JPH053973B2 - - Google Patents
Info
- Publication number
- JPH053973B2 JPH053973B2 JP62304440A JP30444087A JPH053973B2 JP H053973 B2 JPH053973 B2 JP H053973B2 JP 62304440 A JP62304440 A JP 62304440A JP 30444087 A JP30444087 A JP 30444087A JP H053973 B2 JPH053973 B2 JP H053973B2
- Authority
- JP
- Japan
- Prior art keywords
- pressure
- holding
- holding pressure
- temperature
- 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
- 239000011347 resin Substances 0.000 claims description 47
- 229920005989 resin Polymers 0.000 claims description 47
- 238000000034 method Methods 0.000 claims description 40
- 238000001746 injection moulding Methods 0.000 claims description 22
- 238000002347 injection Methods 0.000 claims description 16
- 239000007924 injection Substances 0.000 claims description 16
- 238000001514 detection method Methods 0.000 claims description 4
- 230000014759 maintenance of location Effects 0.000 claims 4
- 230000007547 defect Effects 0.000 description 6
- 238000010438 heat treatment Methods 0.000 description 5
- 230000003287 optical effect Effects 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 238000000465 moulding Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 230000007423 decrease Effects 0.000 description 2
- 238000005429 filling process Methods 0.000 description 2
- 230000000704 physical effect Effects 0.000 description 2
- 238000007711 solidification Methods 0.000 description 2
- 230000008023 solidification Effects 0.000 description 2
- 238000002834 transmittance Methods 0.000 description 2
- 238000013459 approach Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000002950 deficient Effects 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 239000012778 molding material Substances 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
- B29C45/17—Component parts, details or accessories; Auxiliary operations
- B29C45/76—Measuring, controlling or regulating
- B29C45/78—Measuring, controlling or regulating of temperature
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
- B29C45/17—Component parts, details or accessories; Auxiliary operations
- B29C45/76—Measuring, controlling or regulating
- B29C45/77—Measuring, controlling or regulating of velocity or pressure of moulding material
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
- B29C45/17—Component parts, details or accessories; Auxiliary operations
- B29C45/76—Measuring, controlling or regulating
- B29C45/77—Measuring, controlling or regulating of velocity or pressure of moulding material
- B29C2045/773—Zero point correction
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は射出成形の保圧工程の保圧圧力制御に
関し、さらに詳しくは、保圧工程すなわち射出二
次圧力を加える工程を終了する時点を金型に取付
けた温度センサで検出した樹脂温度または金型温
度の変化を優先して決定するよう制御して適切な
時点で保圧工程を終了し充填が完了したキヤビテ
イに必要以上の圧力を負荷することなく安定した
成形の実現を図る射出成形の保圧圧力制御に関す
る。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to holding pressure control in the holding process of injection molding, and more specifically, to controlling the holding pressure at the end of the holding process, that is, the process of applying secondary injection pressure. The system prioritizes changes in resin temperature or mold temperature detected by a temperature sensor attached to the mold, ends the pressure holding process at an appropriate point, and applies more pressure than necessary to the filled cavity. This paper relates to holding pressure control for injection molding, which aims to achieve stable molding without causing any damage.
〔従来の技術〕
射出成形におけるキヤビテイ内への樹脂の充填
完了後の保圧工程の制御は成形品に不良現象が発
生するか否かに重要な影響を与えるため保圧工程
制御には種々の工夫が凝らされ、例えば保圧工程
を多数の時間区間もしくは位置区間に区分しそれ
ぞれに対応する保圧区間を設定して圧力制御を行
うことにより薄肉から厚肉までの幅広い成形品の
成形を良好に行うことができることが知られてい
る。保圧工程を多段の保圧区間に区分して行う圧
力制御は通常は時間区間に対応して設定した一連
の保圧圧力を時間の進行と共にタイマにより次々
と切換えて保圧圧力を変化させるプログラムを用
いるため充填工程完了から経過した時間によりそ
の時点の保圧圧力が規定され、同じく充填工程完
了から経過した時間により保圧圧力制御が終了す
る時点が規定される。[Prior art] In injection molding, the control of the pressure holding process after filling the cavity with resin has an important effect on whether defects occur in the molded product, so various methods are used to control the pressure holding process. For example, by dividing the pressure holding process into multiple time intervals or position intervals and setting corresponding pressure holding intervals to control the pressure, it is possible to mold a wide range of molded products, from thin to thick. It is known that it can be done. Pressure control that divides the pressure holding process into multiple holding pressure intervals is usually a program that changes the holding pressure by switching a series of holding pressures set corresponding to time intervals one after another using a timer as time progresses. Since this is used, the time elapsed from the completion of the filling process defines the holding pressure at that point in time, and the time elapsed from the completion of the filling process similarly defines the time point at which the holding pressure control ends.
一般に、射出成形に使用する樹脂が異なれば溶
融状態から凝固に至るまでの樹脂温度やその過程
での樹脂の状態により適切な保圧制御の態様が異
なり、また使用する樹脂の容量や金型音調装置の
作動状態等の樹脂の物性以外の因子により樹脂が
凝固するまでの時間が異なるため、保圧工程にお
ける圧力制御時間をどのくらいに定めればよいか
判断するには相当な経験を要するのが常である。
特に、すでに樹脂が固化してしまつた状態で保圧
（射出二次圧）をかけたままにしておくと成形品
に内部ひずみが生じるため成形品の強度が低下し
外観に欠陥が生ずる恐れがある。この内部ひずみ
は成形品の物性を変化させ、例えば光学系の部
品、レンズ、光学式デイスク等では光の透過性が
変化し大きな問題となる。 In general, if the resin used for injection molding differs, the appropriate mode of holding pressure control will differ depending on the temperature of the resin from the molten state to solidification and the state of the resin during that process, as well as the capacity of the resin used and the tone of the mold. The time it takes for the resin to solidify varies depending on factors other than the physical properties of the resin, such as the operating conditions of the equipment, so it requires considerable experience to determine the appropriate pressure control time in the pressure holding process. Always.
In particular, if holding pressure (secondary injection pressure) is left on when the resin has already solidified, internal distortion will occur in the molded product, reducing its strength and potentially causing defects in appearance. be. This internal strain changes the physical properties of the molded product, and for example, in optical system parts, lenses, optical disks, etc., the light transmittance changes and becomes a big problem.
従来の区間設定による保圧圧力制御では樹脂の
特性に合致した例えば時間により進行する圧力制
御プログラムを設定するのが困難であつたばかり
か、特に樹脂が凝固を終了して保圧工程を終了す
べき時点が樹脂の容量や金型音調装置の作動状態
等の樹脂特性以外の外的な温度要因により変動す
るため樹脂の溶融−凝固状態と保圧工程終了の時
点とを完全に相関させることができず凝固した樹
脂に過剰な圧力を加え成形不良を招く事態を生じ
この解決が望まれていた。 With conventional holding pressure control using interval settings, it is not only difficult to set a pressure control program that matches the characteristics of the resin, such as one that progresses over time. Since the time varies depending on external temperature factors other than resin characteristics such as the volume of the resin and the operating status of the mold tone adjustment device, it is not possible to completely correlate the melting/solidifying state of the resin with the end of the holding pressure process. However, excessive pressure is applied to the solidified resin, resulting in molding defects, and a solution to this problem has been desired.
本発明は保圧工程のタイマによる圧力制御プロ
グラムの進行に係りなく樹脂温度があらかじめ設
定した保圧終了温度に達したら保圧圧力をゼロと
し保圧工程を終了するよう制御する保圧圧力制御
を実現することを目的とする。
The present invention provides holding pressure control that controls the holding pressure to zero and ends the holding process when the resin temperature reaches a preset holding pressure end temperature, regardless of the progress of the pressure control program using the timer of the holding pressure process. The aim is to realize this.
本発明に係る射出成形の保圧圧力制御方法は、
射出成形の保圧工程における保圧圧力を、射出シ
リンダと連通する油圧系に設けた圧力制御バルブ
の開閉量を制御して射出シリンダ内の油圧調節を
行うことにより制御するよう構成し、予めタイマ
により時間設定した一連の保圧区間にそれぞれ対
応させて保圧圧力設定値を設定し、保圧工程の開
始時点からの時間経過に伴い予め設定した保圧区
間においてそれぞれバルブ開閉量を制御して対応
する保圧圧力設定値となるよう制御してなる射出
成形の保圧圧力制御方法において、
樹脂温度または金型温度を温度センサで検出
し、この検出値を予め設定した保圧終了温度設定
値と比較し、前記検出値が前記設定値と一致した
際に保圧終了信号を出力し、前記保圧工程のタイ
マによる保圧圧力制御に優先して保圧圧力をゼロ
にするよう制御することを特徴とする。
The holding pressure control method for injection molding according to the present invention includes:
The holding pressure in the holding pressure process of injection molding is controlled by controlling the opening/closing amount of a pressure control valve provided in a hydraulic system communicating with the injection cylinder to adjust the hydraulic pressure inside the injection cylinder. The holding pressure set value is set corresponding to each of the series of holding pressure intervals whose time has been set by In an injection molding holding pressure control method that controls the holding pressure to a corresponding holding pressure set value, the resin temperature or mold temperature is detected by a temperature sensor, and this detected value is used as the preset holding pressure end temperature set value. When the detected value matches the set value, a holding pressure end signal is output, and the holding pressure is controlled to be zero, giving priority to holding pressure control by a timer of the holding pressure process. It is characterized by
この場合、樹脂温度または金型温度は、超音波
を用いる温度センサで検出すればキヤビテイ内の
樹脂に直接触れることなく正確に樹脂温度または
金型温度を検出することができ好適である。 In this case, it is preferable to detect the resin temperature or mold temperature with a temperature sensor that uses ultrasonic waves, since the resin temperature or mold temperature can be detected accurately without directly touching the resin in the cavity.
また、本発明に係る前記保圧圧力制御方法を実
施するための保圧圧力制御機構を備える射出成形
機は、射出成形機の保圧工程における保圧圧力
を、射出シリンダと連通する油圧系に設けた圧力
制御バルブの開閉量を制御して射出シリンダ内の
油圧調節を行うことにより制御するよう構成し、
予めタイマにより時間設定した一連の保圧区間に
それぞれ対応させて保圧圧力設定値を設定し、保
圧工程の開始時点からの時間経過に伴い予め設定
した保圧区間においてそれぞれバルブ開閉量を制
御して対応する保圧圧力設定値となるよう制御す
るよう構成してなる射出成形機において、
樹脂温度または金型温度を検出する温度センサ
と、保圧終了温度設定値を設定する設定器とを設
け、前記温度センサにより検出される検出値と前
記設定器により設定された保圧終了温度設定値と
を比較する比較演算部を設け、この比較演算部に
おいて前記検出値が前記設定値と一致した際に保
圧終了信号を出力する保圧終了信号出力部を設
け、さらにこの保圧終了信号出力部から出力され
る保圧終了信号に基づいて前記保圧工程のタイマ
による保圧圧力制御に優先して保圧圧力をゼロに
する圧力制御部を設けることを特徴とする。 Furthermore, an injection molding machine equipped with a holding pressure control mechanism for carrying out the holding pressure control method according to the present invention controls the holding pressure in the holding process of the injection molding machine to a hydraulic system communicating with the injection cylinder. The injection cylinder is configured to be controlled by controlling the amount of opening and closing of a pressure control valve provided to adjust the hydraulic pressure inside the injection cylinder,
The holding pressure setting value is set in correspondence with a series of holding pressure intervals set in advance by a timer, and the valve opening/closing amount is controlled for each preset holding pressure interval as time passes from the start of the pressure holding process. In an injection molding machine configured to control the holding pressure to a corresponding holding pressure setting value, a temperature sensor that detects the resin temperature or mold temperature and a setting device that sets the holding pressure end temperature setting value are used. and a comparison calculation unit for comparing the detection value detected by the temperature sensor and the pressure-holding end temperature setting value set by the setting device, and in the comparison calculation unit, the detection value matches the setting value. A pressure-holding end signal output unit is provided to output a pressure-holding end signal when the pressure-holding end signal is output, and priority is given to the pressure-holding pressure control by the timer of the pressure-holding process based on the pressure-holding end signal output from the pressure-holding end signal output unit. The present invention is characterized in that a pressure control unit is provided to set the holding pressure to zero.
射出成形の保圧工程は、一旦キヤビテイを充填
し終つた後依然として高温溶融状態にある樹脂が
冷却の進行により体積の収縮を始めるのに対応し
て引き続き射出圧を保持しスクリユあるいはプラ
ンジヤの先端にまだ残つている少量の溶融樹脂
（クツシヨン量）をキヤビテイに送り込み冷却に
よる収縮に見合う量の樹脂を補給して成形品の寸
法不良や変形不良等の不良現象発生の抑制を図る
ものであるが、保圧を終了すべき時点に近づくと
樹脂は溶融状態と凝固状態の中間の半流動状態あ
るいは半凝固状態となつているため流動性は低下
し特にプラスチツクレンズやオプチカルデイスク
等の光学系の部品では少量のクツシヨン量の樹脂
を継続して充填するのに必要な保圧圧力は相当強
くする必要がある。このため適切な時点で保圧を
終了しないと成形品に必要以上の圧力がかかり、
過剰圧力による不良成形が発生する。保圧工程終
了時点を時間設定等のプログラムのみにより制御
する従来の保圧圧力制御と異なり、本発明の保圧
圧力制御によれば保圧工程を終了すべき時点の樹
脂の状態を適切に反映する樹脂の温度を検出し樹
脂本来の特性から客観的に推考して設定できる保
圧終了温度設定値と比較し両者が一致するとプロ
グラムの進行に優先して保圧工程を終了させるこ
とができる。
In the pressure holding process of injection molding, once the cavity has been filled, the resin, which is still in a high temperature molten state, begins to shrink in volume as it cools down, so the injection pressure is continued to be maintained at the tip of the screw or plunger. The remaining small amount of molten resin (the amount of cushion) is sent into the cavity to replenish the amount of resin to compensate for the shrinkage due to cooling, thereby suppressing the occurrence of defective phenomena such as dimensional defects and deformation defects in the molded product. When the time to end the holding pressure approaches, the resin is in a semi-fluid or semi-solidified state between the molten state and the solidified state, so the fluidity decreases, especially in optical system parts such as plastic lenses and optical discs. The holding pressure required to continuously fill the cushion with a small amount of resin needs to be quite strong. For this reason, if holding pressure is not finished at an appropriate point, more pressure than necessary will be applied to the molded product.
Poor molding occurs due to excessive pressure. Unlike conventional holding pressure control in which the end point of the holding pressure process is controlled only by programs such as time settings, the holding pressure control of the present invention appropriately reflects the state of the resin at the time when the holding pressure process should end. The temperature of the resin is detected and compared with the pressure-holding end temperature setting value, which can be set by objectively estimating from the resin's original characteristics, and if the two match, the pressure-holding process can be terminated in priority to the program progression.
以下に添付図面により本発明の具体的構成例に
ついてさらに詳細に説明するが、本発明は以下の
実施例にのみ限定されるものではない。
Specific configuration examples of the present invention will be explained in more detail below with reference to the accompanying drawings, but the present invention is not limited only to the following examples.
第１図は本発明により構成した射出成形機の保
圧圧力制御系のブロツク図、第２図は本発明の保
圧圧力制御系を備える射出成形機の要部断面図、
第３図は本発明の保圧圧力制御系の動作説明図で
ある。 FIG. 1 is a block diagram of a holding pressure control system of an injection molding machine constructed according to the present invention, and FIG. 2 is a sectional view of essential parts of an injection molding machine equipped with a holding pressure control system of the present invention.
FIG. 3 is an explanatory diagram of the operation of the holding pressure control system of the present invention.
まず、保圧工程全体を３つの保圧区間に区分し
それぞれの保圧圧力設定値をP0，P1，P2とし保
圧圧力切換時点を充填完了からの時間によりt1，
t2とし保圧終了時点をt3として第１図に示す区間
設定部−圧力設定部１により時間進行によるプロ
グラムを設定する。保圧終了温度設定値をＴとし
成形に使用する樹脂特性に合わせて例えばNO−
FLOW温度以下あるいは固化温度となるよう設
定器２により設定する。 First, the entire holding pressure process is divided into three holding pressure sections, and the holding pressure setting values for each are P 0 , P 1 , and P 2 , and the holding pressure switching time is t 1 , depending on the time from completion of filling.
t 2 and the pressure holding end point is t 3 , a time-progressing program is set by the interval setting unit and pressure setting unit 1 shown in FIG. Set the holding pressure end temperature set value to T, and set it to NO-, for example, according to the characteristics of the resin used for molding.
Set using the setting device 2 so that the temperature is below the FLOW temperature or the solidification temperature.
第２図に示すようにホツパ１０から自重により
加熱シリンダ１２内に落下した成形材料（樹脂）
はバンドヒータ１４による加熱を受けスクリユ１
６の回転で混練されながら加熱シリンダ先端部へ
送られるが、その過程で樹脂は溶融状態となる。
加熱シリンダ先端部に溶融樹脂が貯えられるにつ
れスクリユは後退し射出シリンダ１８内へは油タ
ンクに接続した後退用ポート２０から油が流入
し、所定の位置でスクリユの回転が停止すると油
の流入が停止すると共に加熱シリンダ先端部には
１回分の射出量に相当する所定量の溶融樹脂が充
填される。前進用ポート２２に接続した圧力制御
バルブ（第２図には図示せず）を調節して高圧油
を送り込むとスクリユ１６は高速で前進し金型２
４により形成したキヤビテイ２６内に溶融樹脂が
射出され射出成形が進行する。 As shown in FIG. 2, the molding material (resin) falls from the hopper 10 into the heating cylinder 12 due to its own weight.
The screw 1 is heated by the band heater 14.
The resin is sent to the tip of the heating cylinder while being kneaded by rotation No. 6, and in the process, the resin becomes molten.
As the molten resin is stored at the tip of the heating cylinder, the screw retreats, and oil flows into the injection cylinder 18 from the retreat port 20 connected to the oil tank.When the screw stops rotating at a predetermined position, the oil stops flowing. Upon stopping, the tip of the heating cylinder is filled with a predetermined amount of molten resin corresponding to one injection amount. When the pressure control valve (not shown in FIG. 2) connected to the forwarding port 22 is adjusted to supply high-pressure oil, the screw 16 moves forward at high speed and the mold 2
Molten resin is injected into the cavity 26 formed by step 4, and injection molding proceeds.
射出充填完了後に保圧工程を開始するが、保圧
工程初期では樹脂温度は十分高いため、工程は、
タイマを使用して、時間により設定したプログラ
ムにより第１図に示す圧力制御部３が圧力制御バ
ルブ４の開閉量を制御しつつ進行し、保圧圧力は
第３図に示すように初発保圧圧力P0から時間t1の
時点でP1に切換わり時間t2の時点でP2に切換わる
よう変化する。 The pressure-holding process starts after injection and filling is completed, but the resin temperature is sufficiently high at the beginning of the pressure-holding process, so the process is
Using a timer, the pressure control section 3 shown in Fig. 1 proceeds while controlling the opening/closing amount of the pressure control valve 4 according to a program set according to the time, and the holding pressure is adjusted to the initial holding pressure as shown in Fig. 3. The pressure changes from P 0 to P 1 at time t 1 and to P 2 at time t 2 .
プログラムの進行とは別に樹脂温度または金型
温度（樹脂温度を反映する）を温度センサにより
検出する。温度センサは第２図に示すように例え
ば熱電対を用いる温度センサあるいは赤外線検知
式の温度センサのような一般型温度センサ２８を
金型内に樹脂に直接触れるよう設置する。一般型
温度センサは樹脂のなるべく厚肉部を選んで設置
すると効果的である。成形品の外観にセンサの痕
跡が残るのを嫌う場合は、超音波応用型温度セン
サ３０を樹脂に直接触れないよう設置する。超音
波応用型温度センサ３０は金型外側から樹脂温度
を直接測定することができる。センサ設置位置は
特にゲートあるいはゲート付近のランナ部、キヤ
ビテイ部がよい。 Separately from the progress of the program, the resin temperature or mold temperature (reflecting the resin temperature) is detected by a temperature sensor. As shown in FIG. 2, a general temperature sensor 28, such as a temperature sensor using a thermocouple or an infrared detection type temperature sensor, is installed in the mold so as to be in direct contact with the resin. It is effective to install a general temperature sensor in the thickest part of the resin. If you do not want traces of the sensor to remain on the exterior of the molded product, install the ultrasonic temperature sensor 30 so that it does not come into direct contact with the resin. The ultrasonic temperature sensor 30 can directly measure the resin temperature from outside the mold. Particularly suitable locations for installing the sensor are the gate, the runner section near the gate, and the cavity section.
時間の進行と共にキヤビテイ内の樹脂温度は次
第に低下するが、第１図に示すように温度センサ
５で検出した温度を増幅器または変換器６で増幅
または変換した電気信号とあらかじめ設定器２に
より設定した保圧終了温度設定値（Ｔ）に対応す
る電気信号とが比較演算部７での比較演算の結果
一致すると保圧終了信号出力部８により保圧終了
信号９が出力され、圧力制御部３が圧力制御バル
ブ４を制御し第３図に示すように保圧圧力はプロ
グラムの進行に係りなくゼロとなる。 As time progresses, the resin temperature inside the cavity gradually decreases, but as shown in FIG. When the electric signal corresponding to the pressure-holding end temperature set value (T) matches the result of the comparison calculation in the comparison calculation section 7, the pressure-holding end signal output section 8 outputs the pressure-holding end signal 9, and the pressure control section 3 By controlling the pressure control valve 4, the holding pressure becomes zero regardless of the progress of the program, as shown in FIG.
保圧圧力をゼロとし保圧工程を終了する時点を
金型に取付けた温度センサで検出した温度とあら
かじめ設定した保圧終了温度設定値とが一致した
時点とすることにより、保圧工程の終了を樹脂の
状態を適切に反映する樹脂温度に相関させて規定
することができるため、成形品に必要以上の保圧
が印加されず内部ひずみを低く抑えることが可能
となる。これにより内部ひずみに起因するそりや
光学系部品の光の透過率に影響を与える不良を解
消できる。
By setting the holding pressure to zero and ending the holding process at the point when the temperature detected by the temperature sensor attached to the mold matches the preset holding pressure end temperature set value, the holding pressure process is completed. can be defined in relation to the resin temperature, which appropriately reflects the state of the resin, so that no more than necessary holding pressure is applied to the molded product, making it possible to suppress internal strain to a low level. This makes it possible to eliminate warpage caused by internal strain and defects that affect the light transmittance of optical system components.
第１図は本発明により構成した射出成形機の保
圧圧力制御系のブロツク図、第２図は本発明の保
圧圧力制御系を備える射出成形機の要部断面図、
第３図は本発明の保圧圧力制御系の動作説明図で
ある。
１……区間設定部−圧力設定部、２……設定
器、３……圧力制御部、４……圧力制御バルブ、
５……温度センサ、６……増幅器または変換器、
７……比較演算部、８……保圧終了信号出力部、
９……保圧終了信号、１０……ホツパ、１２……
加熱シリンダ、１４……バンドヒータ、１６……
スクリユ、１８……射出シリンダ、２０……後退
用ポート、２２……前進用ポート、２４……金
型、２６……キヤビテイ、２８……一般型温度セ
ンサ、３０……超音波応用型温度センサ。
FIG. 1 is a block diagram of a holding pressure control system of an injection molding machine constructed according to the present invention, and FIG. 2 is a sectional view of essential parts of an injection molding machine equipped with a holding pressure control system of the present invention.
FIG. 3 is an explanatory diagram of the operation of the holding pressure control system of the present invention. 1... section setting section-pressure setting section, 2... setting device, 3... pressure control section, 4... pressure control valve,
5...Temperature sensor, 6...Amplifier or converter,
7... Comparison calculation section, 8... Pressure holding end signal output section,
9...Pressure end signal, 10...Hopper, 12...
Heating cylinder, 14...Band heater, 16...
Screw, 18... Injection cylinder, 20... Retraction port, 22... Advance port, 24... Mold, 26... Cavity, 28... General type temperature sensor, 30... Ultrasonic applied temperature sensor .
Claims (1)
出シリンダと連通する油圧系に設けた圧力制御バ
ルブの開閉量を制御して射出シリンダ内の油圧調
節を行うことにより制御するよう構成し、予めタ
イマにより時間設定した一連の保圧区間にそれぞ
れ対応させて保圧圧力設定値を設定し、保圧工程
の開始時点からの時間経過に伴い予め設定した保
圧区間においてそれぞれバルブ開閉量を制御して
対応する保圧圧力設定値となるよう制御してなる
射出成形の保圧圧力制御方法において、 樹脂温度または金型温度を温度センサで検出
し、この検出値を予め設定した保圧終了温度設定
値と比較し、前記検出値が前記設定値と一致した
際に保圧終了信号を出力し、前記保圧工程のタイ
マによる保圧圧力制御に優先して保圧圧力をゼロ
にするよう制御することを特徴とする射出成形の
保圧圧力制御方法。 ２ 射出成形機の保圧工程における保圧圧力を、
射出シリンダと連通する油圧系に設けた圧力制御
バルブの開閉量を制御して射出シリンダ内の油圧
調節を行うことにより制御するよう構成し、予め
タイマにより時間設定した一連の保圧区間にそれ
ぞれ対応させて保圧圧力設定値を設定し、保圧工
程の開始時点からの時間経過に伴い予め設定した
保圧区間においてそれぞれバルブ開閉量を制御し
て対応する保圧圧力設定値となるよう制御するよ
う構成してなる射出成形機において、 樹脂温度または金型温度を検出する温度センサ
と、保圧終了温度設定値を設定する設定器とを設
け、前記温度センサにより検出される検出値と前
記設定器により設定された保圧終了温度設定値と
を比較する比較演算部を設け、この比較演算部に
おいて前記検出値が前記設定値と一致した際に保
圧終了信号を出力する保圧終了信号出力部を設
け、さらにこの保圧終了信号出力部から出力され
る保圧終了信号に基づいて前記保圧工程のタイマ
による保圧圧力制御に優先して保圧圧力をゼロに
する圧力制御部を設けることを特徴とする保圧圧
力制御機構を備える射出成形機。[Claims] 1. The holding pressure in the holding pressure process of injection molding is controlled by controlling the opening/closing amount of a pressure control valve provided in a hydraulic system communicating with the injection cylinder to adjust the hydraulic pressure inside the injection cylinder. The holding pressure setting value is set in correspondence with a series of holding pressure intervals whose time has been set in advance by a timer, and the holding pressure setting value is set in correspondence with each of the holding pressure intervals set in advance by a timer, and the holding pressure setting value is set in accordance with a series of holding pressure intervals set in advance by a timer. In an injection molding holding pressure control method that controls the valve opening/closing amount to achieve the corresponding holding pressure set value, the resin temperature or mold temperature is detected with a temperature sensor, and this detected value is set in advance. When the detected value matches the set value, a pressure-holding end signal is output, and the holding pressure is increased in priority to the pressure-holding pressure control by the timer of the pressure-holding process. A method for controlling holding pressure in injection molding, characterized by controlling the holding pressure to zero. 2 The holding pressure in the holding process of the injection molding machine is
It is configured to control the opening/closing amount of a pressure control valve installed in the hydraulic system communicating with the injection cylinder to adjust the hydraulic pressure inside the injection cylinder, and corresponds to a series of pressure holding intervals whose time is set in advance by a timer. to set the holding pressure setting value, and control the valve opening/closing amount in each preset holding pressure interval as time elapses from the start of the holding pressure process to reach the corresponding holding pressure setting value. In an injection molding machine configured as above, a temperature sensor for detecting resin temperature or mold temperature and a setting device for setting a pressure-holding end temperature setting value are provided, and the detection value detected by the temperature sensor and the setting are provided. A comparison calculation unit is provided to compare the pressure retention end temperature setting value set by the pressure retention unit, and a pressure retention end signal output is provided to output a pressure retention end signal when the detected value matches the set value in the comparison calculation unit. Further, a pressure control unit is provided to set the holding pressure to zero, giving priority to the holding pressure control by the timer of the holding process, based on the holding pressure end signal output from the holding pressure end signal output unit. An injection molding machine equipped with a holding pressure control mechanism.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP30444087A JPH01146719A (en) | 1987-12-03 | 1987-12-03 | Dwell pressure controlling method for injection molding and injection molding machine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP30444087A JPH01146719A (en) | 1987-12-03 | 1987-12-03 | Dwell pressure controlling method for injection molding and injection molding machine |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01146719A JPH01146719A (en) | 1989-06-08 |
| JPH053973B2 true JPH053973B2 (en) | 1993-01-19 |
Family
ID=17933034
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP30444087A Granted JPH01146719A (en) | 1987-12-03 | 1987-12-03 | Dwell pressure controlling method for injection molding and injection molding machine |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH01146719A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4511959B2 (en) * | 2005-01-26 | 2010-07-28 | 道男 小松 | Method for producing heat-resistant hollow body made of polylactic acid-containing resin |
| US8309010B2 (en) | 2005-01-26 | 2012-11-13 | Michio Komatsu | Process for production of heat-resistant hollow article made of polylactic acid containing resin |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61255825A (en) * | 1985-05-08 | 1986-11-13 | Mitsubishi Heavy Ind Ltd | Method for changing over multistage injection pressure holding |
-
1987
- 1987-12-03 JP JP30444087A patent/JPH01146719A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61255825A (en) * | 1985-05-08 | 1986-11-13 | Mitsubishi Heavy Ind Ltd | Method for changing over multistage injection pressure holding |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH01146719A (en) | 1989-06-08 |
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