JP2019177416A - Sleeve for die-casting - Google Patents

Sleeve for die-casting Download PDF

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JP2019177416A
JP2019177416A JP2018070007A JP2018070007A JP2019177416A JP 2019177416 A JP2019177416 A JP 2019177416A JP 2018070007 A JP2018070007 A JP 2018070007A JP 2018070007 A JP2018070007 A JP 2018070007A JP 2019177416 A JP2019177416 A JP 2019177416A
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cylinder
sleeve
die
thermal expansion
outer cylinder
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長門 前田
Nagato Maeda
長門 前田
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Proterial Ltd
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Hitachi Metals Ltd
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Abstract

To provide a sleeve for a die-casting, for which heat cracks generated on a ceramic surface of an inner cylinder by thermal shock and breakage of ceramics generated by warpage or bending of an inner cylinder are prevented, even on the occasion of injection of molten metal of 750°C or more, or when the sleeve is filled with such molten metal to a large extent.SOLUTION: A die casting sleeve comprises an outer cylinder made of a low thermal expansion metal material, a tip member made of the low thermal expansion metal material fitted to an inner surface at an injection side of the outer cylinder, and a rear member arranged at a rear end side of a tip member. The rear member is composed of: an intermediate cylinder fitted to an inner surface of the outer cylinder, and an inner cylinder fitted to the inner surface of the intermediate cylinder. The inner cylinder is made of silicon nitride ceramics having a high thermal conductivity and excellent impact resistance and strength. The intermediate cylinder is made of silicon nitride ceramics having a low thermal conductivity. The intermediate cylinder has an engagement part for suppressing elongation due to a temperature rise in die casting operation at the inner cylinder at the rear end side of the intermediate cylinder and the inner cylinder.SELECTED DRAWING: Figure 1

Description

本発明は、銅合金、アルミニウム合金等の非鉄金属の750℃を超える溶湯をダイカスト金型に射出するためのダイカスト用スリーブに関する。   The present invention relates to a die casting sleeve for injecting a molten metal of non-ferrous metal such as copper alloy and aluminum alloy having a temperature exceeding 750 ° C. into a die casting mold.

ダイカストマシンでは、スリーブに溶融金属（溶湯）を供給し、スリーブ内を摺動するプランジャーチップによりスリーブと連通する金型キャビティに溶湯を射出し、溶湯を冷却固化させてダイカスト品を製造する。このため、スリーブの内面には、溶湯により溶損が生じたり、プランジャーチップの摺動により摩耗が生じたりする。スリーブの内面が溶損や摩耗により損傷すると、スリーブとプランジャーチップとの間に溶湯が侵入してスリーブの摺動抵抗が増大し、射出速度が低下するため製品品質が低下する。スリーブとプランジャーチップとの摺動抵抗を低減したり焼付きを防止したりするために多量の潤滑剤を使用すると、溶湯へのガス巻込み等の不純物混入が起こり易くなり、製品品質の低下を招く。   In a die casting machine, molten metal (molten metal) is supplied to a sleeve, and the molten metal is injected into a mold cavity communicating with the sleeve by a plunger tip sliding inside the sleeve, and the molten metal is cooled and solidified to produce a die cast product. For this reason, the inner surface of the sleeve may be melted by the molten metal or worn by sliding the plunger tip. When the inner surface of the sleeve is damaged due to melting or abrasion, the molten metal enters between the sleeve and the plunger tip, the sliding resistance of the sleeve increases, and the injection speed decreases, so the product quality decreases. If a large amount of lubricant is used to reduce the sliding resistance between the sleeve and the plunger tip or prevent seizure, impurities such as gas entrainment in the molten metal are likely to occur, resulting in a decrease in product quality. Invite.

スリーブ内面の溶損及び摩耗を低減するために、従来から金属製外筒内に、セラミックス製内筒を焼嵌めにより装着した複合構造のダイカスト用スリーブが提案されている。   In order to reduce melting damage and wear on the inner surface of the sleeve, a die casting sleeve having a composite structure in which a ceramic inner cylinder is mounted in a metal outer cylinder by shrink fitting has been proposed.

例えば、特開2006-315037号（特許文献1）は、軸方向に湯道となる貫通孔を有し、後方端上部に金属溶湯を注湯するための給湯口を有するとともに、前方端に金属溶湯を成形型へ送り込むための射出口を有する筒体からなり、耐熱金属の外筒と、ジルコニア質セラミックの中間筒と、窒化珪素質セラミックスの内筒とからなるダイカスト用スリーブであって、上記給湯口に対向する下部の厚みが、上部の厚みより大きいことを特徴とするダイカスト用スリーブを開示している。特許文献1は、給湯口に対向する下部の厚みを上部の厚みより大きくすることにより、溶湯をスリーブ内に注湯した場合に発生するスリーブの変形や反りを防止することができ、そのことによりダイカスト用スリーブの耐用寿命を長期化することができると記載している。また、スリーブ内の温度分布を均一とし、スリーブとプランジャとの摺動摩耗を減少させるための加熱ヒーターを付加的に設ける必要がなく、安価で使いやすいスリーブとすることができ、さらに、電気などのユーティリティを使う必要がないため、省資源の点からも環境に優しいスリーブとすることができると記載している。   For example, Japanese Patent Laid-Open No. 2006-315037 (Patent Document 1) has a through-hole serving as a runner in the axial direction, a hot water inlet for pouring molten metal at the upper rear end, and a metal at the front end. A die casting sleeve comprising a cylindrical body having an injection port for feeding molten metal into a mold, comprising a heat resistant metal outer cylinder, a zirconia ceramic intermediate cylinder, and a silicon nitride ceramic inner cylinder, A die casting sleeve is disclosed in which the thickness of the lower portion facing the hot water supply port is larger than the thickness of the upper portion. Patent Document 1 prevents the sleeve from being deformed or warped when the molten metal is poured into the sleeve by making the thickness of the lower part facing the hot water inlet larger than the thickness of the upper part. It describes that the service life of the sleeve for die casting can be extended. In addition, the temperature distribution in the sleeve is made uniform, there is no need to additionally provide a heater for reducing sliding wear between the sleeve and the plunger, and the sleeve can be made cheap and easy to use. Because it is not necessary to use this utility, it is described that the sleeve can be made environmentally friendly from the viewpoint of resource saving.

しかしながら、特許文献２に記載のダイカスト用スリーブを、例えば、溶湯温度が750℃以上になる銅合金等の溶湯の射出に用いた場合、又は700℃前後のアルミニウム合金溶湯であってもスリーブへの溶湯充填率が高い（約60%以上）場合、内筒の窒化珪素質セラミックスに熱衝撃によるヒートクラックが発生し、微小な割れ（剥離）が発生することがある。   However, when the die-casting sleeve described in Patent Document 2 is used, for example, for injection of a molten metal such as a copper alloy having a molten metal temperature of 750 ° C. or higher, or even when the molten aluminum alloy is around 700 ° C. When the molten metal filling rate is high (approximately 60% or more), heat cracks due to thermal shock may occur in the silicon nitride ceramics in the inner cylinder, and micro cracks (peeling) may occur.

特開2004-34055号（特許文献2）は、低熱膨張性金属材料からなる外筒の内面に、サイアロンセラミックスからなる中間筒を設け、該中間筒の内面に、常温における熱伝導率が60 W/(m・K)以上の窒化珪素セラミックスからなる内筒を設けて構成され、該外筒と中間筒との境界部に位置する外筒の内面又は中間筒の外面に、加熱媒体通路を形成したことを特徴とするダイカスト用スリーブを開示している。特許文献2は、加熱媒体通路の内周には熱伝導率が小さいサイアロンセラミックスからなる中間筒、さらに中間筒の外周には低熱膨張性金属材料からなる外筒が配置されるので、中間筒の熱影響による外筒の温度上昇を十分に抑えることができ、このため、外筒と内筒との焼嵌めが緩むことを防止できるとともに、高熱伝導率の窒化珪素製の内筒により、外筒と中間筒との境界部の加熱媒体通路から供給された熱を、境界部から内筒の内面すなわち金属溶湯へ迅速にかつ効率よく伝達でき、溶湯保温性を格段に向上させると記載している。   Japanese Patent Laid-Open No. 2004-34055 (Patent Document 2) discloses that an intermediate cylinder made of sialon ceramics is provided on the inner surface of an outer cylinder made of a low thermal expansion metal material, and the thermal conductivity at room temperature is 60 W on the inner surface of the intermediate cylinder. / (m · K) or more of an inner cylinder made of silicon nitride ceramics, and a heating medium passage is formed on the inner surface of the outer cylinder or the outer surface of the intermediate cylinder located at the boundary between the outer cylinder and the intermediate cylinder A sleeve for die casting is disclosed. In Patent Document 2, an intermediate cylinder made of sialon ceramics having a low thermal conductivity is arranged on the inner circumference of the heating medium passage, and an outer cylinder made of a low thermal expansion metal material is arranged on the outer circumference of the intermediate cylinder. The temperature rise of the outer cylinder due to the heat effect can be sufficiently suppressed, and therefore, the shrink-fit between the outer cylinder and the inner cylinder can be prevented from loosening, and the inner cylinder made of silicon nitride having a high thermal conductivity can be used. It is described that the heat supplied from the heating medium passage at the boundary between the intermediate cylinder and the intermediate cylinder can be transferred quickly and efficiently from the boundary to the inner surface of the inner cylinder, that is, the molten metal, and the molten metal heat retention is greatly improved. .

しかしながら、特許文献2に記載のダイカスト用スリーブは、熱伝導率の低いサイアロンセラミックスからなる中間筒が設けられているため、溶湯が充填されたときに窒化珪素セラミックスからなる内筒と、中間筒及び外筒との温度差が大きくなり、内筒のみが軸方向に大きく伸びて、セラミックスの反りや曲がりなどの不均一な変形が生じる場合がある。特に、溶湯温度が750℃以上になる銅合金等の溶湯の射出に用いた場合、又は700℃前後のアルミニウム合金溶湯であってもスリーブへの溶湯充填率が高い（約60%以上）場合に顕著である。   However, since the die casting sleeve described in Patent Document 2 is provided with an intermediate cylinder made of sialon ceramics having low thermal conductivity, an inner cylinder made of silicon nitride ceramics, an intermediate cylinder, and In some cases, the temperature difference from the outer cylinder increases, and only the inner cylinder extends greatly in the axial direction, resulting in uneven deformation such as warping or bending of the ceramics. Especially when it is used for injection of molten metal such as copper alloy that has a molten metal temperature of 750 ° C or higher, or when the molten metal filling rate of the sleeve is high (approximately 60% or higher) even when molten aluminum alloy is around 700 ° C. It is remarkable.

さらにスリーブ先端部まで全長に渡り一体式のセラミックス構造の為、スリーブ前方（溶湯を射出する金型）側にあるスプルーブッシュや分流子と熱膨張差や摩耗による径差で生じた金型側に射出されず残存した凝固片が射出後プランジャーチップを注湯前位置移動させる際にスリーブ後方側に引き戻されこの凝固片によってセラミックス先端内径端角部に割れやかけ損傷が生じ、これを起点としてスリーブ後方側に向けてセラミックスが大きく破損する場合がある。さらに中間筒加熱構造その外筒に冷却構造を配しているが、外筒部の温度を一定以下に保つ必要があるため、鋳造溶湯による入熱以上に外筒冷却水による抜熱をする必要がある。   Furthermore, because of the integrated ceramic structure over the entire length up to the sleeve tip, the sprue bush and current divider on the front side of the sleeve (the mold that injects the molten metal) and the mold side caused by the difference in thermal expansion and diameter due to wear The remaining solidified piece that has not been injected is pulled back to the sleeve rear side when the plunger tip is moved to a position before pouring after injection, and this solidified piece causes cracking and damage to the inner diameter end corner of the ceramic tip. Ceramics may be greatly damaged toward the rear side. In addition, the intermediate cylinder heating structure has a cooling structure in its outer cylinder, but it is necessary to keep the temperature of the outer cylinder part below a certain level. There is.

特開平2-211960号（特許文献3）は、注入した溶湯を射出プランジャで金型内に充填するダイカストスリーブにおいて、前記ダイカストスリーブを半径方向に分割した３層構造と、最内層（第1層）を保温性の良いセラミック、中間層（第2層）と最外層（第3層）を金属とし、中間層の熱膨張率が最外層の熱膨張率よりも大きい金属とし、かつ軸陽光に複数分割にするとともに軸方向に隙間を形成するよう配設した上、これらの3層を焼嵌めによって組み立てることを特徴とするダイカストスリーブを開示している。特許文献3は、スリーブ内に高温の溶湯を注入しても、第２層の金属の熱膨張率は、第１層のセラミック、第３層の金属に比べて大きいので、第１層や第３層との熱膨張差による隙間の発生を抑止するとともに、熱間時に最も熱膨張の大きな第２層が軸方向に複数分割され、かつ軸方向に隙間を形成するように配列され軸方向への変形代があるため、軸方向の熱応力による無理な変形が防止されると記載している。またこのダイカストスリーブは、組立時に大きな焼嵌め代を必要とせず、小さな焼嵌め代によって組み立てても、溶湯注入の高温時には第１層と第２層とは密着し、第１層のセラミックの反りや曲がりなどの不均一な変形が極力抑えられるので、セラミックの破損や不均一な変形に起因するかじり現象を避けることができる。   Japanese Patent Laid-Open No. 2-221960 (Patent Document 3) discloses a die-cast sleeve in which a molten metal is filled into a mold with an injection plunger, and a three-layer structure in which the die-cast sleeve is divided in the radial direction, and an innermost layer (first layer). ) Is a ceramic with good heat retention, the middle layer (second layer) and the outermost layer (third layer) are metal, the middle layer has a higher coefficient of thermal expansion than that of the outermost layer, and the axial sunlight A die casting sleeve is disclosed, which is divided into a plurality of parts and arranged so as to form a gap in the axial direction, and these three layers are assembled by shrink fitting. In Patent Document 3, even if high temperature molten metal is injected into the sleeve, the thermal expansion coefficient of the second layer metal is larger than that of the first layer ceramic and the third layer metal. The generation of a gap due to a difference in thermal expansion from the three layers is suppressed, and the second layer having the largest thermal expansion during hot operation is divided into a plurality of parts in the axial direction and arranged so as to form a gap in the axial direction. Since there is a deformation allowance, it is described that excessive deformation due to axial thermal stress is prevented. In addition, this die-cast sleeve does not require a large shrinkage allowance at the time of assembly. Even if assembled by a small shrinkage allowance, the first layer and the second layer are in close contact at the high temperature of molten metal injection, and the ceramic warpage of the first layer Since uneven deformation such as bending and bending can be suppressed as much as possible, it is possible to avoid a galling phenomenon due to ceramic breakage or uneven deformation.

しかしながら、特許文献3に記載のダイカスト用スリーブを、例えば、溶湯温度が750℃以上になる銅合金等の溶湯の射出に用いた場合、又は700℃前後のアルミニウム合金溶湯であってもスリーブへの溶湯充填率が高い（約60%以上）場合、第1層のセラミック表面に熱衝撃によるヒートクラックが発生し、微小な割れ（剥離）が発生することがある。さらに、操業中溶湯からの加熱で、外筒熱膨張量＞内筒セラミックス熱膨張量、となれば中間筒とセラミックス内筒間に隙間が生じ、拘束力がなくなりセラミックス割れの可能性が生じる。   However, when the die casting sleeve described in Patent Document 3 is used for injection of a molten metal such as a copper alloy having a molten metal temperature of 750 ° C. or higher, or even when the molten aluminum alloy is around 700 ° C. When the molten metal filling rate is high (about 60% or more), heat cracks due to thermal shock may occur on the ceramic surface of the first layer, and micro cracks (peeling) may occur. Further, if the amount of thermal expansion of the outer cylinder> the amount of thermal expansion of the inner cylinder ceramic due to heating from the molten metal during operation, a gap is generated between the intermediate cylinder and the inner ceramic cylinder, and there is no possibility of cracking due to the absence of binding force.

本発明者らは国際公開第2017/141480号（特許文献4）で、低熱膨張性金属材料からなる外筒と、前記外筒の内面に焼嵌めされた内筒とからなり、前記外筒の外周面には、ダイカストマシンの固定型に固定するためのフランジ部を有し、前記内筒は、射出口側に配置された低熱膨張性金属材料からなる先端部材と、前記先端部材の後端側端面に密着して配置された窒化珪素質セラミックスからなる後方部材とから構成され、前記外筒は、2O〜2OO℃の平均熱膨張係数αAが1〜5×10-6/℃であり、前記先端部材は、2O〜2OO℃の平均熱膨張係数αBが1〜5×10-6/℃であり、αAとαBとの差が-1×10-6/℃以上及び1×10-6/℃以下であり、前記先端部材の軸方向長さ、前記先端部材の内径及び前記フランジ部の位置が特定の関係を満たすように構成したダイカスト用スリーブを開示している。特許文献4は、このような構成を有することにより、先端部材と後方部材とがより密着し、使用時に隙間が形成されにくいため、セラミックスからなる後方部材が破損するといった問題が発生しにくく、かつ破断チル層の形成が防止され、耐久性に優れ、かつ製品不良の発生が少ないダイカスト用スリーブが得られ、さらにプランジャーチップの損傷を防止することができると記載している。 The present inventors have disclosed in International Publication No. 2017/141480 (Patent Document 4) an outer cylinder made of a low thermal expansion metal material and an inner cylinder shrink-fitted on the inner surface of the outer cylinder. The outer peripheral surface has a flange portion for fixing to a fixed die of a die casting machine, and the inner cylinder includes a tip member made of a low thermal expansion metal material disposed on the injection port side, and a rear end of the tip member A rear member made of silicon nitride ceramics disposed in close contact with the side end face, and the outer cylinder has an average coefficient of thermal expansion α A of 2O to 2OO ° C. of 1 to 5 × 10 −6 / ° C. The tip member has an average thermal expansion coefficient α B of 2 to 2OO ° C. of 1 to 5 × 10 −6 / ° C., and the difference between α A and α B is −1 × 10 −6 / ° C. or more and 1 × is at 10 -6 / ° C. or less, the axial length of the tip member, said tip member inner diameter and the flange portion scan for die casting which position is configured to satisfy a specific relationship of It discloses the over drive. Patent Document 4 has such a configuration, so that the tip member and the rear member are more closely attached, and a gap is not easily formed during use, so that the problem that the rear member made of ceramics is less likely to occur, and It is described that a die-casting sleeve is obtained in which the formation of a ruptured chill layer is prevented, durability is excellent, and the occurrence of product defects is small, and damage to the plunger tip can be prevented.

しかしながら、特許文献4に記載のダイカスト用スリーブを、例えば、溶湯温度が750℃以上になる銅合金等の溶湯の射出に用いた場合、又は700℃前後のアルミニウム合金溶湯であってもスリーブへの溶湯充填率が高い（約60%以上）場合、内筒の窒化珪素質セラミックスに熱衝撃によるヒートクラックが発生し、微小な割れ（剥離）が発生することがある。   However, when the die casting sleeve described in Patent Document 4 is used for injection of a molten metal such as a copper alloy having a molten metal temperature of 750 ° C. or higher, or an aluminum alloy molten metal having a temperature of about 700 ° C. is applied to the sleeve. When the molten metal filling rate is high (approximately 60% or more), heat cracks due to thermal shock may occur in the silicon nitride ceramics in the inner cylinder, and micro cracks (peeling) may occur.

特開2006-315037号公報JP 2006-315037 A 特開2004-34055号公報JP 2004-34055 A 特開平2-211960号公報Japanese Patent Laid-Open No. 2-111960 国際公開第2017/141480号International Publication No. 2017/141480

従って、本発明の目的は、750℃以上の溶湯の射出に用いた場合や、スリーブへの溶湯充填率が高い（約60%以上）場合であっても、内筒のセラミックス表面に熱衝撃によって発生するヒートクラックや、内筒のセラミックスの反りや曲がりなどの不均一な変形によって発生するセラミックの破損が防止されたダイカスト用スリーブを提供することである。   Therefore, the object of the present invention is to apply thermal shock to the ceramic surface of the inner cylinder even when it is used for injection of molten metal at 750 ° C. or higher or when the molten metal filling rate into the sleeve is high (approximately 60% or more). It is an object of the present invention to provide a die casting sleeve in which breakage of ceramics caused by non-uniform deformation such as generated heat cracks and warpage or bending of ceramics in an inner cylinder is prevented.

上記目的に鑑み、本発明者らは、金属製外筒内に、セラミックス製内筒を焼嵌めにより装着した複合構造のダイカスト用スリーブについて鋭意検討した。その結果、低熱膨張性金属材料からなる外筒と、前記外筒の内面に焼嵌めされた内筒とからなり、前記内筒は、射出口側に配置された低熱膨張性金属材料からなる先端部材と、前記先端部材の後端側端面に密着して配置された窒化珪素質セラミックスからなる後方部材とから構成されたダイカスト用スリーブの構造を最適化することにより、銅合金等の750℃以上の溶湯の射出に用いた場合やスリーブへの溶湯充填率が高い場合に発生するセラミックス内筒表面の剥離を防止できるとともに、内筒の窒化珪素質セラミックスの反りや曲がりなどの不均一な変形が防止できることを見出し、本発明に想到した。   In view of the above object, the present inventors have intensively studied a die casting sleeve having a composite structure in which a ceramic inner cylinder is mounted in a metal outer cylinder by shrink fitting. As a result, it consists of an outer cylinder made of a low thermal expansion metal material and an inner cylinder shrink-fitted on the inner surface of the outer cylinder, and the inner cylinder has a tip made of a low thermal expansion metal material arranged on the injection port side. By optimizing the structure of the die casting sleeve composed of the member and the rear member made of silicon nitride ceramics disposed in close contact with the rear end side end surface of the tip member, the copper alloy or the like is 750 ° C. or higher. This prevents the inner cylinder surface from peeling off when it is used for injection of molten metal or when the filling rate of the molten metal into the sleeve is high, and causes uneven deformation such as warping or bending of the silicon nitride ceramics in the inner cylinder. The present inventors have found that it can be prevented and have come up with the present invention.

すなわち、本発明のダイカスト用スリーブは、低熱膨張性金属材料からなる外筒と、前記外筒の射出口側の内面に嵌着された低熱膨張性金属材料からなる先端部材と、前記先端部材の後端側端面に密着して配置された後方部材とからなり、
前記後方部材が、前記外筒の内面に嵌着された中間筒と、前記中間筒の内面に嵌着された内筒とから構成され、
前記内筒は、耐熱衝撃温度750℃以上、及び25℃における熱伝導率が25 W/(m・K) 以上の窒化珪素質セラミックスからなり、
前記中間筒は、25℃における熱伝導率が24 W/(m・K)未満の窒化珪素質セラミックスからなり、
前記中間筒及び前記内筒の後端側に、前記内筒のダイカスト稼働時の温度上昇による伸びを抑制するための係合部を有することを特徴とする。 That is, the die casting sleeve of the present invention includes an outer cylinder made of a low thermal expansion metal material, a tip member made of a low thermal expansion metal material fitted to the inner surface of the outer cylinder on the injection port side, and It consists of a rear member arranged in close contact with the end surface on the rear end side,
The rear member is composed of an intermediate cylinder fitted on the inner surface of the outer cylinder, and an inner cylinder fitted on the inner surface of the intermediate cylinder,
The inner cylinder is made of a silicon nitride ceramic having a thermal shock temperature of 750 ° C. or higher and a thermal conductivity of 25 W / (m · K) or higher at 25 ° C.,
The intermediate cylinder is made of a silicon nitride ceramic having a thermal conductivity at 25 ° C. of less than 24 W / (m · K),
It has an engaging part for suppressing the extension by the temperature rise at the time of the die casting operation of the inner cylinder at the rear end side of the intermediate cylinder and the inner cylinder.

前記外筒は、20〜200℃の平均熱膨張係数αAが1〜5×10-6/℃であり、
前記先端部材は、20〜200℃の平均熱膨張係数αBが1〜5×10-6/℃であり、
αAとαBとの差が-1×10-6/℃〜1×10-6/℃であるのが好ましい。 The outer cylinder has an average thermal expansion coefficient α A of 1 to 5 × 10 −6 / ° C. at 20 to 200 ° C.,
The tip member has an average thermal expansion coefficient α B of 20 to 200 ° C. of 1 to 5 × 10 −6 / ° C.,
The difference between α A and α B is preferably −1 × 10 −6 / ° C. to 1 × 10 −6 / ° C.

前記中間筒は、軸方向に分割された複数の部分からなるのが好ましい。   The intermediate cylinder is preferably composed of a plurality of portions divided in the axial direction.

前記中間筒の分割された複数の部分同士の突合せ面は、軸方向に対して15〜75°の角度を有しているのが好ましい。   It is preferable that the butted surfaces of the divided portions of the intermediate cylinder have an angle of 15 to 75 ° with respect to the axial direction.

前記中間筒の分割された複数の部分同士の突合せ面は、前記中間筒の内面側及び外面側に面取部を有するのが好ましい。   It is preferable that the butted surfaces of the divided portions of the intermediate cylinder have chamfered portions on the inner surface side and the outer surface side of the intermediate tube.

前記外筒の厚さは、前記中間筒の厚さと前記内筒の厚さの合計よりも大きいのが好ましい。   It is preferable that the thickness of the outer cylinder is larger than the sum of the thickness of the intermediate cylinder and the thickness of the inner cylinder.

本発明のダイカスト用スリーブは、より高温の射出、又は溶湯充填率が高い射出にも、スリーブ内面溶損やヒートクラック、スリーブ熱変形を発生させないため、高合金アルミニウム溶湯の射出のみならず、銅合金等の750℃以上の溶湯の射出にも好適である。   The die casting sleeve of the present invention does not cause the sleeve inner surface melting damage, heat cracks or sleeve thermal deformation even at higher temperature injection or injection with a high molten metal filling rate. It is also suitable for injecting molten metal of 750 ° C or higher such as alloys.

本発明のダイカスト用スリーブの一例を示す断面図である。It is sectional drawing which shows an example of the sleeve for die-casting of this invention. 本発明のダイカスト用スリーブの後端部（図1のA部分）の構成の一例を拡大して示す断面図である。FIG. 2 is an enlarged sectional view showing an example of a configuration of a rear end portion (A portion in FIG. 1) of the die casting sleeve of the present invention. 本発明のダイカスト用スリーブの後端部の構成の他の例を拡大して示す断面図である。It is sectional drawing which expands and shows the other example of a structure of the rear-end part of the die-casting sleeve of this invention. 本発明のダイカスト用スリーブの後端部の構成のさらに他の例を拡大して示す断面図である。It is sectional drawing which expands and shows another example of the structure of the rear-end part of the die-casting sleeve of this invention. 本発明のダイカスト用スリーブの他の一例を示す断面図である。It is sectional drawing which shows another example of the sleeve for die-casting of this invention. 本発明のダイカスト用スリーブの中間筒の突合せ部（図3のC部分）の一例を示す断面図である。FIG. 4 is a cross-sectional view showing an example of a butting portion (C portion in FIG. 3) of the intermediate cylinder of the die casting sleeve of the present invention. 本発明のダイカスト用スリーブの中間筒の突合せ部の他の例を示す断面図である。It is sectional drawing which shows the other example of the butt | matching part of the intermediate | middle cylinder of the sleeve for die-casting of this invention. 本発明のダイカスト用スリーブのさらに他の一例を示す断面図である。It is sectional drawing which shows another example of the sleeve for die-casting of this invention. 本発明のダイカスト用スリーブのさらに他の一例を示す断面図である。It is sectional drawing which shows another example of the sleeve for die-casting of this invention. 本発明のダイカスト用スリーブにおいて、先端部材と後方部材との突合せ部（図1のB部分）の一例を示す断面図である。FIG. 2 is a cross-sectional view showing an example of a butting portion (a portion B in FIG. 1) between a tip member and a rear member in the die casting sleeve of the present invention. 本発明のダイカスト用スリーブにおいて、先端部材と後方部材との突合せ部の他の例を示す断面図である。In the die-casting sleeve of the present invention, it is a cross-sectional view showing another example of the butted portion of the tip member and the rear member.

本発明の実施形態を、添付図面を参照して以下詳細に説明するが、本発明は勿論それらに限定されるものではない。各実施形態に関する説明は、特に断りがなければ他の実施形態にも適用できる。   Embodiments of the present invention will be described below in detail with reference to the accompanying drawings, but the present invention is of course not limited thereto. The description regarding each embodiment is applicable also to other embodiment unless there is particular notice.

[1] ダイカスト用スリーブ
(1)構成
図1は第一のダイカスト用スリーブ1の実施形態を示す。このダイカスト用スリーブ1は、低熱膨張性金属材料からなる外筒2と、前記外筒2の射出口10側の内面に嵌着された低熱膨張性金属材料からなる先端部材3と、前記先端部材3の後端側端面に密着して配置された後方部材4とを備え、
前記後方部材4は、前記外筒2の内面に嵌着された中間筒5と、前記中間筒5の内面に嵌着された内筒6とから構成され、
前記中間筒5は、25℃における熱伝導率が24 W/(m・K)未満の窒化珪素質セラミックスからなり、
前記内筒6は、耐熱衝撃温度750℃以上、及び25℃における熱伝導率が25 W/(m・K) 以上の窒化珪素質セラミックスからなり、
前記中間筒5の後端側に、前記内筒6のダイカスト稼働時の温度上昇による伸びを抑制するための係合部9を有する。なお本発明において、先端側とは射出口10側のことであり、後端側又は後方側とは射出口10側とは軸方向の反対側のことである。 [1] Die casting sleeve
(1) Configuration FIG. 1 shows an embodiment of a first die casting sleeve 1. This die casting sleeve 1 includes an outer cylinder 2 made of a low thermal expansion metal material, a tip member 3 made of a low thermal expansion metal material fitted to the inner surface of the outer cylinder 2 on the injection port 10 side, and the tip member A rear member 4 disposed in close contact with the rear end side end surface of 3,
The rear member 4 includes an intermediate cylinder 5 fitted to the inner surface of the outer cylinder 2, and an inner cylinder 6 fitted to the inner surface of the intermediate cylinder 5.
The intermediate cylinder 5 is made of a silicon nitride ceramic having a thermal conductivity at 25 ° C. of less than 24 W / (m · K),
The inner cylinder 6 is made of a silicon nitride ceramic having a thermal shock temperature of 750 ° C. or higher and a thermal conductivity of 25 W / (m · K) or higher at 25 ° C.,
On the rear end side of the intermediate cylinder 5, there is an engagement portion 9 for suppressing the elongation due to the temperature rise of the inner cylinder 6 during the die casting operation. In the present invention, the front end side is the injection port 10 side, and the rear end side or the rear side is the opposite side in the axial direction from the injection port 10 side.

外筒2の後端面には後端リング部材8がボルト81により固定されている。外筒2の外周面には先端側に小径部21が形成されており、外筒2の小径部21がダイカストマシン（図示せず）の固定型内に挿入されダイカストマシンに固定される。外筒2は後端面付近の側面に開口部を有し、後方部材4を構成する中間筒5及び内筒6は外筒2の開口部と整合する位置に開口部を有する。連通するこれらの開口部は溶湯の供給口9を構成する。外筒2の寸法は、例えば内径60〜250 mm、外径100〜350 mm、軸方向の全長200〜1300 mmとすることができる。   A rear end ring member 8 is fixed to the rear end surface of the outer cylinder 2 by bolts 81. A small-diameter portion 21 is formed on the outer peripheral surface of the outer cylinder 2 on the distal end side, and the small-diameter portion 21 of the outer cylinder 2 is inserted into a fixed mold of a die casting machine (not shown) and fixed to the die casting machine. The outer cylinder 2 has an opening on the side surface near the rear end surface, and the intermediate cylinder 5 and the inner cylinder 6 constituting the rear member 4 have an opening at a position aligned with the opening of the outer cylinder 2. These communicating openings constitute a molten metal supply port 9. The dimensions of the outer cylinder 2 can be, for example, an inner diameter of 60 to 250 mm, an outer diameter of 100 to 350 mm, and an axial length of 200 to 1300 mm.

外筒2は、低熱膨張金属からなり、20〜200℃の平均熱膨張係数αAが1〜5×10-6/℃であり、20〜600℃の平均熱膨張係数が5〜9.5×10-6/℃である。外筒2は、20℃〜500℃の温度における引張強さが590 MPa以上である高強度低熱膨張金属からなるのが好ましい。 The outer cylinder 2 is made of a low thermal expansion metal, has an average thermal expansion coefficient α A of 20 to 200 ° C. of 1 to 5 × 10 −6 / ° C., and an average thermal expansion coefficient of 20 to 600 ° C. of 5 to 9.5 × 10 -6 / ℃. The outer cylinder 2 is preferably made of a high-strength low thermal expansion metal having a tensile strength of 590 MPa or more at a temperature of 20 ° C. to 500 ° C.

先端部材3は、低熱膨張金属からなり、20〜200℃の平均熱膨張係数αBが1〜5×10-6/℃であり、20〜600℃の平均熱膨張係数が5〜9.5×10-6/℃である。先端部材3は、20℃〜500℃の温度における引張強さが590 MPa以上である高強度低熱膨張金属からなるのが好ましい。 The tip member 3 is made of a low thermal expansion metal, has an average thermal expansion coefficient α B of 20 to 200 ° C. of 1 to 5 × 10 −6 / ° C., and an average thermal expansion coefficient of 20 to 600 ° C. of 5 to 9.5 × 10 -6 / ℃. The tip member 3 is preferably made of a high-strength low thermal expansion metal having a tensile strength of 590 MPa or more at a temperature of 20 ° C. to 500 ° C.

外筒2の20〜200℃の平均熱膨張係数αAと先端部材3の20〜200℃の平均熱膨張係数αBとの差は、-1×10-6/℃〜1×10-6/℃であるのが好ましい。このように外筒2と先端部材3と20〜200℃の平均熱膨張係数の差を小さくすることにより、外筒2と先端部材3とを焼嵌めによって嵌着したときに実用温度域（外筒2の温度が約200℃）で先端部材3が緩むことがない。 The difference between the average thermal expansion coefficient alpha B of 20 to 200 ° C. of the average thermal expansion coefficient alpha A and the tip member 3 of 20 to 200 ° C. of the outer tube 2, -1 × 10 -6 / ℃ ~1 × 10 -6 / ° C is preferred. Thus, by reducing the difference in average thermal expansion coefficient between the outer cylinder 2 and the tip member 3 and 20 to 200 ° C., when the outer cylinder 2 and the tip member 3 are fitted by shrink fitting, the practical temperature range (outside The tip member 3 is not loosened when the temperature of the tube 2 is about 200 ° C.).

セラミック製の後方部材4（中間筒5及び内筒6）の先端側に金属製の先端部材3を設けることにより、セラミックス製の中間筒5及び内筒6が射出口10側の先端に露出せず、セラミックス製の中間筒5及び内筒6の損傷を防ぐことができる。   By providing the metal tip member 3 on the tip side of the ceramic rear member 4 (intermediate tube 5 and inner tube 6), the ceramic intermediate tube 5 and inner tube 6 are exposed at the tip on the injection port 10 side. Therefore, damage to the ceramic intermediate cylinder 5 and the inner cylinder 6 can be prevented.

中間筒5は、熱伝導率が24 W/(m・K)未満の窒化珪素質セラミックスからなり、20〜200℃までの平均熱膨張係数及び20〜600℃までの平均熱膨張係数が6×10-6／℃以下であるのが好ましく、4×10-6／℃以下であるのがより好ましく、1〜4×10-6／℃であるのが最も好ましい。中間筒5は、熱伝導率が24 W/(m・K)未満の窒化珪素質セラミックスからなるため、保温効果が大きく、溶湯の熱によって外筒2が加熱され変形するのを防止する。中間筒5を構成する窒化珪素質セラミックスの熱伝導率は20 W/(m・K)以下であるのが好ましく、18 W/(m・K)以下であるのがより好ましい。 The intermediate cylinder 5 is made of a silicon nitride ceramic having a thermal conductivity of less than 24 W / (m · K), and has an average thermal expansion coefficient of 20 to 200 ° C. and an average thermal expansion coefficient of 20 to 600 ° C. of 6 ×. preferably 10 -6 / of ° C. or less, more preferably at 4 × 10 -6 / ° C. or less, most preferably 1 to 4 × 10 -6 / ° C.. Since the intermediate cylinder 5 is made of silicon nitride ceramics having a thermal conductivity of less than 24 W / (m · K), the heat retention effect is great, and the outer cylinder 2 is prevented from being heated and deformed by the heat of the molten metal. The thermal conductivity of the silicon nitride ceramics constituting the intermediate cylinder 5 is preferably 20 W / (m · K) or less, and more preferably 18 W / (m · K) or less.

内筒6は、耐熱衝撃温度750℃以上、及び25℃における熱伝導率が25 W/(m・K) 以上の窒化珪素質セラミックスからなり、20〜200℃までの平均熱膨張係数及び20〜600℃までの平均熱膨張係数が6×10-6／℃以下であるのが好ましく、4×10-6／℃以下であるのがより好ましく、1〜4×10-6／℃であるのが最も好ましい。 The inner cylinder 6 is made of a silicon nitride ceramic having a thermal shock temperature of 750 ° C. or higher and a thermal conductivity of 25 W / (m · K) or higher at 25 ° C., and has an average thermal expansion coefficient of 20 to 200 ° C. and 20 to 20 ° C. preferably 600 to average thermal expansion coefficient of up to ° C. is 6 × 10 -6 / ℃ or less, and more preferably at 4 × 10 -6 / ℃ less, a 1~4 × 10 -6 / ℃ Is most preferred.

内筒6は、25℃における熱伝導率が25 W/(m・K) 以上の窒化珪素質セラミックスにより形成されているため、溶湯によって加熱されたスリーブ底側の熱を円周方向へ効率的に伝導させることができ、外筒2への加熱を円周方向でより均一にし、ダイカストスリーブの変形を防止することができる。内筒65を構成する窒化珪素質セラミックスの熱伝導率は30 W/(m・K)以上であるのが好ましく、50 W/(m・K)以上であるのがより好ましい。   The inner cylinder 6 is made of silicon nitride ceramics with a thermal conductivity of 25 W / (m · K) or more at 25 ° C, so the heat on the sleeve bottom heated by the molten metal is efficiently distributed in the circumferential direction. The outer cylinder 2 can be heated more uniformly in the circumferential direction, and deformation of the die casting sleeve can be prevented. The thermal conductivity of the silicon nitride ceramic constituting the inner cylinder 65 is preferably 30 W / (m · K) or more, and more preferably 50 W / (m · K) or more.

内筒6は、耐熱衝撃温度750℃以上の窒化珪素質セラミックスにより形成されているため、アルミニウム合金等の非鉄金属の溶湯に対する耐食性、耐摩耗性に優れており、スリーブ内面の溶損及び摩耗を低減できる。耐熱衝撃温度は800 ℃以上であるのが好ましく、900 ℃以上であるのがより好ましい。また内筒6の25℃での4点曲げ強度は、800 MPa以上であるのが好ましく、880 MPa以上であるのがより好ましい。なお耐熱衝撃温度及び4点曲げ強度は、それぞれJIS R1601 2008及びJIS R1648 2002に記載の方法で求めた値である。   Since the inner cylinder 6 is made of silicon nitride ceramics with a thermal shock temperature of 750 ° C. or higher, it has excellent corrosion resistance and wear resistance against non-ferrous metal melts such as aluminum alloys, and prevents damage and wear of the sleeve inner surface. Can be reduced. The thermal shock temperature is preferably 800 ° C. or higher, more preferably 900 ° C. or higher. The four-point bending strength at 25 ° C. of the inner cylinder 6 is preferably 800 MPa or more, and more preferably 880 MPa or more. The thermal shock temperature and 4-point bending strength are values obtained by the methods described in JIS R1601 2008 and JIS R1648 2002, respectively.

中間筒5及び内筒6の後端側には、前記内筒6のダイカスト稼働時の温度上昇による伸びを抑制するための係合部9が設けられている。中間筒5及び内筒6はともに20〜200℃までの平均熱膨張係数が6×10-6／℃以下である窒化珪素質セラミックス及び窒化珪素質セラミックスによって構成されているが、内筒6は直接溶湯に接触しているため中間筒5よりも高温になる。また低熱膨張性金属材料からなる外筒2は、熱伝導率の低い中間筒3を介しているので、内筒2からの熱が伝わりにくく構成されている。このため内筒6は中間筒5及び外筒2よりも軸方向への熱膨張が大きくなり、内筒6と中間筒5との間にズレが発生したり、ダイカストスリーブに反りが発生したりする。中間筒5及び内筒6の後端側に係合部9を設けることにより、内筒6のダイカスト稼働時の温度上昇による伸びを抑制することができ、上記のズレや反りの発生を防止することができる。また内筒6に軸方向の圧縮応力をかけることができるので、内筒6表面の剥離をより防止できる。 On the rear end side of the intermediate cylinder 5 and the inner cylinder 6, an engaging portion 9 is provided for suppressing elongation due to a temperature rise during the die casting operation of the inner cylinder 6. The intermediate cylinder 5 and the inner cylinder 6 are both composed of silicon nitride ceramics and silicon nitride ceramics whose average thermal expansion coefficient from 20 to 200 ° C. is 6 × 10 −6 / ° C. or less. Since it is in direct contact with the molten metal, the temperature is higher than that of the intermediate cylinder 5. Further, the outer cylinder 2 made of a low thermal expansion metal material is interposed through the intermediate cylinder 3 having a low thermal conductivity, so that the heat from the inner cylinder 2 is not easily transmitted. For this reason, the inner cylinder 6 has a larger thermal expansion in the axial direction than the intermediate cylinder 5 and the outer cylinder 2, and a deviation occurs between the inner cylinder 6 and the intermediate cylinder 5, and warping occurs in the die-cast sleeve. To do. By providing the engagement portion 9 on the rear end side of the intermediate cylinder 5 and the inner cylinder 6, it is possible to suppress the elongation due to the temperature rise during the die casting operation of the inner cylinder 6, and to prevent the above-described deviation and warpage. be able to. Further, since the axial compressive stress can be applied to the inner cylinder 6, it is possible to further prevent the surface of the inner cylinder 6 from peeling off.

係合部9は、内筒6が中間筒5に対して軸方向に伸びるのを抑制することのできる構成であればどのような形状でも良い。例えば、図2(a)に示すように、中間筒5の後端側の端部に段差9aを設けて、内筒6に、前記段差9aに対応するように周方向の溝を形成して係合部9を構成しても良い。また図2(b)に示すように、前記段差9aを、傾斜部を有する段差9bとして構成しても良いし、図2(c)に示すように、単に傾斜部9cで構成してもよい。   The engaging portion 9 may have any shape as long as the inner tube 6 can be prevented from extending in the axial direction with respect to the intermediate tube 5. For example, as shown in FIG. 2 (a), a step 9a is provided at the end on the rear end side of the intermediate cylinder 5, and a circumferential groove is formed in the inner cylinder 6 so as to correspond to the step 9a. The engaging portion 9 may be configured. Further, as shown in FIG. 2 (b), the step 9a may be configured as a step 9b having an inclined portion, or may be simply configured by an inclined portion 9c as shown in FIG. 2 (c). .

中間筒5の厚さは内筒6の厚さよりも大きくするのが好ましい。中間筒5を内筒6よりも厚く構成することにより、中間筒5に内筒6を焼嵌めたときに内筒6にかかる周方向の圧縮応力がより大きくなるため、内筒6の耐熱衝撃性及び強度を高め、内筒6表面の剥離を防止できる。中間筒5の厚さは、内筒6の厚さの1.2〜1.5倍であるのがより好ましい。   The thickness of the intermediate cylinder 5 is preferably larger than the thickness of the inner cylinder 6. By configuring the intermediate cylinder 5 to be thicker than the inner cylinder 6, the compressive stress in the circumferential direction applied to the inner cylinder 6 when the inner cylinder 6 is shrink-fitted into the intermediate cylinder 5 becomes larger. Property and strength can be increased, and peeling of the inner cylinder 6 surface can be prevented. The thickness of the intermediate cylinder 5 is more preferably 1.2 to 1.5 times the thickness of the inner cylinder 6.

中間筒5は、図3に示すように、軸方向に分割された複数の部分からなっていてもよい。図3では中間筒5を中間筒5a,5b,5cの3つの部分に分割した構成を示したが、分割数及び分割箇所はこれに限定されない。このように中間筒5を分割することにより、セラミックス製の中間筒5及び内筒6の焼嵌め作業を円滑容易とすることができる。   As shown in FIG. 3, the intermediate cylinder 5 may be composed of a plurality of parts divided in the axial direction. Although FIG. 3 shows a configuration in which the intermediate cylinder 5 is divided into three parts, the intermediate cylinders 5a, 5b, and 5c, the number of divisions and the division location are not limited to this. By dividing the intermediate cylinder 5 in this manner, the shrink-fitting operation of the ceramic intermediate cylinder 5 and the inner cylinder 6 can be facilitated.

分割された複数の中間筒の突合せ部は、図4(a)に示すように、軸方向に対して垂直であっても良いが、図4(b)に示すように、軸方向に対して傾斜しているのがより好ましい。このとき傾斜角αは、15〜75°であるのが好ましく、30〜60°であるのがより好ましい。このように、傾斜を設けることにより、外筒２がダイカスト稼働時のダイカストスリーブの天地の温度差により熱変形（ダイカストスリーブ反り）した場合であっても内筒6にその変形による曲げ応力を軽減するという効果が発揮される。また突合せ部分の端面（突合せ面）は、外筒2が熱変形した場合であっても内筒6にその変形が及ばないように、中間筒5の内面側及び外面側にR面取りを形成するのが好ましい。   As shown in FIG. 4 (a), the butted portions of the plurality of divided intermediate cylinders may be perpendicular to the axial direction, but as shown in FIG. More preferably, it is inclined. At this time, the inclination angle α is preferably 15 to 75 °, and more preferably 30 to 60 °. Thus, by providing the inclination, even when the outer cylinder 2 is thermally deformed (die-cast sleeve warpage) due to the temperature difference of the die-casting sleeve when the die-casting operation is performed, the bending stress due to the deformation on the inner cylinder 6 is reduced. The effect of doing is demonstrated. In addition, the end surface (butting surface) of the butting portion is formed with R chamfering on the inner surface side and outer surface side of the intermediate tube 5 so that the inner tube 6 is not deformed even when the outer tube 2 is thermally deformed. Is preferred.

低熱膨張金属からなる外筒2は、セラミックス製の中間筒5及び内筒6（後方部材4）よりも20〜600℃の熱膨張係数が大きいため、焼嵌め時の加熱温度550〜600℃において、外筒2とセラミックス製の中間筒5及び内筒6の焼嵌め作業が円滑容易にできる。さらに実用温度域（外筒2の温度が約200℃：通常、先端部材3の外周は水冷機構が装備される）においては、外筒2と中間筒5と内筒6との熱膨張係数差が小さいので、外筒2と中間筒5、及び中間筒5と内筒6とが緩むことがなく、強固に装着される。また外筒2と先端部材3とは同じ低熱膨張性金属で構成されており、外筒2の20〜200℃の平均熱膨張係数αAと先端部材3の20〜200℃の平均熱膨張係数αBとの差は、-1×10-6/℃〜1×10-6/℃であるので緩むことがない。従って、ダイカスト鋳造中に先端部材3と後方部材4（中間筒5及び内筒6）との間に隙間が生じにくくなり、隙間にアルミニウムが侵入固化して、プランジャーチップが引っかかって抵抗が増すという問題を防ぐことができる。 The outer cylinder 2 made of a low thermal expansion metal has a coefficient of thermal expansion of 20 to 600 ° C. larger than that of the ceramic intermediate cylinder 5 and inner cylinder 6 (rear member 4), so that the heating temperature during shrink fitting is 550 to 600 ° C. The shrink-fitting operation of the outer cylinder 2, the ceramic intermediate cylinder 5 and the inner cylinder 6 can be performed smoothly and easily. Furthermore, in the practical temperature range (the temperature of the outer cylinder 2 is about 200 ° C .: the outer periphery of the tip member 3 is usually equipped with a water cooling mechanism), the difference in thermal expansion coefficient between the outer cylinder 2, the intermediate cylinder 5 and the inner cylinder 6 Therefore, the outer cylinder 2 and the intermediate cylinder 5, and the intermediate cylinder 5 and the inner cylinder 6 are securely attached without being loosened. Also been configured with the same low thermal expansion metal outer tube 2 and the distal end member 3, the average thermal expansion coefficient of 20 to 200 ° C. of the average thermal expansion coefficient alpha A and the tip member 3 of 20 to 200 ° C. of the outer tube 2 Since the difference from α B is −1 × 10 −6 / ° C. to 1 × 10 −6 / ° C., it does not loosen. Therefore, a gap is hardly formed between the tip member 3 and the rear member 4 (the intermediate cylinder 5 and the inner cylinder 6) during die casting, and aluminum penetrates into the gap and solidifies, and the plunger tip is caught and the resistance is increased. Can be prevented.

外筒2の厚さは中間筒5の厚さと内筒6の厚さの合計よりも大きくなるように構成するのが好ましい。外筒2を中間筒5＋内筒6よりも厚く構成することにより、外筒2に中間筒5及び内筒6を焼嵌めたときに中間筒5及び内筒6にかかる周方向の圧縮応力がより大きくなるため、中間筒5及び内筒6の耐熱衝撃性及び強度を高め、内筒6表面の剥離を防止できる。外筒2の厚さは、中間筒5の厚さと内筒6の厚さの合計の1.2倍以上であるのが好ましく、1.5倍以上であるのがより好ましい。   The thickness of the outer cylinder 2 is preferably configured to be larger than the sum of the thickness of the intermediate cylinder 5 and the thickness of the inner cylinder 6. By configuring the outer cylinder 2 to be thicker than the intermediate cylinder 5 + the inner cylinder 6, when the intermediate cylinder 5 and the inner cylinder 6 are shrink-fitted into the outer cylinder 2, the circumferential compressive stress applied to the intermediate cylinder 5 and the inner cylinder 6 is reduced. Since it becomes larger, the thermal shock resistance and strength of the intermediate cylinder 5 and the inner cylinder 6 can be improved, and peeling of the inner cylinder 6 surface can be prevented. The thickness of the outer cylinder 2 is preferably 1.2 times or more of the total thickness of the intermediate cylinder 5 and the inner cylinder 6, and more preferably 1.5 times or more.

外筒2を構成する低熱膨張金属の20〜200℃の熱膨張係数が1×10-6/℃未満の場合は、580 MPa以上の高強度を有し、かつダイカスト鋳造の繰り返し負荷に耐えうる耐久性に優れた低熱膨張金属を得ることが難しく、焼嵌めの際に外筒2に過大な引張応力が発生して破損のリスクがあり、5×10-6/℃超の場合は中間筒5と外筒2とが緩み、ダイカスト鋳造中に後方部材4の早期割損や先端部材3と後方部材4との間に隙間が生じる。また外筒2を構成する低熱膨張金属の20〜600℃の熱膨張係数が5×10-6/℃未満の場合は、後方部材4（中間筒5及び内筒6）との焼嵌め作業が円滑容易にできず、9.5×10-6/℃超の場合は、相対的に20〜200℃の熱膨張係数も大きくなる。 When the coefficient of thermal expansion at 20 to 200 ° C of the low thermal expansion metal constituting the outer cylinder 2 is less than 1 x 10 -6 / ° C, it has a high strength of 580 MPa or more and can withstand repeated loads of die casting. It is difficult to obtain a low thermal expansion metal with excellent durability, and there is a risk of damage due to excessive tensile stress generated in the outer cylinder 2 during shrink fitting, and an intermediate cylinder when it exceeds 5 × 10 -6 / ° C 5 and the outer cylinder 2 are loosened, and an early breakage of the rear member 4 and a gap between the tip member 3 and the rear member 4 occur during die casting. If the coefficient of thermal expansion at 20 to 600 ° C of the low thermal expansion metal constituting the outer cylinder 2 is less than 5 × 10 -6 / ° C, shrink fitting with the rear member 4 (intermediate cylinder 5 and inner cylinder 6) If it is not smooth and easy, and if it exceeds 9.5 × 10 −6 / ° C., the coefficient of thermal expansion of 20 to 200 ° C. is relatively large.

先端部材3を構成する低熱膨張金属の20〜200℃の熱膨張係数が1×10-6/℃未満の場合は、外筒2より熱膨張係数が小さくなるため、先端部材と外筒2とが緩み、ダイカスト鋳造中に先端部材3と後方部材4との間に隙間が生じ、5×10-6/℃超の場合は、セラミックス製の後方部材4との熱膨張係数の差が大きくなるため、ダイカスト鋳造中にセラミックス製の後方部材4の内径と先端部材3の内径の差（段差）が大きくなりプランジャーチップの摺動抵抗が大きくなる。また先端部材3を構成する低熱膨張金属の20〜600℃の熱膨張係数が5×10-6/℃未満の場合は、先端部材3を外筒2に焼嵌めた際、先端部材3の後端側端面とセラミックス製の後方部材4の射出側端面との密着が得られず、9.5×10-6/℃超の場合は、相対的に20〜200℃の熱膨張係数も大きくなる。 When the coefficient of thermal expansion at 20 to 200 ° C. of the low thermal expansion metal constituting the tip member 3 is less than 1 × 10 −6 / ° C., the coefficient of thermal expansion is smaller than that of the outer cylinder 2, so the tip member and the outer cylinder 2 Is loosened, and a gap is formed between the tip member 3 and the rear member 4 during die casting. When the temperature exceeds 5 × 10 −6 / ° C., the difference in the thermal expansion coefficient with the ceramic rear member 4 increases. Therefore, the difference (step) between the inner diameter of the ceramic rear member 4 and the inner diameter of the tip member 3 is increased during die casting, and the sliding resistance of the plunger tip is increased. If the coefficient of thermal expansion at 20 to 600 ° C. of the low thermal expansion metal constituting the tip member 3 is less than 5 × 10 −6 / ° C., when the tip member 3 is shrink-fitted to the outer cylinder 2, When the end face and the injection-side end face of the ceramic rear member 4 cannot be adhered, and the temperature exceeds 9.5 × 10 −6 / ° C., the coefficient of thermal expansion of 20 to 200 ° C. is relatively large.

外筒の平均熱膨張係数（平均線膨張係数又は平均線膨張率に相当）は、JIS Z 2285-2003「金属材料の線膨張係数の測定方法」に基づいて測定する。セラミックス製内筒の平均熱膨張係数は、JIS R 1618-2002「ファインセラミックスの熱機械分析による熱膨張の測定」に基づいて測定する。平均熱膨張係数の測定装置としては示差膨張式熱機械分析装置を用いる。   The average thermal expansion coefficient (corresponding to the average linear expansion coefficient or the average linear expansion coefficient) of the outer cylinder is measured based on JIS Z 2285-2003 “Measuring method of linear expansion coefficient of metal material”. The average coefficient of thermal expansion of the ceramic inner cylinder is measured based on JIS R 1618-2002 “Measurement of thermal expansion by thermomechanical analysis of fine ceramics”. A differential expansion thermomechanical analyzer is used as a measurement device for the average thermal expansion coefficient.

先端部材3は、図1に示すように外筒2の先端部に焼嵌めにより固定しても良いし、図5(a)に示すように、外筒2及び先端部材3の先端部の突合せ部を全周にわたって溶接して固定してもよいし、図5(b)に示すように、先端部材3に外筒2の外径と同じ外径のフランジ部3aを形成し、フランジ部3aと外筒2との突合せ部を全周にわたって溶接して固定してもよい。先端部材3を外筒2に溶接によって固定した場合、図5(a)及び図5(b)に示すように、外筒2と先端部材3との突合せ部、又は外筒2とフランジ部3aとの突合せ部に、それぞれ溶接部11a又は溶接部11bを有する。このように、外筒2と先端部材3とを溶接により固定することにより、焼嵌めによる固定よりもより確実に先端部材3を外筒2に固定することができる。外筒2と先端部材3との固定は、焼嵌めと溶接とを組み合わせて行ってもよい。   The tip member 3 may be fixed by shrink fitting to the tip of the outer cylinder 2 as shown in FIG. 1, or the butting of the tip of the outer cylinder 2 and the tip member 3 as shown in FIG. The portion may be fixed by welding over the entire circumference, or, as shown in FIG.5 (b), a flange portion 3a having the same outer diameter as the outer diameter of the outer cylinder 2 is formed on the tip member 3, and the flange portion 3a The butted portion between the outer cylinder 2 and the outer cylinder 2 may be fixed by welding over the entire circumference. When the distal end member 3 is fixed to the outer cylinder 2 by welding, as shown in FIGS. 5 (a) and 5 (b), the butted portion of the outer cylinder 2 and the distal end member 3, or the outer cylinder 2 and the flange portion 3a And a welded portion 11b or a welded portion 11b, respectively. Thus, by fixing the outer tube 2 and the tip member 3 by welding, the tip member 3 can be fixed to the outer tube 2 more reliably than by fixing by shrink fitting. The outer tube 2 and the tip member 3 may be fixed by combining shrink fitting and welding.

先端部材2の軸方向長さは、外筒3の軸方向長さの5〜30％であるのが好ましく、10〜30%であるのがより好ましい。特に先端部材3を焼嵌めによって外筒2に固定する場合、先端部材3の軸方向長さが外筒3の軸方向長さの5%未満であると、外筒2による先端部材3への焼嵌め力が低下し、使用中に先端部材3が軸方向に移動して先端部材3と後方部材4との間に隙間が生じたり、セラミックス製後方部材4の先端（射出口側）付近が損傷したりする。先端部材3の軸方向長さが外筒3の軸方向長さの30%超であると、先端部材3の後端側内表面で生じた凝固片がダイカスト製品に混入して、製品に破断チル層が形成され製品不良が発生する可能性がある。   The axial length of the tip member 2 is preferably 5 to 30% of the axial length of the outer cylinder 3, and more preferably 10 to 30%. In particular, when the tip member 3 is fixed to the outer cylinder 2 by shrink fitting, if the axial length of the tip member 3 is less than 5% of the axial length of the outer cylinder 3, The shrink-fit force is reduced, and the tip member 3 moves in the axial direction during use, creating a gap between the tip member 3 and the rear member 4, or near the tip (injection port side) of the ceramic rear member 4 Or damage it. If the axial length of the tip member 3 is more than 30% of the axial length of the outer cylinder 3, the solidified pieces generated on the inner surface of the rear end side of the tip member 3 are mixed into the die-cast product and break into the product. A chill layer may be formed and product defects may occur.

先端部材3の外面の後端側に小径部を有しているのが好ましい。小径部は、図6(a)に示すように、先端部材の後端側の外周面にテーパ12aを設けて形成しても良いし、図6(b)に示すように、先端部材の後端側の外周面に段差12bを設けて形成しても良い。前記小径部の軸方向長さは、先端部材の軸方向長さの2〜20%であるのが好ましく、小径部の最小径dと前記先端部材の外径Dとの比d/Dは、0.98≦d/D＜1であるのが好ましい。このように先端部材が、その外面の後端側に小径部を有していることにより、ダイカスト鋳造中に先端部材が膨張した場合であっても、小径部に対向する外筒との間に空間があるため、この部分の外筒に内圧がかからず、窒化珪素質セラミックス製後方部材の先端側の焼嵌めが緩むのを防ぐことができ、セラミックス先端側の割れを防止することができる。   It is preferable to have a small diameter portion on the rear end side of the outer surface of the tip member 3. The small diameter portion may be formed by providing a taper 12a on the outer peripheral surface on the rear end side of the tip member as shown in FIG. 6 (a), or as shown in FIG. 6 (b). A step 12b may be provided on the outer peripheral surface on the end side. The axial length of the small diameter portion is preferably 2 to 20% of the axial length of the tip member, and the ratio d / D between the minimum diameter d of the small diameter portion and the outer diameter D of the tip member is: It is preferable that 0.98 ≦ d / D <1. Thus, even if the tip member expands during die casting, the tip member has a small diameter portion on the rear end side of the outer surface thereof, so that it is between the outer cylinder facing the small diameter portion. Since there is space, internal pressure is not applied to the outer cylinder of this part, it is possible to prevent loosening of the shrink fit on the front end side of the rear member made of silicon nitride ceramics, and it is possible to prevent cracking on the ceramic front end side .

後方部材は、その先端側内面に面取り部13を有するのが好ましい。前記面取り部13は、軸方向長さ1〜4 mmで内面となす角が5〜50°の角度で形成するのが好ましい。このように後方部材の先端側内面に面取り部を有することにより、セラミックス製後方部材の先端側角部の割れを防止することができる。前記面取り部13は、長さ1〜2 mmで20〜30°の角度で形成するのがより好ましい。   The rear member preferably has a chamfered portion 13 on the inner surface on the front end side. The chamfered portion 13 is preferably formed with an axial length of 1 to 4 mm and an angle of 5 to 50 ° with the inner surface. Thus, by having a chamfered portion on the inner surface on the front end side of the rear member, it is possible to prevent the front end side corner portion of the ceramic rear member from cracking. More preferably, the chamfered portion 13 has a length of 1 to 2 mm and an angle of 20 to 30 °.

先端部材3の少なくとも先端側端面及び内周面には、耐溶損性の高い金属からなる耐食層が形成されているのが好ましい。耐食層の形成は、低熱膨張性金属材料と耐食層の材料とが相互に拡散するような方法での接合、すなわち冶金的な接合によるのが好ましい。このような接合方法として、肉盛溶接、溶射等が挙げられる。特に肉盛溶接は、溶射に比べて厚い層が形成でき、母材と肉盛層とが冶金的接合するため、耐溶損性の高い耐食層が形成されるので好ましい。耐食層の厚さは、好ましくは0.5〜5 mmであり、より好ましくは2〜3 mmである。本発明のダイカスト用スリーブでは、アルミニウム合金などの非鉄金属溶湯は、先端部材の先端側端面及び内周面、後方部材の内周面に直接触れることになるため、先端部材では少なくとも先端側端面及び内周面に耐食層が形成されていればよいが、後方側端面、外周面に耐食層が形成されていても構わない。   It is preferable that a corrosion-resistant layer made of a metal with high resistance to melting damage is formed on at least the end-side end surface and the inner peripheral surface of the tip member 3. The formation of the corrosion-resistant layer is preferably performed by bonding in such a manner that the low thermal expansion metal material and the material of the corrosion-resistant layer diffuse each other, that is, metallurgical bonding. Examples of such a joining method include overlay welding and thermal spraying. In particular, overlay welding is preferable because a thick layer can be formed as compared with thermal spraying, and since the base material and the overlay layer are metallurgically joined, a corrosion resistant layer having high resistance to melting is formed. The thickness of the corrosion resistant layer is preferably 0.5 to 5 mm, more preferably 2 to 3 mm. In the die casting sleeve of the present invention, the non-ferrous metal melt such as an aluminum alloy directly touches the front end side end surface and the inner peripheral surface of the front end member, and the inner peripheral surface of the rear member. The corrosion resistant layer may be formed on the inner peripheral surface, but the corrosion resistant layer may be formed on the rear side end surface and the outer peripheral surface.

(2)材料
(a)中間筒
中間筒を構成する窒化珪素質セラミックスとしては、窒化珪素結晶のSi、Nの一部をAl、Oで置換固溶したサイアロンセラミックスが好ましい。サイアロンセラミックスはサイアロン結晶粒子及びSiO2、Al2O3、希土類酸化物等からなる粒界相から構成されているのが好ましい。サイアロンセラミックスは、窒化珪素結晶にアルミニウム及び酸素が固溶しているため熱伝導率を低くすることができ、25℃における熱伝導率が24 W/(m・K)未満となる。また、サイアロンセラミックスの20〜200℃までの平均熱膨張係数及び20〜600℃までの平均熱膨張係数は1〜4×10-6／℃である。 (2) Material
(a) Intermediate cylinder As the silicon nitride ceramics constituting the intermediate cylinder, sialon ceramics in which a part of Si and N of silicon nitride crystal is substituted and dissolved by Al and O are preferable. The sialon ceramic is preferably composed of sialon crystal particles and a grain boundary phase composed of SiO 2 , Al 2 O 3 , rare earth oxide, and the like. Sialon ceramics can lower the thermal conductivity because aluminum and oxygen are dissolved in silicon nitride crystal, and the thermal conductivity at 25 ° C. is less than 24 W / (m · K). Moreover, the average thermal expansion coefficient of 20 to 200 ° C. and the average thermal expansion coefficient of 20 to 600 ° C. of sialon ceramics are 1 to 4 × 10 −6 / ° C.

(b)内筒
内筒を構成する窒化珪素質セラミックスは、窒化珪素とSiO2、MgO、希土類酸化物等からなる粒界相とからなり、不純物として含まれるアルミニウムが0.1質量％以下であるのが好ましい。また、機械的強度を向上させる目的で金属窒化物、金属炭化物、金属ホウ化物などの微粒子を含有しても良い。このような窒化珪素質セラミックスは、25℃における熱伝導率が25 W/(m・K) 以上であり、20〜200℃までの平均熱膨張係数及び20〜600℃までの平均熱膨張係数が1〜4×10-6／℃である。また耐熱衝撃温度は750℃以上、25℃での4点曲げ強度が800 MPaを超える耐衝撃性及び強度を有する。このような窒化珪素質セラミックスとしては、例えば、特許第4348659号に記載の高熱伝導窒化珪素素質焼結体が挙げられる。 (b) Inner cylinder The silicon nitride ceramic constituting the inner cylinder is composed of silicon nitride and a grain boundary phase composed of SiO 2 , MgO, rare earth oxide, etc., and aluminum contained as impurities is 0.1 mass% or less. Is preferred. Moreover, you may contain fine particles, such as a metal nitride, a metal carbide, and a metal boride, for the purpose of improving mechanical strength. Such silicon nitride ceramics have a thermal conductivity of 25 W / (m · K) or more at 25 ° C., an average thermal expansion coefficient of 20 to 200 ° C. and an average thermal expansion coefficient of 20 to 600 ° C. 1 to 4 × 10 −6 / ° C. The thermal shock temperature is 750 ° C or higher, and the impact resistance and strength of the 4-point bending strength at 25 ° C exceeds 800 MPa. An example of such a silicon nitride ceramic is a high thermal conductivity silicon nitride base sintered body described in Japanese Patent No. 4348659.

(c)外筒
外筒を構成する低熱膨張性金属材料は、29〜35質量%のNi、12〜23質量%のCo、0.5〜1.5質量%のAl及び0.8〜3質量%のTiを含有するFe-Ni-Co-Al-Ti基合金であるのが好ましい。このような材料を用いることにより、外筒の強度を高めることもできる。より好ましくは、30〜35質量%のNi、12〜17質量%のCo、0.5〜1.5質量%のAl及び1.5〜3質量%のTiを含有するFe-Ni-Co-Al-Ti基合金である。Al及びTiは析出強化元素であり、強度（例えば引張強さ）の向上に寄与する。Al及びTiの他に析出強化元素としてはNbを用いることができる。Al及びTiの含有に併せて、Nbを含有してもよい。Nbは2〜5質量％が好ましい。このような外筒を構成する材料は、29〜35質量%のNi、12〜23質量%のCo、0.5〜1.5質量%のAl、0.8〜3質量%のTi、残部Fe及び不可避不純物からなるのが好ましく、30〜35質量%のNi、12〜17質量%のCo、0.5〜1.5質量%のAl及び1.5〜3質量%のTi、残部Fe及び不可避不純物からなるのがさらに好ましい。 (c) Outer cylinder The low thermal expansion metal material constituting the outer cylinder contains 29 to 35 mass% Ni, 12 to 23 mass% Co, 0.5 to 1.5 mass% Al and 0.8 to 3 mass% Ti. Fe-Ni-Co-Al-Ti base alloy is preferable. By using such a material, the strength of the outer cylinder can be increased. More preferably, a Fe-Ni-Co-Al-Ti-based alloy containing 30 to 35 mass% Ni, 12 to 17 mass% Co, 0.5 to 1.5 mass% Al and 1.5 to 3 mass% Ti. is there. Al and Ti are precipitation strengthening elements and contribute to improvement of strength (for example, tensile strength). In addition to Al and Ti, Nb can be used as a precipitation strengthening element. Nb may be contained together with the inclusion of Al and Ti. Nb is preferably 2 to 5% by mass. The material constituting such an outer cylinder is composed of 29 to 35% by mass of Ni, 12 to 23% by mass of Co, 0.5 to 1.5% by mass of Al, 0.8 to 3% by mass of Ti, the balance Fe and inevitable impurities. It is more preferably composed of 30 to 35 mass% Ni, 12 to 17 mass% Co, 0.5 to 1.5 mass% Al and 1.5 to 3 mass% Ti, the balance Fe and inevitable impurities.

外筒をFe-Ni-Co-Al-Ti基合金で構成して熱処理を行うことによって、外筒は高強度になる。熱処理としては、例えば、固溶化処理（900〜1000℃）と、それについで行う時効処理（580〜750℃）との組み合わせが挙げられる。例えば、外筒の300℃及び400℃における引張強さは800 MPa以上であるのが好ましく、900 MPa以上であるのがより好ましい。このような高温強度を有することにより、ダイカスト用スリーブ1内に注入された溶湯を射出する際の内部応力に対してセラミックス製後方部材を十分に保護することができる。また、外筒は室温で、15％以上（特に20％以上）の伸び、20 W/(m・K) 以下の熱伝導率、及び130 GPa以上のヤング率を有するのが好ましい。   By forming the outer cylinder with a Fe—Ni—Co—Al—Ti-based alloy and performing heat treatment, the outer cylinder becomes high in strength. Examples of the heat treatment include a combination of a solution treatment (900 to 1000 ° C.) and an aging treatment (580 to 750 ° C.) performed subsequently. For example, the tensile strength at 300 ° C. and 400 ° C. of the outer cylinder is preferably 800 MPa or more, and more preferably 900 MPa or more. By having such high temperature strength, the ceramic back member can be sufficiently protected against internal stress when the molten metal injected into the die casting sleeve 1 is injected. The outer cylinder preferably has an elongation of 15% or more (particularly 20% or more), a thermal conductivity of 20 W / (m · K) or less, and a Young's modulus of 130 GPa or more at room temperature.

(d)先端部材
先端部材を構成する低熱膨張性金属材料は、外筒を構成する低熱膨張性金属材料と同じ材料、すなわち29〜35質量%のNi、12〜23質量%のCo、0.5〜1.5質量%のAl及び0.8〜3質量%のTiを含有するFe-Ni-Co-Al-Ti基合金であるのが好ましい。より好ましくは、30〜35質量%のNi、12〜17質量%のCo、0.5〜1.5質量%のAl及び1.5〜3質量%のTiを含有するFe-Ni-Co-Al-Ti基合金である。このような先端部材の母材を構成する材料は、29〜35質量%のNi、12〜23質量%のCo、0.5〜1.5質量%のAl、0.8〜3質量%のTi、残部Fe及び不可避不純物からなるのが好ましく、30〜35質量%のNi、12〜17質量%のCo、0.5〜1.5質量%のAl及び1.5〜3質量%のTi、残部Fe及び不可避不純物からなるのがさらに好ましい。 (d) Tip member The low thermal expansion metal material constituting the tip member is the same material as the low thermal expansion metal material constituting the outer cylinder, that is, 29 to 35 mass% Ni, 12 to 23 mass% Co, 0.5 to An Fe—Ni—Co—Al—Ti based alloy containing 1.5% by mass of Al and 0.8 to 3% by mass of Ti is preferred. More preferably, a Fe-Ni-Co-Al-Ti-based alloy containing 30 to 35 mass% Ni, 12 to 17 mass% Co, 0.5 to 1.5 mass% Al and 1.5 to 3 mass% Ti. is there. The material constituting the base material of such a tip member is 29 to 35 mass% Ni, 12 to 23 mass% Co, 0.5 to 1.5 mass% Al, 0.8 to 3 mass% Ti, the balance Fe and unavoidable It is preferably composed of impurities, more preferably 30 to 35% by mass of Ni, 12 to 17% by mass of Co, 0.5 to 1.5% by mass of Al and 1.5 to 3% by mass of Ti, the balance Fe and inevitable impurities. .

先端部材の耐食層を構成する材料は、0.2〜0.7質量%のC、1〜7質量%のCr及び1〜20質量%のNi、残部実質的にFe及び不可避不純物からなるFe-C-Ni-Cr基合金であるのが好ましい。この合金は炭化物が微細に分散しているため耐摩耗性が高く、かつ合金中に分散した炭化物が非鉄溶融金属と反応し難いため耐溶損性に優れている。このFe-C-Ni-Cr基合金は、さらに0.5〜3質量%のMo、0.3〜1.5質量%のV、2質量%以下のCo、0.5質量%以下のAl、0.5質量%以下のTi、0.5質量%以下のSi、1.0質量%以下のMn、0.04質量%以下のP及び0.03質量%以下のSを含有してもよい。このFe-C-Ni-Cr基合金は、さらに0.1〜4質量%のWを含有しても良い。   The material constituting the corrosion resistant layer of the tip member is Fe-C-Ni consisting of 0.2 to 0.7% by mass of C, 1 to 7% by mass of Cr and 1 to 20% by mass of Ni, the balance being substantially Fe and inevitable impurities. -Cr-based alloys are preferred. This alloy has high wear resistance because carbides are finely dispersed, and has excellent corrosion resistance because carbides dispersed in the alloy hardly react with non-ferrous molten metal. This Fe-C-Ni-Cr base alloy is further 0.5-3 mass% Mo, 0.3-1.5 mass% V, 2 mass% or less Co, 0.5 mass% or less Al, 0.5 mass% or less Ti, It may contain 0.5% by mass or less of Si, 1.0% by mass or less of Mn, 0.04% by mass or less of P, and 0.03% by mass or less of S. This Fe—C—Ni—Cr base alloy may further contain 0.1 to 4% by mass of W.

前記耐食層の表面から深さ0.5 mmまでの部分（表層部）は、C含有量が0.2〜0.7質量%、Cr含有量が2〜7質量%であり、Ni含有量が１〜12質量%であるのが好ましい。表層部のC含有量、Cr含有量及びNi含有量が前記の範囲にあることにより、耐食層の表面の耐食性及び耐摩耗性がより優れたものになる。   The portion (surface layer portion) from the surface of the corrosion-resistant layer to a depth of 0.5 mm has a C content of 0.2 to 0.7 mass%, a Cr content of 2 to 7 mass%, and an Ni content of 1 to 12 mass%. Is preferred. When the C content, Cr content, and Ni content of the surface layer are in the above ranges, the corrosion resistance and wear resistance of the surface of the corrosion-resistant layer are further improved.

耐食層は、さらにその表面に厚さ150〜500μmの窒化層を有するのが好ましい。Fe-C-Ni-Cr基合金からなる耐食層は、窒素との親和力が強いCrを含有しているため、合金への窒素の拡散を容易にし、窒化物を多量に含んだ窒化層を形成しやすい。窒化層は最表面に形成される鉄窒化物により溶融金属と反応が起こり難くなる。以上の理由から、耐溶損性に優れたFe-C-Ni-Cr基合金からなる被覆層、及び非鉄溶融金属に接触する最表面部分に形成された窒化層を有する構造とすることにより、非鉄溶融金属との反応に起因する溶損を抑えることができる。また、たとえ窒化層の一部が使用中に消滅した場合にも、Fe-C-Ni-Cr基合金の被覆層の耐溶損性により溶融金属の侵入に基づく溶損が起こり難く、溶損が急速に進行することを抑えることができる。   The corrosion resistant layer preferably further has a nitride layer having a thickness of 150 to 500 μm on the surface thereof. Corrosion-resistant layers made of Fe-C-Ni-Cr-based alloys contain Cr, which has a strong affinity for nitrogen, making it easy to diffuse nitrogen into the alloy and forming a nitride layer containing a large amount of nitride. It's easy to do. The nitride layer is less likely to react with the molten metal due to iron nitride formed on the outermost surface. For the above reasons, a structure having a coating layer made of an Fe-C-Ni-Cr-based alloy having excellent resistance to melting damage and a nitride layer formed on the outermost surface portion in contact with the non-ferrous molten metal can be used. It is possible to suppress melting loss caused by reaction with the molten metal. In addition, even if a part of the nitride layer disappears during use, due to the melt resistance of the coating layer of the Fe-C-Ni-Cr base alloy, the melt damage due to the penetration of the molten metal hardly occurs, Rapid progression can be suppressed.

窒化層は、耐食層の表面に、侵硫窒化、塩浴軟窒化、ガス窒化、ガス軟窒化、プラズマ窒化等の窒化処理により形成することができる。中でも侵硫窒化は、Sを含有するため潤滑性が改善され、プランジャーチップとの摺動抵抗を低減する効果もあるため好ましい。   The nitride layer can be formed on the surface of the corrosion-resistant layer by nitriding treatment such as sulfur nitriding, salt bath soft nitriding, gas nitriding, gas soft nitriding, plasma nitriding. Of these, sulfur nitride is preferable because it contains S and has improved lubricity and reduced sliding resistance with the plunger tip.

[2] ダイカスト用スリーブの製造方法
本発明のダイカスト用スリーブは、中間筒に内筒を焼嵌めて後方部材とし、得られた後方部材を外筒に焼嵌めて冷却した後に、先端部材を外筒の先端部に焼嵌めし嵌着する、又は溶接により固定することによって製造する。先端部材には、必要に応じて、少なくとも先端側端面及び内周面に耐食層を接合する。 [2] Die-casting sleeve manufacturing method The die-casting sleeve according to the present invention is such that an inner cylinder is shrink-fitted into an intermediate cylinder to form a rear member, and the obtained rear member is shrink-fitted to an outer cylinder and cooled, and then a tip member is removed. Manufactured by shrink fitting to the tip of the tube or fixing by welding. A corrosion-resistant layer is joined to the tip member at least on the tip-side end surface and the inner peripheral surface as necessary.

(1)耐食層の接合
先端部材の少なくとも先端側端面及び内周面への耐食層の接合は、先端部材の母材の材料（低熱膨張性金属材料）と耐食層の材料とが相互に拡散するような方法、すなわち冶金的な方法で行うのが好ましい。母材の材料と耐食層の材料とが相互に拡散することにより、母材と耐食層とを高い密着度で接合することができる。このような接合方法として、肉盛溶接、溶射等が挙げられる。特に肉盛溶接は、溶射に比べて厚い層が形成でき、母材と肉盛層とが冶金的接合するため、耐溶損性の高い耐食層が形成されるので好ましい。 (1) Joining the corrosion resistant layer When joining the corrosion resistant layer to at least the tip end surface and inner peripheral surface of the tip member, the base material (low thermal expansion metal material) of the tip member and the corrosion resistant material diffuse to each other. It is preferable to carry out by such a method, that is, a metallurgical method. Since the base material and the corrosion-resistant layer material diffuse to each other, the base material and the corrosion-resistant layer can be joined with high adhesion. Examples of such a joining method include overlay welding and thermal spraying. In particular, overlay welding is preferable because a thick layer can be formed as compared with thermal spraying, and since the base material and the overlay layer are metallurgically joined, a corrosion resistant layer having high resistance to melting is formed.

耐食層を肉盛溶接で形成する場合、１回で所望の厚さに肉盛溶接してもよいが、２回以上に分けて肉盛溶接するのが好ましい。２回に分けて肉盛溶接を行う場合、例えば、１回目は所望の厚さの半分の厚さに肉盛溶接し、２回目に所望の厚さになるように残りの厚さ分を肉盛溶接することによって耐食層を形成する。具体的には、１回目の肉盛溶接では1.5〜2.5 mmの耐食層を形成し、２回目の肉盛溶接では1.5〜2.5 mmの耐食層を形成するのが好ましい。１回目の肉盛溶接の後、表面を0.1〜0.5 mm程度加工除去した後に、２回目の肉盛溶接を行っても良い。２回目の肉盛溶接後、所望の先端部材の内径になるよう表面を加工する。このように２回以上に分けて肉盛溶接を行うことにより、１回目の肉盛溶接において母材に含まれる金属組成が耐食層に拡散した場合でも、２回目の肉盛溶接において耐食層に拡散する母材の金属組成成分を低減することができ、耐食層の最表面の耐溶損性を確保することができる。   When the corrosion-resistant layer is formed by build-up welding, build-up welding may be performed to a desired thickness at one time, but it is preferable to perform build-up welding in two or more steps. When overlay welding is performed in two steps, for example, the first time is overlay welding to half the desired thickness, and the remaining thickness is increased to the desired thickness for the second time. A corrosion-resistant layer is formed by overlay welding. Specifically, it is preferable to form a 1.5-2.5 mm corrosion-resistant layer in the first build-up welding and to form a 1.5-2.5 mm corrosion-resistant layer in the second build-up welding. After the first build-up welding, the second build-up welding may be performed after the surface is processed and removed by about 0.1 to 0.5 mm. After the second overlay welding, the surface is processed so as to have a desired inner diameter of the tip member. In this way, by performing overlay welding in two or more times, even when the metal composition contained in the base material diffuses into the corrosion-resistant layer in the first overlay welding, the corrosion-resistant layer is formed in the second overlay welding. The metal composition component of the base material to diffuse can be reduced, and the corrosion resistance of the outermost surface of the corrosion resistant layer can be ensured.

耐食層の形成後、その表面に窒化層を形成する工程を有しても良い。窒化層は、耐食層の表面に、侵硫窒化、塩浴軟窒化、ガス窒化、ガス軟窒化、プラズマ窒化等の窒化処理により形成することができる。中でも侵硫窒化は、Sを含有するため潤滑性が改善され、プランジャーチップとの摺動抵抗を低減する効果もあるため好ましい。   After the formation of the corrosion resistant layer, a step of forming a nitride layer on the surface may be included. The nitride layer can be formed on the surface of the corrosion-resistant layer by nitriding treatment such as sulfur nitriding, salt bath soft nitriding, gas nitriding, gas soft nitriding, plasma nitriding. Of these, sulfur nitride is preferable because it contains S and has improved lubricity and reduced sliding resistance with the plunger tip.

(2) 焼嵌め
(1) 中間筒への内筒の焼嵌め
中間筒への内筒の焼嵌めは、中間筒を加熱し、内筒を挿入した後、中間筒の先端側及び後端側を先に冷却し、中間筒の中央部を後から冷却することによって行うのが好ましい。このように、中間筒の先端側及び後端側を先に冷却することにより、中間筒の両端部が先に嵌着されるので、中間筒と内筒とを位置ずれが起こらない嵌着することができるとともに、内筒に対して軸方向の圧縮応力を付与することができる。このように中間筒の両端部と中央部との冷却タイミングをずらすには、例えば、中間筒外面を中央部、先端側及び後端側の三箇所に分けてバンドヒーターで加熱し、内筒を挿入後、先端側及び後端側のバンドヒーターの電源を落とし、先端側及び後端側を冷却した後で、中央部のバンドヒーターの電源を落とすことによって行う。 (2) Shrink fit
(1) Shrink fitting of the inner cylinder to the intermediate cylinder For shrink fitting of the inner cylinder to the intermediate cylinder, after heating the intermediate cylinder and inserting the inner cylinder, the front end side and the rear end side of the intermediate cylinder are cooled first. It is preferable to carry out by cooling the central part of the intermediate cylinder later. Thus, by cooling the front end side and the rear end side of the intermediate cylinder first, both end portions of the intermediate cylinder are fitted first, so that the intermediate cylinder and the inner cylinder are fitted so that no positional deviation occurs. And compressive stress in the axial direction can be applied to the inner cylinder. In order to shift the cooling timing of the both ends and the center of the intermediate cylinder in this way, for example, the outer surface of the intermediate cylinder is divided into three portions, the center, the front end, and the rear end, and heated with a band heater, After insertion, the power of the band heater on the front end side and the rear end side is turned off, and after cooling the front end side and the rear end side, the power of the band heater at the center is turned off.

内筒の中間筒への焼嵌めは、焼嵌め率0.1/1000〜0.2/1000で行うのが好ましい。なお焼嵌め率は、内筒の焼嵌め前の外径をd1、中間筒の焼嵌め前の内径をD2としたとき、
焼嵌め率=(d1-D2)/D2
で表される。 The shrink fitting of the inner cylinder to the intermediate cylinder is preferably performed with a shrink fitting ratio of 0.1 / 1000 to 0.2 / 1000. The shrinkage fit rate is the outer diameter before shrink fitting of the inner cylinder d1, and the inner diameter of the intermediate cylinder before shrink fitting is D2.
Shrink fit rate = (d1-D2) / D2
It is represented by

(2) 外筒への後方部材及び先端部材の焼嵌め
外筒への後方部材及び先端部材の焼嵌めは、後方部材を外筒に焼嵌めて冷却した後に、先端部材を外筒の先端部に焼嵌めし嵌着することによって行うのが好ましい。先端部材の焼嵌めは、先端部材が挿入される部分の外筒外面を加熱し、先端部材を後方部材に密着するように挿入後、先端部材の先端側を先に冷却し、先端部材の後端側を後から冷却することによって行うのが好ましい。このように、先端部材の先端側を先に冷却し、先端部材の後端側を後から冷却することにより、先端部材の先端側が先に嵌着され、後端側が遅れて嵌着されるので、セラミックスからなる後方部材と先端部材との端面突合せ部において、軸方向圧縮応力が付与され、後方部材と先端部材との密着度を高めることができる。このように先端部材の先端側と後端側との冷却タイミングをずらすには、例えば、先端部材が挿入される部分の外筒外面をバンドヒーターで加熱し、先端部材を挿入後、バンドヒーターの電源を落とし、先端部材の半長分だけバンドヒーターを後端側にずらすことによって行う。 (2) Shrink fitting of the rear member and the tip member to the outer cylinder The shrink fitting of the rear member and the tip member to the outer cylinder is performed by shrinking the rear member to the outer cylinder and cooling, and then the tip member is moved to the tip of the outer cylinder. It is preferable to carry out by shrink-fitting. In the shrink fitting of the tip member, the outer surface of the outer cylinder of the portion where the tip member is inserted is heated, the tip member is inserted so as to be in close contact with the rear member, the tip side of the tip member is cooled first, and the tip member is Preferably, the end side is cooled later. Thus, by cooling the front end side of the front end member first and cooling the rear end side of the front end member later, the front end side of the front end member is fitted first, and the rear end side is fitted later. In the end face butting portion between the rear member and the tip member made of ceramics, axial compressive stress is applied, and the degree of adhesion between the rear member and the tip member can be increased. In order to shift the cooling timing between the front end side and the rear end side of the tip member in this way, for example, the outer surface of the outer cylinder of the portion where the tip member is inserted is heated with a band heater, and after inserting the tip member, The power is turned off, and the band heater is shifted to the rear end side by half the length of the tip member.

後方部材（セラミックス製内筒及び中間筒）の外筒への焼嵌めは、焼嵌め率1/1000〜2/1000及び焼嵌め温度550〜650℃で行うのが好ましい。先端部材（低熱膨張性金属材料からなる母材にFe-C-Ni-Cr基合金からなる耐食層を形成してなる内筒）の外筒への焼嵌めは、焼嵌め率0/1000〜1/1000及び焼嵌め温度400〜450℃で行うのが好ましく、焼嵌め率は0.05/1000〜0.5/1000であるのがより好ましい。   The shrink fitting of the rear member (the ceramic inner cylinder and the intermediate cylinder) to the outer cylinder is preferably performed at a shrink fitting rate of 1/1000 to 2/1000 and a shrink fitting temperature of 550 to 650 ° C. The shrink fit of the tip member (inner cylinder formed by forming a corrosion resistant layer of Fe-C-Ni-Cr base alloy on the base material of low thermal expansion metal material) to the outer cylinder is 0/1000 ~ It is preferable to carry out at 1/1000 and shrink-fit temperature 400-450 degreeC, and it is more preferable that shrink-fit rate is 0.05 / 1000-0.5 / 1000.

(3) 外筒への先端部材の溶接
後方部材及び先端部材を焼嵌めによって外筒へ固定する代わりに、後方部材を外筒に焼嵌めて冷却した後に、先端部材を溶接によって外筒に固定してもよい。例えば、図5(a)に示すように、外筒2及び先端部材3の先端部の突合せ部を全周にわたって溶接して固定してもよいし、図5(b)に示すように、先端部材3に外筒2の外径と同じ外径のフランジ部3aを形成し、フランジ部3aと外筒2との突合せ部を全周にわたって溶接して固定してもよい。焼嵌めによる固定よりもより確実に先端部材3を外筒2に固定することができる。外筒2と先端部材3との固定は、焼嵌めと溶接とを組み合わせて行ってもよい。 (3) Welding of the tip member to the outer cylinder Instead of fixing the rear member and the tip member to the outer cylinder by shrink fitting, after cooling the rear member by shrink fitting to the outer cylinder, the tip member is fixed to the outer cylinder by welding. May be. For example, as shown in FIG. 5 (a), the abutting portion of the outer cylinder 2 and the tip of the tip member 3 may be fixed by welding over the entire circumference, or as shown in FIG. A flange 3a having the same outer diameter as the outer diameter of the outer cylinder 2 may be formed on the member 3, and the butted portion of the flange 3a and the outer cylinder 2 may be welded and fixed over the entire circumference. The tip member 3 can be fixed to the outer cylinder 2 more reliably than the fixing by shrink fitting. The outer tube 2 and the tip member 3 may be fixed by combining shrink fitting and welding.

本発明を実施例によりさらに詳細に説明するが、本発明はそれらに限定されるものではない。   The present invention will be described in more detail with reference to examples, but the present invention is not limited thereto.

実施例１
以下のようにして、外筒、先端部材、中間筒及び内筒を準備し、焼嵌め及び加工を行い、図1に示す本発明のダイカスト用スリーブ1を作製した。 Example 1
As described below, an outer cylinder, a tip member, an intermediate cylinder, and an inner cylinder were prepared, and shrink fitting and processing were performed to produce a die casting sleeve 1 of the present invention shown in FIG.

(1) 外筒、先端部材、中間筒及び内筒の準備
(a)外筒
32.6質量％のNi、14.9質量％のCo、0.8質量％のAl、2.3質量％のTi、0.04質量％のC、残部Fe及び不可避的不純物からなる高強度低熱膨張性の金属からなる、外径110 mm、内径85 mm及び長さ280 mmの円筒状の外筒を形成した。この外筒の引張強度は1200 MPa、20〜200℃の熱膨張係数は3.2×10-6/℃、20〜300℃の熱膨張係数は3.6×10-6/℃及び20〜600℃の熱膨張係数は9.5×10-6/℃であった。 (1) Preparation of outer cylinder, tip member, intermediate cylinder and inner cylinder
(a) Outer cylinder
Outer diameter composed of 32.6 mass% Ni, 14.9 mass% Co, 0.8 mass% Al, 2.3 mass% Ti, 0.04 mass% C, the balance Fe, and high strength and low thermal expansion metal consisting of inevitable impurities A cylindrical outer cylinder having a diameter of 110 mm, an inner diameter of 85 mm, and a length of 280 mm was formed. The outer cylinder has a tensile strength of 1200 MPa, a thermal expansion coefficient of 20 to 200 ° C. is 3.2 × 10 −6 / ° C., a thermal expansion coefficient of 20 to 300 ° C. is 3.6 × 10 −6 / ° C., and a heat of 20 to 600 ° C. expansion coefficient was 9.5 × 10 -6 / ℃.

(b)先端部材
32.6質量％のNi、14.9質量％のCo、0.8質量％のAl、2.3質量％のTi、0.04質量％のC、残部Fe及び不可避的不純物からなる高強度低熱膨張性の金属からなる母材の先端側端面及び内周面に、SKD61を1.5 mmの厚さで肉盛溶接した後、同様にSKD61を１.5 mmの厚さで肉盛溶接し、さらに600℃10時間の条件で時効処理を行った後、その肉盛層の表面を約0.5 mm加工除去して、外径85 mm、内径60 mm及び長さ30 mmの円筒状部材を得た。この部材の後端側の外周面に長さ10 mm及び軸方向に対して5°傾きのテーパを形成した。この外筒の引張強度は1200 MPa、20〜200℃の熱膨張係数は3.2×10-6/℃、20〜300℃の熱膨張係数は3.6×10-6/℃及び20〜600℃の熱膨張係数は9.5×10-6/℃であった。 (b) Tip member
A base material made of a high-strength, low-thermal-expansion metal consisting of 32.6% Ni, 14.9% Co, 0.8% Al, 2.3% Ti, 0.04% C, the balance Fe, and inevitable impurities After overlay welding SKD61 to a thickness of 1.5 mm on the end surface and inner peripheral surface of the tip side, similarly, overlay welding of SKD61 to a thickness of 1.5 mm is performed, and further aging treatment is performed at 600 ° C. for 10 hours. Thereafter, the surface of the built-up layer was processed and removed by about 0.5 mm to obtain a cylindrical member having an outer diameter of 85 mm, an inner diameter of 60 mm, and a length of 30 mm. A taper having a length of 10 mm and an inclination of 5 ° with respect to the axial direction was formed on the outer peripheral surface of the rear end side of this member. The outer cylinder has a tensile strength of 1200 MPa, a thermal expansion coefficient of 20 to 200 ° C. is 3.2 × 10 −6 / ° C., a thermal expansion coefficient of 20 to 300 ° C. is 3.6 × 10 −6 / ° C., and a heat of 20 to 600 ° C. The expansion coefficient was 9.5 × 10 −6 / ° C.

(c)中間筒
87質量％のSi3N4、6質量％のY2O3、4質量％のAl2O3及び3質量％の21R固溶体からなる原料粉末を湿式混合して噴霧乾燥した後、冷間静水圧プレス（CIP）を用いて100 MPaの圧力で成形し、円筒状の成形体を得た。この成形体を、脱脂後、窒素雰囲気1750℃で焼結し、円筒状サイアロンセラミックスを得た。得られた円筒状サイアロンセラミックスの表面及び内面を加工して、端部に図2(b)に示す形状の段差（高さ1.0 mm）を有し、外径85 mm、内径70 mm及び全長245 mmの中間筒を得た。 (c) Intermediate cylinder
A raw material powder consisting of 87% by mass of Si 3 N 4 , 6% by mass of Y 2 O 3 , 4% by mass of Al 2 O 3 and 3% by mass of 21R solid solution is wet-mixed and spray-dried. Molding was performed at a pressure of 100 MPa using a hydraulic press (CIP) to obtain a cylindrical shaped body. This molded body was degreased and then sintered at 1750 ° C. in a nitrogen atmosphere to obtain cylindrical sialon ceramics. The surface and inner surface of the obtained cylindrical sialon ceramics are processed to have a step (height: 1.0 mm) as shown in FIG. 2 (b) at the end, an outer diameter of 85 mm, an inner diameter of 70 mm, and a total length of 245 An intermediate tube of mm was obtained.

(d)内筒
94質量％のSi3N4、4質量％のY2O3、2質量％のMgOからなる原料粉末を湿式混合して噴霧乾燥した後、冷間静水圧プレス（CIP）を用いて100 MPaの圧力で成形し、円筒状の成形体を得た。この成形体を、脱脂後、窒素雰囲気1700℃で焼結し、円筒状窒化珪素質セラミックスを得た。得られた円筒状窒化珪素質セラミックスの表面及び内面を加工して、端部に図2(b)に示す形状の周方向溝（深さ 1.0 mm）を有し、外径 70 mm、内径 60 mm及び全長 245 mmの内筒を得た。 (d) Inner cylinder
Raw material powder consisting of 94% by mass of Si 3 N 4 , 4% by mass of Y 2 O 3 and 2% by mass of MgO is wet-mixed and spray-dried, and then 100 MPa using a cold isostatic press (CIP) A cylindrical shaped body was obtained by molding at a pressure of 1 m. This molded body was degreased and sintered at 1700 ° C. in a nitrogen atmosphere to obtain a cylindrical silicon nitride ceramic. The surface and inner surface of the obtained cylindrical silicon nitride ceramics are processed to have circumferential grooves (depth: 1.0 mm) with the shape shown in Fig. 2 (b) at the end, an outer diameter of 70 mm, an inner diameter of 60 mm. An inner cylinder of mm and a total length of 245 mm was obtained.

(2)焼嵌め
まず内筒6を中間筒5に、焼嵌め率0.1/1000で焼嵌めし後方部材4を得た。中間筒5への内筒6の焼嵌めは、中間筒5外面を中央部、先端側及び後端側の三箇所に分けてバンドヒーターで加熱し、内筒6を挿入後、先端側及び後端側のバンドヒーターの電源を落とし、先端側及び後端側を冷却した後で、中央部のバンドヒーターの電源を落とすことによって行った。このように、中間筒の先端側及び後端側を先に冷却することにより、中間筒の両端部が先に嵌着されるので、中間筒と内筒とを位置ずれが起こらない嵌着することができた。 (2) Shrink-Fitting First, the inner cylinder 6 was shrink-fitted to the intermediate cylinder 5 at a shrink-fitting rate of 0.1 / 1000 to obtain the rear member 4. The inner cylinder 6 is shrink-fitted into the intermediate cylinder 5 by dividing the outer surface of the intermediate cylinder 5 into a central portion, a front end side, and a rear end side and heating it with a band heater. The power of the band heater at the end side was turned off, the front end side and the rear end side were cooled, and then the power of the band heater at the center was turned off. Thus, by cooling the front end side and the rear end side of the intermediate cylinder first, both end portions of the intermediate cylinder are fitted first, so that the intermediate cylinder and the inner cylinder are fitted so that no positional deviation occurs. I was able to.

次に、後方部材4を外筒2に、焼嵌め率1/1000及び焼嵌め温度650℃で焼嵌めした後、さらに先端部材3を外筒2に、焼嵌め率0.05/1000及び焼嵌め温度250℃で焼嵌めした。先端部材3の焼嵌めは、先端部材3が挿入される部分の外筒外面をバンドヒーターで加熱し、先端部材3を後方部材4に密着するように挿入後、バンドヒーターの電源を落とし、先端部材3の半長分だけバンドヒーターを後端側にずらすことによって行った。このようにして焼嵌めすることにより、先端部材3の先端側が先に冷却され嵌着し、その後、先端部材3の後端側を遅れて嵌着するので、後方部材4と先端部材3との端面突合せ部が強固に密着した。   Next, after the rear member 4 is shrink-fitted to the outer cylinder 2 at a shrink fit rate of 1/1000 and a shrink fit temperature of 650 ° C., the tip member 3 is further shrink-fitted to the outer tube 2 at a shrink fit rate of 0.05 / 1000 and a shrink fit temperature. It was shrink-fitted at 250 ° C. The tip member 3 is shrink-fitted by heating the outer surface of the outer cylinder of the portion where the tip member 3 is inserted with a band heater, and inserting the tip member 3 so that the tip member 3 is in close contact with the rear member 4, and then turning off the power of the band heater. The band heater was shifted toward the rear end side by half the length of member 3. By shrink fitting in this way, the distal end side of the distal end member 3 is cooled and fitted first, and then the rear end side of the distal end member 3 is fitted with a delay, so the rear member 4 and the distal end member 3 The end face butt portion was firmly adhered.

(3)加工
焼嵌め後、内径、外径及び端面を仕上げ加工し、後端リング（長さ50 mm）を装着し、ボルト固定した。なお先端部材の先端側端面（肉盛溶接した面）は加工しなかった。 (3) Processing After shrink fitting, the inner diameter, outer diameter, and end face were finished, and a rear end ring (length 50 mm) was mounted and bolted. In addition, the front end side end surface (surface subjected to overlay welding) of the front end member was not processed.

このようにして作製したダイカスト用スリーブ1を型締力1,650トンの横型ダイカストマシンの溶湯射出装置に装着して、スリーブ内を摺動するSKD61からなるプランジャーチップを使用し、1200℃の銅合金製部品のダイカストに使用した結果、セラミックス内筒表面の剥離や内筒が変形することによるセラミックの破損は発生せず、安定した射出を行えることを確認した。   The die casting sleeve 1 produced in this way is mounted on a molten metal injection device of a horizontal die casting machine with a clamping force of 1,650 tons, using a plunger tip made of SKD61 sliding inside the sleeve, and a copper alloy at 1200 ° C As a result of using it for die casting of manufactured parts, it was confirmed that the ceramic inner cylinder surface was not peeled off or the inner cylinder was deformed, and the ceramic was not damaged.

1・・・ダイカスト用スリーブ
2・・・外筒
3・・・先端部材
3a・・・フランジ部
4・・・後方部材
5・・・中間筒
6・・・内筒
9・・・係合部
8・・・後端リング部材
81・・・ボルト
9・・・係合部
9a・・・段差
9b・・・傾斜部を有する段差
9c・・・傾斜部
10・・・射出口
11a,11b・・・溶接部
12a・・・テーパ
12b・・・段差
13・・・面取り部 1 ... Die-casting sleeve
2 ... Outer cylinder
3 ... Tip member
3a ・ ・ ・ Flange part
4 ... Back member
5 ... Intermediate tube
6 ... Inner cylinder
9 ... engagement part
8 ... Rear end ring member
81 ... Bolt
9 ... engagement part
9a ・ ・ ・ Step
9b ... Step having an inclined portion
9c ・ ・ ・ Inclined part
10 ... Injection port
11a, 11b ... welds
12a ・ ・ ・ Taper
12b ・ ・ ・ Step
13 ... Chamfer

Claims (6)

低熱膨張性金属材料からなる外筒と、前記外筒の射出口側の内面に嵌着された低熱膨張性金属材料からなる先端部材と、前記先端部材の後端側端面に密着して配置された後方部材とからなるダイカスト用スリーブであって、
前記後方部材が、前記外筒の内面に嵌着された中間筒と、前記中間筒の内面に嵌着された内筒とから構成され、
前記内筒は、耐熱衝撃温度750℃以上、及び25℃における熱伝導率が25 W/(m・K) 以上の窒化珪素質セラミックスからなり、
前記中間筒は、25℃における熱伝導率が24 W/(m・K)未満の窒化珪素質セラミックスからなり、
前記中間筒及び前記内筒の後端側に、前記内筒のダイカスト稼働時の温度上昇による伸びを抑制するための係合部を有することを特徴とするダイカスト用スリーブ。 An outer cylinder made of a low thermal expansion metal material, a tip member made of a low thermal expansion metal material fitted on the inner surface of the outer cylinder on the injection port side, and a rear end side end face of the tip member A die casting sleeve comprising a rear member,
The rear member is composed of an intermediate cylinder fitted on the inner surface of the outer cylinder, and an inner cylinder fitted on the inner surface of the intermediate cylinder,
The inner cylinder is made of a silicon nitride ceramic having a thermal shock temperature of 750 ° C. or higher and a thermal conductivity of 25 W / (m · K) or higher at 25 ° C.,
The intermediate cylinder is made of a silicon nitride ceramic having a thermal conductivity at 25 ° C. of less than 24 W / (m · K),
A die-casting sleeve having an engaging portion for suppressing an elongation due to a temperature rise during the die-casting operation of the inner cylinder on the rear end side of the intermediate cylinder and the inner cylinder. 請求項１に記載のダイカスト用スリーブにおいて、
前記外筒は、20〜200℃の平均熱膨張係数αAが1〜5×10-6/℃であり、
前記先端部材は、20〜200℃の平均熱膨張係数αBが1〜5×10-6/℃であり、
αAとαBとの差が-1×10-6/℃〜1×10-6/℃であることを特徴とするダイカスト用スリーブ。 The die-casting sleeve according to claim 1,
The outer cylinder has an average thermal expansion coefficient α A of 1 to 5 × 10 −6 / ° C. at 20 to 200 ° C.,
The tip member has an average thermal expansion coefficient α B of 20 to 200 ° C. of 1 to 5 × 10 −6 / ° C.,
A sleeve for die casting, wherein a difference between α A and α B is -1 × 10 −6 / ° C. to 1 × 10 −6 / ° C. 請求項１又は２に記載のダイカスト用スリーブにおいて、
前記中間筒が、軸方向に分割された複数の部分からなることを特徴とするダイカスト用スリーブ。 The sleeve for die casting according to claim 1 or 2,
A sleeve for die casting, wherein the intermediate cylinder is composed of a plurality of portions divided in the axial direction. 請求項３に記載のダイカスト用スリーブにおいて、
前記中間筒の分割された複数の部分同士の突合せ面が、軸方向に対して15〜75°の角度を有していることを特徴とするダイカスト用スリーブ。 The die-casting sleeve according to claim 3,
The die-casting sleeve, wherein the butted surfaces of the divided portions of the intermediate cylinder have an angle of 15 to 75 ° with respect to the axial direction. 請求項３又は４に記載のダイカスト用スリーブにおいて、
前記中間筒の分割された複数の部分同士の突合せ面は、前記中間筒の内面側及び外面側に面取部を有することを特徴とするダイカスト用スリーブ。 The sleeve for die casting according to claim 3 or 4,
The die casting sleeve according to claim 1, wherein the abutting surfaces of the divided portions of the intermediate cylinder have chamfered portions on the inner surface side and the outer surface side of the intermediate tube. 請求項１〜５いずれかに記載のダイカストスリーブにおいて、
前記外筒の厚さが、前記中間筒の厚さと前記内筒の厚さの合計よりも大きいことを特徴とするダイカスト用スリーブ。 In the die-casting sleeve according to any one of claims 1 to 5,
A die casting sleeve, wherein the outer cylinder has a thickness greater than the total thickness of the intermediate cylinder and the inner cylinder.
JP2018070007A 2018-03-30 2018-03-30 Sleeve for die-casting Pending JP2019177416A (en)

Priority Applications (1)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2022039540A1 (en) * 2020-08-21 2022-02-24 한주금속(주) Titanium insert sleeve of electromagnetic stirring high-pressure casting device
WO2023055012A1 (en) * 2021-09-29 2023-04-06 주식회사 상익기공 Partially replaceable sleeve for die-casting

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2022039540A1 (en) * 2020-08-21 2022-02-24 한주금속(주) Titanium insert sleeve of electromagnetic stirring high-pressure casting device
KR20220023378A (en) * 2020-08-21 2022-03-02 한주금속(주) Titanium insert sleeve of electromagnetic stirring high pressure casting system
KR102411801B1 (en) * 2020-08-21 2022-06-22 한주금속(주) Titanium insert sleeve of electromagnetic stirring high pressure casting system
WO2023055012A1 (en) * 2021-09-29 2023-04-06 주식회사 상익기공 Partially replaceable sleeve for die-casting

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