JP4606702B2

JP4606702B2 - Powder forming method, powder forming apparatus, and powder forming program

Info

Publication number: JP4606702B2
Application number: JP2003053119A
Authority: JP
Inventors: 優小岩; 征規松井; 政雄佐々木; 秀雄佐藤; 聡人花房
Original assignee: Mitsubishi Materials Corp; Mitsubishi Materials Techno Corp
Current assignee: Mitsubishi Materials Corp; Mitsubishi Materials Techno Corp
Priority date: 2003-02-28
Filing date: 2003-02-28
Publication date: 2011-01-05
Anticipated expiration: 2023-02-28
Also published as: JP2004261831A

Description

【０００１】
【発明の属する技術分野】
本発明は、成形用孔の中に粉末材料を充填してこれを圧縮し、圧粉体を成形する粉末成形方法及び粉末成形装置並びに粉末成形用プログラムに関するものである。
【０００２】
【従来の技術】
焼結部品の製造に用いる圧粉体の成形装置は一般に次のような構成となっている。すなわち、ダイ表面に形成された孔に摺動自在に設けられた下パンチと、この下パンチと対向して前記ダイの上方に配設された上パンチとを備えた構成をなし、前記孔内壁面と前記下パンチの上面とがなす空間を成形用孔とし、この成形用孔に粉末材料が充填され、この粉末材料を上下方向から前記上パンチ及び下パンチにより圧縮することにより圧粉体が成形される構成となっている。
【０００３】
このように成形される圧粉体においては、粉末材料の特性バラツキや成形時の温湿度バラツキ等の不可避的な製造条件の変動により、成形される個々の圧粉体ごとで重量バラツキが発生する問題があった。この問題を解決する手段として、所定個数の圧粉体を成形した後に、この最後に成形した圧粉体の重量を測定し、この重量が規格範囲内にあった場合は、この重量に基づいて粉末材料の充填量，すなわち成形用孔の深さを自動で調整する装置が提案されている。また、測定した圧粉体の重量が規格範囲外であった場合には、異常とみなして装置を停止する粉末成形方法が示されている（例えば特許文献１参照）。
【０００４】
しかしながら、前記従来の粉末成形装置及び粉末成形方法によれば、所定個数の圧粉体を成形した後、この最後に成形した圧粉体だけの重量に基づいて粉末材料の充填量を調整することから、例えば、前記製造条件が突発的に変動した場合において、成形された前記圧粉体の重量が規格範囲内にあるが、上限値又は下限値の近傍にあった場合、不適正な制御，すなわちこの後に成形される圧粉体の重量が確実に規格範囲外に至るような制御がなされる場合あり、成形される圧粉体の重量を高精度とすることが困難であるという問題があった。また、前記不適正な制御がなされることにより、成形される圧粉体の重量が規格範囲外になった場合には、装置全体が停止することになるので、製造工数の低下をも招来するという問題があった。
【０００５】
【特許文献１】
実開平０５−０１６２１６号公報
【０００６】
【発明が解決しようとする課題】
本発明は、このような事情を考慮してなされたもので、その目的は、成形時の温湿度バラツキ等の製造条件が変化した場合においても、圧粉体の重量を安定させて成形することができるとともに、高効率生産を実現することができる粉末成形方法及び粉末成形装置並びに粉末成形用プログラムを提供することにある。
【０００７】
【課題を解決するための手段】
前記目的を達成するために、この発明は以下の手段を提案している。
請求項１に係る発明は、成形用孔に焼結用の粉末材料を充填する充填工程と、前記成形用孔に充填された粉末材料を圧縮して圧粉体を成形する圧粉体成形工程と、前記圧粉体を成形する毎に前記圧粉体の重量を測定する重量測定工程とを備えた粉末成形方法であって、前記圧粉体を成形する毎に、前記粉末材料を前記成形用孔に充填するに際し予め、直前に成形した前記圧粉体を含んで当該成形の一定回数前までに成形した一定数量の前記圧粉体の平均重量を第１の演算部により算出し、該平均重量が予め設定された基準となる重量値に対して所定範囲外にあったときにのみ、該平均重量と前記重量値との差分値を算出し、該差分値に基づき、成形される前記圧粉体の重量が前記重量値となるよう、少なくとも前記粉末材料の材質と前記成形用孔の断面積を含む要素により予め設定された、前記成形用孔の深さの変更量と前記差分値との相関関数を用い第２の演算部により前記成形用孔の深さの変更量を求めて前記成形用孔の深さを変更することを特徴とする。
【０００８】
この発明に係る粉末成形方法によれば、粉末材料を成形用孔に充填するに際し予め、直前に成形した前記圧粉体を含んで一定回数前までに成形した一定数量の圧粉体の平均重量を算出し、この算出値に基づいて粉末材料の充填量を設定するため、粉末材料の特性バラツキや成形時の温湿度バラツキ等の製造条件が変化した場合においても、前記充填量の設定が適正になされ、成形される圧粉体の重量が確実に高精度とされることになる。
すなわち、前記製造条件が突発的に変動し、これに伴いこの際に成形した圧粉体の重量が大きく変動した場合においても、この突発的に変動した圧粉体の重量のみならず、この他の既に成形した複数の圧粉体の重量から算出した平均重量に基づいて、成形用孔に充填する粉末材料の充填量を設定するため、この充填量の設定が適正に行われることになる。
従って、成形する全ての圧粉体の重量が確実に高精度とされることになり、更に、不適正な前記充填量の設定に基づく製造停止も回避されることになる。
また、この発明に係る粉末成形方法によれば、前記充填量の設定を、前記平均重量が所定範囲内にあったときは行わず、所定範囲外にあったときに行うので、成形する圧粉体の重量が確実に高精度とされ、この重量を前記所定範囲内及びその近傍に安定させて圧粉体を成形することができるようになる。すなわち、前記所定範囲を圧粉体重量の規格範囲内のうち予め設定された基準となる重量値寄りの更に狭い範囲と設定し、成形した圧粉体の重量が前記所定範囲内にあったときは前記充填量の設定を行わないので、次に成形する際に重量が変動する方向と、前記充填量の設定が変化する方向とが符合して、成形される圧粉体の重量が大きく変動することになる不適切な制御を行うことが回避される。
【０００９】
請求項２に係る発明は、請求項１に記載の粉末成形方法において、前記成形用孔は、ダイに設けられた孔の内壁面と，該孔に相対的に摺動自在に設けられた下パンチの上面とがなす空間とされ、前記成形用孔の深さの変更は、前記下パンチ又は前記ダイを昇降移動させることを特徴とする。
【００１０】
この発明に係る粉末成形方法によれば、算出した圧粉体の平均重量に基づいた粉末材料の充填量の設定を、下パンチ又はダイを昇降移動させることにより行うため、前記設定を容易且つ高精度に行うことができるようになる。従って、成形用孔に充填される粉末材料の量を高精度とすることができ、成形される圧粉体の重量が確実に高精度とされることになる。
【００１１】
請求項３に係る発明は、焼結用の粉末材料が充填される成形用孔を有するダイと、前記成形用孔の中で粉末材料を圧縮して圧粉体を成形する上パンチ及び下パンチと、前記圧粉体を成形用孔から取出し搬送する搬送手段と、該搬送手段によって搬送された前記圧粉体の重量を測定する重量測定手段とを備えた粉末成形装置であって、前記圧粉体を成形する毎に、前記粉末材料を前記成形用孔に充填するに際し予め、直前に成形した前記圧粉体を含んで当該成形の一定回数前までに成形した一定数量の前記圧粉体の平均重量を算出し、該平均重量が予め設定された基準となる重量値に対して所定範囲外にあったときにのみ、該平均重量と前記重量値との差分値に基づいて前記粉末材料の充填量を設定する制御部を備え、該制御部は、前記重量測定手段により測定された前記重量を記憶する記憶部と、該記憶された前記重量のうち、直前に成形した前記圧粉体を含んで一定回数前までに成形した一定数量の前記圧粉体の平均重量を算出する第１の演算部と、前記平均重量が前記重量値に対して所定範囲外にあるか否かを判断する判断部と、前記平均重量と前記重量値との差分値を算出し、前記差分値に基づき、成形される前記圧粉体の重量が前記重量値となるよう、少なくとも前記粉末材料の材質と前記成形用孔の断面積を含む要素により予め設定された、前記成形用孔の深さの変更量と前記差分値との相関関数により前記成形用孔の深さの変更量を算出する第２の演算部とを備えていることを特徴とする。
【００１２】
この発明に係る粉末成形装置によれば、圧粉体を成形する毎に、粉末材料を成形用孔に充填するに際し予め、直前に成形した前記圧粉体を含んで一定回数前までに成形した一定数量の圧粉体の平均重量を算出し、この平均重量が圧粉体重量の予め設定された基準となる重量値に対して所定範囲外にあったときに、算出値に基づいて粉末材料の充填量を設定する制御部を備えているため、製造条件の突発的な変動に伴い、成形される圧粉体の重量が大きく変動した場合においても、適正な前記充填量を算出することができるようになる。従って、成形用孔に適正な量の粉末材料を充填するができ、重量が高精度とされた圧粉体が確実に成形されるようになるため、不適正な前記充填量の設定に基づく製造停止も確実に回避されることになる。
【００１３】
また、この発明に係る粉末成形装置によれば、前記第１の演算部と前記第２の演算部とを備えているので、成形用孔の深さの適切な変更量が確実に算出されることになり、成形用孔に適正な量の粉末材料が確実に充填されることになる。従って、重量が高精度とされた圧粉体が確実に成形されることになるため、不適正な前記充填量の設定に基づく製造停止も確実に回避されることになる。
【００１４】
請求項４に係る発明は、請求項３に記載の粉末成形装置において、前記成形用孔は、前記ダイ表面に設けられた孔の内壁面と、該孔に相対的に摺動自在に設けられた下パンチの上面とがなす空間とされ、前記成形用孔の深さは、前記下パンチ又は前記ダイを昇降移動させることにより変更される構成とされたことを特徴とする。
【００１５】
この発明に係る粉末成形装置によれば、算出した圧粉体の平均重量に基づいた成形用孔の深さの変更を、下パンチ又はダイを昇降移動させることにより行う構成となっているため、この深さの変更を容易且つ高精度に行うことができるようになる。従って、成形用孔に充填される粉末材料の量を高精度とすることができ、成形される圧粉体の重量が確実に高精度とされることになる。
【００１６】
請求項５に係る発明は、成形用孔に充填された焼結用の粉末材料を圧縮して圧粉体を成形する圧粉体成形ステップと、前記圧粉体を成形する毎に該圧粉体の重量を測定する重量測定ステップと、前記測定された重量に基づいて前記粉末材料の充填量を設定する充填量設定ステップとを有する粉末成形用プログラムであって、前記圧粉体を成形する毎に、直前に成形した前記圧粉体を含んで当該成形の一定回数前までに成形した一定数量の前記圧粉体の平均重量を算出する平均重量演算ステップと、前記平均重量が予め設定された基準となる重量値に対して所定範囲外にあるか否かを判断する平均重量判断ステップを有し、前記充填量設定ステップは、前記平均重量が前記所定範囲外にあったときにのみ、該平均重量と前記重量値との差分値を算出し、前記差分値に基づき、成形される前記圧粉体の重量が前記重量値となるよう、少なくとも前記粉末材料の材質と前記成形用孔の断面積を含む要素により予め設定された、前記成形用孔の深さの変更量と前記差分値との相関関数により前記成形用孔の深さの変更量を算出することを特徴とする
【００１７】
この発明に係る粉末成形用プログラムによれば、直前に成形した前記圧粉体を含んで一定回数前までに成形した一定数量の圧粉体の平均重量を算出する平均重量演算ステップを有し、前記充填量設定ステップは、平均重量と重量値との差分値を算出し、差分値に基づき予め設定された、成形用孔の深さの変更量と差分値との相関関数により成形用孔の深さの変更量を算出するため、重量が高精度とされた圧粉体が確実に成形されることになる。
また、前記平均重量が所定範囲外にあるか否かを判断する平均重量判断ステップを有し、前記充填量設定ステップは、前記平均重量が所定範囲外にあったときに前記成形用孔の深さの変更量を算出するので、成形する圧粉体の重量が確実に高精度とされ、この重量を前記所定範囲内及びその近傍に安定させて圧粉体を成形することができるようになる。
【００１８】
【発明の実施の形態】
以下、本発明に係る粉末成形方法及び粉末成形装置並びに粉末成形用プログラムの一実施形態を、図１から図５を参照しながら説明する。
本実施形態に係る粉末成形装置１０は、図１に示すように、昇降自在に支持された上パンチ部２０と、この上パンチ部２０と対向して設けられた下パンチ部３０と、成形された圧粉体を後述する成形用孔から取出し、これを後述する重量測定手段４０に搬送する図示しない搬送手段と、搬送された圧粉体の重量を測定する電子天秤等の重量測定手段４０と、測定された圧粉体の重量と予め設定された基準値とに基づいて，前記成形用孔へ充填する粉末材料の量を算出する制御部５０と、前記成形用孔に粉末材料を充填する図示しない粉末材料充填手段とを備えている。
【００１９】
上パンチ部２０は、前記成形用孔に充填された粉末材料を圧縮する上パンチ２１と、上パンチ２１を前記成形用孔に対して昇降駆動させる上パンチ駆動手段２２と、上パンチ２１及び上パンチ駆動手段２２を支持する上パンチ支持部２３とを備えている。ここで、上パンチ支持部２３の両側部位には、貫通孔が設けられ、この貫通孔に円柱状のガイド部２４が挿通して配設されている。この構成において、上パンチ駆動手段２２が駆動すると、ガイド部２４に沿って上パンチ支持部２３が昇降駆動され、これに伴い上パンチ２１及び上パンチ駆動手段２２も同様にして昇降駆動される構成となっている。
【００２０】
下パンチ部３０は、本体部３１と、本体部３１上面の略中央部に設けられた第１の孔３１ａの底面部に配設されたダイ３２と、ダイ３２上面の略中央部に設けられた第２の孔３２ａに摺動自在に支持された下パンチ３３と、下パンチ３３を昇降駆動させる下パンチ駆動手段３４とを備えている。ここで、ダイ３２に設けられた第２の孔３２ａの内壁面と下パンチ３３の上面とがなす空間が前述した成形用孔３５となる。本実施形態においては、圧粉体を成形する際に成形用孔３５に充填する粉末材料の充填量は、成形用孔３５の深さＡにより設定される，すなわち、下パンチ３３の上面の昇降方向の位置により設定され、この下パンチ３３の位置決めを下パンチ駆動手段３４が行う構成となっている。
【００２１】
制御手段５０は、図２に示すように、重量測定手段４０により測定された圧粉体の重量データに基づいて成形用孔３５に充填する粉末材料の量を演算する演算部５１と、演算部５１が読取り可能なデータ形式に変換するとともに、演算部５１により演算された演算結果を下パンチ駆動手段３４が読取り可能なデータ形式に変換する入出力部５２と、前記圧粉体の重量データを記憶しておく記憶部５３とを備えている。
演算部５１は、記憶部５３に記憶されている圧粉体の重量データのうち、直前に成形した圧粉体を含む所定回数前までに成形した複数の圧粉体の重量の平均値を演算する第１の演算部５１ａと、この平均値と予め設定されている基準となる重量値（以下、「基準値」という）との差分を演算するとともに、この差分に基づいて，成形される圧粉体の重量が基準値となる前記充填量を演算する第２の演算部５１ｂとを備えている。この第２の演算部５１ｂにより演算される前記充填量は、前述したように本実施形態においては、成形用孔３５の深さＡの変更量，すなわち下パンチ３３の移動量である。この第２の演算部５１ｂの演算結果に基づいて、下パンチ駆動手段３４が駆動され、成形される圧粉体の重量が基準値となる前記充填量を実現できる前記深さＡが設定される構成となっている。
【００２２】
次に、以上のように構成された粉末成形装置１０により圧粉体を成形する方法について説明する。この成形方法のフロー図を図３に示す。
まず、図示しない粉末材料充填手段により成形用孔３５に粉末材料を充填（ステップＳ１）した後、上パンチ駆動手段２２を駆動し上パンチ２１を下降させ、前記充填された粉末材料を圧縮し圧粉体を成形する（ステップＳ３）。その後、図示しない搬送手段により圧粉体を重量測定手段４０に搬送し、この重量測定手段４０により前記圧粉体の重量を測定（ステップＳ５）した後、この重量データを制御部５０に送信し、制御部５０の入出力部５２により前記重量データを、演算部５１が読取り可能なデータ形式に変換した後、この変換された重量データを記憶部５３が記憶する（ステップＳ７）。この工程を本実施形態においてはまず４回繰返し行う。
【００２３】
次に、５個目以降の圧粉体の成形方法について説明する。概略説明図を図４に示す。
５個目の圧粉体を成形するに際し、記憶部５３に記憶されている１個目から４個目までの圧粉体の重量データを演算部５１の第１の演算部５１ａに送信し、該部５１ａで１個目から４個目までの圧粉体の重量の平均値を算出し（ステップＳ９）、この平均値を判断部５１ｃに送信し、該部５１ｃでその大きさを判断する（ステップＳ１１）。判断部５１ｃでは、前記平均値が圧粉体重量の規格中心値（１４５．５ｇ）に対して所定の範囲Ｂ（例えば、±０．２ｇ）外にあるか否かを判断する。
【００２４】
この判断結果、前記平均値が前記所定の範囲Ｂ外にあった場合は、この平均値を第２の演算部５１ｂに送信し、該部５１ｂでこの平均値と基準値との差分を算出し（ステップＳ１３）、さらに、前記差分値に基づいて成形用孔３５の深さＡの変更量を算出する（ステップＳ１５）。例えば、基準値の方が平均値より大きい場合は、成形用孔３５に，より大量の粉末材料が充填されるべく深さＡがより深くなるように下パンチ３３を下降させるような変更量を算出し、逆に、基準値の方が平均値より小さい場合は、成形用孔３５に，より少量の粉末材料が充填されるべく深さＡがより浅くなるように下パンチ３３を上昇させるような変更量を算出する。尚、この際の下パンチ３３の具体的な昇降量は、予め設定された前記昇降量と前記差分値との相関関数により決定され、この相関関数は、充填する粉末材料の材質，成形用孔３５の断面積等により決定される。
【００２５】
そして、第２の演算部５１ｂにより算出された前記変更量のデータは、入出力部５２に送信され、該部５２で下パンチ駆動手段３４が読取り可能なデータ形式に変換した後、このデータを下パンチ駆動手段３４に送信して、この駆動手段３４を駆動し下パンチ３３を前記算出した変更量だけ昇降させ深さＡを変更する（ステップＳ１７）。その後、図示しない粉末材料充填手段により、深さＡが変更された成形用孔３５に粉末材料を充填（ステップＳ１９）した後、前述と同様にして、５個目の圧粉体の成形（ステップＳ２１）、この圧粉体の重量測定（ステップＳ２３）、及びこの重量データの記憶（ステップＳ２５）を順次経る。
ここで、前述した判断部５１ｃでの判断（ステップＳ１１）の結果、前記平均値が前記所定範囲Ｂ内であった場合は、前記差分値の算出（ステップＳ１３）、変更量の算出（ステップＳ１５）、及び深さＡの変更（ステップＳ１７）は行わず、直ぐに粉末材料を成形用孔３５に充填（ステップＳ１９）し、前述と同様にして、５個目の圧粉体を成形等する。
【００２６】
次に、６個目の圧粉体を成形するに際しては、記憶部５３に記憶されている１個目から５個目の圧粉体の重量データのうち、２個目から５個目までの重量データを第１の演算部５１ａに送信し、該部５１ａで２個目から５個目までの圧粉体の重量の平均値を算出する。以降、前述した５個目の圧粉体を成形する際と同様にして、６個目の圧粉体を成形する。６個目以降も、前述と同様にして、直前に成形した圧粉体を含む４回前までに成形した４個の圧粉体の重量の平均値を第１の演算部５１ａにより算出し、この平均値の大きさが前記所定の範囲Ｂ外にあるか否かを判断部５１ｃにより判断し、この結果、前記平均値が前記所定範囲Ｂ外にある場合には、この平均値に基づいて成形用孔３５の深さＡを設定した後に、この成形用孔３５に粉末材料を充填し、圧粉体を成形する。
【００２７】
ここで、本実施形態の粉末成形方法及び粉末成形装置により成形した圧粉体の重量の測定データを図５に示す。比較例として、本実施形態の粉末成形方法において圧粉体の平均重量が所定範囲Ｂ外にあるか否かに拘わらず成形用孔３５の深さＡを設定した場合の重量測定データを図６（ａ）に、また、粉末材料の充填量制御を何ら行っていない場合の測定データを図６（ｂ）に各々示す。これらの図において、横軸は成形した圧粉体の順であり、縦軸は圧粉体の重量である。
【００２８】
図５,図６（ｂ）から明らかなように、本実施形態の方法及び装置により成形された圧粉体の重量は、所定領域Ｂ内及びその近傍で安定しており、本実施形態の方法及び装置が圧粉体の重量バラツキ抑制に有用であることが確認できる。ここで、本実施形態の粉末成形方法において圧粉体の平均重量が所定範囲Ｂ外にあるか否かに拘わらず成形用孔３５の深さＡを設定した場合には、図６（ａ）,図６（ｂ）に示すように、粉末材料の充填量制御を何ら行っていない場合より、重量バラツキが大きくなることが確認できる。これは、次に成形する際に重量が変動する方向と、成形用孔３５の深さＡの設定値が変化する方向とが符合して、成形される圧粉体の重量が大きく変動することになる不適切な制御がなされたことが要因と考えられる。
【００２９】
以上説明したように、本実施形態による粉末成形方法及び粉末成形装置によれば、粉末材料を成形用孔３５に充填するに際し予め、直前に成形した圧粉体を含む４回前までに成形した４個の圧粉体の平均重量を第１の演算部５１ａにより算出し、第２の演算部５１ｂにおいて、前記平均重量と基準値との差分を算出し、この差分に基づいて、成形用孔５３の深さＡの変更量を算出するため、粉末材料の特性バラツキや成形時の温湿度バラツキ等の製造条件が変化した場合においても、適正な前記深さＡの変更量を算出でき、成形される圧粉体の重量を確実に高精度とすることができる。
【００３０】
すなわち、前記製造条件が突発的に変動し、これに伴いこの際に成形した圧粉体の重量が変動した場合においても、この突発的に変動した圧粉体の重量のみならず、この他の既に成形した３個の圧粉体の重量から算出した平均重量に基づいて、成形用孔３５の深さＡを設定する，すなわち成形用孔３５に充填する粉末材料の充填量を設定するため、この充填量の設定を適正に行うことができることになる。従って、成形する全ての圧粉体の重量が確実に高精度とすることができ、更に、不適正な前記充填量の設定に基づく製造停止も回避することができるので、高効率生産を実現することができる。
【００３１】
また、成形用孔３５の深さＡの設定を、圧粉体の重量の平均値が所定範囲Ｂ内にあったときは行わず、所定範囲Ｂ外にあったときに行うので、成形する圧粉体の重量を確実に高精度とすることができ、この重量を所定範囲Ｂ内及びその近傍に安定させて圧粉体を成形することができる。すなわち、次に成形する際に重量が変動する方向と、成形用孔３５の深さＡの設定値が変化する方向とが符合して、成形される圧粉体の重量が大きく変動することになる不適切な制御を行うことを回避することができる。
【００３２】
また、成形用孔３５の深さＡの設定を、下パンチ３３をダイ３２に対して相対的に昇降移動させることにより行うため、この設定を容易且つ高精度に行うことができる。従って、成形用孔３５に充填される粉末材料の量を高精度とすることができるので、成形される圧粉体の重量を確実に高精度とすることができる。
さらに、本実施形態においては、前記平均重量が直前に成形した圧粉体の重量を考慮に入れたものとなっているので、より適正な前記深さ設定を行うことができることになる。
【００３３】
なお、本発明は前記実施の形態に限定されるものではなく、本発明の趣旨を逸脱しない範囲において種々の変更を加えることが可能である。例えば、成形用孔３５の深さＡの設定を、下パンチ３３を昇降移動させることにより行ったが、ダイ３２を昇降移動させるようにしてもよく、また、ダイ３２及び下パンチ３３の双方を、深さＡが所定の深さになるように昇降移動させるようにしてもよい。さらに、本実施形態においては、４個の圧粉体を成形した後、これらの平均重量を算出したが、この際の個数は適宜変更してもよい。
【００３４】
【発明の効果】
以上の説明から明らかなように、請求項１に係る発明によれば、直前に成形した前記圧粉体を含んで所定回数前までに成形した複数の圧粉体の平均重量を算出し、平均重量が予め設定された基準となる重量値に対して所定範囲外にあったときにのみ平均重量と前記重量値との差分値に基づき成形用孔の深さを変更するため、製造条件の突発的な変動が発生し、成形した圧粉体の重量も同様に変動した場合においても、前記充填量の設定を適正に行うことができる。従って、成形する全ての圧粉体の重量を確実に高精度とすることができ、更に、不適正な前記充填量の設定に基づく製造停止を確実に回避することができ、高効率生産を実現できる。
【００３５】
また、成形される圧粉体の重量が大きく変動することになる不適切な制御を行うことが回避されるので、成形する圧粉体の重量を確実に高精度とすることができ、この重量を前記所定範囲内及びその近傍に安定させて圧粉体を成形することができる。
【００３６】
請求項２に係る発明によれば、算出した平均重量と前記重量値との差分値に基づき成形用孔の深さを変更するに際し、下パンチ又はダイを昇降移動させるため、成形用孔に充填される粉末材料の量を容易に高精度とすることができ、成形される圧粉体の重量を確実に高精度とすることができる。
【００３７】
請求項３に係る発明によれば、製造条件の突発的な変動に伴い、成形される圧粉体の重量が大きく変動した場合においても、適正な粉末材料の充填量を算出することができる。従って、成形用孔に適正な量の粉末材料が充填されることになり、重量が高精度とされた圧粉体を確実に成形できるため、不適正な前記充填量の設定に基づく製造停止も確実に回避することができる。
【００３８】
また、重量が高精度とされた圧粉体を確実に成形することができるため、不適正な前記充填量の設定に基づく製造停止も確実に回避することができる。
請求項４に係る発明によれば、成形用孔の深さの変更を容易且つ高精度で行うことができるため、成形用孔に充填される粉末材料の量を高精度とすることができ、成形去れる圧粉体の重量を確実に高精度とすることができる。
【００３９】
請求項５に係る発明によれば、圧粉体が成形される毎に、直前に成形した前記圧粉体を含んで当該成形の一定回数前までに成形した一定数量の圧粉体の平均重量を算出する平均重量演算ステップを有し、前記充填量設定ステップは、平均重量と重量値との差分値に基づいて成形用孔の深さの変更量を算出するため、重量が高精度とされた圧粉体を確実に成形することができる。
また、平均重量が所定範囲外にあるか否かを判断する平均重量判断ステップを有し、前記充填量設定ステップは、前記平均重量が所定範囲外にあったときにのみ前記成形用孔の深さの変更量を算出するので、成形する圧粉体の重量を確実に高精度とすることができ、この重量を前記所定範囲内及びその近傍に安定させて圧粉体を成形することができる。
【００４０】
【図面の簡単な説明】
【図１】この発明の一実施形態に係る粉末成形装置の要部を示す概略構成図である。
【図２】図１に示す制御部の要部を示す概略図である。
【図３】この発明の一実施形態に係る粉末成形方法の概略を示すフロー図である。
【図４】成形用孔の深さの変更量を決定する際に用いる圧粉体の平均重量を算出する方法を説明するための説明図である。
【図５】この発明の一実施形態に係る粉末成形方法及び粉末成形装置により成形された圧粉体の重量を示す図である。
【図６】この発明の一実施形態に係る粉末成形方法において、圧粉体の平均重量が所定範囲外にあるか否かに拘わらず成形用孔の深さを設定した場合の圧粉体の重量データ（ａ）と、成形用孔の深さ設定を何ら行っていない場合の圧粉体の重量データ（ｂ）とを示す図である。
【符号の説明】
１０粉末成形装置２１上パンチ３２ダイ３２ａ第２の孔（孔）３３下パンチ３５成形用孔４０重量測定手段５１ａ第１の演算部５１ｂ第２の演算部５１ｃ判断部５３記憶部Ａ成形用孔の深さＢ所定範囲[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a powder molding method, a powder molding apparatus, and a powder molding program for filling a powder material into a molding hole, compressing the powder material, and molding a green compact.
[0002]
[Prior art]
  An apparatus for forming a green compact used for manufacturing sintered parts generally has the following configuration. That is, a structure is provided that includes a lower punch that is slidably provided in a hole formed on the die surface, and an upper punch that is disposed above the die so as to face the lower punch. A space formed by the wall surface and the upper surface of the lower punch is used as a molding hole. The molding hole is filled with a powder material, and the powder material is compressed by compressing the powder material from above and below with the upper punch and the lower punch. It is the structure to be molded.
[0003]
  In the green compacts molded in this way, weight variations occur among the individual green compacts that are molded due to inevitable fluctuations in manufacturing conditions such as variations in the characteristics of the powder material and variations in temperature and humidity during molding. There was a problem. As a means for solving this problem, after molding a predetermined number of green compacts, the weight of the last green compact is measured, and if this weight is within the standard range, An apparatus for automatically adjusting the filling amount of the powder material, that is, the depth of the forming hole has been proposed. Further, a powder molding method is described in which when the weight of the measured green compact is out of the standard range, it is regarded as abnormal and the apparatus is stopped (for example, see Patent Document 1).
[0004]
  However, according to the conventional powder molding apparatus and powder molding method, after a predetermined number of green compacts are molded, the filling amount of the powder material is adjusted based on the weight of only the green compact molded last. From, for example, when the manufacturing conditions suddenly fluctuate, the weight of the molded green compact is within the standard range, but if it is in the vicinity of the upper limit or lower limit, improper control, In other words, there is a case where control is performed so that the weight of the green compact to be molded thereafter is out of the specified range, and it is difficult to make the weight of the green compact to be molded highly accurate. It was. Further, if the weight of the green compact to be molded is out of the standard range due to the improper control, the entire apparatus will be stopped, resulting in a decrease in manufacturing man-hours. There was a problem.
[0005]
[Patent Document 1]
  Japanese Utility Model Publication No. 05-016216
[0006]
[Problems to be solved by the invention]
  The present invention has been made in consideration of such circumstances, and its purpose is to stabilize the weight of the green compact even when manufacturing conditions such as temperature and humidity variations during molding change. It is another object of the present invention to provide a powder forming method, a powder forming apparatus, and a powder forming program capable of realizing high-efficiency production.
[0007]
[Means for Solving the Problems]
  In order to achieve the above object, the present invention proposes the following means.
  The invention according to claim 1 is the molding hole.For sinteringA filling step of filling a powder material, a green compact forming step of forming a green compact by compressing the powder material filled in the molding hole, and each time the green compact is molded, A powder molding method comprising a weight measuring step for measuring weight, each time the green compact is molded, when the powder material is filled in the molding hole in advance,Including the green compact molded just beforeA certain number of molded products up to a certain number of times before the moldingAboveThe average weight of the green compactBy the first calculation unitThe average weight is calculatedPre-set reference weight valueWhen it was out of the prescribed rangeOnly calculating a difference value between the average weight and the weight value, and based on the difference value, at least the material of the powder material and the molding material so that the weight of the green compact to be molded becomes the weight value. The amount of change in the depth of the forming hole is set by the second calculation unit using a correlation function between the amount of change in the depth of the forming hole and the difference value set in advance by an element including the cross-sectional area of the hole. Find and change the depth of the molding holeIt is characterized by that.
[0008]
    According to the powder molding method according to the present invention, when filling the powder material into the molding hole, in advance,Including the green compact molded just beforeCalculate the average weight of a certain number of green compacts molded up to a certain number of times before, and set the filling amount of the powder material based on this calculated value. Even when the manufacturing conditions change, the filling amount is set appropriately, and the weight of the green compact to be molded is surely made highly accurate.
  That is, even when the manufacturing conditions suddenly fluctuate and the weight of the green compact formed at this time fluctuates greatly, not only the suddenly changed weight of the green compact but also other than this Since the filling amount of the powder material to be filled in the molding hole is set based on the average weight calculated from the weights of the plurality of green compacts already molded, the filling amount is appropriately set.
  Accordingly, the weight of all the green compacts to be molded is surely made highly accurate, and furthermore, the production stoppage based on the inappropriate setting of the filling amount is also avoided.
  In addition, according to the powder molding method according to the present invention, the filling amount is set when the average weight is not within the predetermined range, and is set when the average weight is outside the predetermined range. The weight of the body is surely made highly accurate, and the green compact can be molded by stabilizing the weight within the predetermined range and in the vicinity thereof. That is, the predetermined range is within the standard range of the green compact weight.Pre-set reference weight valueWhen the weight of the formed green compact is set within the predetermined range, the filling amount is not set, so the direction in which the weight fluctuates during the next molding, Inappropriate control in which the weight of the green compact to be molded largely fluctuates in accordance with the direction in which the setting of the filling amount changes is avoided.
[0009]
  Claim2The invention according to claim1In the powder molding method described in the above, the molding hole is a space formed by the inner wall surface of the hole provided in the die and the upper surface of the lower punch provided slidably relative to the hole,The change in the depth of the molding hole isThe lower punch or the die is moved up and down.
[0010]
  According to the powder molding method according to the present invention, the setting of the filling amount of the powder material based on the calculated average weight of the green compact is performed by moving the lower punch or the die up and down. It will be possible to do with accuracy. Therefore, the amount of the powder material filled in the molding hole can be made highly accurate, and the weight of the green compact to be molded is surely made highly accurate.
[0011]
  Claim3The invention according toFor sinteringA die having a molding hole filled with a powder material, an upper punch and a lower punch for compressing the powder material in the molding hole to form a green compact, and taking out the green compact from the molding hole A powder molding apparatus comprising a conveying means for conveying and a weight measuring means for measuring the weight of the green compact conveyed by the conveying means, each time the green compact is molded, the powder material Before filling the molding hole,Including the green compact molded just beforeA certain number of molded products up to a certain number of times before the moldingAboveCalculate the average weight of the green compact.Pre-set reference weight valueWhen it was out of the prescribed rangeonlyThe average weightAnd the difference between the weight valueA control unit for setting the filling amount of the powder material on the basis of the storage unit, the control unit is configured to store the weight measured by the weight measuring unit, and among the stored weight,Including the green compact molded just beforeA certain number of molded parts before a certain number of timesAboveA first calculation unit for calculating an average weight of the green compact;A determination unit that determines whether or not the weight value is outside a predetermined range; calculates a difference value between the average weight and the weight value; and based on the difference value, the green compact to be molded A correlation function between the amount of change in the depth of the molding hole and the difference value set in advance by an element including at least the material of the powder material and the cross-sectional area of the molding hole so that the weight becomes the weight value. To change the depth of the molding holeAnd a second calculating unit for calculating.
[0012]
  According to the powder molding apparatus according to the present invention, every time the green compact is molded, when filling the powder material into the molding hole,Including the green compact molded just beforeCalculate the average weight of a certain number of green compacts molded up to a certain number of times before, and this average weight is the weight of the green compact.Pre-set reference weight valueThe control unit for setting the filling amount of the powder material based on the calculated value when it is out of the predetermined range with respect to the Even when the weight largely fluctuates, the appropriate filling amount can be calculated. Therefore, an appropriate amount of powder material can be filled in the molding hole, and a green compact with a high weight can be reliably molded. Therefore, manufacturing based on an inappropriate setting of the filling amount is achieved. Stopping is also avoided reliably.
[0013]
  Also,According to the powder molding apparatus according to the present invention, since it includes the first calculation unit and the second calculation unit,Appropriate depth of molding holeThe amount of change is calculated with certainty, and an appropriate amount of powder material is reliably filled in the molding hole. Accordingly, since the green compact with high accuracy is surely formed, the production stoppage based on the inappropriate setting of the filling amount can be surely avoided.
[0014]
  Claim4The invention according to claim3In the powder molding apparatus described in the above, the molding hole is a space formed by the inner wall surface of the hole provided on the die surface and the upper surface of the lower punch provided slidably relative to the hole. The depth of the molding hole is changed by moving the lower punch or the die up and down.
[0015]
  According to the powder molding apparatus according to the present invention, since the depth of the molding hole is changed based on the calculated average weight of the green compact by moving the lower punch or die up and down, This depth change can be performed easily and with high accuracy. Therefore, the amount of the powder material filled in the molding hole can be made highly accurate, and the weight of the green compact to be molded is surely made highly accurate.
[0016]
  Claim5The invention according to the invention was filled in the molding holeFor sinteringA green compact forming step of compressing the powder material to form a green compact;AboveA powder molding program comprising a weight measuring step for measuring the weight of the green compact each time the green compact is molded, and a filling amount setting step for setting the filling amount of the powder material based on the measured weight And every time the green compact is molded,Including the green compact molded just beforeA certain number of molded products up to a certain number of times before the moldingAboveAn average weight calculating step for calculating an average weight of the green compact;Pre-set reference weight valueAn average weight determining step for determining whether the average weight is outside the predetermined range, and the filling amount setting step is performed when the average weight is outside the predetermined range.Only calculating a difference value between the average weight and the weight value, and based on the difference value, at least the material of the powder material and the molding material so that the weight of the green compact to be molded becomes the weight value. The amount of change in the depth of the forming hole is calculated by a correlation function between the amount of change in the depth of the forming hole and the difference value preset by an element including the cross-sectional area of the hole.It is characterized by
[0017]
  According to the powder molding program according to the present invention,Including the green compact molded just beforeAn average weight calculating step of calculating an average weight of a certain number of green compacts molded up to a certain number of times before, the filling amount setting step,Calculate the difference value between the average weight and the weight value, and calculate the change amount of the forming hole depth based on the correlation function between the change amount of the forming hole depth and the difference value set in advance based on the difference value. DoTherefore, the green compact whose weight is highly accurate is surely formed.
  And an average weight determining step for determining whether or not the average weight is outside a predetermined range, wherein the filling amount setting step is performed when the average weight is outside the predetermined range.Calculate amount of change in forming hole depthTherefore, the weight of the green compact to be molded is surely made highly accurate, and it becomes possible to mold the green compact by stabilizing this weight within the predetermined range and in the vicinity thereof.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
  Hereinafter, an embodiment of a powder forming method, a powder forming apparatus, and a powder forming program according to the present invention will be described with reference to FIGS.
  As shown in FIG. 1, the powder molding apparatus 10 according to the present embodiment is molded with an upper punch portion 20 supported so as to be movable up and down, and a lower punch portion 30 provided to face the upper punch portion 20. A non-illustrated conveying means for taking out the green compact from a molding hole described later and conveying it to a weight measuring means 40 described later; and a weight measuring means 40 such as an electronic balance for measuring the weight of the conveyed green compact; Based on the measured weight of the green compact and a preset reference value, the control unit 50 calculates the amount of powder material to be filled in the molding hole, and fills the molding hole with the powder material. Powder material filling means (not shown).
[0019]
  The upper punch portion 20 includes an upper punch 21 that compresses the powder material filled in the molding hole, an upper punch driving means 22 that drives the upper punch 21 up and down with respect to the molding hole, and the upper punch 21 and the upper punch 21. An upper punch support portion 23 that supports the punch driving means 22 is provided. Here, through holes are provided in both side portions of the upper punch support portion 23, and columnar guide portions 24 are inserted into the through holes. In this configuration, when the upper punch driving means 22 is driven, the upper punch supporting portion 23 is driven up and down along the guide portion 24, and accordingly, the upper punch 21 and the upper punch driving means 22 are driven up and down in the same manner. It has become.
[0020]
  The lower punch portion 30 is provided in the main body portion 31, the die 32 disposed in the bottom surface portion of the first hole 31 a provided in the substantially central portion of the upper surface of the main body portion 31, and the substantially central portion of the upper surface of the die 32. The lower punch 33 is slidably supported in the second hole 32a, and the lower punch drive means 34 is configured to drive the lower punch 33 up and down. Here, the space formed by the inner wall surface of the second hole 32 a provided in the die 32 and the upper surface of the lower punch 33 is the molding hole 35 described above. In the present embodiment, the filling amount of the powder material that fills the molding hole 35 when molding the green compact is set by the depth A of the molding hole 35, that is, ascending and descending the upper surface of the lower punch 33. The lower punch 33 is set by the position in the direction, and the lower punch 33 is positioned by the lower punch driving means 34.
[0021]
  As shown in FIG. 2, the control unit 50 includes a calculation unit 51 that calculates the amount of powder material to be filled in the molding hole 35 based on the weight data of the green compact measured by the weight measurement unit 40, and a calculation unit 51, the input / output unit 52 converts the calculation result calculated by the calculation unit 51 into a data format readable by the lower punch driving unit 34, and the weight data of the green compact. And a storage unit 53 for storing.
  The calculation unit 51 calculates the average value of the weights of a plurality of green compacts molded a predetermined number of times before the green compact data stored in the storage unit 53, including the green compact molded immediately before. Calculating the difference between the first calculation unit 51a and the average value and a reference weight value (hereinafter referred to as “reference value”) set in advance, and forming the pressure based on the difference A second calculation unit 51b that calculates the filling amount at which the weight of the powder becomes a reference value. As described above, the filling amount calculated by the second calculating unit 51b is the amount of change of the depth A of the forming hole 35, that is, the amount of movement of the lower punch 33 in the present embodiment. Based on the calculation result of the second calculation unit 51b, the lower punch driving means 34 is driven, and the depth A that can achieve the filling amount at which the weight of the green compact to be formed becomes a reference value is set. It has a configuration.
[0022]
  Next, a method for forming a green compact with the powder forming apparatus 10 configured as described above will be described. A flow chart of this molding method is shown in FIG.
  First, after filling the molding hole 35 with a powder material by a powder material filling means (not shown) (step S1), the upper punch driving means 22 is driven to lower the upper punch 21, and the filled powder material is compressed and compressed. Powder is formed (step S3). Thereafter, the green compact is conveyed to the weight measuring means 40 by a conveying means (not shown), the weight of the green compact is measured by the weight measuring means 40 (step S5), and the weight data is transmitted to the control unit 50. After the weight data is converted into a data format that can be read by the calculation unit 51 by the input / output unit 52 of the control unit 50, the storage unit 53 stores the converted weight data (step S7). This process is first repeated four times in this embodiment.
[0023]
  Next, a method for forming the fifth and subsequent green compacts will be described. A schematic explanatory diagram is shown in FIG.
  When molding the fifth green compact, the weight data of the first to fourth green compacts stored in the storage unit 53 is transmitted to the first calculation unit 51a of the calculation unit 51, The unit 51a calculates the average value of the weights of the first to fourth green compacts (step S9), transmits this average value to the determination unit 51c, and the unit 51c determines its size. (Step S11). The determination unit 51c determines whether or not the average value is outside a predetermined range B (for example, ± 0.2 g) with respect to the standard center value (145.5 g) of the green compact weight.
[0024]
  As a result of the determination, when the average value is outside the predetermined range B, the average value is transmitted to the second calculation unit 51b, and the difference between the average value and the reference value is calculated by the unit 51b. (Step S13) Further, the amount of change of the depth A of the forming hole 35 is calculated based on the difference value (Step S15). For example, when the reference value is larger than the average value, the amount of change is such that the lower punch 33 is lowered so that the depth A becomes deeper to fill the molding hole 35 with a larger amount of powder material. On the contrary, when the reference value is smaller than the average value, the lower punch 33 is raised so that the depth A becomes shallower so that the molding hole 35 is filled with a smaller amount of powder material. The amount of change is calculated. At this time, the specific lift amount of the lower punch 33 is determined by a correlation function between the preset lift amount and the difference value, and this correlation function includes the material of the powder material to be filled, the molding hole, and the like. It is determined by the cross-sectional area of 35 or the like.
[0025]
  Then, the change amount data calculated by the second calculation unit 51b is transmitted to the input / output unit 52, and after the data is converted into a data format that can be read by the lower punch driving unit 34, the data is converted into the data format. This is transmitted to the lower punch drive means 34, and this drive means 34 is driven to raise and lower the lower punch 33 by the calculated change amount to change the depth A (step S17). Thereafter, the powder material filling means (not shown) fills the molding hole 35 with the depth A changed (step S19), and then the fifth green compact is molded (step S19) as described above. S21), weight measurement of the green compact (step S23), and storage of the weight data (step S25) are sequentially performed.
  Here, if the average value is within the predetermined range B as a result of the determination by the determination unit 51c (step S11), the difference value is calculated (step S13), and the change amount is calculated (step S15). ) And the depth A are not changed (step S17), the powder material is immediately filled into the molding hole 35 (step S19), and the fifth green compact is molded in the same manner as described above.
[0026]
  Next, when the sixth green compact is formed, the second to fifth pieces of weight data of the first to fifth green compacts stored in the storage unit 53 are used. The weight data is transmitted to the first calculation unit 51a, and the average value of the weights of the second to fifth green compacts is calculated by the unit 51a. Thereafter, the sixth green compact is formed in the same manner as the fifth green compact described above. For the sixth and subsequent pieces as well, the first calculation unit 51a calculates the average value of the weights of the four green compacts molded up to four times before including the green compact molded immediately before, The determination unit 51c determines whether or not the average value is outside the predetermined range B. As a result, if the average value is outside the predetermined range B, the average value is determined based on the average value. After setting the depth A of the molding hole 35, the molding hole 35 is filled with a powder material, and a green compact is molded.
[0027]
  Here, FIG. 5 shows measurement data of the weight of the green compact formed by the powder forming method and the powder forming apparatus of the present embodiment. As a comparative example, FIG. 6 shows weight measurement data when the depth A of the molding hole 35 is set regardless of whether or not the average weight of the green compact is outside the predetermined range B in the powder molding method of this embodiment. FIG. 6 (b) shows the measurement data when no control of the filling amount of the powder material is performed in (a). In these figures, the horizontal axis represents the order of the green compact formed, and the vertical axis represents the weight of the green compact.
[0028]
  As is apparent from FIGS. 5 and 6B, the weight of the green compact formed by the method and apparatus of the present embodiment is stable in and around the predetermined region B, and the method of the present embodiment. In addition, it can be confirmed that the apparatus is useful for suppressing the weight variation of the green compact. Here, when the depth A of the molding hole 35 is set regardless of whether or not the average weight of the green compact is outside the predetermined range B in the powder molding method of the present embodiment, FIG. As shown in FIG. 6 (b), it can be confirmed that the weight variation becomes larger than the case where the filling amount control of the powder material is not performed at all. This is because the weight of the green compact to be molded greatly fluctuates in accordance with the direction in which the weight changes in the next molding and the direction in which the setting value of the depth A of the molding hole 35 changes. It is thought that this was caused by inappropriate control.
[0029]
  As described above, according to the powder molding method and the powder molding apparatus according to the present embodiment, when the powder material is filled in the molding hole 35, the powder is molded up to four times before including the green compact molded immediately before. The average weight of the four green compacts is calculated by the first calculation unit 51a, and the second calculation unit 51b calculates the difference between the average weight and the reference value. Based on this difference, the molding hole 53. Since the amount of change in depth A of 53 is calculated, even when the manufacturing conditions such as variations in the characteristics of the powder material and temperature and humidity during molding change, the appropriate amount of change in depth A can be calculated. Thus, the weight of the green compact can be made highly accurate.
[0030]
  That is, even when the manufacturing conditions suddenly fluctuate and the weight of the green compact formed at this time fluctuates, not only the weight of the suddenly compacted green compact but also other In order to set the depth A of the molding hole 35 based on the average weight calculated from the weight of the three green compacts already molded, that is, to set the filling amount of the powder material to be filled in the molding hole 35, This filling amount can be set appropriately. Accordingly, the weight of all the green compacts to be molded can be surely made highly accurate, and furthermore, production stoppage based on an inappropriate setting of the filling amount can be avoided, thereby realizing high-efficiency production. be able to.
[0031]
  Further, the setting of the depth A of the molding hole 35 is not performed when the average value of the weight of the green compact is within the predetermined range B, but is set when it is outside the predetermined range B. The weight of the powder can be surely made highly accurate, and the green compact can be formed by stabilizing this weight within the predetermined range B and in the vicinity thereof. That is, the direction in which the weight fluctuates in the next molding coincides with the direction in which the setting value of the depth A of the molding hole 35 changes, and the weight of the green compact to be molded greatly fluctuates. Inappropriate control can be avoided.
[0032]
  Further, since the setting of the depth A of the forming hole 35 is performed by moving the lower punch 33 up and down relatively with respect to the die 32, this setting can be performed easily and with high accuracy. Therefore, since the amount of the powder material filled in the molding hole 35 can be made highly accurate, the weight of the green compact to be molded can be reliably made highly accurate.
  Furthermore, in the present embodiment, since the average weight takes into consideration the weight of the green compact formed immediately before, more appropriate depth setting can be performed.
[0033]
  The present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention. exampleNaruAlthough the depth A of the shaping hole 35 is set by moving the lower punch 33 up and down, the die 32 may be moved up and down, and both the die 32 and the lower punch 33 may be moved deep. The height A may be moved up and down so as to be a predetermined depth. Furthermore, in this embodiment, after molding four green compacts, the average weight of these was calculated, but the number at this time may be changed as appropriate.Yes.
[0034]
【The invention's effect】
  As is clear from the above description, according to the invention of claim 1,Including the green compact molded just beforeCalculate the average weight of multiple green compacts molded up to a predetermined number of times beforePre-set reference weight valueWhen it was out of the prescribed rangeOnly change the depth of the forming hole based on the difference between the average weight and the weight valueTherefore, even when a sudden change in manufacturing conditions occurs and the weight of the formed green compact also changes, the filling amount can be set appropriately. Therefore, the weight of all green compacts to be molded can be made highly accurate, and furthermore, the production stoppage based on the inappropriate setting of the filling amount can be surely avoided, thereby realizing high-efficiency production. it can.
[0035]
  Moreover, since improper control that greatly changes the weight of the green compact to be molded is avoided, the weight of the green compact to be molded can be surely made highly accurate. Can be compacted within the predetermined range and in the vicinity thereof.The
[0036]
  Claim2According to the invention according toThe depth of the molding hole is changed based on the difference value between the average weight and the weight value.At that time, since the lower punch or die is moved up and down, the amount of the powder material filled in the molding hole can be easily made highly accurate, and the weight of the green compact to be molded is surely made highly accurate. Can do.
[0037]
  Claim3According to the invention according to the above, even when the weight of the green compact to be molded largely fluctuates due to a sudden change in manufacturing conditions, an appropriate filling amount of the powder material can be calculated. Accordingly, an appropriate amount of powder material is filled in the molding hole, and a green compact with a high weight can be reliably formed. Therefore, the production stoppage based on an inappropriate setting of the filling amount is also possible. It can be avoided reliably.
[0038]
  Moreover, since the green compact with high weight can be reliably molded, it is possible to reliably avoid the production stoppage based on the inappropriate setting of the filling amount.
  Claim4According to the invention, since the depth of the molding hole can be changed easily and with high accuracy, the amount of the powder material filled in the molding hole can be made with high accuracy and the molding can be removed. The weight of the green compact can be reliably increased.
[0039]
  Claim5According to the invention according to the above, every time the green compact is molded,Including the green compact molded just beforeAn average weight calculating step of calculating an average weight of a certain number of green compacts molded a certain number of times before the molding, and the filling amount setting step includes:Calculate the amount of change in the depth of the forming hole based on the difference between the average weight and the weight valueTherefore, it is possible to reliably mold the green compact whose weight is high.
  And an average weight determining step for determining whether the average weight is outside a predetermined range, wherein the filling amount setting step is performed only when the average weight is outside the predetermined range.Calculate amount of change in forming hole depthTherefore, the weight of the green compact to be molded can be surely made highly accurate, and the green compact can be molded by stabilizing this weight within the predetermined range and in the vicinity thereof.
[0040]
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing a main part of a powder molding apparatus according to an embodiment of the present invention.
FIG. 2 is a schematic diagram showing a main part of a control unit shown in FIG.
FIG. 3 is a flowchart showing an outline of a powder molding method according to an embodiment of the present invention.
FIG. 4 is an explanatory diagram for explaining a method of calculating an average weight of a green compact used when determining the amount of change in the depth of a forming hole.
FIG. 5 is a view showing the weight of a green compact formed by a powder forming method and a powder forming apparatus according to an embodiment of the present invention.
FIG. 6 shows a powder molding method according to an embodiment of the present invention, in which a green compact is formed when the depth of the molding hole is set regardless of whether or not the average weight of the green compact is out of a predetermined range. It is a figure which shows weight data (a) and the weight data (b) of the green compact in case the depth setting of the shaping | molding hole is not performed at all.
[Explanation of symbols]
  DESCRIPTION OF SYMBOLS 10 Powder shaping | molding apparatus 21 Upper punch 32 Die 32a 2nd hole (hole) 33 Lower punch 35 Hole for shaping | molding 40 Weight measuring means 51a 1st calculating part 51b 2nd calculating part 51c Judgment part 53 Memory | storage part A Molding hole Depth B Predetermined range

Claims

A filling step of filling the molding hole with a powder material for sintering, a green compact molding step of molding the green compact by compressing the powder material filled in the molding hole, and molding the green compact A powder molding method comprising a weight measuring step for measuring the weight of the green compact each time,
Each shaping the green compact, the pressure in advance, a certain quantity molded into up to a certain number of times before the molding comprise the powder compact molded immediately before upon filling the powder material into the molding hole The average weight of the powder is calculated by the first calculation unit , and only when the average weight is out of the predetermined range with respect to a preset reference weight value, the average weight and the weight value are A difference value is calculated, and based on the difference value, the weight of the green compact to be molded is set in advance by elements including at least the material of the powder material and the cross-sectional area of the molding hole. Further, the depth of the forming hole is changed by obtaining the amount of change in the depth of the forming hole by the second calculation unit using a correlation function between the change amount of the depth of the forming hole and the difference value. A powder molding method characterized by:

The powder molding method according to claim 1 ,
The forming hole is a space formed by the inner wall surface of the hole provided in the die and the upper surface of the lower punch provided slidably relative to the hole, and the depth of the forming hole is changed. Is a powder molding method , wherein the lower punch or the die is moved up and down.

A die having a molding hole filled with a powder material for sintering, an upper punch and a lower punch for compressing the powder material in the molding hole to form a green compact, and molding the green compact A powder molding apparatus comprising a conveying means that takes out and conveys from a hole, and a weight measuring means that measures the weight of the green compact conveyed by the conveying means, each time the green compact is molded, wherein the powder material previously upon filling the molding hole, to calculate the average weight of contain the powder compact molded immediately before the green compact constant quantity molded into up to a certain number of times before the molding, the A control unit that sets the filling amount of the powder material based on a difference value between the average weight and the weight value only when the average weight is outside a predetermined range with respect to a weight value serving as a preset reference. The control unit is measured by the weight measuring means A storage unit for storing the serial weight, of the weight which is the storage, the calculating the average weight of the powder compact of certain quantities molded into up to a certain number of times before contain the powder compact molded immediately before A calculation unit, a determination unit that determines whether the average weight is outside a predetermined range with respect to the weight value, a difference value between the average weight and the weight value is calculated, and the difference value is Based on the depth of the molding hole preset by an element including at least the material of the powder material and the cross-sectional area of the molding hole so that the weight of the green compact to be molded becomes the weight value. A powder molding apparatus, comprising: a second calculation unit that calculates a change amount of the depth of the forming hole by a correlation function between the change amount and the difference value .

4. The powder molding apparatus according to claim 3 , wherein the molding hole is formed by an inner wall surface of a hole provided in the die surface and an upper surface of a lower punch provided slidably relative to the hole. A powder molding apparatus characterized in that it is a space, and the depth of the molding hole is changed by moving the lower punch or the die up and down.

A green compact molding step of molding a green compact of powder material for sintering filled in the molding hole by compression, gravimetric weighing the piezoelectric powder in each shaping the green compact And a filling amount setting step for setting a filling amount of the powder material on the basis of the measured weight, each time the compact is molded , the molding formed immediately before and average weight calculation step of calculating an average weight of the powder compact of certain quantities molded into up to a certain number of times before the molding comprise powder compact relative to the weight value the average weight is a predetermined reference An average weight determining step for determining whether the weight is outside the predetermined range, and the filling amount setting step includes the average weight and the weight value only when the average weight is outside the predetermined range. The difference value is calculated based on the difference value. In this case, the depth of the molding hole is preset by an element including at least the material of the powder material and the cross-sectional area of the molding hole so that the weight of the green compact to be molded becomes the weight value. A powder forming program characterized in that a change amount of a depth of the forming hole is calculated from a correlation function between the change amount and the difference value .