JP2000071260A - Molding mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a molding mold of high reliability which can prevent the positional dislocation of a core pin for forming a column-shaped part and a core pin for forming a branch part without causing the remarkable decrease of the flexural strength of the core pin for forming the column-shaped part. SOLUTION: The tip part 7 of a core pin 6 for forming a branch part is formed in the form of a wedge so that a blade part 8 meets the axial direction of a core pin 5 for forming a column-shaped part nearly at right angles, a notch part 10 is formed in a part of the blade part 8, an engagement channel 9 which engages with the wedge-shaped tip part 7 of the core pin 6 is formed in a part of the core pin 5 which is brought into contact with the tip part 7 of the core pin 6, and an intra-channel projection 11 which engages with the notch part 10 of the tip part 7 of the core pin 6 is formed in the channel 9. The projection 11 of the core pin 5 is formed in a shape corresponding to a part (partial column-shaped body) of a column-shaped body whose axial direction is the same with that of the core pin 5, the notch part 10 of the core pin 6 is shaped to engage with the projection 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding die, and more particularly, to a columnar cavity and a branch cavity branched from the columnar cavity through a step of injecting a molding material such as a molten resin into a cavity. The present invention relates to a molding die for producing a molded article having:

[0002]

2. Description of the Related Art For example, a molding material such as a molten resin is injected into a metal mold, and as shown in FIG.
Molded body 5 having a structure in which a branched gap (in this example, a gap orthogonal to the columnar gap 51) 52 is formed.
In the case of manufacturing No. 3, usually, as shown in FIG. 6, a core pin 55 for forming a columnar portion is inserted into a cavity 54 of a mold,
While being arranged, the branch forming core pin 56 was inserted and arranged so as to be orthogonal to the columnar portion forming core pin 55, and the molding material was injected into the cavity 54 to solidify the molding material. Thereafter, a method is used in which the core pin 56 for forming the branch portion is retracted, the mold is divided, and the molded body 53 (FIG. 1) is taken out.

[0003] Conventionally, as a method of assembling the branch-forming core pin 56 integrally with the column-forming core pin 55 by, for example, as shown in FIG. 8, a tip 57 of the branch-forming core pin 56 is used. To the blade 5
8 is processed into a wedge shape substantially perpendicular to the axial direction of the core pin 55 for forming the columnar portion, and the core pin 55 for forming the columnar portion is formed.
The wedge-shaped tip portion 57 of the branch portion forming core pin 56
A V-shaped fitting groove 59 corresponding to the columnar portion is formed by inserting and fitting the distal end portion 57 of the branch portion forming core pin 56 into the fitting groove 59 as shown in FIG. A method of integrally combining the core pin 55 and the branch portion forming core pin 56 is used.

However, in the above method, since the V-shaped fitting groove 59 is formed in the core pin 55 for forming the columnar portion, there is a problem that the bending strength of the core pin 55 for forming the columnar portion is significantly reduced. .

Further, at the abutting portion of the core pin 55 for forming the columnar portion and the core pin 56 for forming the branch portion, the core pin 55 for forming the columnar portion or the core pin 56 for forming the branch portion is formed by cutting the tip 57 of the tip 57 of the core pin 56 for forming the branch portion. There is a possibility that displacement may occur in a direction parallel to the portion 58, and there is a problem that reliability is low.

As shown in FIGS. 10 (a) and 10 (b), a recess 60 is formed at the tip end 57 of the branch portion forming core pin 56 so as to be fitted with the outer peripheral portion of the columnar portion forming core pin 55. As shown in FIGS. 11 (a) and 11 (b), a U-shaped fitting groove 61 is formed in the columnar portion forming core pin 55 to be fitted with the tip portion 57 of the branch portion forming core pin 56. Things have also been done.

However, in the case of the structure shown in FIGS. 10 (a) and 10 (b), the tip 57
As a result, a thin portion 59 having an extremely small thickness is formed, which not only makes processing difficult, but also causes a problem that misalignment between the columnar portion forming core pin 55 and the branch portion forming core pin 56 is likely to occur. .

Also, in the case of the structure shown in FIGS. 11A and 11B, not only does the bending strength of the columnar portion forming core pin 55 drop significantly, but also the columnar portion forming core pin 5 does not.
There is a problem in that the misalignment between the core pin 5 and the branch portion forming core pin 56 is likely to occur.

The present invention solves the above-mentioned problems, and prevents the displacement of the core pin for forming the column portion and the core pin for forming the branch portion without causing a significant decrease in the bending strength of the core pin for forming the column portion. It is an object of the present invention to provide a highly reliable molding die that can perform molding.

[0010]

In order to achieve the above object, a molding die according to the present invention (claim 1) includes a step of injecting a material to be molded into a cavity, and a columnar void inside the cavity. A molding die for producing a molded body having a branch cavity branched from a columnar cavity, wherein a dividable mold body in which a cavity having a shape corresponding to the shape of the molded body is formed. A column-shaped portion forming core pin is provided in the cavity to form a column-shaped void, and a tip is abutted to the column-shaped portion forming core pin in the cavity to form the branching space. And a branch portion forming core pin to be provided, and, of the branch portion forming core pin, a tip portion in contact with the columnar portion forming core pin,
In a wedge shape, the blade portion is substantially perpendicular to the axial direction of the columnar portion forming core pin, and has a shape in which a part of the blade portion is notched, and the columnar portion forming core pin has a branch portion forming core pin. In the portion where the tip portion abuts, a fitting groove for fitting with the wedge-shaped tip portion of the branch portion forming core pin is formed, and the blade portion of the tip portion of the branch portion forming core pin is formed in the fitting groove. An in-groove projection that fits into the cutout portion (notch portion) is formed, and at the fitting portion between the tip of the branch portion forming core pin and the columnar portion forming core pin, the blade portion of the branch portion forming core pin is formed. The notch, the fitting groove of the columnar portion forming core pin and the protrusion in the groove are fitted to each other, and the branching portion forming core pin and the columnar portion forming core pin are integrally combined.

The tip of the branch-forming core pin is wedge-shaped, and the blade has a shape substantially perpendicular to the axial direction of the column-forming core pin, and a notch is provided in a part of the blade. In the columnar portion forming core pin, at the portion where the tip of the branch portion forming core pin abuts, a fitting groove for fitting with the wedge-shaped tip of the branch portion forming core pin is provided, and in the fitting groove, Since the in-groove projection is formed to fit with the notch at the tip of the branch portion forming core pin, the blade portion and the notch of the branch portion forming core pin and the columnar portion forming core pin are fitted. By fitting the groove and the protrusion in the groove, the branch portion forming core pin and the columnar portion forming core pin can be surely combined integrally so as not to cause displacement.

Further, the protrusion in the groove, which is formed in the fitting groove of the core pin for forming the columnar portion and which fits into the notch at the tip of the core pin for forming the branch portion, improves the bending strength of the core pin for forming the columnar portion. Therefore, it is possible to prevent the bending strength from being greatly reduced and improve the reliability.

In the present invention, the term "wedge-like shape in which the blade portion is substantially perpendicular to the axial direction of the core pin for forming the columnar portion" means a substantially wedge-like shape, and the tip portion is rounded. This is a broad concept that includes the shape of the cutting edge and the shape in which the tip of the blade at the tip is cut.

According to a second aspect of the present invention, in the molding die, the protrusion in the groove of the core pin for forming the columnar portion has a portion (partial columnar portion) of the columnar body having the same axial direction as the axial direction of the core pin for forming the columnar portion. ), And the cutout portion of the branch portion forming core pin has a shape that fits into the partial columnar body.

The protrusion in the groove of the core pin for forming a columnar portion is formed in a shape corresponding to a part (partial columnar body) of the columnar body having the same axial direction as the core pin for forming the columnar portion, and the core pin for forming the branch portion is cut. When the notch is shaped to fit with the protrusion in the groove (partial columnar body), the core pin for forming the branch portion and the core pin for forming the columnar portion are surely fitted to each other to prevent the displacement of both. It is possible to
The protrusion in the groove (partial columnar body) reliably suppresses a decrease in bending strength of the core pin for forming the columnar portion, thereby improving reliability.

According to a third aspect of the present invention, in the molding die, a part of the protrusion in the groove of the core pin for forming the columnar portion is formed in a portion where the fitting groove is not formed in the axial direction of the core pin for forming the columnar portion. It reaches the same position as the outer peripheral surface, and is characterized in that a part of the outer peripheral surface of the core pin for forming the columnar portion in the circumferential direction has no step including the fitting groove.

A part of the protrusion in the groove of the core pin for forming a columnar portion reaches in the axial direction of the core pin for forming the columnar portion the same position as the outer peripheral surface of the portion where the fitting groove is not formed,
When a part of the outer peripheral surface of the columnar portion forming core pin in the circumferential direction is configured to have no step including the fitting groove, the bending strength of the columnar portion forming core pin is adjusted to form the fitting groove. It is possible to securely fit the branch portion forming core pin and the columnar portion forming core pin while holding to a degree not inferior to the case where it is not performed, and it is possible to make the present invention more effective it can.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described, and features thereof will be described in more detail. FIG. 1 is a perspective view showing a molded body manufactured using a molding die according to an embodiment of the present invention, and FIGS. 2A and 2B are molding dies for injection molding according to an embodiment of the present invention. FIG. 3 is a cross-sectional view showing a configuration of a main part of the mold, and FIG. 3 is a perspective view showing a main part of the lower mold. FIG. 4 is a perspective view showing a main part of a columnar part forming core pin and a branch part forming core pin, and FIG. 5 is a view showing a state in which the columnar part forming core pin and the branch part forming core pin are engaged with each other. is there.

As shown in FIG. 1, the molding die of this embodiment has a columnar gap 1 therein and a branching gap branched from the columnar gap 1 (in this example, a gap orthogonal to the columnar gap 1).
This is a molding die for producing a molded body 3 made of a resin having a structure in which the molded body 3 is formed, and has a shape corresponding to the molded body 3 as shown in FIG. 2 (a), (b) and FIG. A mold body 20 having a splittable upper mold 21 and a lower mold 22 in which a cavity 4 is formed, and a mold body 20 is provided so as to penetrate the cavity 4, and a lower end of the mold body 20 is formed in the lower mold 22. A fixed core pin (column-forming core pin) 5 for forming the column-shaped gap 1 and a tip 7 having a column-forming core pin 5
Is inserted into the cavity 4 in such a manner as to contact the
A core pin (core pin for forming a branch portion) 6 for forming the branch gap 2 (FIG. 1) and a gate 15 (FIG. 3) as an injection port of a molten resin as a molding material are provided.

The branch-forming core pin 6 is configured to be able to move forward and backward so that the molded body can be taken out of the cavity 4 after molding. That is, on the lower surface side of the upper mold 21, the angular pin 23 and the taper block 24 for linking the branch portion forming core pin 6 with the opening / closing operation of the upper mold 21 and the lower mold 22 are arranged. A pin hole 25 into which the angular pin 23 is fitted and a taper portion 26 which engages with the taper block 24 are provided on the upper surface side of the lower mold 22, and the upper mold 21 and the lower mold 22 are opened and closed. The branch portion forming core pin 6 is configured to advance or retreat in conjunction with the operation.

In the molding die of this embodiment, as shown in FIGS. 4 and 5, the tip 7 of the branch portion forming core pin 6 which comes into contact with the columnar portion forming core pin 5 is used.
Is formed in a wedge shape so that the blade portion 8 is substantially perpendicular to the axial direction of the columnar portion forming core pin 5, and a cutout portion 10 is formed by cutting out a part of the blade portion 8, while the columnar portion is formed. A fitting groove 9 that fits with the wedge-shaped tip 7 of the branch-forming core pin 6 is formed in a portion of the forming core pin 5 where the tip 7 of the branch-forming core pin 6 abuts.
Inside the fitting groove 9, an in-groove projection 11 that fits into the notch 10 of the tip 7 of the branch portion forming core pin 6 is formed.

The in-groove projection 11 has a shape corresponding to a part (partial columnar body) of a columnar body (in this embodiment, a prism) having the same axial direction as the axial direction of the core pin 5 for forming the columnar part. The part 11a of the protrusion 11 in the groove (the part corresponding to the ridge line part of the prism) is located at the same position as the outer peripheral surface of the part where the fitting groove 9 is not formed in the axial direction of the core pin 5 for forming the columnar part. In this portion, a part of the outer peripheral surface of the columnar portion forming core pin 5 including the fitting groove 9 is flat, that is, flat.

Therefore, as shown in FIG. 6, the core pin 5 for forming the column is inserted and disposed in the cavity 4 of the mold, and the core pin 6 for forming the branch is perpendicular to the core pin 5 for forming the column. After the molten resin (the material to be molded) is injected into the cavity 4 and the molten resin is solidified, the core pin 6 for forming the branch portion is retracted, and the mold is divided and molded. When the molded body is manufactured by a method of taking out the body 3 (FIG. 1), the blade portion 8 and the notch portion 10 of the branch portion forming core pin 6 and the columnar portion forming core pin 5 are formed.
The fitting groove 9 and the in-groove projection 11 are fitted to each other, and the branch portion forming core pin 6 and the columnar portion forming core pin 5 are integrally combined. Therefore, it is possible to surely prevent a displacement between the two. Become like

Further, the fitting groove 9 of the core pin 5 for forming the columnar portion is formed.
Of the tip portion 7 of the branch portion forming core pin 6
Is formed with a notched portion (notched portion) 10 so as to fit in the groove. Therefore, as in the conventional case in which only a V-shaped fitting groove is formed, a core pin for forming a columnar portion is formed. 5 can be prevented from lowering in bending strength, and the reliability can be improved.

Further, in the case of this embodiment, a part (a portion corresponding to the ridge of the prism) 11a of the in-groove projection 11 of the core pin 5 for forming the columnar portion is fitted in the axial direction of the core pin 5 for forming the columnar portion. Since it reaches the same position as the outer peripheral surface of the part where the mating groove 9 is not formed, the in-groove projection 11 reduces the bending strength of the columnar part forming core pin due to the formation of the fitting groove 9. It is possible to prevent it efficiently.

Therefore, the columnar portion forming core pin 5 is
It is possible to withstand the bending load applied by the inflow of the molding material into the cavity 4 and to prevent the displacement of the columnar portion forming core pin 5 and the branch portion forming core pin 6 due to the load applied by the inflow resin. Thus, it is possible to obtain a molded body having high shape accuracy.

The shape of the butted portion of the core pin 5 for forming the columnar portion and the core pin 6 for forming the branch portion is not limited to the shape of the above-described embodiment. For example, as shown in FIG. A partially cylindrical in-groove projection 31 is formed on the core pin 5 for forming a branch, and the tip 7 of the core pin 6 for forming a branch portion is formed.
Furthermore, it is also possible to form the cutout portion 30 having a curved shape corresponding to the partial columnar in-groove projection 31. Also,
It is also possible to adopt other shapes as the shape of the butted portion of the core pin 5 for forming the columnar portion and the core pin 6 for forming the branch portion.

In the above embodiment, a molding die for manufacturing a molded body 3 having a columnar cavity 1 and a branch cavity 2 branched at a right angle from the columnar cavity 1 has been described as an example. The present invention can also be applied to a case where a molded body in which the gap 1 and the branch gap 2 are branched at a predetermined angle other than a right angle is manufactured.

The present invention also provides, in yet other respects,
The present invention is not limited to the above embodiment, but relates to the specific shapes of the core pin for forming the columnar portion and the core pin for forming the branch portion, the shape and structure of the mold body and the cavity, the type of the material to be molded, and the like. It is possible to add various applications and modifications within the range of.

[0030]

As described above, in the molding die according to the present invention (claim 1), the tip of the core pin for forming the branch portion is formed in a wedge shape, and the blade portion is formed in the axial direction of the core pin for forming the columnar portion. It has a substantially orthogonal shape, and a cutout is provided in a part of the blade portion, and the wedge-shaped branch portion forming core pin is formed in a portion of the columnar portion forming core pin where the tip of the branch portion forming core pin abuts. Since a fitting groove for fitting with the tip of the branch pin is provided, and a projection in the groove for fitting with the notch of the tip of the branch portion forming core pin is formed in the fitting groove. The blade section and the notch of the section forming core pin are fitted to the fitting groove and the protrusion in the groove of the columnar section forming core pin, so that the branch section forming core pin and the columnar section forming core pin are not displaced. Can be surely combined together.
In addition, the protrusion in the groove formed in the fitting groove of the core pin for forming the columnar portion, which fits into the notch at the tip of the core pin for forming the branch portion, contributes to the improvement of the bending strength of the core pin for forming the columnar portion. Therefore, it is possible to prevent the bending strength from being greatly reduced, and to improve the reliability.

Further, as in the molding die of the second aspect, the protrusion in the groove of the core pin for forming the columnar portion is partially (partial columnar) of the columnar body having the same axial direction as the axial direction of the core pin for forming the columnar portion. If the cutout portion of the branch portion forming core pin is formed into a shape that fits with the in-groove projection (partial columnar body), the branch portion forming core pin and the columnar portion forming core pin can be securely connected. , The displacement between the two can be reliably prevented, and the protrusion in the groove (partial columnar body) reliably prevents the bending strength of the core pin for forming the columnar portion from lowering. Performance can be improved.

Further, as in the molding die of the third aspect, a part of the protrusion in the groove of the core pin for forming the columnar portion is a portion where the fitting groove is not formed in the axial direction of the core pin for forming the columnar portion. In the case where the outer peripheral surface of the core pin for forming the columnar portion has reached the same position as that of the outer peripheral surface of the columnar portion, a part of the outer peripheral surface of the outer peripheral surface of the core pin for forming the columnar portion has no step including the fitting groove. The bending strength of the core pin for the diverging part and the core pin for forming the columnar part can be securely fitted while maintaining the bending strength of the core pin for the same degree as when the fitting groove is not formed. Thus, the present invention can be made more effective.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a molded body manufactured using a molding die according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a configuration of a main part of a molding die for injection molding according to an embodiment of the present invention, in which (a) is a diagram illustrating a state in which an upper mold and a lower mold are separated; (b) is a diagram showing a state where the upper mold and the lower mold are combined.

FIG. 3 is a perspective view showing a configuration of a main part of a lower mold constituting a molding die for injection molding according to an embodiment of the present invention.

FIG. 4 is a perspective view showing a main part of a core pin for forming a columnar portion and a core pin for forming a branch portion, which constitute a molding die for injection molding according to an embodiment of the present invention.

FIG. 5 is a view showing a state in which a core pin for forming a columnar portion and a core pin for forming a branch portion are engaged with each other, which constitute a molding die for injection molding according to an embodiment of the present invention.

FIG. 6 is a view for explaining a method for manufacturing a molded article.

FIG. 7 is a perspective view showing a main part of a core pin for forming a columnar portion and a core pin for forming a branch portion, which constitute a molding die for injection molding according to another embodiment of the present invention.

FIG. 8 is a perspective view showing a main part of a conventional core pin for forming a columnar portion and a core pin for forming a branch portion.

FIG. 9 is a view showing a state in which a conventional core pin for forming a columnar portion and a core pin for forming a branch portion are abutted and engaged.

10A is a perspective view showing a main part of another conventional core pin for forming a columnar portion and a core pin for forming a branch portion, and FIG.
FIG. 5 is a view showing a state in which the core pin for forming a columnar portion and the core pin for forming a branch portion are abutted and engaged.

FIG. 11A is a perspective view showing a main part of still another conventional core pin for forming a columnar portion and a core pin for forming a branch portion, and FIG.
FIG. 4A is a view showing a state in which the columnar portion forming core pin and the branch portion forming core pin of FIG.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 columnar gap 2 branch gap 3 molded body 4 cavity 5 columnar part forming core pin 6 branch part forming core pin 7 tip of branch part forming core pin 8 blade part of branch part forming core pin 9 fitting groove 10, 30 notch Part 11, 31 protrusion in groove 15 gate 20 mold body 21 upper mold 22 lower mold 23 angular pin 24 taper block 25 pin hole 26 taper part

Claims (3)

[Claims] 1. A molding die for producing a molded body having a columnar cavity and a branch cavity branched from the columnar cavity inside through a step of injecting a molding material into a cavity, comprising: A dividable mold main body in which a cavity having a shape corresponding to the shape of the body is formed, and a column-shaped portion forming core pin disposed in the cavity to form the column-shaped space; and the branch space. A branch portion forming core pin disposed in the cavity in such a manner that a tip portion thereof comes into contact with the columnar portion forming core pin, and wherein the branch portion forming core pin has a columnar portion forming portion. The tip portion in contact with the core pin is wedge-shaped, and the blade portion is substantially perpendicular to the axial direction of the columnar portion forming core pin, and has a shape in which a part of the blade portion is cut out. Branch type of core pin In the portion where the tip of the core pin for contact abuts, a fitting groove for fitting with the wedge-shaped tip of the core pin for branching is formed, and in the fitting groove, the tip of the core pin for branching is formed. A protrusion in the groove is formed to be fitted with the cutout portion (notch portion) of the blade, and a branch portion forming core pin is formed at the fitting portion between the tip of the branch portion forming core pin and the columnar portion forming core pin. The fitting portion of the blade portion and the notch portion, the fitting groove of the columnar portion forming core pin and the protrusion in the groove are fitted, and the branch portion forming core pin and the columnar portion forming core pin are integrally combined. Mold for molding. 2. The projection in a groove of the core pin for forming a columnar portion,
It has a shape corresponding to a part (partial columnar body) of a columnar body having the same axial direction as the axial direction of the columnar part forming core pin, and the cutout part of the branch part forming core pin has the same shape as the part. 2. The molding die according to claim 1, wherein the molding die has a shape that fits with the columnar body. 3. A part of the in-groove projection of the core pin for forming a columnar portion extends in the axial direction of the core pin for forming a columnar portion to the same position as the outer peripheral surface of a portion where no fitting groove is formed. 3. The molding die according to claim 1, wherein a part of the outer peripheral surface of the core pin for forming the columnar portion in the circumferential direction has no step including the fitting groove.