JPH0280801A - Hydraulic actuator type speed control device and injection molding machine - Google Patents
Hydraulic actuator type speed control device and injection molding machineInfo
- Publication number
- JPH0280801A JPH0280801A JP23296488A JP23296488A JPH0280801A JP H0280801 A JPH0280801 A JP H0280801A JP 23296488 A JP23296488 A JP 23296488A JP 23296488 A JP23296488 A JP 23296488A JP H0280801 A JPH0280801 A JP H0280801A
- Authority
- JP
- Japan
- Prior art keywords
- speed
- compensation
- hydraulic actuator
- signal
- pressure
- 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.)
- Pending
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- 238000001746 injection moulding Methods 0.000 title claims description 15
- 238000001514 detection method Methods 0.000 claims description 24
- 238000002347 injection Methods 0.000 claims description 19
- 239000007924 injection Substances 0.000 claims description 19
- 230000004043 responsiveness Effects 0.000 abstract description 11
- 230000007423 decrease Effects 0.000 abstract description 2
- 238000010586 diagram Methods 0.000 description 9
- 238000000034 method Methods 0.000 description 6
- 230000004044 response Effects 0.000 description 5
- 230000008569 process Effects 0.000 description 4
- 230000008901 benefit Effects 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 238000006073 displacement reaction Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 238000000465 moulding Methods 0.000 description 2
- 229920005989 resin Polymers 0.000 description 2
- 239000011347 resin Substances 0.000 description 2
- 230000003321 amplification Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 229920005992 thermoplastic resin Polymers 0.000 description 1
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- Fluid-Pressure Circuits (AREA)
- Injection Moulding Of Plastics Or The Like (AREA)
Abstract
Description
【発明の詳細な説明】
〈産業上の利用分野〉
本発明は、速度検出器から出力さイルる油圧アクチュエ
ータの速度検出信号と目標速度値信号との偏差を求め、
この偏差に補償を施した制御信号を上記油圧アクチュエ
ータの圧力ラインに介設した比例式流量方向制御弁に出
力する油圧アクチュエータの速度制御装置および射出成
形機に関する。[Detailed Description of the Invention] <Industrial Application Field> The present invention calculates the deviation between a speed detection signal of a hydraulic actuator outputted from a speed detector and a target speed value signal,
The present invention relates to a hydraulic actuator speed control device and an injection molding machine that output a control signal compensated for this deviation to a proportional flow rate directional control valve provided in the pressure line of the hydraulic actuator.
〈従来の技術〉
従来、この種の油圧アクチュエータの速度制御装置とし
て、例えば第７図に示すようなものが知られている。こ
の速度制御装置は、油圧源３１から油圧シリンダ３２に
至る圧力ライン３３にサーボ弁３４と圧力計３５を介設
するとともに、負荷３６を固定したピストンロット３２
ａの作動速度を検出する速度検出器３７を設け、比較器
３８で目標速度値信号と上記速度検出器３７からの速度
検出信号との偏差を求め、この偏差信号を比例ゲイン等
の補償値が固定されたコントローラ３９に入力して補償
を施し、制御信号として上記サーボ弁３４に出力するも
のである。<Prior Art> Conventionally, as a speed control device for a hydraulic actuator of this type, one shown in FIG. 7, for example, is known. This speed control device includes a servo valve 34 and a pressure gauge 35 interposed in a pressure line 33 extending from a hydraulic source 31 to a hydraulic cylinder 32, and a piston rod 32 to which a load 36 is fixed.
A speed detector 37 is provided to detect the operating speed of a, a comparator 38 calculates the deviation between the target speed value signal and the speed detection signal from the speed detector 37, and this deviation signal is converted into a compensation value such as a proportional gain. The signal is inputted to a fixed controller 39, subjected to compensation, and outputted to the servo valve 34 as a control signal.
〈発明が解決しようとする課題〉
ところで、上記従来例のようにメータイン方式で油圧シ
リンダ３２の作動速度をグローズドループ制御する場合
、一般に制御系の特性が負荷３６の大小によって大きく
変化する。しかるに、上記従来の速度制御装置では、コ
ントローラ３９の補償値が一定値に固定されているため
、この補償値を負荷３６の変動に対応して変更できず、
広い負荷範囲に亘って良好な応答性、安定性等の制御性
能を得るのが難しいという問題がある。例えば、上記コ
ントローラ３９の補償値を高負荷圧力時に良好な応答性
が得られるように設定した場合、第８図に示すように、
油圧シリンダの作動速度は、高負荷圧力時には曲線Ａの
如く振動を殆んど伴わぬ一定高レベルを呈するが、負荷
圧力が曲線りの如く低下すると、曲線Ｂの如（−足代レ
ベルの上下に大きく振動し、制御性能が著しく悪化する
ことが判る。そして、このような制御性能の悪化は、負
荷圧力が低い限り、目標速度が曲線Ｅの如く５０％に上
昇しても、曲線Ｃの如くあまり改善されない。<Problems to be Solved by the Invention> Incidentally, when the operating speed of the hydraulic cylinder 32 is controlled in a meter-in manner in a closed loop as in the conventional example described above, the characteristics of the control system generally vary greatly depending on the magnitude of the load 36. However, in the conventional speed control device described above, since the compensation value of the controller 39 is fixed to a constant value, this compensation value cannot be changed in response to fluctuations in the load 36.
There is a problem in that it is difficult to obtain control performance such as good response and stability over a wide load range. For example, if the compensation value of the controller 39 is set so as to obtain good responsiveness at high load pressure, as shown in FIG.
The operating speed of a hydraulic cylinder exhibits a constant high level with almost no vibration as shown by curve A when the load pressure is high, but when the load pressure decreases in a curved manner, the operating speed changes as shown in curve B (- above and below the leg allowance level). It can be seen that the control performance deteriorates significantly due to large vibrations.As long as the load pressure is low, even if the target speed increases to 50% as shown in curve E, the control performance deteriorates significantly as shown in curve C. Not much improvement.
そこで、本発明の目的は、目標速度値信号と速度検出信
号の偏差に補償を施して制御弁に制御信号を出力するコ
ントローラ等の補償手段の補償値を、負荷圧力に応じて
適切に変化させることにより、広い負荷範囲に亘って良
好な応答性、安定性等の制御性能を得ることができる油
圧アクチュエータの速度制御装置および射出成形機を提
供することである。Therefore, an object of the present invention is to appropriately change the compensation value of a compensation means such as a controller that compensates for the deviation between the target speed value signal and the speed detection signal and outputs the control signal to the control valve in accordance with the load pressure. Accordingly, it is an object of the present invention to provide a speed control device for a hydraulic actuator and an injection molding machine that can obtain control performance such as good response and stability over a wide load range.
く課題を解決するための手段〉
上記目的を達成するため、本発明の油圧アクチュエータ
の速度制御装置は、第１図、第３図に例示するように、
速度検出器３をもつ油圧アクチュエータｌと、この油圧
アクチュエータ１の圧力ラインに介設した比例式流量方
向制御弁２と、上記速度検出器３からの作動速度信号と
目標速度値から作成される制御信号に補償を施して、補
償済制御信号を上記比例式＋１ｉ？Ｅ量方向制御弁２に
出力する補償手段５．８を有するものにおいて、上記油
圧アクチュエータ１の圧力ラインに介設されて負荷圧力
ＰＱを検出する圧力検出器６と、この圧力検出器６から
の検出信号に基づいて、負荷圧力Ｐｅが低いほど上記補
償手段５．８の遅れ要素が大きくなるように上記補償手
段５．８の補償値を変更させる補償値変更手段７．８を
備えたことを特徴とする。Means for Solving the Problems> In order to achieve the above object, the speed control device for a hydraulic actuator of the present invention has the following features as illustrated in FIGS. 1 and 3:
A hydraulic actuator l having a speed detector 3, a proportional flow rate directional control valve 2 interposed in the pressure line of the hydraulic actuator 1, and control created from the operating speed signal from the speed detector 3 and the target speed value. Compensate the signal and convert the compensated control signal into the above proportional equation +1i? In the one having a compensating means 5.8 for outputting an output to the E amount directional control valve 2, there is a pressure detector 6 interposed in the pressure line of the hydraulic actuator 1 to detect the load pressure PQ, and a pressure detector 6 for detecting the load pressure PQ. Compensation value changing means 7.8 is provided for changing the compensation value of the compensation means 5.8 so that the lower the load pressure Pe, the larger the delay element of the compensation means 5.8 based on the detection signal. Features.
また、第５図に例示するように、上記油圧アクチュエー
タを射出シリンダ１１とし、この射出シリンダ１１に同
様の圧力検出器１６と補償値変更手段１７を備えた速度
制御装置を適用して、射出成形機を構成することができ
る。Further, as illustrated in FIG. 5, the hydraulic actuator is an injection cylinder 11, and a speed control device equipped with a similar pressure detector 16 and compensation value changing means 17 is applied to the injection cylinder 11 to perform injection molding. machine can be configured.
く作用〉
油圧アクチュエータ１の負荷が大きい場合、圧力検出器
６から補償値変更手段７．８に高負荷圧力を表わす検出
信号が入力される。そうすると、補償値変更手段７．８
は、補償手段５．８の補償値をその遅れ要素が小さくな
るように変化させる。Effect> When the load on the hydraulic actuator 1 is large, a detection signal representing the high load pressure is input from the pressure detector 6 to the compensation value changing means 7.8. Then, compensation value changing means 7.8
changes the compensation value of the compensation means 5.8 so that its delay element becomes smaller.
油圧アクチュエータｌの速度検出器３からの作動速度信
号を例えば目標速度値信号から減算して作られる制御信
号（偏差信号）は、上記補償手段５゜８によって上記補
償値で補償を施されて、補償済制御信号として比例式流
量方向制御弁２に出力される。すると、高負荷を受けて
作動する油圧アクチュエータｌの速度は、上記比例式流
量方向制御弁２により遅れ要素が小さくなるように制御
されるので、制御系の目標速度値に対する応答性が向上
する。The control signal (deviation signal) generated by subtracting the operating speed signal from the speed detector 3 of the hydraulic actuator l from, for example, the target speed value signal is compensated by the compensation value by the compensation means 5.8, It is output to the proportional flow direction control valve 2 as a compensated control signal. Then, the speed of the hydraulic actuator 1, which operates under high load, is controlled by the proportional flow rate directional control valve 2 so that the delay element becomes small, so that the responsiveness of the control system to the target speed value is improved.
一方、油圧アクチュエータＩの負荷が小さい場合、」−
述と同様の手順で補償手段５，８の補償値は、その遅れ
要素が大きくなるように変更せしめられる。従って、低
負荷を受けて作動する浦圧アクチコエータ１の速度は、
遅れ要素が大きくなるように制御されるので、制御系に
は大きな振動が生しず、安定性が向上する。On the other hand, when the load on hydraulic actuator I is small,
In the same manner as described above, the compensation values of the compensation means 5 and 8 are changed so that the delay element becomes larger. Therefore, the speed of the pressure acticoator 1 operating under low load is:
Since the delay element is controlled to be large, large vibrations do not occur in the control system, improving stability.
〈実施例〉 以下、本発明を図示の実施例により詳細に説明する。<Example> Hereinafter, the present invention will be explained in detail with reference to illustrated embodiments.
第１図は油圧アクチュエータのアナログ式速度制御装置
の一例を示すブロック図であり、油圧アクチュエータｌ
は、その図示しない圧力ラインに介設された比例式流量
方向制御弁たるサーボ弁２によって制御される。即ち、
」−記油圧アクヂュエータｌの作動速度を検出する速度
検出器３からの速度検出信号は、比較器４で目標速度値
信号との偏差が求められ、この偏差信号は、ゲイン値等
の補償値を変更しうる補償手段たる補償回路５で補償を
施されて、補償済制御信号（電流信号）として上記サー
ボ弁２のソレノイドに出力される。FIG. 1 is a block diagram showing an example of an analog speed control device for a hydraulic actuator.
is controlled by a servo valve 2, which is a proportional flow rate directional control valve, installed in the pressure line (not shown). That is,
The speed detection signal from the speed detector 3 that detects the operating speed of the hydraulic actuator l is used to determine the deviation from the target speed value signal in the comparator 4, and this deviation signal is used to calculate the compensation value such as the gain value. The signal is compensated by a compensation circuit 5, which is a variable compensation means, and outputted to the solenoid of the servo valve 2 as a compensated control signal (current signal).
一方、上記油圧アクチュエータ１の圧力ラインには、負
荷圧力ＰＱを検出する圧カセンザ６を設け、この圧力セ
ンサ６の検出信号を、上記補償回路５の補償値を変更さ
せる補償値変更手段たる補償値切換用比較器７に入力し
ている。上記補償値切換用比較器７は、第２図に示すよ
うに、入力される検出信号が表わず負荷圧力ＰＱと比較
ずべきに個の圧力基準値Ｐｉ（１≦ｉ≦に：Ｐ、＞Ｐ２
＞−Ｐｋ）を有し、負荷圧力ＰＱとこれらの圧力基準値
の大小を比較判別して、ＰＱがＰｉ＋、≧Ｐ（ｉ＞Ｐｉ
であるとき、補償回路５の補償値をＧ ｃｉ（但し、Ｉ
）Ｑ≦ＰｋのときはＧ ｃｏ）に設定し、上記補償値Ｇ
ｃｉは、ｉが大きくなるほど即ちＰρが低くなるほど補
償回路５の遅れ要素が大きくなるようになっている。On the other hand, the pressure line of the hydraulic actuator 1 is provided with a pressure sensor 6 for detecting the load pressure PQ, and the detection signal of the pressure sensor 6 is used as a compensation value changing means for changing the compensation value of the compensation circuit 5. It is input to the switching comparator 7. As shown in FIG. 2, the compensation value switching comparator 7 does not display the input detection signal and compares it with the load pressure PQ. >P2
>-Pk), and by comparing and determining the magnitude of the load pressure PQ and these pressure reference values, it is determined that PQ is Pi+, ≧P(i>Pi
, the compensation value of the compensation circuit 5 is G ci (however, I
) When Q≦Pk, set G co) and set the above compensation value G.
ci is such that the larger i is, that is, the lower Pρ is, the larger the delay element of the compensation circuit 5 is.
第３図は油圧アクチュエータのデジタル式速度制御装置
の一例を示すブロック図である。この速度制御装置は、
第１図と同じ油圧アクチュエータ１、サーボ弁２．速度
検出器３．圧力センザ６を備えるとともに、目標速度値
信号と速度検出信号との偏差を求める比較器８ａと、内
蔵の補償値変更手段によって補償値が変更せしめられ、
上記比較器８ａからの偏差信号に補償を施す補償手段と
してのマイクロプロセッサ８ｂからなる制御装置８を備
える。上記マイクロプロセッサ８ｂは、上記偏差信号や
圧力センサ６からの検出信号をデジタル信号に変換する
図示しないＡ／Ｄ変換器、演算プログラムやデータを記
憶するメモリ、データを演算処理するＣＰＵ、演算結果
をＤ／Ａ変換し増幅して出力するＤ／Ａ変換器からなる
。そして、上記ＣＰＵは、圧カセンザ６からの検出信号
の大小に対応して補償値が適宜変化する演算式に従って
、入力データたる上記偏差信号を演算処理し、上記検出
信号が小さい即ち負荷圧力ＰＱが低いほど遅れ要素が大
きくなるような補償済制御信号をサーボ弁２のソレノイ
ドに出力するようになっている。なお、上記演算式は、
マイクロプロセッサのメモリにソフトウェアたる演算プ
ログラムとして記憶されている。FIG. 3 is a block diagram showing an example of a digital speed control device for a hydraulic actuator. This speed control device is
Hydraulic actuator 1 and servo valve 2 as in Fig. 1. Speed detector 3. It is equipped with a pressure sensor 6, a comparator 8a for determining the deviation between the target speed value signal and the speed detection signal, and a built-in compensation value changing means to change the compensation value.
A control device 8 comprising a microprocessor 8b is provided as compensating means for compensating the deviation signal from the comparator 8a. The microprocessor 8b includes an A/D converter (not shown) that converts the deviation signal and the detection signal from the pressure sensor 6 into digital signals, a memory that stores calculation programs and data, a CPU that processes the data, and a CPU that processes the calculation results. It consists of a D/A converter that performs D/A conversion, amplification, and output. Then, the CPU processes the deviation signal, which is input data, according to an arithmetic expression in which the compensation value changes appropriately in accordance with the magnitude of the detection signal from the pressure sensor 6. A compensated control signal is output to the solenoid of the servo valve 2 such that the lower the delay element, the greater the delay element. In addition, the above calculation formula is
It is stored in the memory of the microprocessor as a software calculation program.
第４図は、上記演算プログラムによる演算処理の流れの
概要を示しており、速度制御中は図示の処理ループが所
定時間間隔で繰り返される。即ち、ステップＳ１で目標
速度値信号、速度検出信号および負荷圧力信号が読み込
まれ、ステップＳ２で比較器８ａを介して目標速度値信
号から速度検出信号が減算されて偏差信号が求められる
。次いで、ステップＳ３で負荷圧力の変動による圧油の
圧縮量誤差を負荷圧力の差分を用いて補正して、上記偏
差信号に圧縮性補償を施し、さらにステップＳ４で負荷
圧力と流量間の非線型成分を補正して、上記偏差信号に
圧力−流量特性の補償を施し、最後にステップＳ５で上
記偏差信号に制御系の応答性や安定性を考慮した動特性
の補償を施した後、ステップＳ６で補償済制御信号をサ
ーボ弁２へ出力する。なお、上記動特性の補償が、予め
メモリに記憶され、演算プログラムによって負荷圧力に
応じて適宜選ばれた補償値を有する演算式で行なわれる
のは既に述べたとおりである。FIG. 4 shows an outline of the flow of arithmetic processing by the arithmetic program, and the illustrated processing loop is repeated at predetermined time intervals during speed control. That is, in step S1, the target speed value signal, speed detection signal, and load pressure signal are read, and in step S2, the speed detection signal is subtracted from the target speed value signal via the comparator 8a to obtain a deviation signal. Next, in step S3, an error in the compression amount of pressure oil due to fluctuations in load pressure is corrected using the difference in load pressure, compressibility compensation is applied to the deviation signal, and further, in step S4, nonlinearity between load pressure and flow rate is corrected. The components are corrected, and the pressure-flow characteristics are compensated for the deviation signal.Finally, in step S5, the deviation signal is compensated for the dynamic characteristics in consideration of the responsiveness and stability of the control system, and then in step S6. outputs a compensated control signal to the servo valve 2. As described above, the compensation of the dynamic characteristics is performed using an arithmetic expression that is stored in advance in the memory and has a compensation value that is appropriately selected according to the load pressure by the arithmetic program.
」二対構成のアナログ式速度制御装置（第１図参照）お
よびデジタル式速度制御装置（第３図参照）の制御動作
について次に述へる。The control operations of the two-pair analog speed control device (see FIG. 1) and the digital speed control device (see FIG. 3) will now be described.
４１３圧アクヂコエータの負荷が大きい場合、圧力セン
サ６から補償値切換用比較器７（第１図参照）またはマ
イクロプロセッサ８ｂ（第３図参照）に高い負荷圧力Ｐ
ｆ２を表わす検出信号が入力される。When the load on the 413-pressure actuator is large, the high load pressure P is sent from the pressure sensor 6 to the compensation value switching comparator 7 (see Figure 1) or the microprocessor 8b (see Figure 3).
A detection signal representing f2 is input.
そうすると、補償値切換用比較器７は、補償回路５の補
償値Ｇｃｉを第２図で既述の手順に従ってその遅れ要素
が小さくなるように設定し、あるいはマイクロプロセッ
サ８ｂは、第４図で既述のようにメモリ内から演算プロ
グラムによって選ばれた最適の補償値を有し、出力制御
信号の遅れ要素が小さくなるような演算式を選定する。Then, the compensation value switching comparator 7 sets the compensation value Gci of the compensation circuit 5 according to the procedure already described in FIG. As described above, an arithmetic expression is selected that has the optimum compensation value selected by the arithmetic program from memory and that reduces the delay element of the output control signal.
かくて、油■アクヂュエータ１の速度検出器３からの速
度検出信号と目標速度値信号（Ｊ、比較器４または８ａ
で減算され、偏差信号となって上記補償回路５またはマ
イクロプロセッサ８ｂに入力される。そして、上記偏差
信号は、補償回路５によって上記補償値Ｇｃｉで補償を
施され、あるいはマイクロプロセッサ８ｂによって第４
図で既述の上記演算式（ステップＳ５参照）を含む一連
の補償を施されて、補償済制御信号としてサーボ弁２に
出力される。Thus, the speed detection signal from the speed detector 3 of the oil actuator 1 and the target speed value signal (J, comparator 4 or 8a
is subtracted by , and becomes a deviation signal, which is input to the compensation circuit 5 or the microprocessor 8b. Then, the deviation signal is compensated by the compensation value Gci by the compensation circuit 5, or by the fourth compensation value Gci by the microprocessor 8b.
It is subjected to a series of compensations including the above-mentioned calculation formula (see step S5) already described in the figure, and is output to the servo valve 2 as a compensated control signal.
すると、高負荷を受けて作動する油圧アクヂコエータの
速度は、上記サーボ弁２により遅れ要素が小さくなるよ
うに制御されるので、制御系の目標速度値に対する応答
性が向上する。Then, the speed of the hydraulic actuator that operates under high load is controlled by the servo valve 2 so that the delay element becomes small, so that the responsiveness of the control system to the target speed value is improved.
一方、油圧アクヂコエータの負荷が小さい場合、低い負
荷圧力ｐＱを表わす検出信号に基づいて、」二連と同様
の手順で補償回路５の補償値Ｇｃｉは、その遅れ要素が
大きくなるように設定され、あるいはマイクロプロセッ
サ８ｂは、出力制御信号の遅れ要素が大きくなるような
最適の補償値を有する演算式を選定する。従って、低負
荷を受けて作動する油圧アクチコエータの速度は、遅れ
要素が大きくなるように制御されるので、制御系には大
きな振動が生じず、安定性が向」二する。On the other hand, when the load on the hydraulic actuator is small, based on the detection signal representing the low load pressure pQ, the compensation value Gci of the compensation circuit 5 is set so that its delay element becomes large, using the same procedure as in the case of "double series". Alternatively, the microprocessor 8b selects an arithmetic expression having an optimal compensation value that increases the delay element of the output control signal. Therefore, the speed of the hydraulic acticoator that operates under low load is controlled so that the delay element becomes large, so that large vibrations do not occur in the control system and stability is improved.
このように、上記いずれの実施例でも、負荷圧力Ｐρの
変動に対応して振動が少ない安定性に優れかつ応答性に
優れた良好な速度制御を実現することができるが、第３
図のデジタル式の実施例は、第１図のアナログ式のもの
に比べて、第４図のステップＳ５に示ず動特性の補償の
みならず、ステップＳ３．Ｓ４に示す一層精密な補償を
行なうので、精度の高い速度制御ができるという利点が
ある。In this way, in any of the above embodiments, it is possible to realize excellent speed control with less vibration, excellent stability, and excellent responsiveness in response to fluctuations in the load pressure Pρ.
Compared to the analog version of FIG. 1, the digital embodiment shown in FIG. Since the more precise compensation shown in S4 is performed, there is an advantage that highly accurate speed control can be performed.
また、種々の補償値を演算プログラムを変えることによ
って任意かつ容易に変更することができるので、複雑な
速度制御もきめ細かく行なうことができ、速度制御装置
としての汎用性に優れるという利点がある。Further, since various compensation values can be arbitrarily and easily changed by changing the calculation program, complex speed control can be performed finely, and there is an advantage that it is excellent in versatility as a speed control device.
第５図は、第１図のアナログ式速度制御装置を射出成形
機に適用しノこ例を示すブロック図である。FIG. 5 is a block diagram showing an example in which the analog speed control device of FIG. 1 is applied to an injection molding machine.
この射出成形機は、スクリコーンヤフトＩＯａを回転駆
動するモータｌＯｂとスクリューンヤフ）・１０ａを軸
方向に往復駆動する射出シリンダ１１を有して、熱可塑
性樹脂粒を撹拌・融解して射出する成形機本体ｌＯと、
油圧源１８から４−記射出ンリンダ１１に至る圧力ライ
ン１つに介設したザーボ弁１２および圧力センサ１６と
、上記射出シリンダ１１の位置を検出するポテンショメ
ータからの検出信号を時間微分して速度検出信号を出力
する速度検出器１３と、比較器１４を経て人力される上
記速度検出信号と目標速度値信号との偏差信号に補償を
施して、補償済制御信号をスイ・ノチ２３を介して上記
サーボ弁１２のソレノイド１２ａに出力する速度用の補
償回路１５と、圧力センサ１６からの検出信号（圧力検
出信号）に応じて上記補償回路１５の補償値を変更させ
る補償値切換用比較器１７を備える。以上の各ブロック
は、そのブロック番号の下一桁が等しい第１図中の各ブ
ロックに対応しており、同一のものである。］二二対射
出成形は、さらに圧力センサ１６からの圧力フィードバ
ック信号とスイッチ２４で選択される目標圧力値または
目標背圧値信号との偏差を求める比較器２１と、この比
較器２１から入力される偏差信号に所定の補償値で補償
を施して、補償済制御信号を上記スイッチ２３を介して
サーボ弁１２に出力する圧力用の補償回路２２を備えて
いる。なお、」―記スイソヂ２３は、便宜」二速度用と
圧力用の補償回路１５，２２のいずれか一方に切り換わ
るように図示したが、両補償回路１５．２２からの出力
信号を所定の比で加え合わせてサーボ弁１２に出力する
こともできる。This injection molding machine has a motor 1Ob that rotationally drives a screen screw IOa and an injection cylinder 11 that drives a screw screw 10a reciprocatingly in the axial direction to agitate and melt thermoplastic resin particles and inject them. A molding machine main body lO,
The speed is detected by time-differentiating the detection signals from the servo valve 12 and the pressure sensor 16, which are interposed in one pressure line from the hydraulic power source 18 to the injection cylinder 11, and the potentiometer that detects the position of the injection cylinder 11. A speed detector 13 that outputs a signal and a comparator 14 manually input the speed detection signal and the target speed value signal. A compensation circuit 15 for speed output to the solenoid 12a of the servo valve 12, and a compensation value switching comparator 17 that changes the compensation value of the compensation circuit 15 in accordance with the detection signal (pressure detection signal) from the pressure sensor 16. Be prepared. Each of the above blocks corresponds to each block in FIG. 1 whose last digit of the block number is the same, and is the same. ] The 22-pair injection molding further includes a comparator 21 for determining the deviation between the pressure feedback signal from the pressure sensor 16 and the target pressure value or target back pressure value signal selected by the switch 24; A pressure compensation circuit 22 is provided for compensating the deviation signal obtained by using a predetermined compensation value and outputting a compensated control signal to the servo valve 12 via the switch 23. Although the switch 23 is shown as being switched to either one of the two-speed and pressure compensation circuits 15 and 22 for convenience, the output signals from both compensation circuits 15 and 22 are adjusted to a predetermined ratio. It is also possible to add them together and output them to the servo valve 12.
射出成形機に適用されノこ」−記構酸のアナログ式速度
制御装置の制御動作は、その構成が第１図の速度制御装
置と殆んど同じであるので、本質的には既述の制御動作
と何ら異ならない。従って、樹脂射出時等にスイッチ２
３を速度用の補償回路１５側に切り換えれば、射出シリ
ング１１の作動速度は、高負荷の場合は遅れ要素が小さ
くなるように、低負荷の場合は遅れ要素が大きくなるよ
うに制御されて、応答性や安定性に問題が生じない。The control operation of the analog speed control device applied to an injection molding machine is essentially the same as the speed control device shown in Figure 1, as its configuration is almost the same as the speed control device shown in Fig. It is no different from the control operation. Therefore, when injecting resin, switch 2
3 to the speed compensation circuit 15 side, the operating speed of the injection spool 11 is controlled so that the delay element becomes small when the load is high, and so that the delay element becomes large when the load is low. , there are no problems with responsiveness or stability.
方、樹脂凝固時等にスイッチ２３を圧力用の補償回路２
２側に切り換えれば、射出シリンダ１１の射出圧力が、
フィードバック制御される。さらに、スイッチ２３によ
り両補償回路１５．２２からの出力信号を所定の比で加
え合わせれば、その比に応じて射出シリング１１の作動
速度が射出圧ツノのフィードバック制御と共に良好な応
答性と安定性でもって制御される。On the other hand, when the resin solidifies, the switch 23 is connected to the pressure compensation circuit 2.
If you switch to the 2nd side, the injection pressure of the injection cylinder 11 will be
Feedback controlled. Furthermore, by adding the output signals from both compensation circuits 15 and 22 at a predetermined ratio using the switch 23, the operating speed of the injection sill 11 can be controlled in accordance with the ratio with good responsiveness and stability as well as feedback control of the injection pressure horn. controlled by it.
第６図は、上記射出成形機の速度制御装置の制御動作の
一例を、目標値、補償回路出力、サーボ弁のスプール変
位、射出シリンダの変位お上び作動速度、負荷圧力の時
間変化で示している。この制御過程は、まず時刻１．で
射出シリング制御を表わすモード信号が出力され始め、
スイッチ２３が速度用の補償回路Ｉ５側へ切り換わって
目標速度値が１００％にセットされ、次に時刻し、でス
イッチ２３が両補償回路１５．２２の出力信号を加え合
わずように切り換わり、目標速度値が２０％に減らされ
るとと６に目標圧力値がセットされる。さらに、時刻ｔ
３で目標速度値が５０％に増やされる。FIG. 6 shows an example of the control operation of the speed control device of the injection molding machine, using time changes in target value, compensation circuit output, servo valve spool displacement, injection cylinder displacement and operating speed, and load pressure. ing. This control process begins at time 1. A mode signal indicating injection Schilling control begins to be output at
The switch 23 is switched to the speed compensation circuit I5 side, and the target speed value is set to 100%. Next, at the time, the switch 23 is switched so that the output signals of both compensation circuits 15 and 22 are not added together. , the target pressure value is set to 6 when the target speed value is reduced to 20%. Furthermore, time t
3, the target speed value is increased to 50%.
そして、負荷圧力は、時刻ｔ１〜Ｌ２間が略２０ｋｇ／
Ｃ７１”と高く、時刻ｔ２〜ｔ３間は略Ｏｋｇ／ｃ１１
２、時刻ｔ３以降は略４ｋｇ／ｃｍ、である。The load pressure is approximately 20 kg/L2 between time t1 and L2.
C71” and approximately Okg/c11 between time t2 and t3
2. After time t3, it is approximately 4 kg/cm.
時刻ｔ、〜Ｌ７間では、速度用の補償回路１５のみが働
き、この補償回路１５の補償値Ｇｃｉは、第２図て述べ
たように負荷圧力ＰＱが高いので補償値切換用比較器１
７によって遅れ要素が小さくなるように設定されるから
、補償済制御信号によってサーボ弁１２を介して制御さ
れる射出シリンダ１１の作動速度は、図中の曲線Ａで示
すように良好な応答性てもって制御される。次に、時刻
ｔ２〜ｔ３間では、圧力用の補償回路２２が所定の補償
値にて働らくとともに、負荷圧力Ｐρが低いので速度用
の補償回路１５の補償値Ｇｃｉは遅れ要素が大きくなる
ように設定されるから、合成された補償済制御信号で制
御される射出シリング１１の作動速度および射出圧力は
、図中の曲線Ｂ、Ｄで示すように振動を生じぬ良好な安
定性でもって制御される。さらに、時刻ｔ３以降では、
負荷圧力Ｐρが同じく低いので上述の時刻し、〜し。間
と同様に図中の曲線Ｃで示すように良好な安定性でもっ
て制御される。Between times t and L7, only the speed compensation circuit 15 operates, and the compensation value Gci of this compensation circuit 15 is the same as that of the compensation value switching comparator 1 because the load pressure PQ is high as described in FIG.
Since the delay element is set to be small by 7, the operating speed of the injection cylinder 11 controlled via the servo valve 12 by the compensated control signal has good responsiveness as shown by curve A in the figure. controlled by Next, between times t2 and t3, the pressure compensation circuit 22 operates at a predetermined compensation value, and since the load pressure Pρ is low, the compensation value Gci of the speed compensation circuit 15 is such that the delay element becomes large. Therefore, the operating speed and injection pressure of the injection spool 11, which are controlled by the synthesized compensated control signal, are controlled with good stability without vibration, as shown by curves B and D in the figure. be done. Furthermore, after time t3,
Since the load pressure Pρ is also low, the above-mentioned times are set. As shown by curve C in the figure, the temperature is controlled with good stability.
このように、本実施例で補償回路１５の補償値を負荷圧
力に応じて変化させることによって実現される制御系の
応答性や安定性などの制御性能の改善は、本実施例を示
す第６図と従来例を示す第８図中の曲線Ａ、Ｂ、Ｃを互
いに比較すれば一目瞭然であり、他言を要ざぬであろう
。In this way, the improvement in control performance such as the responsiveness and stability of the control system achieved by changing the compensation value of the compensation circuit 15 according to the load pressure in this embodiment is achieved by the sixth embodiment showing this embodiment. If you compare the curves A, B, and C in FIG. 8 showing the conventional example, it will be obvious at a glance, and no further explanation is necessary.
なお、上記実施例では、アナログ式の速度制御装置を射
出成形機に適用した場合について述へたが、デジタル式
の速度制御装置を適用することもできる。さらに、本発
明が図示の実施例に限られないのはいうまでもない。In the above embodiments, a case has been described in which an analog type speed control device is applied to an injection molding machine, but a digital type speed control device can also be applied. Furthermore, it goes without saying that the present invention is not limited to the illustrated embodiment.
〈発明の効果〉
以」二の説明で明らかなように、本発明の油圧アクチュ
エータの速度制御装置は、油圧アクチュエータの速度検
出器からの速度検出信号と目標速度値信号から制御信号
を作成し、この制御信号に補償手段で補償を施して補償
済制御信号とし、この補償済制御信号を油圧アクチュエ
ータの圧力ラインに介設した比例式流量方向制御弁に出
力するものにおいて、上記圧力ラインの負荷圧ツノを圧
力検出器で検出し、この検出信号に基づき補償値変更手
段によって、負荷圧力が低いほど上記補償手段の遅れ要
素が大きくなるようにその補償値を変更せしめるように
しているので、油圧アクチュエー夕の作動速度について
高負荷圧力時には良好な応答性か、低負荷圧力時には良
好な安定性が夫々得られ、広い負荷範囲に亘って優れた
制御性能を実現することができる。<Effects of the Invention> As is clear from the explanation in Section 2 below, the speed control device for a hydraulic actuator of the present invention creates a control signal from a speed detection signal from a speed detector of a hydraulic actuator and a target speed value signal, This control signal is compensated by a compensation means to obtain a compensated control signal, and this compensated control signal is output to a proportional flow rate directional control valve installed in a pressure line of a hydraulic actuator, in which the load pressure of the pressure line is The horn is detected by a pressure detector, and based on this detection signal, the compensation value changing means changes the compensation value so that the lower the load pressure, the larger the delay element of the compensation means. Regarding the evening operating speed, good response is obtained at high load pressures, and good stability is obtained at low load pressures, making it possible to achieve excellent control performance over a wide load range.
また、この発明の射出成形機は、射出ノリンダの作動速
度について高負荷圧力時には良好な応答性が、低負荷圧
力時には良好な安定性が夫々得られ、広い負荷範囲に亘
って優れた制御性能を実現することができる。In addition, the injection molding machine of the present invention has good responsiveness at high load pressures and good stability at low load pressures with respect to the operating speed of the injection nolinder, and has excellent control performance over a wide load range. It can be realized.
第１図は本発明による油圧アクチュエータのアナログ式
速度制御装置の一実施例を示すブロック図、第２図はこ
の実施例の制御動作を示す図、第３図は本発明による油
圧アクヂ、エータのデジタル式速度制御装置の一実施例
を示すブロック図、第４図はこの実施例の制御動作を示
す図、第５図は第１図の実施例の射出成形機への適用例
を示すブロック図、第６図はこの射出成形機における速
度制御動作の一例を示すグラフ、第７図は従来の油圧ン
リンダの速度制御装置を示すブロック図、第８図は従来
例における速度制御動作を示すグラフである。
ＩＩ＋・油圧アクヂコエータ、
２．１２・サーボ弁、３，１３ 速度検出器、４．１４
・比較器、５．１５ 補償回路、６１６・圧カセンザ、
７．１７・・・補償値切換用比較器、８・・制御装置、
１０・・成形機本体、１９ ・圧力ライン。FIG. 1 is a block diagram showing an embodiment of an analog speed control device for a hydraulic actuator according to the present invention, FIG. 2 is a diagram showing the control operation of this embodiment, and FIG. A block diagram showing an embodiment of the digital speed control device, FIG. 4 is a diagram showing the control operation of this embodiment, and FIG. 5 is a block diagram showing an example of application of the embodiment of FIG. 1 to an injection molding machine. , FIG. 6 is a graph showing an example of the speed control operation in this injection molding machine, FIG. 7 is a block diagram showing a conventional speed control device for a hydraulic cylinder, and FIG. 8 is a graph showing the speed control operation in the conventional example. be. II+・Hydraulic actuator, 2.12・Servo valve, 3,13 Speed detector, 4.14
・Comparator, 5.15 Compensation circuit, 616・Pressure sensor, 7.17... Compensation value switching comparator, 8... Control device,
10. Molding machine body, 19. Pressure line.
Claims (2)
流量方向制御弁（２）を介設するとともに、速度検出器
（３）で検出された上記油圧アクチュエータ（１）の作
動速度を表わす信号と目標速度値から制御信号を作成し
、この制御信号に補償手段（５，８）によって補償を施
して補償済制御信号を上記比例式流量方向制御弁（２）
に出力する油圧アクチュエータの速度制御装置において
、 上記油圧アクチュエータ（１）の圧力ラインに介設され
て負荷圧力（Ｐｌ）を検出する圧力検出器（６）と、こ
の圧力検出器（６）からの検出信号に基づいて、負荷圧
力（Ｐｌ）が低いほど上記補償手段（５，８）の遅れ要
素が大きくなるように上記補償手段（５，８）の補償値
を変更させる補償値変更手段（７，８）を備えたことを
特徴とする油圧アクチュエータの速度制御装置。(1) A proportional flow rate directional control valve (2) is interposed in the pressure line of the hydraulic actuator (1), and a signal indicating the operating speed of the hydraulic actuator (1) detected by a speed detector (3) is connected to the pressure line of the hydraulic actuator (1). A control signal is created from the target speed value, this control signal is compensated by the compensation means (5, 8), and the compensated control signal is applied to the proportional flow directional control valve (2).
In the speed control device for a hydraulic actuator that outputs an output to Compensation value changing means (7) for changing the compensation value of the compensating means (5, 8) so that the lower the load pressure (Pl) is, the larger the delay element of the compensating means (5, 8) is based on the detection signal. , 8) A speed control device for a hydraulic actuator.
例式流量方向制御弁（１２）を介設するとともに、速度
検出器（１３）で検出された上記射出シリンダ（１１）
の作動速度を表わす信号と目標速度値から制御信号を作
成し、この制御信号に補償手段（１５）によって補償を
施して補償済制御信号を上記比例式流量方向制御弁（１
２）に出力する射出成形機において、 上記射出シリンダ（１１）の圧力ライン（１９）に介設
されて負荷圧力（Ｐｌ）を検出する圧力検出器（１６）
と、この圧力検出器（１６）からの検出信号に基づいて
、負荷圧力（Ｐｌ）が低いほど上記補償手段（１５）の
遅れ要素が大きくなるように上記補償手段（１５）の補
償値を変更させる補償値変更手段（１７）を備えたこと
を特徴とする射出成形機。(2) A proportional flow rate directional control valve (12) is installed in the pressure line (19) of the injection cylinder (11), and the injection cylinder (11) is detected by a speed detector (13).
A control signal is created from a signal representing the operating speed of the valve and a target speed value, and this control signal is compensated by the compensation means (15), and the compensated control signal is applied to the proportional flow rate directional control valve (15).
In the injection molding machine outputting to 2), a pressure detector (16) is installed in the pressure line (19) of the injection cylinder (11) to detect the load pressure (Pl).
Based on the detection signal from the pressure detector (16), the compensation value of the compensation means (15) is changed such that the lower the load pressure (Pl), the greater the delay element of the compensation means (15). An injection molding machine characterized by comprising compensation value changing means (17) for changing the compensation value.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23296488A JPH0280801A (en) | 1988-09-16 | 1988-09-16 | Hydraulic actuator type speed control device and injection molding machine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23296488A JPH0280801A (en) | 1988-09-16 | 1988-09-16 | Hydraulic actuator type speed control device and injection molding machine |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0280801A true JPH0280801A (en) | 1990-03-20 |
Family
ID=16947633
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP23296488A Pending JPH0280801A (en) | 1988-09-16 | 1988-09-16 | Hydraulic actuator type speed control device and injection molding machine |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0280801A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH03107502U (en) * | 1990-02-22 | 1991-11-06 | ||
| JPH06106592A (en) * | 1991-12-17 | 1994-04-19 | Nissei Plastics Ind Co | Method and apparatus for controlling molding machine |
| JP2009510357A (en) * | 2005-09-30 | 2009-03-12 | キャタピラー インコーポレイテッド | Hydraulic system with increased pressure compensation |
| JPWO2008081643A1 (en) * | 2006-12-28 | 2010-04-30 | 三菱電機株式会社 | EGR valve control device |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS59103104A (en) * | 1982-12-03 | 1984-06-14 | Toshiba Corp | Process control method |
| JPS62151315A (en) * | 1985-12-26 | 1987-07-06 | Nissei Plastics Ind Co | Controller of fluid pressure actuator |
| JPS636203A (en) * | 1986-06-26 | 1988-01-12 | Sumitomo Heavy Ind Ltd | Characteristic compensation method in hydraulic actuator speed control |
| JPS6388305A (en) * | 1986-09-30 | 1988-04-19 | Sumitomo Kenki Kk | Speed controller for hydraulic rotary member |
-
1988
- 1988-09-16 JP JP23296488A patent/JPH0280801A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS59103104A (en) * | 1982-12-03 | 1984-06-14 | Toshiba Corp | Process control method |
| JPS62151315A (en) * | 1985-12-26 | 1987-07-06 | Nissei Plastics Ind Co | Controller of fluid pressure actuator |
| JPS636203A (en) * | 1986-06-26 | 1988-01-12 | Sumitomo Heavy Ind Ltd | Characteristic compensation method in hydraulic actuator speed control |
| JPS6388305A (en) * | 1986-09-30 | 1988-04-19 | Sumitomo Kenki Kk | Speed controller for hydraulic rotary member |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH03107502U (en) * | 1990-02-22 | 1991-11-06 | ||
| JPH06106592A (en) * | 1991-12-17 | 1994-04-19 | Nissei Plastics Ind Co | Method and apparatus for controlling molding machine |
| JP2009510357A (en) * | 2005-09-30 | 2009-03-12 | キャタピラー インコーポレイテッド | Hydraulic system with increased pressure compensation |
| JPWO2008081643A1 (en) * | 2006-12-28 | 2010-04-30 | 三菱電機株式会社 | EGR valve control device |
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