JPH039821B2 - - Google Patents
Info
- Publication number
- JPH039821B2 JPH039821B2 JP60161377A JP16137785A JPH039821B2 JP H039821 B2 JPH039821 B2 JP H039821B2 JP 60161377 A JP60161377 A JP 60161377A JP 16137785 A JP16137785 A JP 16137785A JP H039821 B2 JPH039821 B2 JP H039821B2
- Authority
- JP
- Japan
- Prior art keywords
- melting point
- casting
- low melting
- point substance
- base metal
- 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
- 238000002844 melting Methods 0.000 claims description 109
- 230000008018 melting Effects 0.000 claims description 102
- 238000005266 casting Methods 0.000 claims description 101
- 239000000126 substance Substances 0.000 claims description 80
- 239000010953 base metal Substances 0.000 claims description 60
- 229910052751 metal Inorganic materials 0.000 claims description 57
- 239000002184 metal Substances 0.000 claims description 57
- 239000000463 material Substances 0.000 claims description 35
- 238000000034 method Methods 0.000 claims description 33
- 238000004519 manufacturing process Methods 0.000 claims description 25
- 239000011148 porous material Substances 0.000 claims description 9
- 229920005992 thermoplastic resin Polymers 0.000 claims description 6
- 150000002484 inorganic compounds Chemical class 0.000 claims description 4
- 229910010272 inorganic material Inorganic materials 0.000 claims description 4
- 239000007787 solid Substances 0.000 claims description 4
- 239000007791 liquid phase Substances 0.000 claims description 3
- 239000012071 phase Substances 0.000 claims description 3
- 229910000838 Al alloy Inorganic materials 0.000 description 16
- 229910045601 alloy Inorganic materials 0.000 description 9
- 239000000956 alloy Substances 0.000 description 9
- 239000000835 fiber Substances 0.000 description 9
- 239000002131 composite material Substances 0.000 description 8
- 238000010438 heat treatment Methods 0.000 description 7
- 239000010935 stainless steel Substances 0.000 description 7
- 229910001220 stainless steel Inorganic materials 0.000 description 7
- 239000011701 zinc Substances 0.000 description 7
- 239000003779 heat-resistant material Substances 0.000 description 6
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 5
- 239000011734 sodium Substances 0.000 description 5
- 230000006866 deterioration Effects 0.000 description 4
- 229910052745 lead Inorganic materials 0.000 description 4
- 239000000155 melt Substances 0.000 description 4
- 150000003839 salts Chemical group 0.000 description 4
- 229910052708 sodium Inorganic materials 0.000 description 4
- 239000000243 solution Substances 0.000 description 4
- 229910000601 superalloy Inorganic materials 0.000 description 4
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 3
- 238000002485 combustion reaction Methods 0.000 description 3
- 238000009413 insulation Methods 0.000 description 3
- 229910052725 zinc Inorganic materials 0.000 description 3
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 2
- 229910000978 Pb alloy Inorganic materials 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 2
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 2
- 229910052797 bismuth Inorganic materials 0.000 description 2
- JCXGWMGPZLAOME-UHFFFAOYSA-N bismuth atom Chemical compound [Bi] JCXGWMGPZLAOME-UHFFFAOYSA-N 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000000446 fuel Substances 0.000 description 2
- 229910001026 inconel Inorganic materials 0.000 description 2
- 239000011810 insulating material Substances 0.000 description 2
- 150000002739 metals Chemical class 0.000 description 2
- 229920000515 polycarbonate Polymers 0.000 description 2
- 239000004417 polycarbonate Substances 0.000 description 2
- 239000004576 sand Substances 0.000 description 2
- 238000007711 solidification Methods 0.000 description 2
- 230000008023 solidification Effects 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- 230000003746 surface roughness Effects 0.000 description 2
- 229910001208 Crucible steel Inorganic materials 0.000 description 1
- 229910052581 Si3N4 Inorganic materials 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- -1 and placed in a mold Substances 0.000 description 1
- 239000001996 bearing alloy Substances 0.000 description 1
- 238000009750 centrifugal casting Methods 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 239000000567 combustion gas Substances 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000018109 developmental process Effects 0.000 description 1
- 238000004512 die casting Methods 0.000 description 1
- 238000005553 drilling Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 229910001293 incoloy Inorganic materials 0.000 description 1
- 229910052738 indium Inorganic materials 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 238000003754 machining Methods 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 238000010791 quenching Methods 0.000 description 1
- 230000000171 quenching effect Effects 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 1
- 239000000779 smoke Substances 0.000 description 1
- 229910000679 solder Inorganic materials 0.000 description 1
- 239000006104 solid solution Substances 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 230000006641 stabilisation Effects 0.000 description 1
- 238000011105 stabilization Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B3/00—Engines characterised by air compression and subsequent fuel addition
- F02B3/06—Engines characterised by air compression and subsequent fuel addition with compression ignition
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
- F05C—INDEXING SCHEME RELATING TO MATERIALS, MATERIAL PROPERTIES OR MATERIAL CHARACTERISTICS FOR MACHINES, ENGINES OR PUMPS OTHER THAN NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES
- F05C2201/00—Metals
- F05C2201/02—Light metals
- F05C2201/021—Aluminium
Landscapes
- Pistons, Piston Rings, And Cylinders (AREA)
Description
【発明の詳細な説明】
産業上の利用分野
この発明は、デイーゼルエンジン用断熱ピスト
ンの如く、断熱等の目的のため空洞（中空部）を
内部に形成した中空鋳物を製造する方法に関する
ものである。[Detailed Description of the Invention] Industrial Application Field This invention relates to a method for manufacturing a hollow casting having a cavity (hollow part) formed therein for purposes such as heat insulation, such as an insulating piston for a diesel engine. .
従来の技術
近年に至り、デイーゼルエンジンにおいてはそ
の燃焼室を高温化して燃費の改善を図るとともに
始動初期の不完全燃焼を防止するため、ピストン
頂面部を断熱化することが検討されている。BACKGROUND OF THE INVENTION In recent years, in diesel engines, in order to increase the temperature of the combustion chamber to improve fuel efficiency and to prevent incomplete combustion in the early stages of engine startup, it has been considered to insulate the top surface of the piston.
ピストン頂面部を断熱化するための有効な手段
としては、ピストン頂面の直下に空洞を形成して
その空洞部により断熱を図り、かつ断熱による頂
面温度上昇に対処するために、頂面を断熱材で形
成しておく方法が知られている。具体的には、例
えばインコネルの如き超合金などからなる断熱材
によつて頂面を形成し、その頂面耐熱材とピスト
ン母材との間に空洞部を設けて両者をボルト止め
する方法が知られている。しかしながらこの方法
では、頂面材やピストン母材に予め穴加工、ネジ
加工等の機械加工を施しておく必要があり、しか
もボルト止めの作業を必要とするため、生産性が
低く、高コストとならざるを得ないという問題が
あり、またピストン稼動時に母材、特にボルト穴
の部分がクリープ変形して頂面耐熱材−母材間の
有効な接合強度が得られなくなるという問題があ
つた。 An effective means for insulating the top surface of the piston is to form a cavity directly below the top surface of the piston and use that cavity to insulate the top surface. A method is known in which it is made of a heat insulating material. Specifically, there is a method in which the top surface is formed of a heat insulating material made of a superalloy such as Inconel, a cavity is provided between the top heat resistant material and the piston base material, and the two are bolted together. Are known. However, with this method, it is necessary to machine the top surface material and the piston base material in advance, such as drilling holes and threading, and also requires bolting, resulting in low productivity and high cost. There is also the problem that when the piston operates, the base metal, especially the bolt hole portion, undergoes creep deformation, making it impossible to obtain effective bonding strength between the top heat-resistant material and the base metal.
そこで頂面耐熱材を母材に強固に接合すること
ができ、しかも高コスト化を招いたり生産性の低
下を招いたりすることなく、頂面直下に断熱用の
空洞を有するピストンを製造し得る方法の開発が
強く望まれている。このような方法の一つとして
は、ピストン母材の鋳造時に頂面耐熱材を鋳ぐる
みによつて一体に保持しかつ頂面耐熱材の直下に
空洞部を残して鋳造する鋳ぐるみ鋳造法の適用が
考えられる。この場合、鋳ぐるみを円滑に行な
い、しかもピストン母材の鋳造欠陥の発生防止や
組織微細化を図るために、鋳造法としては所謂高
圧鋳造法などの加圧鋳造法を適用することが最適
と考えられる。 Therefore, it is possible to firmly bond the top heat-resistant material to the base material, and it is also possible to manufacture a piston with a heat-insulating cavity directly below the top surface without increasing costs or reducing productivity. Development of a method is strongly desired. One such method is the cast-in casting method, in which the top heat-resistant material is held together by the cast-ins during casting of the piston base material, and a cavity is left directly below the top heat-resistant material. Possible applications. In this case, it is best to apply a pressure casting method such as the so-called high-pressure casting method to ensure smooth casting, prevent casting defects in the piston base material, and refine the structure. Conceivable.
ところで鋳物の内部に空洞を形成する方法とし
ては、シエル中子等の砂中子を鋳ぐるんで鋳造し
た後、中子砂を鋳物内部から取出す方法が一般的
であり、また一部では水等の溶媒に容易に溶解さ
せ得る材料からなる中子、例えば塩中子を使用し
て鋳造し、鋳造後に中子を溶出除去させる方法も
採用されている。 By the way, a common method for forming a cavity inside a casting is to cast a sand core such as a shell core, and then take out the core sand from inside the casting. A method has also been adopted in which a core made of a material that can be easily dissolved in a solvent, such as a salt core, is used for casting, and the core is eluted and removed after casting.
発明が解決すべき問題点
前述のように砂中子を用いて高圧鋳造法を適用
した場合、溶湯に加わる高圧によつて溶湯が中子
内に含浸され、その結果、鋳物内から中子砂を除
去することが困難となる。また塩中子を用いた場
合、一般に塩中子は脆いため高圧鋳造では割れ易
く、そのため高圧鋳造によつて割れた部分に溶湯
が差し込んで、空洞部が分断されてしまう問題が
あるほか、塩中子は一般に表面粗度が悪く、その
ためその塩中子により形成される空洞部の表面粗
度も悪くなる問題がある。Problems to be Solved by the Invention When a high-pressure casting method is applied using a sand core as described above, the molten metal is impregnated into the core due to the high pressure applied to the molten metal, and as a result, the core sand is removed from the casting. It becomes difficult to remove. In addition, when using a salt core, salt cores are generally brittle and easily break during high-pressure casting, so there is a problem that molten metal can enter the cracked part during high-pressure casting, dividing the cavity. The core generally has a poor surface roughness, and therefore the surface roughness of the cavity formed by the salt core also becomes poor.
したがつて従来は高圧鋳造法の如き加圧鋳造法
によつて鋳物内部に任意の形状の空洞部を形成す
ることは極めて困難であつた。 Therefore, conventionally, it has been extremely difficult to form a cavity of an arbitrary shape inside a casting by a pressure casting method such as a high-pressure casting method.
この発明は以上の事情を背景としてなされたも
ので、前述のような問題が発生することなく、加
圧鋳造により内部に空洞を有する鋳物、例えば断
熱ピストンを支障なく製造し得る方法を提供する
ことを目的とするものである。 The present invention has been made against the background of the above-mentioned circumstances, and an object of the present invention is to provide a method for producing a casting having an internal cavity, such as an insulating piston, without any trouble by pressure casting without causing the above-mentioned problems. The purpose is to
問題点を解決するための手段
この発明の方法は、加圧鋳造によつて内部に空
洞を有する中空鋳物を鋳造するにあたり、常温で
は固体状態を保ちかつ鋳物母材金属の融点よりも
低い加熱温度で溶融する低融点物質を予め前記空
洞の形状に作つておき、その低融点物質を母材金
属溶湯が直接接しないように、その低融点物質を
注湯時の母材金属溶湯温度（すなわち注湯温度）
より融点が高くかつ母材金属溶湯に対して安定な
多孔質体で覆つた状態で鋳型内に配置し、母材金
属溶湯を鋳型内に注湯して加圧鋳造することによ
り前記低融点物質を鋳ぐるんだ鋳物を作成し、そ
の後母材金属の融点より低くかつ前記低融点物質
の融点以上の温度で前記鋳物を加熱して前記低融
点物質を溶融除去し、内部に空洞を有する中空鋳
物を製造することを特徴とするものである。Means for Solving the Problems The method of the present invention, when casting a hollow casting having an internal cavity by pressure casting, maintains a solid state at room temperature and at a heating temperature lower than the melting point of the base metal of the casting. A low melting point substance that melts at water temperature)
The low melting point substance is placed in a mold while being covered with a porous material that has a higher melting point and is stable over the molten base metal, and the molten base metal is poured into the mold and pressure cast. After that, the casting is heated at a temperature lower than the melting point of the base metal and higher than the melting point of the low melting point substance to melt and remove the low melting point substance, thereby forming a hollow cavity having a cavity inside. It is characterized by manufacturing castings.
ここで、前記低融点物質としては、熱可塑性樹
脂、無機化合物、もしくは金属を用いることがで
きる。そしてその低融点物質である金属として
は、鋳物母材金属と液相状態で２相分離し、かつ
相互の溶解度が極めて小さい金属を用いることが
望ましい。 Here, as the low melting point substance, a thermoplastic resin, an inorganic compound, or a metal can be used. As the metal that is the low melting point substance, it is desirable to use a metal that separates into two phases from the casting base metal in a liquid phase state and has extremely low mutual solubility.
作 用
この発明の方法においては、前述のように常温
では固体状態を保ちかつ鋳物母材金属の融点より
も低い加熱温度で溶融する低融点物質を用い、最
終的に形成すべき空洞の形状にその低融点物質を
成形しておき、その低融点物質に母材金属溶湯が
直接接しないように、その低融点物質を注湯時の
母材金属溶湯温度（すなわち注湯温度）より融点
が高くかつ母材金属溶湯に対して安定な多孔質体
で覆つた状態で鋳型内に配置してアルミニウム合
金等の母材金属を注湯し、加圧鋳造する。Function As mentioned above, in the method of this invention, a low melting point substance that remains solid at room temperature and melts at a heating temperature lower than the melting point of the casting base metal is used, and the material is shaped into the shape of the cavity to be finally formed. The low melting point substance is formed into a mold, and in order to prevent the base metal molten metal from coming into direct contact with the low melting point substance, the low melting point substance is molded at a temperature higher than the base metal molten metal temperature (i.e. the pouring temperature) at the time of pouring. Then, the molten base metal is covered with a porous body that is stable to the base metal, and placed in a mold, and a base metal such as an aluminum alloy is poured into the mold, followed by pressure casting.
ここで、前記低融点物質を多孔質体で覆わずに
高温の母材溶湯を注湯した場合には、低融点物質
は母材溶湯との接触により急速に温度上昇して直
ちに溶融し、その溶融金属が母材溶湯中へ拡散し
て母材の機械的強度などの各種特性の劣化を招く
原因となり、また溶湯加圧力に対し空洞形状を保
てなくなつて、最終製品鋳物において所要の形状
の空洞が得られなくなる。しかしながらこの発明
の方法の場合には、低融点物質を多孔質体で覆つ
ているため、注湯した母材溶湯は直ちには低融点
物質に接触しない。すなわち母材溶湯に加圧力が
加えられて多孔質体に含浸され、その母材溶湯が
多孔質体内の空隙を透過してからはじめて低融点
物質に接触することになる。このように注湯時に
は母材溶湯が直接低融点物質に接触せず、しかも
母材溶湯と低融点物質との間に介在する多孔質体
は多孔質であるが故にその断熱性が高いから、注
湯時においては低融点物質の温度はさほど上昇せ
ず、したがつて低融点物質が直ちに溶融してしま
うことが防止される。そして加圧力が加えられれ
ば母材溶湯は前述のように多孔質体の空隙を透過
して低融点物質に接する状態が生じるが、高圧鋳
造の如き加圧鋳造では、その加圧力によつて母材
溶湯と金型表面との接触状態が極めて良好となる
ため母材溶湯は急速に冷却凝固され、したがつて
母材と低融点物質との接触によりその接触部で低
融点物質が溶融しても、その溶融物質が母材中に
拡散することがなく、鋳物母材の特性を劣化させ
ることが防止される。また上述のように加圧鋳造
により母材溶湯が急速冷却されるため、母材溶湯
が多孔質体を透過して低融点物質に母材が接触し
てもその接触部で低融点物質がその溶融温度以上
となつている期間は極めて短時間に過ぎず、した
がつて接触部での低融点物質溶融量もさほど多く
はなく、このことも鋳物母材特性劣化の防止に寄
与する。さらに、母材溶湯が急速に冷却・凝固さ
れる結果、多孔質体を連通して低融点物質の部分
まで侵入する母材の量は極くわずかとなり、その
ため後に空洞となるべき部分の形状は実質的に保
持されることになる。 Here, if high-temperature base metal molten metal is poured into the low melting point substance without covering it with a porous material, the low melting point substance will rapidly rise in temperature due to contact with the base metal molten metal and will melt immediately. The molten metal diffuses into the molten base metal, causing deterioration of various properties such as mechanical strength of the base metal, and also makes it impossible to maintain the hollow shape against the pressure applied to the molten metal, making it difficult to maintain the desired shape in the final product casting. It becomes impossible to obtain a cavity. However, in the method of the present invention, since the low melting point substance is covered with a porous material, the poured base metal molten metal does not immediately come into contact with the low melting point substance. That is, pressure is applied to the molten base metal to impregnate the porous body, and the molten base metal comes into contact with the low melting point substance for the first time after passing through the voids within the porous body. In this way, the molten base metal does not come into direct contact with the low melting point substance during pouring, and the porous body interposed between the molten base metal and the low melting point substance is porous and therefore has high insulation properties. During pouring, the temperature of the low melting point substance does not rise significantly, and therefore the low melting point substance is prevented from melting immediately. When pressure is applied, the molten base metal passes through the pores of the porous body and comes into contact with the low melting point material as described above, but in pressure casting such as high pressure casting, the pressure Since the contact between the molten metal and the mold surface is extremely good, the molten base metal is rapidly cooled and solidified, and the low melting point substance is melted at the contact area due to the contact between the base metal and the low melting point substance. However, the molten substance does not diffuse into the base material, and deterioration of the properties of the casting base material is prevented. In addition, as mentioned above, the molten base metal is rapidly cooled by pressure casting, so even if the molten base metal passes through the porous body and comes into contact with a low-melting point substance, the low-melting point substance will be removed at the contact area. The period during which the temperature is above the melting temperature is only extremely short, and therefore the amount of melting of the low melting point substance at the contact portion is not so large, which also contributes to preventing deterioration of the properties of the casting base material. Furthermore, as the molten base metal is rapidly cooled and solidified, the amount of base metal that communicates with the porous body and penetrates into the low melting point material is extremely small, so the shape of the part that will later become a cavity is will essentially be retained.
このようにして、加圧鋳造して得られた鋳物
を、金型から取り出した後、母材の融点よりも低
くかつ低融点物質の融点以上の温度で加熱すれ
ば、低融点物質が溶融して、所定の流出路を経て
外部へ流出除去され、その低融点物質が存在して
いた部分が空洞として残ることになる。ここで、
前記流出路としては、通常は鋳造後に鋳物外部か
ら低融点物質の部分まで連結する穴を形成すれば
良いが、鋳造時に低融点物質の一部が金型表面に
接するようにした場合には、その部分が鋳物外部
に露呈することとなり、したがつてその露呈部分
が流出路となるから、鋳造後に改めて流出路を形
成する必要はない。 In this way, if the casting obtained by pressure casting is removed from the mold and heated to a temperature lower than the melting point of the base material and higher than the melting point of the low melting point substance, the low melting point substance will melt. Then, the low melting point substance is removed by flowing out to the outside through a predetermined outflow path, and the portion where the low melting point substance was present remains as a cavity. here,
Normally, the outflow path can be formed by forming a hole connecting the outside of the casting to the part of the low melting point substance after casting, but if a part of the low melting point substance comes into contact with the mold surface during casting, Since that portion is exposed to the outside of the casting and therefore serves as an outflow path, there is no need to form a new outflow path after casting.
以上のようにして、鋳造時に配置した低融点物
質の部分に、その低融点物質の形状寸法に実質的
に相当する空洞部を有する鋳物を得ることができ
る。ここで、低融点物質を覆つていた多孔質体は
母材金属と複合された層となり、この層は複合化
により高強度となるから、空洞部の周囲が強化さ
れることになり、耐久性を向上させる役割を果た
す。 In the manner described above, it is possible to obtain a casting having a cavity substantially corresponding to the shape and dimensions of the low melting point material in the portion of the low melting point material placed during casting. Here, the porous material covering the low-melting point substance becomes a layer composited with the base metal, and this layer becomes highly strong due to the composite, so the area around the cavity is strengthened and durable. It plays a role in improving sexuality.
なお低融点物質を最終的に溶融させて除去する
処理は、鋳物に対する熱処理と兼ねて行なうこと
ができる。すなわち例えばアルミニウム合金製ピ
ストン鋳物の場合、溶体化処理後焼入れし、その
後安定化処理する所謂T7処理を施すのが一般的
であるが、この処理で低融点物質の溶融除法を行
なうことができ、したがつてその場合には別に溶
融除去のための加熱を行なう必要がない。 Note that the process of finally melting and removing the low melting point substance can be performed concurrently with the heat treatment of the casting. For example, in the case of aluminum alloy piston castings, it is common to perform so-called T7 treatment, which is solution treatment followed by quenching and then stabilization treatment, but this treatment can melt and remove low melting point substances. Therefore, in that case, there is no need to separately perform heating for melting and removal.
発明を実施するための具体的な説明
この発明の具体的構成について、第１図に示す
ような断熱ピストンを製造する場合を例にとつて
以下に説明する。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A specific configuration of the present invention will be described below, taking as an example a case where a heat insulating piston as shown in FIG. 1 is manufactured.
第１図に示すような中空断熱ピストンを製造す
る場合は、第２図〜第４図に示すような多孔質体
１、低融点物質２、および耐熱金属板３を予め用
意しておき、これらを第５図に示すように組合せ
る。 When manufacturing a hollow heat-insulating piston as shown in FIG. 1, a porous body 1, a low melting point substance 2, and a heat-resistant metal plate 3 as shown in FIGS. 2 to 4 are prepared in advance. are combined as shown in FIG.
前記低融点物質２は、常温付近では固体状態を
保ち、かつ鋳造すべき母材金属例えばアルミニウ
ム合金の融点よりも低い温度に加熱された場合に
溶融し得る物質であればよく、低融点金属、熱可
塑性樹脂、無機化合物のいずれを用いても良い。 The low melting point substance 2 may be any substance that maintains a solid state near room temperature and can melt when heated to a temperature lower than the melting point of the base metal to be cast, such as an aluminum alloy, and may include a low melting point metal, Either a thermoplastic resin or an inorganic compound may be used.
ここでAl合金を鋳物母材とする断熱ピストン
を製造する場合には、低融点物質としては単に
Al合金よりも低融点であるばかりでなく、鋳造
後に行なう溶体化処理温度以下で溶融する物質を
用いることが望ましく、その意味から、Pb（鉛；
融点約327℃）もしくはPbを主成分とする合金を
用いることが最も望ましい。Al合金の溶体化処
理温度以下の融点のPb合金としては、例えば軸
受合金JIS9種（WJ9）、はんだ用合金JIS硬鉛板４
種（HPb4）、あるいは活字用合金JIS活字合金地
金１種10号などを用いることができる。またAl
合金を母材鋳物とする場合、PbやPb合金のほか、
Al合金よりも融点が低い金属、例えばNa（ナト
リウム）、Bi（ビスマス）、Sn（スズ）、Zn（亜鉛）
など、あるいはポリカーボネートやPBTなどの
熱可塑性樹脂を用いることができる。 When manufacturing heat insulating pistons using Al alloy as a casting base material, it is necessary to use only Al alloy as a low melting point material.
It is desirable to use a substance that not only has a lower melting point than Al alloy, but also melts at a temperature lower than the temperature of the solution treatment performed after casting, and for that reason, Pb (lead;
It is most desirable to use an alloy whose main component is Pb (melting point approximately 327°C) or Pb as a main component. Examples of Pb alloys with a melting point below the solution treatment temperature of Al alloys include bearing alloy JIS class 9 (WJ9), solder alloy JIS hard lead plate 4
Seed (HPb4), type alloy JIS type alloy ingot type 1 No. 10, etc. can be used. Also Al
When using alloy as base material casting, in addition to Pb and Pb alloy,
Metals with a lower melting point than Al alloys, such as Na (sodium), Bi (bismuth), Sn (tin), Zn (zinc)
Alternatively, thermoplastic resins such as polycarbonate and PBT can be used.
なお空洞部の形状を極めて良好に保つ必要があ
る場合には、母材金属と反応せずに溶融する熱可
塑性樹脂や種々の無機化合物、あるいは母材金属
と液相状態で２相分離しほとんど固溶しない金属
を用いることが望ましい。このような金属として
は、母材金属がAlである場合、Pb、Bi、Cd、
In、Naなどがある。 In addition, if it is necessary to maintain the shape of the cavity extremely well, it is necessary to use thermoplastic resins and various inorganic compounds that melt without reacting with the base metal, or that separate into two phases from the base metal in a liquid phase. It is desirable to use a metal that does not form a solid solution. Such metals include, when the base metal is Al, Pb, Bi, Cd,
In, Na, etc.
多孔質体１は注湯すべき母材金属例えばアルミ
ニウム合金の溶湯に対して安定であつてその注湯
温度よりも高融点の物質からなるものである。こ
の多孔質体１は、母材金属溶湯の注湯時に低融点
物質の温度が可及的に上昇しないように、熱伝導
率が低いことが望ましく、その意味からセラミツ
ク多孔質体、例えばアルミナあるいは窒化ケイ素
等の短繊維成形体を使用することが好ましく、ま
たこのほかステンレス繊維成形体等の金属質多孔
質体を用いることもできる。これらに限定されな
いことももちろんである。なお多孔質体１は、要
は母材金属注湯時にその母材溶湯が直接低融点物
質に接触することを防止するためのものであり、
その観点から体積率５％以上が望ましく、一方余
り体積率が高過ぎれば母材金属との複合化が困難
となるから、体積率60％以下とすることが好まし
い。このような多孔質体１は、前記低融点物質２
を覆うような形状に予め作成しておく。但し低融
点物質２の外面の全てを覆う必要はなく、要は注
湯時に母材金属溶湯が直接低融点物質２に接しな
いように覆えば良い。すなわち第１図の断熱ピス
トンを作成する場合、低融点物質２の一面は耐熱
金属板３に覆われて母材金属に接しないから、そ
の面を除いた残りの面を多孔質体１が覆うよう
に、前記円盤状の低融点物質２が嵌め込まれる凹
部１Ａを一面側に形成しておけば良い。 The porous body 1 is made of a material that is stable with respect to the base metal to be poured, such as a molten aluminum alloy, and has a melting point higher than the pouring temperature. It is desirable that the porous body 1 has a low thermal conductivity so that the temperature of the low melting point substance does not rise as much as possible during pouring of the base metal molten metal, and for that reason, it is preferable to use a porous ceramic body such as alumina or It is preferable to use a short fiber molded body such as silicon nitride, and it is also possible to use a metallic porous body such as a stainless steel fiber molded body. Of course, it is not limited to these. The purpose of the porous body 1 is to prevent the molten base metal from coming into direct contact with a low-melting point substance when pouring the base metal.
From this point of view, a volume fraction of 5% or more is desirable; on the other hand, if the volume fraction is too high, it becomes difficult to form a composite with the base metal, so a volume fraction of 60% or less is preferred. Such a porous body 1 includes the low melting point substance 2
Create a shape in advance to cover the . However, it is not necessary to cover the entire outer surface of the low melting point substance 2, and it is sufficient to cover the base metal molten metal so that it does not come into direct contact with the low melting point substance 2 during pouring. In other words, when creating the heat-insulating piston shown in Fig. 1, one side of the low-melting point material 2 is covered with the heat-resistant metal plate 3 and does not come into contact with the base metal, so the porous body 1 covers the remaining surface except for that side. Thus, a recess 1A into which the disk-shaped low melting point substance 2 is fitted may be formed on one side.
耐熱金属板３はこの発明の方法では基本的に必
須のものではないが、特に断熱ピストンを対象と
する場合には必要となる。すなわちこの断熱金属
板３は断熱ピストンの頂面部を形成するものであ
つて、耐熱性の高い金属、例えばSUS304等のス
テンレス鋼、あるいはJIS SUH系の耐熱鋼、さ
らにはインコロイ等のFeの基耐熱合金（Fe基超
合金）、インコネル等のNi基耐熱合金（Ni基超合
金）、Nivco等のCo基耐熱合金（Co基超合金）、
さらにはJIS SCH系の鋳鋼等を用いることがで
きる。この耐熱金属板３は、図示の例では円板の
周囲をほぼ直角に折曲げて凹部３Ａを形成し、か
つその折曲げられた部分３Ｂの先端部３Ｃをさら
に内側へ直角に折曲げた形状に作られたものであ
り、例えば液圧成形によつて加工されている。そ
してこのような形状の耐熱金属板３の凹部３Ａの
底面に前記低融点物質２の一面が接するように低
融点物質２および多孔質体１が組合される。 Although the heat-resistant metal plate 3 is not basically essential in the method of the present invention, it is necessary especially when a heat-insulating piston is targeted. In other words, this insulating metal plate 3 forms the top surface of the insulating piston, and is made of a highly heat-resistant metal, such as stainless steel such as SUS304, JIS SUH heat-resistant steel, or Fe-based heat-resistant steel such as Incoloy. alloys (Fe-based superalloys), Ni-based heat-resistant alloys such as Inconel (Ni-based superalloys), Co-based heat-resistant alloys such as Nivco (Co-based superalloys),
Furthermore, JIS SCH cast steel or the like can be used. In the illustrated example, the heat-resistant metal plate 3 has a shape in which the periphery of a circular plate is bent approximately at right angles to form a recessed portion 3A, and the tip portion 3C of the bent portion 3B is further bent inward at a right angle. It is manufactured by, for example, hydroforming. Then, the low melting point substance 2 and the porous body 1 are combined so that one surface of the low melting point substance 2 is in contact with the bottom surface of the recess 3A of the heat resistant metal plate 3 having such a shape.
以上のように多孔質体１、低融点物質２および
耐熱金属板３を組合せて、第６図に示すように加
圧鋳造用鋳型、例えば高圧鋳造用金型５内の所要
位置に配置する。すなわち図示の断熱ピストンの
場合、耐熱金属板３が金型５の底面に接するよう
に配置する。なお第６図において６は加圧パン
チ、７は鋳物取出用のノツクアウトピンである。 As described above, the porous body 1, the low melting point substance 2, and the heat-resistant metal plate 3 are combined and placed at a predetermined position in a pressure casting mold, for example, a high pressure casting mold 5, as shown in FIG. That is, in the case of the illustrated heat-insulating piston, the heat-resistant metal plate 3 is arranged so as to be in contact with the bottom surface of the mold 5. In FIG. 6, 6 is a pressure punch, and 7 is a knockout pin for taking out the casting.
次いでアルミニウム合金溶湯等の鋳物母材溶湯
８を金型５内に注湯する。この際には、既に述べ
たように母材溶湯８が直接低融点物質２に接触せ
ず、そのため低融点物質２は未だ溶融しない。 Next, a casting base material molten metal 8 such as an aluminum alloy molten metal is poured into the mold 5. At this time, as described above, the base metal molten metal 8 does not directly contact the low melting point substance 2, and therefore the low melting point substance 2 is not yet melted.
続いて加圧パンチ６などによつて母材溶湯８を
加圧すれば、その加圧力によつて母材溶湯８は多
孔質体１に含浸され、その部分が母材金属と多孔
質体との複合部９となる。この際、多孔質体１の
内部の空隙を透過した母材溶湯８が多孔質体１で
覆われた低融点物質２に接触してその接触部で低
融点物質が一部溶融することもあるが、既に述べ
たように加圧力によつて母材溶湯８が急速に冷却
凝固せしめられる結果、その溶融物質が鋳物母材
中に拡散することが防止され、鋳物母材の特性劣
化が防止される。ここで、加圧力の程度は特に限
定しないが、引け巣等の発生を防止しかつ鋳造組
織を微細化させ、しかも金型５と母材溶湯８との
接触状態を良好にして急速冷却凝固を促進させる
とともに多孔質体１に母材溶湯８を充分に含浸さ
せるためには、300Kg／cm2程度以上の加圧力とす
ることが望ましい。また加圧鋳造法としては、パ
ンチによつて加圧する高圧鋳造法のほか、いわゆ
るダイキヤスト法などを適用でき、また鋳物の形
状によつては遠心鋳造法を適用することもでき
る。なお加圧力は母材溶湯８の完全凝固まで保持
する。 Subsequently, when the base metal molten metal 8 is pressurized using a pressure punch 6 or the like, the base metal molten metal 8 is impregnated into the porous body 1 by the pressurizing force, and that part is separated from the base metal and the porous body. becomes a composite part 9. At this time, the base metal molten metal 8 that has passed through the voids inside the porous body 1 may come into contact with the low melting point substance 2 covered with the porous body 1, and the low melting point substance may partially melt at the contact area. However, as mentioned above, as the molten base metal 8 is rapidly cooled and solidified by the applied pressure, the molten substance is prevented from diffusing into the casting base material, and deterioration of the characteristics of the casting base material is prevented. Ru. Here, the degree of pressurizing force is not particularly limited, but it prevents the occurrence of shrinkage cavities, etc., makes the casting structure finer, and also improves the contact state between the mold 5 and the base metal molten metal 8 to achieve rapid cooling and solidification. In order to accelerate the process and to sufficiently impregnate the porous body 1 with the base metal molten metal 8, it is desirable to use a pressure of about 300 kg/cm 2 or more. Further, as the pressure casting method, in addition to a high pressure casting method in which pressure is applied by a punch, a so-called die casting method can be applied, and depending on the shape of the casting, a centrifugal casting method can also be applied. Note that the applied pressure is maintained until the base metal molten metal 8 completely solidifies.
このようにして多孔質体１が母材との複合部９
となりかつ低融点物質２と耐熱金属板３がアルミ
ニウム合金等の母材１２によつて鋳ぐるみされた
断熱ピストン用鋳物を金型５から取出した状態を
第７図に示す。 In this way, the porous body 1 forms a composite part 9 with the base material.
FIG. 7 shows a state in which a heat-insulating piston casting, in which a low-melting point substance 2 and a heat-resistant metal plate 3 are surrounded by a base material 12 such as an aluminum alloy, is removed from the mold 5.
次いで、第７図の断熱ピストン用鋳物の場合に
は、低融点物質２に連通する流出路１０を形成し
た後、母材の融点よりも低くかつ低融点物質の融
点以上の温度に加熱する。斯くすれば低融点物質
が溶融流出してその部分が空洞４となる。この後
には必要に応じて適宜機械加工し、前記流出路１
０を例えばネジ１１などによつて埋めれば、第１
図に示すような断熱ピストンが得られる。 Next, in the case of the adiabatic piston casting shown in FIG. 7, after forming an outflow passage 10 communicating with the low melting point substance 2, it is heated to a temperature lower than the melting point of the base material and higher than the melting point of the low melting point substance. In this way, the low melting point substance melts and flows out, and that part becomes the cavity 4. After this, the outflow path 1 is machined as necessary.
If 0 is filled with, for example, screw 11, the first
An adiabatic piston as shown in the figure is obtained.
ここで、アルミニウム合金鋳物で自動車ピスト
ンを作成する場合、鋳造後にT7処理を行なうの
が一般的であるが、その場合T7処理によつて前
記低融点物質を溶融除去することができ、したが
つて別途低融点物質溶融除去のための加熱を行な
う必要がない。 Here, when making automobile pistons from aluminum alloy castings, it is common to perform T7 treatment after casting, but in that case, the low melting point substance can be melted and removed by T7 treatment. There is no need to separately perform heating to melt and remove the low melting point substance.
以上のようにして得られた断熱ピストンは第１
図に示すように、頂面部が耐熱金属板３で形成さ
れるとともに、その直下に断熱用の空洞部４が形
成され、しかもその断熱用の空洞部４の周囲およ
び下側は金属−多孔質体の複合部９で強化されて
いることになる。 The adiabatic piston obtained as above is the first
As shown in the figure, the top surface is formed of a heat-resistant metal plate 3, and a heat-insulating cavity 4 is formed directly below it, and the surroundings and lower side of the heat-insulating cavity 4 are made of metal-porous material. This means that the composite part 9 of the body is strengthened.
なおここで耐熱金属板３の周辺の折曲げた部分
３Ｂ，３Ｃによつて囲まれる部分３Ｄには、注湯
時に時孔質体１を透過した母材溶湯８が侵入し、
したがつて耐熱金属板３はその部分で強固に保持
されることになる。 Note that the base metal molten metal 8 that has passed through the porous body 1 during pouring enters the portion 3D surrounded by the bent portions 3B and 3C around the heat-resistant metal plate 3, and
Therefore, the heat-resistant metal plate 3 is firmly held at that portion.
以上の例では断熱ピストンの例について説明し
たが、その他の中空鋳物にもこの発明の方法を適
用できることは勿論である。 In the above example, an example of an adiabatic piston was explained, but it goes without saying that the method of the present invention can also be applied to other hollow castings.
実施例
実施例 １
第１図に示すような断熱ピストンを製造するに
あたり、第２図〜第４図に示すような形状の多孔
質体１、低融点物質２および耐熱金属板３を用意
した。多孔質体１としてはかさ密度0.17ｇ／c.c.の
アルミナ短繊維成形体を用い、その寸法は外形
70.2mm、全厚み30mm、凹部１Ａの径60mm、凹部１
Ａの深さ10mmとした。低融点物質２としてはPb
（鉛）を用い、その径は60mm、厚みは10mmとした。
また耐熱金属板３としては液圧成形したSUS304
の厚み４mmのステンレス板を用い、その外径は83
mm、高さは15mm、凹部３Ａの開口端の内径は70mm
とした。Examples Example 1 In manufacturing a heat insulating piston as shown in FIG. 1, a porous body 1, a low melting point substance 2, and a heat-resistant metal plate 3 having shapes as shown in FIGS. 2 to 4 were prepared. As the porous body 1, an alumina short fiber molded body with a bulk density of 0.17 g/cc is used, and its dimensions are as follows:
70.2mm, total thickness 30mm, diameter of recess 1A 60mm, recess 1
The depth of A was 10 mm. Pb as low melting point substance 2
The diameter was 60 mm and the thickness was 10 mm.
In addition, the heat-resistant metal plate 3 is made of SUS304 that has been formed using hydraulic pressure.
A stainless steel plate with a thickness of 4 mm is used, and its outer diameter is 83 mm.
mm, height is 15mm, inner diameter of opening end of recess 3A is 70mm
And so.
これらを第５図に示すように組合せて、第６図
に示すように金型５内に配置し、温度720℃のア
ルミニウム合金（JIS AC8A；Al−12.0％Si−1.2
％Cu−1.0％Mg−2.0％Ni−0.3％Fe）の溶湯８を
注湯し、続いて加圧パンチ６により500Kg／cm2の
圧力を加えて高圧鋳造を行なつた。なお加圧力は
アルミニウム合金溶湯の完全凝固まで保持した。
凝固後に鋳物を金型から取出して第７図に示すよ
うな内径３mmの流出路１０を機械加工によつて形
成した後、その流出路１０を下向きにした状態で
T7熱処理（溶体化490℃×４時間、時効処理220
℃×８時間）を施した。この熱処理後の鋳物を調
べたところ、内部のPb（低融点物質２）は完全に
流出除去されており、ピストン内部にそのPbの
当初の形状、寸法に実質的に相当する空洞部４が
形成されていることが確認された。 These were combined as shown in Fig. 5, placed in a mold 5 as shown in Fig. 6, and aluminum alloy (JIS AC8A; Al-12.0%Si-1.2
% Cu - 1.0% Mg - 2.0% Ni - 0.3% Fe) was poured into the mold, and then a pressure of 500 kg/cm 2 was applied using a pressure punch 6 to perform high-pressure casting. The applied pressure was maintained until the molten aluminum alloy completely solidified.
After solidification, the casting was taken out of the mold and an outflow passage 10 with an inner diameter of 3 mm as shown in Fig. 7 was formed by machining, and then the outflow passage 10 was turned downward.
T7 heat treatment (solution treatment 490℃ x 4 hours, aging treatment 220℃
℃ x 8 hours). When we examined the casting after this heat treatment, we found that the Pb (low melting point substance 2) inside had been completely removed and a cavity 4 was formed inside the piston that substantially corresponded to the original shape and dimensions of the Pb. It was confirmed that
その後、機械加工を行なつてピストン形状と
し、さらに前記流出路１０をステンレス製のネジ
１１で埋めて最終的に第１図に示すような断熱ピ
ストンを得た。 Thereafter, it was machined into a piston shape, and the outflow passage 10 was filled with stainless steel screws 11 to finally obtain a heat insulating piston as shown in FIG.
また低融点物質２としてPbの代わりに、Al合
金よりも融点が低い金属であるNa（ナトリウム）、
Bi（ビスマス）、Sn（スズ）、Zn（亜鉛）、また熱可
塑性樹脂であるポリカーボネートやPBTを用い、
それぞれ前記と同じ条件、同じ方法でピストンを
製造したところ、第１図に示すピストンと実質的
に同様な空洞部を有するピストンを得ることがで
きた。 In addition, as the low melting point substance 2, instead of Pb, Na (sodium), which is a metal with a lower melting point than Al alloy,
Using Bi (bismuth), Sn (tin), Zn (zinc), and thermoplastic resins such as polycarbonate and PBT,
When pistons were manufactured under the same conditions and by the same method as described above, it was possible to obtain a piston having a cavity substantially similar to the piston shown in FIG.
実施例 ２
第８図に示すような断熱ピストンを製造するに
あたり、多孔質体１として第９図Ａ，Ｂに示すよ
うな形状寸法のステンレス短繊維成形体を用い、
また低融点物質２として第１０図に示すような形
状寸法のPbを用い、さらに断熱金属板３として
第１１図Ａ，Ｂに示すような寸法形状のSUS304
のステンレス板を用い、これらを第１２図に示す
ように組合せて、第１３図に示すように高圧鋳造
用金型５内に配置し、以下実施例１と同じ方法で
JIS AC8A合金を母材とするピストンを製造し
た。なおステンレス短繊維成形体としては、単位
繊維形状が44μｍ×55μｍ×３mmで成形体かさ密
度が2.36ｇ／c.c.のものを用いた。この場合にも第
８図に示すようにPbの当初の形状寸法に実質的
に対応する空洞部４を有する断熱ピストンを得る
ことができた。Example 2 In manufacturing a heat insulating piston as shown in FIG. 8, a short stainless steel fiber molded body having the shape and dimensions as shown in FIGS. 9A and B was used as the porous body 1,
In addition, as the low melting point substance 2, Pb with the shape and dimensions as shown in Fig. 10 was used, and as the heat insulating metal plate 3, SUS304 with the dimensions and shape as shown in Fig. 11A and B was used.
These stainless steel plates were assembled as shown in FIG. 12, placed in a high-pressure casting mold 5 as shown in FIG. 13, and then carried out in the same manner as in Example 1.
A piston was manufactured using JIS AC8A alloy as the base material. The stainless steel short fiber molded body used had a unit fiber shape of 44 μm x 55 μm x 3 mm and a molded body bulk density of 2.36 g/cc. In this case as well, it was possible to obtain an adiabatic piston having a cavity 4 substantially corresponding to the original shape and dimensions of Pb, as shown in FIG.
以上の実施例１および実施例２により得られた
断熱ピストンは、いずれも頂面耐熱材（耐熱金属
板３）と母材との間の接合程度が極めて高く、断
熱性も良好であり、かつ空洞部周辺が複合強化さ
れた構造となつているため優れた耐久性を示すこ
とが確認された。また燃焼特性試験を行なつたと
ころ、始動時から高負荷稼動時に至るまで、従来
の通常のアルミニウム合金製ピストンと比較して
不完全燃焼ガス（スモーク）の発生時間、量が明
らかに減少し、かつ燃費の向上も達成されてお
り、デイーゼルエンジン用ピストンとして極めて
優れていることが明らかとなつた。 Both of the heat-insulating pistons obtained in Example 1 and Example 2 have an extremely high degree of bonding between the top heat-resistant material (heat-resistant metal plate 3) and the base material, and have good heat insulation properties. It has been confirmed that the structure around the cavity has a composite reinforced structure, which provides excellent durability. In addition, when we conducted combustion characteristics tests, we found that the time and amount of incomplete combustion gas (smoke) was clearly reduced compared to conventional aluminum alloy pistons, from the time of startup to the time of high-load operation. Moreover, improved fuel efficiency was also achieved, making it clear that the piston is extremely excellent as a piston for diesel engines.
実施例 ３
次にピストン以外の中空鋳物、すなわち第１４
図に示すような鋳物を製造した実施例を記す。Example 3 Next, hollow castings other than the piston, that is, the 14th
An example in which a casting as shown in the figure was manufactured will be described.
第１５図に示すような形状寸法のPbを低融点
物質２として用い、この低融点物質２を第１６図
に示すように多孔質体１としてのアルミナ短繊維
で覆い、その一方の面1Bが金型底面側に接する
ように第１７図に示す如く高圧鋳造用金型５内に
配置し、550℃のZn（亜鉛）溶湯８を注湯し、500
Kg／cm2の加圧力を加えて高圧鋳造して、第１８図
に示すようにアルミナ短繊維多孔質体１の部分が
複合部９となつた鋳物を作成した。なお第１８図
において１３はZn母材である。得られた鋳物を
面1Bが下向きとなるように保持して大気中にお
いて350℃で３時間加熱保持した。その結果、低
融点物質２としてのPbは完全に流出除去されて、
内部が空洞化され、しかもその空洞部４の周辺が
複合強化された鋳物（第１４図）を得ることがで
きた。 Pb having the shape and dimensions as shown in Fig. 15 is used as the low melting point substance 2, and this low melting point substance 2 is covered with alumina short fibers as the porous body 1 as shown in Fig. 16, and one side 1B of It is placed in a high-pressure casting mold 5 as shown in Fig. 17 so as to be in contact with the bottom side of the mold, and 550°C molten Zn (zinc) metal 8 is poured into the mold,
High-pressure casting was performed by applying a pressing force of Kg/cm 2 to produce a casting in which the alumina short fiber porous material 1 became a composite part 9 as shown in FIG. In addition, in FIG. 18, 13 is a Zn base material. The obtained casting was held with the surface 1B facing downward and heated and held at 350° C. for 3 hours in the atmosphere. As a result, Pb as the low melting point substance 2 was completely removed and
It was possible to obtain a casting (Fig. 14) in which the inside was hollow and the periphery of the hollow part 4 was compositely reinforced.
発明の効果
以上の実施例からも明らかなようにこの発明の
方法によれば、内部に任意の形状の空洞部を有す
る鋳物を簡単かつ容易に製造することができ、し
かも空洞部を形成すると同時にその近傍を多孔質
体と母材金属との複合部として強化することがで
きる。したがつてこの発明の方法は、頂面直下に
空洞部を有する断熱ピストンの製造に適用して有
益なものである。Effects of the Invention As is clear from the above embodiments, according to the method of the present invention, it is possible to simply and easily produce a casting having a cavity of any shape inside, and also to form the cavity at the same time. The vicinity thereof can be strengthened as a composite part of the porous body and the base metal. Therefore, the method of the present invention is useful when applied to the manufacture of an insulated piston having a cavity immediately below the top surface.
第１図はこの発明の方法により製造される中空
鋳物の一例としての断熱ピストンを示す切欠斜視
図、第２図は第１図のピストンの製造に使用され
る多孔質体を示す切欠斜視図、第３図は第１図の
ピストンの製造に使用される低融点物質を示す斜
視図、第４図は第１図のピストンの製造に使用さ
れる耐熱金属板を示す切欠斜視図、第５図は第２
図から第４図に示される各部材を組合せた状態を
示す縦断面図、第６図は第１図のピストンの製造
過程における母材溶湯注湯時の状況を模式的に示
す縦断面図、第７図は第１図のピストンの製造過
程における鋳造後低融点物質除去前の状況を示す
縦断面図である。第８図はこの発明の方法により
製造される中空鋳物としての断熱ピストンの他の
例を示す縦断面図、第９図Ａ，Ｂは第８図のピス
トンの製造に使用される多孔質体を示す図で、Ａ
はその斜視図、Ｂは縦断面図、第１０図は第８図
のピストンの製造に使用される低融点物質（Pb）
の斜視図、第１１図Ａ，Ｂは第８図のピストンの
製造に使用される耐熱金属板を示す図で、Ａはそ
の斜視図、Ｂは縦断面図、第１２図は第９図〜第
１１図に示される各部材を組合せた状態を示す縦
断面図、第１３図は第８図のピストンの製造過程
における母材溶湯注湯時の状況を模式的に示す縦
断面図である。第１４図はこの発明の方法により
製造される中空鋳物の他の例を示す縦断面図、第
１５図は第１４図の中空鋳物の製造に使用される
低融点物質（Pb）の斜視図、第１６図は第１５
図の低融点物質を多孔質体（アルミナ短繊維成形
体）で覆つた状態を示す縦断面図、第１７図は第
１４図の中空鋳物の製造過程における母材溶湯注
湯時の状況を模式的に示す縦断面図、第１８図は
第１４図の中空鋳物の製造過程における鋳造後低
融点物質除去前の状況を示す縦断面図である。
１……多孔質体、２……低融点物質、４……空
洞部、８……母材溶湯。
FIG. 1 is a cutaway perspective view showing a heat insulating piston as an example of a hollow casting manufactured by the method of the present invention, FIG. 2 is a cutaway perspective view showing a porous body used in manufacturing the piston of FIG. 1, Figure 3 is a perspective view showing a low melting point material used in manufacturing the piston shown in Figure 1, Figure 4 is a cutaway perspective view showing a heat-resistant metal plate used in manufacturing the piston shown in Figure 1, and Figure 5. is the second
6 is a longitudinal sectional view schematically showing the state of pouring the molten base metal in the manufacturing process of the piston shown in FIG. 1, FIG. 7 is a longitudinal cross-sectional view showing the state of the piston shown in FIG. 1 in the manufacturing process after casting and before removal of low-melting point substances. FIG. 8 is a longitudinal sectional view showing another example of a heat insulating piston as a hollow casting manufactured by the method of the present invention, and FIGS. 9A and B show a porous body used in manufacturing the piston of FIG. 8. In the diagram shown, A
is a perspective view thereof, B is a longitudinal sectional view, and Fig. 10 is a low melting point material (Pb) used for manufacturing the piston shown in Fig. 8.
11A and 11B are views showing the heat-resistant metal plate used for manufacturing the piston shown in FIG. 8, A is a perspective view thereof, B is a vertical sectional view, and FIG. FIG. 11 is a longitudinal cross-sectional view showing a state in which the respective members shown in FIG. FIG. 14 is a longitudinal sectional view showing another example of a hollow casting manufactured by the method of the present invention, FIG. 15 is a perspective view of a low melting point substance (Pb) used for manufacturing the hollow casting shown in FIG. 14, Figure 16 is the 15th
Figure 17 is a longitudinal cross-sectional view showing the state in which the low melting point substance is covered with a porous material (alumina short fiber compact), and Figure 17 is a schematic diagram of the situation during pouring of the base material molten metal in the manufacturing process of the hollow casting shown in Figure 14. FIG. 18 is a longitudinal sectional view showing the state of the hollow casting shown in FIG. 14 before removal of low melting point substances after casting in the manufacturing process of the hollow casting. 1... Porous body, 2... Low melting point substance, 4... Cavity, 8... Molten base material.
Claims (1)
物を鋳造するにあたり、常温では固体状態を保ち
かつ鋳物母材金属の融点よりも低融点の物質を予
め前記空洞の形状に作つておき、その低融点物質
に母材金属溶湯が直接接しないように、その低融
点物質を注湯時の母材金属溶湯温度よりも融点が
高くかつ母材金属溶湯に対して安定な多孔質体で
覆つた状態で鋳型内に配置し、母材金属溶湯を鋳
型内に注湯して加圧鋳造することにより前記低融
点物質を鋳ぐるんだ鋳物を作成し、その後母材金
属の融点より低くかつ電気低融点物質の融点以上
の温度で前記鋳物を加熱して前記低融点物質を溶
融除去し、内部に空洞を有する中空鋳物を製造す
ることを特徴とする中空鋳物の製造方法。 ２ 前記低融点物質として、熱可塑性樹脂、無機
化合物、もしくは金属を用いる特許請求の範囲第
１項記載の中空鋳物の製造方法。 ３ 前記低融点物質の金属として、鋳物母材金属
と液相状態で２相分離しかつ相互の溶解度が小さ
い金属を用いる特許請求の範囲第２項記載の中空
鋳物の製造方法。 ４ 前記中空鋳物として、空洞部を断熱部とした
断熱部材用の鋳物を製造する特許請求の範囲第１
項記載の中空鋳物の製造方法。 ５ 前記中空鋳物として、頂面直下の空洞部を断
熱部とした断熱ピストンを製造する特許請求の範
囲第１項記載の中空鋳物の製造方法。[Scope of Claims] 1. When casting a hollow casting having an internal cavity by pressure casting, a substance that remains solid at room temperature and has a melting point lower than that of the casting base metal is preliminarily formed into the shape of the cavity. In order to prevent the base metal molten metal from coming into direct contact with the low melting point substance, the low melting point substance must be placed in a material that has a melting point higher than the base metal molten temperature at the time of pouring and is stable with respect to the base metal molten metal. The molten base metal is placed in a mold while being covered with a porous material, and the molten base metal is poured into the mold and pressure cast to create a casting in which the low melting point substance is cast. A method for manufacturing a hollow casting, characterized in that the casting is heated at a temperature lower than the melting point of the electric low melting point substance and higher than the melting point of the electric low melting point substance to melt and remove the low melting point substance to produce a hollow casting having a cavity inside. . 2. The method for producing a hollow casting according to claim 1, wherein the low melting point substance is a thermoplastic resin, an inorganic compound, or a metal. 3. The method for producing a hollow casting according to claim 2, wherein the metal of the low melting point substance is a metal that separates into two phases from the casting base metal in a liquid phase state and has low mutual solubility. 4. Claim 1, wherein the hollow casting is a casting for a heat insulating member in which the hollow part is a heat insulating part.
A method for producing a hollow casting as described in Section 1. 5. The method for manufacturing a hollow casting according to claim 1, wherein the hollow casting is an insulating piston in which a cavity directly below the top surface is a heat insulating part.
Priority Applications (6)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16137785A JPS6221456A (en) | 1985-07-22 | 1985-07-22 | Production of hollow casting |
| US06/883,825 US4712600A (en) | 1985-07-12 | 1986-07-09 | Production of pistons having a cavity |
| CA000513601A CA1271615A (en) | 1985-07-12 | 1986-07-11 | Production of pistons having a cavity |
| EP86109510A EP0209090B1 (en) | 1985-07-12 | 1986-07-11 | Production of pistons having a cavity |
| DE8686109510T DE3680965D1 (en) | 1985-07-12 | 1986-07-11 | MANUFACTURING PISTON WITH A CAVITY. |
| AU60093/86A AU597889B2 (en) | 1985-07-12 | 1986-07-11 | Production of pistons having a cavity |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16137785A JPS6221456A (en) | 1985-07-22 | 1985-07-22 | Production of hollow casting |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6221456A JPS6221456A (en) | 1987-01-29 |
| JPH039821B2 true JPH039821B2 (en) | 1991-02-12 |
Family
ID=15733932
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP16137785A Granted JPS6221456A (en) | 1985-07-12 | 1985-07-22 | Production of hollow casting |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6221456A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2011104836A1 (en) | 2010-02-25 | 2011-09-01 | トヨタ自動車株式会社 | Manufacturing method for hollow cast, and manufacturing method for piston for internal combustion engine |
| DE102010000450B4 (en) * | 2009-02-25 | 2015-07-09 | Toyota Jidosha Kabushiki Kaisha | A method of making a hollow casting and method of making a void-forming member for use therefor |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0260763U (en) * | 1988-10-28 | 1990-05-07 | ||
| KR101444354B1 (en) * | 2013-01-21 | 2014-09-24 | 주식회사 티앤머티리얼스 | Mold which is useful to pressure-impregnation process |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5528780A (en) * | 1978-08-23 | 1980-02-29 | Shigeo Kurihara | Methane gas generating apparatus |
| JPS60119348A (en) * | 1983-11-30 | 1985-06-26 | Izumi Jidosha Kogyo Kk | Piston of internal-combustion engine and manufacture thereof |
| JPS60166158A (en) * | 1984-02-07 | 1985-08-29 | Izumi Jidosha Kogyo Kk | Production of piston for internal-combustion engine |
-
1985
- 1985-07-22 JP JP16137785A patent/JPS6221456A/en active Granted
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5528780A (en) * | 1978-08-23 | 1980-02-29 | Shigeo Kurihara | Methane gas generating apparatus |
| JPS60119348A (en) * | 1983-11-30 | 1985-06-26 | Izumi Jidosha Kogyo Kk | Piston of internal-combustion engine and manufacture thereof |
| JPS60166158A (en) * | 1984-02-07 | 1985-08-29 | Izumi Jidosha Kogyo Kk | Production of piston for internal-combustion engine |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102010000450B4 (en) * | 2009-02-25 | 2015-07-09 | Toyota Jidosha Kabushiki Kaisha | A method of making a hollow casting and method of making a void-forming member for use therefor |
| WO2011104836A1 (en) | 2010-02-25 | 2011-09-01 | トヨタ自動車株式会社 | Manufacturing method for hollow cast, and manufacturing method for piston for internal combustion engine |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6221456A (en) | 1987-01-29 |
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