JP2009056750A - Injection molding die for manufacturing multiple articles - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To control filling balance of a resin in each cavity of an injection molding die for manufacturing multiple articles while the die is installed in a molding machine. <P>SOLUTION: The injection molding die 1 comprises a side gate type molding die for manufacturing two articles, and cavities 4 and 5 of the same shape are formed between a cavity plate 2 in a fixing side and a cavity plate 3 in a movable side. A resin flow channel is branched in an opposite direction against a sprue part 6 to form a lateral runner part 7 and reaches the cavities 4 and 5 through gates 8, 8. A resin flow rate controlling die 9 for a resin, which has almost a cylindrical shape and is installed in an intermittent position of the side runner 7, can be moved under slewing, and fixed on a cavity spacer 10 on a fixing side by a fixing bolt 11. A controlling runner 9a having the same width with and communicating to the lateral runner part 7 across the center is formed on an upper surface of the resin flow rate controlling die 9. Stepped stop holes 9b are formed in a circular shape near an outer periphery, and further two holes 9d are opened in point symmetrical positions about the center. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an injection mold and, more particularly, to a multi-cavity injection mold that facilitates the filling of resin into each cavity.

  Conventionally, in a multi-cavity injection mold, the resin flow path from the sprue part to each cavity has manufacturing variations, so that there is a difference in the resin filling completion time in each cavity and molding is performed there. Product quality varies. Therefore, it is necessary to balance the filling of the resin between the cavities in order to make the quality of the product uniform. Before the mold is completed, the mold is removed from the trial molding and molding machine. The mold correction is repeated many times.

Accordingly, various methods have been proposed in order to make the filling completion time of each cavity of the multi-cavity injection mold uniform. For example, there is a type in which a step is provided in a runner portion in a mold and a filling balance is achieved by a pressure difference (see Patent Document 1). In addition, there are various types of pins that change the cross section of the runner portion in the runner portion that leads to each cavity to obtain a filling balance (see Patent Document 2, Patent Document 3, and Patent Document 4).
JP 2005-324420 A JP 2002-292691 JP 09-141704 A JP 2001-269970 A

  However, in Patent Document 1, even if the resin filling balance is lost as a result of molding, the mold cannot be finely adjusted again. In Patent Documents 2 and 3, it is necessary to reassemble the mold to perform adjustment. In Patent Document 4, an internal pressure sensor and its mounting work are required, and the mold structure becomes complicated and expensive. Thus, in the conventional method, it is necessary to disassemble and re-adjust the mold, and the mold cannot be adjusted while it is attached to the molding machine. In addition, the mold structure is complicated and expensive. There is a problem that fine adjustment cannot be performed again.

  The above invention has been made to solve such a conventional problem, and the object thereof is to easily adjust the resin filling balance of each cavity without taking down the mold from the molding machine. The object is to provide a multi-cavity injection mold that can make the quality of products molded in each cavity uniform.

  The means of the present invention for solving the above-mentioned problems has a plurality of cavities formed between the fixed side mold and the movable side mold, and a lateral runner heading from the sprue portion to each of the cavities as a resin flow path Is a multi-piece injection mold that simultaneously molds a plurality of resin molded products, and an adjustment runner portion having the same cross-sectional dimension as the transverse runner portion so as to cross the transverse runner portion. In the multi-piece injection mold in which the resin flow rate adjusting piece is arranged and the resin flow rate adjusting piece is moved by a small amount to adjust the resin flow rate of the lateral runner part, the resin flow rate adjusting piece is provided. The piece has a substantially cylindrical shape, and a scale from the outer periphery to the center is formed on the upper surface of the resin flow rate adjusting piece. The upper surface of the cavity plate around the resin flow rate adjusting piece corresponds to the scale. Characterized in that that tally has is formed.

  In addition, at least two holes are formed at points symmetrical with respect to the center of the upper surface of the resin flow rate adjusting piece.

  As described above, according to the present invention, there are a plurality of cavities formed between the fixed side mold and the movable side mold, and the lateral runner parts are directed from the sprue part to the respective cavities as resin flow paths. Is a multi-piece injection mold for simultaneously molding a plurality of resin molded products, and has an adjustment runner portion having the same cross-sectional dimension as the transverse runner portion so as to cross the transverse runner portion. In the multi-piece injection mold in which a resin flow rate adjusting piece is arranged and the resin flow rate adjusting piece is moved by a small amount to adjust the resin flow rate of the lateral runner portion, the resin flow rate adjusting piece Has a substantially cylindrical shape, and a scale from the outer periphery to the center is formed on the upper surface of the resin flow rate adjusting piece, and the upper surface of the cavity plate around the resin flow rate adjusting piece corresponds to the scale. Since the mark is formed, it is easy to quantitatively check the fine adjustment of the resin flow rate with the injection mold attached to the injection molding machine, and the resin filling between the cavities Balance can be easily taken.

  In addition, since at least two holes are formed at positions that are point-symmetric with respect to the center of the upper surface of the resin flow rate adjusting piece, a small amount of movement of the resin flow rate adjusting piece can be turned using a simple tool. Easy to do.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a plan view of a main part showing a resin flow path of a two-piece injection mold according to a first embodiment of the present invention, and FIG. 2 is a main part of the injection mold showing the AA cross section of FIG. FIG. 3 is a plan view of the resin flow rate adjusting piece, and FIG. 4 is a front view of the resin flow rate adjusting piece. FIG. 5 is a plan view of a two-piece injection mold for explaining the operation of the resin flow rate adjusting piece.

  First, the configuration of the first embodiment of the present invention will be described with reference to FIGS. A two-piece injection mold 1 according to an embodiment of the present invention is a side-gate type two-plate mold, a fixed-side cavity plate 2 that is a fixed-side mold and a movable-side cavity plate that is a movable-side mold. 3 are formed with cavities 4 and 5 having the same shape. The resin flow path branches from the sprue portion 6 to opposite sides and reaches the cavities 4 and 5 through gates 8 and 8 at the tip of the lateral runner portion 7 formed on the upper surface of the movable cavity plate 3.

  A substantially cylindrical resin flow rate adjusting piece 9 shown in FIGS. 3 and 4 is disposed in the middle of the lateral runner portion 7. The resin flow rate adjusting piece 9 is turnable and is fixed on the fixed side cavity spacer 10 with fixing bolts 11. On the upper surface of the resin flow rate adjusting piece 9, there is formed an adjustment runner portion 9a having the same width across the center and communicating with the lateral runner portion 7, and a stepped stop hole 9b is formed in an arc shape near the outer periphery. . In addition, at least two holes 9d are opened at positions symmetrical with respect to the center. Further, a plurality of linear scales 9c directed toward the center are formed on the outer periphery on the opposite side of the stepped stop hole 9b. An alignment mark 2a corresponding to the scale 9c is formed on the upper surface of the movable cavity plate 2 which is a plate around the resin flow rate adjusting piece 9.

  Next, the operation of the present embodiment will be described with reference to FIG. When this injection mold 1 is completed, it is molded on a trial basis, and the filling condition of the resin into the cavities 4 and 5 is confirmed. At this time, if it is found that the resin arrives at one cavity 4 earlier than the resin arrives at the other cavity 5, the fixing bolt 11 on the cavity 5 side is removed without lowering the mold from the molding machine. Temporarily loosen and turn the resin flow rate adjusting piece 9 with the hole 9d as a clue to turn the position where it originally communicated by a small amount. A slight deviation is caused in the connecting portion between the lateral runner portion 7 and the adjustment runner portion 9a. As a result, the runner width is narrowed at the connecting portion and the resin flow rate is reduced, so that the arrival of the resin in the cavity 5 can be delayed. If the resin arrives at the cavity 4 earlier, the resin flow rate adjusting piece 9 on the cavity 4 side is similarly adjusted. By using the scale 9c and the alignment mark 2a, it is easy to quantitatively confirm the movement amount. In this manner, the resin filling balance between the cavity 4 and the cavity 5 can be easily adjusted.

  Next, the effect of the first embodiment will be described. Since the resin flow rate adjusting piece 9 is disposed in the middle of the lateral runner portion 7 and the position of the resin flow rate adjusting piece 9 is finely adjusted, the resin flow rate can be reduced. Thus, the resin filling balance between the cavity 4 and the cavity 5 can be easily adjusted with the mold mounted on the molding machine. In addition, since the resin flow rate adjusting piece 9 is cylindrical and has two holes 9d, a small amount of position can be easily moved by using a simple tool as a clue. Further, since the scale 9c is provided on the resin flow rate adjusting piece 9 and the alignment mark 2a is provided on the movable cavity plate 2, it is easy to check the position of the resin flow rate adjusting piece 9 by using these, and the adjustment is accurate in a short time. Can be done. Since the number of trial moldings can be reduced, the adjustment time of the mold is shortened, which contributes to the cost reduction of the mold.

  Next, a multi-cavity injection mold that is a second embodiment of the present invention will be described. FIG. 6 is a plan view showing a resin flow path of a multi-cavity injection mold according to the second embodiment of the present invention. FIG. 7 is a cross-sectional view showing the AA cross section of FIG.

  First, the configuration of the present embodiment will be described. 6 and 7, an injection mold 21 is an example in which the present invention is applied to a three-plate mold, and is a pinpoint gate type four-piece mold. The injection mold 21 is composed of a fixed mold in which a runner stripper plate 24, a runner plate 22, and a fixed cavity plate 26 are laminated, and a movable mold including a movable cavity plate 25 and the like. The resin flow path continues from the sprue portion 23 formed on the runner stripper plate 24 to the lateral runner portion 27 formed on the upper surface of the runner plate 22 and branches to both sides at right angles at a branch point P1 at the tip of the lateral runner portion 27. To the branch point P2, which is the leading end of

  A resin flow rate adjusting piece 9 is disposed so as to cross the lateral runner portion 27 between the branch points P1 and P2. The lateral runner portion 27 further branches at right angles to the both sides at the branch point P2 and goes to the longitudinal runner portions 28 and 28 and other two longitudinal runner portions (not shown). The vertical runner portion 28 reaches a gate 29 that is a pinpoint gate formed on the fixed-side cavity plate 26, and the gate 29 is connected to a cavity 30 formed on the upper surface of the movable-side cavity plate 25. The configuration of other vertical runners is the same. Since the configuration and operation of the resin flow rate adjusting piece 9 are the same as those of the first embodiment, the description thereof is omitted.

  Next, the effect of the second embodiment will be described. Since the resin flow rate adjusting piece 9 is disposed in the middle of the lateral runner portion 27 and the position of the resin flow rate adjusting piece 9 is finely adjusted so that the resin flow rate can be reduced, it is necessary to process the mold. Thus, the resin filling balance between the cavities 30 ahead of the branch point P2 can be easily adjusted with the mold attached to the molding machine.

  Next, the multi-piece injection mold which is the 3rd Embodiment of this invention is demonstrated. FIG. 8 is a plan view showing the resin flow path of the movable side mold of the multi-cavity injection mold according to the third embodiment of the present invention.

  First, the configuration of the present embodiment will be described with reference to FIG. Since this embodiment is the same as the first embodiment, detailed description thereof is omitted. The difference between the two is the position where the resin flow rate adjusting piece 9 is disposed. In the injection mold 31, the resin flow rate adjusting piece 9 is disposed so as to be directly connected to the gate 8.

  Next, the operation and effect of the present embodiment will be described. When the adjustment amount of the resin flow rate adjusting piece 9 is small, the width of the runner is only narrowed at the connection point between the runner 7 and the adjustment runner portion 9a. However, when the adjustment amount is larger than a certain amount, the width of the gate 8 is also reduced. It becomes like this. This can further increase the effect.

Next, an injection mold according to a fourth embodiment of the present invention will be described. FIG. 9 is a plan view showing a resin flow path of a multi-cavity injection mold according to the fourth embodiment of the present invention. Since this embodiment is substantially the same as the first embodiment, detailed description thereof is omitted. In the injection mold 41, the width of one lateral runner portion 7 to be balanced is formed larger than the width of the other runner portion 47. Therefore, by arranging the resin flow rate adjusting piece 9 only in one lateral runner portion 7 and adjusting only the resin flow rate adjusting piece 9, it is possible to balance the filling of the resin in both the cavities 4 and 5. In this case, it is possible to reduce the cost by making the mold simpler.

  In each of the embodiments described above, the resin flow rate adjusting piece 9 has a cylindrical shape. However, the resin flow rate adjusting piece is not necessarily limited to this shape. It may be movable in a direction perpendicular to the part.

It is a principal part top view which shows the resin flow path of the multi-piece injection mold which is the 1st Embodiment of this invention. It is principal part sectional drawing which shows the AA cross section of FIG. It is a top view of a resin flow rate adjustment piece. It is a front view of a resin flow rate adjustment piece. It is a principal part top view for demonstrating the effect | action of the multi-cavity injection mold which is the 1st Embodiment of this invention. It is a principal part top view which shows the resin flow path of the injection mold which is the 2nd Embodiment of this invention. It is sectional drawing which shows the AA cross section of FIG. It is a principal part top view which shows the resin flow path of the injection mold which is the 3rd Embodiment of this invention. It is a principal part top view which shows the resin flow path of the injection mold which is the 4th Embodiment of this invention.

Explanation of symbols

1, 21, 31, 41 Injection mold 2 Movable cavity plate 2a Alignment mark 4, 5, 30 Cavity 6, 23 Sprue part 7, 27, 47 Horizontal runner part 9 Resin flow rate adjusting piece 9a Adjustment runner part 9c Scale 9d Hole 22 Runner plate 28 Vertical runner part

Claims (2)

  It has a plurality of cavities formed between the fixed side mold and the movable side mold, and a lateral runner part from the sprue part to each of the cavities is formed as a resin flow path. It is a multi-piece injection mold to be molded, and a resin flow rate adjusting piece having an adjustment runner part having the same cross-sectional dimension as the horizontal runner part is arranged so as to cross the horizontal runner part. In the multi-piece injection mold in which the resin flow rate adjusting piece is moved by a small amount to adjust the resin flow rate of the lateral runner portion, the resin flow rate adjusting piece has a substantially cylindrical shape. A scale from the outer periphery to the center is formed on the upper surface of the piece, and a mark corresponding to the scale is formed on the upper surface of the cavity plate around the resin flow rate adjusting piece. Several cavity injection molding die.   2. The multi-cavity injection mold according to claim 1, wherein at least two holes are formed at positions symmetrical with respect to the center of the upper surface of the resin flow rate adjusting piece.

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