Metal mold

Abstract

To provide a metal mold which improves cooling efficiency while securing strength of an insert.SOLUTION: A metal mold 1 including a coolant holding space 12 charging / discharging coolant R therein comprises: an insert 10 with a rib 14 partitioning the coolant holding space 12 into a plurality of split spaces 13; and a closing member which is arranged at a back face 10b of the insert 10 to block the opening of the split spaces 13. The rib 14 is formed extending from an inner peripheral surface 10c of the insert 10 forming the coolant holding space 12 to an end face 20a of the closing member at a coolant holding space 12 side.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a mold. [Background technology]

[0002] For example, in various castings such as die casting, high-temperature molten metal is injected into a cavity of a mold to form a molded product having a shape corresponding to the shape of the cavity. In recent years, in order to improve productivity, the molding cycle time has been shortened, and the cooling time of the mold has been shortened accordingly. When the cooling time of the mold is shortened, the temperature of the mold increases, and the molded product is likely to suffer from seizure or galling defects, and heat cracks due to thermal fatigue of the mold itself. For this reason, a technology has been proposed to improve the cooling efficiency of the mold by circulating a refrigerant through a cooling passage provided inside the mold.

[0003] Patent Document 1 discloses an injection molding device which includes a refrigerant flow path provided within a molding die through which a refrigerant flows, and a cooling flow path which guides the refrigerant flowing through the refrigerant flow path to the vicinity of a target to be cooled within the molding die, wherein the flow path direction of an upstream portion of the refrigerant flow path which connects to an inlet of the cooling flow path is in a direction which allows the refrigerant to flow in the flow path direction of the cooling flow path, and the diameter of the inlet of the cooling flow path is larger than the diameter of the refrigerant flow path which is connected to the inlet. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2009-196138 A Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, a mold includes a fixed-side mold plate (cavity plate, female mold) and a movable-side mold plate (core plate, male mold) that are arranged opposite each other. A recess is formed on each of the opposing surfaces of the fixed-side mold plate and the movable-side mold plate, and a nest having a mold surface that forms a part of a cavity into which a molding material such as high-temperature molten metal is injected may be attached in each recess. In order to improve the cooling efficiency of the mold, it is possible to provide a cooling flow path with a large opening (entrance) inside the nest. However, if a large space is provided inside the nest as a cooling flow path, although high cooling efficiency can be obtained, there is a problem that the strength of the nest is insufficient. If the strength of the nest is insufficient, there is a risk that the nest will crack due to the casting pressure or thermal deformation generated during casting.

[0006] The present disclosure has been made to solve such problems, and has an object to provide a mold in which cooling efficiency is improved while ensuring the strength of the insert. [Means for solving the problem]

[0007] A mold in one embodiment has a refrigerant holding space therein through which a refrigerant is supplied and discharged, and includes a nest with ribs that divide the refrigerant holding space into a number of partition spaces, and a closing member attached to the back surface of the nest for closing the openings of the partition spaces, the ribs being formed to extend from the inner peripheral surface of the nest which forms the refrigerant holding space towards the end face of the closing member on the refrigerant holding space side. Effect of the Invention

[0008] According to the present disclosure, it is possible to provide a mold in which the cooling efficiency is improved while ensuring the strength of the insert. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic cross-sectional view showing a part of a mold according to a first embodiment. [Diagram 2] FIG. 2 is a schematic rear view showing a mold insert according to the first embodiment. [Diagram 3]FIG. 2 is a schematic front view showing a cooling plate of the mold according to the first embodiment. [Figure 4] FIG. 13 is a schematic rear view showing a mold insert according to a modified example of the first embodiment. [Diagram 5] FIG. 11 is a schematic front view showing a cooling plate of a mold according to a modified example of the first embodiment. [Figure 6] FIG. 11 is a schematic cross-sectional view showing a part of a mold of a comparative example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] First embodiment Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. However, the present disclosure is not limited to the following embodiment. In addition, in order to clarify the description, the following description and drawings are appropriately simplified. What is shown in the drawings is only a part of the whole, and in reality, many other configurations that are not shown are included. In the following description, the same or equivalent elements are given the same reference numerals, and duplicated descriptions are omitted.

[0011] Fig. 1 is a schematic cross-sectional view showing a part of a mold according to embodiment 1. As shown in Fig. 1, the mold 1 according to this embodiment has a mother die (not shown), a insert 10, and a cooling plate 20. The mold 1 is used, for example, in die casting in which high-temperature molten metal is injected into a cavity of the mold 1 to form a molded product having a shape corresponding to the shape of the cavity.

[0012] The material of the insert 10 is a metal material such as steel. Examples of the material of the insert 10 include steel such as alloy tool steel. In this embodiment, the material of the insert 10 is SKD61, which is a type of alloy tool steel. The insert 10 is detachably attached together with the cooling plate 20 to a recess formed on the cavity side of the mother mold. The insert 10 has a plurality of fastening holes 11 through which fastening members 21 for fixing the cooling plate 20 are inserted on the back surface 10b of the insert 10 opposite to the mold surface 10a. For example, bolts can be used as the fastening members 21. The insert 10 is held in the mother mold by fitting into the recess while being fixed to the cooling plate 20.

[0013] The insert 10 has a refrigerant holding space 12 therein, into which the refrigerant R is supplied and discharged. As the refrigerant R, a gas refrigerant or a liquid refrigerant can be used. In particular, cooling water, which is a liquid refrigerant, is suitable as the refrigerant R. The insert 10 has ribs 14 for dividing the refrigerant holding space 12 into a plurality of partition spaces 13. The ribs 14 are formed so as to extend from an inner circumferential surface 10c of the insert 10 that forms the refrigerant holding space 12 toward an end surface 20a on the cavity side (the refrigerant holding space 12 side) of the cooling plate 20. By providing the ribs 14 inside the insert 10, the strength of the insert 10 having the refrigerant holding space 12 therein can be increased. In order to further increase the strength of the insert 10, it is preferable that the ribs 14 are formed so as to reach the end surface 20a from the inner circumferential surface 10c.

[0014] Each divided space 13 is recessed from the rear surface 10b toward the mold surface 10a. That is, each divided space 13 is open to the rear surface 10b. The multiple divided spaces 13 are independent spaces inside the insert 10. The size of each divided space 13 can be appropriately designed in consideration of the strength of the insert 10. In order to improve the cooling efficiency, it is preferable that the size of each divided space 13 is as large as possible without impairing the strength of the insert 10. From the viewpoint of improving the cooling efficiency while ensuring the strength of the insert 10, it is preferable that the thickness of the insert 10 from the mold surface 10a to the inner peripheral surface 10c is about 15 to 30 mm, for example.

[0015] Here, Fig. 2 is a schematic rear view showing the insert of the mold according to the first embodiment. As shown in Fig. 2, in this embodiment, ribs 14 having a cross-shaped planar shape and extending in the vertical direction from the inner peripheral surface 10c to the end surface 20a divide the refrigerant holding space 12 into four divided spaces 13. The multiple divided spaces 13 are provided at positions avoiding the fastening holes 11 so as not to interfere with the fastening holes 11. Such divided spaces 13 are formed, for example, by cutting out the rear surface 10b of the insert 10 before cutting.

[0016] Furthermore, as shown in FIG. 1, the insert 10 has a first seal member 16 attached to a first annular groove 15 formed on the back surface 10b so as to surround the refrigerant holding space 12. For example, an O-ring can be used as the first seal member 16. The first seal member 16 is a component that prevents the refrigerant R from leaking to the outside from a gap between the insert 10 and the cooling plate 20 (more specifically, a gap between the back surface 10b and the end surface 20a). By attaching the first seal member 16 to the first annular groove 15, the insert 10 is fixed to the cooling plate 20 in a liquid-tight manner. As shown in FIG. 2, the first annular groove 15 to which the first seal member 16 is attached is formed outside the refrigerant holding space 12 and inside the fastening holes 11 provided at the four corners of the back surface 10b.

[0017] As shown in FIG. 1, the cooling plate 20 is attached to the rear surface 10b and is a blocking member that blocks the openings of each partition space 13. The material of the cooling plate 20 is a metal material such as steel. Examples of the material of the cooling plate 20 include steel such as chromium molybdenum steel and prehardened steel. In this embodiment, the material of the cooling plate 20 is SCM435, which is a type of chromium molybdenum steel. The cooling plate 20 is fixed to the rear surface 10b by fastening members 21 inserted into the four corners of the cooling plate 20. The cooling plate 20 has a planar shape substantially the same as that of the rear surface 10b and is formed into a plate shape having a predetermined thickness. The end surface 20a of the cooling plate 20 may have a protrusion 22 that has a planar shape substantially the same as the openings of the partition spaces 13 and protrudes from the end surface 20a toward the partition spaces 13 so as to correspond to each partition space 13. By fitting the projections 22 of the cooling plate 20 attached to the insert 10 into the openings of the corresponding divided spaces 13, each divided space 13 is appropriately sealed.

[0018] The cooling plate 20 has therein a supply flow passage 23 that supplies the coolant R to the partition spaces 13, and a discharge flow passage 24 that discharges the coolant R from the partition spaces 13. The upstream end of the supply flow passage 23 is connected to a coolant supply means (not shown) provided outside the cooling plate 20, and the downstream end is connected to one of the multiple partition spaces 13 via an inlet 23a. The upstream end of the discharge flow passage 24 is connected to one of the multiple partition spaces 13 via an outlet 24a, and the downstream end is connected to a coolant discharge means (not shown) provided outside the cooling plate 20. The mold 1 can supply and discharge the coolant R to and from the partition spaces 13 via the supply flow passage 23 and the discharge flow passage 24, thereby circulating the coolant R.

[0019] Furthermore, the cooling plate 20 has therein a connecting flow passage 25 that connects the partition spaces 13 to each other. The upstream end of the connecting flow passage 25 communicates with one partition space 13 via an outlet 25a, and the downstream end of the connecting flow passage 25 communicates with the other partition space 13 via an inlet 25b. The mold 1 can circulate the refrigerant R inside the cooling plate 20 by the connecting flow passage 25.

[0020] Here, FIG. 3 is a schematic front view showing the cooling plate of the mold according to the first embodiment. As shown in FIG. 3, from the viewpoint of improving the cooling efficiency, it is preferable that a plurality of supply flow paths 23 and discharge flow paths 24 are connected inside the cooling plate 20 so that at least one supply flow path 23 and one discharge flow path 24 are connected to each partition space 13. For example, the mold 1 may have a structure in which the refrigerant is circulated to the plurality of partition spaces 13 through a gap between the end surface 20a and the rib 14 that extends from the inner circumferential surface 10c and does not reach the end surface 20a. However, in such a structure, the refrigerant R may not circulate sufficiently to the vicinity of the mold surface 10a. Even in the mold 1 in which the refrigerant R may not circulate sufficiently to the vicinity of the mold surface 10a, by connecting at least one supply flow path 23 and one discharge flow path 24 to each partition space 13, the refrigerant R can circulate sufficiently to the vicinity of the mold surface 10a, thereby improving the cooling efficiency. From the viewpoint of suitably circulating the refrigerant R inside the cooling plate 20, it is preferable that a plurality of connection flow paths 25 are provided inside the cooling plate 20 so as to connect the plurality of partition spaces 13 to one another.

[0021] Inlets 23a, 25b through which the refrigerant R flows into the partition space 13 and outlets 24a, 25a through which the refrigerant R flows out from the partition space 13 open on the end face 20a of the protrusion 22. The openings of the inlets 23a, 25b and the outlets 24a, 25a are each smaller than the opening of the partition space 13. The opening locations of the inlets 23a, 25b and the outlets 24a, 25a can be appropriately changed in design.

[0022] The arrows in Fig. 1 indicate the flow direction F of the refrigerant R when cooling the mold 1. When the refrigerant R is supplied from the refrigerant supply means, the refrigerant R supplied by the refrigerant supply means passes through the supply flow path 23 and flows into the partition spaces 13 from the inlet 23a. When the refrigerant R that has flowed through the partition spaces 13 flows out from the outlet 24a to the discharge flow path 24, it is discharged through the discharge flow path 24 to the refrigerant discharge means. When the refrigerant R that has flowed through the partition spaces 13 flows out from the outlet 25a to the connecting flow path 25, it passes through the connecting flow path 25 and flows into another partition space 13 from the inlet 25b. Thus, in the mold 1, the insert 10 is cooled by the refrigerant R flowing through the multiple partition spaces 13.

[0023] Here, FIG. 6 is a schematic cross-sectional view showing a part of a mold of a comparative example. As shown in FIG. 6, the mold 1000 of the comparative example has a nest 100 detachably attached to a recess formed on the cavity side of the mother mold. The nest 100 has a plurality of cooling holes 130 therein through which the refrigerant R is supplied and discharged. Each cooling hole 130 has an elongated cross-sectional shape extending in the vertical direction from the back surface 100b of the nest 100 toward the mold surface 100a. The cooling hole 130 is provided with a cooling pipe 131 for forming a flow path for circulating the refrigerant R to the cooling hole 130. The cooling hole 130 is sealed by a seal member 160 attached so as to close the opening of the cooling hole 130. One end of a pipe 161 is connected to the cooling hole 130 via the seal member 160. The multiple pipes 161 include those that form a supply flow path that supplies the refrigerant R to the flow path, and those that form a discharge flow path that discharges the refrigerant R from the flow path, and may also include those that form connecting flow paths that connect the cooling holes 130 to each other.

[0024] In such a mold 1000, in order to prevent cracking of the cooling pipe 131 and to ensure the viability of the seal member 160, the cooling holes 130 need to be arranged at a predetermined interval from each other inside the nest 100. Therefore, since the arrangement and number of the cooling holes 130 are limited, the cooling performance of the cooling holes 130 is limited, and a problem occurs that the cooling efficiency of the mold 1000 cannot be sufficiently improved. In addition, in such a mold 1000, various parts such as the cooling pipe 131, the seal member 160, the piping 161, and joints connecting the piping 161 to each other need to be provided for each cooling hole 130, which increases the number of parts of the mold 1000 and complicates the structure of the mold 1000, resulting in a problem that the maintainability of the mold 1000 is reduced.

[0025] To address these problems, the mold 1 according to this embodiment has a dividing space 13 inside the insert 10, which is a larger space than the above-mentioned cooling hole 130, and therefore the cooling efficiency of the mold 1 can be improved. Furthermore, in the mold 1 according to this embodiment, in order to increase the strength of the insert 10, ribs 14 extending from the inner peripheral surface 10c toward the end surface 20a are provided inside the insert 10. In this way, according to the mold 1 according to this embodiment, the strength of the insert 10 can be ensured while the cooling efficiency can be increased.

[0026] Moreover, the cooling plate 20 of the mold 1 according to this embodiment has therein a supply flow path 23 that supplies the refrigerant R to the partition spaces 13, and a discharge flow path 24 that discharges the refrigerant R from the partition spaces 13. With this configuration, the refrigerant R can be circulated by supplying and discharging it to and from the partition spaces 13, so that the insert 10 can be efficiently cooled.

[0027] Moreover, the cooling plate 20 of the mold 1 according to this embodiment has therein a connecting flow path 25 that connects the partition spaces 13 with each other. With this configuration, the refrigerant R circulates inside the cooling plate 20, so that the number of parts of the mold 1 can be reduced and the structure of the mold 1 can be simplified, compared with the case where a part for circulating the refrigerant R, such as a cooling pipe 131, needs to be provided for each cooling hole 130 as in the mold 1000 of the comparative example. As a result, the maintainability of the mold 1 can be improved.

[0028] Moreover, the insert 10 of the mold 1 according to this embodiment has a first seal member 16 attached to a first annular groove 15 formed in the back surface 10b so as to surround the refrigerant holding space 12. In the mold 1 according to this embodiment, the metal-to-metal contact between the back surface 10b and the end surface 20a can suppress leakage of the refrigerant R to the outside, so there is no need to provide a component such as the first seal member 16 for each divided space 13 to prevent leakage of the refrigerant R to the outside. Therefore, according to the mold 1 according to this embodiment, the number of components of the mold 1 can be reduced and the structure of the mold 1 can be simplified. As a result, the maintainability of the mold 1 can be improved.

[0029] [Variations] The present disclosure is not limited to the above-mentioned embodiment, and can be appropriately modified within the scope of the present disclosure. For example, in the above-mentioned embodiment, the nest 10 in which the fastening holes 11 are provided at the four corners of the back surface 10b is taken as an example, but the present disclosure is not limited to this. Therefore, FIG. 4 is a schematic rear view showing a nest of a mold according to a modified example of the first embodiment. As shown in FIG. 4, the fastening holes 11 can be provided at various positions on the back surface 10b of the nest 10. In addition to the fastening holes 11, the nest 10 shown in FIG. 4 may be provided with insertion holes 17 for inserting shooting pins, ejection pins, etc., and such insertion holes 17 can also be provided at various positions on the back surface 10b. In this case, inside the nest 10, the multiple division spaces 13 in which the refrigerant holding space 12 is divided by the ribs 14 are each provided at a position that avoids interference elements such as the fastening holes 11 and the insertion holes 17. The ribs 14 are formed between adjacent division spaces 13.

[0030] 4 has, instead of the first annular groove 15, a plurality of second annular grooves 18 formed in the rear surface 10b so as to surround the plurality of partition spaces 13 individually. Then, a second seal member 19 is attached to each of the second annular grooves 18 instead of the first seal member 16. In this manner, the mold 1 may use the second seal member 19 for each partition space 13 to suppress leakage of the refrigerant R as necessary.

[0031] 5 is a schematic front view showing a cooling plate of a mold according to a modified example of the first embodiment. The cooling plate 20 shown in FIG. 5 is fixed to the back surface 10b by a plurality of fastening members 21 inserted into the cooling plate 20 so as to correspond to the positions of the fastening holes 11. The cooling plate 20 is also provided with insertion holes 26 for inserting shooting pins, ejection pins, and the like. Therefore, inside the cooling plate 20, the supply flow paths 23, the discharge flow paths 24, and the connection flow paths 25 are provided at positions that avoid interfering elements such as the fastening members 21 and the insertion holes 26. The number of the supply flow paths 23, the discharge flow paths 24, and the connection flow paths 25 can be appropriately increased or decreased depending on the structure of the cooling plate 20. The supply flow paths 23, the discharge flow paths 24, and the connection flow paths 25 may be omitted as necessary.

[0032] In addition, in the above embodiment and its modified examples, the closing member is the cooling plate 20, but the present invention is not limited to this. For example, the closing member may be a mother mold to which the insert 10 is attached. When the closing member is a mother mold, the cooling plate 20 is omitted, and the insert 10 is detachably attached to a recess in the mother mold. In this case, the mother mold may have the supply flow path 23 and the discharge flow path 24 therein, and may have the connection flow path 25 therein. [Explanation of symbols]

[0033] 1, 1000 molds 10, 100 nested 10a, 100a mold surface 10b, 100b back surface 10c inner peripheral surface 11 fastening hole 12 refrigerant holding space 13 dividing space 14 rib 15: first annular groove; 16: first seal member 17: insertion hole; 18: second annular groove; 19: second seal member 20 cooling plate 20a end surface 21 fastening member 22 protrusion 23 Supply flow path 23a Inlet 24 Discharge flow path 24a Outlet 25 Connection flow path 25a Outlet 25b Inlet 26 Insertion hole 130 cooling hole 131 cooling pipe 160 sealing member 161 piping F Flow direction R Refrigerant

Claims

1. a refrigerant holding space for supplying and discharging a refrigerant therein, the refrigerant holding space being provided with ribs for dividing the refrigerant holding space into a plurality of partition spaces; a closing member attached to a rear surface of the insert and closing an opening of the dividing space, The rib is formed in a mold so as to extend from an inner peripheral surface of the insert that forms the refrigerant holding space toward an end surface of the closing member that faces the refrigerant holding space.

2. The blocking member is The mold according to claim 1 , further comprising: a supply passage for supplying the coolant to the partition space; and a discharge passage for discharging the coolant from the partition space.

3. The mold according to claim 1 , wherein the closing member has therein a connecting flow passage that connects the divided spaces with each other.

4. The mold according to claim 1 , wherein the insert has a first seal member attached to a first annular groove formed in the rear surface so as to surround the refrigerant holding space.

5. The mold according to claim 1 , wherein the insert has second seal members attached to a plurality of second annular grooves formed in the rear surface so as to surround the plurality of divided spaces individually.

Images