viewed in the flow direction D1, and therefore, direct collision of the molten metal with the root portion 162 can be prevented, thereby preventing damage to the protrusion 155.

[0025] According to the mold apparatus 100 of the first embodiment described above, the upstream portions UP of the multiple protrusions 155 located on the upstream side of the flow of the molten metal protrude from the bottom Bt of the recess 156 formed in the sprue bushing 150, the recess 156 having a depth direction intersecting the flow direction D1 of the molten metal, and therefore, it is possible to prevent the molten metal flowing from the gate Gt from directly contacting the base portions 162 of the multiple protrusions 155. This makes it possible to prevent cracks from occurring in the base portions 162 of the multiple protrusions 155 or the protrusions 155 from breaking at the base portions 162 due to such direct contact.

[0026] Furthermore, the downstream portion DP, which is located downstream of the flow among the multiple protrusions 155, protrudes from the bottom Bt of the recess 156 together with the upstream portion UP, thereby preventing the molten metal from coming into direct contact with the base portion of the downstream portion DP, thereby further reducing damage to the multiple protrusions 155.

[0027] Furthermore, in each protrusion 155, the surface S2 that intersects with the flow direction D1 has a tapered shape that gradually becomes thinner along the protrusion direction (+X direction) when viewed in the flow direction D1. This makes it possible to better suppress damage to the multiple protrusions 155 caused by the collision of molten metal compared to a configuration in which the shape gradually becomes thicker along the protrusion direction or a configuration in which the thickness is constant along the protrusion direction.

[0028] Furthermore, because the gate Gt and the multiple protrusions 155 are formed on sprue bushing 150 that are different from those on fixed mold 120 and movable mold 110, parts that are prone to deterioration due to injection of molten metal, collision of foreign matter, etc. can be easily replaced. Furthermore, because gate Gt faces the lowest part of cavity 190 and the multiple protrusions 155 are arranged in an arc shape so as to surround only at least a portion of the upper part of gate Gt, protrusions are provided in positions necessary for removing foreign matter based on the flow of molten metal, and protrusions 155 are not provided in locations where protrusions 155 are less necessary, such as below gate Gt, deterioration of sprue bushing 150 over time can be suppressed, and manufacturing of sprue bushing 150 can be simplified, reducing manufacturing costs.

[0029] Furthermore, since the sprue bushing 150 is sandwiched between the general-purpose mold 140 and the dedicated mold 130 in the vertical direction, it is possible to prevent the sprue bushing 150 from shifting in position due to the impact of the injection of molten metal, for example.

[0030] B. Second embodiment: 10 is an enlarged schematic view showing the vicinity of the protruding portion 155a in the sprue bushing 150 of the second embodiment. The mold apparatus 100 of the second embodiment differs from the sprue bushing 150 of the first embodiment in that a plurality of protruding portions 155a are provided instead of the plurality of protruding portions 155, and in that a recess 156a is provided instead of the recess 156. The other configuration of the mold apparatus 100 of the second embodiment is the same as that of the first embodiment, so the same components are denoted by the same reference numerals and detailed description thereof will be omitted.

[0031] 10, the recess 156a of the second embodiment is formed only on the upstream side of the plurality of protrusions 155a in the flow direction D1, and is not provided on the downstream side. Therefore, in the protrusions 155a of the second embodiment, the base portion of the downstream portion DP is not connected to the bottom of the recess, but is directly connected to the notch 158.

[0032] Even in this configuration, the base portion 162 of the upstream portion UP protrudes from the bottom Bt of the recess 156a. Therefore, the mold apparatus 100 of the second embodiment has the same effects as the mold apparatus 100 of the first embodiment.

[0033] C. Other Embodiments: (C1) In each embodiment, the multiple protrusions 155, 155a are all provided on the sprue bushing 150, but the present disclosure is not limited to this. They may also be provided on the dedicated mold 130 or the general-purpose mold 140. By providing the multiple protrusions 155, 155a on the dedicated mold 130, the distance from the gate Gt to the protrusions 155, 155a can be made longer than in a configuration in which the protrusions are provided on the sprue bushing 150, and melting damage to the protrusions 155, 155a can be suppressed. Furthermore, in a configuration in which the multiple protrusions 155, 155a are provided on the general-purpose mold 140, a cylindrical through-hole may be formed in the general-purpose mold 140, and the sprue bushing 150 may be inserted and fixed into the through-hole.

[0034] (C2) In each embodiment, the surface S2 of the multiple protrusions 155, 155a has a tapered shape that gradually narrows along the protrusion direction (+X direction) when viewed in the flow direction D1, but the present disclosure is not limited to this. The surface S2 may have a shape that gradually widens along the protrusion direction, or a configuration in which the thickness is constant along the protrusion direction.

[0035] (C3) In each embodiment, the multiple protrusions 155, 155a are arranged side by side above the gate Gt in an arc-like shape in plan view, with a predetermined interval between them. However, the present disclosure is not limited to this. For example, in a configuration in which the notch provided in the +X-direction end 157 of the sprue bushing 150 is formed around the entire periphery of the end opening of the molten metal flow path 153 and the end surface S1 of the end 157 does not contact the movable mold 110, the protrusions 155, 155a may be arranged side by side or below the gate Gt in an arc-like shape in plan view, with a predetermined interval between them, rather than being limited to being arranged above the gate Gt. That is, they may generally be arranged around at least a portion of the periphery of the gate Gt.

[0036] (C4) The mold apparatus 100 of each embodiment is merely an example and can be modified in various ways. For example, the depth direction of the recesses 156, 156a is perpendicular to the flow direction D1, but it may intersect at any angle other than 90 degrees.

[0037] The present disclosure is not limited to the above-described embodiments and can be realized in various configurations without departing from the spirit thereof. For example, the technical features in each embodiment corresponding to the technical features in each aspect described in the Summary of the Invention section can be appropriately replaced or combined to solve some or all of the above-described problems or achieve some or all of the above-described effects. Furthermore, if a technical feature is not described as essential in this specification, it can be appropriately deleted. [Explanation of symbols]

[0038] 10... Die-casting apparatus, 100... Mold device, 110... Movable mold, 111... Pressure path, 120... Fixed mold, 130... Dedicated mold, 140... General-purpose mold, 150... Sprue bush, 151... Main body, 152... Flange portion, 153... Molten metal flow path, 154... Bolt, 155... Protrusion, 155a... Protrusion, 156... Recess, 156a... Recess, 157... End, 158... Notch, 161... Tip portion, 162... Root Base portion, 190...cavity, 200...injection sleeve, 210...spruing port, 250...plunger, 260...rod, 300...pressure reducing device, 310...pressure reducing valve, 955...protrusion, 958...notch, 961...tip portion, 962...root portion, Bt...bottom, CK...crack, CX...center axis, D1...flow direction, D9...flow direction, DP...downstream portion, Gt...gate, S1...end face, S2...face, UP...upstream portion

Claims

1. A die casting mold apparatus in which a cavity is formed, a mold member that forms at least a part of the cavity, the mold member having a plurality of protrusions formed at least partly around a gate that is an inlet for molten metal into the cavity; the plurality of protrusions protrude into the cavity, an upstream portion, which is a portion of the plurality of protrusions located upstream of the flow of the molten metal, protrudes from a bottom of a recess formed in the mold member, the recess having a depth direction intersecting with the direction of the flow of the molten metal; Mold equipment.

2. The mold apparatus according to claim 1, A downstream portion, which is a portion of the plurality of protrusions located downstream in the flow, protrudes from the bottom of the depression together with the upstream portion. Mold equipment.

3. The mold apparatus according to claim 1, In each of the protrusions, a surface intersecting the flow direction has a tapered shape that gradually becomes narrower along the protrusion direction when viewed in the flow direction. Mold equipment.

4. The mold apparatus according to any one of claims 1 to 3, a fixed mold, a movable mold, and a cylindrical sprue bushing that functions as the mold member and is fixed to the fixed mold when in use; the sprue bushing has the gate facing the cavity and a molten metal flow path communicating with an injection sleeve that supplies the molten metal to the mold device, the gate faces the bottom of the cavity; The plurality of protrusions are arranged in an arc shape so as to surround only an upper portion of the gate and to surround at least a portion of the upper portion. Mold equipment.

5. The mold apparatus according to claim 4, The fixed mold has a general-purpose mold and a dedicated mold located above the general-purpose mold, the sprue bushing is disposed between the general-purpose mold and the dedicated mold in the vertical direction. Mold equipment.

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