JP2924697B2 - Hydraulic circuit of injection molding machine - Google Patents
Hydraulic circuit of injection molding machineInfo
- Publication number
- JP2924697B2 JP2924697B2 JP5769495A JP5769495A JP2924697B2 JP 2924697 B2 JP2924697 B2 JP 2924697B2 JP 5769495 A JP5769495 A JP 5769495A JP 5769495 A JP5769495 A JP 5769495A JP 2924697 B2 JP2924697 B2 JP 2924697B2
- Authority
- JP
- Japan
- Prior art keywords
- hydraulic
- return pipe
- screw
- cylinder
- pressure control
- 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
【０００１】[0001]
【産業上の利用分野】本発明はインラインスクリュタイ
プの油圧式射出成形機の油圧回路に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic circuit of an in-line screw type hydraulic injection molding machine.
【０００２】[0002]
【従来の技術】射出成形機の油圧回路として、図２に示
すものが知られている。これについて説明すると、油圧
源１は、ダイレクト制御可変吐出ポンプシステムとなっ
ており、作動油の流量制御と圧力制御を斜板制御で行う
ことができる可変吐出ポンプ（メインポンプ）２と、定
吐出ポンプ（サブポンプ）３及びそれらのポンプ２，３
を作動させる電動機４を備える。この油圧源１の可変吐
出ポンプ２には、油圧モータ６と油圧シリンダ（射出シ
リンダ）７が管路８で接続され、また油圧モータ９が管
路１０で接続されている。油圧モータ６は加熱シリンダ
１１に挿入されたスクリュ１２を周方向に回転させるも
のであり、また油圧シリンダ７はスクリュ１２を軸方向
に移動させるものである。管路８には、４ポート３位置
電磁切換弁１３と４ポート２位置電磁切換弁１４が設け
られ、また他の管路１０には４ポート３位置電磁切換弁
１５が設けられている。2. Description of the Related Art FIG. 2 shows a known hydraulic circuit of an injection molding machine. To explain this, the hydraulic power source 1 is a direct control variable discharge pump system, and a variable discharge pump (main pump) 2 which can perform flow control and pressure control of hydraulic oil by swash plate control, and a constant discharge. Pumps (sub-pumps) 3 and their pumps 2, 3
And an electric motor 4 for operating the motor. A hydraulic motor 6 and a hydraulic cylinder (injection cylinder) 7 are connected to a variable discharge pump 2 of the hydraulic source 1 via a pipeline 8, and a hydraulic motor 9 is connected via a pipeline 10. The hydraulic motor 6 rotates the screw 12 inserted in the heating cylinder 11 in the circumferential direction, and the hydraulic cylinder 7 moves the screw 12 in the axial direction. The pipeline 8 is provided with a 4-port 3-position electromagnetic switching valve 13 and a 4-port 2-position electromagnetic switching valve 14, and the other pipeline 10 is provided with a 4-port 3-position electromagnetic switching valve 15.
【０００３】電磁切換弁１３は、ソレノイドａを励磁す
ると、可変吐出ポンプ２を油圧シリンダ７の前進側シリ
ンダ室７ａに連絡し、また他のソレノイドｂを励磁する
と、可変吐出ポンプ２を油圧モータ６に連絡するととも
に、油圧シリンダ７の前進側シリンダ室７ａを戻り管１
６に連絡し、更にソレノドイａ，ｂを消磁すると、可変
吐出ポンプ２と油圧モータ６及び油圧シリンダ７のシリ
ンダ室７ａの連絡を断って油圧モータ６と油圧シリンダ
７のシリンダ室７ａを戻り管１６に連絡する構成とされ
ている。戻り管１６には電磁比例圧力制御弁１７が設け
られている。When the solenoid a is excited, the electromagnetic switching valve 13 connects the variable discharge pump 2 to the forward cylinder chamber 7a of the hydraulic cylinder 7, and when the other solenoid b is excited, the variable discharge pump 2 connects the variable discharge pump 2 to the hydraulic motor 6. And the forward cylinder chamber 7a of the hydraulic cylinder 7 is returned to the return pipe 1
When the solenoids a and b are demagnetized, the communication between the variable discharge pump 2 and the hydraulic motor 6 and the cylinder chamber 7a of the hydraulic cylinder 7 is cut off, and the hydraulic motor 6 and the cylinder chamber 7a of the hydraulic cylinder 7 are returned to the return pipe 16. It is configured to be contacted. The return pipe 16 is provided with an electromagnetic proportional pressure control valve 17.
【０００４】また、電磁切換弁１４は、ソレノイドｂを
励磁すると、可変吐出ポンプ２を油圧シリンダ７の後退
側シリンダ室７ｂに連絡するとともに前進側シリンダ室
７ａを戻り管１９に連絡し、ソレノイドｂを消磁する
と、可変吐出ポンプ２とシリンダ室７ａの連絡を断って
他のシリンダ室７ｂを戻り管１９に連絡する構成とされ
ている。When the solenoid b is energized, the electromagnetic switching valve 14 connects the variable discharge pump 2 to the retraction cylinder chamber 7b of the hydraulic cylinder 7 and the advancing cylinder chamber 7a to the return pipe 19, and the solenoid b , The communication between the variable discharge pump 2 and the cylinder chamber 7a is cut off, and the other cylinder chamber 7b is connected to the return pipe 19.
【０００５】また、電磁切換弁１５は、ソレノイドａを
励磁すると、可変吐出ポンプ２を油圧モータ９の図で左
側のポートに連絡するとともに、油圧モータ９の右側の
ポートを戻り管２０に連絡し、またソレノイドｂを励磁
すると、可変吐出ポンプ２を油圧モータ９の右側のポー
トに連絡するとともに、油圧モータ９の左側のポートを
戻り管２０に連絡し、更にソレノイドａ，ｂを消磁する
と、可変吐出ポンプ２及び戻り管２０と油圧モータ９の
連絡を断つ構成とされている。戻り管２０にはカウンタ
ーバランス弁２１が設けられている。戻り管１６，２０
の管端は油圧タンク２２に開口している。油圧モータ９
は、回転テーブル等の負荷２３を作動させるものであ
る。When the solenoid a is excited, the electromagnetic switching valve 15 connects the variable discharge pump 2 to the port on the left side of the hydraulic motor 9 in the figure and connects the port on the right side of the hydraulic motor 9 to the return pipe 20. When the solenoid b is excited, the variable discharge pump 2 is connected to the right port of the hydraulic motor 9, the left port of the hydraulic motor 9 is connected to the return pipe 20, and when the solenoids a and b are demagnetized, the variable The connection between the discharge pump 2 and the return pipe 20 and the hydraulic motor 9 is cut off. The return pipe 20 is provided with a counterbalance valve 21. Return pipe 16,20
Is open to the hydraulic tank 22. Hydraulic motor 9
Operates the load 23 such as a rotary table.
【０００６】油圧源１の定吐出ポンプ３には、油圧モー
タや油圧シリンダ等のアクチュエータ２５，２６，２７
が管路２８で接続されている。管路２８から戻り管２９
が分岐され、その戻り管２９にはリリーフ弁３０が設け
られている。リリーフ弁３０は電磁弁３１によって作動
を制御される。The constant discharge pump 3 of the hydraulic power source 1 includes actuators 25, 26, 27 such as a hydraulic motor and a hydraulic cylinder.
Are connected by a pipe 28. Return pipe 29 from pipe 28
The return pipe 29 is provided with a relief valve 30. The operation of the relief valve 30 is controlled by the solenoid valve 31.
【０００７】上記射出成形機の油圧回路においては、図
の状態で油圧源１を作動させて電磁切換弁１３のソレノ
イドｂを励磁すると、油圧モータ６が作動してスクリュ
１２を回転させる。スクリュ１２は回転しながら図で右
に後退して樹脂を可塑化し計量する。この際電磁比例圧
力制御弁１７は、スクリュ１２の後退に伴って油圧シリ
ンダ７のシリンダ室７ａから戻り管１６を通って油タン
ク２２に流れる作動油の抵抗となりスクリュ１２の後退
に背圧をかける。In the hydraulic circuit of the injection molding machine, when the hydraulic source 1 is operated in the state shown in the drawing to excite the solenoid b of the electromagnetic switching valve 13, the hydraulic motor 6 operates to rotate the screw 12. The screw 12 retreats to the right in the figure while rotating, plasticizes the resin, and measures it. At this time, the electromagnetic proportional pressure control valve 17 becomes a resistance of hydraulic oil flowing from the cylinder chamber 7a of the hydraulic cylinder 7 through the return pipe 16 to the oil tank 22 with the retreat of the screw 12, and applies a back pressure to the retreat of the screw 12. .
【０００８】また、電磁切換弁１５のいずれかのソレノ
イドａ，ｂを励磁すると、油圧モータ９が作動して負荷
２３をソレノイドａ，ｂの選択によって定まる方向に回
転させる。油圧モータ９の回転駆動に働いた作動油は、
戻り管２０を通って油圧タンク２２に流れる。戻り管２
０に設けられたカウンターバランス弁２１は、ブレーキ
として働き、慣性を有する負荷２３の回転制御を円滑に
する。When one of the solenoids a and b of the electromagnetic switching valve 15 is excited, the hydraulic motor 9 operates to rotate the load 23 in a direction determined by the selection of the solenoids a and b. Hydraulic oil that has worked to rotate the hydraulic motor 9 is:
It flows through the return pipe 20 to the hydraulic tank 22. Return pipe 2
The counterbalance valve 21 provided at 0 works as a brake and smoothes the rotation control of the load 23 having inertia.
【０００９】電磁弁３１の励磁で固定ポンプ３はリリー
フ弁３０の設定圧力でリリーフする（固定ポンプの負荷
状態）。また電磁弁３１の消磁で固定ポンプ３はアンロ
ードする（固定ポンプの無負荷状態）。When the solenoid valve 31 is excited, the fixed pump 3 is relieved by the set pressure of the relief valve 30 (the load state of the fixed pump). The fixed pump 3 is unloaded by the demagnetization of the solenoid valve 31 (the fixed pump is in a no-load state).
【００１０】[0010]
【発明が解決しようとする課題】ところで、図２及びこ
れの説明から分るように、ダイレクト制御型の可変吐出
ポンプ２で駆動するタイプの射出成形機では、作動油の
流量及び圧力制御は可変吐出ポンプ２の斜板制御のみで
行えるので、通常、定吐出ポンプで駆動するタイプの成
形機に必要な、電磁比例流量制御弁と電磁比例圧力制御
弁が不要である。しかしながら、すべてのアクチュエー
タの圧力制御を成形機のコントローラで電気的に制御す
る要求がある場合は、背圧制御のみ電磁比例圧力制御弁
１７を装備する必要がある。As will be understood from FIG. 2 and the description thereof, in the injection molding machine of the type driven by the direct control type variable discharge pump 2, the flow rate and pressure control of the working oil are variable. Since it can be performed only by controlling the swash plate of the discharge pump 2, the electromagnetic proportional flow control valve and the electromagnetic proportional pressure control valve, which are normally required for a molding machine driven by a constant discharge pump, are unnecessary. However, when there is a request to electrically control the pressure control of all the actuators by the controller of the molding machine, it is necessary to provide the electromagnetic proportional pressure control valve 17 only for the back pressure control.
【００１１】また、負荷２３が無視できない慣性を持つ
場合、円滑な回転制御を行うためには、ブレーキ用とし
てカウンターバランス弁２１を用いる必要がある。更
に、油圧源１に定吐出ポンプ３を追加した場合には、専
用のリリーフ弁３０等が必要になる。If the load 23 has inertia that cannot be ignored, it is necessary to use the counterbalance valve 21 for braking in order to perform smooth rotation control. Further, when the constant discharge pump 3 is added to the hydraulic pressure source 1, a dedicated relief valve 30 and the like are required.
【００１２】このようなことから、従来の射出成形機の
油圧回路は、構成が全体として複雑になるという問題点
がある。For this reason, the hydraulic circuit of the conventional injection molding machine has a problem that the configuration becomes complicated as a whole.
【００１３】本発明は、一つの電磁比例圧力制御弁を多
目的に使用することができる、構成の簡単な射出成形機
の油圧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 a hydraulic circuit of an injection molding machine having a simple structure, in which one electromagnetic proportional pressure control valve can be used for multiple purposes.
【００１４】本発明の目的は、電磁比例圧力制御弁をサ
ージカット弁として機能させることこができる射出成形
機の油圧回路を提供することである。An object of the present invention is to provide a hydraulic circuit of an injection molding machine that can function an electromagnetic proportional pressure control valve as a surge cut valve.
【００１５】[0015]
【課題を解決するための手段】上記の目的を達成するた
めに、請求項１に係る発明は、油圧源に、加熱シリンダ
に挿入されたスクリュを周方向に回転させる油圧モータ
と、上記スクリュを軸方向に移動させる油圧シリンダ、
及び他の１以上のアクチュエータが管路によって接続さ
れ、上記油圧モータの作動で上記スクリュを回転させな
がら後退させて樹脂を計量する際に上記油圧シリンダの
前進側シリンダ室の作動油を油タンクに戻す第１戻り管
に、上記スクリュの後退移動に背圧をかける電磁比例圧
力制御弁が設けられた射出成形機の油圧回路において、
上記他のアクチュエータの作動油を油タンクに戻す少な
くとも１本の第２戻り管を、上記第１戻り管の上記電磁
比例圧力制御弁の上流側に接続し、上記第１戻り管と上
記第２戻り管にそれらの戻り管を開閉する電磁切換弁を
設けた構成とした。In order to achieve the above object, an invention according to claim 1 comprises a hydraulic source for rotating a screw inserted into a heating cylinder in a circumferential direction, a hydraulic motor, and a hydraulic motor. A hydraulic cylinder that moves in the axial direction,
And one or more other actuators are connected by a pipeline, and when the resin is measured by rotating the screw by operating the hydraulic motor and retreating, the hydraulic oil in the forward cylinder chamber of the hydraulic cylinder is supplied to the oil tank. In a hydraulic circuit of an injection molding machine provided with an electromagnetic proportional pressure control valve for applying a back pressure to a backward movement of the screw in a first return pipe to be returned,
At least one second return pipe for returning the hydraulic oil of the other actuator to the oil tank is connected to the first return pipe upstream of the electromagnetic proportional pressure control valve, and the first return pipe and the second return pipe are connected to each other. The return pipe was provided with an electromagnetic switching valve for opening and closing the return pipes.
【００１６】また、請求項２に係る発明は、油圧源に、
加熱シリンダに挿入されたスクリュを周方向に回転させ
る油圧モータと、上記スクリュを軸方向に移動させる油
圧シリンダが管路によって接続され、上記油圧モータの
作動で上記スクリュを回転させながら後退させて樹脂を
計量する際に上記油圧シリンダの前進側シリンダ室の作
動油を油タンクに戻す戻り管に、上記スクリュの後退移
動に背圧をかける電磁比例圧力制御弁が設けられた射出
成形機の油圧回路において、上記戻り管に、上記油圧モ
ータの作動で上記スクリュを回転させながら後退させて
樹脂を計量する際に戻り管を第１位置において油タンク
に連通させ、また上記スクリュを前進させて加熱シリン
ダから樹脂を射出する際に油圧源の作動油を油圧シリン
ダの前進側シリンダ室に供給する管路に上記電磁比例圧
力制御弁を第２位置において連結管を介して連絡する電
磁切換弁を設けた構成とした。[0016] According to a second aspect of the present invention, the hydraulic pressure source includes:
A hydraulic motor that rotates the screw inserted in the heating cylinder in the circumferential direction and a hydraulic cylinder that moves the screw in the axial direction are connected by a pipeline, and the hydraulic motor is operated to retreat the screw while rotating the screw. Hydraulic circuit of an injection molding machine provided with an electromagnetic proportional pressure control valve for applying back pressure to the backward movement of the screw in a return pipe for returning hydraulic oil in the forward cylinder chamber of the hydraulic cylinder to the oil tank when measuring the hydraulic cylinder In the return pipe, when returning the screw while rotating the screw by the operation of the hydraulic motor to measure the resin, the return pipe communicates with the oil tank at the first position, and the screw is advanced to heat the cylinder. The above-mentioned electromagnetic proportional pressure control valve is placed in the pipeline that supplies the hydraulic oil of the hydraulic source to the cylinder chamber on the forward side of the hydraulic cylinder when the resin is injected from the cylinder. It has a structure in which a solenoid switching valve in communication through the connecting pipe in.
【００１７】第２戻り管に別の戻り管を並設し、上記第
２戻り管に設けられた電磁切換弁はそれらの戻り管を択
一的に開閉する構成とすることができる。また電磁比例
圧力制御弁が設けられた戻り管に他の戻り管を並設し、
上記電磁比例圧力制御弁の戻り管に設けられた電磁切換
弁はそれらの戻り管を択一的に開閉する構成とすること
ができる。Another return pipe may be arranged in parallel with the second return pipe, and the electromagnetic switching valve provided on the second return pipe may be configured to selectively open or close the return pipes. In addition, another return pipe is provided in parallel with the return pipe provided with the electromagnetic proportional pressure control valve,
The electromagnetic switching valve provided on the return pipe of the electromagnetic proportional pressure control valve may be configured to selectively open or close the return pipe.
【００１８】[0018]
【作用】請求項１に係る発明においては、電磁切換弁で
開とされた戻り管を作動油が流れ、電磁比例圧力制御弁
はその作動油を任意の設定圧力で油タンクに戻す。した
がって、電磁比例圧力制御弁を油圧モータとアクチュエ
ータの作動目的に応じ、背圧弁のほか、カウンターバラ
ンス弁やリリーフ弁などとして多目的に使用することが
できる。According to the first aspect of the present invention, hydraulic oil flows through the return pipe opened by the electromagnetic switching valve, and the electromagnetic proportional pressure control valve returns the hydraulic oil to the oil tank at an arbitrary set pressure. Therefore, the electromagnetic proportional pressure control valve can be used for various purposes, such as a counterbalance valve and a relief valve, in addition to the back pressure valve, according to the operation purpose of the hydraulic motor and the actuator.
【００１９】請求項２に係る発明においては、電磁切換
弁で戻り管を油圧タンクに連通させると、計量工程にお
いて電磁比例圧力制御弁は背圧弁として機能する。また
油圧源の作動油を油圧シリンダの前進側シリンダ室に供
給する管路に上記電磁比例圧力制御弁を電磁切換弁で連
絡すると、射出工程において充填工程（速度制御）から
保圧工程に（圧力制御）に切り換わる時に、電磁比例圧
力制御弁はサージカット弁として働き、サージ圧力を逃
がす。According to the second aspect of the present invention, when the return pipe is connected to the hydraulic tank by the electromagnetic switching valve, the electromagnetic proportional pressure control valve functions as a back pressure valve in the measuring step. Also, when the above-mentioned electromagnetic proportional pressure control valve is connected to the pipeline for supplying the hydraulic oil of the hydraulic source to the forward cylinder chamber of the hydraulic cylinder by an electromagnetic switching valve, the injection process shifts from the filling process (speed control) to the pressure-holding process. When switching to (control), the electromagnetic proportional pressure control valve acts as a surge cutoff valve to release surge pressure.
【００２０】第２戻り管に設けられた電磁切換弁によっ
て第２戻り管と別の戻り管とを択一的に開閉する構成と
した場合、及び電磁比例圧力制御弁の戻り管に設けられ
た電磁切換弁によってその戻り管と他の戻り管とを択一
的に開閉する構成とした場合は、電磁比例圧力制御弁を
使用せずに作動油を直接戻すことができる。When the second return pipe and the other return pipe are selectively opened and closed by an electromagnetic switching valve provided on the second return pipe, and when the electromagnetic return valve of the electromagnetic proportional pressure control valve is provided. When the return pipe and the other return pipe are selectively opened and closed by the electromagnetic switching valve, the hydraulic oil can be returned directly without using the electromagnetic proportional pressure control valve.
【００２１】[0021]
【実施例】図１は本発明に係る射出成形機の油圧回路の
一実施例を示す。なお、図２の油圧回路と同一の部材等
には同一の符号を付してその詳しい説明を省略する。符
号３５と３６は共に４ポート３位置電磁切換弁である。
電磁切換弁３５は、そのＡポートを、油圧モータ６と油
圧シリンダ７の前進側シリンダ室７ａに作動油を供給す
る管路８ａから分岐された連結管３７に、またＢポート
を戻り管１６の上流部１６ａに、Ｐポートを戻り管１６
の下流部１６ｂに、更にＴポートを他の戻り管３８にそ
れぞれ接続して設けられている。FIG. 1 shows an embodiment of a hydraulic circuit of an injection molding machine according to the present invention. The same members and the like as those of the hydraulic circuit in FIG. 2 are denoted by the same reference numerals, and detailed description thereof will be omitted. Reference numerals 35 and 36 are 4 port 3 position electromagnetic switching valves.
The electromagnetic switching valve 35 has its A port connected to a connecting pipe 37 branched from a pipeline 8a for supplying hydraulic oil to the hydraulic motor 6 and the forward cylinder chamber 7a of the hydraulic cylinder 7, and the B port connected to the return pipe 16. Return the P port to the upstream pipe 16a
The T port is connected to each of the other return pipes 38 at the downstream portion 16b.
【００２２】電磁切換弁３５は、ソレノイドａを励磁す
ると、連結管３７を戻り管１６の下流部１６ｂに連絡す
るとともに戻り管１６の上流部１６ａを戻り管３８に連
絡し、またソレノイドｂを励磁すると（ソレノイドａは
消磁）、戻り管１６の上流部１６ａを下流部１６ｂに連
絡するとともに連結管３７と戻り管３８を閉じ、更にソ
レノイドａ，ｂを消磁して中立位置にすると、連結管３
７と戻り管１６の下流部１６ｂを閉じるとともに戻り管
１６の上流部１６ａを戻り管３８に連絡する構成とされ
ている。When the solenoid a is excited, the solenoid switching valve 35 connects the connecting pipe 37 to the downstream part 16b of the return pipe 16, connects the upstream part 16a of the return pipe 16 to the return pipe 38, and excites the solenoid b. Then (solenoid a is demagnetized), the upstream part 16a of the return pipe 16 is connected to the downstream part 16b, the connection pipe 37 and the return pipe 38 are closed, and the solenoids a and b are demagnetized to the neutral position.
7 and the downstream part 16 b of the return pipe 16 are closed, and the upstream part 16 a of the return pipe 16 is connected to the return pipe 38.
【００２３】また、電磁切換弁３６は、Ａポートを管路
２８から分岐された戻り管３９の上流部３９ａに、Ｂポ
ートを戻り管２０の上流部２０ａに、またＰポートを、
電磁切換弁３５と電磁比例圧力制御弁１７の間において
戻り管１６に接続された戻り管２０の下流部２０ｂ（戻
り管３９の下流部３９ｂ）に、更にＴポートを別の戻り
管４０にそれぞれ接続して設けられている。The electromagnetic switching valve 36 has an A port connected to the upstream portion 39a of the return pipe 39 branched from the pipe 28, a B port connected to the upstream portion 20a of the return pipe 20, and a P port connected to the upstream portion 20a of the return pipe 20.
Between the electromagnetic switching valve 35 and the electromagnetic proportional pressure control valve 17, the downstream port 20 b of the return pipe 20 connected to the return pipe 16 (downstream section 39 b of the return pipe 39) and the T port to another return pipe 40. The connection is provided.
【００２４】この電磁切換弁３６は、ソレノイドａを励
磁すると、戻り管３９の上流部３９ａを下流部３９ｂに
連絡するとともに戻り管２０の上流部２０ａを戻り管４
０に連絡し、またソレノイドｂを励磁すると、戻り管３
９の上流部３９ａを戻り管４０に連絡するとともに戻り
管２０の上流部２０ａを下流部２０ｂに連絡し、更にソ
レノイドａ，ｂを消磁して中立位置にすると、戻り管２
０，３９の上流部２０ａ，３９ａを戻り管４０に連絡し
て下流部２０ｂ（３９ｂ）を閉じる構成とされている。When the solenoid a is excited, the electromagnetic switching valve 36 connects the upstream portion 39a of the return pipe 39 to the downstream portion 39b and connects the upstream portion 20a of the return pipe 20 to the return pipe 4a.
0, and when the solenoid b is excited, the return pipe 3
9 is connected to the return pipe 40, the upstream section 20a of the return pipe 20 is connected to the downstream section 20b, and the solenoids a and b are demagnetized to the neutral position.
The upstream portions 20a and 39a of the 0 and 39 are connected to the return pipe 40 to close the downstream portion 20b (39b).
【００２５】次に上記の構成とされた本発明に係る射出
成形機の油圧回路の作用を説明する。図の状態で油圧源
１を作動させ、電磁切換弁１３，３５のソレノイドｂを
励磁すると、油圧モータ６が作動してスクリュ１２を回
転させ、計量工程に入る。この際電磁比例圧力制御弁１
７は、従来同様に戻り管１６を流れる作動油を設定圧で
油圧タンク２２に逃がし、スクリュ１２の後退に背圧を
かける。Next, the operation of the hydraulic circuit of the injection molding machine according to the present invention having the above configuration will be described. When the hydraulic power source 1 is operated in the state shown in the figure and the solenoid b of the electromagnetic switching valves 13 and 35 is excited, the hydraulic motor 6 is operated to rotate the screw 12, and the measuring process is started. At this time, the electromagnetic proportional pressure control valve 1
The reference numeral 7 releases the hydraulic oil flowing through the return pipe 16 to the hydraulic tank 22 at a set pressure as in the conventional case, and applies a back pressure to the retreat of the screw 12.
【００２６】上記の計量工程から射出工程に入る場合
は、樹脂の充填に必要な速度が得られるよう、十分に高
い圧力指令値を可変吐出ポンプ２に与え、電磁切換弁１
３のソレノイドａを励磁する。これより、可変吐出ポン
プ２から吐出された作動油が管路８ａを通って油圧シリ
ンダ７の前進側シリンダ室７ａに供給されるので、油圧
シリンダ７が縮小してスクリュ１２を図で左に前進さ
せ、樹脂を金型（図示せず）に射出する。油圧シリンダ
７の後退側シリンダ室７ｂの作動油は、電磁切換弁１４
のＢ−Ｔポートと戻り管１９を通って油タンク２２に戻
る。When the injection process is started from the above-mentioned metering process, a sufficiently high pressure command value is applied to the variable discharge pump 2 so that the speed required for filling the resin is obtained, and the electromagnetic switching valve 1
3 excites the solenoid a. As a result, the hydraulic oil discharged from the variable discharge pump 2 is supplied to the forward cylinder chamber 7a of the hydraulic cylinder 7 through the pipeline 8a, so that the hydraulic cylinder 7 contracts and the screw 12 moves forward to the left in the drawing. Then, the resin is injected into a mold (not shown). The hydraulic oil in the retraction cylinder chamber 7 b of the hydraulic cylinder 7 is supplied to the electromagnetic switching valve 14.
To the oil tank 22 through the BT port and the return pipe 19.
【００２７】速度（流量）制御の充填工程の始めから圧
力制御の保圧工程に入るまでの適当な時期に、可変吐出
ポンプ２に与えた圧力指令値に見合う圧力指令値よりも
若干（例えば、３〜５kgf/cm2 ）高い圧力指令値をコン
トローラ（図示せず）で演算して電磁比例圧力制御弁１
７に与え、また電磁切換弁３５のソレノイドａを励磁し
ておく。At an appropriate time from the start of the filling process of the speed (flow rate) control to the start of the pressure holding process of the pressure control, the pressure command value corresponding to the pressure command value given to the variable discharge pump 2 is slightly smaller (for example, 3 to 5 kgf / cm 2 ) A high pressure command value is calculated by a controller (not shown) and the electromagnetic proportional pressure control valve 1 is calculated.
7 and the solenoid a of the electromagnetic switching valve 35 is excited.
【００２８】充填工程から保圧工程に移行する瞬間、可
変吐出ポンプ２は、それまで必要流量を得るために傾斜
させていた斜板を、圧力保持に必要な微少流量となるよ
うに立てるが、斜板を立て終るまでの間に必要以上の作
動油を吐出するため、可変吐出ポンプ２に設定された圧
力より大きいサージ圧が発生する。しかし、電磁切換弁
３５のソレノイドａの励磁によって管路８ａに戻り管１
６の下流部１６ｂが連結管３７を介して連絡されている
ので、電磁比例圧力制御弁１７はサージカット弁として
働いてサージ圧を逃がす。なお、充填工程から保圧工程
に移行する瞬間に生じるサージ圧だけを逃がすのであれ
ば、サージ圧の発生後、それまで高くされていた圧力設
定値を保圧工程が終了しないうちに元に戻し、また電磁
切換弁３５のソレノイドａを消磁してもよいが、通常
は、保圧工程が終了する迄、上記の状態を保持し、射出
工程中に生じる他のサージ圧も逃がす。At the moment when the process shifts from the filling process to the pressure-holding process, the variable discharge pump 2 raises the swash plate, which has been inclined to obtain the required flow rate, so that the swash plate has a small flow rate required for maintaining the pressure. Unnecessary hydraulic oil is discharged until the swash plate is completely raised, and a surge pressure greater than the pressure set in the variable discharge pump 2 is generated. However, when the solenoid a of the electromagnetic switching valve 35 is excited, the return to the pipe 8a
Since the downstream portion 16b of the valve 6 is connected via the connecting pipe 37, the electromagnetic proportional pressure control valve 17 functions as a surge cut valve to release the surge pressure. If only the surge pressure generated at the moment of shifting from the filling process to the pressure holding process is released, after the surge pressure is generated, the pressure set value that had been raised up to that point must be restored before the pressure holding process ends. The solenoid a of the electromagnetic switching valve 35 may be demagnetized. However, usually, the above state is maintained until the pressure holding step is completed, and other surge pressure generated during the injection step is released.
【００２９】射出成形に関係なくスクリュ１２を後退さ
せる必要が生じた場合は、図の状態から電磁切換弁１４
のソレノイドｂを励磁する。これにより、作動油が管路
８ｂを通って油圧シリンダ７の後退側シリンダ室７ｂに
供給されるので、油圧シリンダ７は伸長してスクリュ１
２を後退させる。If it becomes necessary to retract the screw 12 irrespective of the injection molding, the electromagnetic switching valve 14 is switched from the state shown in FIG.
Is excited. As a result, the hydraulic oil is supplied to the retreating cylinder chamber 7b of the hydraulic cylinder 7 through the pipeline 8b, so that the hydraulic cylinder 7 extends to
2 is retracted.
【００３０】電磁切換弁１５のいずれかのソレノイド
ａ，ｂを励磁すると、油圧モータ（アクチュエータ）９
が作動して負荷２３を動かし、アクチュエータ９を作動
させた作動油は戻り管２０の上流部２０ａと戻り管４０
を通って油タンク２２に戻る。負荷２３が円滑な制御を
阻害する慣性を持つような場合は、電磁切換弁３６のソ
レノイドｂを励磁して電磁比例圧力制御弁１７に作動油
が流れるようにする。この状態では、電磁比例圧力制御
弁１７はカウンターバランス弁として働き、任意の設定
圧力となるように作動油を絞って油タンク２２に流し、
負荷２３の動きに制動をかける。このため負荷２３を円
滑に制御できるようになる。When one of the solenoids a and b of the electromagnetic switching valve 15 is excited, the hydraulic motor (actuator) 9
Operates to move the load 23 and actuate the actuator 9 so that the operating oil flows upstream of the return pipe 20 and the return pipe 40.
And returns to the oil tank 22. When the load 23 has inertia that impedes smooth control, the solenoid b of the electromagnetic switching valve 36 is excited to allow the hydraulic oil to flow through the electromagnetic proportional pressure control valve 17. In this state, the electromagnetic proportional pressure control valve 17 functions as a counterbalance valve, squeezes the working oil to an arbitrary set pressure, and flows the oil to the oil tank 22,
The movement of the load 23 is braked. Therefore, the load 23 can be controlled smoothly.
【００３１】なお、電磁比例圧力制御弁１７は、コント
ローラにより任意に圧力設定できるので、慣性負荷回転
の、加速時、定常時、減速時等、動作過程を細分して各
々最良の圧力を設定し、負荷の動特性を向上することが
できる。Since the pressure of the electromagnetic proportional pressure control valve 17 can be arbitrarily set by the controller, the operation process of the inertial load rotation, such as acceleration, steady state, and deceleration, is subdivided to set the best pressure. Thus, the dynamic characteristics of the load can be improved.
【００３２】電磁切換弁３６のソレノイドａを励磁した
場合、電磁比例圧力制御弁１７は、定吐出ポンプ３から
吐出された作動油をアクチュエータ２５，２６，２７に
供給する管路２８のリリーフ弁として機能する。When the solenoid a of the electromagnetic switching valve 36 is excited, the electromagnetic proportional pressure control valve 17 serves as a relief valve for the pipe 28 that supplies the hydraulic oil discharged from the constant discharge pump 3 to the actuators 25, 26, 27. Function.
【００３３】なお、サージ圧は、定吐出ポンプを使用し
た油圧回路においても生じるので（但し、可変吐出ポン
プの場合よりも小さいのが普通である。）、本発明は定
吐出ポンプを使用した油圧回路にも適用することができ
る。また、アクチュエータ９，２５，２６，２７の戻り
管２０，３９の数は、２本に限られるものではなく、１
本（戻り管２０或いは戻り管３９だけの場合）、或いは
３本以上でも本発明を実施することができる。各管路や
各戻り管等の構成、及び各電磁切換弁の種類や構造等は
図のものに限られるものではなく、また、電磁切換弁３
５，３６を一つに纒めるなど、種々の変形が可能であ
る。Since the surge pressure also occurs in a hydraulic circuit using a constant discharge pump (however, it is usually smaller than that in the case of a variable discharge pump), the present invention provides a hydraulic pressure using a constant discharge pump. It can also be applied to circuits. Further, the number of return pipes 20, 39 of the actuators 9, 25, 26, 27 is not limited to two, but may be one.
The present invention can be practiced with a book (in the case of only the return pipe 20 or the return pipe 39), or with three or more pipes. The configuration of each conduit and each return pipe, and the type and structure of each electromagnetic switching valve are not limited to those shown in the drawings.
Various modifications are possible, such as combining 5 and 36 into one.
【００３４】[0034]
【発明の効果】以上説明したように、請求項１に係る射
出成形機の油圧回路は、油圧源に、加熱シリンダに挿入
されたスクリュを周方向に回転させる油圧モータと、上
記スクリュを軸方向に移動させる油圧シリンダ、及び他
の１以上のアクチュエータが管路によって接続され、上
記油圧モータの作動で上記スクリュを回転させながら後
退させて樹脂を計量する際に上記油圧シリンダの前進側
シリンダ室の作動油を油タンクに戻す第１戻り管に、上
記スクリュの後退移動に背圧をかける電磁比例圧力制御
弁が設けられた射出成形機の油圧回路において、上記他
のアクチュエータの作動油を油タンクに戻す少なくとも
１本の第２戻り管が、上記第１戻り管の上記電磁比例圧
力制御弁の上流側に接続され、上記第１戻り管と上記第
２戻り管にはそれらの戻り管を開閉する電磁切換弁が設
けられた構成とされているので、一つの電磁比例圧力制
御弁を油圧モータとアクチュエータの作動目的に応じ、
背圧弁、カウンターバランス弁、或いはリリーフ弁など
として多目的に使用することができ、油圧回路の全体構
成を簡単にすることができる。As described above, the hydraulic circuit of the injection molding machine according to the first aspect of the present invention comprises a hydraulic source for rotating a screw inserted into a heating cylinder in a circumferential direction, and a hydraulic motor for rotating the screw in an axial direction. The hydraulic cylinder and the other one or more actuators are connected by a pipe line, and when the resin is measured by rotating the screw backward by operating the hydraulic motor to measure the resin, the hydraulic cylinder moves forward in the forward cylinder chamber of the hydraulic cylinder. In a hydraulic circuit of an injection molding machine in which a first return pipe for returning hydraulic oil to an oil tank is provided with an electromagnetic proportional pressure control valve for applying a back pressure to the backward movement of the screw, the hydraulic oil of the other actuator is supplied to an oil tank. At least one second return pipe is connected to the first return pipe upstream of the electromagnetic proportional pressure control valve, and is connected to the first return pipe and the second return pipe. Since the electromagnetic switching valve for opening and closing the return pipe is configured provided, according to one of the electromagnetic proportional pressure control valve actuation purposes of the hydraulic motor and the actuator,
It can be used for multiple purposes as a back pressure valve, a counterbalance valve, a relief valve, or the like, and can simplify the entire configuration of the hydraulic circuit.
【００３５】また、請求項２に係る射出成形機の油圧回
路は、油圧源に、加熱シリンダに挿入されたスクリュを
周方向に回転させる油圧モータと、上記スクリュを軸方
向に移動させる油圧シリンダが管路によって接続され、
上記油圧モータの作動で上記スクリュを回転させながら
後退させて樹脂を計量する際に上記油圧シリンダの前進
側シリンダ室の作動油を油タンクに戻す戻り管に、上記
スクリュの後退移動に背圧をかける電磁比例圧力制御弁
が設けられた射出成形機の油圧回路において、上記戻り
管には、上記油圧モータの作動で上記スクリュを回転さ
せながら後退させて樹脂を計量する際に戻り管を第１位
置において油タンクに連通させ、また上記スクリュを前
進させて加熱シリンダから樹脂を射出する際に油圧源の
作動油を油圧シリンダの前進側シリンダ室に供給する管
路に上記電磁比例圧力制御弁を第２位置において連結管
を介して連絡する電磁切換弁が設けられた構成とされて
いるので、電磁比例圧力制御弁を背圧弁のほか、サージ
カット弁として機能させることができ、この場合も油圧
回路の全体構造を簡単にすることができる。またサージ
圧を除いて保圧力を精度よく制御できるので、良好な成
形品を得ることができる。According to a second aspect of the present invention, the hydraulic circuit of the injection molding machine includes a hydraulic motor for rotating a screw inserted into the heating cylinder in a circumferential direction and a hydraulic cylinder for moving the screw in an axial direction. Connected by conduit,
When the resin is measured by retracting while rotating the screw by the operation of the hydraulic motor, the back pressure is applied to the return pipe for returning the hydraulic oil in the forward-side cylinder chamber of the hydraulic cylinder to the oil tank when the screw is retracted. In the hydraulic circuit of an injection molding machine provided with an electromagnetic proportional pressure control valve to be applied, the return pipe is provided with a first return pipe when the resin is measured while the screw is rotated by the operation of the hydraulic motor to retreat while the resin is being measured. In the position, the electromagnetic proportional pressure control valve is connected to a line for supplying hydraulic oil of a hydraulic pressure source to a forward cylinder chamber of the hydraulic cylinder when the resin is injected from the heating cylinder by advancing the screw and injecting the resin from the heating cylinder. The electromagnetic proportional pressure control valve is configured as a surge cut-off valve in addition to the back pressure valve because the electromagnetic switching valve communicating via the connecting pipe at the second position is provided. Is to be able, it is possible to simplify the overall structure of the hydraulic circuit also in this case. In addition, since the holding pressure can be accurately controlled except for the surge pressure, a good molded product can be obtained.
【図１】 本発明に係る射出成形機の油圧回路の一実施
例を示す図である。FIG. 1 is a view showing one embodiment of a hydraulic circuit of an injection molding machine according to the present invention.
【図２】 従来の射出成形機の油圧回路の図である。FIG. 2 is a diagram of a hydraulic circuit of a conventional injection molding machine.
１ 油圧源 ２ 可変吐出ポンプ ３ 定吐出ポンプ ６ 油圧モータ ７ 油圧シリンダ ７ａ 前進側シリンダ室 ７ｂ 後退側シリンダ室 ８，８ａ，８ｂ 管路 ９ 油圧モータ（アクチュエータ） １０ 管路 １１ 加熱シリンダ １２ スクリュ １６ 戻り管 １６ａ 上流部 １６ｂ 下流部 １７ 電磁比例圧力制御弁 ２０ 戻り管 ２０ａ 上流部 ２０ｂ 下流部 ２２ 油タンク ２５，２６，２７ アクチュエータ ３５，３６ 電磁切換弁 ３７ 連結管 ３８，３９，４０ 戻り管 DESCRIPTION OF SYMBOLS 1 Hydraulic power source 2 Variable discharge pump 3 Constant discharge pump 6 Hydraulic motor 7 Hydraulic cylinder 7a Forward cylinder chamber 7b Retract cylinder chamber 8, 8a, 8b Pipe 9 Hydraulic motor (actuator) 10 Pipe 11 Heating cylinder 12 Screw 16 Return Pipe 16a Upstream section 16b Downstream section 17 Electromagnetic proportional pressure control valve 20 Return pipe 20a Upstream section 20b Downstream section 22 Oil tank 25, 26, 27 Actuator 35, 36 Electromagnetic switching valve 37 Connecting pipe 38, 39, 40 Return pipe
───────────────────────────────────────────────────── フロントページの続き (58)調査した分野(Int.Cl.6，ＤＢ名) B29C 45/46 - 45/50 B29C 45/82 ──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. 6 , DB name) B29C 45/46-45/50 B29C 45/82
Claims (4)
クリュを周方向に回転させる油圧モータと、上記スクリ
ュを軸方向に移動させる油圧シリンダ、及び他の１以上
のアクチュエータが管路によって接続され、上記油圧モ
ータの作動で上記スクリュを回転させながら後退させて
樹脂を計量する際に上記油圧シリンダの前進側シリンダ
室の作動油を油タンクに戻す第１戻り管に、上記スクリ
ュの後退移動に背圧をかける電磁比例圧力制御弁が設け
られた射出成形機の油圧回路において、上記他のアクチ
ュエータの作動油を油タンクに戻す少なくとも１本の第
２戻り管が、上記第１戻り管の上記電磁比例圧力制御弁
の上流側に接続され、上記第１戻り管と上記第２戻り管
にはそれらの戻り管を開閉する電磁切換弁が設けられた
ことを特徴とする射出成形機の油圧回路。A hydraulic motor for rotating a screw inserted into a heating cylinder in a circumferential direction, a hydraulic cylinder for moving the screw in an axial direction, and one or more other actuators are connected to a hydraulic source via a pipeline. When the resin is measured by moving the screw backward while rotating the screw by the operation of the hydraulic motor, the first return pipe for returning the hydraulic oil in the forward-side cylinder chamber of the hydraulic cylinder to the oil tank when the screw is moved backward. In a hydraulic circuit of an injection molding machine provided with an electromagnetic proportional pressure control valve for applying a back pressure, at least one second return pipe for returning hydraulic oil of the other actuator to an oil tank is provided in the first return pipe. An electromagnetic switching valve connected to the upstream side of the electromagnetic proportional pressure control valve, wherein the first return pipe and the second return pipe are provided with an electromagnetic switching valve for opening and closing the return pipes. Hydraulic circuit of the forming machine.
クリュを周方向に回転させる油圧モータと、上記スクリ
ュを軸方向に移動させる油圧シリンダが管路によって接
続され、上記油圧モータの作動で上記スクリュを回転さ
せながら後退させて樹脂を計量する際に上記油圧シリン
ダの前進側シリンダ室の作動油を油タンクに戻す戻り管
に、上記スクリュの後退移動に背圧をかける電磁比例圧
力制御弁が設けられた射出成形機の油圧回路において、
上記戻り管には、上記油圧モータの作動で上記スクリュ
を回転させながら後退させて樹脂を計量する際に戻り管
を第１位置において油タンクに連通させ、また上記スク
リュを前進させて加熱シリンダから樹脂を射出する際に
油圧源の作動油を油圧シリンダの前進側シリンダ室に供
給する管路に上記電磁比例圧力制御弁を第２位置におい
て連結管を介して連絡する電磁切換弁が設けられたこと
を特徴とする射出成形機の油圧回路。2. A hydraulic motor for rotating a screw inserted into a heating cylinder in a circumferential direction and a hydraulic cylinder for moving the screw in an axial direction are connected to a hydraulic source by a pipeline, and the hydraulic motor operates when the hydraulic motor operates. An electromagnetic proportional pressure control valve that applies back pressure to the backward movement of the screw is located on the return pipe that returns the hydraulic oil in the forward cylinder chamber of the hydraulic cylinder to the oil tank when the resin is measured by moving backward while rotating the screw. In the hydraulic circuit of the provided injection molding machine,
When returning the resin to the return pipe while rotating the screw by the operation of the hydraulic motor to measure the resin, the return pipe is communicated with the oil tank at the first position, and the screw is advanced to move the screw from the heating cylinder. An electromagnetic switching valve for communicating the above-mentioned electromagnetic proportional pressure control valve at a second position via a connecting pipe is provided in a pipeline for supplying hydraulic oil of a hydraulic source to a forward cylinder chamber of a hydraulic cylinder when injecting resin. A hydraulic circuit for an injection molding machine, characterized in that:
記第２戻り管に設けられた電磁切換弁はそれらの戻り管
を択一的に開閉する構成とされたことを特徴とする請求
項１記載の射出成形機の油圧回路。3. A return pipe is provided in parallel with the second return pipe, and an electromagnetic switching valve provided on the second return pipe is configured to selectively open or close the return pipe. The hydraulic circuit of an injection molding machine according to claim 1, wherein
に他の戻り管が並設され、上記電磁比例圧力制御弁の戻
り管に設けられた電磁切換弁はそれらの戻り管を択一的
に開閉する構成とされたことを特徴とする請求項１又は
２記載の射出成形機の油圧回路。4. A return pipe provided with an electromagnetic proportional pressure control valve is provided with another return pipe in parallel, and an electromagnetic switching valve provided on a return pipe of the electromagnetic proportional pressure control valve selects one of the return pipes. The hydraulic circuit for an injection molding machine according to claim 1, wherein the hydraulic circuit is configured to be opened and closed in a dynamic manner.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5769495A JP2924697B2 (en) | 1995-03-16 | 1995-03-16 | Hydraulic circuit of injection molding machine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5769495A JP2924697B2 (en) | 1995-03-16 | 1995-03-16 | Hydraulic circuit of injection molding machine |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH08252846A JPH08252846A (en) | 1996-10-01 |
| JP2924697B2 true JP2924697B2 (en) | 1999-07-26 |
Family
ID=13063060
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5769495A Expired - Fee Related JP2924697B2 (en) | 1995-03-16 | 1995-03-16 | Hydraulic circuit of injection molding machine |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2924697B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3386419B2 (en) * | 1999-09-22 | 2003-03-17 | 日精樹脂工業株式会社 | Electric injection device |
| CN114001059A (en) * | 2021-08-25 | 2022-02-01 | 海天塑机集团有限公司 | V-shaped injection hydraulic oil way of injection molding machine |
-
1995
- 1995-03-16 JP JP5769495A patent/JP2924697B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH08252846A (en) | 1996-10-01 |
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