JP2008168298A - Structure of die - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve problems about burrs by adopting a novel structure for the clearance between the opposed walls of a plurality of inserts. <P>SOLUTION: A die has the structure in which a cavity 8 is configured by a plurality of inserts 2, 3 arranged inside the die. In the clearance 9 having a specified width W0 to be formed between the opposed wall surfaces 10, 11 of neighboring inserts 2, 3, a minute passage 12 is formed so as to have a first width W1 wider than the specified width W0 within a first region from the surface 8a of the cavity to a first specified depth D1, and a residence portion 13 is formed so as to have a second width W2 wider than the first width W1 of the minute passage 12 within a second region from the first specified depth D1 to a second specified depth D2 located on the opposite side of the cavity 8 side. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a die structure for die casting and the like, and more specifically, to solve a problem related to burrs formed in a molded product after demolding when a molten metal enters a gap existing in the die. Regarding technology.

  As disclosed in Patent Document 1, the structure of a conventional die casting mold is generally a combination of a movable mold and a fixed mold. That is, a cavity is formed in the internal space between the movable mold and the fixed mold, and a molten metal such as an aluminum alloy is injected into the cavity.

  In addition, in such die casting molds, a split type mold consisting of multiple inserts is constructed to realize a complex molding shape and a technology that facilitates replacement when the cavity surface wears, etc. Has been. For example, in the movable mold, the main mold has two nestings.

  Here, as described above, in the case of forming a split mold from a plurality of inserts, the molten metal enters the gap formed between the opposing wall surfaces of the adjacent inserts, and the invaded molten metal solidifies. It will remain as burrs in the molded product after demolding. Conventionally, it is difficult to predict the height dimension of this burr, which adversely affects product quality, and a dedicated process for removing the burr may be required.

  Further, if burrs are dropped from the molded product and remain in the gap, a concave defect is formed in the subsequent molding.

  In particular, when injection casting is performed at a high pressure and a high speed, even if the gap is fine, the molten metal tends to enter.

  Further, the thermal expansion and contraction are repeated, or the collision of the high-pressure molten metal is repeated, so that the gap gradually expands. Particularly, the corner of the opening of the gap becomes gentle, and the size of the generated burr is increased. It will also expand.

  As described above, handling of burrs generated due to the intrusion of molten metal into the gap is a problem, and solving this problem is a problem.

However, the gaps between the opposing wall surfaces of a plurality of nests are indispensable from the viewpoint of assembly and removal from the main mold, and solving the problem in the direction of eliminating these gaps completely is not possible. It will be impossible.
Japanese Utility Model Publication No. 2-53856

  Therefore, the present invention solves the problem related to burrs by adopting a new structure for the gaps between the opposing wall surfaces of a plurality of nests.

  The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.

That is, as described in claim 1,
A mold structure in which a plurality of inserts are provided inside the mold, and a cavity is formed by the plurality of inserts,
In the gap of the defined width formed between the opposing wall surfaces of adjacent nests,
For the first range from the cavity surface to the first specified depth,
A microchannel configured with a first width wider than the specified width is formed,
For the second range from the first specified depth to the second specified depth located in the direction opposite to the cavity side,
A mold structure is provided in which a staying portion having a second width wider than the first width of the microchannel is formed.

Moreover, as described in claim 2,
The first width of the microchannel is designed to have a dimension that allows the molten metal injected into the cavity to be guided to the staying portion.

Moreover, as described in claim 3,
About the said retention part, the latching | locking part which retains in the said retention part and latches the solidified solidified in the boundary part of the said microchannel and the said retention part shall be formed.

Moreover, as described in claim 4,
The first specified depth is designed to have a depth dimension smaller than the burr height dimension for satisfying the quality standard of the molded product after demolding.

Moreover, as described in claim 5,
The staying portion is formed on the opposing wall surface of one of the adjacent nestings.

  As effects of the present invention, the following effects can be obtained.

  That is, in the invention described in claim 1, since the height of the burr part formed in the molded product after demolding is constant, the burr part can be easily managed and is always constant. It becomes possible to obtain quality.

  Moreover, in invention of Claim 2, it becomes possible to guide a molten metal to a retention part reliably.

  In the invention according to claim 3, it is possible to generate stress concentration at the boundary between the solidified product and the burr part, and it is possible to more easily divide the boundary.

  Further, in the invention described in claim 4, it is possible to satisfy the specified quality standard without performing dedicated processing for removing the burr part, and it is possible to shorten the processing time. It becomes.

  In the invention according to claim 5, adjacent nesting members can be detached and replaced independently.

Next, embodiments of the invention will be described.
As shown in FIG. 1, the present invention can be applied to a die-casting die that constitutes a split-type die composed of a plurality of inserts.
In the configuration shown in FIG. 1, two nestings 2 and 3 are assembled to a movable mold 1 which is a main mold. Further, the insert 5 is assembled to the fixed mold 4 which is the other main mold. The movable mold 1 is configured to move in the vertical direction in the figure with respect to the fixed mold 4, and when the mold is closed, a predetermined cavity 8 is formed between the inserts 2, 3, and 5. A molten metal (not shown) is injected into the cavity 8 by a tip 7 that slides in a sleeve 6 provided in the mold 4.

FIG. 2A shows an enlarged view of the gap 9 formed between the opposing wall surfaces 10 and 11 of the inserts 2 and 3.
Due to the presence of the gap 9, there is a problem that molten metal enters the gap 9 during molding and burrs are generated in the product after demolding, or what remains in the gap 9 after solidification enters the product as impurities. In principle, it is preferable not to form the gap 9.
However, if it is assumed that the gap 9 does not exist, the processing accuracy of the opposing wall surfaces 10 and 11 of the two inserts 2 and 3 and the mounting accuracy of the inserts 2 and 3 with respect to the main mold (movable mold 1) are very high. The accuracy is required, which is impossible in practice. Further, in order to allow the inserts 2 and 3 to be individually replaced, it is desirable that the gaps 9 are formed so that they can be smoothly removed and assembled without causing friction between the opposing wall surfaces 10 and 11. . From such a viewpoint, the gap 9 is intentionally provided and the design is performed.

  As shown in FIG. 2 (a), a plurality of inserts 2 and 3 are provided inside the mold, and a plurality of inserts 2 and 3 form a cavity 8, which are adjacent to each other. In the gap 9 having the specified width W0 formed between the opposing wall surfaces 10 and 11 of the inserts 2 and 3, the first range A1 from the cavity surface 8a to the first specified depth D1 is wider than the specified width W0. A micro flow path 12 having a first width W1 is formed, and a second range A2 from the first specified depth D1 to a second specified depth D2 located in a direction opposite to the cavity 8 side. The retention portion 13 is formed to have a second width W2 wider than the first width W1 of the microchannel 12.

  Further, as shown in FIG. 2 (a), regarding the design of each of the widths WO, W1, and W2, first, the specified width W0 satisfies the requirements for the interchangeability of the inserts 2 and 3 as described above. In addition, the gap 9 is designed to have a size such that the molten metal does not enter deeper than the staying portion 13. The specific value of the specified width W0 of the gap 9 is appropriately designed according to the characteristics (material / temperature) of the molten metal, the size of the insert, and the like.

  Further, as shown in FIG. 2A, the first width W1 is designed for the micro flow path 12 in the first range A1, and the molten metal injected into the cavity 8 is allowed to pass through the micro flow path 12. It is designed to have dimensions that allow it to be guided to the staying portion 13. The specific value of the first width W1 of the microchannel 12 is appropriately designed according to the characteristics (material / temperature) of the molten metal, the size of the insert, and the like.

  Further, as shown in FIG. 2 (a), the second width W2 is designed for the retention portion 13 in the second range A2, and the molten metal that has entered through the microchannel 12 is retained and retained. It is designed to have dimensions that allow the solidified material 14 that has been solidified later to not escape into the microchannel 12. In addition, about the specific value of the 2nd width W2 of the retention part 13, it designs suitably by the characteristic (raw material and temperature) of a molten metal, the magnitude | size of a nest | insert, etc.

  Further, as shown in FIG. 2 (a), the retention portion 13 is engaged with the solidified material 14 that is retained in the retention portion 13 and solidified at the boundary portion between the minute flow path 12 and the retention portion 13. A stop 13a is formed. In the present embodiment, a so-called undercut portion is formed in the locking portion 13a so that the top surface 13b formed between the microchannel 12 and the staying portion 13 is substantially horizontal. It is said. As will be described later, the locking portion 13a causes the solidified material 14 to be caught by the locking portion 13a, so that the burr portion 15 formed in the microchannel 12 is separated from the solidified material 14, and the solidified material 14 is solidified. The article 14 can be prevented from coming out into the cavity 8.

  In the present embodiment, the top surface 13b is substantially horizontal, and the angle formed by the top surface 13b and the microchannel 12 in the cross-sectional view of FIG. The engaging portion 13a is configured, but the engaging portion 13a having an acute angle formed by the top surface 13b and the microchannel 12 may be configured. According to such an acute angle, stress concentration can be generated at the boundary between the solidified material 14 and the burr part 15, and the boundary can be more easily divided.

  Further, as shown in FIGS. 2A and 2B, the first specified depth D1 is smaller than the burr height dimension R1 for satisfying the quality standard of the molded product 30 after demolding. Is going to be designed. Thereby, the height of the burr part 15 formed in the molded product 30 after demolding can be set to a height dimension R2 smaller than the burr height dimension R1. As a result, the specified quality standard can be satisfied without performing a dedicated process for removing the burrs 15, and the processing time can be shortened. Further, according to the design or the like of the locking part 13a, the burr part 15 is reliably separated from the solidified material 14 in the locking part 13a, so that the burr part 15 always has a constant height dimension R2. Therefore, it is possible to easily manage the burr portion 15 and to always obtain a certain quality.

Further, as shown in FIG. 3, in the present embodiment, the staying portion 13 is formed on the opposing wall surface 10 of one of the adjacent inserts 2 and 3.
This is to make it possible to remove and replace the adjacent nests 2 and 3 independently. As shown in the right view of FIG. 3, both opposing wall surfaces 10 of the adjacent nests 2A and 3A are assumed.・ As for 11, if the retention portion 13 </ b> A is formed, even if any one of the inserts 2 </ b> A and 3 </ b> A is moved upward in the figure, the solidified material 14 </ b> A cannot be moved due to being caught. Therefore, either one of the inserts 2A and 3A cannot be detached independently. In this respect, in the present embodiment, as shown in the left diagram of FIG. 3, the retention portion 13 is formed only on the opposing wall surface 10 of one of the inserts 2. It is possible to remove the coagulated substance 14 along with this.

  This makes it possible to replace one of the nests alone. For example, when the wear of the cavity surface of one of the nests 2 is severe and requires replacement, the nest 2 can be replaced alone. The other nesting 3 can be used continuously. As a result, the inserts 2 and 3 (molds) can be used for a long period of time, and the maintenance frequency can be reduced and the replacement work can be facilitated. In addition, by making it possible to replace it alone, it is possible to produce a molded product having a different shape with respect to the part of the replaced nest by replacing one nest with a nest having a cavity surface of another shape. Become.

Next, formation of the burr part 15 when injection molding using the inserts 2 and 3 constituting the gap 9 as described above is performed will be described.
As shown in FIG. 4, when the molten metal is injected for the first time, before the injection is started, the gap 9 and the staying portion 13 are in a state where there is no molten metal and solidified material (state) S1). And when the molten metal 20 is inject | emitted, the molten metal 20 penetrate | invades from the said micro flow path 12, and the molten metal 20 is satisfy | filled in the retention part 13 (state S2). When the molded product 30 is removed after solidification, the solidified material 14 formed in the staying portion 13 and the microchannel 12 are formed by the locking portion 13a (see FIG. 2). The burr part 15 thus formed is divided, and the burr part 15 is removed from the gap 9 together with the molded product 30 (state S3).

  Thus, when the first injection molding is performed, as shown in the state 3, the solidified matter 14 remains in the staying portion 13. In the second and subsequent injection moldings, the molten metal 20 is allowed to enter the micro flow channel 12 by the solidified material 14 (state S4), and the molten metal 20 that has entered the micro flow channel 12 is solidified after solidification. Then, it becomes the burr part 15 and is removed from the gap 9 together with the molded product 30 (state S5).

  As described above, in the first injection molding, first, the stay portion 13 is filled with the solidified material 14, and in the second and subsequent injection moldings, the intrusion of the molten metal 20 is a range in which the microchannel 12 is formed. Will be acceptable. As a result, the height of the burrs 15 formed on the molded product 30 after demolding is constant, and as described above, management of the burrs 15 is facilitated, and always It becomes possible to obtain a certain quality.

  Although the above example has been described by using an example of injection molding, the present invention is generally applicable to a mold apparatus in which a split type insert is used in a molding process by solidification of a liquid substance. The application range is wide.

The figure shown about the structural example of the metal mold | die of the casting apparatus to which this invention is applied. (A) is a figure shown about the structure of each site | part of a clearance gap before a molten metal is inject | emitted. (B) is a figure which shows about the solidified material formed in a retention part after solidification of a molten metal, and the burr | flash part formed in a molded article. The figure shown about the single exchange possibility in the Example which comprises a stay part about one of the adjoining nests. The figure which shows the mode of the injection molding performed in the nesting to which this invention is applied about stepwise.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Movable type 2 Nesting 3 Nesting 4 Fixed type 5 Nesting 6 Sleeve 7 Tip 8 Cavity 8a Cavity surface 9 Crevice 10 Opposite wall 11 Opposite wall 12 Micro flow path 13 Retention part 13a Locking part 14 Solid matter 15 Burr part

Claims (5)

A mold structure in which a plurality of inserts are provided inside the mold, and a cavity is formed by the plurality of inserts,
In the gap of the defined width formed between the opposing wall surfaces of adjacent nests,
For the first range from the cavity surface to the first specified depth,
A microchannel configured with a first width wider than the specified width is formed,
For the second range from the first specified depth to the second specified depth located in the direction opposite to the cavity side,
A mold structure in which a retention portion having a second width wider than the first width of the microchannel is formed.   2. The mold structure according to claim 1, wherein the first width of the microchannel is designed to have a dimension that allows the molten metal injected into a cavity to be guided to the staying portion.   The retention portion is formed at a boundary portion between the micro flow channel and the retention portion, and a locking portion that retains in the retention portion and locks with a solidified solidified substance is formed. Or the metal mold | die structure of Claim 2.   The first specified depth is designed to have a depth dimension smaller than a burr height dimension for satisfying a quality standard of a molded product after demolding. 4. The mold structure according to any one of 3. The mold structure according to any one of claims 1 to 4, wherein the staying portion is formed on an opposing wall surface of one of the adjacent inserts.

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