JP2917088B2 - Control method of injection molding machine - Google Patents
Control method of injection molding machineInfo
- Publication number
- JP2917088B2 JP2917088B2 JP22702393A JP22702393A JP2917088B2 JP 2917088 B2 JP2917088 B2 JP 2917088B2 JP 22702393 A JP22702393 A JP 22702393A JP 22702393 A JP22702393 A JP 22702393A JP 2917088 B2 JP2917088 B2 JP 2917088B2
- Authority
- JP
- Japan
- Prior art keywords
- injection
- molding machine
- mold opening
- mold
- injection molding
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Landscapes
- Injection Moulding Of Plastics Or The Like (AREA)
Description
【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION
【０００１】[0001]
【産業上の利用分野】本発明は射出成形機の制御方法に
関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling an injection molding machine.
【０００２】[0002]
【従来の技術】一般に、樹脂の射出成形においては、射
出速度を高速に維持したままで射出を行うと、オーバパ
ックの現象が現れ易くなるので、金型内に溶融樹脂が満
杯になる直前、すなわち充填完了直前に射出速度を低速
に切換えるようにしている。この切換タイミングは経験
的に設定されており、切換えが早すぎると成形品の薄肉
部分が固化して未充填現象が発生してしまう。2. Description of the Related Art In general, in injection molding of a resin, if the injection is performed while maintaining the injection speed at a high speed, an overpack phenomenon is likely to appear. That is, the injection speed is switched to a low speed immediately before the filling is completed. This switching timing is set empirically. If the switching is performed too early, the thin portion of the molded product is solidified, and an unfilled phenomenon occurs.
【０００３】この点を配慮し、射出速度を検出して低速
に落ちてきたら射出工程から保圧工程に切換えるという
方法も提案されているが、射出速度の低下は、金型内の
樹脂圧が上昇することで抵抗が増加して生ずるので、切
換えタイミングに遅れを生じ易いという欠点がある。In consideration of this point, there has been proposed a method of detecting the injection speed and switching from the injection process to the pressure holding process when the injection speed drops to a low speed. However, the decrease in the injection speed is caused by the resin pressure in the mold. As the resistance rises due to the rise, the switching timing is liable to be delayed.
【０００４】以上のような欠点を解決する制御方法とし
て、以下に述べるように、金型の型開量に注目した方法
が知られている。As a control method for solving the above-mentioned drawbacks, there has been known a method which pays attention to a mold opening amount as described below.
【０００５】すなわち、金型内への溶融樹脂の充填時に
金型が微小量開くことに着目し、型開量を設定して射出
圧力や保圧を制御する方法であり、例えば特公昭５９−
２９４１５号公報に開示されている。[0005] That is, attention is paid to the fact that the mold is opened by a very small amount when the mold is filled with the molten resin, and the injection pressure and the holding pressure are controlled by setting the mold opening amount.
No. 29415.
【０００６】[0006]
【発明が解決しようとする課題】上記の制御方法によれ
ば、射出圧力を補正した時、金型内樹脂圧が低ければ型
開量の変化度は大きく、大きな修正効果が得られる。し
かしながら、金型内樹脂圧が高くなるにつれて、射出圧
力という成形品外部の圧力で金型内樹脂圧を高めるの
で、型開量を補正する効果には限界があり、バリ、変
形、コーナ部分の偏肉といった不具合を発生することが
ある。According to the above-described control method, when the injection pressure is corrected, if the resin pressure in the mold is low, the degree of change in the mold opening amount is large, and a large correction effect can be obtained. However, as the resin pressure in the mold increases, the resin pressure in the mold is increased by the injection pressure, which is the pressure outside the molded product. Therefore, there is a limit to the effect of correcting the mold opening amount. Problems such as uneven thickness may occur.
【０００７】以上のような問題点に鑑み、本発明の課題
は、樹脂の充填完了直前に要求される射出速度や射出圧
力の切換えタイミングを、成形サイクル内で変化する型
開量の変化量を監視して自動的に割り出すことができる
ようにした射出成形機の制御方法を提供することにあ
る。[0007] In view of the above problems, an object of the present invention is to change the timing of switching the injection speed and injection pressure required immediately before the completion of filling of the resin with the change amount of the mold opening amount that changes within the molding cycle. An object of the present invention is to provide a control method for an injection molding machine which can be monitored and automatically determined.
【０００８】[0008]
【課題を解決するための手段】本発明は、型開量を検出
して成形条件を自動修正する射出成形機の制御方法にお
いて、各成形サイクルにおける射出工程中に前記型開量
の時間に対する変化量、又は前記変化量と相関した値を
算出し、該算出結果とあらかじめ定められた設定値との
比較結果に基づいて前記型開量の急激な上昇現象を検出
し、前記急激な上昇現象の検出時に射出シリンダにおけ
る射出速度や射出圧力の修正制御を行うことを特徴とす
る。According to the present invention, there is provided a control method of an injection molding machine for automatically correcting a molding condition by detecting a mold opening amount , wherein a change of the mold opening amount with respect to time during an injection step in each molding cycle. Amount, or a value correlated with the change amount, and based on a comparison result between the calculation result and a predetermined set value, a rapid rise phenomenon of the mold opening amount is detected.
However, when the rapid rise phenomenon is detected,
And performing correction control of the injection speed and injection pressure that.
【０００９】なお、前記変化量と相関した値として、あ
る時刻における前記変化量とこれより１回前に算出され
た前記変化量との比を用いる。As a value correlated with the change amount, a ratio between the change amount at a certain time and the change amount calculated one time before the change amount is used.
【００１０】[0010]
【実施例】本発明の実施例を説明する前に、本発明がな
された背景について説明する。図１は１回の成形サイク
ルにおける型開量（実線で示す）と射出速度（破線で示
す）の時間変化を示し、急激な立上りを呈している領域
Ｐ１は、樹脂の完全充填時の型開量上昇現象を示す。型
開量について言えば、Ｔ１時点で射出を開始してから樹
脂充填中はほとんど０に近い数値のままで推移するが、
完全充填の直前に、金型キャビティ内において未だ逃げ
きれないガス等の気体が一種のダンパとして存在するう
ちに、型開量はＴ２時点で急激に立上がってくることを
見い出した。しかも、この時点は、Ｔ３で示す射出速度
を低速に切換えるに適したタイミングであることを見い
出した。DESCRIPTION OF THE PREFERRED EMBODIMENTS Before describing embodiments of the present invention, the background on which the present invention is made will be described. FIG. 1 shows a time change of the mold opening amount (indicated by a solid line) and the injection speed (indicated by a dashed line) in one molding cycle, and a region P1 exhibiting a sharp rise is a mold opening when the resin is completely filled. It shows the phenomenon of quantity increase. Speaking of the mold opening amount, while the resin is being filled after the injection is started at the time T1, the value remains almost at 0,
Immediately before the complete filling, it was found that the mold opening amount suddenly rises at time T2 while a gas such as a gas that still cannot escape in the mold cavity exists as a kind of damper. In addition, it has been found that this time is a timing suitable for switching the injection speed indicated by T3 to a low speed.
【００１１】以上のような知見にもとづいて、本発明
は、成形サイクル内で変化する型開量の変化量を監視し
て射出速度の切換えタイミングを割り出すようにしたも
のであり、以下に図２を参照して説明する。Based on the above knowledge, the present invention monitors the amount of change in the mold opening that changes within the molding cycle to determine the timing of switching the injection speed. This will be described with reference to FIG.
【００１２】型締シリンダ１によりプラテン２が移動
し、金型３を型締する。射出シリンダ４によりスクリュ
５がノズル６側に前進し、溶融樹脂７を金型３のキャビ
ティ内に充填する。この時、一対の金型３の合わせ目に
は、微小の型開量が生ずることは周知である。この型開
量は、金型３やプラテン２に設けた位置検出器９と突当
てブロック１０により検出される。制御装置２０は、位
置検出器９からの検出信号により、後述する射出速度の
切替え制御を行う。The platen 2 is moved by the mold clamping cylinder 1 to clamp the mold 3. The screw 5 advances to the nozzle 6 side by the injection cylinder 4, and the molten resin 7 is filled in the cavity of the mold 3. At this time, it is well known that a small amount of mold opening occurs at the joint between the pair of molds 3. This mold opening is detected by the position detector 9 and the abutment block 10 provided on the mold 3 and the platen 2. The control device 20 controls the switching of the injection speed, which will be described later, based on the detection signal from the position detector 9.
【００１３】本実施例では、位置検出器９の他に、型締
力検出器２１、射出圧力検出器２２を備え、制御装置２
０はこれらの検出器からの検出信号にもとづいて型締シ
リンダ１の駆動源２３、射出シリンダ４の駆動源２４を
制御するが、これらの制御は知られているので説明は省
略する。設定部２５は、後述する制御に必要な設定値を
入力するものである。In this embodiment, in addition to the position detector 9, a mold clamping force detector 21 and an injection pressure detector 22 are provided.
0 controls the drive source 23 of the mold clamping cylinder 1 and the drive source 24 of the injection cylinder 4 based on the detection signals from these detectors, but since these controls are known, the description is omitted. The setting unit 25 is for inputting a set value required for control described later.
【００１４】以下に、射出速度の切換制御について説明
する。射出開始から保圧工程への切換えまでの区間で型
開量をＬとすると、制御装置２０は、各成形サイクル毎
に１サイクル時間より十分短かい任意のサンプリング周
期で位置検出器９で検出された型開量をサンプリングす
る。そして、ある時刻の型開量Ｌn と次の周期の型開量
Ｌ（n+1 ）の差（Ｌ（n+1 ）−Ｌn ）（変化量）をΔＬ
n とすると、その１つ前の差ΔＬ（n-1 ）との比を計算
する。制御装置２０は、上記比が設定部２５で設定され
た範囲に入るかどうかの判定動作を行い、上記比が設定
範囲に入ると、射出速度を低速に切換えたり、射出系に
ブレーキをかけて射出圧力を切り換える等の制御動作を
行う。Hereinafter, the switching control of the injection speed will be described. Assuming that the mold opening amount is L in a section from the start of injection to the switching to the pressure-holding step, the control device 20 detects the position by the position detector 9 at an arbitrary sampling cycle sufficiently shorter than one cycle time for each molding cycle. The mold opening is sampled. Then, the difference in mold opening amount of the mold opening amount L n and the next period of a time L (n + 1) to (L (n + 1) -L n) ( change amount) [Delta] L
When n, to calculate the ratio of the immediately preceding difference ΔL (n-1). The control device 20 performs an operation of determining whether or not the above ratio is within the range set by the setting unit 25. When the above ratio is within the set range, the injection speed is switched to a low speed or the injection system is braked. Control operations such as switching the injection pressure are performed.
【００１５】なお、型開量の検出値は、タイバー間を測
定した時には、金型のプラテン間のみを測定した時に比
べ、通常、少なくとも５倍以上の違いを見せる。しかる
に、本発明の如き方法を採用することにより、型開量の
絶対値の大きさをキャンセルすることができ、位置検出
器の取付方法、取付精度等の影響を受けず、したがって
位置検出器に応じて設定値を変える必要が無い。また、
ノイズが入ると上記比は過大な値を示すが、上記比に範
囲を設定することにより、ノイズの場合には上記比は設
定範囲から外れるので、誤認も少ない。この範囲として
は、通常、１以上、１０以下の値が選ばれる。また、型
開量のサンプリング周期としては、制御装置２０におい
て上記のような比の演算および判定動作に必要な時間が
確保できる最短時間まで短縮できる。[0015] The detected value of the mold opening amount usually shows at least a five-fold difference when measuring between the tie bars as compared with when measuring only between the platens of the mold. However, by employing the method of the present invention, it is possible to cancel the absolute value of the mold opening amount, and it is not affected by the mounting method of the position detector, the mounting accuracy, and the like. There is no need to change the setting values accordingly. Also,
When noise enters, the above ratio shows an excessive value, but by setting a range for the above ratio, in the case of noise, the above ratio falls out of the set range, so that there is less erroneous recognition. As this range, a value of 1 or more and 10 or less is usually selected. In addition, the sampling period of the mold opening amount can be reduced to the shortest time in which the time required for the above-described ratio calculation and determination operation in the control device 20 can be secured.
【００１６】以上のように、本発明では金型３や成形品
部８の形状が変わってもその都度設定値を変える必要は
無く、充填完了直前の型開量の急激な立上がり（図２に
Ｔ２で示す時点）を、成形品部８からの反力Ｆによる型
開量の時間変化量にもとづいて正確に検出することがで
きる。As described above, according to the present invention, it is not necessary to change the set value each time the shape of the mold 3 or the molded article portion 8 changes, and the mold opening amount immediately rises immediately before the filling is completed (see FIG. 2). (Time point indicated by T2) can be accurately detected based on the amount of time change of the mold opening amount due to the reaction force F from the molded article portion 8.
【００１７】[0017]
【発明の効果】以上説明してきたように本発明によれ
ば、樹脂の充填完了直前のタイミング検出を、金型や成
形品部の形状変化の影響を受けることなく正確に行うこ
とができるので、射出速度の切換えをタイミング良く行
うことができ、その結果、バリやオーバパックを減らせ
ると共に、ショートショット等も低減することができ
る。As described above, according to the present invention, the timing detection immediately before the completion of the filling of the resin can be accurately performed without being affected by the shape change of the mold and the molded product. Switching of the injection speed can be performed with good timing. As a result, burrs and overpack can be reduced, and short shots and the like can be reduced.
【図１】本発明の原理を説明するために、１成形サイク
ルにおける型開量と射出速度の時間変化を示した特性図
である。FIG. 1 is a characteristic diagram showing a time change of a mold opening amount and an injection speed in one molding cycle in order to explain the principle of the present invention.
【図２】本発明の一実施例の概略構成を示した図であ
る。FIG. 2 is a diagram showing a schematic configuration of an embodiment of the present invention.
１ 型締シリンダ ２ プラテン ３ 金型 ４ 射出シリンダ ５ スクリュ ６ ノズル ７ 溶融樹脂 ８ 成形品部 ９ 位置検出器 １０ 突当てブロック ２２ 型締力検出器 ２２ 射出圧力検出器 ２３，２４ 駆動源 REFERENCE SIGNS LIST 1 mold clamping cylinder 2 platen 3 mold 4 injection cylinder 5 screw 6 nozzle 7 molten resin 8 molded part 9 position detector 10 butting block 22 mold clamping force detector 22 injection pressure detector 23, 24 drive source
Claims (2)
る射出成形機の制御方法において、各成形サイクルにお
ける射出工程中に前記型開量の時間に対する変化量、又
は前記変化量と相関した値を算出し、該算出結果とあら
かじめ定められた設定値との比較結果に基づいて前記型
開量の急激な上昇現象を検出し、前記急激な上昇現象の
検出時に射出シリンダにおける射出速度や射出圧力の修
正制御を行うことを特徴とする射出成形機の制御方法。1. A method of controlling an injection molding machine for automatically correcting a molding condition by detecting a mold opening amount , wherein the mold opening amount changes with time or correlates with the change amount during an injection step in each molding cycle. value is calculated, the type based on a comparison result between the set value determined in advance and the result output the calculated
Detecting the rapid rise of the opening amount,
A control method for an injection molding machine, wherein correction control of an injection speed and an injection pressure in an injection cylinder is performed upon detection .
おいて、前記変化量と相関した値として、ある時刻にお
ける前記変化量とこれより１回前に算出された前記変化
量との比を用いることを特徴とする射出成形機の制御方
法。2. The control method for an injection molding machine according to claim 1, wherein a ratio between the change amount at a certain time and the change amount calculated one time before the change amount is set as a value correlated with the change amount. A method for controlling an injection molding machine, which is used.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22702393A JP2917088B2 (en) | 1993-09-13 | 1993-09-13 | Control method of injection molding machine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22702393A JP2917088B2 (en) | 1993-09-13 | 1993-09-13 | Control method of injection molding machine |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0780906A JPH0780906A (en) | 1995-03-28 |
| JP2917088B2 true JP2917088B2 (en) | 1999-07-12 |
Family
ID=16854308
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP22702393A Expired - Fee Related JP2917088B2 (en) | 1993-09-13 | 1993-09-13 | Control method of injection molding machine |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2917088B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| IT201800002639A1 (en) | 2018-02-13 | 2019-08-13 | Inglass Spa | PROCEDURE AND EQUIPMENT FOR INJECTION MOLDING OF PLASTIC MATERIALS |
-
1993
- 1993-09-13 JP JP22702393A patent/JP2917088B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0780906A (en) | 1995-03-28 |
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