JP2010110893A - Mold for injection molding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a molding from remaining in a fixed mold when a mold for injection molding is opened. <P>SOLUTION: The mold 10 for injection molding has an angular pin 34 in which one end is fixed to a movable template 26 and the other end is free and which extends slantingly in the mold opening direction, an inclined hole 37 into which the angular pin 34 is inserted, a slide core 35 which forms part of a cavity 36, a slide core plate 25 which supports the slide core 35 movably perpendicularly to the mold opening direction, and a slide core plate moving mechanism 29 which moves the slide core plate 25 in the mold opening direction. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an injection mold for molding a molded product having an undercut portion.

  In the mold for injection molding, when molding a molded product, set the cavity placement etc. so that the mold release resistance of the movable side mold is larger than the fixed side mold, and the movable side mold when opening the mold The molded product is released from the mold.

  However, when actually molded, the fixed side mold has a larger mold release resistance, and the molded product cannot be released from the fixed side mold, which may cause a problem that molding cannot be performed. is there.

  In such a case, for example, as shown in FIGS. 16 and 17, a molded product 143 formed between the fixed mold 111 and the movable mold 112 is used as the movable mold 112 when the mold is opened. In order to leave it, a Z-type eject pin 141 was used. The Z-shaped eject pin 141 is formed with a notch groove 141 a. The notch groove 141 a bites into the molded product 143, and the molded product 143 is reliably left in the movable mold 112. However, in this case, the shape of the molded product 143 cannot be achieved as designed, or the secondary processing is required.

  On the other hand, for example, Patent Document 1 discloses a technique that includes a nesting for releasing a molded product from a fixed mold when the mold is opened, and an urging unit that urges the nesting toward the movable mold. It is disclosed.

Accordingly, the undercut portion of the molded product is not cut off when the mold is opened, and the molded product can be reliably left in the movable mold.
JP 2004-1360 A

  However, according to Patent Document 1, the molded product is released from the insert in the middle of mold opening. However, the insert may be caught by the fixed mold or may be released smoothly due to a failure of the biasing means. There was a fear that it could not be done.

  The present invention has been made to solve such a problem, and an object of the present invention is to provide an injection mold that can reliably prevent a molded product from remaining in a fixed mold when the mold is opened. .

The present invention
In the mold for injection molding,
An angular pin having one end fixed to the movable side mold plate and the other end extending in a slanting manner with respect to the mold opening direction at the free end;
A slide core having a hole for inserting the angular pin and forming a part of the cavity;
A slide core plate that supports the slide core so as to be movable in a direction perpendicular to the mold opening direction;
A slide core plate moving mechanism for moving the slide core plate in the mold opening direction.

Further, the present invention provides the above injection mold,
The slide core plate moving mechanism is
It has a slide core plate moving pin that is mounted on an ejector plate that moves in the mold opening direction and moves the slide core plate in the mold opening direction.

Further, the present invention provides the above injection mold,
It further has a slide core plate movement restriction mechanism that restricts the amount of mold opening between the ejector plate that moves in the mold opening direction and the fixed side mold plate.

Further, the present invention provides the above injection mold,
The slide core plate is
A part of the cavity is formed on the same surface as the surface supporting the slide core.

  According to the present invention, it is possible to reliably prevent the molded product from remaining in the fixed mold when the mold is opened. And the molded product remaining in the movable mold can be reliably released.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[First Embodiment]
FIG. 1 is a cross-sectional view of an injection mold according to the first embodiment.

The injection mold 10 includes a fixed mold 11 and a movable mold 12 that are arranged to face each other across a _first parting line (PL ₁ ).
The movable mold 12 is arranged so as to be movable in the mold release direction (left and right direction in FIG. 1) with respect to the fixed mold 11.

The fixed-side mold 11 is in close contact with the fixed-side mold plate 13, the runner stripper plate 14 disposed in close contact with the fixed-side mold plate 13 and the second parting line (PL ₂ ), and the runner stripper plate 14. The fixed side mounting plate 15 is disposed.

  Further, a projecting piece 16 and a projecting piece 18 are provided on the side surfaces of the runner stripper plate 14 and the fixed-side template 13 respectively. On the projecting piece 16 of the runner stripper plate 14, a fixed-side template pulling link 17 is extended along the mold release direction. The fixed-side template pulling link 17 is slidably inserted into the projecting piece 18 of the fixed-side template 13. On the free end side of the fixed-side template pulling link 17, a head 19 for retaining is formed.

  The fixed-side template pulling link 17 serves to determine a stroke limit when the fixed-side template 13 is opened. That is, as shown in FIG. 3 to be described later, the fixed-side template 13 also moves in the releasing direction together with the movable-side mold 12 at the time of releasing, but the fixed-side template 13 is moved in the middle of the fixed-side template pulling link. 17 is caught on the head 19 and stops at that position.

A central sprue 20 is formed through the central portion (on the mold center axis side) of the fixed side mounting plate 15 and the runner stripper plate 14. The fixed-side template 13 has an opening 23 and a relief space 24 communicating with the opening 23 at the center on the side facing the _first parting line (PL ₁ ).

In addition, a runner 21 communicating with the central sprue 20 is formed on the fixed side template 13 in a direction orthogonal to the mold opening direction. Further, two branch sprues 22 are formed substantially parallel to the mold opening direction via the runner 21. The sprue 20 and 22 and the runner 21 form a resin injection path.

The movable side mold 12 includes a slide core plate 25 which is disposed in close contact with the fixed side mold plate 13 and the first parting line (PL ₁ ), a movable side mold plate 26 which is in close contact with the slide core plate 25, A spacer block 27 is in close contact with the movable side mold plate 26, and a movable side mounting plate 28 is in close contact with the spacer block 27.

  A movable side insert 33 is integrally fixed to the center of the mold of the movable side mold plate 26, and one end is fixed to the movable side mold plate 26 and the other end is a free end with respect to the mold opening direction. An angular pin 34 extending in an inclined manner is fixed.

Further, the slide core 35 is closely disposed on the slide core plate 25 so as to be slidable in a direction orthogonal to the mold opening direction through the _first parting line (PL ₁ ). The slide core 35 is regulated by a guide rail (not shown) so as to be movable on the slide core plate 25 in a direction orthogonal to the mold opening direction.

  At the center of the mold of the slide core 35, there are a through hole 30 penetrating in the mold opening direction, and an undercut forming space 31 communicating with the through hole 30 and projecting in a direction perpendicular to the mold opening direction (downward in FIG. 1). And are formed. Then, the movable side insert 33 is inserted into the through-hole 30 during mold clamping to form the cavity 36. The cavity 36 includes a bottomed cylindrical portion having a bottom surface 36 a and a side surface 36 b and an undercut forming space 31.

Thus, the slide core 35 forms a part of the side surface 36 b of the cavity 36 and the undercut forming space 31.
In addition, although this embodiment demonstrated the case where the undercut formation space 31 protruded to one side (downward of FIG. 1) orthogonal to the mold opening direction, it is not restricted to this. For example, the undercut formation space 31 may protrude in both directions (upward and downward in FIG. 1) perpendicular to the mold opening direction.

  Further, the slide core 35 is formed with an inclined hole 37 into which the angular pin 34 is inserted. The angular pin 34 extends through the inclined hole 37 to the escape space 24.

  Further, a slide core plate moving mechanism 29 is provided inside the spacer block 27. The slide core plate moving mechanism 29 includes an ejector plate upper 39, an ejector plate lower 40, an ejector pin 41, and a slide core plate moving pin 42. The ejector pin 41 is disposed so as to be sandwiched between the upper ejector plate 39 and the lower ejector plate 40 at the center of the mold, and the slide core plate moving pin 42 is disposed around the mold.

Next, the operation will be described.
(Procedure 1)
In FIG. 2, the resin 38 is filled from the central sprue 20 into the cavity 36 with the mold closed. Further, the pressure holding state is maintained at a predetermined pressure with respect to the filled resin 38. Thereafter, the fixed mold 11 and the movable mold 12 are cooled to a predetermined temperature. Thereby, the resin 38 in the cavity 36 is solidified.
(Procedure 2)
Next, as shown in FIG. 3, the movable-side mold 1 is opened by a mold opening operation of a mold clamping unit (not shown).
2 and the stationary side template 13 are opened in the mold opening direction with the _second parting line (PL ₂ ) as a boundary with respect to the runner stripper plate 14. Thereby, the stationary side template 13 and the runner stripper plate 14 are separated from each other.

At this time, the separation distance between the fixed-side template 13 and the runner stripper plate 14 is regulated by the length of the fixed-side template pulling link 17. At the same time, the flow path resin 44 solidified at the central sprue 20, the runner 21, and the branch sprue 22 is torn off at the pin gate.
(Procedure 3)
Next, as shown in FIG. 4, due to the further mold opening, the fixed side mold plate pulling link 17 causes the gap between the fixed side mold plate 13 and the runner stripper plate 14 not to be opened any further.

Thereafter, the fixed-side mold plate 13 and the slide core plate 25 are opened in the mold opening direction with the _first parting line (PL ₁ ) as a boundary. At this time, the slide core 35 supported by the angular pin 34 is kept in close contact with the slide core plate 25.

Further, since most of the periphery of the molded product 43 is in contact with the movable side insert 33 and the slide core 35, the molded product 43 can be reliably released from the fixed side mold 11.
(Procedure 4)
Next, as shown in FIG. 5, the upper ejector plate 39 and the lower ejector plate 40 are projected and moved toward the fixed mold 11 (leftward in FIG. 5), and the slide core plate moving pin 42 is projected in the same direction. . Thereby, the slide core plate 25 is separated from the movable side mold plate 26. At this time, the slide core 35 moves along the angular pin 34 in a direction perpendicular to the mold opening direction so as to be away from the mold axis center. In this case, the slide core 35 slides while being regulated by a guide rail (not shown).

  Further, the molded product 43 (including the undercut portion) is released from the slide core 35 by moving the slide core 35 in a direction orthogonal to the mold opening direction. At the same time, the molded product 43 is released from the movable side insert 33 by the ejection of the ejector pin 41.

  According to the present embodiment, the angular pin 34, the inclined core 37 into which the angular pin 34 is inserted, the slide core 35 that forms part of the cavity 36 including the undercut forming space 31, and the slide core 35. The slide core plate 25 is movably supported in a direction perpendicular to the mold opening direction, and the slide core plate moving mechanism 29 is configured to move the slide core plate 25 in the mold opening direction. It is possible to reliably prevent the fixed side mold 11 from remaining.

Then, the molded product 43 remaining in the movable mold 12 can be ejected by the ejector pin 41 and reliably released.
In this embodiment, the slide core plate moving mechanism 29 is mounted on the upper ejector plate 39 and the lower ejector plate 40 and has the slide core plate moving pin 42 for moving the slide core plate 25 in the mold opening direction. The ejector mechanism of the illustrated mold clamping unit can be used, and the structure of the injection mold 10 can be simplified.
[Second Embodiment]
FIG. 6 is a cross-sectional view of an injection mold according to the second embodiment. In addition, the same code | symbol is attached | subjected and demonstrated to the member which is the same as that of 1st Embodiment, or corresponds.

In the present embodiment, the projecting pieces 4 are respectively formed on the side surface portions of the fixed-side template 13 and the slide core plate 25.
7, a projecting piece 48 is provided, and a slide core plate pulling link 46 as a slide core plate movement restricting mechanism is extended from the projecting piece 47 of the fixed-side template 13 along the releasing direction.

  The slide core plate pulling link 46 is slidably inserted into the projecting piece 48 of the slide core plate 25. On the free end side of the slide core plate pulling link 46, a head 49 for retaining is formed.

In this embodiment, the slide core plate moving pin 42 is integrally fixed to the slide core plate 25. Other configurations are the same as those of the first embodiment.
Next, the operation will be described.
(Procedure 1)
In FIG. 7, with the mold closed, the cavity 36 is filled with resin from the central sprue 20, and then the pressure holding state is maintained at a predetermined pressure. Thereafter, the fixed mold 11 and the movable mold 12 are cooled to a predetermined temperature. Thereby, the resin in the cavity 36 is solidified and the molded product 43 is molded.
(Procedure 2)
Next, as shown in FIG. 8, by the mold opening operation of a mold clamping unit (not shown), the stationary side mold plate 13 and the runner stripper plate 14 are in the mold opening direction with the _second parting line (PL ₂ ) as a boundary. To be opened. At this time, the separation distance between the fixed-side template 13 and the runner stripper plate 14 is regulated by the length of the fixed-side template pulling link 17. At the same time, the flow path resin 44 solidified at the central sprue 20, the runner 21, and the branch sprue 22 is torn off at the pin gate portion and taken out and removed.
(Procedure 3)
By further mold opening, as shown in FIG. 9, the fixed side mold plate 13 and the runner stripper plate 14 are not further opened by the action of the fixed side template pulling link 17.

Next, the fixed-side template 13 and the slide core plate 25 are opened with the first parting line (PL ₁ ) as a boundary. At this time, the slide core 35 supported by the angular pin 34 is opened while being in close contact with the slide core plate 25.

Most of the molded product 43 is in contact with the movable side insert 33 and the slide core 35. For this reason, the molded product 43 can be reliably released without remaining in the fixed mold 11.
The above (Procedure 1) to (Procedure 3) are the same as those in the first embodiment.
(Procedure 4)
Next, as shown in FIG. 10, when the mold is further opened, the opening amount between the fixed side mold plate 13 and the slide core plate 25 is restricted by the slide core plate pulling link 46 and stopped. After that, the space between the slide core plate 25 and the movable side mold plate 26 opens. As a result, the slide core plate 25 is separated from the movable mold plate 26 in the mold opening direction by an amount corresponding to the protruding amount of the slide core plate moving pin 42.

  At this time, the slide core 35 moves along the angular pin 34 in a direction orthogonal to the mold opening direction while being regulated by a guide rail (not shown). At this time, the slide core plate moving pin 42 fixed to the slide core plate 25 advances the ejector plate upper 39 and the ejector plate lower 40 in the mold opening direction (to the left in the figure), and the molded product 43 is moved to the movable side. The mold is released from the nest 33.

According to this embodiment, the molded product 43 can be reliably released from the movable mold 12. That is, since it has the slide core plate tension link 46 which restricts the mold opening amount of the ejector plate upper 39 and the ejector plate lower 40 and the fixed side mold plate 13, the molded product 4
3 can be reliably released from the movable mold 12.

Moreover, according to this embodiment, since the molded product 43 can be released from the movable mold 12 in the mold opening process, the molded product ejection process can be shortened.
[Third Embodiment]
FIG. 11 is a cross-sectional view of an injection mold according to the third embodiment. In addition, the same code | symbol is attached | subjected and demonstrated to the member which is the same as that of 1st Embodiment, or corresponds.

  In the present embodiment, the slide core plate 25 is characterized in that a part of the cavity 36 is formed on the same surface 25 a as the surface supporting the slide core 35. That is, the slide core plate 25 supports the slide core 35 so as to be movable in a direction orthogonal to the mold opening direction, and further, the cavity 36 is formed on the same surface 25a as the surface supporting the slide core 35 at the center of the mold. Form a part of In the present embodiment, the ejector pin 41 is not necessary.

Next, the operation will be described.
(Procedure 1)
In FIG. 12, with the mold closed, the cavity 36 is filled with resin from the central sprue 20, and then the pressure holding state is maintained at a predetermined pressure. Thereafter, the fixed mold 11 and the movable mold 12 are cooled to a predetermined temperature. Thereby, the resin in the cavity 36 is solidified and the molded product 43 is molded.
(Procedure 2)
Next, as shown in FIG. 13, by the mold opening operation of the mold clamping unit (not shown), the fixed side mold plate 13 and the runner stripper plate 14 are in the mold opening direction with the _second parting line (PL ₂ ) as a boundary. To be opened. At this time, the separation distance between the fixed-side template 13 and the runner stripper plate 14 is regulated by the length of the fixed-side template pulling link 17. At the same time, the flow path resin 44 solidified at the central sprue 20, the runner 21, and the branch sprue 22 is torn off at the pin gate portion and taken out and removed.

The above (Procedure 1) and (Procedure 2) are the same as those in the first embodiment.
(Procedure 3)
Next, as shown in FIG. 14, no further opening between the fixed side mold plate 13 and the runner stripper plate 14 due to the action of the fixed side mold plate pulling link 17 due to further mold opening.

Thereafter, the fixed-side template 13 and the slide core plate 25 are opened with the first parting line (PL ₁ ) as a boundary. At this time, since most of the molded product 43 is in contact with the movable side insert 33 and the slide core 35, the molded product 43 can be reliably released without remaining in the fixed side mold 11.
(Procedure 4)
Next, as shown in FIG. 15, the ejector rod of the mold clamping unit (not shown) is moved forward (to the left in the figure) to push the ejector plate upper 39 and the ejector plate lower 40. As a result, the slide core plate 25 is moved in the mold opening direction in a manner protruding from the slide core plate moving pin 42 and is separated from the movable side mold plate 26.

At this time, the slide core 35 moves in a direction orthogonal to the mold opening direction while being regulated by a guide rail (not shown) along the angular pin 34. In this case, since a part of the cavity 36 is formed by the surface 25a of the slide core plate 25, the slide core plate 25 is protruded while the molded product 43 is held by the surface 25a, so that the slide core 35 is molded. 43 can be removed. At the same time, the molded product 43 is released from the movable side insert 33.

According to the present embodiment, as in the first embodiment, the molded product 43 can be reliably released from the movable mold 12 without remaining in the fixed mold 11.
In addition, according to the present embodiment, the molded product 43 can be released from the movable mold 12 by the slide core plate 25, so that the ejector pin 41 does not need to be ejected. For this reason, the molded product 43 in which an ejector trace does not remain can be obtained.

It is sectional drawing of the metal mold | die for injection molding of 1st Embodiment. It is a figure which shows a mold release process same as the above. It is a figure which shows a mold release process same as the above. It is a figure which shows a mold release process same as the above. It is a figure which shows a mold release process same as the above. It is sectional drawing of the metal mold | die for injection molding of 2nd Embodiment. It is a figure which shows a mold release process same as the above. It is a figure which shows a mold release process same as the above. It is a figure which shows a mold release process same as the above. It is a figure which shows a mold release process same as the above. It is sectional drawing of the metal mold | die for injection molding of 3rd Embodiment. It is a figure which shows a mold release process same as the above. It is a figure which shows a mold release process same as the above. It is a figure which shows a mold release process same as the above. It is a figure which shows a mold release process same as the above. It is sectional drawing of the conventional injection mold. It is sectional drawing of an eject pin same as the above.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Injection mold 11 Fixed side mold 12 Movable side mold 13 Fixed side mold plate 14 Ranna stripper plate 15 Fixed side mounting plate 16 Projection piece 17 Fixed side mold plate tension link 18 Projection piece 19 Head 20 Central sprue 21 Runner 22 Branch sprue 23 Opening 24 Escape space 25 Slide core plate 25a Surface 26 Movable side mold plate 27 Spacer block 28 Movable side mounting plate 29 Slide core plate moving mechanism 30 Through hole 31 Undercut formation space 33 Movable side nest 34 Angular pin 35 Slide core 36 Cavity 36a Bottom surface 36b Side surface 37 Inclined hole 38 Resin 39 Upper ejector plate 40 Ejector plate lower 41 Ejector pin 42 Slide core plate moving pin 43 Molded product 44 Flow path section resin 46 Slide core plate pulling link 47 Projection piece 8 projecting pieces 49 head

Claims (4)

In the mold for injection molding,
An angular pin having one end fixed to the movable side mold plate and the other end extending in a slanting manner with respect to the mold opening direction at the free end;
A slide core having a hole for inserting the angular pin and forming a part of the cavity;
A slide core plate that supports the slide core so as to be movable in a direction perpendicular to the mold opening direction;
An injection mold, comprising: a slide core plate moving mechanism that moves the slide core plate in a mold opening direction. The slide core plate moving mechanism is
The injection mold according to claim 1, further comprising a slide core plate moving pin that is mounted on an ejector plate that moves in a mold opening direction and moves the slide core plate in a mold opening direction. The injection mold according to claim 1, further comprising a slide core plate movement restriction mechanism for restricting a mold opening amount between the ejector plate moving in the mold opening direction and the fixed side mold plate. The slide core plate is
The mold for injection molding according to claim 1, wherein a part of the cavity is formed on the same surface as the surface supporting the slide core.

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