JP2010075939A - Die-casting die - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a die-casting die which has increased cooling efficiency by efficiently passing a cooling medium through the inner recessed part of a spool core, and can be highly efficiently cooled. <P>SOLUTION: The die-casting die 10 includes: a plunger tip 45 advancing the inside of a cylindrical spool bush 40 and pressing a molten metal; a spool core 50 arranged in front of the spool bush 40, receiving the molten metal pressed by the plunger tip 45 at a colliding part 55 and introducing the molten metal into a runner 16; and cooling members 60, 62 for cooling the spool core 50 from the inside by passing the cooling medium through the inner recessed part 57 of the spool core 50. In the cooling members 60, 62, a flow passage provided at the internal region of the colliding part 55 of the spool core 50 is formed, and also, the recessed part is formed over almost the half-circumferential face at the internal region of a runner part 56 continuing to the colliding part 55. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a die casting mold, and more particularly to a die casting mold that efficiently cools a molten metal during high pressure casting.

  Conventionally, in die casting molds that perform high pressure casting, the sprue core (divider) placed in front of the sprue bush receives the molten metal pressed by the plunger tip at the collision part and guides it to the runner. Become. For example, in the case of aluminum, the temperature of the molten metal is about 700 ° C., and the temperature of the mold is about 400 ° C. at this time. Above all, the temperature of the sprue core (divider) greatly exceeds 400 ° C.

  In order to cool the molten metal by cooling such a sprue core (divider), conventionally, there is a method in which cooling water is filled into the inner recess of the sprue core using cooling water inflow and discharge pipes and circulated. It was used.

In addition, it has also been proposed to arrange an inner member that forms a passage of cooling water in an internal recess of the sprue core (see, for example, Patent Document 1).
JP-A-2005-74445

  However, in the system in which the internal recess of the sprue core is filled with cooling water and circulated, the cooling water stays in the recess due to turbulent flow, the flow rate of the circulating cooling water decreases, and the heat extraction efficiency is poor. For this reason, if sufficient time is not taken for cooling, the quality is greatly affected, such as rupture due to delay in molten metal solidification. In order to avoid this, it takes a sufficient time for cooling, and as a result, the casting cycle is long and the production efficiency cannot be improved.

  Moreover, the thing of patent document 1 cools only the inner surface vicinity among the internal recesses of a sprue core, and also the whole inner surface vicinity. However, the entire sprue core does not necessarily become high temperature, and in order to increase the cooling efficiency, it is desirable to cool only the high temperature part. However, as in Patent Document 1, when cooling the entire inner surface of the internal recess of the sprue core, a desired cooling efficiency cannot be obtained.

  The present invention has been made to solve the above-described problems, and is a die-casting die capable of increasing the cooling efficiency by efficiently passing a cooling medium through the internal recess of the sprue core and performing heat drawing with high efficiency. The purpose is to provide.

  The invention according to claim 1 is a plunger tip that moves forward in the cylindrical sprue bush and presses the molten metal, and is disposed in front of the sprue bush and receives the molten metal pressed by the plunger tip at the collision portion. A die casting mold comprising a sprue core that leads to the runner and a cooling member that cools the sprue core from the inside through a cooling medium in an internal recess of the sprue core, wherein the cooling member is connected to the collision part of the sprue core. The die casting mold is characterized in that a flow path provided in an inner region is formed, and a recess is formed over a substantially half circumferential surface of an inner region of the runner portion connected to the collision portion.

  The invention according to claim 2 is the die-casting mold according to claim 1, wherein the gate sleeve has a runner portion that is disposed around the sprue core and that forms a space for the runner between the runner portion of the sprue core. Further, the gate sleeve is provided with a cooling medium flow path including a flow path extending in the front-rear direction inside the runner portion.

  According to a third aspect of the present invention, in the die casting mold according to the first or second aspect, the cooling member includes a cooling medium supply path for supplying a cooling medium to an inner region of the collision portion, and the runner portion. A die casting mold having a cooling medium discharge path for discharging a cooling medium from an inner region.

  The invention according to claim 4 is the die casting mold according to claim 3, wherein the recess is located above the cooling member, and the coolant supplied from the coolant supply path located below the recess is The flow path constituted by the flow path and the back surface of the collision part rises to the concave part, and passes through the flow path constituted by the concave part and the back surface of the runner part from the cooling medium discharge path. A die-casting mold characterized by being discharged.

  According to a fifth aspect of the present invention, in the die casting mold according to any one of the first to fourth aspects, a chromium nitride process is performed on the surface of the sprue core including at least the collision portion on the surface of beryllium copper (BeCu). It is a die-casting mold characterized by comprising the above-mentioned material.

  According to the present invention, it is possible to concentrate and cool the collision part and the runner part, which are the hottest, among the sprue cores, so that the cooling efficiency is high and the heat can be drawn with high efficiency. In addition, product defects are reduced and productivity can be improved.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a sectional view showing an embodiment of a die casting mold according to the present invention, and FIG. 2 is an enlarged sectional view of a main part. The die casting mold 10 includes a fixed mold 20 and a movable mold 30, and a cavity 15 is formed at a joint portion between the fixed mold 20 and the movable mold 30.

  The die casting mold 10 includes a cylindrical sprue bush (sleeve) 40 that communicates with the cavity 15 via a runner 16 and a gate 17. A plunger tip 45 is provided in the sprue bush 40 so as to be able to advance and retreat. The plunger tip 45 advances and presses the molten metal (not shown) so that the molten metal is fed into the cavity 15 via the runner 16 and the gate 17. It is configured.

  Further, the die casting mold 10 includes a sprue core 50, a cooling member 60, and a spout sleeve 70 in a path while the molten metal is pushed out of the sprue bush 40 and passes through the runner 16.

  As shown in FIGS. 2, 3, and 4, the sprue core 50 is disposed in front of the sprue bush 40, receives the molten metal pressed by the plunger tip 45, and guides it to the runner 16. Therefore, the sprue core 50 includes a collision portion (pressure receiving portion) 55 having a pressure receiving surface (collision surface) substantially orthogonal to the advancing / retreating direction of the plunger tip 45 at the tip.

  The sprue core 50 includes a runner portion 56 that guides the molten metal that has collided with the collision portion 55 from the collision portion 55 to the upper side of the sprue core 50. The runner portion 56 is formed above the sprue core 50 and forms a space for the runner 16 between the outside thereof, that is, a runner portion 76 described later of the gate sleeve 70.

  Further, the sprue core 50 includes an internal recess 57 that is open at an end portion (base end side) opposite to the collision portion 55. By this internal recess 57, the collision part 55 and the runner part 56 have a thickness that maintains the necessary strength, and are formed to have a thickness that is suitable for cooling from the inside, that is, not too thick. Yes. The internal recess 57 has a substantially frustoconical shape with a tapered taper from the opening end side toward the collision portion 55.

  As shown in FIGS. 2, 5, and 6, the cooling member 60 cools the sprue core 50 from the inside by passing a cooling medium (for example, cooling liquid such as cooling water) through the internal recess 57 of the sprue core 50. is there. Therefore, the cooling member 60 has a shape that can be accommodated in the internal recess 57 of the sprue core 50, and has a length that protrudes outward from the opening end of the sprue core 50 when accommodated in the internal recess 57. Yes.

  The portion of the cooling member 60 that fits in the inner recess 57 of the sprue core 50 is formed from the contour corresponding to the shape of the tapered inner recess 57 of the sprue core 50 into the inner region of the collision portion 55 and the inner region of the runner portion 56. The cooling medium is formed in a shape that forms a flow path. That is, the cooling member 60 includes a first region (an inner region of the collision portion 55) through which the cooling medium passes on the inner surface (back surface) side of the collision portion 55 of the sprue core 50, and a runner portion connected to the collision portion 55. A second region (an inner region of the runner portion 56) through which the cooling medium passes is provided on the inner surface (back surface) side of 56, and the cooling medium does not pass through a region in contact with the inner surface of the sprue core 50 excluding both regions. It is configured in a shape.

  Specifically, when the cooling member 60 is housed in the internal recess 57 of the sprue core 50, the front end surface of the cooling member 60 contacts the inner surface (back surface) of the collision portion 55. A plurality of (two symmetrically in FIG. 6) concave grooves 65 are formed on the front end surface, and the concave grooves 65 constitute a flow path for the cooling medium. That is, since only the portion of the groove 65 forms a space between the front end portion of the cooling member 60 and the inner surface (back surface) of the collision portion 55 of the sprue core 50, the cooling medium can flow, and the groove 65 Since no space is formed between the other portion and the inner surface (back surface) of the collision portion 55, the cooling medium cannot flow. The depth of the concave groove 65 is substantially constant. Therefore, the concave groove 65 constitutes a flow path in the inner region of the collision portion 55 of the sprue core 50.

  In addition, when the cooling member 60 is housed in the internal recess 57 of the sprue core 50, a space is formed between the inner surface (back surface) of the runner portion 56 of the sprue core 50 in the upper part continuing from the front end portion of the cooling member 60. A recess 66 is formed through which the cooling medium can flow. The axial length of the recess 66 (the length in the left-right direction in FIGS. 2 and 5) is longer than the axial length of the runner portion 56 so that the runner portion 56 can be effectively cooled. Similarly, the circumferential direction length (refer FIG. 6) of the recessed part 66 is formed longer than the circumferential direction length (refer FIG. 4) of the runner part 56 so that the runner part 56 can be cooled effectively. . The depth of the recess 66 is substantially constant. Accordingly, the recess 66 constitutes a flow path in the inner region of the runner portion 56 of the sprue core 50.

  When the cooling member 60 is housed in the internal recess 57 of the sprue core 50, portions other than the concave groove 65 and the concave portion 66 of the cooling member 60 are in contact with the inner surface (back surface) of the internal recess 57 of the sprue core 50. And since a space is not formed between the inner surface (back surface), a cooling medium cannot flow.

  The cooling member 60 further includes a cooling medium supply path 67 for supplying a cooling medium to the concave groove 65 as a flow path in the first region (inner region of the collision portion 55), and a second region (of the runner portion 56). A cooling medium discharge path 68 for discharging the cooling medium from a recess 66 as a flow path in the inner region) is provided inside. When the cooling member 60 is housed in the internal recess 57 of the sprue core 50, the inlet port 67 i of the cooling medium supply path 67 and the cooling medium discharge path are formed in a portion (lower part) protruding outward from the open end of the sprue core 50. 68 outlet ports 68o are open.

  The cooling medium supply path 67 extends linearly from the inlet port 67 i to the front end along the axial direction of the central lower portion of the cooling member 60, and is located at the same depth as the bottom surface of the groove 65 from the front end surface of the cooling member 60. And communicates with one end of the groove 65. The other end of the recessed groove 65 communicates with the distal end side of the recessed portion 66. The cooling medium discharge path 68 extends linearly from the outlet port 68o at the center upper portion of the cooling member 60 along the axial direction, opens to a position on the base end side of the recess 66, and communicates with the base end side of the recess 66. ing.

  As shown in FIGS. 2, 7, and 8, the sprue sleeve 70 is installed adjacent to the front of the sprue bush 40 and is in close contact with the peripheral surface of the sprue core 50 leaving the runner 16 through which the molten metal passes. . In other words, the gate sleeve 70 is provided with a runner portion 76 that is located above the runner portion 56 of the sprue core 50 with a space for the runner 16 therebetween.

  Further, the gate sleeve 70 includes a flow path 77 for a cooling medium inside the runner portion 76. The flow path 77 includes a plurality of (three in FIG. 8) elongated holes 77a extending in the axial direction at the upper part of the gate sleeve 70, and these elongated holes 77a are hatched in FIGS. A partition by a baffle plate 78 is provided. That is, the inner space of each elongated hole 77a is divided into left and right by the baffle plate 78, and the left and right spaces communicate with each other only at the tip (left end in FIG. 7). These elongated holes 77a are communicated with a plurality of (three in FIG. 8) elongated holes 77b extending along a cross section perpendicular to the axial direction of the gate sleeve 70, and further a plurality (four in FIG. 8). The flow path 77 is configured by communicating with an inlet port 77i and an outlet port 77o provided at the lower part of the gate sleeve 70 by the long holes 77b of the book.

  The long holes 77a provided with these partition structures (baffle plates 78) and the long holes 77b not provided with the partition structures are all formed in such a manner that linear straight holes are successively communicated. , 77b is sealed to form a flow path 77 from the inlet port 77i to the outlet port 77o. Therefore, in order to form the flow path 77, for example, it is unnecessary to form a gate sleeve by forming an annular groove on the outer periphery of one annular member and then welding another annular member on the outside thereof. The gate sleeve 70 can form the flow path 77 by drilling one member.

  The die casting mold 10 configured as described above first fills the cavity 15 with molten metal when performing die casting. That is, when the plunger tip 45 advances and presses the molten metal in the sprue bush 40, the molten metal is fed into the cavity 15 through the runner 16 and the gate 17. At this time, the collision part 55 of the sprue core 50, the runner part 56 of the sprue core 50 that sandwiches the runner 16 and the runner part 76 of the gate sleeve 70 are particularly hot.

  Subsequently, the mold is cooled. That is, the cooling medium is continuously supplied from the inlet port 67i of the cooling member 60 for a predetermined time, and the cooling medium is continuously supplied from the inlet port 77i of the gate sleeve 70 for a predetermined time.

  The cooling medium supplied to the inside of the cooling member 60 from the inlet port 67i flows into the one end of the concave groove 65 from the tip through the cooling medium supply path 67, and passes through the concave groove 65 (rises) to the other end. From the base end side to the coolant discharge path 68 through the recess 66 (up the gentle upward slope due to the taper), and through the coolant discharge path 68 to the outlet port 68o. To the outside of the cooling member 60. Such a circulation by the cooling medium is continuously performed at a high speed (fast flow rate) for a predetermined time, whereby the collision portion 55 of the sprue core 50 is effectively cooled from the inner surface (back surface). Moreover, the runner part 56 of the sprue core 50 is also effectively cooled from the inner surface (back surface).

  On the other hand, the cooling medium supplied from the inlet port 77 i to the inside of the gate sleeve 70 passes through the elongated hole 77 b of the flow path 77 (up) to the runner portion 76, and reaches the runner portion 76. The three (three in FIG. 8) elongated holes 77a sequentially pass through the left space and right space (see FIG. 8) partitioned by the baffle plate 78, and then pass through the elongated holes 77b of the flow path 77 (lower). E) discharged to the outside of the gate sleeve 70 from the outlet port 77o. Since such circulation by the cooling medium is continuously performed at a high speed for a predetermined time, the runner portion 76 of the gate sleeve 70 is effectively cooled from the inside.

  Thereby, the collision part 55 and runner part 56 which become the highest temperature among the sprue cores 50 can be concentrated and cooled, so that the cooling efficiency is high and the heat can be drawn with high efficiency. Therefore, a high-quality product free from delay in solidification can be obtained in a short time, and the processing cycle can be shortened.

  In order to investigate the cooling efficiency of the die casting mold 10 according to the above embodiment, three types of samples were prepared as follows.

Sample 1:
As the material of the sprue core 50, a material obtained by performing chromium nitriding treatment on the surface of beryllium copper (BeCu) was used. SKD was used as the material of the gate sleeve 70. The die casting mold 10 is configured by using the sprue core 50 and the gate sleeve 70 as parts. This die casting mold 10 was designated as Sample 1.

Sample 2:
SKD was used as the material for the sprue core 50 and the gate sleeve 70. The die casting mold 10 is configured by using the sprue core 50 and the gate sleeve 70 as parts. This die casting mold 10 was designated as sample 2.

Sample 3:
The sprue core used was a conventional sprue core that circulates by filling the internal recess with cooling water using cooling water inflow and discharge pipes. As the gate sleeve, an annular groove is formed on the outer periphery of one annular member, and another annular member is welded to the outside thereof, so that a conventional gate sleeve having the annular groove as a flow path is used. Both the sprue core and the gate sleeve are made of SKD. A die casting mold was constructed by using the sprue core and the gate sleeve as parts. This die casting mold was designated as Sample 3.

  Using the above three types of die casting molds, the cavity was filled with molten metal, and then the mold was cooled for a predetermined time, and the temperature of each part of the mold was measured. As a result, the temperature of the sprue core and the gate sleeve in the die casting die of Sample 3 was the highest. On the other hand, the temperature of the sprue core 50 and the spout sleeve 70 in the die-casting mold 10 of the sample 2 both decreased as compared with the sprue core and the spout sleeve of the sample 3. Further, the temperature of the sprue core 50 and the gate sleeve 70 in the die-casting die 10 of the sample 1 was the lowest temperature, and the temperature was further drastically lowered as compared to the sprue core 50 and the gate gate 70 in the die-casting die 10 of the sample 2. .

  Therefore, in the case of the die-casting die 10 according to the above embodiment, the cooling structure of the sprue core 50 and the gate gate 70 is different from the cooling structure of the conventional sprue core and gate gate, so even if the material is the same SKD, It can be seen that the cooling efficiency is improved.

  In addition to the cooling structure of the sprue core 50 and the sprue sleeve 70, it can be seen that the cooling efficiency is further improved by using a material in which the surface of beryllium copper (BeCu) is subjected to chromium nitriding as the material of the sprue core 50. . Furthermore, it is preferable to use a material in which the surface of beryllium copper (BeCu) is subjected to chromium nitriding treatment also in the gate sleeve.

  9 and 10 are enlarged sectional views showing other embodiments of the cooling member. The cooling member 62 is different from the cooling member 60 shown in FIGS. 5 and 6 in the configuration of the first region (the inner region of the collision portion 55). That is, when the cooling member 62 is stored in the internal recess 57 of the sprue core 50, the front end surface of the cooling member 62 contacts the inner surface (back surface) of the collision portion 55. On the front end surface, a semicircular arc-shaped groove 65 whose center communicates with the cooling medium supply path 67 and a plurality of (five symmetrically five in FIG. 10) concave grooves 65 extending radially from the cooling medium supply path 67. Are formed, and these concave grooves 65 constitute a flow path of the cooling medium. That is, since only the portion of the groove 65 forms a space between the tip of the cooling member 62 and the inner surface (back surface) of the collision portion 55 of the sprue core 50, the cooling medium can flow, and the groove 65 Since no space is formed between the other portion and the inner surface (back surface) of the collision portion 55, the cooling medium cannot flow. The depth of the concave groove 65 is slightly shallower than that of the cooling member 60, but is almost constant. Therefore, the concave groove 65 constitutes a flow path in the inner region of the collision portion 55 of the sprue core 50.

  In addition, the cooling member 62 is wider than the cooling member 60 shown in FIGS. 5 and 6, and the width of each of the concave grooves 65 is wide. A large amount of the cooling medium can flow without reducing the flow rate. Further, since the cooling member 62 has a smaller bending angle at the bent portion of the concave groove 65 than the cooling member 60 shown in FIGS. 5 and 6, the resistance when the cooling medium passes therethrough is small and smooth. A cooling medium can be flowed.

  In addition, when the cooling member 62 is housed in the internal recess 57 of the sprue core 50, a space is formed between the cooling member 62 and the inner surface (back surface) of the runner portion 56 of the sprue core 50 at the upper part continuing from the tip portion. A recess 66 is formed through which the cooling medium can flow. Accordingly, as in the case of the cooling member 60, the recess 66 constitutes a flow path in the inner region of the runner portion 56 of the sprue core 50.

  When the cooling member 62 is housed in the internal recess 57 of the sprue core 50, the portions other than the concave groove 65 and the concave portion 66 of the cooling member 62 are in contact with the inner surface (back surface) of the internal recess 57 of the sprue core 50. Since no space is formed between the inner surface (back surface) and the cooling medium cannot flow, the same as in the case of the cooling member 60.

  In the case of a die-casting die (not shown) using this cooling member 62 instead of the cooling member 60 shown in FIGS. 5 and 6, the cooling medium in the first region (the inner region of the collision portion 55). The flow rate and flow rate can be improved. Therefore, especially the cooling efficiency of the collision part 55 of the sprue core 50 is high, the heat extraction efficiency of the molten metal corresponding to this part is high, and it can be solidified in a shorter time. As a result, the processing cycle can be further shortened.

It is sectional drawing which shows one Embodiment of the die-casting metal mold | die by this invention. It is an expanded sectional view of the principal part of the die-casting die shown in FIG. It is an expanded sectional view of the sprue core of the die-casting mold of FIG. It is a right view of the sprue core of FIG. It is an expanded sectional view of the member for cooling of the die-casting die of FIG. FIG. 6 is a right side view of the cooling member of FIG. 5. It is an expanded sectional view of the gate sleeve of the die-casting mold of FIG. It is a left view of the gate gate of FIG. It is an expanded sectional view showing other embodiments of a member for cooling. FIG. 10 is a right side view of the cooling member of FIG. 9.

Explanation of symbols

10 Die Casting Mold 15 Cavity 16 Runner 17 Gate 20 Fixed Mold 30 Movable Mold 40 Sprue Bush (Sleeve)
45 Plunger tip 50 Sprue core
55 Collision part 56 Runner part 57 Internal recess 60, 62 Cooling member 65 Concave groove (flow path)
66 Concave part 67 Cooling medium supply path 68 Cooling medium discharge path 70 Gate gate 76 Runner part 77 Channel 78 Baffle plate

Claims (5)

A plunger tip that moves forward in the cylindrical sprue bush and presses the molten metal;
A sprue core that is disposed in front of the sprue bush and that receives the molten metal pressed by the plunger tip at a collision portion and guides it to a runner;
In a die casting mold comprising: a cooling member that cools the sprue core from the inside through a cooling medium in the internal recess of the sprue core,
A flow path having the cooling member in the inner region of the collision portion of the sprue core is formed, and a recess is formed over a substantially half circumferential surface of the inner region of the runner portion connected to the collision portion. Die casting mold. Further comprising a gate sleeve having a runner portion disposed around the sprue core and forming a space for the runner between the sprue core and the runner portion;
The die casting mold according to claim 1, wherein the gate sleeve includes a cooling medium flow path including a flow path extending in the front-rear direction inside the runner portion.   The cooling member includes therein a cooling medium supply path for supplying a cooling medium to an inner area of the collision portion, and a cooling medium discharge path for discharging the cooling medium from an inner area of the runner portion. The die-casting die according to claim 1 or 2.   The recess is located above the cooling member, and the cooling medium supplied from the cooling medium supply path located below the recess has a flow path constituted by the flow path and the back surface of the collision part. 4. The die casting mold according to claim 3, wherein the die casting mold rises to reach the concave portion, and is discharged from the cooling medium discharge passage through a flow path constituted by the concave portion and the back surface of the runner portion.   5. The die-casting die according to claim 1, wherein a portion including at least the collision portion of the sprue core is made of a material obtained by performing chromium nitriding treatment on the surface of beryllium copper (BeCu). .

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