JP4129728B2

JP4129728B2 - Method and apparatus for stabilizing sand properties before molding machine

Info

Publication number: JP4129728B2
Application number: JP2002295726A
Authority: JP
Inventors: 理西田
Original assignee: Sintokogio Ltd
Current assignee: Sintokogio Ltd
Priority date: 2002-10-09
Filing date: 2002-10-09
Publication date: 2008-08-06
Anticipated expiration: 2022-10-09
Also published as: JP2004130329A

Description

【０００１】
【発明の属する技術分野】
本発明は、バッチ式混練機により混練された混練砂の排出時の砂をサンプリングして砂性状を測定すると共にその結果を次回の砂混練にフィードバックして混練砂の砂性状を安定化させ、造型機へ輸送する造型機前の砂性状安定化方法及びその装置に関する。
【０００２】
【従来の技術】
従来、造型機前の砂性状を安定化させる方法及び装置としては、回収砂の砂温によって、バッチ式混練機の制御パラメータ（例えば、コンパクタビリティ）を増減するもの（例えば、特許文献１及び特許文献２参照。）である。しかし、この方法及び装置では、混練砂をサンプリングしてコンパクタビリティ値、回収砂温度・水分値等を測定し、その結果を次回バッチのバッチ式混練機にフィードバックして鋳物砂の混練を制御している。
【０００３】
【特許文献１】
特公平１−１５８２５号公報（第１〜２ペ−ジ、図１）
【特許文献２】
特公平３−７６７１０号公報（第１〜２ペ−ジ、図１）
【０００４】
【発明が解決しようとする課題】
上記のような鋳物砂の混練制御では混練排出後の混練砂を造型機へ輸送する間に水分を蒸発させたり、砂温度降下により砂性状に大きく影響すると共に時間要素でも不安定になるため、正確な時間管理をする必要があるが、これらを勘案した造型機前の砂性状を安定させることができなかった。
本発明は上記の問題に鑑みてなされたもので、造型機前の混練砂の砂性状と、バッチ式混練機排出時の混練砂の砂性状との間の時間要素を考慮した混練制御をする造型機前の砂性状安定化方法及びその装置を提供することを目的とする。
【０００５】
【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、本発明における造型機前の砂性状安定化方法は、バッチ式混練機により混練された混練砂の排出時の砂をサンプリングして砂性状を測定すると共にその結果を次回の砂混練にフィードバックして混練砂の砂性状を安定化させ、造型機へ輸送する造型機前の砂性状安定化方法であって、
バッチ式混練機から混練砂が排出されるときの時刻と混練砂の砂性状測定値を測定する工程と、該時刻と混練砂の砂性状測定値および砂性状目標値を記憶する工程と、前記混練砂が前記造型機に排出される時刻と混練砂の砂性状測定値を測定すると共にこれを記憶する工程と、前回の混練時刻を算出する工程と、該算出混練時刻におけるバッチ式混練機排出時の砂性状測定値を検索し読み出す工程と、該算出したバッチ式混練機排出時刻における砂性状測定値と前回造型機前の砂性状測定値とから砂輸送経路による砂性状測定値の変化量を算出する工程と、造型機前の砂性状目標値と前回造型機前の砂性状測定値との偏差を算出する工程と、該偏差を砂輸送経路による砂性状測定値の変化量の比率で補正して砂性状補正値を算出する工程と、前回バッチ混練の砂性状目標値の記憶から次バッチ混練の砂性状目標値に前記砂性状補正値を反映して次バッチ砂性状目標値を算出する工程と、この次バッチ砂性状目標値に基づいて次バッチ混練の際にバッチ式混練機の砂性状コントロールをする工程と、を備えたことを特徴とする。
【００１３】
そして、本発明における造型機前の砂性状安定化装置は、バッチ式混練機の側壁に備えられて、バッチ式混練機排出時の時刻及び砂性状測定値を測定するバッチ式混練機排出時の砂性状測定手段と、バッチ式混練機排出時の時刻と測定値および砂性状目標値を記憶する記憶手段と、造型機前に備えられて、造型機前の混練砂排出時の時刻及び砂性状測定値を測定する造型機前の砂性状測定手段と、造型機前の時刻と測定値を記憶する記憶手段と、前回造型機前の測定時刻から輸送時間前のバッチ式混練機排出時刻及び砂性状測定値の検索手段と、造型機前の砂性状目標値を設定する設定手段と、前回造型機前の砂性状測定値と砂性状目標値との偏差を算出する偏差算出手段と、砂輸送経路による砂性状測定値の変化量を算出する変化量算出手段と、該偏差を砂輸送経路による砂性状測定値の比率で補正して砂性状補正値を算出する変化量補正手段と、前回バッチのバッチ式混練機砂性状目標値の記憶手段からの読み出し手段と、前回バッチ混練の砂性状目標値の記憶から次バッチ混練の砂性状目標値に前記砂性状補正値を反映して次バッチ混練の砂性状目標値を算出する算出手段と、この次バッチ砂性状目標値に基づいて次バッチ混練の際にバッチ式混練機の砂性状コントロールをする次バッチ混練制御手段と、を具備したことを特徴とする。
【００１４】
【発明の実施の形態】
以下本発明の実施の形態を図面に基づき詳しく説明する。図１においてバッチ式混練機１の側壁には砂サンプリング機構付き砂性状計測機（「第１砂性状計測機」以下同じ）２が配設されている。また、バッチ式混練機１の下部には砂ホッパ３が配置され、該砂ホッパ３の下部に混練砂の輸送手段であるベルトフィ−ダ４が設けられている。
【００１５】
該ベルトフィ−ダ７の先端は、造型機５の上部に配置された砂ホッパ６の上方に臨んで配置されていると共に該砂ホッパ６の下部にベルトフィ−ダ７が設置されている。該ベルトフィ−ダ７の先端は造型機５のシュ−トホッパ上部に臨んで配置されている。
【００１６】
また前記砂ホッパ６の側壁には後述の微押圧電動シリンダ３００（図３参照）を付属の砂サンプリング機能付き砂性状計測機（「第2砂性状計測機」以下同じ）８が取付けられている。また前記砂サンプリング機能付き砂性状計測機２及び微押圧電動シリンダ３００を付属の砂サンプリング機能付き砂性状計測機８は、各砂性状を計測採取し演算処理する記憶演算機能付制御盤９が電気的に接続されている。
【００１７】
次に図２に砂サンプリング機能付き砂性状計測機２の具体例を示す。バッチ式混練機１の側壁に備えられて、サンプリングスクリュー２０９を変速機構２１０付き無段変速電動機２１１で回転させている。砂サンプリング機能付き砂性状計測機２には、水分センサ２１２およびコンパクタビリティ測定用のエンコーダ２１３が配置してある。また、採取砂を圧縮するスクイズシリンダ２１４と砂かきあるいは邪魔板としてスクレープシリンダ２１５がある。計測する砂性状は、水分、砂温およびコンパクタビリティである。
【００１８】
次に図３に造型機５直前で混練砂をサンプリングし、計測する微押圧砂サンプリング機能付き砂性状計測機８の具体例を示す。
バッチ式混練機１側壁での砂押出し機能を持たせるため、砂サンプリング機構内に、造型砂を微押圧する微押圧電動シリンダ３００が設置されている。その他は、前記砂サンプリング機能付き砂性状計測機２と同様に、サンプリングスクリュー３０９を必要に応じて変速する変速機構３１０、無段変速電動機３１１、水分センサ３１２およびコンパクタビリティ測定用のエンコーダ３１３が配置してある。また、採取砂を圧縮するスクイズシリンダ３１４と砂かきあるいは邪魔板としてスクレープシリンダ３１５がある。計測する砂性状は、水分、砂温およびコンパクタビリティである。
【００１９】
次にバッチ式混練機１の側壁及び造型機前の砂性状を測定して次回の混練にフィードバッグする方法を図４を用いて説明する。
まずバッチ式混練機排出時の砂性状目標値設定手段１１からバッチ式混練機排出時の砂性状目標値と、バッチ式混練機排出時の砂性状測定手段１２により砂性状測定値を収集し、バッチ式混練機排出時の砂性状測定時刻と共に砂性状測定値をバッチ式混練機排出時の測定値等記憶手段１３にて記憶する。
【００２０】
造型機前の砂性状測定手段１４により、造型機前の砂性状測定値を収集し、造型機前の砂性状測定時刻と共に砂性状測定値を造型機前の測定値等記憶手段１５にて記憶する。
【００２１】
造型機前の測定値等記憶手段１５のデータから、前回造型機前の砂性状測定時刻・測定値検索手段１６にて、前回造型機前の砂性状測定時刻・測定値を得る。
前回造型機前測定時刻から輸送時間前のバッチ式混練機排出時刻の測定値検索手段１７で、前回造型機前の砂性状測定時刻と、所定のバッチ式混練機から造型機までの砂輸送時間から、その相当砂の前回の混練時刻を算出し、バッチ式混練機排出時の測定値等記憶手段１２から、算出混練時刻におけるバッチ式混練機排出時の砂性状測定値を検索し読み出す。
【００２２】
算出した混練時刻におけるバッチ式混練機排出時の砂性状測定値と前回造型機前の砂性状測定値とから、砂輸送経路による砂性状測定値の変化量算出手段２０により、砂輸送経路による砂性状測定値の変化量を算出する。
【００２３】
造型機前の砂性状目標値設定手段１８から造型機前の砂性状目標値を得る。前回造型機前の砂性状測定値と目標値との偏差算出手段１９にて、造型機前の砂性状目標値と前回造型機前の砂性状測定値からその偏差を算出する。
【００２４】
算出混練時刻におけるバッチ式混練機排出時の砂性状測定値と造型機前の砂性状目標値との偏差の砂輸送経路による砂性状測定値の変化量補正手段２１にて、造型機前の砂性状測定値と目標値との偏差を砂輸送経路による砂性状測定値の変化量の比率で補正して、砂性状補正値を算出する。
【００２５】
前回バッチのバッチ式混練機砂性状目標値の記憶装置からの読出手段２２から前回バッチのバッチ式混練機砂性状目標値を求める。次バッチ混練の砂性状目標値算出手段２３にて、この砂性状目標値に砂性状補正値を反映して次バッチ砂性状目標値を決定する。そして、次バッチ混練制御手段２４にてバッチ式混練機の砂性状コントロールを実施する。
なお、実施例で採用した砂性状パラメータは、絶対測定であり、測定精度が高い、コンパクタビリティを採用し、バッチ式混練機への添加制御には、注水量とした。
【００２６】
【発明の効果】
以上の説明から明らかなように本発明は、造型機前排出の時刻及び砂性状と、バッチ式混練機排出時の時刻及び砂性状を測定して混練砂輸送の時間要素を考慮した砂性状の補正をしてバッチ式混練機を制御コントロールするものであるから、造型機への砂投入に合わせた混練制御をすることができるようになり、造型機前の混練砂の砂性状を安定化させることができる。
【図面の簡単な説明】
【図１】本発明の実施例を示すブロック図である。
【図２】砂サンプリング機能付き砂性状計測機の構成図である。
【図３】微押圧砂サンプリング機能付き砂性状計測機の構成図である。
【図４】本発明の操作工程を示すフロ−チャ−ト図である。
【符号の説明】
１バッチ式混練機
２砂サンプリング機能付き砂性状計測機
３６砂ホッパ
４７ベルトフィ−ダ
５造型機
８微押圧砂サンプリング機能付き砂性状計測機
９制御盤
２０９３０９サンプリングスクリュ−
２１０３１０変速機構
２１１３１１無段変速機
２１２３１２水分センサ−
２１３３１３エンコ−ダ
２１４３１４スクイズシリンダ
２１５３１５スクレ−プシリンダ[0001]
BACKGROUND OF THE INVENTION
The present invention samples the sand at the time of discharge of the kneaded sand kneaded by the batch type kneader to measure the sand properties and feed back the result to the next sand kneading to stabilize the sand properties of the kneaded sand. The present invention relates to a method for stabilizing sand properties before a molding machine to be transported to a molding machine and an apparatus therefor.
[0002]
[Prior art]
Conventionally, as a method and apparatus for stabilizing the sand property before the molding machine, the control parameter (for example, compactability) of the batch kneader is increased or decreased depending on the sand temperature of the recovered sand (for example, Patent Document 1 and Patent) Reference 2). However, in this method and apparatus, the kneaded sand is sampled to measure the compactability value, recovered sand temperature, moisture value, etc., and the results are fed back to the batch batch kneader of the next batch to control the kneading of the foundry sand. ing.
[0003]
[Patent Document 1]
Japanese Patent Publication No. 1-15825 (Pages 1 and 2, FIG. 1)
[Patent Document 2]
Japanese Examined Patent Publication No. 3-76710 (Pages 1 and 2, FIG. 1)
[0004]
[Problems to be solved by the invention]
In the kneading control of the casting sand as described above, moisture is evaporated while the kneaded sand after being kneaded and discharged is transported to the molding machine, or the sand property is greatly affected by the sand temperature drop and the time factor becomes unstable. Although it is necessary to manage the time accurately, the sand property before the molding machine considering these factors could not be stabilized.
The present invention has been made in view of the above problems, and performs kneading control in consideration of the time factor between the sand property of the kneaded sand before the molding machine and the sand property of the kneaded sand when discharged from the batch kneader. An object of the present invention is to provide a sand property stabilization method and apparatus therefor before a molding machine.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the sand property stabilization method before the molding machine according to the present invention measures the sand property by sampling the sand when discharging the kneaded sand kneaded by the batch kneader and results thereof. Is fed back to the next sand kneading to stabilize the sand property of the kneaded sand, and is a method for stabilizing the sand property before the molding machine to be transported to the molding machine,
A step of measuring the time when the kneaded sand is discharged from the batch-type kneader and a sand property measurement value of the kneaded sand, a step of storing the time, a sand property measurement value of the kneaded sand, and a sand property target value; Measuring the time when the kneaded sand is discharged to the molding machine and measuring the sand property measurement value of the kneaded sand and storing it, calculating the previous kneading time, and discharging the batch kneader at the calculated kneading time The amount of change in the sand property measurement value by the sand transport route from the process of searching and reading the sand property measurement value at the time, the sand property measurement value at the calculated batch kneader discharge time and the sand property measurement value before the previous molding machine The difference between the sand property target value before the molding machine and the sand property measurement value before the previous molding machine, and the deviation as the ratio of the change in the sand property measurement value by the sand transport route. Correcting and calculating a sand property correction value; A step of calculating the next batch sand property target value by reflecting the sand property correction value to the sand property target value of the next batch kneading from the memory of the sand batch target value of the second batch kneading, and based on the next batch sand property target value a step of sand properties control batch kneader during the next batch kneading Te, you comprising the.
[0013]
And the sand property stabilizing device before the molding machine in the present invention is provided on the side wall of the batch kneader, and measures the time when the batch kneader is discharged and the measured value of the sand property when discharging the batch kneader. Sand property measuring means, storage means for storing the time and measured value at the time of discharging the batch type kneader, and sand property target value, and the time and sand property at the time of discharging the kneaded sand before the molding machine. and sand texture measuring means before the molding machine for measuring a measurement value, storage means for storing the measured values and the time before the molding machine, before transportation time from the previous molding machine before the measurement time batch kneaders discharge time and sand Property measurement value retrieval means, setting means for setting a sand property target value before the molding machine, deviation calculating means for calculating a deviation between the sand property measurement value and the sand property target value before the molding machine, and sand transportation change amount calculation hand for calculating a change amount of sand texture measurements by path When the read means from the change amount correcting means and the storage means of a batch type kneader sand properties target value of the previous batch the deviation calculates the sand property correction value by correcting a ratio of sand texture measurements by sand transport pathway When a calculation means for calculating a sand properties target value for the next batch kneading the storage of sand properties target value of the previous batch kneading reflects the sand property correction value in the sand properties target value for the next batch kneading, the following batch sand And a next batch kneading control means for controlling sand properties of the batch kneader at the time of the next batch kneading based on the property target value .
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In FIG. 1, a sand property measuring machine with a sand sampling mechanism (hereinafter the same as “first sand property measuring machine”) 2 is disposed on the side wall of the batch kneader 1. A sand hopper 3 is disposed at the bottom of the batch kneader 1, and a belt feeder 4 serving as a means for transporting the kneaded sand is provided at the bottom of the sand hopper 3.
[0015]
The front end of the belt feeder 7 is disposed above the sand hopper 6 disposed at the upper portion of the molding machine 5, and the belt feeder 7 is disposed at the lower portion of the sand hopper 6. The front end of the belt feeder 7 is disposed so as to face the upper portion of the shot hopper of the molding machine 5.
[0016]
Also attached to the side wall of the sand hopper 6 is a fine sanding electric cylinder 300 (see FIG. 3), which will be described later, and an attached sand property measuring machine with a sand sampling function (hereinafter the same as the “second sand property measuring machine”) 8. . Further, the sand property measuring machine 2 with sand sampling function and the sand property measuring machine 8 with sand sampling function attached to the fine press electric cylinder 300 are electrically connected to the control panel 9 with a memory operation function for measuring and sampling each sand property. Connected.
[0017]
Next, FIG. 2 shows a specific example of the sand property measuring machine 2 with a sand sampling function. A sampling screw 209 provided on the side wall of the batch kneader 1 is rotated by a continuously variable transmission motor 211 with a transmission mechanism 210. The sand property measuring machine 2 with a sand sampling function is provided with a moisture sensor 212 and an encoder 213 for measuring compactability. Further, there are a squeeze cylinder 214 for compressing the collected sand and a scrape cylinder 215 as a sand scraper or a baffle plate. The sand properties to be measured are moisture, sand temperature and compactability.
[0018]
Next, FIG. 3 shows a specific example of the sand property measuring machine 8 with a fine press sand sampling function for sampling and measuring the kneaded sand immediately before the molding machine 5.
In order to provide a sand extrusion function at the side wall of the batch type kneader 1, a fine pressing electric cylinder 300 for finely pressing the molding sand is installed in the sand sampling mechanism. Other than this, like the sand property measuring machine 2 with the sand sampling function, a speed change mechanism 310 that changes the speed of the sampling screw 309 as necessary, a continuously variable transmission motor 311, a moisture sensor 312, and an encoder 313 for measuring the compactability are arranged. It is. Further, there is a squeeze cylinder 314 for compressing the collected sand and a scrape cylinder 315 as a sand scraper or a baffle plate. The sand properties to be measured are moisture, sand temperature and compactability.
[0019]
Next, a method of measuring the side wall of the batch kneader 1 and the sand property before the molding machine and feeding it back to the next kneading will be described with reference to FIG.
First, sand property target values at the time of discharging the batch type kneader are collected from the sand property target value setting means 11 at the time of discharging the batch type kneader, and the sand property measuring values are collected by the sand property measuring means 12 at the time of discharging the batch type kneader, The sand property measurement value together with the sand property measurement time at the time of discharging the batch type kneader is stored in the storage means 13 such as the measured value at the time of discharging the batch type kneader.
[0020]
The sand property measurement value before the molding machine is collected by the sand property measurement means 14 before the molding machine, and the sand property measurement value is stored in the measurement value storage means 15 before the molding machine together with the sand property measurement time before the molding machine. To do.
[0021]
The sand property measurement time / measurement value before the molding machine is obtained by the sand property measurement time / measurement value search means 16 before the molding machine from the data stored in the measurement value storage unit 15 before the molding machine.
In the batch value kneader discharge time measurement value retrieval means 17 before the transport time from the previous measurement time before the molding machine, the sand property measurement time before the previous molding machine and the sand transport time from the predetermined batch kneader to the molding machine. Then, the previous kneading time of the corresponding sand is calculated, and the sand property measurement value at the time of discharging the batch kneader at the calculated kneading time is retrieved and read from the storage unit 12 of the measured value at the time of discharging the batch kneader.
[0022]
Based on the sand property measurement value at the time of discharging the batch type kneader at the calculated kneading time and the sand property measurement value before the previous molding machine, the sand property route sand by the sand transport route is calculated by the change amount calculation means 20 of the sand property measurement value by the sand transport route. The amount of change in the property measurement value is calculated.
[0023]
The sand property target value before the molding machine is obtained from the sand property target value setting means 18 before the molding machine. The deviation calculating means 19 between the sand property measurement value before the previous molding machine and the target value calculates the deviation from the sand property target value before the molding machine and the sand property measurement value before the previous molding machine.
[0024]
At the calculated kneading time, the sand property before the molding machine is corrected by the change amount correcting means 21 of the sand property measured value by the sand transport path of the deviation between the sand property measured value at the time of discharging the batch kneader and the sand property target value before the molding machine. The sand property correction value is calculated by correcting the deviation between the property measurement value and the target value by the ratio of the change amount of the sand property measurement value by the sand transport route.
[0025]
The batch type kneader sand property target value of the previous batch is obtained from the reading unit 22 from the storage device of the batch type kneader sand property target value of the previous batch. The next batch sand property target value is determined by reflecting the sand property correction value to the sand property target value by the sand property target value calculating means 23 for the next batch kneading. Then, the sand property control of the batch kneader is performed by the next batch kneading control means 24.
In addition, the sand property parameter employ | adopted in the Example was an absolute measurement, the measurement accuracy was high, the compactability was employ | adopted, and the amount of water injection was used for the addition control to a batch type kneader.
[0026]
【The invention's effect】
As is apparent from the above description, the present invention is a sand property that takes into account the time factor of kneading sand transport by measuring the time and sand property before discharging from the molding machine and the time and sand property when discharging from the batch kneader. Because it corrects and controls the batch-type kneader, it becomes possible to control kneading in accordance with the input of sand into the molding machine and stabilize the sand properties of the kneading sand before the molding machine. be able to.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an embodiment of the present invention.
FIG. 2 is a configuration diagram of a sand property measuring machine with a sand sampling function.
FIG. 3 is a configuration diagram of a sand property measuring machine with a fine-pressing sand sampling function.
FIG. 4 is a flowchart showing the operation process of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Batch type kneading machine 2 Sand property measuring machine 3 with sand sampling function 6 6 Sand hopper 4 7 Belt feeder 5 Molding machine 8 Sand property measuring machine 9 with fine press sand sampling function Control panel 209 309 Sampling screw
210 310 Transmission mechanism 211 311 Continuously variable transmission 212 312 Moisture sensor
213 313 Encoder 214 314 Squeeze cylinder 215 315 Scrap cylinder

Claims

The sand at the time of discharge of the kneaded sand kneaded by the batch kneader is sampled to measure the sand properties, and the results are fed back to the next sand kneading to stabilize the sand properties of the kneaded sand and transported to the molding machine A method for stabilizing sand properties in front of a molding machine,
A step of measuring the time when the kneaded sand is discharged from the batch-type kneader and a sand property measurement value of the kneaded sand, a step of storing the time, a sand property measurement value of the kneaded sand, and a sand property target value ; a step of storing it together with kneading sand measure sand texture measuring values of time and kneaded sand is discharged into the molding machine, a step of calculating the last time of the kneading time, the calculated output batch kneaders in the kneading time Changes in the sand property measurement value by the sand transport route from the process of searching and reading the sand property measurement value at the time of discharge, the sand property measurement value at the time of discharge of the calculated batch type kneader, and the sand property measurement value before the previous molding machine a step of calculating the amount of pre-molding machine sand texture target value and the previous previous molding machine and calculating the deviation between the sand of Johaka value, the deviation of the variation amount of the sand texture measurements by sand transport pathway A step of calculating a sand property correction value by correcting with a ratio; Calculating a subsequent batch sand texture target value from the storage of sand properties target times batch kneading reflects the sand property correction value in the sand properties target value for the next batch kneading, based on the following batch sand properties target value And a step of controlling the sand property of the batch kneader at the time of the next batch kneading, and a method for stabilizing the sand property before the molding machine.

The sand at the time of discharge of the kneaded sand kneaded by the batch kneader is sampled to measure the sand properties, and the results are fed back to the next sand kneading to stabilize the sand properties of the kneaded sand and transported to the molding machine A sand property stabilizing device in front of a molding machine,
Provided on the side wall of a batch type kneader, a batch kneader sand texture measuring means during discharge of measuring time and sand texture measuring value during batch kneaders discharge, the time during batch kneaders emissions measurements Storage means for storing values and sand property target values , sand property measuring means provided before the molding machine, for measuring the time when the kneaded sand is discharged before the molding machine and measured sand property values , and molding Storage means for storing the time and measured value before the machine, batch-type kneader discharge time and transport property measuring time before the transport time from the previous measurement time before the molding machine, and sand property target value before the molding machine setting means for setting a sand texture measuring values before the previous molding machine and a deviation calculating means for calculating a deviation between the sand properties desired value, the change amount calculating means for calculating a change amount of sand texture measurements by sand transport pathway If, complement the deviation in a ratio of sand texture measurements by sand transport pathway A change amount correction means for calculating a sand property correction value by a read means from the storage means of a batch type kneader sand properties target value of the previous batch from the storage of sand properties target value of the previous batch kneading the following batch kneading A calculation means for calculating the sand property target value for the next batch kneading by reflecting the sand property correction value on the sand property target value , and a batch kneader of the batch type kneader at the time of the next batch kneading based on the next batch sand property target value. And a next batch kneading control means for controlling the sand property, and a sand property stabilizing device before the molding machine.