JP2004237541A - Mold opening/closing device of injection molding machine - Google Patents

Mold opening/closing device of injection molding machine Download PDF

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Publication number
JP2004237541A
JP2004237541A JP2003028398A JP2003028398A JP2004237541A JP 2004237541 A JP2004237541 A JP 2004237541A JP 2003028398 A JP2003028398 A JP 2003028398A JP 2003028398 A JP2003028398 A JP 2003028398A JP 2004237541 A JP2004237541 A JP 2004237541A
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speed
motor
moment
inertia
molding machine
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JP4278396B2 (en
Inventor
Moritoki Ito
守十樹 伊藤
Mamoru Teramura
守 寺村
Yukihiko Kobayashi
幸彦 小林
Yasushi Igawa
康 井川
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Mitsubishi Electric Corp
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Mitsubishi Electric Corp
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Abstract

<P>PROBLEM TO BE SOLVED: To obtain the mold opening/closing device of an injection molding machine which can stably control the response of a motor speed control system. <P>SOLUTION: The device has an encoder 31 which detects the rotational angle of a motor 3 and generates a position detection signal, a differentiator 35 which differentiates the position detection signal and generates a speed detection signal, a speed controller 37 which generates an electric current command signal of the motor 3 based on a speed deviation signal to be the difference between a speed command signal and the speed detection signal and by using a speed gain, a moment of inertia calculation means for calculating the moment of inertia of a movable board 13 based on the position detection signal, and a gain setting device 53 for changing the speed gain based on the change of the moment of inertia. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は射出成形機の金型開閉装置の改良に関し、金型の開閉を速やかに制御するものである。
【０００２】
【従来の技術】
従来の射出成形機における金型の開閉装置（開閉方法）を特開平１０−６６８号公報によって説明する。該公報に記載された開閉装置（開閉方法）によれば、型開閉駆動源による駆動力を、リンク機構を介して可動盤に伝達して、型開閉動作を行う成形機の型開き制御方法において、型開き行程の高速領域における設定速度の如何にかかわらず、減速開始から型開き完了位置までの時間を一定に制御するものである。
【０００３】
上記のような金型の開閉装置（開閉方法）によれば、型開き終了時におけるショックの発生を可及的に抑止し得、型開き完了位置のバラツキの少ない型開き制御方法が実現できる。また、型開き行程の速度設定作業を容易なものとでき、使い勝手が向上するものである。
【０００４】
【発明が解決しようとする課題】
しかしながら、リンク機構を介した可動盤の移動位置によって可動盤を駆動するモータに加わる慣性モーメントが変化する。このため、可動盤の前進、後退の移動、すなわち、金型の開閉によって可動盤を駆動するモータの速度制御系の応答性が異なっていた。したがって、速度指令信号に基いてモータを速度制御する速度制御器の速度ゲインの設定を、速度制御系の発振を抑制するために低く設定すると、応答性が低下するという問題点があった。
【０００５】
本発明は、上記課題を解決するためになされたもので、可動盤を駆動するモータの速度制御器の速度ゲインを、上記慣性モーメントの変化に対応した値に変化させることにより、モータの速度制御系の応答を安定に制御し得る射出成形機の金型開閉装置を提供することを目的とするものである。
【０００６】
【課題を解決するための手段】
本発明に係る射出成形機の金型開閉装置は、位置指令信号によりモータをサーボ制御して可動部を移動することにより金型を開閉する射出成形機の金型開閉装置において、前記モータの回転角度を検出して位置検出信号を発生する角度検出手段と、前記モータの回転速度を検出して速度検出信号を発生する速度検出手段と、前記位置指令信号に基いて速度指令信号を発生する位置制御手段と、前記速度指令信号と前記速度検出信号との差となる速度偏差信号に基くと共に、速度ゲインを用いて前記モータに電流を流す電流指令信号を発生する速度制御手段と、前記位置検出信号に基いて前記可動部の慣性モーメントを算出する慣性モーメント算出手段と、該慣性モーメント算出手段により算出された前記慣性モーメントの変化に基いて前記速度ゲインを変更するゲイン設定手段と、を備えたことを特徴とするものである。
かかる金型の開閉装置によれば、可動盤を駆動するモータの速度制御手段の速度ゲインを、可動部の慣性モーメントの変化に対応した値に設定できる。したがって、モータの速度制御系が安定になるので、金型を成す可動部の速度制御が円滑になるという効果がある。
【０００７】
他の発明に係る射出成形機の金型開閉装置におけるゲイン設定手段は、モータの速度制御系における速度ループの閉ループ伝達関数がほぼ一定になるようにする、ことを特徴とするものである。
かかる金型の開閉装置によれば、金型の可動部をも含めたモータの速度制御系が極めて安定するという効果がある。
【０００８】
他の発明に係る射出成形機の金型開閉装置は、モータと可動部とを連結すると共に、前記モータの回転に基いて前記可動部を直線動作させるリンク機構とを備えたことを特徴とするものである。
かかる金型の開閉装置によれば、モータの回転によりリンク機構を介して金型の可動部が直線動作するので、可動部を直線動作させる機構が簡易になると共に、可動部の慣性モーメントの算出が簡易になり、速度制御手段の速度ゲインの設定も簡易になるという効果がある。
【０００９】
他の発明に係る射出成形機の金型開閉装置におけるゲイン設定手段は、可動部の質量、リンク機構の構成に基く定数を入力する入力手段と、入力された前記質量、定数を記憶する記憶手段とを備え、慣性モーメント算出手段は、該記憶手段に記憶された前記質量、定数を用いて前記慣性モーメントを算出する、ことを特徴とするものである。
かかる金型の開閉装置によれば、簡易に速度制御系の速度ゲインを設定できるという効果がある。
【００１０】
【発明の実施の形態】
実施の形態１．
本発明の一実施の形態を図１乃至図３によって説明する。図１は電動射出成形機の全体構成図、図２は図１に示す金型の開閉機構を示す機械モデル図、図３は図１に示す電動射出成形機の速度制御系のブロック図である。
図１において、電動射出成形機１は、原料樹脂を加熱溶融して射出する射出部と、溶融された樹脂を金型内部に流し込んで成形品を生成する金型１６と、金型１６を開閉制御する開閉機構１０と、該開閉機構１０を制御する制御部と、制御部の速度制御器３７の速度ゲインをモータ３の全慣性モーメントＪに応じて設定するゲイン設定手段としてのゲイン設定部５０とから成っている。
【００１１】
射出部は、シリンダー２０の内部に樹脂を送り込むスクリュー２２から成っており、金型１６は固定された固定盤１７と、開閉機構１０により矢印Ａ，Ｂの水平方向に移動する可動部としての可動盤１５とから成っている。
開閉機構１０は、モータ３の軸３ａに一端が連結固定された短辺アーム１１と、一端が短辺アーム１１の他端に固定されると共に、他端が可動盤１５の中央部に固定された長片アーム１３とから成っており、リンクが短辺アーム１１と長辺アーム１３とにより形成されことで、モータ５の回転により短辺アーム１１が回転して長辺アーム１３を介して可動盤１５が矢印Ａ，Ｂ方向に直動移動して金型１６が開閉するように形成されている。
【００１２】
制御手段としての制御部は、モータ３の回転角度としての位置検出信号θｒｍを検出する角度検出手段としてのエンコーダ３１と、位置指令信号θ＊ｒｍと位置検出信号θｒｍとの差を求めて位置偏差信号を発生する減算器３２と、位置偏差信号を入力して速度指令信号ω＊ｒｍを発生する位置制御手段としての位置制御器３３と、位置検出信号θｒｍを微分して速度検出信号ωｒｍを発生する微分器３５と、速度指令信号ω＊ｒｍと速度検出信号ωｒｍとの差となる速度偏差信号を発生する減算器３４と、速度ゲインを有し、入力された速度偏差信号に速度ゲインを乗じて電流指令信号ｉ＊ｇａを発生する速度制御手段としての速度制御器３７と、電流指令信号ｉ＊ｇａに基いて電流を流す電流制御器３９とを備えている。
なお、エンコーダ３１と微分器３３とにより速度検出手段を成している。
【００１３】
金型１６の可動盤１５の慣性力Ｆ（Ｎ）は、可動盤１３の質量をｍ（ｋｇ）、加速度をα（ｍ／ｓｅｃ２）とすると下式となる。
Ｆ＝ｍ・α＝ｍ・（ｄ２ｘ／ｄｔ２） ・・・・・（１）
一方、図２に示す金型１６の開閉機構１０を示すモデル図により長辺アーム１１の長さをＬ（ｍ）、短辺アーム１３の長さをｒ（ｍ）としてＸ軸成分の長さをｘ（ｍ）とすると、下式を得る。
ｘ＝ｒ・ｃｏｓθ＋Ｌ・ｃｏｓφ ・・・・・ （２）
ここに、θ＝ωｔ：モータ３の回転角度 （ｒａｄ）
また、開閉機構１０を成す短辺アーム１１と長辺アーム１３とのＹ軸成分の長さが等しいので、下式を得る。
ｒ・ｓｉｎθ＝Ｌ・ｓｉｎφ ・・・・・（３）
ここに、φ：長辺アーム１３が可動盤１５の直動方向と成す角度（ｒａｄ）
上記（３）を上記（２）式に代入して開閉機構１０のＸ成分を求めると下式となる。
ｘ＝ｒ｛１−（ｒ／Ｌ）２ｓｉｎ２θ｝１／２ ・・・・・（４）
一方、長辺アーム１３の長さＬ≫短辺アーム１１の長さをｒであるから、ｒ／Ｌ≪１となり、上式（４）式を整理して開閉機構１０のＸ成分を求めると下式となる。
ｘ＝ｒ［ｃｏｓθ＋Ｌ／ｒ｛１−１／２（ｒ／Ｌ）２ｓｉｎ２θ｝］・・・・（５）
ここで、ｓｉｎθ＝（１−ｃｏｓ２θ）／２の関係を用いて上記（５）式を整理すると下式を得る。
ｘ＝Ｌ−ｒ｛ｒ／（４Ｌ）−ｃｏｓωｔ−ｒ／（４Ｌ）ｃｏｓ２ωｔ｝・・・・（６）
上記（６）式を上記（１）式に代入して金型１６の可動盤１５の慣性力Ｆ（Ｎ）を求めると、下式となる。
Ｆ＝ｍ・（ｄ２ｘ／ｄｔ２）＝−ｍ・ｒ・ω｛ｃｏｓωｔ＋（ｒ／Ｌ）ｃｏｓ２ωｔ｝・・・（７）
上記（７）式が示すように可動盤１５の慣性力Ｆは、モータ３の回転角度θ、すなわち、短辺アーム１１の回転角度θによって変化する。
【００１４】
モータ３から見た可動盤１５の慣性モーメントＪｒは、下記となる。

Figure 2004237541
すなわち、モータ３の回転角度ωｔ（θ）、モータ３の角速度ωを検出することにより可動盤１５の慣性モーメントＪｒを求めることができる。
【００１５】
一方、図３に示すように金型開閉装置の速度制御ループの閉ループ伝達関数Ｇｃは、位置制御器３３の位置ゲインをＫｓｐ、速度制御器３７をＰＩ制御として速度ゲインとしてそれぞれの比例ゲインをＫｓｐ、積分ゲインをＫｓｉ、電流制御器３９の電流制御ゲインをＫＴ、モータ３に加わる全慣性モーメントをＪ、ラプラス演算子をｓとすると、「ＡＣサーボシステムの理論と設計の実際」、総合電子出版社、杉本英彦編著、第４版、第１７３頁より下式となる。
Ｇｃ＝ＫＴ（Ｋｓｐ・ｓ＋Ｋｓｉ）／（Ｊ・ｓ２＋ＫＴ・Ｋｓｐ・ｓ＋ＫＴ・Ｋｓｉ）・・ （９）
ここで、閉ループ伝達関数Ｇｃは、簡略化のために速度制御器３７をＰ制御のみとすると下式となる。
Ｇｃ＝ＫＴ・Ｋｓｐ・ｓ／（Ｊ・ｓ２＋ＫＴ・Ｋｓｐ・ｓ） ・・・（１０）
ここに、Ｊ＝Ｊｍ＋Ｊｒ
Ｊｍ：モータ３の慣性モーメント、Ｊｒ：可動盤１５の慣性モーメント
【００１６】
ゲイン設定部５０は、短辺アーム１１の長さｒ（ｍ）、長辺アーム１３の長さＬ（ｍ）、可動盤１５の質量（ｋｇ）、モータ３の慣性モーメントＪｍ（ｋｇ・ｍ２）を入力するキーボードかな成る入力部５１と、可動盤１５の移動により変化する慣性モーメントＪｒに応じて速度制御系の閉ループ伝達関数が一定に成るように速度ゲインを設定するゲイン設定器５０を備え、ゲイン設定器５０は、入力された上記数値を、インターフェイス（図示せず）を介して記憶するＲＡＭ５３ａと、上記（８）式、（１０）式の演算式を記憶したＲＯＭ５３ｒと、演算機能を有するＣＰＵ５３ｃとを備えている。なお、ＲＯＭ５３ｒに記憶された上記（８）式を実行することが、慣性モーメント算出手段となる。
【００１７】
上記のように構成された射出成形機の金型開閉装置を図１乃至図３によって説明する。まず、短辺アーム１１の長さｒ（ｍ）、長辺アーム１３の長さＬ（ｍ）、可動盤１５の質量（ｋｇ）、モータ３の慣性モーメントＪｍを入力部５１に入力してインターフェイス（図示せず）を介してゲイン設定器５０のＲＡＭ５３ａに記憶する。
いま、金型１６が開放状態で、モータ３の位置指令信号θ＊ｒｍに基づてモータ３を回転すると、エンコーダ３１が位置検出信号θｒｍを発生して減算器３２に入力する。減算器３２は位置指令信号θ＊ｒｍと位置検出信号θｒｍとの差となる位置偏差信号を発生を減算器３４に入力する。一方、微分器３５は位置検出信号θｒｍを微分して速度検出信号ωｒｍを減算器３４に入力する。減算器３４は速度指令信号ω＊ｒｍと速度検出信号ωｒｍとの差となる速度偏差信号を発生して速度制御器３７に入力する。
【００１８】
ゲイン設定器５３におけるＣＰＵ５３ｃは、エンコーダ３１により検出したモータ３の位置検出信号θｒｍと、該位置検出信号θｒｍからモータ３の角速度ωを求めて上記（８）式より可動盤１５の慣性モーメントＪｒを求め、全慣性モーメントＪを慣性モーメントＪｒと慣性モーメントＪｍとの和により求める。
さらに、ＣＰＵ５３ｃは、上記（１０）式より速度制御ループの伝達関数が一定になるような速度ゲインを求め、該速度ゲインを速度制御器３７に設定する。速度制御器３７は、速度偏差信号を入力して、設定された速度ゲインにより電流指令信号ｉ＊ｇａを発生し、電流制御器３９を介してモータ３を制御する。
【００１９】
上記のような金型の開閉装置１によれば、可動盤１５を駆動するモータ３の速度制御器３７の速度ゲインを、可動盤１５の移動に伴い変化する慣性モーメントＪｒの変化に対応した値、すなわち、モータの速度制御系の応答を一定に制御したので、可動盤１５を円滑に速度制御しなから移動できる。
【図面の簡単な説明】
【図１】図１は電動射出成形機の全体構成図である。
【図２】図１に示す金型の開閉機構を示すモデル図である。
【図３】図１に示す速度制御系のブロック図である。
【符号の説明】
３ モータ、１５ 可動盤、１６ 金型、３１ エンコーダ、３３ 位置制御器、３７ 速度制御器、５３ ゲイン設定器。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an improvement in a mold opening and closing device of an injection molding machine, and is intended to quickly control the opening and closing of a mold.
[0002]
[Prior art]
A mold opening / closing device (opening / closing method) in a conventional injection molding machine will be described with reference to JP-A-10-668. According to the opening / closing device (opening / closing method) described in the publication, a driving force of a mold opening / closing drive source is transmitted to a movable platen via a link mechanism to perform a mold opening / closing operation of a molding machine. Regardless of the set speed in the high speed region of the mold opening stroke, the time from the start of deceleration to the mold opening completion position is controlled to be constant.
[0003]
According to the mold opening / closing device (opening / closing method) as described above, the occurrence of a shock at the end of mold opening can be suppressed as much as possible, and a mold opening control method with less variation in the mold opening completion position can be realized. Further, the speed setting work of the mold opening stroke can be made easy, and the usability is improved.
[0004]
[Problems to be solved by the invention]
However, the moment of inertia applied to the motor that drives the movable plate changes depending on the position of the movable plate moved via the link mechanism. For this reason, the responsiveness of the speed control system of the motor that drives the movable plate by moving the movable plate forward and backward, that is, opening and closing the mold, has been different. Therefore, when the speed gain of the speed controller that controls the speed of the motor based on the speed command signal is set low in order to suppress the oscillation of the speed control system, there is a problem that the responsiveness is reduced.
[0005]
SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem, and the speed control of a motor that drives a movable plate is changed by changing the speed gain of the motor to a value corresponding to the change in the moment of inertia. It is an object of the present invention to provide a mold opening / closing device for an injection molding machine capable of stably controlling the response of a system.
[0006]
[Means for Solving the Problems]
A mold opening and closing device for an injection molding machine according to the present invention is a mold opening and closing device for an injection molding machine that opens and closes a mold by moving a movable portion by servo-controlling a motor according to a position command signal. Angle detecting means for detecting an angle to generate a position detection signal; speed detecting means for detecting a rotation speed of the motor to generate a speed detection signal; and a position for generating a speed command signal based on the position command signal. Control means; speed control means for generating a current command signal for flowing a current to the motor using a speed gain based on a speed deviation signal which is a difference between the speed command signal and the speed detection signal; and An inertia moment calculating means for calculating an inertia moment of the movable part based on the signal, and the speed based on a change in the inertia moment calculated by the inertia moment calculating means. And gain setting means for changing the gain, is characterized in that it comprises a.
According to such a mold opening and closing device, the speed gain of the speed control means of the motor for driving the movable plate can be set to a value corresponding to a change in the inertia moment of the movable portion. Therefore, since the speed control system of the motor becomes stable, there is an effect that the speed control of the movable portion forming the mold becomes smooth.
[0007]
The gain setting means in the mold opening and closing device of the injection molding machine according to another invention is characterized in that the closed loop transfer function of the speed loop in the speed control system of the motor is substantially constant.
According to such a mold opening and closing device, there is an effect that the speed control system of the motor including the movable part of the mold is extremely stable.
[0008]
A mold opening and closing device for an injection molding machine according to another invention is characterized in that it has a link mechanism for connecting a motor and a movable part and for linearly operating the movable part based on rotation of the motor. Things.
According to such a mold opening and closing device, since the movable portion of the mold linearly operates via the link mechanism by the rotation of the motor, the mechanism for linearly operating the movable portion is simplified, and the moment of inertia of the movable portion is calculated. And the setting of the speed gain of the speed control means is also simplified.
[0009]
The gain setting means in the mold opening / closing device of the injection molding machine according to another invention is an input means for inputting a constant based on the mass of the movable portion and the configuration of the link mechanism, and a storage means for storing the input mass and the constant. Wherein the moment of inertia calculation means calculates the moment of inertia using the mass and the constant stored in the storage means.
According to such a mold opening and closing device, there is an effect that the speed gain of the speed control system can be easily set.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiment 1 FIG.
One embodiment of the present invention will be described with reference to FIGS. 1 is an overall configuration diagram of an electric injection molding machine, FIG. 2 is a mechanical model diagram showing an opening and closing mechanism of a mold shown in FIG. 1, and FIG. 3 is a block diagram of a speed control system of the electric injection molding machine shown in FIG. .
In FIG. 1, an electric injection molding machine 1 includes an injection unit that heats and melts a raw material resin, injects the molten resin into a mold to generate a molded product, and opens and closes the mold 16. An opening / closing mechanism 10 for controlling; a control section for controlling the opening / closing mechanism 10; and a gain setting section 50 as gain setting means for setting a speed gain of a speed controller 37 of the control section according to the total inertia moment J of the motor 3. And consists of
[0011]
The injection unit is composed of a screw 22 for feeding the resin into the cylinder 20. The mold 16 is movable as a fixed platen 17 and a movable unit that moves in the horizontal direction of arrows A and B by the opening and closing mechanism 10. And a board 15.
The opening / closing mechanism 10 has a short side arm 11 having one end connected and fixed to the shaft 3 a of the motor 3, one end fixed to the other end of the short side arm 11, and the other end fixed to the center of the movable platen 15. The link is formed by the short side arm 11 and the long side arm 13, and the short side arm 11 is rotated by the rotation of the motor 5 and is movable via the long side arm 13. The board 15 is formed so as to move linearly in the directions of arrows A and B to open and close the mold 16.
[0012]
The control unit as the control unit determines the position deviation between the position command signal θ * rm and the position detection signal θrm with the encoder 31 as the angle detection unit that detects the position detection signal θrm as the rotation angle of the motor 3. A subtractor 32 for generating a signal, a position controller 33 as a position control means for generating a speed command signal ω * rm by inputting a position deviation signal, and generating a speed detection signal ωrm by differentiating the position detection signal θrm. And a subtractor 34 that generates a speed deviation signal that is a difference between the speed command signal ω * rm and the speed detection signal ωrm, and has a speed gain, and multiplies the input speed deviation signal by the speed gain. It includes a speed controller 37 as a speed control means for generating a current command signal i * ga, and a current controller 39 to flow a current based on the current command signal i * ga Te.
Note that the encoder 31 and the differentiator 33 constitute a speed detecting means.
[0013]
The inertia force F (N) of the movable platen 15 of the mold 16 is given by the following formula, where the mass of the movable platen 13 is m (kg) and the acceleration is α (m / sec 2 ).
F = m · α = m · (d 2 x / dt 2 ) (1)
On the other hand, according to a model diagram showing the opening / closing mechanism 10 of the mold 16 shown in FIG. 2, the length of the long side arm 11 is L (m), and the length of the short side arm 13 is r (m). Is x (m), the following equation is obtained.
x = r · cos θ + L · cos φ (2)
Where θ = ωt: rotation angle of the motor 3 (rad)
Further, since the lengths of the Y-axis components of the short side arm 11 and the long side arm 13 forming the opening / closing mechanism 10 are equal, the following equation is obtained.
r · sin θ = L · sin φ (3)
Here, φ: angle (rad) formed between the long side arm 13 and the linear motion direction of the movable platen 15
When the X component of the opening / closing mechanism 10 is obtained by substituting the equation (3) into the equation (2), the following equation is obtained.
x = r {1− (r / L) 2 sin 2 θ} 1/2 (4)
On the other hand, since the length L of the long side arm 13≫the length of the short side arm 11 is r, r / L≪1, and the above equation (4) is rearranged to obtain the X component of the opening / closing mechanism 10. It becomes the following formula.
x = r [cos θ + L / r {1-1 / 2 (r / L) 2 sin 2 θ}] (5)
Here, by rearranging the above equation (5) using the relationship sin θ = (1−cos 2θ) / 2, the following equation is obtained.
x = L−r {r / (4L) −cosωt−r / (4L) cos2ωt} (6)
When the above equation (6) is substituted into the above equation (1) to obtain the inertial force F (N) of the movable platen 15 of the mold 16, the following equation is obtained.
F = m · (d 2 x / dt 2 ) = − m · r · ω {cosωt + (r / L) cos2ωt} (7)
As indicated by the above equation (7), the inertial force F of the movable platen 15 changes depending on the rotation angle θ of the motor 3, that is, the rotation angle θ of the short side arm 11.
[0014]
The moment of inertia Jr of the movable platen 15 as viewed from the motor 3 is as follows.
Figure 2004237541
That is, by detecting the rotation angle ωt (θ) of the motor 3 and the angular velocity ω of the motor 3, the moment of inertia Jr of the movable platen 15 can be obtained.
[0015]
On the other hand, as shown in FIG. 3, the closed-loop transfer function Gc of the speed control loop of the mold opening / closing device is such that the position gain of the position controller 33 is Ksp, the speed controller 37 is PI control, and the proportional gain is Ksp. Assuming that the integral gain is Ksi, the current control gain of the current controller 39 is KT, the total moment of inertia applied to the motor 3 is J, and the Laplace operator is s, "Theory and Design of AC Servo System", General Electronic Publishing The following formula is used from the fourth edition, page 173, edited by Shahiko Sugimoto.
Gc = K T (Ksp · s + Ksi) / (J · s 2 + KT · Ksp · s + K T · Ksi) ·· (9)
Here, the closed loop transfer function Gc is given by the following equation when the speed controller 37 is set to only the P control for simplification.
Gc = KT · Ksp · s / (J · s 2 + KT · Ksp · s) (10)
Where J = Jm + Jr
Jm: Moment of inertia of motor 3, Jr: Moment of inertia of movable platen 15
The gain setting unit 50 includes a length r (m) of the short side arm 11, a length L (m) of the long side arm 13, a mass (kg) of the movable platen 15, and a moment of inertia Jm (kg · m 2 ), And a gain setting device 50 for setting the speed gain so that the closed loop transfer function of the speed control system becomes constant in accordance with the inertia moment Jr that changes as the movable platen 15 moves. The gain setting device 50 has a RAM 53a for storing the input numerical values via an interface (not shown), a ROM 53r for storing the arithmetic expressions of the above equations (8) and (10), and an arithmetic function. And a CPU 53c. Executing the above equation (8) stored in the ROM 53r is an inertia moment calculating means.
[0017]
The mold opening / closing device of the injection molding machine configured as described above will be described with reference to FIGS. First, the length r (m) of the short side arm 11, the length L (m) of the long side arm 13, the mass (kg) of the movable platen 15, and the moment of inertia Jm of the motor 3 are input to the input unit 51 and interfaced. (Not shown) and stored in the RAM 53a of the gain setting unit 50.
Now, when the motor 16 is rotated based on the position command signal θ * rm of the motor 3 in the open state of the mold 16, the encoder 31 generates a position detection signal θrm and inputs it to the subtractor 32. The subtractor 32 inputs a generation of a position deviation signal which is a difference between the position command signal θ * rm and the position detection signal θrm to the subtractor 34. On the other hand, the differentiator 35 differentiates the position detection signal θrm and inputs the speed detection signal ωrm to the subtractor 34. The subtractor 34 generates a speed deviation signal which is a difference between the speed command signal ω * rm and the speed detection signal ωrm, and inputs the speed deviation signal to the speed controller 37.
[0018]
The CPU 53c of the gain setting unit 53 obtains the position detection signal θrm of the motor 3 detected by the encoder 31 and the angular velocity ω of the motor 3 from the position detection signal θrm, and calculates the inertia moment Jr of the movable platen 15 from the above equation (8). Then, the total moment of inertia J is determined by the sum of the moment of inertia Jr and the moment of inertia Jm.
Further, the CPU 53c obtains a speed gain such that the transfer function of the speed control loop becomes constant from the above equation (10), and sets the speed gain in the speed controller 37. The speed controller 37 receives the speed deviation signal, generates a current command signal i * ga according to the set speed gain, and controls the motor 3 via the current controller 39.
[0019]
According to the mold opening and closing device 1 as described above, the speed gain of the speed controller 37 of the motor 3 that drives the movable platen 15 is set to a value corresponding to the change in the inertia moment Jr that changes with the movement of the movable platen 15. That is, since the response of the motor speed control system is controlled to be constant, the movable platen 15 can be moved while the speed is smoothly controlled.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram of an electric injection molding machine.
FIG. 2 is a model diagram showing an opening and closing mechanism of the mold shown in FIG.
FIG. 3 is a block diagram of a speed control system shown in FIG. 1;
[Explanation of symbols]
3 motor, 15 movable boards, 16 molds, 31 encoders, 33 position controllers, 37 speed controllers, 53 gain setting devices.

Claims (4)

位置指令信号によりモータをサーボ制御して可動部を移動することにより金型を開閉する射出成形機の金型開閉装置において、
前記モータの回転角度を検出して位置検出信号を発生する角度検出手段と、
前記モータの回転速度を検出して速度検出信号を発生する速度検出手段と、
前記位置指令信号に基いて速度指令信号を発生する位置制御手段と、
前記速度指令信号と前記速度検出信号との差となる速度偏差信号に基くと共に、速度ゲインを用いて前記モータに電流を流す電流指令信号を発生する速度制御手段と、
前記位置検出信号に基いて前記可動部の慣性モーメントを算出する慣性モーメント算出手段と、
該慣性モーメント算出手段により算出された前記慣性モーメントの変化に基いて前記速度ゲインを変更するゲイン設定手段と、
を備えたことを特徴とする射出成形機の金型開閉装置。In a mold opening and closing device of an injection molding machine that opens and closes a mold by moving a movable part by servo-controlling a motor by a position command signal,
Angle detection means for detecting a rotation angle of the motor to generate a position detection signal,
Speed detection means for detecting a rotation speed of the motor to generate a speed detection signal,
Position control means for generating a speed command signal based on the position command signal,
A speed control unit that generates a current command signal that causes a current to flow through the motor using a speed gain based on a speed deviation signal that is a difference between the speed command signal and the speed detection signal,
Moment of inertia calculation means for calculating the moment of inertia of the movable part based on the position detection signal,
Gain setting means for changing the speed gain based on a change in the inertia moment calculated by the inertia moment calculation means;
A mold opening / closing device for an injection molding machine, comprising: 前記速度ゲインの値は、前記モータの速度制御系における速度ループの閉ループ伝達関数がほぼ一定になる、
ことを特徴とする請求項１に記載の射出成形機の金型開閉装置。The value of the speed gain, the closed loop transfer function of the speed loop in the speed control system of the motor becomes substantially constant,
The mold opening and closing device for an injection molding machine according to claim 1, wherein: 前記モータと前記可動部とを連結すると共に、前記モータの回転に基いて前記可動部を直線動作させるリンク機構と、
を備えたことを特徴とする請求項１又は２に記載の射出成形機の金型開閉装置。A link mechanism that connects the motor and the movable part, and linearly moves the movable part based on rotation of the motor,
The mold opening and closing device for an injection molding machine according to claim 1 or 2, further comprising: 前記ゲイン設定手段は、前記可動部の質量、前記リンク機構の構成に基く定数を入力する入力手段と、入力された前記質量、定数を記憶する記憶手段とを備え、
慣性モーメント算出手段は、該記憶手段に記憶された前記質量、定数を用いて前記慣性モーメントを算出する、
ことを特徴とする請求項３に記載の射出成形機の金型開閉装置。The gain setting unit includes an input unit that inputs a constant based on the mass of the movable unit and the configuration of the link mechanism, and a storage unit that stores the input mass and the constant.
The moment of inertia calculation means calculates the moment of inertia using the mass and a constant stored in the storage means,
The mold opening / closing device for an injection molding machine according to claim 3, wherein:
JP2003028398A 2003-02-05 2003-02-05 Mold opening / closing device of injection molding machine Expired - Fee Related JP4278396B2 (en)

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Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007290786A (en) * 2006-04-21 2007-11-08 Ihi Corp Cooperative carrier control device of duplicate hoisting crane and cooperative carrier control method of duplicate hoisting crane
AT504927B1 (en) * 2007-03-02 2009-04-15 Engel Austria Gmbh CHARACTER DETECTION IN AN INJECTION MOLDING MACHINE
WO2010029900A1 (en) * 2008-09-10 2010-03-18 東洋機械金属株式会社 Forming machine
JP2010094726A (en) * 2008-10-20 2010-04-30 Toshiba Mach Co Ltd Mold clamping apparatus and control device for mold clamping apparatus
JP2014131836A (en) * 2013-01-04 2014-07-17 Toshiba Mach Co Ltd Calculation method of moment of inertia, and mold clamping device

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007290786A (en) * 2006-04-21 2007-11-08 Ihi Corp Cooperative carrier control device of duplicate hoisting crane and cooperative carrier control method of duplicate hoisting crane
AT504927B1 (en) * 2007-03-02 2009-04-15 Engel Austria Gmbh CHARACTER DETECTION IN AN INJECTION MOLDING MACHINE
DE102008011695B4 (en) 2007-03-02 2018-12-13 Engel Austria Gmbh Inertia detection in an injection molding machine
WO2010029900A1 (en) * 2008-09-10 2010-03-18 東洋機械金属株式会社 Forming machine
JP2010064349A (en) * 2008-09-10 2010-03-25 Toyo Mach & Metal Co Ltd Molding machine
JP2010094726A (en) * 2008-10-20 2010-04-30 Toshiba Mach Co Ltd Mold clamping apparatus and control device for mold clamping apparatus
JP2014131836A (en) * 2013-01-04 2014-07-17 Toshiba Mach Co Ltd Calculation method of moment of inertia, and mold clamping device

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