JPH0525870Y2 - - Google Patents
Info
- Publication number
- JPH0525870Y2 JPH0525870Y2 JP1990077967U JP7796790U JPH0525870Y2 JP H0525870 Y2 JPH0525870 Y2 JP H0525870Y2 JP 1990077967 U JP1990077967 U JP 1990077967U JP 7796790 U JP7796790 U JP 7796790U JP H0525870 Y2 JPH0525870 Y2 JP H0525870Y2
- Authority
- JP
- Japan
- Prior art keywords
- pressure
- valve
- actuator
- flow rate
- injection
- 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 - Lifetime
Links
- 238000002347 injection Methods 0.000 claims description 29
- 239000007924 injection Substances 0.000 claims description 29
- 239000011347 resin Substances 0.000 claims description 14
- 229920005989 resin Polymers 0.000 claims description 14
- 239000010720 hydraulic oil Substances 0.000 claims description 11
- 238000001746 injection moulding Methods 0.000 claims description 11
- 238000010438 heat treatment Methods 0.000 claims description 4
- 230000001105 regulatory effect Effects 0.000 description 18
- 230000007423 decrease Effects 0.000 description 9
- 238000010586 diagram Methods 0.000 description 6
- 230000001276 controlling effect Effects 0.000 description 3
- 239000012530 fluid Substances 0.000 description 3
- 238000004891 communication Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000012423 maintenance Methods 0.000 description 2
- 230000007547 defect Effects 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000007257 malfunction Effects 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 239000003921 oil Substances 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
Landscapes
- Injection Moulding Of Plastics Or The Like (AREA)
Description
【考案の詳細な説明】
〔産業上の利用分野〕
本考案は、射出成形機において樹脂の射出速度
を制御する制御回路に関する。[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a control circuit for controlling the injection speed of resin in an injection molding machine.
加熱シリンダ内に挿入されたスクリユを、油圧
ポンプから供給される作動油によつて作動させら
れるアクチユエータで軸方向に前進させて射出ノ
ズルから樹脂を金型内に射出するインラインスク
リユ方式等の射出成形機における射出速度制御回
路として、従来、次のような回路が知られてい
る。
Injection such as the in-line screw method, in which a screw inserted into a heating cylinder is advanced in the axial direction by an actuator operated by hydraulic oil supplied from a hydraulic pump, and resin is injected into the mold from an injection nozzle. Conventionally, the following circuits are known as injection speed control circuits for molding machines.
第４図は、圧力マツチ回路を示すもので、油圧
ポンプ１に、スクリユ（図示せず）を作動させる
射出シリンダ等のアクチユエータ２を接続してい
る主管３に、油圧ポンプ１からアクチユエータ２
に流れる作動油の流量を調整する流量調整弁４が
設けられている。この流量調整弁４の２次側には
圧力調整弁５がパイロツト管６によつて接続さ
れ、また、流量調整弁４の１次側には圧力補償弁
７が分岐管８で接続されるとともに、該圧力補償
弁７のスプールのスプリング７ａ側に上記パイロ
ツト管６がベント管９で接続されている。符号１
０はベント管９に接続された安全弁である。 FIG. 4 shows a pressure match circuit, in which a main pipe 3 connects an actuator 2 such as an injection cylinder that operates a screw (not shown) to a hydraulic pump 1.
A flow rate adjustment valve 4 is provided to adjust the flow rate of hydraulic oil flowing into the hydraulic fluid. A pressure regulating valve 5 is connected to the secondary side of the flow rate regulating valve 4 through a pilot pipe 6, and a pressure compensating valve 7 is connected to the primary side of the flow rate regulating valve 4 through a branch pipe 8. The pilot pipe 6 is connected to the spring 7a side of the spool of the pressure compensating valve 7 by a vent pipe 9. code 1
0 is a safety valve connected to the vent pipe 9.
この回路においては、アクチユエータ２の行程
中の速度は流量調整弁４で、また行程中の圧力は
圧力調整弁５でそれぞれ制御する。そして樹脂の
射出充填中に負荷圧の変化があつた場合、アクチ
ユエータ２に供給される作動油のＹ点での圧力が
変動し、またＹ点での圧力はパイロツト管６とベ
ント管９を介して圧力補償弁７のスプールのスプ
リング７ａ側にかかる結果、油圧ポンプ１側のＸ
点の圧力がＹ点の圧力に追従して増減することと
なり、Ｘ点とＹ点における圧力差は圧力補償弁７
のスプリング７ａの力と同一に保たれる。このた
め、アクチユエータ２は負荷の変動に関係なく流
量調整弁４の絞り前後の差圧が一定をなることよ
り一定の速度でスクリユを前進させ、樹脂を射出
させる。 In this circuit, the speed of the actuator 2 during its stroke is controlled by a flow rate regulating valve 4, and the pressure during its stroke is controlled by a pressure regulating valve 5, respectively. If the load pressure changes during resin injection and filling, the pressure at point Y of the hydraulic oil supplied to actuator 2 will fluctuate, and the pressure at point Y will change through pilot pipe 6 and vent pipe 9. As a result, X on the hydraulic pump 1 side is applied to the spring 7a side of the spool of the pressure compensation valve 7.
The pressure at point increases or decreases following the pressure at point Y, and the pressure difference between point X and point Y is determined by pressure compensation valve 7.
The force of the spring 7a is kept the same as that of the spring 7a. Therefore, the actuator 2 advances the screw at a constant speed and injects the resin since the differential pressure before and after the throttle of the flow rate regulating valve 4 remains constant regardless of load fluctuations.
また、第５図は流量マツチ回路を示すもので、
油圧ポンプ１にアクチユエータ２を接続している
主管３に、油圧ポンプ１側から、圧力制御弁２
１、圧力補償弁２２、及び流量調整弁２３が上記
の順に設けられている。流量調整弁２３の２次側
の主管３にパイロツト管２４の一端が接続され、
該パイロツト管２４の他端は、圧力調整弁２２の
スプールのスプリング２２ａ側に接続されてい
る。また、圧力制御弁２１のスプールのスプリン
グ２１ａ側に電磁比例リリーフ弁２５が接続され
ている。符号２６はアキユムレータである。 Also, Figure 5 shows the flow rate match circuit.
A pressure control valve 2 is connected from the hydraulic pump 1 side to the main pipe 3 that connects the actuator 2 to the hydraulic pump 1.
1, a pressure compensation valve 22, and a flow rate adjustment valve 23 are provided in the above order. One end of the pilot pipe 24 is connected to the main pipe 3 on the secondary side of the flow rate adjustment valve 23,
The other end of the pilot pipe 24 is connected to the spring 22a side of the spool of the pressure regulating valve 22. Further, an electromagnetic proportional relief valve 25 is connected to the spring 21a side of the spool of the pressure control valve 21. Reference numeral 26 is an accumulator.
この回路の場合においても、流量調整弁２３の
前後のＸ点とＹ点の圧力差は圧力補償弁２２によ
り一定に保たれるため、アクチユエータ２の速度
は行程中の負荷の変化にかかわりなく一定であ
る。 Even in the case of this circuit, the pressure difference between points X and Y before and after the flow rate adjustment valve 23 is kept constant by the pressure compensation valve 22, so the speed of the actuator 2 remains constant regardless of changes in load during stroke. It is.
さらに、第６図はパワーマツチ回路を示す。こ
の回路の場合は、可変容量形油圧ポンプ３１にア
クチユエータ２を接続している主管３に流量調整
弁４が設けられている。また油圧ポンプ３１と流
量調整弁４との間の主管３に、油圧ポンプ３１側
から、圧力制御弁３２、安全弁３３、及び圧力補
償弁３４の順にそれぞれ接続されている。また、
圧力補償弁３４のスプールのスプリング３４ａ側
はパイロツト管３５によつて流量調整弁４の２次
側の主管３に連絡され、圧力補償弁３４は圧力制
御弁３２に接続管３６で接続されるとともに、圧
力制御弁３２は油圧ポンプ３１の流量制御シリン
ダ３１ａに制御管３７で接続されている。 Furthermore, FIG. 6 shows a power match circuit. In the case of this circuit, a flow rate regulating valve 4 is provided in a main pipe 3 that connects an actuator 2 to a variable displacement hydraulic pump 31. Further, a pressure control valve 32, a safety valve 33, and a pressure compensation valve 34 are connected to the main pipe 3 between the hydraulic pump 31 and the flow rate regulating valve 4 in this order from the hydraulic pump 31 side. Also,
The spring 34a side of the spool of the pressure compensation valve 34 is connected to the main pipe 3 on the secondary side of the flow rate adjustment valve 4 through a pilot pipe 35, and the pressure compensation valve 34 is connected to the pressure control valve 32 through a connection pipe 36. , the pressure control valve 32 is connected to the flow rate control cylinder 31a of the hydraulic pump 31 through a control pipe 37.
更にまた、圧力制御弁３２のスプールのスプリ
ング３２ａ側には圧力調整弁３８が連通管３９で
接続されている。安全弁３３は、最高回路圧を規
制する。 Furthermore, a pressure regulating valve 38 is connected to the spring 32a side of the spool of the pressure regulating valve 32 through a communication pipe 39. The safety valve 33 regulates the maximum circuit pressure.
この回路において、射出行程中、つまり流量制
御の際は、圧力制御弁３２は図示の位置で固定さ
れていて機能せず、圧力補償弁３４だけがスプー
ル左のポンプ圧と、スプール右の負荷圧プラスス
プリング３４ａの力でバランスする。すなわち、
油圧ポンプ３１から吐出される作動油の流量が、
アクチユエータ２が設定速度でスクリユを移動さ
せるのに必要な流量よりも多くなつた場合、圧力
補償弁３４の左側の圧力が上昇してスプールが右
に動き、作動油が接続管３６と圧力制御弁３２、
及び制御管３７を通つて油圧ポンプ３１の流量制
御シリンダ３１ａに導かれ、ポンプ斜板の傾きを
小さくして作動油の吐出量を少なくする。この作
用で作動油の必要流量と吐出量が適正な関係とな
り、Ｘ点とＹ点の圧力差を一定とする。 In this circuit, during the injection stroke, that is, when controlling the flow rate, the pressure control valve 32 is fixed at the position shown and does not function, and only the pressure compensation valve 34 controls the pump pressure on the left side of the spool and the load pressure on the right side of the spool. It is balanced by the force of the positive spring 34a. That is,
The flow rate of hydraulic oil discharged from the hydraulic pump 31 is
When the flow rate of the actuator 2 exceeds that required to move the screw at the set speed, the pressure on the left side of the pressure compensating valve 34 increases and the spool moves to the right, causing hydraulic oil to flow between the connecting pipe 36 and the pressure control valve. 32,
The oil is guided to the flow rate control cylinder 31a of the hydraulic pump 31 through the control pipe 37, and the inclination of the pump swash plate is reduced to reduce the amount of hydraulic fluid discharged. This action creates an appropriate relationship between the required flow rate and discharge amount of hydraulic oil, and makes the pressure difference between point X and point Y constant.
上記三例のいずれの回路の場合も、金型の構造
等の影響で負荷圧が変動しても、圧力補償弁７，
２２，３４の働きで作動油の供給圧が負荷圧に追
従して増減し、アクチユエータ２によるスクリユ
の前進速度が一定に保たれるので、金型に樹脂を
無理に押し込むこととなり、その結果、成形品に
ソリ等の不具合が発生することがある。 In any of the three circuits above, even if the load pressure fluctuates due to the structure of the mold, the pressure compensation valve 7,
22 and 34, the hydraulic fluid supply pressure increases and decreases in accordance with the load pressure, and the forward speed of the screw by the actuator 2 is kept constant, so the resin is forced into the mold, and as a result, Malfunctions such as warping may occur in molded products.
上記の不具合を解消するものとして特公昭59−
15295号公報に見るように、スクリユを軸方向に
移動させる射出シリンダ（アクチユエータ）を多
段にして、樹脂の射出充填中における負荷の増減
にならつて射出速度を変化させるものが提案され
ている。 As a solution to the above-mentioned problems, the
As seen in Japanese Patent No. 15295, it has been proposed that the injection cylinder (actuator) for moving the screw in the axial direction is multi-staged, and the injection speed is changed in accordance with the increase and decrease of the load during injection and filling of resin.
ところが、多段構造の射出シリンダは構造が複
雑で高価につく上、保守が面倒であり、しかも既
存の射出成形機に実施できない、といつた問題点
がある。
However, the multi-stage injection cylinder has problems such as a complex structure, high cost, troublesome maintenance, and inability to be applied to existing injection molding machines.
本考案は、構造が簡単で安価につき、保守が容
易である上、既存の射出成形機に簡単に適用する
ことができる射出成形機の射出速度制御回路を提
供することを目的とする。 SUMMARY OF THE INVENTION An object of the present invention is to provide an injection speed control circuit for an injection molding machine that has a simple structure, is inexpensive, easy to maintain, and can be easily applied to existing injection molding machines.
上記の目的を達成するために、本考案は、加熱
シリンダ内に挿入されたスクリユを軸方向に前進
させて射出ノズルから樹脂を金型内に射出させる
アクチユエータに、該アクチユエータを作動させ
る油圧ポンプが流量調整弁を介して連絡され、上
記流量調整弁には、油圧ポンプからアクチユエー
タに送られる作動油の流量調整弁の前後の圧力差
を、アクチユエータからフイードバツクされる負
荷圧で作動させられて一定に保つ圧力補償弁が付
設された射出成形機の射出速度制御回路におい
て、上記圧力補償弁の油圧回路に、該油圧回路を
閉じて圧力補償弁の機能を喪失させる切換弁が設
けられた構成とした。
In order to achieve the above object, the present invention includes an actuator that advances a screw inserted into a heating cylinder in the axial direction and injects resin into a mold from an injection nozzle, and a hydraulic pump that operates the actuator. The flow rate adjustment valve is operated by the load pressure fed back from the actuator to maintain a constant pressure difference across the flow rate adjustment valve of the hydraulic oil sent from the hydraulic pump to the actuator. In the injection speed control circuit of an injection molding machine equipped with a pressure compensation valve, the hydraulic circuit of the pressure compensation valve is provided with a switching valve that closes the hydraulic circuit and loses the function of the pressure compensation valve. .
切換弁を開いた状態においては、圧力補償弁が
働いて流量調整弁の前後の圧力差を一定に保つ。
このため、アクチユエータは負荷の変動に関係な
く一定の速度でスクリユを前進させ、樹脂を金型
内に射出させる。
When the switching valve is open, the pressure compensating valve works to maintain a constant pressure difference across the flow rate regulating valve.
Therefore, the actuator moves the screw forward at a constant speed regardless of changes in load, and injects the resin into the mold.
また、切換弁を閉じた場合は、圧力補償弁の上
記の機能が失われる。この場合アクチユエータ
は、負荷が大きくなるとこれに応じてスクリユの
前進速度を低下させるとともに、負荷が小さくな
るとスクリユの前進速度を早くする。したがつて
樹脂は金型中に無理なく円滑に充填されるように
なり、ソリ等の不具合が防止される。 Further, when the switching valve is closed, the above-mentioned function of the pressure compensation valve is lost. In this case, the actuator reduces the forward speed of the screw in response to an increase in load, and increases the forward speed of the screw in response to a decrease in load. Therefore, the resin can be smoothly filled into the mold without strain, and defects such as warping can be prevented.
第１図は本考案の第１実施例を示す。この射出
成形機の射出速度制御回路は第４図の回路を改良
したものであり、パイロツト管６の主管３とベン
ト管９との間に電磁切換弁１１を設けて成る。な
お、第１図において第４図と同一の部材には同一
の参照符号を付してその詳しい説明は省略する。
この射出速度制御回路の場合は、切換弁１１を図
のように開き、ベント管９と共に圧力補償弁７の
油圧回路を構成するパイロツト管６を開放する
と、アクチユエータ２からフイードバツクされる
負荷圧が圧力補償弁７のスプールのスプリング７
ａ側に作用するようになるため、流量調整弁４の
前後におけるＸ点とＹ点の圧力差は圧力補償弁７
によつて一定に保持されるようになる。また、切
換弁１１のスプールを第１図で左に動かしてパイ
ロツト管６を閉じ射出動作を行うと、アクチユエ
ータ２の負荷圧が圧力補償弁７に作用することは
なく、圧力補償弁７の圧力補償機能が失われる。
すなわち、この場合においては油圧ポンプ１のＸ
点での圧力は、圧力調整弁５の設定圧力まで上昇
し固定される。そしてこのときアクチユエータ２
への供給圧（Ｙ点での圧力）は第４図の回路同様
に負荷により増減するが、上記のようにＸ点での
圧力が固定されているため、Ｘ点とＹ点の圧力差
が変化する。故に流量調整弁４の開度が一定であ
つても、アクチユエータ２への作動油の供給流量
が増減し、スクリユの前進速度が変化することと
なる。この結果、金型内の抵抗の大きい箇所に充
填中は速度が遅く、逆の場合遅くなるという射出
動作が自動的に得られ、ソリ等の不具合が解消す
る。
FIG. 1 shows a first embodiment of the invention. The injection speed control circuit of this injection molding machine is an improved version of the circuit shown in FIG. In FIG. 1, the same members as in FIG. 4 are given the same reference numerals, and detailed explanation thereof will be omitted.
In the case of this injection speed control circuit, when the switching valve 11 is opened as shown in the figure and the pilot pipe 6, which together with the vent pipe 9 constitutes the hydraulic circuit of the pressure compensation valve 7, is opened, the load pressure fed back from the actuator 2 becomes Spring 7 of the spool of the compensation valve 7
Since it acts on the a side, the pressure difference between point X and point Y before and after the flow rate adjustment valve 4 is reduced by the pressure compensation valve 7.
It will be held constant by . Furthermore, if the spool of the switching valve 11 is moved to the left in FIG. 1 to close the pilot pipe 6 and perform the injection operation, the load pressure of the actuator 2 will not act on the pressure compensation valve 7, and the pressure of the pressure compensation valve 7 will be reduced. Compensation function is lost.
That is, in this case, X of the hydraulic pump 1
The pressure at the point rises to the set pressure of the pressure regulating valve 5 and is fixed. At this time, actuator 2
The supply pressure (pressure at point Y) increases or decreases depending on the load as in the circuit shown in Figure 4, but since the pressure at point X is fixed as described above, the pressure difference between points X and Y is Change. Therefore, even if the opening degree of the flow rate regulating valve 4 is constant, the flow rate of the hydraulic oil supplied to the actuator 2 increases or decreases, and the forward speed of the screw changes. As a result, an injection operation is automatically obtained in which the injection speed is slow during filling into a location with high resistance in the mold, and slow in the opposite case, and problems such as warpage are eliminated.
第２図は本考案の第２実施例を示す。この射出
速度制御回路は第５図の回路を改良したもので、
圧力補償弁２２の油圧回路を構成するパイロツト
管２４に電磁切換弁２７を設けて成る。この例に
おいても第５図と同一の部材には同一の参照符号
を付してその詳しい説明は省略する。 FIG. 2 shows a second embodiment of the invention. This injection speed control circuit is an improved version of the circuit shown in Figure 5.
A pilot pipe 24 constituting the hydraulic circuit of the pressure compensation valve 22 is provided with an electromagnetic switching valve 27. In this example as well, the same members as in FIG. 5 are given the same reference numerals, and detailed explanation thereof will be omitted.
この射出速度制御回路の場合においても、図の
ように切換弁２７でパイロツト管２４を連通する
と圧力補償弁２２は正常に働き、また切換弁２７
でパイロツト管２４の連通を断つと、圧力補償弁
２２の圧力補償機能が喪失される。このときＸ点
の圧力は電磁比例リリーフ弁２５により遠隔操作
される圧力制御弁２１の設定圧で固定され、第１
図の場合と同様に、スクリユの前進速度は金型内
抵抗にならつた充填速度となり、ソリ等が防止さ
れる。 Even in the case of this injection speed control circuit, if the pilot pipe 24 is communicated with the switching valve 27 as shown in the figure, the pressure compensating valve 22 works normally, and the switching valve 27
When the communication with the pilot pipe 24 is cut off, the pressure compensation function of the pressure compensation valve 22 is lost. At this time, the pressure at point X is fixed at the set pressure of the pressure control valve 21 remotely controlled by the electromagnetic proportional relief valve 25, and
As in the case shown in the figure, the advancing speed of the screw is a filling speed that follows the internal resistance of the mold, and warping, etc., is prevented.
第３図は、第６図の制御回路を改良した本考案
の第３実施例を示す。この射出速度制御回路は、
圧力補償弁３４の油圧回路を構成する接続管３６
に電磁切換弁４０を設けて成る。この実施例にお
いても第６図と同一の部材には同一の参照符号を
付してその詳しい説明は省略する。 FIG. 3 shows a third embodiment of the present invention, which is an improvement on the control circuit shown in FIG. This injection speed control circuit is
A connecting pipe 36 that constitutes the hydraulic circuit of the pressure compensation valve 34
An electromagnetic switching valve 40 is provided in the main body. In this embodiment as well, the same members as in FIG. 6 are designated by the same reference numerals, and detailed explanation thereof will be omitted.
この制御回路においても、図のように切換弁４
０を開くと圧力補償弁３４が正常に働くため、流
量調整弁４の前後の圧力差が一定に保たれ、アク
チユエータ２は負荷圧の変動に関係なくスクリユ
を一定速度で前進させる。 In this control circuit as well, as shown in the figure, the switching valve 4
When 0 is opened, the pressure compensating valve 34 works normally, so the pressure difference before and after the flow regulating valve 4 is kept constant, and the actuator 2 advances the screw at a constant speed regardless of fluctuations in the load pressure.
また切換弁４０で接続管３６を閉じると、アク
チユエータの負荷圧の増減を、油圧ポンプ３１を
制御するフイードバツク信号として流量制御シリ
ンダ３１ａに伝えることができなくなる。すなわ
ち、流量制御中であつても、Ｘ点の圧力は圧力調
整弁３８により設定される最高圧で固定される。
そのため流量調整弁４の前後の圧力差はアクチユ
エータ負荷の変化に応じて増減するから、射出行
程中の場合には供給される作動油の流量が金型内
の抵抗等にならつて自動的に増減し、この場合も
ソリ等が防止される。 Further, when the connecting pipe 36 is closed by the switching valve 40, the increase or decrease in the load pressure of the actuator cannot be transmitted to the flow rate control cylinder 31a as a feedback signal for controlling the hydraulic pump 31. That is, even during flow rate control, the pressure at point X is fixed at the highest pressure set by the pressure regulating valve 38.
Therefore, the pressure difference before and after the flow rate adjustment valve 4 increases or decreases according to changes in the actuator load, so during the injection stroke, the flow rate of the supplied hydraulic oil automatically increases or decreases according to the resistance inside the mold. However, in this case as well, warping and the like are prevented.
なお、圧力調整弁３８は金型への樹脂の充填終
了後における樹脂圧力（保圧）を制御する。 Note that the pressure regulating valve 38 controls the resin pressure (holding pressure) after filling the mold with resin.
切換弁１１，２７，４０は電磁式に限らず手動
等によつて切換え操作ができる構造のものを用い
ることもできる。 The switching valves 11, 27, and 40 are not limited to electromagnetic types, but may also be of a structure that allows manual switching operation.
以上説明したように、本考案に係る射出成形機
の射出速度制御回路は、加熱シリンダ内に挿入さ
れたスクリユを軸方向に前進させて射出ノズルか
ら樹脂を金型内に射出させるアクチユエータに、
該アクチユエータを作動させる油圧ポンプが流量
調整弁を介して連絡され、上記流量調整弁には、
油圧ポンプからアクチユエータに送られる作動油
の流量調整弁の前後の圧力差を、アクチユエータ
からフイードバツクされる負荷圧で作動させられ
て一定に保つ圧力補償弁が付設された射出成形機
の射出速度制御回路において、上記圧力補償弁の
油圧回路に、該油圧回路を閉じて圧力補償弁の機
能を喪失させる切換弁が設けられた構成とされて
いるので、切換弁の切換えでアクチユエータの作
動形態を選択し、金型の構造や成形品等に適合さ
せて樹脂を金型内に充填することができ、成形品
のソリ等の支障を防止することができる。また、
流量調整弁の油圧回路に切換弁を組み込むだけで
あるので、構造が簡単で経済的であり、保守も容
易であるとともに、既存の射出成形機に至極簡単
に実施することができる。
As explained above, the injection speed control circuit of the injection molding machine according to the present invention has an actuator that advances the screw inserted in the heating cylinder in the axial direction and injects the resin from the injection nozzle into the mold.
A hydraulic pump that operates the actuator is connected via a flow rate adjustment valve, and the flow rate adjustment valve includes:
An injection speed control circuit for an injection molding machine equipped with a pressure compensation valve that maintains the pressure difference before and after the flow rate adjustment valve of the hydraulic oil sent from the hydraulic pump to the actuator at a constant level by using the load pressure fed back from the actuator. In this case, the hydraulic circuit of the pressure compensation valve is provided with a switching valve that closes the hydraulic circuit and loses the function of the pressure compensation valve, so the operating mode of the actuator can be selected by switching the switching valve. The resin can be filled into the mold in accordance with the structure of the mold, the molded product, etc., and problems such as warping of the molded product can be prevented. Also,
Since the switching valve is simply incorporated into the hydraulic circuit of the flow rate regulating valve, the structure is simple and economical, maintenance is easy, and it can be implemented extremely easily in an existing injection molding machine.
第１図は本考案の第１実施例を示す構成図、第
２図は本考案の第２実施例を示す構成図、第３図
は本考案の第３実施例の構成図である。第４図は
従来の射出速度制御回路の構成図、第５図は従来
の他の制御回路の構成図、第６図は従来の別の制
御回路の構成図である。
１……油圧ポンプ、２……アクチユエータ、
４，２３……流量調整弁、６……パイロツト管
（油圧回路）、７，２２，３４……圧力補償弁、１
１，２７，４０……切換弁、２４……パイロツト
管（油圧回路）、３６……接続管（油圧回路）。
FIG. 1 is a block diagram showing a first embodiment of the present invention, FIG. 2 is a block diagram showing a second embodiment of the present invention, and FIG. 3 is a block diagram of a third embodiment of the present invention. FIG. 4 is a block diagram of a conventional injection speed control circuit, FIG. 5 is a block diagram of another conventional control circuit, and FIG. 6 is a block diagram of another conventional control circuit. 1... Hydraulic pump, 2... Actuator,
4, 23...Flow rate adjustment valve, 6...Pilot pipe (hydraulic circuit), 7, 22, 34...Pressure compensation valve, 1
1, 27, 40...Switching valve, 24...Pilot pipe (hydraulic circuit), 36...Connecting pipe (hydraulic circuit).
Claims (1)
に前進させて射出ノズルから樹脂を金型内に射出
させるアクチユエータに、該アクチユエータを作
動させる油圧ポンプが流量調整弁を介して連絡さ
れ、上記流量調整弁には、油圧ポンプからアクチ
ユエータに送られる作動油の流量調整弁の前後の
圧力差を、アクチユエータからフイードバツクさ
れる負荷圧で作動させられて一定に保つ圧力補償
弁が付設された射出成形機の射出速度制御回路に
おいて、上記圧力補償弁の油圧回路に、該油圧回
路を閉じて圧力補償弁の機能を喪失させる切換弁
が設けられたことを特徴とする射出成形機の射出
速度制御回路。 A hydraulic pump that operates the actuator is connected to an actuator that advances a screw inserted in a heating cylinder in the axial direction to inject resin into a mold from an injection nozzle through a flow rate adjustment valve. The injection molding machine is equipped with a pressure compensation valve that is operated by the load pressure fed back from the actuator to maintain a constant pressure difference across the flow rate adjustment valve of the hydraulic oil sent from the hydraulic pump to the actuator. An injection speed control circuit for an injection molding machine, characterized in that, in the speed control circuit, the hydraulic circuit of the pressure compensation valve is provided with a switching valve that closes the hydraulic circuit and loses the function of the pressure compensation valve.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1990077967U JPH0525870Y2 (en) | 1990-07-23 | 1990-07-23 |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1990077967U JPH0525870Y2 (en) | 1990-07-23 | 1990-07-23 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0437323U JPH0437323U (en) | 1992-03-30 |
| JPH0525870Y2 true JPH0525870Y2 (en) | 1993-06-30 |
Family
ID=31620827
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1990077967U Expired - Lifetime JPH0525870Y2 (en) | 1990-07-23 | 1990-07-23 |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0525870Y2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07290549A (en) * | 1994-04-25 | 1995-11-07 | Niigata Eng Co Ltd | Hydraulic circuit of injection molding machine |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0425521Y2 (en) * | 1985-03-27 | 1992-06-18 |
-
1990
- 1990-07-23 JP JP1990077967U patent/JPH0525870Y2/ja not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07290549A (en) * | 1994-04-25 | 1995-11-07 | Niigata Eng Co Ltd | Hydraulic circuit of injection molding machine |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0437323U (en) | 1992-03-30 |
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