JPS6281258A - Pressure controlling method for casting machine - Google Patents

Abstract

PURPOSE:To produce castings having the same quality by counting the number of pouring and correcting the pressure during the pressurization in accordance with the count value in the stage of exerting the pressure to the molten metal in a holding furnace and pouring the molten metal into a casting mold so that the pressure on the molten metal in the pouring port is made always the same in spite of a fall of the molten metal level in the holding furnace. CONSTITUTION:A pressurization curve generator 4 generates the signal at which the pressure in the holding furnace 9 is made optimum for initial casting. Said signal is determined as the set value of a pressure controller 6. The pressure controller 6 receives the signal for the inside pressure of the holding furnace measured by a pressure gage 7 as the measured value and makes the feedback control by the deviation of said value from the set value, then the controller controls the opening degree of a valve 8 in such a manner that the holding furnace is pressurized to conform to the pressurization curve. A counter 2 which counts the number of casting increases the count by each one time by a start command 1. The set value of the controller 6 is corrected by as much as the number of casting, i.e., the pressure component proportional to the count value of the counter 2 with respect to the set value from the generator 4.

Description

【発明の詳細な説明】 〔発明の利用分野〕 本発明は、アルミニウムなどの鋳造機の加圧時の圧力制
御方法に関するものであり、特に同一形状のアルミニウ
ムなどの金属のダイキャストを連続して鋳造を行なうに
際しての好適な圧力制御の補正方法に関する。[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a method for controlling pressure when pressurizing a casting machine for aluminum or the like, and particularly for continuously die-casting aluminum or other metals of the same shape. The present invention relates to a suitable correction method for pressure control during casting.

〔発明の背景〕[Background of the invention]

従来のアルミニウムなどの金属溶湯の鋳造機における鋳
造時の圧力制御方法としては、鋳造ごとに低下してゆく
金属溶湯保温炉内の湯面の高さに関係なく、毎日同一の
加圧曲線に基づき圧力制御する方法が一般的であったが
、このような圧力制御方法では、鋳造機の鋳型への注入
口圧力が、保温炉内の金属溶湯の湯面の高さが低下する
にしたがって、低下していくため均一な注入口圧力で溶
湯を鋳型へ注入することができず、均一な品質の全域鋳
物を量産することが困離であった。Conventional methods for controlling the pressure during casting in casting machines for molten metal such as aluminum are based on the same pressure curve every day, regardless of the height of the molten metal in the molten metal insulating furnace, which decreases with each casting. The most common method was to control the pressure, but in this pressure control method, the pressure at the inlet of the casting machine into the mold decreases as the level of the molten metal in the insulating furnace decreases. As a result, it was not possible to inject molten metal into the mold with uniform inlet pressure, making it difficult to mass-produce castings with uniform quality over the entire area.

また、前述のような欠点を解消する方法として、各注入
回毎に、一定の圧力を付加してゆく圧力制御方法も用い
られるようになったが、この方法でも、保温炉が円筒形
あるいは角柱形の場合はめる程度の効果は期待できるも
のの、第２図に示すような一般的に用いられる先細り形
状の保温炉の場合は、溶湯面の高さ低下が一定とならな
いため、各注入毎に一定の圧力を付加しても、鋳型注入
口圧力に変化が生じてしまうことになる。In addition, as a method to eliminate the above-mentioned drawbacks, a pressure control method has been used in which a constant pressure is applied for each injection, but even with this method, if the insulating furnace is cylindrical or prismatic, In the case of a shape, the effect can be expected to the extent that it can be fitted, but in the case of a generally used tapered-shaped heat retention furnace as shown in Figure 2, the height of the molten metal surface does not decrease uniformly, so the drop in height is constant for each injection. Even if a pressure of

さらに、多数の圧力曲線を用意し、各注入回毎にその多
数の圧力曲線の中から対応する圧力曲線を選択し、その
圧力曲線に基づいて加圧する方法も開発されたが、この
方法は、多数の加圧曲線を予め作成しておかなければな
らずしかも制御装置が複雑であるため、実操業としては
適用が困難であった。Furthermore, a method was developed in which a large number of pressure curves are prepared, a corresponding pressure curve is selected from among the large number of pressure curves for each injection, and pressure is applied based on that pressure curve. Since a large number of pressurization curves must be created in advance and the control device is complicated, it is difficult to apply this method in actual operation.

〔発明の目的〕[Purpose of the invention]

本発明の目的は、アルミニウムなどの金属溶湯を繰返し
て鋳造機の鋳型へ供給するに際して、問題となってい友
前述の問題点を解決し、複雑な形状の保温炉を使用し之
場合にも、初回の鋳造から最後の鋳造まで、良質の鋳物
を得る好適な圧力制御方法を提供することにある。The purpose of the present invention is to solve the above-mentioned problems that occur when repeatedly feeding molten metal such as aluminum to the mold of a casting machine, and to solve the problem even when a heat retention furnace with a complicated shape is used. The object of the present invention is to provide a suitable pressure control method for obtaining high-quality castings from the first casting to the final casting.

〔発明の概要〕[Summary of the invention]

本発明は、アルミニウムなどの金属を繰り返して鋳型へ
注入し鋳物を得るに際して、注入口圧力が鋳造回数に応
じ定圧力分だけ低下することに着目し、鋳造回数を計数
するカウンタを設け、その計数値により加圧曲線を補正
し、アルミニウムなどの金萬醪湯の注入口における加圧
曲線の変動を無くすものである。The present invention focuses on the fact that when metal such as aluminum is repeatedly injected into a mold to obtain a casting, the injection port pressure decreases by a constant pressure depending on the number of castings, and a counter is provided to count the number of castings. The pressure curve is corrected using numerical values to eliminate fluctuations in the pressure curve at the injection port for kinmanmomi-yu (aluminum, etc.).

このような鋳造装置における注入圧力制御方法は、本来
、注入口の注入圧力を測定し、圧力制御を行なうべきで
あるが、注入口の温度が高く、直接測定は困難である。The injection pressure control method in such a casting apparatus should originally measure the injection pressure at the injection port and control the pressure, but the temperature of the injection port is high and direct measurement is difficult.

そこで、本発明者等は、注入口の圧力Ｐｏと保温炉内圧
力Ｐとの間に次式で表わされる関係がらることに着目し
、その計算式に基づいて、注入口圧力を一定に補正する
ことができることを知見して本発明を完成したものであ
る。Therefore, the present inventors focused on the relationship expressed by the following formula between the pressure Po of the injection port and the pressure P inside the heat retention furnace, and based on the calculation formula, corrected the pressure of the injection port to a constant value. The present invention was completed by discovering that this can be done.

Ｐ＝Ｐｏ＋Ｈ嗜ｄ　　　　　　・・・・・・・・・（１
）Ｐ：保温炉内圧力（ｍ　Ｈｚ　Ｏ） Ｐｏニストーク注入口圧力（ｍｍ　Ｈ２０）Ｈニストー
ク注入口と金属溶湯面の高さの差（−） ｄ：熔融金属比重（ｇ／ｃｃ） Ｈ＝ＨＯ＋　ｆ　（Ｎ　）　　　　　　・−・・・−（
２）Ｈｏ：鋳造開始時点のストーク注入口と金属溶湯面
の高さの差。P=Po+H d・・・・・・・・・(1
) P: Pressure inside heat retention furnace (m Hz O) Po Nistoke inlet pressure (mm H20) H Difference in height between Nistoke inlet and molten metal surface (-) d: Molten metal specific gravity (g/cc) H=HO+ f (N) ・−・・・−(
2) Ho: Difference in height between the stalk injection port and the molten metal surface at the start of casting.

Ｎ：注入回数 ｆ　（Ｎ）　：保温炉の形状および１回の注入量が定ま
れば決定されるＮの関数 すなわち、保温炉および１回の注入量に応じて予めｆ　
（Ｎ）を定めておけば、Ｎ回目の保温炉の圧力Ｐは（１
）式および（２）式よりＰ　＝　Ｐｏ　＋（Ｈｏ＋ｆ（
’ａ）・ｄとして計算補正することができる。N: Number of injections f (N): A function of N that is determined once the shape of the heating furnace and the amount of injection per injection are determined.
(N), the pressure P of the Nth insulating furnace is (1
) and (2), P = Po + (Ho+f(
The calculation can be corrected as 'a) and d.

因みに、保温炉の形状が円筒形又は角柱形の場合は、前
記ｆ〜は下式のとおりとなり 但し、Ａ：保温炉の断面積 ｖ：１回の注湯黛 この場合のＮ回目の保温炉内の補正圧力は下式で計算す
ることができる。Incidentally, if the shape of the heat retention furnace is cylindrical or prismatic, the above f ~ will be as shown in the following formula. However, A: Cross-sectional area of the heat retention furnace v: 1 pouring of molten metal In this case, the Nth heat retention furnace The corrected pressure within can be calculated using the formula below.

〔発明の実施例〕[Embodiments of the invention]

以下、本発明の推奨される一実施例を第１図によって説
明する。Hereinafter, a recommended embodiment of the present invention will be described with reference to FIG.

加圧曲線発生器４は、保温炉の加圧が初回の鋳造に最適
となる信号を発生し、圧力調節計６の設だ値となる。圧
力調節計６は、保温炉９の内圧を圧力計７の信号をカ１
１定値とし、設定値との偏差によるフィードバック制御
を行ない、保温炉が加圧曲線どおりに加圧されるように
弁８の開度調節を行なう。鋳造回数を計数するカウンタ
２ば、スタート指令１により１回ずつ増加し、溶融アル
ミニウムが空となるとリセット指令により初期随にリセ
ットされる。圧力調節計６の設定値は、加圧曲線発生器
よりの設定値に対して、加算器５で鋳造回数すなわち、
カウンタ２の計数値に比例した圧力分だけ補正される。The pressurization curve generator 4 generates a signal that makes the pressurization of the insulating furnace optimal for the first casting, which becomes the set value of the pressure regulator 6. The pressure regulator 6 adjusts the internal pressure of the heat-retaining furnace 9 by adjusting the signal from the pressure gauge 7.
1 constant value, feedback control is performed based on the deviation from the set value, and the opening degree of the valve 8 is adjusted so that the heat retention furnace is pressurized according to the pressurization curve. A counter 2 for counting the number of castings is incremented by one in response to the start command 1, and is reset at an initial stage by a reset command when the molten aluminum becomes empty. The set value of the pressure regulator 6 is determined by the adder 5 as the number of castings, that is, with respect to the set value from the pressure curve generator.
The pressure is corrected by an amount proportional to the count value of the counter 2.

カウンタの計数値と補正圧力匝は次の前提で求められる
。The count value of the counter and the corrected pressure value are obtained based on the following assumptions.

保温炉９は円柱状であり、溶融アルミニウム１０の容積
は、アルミニウム湯面１２の高さに比例する。したがっ
て、毎回同一の鋳物を鋳造すると、アルミニウム湯面の
低下中は毎回同一となる。The heat retention furnace 9 has a cylindrical shape, and the volume of the molten aluminum 10 is proportional to the height of the aluminum molten metal surface 12. Therefore, if the same casting is cast every time, the aluminum melt level will be the same every time while it is falling.

また、アルミニウム注入口１１の圧力は、保温炉内の圧
力（圧力計７で測定）からアルミニウム注入口１１とア
ルミニウム湯面１３の差に溶融アルミニラ・ムの比重を
乗じた値（アルミニウムヘッド圧と呼ぶ）を減じた圧力
となる。The pressure of the aluminum injection port 11 is calculated by multiplying the difference between the aluminum injection port 11 and the aluminum surface 13 by the specific gravity of the molten aluminum from the pressure inside the heat insulating furnace (measured with the pressure gauge 7). The pressure is reduced by

したがって注入口１１の圧力を毎鋳造とも同一とするた
めには鋳造ごとに増加するアルミニウムヘッド圧を保温
炉の内圧に加算すればよい。Therefore, in order to make the pressure of the injection port 11 the same for each casting, the aluminum head pressure that increases for each casting may be added to the internal pressure of the heat retention furnace.

加算分となるアルミニウムヘッド圧は、初回力らの鋳造
回数を計数するカウンタ２の計数直に、１回の鋳造で低
下するアルミニウム湯面の低下化と溶融アルミニウムの
比重を乗じることによって求められる。この演算はカウ
ンタ２と比率設定体３で行なっている。The additional aluminum head pressure is obtained by multiplying the count of the counter 2 that counts the number of castings from the initial force by the decrease in the aluminum level that decreases in one casting and the specific gravity of molten aluminum. This calculation is performed by a counter 2 and a ratio setting body 3.

〔発明の効果〕〔Effect of the invention〕

本発明によれば、アルミニウムなどの金属の鋳造がくり
返し行なわれ保温炉場面が低下しても、鋳造時の金属溶
湯の注入口の圧力は簡素な制御榛構で迅速に補正＋１ｉ
ｌＪ御され、初回から最後の鋳造まで同一状態となる。According to the present invention, even if metals such as aluminum are repeatedly cast and the temperature of the insulating furnace decreases, the pressure at the inlet for molten metal during casting can be quickly corrected by +1i with a simple control system.
LJ is controlled and the condition remains the same from the first to the last casting.

このため同一品質の金属鋳物を得ることができる。Therefore, metal castings of the same quality can be obtained.

特に、本発明によれば、円筒形おるいは角柱形の保温炉
ばかりでなく、この種の保温炉として通常用いられる先
細りの異形状の保温炉を用いても金＠溶湯の注入口圧力
を常に一定に制御できるという実操業上極めてすぐれた
効果を得ることができる。In particular, according to the present invention, the inlet pressure of gold@molten metal can be controlled not only by a cylindrical or prismatic heat insulating furnace, but also by using a tapered, irregularly shaped heat insulating furnace that is commonly used as this kind of heat insulating furnace. It is possible to obtain an extremely excellent effect in actual operation that constant control can be performed at all times.

【図面の簡単な説明】[Brief explanation of drawings]

再１図は本発明を円柱状の保温炉を用いた場合の実施列
を示す図、第２図は他の形状の保温炉を用いた場合の実
施例を示す図、および第３図はコンピュータを利用した
フローチャートを示す図で）　　ある。 ２・・・カラ／り、４・・・加圧曲線発生器、５・・・
加算器。 ６・・・圧力調節計、９・・・保温炉、１０・・・アル
ミニウム溶湯、１１・・・注入口、１２・・・鋳型、１
３・・・湯面。Figure 1 is a diagram showing an example of implementing the present invention using a cylindrical heat retention furnace, Figure 2 is a diagram showing an example in which a heat retention furnace of another shape is used, and Figure 3 is a diagram showing a computer system. This is a diagram showing a flowchart using . 2... Color/li, 4... Pressure curve generator, 5...
Adder. 6... Pressure regulator, 9... Heat retention furnace, 10... Molten aluminum, 11... Inlet, 12... Mold, 1
3... Hot water surface.

Claims (1)

【特許請求の範囲】[Claims] １、保温炉内の金属溶湯に圧力を加えて、鋳型内へ金属
溶湯を圧入するに際しての圧力制御方法において、注入
回数を計数し、該計数値に基づいて、加圧時の加圧曲線
を補正することを特徴とする鋳造機における圧力制御方
法。1. In the pressure control method when applying pressure to the molten metal in the heat retention furnace and pressuring the molten metal into the mold, the number of injections is counted, and the pressure curve during pressurization is calculated based on the counted value. A pressure control method in a casting machine characterized by correcting the pressure.