JP2005022225A - Method for setting operation condition of injection molding machine and mold used in injection molding machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for easily setting the operation condition of an injection molding machine for molding a resin molded product having no flaw, and a mold used in the injection molding machine. <P>SOLUTION: The flowing length of the molten resin material, which is injected in the bar flow cavity 45 provided to the mold 30, is measured at each of a plurality of the extrusion positions of a screw member 13 under the operation condition of the injection molding machine 20 for molding the resin molded product having no flaw. In the setting of the operation condition of another injection molding machine, the operation condition is adjusted so that the flowing length equal to that at each of extrusion positions is obtained in another injection molding machine when the molten resin material is injected in the bar flow cavity 45 from the injection molding machine. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【００４４】
【表２】

【００４５】
次に、図６に示すように、溶融樹脂材料をバーフローキャビティ４５に案内するように、開放弁体５３と閉鎖弁体５４とを付け替え、第二分岐路３７を開放状態に保持する。その後、求められた最適な運転条件下で射出成形機２０からバーフローキャビティ４５に溶融樹脂材料を注入する。この際、スクリュー部材１３をその引戻し位置Ｓ１（１５０ｍｍ）からシリンダ１２の射出口１８に向けて、押出位置Ｓ２（７０ｍｍ）まで移動させることにより、溶融樹脂材料をバーフローキャビティ４５に注入した後、スクリュー部材１３を停止させる。その後、可動型板２２の移動により金型３０を分割し、バーフローキャビティ４５内で冷却固化された樹脂材料を取り出す。取り出した樹脂材料からバーフローキャビティ４５内に刻まれた目盛り５０を読み取ることにより、スクリュー部材１３を停止させた押出位置Ｓ２における溶融樹脂材料の流動長Ｌ１を計測する。バーフローキャビティ４５から取り出された樹脂材料には目盛り５０が転写されているため、容易に目盛り５０を読み取ることができる。
【００４６】
押出位置Ｓ２における流動長Ｌ１の計測後、金型３０内の残留樹脂材料を取り除く。再びバーフローキャビティ４５への溶融樹脂材料の注入のためにスクリュー部材１３を引戻し位置Ｓ１まで一旦戻す。固定型板２１及び可動型板２２の両分割面２１ａ，２２ａを当接させた後、引戻し位置Ｓ１から次の押出位置Ｓ３（４０ｍｍ）までスクリュー部材１３を移動させて溶融樹脂材料をバーフローキャビティ４５に注入する。押出位置Ｓ２での計測と同様に、最適な運転条件下での押出位置Ｓ３における流動長Ｌ２を計測する。その後、各押出位置Ｓ４（２５ｍｍ），Ｓ５（１０ｍｍ）における各流動長Ｌ３，Ｌ４の計測毎に、バーフローキャビティ４５への溶融樹脂材料の注入のためにスクリュー部材１３を一旦引戻し位置Ｓ１まで戻し、以下同様に順次流動長Ｌ３、Ｌ４を計測する。
【００４７】
計測された各押出位置Ｓ２〜Ｓ５における各流動長Ｌ１〜Ｌ４を、次表に示す。
【００４８】
【表３】

【００４９】
上記のように流動長が計測され、成形不良を生じることのない最適な運転条件下で運転していた射出成形機２０が例えば故障を生じ、射出成形機２０を他の新たな射出成形機と交換する場合、この新たな射出成形機の運転条件の設定のために、金型３０のバーフローキャビティ４５と、計測された各押出位置Ｓ２〜Ｓ５における各流動長Ｌ１〜Ｌ４のデータとが用いられる。
【００５０】
この場合、先ず、図６に示すように、溶融樹脂材料をバーフローキャビティ４５に案内するように、第一分岐路３６を閉鎖弁体５４で閉鎖し、新たな最適運転条件を求めるために新たな射出成形機からバーフローキャビティ４５に溶融樹脂材料を注入する。先の射出成形機２０での計測と同様にスクリュー部材１３の各押出位置Ｓ２〜Ｓ５における溶融樹脂材料の各流動長が計測され、各押出位置Ｓ２〜Ｓ５での流動長が先の射出成形機２０で計測された流動長Ｌ１〜Ｌ４に等しくなるように、スクリュー部材１３の射出速度及び射出圧力等が調整される。この調整に際し、先に得られた表２の射出速度Ｖ１〜Ｖ４及び射出圧力Ｐ１〜Ｐ４を参考にして射出速度及び射出圧力を微調整すれば、より迅速に測定データと一致する流動長が得られるように運転条件を設定することができる。先の射出成形機２０で計測された各押出位置Ｓ２〜Ｓ５における各流動長Ｌ１〜Ｌ４に等しい流動長が新たな射出成形機で得られたとき、その流動長を与えた最適な運転条件が新たな射出成形機に設定されることとなる。
【００５１】
従って、その新たに設定された最適な運転条件下で、図３に示すように、溶融樹脂材料を製品部キャビティ４９に案内するように、再び開放弁体５３と閉鎖弁体５４とを付け替え、第二分岐路３７を閉鎖弁体５４により閉鎖状態に保持した状態で、新たな射出成形機から製品部キャビティ４９に溶融樹脂材料を注入することにより、バリ、ひけ、充填不足等の成形不良を生じることなく、製品部キャビティ４９で製品となる樹脂成形品を成形することができる。
【００５２】
前記したように、本実施の形態に係る射出成形機２０の運転条件設定方法によれば、射出成形機２０に設定された最適な運転条件下で求められた溶融樹脂材料の流動長に関するデータを用いることにより、他の射出成形機についての最適運転条件をこの流動長を基に見出すことができ、これにより、従来のように製品部キャビティ４９でショートショットを繰り返し成形することによる試行錯誤を行うことなく、迅速かつ容易にこの最適運転条件を設定することができる。
【００５３】
また、本実施の形態によれば、固定型板２１及び可動型板２２を分解することなく、両型板２１，２２を分離させた状態で開放弁体５３及び閉鎖弁体５４を付け替えることができる。この両弁体５３，５４の付替えにより第一分岐路３６及び第二分岐路３７を切り替えることができ、これにより製品部キャビティ４９及びバーフローキャビティ４５に選択的に溶融樹脂材料を案内することができる。
【００５４】
さらに、バーフローキャビティ４５は、製品部キャビティ４９と分岐路３６，３７を介して一つの金型３０内に形成されていることから、流動長の計測専用の金型を別に用意する必要はなく、バーフローキャビティ４５が形成された金型３０を用いることにより、従来のように製品部キャビティ４９で成形した成形品の良否から設定条件が最適であるか否かを判定するのではなく、溶融樹脂材料の流動長をバーフローキャビティ４５に刻まれた目盛り５０から目視により判定することができる。
【００５５】
本実施の形態では、計測手段を構成するバーフローキャビティ４５と、製品部キャビティ４９とが分岐路３６，３７を介して一つの金型３０内に形成された例を示したが、樹脂成形品を成形するための製品部キャビティ４９が形成された金型とは別に、溶融樹脂材料の流動長を計測するためのバーフローキャビティ４５が形成された金型を用いて本発明に係る運転条件設定方法を実施することができる。
【００５６】
また、本発明に係るバーフローキャビティ４５を、Ｓ字型に形成することに代えて、例えば渦巻状に形成するなど、適宜、所望の形状に配置することができる。また、バーフローキャビティ４５内に刻まれた目盛り５０をバーフローキャビティ４５内から可動型板２２の分割面２２ａにはみ出すように刻むことにより、樹脂成形品をバーフローキャビティ４５から取り出すことなく、分割面２２ａ上で溶融樹脂材料の流動長を計測することができる。
【００５７】
さらに、開放弁体５３及び閉鎖弁体５４を弁体取付部５１ａ，５２ａ，５１ｂ，５２ｂに保持させるために、本実施の形態ではネジ部材５５を用いたが、ネジ部材５５に代えて、それ以外の保持手段を用いることができる。
【００５８】
バーフローキャビティ４５の容量は、射出成形機２０の設定に影響を及ぼさない範囲で製品部キャビティ４９の容量に略等しければよい。
【００５９】
本発明に係る射出成形機２０の運転条件設定方法及びそれに使用する金型３０は、プランジャ部材１３としてピストンを用いた押出成形機などの射出成形機２０以外の成形機でも用いることができる。
【００６０】
【発明の効果】
本発明によれば、欠陥のない樹脂成形品を成形する射出成形機の運転条件下で、プランジャ部材の押出位置毎における前記射出成形機から計測手段に注入された溶融樹脂材料の流動長を計測し、この計測データを基に他の射出成形機の最適な運転条件を見出すことができる。これにより製品部キャビティでショートショットを繰り返し成形することによる試行錯誤なく、迅速かつ容易に最適運転条件を設定することができる。
【図面の簡単な説明】
【図１】本発明に係る射出成形機及び金型を概略的に示す縦断面図である。
【図２】本発明に係る金型の固定型板の分割面を金型に設けられた製品部キャビティに溶融樹脂材料を選択的に導入するように弁体を配置させた状態で示す平面図である。
【図３】本発明に係る金型の可動型板の分割面を金型に設けられた製品部キャビティに溶融樹脂材料を選択的に導入するように弁体を配置させた状態で示す平面図である。
【図４】本発明に係る開放弁部材を示す縦断面図である。
【図５】本発明に係る閉鎖弁部材を示す縦断面図である。
【図６】本発明に係る金型の可動型板の分割面を金型に設けられたバーフローキャビティに溶融樹脂材料を選択的に導入するように弁体を配置させた状態で示す平面図である。
【符号の説明】
３０ 金型
１３ プランジャ部材（スクリュー部材）
２０ 射出成形機
４５ 計測手段（バーフローキャビティ）
Ｓ１，Ｓ２，Ｓ３，Ｓ４，Ｓ５ 押出位置
Ｌ１、Ｌ２，Ｌ３，Ｌ４ 流動長
３６，３７ 分岐路（第一分岐路、第二分岐路）
３３ａ，３４，３３ｂ，３６，３７ 流路（一次スプルー、ランナ、二次スプルー、第一分岐路、第二分岐路）
４９ 製品部キャビティ
５３，５４ 弁体（開放弁体、閉鎖弁体）
５０ 目盛り
２１ａ，２２ａ 分割面
２１ 固定型板
２２ 可動型板
３６ａ，３７ａ，３６ｂ，３７ｂ 分岐溝部
５３ａ，５３ｂ 開放弁部材
５４ａ，５４ｂ 閉鎖弁部材
５１ａ，５２ａ，５１ｂ，５２ｂ 凹所（弁体取付部）[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an operating condition setting method for setting operating conditions of an injection molding machine to mold a resin molded product having no defects such as so-called sinks, and a mold used therefor.
[0002]
[Prior art]
Conventionally, in order to mold a resin molded product using an injection molding machine without causing molding defects such as burrs, sink marks and insufficient filling, the product part cavity formed in the mold for molding the resin molded product Prior to the injection of the molten resin material to form a resin molded product, it is necessary to set the optimum operating conditions for the injection molding machine. Depending on the setting contents of the operating conditions, the appearance and dimensions of the obtained molded product, and further the physical properties such as strength of the resin molded product are changed. Since there are a large number of combinations of setting parameters for placing the injection molding machine in the optimum operating state, it is difficult to calculate the optimum operating conditions by calculation.
[0003]
Therefore, from the condition of intentionally forming a short shot, that is, underfilling in the product part cavity, with operating conditions such as injection speed, injection pressure and screw position, which are representative operating conditions among these operating conditions, as setting parameters, The method of finding optimal operating conditions by repeating trial and error while gradually changing the operating conditions toward non-defective products was adopted.
[0004]
[Problems to be solved by the invention]
However, when an injection molding machine that has been operated under such optimum operating conditions has failed, for example, if the injection molding machine is replaced with another new injection molding machine and the same resin molded product is molded, a new one is required. Even if the new injection molding machine is an injection molding machine of the same standard as the previous one, there are manufacturing errors depending on the machine, so the optimum operating conditions found in the previous injection molding machine are set in the new injection molding machine. Even if it is operated under this setting, the optimum operating state cannot be accurately reproduced. Therefore, every time an injection molding machine is replaced with another injection molding machine, it is necessary to perform trial and error with repeated short shots to the product cavity of the mold in order to find the optimum operating conditions for the injection molding machine. There is a drawback that this trial and error takes a lot of time and effort.
[0005]
An object of the present invention is to provide a method for setting operating conditions of an injection molding machine that can easily set operating conditions of an injection molding machine for molding a resin molded product having no defects as compared with the conventional one, and a mold used therefor Is to provide.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, the invention according to claim 1 is an operating condition of an injection molding machine provided with a plunger member for extruding a molten resin material into the mold in order to mold a resin molded product with the mold. The injection molding machine injects the molten resin material into the mold to become a product, that is, under the operating conditions for molding a resin molded product having no defects, the injection molding machine to the measuring means. The molten resin material is injected, the flow length of the molten resin material in the measuring means at each of the plurality of extrusion positions of the plunger member of the injection molding machine is measured, and the resin from the other injection molding machine to the mold Prior to manufacturing a resin molded product by injecting a material, the molten resin material is injected into the measuring means from the other injection molding machine at each extrusion position of the other injection molding machine corresponding to each extrusion position. Each before And setting the operating condition of the other injection molding machine to obtain a flow length equal to measured the flow length of the extruded each position.
[0007]
The invention according to claim 2 is the invention according to claim 1, wherein the plunger member is a screw member.
[0008]
Invention of Claim 3 is a metal mold | die which receives injection | pouring of molten resin material from an injection molding machine, Comprising: In this metal mold | die, the molten resin extruded from the said injection molding machine which has two branch paths A flow path for guiding the material into the mold, a product part cavity for a resin molded product communicating with one of the branch paths of the flow path, and a product part cavity communicating with the other branch path of the flow path And a valve body for selectively blocking one of the branch passages, and the molten resin material is disposed from one end to the other end of the bar flow cavity. It is an elongate cavity which can be inject | poured, The scale for reading the flow length of the said molten resin material is attached | subjected along the extension direction of this cavity, It is characterized by the above-mentioned.
[0009]
The invention described in claim 4 is a mold according to the invention described in claim 3, wherein each of the molds has a divided surface, and has a fixed mold plate and a movable mold plate that can contact each other on the divided surface. The product part cavity is disposed on the dividing surface of the fixed mold plate, and the bar flow cavity is disposed on the dividing surface of the movable mold plate.
[0010]
According to a fifth aspect of the present invention, in the third aspect of the present invention, each of the branch paths is constituted by a branch groove portion formed in each of the split surfaces of the two mold plates, and the valve body is the branch path. And a pair of closing valve members for jointly closing the branch path to each other, and each branch groove portion includes the pair of opening valves. A recess is formed in which one of the member and the pair of closing valve members is replaceably accommodated, and each of the opening valve members and each of the closing valve members can be selectively positioned in each of the recesses. It is characterized by that.
[0011]
According to a sixth aspect of the present invention, in the third aspect of the present invention, the injection molding machine includes a screw member that moves toward an extrusion position to extrude the molten resin material, and the product portion from the injection molding machine. Under the operating conditions of molding a resin molded product having no defects by injecting the molten resin material into the cavity, the product part cavity is selectively closed with the valve body from the injection molding machine to the bar flow cavity. The molten resin material is injected, the flow length of the molten resin material in the bar flow cavity at each of the plurality of extrusion positions of the screw member of the injection molding machine is read from the scale, and another injection molding machine Prior to injecting the molten resin material into the product part cavity and molding the resin molded product, the bar flow cartridge is transferred from the other injection molding machine. For injecting the molten resin material into the tee, an operating condition for each extrusion position is set to obtain a flow length equal to the flow length at the extrusion position corresponding to each extrusion position of the screw member read from the scale. The molten resin is injected into the product part cavity with the valve body closed with the valve body from the other injection molding machine under the set operating conditions to form a molded product. .
[0012]
According to the configuration of claim 1, under the optimum operating conditions of an injection molding machine that molds a resin molded product having no defects, the melt injected from the injection molding machine into the measuring means at each plunger member extrusion position The flow length of the resin material is measured. Thereby, even when it is replaced with another injection molding machine, the molten resin material is injected from the other injection molding machine into the measuring means, and the operating conditions are adjusted so that a flow length equal to the flow length can be obtained. Thus, it is possible to easily obtain optimum operating conditions without trial and error by repeatedly forming short shots in the product portion cavity.
[0013]
By deliberately forming a short shot in the product cavity and adjusting and setting the operating conditions gradually toward a good product through repeated trial and error, the short shot has a large separation resistance from the mold. The more complex the resin molded product that is molded in the product cavity, the more time is required to take out the short shots molded there, and it is not easy to determine the quality. It takes skill and experience to gain.
[0014]
On the other hand, according to the method of the present invention, as described above, by measuring the flow length of the molten resin material injected into the measuring means, the setting condition that gives this flow length can be obtained without requiring skill or experience. Since it is possible to immediately determine whether or not it is the optimum operation condition, it is possible to find the optimum operation condition quickly and easily compared to the conventional case, and to set the optimum operation condition.
[0015]
According to the structure of Claim 2, a screw member can be used for a plunger member.
[0016]
According to the structure of Claim 3 and Claim 6, since the product part cavity and the bar flow cavity are formed in one metal mold | die via a branch path, the flow length of molten resin material is measured. Therefore, it is not necessary to prepare a dedicated mold separately, and the molten resin material can be selectively guided to the product cavity and the bar flow cavity by replacing the valve body provided in the branch path. Accordingly, it is possible to easily perform the molding of the resin molded product in the product portion cavity and the measurement of the flow length of the molten resin material in the bar flow cavity.
[0017]
Further, in the conventional method, when the short shot is formed by the product part cavity for forming the resin molded product having a complicated shape as described above, it is difficult to take out the formed short shot. Has a long and simple shape, it is easy to take out the resin molded product without taking time and effort when taking out the resin molded product used to measure the flow length in the bar flow cavity from the bar flow cavity. it can. In addition, since the bar flow cavity is graduated, the flow length of the molten resin material injected into the bar flow cavities at each screw member extrusion position can be visually determined from the scale. The operation condition setting method for an injection molding machine according to the invention can be more easily implemented.
[0018]
Therefore, instead of this injection molding machine, even when molding a resin molded product using another injection molding machine, the molten resin material is injected into the bar flow cavity from the other injection molding machine, By adjusting the operating conditions so that a flow length equal to the measured flow length can be obtained from the bar flow cavity, the optimum operating conditions can be easily achieved without trial and error by repeatedly forming short shots in the product cavity. Can be found.
[0019]
According to the configuration of the fourth aspect, since the bar flow cavity is formed on the dividing surface of the movable mold plate, it is easily injected into the bar flow cavity by the separation operation of the fixed mold plate and the movable mold plate. The flow length of the molten resin material can be measured. Further, since the bar flow cavity is formed on the dividing surface of the movable mold plate, the resin molded product molded by the bar flow cavity can be easily taken out.
[0020]
According to the configuration of the fifth aspect, the pair of open valve members jointly close each other to leave the branch path in a state where the recess is filled, and the pair of close valve members jointly cooperate with each other. Is closed. By installing these both valve members in the recess so that they can be replaced, the branch path can be easily switched, and the open valve member arranged in the recess is made of molten resin material by intrusion of the molten resin material into the recess. The change of the volume is prevented and the branch path is left open, so that the molten resin material can be selectively guided to the product portion cavity and the bar flow cavity without changing the volume of the molten resin material. In addition, since the opening valve member and the closing valve member are attached to both split surfaces of the fixed mold plate and the movable mold plate constituting the mold, when switching the branch path by both valve members, The branch path can be switched on the dividing plane without disassembling each.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0022]
FIG. 1 shows an injection molding apparatus 10 according to the present invention. The injection molding apparatus 10 includes an injection molding machine 20 and a mold 30 that receives injection of a molten resin material from the injection molding machine.
[0023]
The injection molding machine 20 includes a cylinder 12 provided with a hopper 11 and a plunger member 13 provided in the cylinder so as to be slidable in the axial direction of the cylinder. In the illustrated example, the plunger member 13 is constituted by a screw member 13 that is driven and rotated coaxially with the cylinder 12 by a hydraulic motor 14.
[0024]
As is well known, the resin material supplied from the hopper 11 to the cylinder 12 is melted in the cylinder 12 by a plurality of heaters 15 installed on the peripheral wall of the cylinder 12. The melted resin material is sent to the pressurizing chamber 16 in front of the screw member 13 in the cylinder 12 by the rotation of the screw member 13 in a predetermined pull-back position. When a predetermined amount of molten resin material accumulates in the pressurizing chamber 16 of the cylinder 12, the rotation of the screw member 13 stops. The screw member 13 is moved by the pressure from the injection cylinder 17 provided at the rear end thereof without rotating toward the injection port 18 provided at the front end of the cylinder 12. Due to the pressurization caused by the movement of the screw member 13, the molten resin material is injected into the mold 30 from the injection port 18 of the cylinder 12. The tip of the screw member 13 is provided with a well-known backflow prevention valve 19 that prevents backflow of the molten resin material to be injected. After injecting the molten resin material, the screw member 13 moves back to the above-described pull-back position while rotating by the operation of the hydraulic motor 14 and the injection cylinder 17.
[0025]
The mold 30 includes a fixed mold plate 21 and a movable mold plate 22. Both mold plates 21 and 22 have divided surfaces 21a and 22a, respectively, and can be brought into contact with each other at the divided surfaces 21a and 22a. In the illustrated example, the fixed mold plate 21 includes a first plate portion 23 and a second plate portion 24, and can be brought into contact with each other at the respective separation surfaces 23a and 24a. A mounting plate 25 is attached to the second plate portion 24 on the opposite side of the separation surface 24a. The fixed mold plate 21 is fixed to a fixed die plate 26 fixedly provided in the injection molding apparatus 10 via the mounting plate 25. The movable plate 22 has a mounting plate 27 attached to the opposite side of the dividing surface 22a, and the movable mold plate 22 is fixed to the movable die plate 28 of the injection molding apparatus 10 via the mounting plate 27. The movable die plate 28 is movable in a direction approaching the fixed die plate 26 and a direction away from the fixed die plate 26. By this movement, the movable mold plate 22 fixed to the movable die plate 28 is separated from the fixed mold plate 21 and the abutting position where the movable mold plate 22 is in contact with the fixed mold plate 21 indicated by the line AA in FIG. It is possible to move between the take-out position for taking out the resin molded product molded from the divided surface 22a of the plate 22. In order to guide the movement of the movable mold plate 22, a guide pin G (see FIG. 2) is provided on the dividing surface 21A of the fixed mold plate 21, and a guide pin is provided on the dividing surface 22a of the movable mold plate 22. A receiving guide hole H (see FIG. 3) is provided.
[0026]
The mounting plate 25 attached to the fixed mold plate 21 includes a sprue bush 31 having a receiving port 29 for the mold 30 to receive the injection of the molten resin material from the injection molding machine 20, and the cylinder 12 is exposed to the receiving port 29. A locate ring 32 for aligning the outlet 18 is attached. The sprue bush 31 penetrates the mounting plate 25 and the second plate portion 24 in the plate thickness direction. By the sprue bush 31, a primary sprue 33 a that penetrates the second plate portion 24 in the plate thickness direction from the mounting plate 25 toward the separation surface 24 a is formed in the second plate portion 24. The tip end of the primary sprue 33a is connected to one end of a runner 34 formed along the separation surface 23a on the separation surface 23a of the first plate portion 23. The other end of the runner 34 is connected to one end of a secondary sprue 33b that penetrates the first plate portion 23 in the thickness direction from the separation surface 23a toward the division surface 21a. The other end of the secondary sprue 33b opens to the dividing surface 21a of the fixed mold plate 21. The primary sprue 33a, the runner 34, and the secondary sprue 33b guide the molten resin material injected from the injection molding machine 20 to the mold 30 to the divided surfaces 21a and 22a, respectively.
[0027]
As shown in FIG. 2, the other end of the secondary sprue 33 b that opens to the dividing surface 21 a, that is, an opening 35, and a semicircular cross section are introduced into the dividing surface 21 a of the fixed mold 21 from the opening 35. There are provided two branch groove portions 36a and 37a for branching the molten resin material and a recess 39 for molding a resin molded product.
[0028]
In the illustrated example, the recess 39 has a rectangular opening 40 formed in the dividing surface 21 a of the fixed mold 21. Further, in the recess 39, three convex portions 41, 41, 41 are arranged at intervals.
[0029]
On the other hand, the split surface 22a of the movable mold plate 22 has branch groove portions 36b and 37b having the same shape as the branch groove portions 36a and 37a formed on the split surface 21a of the fixed mold plate 21 as shown in FIG. It is provided at a position corresponding to the branch groove portions 36 a and 37 a formed on the plate 21. The branch groove portion 36a and the branch groove portion 36b cooperate with each other from the opening 35 in the product portion cavity to be described later at a contact position where both the divided surfaces 21a and 22a contact each other by the movement of the movable mold plate 22 toward the fixed mold plate 21. The first branch path 36 having a circular cross section extending to 49 is defined, and the branch groove section 37a and the branch groove section 37b cooperate with each other to form a second branch path 37 having a circular cross section extending from the opening 35 to a bar flow cavity 45 described later. Stipulate. Further, on the dividing surface 22 a of the movable mold plate 22, gates 42 and 43 connected to both ends of the branch groove portions 36 b and 37 b, a product core 44 communicating with the branch groove portion 36 b via the gate 42, and the gate 43 And a bar flow cavity 45 communicating with the branch groove portion 37b.
[0030]
The product part core 44 has the convex part 47 which protruded from the division surface 22a of the movable mold plate 22 in the example of illustration. The convex portion 47 is fitted with a concave portion 39 formed on the dividing surface 21a of the fixed mold plate 21 at a predetermined interval. Further, the convex portion 47 is provided with three concave portions 48, 48, 48 at intervals. When the two split surfaces 21 a and 22 a come into contact with each other due to the movement of the movable mold plate 22, the convex portions 41, 41 and 41 of the recess 39 are spaced apart from the concave portions 48, 48 and 48 of the product portion core 44 by a predetermined distance. Is accepted. The product portion cavity 49 is defined by this interval.
[0031]
The bar flow cavity 45 is formed of a semicircular concave groove. The concave groove has a first straight portion 45a whose upper end is connected to the gate 43 on the dividing surface 22a and parallel to the product core 44, and a second lower end connected to the lower end of the first straight portion 45a and parallel to the first straight portion 45a. It consists of a straight line part 45b and a third straight line part 45c that is parallel to the second straight line part 45b, whose upper end is connected to the upper end of the second straight line part 45b and whose other end is closed, and has an S-shape as a whole. . Further, the bar flow cavity 45 has a simple shape as compared with the product part cavity 49 having a complicated shape, and has a capacity equal to the capacity of the product part cavity 49, and the scale 50 extends on the concave surface. It is carved at predetermined intervals along the direction.
[0032]
As shown in FIG. 2, recesses having the same shape across the branch groove portion 36a and the branch groove portion 37a are provided in the intermediate portions of the two branch groove portions 36a and 37a formed on the dividing surface 21a of the fixed mold plate 21, respectively. A valve body mounting portion 51a and a valve body mounting portion 52a are formed. In order to selectively supply the molten resin material introduced from the opening 35 to the branch groove portions 36a and 37a to the product portion cavity 49 and the bar flow cavity 45, the valve body mounting portions 51a and 52a have the same outer dimensions. Any one of the open valve member 53 a and the close valve member 54 a having the above is detachably attached by the screw member 55.
[0033]
On the other hand, as shown in FIG. 3, the dividing surface 22a of the movable mold plate 22 has recesses of the same shape at positions corresponding to the valve body mounting portions 51a and 52a formed on the dividing surface 21a of the fixed mold plate 21. Valve body mounting portions 51b and 52b each having a location are formed. An open valve member 53b and a close valve member 54b having the same external dimensions are detachably attached to the valve body attaching portions 51b and 52b by screw members 55.
[0034]
As shown in FIG. 4, the pair of release valve members 53 a and 53 b have contact surfaces 56 a and 56 b that contact each other at the contact positions of the fixed mold plate 21 and the movable mold plate 22, respectively. At the abutting position, the abutting surfaces 56a and 56b do not protrude from the dividing surfaces 21a and 22a together with the screw members 55 so as not to prevent the abutting of the dividing surfaces 21a and 22a, respectively. Become one. The contact surfaces 56a and 56b are formed with notches 59 having arcuate surfaces 58 having the same shape as the branch groove portions 36a, 36b, 37a and 37b of the branch paths 36 and 37, respectively.
[0035]
On the other hand, as shown in FIG. 5, the pair of shut-off valve members 54a and 54b have contact surfaces 57a and 57b that contact each other at the contact positions, respectively. These contact surfaces 57a and 57b project from the split surfaces 21a and 22a together with the screw member 55 so as not to prevent the contact of both split surfaces 21a and 22a in the same manner as the open valve members 53a and 53b. It becomes flush with the dividing surfaces 21a and 22a. The contact surfaces 57a and 57b are not formed with the notches 59 as formed in the release valve members 53a and 53b.
[0036]
Therefore, for example, a pair of open valve bodies 53a and 53b are respectively attached to the valve body attaching portions 51a and 51b formed in the first branch passage 36, and a pair is attached to the valve body attaching portions 52a and 52b formed in the second branch passage 37. When the shut-off valve members 54a and 54b are attached, the pair of open valve members 53a and 53b has a circular arc surface 58 continuously forming a part of the first branch path 36, and the contact surfaces 56a and At the time of abutting 56b, the first branch passage 36 is filled with the valve body attachment portions 51a and 52b together without causing a change in the volume of the molten resin material by the valve body attachment portions 51a and 51b of the first branch passage 36. An open valve body 53 for keeping the valve in an open state is configured. On the other hand, the pair of closing valve members 54a and 54b constitutes a closing valve body 54 that reliably closes the second branch passage 37 in cooperation with each other when the both contact surfaces 57a and 57b contact. As described above, the branch groove portions 36a, 37a, 36b, and 37b to which the open valve body 53 and the closed valve body 54 are selectively attached constitute the branch paths 36 and 37 by the contact of the two divided surfaces 21a and 22a. The branch paths 36 and 37 together with the primary sprue 33a, the runner 34, and the secondary sprue 33b constitute a flow path for guiding the molten resin material to the product portion cavity 49 and the bar flow cavity 45 in the mold 30. From this, by replacing the opening valve body 53 and the closing valve body 54 with each other, the product portion cavity 49 or the second branch path 37 in which the molten resin material introduced from the opening 35 communicates with the first branch path 36. Can be selectively guided to a bar flow cavity 45 communicating with the.
[0037]
A method for setting operating conditions of an injection molding machine using the mold 30 provided with the bar flow cavity 45 according to the present invention will be described.
[0038]
In order to form a resin molded product in the product portion cavity 49 of the mold 30 without causing molding defects such as burrs, sink marks and short shots (underfilling) using the injection molding machine 20, prior to this resin molding, The optimum operating conditions are set in the injection molding machine 20 by the same method as in. This operating condition includes the injection pressure when the screw member 13 injects the molten resin material, the injection speed that sequentially changes in accordance with the shape of the resin molded product to be molded, and a plurality of screw members 13 when the injection speed changes. There are extrusion positions.
[0039]
In order to set the optimum operating conditions of the injection molding machine 20 using the product part cavity 49 of the mold 30, first, the molten resin material introduced from the opening 35 of the secondary sprue 33b is shown in FIGS. As shown in FIG. 5, the closing valve body 54 is attached to the valve body attaching portions 52a and 52b so as to flow through the first branch path 36 in the direction of the arrow and be guided to the product portion cavity 49 via the gate 42. The open valve body 53 is attached to the attachment portions 51a and 51b. As a result, the first branch path 36 is selectively held open.
[0040]
Due to trial and error similar to the conventional method involving repeated injection of the molten resin material from the injection molding machine 20 into the product portion cavity 49, the resin molded product formed in the product portion cavity 49 may have burrs, sink marks, insufficient filling, etc. Optimal operating conditions are found for each set parameter such as the above-described injection pressure, injection speed, and each extrusion position that becomes the change point, which can realize an optimal operating state in which molding defects do not occur.
[0041]
An example of the optimum operating conditions found is shown in the following table. S1 to S5 in Table 1 indicate the extrusion positions of the screw member 13 when the injection speed changes. Extrusion positions S1 to S5 are distances from the tip of the screw member 13 to the injection port 18 of the cylinder 12, and S1 is a retracting position of the screw member 13.
[0042]
The injection speed and the injection pressure change at each of the extrusion positions S1 to S5. In Table 2, V1 to V4 indicate injection speeds between the respective extrusion positions, and P1 to P4 indicate injection pressures between the respective extrusion positions. As is well known in the art, the injection pressure V and the injection pressure P when the molten resin material is injected when the valve provided in the hydraulic control device (not shown) is fully opened are set to 100%. It is a ratio.
[0043]
[Table 1]

[0044]
[Table 2]

[0045]
Next, as shown in FIG. 6, the open valve body 53 and the close valve body 54 are replaced so that the molten resin material is guided to the bar flow cavity 45, and the second branch path 37 is held open. Thereafter, a molten resin material is injected into the bar flow cavity 45 from the injection molding machine 20 under the optimum operating conditions obtained. At this time, after the molten resin material is injected into the bar flow cavity 45 by moving the screw member 13 from the pullback position S1 (150 mm) toward the injection port 18 of the cylinder 12 to the extrusion position S2 (70 mm), The screw member 13 is stopped. Thereafter, the mold 30 is divided by the movement of the movable mold plate 22, and the resin material cooled and solidified in the bar flow cavity 45 is taken out. By reading the scale 50 carved in the bar flow cavity 45 from the taken out resin material, the flow length L1 of the molten resin material at the extrusion position S2 where the screw member 13 is stopped is measured. Since the scale 50 is transferred to the resin material taken out from the bar flow cavity 45, the scale 50 can be easily read.
[0046]
After measurement of the flow length L1 at the extrusion position S2, the residual resin material in the mold 30 is removed. The screw member 13 is once returned to the pull-back position S1 for again injecting the molten resin material into the bar flow cavity 45. After bringing the split surfaces 21a and 22a of the fixed mold plate 21 and the movable mold plate 22 into contact with each other, the screw member 13 is moved from the pull-back position S1 to the next extrusion position S3 (40 mm), and the molten resin material is transferred to the bar flow cavity. 45 is injected. Similar to the measurement at the extrusion position S2, the flow length L2 at the extrusion position S3 under the optimum operating condition is measured. Thereafter, each time the flow lengths L3 and L4 are measured at the extrusion positions S4 (25 mm) and S5 (10 mm), the screw member 13 is temporarily returned to the pull-back position S1 in order to inject the molten resin material into the bar flow cavity 45. In the same manner, the flow lengths L3 and L4 are sequentially measured.
[0047]
The flow lengths L1 to L4 at the measured extrusion positions S2 to S5 are shown in the following table.
[0048]
[Table 3]

[0049]
As described above, the flow length is measured, and the injection molding machine 20 that has been operated under the optimum operating conditions without causing molding defects, for example, causes a failure, and the injection molding machine 20 is replaced with another new injection molding machine. In the case of replacement, in order to set the operating conditions of the new injection molding machine, the bar flow cavity 45 of the mold 30 and the data of the flow lengths L1 to L4 at the measured extrusion positions S2 to S5 are used. It is done.
[0050]
In this case, first, as shown in FIG. 6, the first branch path 36 is closed with the closing valve body 54 so as to guide the molten resin material to the bar flow cavity 45, and a new optimum operating condition is obtained. A molten resin material is injected into the bar flow cavity 45 from a different injection molding machine. Similarly to the measurement at the previous injection molding machine 20, the flow lengths of the molten resin material at the extrusion positions S2 to S5 of the screw member 13 are measured, and the flow lengths at the extrusion positions S2 to S5 are the previous injection molding machines. The injection speed, injection pressure, and the like of the screw member 13 are adjusted so as to be equal to the flow lengths L1 to L4 measured at 20. In this adjustment, if the injection speed and the injection pressure are finely adjusted with reference to the injection speeds V1 to V4 and the injection pressures P1 to P4 obtained in Table 2, the flow length that matches the measurement data can be obtained more quickly. Operating conditions can be set. When a flow length equal to each flow length L1 to L4 at each of the extrusion positions S2 to S5 measured by the previous injection molding machine 20 is obtained with a new injection molding machine, the optimum operating condition giving the flow length is It will be set to a new injection molding machine.
[0051]
Therefore, under the newly set optimum operating conditions, as shown in FIG. 3, the opening valve body 53 and the closing valve body 54 are replaced again so as to guide the molten resin material to the product portion cavity 49, By injecting the molten resin material into the product portion cavity 49 from a new injection molding machine with the second branch path 37 held closed by the closing valve body 54, molding defects such as burrs, sink marks, insufficient filling, and the like can be obtained. A resin molded product to be a product can be molded in the product portion cavity 49 without being generated.
[0052]
As described above, according to the operation condition setting method of the injection molding machine 20 according to the present embodiment, the data relating to the flow length of the molten resin material obtained under the optimum operation condition set in the injection molding machine 20 is obtained. By using it, the optimum operating conditions for other injection molding machines can be found based on this flow length, and this makes trial and error by repeatedly molding short shots in the product cavity 49 as in the prior art. This optimum operating condition can be set quickly and easily.
[0053]
Further, according to the present embodiment, it is possible to replace the open valve body 53 and the closed valve body 54 in a state where both the mold plates 21 and 22 are separated without disassembling the fixed mold plate 21 and the movable mold plate 22. it can. The first branch path 36 and the second branch path 37 can be switched by changing both the valve bodies 53 and 54, thereby selectively guiding the molten resin material to the product portion cavity 49 and the bar flow cavity 45. Can do.
[0054]
Further, since the bar flow cavity 45 is formed in one mold 30 via the product portion cavity 49 and the branch paths 36 and 37, it is not necessary to prepare a separate mold for measuring the flow length. By using the mold 30 in which the bar flow cavity 45 is formed, it is not necessary to determine whether the setting conditions are optimal based on the quality of the molded product molded in the product portion cavity 49 as in the past, but to melt. The flow length of the resin material can be visually determined from the scale 50 carved in the bar flow cavity 45.
[0055]
In the present embodiment, an example in which the bar flow cavity 45 constituting the measuring means and the product part cavity 49 are formed in one mold 30 via the branch paths 36 and 37 is shown. The operating condition setting according to the present invention is carried out using a mold in which a bar flow cavity 45 for measuring the flow length of the molten resin material is used separately from the mold in which the product part cavity 49 for molding the mold is formed. The method can be carried out.
[0056]
Further, the bar flow cavity 45 according to the present invention can be appropriately arranged in a desired shape, for example, in a spiral shape instead of being formed in an S shape. Further, the scale 50 engraved in the bar flow cavity 45 is engraved so as to protrude from the bar flow cavity 45 to the dividing surface 22a of the movable mold plate 22, so that the resin molded product can be divided without taking out from the bar flow cavity 45. The flow length of the molten resin material can be measured on the surface 22a.
[0057]
Furthermore, in order to hold the opening valve body 53 and the closing valve body 54 in the valve body mounting portions 51a, 52a, 51b, and 52b, the screw member 55 is used in the present embodiment. Other holding means can be used.
[0058]
The capacity | capacitance of the bar flow cavity 45 should just be substantially equal to the capacity | capacitance of the product part cavity 49 in the range which does not affect the setting of the injection molding machine 20. FIG.
[0059]
The operating condition setting method of the injection molding machine 20 according to the present invention and the mold 30 used therein can be used in molding machines other than the injection molding machine 20 such as an extrusion molding machine using a piston as the plunger member 13.
[0060]
【The invention's effect】
According to the present invention, the flow length of the molten resin material injected into the measuring means from the injection molding machine at each plunger member extrusion position is measured under the operating conditions of the injection molding machine that molds a resin molded product having no defects. Then, based on this measurement data, it is possible to find the optimum operating conditions for other injection molding machines. Thus, the optimum operating conditions can be set quickly and easily without trial and error by repeatedly forming short shots in the product cavity.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view schematically showing an injection molding machine and a mold according to the present invention.
FIG. 2 is a plan view showing a state in which a valve body is arranged so as to selectively introduce a molten resin material into a product portion cavity provided in the mold, on a divided surface of a fixed mold plate of the mold according to the present invention; It is.
FIG. 3 is a plan view showing a dividing surface of a movable mold plate of a mold according to the present invention in a state where a valve body is arranged so as to selectively introduce a molten resin material into a product part cavity provided in the mold. It is.
FIG. 4 is a longitudinal sectional view showing an open valve member according to the present invention.
FIG. 5 is a longitudinal sectional view showing a closing valve member according to the present invention.
FIG. 6 is a plan view showing a dividing surface of a movable mold plate of a mold according to the present invention in a state where a valve body is arranged so as to selectively introduce a molten resin material into a bar flow cavity provided in the mold. It is.
[Explanation of symbols]
30 mold
13 Plunger member (screw member)
20 Injection molding machine
45 Measuring means (Bar flow cavity)
S1, S2, S3, S4, S5 Extrusion position
L1, L2, L3, L4 Flow length
36, 37 Branch (first branch, second branch)
33a, 34, 33b, 36, 37 flow path (primary sprue, runner, secondary sprue, first branch path, second branch path)
49 Product cavity
53,54 Valve body (open valve body, closed valve body)
50 scales
21a, 22a Dividing surface
21 Fixed template
22 Movable template
36a, 37a, 36b, 37b Branch groove
53a, 53b Opening valve member
54a, 54b Closing valve member
51a, 52a, 51b, 52b Recess (Valve attachment)

Claims (6)

A method of setting operating conditions of an injection molding machine provided with a plunger member for extruding a molten resin material into the mold to mold a resin molded product with a mold,
A plunger member of the injection molding machine is formed by injecting the molten resin material from the injection molding machine to the measuring means under an operating condition of molding a resin molded product as a product by injecting the molten resin material into the mold from the injection molding machine. Measuring the flow length of the molten resin material in the measuring means at each of the plurality of extrusion positions,
Prior to manufacturing a resin molded product by injecting a resin material from another injection molding machine into the mold, injection of a molten resin material from the other injection molding machine into the measuring means corresponds to each extrusion position. The operation condition of the other injection molding machine is set to obtain a flow length equal to the flow length measured for each of the extrusion positions at each extrusion position of the other injection molding machine. Operation condition setting method for injection molding machines. The operating condition setting method according to claim 1, wherein the plunger member is a screw member. A mold for injecting molten resin material from an injection molding machine, the mold having two branch paths, and a flow for guiding the molten resin material extruded from the injection molding machine into the mold A bar flow having a capacity equal to the capacity of the product part cavity communicating with the other branch path of the channel, a product part cavity for the resin molded product communicating with the one branch path of the channel A cavity and a valve body for selectively blocking one of the branch paths are provided,
The bar flow cavity is an elongated cavity into which the molten resin material can be injected from one end to the other end, and a scale for reading the flow length of the molten resin material is attached along the extending direction of the cavity. Mold characterized by being made. Each of the molds has a divided surface and a fixed mold plate and a movable mold plate that can come into contact with each other on the divided surface, and the product portion cavity is disposed on the divided surface of the fixed mold plate. The mold according to claim 3, wherein the bar flow cavity is disposed on the dividing surface of the movable mold plate. Each of the branch passages is constituted by a branch groove portion formed on each of the dividing surfaces of the both mold plates, and the valve body has a pair of open valve members for keeping the branch passages in an open state together with each other, and A pair of closing valve members for putting the branch paths together in a shut-off state are provided, and each of the branch groove portions accommodates either the pair of opening valve members or the pair of closing valve members in a replaceable manner. 4. The mold according to claim 3, wherein a recess is formed, and each open valve member and each close valve member can be selectively positioned in each recess. The injection molding machine includes a screw member that moves toward an extrusion position to extrude a molten resin material,
The product part cavity is selectively closed by the valve body from the injection molding machine under the operating condition of molding a resin molded product as a product by injecting the molten resin material from the injection molding machine into the product part cavity. The molten resin material is injected into the bar flow cavity in a state where the flow length of the molten resin material in the bar flow cavity at each of the plurality of extrusion positions of the screw member of the injection molding machine is scaled. Read from the
Prior to injecting the molten resin material into the product part cavity from another injection molding machine and molding the resin molded product, the molten resin material is injected into the bar flow cavity from the other injection molding machine. In order to obtain a flow length equal to the flow length at the extrusion position corresponding to each of the extrusion positions of the screw member read from the scale, operating conditions for each of the extrusion positions are set, and the other conditions are set under the set operating conditions. The mold according to claim 3, wherein the molten resin is injected into the product portion cavity in a state where the bar flow cavity is closed with the valve body from the injection molding machine of claim 3 to form a molded product.

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