JPH01143752A - Casting for compressor and its manufacture - Google Patents
Casting for compressor and its manufactureInfo
- Publication number
- JPH01143752A JPH01143752A JP30249987A JP30249987A JPH01143752A JP H01143752 A JPH01143752 A JP H01143752A JP 30249987 A JP30249987 A JP 30249987A JP 30249987 A JP30249987 A JP 30249987A JP H01143752 A JPH01143752 A JP H01143752A
- Authority
- JP
- Japan
- Prior art keywords
- casting
- compressor
- temperature
- mold
- rib
- 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.)
- Granted
Links
- 238000005266 casting Methods 0.000 title claims abstract description 69
- 238000004519 manufacturing process Methods 0.000 title claims description 8
- 229910000838 Al alloy Inorganic materials 0.000 claims abstract description 20
- 230000007547 defect Effects 0.000 claims abstract description 18
- 229910017818 Cu—Mg Inorganic materials 0.000 claims abstract description 10
- 229910018505 Ni—Mg Inorganic materials 0.000 claims abstract description 9
- 239000013078 crystal Substances 0.000 claims abstract description 6
- 238000009826 distribution Methods 0.000 claims abstract description 6
- 229910018566 Al—Si—Mg Inorganic materials 0.000 claims abstract description 5
- 230000001105 regulatory effect Effects 0.000 claims abstract description 5
- 238000000034 method Methods 0.000 claims description 10
- 229910052751 metal Inorganic materials 0.000 abstract description 14
- 239000002184 metal Substances 0.000 abstract description 14
- 239000000203 mixture Substances 0.000 abstract description 4
- 238000007711 solidification Methods 0.000 description 13
- 230000008023 solidification Effects 0.000 description 13
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 10
- 238000001816 cooling Methods 0.000 description 9
- 229910045601 alloy Inorganic materials 0.000 description 6
- 239000000956 alloy Substances 0.000 description 6
- 239000003507 refrigerant Substances 0.000 description 6
- 210000001787 dendrite Anatomy 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 238000009987 spinning Methods 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- 229910007981 Si-Mg Inorganic materials 0.000 description 2
- 229910008316 Si—Mg Inorganic materials 0.000 description 2
- 230000001276 controlling effect Effects 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 230000035515 penetration Effects 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- 229910001018 Cast iron Inorganic materials 0.000 description 1
- 229910007933 Si-M Inorganic materials 0.000 description 1
- 229910008286 Si—Cu—Ni Inorganic materials 0.000 description 1
- 229910008318 Si—M Inorganic materials 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 238000009529 body temperature measurement Methods 0.000 description 1
- 230000015271 coagulation Effects 0.000 description 1
- 238000005345 coagulation Methods 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000007872 degassing Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 238000013022 venting Methods 0.000 description 1
- 239000013585 weight reducing agent Substances 0.000 description 1
Abstract
Description
（産業上の利用分野）
本発明は圧縮機用鋳物の製造に係り、より詳細には、渦
巻形状の比較的高いリブを有する圧縮機用鋳物をアルミ
ニウム合金の低圧鋳造で一体的に製造する技術に関する
。
（従来の技術及び解決しようとする問題点）従来より、
第１図に示すような中心部に渦巻形状の比較的高いリブ
を有する圧縮機用部品は、高い強度が必要とされるため
、アルミニウム合金鋳物はあまり採用されず、鋳鉄等が
採用されている。
しかし、近年、軽量化、小型化等の要望が強まるにつれ
て、アルミニウム合金で一体的に鋳造する試みがなされ
るようになってきた。
しかし乍ら、この種の形状の鋳物に試みられている低圧
鋳造法では、渦巻状の比較的高いリブ部に溶湯が均一に
まわらず、不廻り、湯境い等の表面欠陥が現われるばか
りでなく、型温が高いほどシュリンケージ欠陥が増加し
、大きく増大して鋳物の疲労強度を害するという問題が
あった。このため、圧縮機用部品をアルミニウム合金で
一体的に鋳造する技術の改善が望まれていた。
本発明は、か）る事情に鑑みてなされたものであって、
鋳造欠陥がなく所要の機械的性質を備えた圧縮機用アル
ミニウム合金鋳物を提供し、またその製造方法を提供す
ることを目的とするものである。
（問題点を解決するための手段）
上記目的を達成するため１本発明者は、中心部に渦巻状
の比較的高いリブを有する圧縮機用部品をアルミニウム
合金にて低圧鋳造する際の特に湯廻り性について研究を
重ねたところ、従来の低圧鋳造法の場合、一般に３５０
℃以上の型温か採用されているが、鋳物の湯廻り性を改
善するには金型温度を高くするほど良好とされる一般的
常識とは逆に、金型、特にリブ周辺部の上型の温度が特
定の温度を超えると湯廻り不良が頻発する現象が生ずる
ことを究明した。
そこで、その対応策について更に種々実験研究を重ねた
結果、特定のアルミニウム合金系を用いて上型及び下型
の型温をコントロールするならば、指向性凝固によって
結晶粒サイズ及び分布を制御でき、機械的性質の確保と
共に不廻り、湯境い等の表面欠陥或いはシュリンケージ
欠陥の少ない健全な圧縮機用部品が得られることを見い
出し、ここに本発明をなしたものである。
すなわち、本発明に係る圧縮機用部品は、中心部に渦巻
状の比較的高いリブを有する圧縮機用部品のアルミニウ
ム合金鋳物において、該アルミニウム合金がＡｌ１−８
１−Ｍｇ系、Ａｌ−Ｓｉ−Ｃｕ−Ｍｇ系又はＡ Ｑ −
Ｓｉ −Ｃｕ −Ｎｉ−Ｍｇ系であって。
結晶粒サイズが１０〜５０μ璽で且つリブ先端から根元
に向って大きくなる分布を有し、鋳造欠陥の大きさを５
００μ麗以下に規制したことを特徴とするものである。
また、その製造方法は、中心部に渦巻状の比較的高いリ
ブを有する圧縮機用鋳物をＡΩ−８１−Ｍｇ系、Ａｌ−
Ｓｉ−Ｃｕ−Ｍｇ系、又はＡｌＡｌ−Ｓｉ−Ｃｕ−Ｎｉ
−系アルミニウム合金の低圧鋳造にて製造するに際し、
金型温度゛を、リブ周辺に対応する上型中心部を２００
〜３５０℃、下型を２５０〜４００℃に制御して鋳造す
ることを特徴とするものである。
以下に本発明を更に詳細に説明する。
アルミニウム合金製圧縮機用鋳物は、第１図の断面図で
も示されるとおり、リブは軸対称とはなっておらず、当
然、リブを形成する上型の部分も熱容量的↓こアンバラ
ンスになっている。したがって、溶湯の持込む熱を吸収
する金型は各部分において温度差を生じることになる。
しかも、一方では、断面上、高さ及び厚さの全く同じ形
状のリブを有しているため、このような各々のリブ形状
の中に均一に且つ同じタイミングで溶湯を下方から上方
に向けて充填することは非常に困難である。
すなわち、溶湯が下方から充填されていく際。
溶湯がリブ形状の部分に差し掛かると、温度の高いリブ
形状部から先に充填され、温度の低い部分が取り残され
る、所謂選択的渦流れを生ずることになる。
このため、渦巻状の比較的高いリブを有する圧縮機用鋳
物の場合は、形状的要因から、一般鋳物と異なり、不廻
り、湯境い改善のために型温を上げすぎることはできな
いことが判明した。
因みに、本発明者は、種々実験の結果、Ａｌ−Ｓｉ−Ｍ
ｇ系、Ａｌ−Ｓｉ−Ｃｕ−Ｍｇ系及びＡｌ−５ｉ−Ｃｕ
−Ｎｉ−Ｍｇ系合金では、通常の低圧鋳造法による金型
温度３５０〜５５０℃を採用した場合、上型温度が３５
０℃を超えると選択的湯流れを生じ始めることを確認し
た。
本発明法においては、このような知見に基づき、圧縮機
用鋳物の低圧鋳造に際して、上型及び下型の型温を温度
制御することとしたものであって、以下の態様により低
圧鋳造を実施する。
選択的湯流れ防止の面からすると、型温は低いほど良い
のであるが、上型中心部、すなわちリブ周辺に対応する
上型温度が２００℃未満では、溶湯の充填中に局部的な
凝固が始まり、別の不廻り、湯境い等の表面欠陥が生じ
るので、好ましくない。
また、３５０℃を超えると前述の如く選択内湯流れが生
じ、これに起因する湯廻り不良が発生するので好ましく
ない。
したがって、上型中心部の温度は２００〜３５０℃の範
囲にコントロールする必要がある。
一方、圧縮機用鋳物は、その使用用途かちリブ部及び下
部に繰り返し荷重がかかるため、引張強さで約３６ ｋ
ｇｆ／ａｍ”以上ノ強度並びニ１０．Ｏｋｇｆ／＠■２
で２ Ｘ １０’サイクル程度の疲労強度が必要である
。これらを満足するためには、指向性凝固を促進し、内
部欠陥を最小限に抑制する必要がある。したがって、対
応する下型温度は、この指向性凝固を阻害するような温
度であってはならない。
指向性凝固を害さない温度とすれば、上型温度と同じか
、或いはそれよりも高く設定すればよいが、高すぎると
凝固時間を引き伸ばし、シュリンケージ欠陥が生じ、鋳
物の機械的性質を阻害する。また、凝固時間が長くなる
、すなわち、凝固速度が遅くなると、結晶粒サイズ（Ｄ
、Ａ、Ｓ、Ｉ［）が太きくなる。結晶粒サイズは機械的
性質に大きく影響することはよく知られているところで
あり、圧縮機用鋳物の場合、結晶粒サイズは５０μｍ以
下に制御しなければならない、なお、Ｄ、Ａ、Ｓ、１１
はデンドライト・アーム・スペーシング■の略語で、デ
ンドライト（第１枝）の側面から枝状に張り出したデン
ドライト（デンドライト・アーム・第２枝）のアーム間
の間隔を称するものである。
これらの理由から、下型温度の上限は４００℃に止める
必要がある。しかし、低すぎると溶湯がリブ形状部に充
填する前に凝固し始め、不廻り、湯境いの原因となるの
で、下型温度の下限は２５０℃に止める必要がある。
したがって、下型の温度は２５０〜４００℃の範囲にコ
ントロールする必要がある。
なお、低圧鋳造の他の条件、例えば、上型及び下型の型
温制御方式としては、型内に冷却機構（例、冷媒貫流用
冷却穴）及び測温手段（例、熱電対）を設けて型温制御
部に接続させればよく、また、溶湯温度、充填速度等は
適宜法めることができ、特に制限はされない。
次に、上記低圧鋳造法により得られる圧縮機用鋳物につ
いて説明する。
圧縮機用鋳物の形状としては、第１図に示した形状寸法
に限らず、渦巻の数、リブの高さ及び厚さ等々は種々の
変形が可能であるが、要はリブの高さｈが厚さｔの約５
倍以上の如く比較的高い形状の場合に効果的である。
材質としては、圧縮機用部品に要求される機械的性質（
引張強さ、疲労強度など）、鋳造性等々を考慮して、Ａ
ｌ−Ｓｉ−Ｍｇ系、Ａｌ−８Ｌ−Ｃｕ−Ｍｇ系又はＡ
Ｑ −Ｓｉ −Ｃｕ −Ｎｉ −Ｍｇ系の鋳造用アルミ
ニウム合金を選定すればよい。その組成としては、Ａｌ
−Ｓｉ−Ｍｇ系ではＪ Ｉ ５ＡＣ４Ｃ１ＡＣ４ＣＨな
ど、Ａｌ−Ｓｉ−Ｃｕ−Ｎｉ−Ｍｇ系ではＪＩＳＡＣ８
Ｂ、ＡＣ８Ｃなど、Ａｌ−Ｓｉ−Ｃｕ−Ｎｉ−Ｍｇ系で
はＪ Ｉ ５ＡＣ８Ａなどを挙げることができる。
このような組成のアルミニウム合金を上記低圧鋳造法で
鋳造することにより、指向性凝固が進められ、結晶粒サ
イズが５０μｍ以下でリブ先端から根元に向って大きく
なる分布のものが得られる。
なお、５０μ園を超えると圧縮機用部品に要求される機
械的性質が不充分となり、好ましくなく、また結晶粒サ
イズが１０μｍ未満になるような冷却速度を与える金型
温度では鋳物全体の指向性凝固が図れないので好ましく
ない。更には、指向性凝固により不廻り、湯境い等の内
部欠陥の極めて少ない鋳物が得られる。
一方、疲労強度にはシュリンケージ等の鋳物内部の不連
続点の大きさや数が大きく影響するので、このような鋳
造欠陥は少なくとも５００μ園以下の大きさまで抑制さ
れねばならない。上型及び下型の温度差が大きすぎると
シュリンケージ等が発生しやすくなるが、前述の型温の
範囲で上型及び下型を適宜温度制御することにより、鋳
造欠陥の大きさを上記の如く抑制することが可能である
。
次に本発明の実施例を示す。
（実施例）
第２図は本発明法の実施に用いる低圧鋳造装置及び金型
関係の一例を示したものである。
本実施例における金型は、高さ約４０■醜、幅約７■の
比較的高い渦巻状リブ１を中心部に有する形状の圧縮機
用鋳物を鋳造するべく設計された金型であって、リブ部
を形成する上型２の部分の間に約１０鵬腸φの冷却穴３
が複数個設けられ、これに空気や水或いはその混合冷媒
を貫流させることにより、第１図に示す斜線部（リブを
形成する上型部分）を冷却するようになっている。上型
２のリブ形成部の上方には、測温用の熱電対を挿入する
熱電対用穴４が１個又は複数個設けられ、その他、リブ
部上端の適当な箇所に複数個のガス抜き機構５が設けら
れている。
型温は冷媒の貫通量、貫通時期及び時間によって制御で
きるようになっており、型の設定温度は前記り、Ａ、Ｓ
、Ｉ［のサイズを確認しながら、最適温度を選択すれば
よい。
一方、下型６は、中央部に湯ロアを有し、ストーク８の
上部に設置されており、製品部Ｗは、湯ロアをストーク
８を介して下方に準備される溶湯（図示せず）に通じて
いる。また第２図に示すように、湯口部の周囲の下型６
には冷却穴９が設けられており、上型冷却と同様に空気
や水或いはその混合冷媒が貫流するようになっており、
これにて下型温度は上型温度と同様に制御される。なお
、下型６にも必要に応じ測温用熱電対を設けることは云
うまでもない。
準備される溶湯としては、例えば、Ａｌ−Ｓｉ−Ｍｇ系
の４ＣＨ合金及びＡｌ−Ｓｉ−Ｃｕ−Ｍｇ系のＡＣ８Ｃ
合金を常法によって溶解し、溶湯処理（脱ガスなど）を
施した後、ストーク下部に６７０〜７４０℃に保持する
。保持温度は合金の種類によって適当に選択される。
そして、低圧鋳造の常法により、溶湯をストーク８と湯
ロアを介して製品部Ｗに押し上げ、リブ部に平均的に充
填していくようにする。この際、湯の充填（上昇）速度
は選択的渦流れを助長しない速度とすることが必要であ
る。
最後に、湯口部の途中まで凝固が進んだ後、未凝固溶湯
をストーク８を介して元の湯溜め（図示せず）に戻し、
１サイクルが終了する。
本実施例においては、上述の金型及び装置を使用し、Ａ
ｍ−８１−Ｍｇ系０）ＡＣ４ＣＨ合金とＡｆｌ−Ｓｉ−
Ｃｕ−Ｍｇ系のＡＣ８Ｇ合金ニツいて、第１表に示す条
件にてそれぞれ鋳造数５０回の低圧鋳造試験を行った。
試験後、得られた鋳物製品の鋳造欠陥を調べると共に、
一部（Ａ Ｃ８Ｃのもの）について鋳物製品の円板部か
ら試験片を切り出し、Ｔ６処理を施して機械的性質を調
べた。それらの結果を第１表及び第２表に示す。
本発明例はいずれも高歩留りで安定して高い強度を示し
、必要強度（引張強さ： ３６ ｋｇｆ／＋＋＋ｍ”以
上、疲労強度： １０ 、 Ｏｋｇｆ／ｎ＋ｍ”で２
Ｘ １０’サイクル以上）を満足していた。結晶粒サイ
ズは１５〜４０μ腸でリブ先端から根元に向って大きく
なっている分布であった。また、ミクロ欠陥も指向性凝
固により大幅に減少し、５００μ論を超すものは認めら
れなかった。
一方、比較例においては、金型温度が高すぎる例ではシ
ュリンケージや湯境い、不廻りなどが多発し、また金型
温度が低すぎる例では不廻りが多発し、いずれも歩留り
が極めて低く、かつ機械的性質が劣っている。(Industrial Application Field) The present invention relates to the manufacture of compressor castings, and more specifically, technology for integrally manufacturing compressor castings having spiral-shaped relatively high ribs by low-pressure casting of aluminum alloy. Regarding. (Conventional technology and problems to be solved) Conventionally,
As shown in Figure 1, compressor parts that have relatively high spiral-shaped ribs in the center require high strength, so aluminum alloy castings are not often used, and cast iron etc. are used instead. . However, in recent years, as demands for weight reduction and miniaturization have become stronger, attempts have been made to integrally cast aluminum alloys. However, with the low-pressure casting method that has been attempted for castings of this kind of shape, the molten metal does not spread evenly around the relatively high spiral ribs, resulting in surface defects such as uneven rotation and hot spots. However, there was a problem in that the higher the mold temperature, the more the shrinkage defects increased, and they increased significantly, impairing the fatigue strength of the casting. For this reason, it has been desired to improve the technology for integrally casting compressor parts from aluminum alloy. The present invention has been made in view of the above circumstances, and
The object of the present invention is to provide an aluminum alloy casting for a compressor that is free from casting defects and has required mechanical properties, and also to provide a method for producing the same. (Means for Solving the Problems) In order to achieve the above object, the inventors of the present invention have developed a method for producing compressor parts having relatively high spiral ribs in the center, especially when low-pressure casting aluminum alloy is used. After repeated research on spinability, we found that in the case of conventional low-pressure casting methods, generally 350
A mold temperature of ℃ or higher is adopted, but contrary to the common wisdom that the higher the mold temperature is, the better the flowability of castings. It has been discovered that when the temperature of the hot water exceeds a certain temperature, a phenomenon occurs in which poor water supply occurs frequently. Therefore, as a result of various experimental research on countermeasures, we found that if we use a specific aluminum alloy system and control the mold temperature of the upper and lower molds, we can control the grain size and distribution through directional solidification. The present invention has been made based on the discovery that it is possible to obtain sound compressor parts that have good mechanical properties and are free from surface defects such as deformation, hot spots, etc., or shrinkage defects. That is, the compressor part according to the present invention is an aluminum alloy casting of a compressor part having a relatively high spiral rib in the center, and the aluminum alloy is Al1-8.
1-Mg system, Al-Si-Cu-Mg system or A Q -
It is a Si-Cu-Ni-Mg system. The crystal grain size is 10 to 50μ, and the distribution increases from the tip of the rib to the root, and the size of the casting defect is 5.
It is characterized by being regulated to less than 00 μl. In addition, the manufacturing method uses AΩ-81-Mg series, Al-
Si-Cu-Mg system or AlAl-Si-Cu-Ni
- When manufacturing by low pressure casting of aluminum alloy,
The mold temperature is set to 200℃ at the center of the upper mold corresponding to the rib area.
It is characterized by casting at ~350°C and controlling the lower mold temperature at 250~400°C. The present invention will be explained in more detail below. As shown in the cross-sectional view in Figure 1, the aluminum alloy castings for compressors have ribs that are not axially symmetrical, and naturally the upper die that forms the ribs also has an unbalanced heat capacity. ing. Therefore, a mold that absorbs the heat brought in by the molten metal will have temperature differences in each part. Moreover, on the other hand, since the ribs have the same cross-sectional shape, height, and thickness, the molten metal is directed uniformly and at the same timing from below to above within each rib shape. It is very difficult to fill. In other words, when molten metal is filled from below. When the molten metal approaches the rib-shaped portions, the rib-shaped portions with higher temperatures are filled first, leaving the lower temperature portions behind, creating a so-called selective vortex flow. For this reason, in the case of compressor castings that have relatively high spiral ribs, unlike general castings, due to the shape factor, it is not possible to raise the mold temperature too much in order to improve the looseness and hot water quality. found. Incidentally, as a result of various experiments, the present inventor found that Al-Si-M
g-based, Al-Si-Cu-Mg-based, and Al-5i-Cu
- For Ni-Mg alloys, when a mold temperature of 350 to 550°C is used in the normal low-pressure casting method, the upper mold temperature is 35°C.
It was confirmed that selective hot water flow began to occur when the temperature exceeded 0°C. Based on this knowledge, in the method of the present invention, the temperature of the upper and lower molds is controlled during low-pressure casting of castings for compressors, and the low-pressure casting is carried out in the following manner. do. From the standpoint of selectively preventing melt flow, the lower the mold temperature is, the better; however, if the upper mold temperature at the center of the upper mold, that is, around the ribs, is less than 200°C, local solidification may occur during filling of the molten metal. This is undesirable because it causes surface defects such as cracks, other irregularities, and hot spots. Furthermore, if the temperature exceeds 350°C, selective internal flow will occur as described above, which will cause poor water circulation, which is not preferable. Therefore, the temperature at the center of the upper mold must be controlled within the range of 200 to 350°C. On the other hand, castings for compressors have a tensile strength of approximately 36 kg due to repeated loads being applied to the ribs and lower part depending on the intended use.
gf/am” or more strength lined 10.Okgf/@■2
A fatigue strength of about 2 x 10' cycles is required. In order to satisfy these requirements, it is necessary to promote directional solidification and minimize internal defects. Therefore, the corresponding lower mold temperature must not be such as to inhibit this directional solidification. As long as the temperature does not harm directional solidification, it should be set at the same level as the upper mold temperature or higher, but if it is too high, the solidification time will be prolonged, shrinkage defects will occur, and the mechanical properties of the casting will be impaired. do. In addition, as the solidification time becomes longer, that is, the solidification rate becomes slower, the grain size (D
, A, S, I[) become thicker. It is well known that grain size greatly affects mechanical properties, and in the case of compressor castings, grain size must be controlled to 50 μm or less.
is an abbreviation for dendrite arm spacing (■), which refers to the spacing between the arms of dendrites (dendritic arms, second branches) that extend like branches from the side of the dendrite (first branch). For these reasons, the upper limit of the lower mold temperature must be kept at 400°C. However, if the temperature is too low, the molten metal will begin to solidify before it fills the rib-shaped portions, causing non-spinning and melting, so the lower limit of the lower mold temperature must be kept at 250°C. Therefore, the temperature of the lower mold must be controlled within the range of 250 to 400°C. In addition, other conditions for low-pressure casting, such as the mold temperature control method for the upper and lower molds, include providing a cooling mechanism (e.g. cooling hole for refrigerant flow through) and temperature measuring means (e.g. thermocouple) in the mold. The molten metal temperature, filling speed, etc. can be set as appropriate and are not particularly limited. Next, a compressor casting obtained by the above-mentioned low pressure casting method will be explained. The shape of the casting for a compressor is not limited to the shape and dimensions shown in Figure 1, but the number of spirals, the height and thickness of the ribs, etc. can be modified in various ways, but the key point is the height h of the ribs. is about 5 of the thickness t
This is effective when the shape is relatively high, such as double or more. The material has the mechanical properties required for compressor parts (
Considering tensile strength, fatigue strength, etc.), castability, etc., A
l-Si-Mg system, Al-8L-Cu-Mg system or A
A Q-Si-Cu-Ni-Mg based aluminum alloy for casting may be selected. Its composition is Al
-Si-Mg type J I 5AC4C1AC4CH etc., Al-Si-Cu-Ni-Mg type JISAC8
Examples of Al-Si-Cu-Ni-Mg type materials include JI5AC8A and the like. By casting an aluminum alloy having such a composition using the above-mentioned low-pressure casting method, directional solidification is promoted, and a crystal grain size of 50 μm or less with a distribution that increases from the tip of the rib toward the root can be obtained. In addition, if it exceeds 50 μm, the mechanical properties required for compressor parts will be insufficient, which is undesirable, and if the mold temperature provides a cooling rate that reduces the crystal grain size to less than 10 μm, the directivity of the entire casting will decrease. This is not preferable because coagulation cannot be achieved. Furthermore, directional solidification makes it possible to obtain castings with extremely few internal defects such as deformation and hot spots. On the other hand, since fatigue strength is greatly influenced by the size and number of discontinuous points inside the casting, such as shrinkage, such casting defects must be suppressed to a size of at least 500 μm or less. If the temperature difference between the upper mold and the lower mold is too large, shrinkage etc. are likely to occur, but by appropriately controlling the temperature of the upper mold and lower mold within the mold temperature range described above, the size of the casting defect can be reduced to the above-mentioned value. It is possible to suppress it as follows. Next, examples of the present invention will be shown. (Example) FIG. 2 shows an example of a low-pressure casting apparatus and a mold used in carrying out the method of the present invention. The mold in this example is a mold designed to cast a compressor casting having a relatively tall spiral rib 1 in the center with a height of approximately 40 cm and a width of approximately 7 cm. , a cooling hole 3 of about 10 mm diameter is installed between the parts of the upper mold 2 forming the rib part.
A plurality of refrigerants are provided, and by allowing air, water, or a mixed refrigerant thereof to flow through the refrigerant, the shaded area (the upper mold part forming the ribs) shown in FIG. 1 is cooled. One or more thermocouple holes 4 for inserting thermocouples for temperature measurement are provided above the rib forming part of the upper mold 2, and a plurality of gas vent holes are provided at appropriate locations on the upper end of the rib part. A mechanism 5 is provided. The mold temperature can be controlled by the refrigerant penetration amount, penetration timing, and time, and the mold temperature settings are as described above, A, S
, I [ and select the optimum temperature while checking the size of I[. On the other hand, the lower mold 6 has a hot water lower in the center part and is installed on the upper part of the stalk 8, and the product section W has a hot water lower through the stalk 8 and a prepared molten metal (not shown). is familiar with In addition, as shown in FIG. 2, the lower mold 6 around the sprue
A cooling hole 9 is provided in the cooling hole 9, through which air, water, or a mixed refrigerant thereof flows through, as in the case of upper mold cooling.
In this way, the lower mold temperature is controlled in the same way as the upper mold temperature. It goes without saying that the lower mold 6 may also be provided with a temperature measuring thermocouple if necessary. Examples of the prepared molten metal include Al-Si-Mg based 4CH alloy and Al-Si-Cu-Mg based AC8C.
After the alloy is melted by a conventional method and subjected to molten metal treatment (degassing, etc.), it is maintained at a temperature of 670 to 740°C at the lower part of the stalk. The holding temperature is appropriately selected depending on the type of alloy. Then, by the usual method of low-pressure casting, the molten metal is pushed up to the product part W via the stalk 8 and the melt lower, and is evenly filled into the rib part. At this time, it is necessary to set the filling (rising) speed of the hot water at a speed that does not promote selective vortex flow. Finally, after solidification has progressed halfway through the sprue, the unsolidified molten metal is returned to the original sump (not shown) via the stalk 8.
One cycle ends. In this example, the above-mentioned mold and device were used, and A
m-81-Mg series 0) AC4CH alloy and Afl-Si-
A low-pressure casting test was conducted on the Cu-Mg-based AC8G alloy under the conditions shown in Table 1, with each casting being performed 50 times. After the test, we inspected the obtained casting products for casting defects, and
A test piece was cut out from the disc part of the cast product (A C8C), subjected to T6 treatment, and its mechanical properties were examined. The results are shown in Tables 1 and 2. All of the examples of the present invention have a high yield and stably exhibit high strength, and the required strength (tensile strength: 36 kgf/+++m" or more, fatigue strength: 10, Okgf/n+m" of 2)
X 10' cycles or more). The crystal grain size was 15 to 40 microns, with a distribution increasing from the tip of the rib to the root. Further, micro defects were also significantly reduced by directional solidification, and no defects exceeding 500 μm were observed. On the other hand, in the comparative examples, cases where the mold temperature was too high caused frequent shrinkage, overflow, and non-spinning, and cases where the mold temperature was too low caused frequent non-spinning, resulting in extremely low yields. , and has poor mechanical properties.
（発明の効果）
以上詳述したように、本発明によれば、渦巻状の比較的
高いリブを有する圧縮機用アルミニウム合金鋳物を低圧
鋳造で製造するに際し、特定成分系のアルミニウム合金
を用いると共に上型中心部と下型の各型温を制御するの
で、指向性凝固が促進され、鋳造欠陥が極めて少なく、
結晶粒サイズがコントロールされ且つ所望の機械的性質
を有する高品質の圧縮機用鋳物を高歩留りで安定して得
ることができる。(Effects of the Invention) As detailed above, according to the present invention, when producing an aluminum alloy casting for a compressor having relatively high spiral ribs by low pressure casting, an aluminum alloy of a specific composition is used and Since the temperature of each mold in the center of the upper mold and the lower mold is controlled, directional solidification is promoted and casting defects are extremely reduced.
High quality compressor castings with controlled grain size and desired mechanical properties can be stably obtained at a high yield.
第１図（ａ）、（ｂ）は圧縮機用鋳物を示す図で、（ａ
）は平面図、（ｂ）は側面図、
第２図は本発明の実施に用いる低圧鋳造用装置及び金型
関係の一例を示す説明断面図である。
１・・・渦巻状リブ、２・・・上型、３・・・上型用冷
却穴、４・・・熱電対用穴、５・・・ガス抜き機構、６
・・・下型、７・・・湯口、８・・・ストーク、９・・
・下型用冷却穴、Ｗ・・・製品部。
第１図Figures 1 (a) and (b) are diagrams showing a casting for a compressor; (a)
) is a plan view, (b) is a side view, and FIG. 2 is an explanatory cross-sectional view showing an example of a low-pressure casting apparatus and a mold used in carrying out the present invention. DESCRIPTION OF SYMBOLS 1... Spiral rib, 2... Upper die, 3... Cooling hole for upper die, 4... Hole for thermocouple, 5... Gas venting mechanism, 6
... lower mold, 7... sprue, 8... stoke, 9...
・Cooling hole for lower mold, W...Product part. Figure 1
Claims (3)
用部品のアルミニウム合金鋳物において、該アルミニウ
ム合金がＡｌ−Ｓｉ−Ｍｇ系、Ａｌ−Ｓｉ−Ｃｕ−Ｍｇ
系又はＡｌ−Ｓｉ−Ｃｕ−Ｎｉ−Ｍｇ系であって、結晶
粒サイズが１０〜５０μｍで且つリブ先端から根元に向
って大きくなる分布を有し、鋳造欠陥の大きさを５００
μｍ以下に規制したことを特徴とする圧縮機用鋳物。(1) In aluminum alloy castings for compressor parts having a relatively high spiral rib in the center, the aluminum alloy is Al-Si-Mg-based, Al-Si-Cu-Mg
system or Al-Si-Cu-Ni-Mg system, the crystal grain size is 10 to 50 μm, and the distribution increases from the tip of the rib to the root, and the size of the casting defect is 500 μm.
A casting for a compressor, characterized by being regulated to less than μm.
用鋳物をＡｌ−Ｓｉ−Ｍｇ系、Ａｌ−Ｓｉ−Ｃｕ−Ｍｇ
系又はＡｌ−Ｓｉ−Ｃｕ−Ｎｉ−Ｍｇ系アルミニウム合
金の低圧鋳造にて製造するに際し、金型温度を、リブ周
辺に対応する上型中心部を２００〜３５０℃、下型を２
５０〜４００℃に制御して鋳造することを特徴とする圧
縮機用鋳物の製造方法。(2) Compressor castings with relatively high spiral ribs in the center are Al-Si-Mg based, Al-Si-Cu-Mg
When producing Al-Si-Cu-Ni-Mg-based aluminum alloys by low-pressure casting, the mold temperature is set at 200 to 350°C at the center of the upper mold corresponding to the rib periphery and at 200°C at the lower mold.
A method for producing a casting for a compressor, which comprises casting at a controlled temperature of 50 to 400°C.
く設定する特許請求の範囲第２項記載の方法。(3) The method according to claim 2, wherein the lower mold temperature is set equal to or higher than the upper mold center temperature.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP30249987A JPH01143752A (en) | 1987-11-30 | 1987-11-30 | Casting for compressor and its manufacture |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP30249987A JPH01143752A (en) | 1987-11-30 | 1987-11-30 | Casting for compressor and its manufacture |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01143752A true JPH01143752A (en) | 1989-06-06 |
| JPH0358823B2 JPH0358823B2 (en) | 1991-09-06 |
Family
ID=17909696
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP30249987A Granted JPH01143752A (en) | 1987-11-30 | 1987-11-30 | Casting for compressor and its manufacture |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH01143752A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9248053B2 (en) | 2008-12-18 | 2016-02-02 | Unicharm Corporation | Manufacturing method and manufacturing equipment of composite body of sheet-like member of absorbent article |
| JP2016200536A (en) * | 2015-04-13 | 2016-12-01 | 株式会社Ihi | Measurement apparatus and combustion furnace facility |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5666371A (en) * | 1979-10-30 | 1981-06-04 | Hitachi Metals Ltd | Die casting method of aluminum alloy casting |
-
1987
- 1987-11-30 JP JP30249987A patent/JPH01143752A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5666371A (en) * | 1979-10-30 | 1981-06-04 | Hitachi Metals Ltd | Die casting method of aluminum alloy casting |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9248053B2 (en) | 2008-12-18 | 2016-02-02 | Unicharm Corporation | Manufacturing method and manufacturing equipment of composite body of sheet-like member of absorbent article |
| JP2016200536A (en) * | 2015-04-13 | 2016-12-01 | 株式会社Ihi | Measurement apparatus and combustion furnace facility |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0358823B2 (en) | 1991-09-06 |
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