JP4787793B2 - Manufacturing method of large-sized high-density compact - Google Patents
Manufacturing method of large-sized high-density compact Download PDFInfo
- Publication number
- JP4787793B2 JP4787793B2 JP2007164014A JP2007164014A JP4787793B2 JP 4787793 B2 JP4787793 B2 JP 4787793B2 JP 2007164014 A JP2007164014 A JP 2007164014A JP 2007164014 A JP2007164014 A JP 2007164014A JP 4787793 B2 JP4787793 B2 JP 4787793B2
- Authority
- JP
- Japan
- Prior art keywords
- density
- pressure
- molding
- packed bed
- powder
- 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 - Fee Related
Links
Images
Landscapes
- Powder Metallurgy (AREA)
Description
本発明は、型潤滑法により大型高密度圧粉成形体を製造する方法に関する。 The present invention relates to a method for producing a large-scale high-density green compact by a mold lubrication method.
粉末冶金により製造される部品は、主にカムや歯車など自動車に使用される機械焼結部品であるが、近年は、圧粉磁心など磁性材料として使用されることが検討され、モータのコアなどに実用化されている。磁性部品として使用する場合は、磁気特性の観点から圧粉成形体（以下、単に「成形体」ともいう。）に高密度であることが要求される。特にモータのステータやロータといったコアに使用する場合には、競合する電気鉄板や電磁鋼板と同等の特性を発揮させるために、成形体の密度として７．５５ｇ／ｃｍ３以上、望ましくは７．６０ｇ／ｃｍ３以上といった非常に高い密度が要求される。なお、機械焼結部品では成形体の密度は７．２ｇ／ｃｍ３程度で十分である。 Parts manufactured by powder metallurgy are machine-sintered parts used mainly in automobiles such as cams and gears. However, in recent years, it has been considered to be used as magnetic materials such as dust cores, motor cores, etc. Has been put to practical use. When used as a magnetic component, a compacted green body (hereinafter, also simply referred to as “molded body”) is required to have a high density from the viewpoint of magnetic properties. In particular, when used for a core such as a stator or rotor of a motor, the density of the formed body is 7.55 g / cm 3 or more, preferably 7.60 g in order to exhibit the same characteristics as competing electric iron plates and electromagnetic steel plates. A very high density of at least / cm 3 is required. In the case of mechanically sintered parts, a density of the molded body of about 7.2 g / cm 3 is sufficient.
しかしながら、上記のような高密度化を実現するためには面圧１０ｔｏｎ／ｃｍ２以上の高圧で成形する必要があり、プレスの能力の制約から大型のモータ用のコア材への適用は困難とされ、実用化された例でも小型のモータ用のものに限られていた（後記実施例中の表２に関する説明参照）。 However, in order to realize the above-described high density, it is necessary to mold at a high pressure of 10 ton / cm 2 or more, and it is difficult to apply to a core material for a large motor due to the limitation of press capability. However, even the practical examples are limited to those for small motors (see the description regarding Table 2 in the examples below).
ところで、電磁鋼板などの板材を積層した積層磁心は、板面内方向の磁気特性には優れるものの、板厚方向の磁気特性に劣るため、磁気回路の設計は２次元的なものに制約されるという欠点があった。これに対し、粉末を固めた圧粉体である圧粉磁心は、等方的な磁気特性を有するため、３次元的な磁気回路の設計が可能であり、モータの設計の自由度を上げ得る材料として注目されている。 By the way, a laminated magnetic core in which plate materials such as electromagnetic steel plates are laminated is excellent in magnetic properties in the in-plane direction, but is inferior in magnetic properties in the plate thickness direction. There was a drawback. On the other hand, since the powder magnetic core, which is a compacted powder, has isotropic magnetic characteristics, it is possible to design a three-dimensional magnetic circuit and increase the degree of freedom in motor design. It is attracting attention as a material.
大型のモータ用のコア材に適用するためには、大型でかつ高密度の成形体を得る必要があるが、上記のような事情から、大型でかつ高密度の成形体の製造技術が確立されていないのが現状である。 In order to be applied to a core material for a large motor, it is necessary to obtain a large and high-density molded body. From the above circumstances, a manufacturing technology for large and high-density molded bodies has been established. The current situation is not.
そこで発明者らは、まず、圧粉磁心の大型モータへの適用の可能性を検討するため、大型高密度成形体の試作を試みた。しかしながら、粉末の充填量が多いため、粉末充填層中に含まれる空気の量も多く、圧縮成形の際にはこの空気ごと圧縮されるので、成形体内部には圧縮された空気が取り残される。このような成形体内部における圧縮空気の残存は、成形体の密度の向上を阻害するばかりでなく、圧縮荷重除去時に成形体内部からの空気の膨張により成形体に割れが生じることがわかった。 Therefore, the inventors first tried to manufacture a large-scale high-density molded body in order to examine the possibility of applying the dust core to a large-sized motor. However, since the amount of powder filling is large, the amount of air contained in the powder packed bed is also large, and this air is compressed together during compression molding, so that the compressed air remains in the molded body. It has been found that such residual compressed air in the molded body not only hinders the improvement of the density of the molded body, but also cracks in the molded body due to the expansion of air from inside the molded body when the compression load is removed.
なお、従来の成形技術では、小型の成形体においては、このような残存空気に起因する割れの問題は報告されていないものの、特許文献１に記載されているように、薄型形状の圧粉成形体では空気の閉じ込みにより所定の密度が得られないことが知られており、その解決策として浮動状態のパンチを用いることが提案されている。
そこで本発明は、型潤滑成形法により大型の圧粉成形体を製造する場合においても、内部の残存空気に起因する割れを防止しつつ、高密度化を達成しうる、大型高密度圧粉成形体の製造方法を提供することを目的とする。 Accordingly, the present invention provides a large-scale high-density powder molding that can achieve high density while preventing cracking due to residual air inside even when producing a large-sized powder compact by a mold lubrication molding method. It aims at providing the manufacturing method of a body.
金型に充填された粉末中には容積率で約７０％もの空気が含まれる（上記特許文献１の段落［０００５］参照）ことから、この粉末を、従来のように最初から高圧で加圧成形すると、金型内壁近くの粉末から塑性変形が起こり、成形体表面が緻密化するため、成形体内部に空気が取り残され、上記のような問題が生じるものと想定される。そこで、本発明者らは、上記課題を解決するには、本格的な加圧成形に先立って、まず、空気を粉末中から押し出すことが必要と考え、種々検討を行った。検討の結果、極低圧力で加圧した状態で一定時間保持することにより、成形体表面の緻密化を防止しつつ粉末中の空気を押し出すことができ、その後、より高い成形圧力で圧縮成形しても、割れが発生することなく、健全で高密度の成形体が得られることを見出した。 Since the powder filled in the mold contains about 70% of air by volume (see paragraph [0005] of Patent Document 1), the powder is pressurized from the beginning at a high pressure as in the past. When it is molded, plastic deformation occurs from the powder near the inner wall of the mold, and the surface of the molded body is densified. Therefore, it is assumed that air remains in the molded body and the above-described problems occur. Therefore, the present inventors considered that it was necessary to extrude air from the powder first before full-scale pressure forming in order to solve the above-mentioned problems, and conducted various studies. As a result of the examination, by holding for a certain period of time in a state of being pressurized at an extremely low pressure, it is possible to extrude the air in the powder while preventing densification of the surface of the molded body, and then compression molding at a higher molding pressure However, it has been found that a sound and high-density molded body can be obtained without cracking.
上記知見に基づき完成した発明は以下のとおりである。 Inventions completed based on the above findings are as follows.
請求項１に記載の発明は、成形型内に軟磁性粉末を９ｃｍ以上の深さに充填して圧縮成形し、密度が７．５５ｇ／ｃｍ３以上の大型高密度圧粉成形体を製造する方法であって、１００ＭＰａ以上、４００ＭＰａ以下の脱気圧力で加圧した状態で、下記式の関係を満たす保持時間Ｔ（ｍｉｎ）だけ保持して充填層内の空気を脱気する脱気工程と、前記脱気圧力より高い成形圧力で圧縮成形する圧縮成形工程と、を備えたことを特徴とする大型高密度圧粉成形体の製造方法である。
式 Ｔ＝（Ｌ×Ｄ）／Ｋ
ここに、Ｌ：前記充填層の深さ（ｃｍ）、Ｄ：前記充填層の水平断面に内接する円の直径（ｃｍ）、Ｋ：６０以下の定数である。
According to the first aspect of the present invention, a soft magnetic powder is filled in a molding die to a depth of 9 cm or more and compression-molded to produce a large-scale high-density compact with a density of 7.55 g / cm 3 or more. A degassing step of degassing the air in the packed bed by holding for a holding time T (min) satisfying the relationship of the following formula in a state of being pressurized at a degassing pressure of 100 MPa or more and 400 MPa or less: And a compression molding step of compression molding at a molding pressure higher than the deaeration pressure.
Formula T = (L × D) / K
Here, L: depth (cm) of the packed bed, D: diameter of a circle inscribed in the horizontal section of the packed bed (cm), and K: a constant of 60 or less.
請求項２に記載の発明は、前記圧縮成形工程において、成形最高圧力まで毎分５００ＭＰａ以上の加圧速度で昇圧する請求項１に記載の大型高密度圧粉成形体の製造方法である。 The invention according to claim 2, in said compression molding step, a method for manufacturing a large-sized high-density green compact according to claim 1 for boosting per minute 500MPa or more pressurization rate to the forming maximum pressure.
本発明によれば、極低圧力の脱気圧力にて一定時間保持して充填層内の空気を脱気してから、圧力を高めて圧縮成形を行うことで、圧粉成形体の内部に圧縮空気が残留することが抑制されるので、大型の圧粉成形体であっても、圧縮荷重除去時の圧縮空気の膨張による割れが防止されるとともに、高密度化が達成できる。 According to the present invention, the degassing pressure is kept at a very low pressure for a certain period of time to deaerate the air in the packed bed, and then the pressure is increased and compression molding is performed. Since it is suppressed that compressed air remains, even if it is a large compacting body, the crack by the expansion of compressed air at the time of compression load removal is prevented, and high density can be achieved.
本発明に係る大型高密度圧粉成形体の製造方法は、成形型内に難磁性粉末を９ｃｍ以上の深さに充填して圧縮成形し、密度が７．５５ｇ／ｃｍ３以上の大型高密度圧粉成形体を製造する方法であって、１００ＭＰａ以上、４００ＭＰａ以下の脱気圧力で加圧した状態で一定時間保持して充填層内の空気を脱気する脱気工程と、前記脱気圧力より高い成形圧力で圧縮成形する圧縮成形工程と、を備えたことを特徴とする。 In the method for producing a large-scale high-density green compact according to the present invention, a large-diameter high-density material having a density of 7.55 g / cm 3 or more is formed by filling a molding die with a hard magnetic powder to a depth of 9 cm or more and compression-molding it. A method for producing a green compact, a deaeration step of deaeration of air in a packed bed while maintaining a depressurization pressure of 100 MPa or more and 400 MPa or less for a certain period of time, and the deaeration pressure A compression molding step of compression molding at a higher molding pressure.
以下、上記本発明を構成する各要件について、図１および２を参照しつつ、さらに詳細に説明する。 Hereinafter, each requirement constituting the present invention will be described in more detail with reference to FIGS.
成形型としては、ダイス鋼など一般的な金型材料にて製作された金型を用い、この内壁面にステアリン酸亜鉛、ステアリン酸カルシウムなどの冷間成形用潤滑剤、あるいはＭＣＡなどの温間整形用潤滑剤を塗付したものを用いることができる。 As a mold, a mold made of a general mold material such as die steel is used, and a cold forming lubricant such as zinc stearate or calcium stearate or warm shaping such as MCA is used on the inner wall surface. The thing which apply | coated the lubrication agent can be used.
充填層の深さを９ｃｍ以上としたのは、本発明の製造方法は、このような深い粉末充填層を用いて大型の圧粉成形体を製造するのに適しており、粉末充填層の深さが１０ｃｍ以上の場合に適用するのがより望ましい。このような粉末充填層を圧縮成形して得られる圧粉成形体の高さとしては、３ｃｍ以上のものが対象となる。 The reason why the depth of the packed bed is set to 9 cm or more is that the manufacturing method of the present invention is suitable for manufacturing a large green compact using such a deep powder packed bed. It is more desirable to apply when the thickness is 10 cm or more. The height of the green compact obtained by compression-molding such a powder packed layer is 3 cm or more.
軟磁性粉末としては、純鉄粉、鉄基合金粉、またはこれらの混合粉を用いることができる。さらには、上記粉末と絶縁材料粉末とを混合したものや、上記粉末の表面に絶縁材料を被覆したものも好適に用いることもできる。 As the soft magnetic powder, pure iron powder, iron-base alloy powder, or a mixed powder thereof can be used. Furthermore, a mixture of the above powder and an insulating material powder, or a powder whose surface is coated with an insulating material can also be suitably used.
なお、上記絶縁材料としては、フェノール、エポキシ、ポリイミド、シリコーンなどの熱硬化性樹脂の他、ポリアミドなどの熱可塑性樹脂などの有機材料、りん酸皮膜などの無機系皮膜、シリカ、アルミナなどの酸化物、ＢＮなどの窒化物などの無機材料を用いることができる。また、上記材料の２種以上を混合したもの、あるいは複合したものを用いることもできる。 The insulating material includes thermosetting resins such as phenol, epoxy, polyimide, and silicone, organic materials such as thermoplastic resins such as polyamide, inorganic coatings such as phosphoric acid coatings, and oxidations such as silica and alumina. And inorganic materials such as nitrides such as BN can be used. Moreover, what mixed 2 or more types of the said material, or the composite thing can also be used.
さらには、上記粉末に必要によりステアリン酸亜鉛、ステアリン酸カルシウムなど従来から圧粉成形体の成形の際に用いられている一般的な潤滑剤を少量添加したものを用いることもできる。 Furthermore, if necessary, a powder obtained by adding a small amount of a general lubricant conventionally used for forming a green compact, such as zinc stearate and calcium stearate, may be used.
また、大型高密度圧粉成形体の密度を７．５５ｇ／ｃｍ３以上としたのは、大型のモータのコア等に要求される磁気特性を備えたものとするためである。大型高密度圧粉成形体の密度は、７．６０ｇ／ｃｍ３以上とするのが望ましく、７．６５ｇ／ｃｍ３以上とするのがさらに望ましい。 The reason why the density of the large-scale high-density compact is 7.55 g / cm 3 or more is to provide magnetic properties required for the core of a large motor. The density of large high density green compact is desirably a 7.60 g / cm 3 or more, and more desirably set to 7.65 g / cm 3 or more.
〔脱気工程〕
上記成形型内に所定の深さに充填した難磁性粉末に対し、所定の脱気圧力にて加圧した状態で一定時間保持して充填層内の空気の脱気を行う（図１参照）。
[Deaeration process]
The hard magnetic powder filled at a predetermined depth in the mold is held for a certain period of time in a state where it is pressurized at a predetermined degassing pressure to degas the air in the packed bed (see FIG. 1). .
上記脱気圧力として、１００ＭＰａ以上、４００ＭＰａ以下としたのは、１００ＭＰａ未満では加圧力が低すぎて充填層中から空気が十分に抜け切らず、その後の圧縮成形により残存空気が内部に閉じ込められて成形体に割れが発生してしまい、一方、４００ＭＰａを超えると成形体表面が緻密化してやはり空気が内部に閉じ込められ、その後の圧縮成形により残存空気が内部に閉じ込められて成形体に割れが発生してしまうためである。 The deaeration pressure is set to 100 MPa or more and 400 MPa or less because if the pressure is less than 100 MPa, the applied pressure is too low and the air does not sufficiently escape from the packed bed, and the remaining air is trapped inside by the subsequent compression molding. On the other hand, cracks occur in the molded body. On the other hand, when the pressure exceeds 400 MPa, the surface of the molded body becomes dense and air is confined inside. It is because it will do.
上記脱気圧力での保持時間Ｔ（ｍｉｎ）は、短すぎると空気が十分に抜け切らないので、充填層の大きさに応じて、下記式（１）の関係を満たすように設定することが推奨される（後記実施例参照）。 The holding time T (min) at the above deaeration pressure is set so as to satisfy the relationship of the following formula (1) according to the size of the packed bed, because air is not sufficiently removed if it is too short. Recommended (see Examples below).
Ｔ＝（Ｌ×Ｄ）／Ｋ … 式（１）
ここに、Ｌ：充填層の深さ（ｃｍ）、Ｄ：充填層の水平断面に内接する円の直径（ｃｍ）、Ｋ：６０以下の定数である。
T = (L × D) / K (1)
Here, L: depth of packed bed (cm), D: diameter of a circle inscribed in the horizontal section of packed bed (cm), K: constant of 60 or less.
ここで、保持時間Ｔが（Ｌ×Ｄ）に比例するとしたのは、充填層内部に存在する空気は、脱気圧力での加圧状態を保持することによって、充填層内部から充填層中を移動して金型内壁面に到達した後、金型内壁面に沿って外部に抜けていくと想定されることから、空気が抜け切るための保持時間Ｔは、充填層の水平方向の差し渡しに相当するＤと充填層の深さＬとにそれぞれ比例すると考えられるからである。 Here, the retention time T is proportional to (L × D) because the air existing in the packed bed is maintained in the pressurized state at the deaeration pressure from the packed bed to the inside of the packed bed. Since it is assumed that after moving and reaching the inner wall surface of the mold, it is assumed that it will escape to the outside along the inner wall surface of the mold. This is because it is considered to be proportional to the corresponding D and the depth L of the packed bed.
また、水平方向の差し渡しの指標として、充填層の水平断面に内接する円（以下「充填層水平断面内接円」という。）の直径を用いたのは、充填層の水平断面中心に存在する空気は、充填層中を最短経路にて移動し金型内壁面に到達すると想定されることから、充填層の水平断面中心から金型内壁面のうち最も近い距離、すなわち、充填層水平断面内接円の直径で評価するのが妥当と判断したことによる。例えば、図２に示すように、充填層の水平断面が十字形の場合には、充填層水平断面内接円は、十字形の４つの凹部の各頂点を通る円となる。 In addition, the diameter of a circle inscribed in the horizontal section of the packed bed (hereinafter referred to as “filled bed horizontal section inscribed circle”) is used at the center of the horizontal section of the packed bed as an index of horizontal passing. Since air is assumed to move in the packed bed along the shortest path and reach the inner wall surface of the mold, the closest distance from the horizontal sectional center of the packed bed to the inner wall surface of the mold, that is, within the packed bed horizontal section. This is because it was judged appropriate to evaluate by the diameter of the tangent circle. For example, as shown in FIG. 2, when the horizontal cross section of the packed bed has a cross shape, the inscribed circle of the packed bed horizontal cross section is a circle that passes through each vertex of the four cross-shaped recesses.
本発明に係る製造方法は、内接円直径Ｄの値が１０ｃｍ以上、さらには１２ｃｍ以上、特に１５ｃｍ以上の場合に適用するのが望ましい。 The production method according to the present invention is preferably applied when the value of the inscribed circle diameter D is 10 cm or more, further 12 cm or more, and particularly 15 cm or more.
また、定数Ｋの値は、６０以下とすることで、脱気圧力での保持時間Ｔが十分に確保され、脱気が確実に行われる点では好ましいが、Ｋの値を小さくしすぎると前記保持時間Ｔが長くなりすぎて生産性を低下させるので、２０以上、さらには３０以上とするのが望ましい。 Further, the value of the constant K is preferably 60 or less, so that the holding time T at the deaeration pressure is sufficiently secured and the deaeration is reliably performed. However, if the value of K is too small, Since the holding time T becomes too long and the productivity is lowered, it is desirable to set it to 20 or more, more preferably 30 or more.
〔圧縮成形工程〕
上記脱気工程終了後、上記脱気圧力から、所望の成形体密度が得られるような成形最高圧力まで昇圧して粉末充填層の圧縮成形を行うことで、割れのない高密度の圧粉成形体が得られる（図１参照）。
[Compression molding process]
After the degassing step, high pressure compaction without cracks is achieved by increasing the pressure from the degassing pressure to the maximum molding pressure that can achieve the desired density of the compact and compressing the powder-filled layer. A body is obtained (see FIG. 1).
ここで、圧縮成形工程での昇圧速度が低すぎると、成形中の塑性変形により粉末が加工硬化して成形体の高密度化が阻害されるため、上記圧縮成形工程において、成形最高圧力まで毎分５００ＭＰａ以上の昇圧速度（図１中のΔＰ／Δｔに相当）で成形圧力を上昇させるのが推奨される。 Here, if the pressurization speed in the compression molding process is too low, the powder is work-hardened due to plastic deformation during molding and the densification of the molded body is hindered. It is recommended to increase the molding pressure at a pressure increase rate of 500 MPa or more (corresponding to ΔP / Δt in FIG. 1).
本発明に係る製造方法の作用効果を確証するため、以下の成形試験を実施した。
軟磁性粉末として純鉄粉（株式会社神戸製鋼所製、商品名「アトメル３００ＮＨ」、平均粒径：約８０μｍ）を用いた。
In order to confirm the effect of the manufacturing method according to the present invention, the following molding test was performed.
As the soft magnetic powder, pure iron powder (manufactured by Kobe Steel, trade name “Atmel 300NH”, average particle diameter: about 80 μm) was used.
この粉末を、潤滑剤としてステアリン酸カルシウムを塗付量１ｍｇ／ｃｍ２にて塗付したシリンダ（円柱）状の金型（内径１５ｍｍ）内に所定の深さになるように充填し、３００ｔ油圧プレス（株式会社神戸製鋼所製）を用いて成形温度１３０℃（一定）で、種々の成形条件にて加圧成形を行った。 This powder was filled in a cylinder (column) -like mold (inner diameter: 15 mm) coated with calcium stearate as a lubricant at a coating amount of 1 mg / cm 2 , and a 300-t hydraulic press. (Made by Kobe Steel Co., Ltd.) was subjected to pressure molding under various molding conditions at a molding temperature of 130 ° C. (constant).
得られた成形体の密度は、成形体の質量と外形寸法より算出した体積から計算で求めた。また、成形体の割れの有無は目視により判定した。 The density of the obtained molded body was calculated from the volume calculated from the mass of the molded body and the external dimensions. Moreover, the presence or absence of the crack of a molded object was determined visually.
表１に、成形条件および成形試験の結果を示す。 Table 1 shows the molding conditions and the results of the molding test.
ちなみに、参考例として、表２に、脱気操作（脱気工程）を行わずに直ちに高圧で圧縮成形を行う、従来の一般的な成形方法で製作した成形体の性状を示した。試験Ｎｏ．Ｒ１では、脱気操作を行わなくても、割れが発生することなく、７．６５ｇ／ｃｍ３といった高密度の成形体が得られているものの、外径４．５ｃｍ、内径３．３ｃｍという比較的薄肉の部材にすぎない。また、試験Ｎｏ．Ｒ２では、充填層の深さおよび水平断面直径とも大きな部材であり、割れの発生もないものの、成形体密度は７．３５ｇ／ｃｍ３に留まっている。
上記表１の試験Ｎｏ．１〜６に示すように、脱気圧力が低すぎる場合（試験Ｎｏ．１）および高すぎる場合（試験Ｎｏ．６）は、成形体に割れが発生し、密度の測定もできなかったのに対し、脱気圧力が本発明の要件である１００ＭＰａ以上、４００ＭＰａ以下を満足する場合（試験Ｎｏ．２〜５）は、成形体に割れが発生することがなく、密度も７．６５ｇ／ｃｍ３が得られた。 Test No. in Table 1 above. As shown in 1-6, when the deaeration pressure was too low (Test No. 1) and too high (Test No. 6), the molded body was cracked and the density could not be measured. On the other hand, when the deaeration pressure satisfies the requirement of 100 MPa or more and 400 MPa or less (test Nos. 2 to 5) of the present invention, the molded body is not cracked and the density is 7.65 g / cm 3. was gotten.
また、同表の試験Ｎｏ．７〜１２に示すように、脱気圧力での保持時間Ｔが短すぎ、Ｋ値［＝（Ｌ×Ｄ）／Ｔ］が６０を超えて大きすぎる場合（試験Ｎｏ．７，８）は、成形体に割れが発生し、密度の測定もできなかったのに対し、保持時間Ｔが十分長く、Ｋ値が本発明の要件である６０以下を満足する場合（試験Ｎｏ．９〜１２）は、成形体に割れが発生することがなく、密度も７．６５ｇ／ｃｍ３が得られた。 In addition, test No. in the same table. As shown in 7 to 12, when the holding time T at the deaeration pressure is too short and the K value [= (L × D) / T] exceeds 60 (test Nos. 7 and 8), When the molded body was cracked and the density could not be measured, when the holding time T was sufficiently long and the K value satisfied 60 or less, which is a requirement of the present invention (Test Nos. 9-12) The molded body was not cracked, and a density of 7.65 g / cm 3 was obtained.
また、同表の試験Ｎｏ．１３〜１８に示すように、圧縮成形時の昇圧速度が高くなるほど成形体密度は上昇しており、昇圧速度が毎分５００ＭＰａ以上になると（試験Ｎｏ．１６〜１８）、成形体密度は７．６５ｇ／ｃｍ３以上が得られることがわかった。 In addition, test No. in the same table. As shown in 13 to 18, the compact density increases as the pressurization speed during compression molding increases. When the pressurization speed reaches 500 MPa or more (Test Nos. 16 to 18), the compact density is 7. It was found that 65 g / cm 3 or more was obtained.
なお、同表の試験Ｎｏ．１９〜２４に示すように、充填深さが９ｃｍより浅い場合（試験Ｎｏ．１９〜２１）は、脱気圧力が１００ＭＰａ未満であっても、成形体に割れが発生せず、密度も７．６５ｇ／ｃｍ３が得られている。しかしながら、得られる成形体は比較的薄手のものであるので、本発明に係る製造方法が対象とする大型高密度圧粉成形体には含まれない。 In addition, test No. of the same table | surface. As shown in 19 to 24, when the filling depth is shallower than 9 cm (Test Nos. 19 to 21), even if the deaeration pressure is less than 100 MPa, the molded body does not crack and the density is 7. 65 g / cm 3 is obtained. However, since the obtained molded body is relatively thin, it is not included in the large-scale high-density powder molded body targeted by the production method according to the present invention.
Claims (2)
式 Ｔ＝（Ｌ×Ｄ）／Ｋ
ここに、Ｌ：前記充填層の深さ（ｃｍ）、Ｄ：前記充填層の水平断面に内接する円の直径（ｃｍ）、Ｋ：６０以下の定数である。 A method for producing a large, high-density, compacted compact having a density of 7.55 g / cm 3 or more by filling a molding die with soft magnetic powder to a depth of 9 cm or more, and having a density of 7.55 g / cm 3 or more. in the following a pressurized state in the degassing pressure, and degassing step of degassing the air only held to packed bed holding time T (min) which satisfies the following equation, the higher the degassing pressure molding pressure And a compression molding step for compression molding with a large-sized high-density compacted body.
Formula T = (L × D) / K
Here, L: depth (cm) of the packed bed, D: diameter of a circle inscribed in the horizontal section of the packed bed (cm), and K: a constant of 60 or less.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2007164014A JP4787793B2 (en) | 2007-06-21 | 2007-06-21 | Manufacturing method of large-sized high-density compact |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2007164014A JP4787793B2 (en) | 2007-06-21 | 2007-06-21 | Manufacturing method of large-sized high-density compact |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2009001867A JP2009001867A (en) | 2009-01-08 |
| JP4787793B2 true JP4787793B2 (en) | 2011-10-05 |
Family
ID=40318570
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2007164014A Expired - Fee Related JP4787793B2 (en) | 2007-06-21 | 2007-06-21 | Manufacturing method of large-sized high-density compact |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP4787793B2 (en) |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5430147B2 (en) * | 1973-01-17 | 1979-09-28 | ||
| JPS6045998B2 (en) * | 1981-12-24 | 1985-10-14 | 株式会社日型 | Powder raw material compression molding press and powder raw material compression molding method using the press |
| JP2002237406A (en) * | 2001-12-19 | 2002-08-23 | Aichi Steel Works Ltd | Method of manufacturing magnetically anisotropic resin- bonded magnet |
| JP4462967B2 (en) * | 2004-03-11 | 2010-05-12 | 日立粉末冶金株式会社 | Method for producing soft magnetic member by powder metallurgy |
-
2007
- 2007-06-21 JP JP2007164014A patent/JP4787793B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JP2009001867A (en) | 2009-01-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP7127270B2 (en) | Shaft integrated bond magnet | |
| JP2009041109A (en) | Powder metallurgical body with compacted surface | |
| WO2006106566A1 (en) | Soft magnetic material and process for producing green compact | |
| JP2010010426A (en) | Inductor and method of manufacturing the same | |
| CN110193601B (en) | Preparation method of double-layer or multi-layer refractory metal composite pipe | |
| JP4787793B2 (en) | Manufacturing method of large-sized high-density compact | |
| JP2016207710A (en) | Manufacturing method of magnet and magnet | |
| JP5765490B2 (en) | Sliding member and manufacturing method of sliding member | |
| JP2008272774A (en) | Die for compacting, and green compact compacted by the die for compacting | |
| JP2005256073A (en) | Method for manufacturing soft magnetic member by powder metallurgy method | |
| WO2016035670A1 (en) | Radially anisotropic sintered ring magnet and manufacturing method therefor | |
| JP5802413B2 (en) | Bond magnet and manufacturing method thereof | |
| JP2017033980A (en) | Manufacturing method of magnet, and magnet | |
| JP2011219827A (en) | Method for producing sintered part and powder molding die | |
| JP2005248274A (en) | Soft magnetic material and method for producing green compact | |
| JP2011035005A (en) | Method of manufacturing dust core | |
| WO2018225803A1 (en) | Mold component manufacturing method and mold component | |
| JP2017011158A (en) | Magnet manufacturing method and magnet | |
| JP2009218268A (en) | Manufacturing method of powder magnetic core and mold used for the same | |
| JP2017022198A (en) | Manufacturing method for magnet and magnet | |
| JP2005072112A (en) | Forming method of dust core | |
| JP6331558B2 (en) | Die for powder molding | |
| JP2013241637A (en) | Green compact, mechanical component, and method for producing the green compact | |
| JP2009167482A (en) | Method for producing connecting rod, and connecting rod | |
| JP2011157612A (en) | Method for producing sintered component |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20090929 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20110309 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20110315 |
|
| RD02 | Notification of acceptance of power of attorney |
Free format text: JAPANESE INTERMEDIATE CODE: A7422 Effective date: 20110408 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A821 Effective date: 20110411 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20110419 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20110705 |
|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20110715 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 4787793 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20140722 Year of fee payment: 3 |
|
| LAPS | Cancellation because of no payment of annual fees |