JP3662845B2

JP3662845B2 - Manufacturing method of cylindrical sintered parts with horizontal holes

Info

Publication number: JP3662845B2
Application number: JP2000396943A
Authority: JP
Inventors: 元博宮坂
Original assignee: Hitachi Powdered Metals Co Ltd
Current assignee: Resonac Corp
Priority date: 2000-12-27
Filing date: 2000-12-27
Publication date: 2005-06-22
Anticipated expiration: 2020-12-27
Also published as: JP2002194403A

Description

【０００１】
【発明の属する技術分野】
この発明は主に粉末冶金製品の製造に関するものであり、特に円筒，角筒など中空の筒状で、その軸心に対して横方向に貫通する孔（以下横孔という）のある形状の焼結部品を製造する方法に関するものである。
【０００２】
横孔のある筒状部品は種々の機械に用いられるが、円筒状のものの用途の一例として、内燃機関の過給機（ターボチャージャー）の軸受が挙げられる。ターボチャージャーは、基本的には回転軸の一端に排気ガスで駆動されるタービンを，他の一端には空気（または混合気）を圧縮してエンジンのシリンダーに送り込むコンプレッサーを具え、回転軸の中間を滑り軸受で支持する機構になっている。タービンは排気ガスによって高温になり、また作動時には極めて高速で回転するので、その軸受には通常の滑り軸受ではなく、図５に例示したような浮動式滑り軸受（ｆｌｏａｔｉｎｇｂｅａｒｉｎｇ）が用いられている。
【０００３】
即ち、円筒状の軸受１０は側面に数個の通油孔１１を具え、軸受内面と回転軸との間，および軸受外面とハウジングとの間の双方に一様な隙間を保った状態で遊嵌している。そして、これらの隙間に通油孔を介して潤滑油（エンジンオイル利用）を循環させることにより、軸受を油膜で浮動させている。また、タービンなどからの伝熱を考慮して、軸受の材質にはアルミニウム合金，青銅，黄銅などが通常用いられている。
【０００４】
【従来の技術】
粉末冶金法では、目的製品と同一かまたは極めて近い形状の圧粉体を成形し、それを焼結することにより、僅かな後加工で所望の製品を得られることが特徴の一つとなっている。そして本件の場合、横孔（原料粉の圧縮成形方向に対して横方向に貫通する孔）のある筒状の圧粉体を得るためには粉末の圧縮方向に対して横方向から、横孔に対応する形状の中子をダイ内に出入させる必要がある。
【０００５】
その場合、中子（ピン）のセットと粉末充填・圧縮成形との前後関係について種々の方式があり、例えば特公昭52−8551号公報，特開平 4−327398号公報には予めピンをセットした状態で粉末を充填する方法、実公昭51− 46415号公報，特開昭54− 91877号公報には粉末を充填した状態でピンを貫通させて圧縮成形する方法、特開昭58−141896号公報には粉末の充填〜圧縮成形後に、圧粉体にピンを貫通させて横孔を形成する方法が開示されている。
【０００６】
【発明が解決しようとする課題】
しかしこれらの方式では、本来は上下方向に作動すれば足りる成形金型に、横方向に作動する部材を組み込むこととなるため金型の構造が複雑で高価になり、これを取り付けて成形する粉末プレスやダイセットもその機構，制御方式が複雑になるという問題がある。また、方式によっては横孔部分の圧粉密度が他の部分よりも低くなったり、横孔の近傍に潜在クラックを生じて製品の品質に影響するなどの問題もあった。そこでこの発明の課題は、圧粉体の段階で横孔を形成する代わりに、通常の粉末成形手段と（焼結後の）塑性加工との組み合わせによって所望の横孔を形成させることにある。
【０００７】
【課題を解決するための手段】
先ず、この発明を図１の（イ）に示す形状の部品、即ち横孔１１を具える軸受１０の場合について、概念的に説明する。この場合、第一段階として粉末冶金の通常の手段により同図（ロ）のように、横孔を形成する位置を起点として軸受の下端（正確には上下何れか一方の端面）に開口する縦溝１２を具える形状の焼結体を作製する。この溝は上端が半円状で、その幅は目的とする横孔の径と等しくしてある。この様な、製品の一端から垂直に伸びる横幅が一様な縦溝は、二重のパンチを用いて容易に成形することができる。
【０００８】
次いで、（ロ）図の焼結体に金型内で塑性加工を施して縦溝近傍の材料を変形流動させ、（ハ）図に示すように縦溝の部分をその両側から充填することにより横孔１１を形成させる。但し、そのためには縦溝部分の充填用の材料が必要な訳で、その分の材料は、縦溝の近傍（円筒状焼結体の内周面か外周面）に予め付加しておく。その部材を充填代と呼ぶことにすると、この充填代については図１に表示するのは困難なので、以下に述べる実施態様において説明する。なお図１〜図４のそれぞれに含まれる図面（加工工程の各段階を示す部分図）には、全体を通じて一連の枝番を付けてある。
【０００９】
【発明の実施の形態】
（実施例１）目的とする製品は内径１０ｍｍ，外径１６ｍｍ，長さ４０ｍｍの中空円筒形で、その全長方向中央の側壁には直径３ｍｍの孔が３箇所、円周を均分する位置に設けられている。図２はこの製品を製造する過程の一態様を説明するもので、先ず、（ニ）に示す形状の素形材を七三黄銅（Ｃｕ−30％Ｚｎ）の焼結合金（焼結密度７．３ｇ／ｃｍ³）で作製した。
【００１０】
この素形材は、横孔に代えて各孔の位置から垂直下方に、素形材の端面に開く縦溝１２を具えている。そしてその内周面は、円筒の上半分では製品所定の内径寸法になっているが、下半分、即ち横孔の中心に相当する箇所よりも下の部分はやや狭くして、縦溝１２を埋める材料分として過不足ない量の、この場合は厚さ約０．９ｍｍの充填代１３を付加してある。この充填代１３は、（ニ）の断面図の右側において、軸受内周面を下方に延長した仮想線（破線）より内側の部分である。
【００１１】
次にこの素形材の姿勢を、その天地を逆に、即ち縦溝の開口部が上に来る向きに転換する。そしてその姿勢のまま、（ホ）に示すような金型を用いて塑性加工を施す。この金型はダイ２０，コアロッド２１および下パンチ２２で形成され、ダイ２０の型孔径は製品の外径に対応し、コアロッド２１の太さは製品所定の内径寸法に対応している。
【００１２】
この金型内に素形材を上パンチ２３で圧入していくと、内側上部にある充填代１３の部分はコアロッド２１に拡径されて塑性変形し漸次上方や外周方向に移動しようとする。然し焼結体の外周はダイ２０に，上端面は上パンチ２３によって閉塞されているために、充填代の部分の材料は唯一開放されている縦溝１２内に塑性流動して縦溝を充填する。充填された溝の部分を、（ホ）の断面図に破線のハッチングで示してある。なお金型の各部材の名称については、この明細書では粉末冶金の分野における金型用語を用いている。
【００１３】
次に、この様にして塑性加工された焼結体を金型から押し出せば（ヘ）に示す製品が得られる。この製品は内径をコアロッド２１に，外径をダイ２０によって矯正され、且つ（ヘ）に示すように、所定の位置に横孔１１が形成されている。この塑性加工で得られる横孔は、その形状が材料の流れに従って雨滴状になり、真円にはならない。然し、用途が流体の流通用などならば支障なく用いることができる。なお製品の用途によっては、両側から流れ込んで縦溝を埋める充填代の量を加減することにより、横孔に続く細い溝を残すことも可能である。
【００１４】
（実施例２）この実施例は、目的とする製品の形状，寸法および材質は実施例１の場合と同一であるが、縦溝１２を埋めるための充填代１３を実施例１では内周側に設けたのに対して、この実施例では外周側に設けた点が異なっている。図３はこの実施例における製造過程を説明するもので、先ず（ト）に示す形状の素形材を、七三黄銅の焼結合金（焼結密度７．３ｇ／ｃｍ³）で作製した。
【００１５】
この素形材は、実施例１の場合と同じく横孔に代えて各孔の位置から垂直下方に、素形材の端面に開く縦溝１２を具えている。そして内周面（軸受面）は製品所定の一様な内径寸法に作られ、またその外周面は、円筒の上半分では製品所定の外径寸法になっているが、下半分、即ち横孔の中心に相当する箇所よりも下の部分はやや太くして、縦溝１２を埋める材料分として過不足ない量の、この場合は厚さ約０．５ｍｍの充填代１３を付加してある。この充填代１３は、（ト）の断面図で軸受外周面を下方に延長した仮想線（破線）より外側の部分である。
【００１６】
次に、この素形材の姿勢を、縦溝の開口部が上に来る向きに上・下反転する。そしてその姿勢のまま、（チ）に示す金型を用いて塑性加工を施す。即ち焼結体をダイ２０，コアロッド２１および下パンチ２２で形成された金型内に上パンチ２３で圧入していくと、外側上部の充填代１３の部分はダイ２０によって縮径されて塑性変形し、漸次上方や内周側に移動しようとする。然るに焼結体の内周はコアロッド２１に，上端面は上パンチ２３によって閉塞されているため、充填代の部分の材料は唯一開放されている縦溝１２内に塑性流動して縦溝を充填する。充填された溝の部分を、（チ）図には破線のハッチングで示してある。
【００１７】
次に、この様にして塑性加工された焼結体を金型から押し出せば（リ）に示す製品が得られる。この製品は内径をコアロッド２１に，外径をダイ２０によって矯正され、且つ（リ）に示すように、所定の位置に横孔１１が形成されている。なお、この製品は実施例１で（ヘ）に示した製品と全く等しい。従って、横孔の形状などについての説明は重複するので省略する。
【００１８】
（実施例３）この実施例では、内周の両端部が所定の内径寸法に形成されて回転軸を２点支持し、中間部はその径が両端部よりも大きくて“逃げ部”として機能し、且つ、その中間部の側壁に横孔のある焼結軸受を製造する態様について説明する。この実施例における製造過程は図４の通りで、図中の（ヌ）は、焼結合金で作られた塑性加工前の素形材の形状を示している。
【００１９】
この素形材は、横孔に代えて各孔の位置から垂直下方に、素形材の端面に開く縦溝１２を具える点は上述の実施例２の場合と同様であり、ただ、軸孔の形状が異なっている。即ちこの実施例では軸孔が段付き形状で、上端の小径部が所定の内径寸法に作られて軸受部として機能する。その下の大径部は、回転軸との間に適切な隙間を保って摺動に対する逃げ，或いは油溜まりとして機能し得るよう、軸受部より若干大きい内径寸法にしてある。素形材の外周は製品所定の外径寸法になっている。
【００２０】
図４の（ル）はこの素形材に所要の塑性加工を施す金型の要部断面を示すもので、コアロッド２１は製品の軸受部孔径（即ち素形材の小径部孔径）に対応する太さに作られ、ダイ２０の型孔は上端面から所要の深さまでは製品の外周に対応する直径で、それより下部は絞られている。この金型内に素形材を上パンチ２３で圧入していくと、初めの段階ではダイの型孔は素形材の外周に，コアロッドは素形材上端の小径部に滑合し、コアロッドの下側は遊んでいる。やがて素形材の下端がダイの絞り部に達し、さらに押し込まれると、素形材の下部は縦溝１２を下から閉じ乍ら縮径されてゆき、その内周はコアロッド２１によって製品所定の内径寸法に仕上げられる。素形材の下降は下パンチ２２によって、縦溝１２の上端に横孔１１が残る位置で停止する。
【００２１】
次に、この様にして塑性加工された焼結体を金型から押し出せば（ヲ）に示す製品が得られる。この製品では、所定の位置に横孔１１が形成されていることは前記各実施例の場合と同様であるが、内径の中間に“逃げ部”を具えている点が新たな特徴となっている。即ち素形材の内周の大径部は、その下端部は絞り込まれて内周上端の小径部と共に２点支持の軸受部を形成するが、大径部の中間部分は変形せずにそのまま残り、そこが逃げ部となる訳である。因みに、この態様の場合は前２例と異なり縦溝１２の周囲の部材が内・外径ともに縮径され、それに伴い溝幅も縮小しやがて閉じるので、前２例のような余分の材料を充填代として用意する必要は特にない。
【００２２】
【発明の効果】
以上に詳述した通り、粉末冶金法と塑性加工法を併用するこの発明によれば、筒状でその側壁に横孔の明いた形状の焼結部品を容易に製造することができる。また、その様な部品の用途が軸受である場合は、回転軸を軸受の両端で支持してその中間に逃げ部がある２点支持型で、且つその中間部に横孔がある焼結軸受の製造方法としても有益なものである。
【図面の簡単な説明】
【図１】横孔付きの焼結円筒を製造する、この発明の原理を説明する図面である。
【図２】この発明による製造過程の一態様（実施例１）を説明する図面である。
【図３】この発明による製造過程の、他の態様（実施例２）を説明する図面である。
【図４】この発明による製造過程の、他の態様（実施例３）を説明する図面である。
【図５】この発明による製造過程の、他の態様（実施例３）を説明する図面である。
【符号の説明】
１０…中空円筒（軸受），１１…横孔，１２…縦溝，１３…充填代，２０…ダイ，２１…コアロッド，２２…下パンチ，２３…上パンチ。[0001]
BACKGROUND OF THE INVENTION
The present invention mainly relates to the manufacture of powder metallurgy products. In particular, the present invention relates to a hollow cylindrical shape such as a cylinder or a square tube, and has a shape with a hole penetrating in the lateral direction with respect to the axis (hereinafter referred to as a horizontal hole). The present invention relates to a method for manufacturing a bonded part.
[0002]
Cylindrical parts having a horizontal hole are used in various machines, and an example of the use of a cylindrical one is a bearing of a turbocharger of an internal combustion engine. A turbocharger basically has a turbine driven by exhaust gas at one end of the rotating shaft, and a compressor that compresses air (or mixture) into the cylinder of the engine at the other end, and is located in the middle of the rotating shaft. It is a mechanism to support with a slide bearing. Since the turbine is heated by exhaust gas and rotates at a very high speed during operation, a floating sliding bearing as illustrated in FIG. 5 is used for the bearing instead of a normal sliding bearing. .
[0003]
That is, the cylindrical bearing 10 has several oil passage holes 11 on the side surface, and is free to maintain a uniform clearance between the bearing inner surface and the rotating shaft and between the bearing outer surface and the housing. It is fitted. Then, the lubricating oil (using engine oil) is circulated through these gaps through the oil passage holes, so that the bearing is floated by the oil film. In consideration of heat transfer from a turbine or the like, an aluminum alloy, bronze, brass, or the like is usually used as a bearing material.
[0004]
[Prior art]
One of the features of the powder metallurgy method is that a desired product can be obtained with a slight amount of post-processing by forming a green compact that is the same as or very close to the target product and sintering it. . And in this case, in order to obtain a cylindrical green compact with a horizontal hole (a hole penetrating in the direction transverse to the compression molding direction of the raw material powder), the horizontal hole from the direction transverse to the powder compression direction. It is necessary to allow the core corresponding to the shape to enter and exit the die.
[0005]
In that case, there are various methods for the relationship between the setting of the core (pin) and the powder filling / compression molding. For example, Japanese Patent Publication No. 52-8551 and Japanese Patent Laid-Open No. 4-327398 have pins set in advance. A method of filling powder in a state, Japanese Utility Model Publication No. 51-46415, Japanese Patent Application Laid-Open No. 54-91877, a method of compression molding by penetrating a pin in a state of powder filling, Japanese Patent Application Laid-Open No. 58-141896 Discloses a method of forming a lateral hole by inserting a pin through a green compact after powder filling to compression molding.
[0006]
[Problems to be solved by the invention]
However, in these methods, a mold that is only required to operate in the up-and-down direction is incorporated with a member that operates in the horizontal direction, so the structure of the mold becomes complicated and expensive. The press and die set also have a problem that their mechanism and control method are complicated. In addition, depending on the method, there is a problem that the dust density in the horizontal hole portion is lower than that in other portions, or a latent crack is generated in the vicinity of the horizontal hole, affecting the quality of the product. Therefore, an object of the present invention is to form desired lateral holes by a combination of normal powder forming means and plastic working (after sintering) instead of forming lateral holes at the green compact stage.
[0007]
[Means for Solving the Problems]
First, the present invention will be conceptually described with respect to a part having the shape shown in FIG. In this case, as a first step, as shown in FIG. 5 (b), the vertical opening that opens to the lower end of the bearing (exactly one of the upper and lower end surfaces) starts from the position where the horizontal hole is formed as shown in FIG. A sintered body having a shape including the groove 12 is produced. This groove has a semicircular upper end, and its width is equal to the diameter of the intended horizontal hole. Such a longitudinal groove having a uniform width extending vertically from one end of the product can be easily formed using a double punch.
[0008]
Next, (b) by subjecting the sintered body in the figure to plastic working in the mold to deform and flow the material in the vicinity of the longitudinal groove, and (c) filling the longitudinal groove portion from both sides as shown in the figure. A lateral hole 11 is formed. However, for that purpose, a material for filling the longitudinal groove portion is necessary, and the material for that portion is added in advance in the vicinity of the longitudinal groove (inner peripheral surface or outer peripheral surface of the cylindrical sintered body). If the member is called a filling allowance, it is difficult to display the filling allowance in FIG. 1 and will be described in the embodiment described below. Note that a series of branch numbers are attached to the drawings included in each of FIGS.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
(Example 1) The target product is a hollow cylindrical shape having an inner diameter of 10 mm, an outer diameter of 16 mm, and a length of 40 mm. Three holes with a diameter of 3 mm are provided in the center wall in the full length direction at a position that equalizes the circumference. Is provided. FIG. 2 explains one aspect of the process of manufacturing this product. First, a shaped material having the shape shown in (d) is made of a sintered alloy of seven three brasses (Cu-30% Zn) (sintered density 7). ³ g / cm ³ ).
[0010]
This raw material has a vertical groove 12 which opens in the end face of the raw material vertically below the position of each hole instead of the horizontal hole. The inner peripheral surface has a predetermined inner diameter dimension in the upper half of the cylinder, but the lower half, that is, the portion below the portion corresponding to the center of the horizontal hole is slightly narrowed, and the vertical groove 12 is formed. In this case, a filling allowance 13 having a thickness of about 0.9 mm is added as a material to be filled. This filling allowance 13 is a portion inside a virtual line (broken line) obtained by extending the bearing inner peripheral surface downward on the right side of the sectional view of (d).
[0011]
Next, the shape of the base material is changed to the direction in which the top and bottom are turned upside down, that is, in the direction in which the opening of the longitudinal groove comes up. And with that posture, plastic working is performed using a mold as shown in (e). This die is formed of a die 20, a core rod 21, and a lower punch 22. The die hole diameter of the die 20 corresponds to the outer diameter of the product, and the thickness of the core rod 21 corresponds to a predetermined inner diameter dimension of the product.
[0012]
When the base material is press-fitted into the mold with the upper punch 23, the portion of the filling allowance 13 on the inner upper side is expanded in diameter by the core rod 21 and plastically deforms and gradually moves upward or in the outer peripheral direction. However, since the outer periphery of the sintered body is closed by the die 20 and the upper end surface is closed by the upper punch 23, the material of the portion of the filling allowance is plastically flowed into the vertical groove 12 to fill the vertical groove. To do. The filled groove portion is indicated by broken line hatching in the sectional view of (e). In addition, about the name of each member of a metal mold | die, this specification uses the metal mold | die terminology in the field of powder metallurgy.
[0013]
Next, the product shown in (f) can be obtained by extruding the plastically processed sintered body from the mold. In this product, the inner diameter is corrected by the core rod 21 and the outer diameter is corrected by the die 20, and as shown in (f), the horizontal hole 11 is formed at a predetermined position. The shape of the horizontal hole obtained by this plastic working becomes raindrops according to the material flow, and does not become a perfect circle. However, if the application is for fluid distribution, it can be used without any problem. Depending on the application of the product, it is possible to leave a narrow groove following the horizontal hole by adjusting the amount of filling allowance that flows from both sides to fill the vertical groove.
[0014]
(Embodiment 2) In this embodiment, the shape, dimensions, and material of the target product are the same as those in Embodiment 1, but the filling allowance 13 for filling the longitudinal groove 12 is the inner peripheral side in Embodiment 1. In this embodiment, the difference is that it is provided on the outer peripheral side. FIG. 3 illustrates the production process in this example. First, a shaped material having the shape shown in (g) was prepared from a sintered alloy of seven three brasses (sintering density 7.3 g / cm ³ ).
[0015]
In the same manner as in the first embodiment, this raw material has a vertical groove 12 that opens in the end face of the raw material, vertically downward from the position of each hole, instead of a horizontal hole. The inner peripheral surface (bearing surface) is made to have a predetermined uniform inner diameter, and the outer peripheral surface has a predetermined outer diameter in the upper half of the cylinder. A portion below the portion corresponding to the center of the center is slightly thickened, and a filling allowance 13 having a thickness of about 0.5 mm in this case is added in an amount sufficient to fill the vertical groove 12 in this case. This filling allowance 13 is a portion outside a virtual line (broken line) obtained by extending the bearing outer peripheral surface downward in the sectional view of (g).
[0016]
Next, the posture of the shaped member is reversed up and down so that the opening of the longitudinal groove comes upward. And with that posture, plastic working is performed using the mold shown in (h). That is, when the sintered body is press-fitted into the mold formed by the die 20, the core rod 21 and the lower punch 22 with the upper punch 23, the outer upper filling allowance 13 is reduced in diameter by the die 20 and plastically deformed. Then, it gradually tries to move upward or to the inner circumference side. However, since the inner periphery of the sintered body is closed by the core rod 21 and the upper end surface is closed by the upper punch 23, the material of the filling allowance is plastically flowed into the longitudinal groove 12 which is only opened to fill the longitudinal groove. To do. The filled groove portion is indicated by broken-line hatching in FIG.
[0017]
Next, if the sintered body plastically processed in this way is extruded from the mold, the product shown in (i) is obtained. In this product, the inner diameter is corrected by the core rod 21 and the outer diameter is corrected by the die 20 and, as shown in (i), the lateral hole 11 is formed at a predetermined position. This product is exactly the same as the product shown in (f) in Example 1. Accordingly, the description of the shape of the horizontal hole and the like is redundant and will be omitted.
[0018]
(Embodiment 3) In this embodiment, both end portions of the inner periphery are formed to have a predetermined inner diameter size to support the rotating shaft at two points, and the intermediate portion is larger in diameter than both end portions and functions as a “relief portion”. And the aspect which manufactures the sintered bearing which has a horizontal hole in the side wall of the intermediate part is demonstrated. The manufacturing process in this example is as shown in FIG. 4, and (nu) in the figure indicates the shape of the shaped material made of a sintered alloy before plastic working.
[0019]
This raw material is the same as that of the above-described second embodiment in that it includes vertical grooves 12 that open vertically on the end face of the raw material, instead of the horizontal holes, vertically below the position of each hole. The hole shape is different. That is, in this embodiment, the shaft hole has a stepped shape, and the small diameter portion at the upper end is made to have a predetermined inner diameter and functions as a bearing portion. The large-diameter portion below the inner-diameter portion has a slightly larger inner diameter than the bearing portion so as to function as an escape against sliding or an oil reservoir while maintaining an appropriate gap with the rotating shaft. The outer periphery of the base material has a predetermined outer diameter.
[0020]
FIG. 4 (le) shows a cross-section of the main part of a mold that performs the necessary plastic working on the base material, and the core rod 21 corresponds to the bearing part hole diameter of the product (that is, the small diameter part hole diameter of the base material). The die 20 has a diameter corresponding to the outer periphery of the product at a required depth from the upper end surface, and the lower portion is narrowed. When the base material is press-fitted into the mold with the upper punch 23, in the initial stage, the die hole of the die slides on the outer periphery of the base material, and the core rod slides on the small diameter part at the upper end of the base material. The underside is playing. Eventually, when the lower end of the shaped material reaches the narrowed portion of the die and is further pushed in, the lower portion of the shaped material is reduced in diameter while closing the longitudinal groove 12 from below, and the inner circumference is determined by the core rod 21 according to a predetermined product. Finished to the inner diameter. The lowering of the base material is stopped by the lower punch 22 at a position where the horizontal hole 11 remains at the upper end of the vertical groove 12.
[0021]
Next, if the sintered body plastically processed in this way is extruded from the mold, the product shown in (v) is obtained. In this product, the horizontal hole 11 is formed at a predetermined position as in the case of each of the above embodiments. However, a new feature is that an “escape portion” is provided in the middle of the inner diameter. Yes. That is, the large-diameter portion of the inner periphery of the base material is narrowed at the lower end portion to form a two-point supported bearing portion together with the small-diameter portion at the upper end of the inner periphery, but the intermediate portion of the large-diameter portion is not deformed as it is. The rest is a translation. Incidentally, in the case of this embodiment, unlike the previous two examples, the members around the longitudinal groove 12 are reduced in diameter both inside and outside, and the groove width is also reduced accordingly, so the extra material as in the previous two examples is used. There is no need to prepare as a filling allowance.
[0022]
【The invention's effect】
As described in detail above, according to the present invention using both the powder metallurgy method and the plastic working method, it is possible to easily manufacture a sintered part having a cylindrical shape and a side hole formed in the side wall. In addition, when such a part is used as a bearing, a sintered bearing having a two-point support type in which a rotating shaft is supported at both ends of the bearing and a relief portion is provided in the middle, and a horizontal hole is provided in the middle portion. It is also useful as a manufacturing method.
[Brief description of the drawings]
FIG. 1 is a drawing for explaining the principle of the present invention for producing a sintered cylinder with a horizontal hole.
FIG. 2 is a drawing for explaining an embodiment (Example 1) of the manufacturing process according to the present invention.
FIG. 3 is a drawing for explaining another aspect (Example 2) of the manufacturing process according to the present invention.
FIG. 4 is a drawing for explaining another aspect (Example 3) of the manufacturing process according to the present invention.
FIG. 5 is a drawing for explaining another aspect (Example 3) of the manufacturing process according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Hollow cylinder (bearing), 11 ... Horizontal hole, 12 ... Vertical groove, 13 ... Filling allowance, 20 ... Die, 21 ... Core rod, 22 ... Lower punch, 23 ... Upper punch

Claims

When manufacturing a sintered part of a cylindrical shape that has a hole penetrating in the lateral direction with respect to the central axis (hereinafter referred to as a horizontal hole) on its side wall, the position where the horizontal hole is first formed is the starting point. Produce a shaped material (sintered body) with a vertical groove opening at the lower end of the cylindrical part and a material filling the groove as a filling allowance, and then subject the shaped material to plastic working A method of manufacturing a cylindrical sintered part with a horizontal hole, characterized in that the vertical groove is filled by plastic flow except for the position of forming a horizontal hole at its upper end.

The manufacturing method of the cylindrical sintered part with a horizontal hole of Claim 1 which is the inner peripheral side of the raw material lower part adjacent to a vertical groove, and the position which provides a filling allowance is lower than the horizontal hole formation position of a side wall.

The manufacturing method of the cylindrical sintered part with a horizontal hole of Claim 1 which is the outer peripheral side of the raw material lower part adjacent to a vertical groove, and the position which provides a filling allowance is below the horizontal hole formation position of a side wall.

When manufacturing a sintered part of a cylindrical shape that has a hole penetrating in the lateral direction with respect to the central axis (hereinafter referred to as a horizontal hole) on its side wall, the position where the horizontal hole is first formed is the starting point. An element having a longitudinal groove opened at the lower end of the cylindrical part, and an inner periphery (shaft hole) of the cylindrical part having a stepped shape of a small diameter part having a predetermined inner diameter dimension and a large diameter part below the product. After forming the shape (sintered body), plastic processing is applied to the lower part of the shape material to reduce both the inner and outer diameters, and the vertical groove is closed except for the position of the horizontal hole at the upper end, and the shaft hole A method of manufacturing a sintered bearing with a horizontal hole of a both-ends support type, wherein the lower end of the product is finished to a predetermined inner diameter.