JP3571797B2

JP3571797B2 - Quantitative filling device

Info

Publication number: JP3571797B2
Application number: JP12130295A
Authority: JP
Inventors: 勝三川西
Original assignee: Yamato Scale Co Ltd
Current assignee: Yamato Scale Co Ltd
Priority date: 1995-05-19
Filing date: 1995-05-19
Publication date: 2004-09-29
Anticipated expiration: 2019-09-29
Also published as: JPH08313327A

Description

【０００１】
【産業上の利用分野】
本発明は、大投入された被計量物の不足重量を容量の異なる複数の加算投入貯槽を組み合わせて補うことによって重量調節を行う定量充填装置に関し、より詳細には、この組み合わせの変化によって段階的に変化する加算用の被計量物の投入重量差のズレを補正するための加算補助槽を設けた定量充填装置に関する。
【０００２】
【従来の技術】
粉粒体の定量充填は古くから行われており、その中で、升はかり、即ち容積計量は以前から広く採用されている。その後、計量の正確さが要求されるようになるに伴い、容積計量は重量による計量に変わってきた。しかし、重量計量は比較的速い速度で所謂大投入を行い、その後、低速の微量投入により目標重量まで充填を行うため、充填速度を大きくすることができないという問題点がある。
【０００３】
この問題点を解決するために、充填速度の向上を図った定量充填装置が例えば特開昭６２−９２２６号公報等に開示されている。このタイプの定量充填装置では、目標重量より小さく且つ目標重量に近い重量の被計量物が大投入用の貯槽に投入されるとともに、目標重量に満たない不足分を補うための、同じ容量を有する複数の補助槽が設けられる。そして、この装置では、各補助槽に貯溜される被計量物の重量にバラツキが生ずるのを利用して定量充填が行われる。即ち、この装置では、目標重量から大投入貯槽内の被計量物の重量を差し引いた不足重量が求められ、この不足重量に最も近い補助槽の組合せが選択される。このような同じ容量の複数の補助槽を設けることにより、目標重量に近い重量の被計量物の充填が可能となっている。また、この定量充填装置では投入しながらの計量が行われないため、充填速度を大きくすることが可能となっている。
【０００４】
【発明が解決しようとする課題】
しかしながら、上記公報に記載のタイプの定量充填装置では、大投入用の貯槽内に投入される被計量物の重量のバラツキが大きい場合、全ての補助槽を選択しても不足重量を補うことができない場合が生じる。本発明者はこの問題点を解決した定量充填装置として、図５に示すものを既に開示している（特願平７−８１０３４号）。同図に示す装置は、目標重量の被計量物を箱、袋等の所定の容器に充填するために使用されるものであり、ロードセル７を備えた大投入貯槽１と、容量比が１：２：４：８：１６の５つの加算貯槽４ａ〜ｅとを有している。大投入貯槽１と５つの加算貯槽４ａ〜ｅには投入装置１１から被計量物が投入される。また、５つの加算貯槽４ａ〜ｅにはそれぞれロードセル２ａ〜ｅが設けられており、加算投入用の被計量物の重量が計量される。大投入貯槽１及び加算貯槽４ａ〜ｅ内の被計量物は、シュート９を通じて箱、袋等の容器１０に排出される。
【０００５】
この装置では、大投入貯槽１に投入された被計量物の全重量が大投入重量Ｗ_ａとしてロードセル７により計量され、それと同時に、各加算貯槽４ａ〜ｅに投入された被計量物の重量がそれぞれロードセル２ａ〜ｅにより計量される。そして、不足重量Ｗ_ｄ＝Ｗ_ａ−Ｗ_ｏが最もゼロに近くなるように加算貯槽の組合せが選択され、選択された加算貯槽内の被計量物が大投入貯槽１内の被計量物とともに排出され、容器１０に充填される。この装置では、加算貯槽４ａ〜ｅの容量比が１：２：４：８：１６となっているので、加算貯槽４ａ〜ｅの組合せにより、最小の加算貯槽４ａに貯溜されている被計量物の重量の１から３１倍までの３１段階の加算用の被計量物を、容量比１の投入重量差で準備したことになる。即ち、容量比１の間隔で加算投入を行うことができる。従って、この装置によれば被計量物の重量を広い範囲で調節でき、しかも重量の微調節が可能となっている。
【０００６】
図５の装置では、被計量物のかさ密度が変化する場合、その変化が全ての加算貯槽４ａ〜ｅ内で同じ方向であれば、加算貯槽４ａ〜ｅの組合せにより準備できる加算用の被計量物の投入重量差は等しくなるので、不足重量Ｗ_ｄがどのような値でも、容量比１から３１段階の範囲ならば加算投入により補正することができる。しかし、かさ密度の変化の方向が各加算貯槽４ａ〜ｅで異なる場合、以下のような問題が生じる。例えば、容量比１：２：４：８の加算貯槽４ａ〜ｄ内の被計量物のかさ密度が２０％増加し、容量比１６の加算貯槽４ｅ内の被計量物のかさ密度が２０％減少した場合を考える。簡単のために被計量物のかさ密度を１とすると、この場合、加算貯槽４ａ〜ｄの組合せ（合計の容量比１５）によって準備される加算用の被計量物の重量は１．２×１５＝１８．０となり、一方、この組合せより容量比が１だけ大きい加算貯槽４ｅ（容量比１６）によって準備される加算用の被計量物の重量は０．８×１６＝１２．８となる。この値１２．８は他の加算貯槽４ａ〜ｄの組合せによって補うことができるので、加算貯槽４ｅを設けた意義が失われてしまう。
【０００７】
また逆に、加算貯槽４ａ〜ｄ内の被計量物のかさ密度が２０％減少し、加算貯槽４ｅ内の被計量物のかさ密度が２０％増加した場合を考えると、この場合の加算貯槽４ａ〜ｄの組合せ（合計の容量比１５）によって準備される加算用の被計量物の重量は０．８×１５＝１２．０となり、一方、この組合せより容量比が１だけ大きい加算貯槽４ｅ（容量比１６）によって準備される加算用の被計量物の重量は１．２×１６＝１９．２となる。この場合、準備される加算用の被計量物の重量は、図６に示すように、１１．２，１２．０，１９．２，２０．０となり、容量比１５から１６の間に１９．２−１２．０＝７．２という非常に大きな投入重量差が生じ、この間では被計量物の重量の微調節ができないこととなる。
【０００８】
本発明はこのような従来技術の問題点を解決するために為されたものであり、本発明の目的は、被計量物のかさ比重が変化した場合にも、被計量物の微調整が広範囲で可能な定量充填装置を提供することである。
【０００９】
【課題を解決するための手段】
本発明の定量充填装置は、目標重量より小さく且つ該目標重量に近い重量の被計量物を貯溜し計量手段を有する大投入貯槽と、それぞれ計量手段を有し、前記目標重量から前記大投入貯槽内の被計量物の重量を差し引いた不足重量を補充する加算投入用の被計量物を貯溜する少なくとも２種類の異なる容量からなる複数の加算貯槽と、前記加算貯槽の組合せを選択して前記加算投入用の被計量物を所定の投入重量差をもって段階的に変化させる制御装置と、該制御装置によって前記加算貯槽の組合せを選択するに際し、前記組合せの変化によって段階的に変化する加算投入用の被計量物のかさ密度のバラツキによって生ずる前記投入重量差のズレを補正するための、計量手段を有する一又は複数の加算補助槽とを備えたことを特徴とする。
【００１０】
また、本発明の定量充填装置は、上記構成に於いて、前記加算貯槽が、下記の容量
【００１１】
【数４】

【００１２】
をそれぞれ有するｍ個の加算貯槽を少なくとも包含している構成とすることができる。
【００１３】
更に、本発明の定量充填装置は、前記加算補助槽が、下記の容量
【００１４】
【数５】

【００１５】
をそれぞれ有するｐ個の加算補助槽を少なくとも包含している構成とすることができる。
【００１６】
また、本発明の定量充填装置は、前記正の実数ｒ及びｓが等しい構成とすることができる。
【００１７】
また、本発明の定量充填装置は、前記正の実数ｒ及びｓが共に２である構成とすることができる。
【００１８】
更に、本発明の定量充填装置は、前記加算貯槽内の被計量物のかさ密度の最大のバラツキ率をα、前記ｍ個の加算貯槽のうち最大のものの容積をＶ_ｍａｘ、ｐ個の前記加算補助槽の合計の容量をＡとした場合、前記加算補助槽の数ｐが、下記の式
【００１９】
【数６】

【００２０】
を満たす整数である構成とすることができる。
【００２１】
更に、本発明の定量充填装置は、前記大投入貯槽が、それぞれ計量手段を有する主投入貯槽と減算補助槽とを備え、該減算補助槽は被計量物を排出せずに保持することにより、前記投入重量差を減少させる補正を行う構成を付加することができる。
【００２２】
また、本発明の定量充填装置は、前記加算補助槽が単一槽であり、前記加算補助槽及び前記減算補助槽は、前記加算貯槽のうち最大のものの容積をＶ_ｍａｘとした場合、２αｄＶ_ｍａｘ−ａｄ〜２αｄＶ_ｍａｘ＋ａｄの間の重量の被計量物を貯溜し得る容量を有している構成を付加することができる。
【００２３】
【作用】
本発明の定量充填装置は、被計量物の大まかな投入、即ち大投入を行う大投入貯槽と、この大投入によっては目標重量に達しない不足重量を補うための少なくとも２種類の異なる容量からなる複数の加算貯槽とが設けられている。大投入貯槽と各加算貯槽には、それぞれ計量手段が設けられている。制御装置は各計量手段から得られる各加算貯槽内の被計量物の重量に基づいて、上述の不足重量に最も近くなる加算貯槽の組合せを選択する。
【００２４】
このように選択される加算貯槽の組合せを変えることにより、加算投入用の被計量物は所定の投入重量差をもって段階的に変化する。しかし、被計量物のかさ密度のバラツキが生じ、加算貯槽ごとにかさ密度が異なる場合、加算貯槽の組合せを変化させることによる被計量物の投入重量差に部分的なズレが生じる場合がある。本発明の装置では、この投入重量差のズレを補正するための一又は複数の加算補助槽が設けられている。即ち、選択された加算貯槽の組合せによれば投入重量差が大きくなる場合、選択された加算貯槽から供給されるべき被計量物の一部を、加算補助槽から供給される被計量物によって肩代わりすることによって不足重量が補正される。加算補助槽の数及び容量は、被計量物のかさ密度のバラツキ率を考慮して定められる。
【００２５】
本発明の装置では、加算貯槽は下記の式で表される容量を有する少なくともｍ個の加算貯槽を包含する構成とすることができる。
【００２６】
【数７】

【００２７】
この加算貯槽の構成によって、加算貯槽の組合せを変化させることにより不足重量をほぼ等間隔で補うことができ、加算用の被計量物の投入重量差のズレを補正する加算補助槽の容量を小さくすることができる。
【００２８】
また、本発明の装置では、加算補助槽は下記の式で表される容量を有する少なくともｐ個の加算補助槽を包含する構成とすることができる。
【００２９】
【数８】

【００３０】
この補助槽の構成により、被計量物のかさ密度のバラツキによって生じる投入重量差のズレをほぼ等間隔で補うことができる。
【００３１】
また、上記構成に於いて正の実数ｒと正の実数ｓとを等しくすることにより、更に、正の実数ｒと正の実数ｓを共に２とすることにより、比較的簡単な構成で同様の効果を得ることができる。
【００３２】
正の実数ｒとｓとを共に２とした構成の装置に於いては、加算補助槽の数ｐ及びその容量を以下のようにして定めることができる。まず、加算貯槽内の被計量物のかさ比重の基準値をｄ、被計量物のかさ密度の最大のバラツキ率をαとすると、加算投入用の被計量物に生じる最大の投入重量差Ｗ_ｍａｘは、最大の容量を有する加算貯槽に最大のかさ密度の被計量物が投入され、かつ、この最大の加算貯槽以外の加算貯槽に最小のかさ密度の被計量物が投入された場合に生じる。即ち、最大の投入重量差Ｗ_ｍａｘは、
【００３３】
【数９】

【００３４】
ここで、（２^ｍ−１−１）≒２^ｍ−１とし、上記のｍ個の加算貯槽のうち最大のものの容積をＶ_ｍａｘすると、上式は、
【００３５】
【数１０】

【００３６】
となる。即ち、生じ得る最大の投入重量差Ｗ_ｍａｘは、最大の加算貯槽に基準値ｄのかさ密度の被計量物が投入された場合の２倍の重量に相当している。この最大投入重量差Ｗ_ｍａｘよりも、加算補助槽内の合計の被計量物の重量が大きければ、加算補助槽の組合せの選択によって投入重量差Ｗ_ｍａｘの間を補うことができることとなる。即ち、ｐ個の前記加算補助槽の合計の容量をＡとした場合、以下の関係が成立すればよいことになる。
【００３７】
【数１１】

【００３８】
従って、下記の式が成立すればよいことになる。
【００３９】
【数１２】

【００４０】
本発明の他の構成では、大投入貯槽を主投入貯槽と減算補助槽とによって構成することができる。この構成の装置では、減算補助槽は被計量物を排出せずに保持することにより、最大投入重量差Ｗ_ｍａｘを減少させる補正を行うことができる。
【００４１】
更に、上記構成の装置では、減算補助槽の容量を２αｄＶ_ｍａｘ−ａｄ〜２αｄＶ_ｍａｘ＋ａｄの範囲の重量の被計量物を貯溜し得るように構成することができる。この構成により、最大投入重量差Ｗ_ｍａｘをほぼ相殺する補正を行うことができる。
【００４２】
【実施例】
本発明の実施例について、図面を参照しながらより詳細に説明する。
【００４３】
図１は本発明の第一の実施例に係る定量充填装置の概略構成を示している。本実施例の定量充填装置は、目標重量Ｗ_ｏの被計量物を箱、袋等の所定の容器に充填するために使用されるものであり、大投入用の被計量物を貯溜する大投入貯槽１と、加算投入用の５つの加算貯槽４ａ，４ｂ，４ｃ，４ｄ及び４ｅと、投入重量差を補正する３つの加算補助槽１４ａ，１４ｂ及び１４ｃとを有している。大投入貯槽１と加算貯槽４ａ〜ｅと加算補助槽１４ａ〜ｃには、投入装置１１から被計量物が、例えば擦り切りによりほぼ同時に投入される。大投入貯槽１にはロードセル７が設けられており、大投入貯槽１に投入される大投入用の被計量物の重量は、このロードセル７により計量される。５つの加算貯槽４ａ〜ｅにもそれぞれロードセル２ａ，２ｂ，２ｃ，２ｄ及び２ｅが設けられており、加算投入用の被計量物のそれぞれの重量が計量される。更に、本実施例の装置では、加算補助槽１４ａ〜ｃにもそれぞれロードセル１２ａ，１２ｂ及び１２ｃが設けられている。ロードセル７、ロードセル２ａ〜ｅ及びロードセル１２ａ〜ｃからの出力は、制御装置（図示せず）に入力される。
【００４４】
大投入貯槽１の底部には被計量物を排出するためのゲート８が設けられており、また、加算貯槽４ａ〜ｅ及び加算補助槽１４ａ〜ｃにもそれぞれ独立に開閉するゲート６及びゲート１６が設けられている。大投入貯槽１、加算貯槽４ａ〜ｅ及び加算補助槽１４ａ〜ｃ内の被計量物は、シュート９を通じて箱、袋等の容器１０に排出される。上述のゲート８、ゲート６及びゲート１６の開閉は、前述の図示しない制御装置の制御の下に行われる。
【００４５】
本実施例では、加算貯槽４ａ〜ｅの容量比は、ｓ^ｋ−１（ｓは正の実数、ｋ≦ｍ、ｍ＝加算貯槽の数）の式に於いて、ｓ＝２及びｍ＝５とした比、即ち、１：２：４：８：１６に設定されている。従って、本実施例では加算投入用の被計量物は、基準となる加算貯槽を最小の加算貯槽４ａとし、その容量をａとすると、１ａから２^５−１＝３１ａまでの加算投入用の被計量物を準備したことになり、加算投入用の被計量物の投入重量差は、被計量物のかさ密度が基準値（平均値）ｄをとるとすると、ａｄとなる。即ち、かさ密度が基準値ｄの場合、加算投入用の被計量物をａｄづつ変化させることができることになる。
【００４６】
一方、加算補助槽１４ａ〜ｃの容量比は、ｒ^ｋ−１（ｒは正の実数、０＜ｋ（整数）≦ｐ）の式に於いて、適当な正の実数ｒを用いることにより設定することができ、この容量比に応じて加算補助槽の数ｐを定めることができる。本実施例ではｒは前述のｓと同じ値、即ちｒ＝２に設定され、基準となる加算補助貯槽を最小の加算補助槽１４ａとし、その容量ｂを最小の加算貯槽４ａの容量ａと同じに設定されている。この場合、全加算補助槽内の被計量物の重量は、以下のように表される。
【００４７】
【数１３】

【００４８】
この値が、被計量物のかさ密度の最大のバラツキ率α＝０．２、上記ｍ＝５及び上記ｓ＝２を２ｄＶ_ｍａｘ＝２αｄａｓ^ｍ−１に代入した０．４×１６ａｄ＝６．４ａｄより大きくなるように、加算補助槽の数ｐの値が決定される。即ち、本実施例では加算補助槽の数ｐ＝３（７ａｄ）となる。また、３つの加算補助槽１４ａ〜ｃの各容量は、ｒ^ｋ−１に於いてｒ＝２、ｋ＝１，２，３とした値の比に従い、ａｄ，２ａｄ，４ａｄとなる。
【００４９】
本実施例では加算貯槽４ａ〜ｅのうちの小さいものから３つ、即ち加算貯槽４ａ〜ｃと同じ容量の加算補助槽１４ａ〜ｃを設けたことにより、本実施例の構成で生じ得る最大投入重量差Ｗ_ｍａｘ６．４ａｄを、加算貯槽４ａ〜ｃと同じ投入重量差で補正することができる。
【００５０】
図２に本実施例の第二の実施例に係る定量充填装置の概略構成図を示す。本実施例の装置は、前述の図１の装置と以下の点で異なっている。即ち、図２の装置では、加算補助槽１４ａ〜ｃに代えてロードセル１２を備えた単一の加算補助槽１４が設けられるとともに、大投入貯槽１がゲート８ａを備えた主投入貯槽１ａとゲート８ｂを備えた減算補助槽１ｂとによって構成されている。大投入用の被計量物は主投入貯槽１ａと減算補助槽１ｂとに分割して投入され、それぞれロードセル７ａ及び７ｂによって重量が計量される。図２の他の構成部分は図１と同様であり、対応する部分には同じ符号が付してある。
【００５１】
加算補助槽１４及び減算補助槽１ｂの容量は、被計量物のかさ密度の最大のバラツキ率α＝０．２、ｍ＝５及びｓ＝２を２ｄＶ_ｍａｘ＝２αａｓ^ｍ−１に代入した６．４ａを中心とした±ａの範囲に設定される。本実施例では加算補助槽１４及び減算補助槽１ｂの容量を６．４ａとした。
【００５２】
加算補助槽１４及び減算補助槽１ｂの機能を図３及び図４に従って説明する。
【００５３】
図３では、加算貯槽４ａ〜ｄに最も大きいかさ密度α＝１．２の被計量物が投入され、加算貯槽４ｅに最も小さいかさ密度α＝０．８の被計量物が投入された場合が示されている。図３（ａ）は加算貯槽の組合せを変えて加算投入用の被計量物を最小単位容量づつ増加させる場合を示しており、Ａ１では加算貯槽４ｂ〜ｄが選択されて（２＋４＋８）×１．２＝１６．８ａｄ（容量比１４）の加算投入用の被計量物が準備されている。なお、図３及び図４では簡単のためにａｄを省略してある。次に、Ａ２では最小単位の容積を有する加算貯槽４ａが加えられ、加算貯槽４ａ〜ｄの合計の被計量物の重量１８．０ａｄ（容量比１５）が加算投入用の被計量物となる。続いて、更に加算貯槽用の被計量物を容量比１６に増加させる場合、通常では加算貯槽４ｅのみが選択されるが、上述のようにこの加算貯槽４ｅには最小のかさ密度α＝０．８の被計量物が投入されているので、Ａ３に示すように１６×０．８＝１２．８ａｄとなり、加算用の被計量物の重量は大きく減少してしまう。そこで、本実施例では、図３（ｂ）のＢ１に示すように、加算補助槽４の被計量物をも加えることにより、１２．８＋６．４＝１９．２ａｄとなり、加算用の被計量物の投入重量差のズレは補正される。
【００５４】
また、図４では、加算貯槽４ａ〜ｄに最も小さいかさ密度α＝０．８の被計量物が投入され、加算貯槽４ｅに最も大きいかさ密度α＝１．２の被計量物が投入された場合が示されている。図４（ａ）は加算貯槽の組合せを変えて加算用の被計量物を最小単位容量づつ増加させる場合を示しており、Ｃ１では加算貯槽４ｂ〜ｄが選択されて（２＋４＋８）×０．８＝１１．２ａｄ（容量比１４）の加算用の被計量物が準備されている。次に、Ｃ２では最小単位の容積を有する加算貯槽４ａが加えられ、加算貯槽４ａ〜ｄの合計の被計量物の重量１２．０ａｄ（容量比１５）が加算用の被計量物となる。続いて、更に加算貯槽用の被計量物を容量比１６に増加させる場合、通常では加算貯槽４ｅが選択されるが、上述のようにこの加算貯槽４ｅには最大のかさ密度α＝１．２の被計量物が投入されているので、Ｃ３に示すように１６×１．２＝１９．２ａｄとなり、加算用の被計量物の重量は大きく増加してしまう。そこで、本実施例では、図４（ｂ）のＤ１に示すように、減算補助槽１ｂの被計量物を排出しないこととすると、１９．２−６．４＝１２．８ａｄとなり、加算用の被計量物の投入重量差のズレは補正される。
【００５５】
上記各実施例では、容量比が１：２：４：８：１６の加算貯槽を５つ設けた場合について説明したが、本発明はこれに限定されるものではなく、少なくとも２種類の異なる容量からなる複数の加算貯槽を有する装置に適用することができ、また、加算補助槽の数も任意とすることができる。
【００５６】
また、上記各実施例では正の実数ｓ及びｒを２とした場合について説明したがこれに限定されるものではなく、これ以外の整数でも、また、小数であってもよい。更に、正の実数ｓとｒ、及びｂとａは互いに異なっていてもよく、この場合には、加算貯槽のみにより得られる投入重量差と加算補助槽を加えて得られる投入重量差とは異なるものとなる。
【００５７】
【発明の効果】
本発明の定量充填装置では、加算貯槽に投入される被計量物のかさ比重が変化した場合に生じる投入重量差のズレは、その程度に応じた数及び容量の加算補助槽を設けることにより補正される。従って、本発明によれば、被計量物のかさ比重が変化した場合にも、被計量物の微調整が広範囲で可能となっている。
【００５８】
また、減算補助槽を設けた本発明の構成では、減算補助槽内の被計量物を排出せずに保持しておくことにより、最大投入重量差Ｗ_ｍａｘを減少させる補正を行うことができ、このことによっても広範囲の重量調節が可能となっている。
【図面の簡単な説明】
【図１】本発明の第一の実施例に係る定量充填装置の概略構成図である。
【図２】本発明の第二の実施例に係る定量充填装置の概略構成図である。
【図３】加算補助槽の機能説明図である。
【図４】減算補助槽の機能説明図である。
【図５】加算貯槽を備えた定量充填装置の概略構成図である。
【図６】被計量物のかさ比重の変化により加算投入される被計量物の投入重量差がずれる様子を示す図である。
【符号の説明】
１…大投入貯槽
１ａ…主投入貯槽
１ｂ…減算補助槽
２ａ，２ｂ，２ｃ，２ｄ，２ｅ…ロードセル
４，４ａ，４ｂ，４ｃ，４ｄ…加算貯槽
６，８，８ａ，８ｂ，１６…ゲート
７，７ａ，７ｂ…ロードセル
９…シュート
１０…容器
１１…投入装置
１２ａ，１２ｂ，１２ｃ…ロードセル
１４ａ，１４ｂ，１４ｃ…加算補助槽[0001]
[Industrial applications]
The present invention relates to a fixed-quantity filling apparatus that performs weight adjustment by compensating for the insufficient weight of a large input object to be measured by combining a plurality of additional input storage tanks having different capacities. The present invention relates to a fixed-quantity filling device provided with an addition auxiliary tank for correcting a deviation of a difference in the input weight of an object to be weighed, which changes to a value.
[0002]
[Prior art]
Quantitative filling of powders and granules has been performed for a long time, in which weighing, that is, volumetric measurement, has been widely adopted for a long time. Later, as weighing accuracy became required, volumetric weighing was replaced by weighing. However, there is a problem that the filling speed cannot be increased because the so-called large dosing is performed at a relatively high speed, and then the filling is performed up to the target weight by a small amount of low-speed dosing.
[0003]
In order to solve this problem, a quantitative filling apparatus for improving the filling speed is disclosed in, for example, JP-A-62-2226. In this type of fixed-quantity filling apparatus, an object to be weighed having a weight smaller than the target weight and close to the target weight is charged into the large-capacity storage tank, and has the same capacity to compensate for a shortage less than the target weight. A plurality of auxiliary tanks are provided. In this apparatus, the fixed amount is filled by utilizing the fact that the weight of the objects stored in each auxiliary tank varies. That is, in this apparatus, the underweight obtained by subtracting the weight of the object to be weighed in the large input storage tank from the target weight is obtained, and the combination of the auxiliary tanks closest to the insufficient weight is selected. By providing such a plurality of auxiliary tanks having the same capacity, it is possible to fill an object to be weighed having a weight close to the target weight. In addition, since the metering is not performed while the fixed filling device is charged, the filling speed can be increased.
[0004]
[Problems to be solved by the invention]
However, in the fixed-quantity filling device of the type described in the above publication, when the weight of the objects to be weighed to be charged into the large storage tank has a large variation, it is possible to compensate for the insufficient weight even if all the auxiliary tanks are selected. In some cases, it is not possible. The inventor of the present invention has already disclosed a fixed-quantity filling apparatus as shown in FIG. 5 which has solved this problem (Japanese Patent Application No. 7-81034). The apparatus shown in FIG. 1 is used for filling a target container having a target weight into a predetermined container such as a box or a bag, and has a large input storage tank 1 having a load cell 7 and a capacity ratio of 1: It has five addition storage tanks 4a to 4e of 2: 4: 8: 16. An object to be weighed is charged from the charging device 11 into the large charging storage tank 1 and the five additional storage tanks 4a to 4e. Also, load cells 2a to e are provided in the five addition storage tanks 4a to 4e, respectively, and the weights of objects to be added and weighed are weighed. The objects to be weighed in the large input storage tank 1 and the addition storage tanks 4a to 4e are discharged through a chute 9 into a container 10 such as a box or a bag.
[0005]
In this apparatus, the total weight of the objects to be weighed which have been put into the large input reservoirs 1 are weighed by the load cell 7 as full flow weight W _a, at the same time, the weight of the objects to be weighed which are put into the addition reservoir 4a~e Each is measured by the load cells 2a to 2e. The lack of weight W _{d =} W _a -W _o combinations of nearby so as summed reservoir most zero is selected, along with the objects to be weighed inside the objects to be weighed full flow tank 1 in the addition tank selected discharge And filled into the container 10. In this apparatus, since the capacity ratio of the addition storage tanks 4a to 4e is 1: 2: 4: 8: 16, the objects to be weighed stored in the smallest addition storage tank 4a are determined by the combination of the addition storage tanks 4a to 4e. That is, the object to be weighed for addition in 31 stages from 1 to 31 times the weight of the sample is prepared with the input weight difference of the volume ratio of 1. That is, the addition can be performed at intervals of the capacity ratio of 1. Therefore, according to this device, the weight of the object to be weighed can be adjusted in a wide range, and the weight can be finely adjusted.
[0006]
In the apparatus shown in FIG. 5, when the bulk density of the object to be measured changes, if the change is in the same direction in all of the addition storage tanks 4a to e, the addition measurement to be prepared can be prepared by a combination of the addition storage tanks 4a to e. since things turned weight difference is equal to, any value insufficient weight W _d can, can be corrected by adding charged if the range of the volume ratio 1 of 31 stages. However, when the direction of the change in the bulk density differs in each of the addition storage tanks 4a to 4e, the following problem occurs. For example, the bulk density of the objects to be weighed in the additional storage tanks 4a to 4d having a capacity ratio of 1: 2: 4: 8 increases by 20%, and the bulk density of the objects to be weighed in the additional storage tank 4e having a capacity ratio of 16 decreases by 20%. Consider the case. Assuming that the bulk density of the object to be weighed is 1 for simplicity, in this case, the weight of the object to be weighed prepared by the combination of the addition storage tanks 4a to 4d (total capacity ratio 15) is 1.2 × 15. = 18.0, while the weight of the object to be weighed prepared by the addition storage tank 4e (capacity ratio 16) whose capacity ratio is larger by 1 than this combination is 0.8 × 16 = 12.8. Since this value 12.8 can be supplemented by a combination of the other additional storage tanks 4a to 4d, the significance of providing the additional storage tank 4e is lost.
[0007]
Conversely, considering the case where the bulk density of the objects in the addition storage tanks 4a to 4d decreases by 20% and the bulk density of the objects in the addition storage tank 4e increases by 20%, the addition storage tank 4a in this case is considered. Ｄd (total capacity ratio 15), the weight of the object to be weighed for addition is 0.8 × 15 = 12.0, while the addition storage tank 4e (1) having a capacity ratio larger by 1 than this combination. The weight of the object to be weighed prepared by the capacity ratio 16) is 1.2 × 16 = 19.2. In this case, the weight of the prepared object to be weighed is 11.2, 12.0, 19.2, and 20.0 as shown in FIG. An extremely large difference in input weight of 2-12.0 = 7.2 occurs, and during this time, the weight of the object to be weighed cannot be finely adjusted.
[0008]
The present invention has been made to solve such problems of the prior art, and an object of the present invention is to finely adjust an object to be weighed even when the bulk specific gravity of the object changes. It is to provide a fixed-quantity filling device which can be used in the above.
[0009]
[Means for Solving the Problems]
The fixed-quantity filling device according to the present invention has a large input storage tank that stores an object to be weighed that is smaller than a target weight and is close to the target weight and has a weighing unit, and each has a weighing unit. A combination of a plurality of additional storage tanks of at least two kinds of different capacities for storing additional objects to be weighed for addition to replenish the insufficient weight obtained by subtracting the weight of the objects to be weighed, and a combination of the additional storage tanks; A control device that changes the object to be weighed in a stepwise manner with a predetermined difference in the weight of the input, and a selection device for the addition charging that changes stepwise due to the change in the combination when the combination of the addition storage tanks is selected by the control device. One or a plurality of addition auxiliary tanks having a weighing means for correcting a deviation of the input weight difference caused by a variation in the bulk density of the objects to be weighed are provided.
[0010]
Further, in the quantitative filling device of the present invention, in the above configuration, the addition storage tank has the following capacity.
(Equation 4)

[0012]
May be configured to include at least m addition storage tanks each having
[0013]
Further, in the quantitative filling device of the present invention, the addition auxiliary tank has the following capacity.
(Equation 5)

[0015]
And at least p addition auxiliary tanks each having the following formula:
[0016]
Further, the quantitative filling device of the present invention can be configured such that the positive real numbers r and s are equal.
[0017]
Further, the quantitative filling device of the present invention may be configured such that the positive real numbers r and s are both 2.
[0018]
Further, the quantitative filling device of the present invention is characterized in that the maximum variation rate of the bulk density of the objects to be weighed in the additional storage tank is α, the volume of the largest one of the m additional storage tanks is V _max , and the p additional When the total capacity of the auxiliary tanks is A, the number p of the additional auxiliary tanks is expressed by the following formula:
(Equation 6)

[0020]
May be an integer that satisfies
[0021]
Further, the quantitative filling device of the present invention, the large input storage tank includes a main input storage tank and a subtraction auxiliary tank each having a measuring means, by holding the subtraction auxiliary tank without discharging the object to be measured, A configuration for performing a correction for reducing the input weight difference can be added.
[0022]
In addition, in the quantitative filling device of the present invention, when the addition auxiliary tank is a single tank, and the addition auxiliary tank and the subtraction auxiliary tank have a maximum volume of V _{max of the} addition storage tank, 2αdV _max It is possible to add a configuration having a capacity capable of storing an object to be weighed having a weight between −ad and 2αdV _max + ad.
[0023]
[Action]
The quantitative filling apparatus of the present invention comprises a large charging storage tank for roughly charging, that is, a large charging of an object to be weighed, and at least two different capacities for compensating for a shortage that does not reach the target weight by this large charging. A plurality of additional storage tanks are provided. Measuring means is provided in each of the large input storage tank and each addition storage tank. The control device selects a combination of the additional storage tanks that is closest to the above-described insufficient weight based on the weight of the object to be weighed in each additional storage tank obtained from each weighing unit.
[0024]
By changing the combination of the addition storage tanks selected in this way, the objects to be added for addition change stepwise with a predetermined difference in the input weight. However, when the bulk density of the objects to be weighed varies, and the bulk density differs for each additional storage tank, a difference in the input weight of the objects to be weighed due to changing the combination of the additional storage tanks may occur. In the apparatus of the present invention, one or a plurality of addition auxiliary tanks for correcting the deviation of the input weight difference are provided. That is, when the input weight difference is large according to the combination of the selected addition storage tanks, a part of the object to be supplied from the selected addition storage tank is replaced by the object to be supplied from the addition auxiliary tank. By doing so, the insufficient weight is corrected. The number and capacity of the addition auxiliary tanks are determined in consideration of the variation rate of the bulk density of the objects to be weighed.
[0025]
In the apparatus of the present invention, the addition storage tank may be configured to include at least m addition storage tanks having a capacity represented by the following formula.
[0026]
(Equation 7)

[0027]
Due to the configuration of the addition storage tank, the insufficient weight can be compensated for at approximately equal intervals by changing the combination of the addition storage tanks, and the capacity of the addition auxiliary tank for correcting the deviation of the input weight difference of the objects to be added for addition is reduced. can do.
[0028]
Further, in the apparatus of the present invention, the addition auxiliary tank may be configured to include at least p addition auxiliary tanks having a capacity represented by the following formula.
[0029]
(Equation 8)

[0030]
With the configuration of the auxiliary tank, it is possible to compensate for the difference in the input weight caused by the variation in the bulk density of the objects to be weighed at substantially equal intervals.
[0031]
In the above configuration, the positive real number r and the positive real number s are made equal to each other, and furthermore, both the positive real number r and the positive real number s are set to 2, thereby obtaining a similar simple configuration. The effect can be obtained.
[0032]
In an apparatus having a configuration in which both the positive real numbers r and s are set to 2, the number p and the capacity of the addition auxiliary tanks can be determined as follows. First, assuming that the reference value of the bulk specific gravity of the object to be weighed in the addition storage tank is d and the maximum variation rate of the bulk density of the object to be weighed is α, the maximum input weight difference W _max generated in the object to be added and added is W _max. Occurs when the object to be weighed having the maximum bulk density is charged into the addition storage tank having the maximum capacity, and the object to be weighed having the minimum bulk density is charged into the addition storage tanks other than the maximum addition storage tank. That is, the maximum input weight difference W _max is:
[0033]
(Equation 9)

[0034]
Here, assuming that (2 ^m−1 −1) −１2 ^m−1 and the volume of the largest one of the above-mentioned m addition storage tanks is V _max , the above equation becomes:
[0035]
(Equation 10)

[0036]
It becomes. In other words, the largest possible input weight difference W _max is equivalent to twice the weight of a case where an object to be weighed having a bulk density of the reference value d is loaded into the largest addition storage tank. If the total weight of the objects to be weighed in the addition auxiliary tank is larger than the maximum input weight difference W _max , the input weight difference W _max can be compensated by selecting the combination of the addition auxiliary tanks. That is, when the total capacity of the p number of auxiliary tanks is A, the following relationship only needs to be established.
[0037]
(Equation 11)

[0038]
Therefore, the following equation should be satisfied.
[0039]
(Equation 12)

[0040]
In another configuration of the present invention, the large input storage tank can be configured by the main input storage tank and the subtraction auxiliary tank. In the apparatus having this configuration, the subtraction auxiliary tank holds the object to be weighed without discharging it, so that the correction for reducing the maximum input weight difference _Wmax can be performed.
[0041]
Furthermore, in the apparatus having the above-described configuration, the capacity of the subtraction auxiliary tank can be configured to store the object to be weighed in the range of 2αdV _max −ad to 2αdV _max + ad. With this configuration, it is possible to perform a correction that almost cancels the maximum input weight difference _Wmax .
[0042]
【Example】
Embodiments of the present invention will be described in more detail with reference to the drawings.
[0043]
FIG. 1 shows a schematic configuration of a quantitative filling device according to a first embodiment of the present invention. Determination filling apparatus of the present embodiment, the box the objects to be weighed of the target weight W _o, is what is used to fill a predetermined container bags, etc., full flow for reserving the objects to be weighed for the full flow It has a storage tank 1, five

addition storage tanks

4a, 4b, 4c, 4d and 4e for addition and addition, and three addition

auxiliary tanks

14a, 14b and 14c for correcting a difference in input weight. The objects to be weighed are charged into the large charging storage tank 1, the additional storage tanks 4a to 4e, and the addition auxiliary tanks 14a to 14c almost simultaneously from the charging device 11, for example, by rubbing. The large input storage tank 1 is provided with a load cell 7, and the weight of the large input object to be input into the large input storage tank 1 is measured by the load cell 7.

Load cells

2a, 2b, 2c, 2d, and 2e are also provided in the five addition storage tanks 4a to 4e, respectively, and the weights of the objects to be added and added are weighed. Further, in the apparatus of the present embodiment, the load cells 12a, 12b and 12c are provided in the addition auxiliary tanks 14a to 14c, respectively. Outputs from the load cell 7, the load cells 2a to e, and the load cells 12a to 12c are input to a control device (not shown).
[0044]
A gate 8 for discharging the objects to be weighed is provided at the bottom of the large input storage tank 1, and the addition storage tanks 4a to e and the addition auxiliary tanks 14a to 14c also open and close independently of each other. Is provided. The objects to be weighed in the large input storage tank 1, the addition storage tanks 4a to 4e, and the addition auxiliary tanks 14a to 14c are discharged through the chute 9 to the container 10 such as a box or a bag. The opening and closing of the gate 8, the gate 6, and the gate 16 described above are performed under the control of the above-mentioned control device (not shown).
[0045]
In this embodiment, the capacity ratio of the additional storage tanks 4a to 4e is s ^k-1 (s is a positive real number, k ≦ m, m = the number of additional storage tanks), and s = 2 and m = 5. , Ie, 1: 2: 4: 8: 16. Accordingly, the articles for adding is turned in this embodiment, an addition tank as a reference the smallest sum reservoir 4a, when its capacity as a, the for summing-up from 1a to 2 ⁵ -1 = 31a This means that the weighing object is prepared, and the difference between the weights of the objects to be weighed for addition is ad when the bulk density of the weighing object takes a reference value (average value) d. That is, when the bulk density is the reference value d, the objects to be added for addition can be changed by ad.
[0046]
On the other hand, the capacity ratio of the addition auxiliary tanks 14a to 14c is set by using an appropriate positive real number r in an equation of rk ^-1 (r is a positive real number, 0 <k (integer) ≦ p). The number p of the addition auxiliary tanks can be determined according to the capacity ratio. In the present embodiment, r is set to the same value as s described above, that is, r = 2, the reference addition auxiliary tank is the minimum addition auxiliary tank 14a, and its capacity b is the same as the capacity a of the minimum addition storage tank 4a. Is set to In this case, the weight of the object to be weighed in the total addition auxiliary tank is expressed as follows.
[0047]
(Equation 13)

[0048]
This value is 0.4 × 16ad = 6.4ad obtained by substituting the maximum variation rate α of the bulk density of the object to be weighed into α = 0.2, the above m = 5 and the above s = 2 into 2dV _max = 2αdas ^m-1. The value of the number p of the addition auxiliary tanks is determined so as to be larger. That is, in the present embodiment, the number p of the addition auxiliary tanks is 3 (7ad). In addition, the respective capacities of the three addition auxiliary tanks 14a to 14c are ad, 2ad, and 4ad according to the ratio of the values of r = 2 and k = 1, 2, and 3 at rk ^-1 .
[0049]
In the present embodiment, by providing three of the addition storage tanks 4a to e from the smallest one, that is, the addition auxiliary tanks 14a to 14c having the same capacity as the addition storage tanks 4a to 4c, the maximum input that can occur in the configuration of this embodiment is provided. The weight difference W _max 6.4ad can be corrected with the same input weight difference as the addition storage tanks 4a to 4c.
[0050]
FIG. 2 shows a schematic configuration diagram of a quantitative filling device according to a second embodiment of the present embodiment. The apparatus of this embodiment differs from the apparatus of FIG. 1 described above in the following points. That is, in the apparatus of FIG. 2, a single addition auxiliary tank 14 having a load cell 12 is provided instead of the addition auxiliary tanks 14a to 14c, and the large input storage tank 1 is connected to the main input storage tank 1a having a gate 8a. 8b. The object to be weighed for large input is divided and input into the main input storage tank 1a and the subtraction auxiliary tank 1b, and the weight is measured by the

load cells

7a and 7b, respectively. The other components in FIG. 2 are the same as those in FIG. 1, and the corresponding components are denoted by the same reference numerals.
[0051]
5. The capacities of the addition auxiliary tank 14 and the subtraction auxiliary tank 1b are obtained by substituting the maximum variation rate α = 0.2, m = 5 and s = 2 of the bulk density of the object to be measured into 2dV _max = 2αas ^m−1 . 4a is set in the range of ± a. In this embodiment, the capacity of the addition auxiliary tank 14 and the subtraction auxiliary tank 1b is set to 6.4a.
[0052]
The functions of the addition auxiliary tank 14 and the subtraction auxiliary tank 1b will be described with reference to FIGS.
[0053]
In FIG. 3, there is a case where an object to be weighed having the largest bulk density α = 1.2 is added to the addition storage tanks 4a to 4d, and an object to be weighed having the smallest bulk density α = 0.8 is added to the addition storage tank 4e. It is shown. FIG. 3A shows a case where the objects to be weighed for addition are increased by the minimum unit capacity by changing the combination of the addition storage tanks. In A1, the addition storage tanks 4b to 4d are selected and (2 + 4 + 8) × 1. An object to be weighed for addition and input of 2 = 16.8 ad (capacity ratio 14) is prepared. In FIGS. 3 and 4, ad is omitted for simplicity. Next, at A2, an addition storage tank 4a having a minimum unit volume is added, and the total weight of the objects to be weighed of 18.0ad (capacity ratio 15) in the addition storage tanks 4a to 4d is the object to be added and charged. Subsequently, when the object to be weighed for the additional storage tank is further increased to the capacity ratio 16, only the additional storage tank 4e is normally selected, but as described above, the minimum bulk density α = 0. Since eight objects to be weighed are loaded, 16 × 0.8 = 12.8ad as shown in A3, and the weight of the objects to be weighed for addition is greatly reduced. Therefore, in this embodiment, as shown in B1 of FIG. 3B, by adding the object to be weighed in the addition auxiliary tank 4, 12.8 + 6.4 = 19.2ad, and the object to be added is added. Is corrected.
[0054]
In FIG. 4, the objects to be weighed having the smallest bulk density α = 0.8 are loaded into the additional storage tanks 4a to 4d, and the objects to be weighed having the largest bulk density α = 1.2 are loaded into the additional storage tank 4e. The case is shown. FIG. 4A shows a case where the objects to be added are increased by the minimum unit capacity by changing the combination of the addition storage tanks. In C1, the addition storage tanks 4b to 4d are selected and (2 + 4 + 8) × 0.8. An object to be weighed for addition of = 11.2ad (capacity ratio 14) is prepared. Next, in C2, the addition storage tank 4a having the minimum unit volume is added, and the total weight 12.0ad (capacity ratio 15) of the objects to be weighed in the addition storage tanks 4a to 4d becomes the object to be weighed for addition. Subsequently, when the object to be weighed for the additional storage tank is further increased to the capacity ratio 16, the additional storage tank 4e is normally selected, but as described above, the maximum bulk density α = 1.2 is set in the additional storage tank 4e. Since the object to be weighed is input, 16 × 1.2 = 19.2ad as shown in C3, and the weight of the object to be weighed for addition greatly increases. Therefore, in the present embodiment, as shown in D1 of FIG. 4B, if the object to be weighed is not discharged from the subtraction auxiliary tank 1b, 19.2-6.4 = 12.8ad, which is a value for addition. The deviation of the difference in the input weight of the objects to be weighed is corrected.
[0055]
In each of the above embodiments, the case where five addition storage tanks having a capacity ratio of 1: 2: 4: 8: 16 is provided, but the present invention is not limited to this, and at least two types of different storage capacity are provided. Can be applied to an apparatus having a plurality of addition storage tanks, and the number of addition auxiliary tanks can be arbitrary.
[0056]
Further, in each of the above embodiments, the case where the positive real numbers s and r are set to 2 is described. However, the present invention is not limited to this, and other integers or decimal numbers may be used. Further, the positive real numbers s and r, and b and a may be different from each other, and in this case, the input weight difference obtained only by the addition storage tank and the input weight difference obtained by adding the addition auxiliary tank are different. It will be.
[0057]
【The invention's effect】
In the fixed-quantity filling device of the present invention, the deviation of the input weight difference caused when the bulk specific gravity of the object to be weighed charged in the addition storage tank changes is corrected by providing an addition auxiliary tank having a number and capacity according to the degree. Is done. Therefore, according to the present invention, fine adjustment of the object to be weighed can be performed in a wide range even when the bulk specific gravity of the object to be weighed changes.
[0058]
In addition, in the configuration of the present invention in which the subtraction auxiliary tank is provided, the object to be weighed in the subtraction auxiliary tank is held without being discharged, so that a correction for reducing the maximum input weight difference W _max can be performed. This also allows a wide range of weight adjustment.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a quantitative filling device according to a first embodiment of the present invention.
FIG. 2 is a schematic configuration diagram of a quantitative filling device according to a second embodiment of the present invention.
FIG. 3 is a diagram illustrating the function of an addition auxiliary tank.
FIG. 4 is a diagram illustrating the function of a subtraction auxiliary tank.
FIG. 5 is a schematic configuration diagram of a fixed quantity filling device provided with an addition storage tank.
FIG. 6 is a diagram showing a state in which the difference in the input weight of the objects to be added is shifted due to a change in the bulk specific gravity of the objects to be weighed.
[Explanation of symbols]
Reference Signs List 1 large input storage tank 1a main input storage tank 1b subtraction

auxiliary tanks

2a, 2b, 2c, 2d, 2e

load cells

4, 4a, 4b, 4c, 4d

addition storage tanks

6, 8, 8a, 8b, 16

gate

7 , 7a, 7b Load cell 9 Chute 10 Container 11 Loading device 12a, 12b,

12c Load cell

14a, 14b, 14c Addition auxiliary tank

Claims

A large input storage tank having a weighing means for storing an object to be weighed having a weight smaller than the target weight and close to the target weight,
A plurality of storage units each having at least two different capacities for storing an object to be added for addition to supplement an insufficient weight obtained by subtracting the weight of the object to be weighed in the large input storage tank from the target weight; An additive storage tank,
A control device that selects a combination of the addition storage tanks and changes the objects to be weighed for addition and addition stepwise with a predetermined difference in input weight,
In selecting a combination of the addition storage tanks by the control device, one or more addition auxiliary tanks having a weighing means for correcting a deviation of the input weight difference caused by a variation in bulk density of the objects to be weighed. A quantitative filling device, comprising:

The addition storage tank has the following capacity

The fixed-quantity filling apparatus according to claim 1, wherein at least m addition storage tanks each having the following are included.

The addition auxiliary tank has the following capacity

The quantitative filling device according to claim 1 or 2, further comprising at least p addition auxiliary tanks each having:

4. The quantitative filling device according to claim 3, wherein the positive real numbers r and s are equal.

The quantitative filling device according to claim 4, wherein both the positive real numbers r and s are 2.

The maximum variation rate of the bulk density of the objects to be weighed in the addition storage tank was α, the volume of the largest one of the m addition storage tanks was V _max , and the total capacity of the p addition auxiliary tanks was A. In the case, the number p of the addition auxiliary tank is expressed by the following equation.

The quantitative filling device according to claim 5, wherein the constant filling device satisfies:

The large input storage tank includes a main input storage tank having a weighing means and a subtraction auxiliary tank, and the subtraction auxiliary tank performs correction to reduce the input weight difference by holding the object to be measured without discharging the object. 7. The fixed-quantity filling device according to claim 1, wherein:

The addition an auxiliary tank is a single tank, the addition auxiliary tank and the subtraction auxiliary tank, when the volume of the largest of said summed reservoir was _{V max,} weights between 2αdV _{_max} -ad~2αdV _max + ad 8. The fixed-quantity filling device according to claim 7, having a capacity capable of storing the object to be weighed.