JPH0513751B2 - - Google Patents
Info
- Publication number
- JPH0513751B2 JPH0513751B2 JP19099784A JP19099784A JPH0513751B2 JP H0513751 B2 JPH0513751 B2 JP H0513751B2 JP 19099784 A JP19099784 A JP 19099784A JP 19099784 A JP19099784 A JP 19099784A JP H0513751 B2 JPH0513751 B2 JP H0513751B2
- Authority
- JP
- Japan
- Prior art keywords
- hot water
- flow rate
- air
- crucible
- stalk
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 82
- 238000005266 casting Methods 0.000 claims description 22
- 230000007246 mechanism Effects 0.000 claims description 12
- 230000008859 change Effects 0.000 claims description 11
- 238000003860 storage Methods 0.000 claims description 7
- 229910052751 metal Inorganic materials 0.000 description 27
- 239000002184 metal Substances 0.000 description 27
- 238000010586 diagram Methods 0.000 description 6
- 230000006870 function Effects 0.000 description 5
- 230000001276 controlling effect Effects 0.000 description 4
- 230000007423 decrease Effects 0.000 description 4
- 238000000034 method Methods 0.000 description 4
- 230000008569 process Effects 0.000 description 3
- 230000000875 corresponding effect Effects 0.000 description 2
- 239000012811 non-conductive material Substances 0.000 description 2
- 238000004904 shortening Methods 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000002596 correlated effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 238000007711 solidification Methods 0.000 description 1
- 230000008023 solidification Effects 0.000 description 1
- 238000011144 upstream manufacturing Methods 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D18/00—Pressure casting; Vacuum casting
- B22D18/08—Controlling, supervising, e.g. for safety reasons
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Casting Support Devices, Ladles, And Melt Control Thereby (AREA)
Description
【発明の詳細な説明】
(産業上の利用分野)
本発明は、低圧鋳造機の鋳型キヤビテイ内に充
填される溶湯の充填速度を制御する給湯制御装置
の改良に関するものである。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement in a hot water supply control device for controlling the filling rate of molten metal filling into a mold cavity of a low pressure casting machine.
(従来の技術)
一般に、この種の低圧鋳造機は、溶湯を収容す
るるつぼを気密状に覆う加圧室と、その上方に配
置された鋳型とを備えてなり、加圧室にエアを供
給してるつぼからストークを介して鋳型のキヤビ
テイ内に湯を低圧で充填することにより、例えば
エンジンのアルミニウム製シリンダヘツド等の鋳
物を鋳造するようにしたものである。(Prior Art) Generally, this type of low-pressure casting machine is equipped with a pressurizing chamber that airtightly covers a crucible containing molten metal, and a mold placed above the pressurizing chamber, and air is supplied to the pressurizing chamber. By filling the cavity of a mold with hot water from a crucible through a stalk at low pressure, a cast product such as an aluminum cylinder head for an engine can be cast.
ところで、この低圧鋳造機では、鋳型キヤビテ
イ内への湯の充填速度が速すぎると、湯の乱流に
よる鋳物内に空気等が巻き込まれてブローホール
等が生じ、逆に湯の充填速度が遅すぎると、給湯
途中で湯の一部が早期に凝固する等の鋳造欠陥が
生じるという問題があり、湯の充填速度を一定に
保つ必要がある。したがつて、鋳型キヤビテイ内
への給湯に伴い、るつぼ内の湯のレベルが低下し
て該レベルと鋳型キヤビテイとの高低差、つまり
ヘツド差が増大したときには、それに応じて加圧
室に対するエアの圧力を増大させることが要求さ
れる。 By the way, in this low-pressure casting machine, if the filling speed of hot water into the mold cavity is too fast, air etc. will be drawn into the casting due to the turbulent flow of the hot water, causing blowholes, etc., and conversely, the filling speed of hot water will be slow. If it is too high, there is a problem that casting defects such as early solidification of a part of the hot water during the supply of hot water occur, so it is necessary to keep the filling speed of hot water constant. Therefore, when the level of hot water in the crucible decreases as hot water is supplied into the mold cavity and the height difference between the level and the mold cavity, that is, the head difference increases, the air supply to the pressurizing chamber increases accordingly. Increased pressure is required.
そこで、このような要求を満たすべく、従来、
例えば実開昭55−111663号公報に開示されている
ように、湯を鋳型キヤビテイ内に充填するシヨツ
ト回数が増加するのに応じてエア供給系路に設け
た減圧弁を段階的に開いて、加圧室のエア圧力を
ぬつぼ内の湯のレベル低下を見越して上げてゆく
ようにしたものが提案されている。 Therefore, in order to meet such demands, conventionally,
For example, as disclosed in Japanese Utility Model Application No. 55-111663, a pressure reducing valve provided in an air supply system is opened in stages as the number of shots to fill a mold cavity with hot water increases. A system has been proposed in which the air pressure in the pressurized chamber is increased in anticipation of a drop in the level of hot water in the crucible.
(発明が解決しようとする問題点)
しかしながら、上記従来のものでは、エアの加
圧力をシヨツト毎に段階的にかつ画一的に制御し
ているため、るつぼが空状態になると新たに補給
される溶湯の補給量のばらつきによつて制御誤差
が生じるという問題があつた。しかも、加圧エア
の流量が一定であるので、加圧時に上記溶湯補給
に伴う炉蓋の気密性不足に起因するエア洩れ等が
生じても、その補正を行うことができず、その結
果、高精度で高品質の鋳造品を鋳造することが困
難であつた。(Problem to be Solved by the Invention) However, in the conventional method described above, the pressurizing force of air is controlled stepwise and uniformly for each shot, so when the crucible becomes empty, a new one is refilled. There was a problem in that control errors occurred due to variations in the amount of molten metal replenished. Moreover, since the flow rate of pressurized air is constant, even if air leakage occurs due to lack of airtightness of the furnace lid due to the replenishment of molten metal during pressurization, it cannot be corrected, and as a result, It has been difficult to cast high-precision, high-quality cast products.
また、加圧エアの流量制御が行われていないの
で、湯のシヨツト回数が増加してるつぼ内の湯の
レベルが低下する程給湯時間が長くなり、給湯時
間のばらつきが大きくなるという問題もあつた。 In addition, since the flow rate of pressurized air is not controlled, there is a problem that the number of hot water shots increases and the level of hot water in the crucible decreases, making the hot water supply time longer and the dispersion of hot water supply time becoming larger. Ta.
本発明はかかる点に鑑みてなされたもので、そ
の目的とするところは、低圧鋳造機の給湯時に湯
がストーク上部に上昇したときの加圧エアの供給
状態を検出してそれを最適条件と比較し、その差
に基づいて鋳型キヤビテイ内に湯を充填するため
のエアの加圧力および流量を最適制御状態で制御
するようにすることにより、るつぼ内の湯量の変
化に拘らず、ストーク上部から鋳型キヤビテイ内
に充填される湯の流速を一定に正確に制御し得る
ようにし、よつて低圧鋳造機による鋳造品の品質
の向上および鋳造時間の短縮化を図ることにあ
る。 The present invention has been made in view of the above, and its purpose is to detect the supply state of pressurized air when hot water rises to the upper part of the stalk during hot water supply in a low-pressure casting machine, and to set it as the optimum condition. By comparing the results and controlling the air pressure and flow rate for filling the mold cavity in an optimal state based on the difference, the flow rate from the top of the stalk is controlled regardless of changes in the amount of hot water in the crucible. The purpose of the present invention is to enable constant and accurate control of the flow rate of hot water filled into a mold cavity, thereby improving the quality of cast products and shortening casting time using a low-pressure casting machine.
(問題点を解決するための手段)
上記目的を達成するため、本発明の解決手段
は、低圧鋳造機の加圧室に連通し、流量制御弁お
よび圧力制御弁が介設されたエア供給系路と、上
記両制御弁の各開度を制御するサーボ機構と、上
記加圧室内に設けられた圧力検出器と、鋳造材の
ストークの上部にその通路方向に一定の距離をへ
だてて設けられた一対の湯検出器と、湯が上記ス
トーク上部に達したときの加圧力に対するヘツド
差を化特性、鋳造機のるつぼ内の湯のヘツド差に
対るる加圧室の容積変化特性および該ヘツド差に
対するストーク内の湯の流速変化特性をそれぞれ
記憶する記憶部と、上記るつぼ内の所定レベルに
ある湯がストーク上部に達したときのエアの加圧
力、その流量および湯の流速の各値ならびに上記
ストーク上部からキヤビテイ内への湯の充填時の
エアの加圧力、その流量、加圧室の容積および湯
の流速の各値をパターンとして設定記憶する一
方、実際に湯がストーク上部に達したときの上記
各検出器からの出力信号と上記比較部での比較対
応信号とをもとに上記パターンの設定値との差を
求め、その差に応じて上記両サーボ機構に対して
キヤビテイへ湯を送るためのエアの加圧力および
流量の各信号を出力する制御部とを備えた構成と
している。(Means for Solving the Problems) In order to achieve the above object, the present invention provides an air supply system that communicates with a pressurizing chamber of a low-pressure casting machine and is provided with a flow rate control valve and a pressure control valve. a servo mechanism for controlling the respective opening degrees of both of the control valves, a pressure detector provided in the pressurizing chamber, and a pressure detector provided in the upper part of the cast material stalk at a certain distance in the direction of the passage. A pair of hot water detectors, characteristics that determine the head difference with respect to the pressurizing force when the hot water reaches the upper part of the stalk, volume change characteristics of the pressurizing chamber with respect to the head difference of the hot water in the crucible of the casting machine, and the head difference a memory unit that stores the flow rate change characteristics of the hot water in the stoke relative to the difference; and the values of the pressurizing force of the air, the flow rate, and the flow rate of the hot water when the hot water at a predetermined level in the crucible reaches the upper part of the stoke; The values of the air pressurization force, its flow rate, the volume of the pressurizing chamber, and the hot water flow rate when filling hot water from the top of the stoke into the cavity are set and memorized as a pattern, and when hot water actually reaches the top of the stoke. The difference between the set value of the pattern is calculated based on the output signal from each of the above detectors and the comparison corresponding signal from the comparison section, and hot water is sent to the cavity for both the servo mechanisms according to the difference. The structure includes a control section that outputs signals for pressurizing force and flow rate of air to send the air.
(作用)
上記構成により、本発明では、るつぼ内の湯が
鋳型キヤビテイ内に最適の流速で充填されるとき
の加圧室に対するエアの加圧力およびその流量が
パターンとして設定記憶されており、湯を鋳型内
に充填するシヨツト毎に、実際に湯がキヤビテイ
内に充填される際のエアの加圧力および流量が上
記設定されているパターンの設定値に基づいて補
正される。そのため、シヨツト回数の増加によつ
てるつぼ内の湯のレベルが低下し、あるいはるつ
ぼにエア洩れ等が生じても、それらの影響を受け
ることなく上記鋳型キヤビテイ内への湯の充填速
度が最適値に制御される。(Function) With the above configuration, in the present invention, the pressurizing force of air to the pressurizing chamber and its flow rate when the hot water in the crucible is filled into the mold cavity at the optimum flow rate are set and memorized as a pattern, and the hot water is stored as a pattern. For each shot in which hot water is filled into a mold, the pressurizing force and flow rate of air when hot water is actually filled into the cavity are corrected based on the set values of the pattern set above. Therefore, even if the level of hot water in the crucible decreases due to an increase in the number of shots, or air leaks occur in the crucible, the filling speed of the hot water into the mold cavity is maintained at the optimum value without being affected by these factors. controlled by.
(実施例)
以下、本発明の実施例を図面に基づいて詳細に
説明する。(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings.
第1図は本発明の実施例に係る低圧鋳造機の給
湯制御装置を示し、1は低圧鋳造機の炉本体であ
つて、該炉本体1は上面が開放された箱状に形成
され、その内部には溶湯(溶融金属)を収容する
導電性のるつぼ2が担台3上に載置されて収納さ
れ、炉本体1の内壁面には上記るつぼ2内の溶湯
を加熱してその凝固を阻止するヒータ4,4,…
…が配設されている。また、上記炉本体1の上面
開放口は着脱可能な炉蓋5によつて気密状に閉塞
されており、よつて炉本体1内部にはるつぼ2を
覆う密閉状の加圧室6が形成されている。そし
て、この加圧室6には開閉式給気弁を介設したエ
ア供給系路8と、開閉式排気弁9を介設したエア
排気系路10とが連通されている。 FIG. 1 shows a hot water supply control device for a low-pressure casting machine according to an embodiment of the present invention, in which 1 is a furnace body of the low-pressure casting machine, and the furnace body 1 is formed in a box shape with an open top surface. Inside, a conductive crucible 2 containing molten metal (molten metal) is placed on a carrier 3 and housed, and on the inner wall surface of the furnace body 1 is a container that heats the molten metal in the crucible 2 to solidify it. Blocking heaters 4, 4,...
...is arranged. Further, the upper opening of the furnace body 1 is hermetically closed by a removable furnace lid 5, so that a sealed pressurized chamber 6 covering the crucible 2 is formed inside the furnace body 1. ing. The pressurizing chamber 6 is communicated with an air supply line 8 having an open/close type air supply valve interposed therebetween, and an air exhaust line 10 having an open/close type exhaust valve 9 interposed therebetween.
上記炉蓋5の中央部には貫通孔5aが形成さ
れ、該貫通孔5aには非導電性材料よりなるスト
ーク11がその上端フランジ部11aを炉蓋5上
面に当接せしめ、かつ下部を上記るつぼ2内の溶
湯に浸漬せしめて嵌装されている。また、上記炉
蓋5の上面には上型12および下型13よりなる
鋳型14が上記ストーク11のフランジ部11a
を炉蓋5上面とで気密シールして狭圧するように
固定され、上記上型12の下面および下型13の
上面にはそれぞれキヤビテイ15を形成する成型
面12a,13aが設けられ、該キヤビテイ15
内には中子Cが嵌入配置されている。また、上記
キヤビテイ15は下型13に貫通形成した湯口1
6を介して上記ストーク11の上端開口部に連通
されており、炉本体1の加圧室6内にエア供給系
路8を介して加圧エアを供給し、そのエアの加圧
力によりるつぼ2内の溶湯を加圧してそれをるつ
ぼ2からストーク11を介して鋳型14のキヤビ
テイ15内に充填することにより、鋳物を鋳造す
るように構成されている。 A through hole 5a is formed in the center of the furnace lid 5, and a stalk 11 made of a non-conductive material has its upper end flange 11a in contact with the upper surface of the furnace lid 5, and its lower part is connected to the upper surface of the furnace lid 5. It is fitted and immersed in the molten metal in the crucible 2. Further, on the upper surface of the furnace lid 5, a mold 14 consisting of an upper mold 12 and a lower mold 13 is installed at the flange portion 11a of the stalk 11.
The molding surfaces 12a and 13a forming a cavity 15 are provided on the lower surface of the upper mold 12 and the upper surface of the lower mold 13, respectively.
A core C is fitted inside. Further, the cavity 15 has a sprue 1 formed through the lower mold 13.
6 to the upper end opening of the stalk 11, and supplies pressurized air into the pressurizing chamber 6 of the furnace body 1 via the air supply line 8, and the pressurizing force of the air causes the crucible 2 to It is configured to cast a casting by pressurizing the molten metal therein and filling it from the crucible 2 through the stalk 11 into the cavity 15 of the mold 14.
また、上記給気弁7よりも上流側のエア供給系
路8には該エア供給系路8を流れるエアの流量を
調整する流量制御弁17と、エアの圧力を調整す
る圧力制御弁18とが介設され、上記流量制御弁
17にはその開度を制御する流量制御弁サーボ機
構19が、圧力制御弁18には同様にその開度を
制御する圧力制御弁サーボ機構20がそれぞれ付
設されている。 Further, the air supply line 8 on the upstream side of the air supply valve 7 includes a flow control valve 17 for adjusting the flow rate of air flowing through the air supply line 8, and a pressure control valve 18 for adjusting the pressure of the air. The flow control valve 17 is provided with a flow control valve servo mechanism 19 that controls its opening degree, and the pressure control valve 18 is provided with a pressure control valve servo mechanism 20 that similarly controls its opening degree. ing.
一方、上記加圧室6内に臨む炉蓋5内面には加
圧室6内のエア圧力を検出する圧力検出器21が
取り付けられている。また、上記非導電性材料よ
りなるストーク11の上部の壁部内には、その上
端位置、つまり鋳型14の湯口16に近接した位
置に溶湯を検出する湯検出器としての上側電極2
2が、また該上側電極22よりもストーク11の
進路方向下側に一定の距離lを隔てた位置に溶湯
を検出する湯検出器としての下側電極23がそれ
ぞれストーク11内を流れる溶湯と接触可能に埋
設されている。 On the other hand, a pressure detector 21 for detecting the air pressure inside the pressurizing chamber 6 is attached to the inner surface of the furnace lid 5 facing into the pressurizing chamber 6. Further, in the upper wall of the stalk 11 made of the non-conductive material, there is an upper electrode 2 as a molten metal detector for detecting molten metal at its upper end position, that is, at a position close to the sprue 16 of the mold 14.
2, and a lower electrode 23 serving as a hot metal detector for detecting molten metal at a position spaced a certain distance l below the upper electrode 22 in the travel direction of the stalk 11, respectively, comes into contact with the molten metal flowing inside the stalk 11. Possibly buried.
さらに、上記圧力検出器21、両電極22,2
3および導電性材料よりなるるつぼ2は、圧力検
出器21の出力信号および電極22,23の溶湯
検出信号を受けて上記両サーボ機構19,20を
制御するCPUを内蔵した制御部24に接続され、
該制御部24は記憶部30に接続されている。該
記憶部30は、第2図に示すように、Nシヨツト
目に加圧室6内への加圧エアの供給により湯がス
トーク11内を上昇してその上側電極22の位置
に到達した場合において、そのエアの加圧力PAN
の変化に応じてるつぼ2内の湯面とストーク11
内の湯面との間の高低差、すなわち位置ヘツド差
hNが変化するときのPAN=ρhN(ρは溶湯の密度)
で表される特性と、そのるつぼ2内の湯のヘツド
差hNの変化に応じて加圧室6内の容積VANが変化
するときの第4図に示される特性と、上記ヘツド
差hNの変化に応じてストーク11内の湯の流速
VANが変化するときの第5図に示される特性との
3つの特性をそれぞれ記憶している。 Furthermore, the pressure detector 21, both electrodes 22, 2
3 and the crucible 2 made of conductive material are connected to a control unit 24 containing a CPU that controls both the servo mechanisms 19 and 20 in response to the output signal of the pressure detector 21 and the molten metal detection signals of the electrodes 22 and 23. ,
The control section 24 is connected to a storage section 30. As shown in FIG. 2, the storage unit 30 stores information when hot water rises in the stalk 11 and reaches the position of the upper electrode 22 by supplying pressurized air into the pressurizing chamber 6 at the Nth shot. , the pressurizing force of the air P AN
The hot water level in the crucible 2 and the stoke 11 according to changes in
The height difference between the inside and the hot water level, that is, the positional head difference
P AN when h N changes = ρh N (ρ is the density of the molten metal)
The characteristics shown in FIG. 4 when the volume V AN in the pressurizing chamber 6 changes according to the change in the head difference h N of the hot water in the crucible 2, and the above head difference h The flow rate of hot water in the stalk 11 depending on the change in N.
Three characteristics are memorized, including the characteristics shown in FIG. 5 when V AN changes.
一方、上記制御部24は、第3図に詳示するよ
うに、上記圧力検出器21からの出力信号を増巾
するアンプ25と、上記両電極22,23からの
信号およびるつぼ2のアース信号に基づいて湯が
ストーク11内を下部電極23から上部電極22
へ上昇するまでの通過時間tNを計測するタイマ2
6と、上記アンプ25およびタイマ26からの出
力を入力/o27を介して受け、その出力信号
および上記記憶部30からの信号を演算処理して
その結果を出力/o28を介して上記両サーボ
機構19,20に出力する演算部29とからなつ
ている。そして、この制御部24は、るつぼ2に
所定のシヨツト分の溶湯が収容された後、そのる
つぼ2内の所定レベルにある湯が1シヨツト目に
ストーク11上部の上側電極22に上昇到達した
ときのエアの加圧力PA、その流量QAおよび溶湯
の流速VAの各値と、その後、湯がさらに上昇し
てストーク11上部から鋳型14の湯口16を通
つてキヤビテイ15内に充填されたときのエアの
加圧力PB、その流量QB、加圧室6の容積VOおよ
び溶湯の流速VBの各値とのパターンを設定記憶
する機能を有している。また、制御部24は、実
際に湯がストーク11上部の上側電極22の位置
に達したときに上記圧力検出器21および両電極
22,23から発せられる出力信号と、該出力信
号を上記記憶部30で比較的対応させて得られる
比較対応信号とをもとに、上記設定記憶されてい
るパターンの所定値との差を補正量とし求め、そ
の差に応じて上記両サーボ機構19,20に対し
てキヤビテイ15内へ湯を送るためのエアの加圧
力PBNおよび流量QBNの各信号を出力する機能を
も備えている。 On the other hand, as shown in detail in FIG. 3, the control section 24 includes an amplifier 25 that amplifies the output signal from the pressure detector 21, signals from both the electrodes 22 and 23, and a ground signal from the crucible 2. Based on this, hot water flows inside the stalk 11 from the lower electrode 23 to the upper electrode 22.
Timer 2 measures the passing time tN until it rises to
6, receives the output from the amplifier 25 and the timer 26 via the input/o27, processes the output signal and the signal from the storage section 30, and outputs the result via the servo mechanism/o28. 19 and 20. Then, after a predetermined shot of molten metal is stored in the crucible 2, when the melt at a predetermined level in the crucible 2 rises and reaches the upper electrode 22 at the top of the stoke 11 for the first shot, After that, the molten metal rises further and fills the cavity 15 from the upper part of the stoke 11 through the sprue 16 of the mold 14. It has a function of setting and storing patterns of each value of the pressurizing force P B of the air, its flow rate Q B , the volume V O of the pressurizing chamber 6, and the flow velocity V B of the molten metal. The control unit 24 also stores an output signal emitted from the pressure detector 21 and both electrodes 22, 23 when the hot water actually reaches the position of the upper electrode 22 at the top of the stalk 11, and the output signal into the storage unit. Based on the comparative correspondence signal obtained by relatively corresponding in step 30, the difference from the predetermined value of the set and memorized pattern is determined as a correction amount, and both the servo mechanisms 19 and 20 are adjusted according to the difference. On the other hand, it also has a function of outputting signals of the air pressurizing force P BN and flow rate Q BN for sending hot water into the cavity 15.
次に、上記実施例の作用について説明するに、
低圧鋳造機の炉本体1内のるつぼ2内に所定量の
溶湯が配入された後、炉蓋5により炉本体1が密
閉される。その状態で排気弁9が閉じ、給気弁7
が開いて上記炉本体1内の加圧室6に加圧エアが
供給されると、その加圧力によりるつぼ2内の溶
湯が加圧されてるつぼ2内からストローク11を
介して鋳型14のキヤビテイ15内に充填され
る。そして、所定時間経過後、上記キヤビテイ1
5内の溶湯が加圧されながら凝固すると、上記給
気弁7が閉じるとともに排気弁9が開いて加圧室
6内の加圧力が低下し、この加圧室6内の圧力低
下により上記ストーク11内の溶湯が下降移動し
てるつぼ2内に戻り、以上によつて鋳型14のキ
ヤビテイ15に対する鋳造の1シヨツトが終了す
る。以後は上記と同様のシヨツトが繰り返され、
るつぼ2内の溶湯のレベルが所定レベルに低下す
ると、炉蓋5が開けられて新たにるつぼ2内に所
定量の溶湯が補給される。 Next, to explain the operation of the above embodiment,
After a predetermined amount of molten metal is placed in a crucible 2 in a furnace body 1 of a low-pressure casting machine, the furnace body 1 is sealed with a furnace lid 5. In this state, the exhaust valve 9 is closed and the air supply valve 7 is closed.
When the pressurized air is supplied to the pressurized chamber 6 in the furnace body 1, the molten metal in the crucible 2 is moved from the pressurized crucible 2 into the cavity of the mold 14 via the stroke 11. 15 is filled. Then, after a predetermined period of time has passed, the cavity 1
When the molten metal in the pressurizing chamber 5 solidifies while being pressurized, the air supply valve 7 closes and the exhaust valve 9 opens, reducing the pressurizing pressure in the pressurizing chamber 6. Due to this decrease in pressure in the pressurizing chamber 6, the above-mentioned stalk The molten metal in the mold 11 moves downward and returns into the crucible 2, and one shot of casting into the cavity 15 of the mold 14 is thus completed. After that, the same shot as above is repeated,
When the level of the molten metal in the crucible 2 drops to a predetermined level, the furnace lid 5 is opened and a predetermined amount of molten metal is newly replenished into the crucible 2.
その場合、Nシヨツト目に鋳型14のキヤビテ
イ15内に湯が充填されるときの上記加圧室6に
対するエアの加圧力PBNおよび流量QBNは制御部
24によつて制御される。その手順を第6図に示
すフローチヤートにより詳述すると、先ず、スタ
ート後のステツプS1において、Nシヨツト目に湯
が上側電極22位置に上昇したときの圧力検出器
21および電極22,23からの出力信号によつ
て、加圧室6内のエアの加圧力PANと両電極2
2,23間を上昇する溶湯の通過時間tNとを入力
する。この後、ステツプS2において、上記入力さ
れた溶湯通過時間tNから溶湯の平均流速V′AN=
l/tNを求めたのち、ステツプS3に移つて上記入
力された加圧力PANを記憶部30に記憶されてい
る3つの特性の各々と比較対応させてヘツド差hN
=PAN/ρ、湯の流速VANおよび加圧室6の容積
VANを求める。次いで、ステツプS4において、上
記ステツプS2およびS3で求められた湯の平均流速
V′ANおよび流速VANによつて加圧室6からのエア
のリリーフ状態を示す加圧効率η=V′AN/VANを
算出するとともに、上記ステツプS3で求められた
加圧室6の容積VANと既に記憶されている加圧室
6の容積VOとによつて加圧室6の気体部分の容
積比率ξ=VAN/VOを算出する。この後、ステツ
プS5に移つて、上記記憶されているパターンの設
定値の中から湯のキヤビテイ15への充填時のエ
アの流量QBおよび加圧力PBと、湯のストーク1
1上部への到達時のエアの加圧力PAとを読み出
すとともに、その両加圧力PA,PBによつて湯の
キヤビテイ15内への充填に必要な充填圧力△P
=PB−PAを求める。その後のステツプS6におい
て、上記パターンのエア流量QBに容積比率ξ=
(VAN/VO)に乗じ、かつそれを加圧効率η(=
V′AN/VAN)で割ることにより、Nシヨツト目に
湯が鋳型14のキヤビテイ15内に充填されると
きのエアの流量QBN=QB×(VAN/VO)÷(V′AN/
VAN)
を算出するとともに、上記Nシヨツト目のストー
ク11上部への湯の到達時におけるエア加圧力
PANに上記充填圧力△P(=PB−PA)を加えるこ
とにより、Nシヨツト目に湯がキヤビテイ15内
に充填されるときのエアの加圧力
PBN=PAN+PB−PA
を算出する。しかる後、ステツプS7において、上
記ステツプS6で算出されたエアの加圧力PBNおよ
び流量QBNに対する圧力制御弁18および流量制
御弁17の開度関数f(PBN)、f(QBN)を求め、
次のステツプS8においてその関数f(PBN)および
f(QBN)をそれぞれエア供給系路8の圧力制御
弁サーボ機構19および流量制御弁サーボ機構2
0に出力し、以上によつて制御の1サイクルが終
了する。 In this case, the pressurizing force P BN and flow rate Q BN of air to the pressurizing chamber 6 when the cavity 15 of the mold 14 is filled with hot water at the Nth shot are controlled by the control section 24 . The procedure is explained in detail using the flowchart shown in FIG. 6. First, in step S1 after the start, when the hot water rises to the upper electrode 22 position at the N shot, the pressure detector 21 and the electrodes 22, 23 are detected. The pressure P AN of the air in the pressure chamber 6 and both electrodes 2 are determined by the output signal of
Input the passing time t N of the molten metal rising between 2 and 23. After this, in step S2 , the average flow velocity of the molten metal V ′ AN =
After calculating l/t N , the process moves to step S3 , where the input pressure P AN is compared and correlated with each of the three characteristics stored in the storage unit 30, and the head difference h N is calculated.
= P AN /ρ, flow rate of hot water V AN and volume of pressurizing chamber 6
Find VAN . Next, in step S4 , the average flow velocity of the hot water determined in steps S2 and S3 is calculated.
The pressurizing efficiency η = V' AN /V AN , which indicates the state of air relief from the pressurizing chamber 6, is calculated using V' AN and the flow rate V AN , and the pressurizing chamber 6 obtained in step S 3 above is calculated. The volume ratio ξ=V AN / V O of the gas portion of the pressurizing chamber 6 is calculated from the volume V AN of the pressurizing chamber 6 and the already stored volume V O of the pressurizing chamber 6. After that, the process moves to step S5 , and from among the set values of the pattern stored above, the air flow rate Q B and pressurizing force P B when filling the hot water cavity 15, and the hot water stalk 1 are determined.
1. Read the pressurizing force P A of the air when it reaches the upper part, and calculate the filling pressure △P necessary to fill the cavity 15 with hot water based on both pressurizing forces P A and P B
Find =P B −P A. In the subsequent step S6 , the volume ratio ξ =
(V AN /V O ), and multiply it by the pressurization efficiency η (=
By dividing by V′ AN /V AN ), the air flow rate when the cavity 15 of the mold 14 is filled with hot water at the N shot is calculated: Q BN = Q B × (V AN /V O ) ÷ (V′ AN /
In addition to calculating the air pressure when the hot water reaches the upper part of the stalk 11 of the Nth shot,
By adding the above filling pressure △P (=P B - P A ) to P AN , the pressurizing force of air when hot water is filled into the cavity 15 at the N shot is P BN = P AN + P B - P A Calculate. Thereafter, in step S 7 , the opening functions f(P BN ) and f( Q BN ),
In the next step S8 , the functions f(P BN ) and f(Q BN ) are applied to the pressure control valve servo mechanism 19 and flow control valve servo mechanism 2 of the air supply line 8, respectively.
0, and one cycle of control is thus completed.
したがつて、この実施例では、配湯後の1シヨ
ツト目に湯がストーク11上部の上側電極22位
置を通過した後、鋳型14のキヤビテイ15内に
充填されるときのエアの加圧力PBおよび流量QB
がパターンとして制御部24に設定記憶され、そ
れ以後のシヨツトでは、上記鋳型14のキヤビテ
イ15への湯の充填時のエアの加圧力PBNおよび
流量QBNは、第7図に加圧力の例で示すようにキ
ヤビテイ15内への湯の充填速度が1シヨツト目
と同じになるように補正されるので、るつぼ2内
の湯量の変化に拘らす鋳型14のキヤビテイ15
内への湯の充填速度を一定に保つことができ、鋳
造品の品質を向上させることができる。 Therefore, in this embodiment, the pressurizing force P B of air when the hot water is filled into the cavity 15 of the mold 14 after passing through the upper electrode 22 position on the upper part of the stalk 11 in the first shot after dispensing the hot water . and flow rate Q B
is set and stored in the control unit 24 as a pattern, and in subsequent shots, the pressurizing force PBN and flow rate QBN of the air when filling the cavity 15 of the mold 14 with hot water are shown in FIG. 7 as an example of the pressurizing force. As shown in , since the filling speed of the hot water into the cavity 15 is corrected to be the same as the first shot, the cavity 15 of the mold 14 is adjusted to be the same as the first shot.
The filling speed of hot water into the interior can be kept constant, and the quality of the cast product can be improved.
また、シヨツト回数が増えるのに伴つて加圧室
6に供給するエアの流量QBNが増量補正されるの
で、るつぼ2内の湯のレベルが変化しても、それ
に関係なく湯のるつぼ2内への供給時間を略一定
に保つことができる。 In addition, as the number of shots increases, the flow rate Q BN of air supplied to the pressurizing chamber 6 is corrected to increase, so even if the level of hot water in the crucible 2 changes, the amount of hot water in the crucible 2 is increased regardless of the change in the level of hot water in the crucible 2. The supply time can be kept approximately constant.
(発明の効果)
以上説明したように、本発明によれば、低圧鋳
造機の給湯時に加圧エアにより湯が上昇してスト
ーク上部に対したときの該加圧エアの供給状態を
検出し、それを最適条件と比較してその差に応じ
てエアの加圧力およびその流量を制御するように
したことにより、るつぼ内の湯量の変化やるつぼ
内からのエア洩れ等の影響に拘らず、鋳型キヤビ
テイ内への湯の充填速度を正確に一定に保つこと
ができ、よつて低圧鋳造機による鋳造品の品質向
上および鋳造時間の短縮化を図ることができるも
のである。(Effects of the Invention) As explained above, according to the present invention, when hot water rises due to pressurized air and hits the upper part of the stalk during hot water supply in a low-pressure casting machine, the supply state of the pressurized air is detected, By comparing this with the optimum conditions and controlling the air pressure and flow rate according to the difference, the mold can be molded regardless of changes in the amount of hot water in the crucible or air leakage from inside the crucible. The filling rate of hot water into the cavity can be maintained accurately and constant, thereby improving the quality of products cast by the low-pressure casting machine and shortening the casting time.
図面は本発明の実施例を示すもので、第1図は
全体構成図、第2図は鋳造機のストーク上部に湯
が上昇したときの模式説明図、第3図は制御系の
ブロツク図、第4図はヘツド差に対する加圧室の
容積変化特性を示す説明図、第5図はヘツド差に
対す湯の流速変化特性を示す説明図、第6図は制
御フローチヤート図、第7図は給湯シヨツト回数
の増加に伴う加圧パターンの変化を示す説明図で
ある。
1……炉本体、2……るつぼ、6……加圧室、
8……エア供給系路、11……ストーク、14…
…鋳型、15……キヤビテイ、17……流量制御
弁、18……圧力制御弁、19,20……サーボ
機構、21……圧力検出器、22,23,……電
極、24……制御部、30……記憶部。
The drawings show an embodiment of the present invention; Fig. 1 is an overall configuration diagram, Fig. 2 is a schematic explanatory diagram when hot water rises to the upper part of the stalk of the casting machine, and Fig. 3 is a block diagram of the control system. Fig. 4 is an explanatory diagram showing the volume change characteristics of the pressurizing chamber with respect to the head difference, Fig. 5 is an explanatory diagram showing the flow rate change characteristic of hot water with respect to the head difference, Fig. 6 is a control flowchart, and Fig. 7 is FIG. 3 is an explanatory diagram showing a change in the pressurization pattern as the number of hot water shots increases. 1...furnace body, 2...crucible, 6...pressurization chamber,
8...Air supply system line, 11...Stoke, 14...
... Mold, 15 ... Cavity, 17 ... Flow rate control valve, 18 ... Pressure control valve, 19, 20 ... Servo mechanism, 21 ... Pressure detector, 22, 23, ... Electrode, 24 ... Control section , 30...Storage section.
Claims (1)
からストークを介して鋳型のキヤビテイ内に湯を
充填して鋳造する低圧鋳造機において、上記加圧
室に連通し、流量制御弁および圧力制御弁が介設
されたエア供給系路と、上記両制御弁の各開度を
制御するサーボ機構と、上記加圧室内に設けられ
た圧力検出器と、上記ストークの上部にその通路
方向に一定距離を隔てて設けられた一対の湯検出
器と、湯がストーク上部に達したときの加圧力に
対するヘツド差変化特性と、るつぼ内の湯のヘツ
ド差に対する加圧室の容積変化特性と、該ヘツド
差に対するストーク内の湯の流速変化特性とをそ
れぞれ記憶する記憶部と、るつぼ内の所定レベル
にある湯がストーク上部に達したときのエアの加
圧力、その流量および湯の流速の各値ならびに上
記ストーク上部からキヤビテイ内への湯の充填時
のエアの加圧力、その流量、加圧室の容積および
湯の流速の各値のパターンを設定記憶する一方、
実際に湯がストーク上部に達したときの上記各検
出器からの出力信号と上記記憶部での比較対応信
号とを基に上記パターンの設定値との差を求め、
その差に応じて上記両サーボ機構に対してキヤビ
テイ内へ湯を送るためのエアの加圧力および流量
の各信号を出力する制御部とからなることを特徴
とする低圧鋳造機の給湯制御装置。1. In a low-pressure casting machine that supplies air to a pressurized chamber that covers a crucible, and fills hot water from the crucible into the cavity of a mold via a stalk for casting, the pressurized chamber is connected to the pressurized chamber, and a flow rate control valve and a pressure control valve are connected to the pressurized chamber. An air supply line in which a valve is installed, a servo mechanism that controls the opening degrees of the two control valves, a pressure detector installed in the pressurizing chamber, and a pressure sensor installed in the upper part of the stalk that is constant in the direction of the passage. A pair of hot water detectors installed at a distance, a head difference change characteristic with respect to the pressurizing force when the hot water reaches the upper part of the stalk, a volume change characteristic of the pressurizing chamber with respect to the head difference of the hot water in the crucible, and A memory unit that stores the flow rate change characteristics of the hot water in the stoke relative to the head difference, and values of the pressurizing force of the air, its flow rate, and the flow rate of the hot water when the hot water at a predetermined level in the crucible reaches the upper part of the stoke. Also, while setting and memorizing the patterns of each value of the pressurizing force of air, its flow rate, the volume of the pressurizing chamber, and the flow rate of hot water when filling hot water from the upper part of the stalk into the cavity,
Find the difference between the set value of the pattern based on the output signal from each of the detectors when the hot water actually reaches the top of the stalk and the comparison corresponding signal in the storage section,
A hot water supply control device for a low-pressure casting machine, comprising a control section that outputs signals of pressurizing force and flow rate of air for sending hot water into the cavity to both the servo mechanisms according to the difference.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP19099784A JPS6171166A (en) | 1984-09-12 | 1984-09-12 | Device for controlling pouring of low-pressure casting machine |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP19099784A JPS6171166A (en) | 1984-09-12 | 1984-09-12 | Device for controlling pouring of low-pressure casting machine |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS6171166A JPS6171166A (en) | 1986-04-12 |
JPH0513751B2 true JPH0513751B2 (en) | 1993-02-23 |
Family
ID=16267143
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP19099784A Granted JPS6171166A (en) | 1984-09-12 | 1984-09-12 | Device for controlling pouring of low-pressure casting machine |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS6171166A (en) |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS63220969A (en) * | 1987-03-10 | 1988-09-14 | Ckd Corp | Low pressure casting method |
JPH01180774A (en) * | 1987-12-28 | 1989-07-18 | Morita Mfg Co Ltd | Automatic precision casting method and its device |
CN108580847B (en) * | 2018-07-26 | 2020-09-01 | 哈尔滨工业大学 | Nonlinear pressurization control system for differential pressure casting forming of complex metal component |
JP2020163399A (en) * | 2019-03-28 | 2020-10-08 | 宇部興産機械株式会社 | Casting device |
-
1984
- 1984-09-12 JP JP19099784A patent/JPS6171166A/en active Granted
Also Published As
Publication number | Publication date |
---|---|
JPS6171166A (en) | 1986-04-12 |
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