JP2023161746A - Metal mold device - Google Patents

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

The present disclosure relates to a mold apparatus for die casting.

In die casting, molten metal such as aluminum is supplied from an injection sleeve to a cavity formed inside a mold device. Generally, an initially solidified layer is formed on the inner peripheral 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 together with the molten metal, there is a risk that these will be mixed into the inside of the cast product. 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 having a plurality of protrusions is sometimes provided near the gate (casting port) of the mold device in order to suppress foreign matter from entering the cavity. As such a member, Patent Document 1 proposes providing a comb-shaped blocking member in a runner (molten metal flow path).

Japanese Patent Application Publication No. 7-204821

However, in the blocking member of Patent Document 1, the protruding comb teeth come into contact with the high-temperature molten metal, so the comb teeth may crack from their roots due to thermal stress caused by sudden temperature changes, and in some cases, the comb teeth may break. There may also be problems such as defects and contamination in products. Therefore, in a mold device, a technique is desired that can suppress damage to a plurality of protrusions for suppressing foreign matter from entering the cavity.

The present disclosure can be realized as the following forms.

(1) According to one embodiment of the present disclosure, a die device for die casting in which a cavity is formed is provided. This mold device is a mold member that forms at least a part of the cavity, and has a plurality of protrusions formed at least in part around a gate that is an entrance of molten metal into the cavity. The plurality of protrusions protrude into the cavity, and an upstream portion of the plurality of protrusions that is located on the upstream side of the flow of the molten metal is a depression formed in the mold member. It protrudes from the bottom of the depression whose depth direction is the direction intersecting the flow.
According to this type of mold device, the upstream portion, which is a portion of the plurality of protrusions located on the upstream side of the flow of molten metal, is a depression formed in the mold member in a direction crossing the flow of molten metal. Since it protrudes from the bottom of the depression whose depth direction is , it is possible to prevent the molten metal flowing in from the gate from coming into direct contact with the root portions of the plurality of protrusions. Therefore, damage to the plurality of protrusions, such as cracks occurring at the root portions of the plurality of protrusions or breakage of the protrusions from the root portions, due to such direct contact can be suppressed.
(2) In the mold device of the above embodiment, a downstream portion, which is a portion of the plurality of protrusions located on the downstream side of the flow, may protrude from the bottom of the depression together with the upstream portion.
According to this type of mold device, the downstream part, which is a part located on the downstream side of the flow among the plurality of protrusions, protrudes from the bottom of the recess together with the upstream part, so that the molten metal does not reach the root part of the downstream part. Direct contact can be suppressed, and damage to the plurality of protrusions can be further suppressed.
(3) In the mold device of the above embodiment, in each of the protrusions, a surface that intersects with the flow direction may have a tapered shape that gradually becomes thinner along the protrusion direction when viewed in the flow direction. .
According to this type 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 from the flow direction. Damage to the plurality of protrusions caused by collisions of molten metal can be more suppressed compared to a configuration in which the thickness gradually increases along the protrusion direction or a configuration in which the thickness is uniform along the protrusion direction.
(4) The mold device of the above embodiment includes a fixed mold, a movable mold, and a cylindrical sprue bush that functions as the mold member and is used while being fixed to the fixed mold, and the sprue bush includes: the gate facing the cavity; and a molten metal flow path communicating with an injection sleeve for supplying the molten metal to the mold apparatus, the gate facing a lowermost part of the cavity and connecting the plurality of protrusions. The portions may be arranged in an arc shape so as to surround at least a portion above the gate.
According to this type of mold device, the gate and the plurality of protrusions are formed on a sprue bush that is different from those of the fixed type and the movable type, so it is easy to remove parts that are likely to deteriorate due to injection of molten metal or collision with foreign objects. can be exchanged for Further, since the gate faces the lowest part of the cavity and the plurality of protrusions are arranged in an arc shape so as to surround at least a part of the upper part of the gate, In addition to providing the protrusions at the positions necessary for removing foreign matter, the protrusions are not provided in areas where the need for protrusions is low, such as below the gate, so deterioration of the sprue bushing over time can be suppressed, and the sprue The bush can be manufactured easily and manufacturing costs can be suppressed.
(5) In the mold device of the above aspect, the fixed mold has a general-purpose mold and a dedicated mold located above the general-purpose mold, and the sprue bushing is arranged between the general-purpose mold and the dedicated mold. They may be arranged to be sandwiched in the vertical direction.
According to this type of mold device, the sprue bushing is placed between the general-purpose mold and the dedicated mold in the vertical direction, so it is possible to suppress misalignment of the sprue bushing caused by the impact of molten metal injection. .
The present disclosure can also be implemented in various forms. For example, it can be realized in the form of a die-casting device, a die-casting method, a sprue bushing device, or the like.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram schematically showing a die casting device to which a mold device according to an embodiment of the present disclosure is applied. It is a perspective view showing a sprue bush. It is a perspective view showing a sprue bush. It is a perspective view showing a sprue bush. It is a top view showing a sprue bush. It is a partial sectional view of a sprue bush. FIG. 3 is a perspective view schematically showing the detailed configuration of a protrusion. It is an explanatory view explaining the effect of providing a depression. It is a schematic diagram which expands and shows the protrusion part in the sprue bush of a comparative example. FIG. 7 is an enlarged schematic diagram showing the vicinity of a protrusion in a sprue bushing according to a second embodiment.

A. First embodiment:
A1. overall structure:
FIG. 1 is an explanatory diagram schematically showing a die-casting apparatus 10 to which a mold apparatus 100 according to an embodiment of the present disclosure is applied. The die casting apparatus 10 is an apparatus that pours molten metal (molten metal) into a cavity 190 formed by a mold apparatus 100 to manufacture a cast product. 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 may be any type of molten metal. In FIG. 1, an X-axis, a Y-axis, and a Z-axis that are orthogonal to each other are shown. In this embodiment, the -Z direction corresponds to the vertically downward direction. Note that the XYZ axes in other figures correspond to the XYZ axes in FIG. In this embodiment, the "X-axis direction" is a general term for the +X direction and the -X direction.

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

The mold device 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 surface of the movable mold 110 in the -X direction, in other words, the end surface facing the fixed mold 120, and a concave portion continuing from the opening is formed. By closing this opening with the fixed mold 120, a cavity 190 is formed inside the mold device 100. A pressure path 111 is formed inside the movable mold 110 and communicates with the above-mentioned recess forming a part of the cavity 190. In this embodiment, the die-casting apparatus 10 performs die-casting by a method called a vacuum die-casting method or a reduced-pressure die-casting method. The pressure path 111 is used as a discharge path for air inside the cavity 190 when the pressure inside the cavity 190 is reduced.

The fixed mold 120 includes a dedicated mold 130 and a general-purpose mold 140. The dedicated mold 130 is arranged to face the movable mold 110 in the X-axis direction, and forms a part of the cavity 190. The dedicated mold 130 is a mold member provided exclusively for each cast product in order to form a cavity 190 shape that conforms to the shape of the cast product. Therefore, it can be replaced every time the type of casting changes. The dedicated mold 130 is arranged above the general-purpose mold 140. The general-purpose mold 140 is arranged to face the movable mold 110 in the X-axis direction. However, unlike the dedicated mold 130, a cavity 190 is not formed. The general-purpose mold 140 supports the dedicated mold 130 and also plays the role of fixing the sprue bushing 150.

The sprue bushing 150 is a cylindrical member and has a molten metal channel 153 at one end that functions as a gate Gt. The sprue bushing 150 has a function of forming a gate Gt and a function of controlling the temperature of the molten metal flow path 153. Such temperature control is achieved, for example, by allowing a cooling medium to flow through a cooling medium flow path formed within the sprue bushing 150. The sprue bush 150 is vertically sandwiched between the dedicated mold 130 and the general-purpose mold 140. Sprue bushing 150 is removably fixed to 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 a "mold member" in the present disclosure.

The injection sleeve 200 is a cylindrical member, and one end (the end in the +X direction) is connected to an opening of the sprue bushing 150 (a central opening of 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 in the X-axis direction, and by moving forward, the plunger 250 injects the molten metal injected 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. Then, the plunger 250 moves forward or backward by the driving force of the hydraulic system. FIG. 1 shows a forward direction in which the plunger 250 approaches the mold apparatus 100 and a backward direction in the opposite direction.

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 via the pressure path 111. The pressure reducing device 300 may be configured by, for example, 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 reduction valve 310 is opened, and the air inside the cavity 190 is discharged by the pressure reduction device 300. Note that 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.

A2. Detailed configuration of sprue bush 150:
2, 3 and 4 are perspective views showing the sprue bushing 150. FIG. 5 is a plan view showing the 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 VI-VI cross section shown in FIG.

As shown in FIGS. 2 to 5, the sprue bushing 150 has a cylindrical external shape with a central axis CX parallel to the X-axis direction. Sprue bushing 150 includes a main body portion 151, a flange portion 152, and a plurality of protrusions 155.

The main body portion 151 has a cylindrical external shape, and has a molten metal flow path 153 formed therein. Molten metal channel 153 communicates with the inside of injection sleeve 200 . A cooling medium flow path (not shown) is formed inside the main body portion 151 . The flange portion 152 has a larger outer diameter than the main body portion 151. The flange portion 152 is continuous with the end portion of the main body portion 151 in the −X direction. The sprue bushing 150 is fixed to the fixed mold 120 (general-purpose mold 140) by a pair of bolts 154 at the flange portion 152.

As shown in FIGS. 3 and 4, a notch 158 having an arcuate shape in plan view is provided in the upper portion of the end 157 of the sprue bushing 150 in the +X direction. An end surface S1 of the end portion 157 in the +X direction is in contact with an end surface of the movable mold 110 in the −X direction. Therefore, the molten metal flowing through the molten metal channel 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 a gate Gt. A plurality of protrusions 155 are provided in the notch 158 . The plurality of protrusions 155 are arranged in a part around the gate Gt, specifically, above the gate Gt, in an arc shape in a plan view at predetermined intervals. In other words, the plurality of protrusions 155 are arranged in a comb-teeth shape above the gate Gt.

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

FIG. 7 is a perspective view schematically showing the detailed configuration of the protrusion 155. As shown in FIG. In FIG. 7, one protrusion 155 is shown in an enlarged manner, and the flow direction D1 is shown by a white arrow. Since the protrusion 155 protrudes from the bottom Bt of the depression 156, the tip portion 161 of the protrusion 155 is exposed in the cavity 190 when viewed in the flow direction D1. On the other hand, the root portion 162 of the protrusion 155 is accommodated within the recess 156 and is therefore not exposed within the cavity 190 when viewed in the flow direction D1.

In the protruding portion 155, a surface S2 that intersects with the flow direction D1 has a tapered shape that gradually becomes thinner along the protruding direction, that is, the +X direction. As the distance from the root portion 162 increases along the +X direction, the stress applied to the root portion when the supplied molten metal collides may increase. Therefore, by making the surface S2 of the protruding part 155 into the tapered shape as described above, when the molten metal collides, excessive stress is suppressed from being applied to the root part of the protruding part 155, and the protruding part 155 is damaged. I try to refrain from doing that.

FIG. 8 is an explanatory diagram illustrating the effect of providing the depression 156. FIG. 8 schematically shows an enlarged view of the protrusion 155 and the depression 156 when viewed in the −Y-axis direction. The molten metal heading into the cavity 190 from the gate Gt, that is, the molten metal flowing in the flow direction D1, collides with the upstream portion UP of the protrusion 155 located on the upstream side in the flow direction D1. Here, as described above, the root portion 162 of the protrusion 155 is not exposed from the cavity 190 when viewed in the flow direction D1. Therefore, the molten metal heading into the cavity 190 from the gate Gt 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 in the X-axis direction and in the Z-axis direction. Therefore, when the molten metal collides, stress is prevented from concentrating on any part, and damage such as cracking in the protrusion 155 is suppressed. In this embodiment, the root portion of the downstream portion DP of the protrusion 155 is also accommodated in the recess 156. Therefore, even if a downward flow of molten metal occurs, damage to the protrusion 155 is suppressed.

FIG. 9 is an enlarged schematic diagram showing a protrusion 955 in a sprue bushing of a comparative example. The protruding part 955 included in the sprue bushing of the comparative example is arranged in the cavity 990 so as to protrude in the +X direction, similarly to the protruding part 155 of the embodiment. In the sprue bushing of the comparative example, no recess is provided, and therefore, the tip portion 961 and the root portion 962 of the protruding portion 955 are both exposed in the cavity 990 when viewed in the molten metal flow direction D9. There is. Therefore, the molten metal supplied from the gate Gt collides not only with the tip portion 961 but also with the root portion 962. Here, since the root portion 962 is perpendicular to the surface of the notch 958, if the molten metal collides with the root portion 962, there is a risk that a crack CK will occur from the boundary between the root portion 962 and the notch 958.

On the other hand, in the sprue bushing 150 of this embodiment, as described above, the root portion 162 is not exposed inside the cavity 190 when viewed in the flow direction D1, so that direct collision of the molten metal with the root portion 162 is prevented. Therefore, damage to the protrusion 155 can be suppressed.

According to the mold apparatus 100 of the first embodiment described above, the upstream portion UP located on the upstream side of the flow of molten metal in the plurality of protrusions 155 is the depression 156 formed in the sprue bushing 150 and is Since it protrudes from the bottom Bt of the depression 156 whose depth direction is the direction intersecting the flow direction D1, it is possible to prevent the molten metal flowing in from the gate Gt from coming into direct contact with the root portion 162 of the plurality of protrusions 155. . Therefore, it is possible to prevent cracks from occurring at the root portions 162 of the plurality of protrusions 155 or breakage of the protrusions 155 from the root portions 162 due to such direct contact.

Moreover, since the downstream part DP located on the downstream side of the flow in the plurality of protrusions 155 protrudes from the bottom part Bt of the depression 156 together with the upstream part UP, the molten metal directly contacts the root part of the downstream part DP. Therefore, damage to the plurality of protrusions 155 can be further suppressed.

In addition, in each protrusion 155, the surface S2 intersecting the flow direction D1 has a tapered shape that gradually becomes thinner along the protrusion direction (+X direction) when viewed from the flow direction D1. Compared to a configuration in which the thickness gradually increases along the protrusion direction or a configuration in which the thickness is constant along the protrusion direction, damage to the plurality of protrusions 155 caused by collisions of molten metal can be further suppressed.

In addition, since the gate Gt and the plurality of protrusions 155 are formed on a sprue bushing 150 that is different from the fixed mold 120 and the movable mold 110, parts that tend to deteriorate due to injection of molten metal, collision with foreign objects, etc. can be easily replaced. . Further, since the gate Gt faces the lowest part of the cavity 190, and the plurality of protrusions 155 are arranged in an arc shape so as to surround at least a portion above the gate Gt, the molten metal In addition to providing the protrusions at the positions necessary for removing foreign matter based on the flow, the protrusions 155 are not provided in areas where the need for the protrusions 155 is low, such as below the gate Gt. Deterioration can be suppressed, the manufacture of the sprue bushing 150 can be facilitated, and manufacturing costs can be suppressed.

In addition, since the sprue bushing 150 is vertically sandwiched between the general-purpose mold 140 and the dedicated mold 130, it is possible to suppress misalignment of the sprue bushing 150 caused by the impact of molten metal injection.

B. Second embodiment:
FIG. 10 is an enlarged schematic diagram showing the vicinity of the protrusion 155a in the sprue bushing 150 of the second embodiment. The mold device 100 of the second embodiment has the first feature in that a plurality of protrusions 155a are provided instead of the plurality of protrusions 155, and a recess 156a is provided instead of the recess 156. This is different from the sprue bush 150 of the embodiment. The other configurations of the mold apparatus 100 of the second embodiment are the same as those of the first embodiment, so the same components are denoted by the same reference numerals and detailed description thereof will be omitted.

As shown in FIG. 10, the depression 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 protruding portion 155a of the second embodiment, the root portion of the downstream portion DP is not connected to the bottom of the recess but directly connected to the notch portion 158.

Also in this configuration, the root portion 162 of the upstream portion UP protrudes from the bottom portion Bt of the recess 156a. Therefore, the mold device 100 of the second embodiment has the same effects as the mold device 100 of the first embodiment.

C. Other embodiments:
(C1) In each embodiment, the plurality of protrusions 155, 155a are both provided on the sprue bushing 150, but the present disclosure is not limited thereto. It may be provided in the dedicated mold 130 or the general purpose mold 140. By providing the plurality of protrusions 155, 155a in the dedicated mold 130, the distance from the gate Gt to the protrusions 155, 155a can be made longer than in the configuration in which the protrusions 155, 155a are provided in the sprue bushing 150, and the protrusions 155, 155a are prevented from being melted and damaged. can be suppressed. Further, in a configuration in which the plurality of protrusions 155, 155a are provided in the general-purpose mold 140, a cylindrical through hole may be provided in the general-purpose mold 140, and the sprue bushing 150 may be inserted and fixed into the through hole.

(C2) In each embodiment, the surface S2 of the plurality of protrusions 155, 155a has a tapered shape that becomes gradually thinner along the protrusion direction (+X direction) when viewed from the flow direction D1, but the present disclosure is not limited to this. The shape may be such that the thickness gradually increases along the protrusion direction, or the thickness may be constant along the protrusion direction.

(C3) In each of the embodiments, the plurality of protrusions 155, 155a are arranged in a circular arc shape in a plan view above the gate Gt at predetermined intervals, but the present disclosure is not limited thereto. . For example, a notch provided at the end 157 of the sprue bushing 150 in the +X direction is formed all around the end opening of the molten metal flow path 153, and the end surface S1 of the end 157 is in contact with the movable mold 110. In a configuration in which the gates are not provided, they may be arranged not only above the gate Gt but also on the sides and below, in an arc shape in a plan view, spaced apart by a predetermined interval. That is, in general, it may be arranged at least partially around the gate Gt.

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

The present disclosure is not limited to the embodiments described above, and can be implemented in various configurations without departing from the spirit thereof. For example, the technical features in each embodiment that correspond to the technical features in each form described in the column of the summary of the invention may be used to solve some or all of the above-mentioned problems, or to achieve the above-mentioned effects. In order to achieve some or all of the above, it is possible to perform appropriate replacements or combinations. Further, unless the technical feature is described as essential in this specification, it can be deleted as appropriate.

DESCRIPTION OF SYMBOLS 10... Die casting equipment, 100... Mold device, 110... Movable type, 111... Pressure path, 120... Fixed type, 130... Special type, 140... General purpose type, 150... Sprue bushing, 151... Main body part, 152... Flange Part, 153... Molten metal channel, 154... Bolt, 155... Protrusion, 155a... Protrusion, 156... Recess, 156a... Recess, 157... End, 158... Notch, 161... Tip portion, 162... Root portion, 190... Cavity, 200... Injection sleeve, 210... Pouring port, 250... Plunger, 260... Rod, 300... Pressure reducing device, 310... Pressure reducing valve, 955... Protrusion, 958... Notch, 961... Tip portion, 962... Root Part, Bt...Bottom, CK...Crack, CX...Central axis, D1...Flow direction, D9...Flow direction, DP...Downstream part, Gt...Gate, S1...End face, S2...Surface, UP...Upstream part

Claims (5)

A mold device for die casting in which a cavity is formed,
A mold member forming at least a part of the cavity, the mold member having a plurality of protrusions formed at least in part around a gate that is an entrance of molten metal into the cavity,
The plurality of protrusions protrude into the cavity,
The upstream portion, which is a portion located on the upstream side of the flow of the molten metal in the plurality of protrusions, is a depression formed in the mold member, and the depth direction is a direction that intersects with the direction of the flow. protruding from the bottom of the depression,
Mold equipment. The mold device according to claim 1,
A downstream part, which is a part of the plurality of protrusions located on the downstream side of the flow, protrudes from the bottom of the depression together with the upstream part.
Mold equipment. The mold device according to claim 1,
In each of the protrusions, a surface intersecting the flow direction has a tapered shape that gradually becomes thinner along the protrusion direction when viewed in the flow direction.
Mold equipment. The mold device according to any one of claims 1 to 3,
A fixed mold, a movable mold, and a cylindrical sprue bush that functions as the mold member and is used while being fixed to the fixed mold,
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 at least a portion above the gate.
Mold equipment. The mold device according to claim 4,
The fixed type has a general-purpose type and a dedicated type located above the general-purpose type,
The sprue bushing is arranged to be vertically sandwiched between the general-purpose type and the special-purpose type.
Mold equipment.

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