JP2004292851A

JP2004292851A - Method and apparatus for quenching hollow rack

Info

Publication number: JP2004292851A
Application number: JP2003083693A
Authority: JP
Inventors: Masato Ishikawa; 政登石川; Yoshihisa Mikami; 嘉久三上
Original assignee: Showa Corp
Current assignee: Showa Corp
Priority date: 2003-03-25
Filing date: 2003-03-25
Publication date: 2004-10-21
Anticipated expiration: 2023-03-25
Also published as: JP3986456B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide a quenching method for hollow rack by which the deformation of a material to be quenched is easily corrected, restricted and cooled in the case of quenching the material to be quenched of the hollow rack which may easily deform with heating. <P>SOLUTION: In the quenching method, after restricting the material 1 to be quenched of the hollow rack with at least four clampers 21 to 24 at the upper and lower parts and the right and left parts, quenching liquid is injected. After restricting the material 1 to be quenched from the upper and lower direction crossing a rack gear face at the right angle with the upper and the lower clampers 21, 22, the material 1 to be quenched is restricted from the right and left direction with the right and the left clampers 24, 23. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は円筒状のラックバーの長手方向の少なくとも一部にラック歯面を備えた中空ラックの焼入れ方法及び装置に関する。
【０００２】
【従来の技術】
中空ラックの焼入れ装置として、特許文献１に記載の如く、上型の突部と下型の突部により加熱した中空ラックの被焼入材を拘束した状態で焼入れ液を噴射するものがある。
【０００３】
他の中空ラックの焼入れ装置として、特許文献２に記載の如く、４つの拘束治具により加熱した中空ラックの被焼入材を拘束した状態で、焼入れ液を噴射するものがある。
【０００４】
【特許文献１】
特許３２０５４１２（１頁、図１）
【０００５】
【特許文献２】
特開２００１−１１５３６（４頁、図１）
【０００６】
【発明が解決しようとする課題】
特許文献１の焼入れ装置には以下の問題点がある。
▲１▼中空ラックの被焼入材は加熱により変形し易く、上型の凸部と下型の凸部により被焼入材の断面の全周を一挙に拘束しようとすると、上型の凸部と下型の凸部の拘束領域から被焼入材の変形曲がり部がはみ出て拘束できないことがある。
【０００７】
▲２▼上下型にそれらの凸部を一体に形成しており、被焼入材の断面形状が変われば、上下型の全体を交換する必要がある。
【０００８】
特許文献２の焼入装置には以下の問題点がある。
▲１▼中空ラックの被焼入材は加熱により変形し易く、４つの拘束治具により被焼入材の断面の全周を一挙に拘束しようとすると、４つの拘束治具の拘束領域から被焼入材の変形曲がり部がはみ出て拘束できないことがある。
【０００９】
▲２▼４つの拘束治具のそれぞれを油圧等により個別に進退させ、しかも互いに同期的に進退させる必要があり、構成が複雑になる。
【００１０】
本発明の課題は、加熱によって変形し易い中空ラックの被焼入材を焼入れするに際し、被焼入材の変形を容易に矯正して拘束し、冷却することにある。
【００１１】
本発明の他の課題は、焼入装置の構成の簡素を図ることにある。
【００１２】
【課題を解決するための手段】
請求項１の発明は、中空ラックの被焼入材を上下左右の少なくとも４つのクランパにより拘束した後に、焼入れ液を噴射する中空ラックの焼入れ方法において、上下のクランパによって被焼入材をそのラック歯面に直交する上下方向から拘束した後、左右のクランパによって被焼入材を左右方向から拘束するようにしたものである。
【００１３】
請求項２の発明は、中空ラックの被焼入材を上下左右の少なくとも４つのクランパにより拘束した後に、焼入れ液を噴射する中空ラックの焼入れ装置において、上型と下型を相対移動可能に設け、上型に上クランパを上下動可能に設け、下型に下クランパを上下動可能に設け、下型と上型の一方に左右のクランパを左右動可能に設け、上下のクランパにより被焼入材をそのラック歯面に直交する上下方向から拘束可能にし、上下のクランパが左右のクランパより先に被焼入材を拘束可能にしたものである。
【００１４】
請求項３の発明は、請求項２の発明において更に、前記上クランパが上型に支持された弾発体により最終拘束位置よりも突出する側に初期設定され、上下型の相対移動にともなう被焼入材との衝合により弾発体に抗して最終拘束位置まで移動可能にされ、下クランパが下型に支持された弾発体により最終拘束位置よりも突出する側に初期設定され、上下型の相対移動にともなう被焼入材との衝合により弾発体に抗して最終拘束位置まで移動可能にされ、左右のクランパが下型と上型の一方に支持された弾発体により最終拘束位置よりも引込み側に初期設定され、上下型の相対移動により上下のクランパが先に被焼入材を拘束した状態下で、該左右のクランパを上下型の相対移動に連動して弾発体に抗して最終拘束位置まで移動可能にするようにしたものである。
【００１５】
請求項４の発明は、請求項３の発明において更に、前記左右のクランパを下型と上型の一方に支持する状態下で、下型と上型の他方に設けたくさび部により左右のクランパを初期設定位置から最終拘束位置に押動可能にするようにしたものである。
【００１６】
請求項５の発明は、請求項４の発明において更に、前記上下型の型当たり面が接した状態において、上クランパを上型のストッパ面により最終拘束位置に設定し、下クランパを下型のストッパ面により最終拘束位置に設定し、左右のクランパを下型と上型の他方に設けたくさび部により最終拘束位置に設定可能にするようにしたものである。
【００１７】
請求項６の発明は、請求項５の発明において更に、前記上下左右の全てのクランパを最終拘束位置に設定した状態で、それら全てのクランパの先端面が互いに被焼入材の断面形状と同一形状を区画形成するようにしたものである。
【００１８】
請求項７の発明は、請求項２〜６のいずれかの発明において更に、前記上下型が、上下左右の全てのクランパを最終拘束位置に設定した状態で、相隣るクランパの間を通して被焼入材に焼入れ液を噴射する噴射口を備えるようにしたものである。
【００１９】
請求項８の発明は、請求項２〜７のいずれかの発明において更に、前記被焼入材のラック歯面に下クランパの先端面を当てる状態で、下クランパの先端面は平面状をなすものにし、上クランパと左右のクランパの先端面には液流通溝を設けるようにしたものである。
【００２０】
【発明の実施の形態】
図１は焼入装置による被焼入材の加熱状態を示す正面図、図２は焼入装置による被焼入材の拘束冷却状態を示す正面図、図３は図１のＩＩＩ−ＩＩＩ線に沿う矢視図、図４は上型を示し、（Ａ）は断面図、（Ｂ）は下面図、図５は下型を示し、（Ａ）は断面図、（Ｂ）は上面図、図６は下クランパを示し、（Ａ）は側面図、（Ｂ）は平面図、（Ｃ）は（Ａ）のＣ−Ｃ線に沿う断面図、図７は下クランパを示し、（Ａ）は側面図、（Ｂ）は平面図、（Ｃ）は（Ａ）のＣ−Ｃ線に沿う断面図、図８は上クランパを示し、（Ａ）は側面図、（Ｂ）は平面図、（Ｃ）は（Ａ）のＣ−Ｃ線に沿う断面図、図９は左右のクランパを示し、（Ａ）は側面図、（Ｂ）は平面図、（Ｃ）は（Ｂ）のＣ−Ｃ線に沿う断面図である。
【００２１】
焼入装置１０は、中空ラックの被焼入材１を焼入れ可能にする。被焼入材１は、円管状をなし、長手方向の一定長さ範囲において、周方向の一部にラック歯面２を形成する。ラック歯面２は相隣るラック歯の刃先を互いに単一平面状に配置する。
【００２２】
焼入装置１０は、図１〜図３に示す如く、左右のコラム１１、１２に、上下型１３、１４のベース１５、１６を上下動可能にガイドし、不図示の昇降装置により上下型１３、１４を対向移動可能にする。
【００２３】
焼入装置１０は、上下型１３、１４で挟まれる上下方向中央部の焼入作業位置に、不図示のラック保持装置に保持される被焼入材１を位置付ける。
【００２４】
焼入装置１０は、加熱装置１７を有する。加熱装置１７は、高周波誘導加熱装置等からなり、待機位置から焼入作業位置に向けて前進し、ワーク保持装置に保持されている被焼入材１を加熱し、その後、待機位置に復帰する。加熱装置１７による加熱中に、被焼入材１はワーク保持装置により自軸まわりに回転せしめられる。
【００２５】
焼入装置１０は、上下左右の少なくとも４つのクランパ２１〜２４を有し、上型１３に上クランパ２１を上下動可能に設け、下型１４に下クランパ２２を上下動可能に設け、下型１４に左右のクランパ２３、２４を左右動可能に設ける。焼入装置１０は、上下のクランパ２１、２２により加熱状態にある被焼入材１をそのラック歯面２に直交する上下方向から挟圧して拘束可能にし、その後、左右のクランパ２３、２４により被焼入材１を左右方向から挟圧して拘束可能にするものであり、上下のクランパ２１、２２が左右のクランパ２３、２４より先に被焼入材１を拘束可能にする。
【００２６】
ここで、上クランパ２１は、上型１３の中心軸上に設けた凹状ガイド１３Ａによって上下動可能にガイドされ、凹状ガイド１３Ａの奥側のばね格納孔１３Ｂに内蔵されて上型１３に支持された圧縮コイルばね等の弾発体３１により、該上クランパ２１が被焼入材１を最終的に拘束する最終拘束位置よりも突出する側に初期設定され、上下型１３、１４の接近動にともなう該上クランパ２１と被焼入材１との衝合により弾発体３１に抗して最終拘束位置まで移動可能にされる。上クランパ２１は、最終拘束位置において、凹状ガイド１３Ａとばね格納孔１３Ｂとの段差面からなるストッパ面１３Ｃに衝合して移動ロックされる。上クランパ２１の最終拘束位置は、ストッパ面１３Ｃ上に積層されるシム１３Ｄにより調整できる。
【００２７】
下クランパ２２は、下型１４の中心軸上に設けた凹状ガイド１４Ａによって上下動可能にガイドされ、凹状ガイド１４Ａの奥側のばね格納孔１４Ｂに内蔵されて下型１４に支持された圧縮コイルばね等の弾発体３２により、該下クランパ２２が被焼入材１を最終的に拘束する最終拘束位置よりも突出する側に初期設定され、上下型１３、１４の接近動にともなう該下クランパ２２と被焼入材１との衝合により弾発体３２に抗して最終拘束位置まで移動可能にされる。下クランパ２２は、最終拘束位置において、凹状ガイド１４Ａとばね格納孔１４Ｂとの段差面からなるストッパ面１４Ｃに衝合して移動ロックされる。下クランパ２２の最終拘束位置は、ストッパ面１４Ｃ上に積層されるシム１４Ｄにより調整できる。
【００２８】
左右のクランパ２３、２４は、下型１４の左右に設けたＬ型ガイド４１、４２の水平スライド面４１Ａ、４２Ａに左右動可能にガイドされる。クランパ２３、２４の背面に連結された連結ロッド４３、４４は、Ｌ型ガイド４１、４２の垂直壁４１Ｂ、４２Ｂを貫通し、貫通端に固定の止め具４３Ａ、４４Ａと垂直壁４１Ｂ、４２Ｂとの間に、ゴム塊等の弾発体４５、４６を挟み込み保持する。弾発体４５、４６は、左右のクランパ２３、２４を最終拘束位置よりも引込み側、本実施形態では垂直壁４１Ｂ、４２Ｂに接する側に初期設定する。
【００２９】
左右のクランパ２３、２４は、上下型１３、１４の接近動により上下のクランパ２１、２２が先に被焼入材１に衝合して該被焼入材１を拘束した状態下で（上下のクランパ２１、２２が最終拘束位置に到達して拘束完了した状態でも良いし、最終拘束位置に未だ到達せずに拘束中間過程にある状態でも良い）、クランパ２１、２２の移動に連動して弾発体４５、４６に抗し、弾発体４５、４６を圧縮変形させつつ、最終拘束位置まで移動可能にされる。
【００３０】
本実施形態において、左右のクランパ２３、２４は、上型１３において上クランパ２１の両側にて下方に突設したくさび部５１、５２により、初期設定位置から最終拘束位置に押動可能にされる。くさび部５１、５２は、上下型１３、１４の接近動により、左右のクランパ２３、２４の背面とＬ型ガイド４１、４２の垂直壁４１Ｂ、４２Ｂとの間に進入し、クランパ２３、２４を水平スライド面４１Ａ、４２Ａ上で最終拘束位置に向けて押動する。
【００３１】
焼入装置１０は、上下型１３、１４が接近動してそれらの型当たり面６１、６２が接した状態において、上クランパ２１を上型１３のストッパ面１３Ｃにより最終拘束位置に設定し、下クランパ２２を下型１４のストッパ面１４Ｃにより最終拘束位置に設定し、左右のクランパ２３、２４を上型１３に設けたくさび部５１、５２により最終拘束位置に設定する。
【００３２】
そして、上下左右の全てのクランパ２１〜２４を上述の如くにして最終拘束位置に設定した状態で、それら全てのクランパ２１〜２４の先端面２１Ａ〜２４Ａが、互いに被焼入材１の断面形状と同一形状を区画形成する。クランパ２１〜２４の先端面２１Ａ〜２４Ａは、隙間なく、又は微小隙間を介して、被焼入材１の外周を囲む。
【００３３】
焼入装置１０は、上下左右の全てのクランパ２１〜２４を最終拘束位置に設定した状態で、図２に示す如く、上下型１３、１４が、相隣るクランパ２１〜２４の間を通して、被焼入材１に焼入れ液を噴射する噴射口７１、７２、７３、７４を備える。上型１３は、図４に示す如く、焼入液供給源に連なる焼入液供給路７０Ａ、７０Ｂを有し、焼入液供給路７０Ａ、７０Ｂのそれぞれに噴射口７１、７２を連通する。下型１４は、図５に示す如く、焼入液供給源に連なる焼入液供給路７０Ｃ、７０Ｄを有し、焼入液供給路７０Ｃ、７０Ｄのそれぞれに噴射口７３、７４を連通する。噴射口７１〜７４は、被焼入材１の長手方向に沿う多数の孔列（スリットでも可）からなる。噴射口７１〜７４は、被焼入材１の周方向の４等配位置（９０度間隔をなす各位置）に対応し、噴射口７３、７４は被焼入材１のラック歯面２の両側部に対応する。
【００３４】
焼入装置１０は、被焼入材１のラック歯面２に下クランパ２２の先端面２２Ａを当てる状態で、該クランパ２２の先端面２２Ａを図６に示す如く、被焼入材１のラック歯面２の刃先が形成する単一平面に沿う如くの平面状をなす平坦面８２からなるものにする。また、焼入装置１０は、上クランパ２１と左右のクランパ２３、２４の先端面２１Ａ、２３Ａ、２４Ａのそれぞれを図８、図９に示す如く、被焼入材１の円弧面に沿う如くの円弧面８１、８３、８４からなるものにし、各先端面２１Ａ、２３Ａ、２４Ａにはそれぞれ縦横の液流通溝８１Ａ、８１Ｂ、８３Ａ、８３Ｂ、８４Ａ、８４Ｂを設ける。
【００３５】
尚、焼入装置１０は、被焼入材１のラック歯面２以外の部分に当たる下クランパ２２の先端面２２Ａを、図７に示す如く、被焼入材１の円弧面に沿う如くの円弧面８５からなるものにし、各先端面２２Ａに縦横の液流通溝８５Ａ、８５Ｂを設ける。
【００３６】
焼入装置１０による被焼入材１の焼入方法は以下の手順でなされる。
（１）ラック素材となる中空管にラック歯を形成して被焼入材１を得た後、被焼入材１のラック歯面２を含む全体を加熱装置１７により同時に加熱する。被焼入材１は加熱による歪として、被焼入材１のラック歯面２に直交する上下方向に例えば０．６６ｍｍの曲がり量を生じた。
【００３７】
（２）加熱された被焼入材１を焼入作業位置にセットする。
（３）上下型１３、１４を接近動させ、先ず上下のクランパ２１、２２により被焼入材１を上下方向から拘束開始する。
【００３８】
（４）上下型１３、１４を接近動の最終段階で、左右のクランパ２３、２４により被焼入材１を左右方向から拘束開始する。
【００３９】
（５）上下型１３、１４の型当たり面６１、６２が接した状態において、上下左右のクランパ２１〜２４のそれぞれをそれらの最終拘束位置に設定し、クランパ２１〜２４による被焼入材１の拘束を完了する。
【００４０】
（６）上下型１３、１４の噴射口７１〜７４から焼入液を噴射し、被焼入材１のラック歯面２を含む全体を冷却する。クランパ２１〜２４により被焼入材１の全体を拘束しながら冷却したから、被焼入材１の曲がり量は０．０５ｍｍに減じられた。
【００４１】
本実施形態によれば以下の作用効果を奏する。
（請求項１、２に対応する作用効果）
▲１▼中空ラックの被焼入材１は、加熱によって、ラック歯面２に直交する上下方向に反りを生じ易い。上下のクランパ２１、２２により被焼入材１をまず上下方向から拘束して矯正し、その後、左右のクランパ２３、２４を含む左右上下の全てのクランパ２１〜２４で被焼入材１の断面の全周を拘束するから、被焼入材１の変形曲がり部を左右上下のクランパ２１〜２４の拘束領域からはみ出しさせることなく、被焼入材１の変形を容易に矯正して拘束できる。
【００４２】
▲２▼上型１３に上クランパ２１を設け、下型１４に下クランパ２２と左右のクランパ２３、２４を設けたから、被焼入材１の断面形状が変わっても、左右上下のクランパ２１〜２４だけを交換すれば足り、上下型１３、１４の全体を交換する必要がない。
【００４３】
（請求項３に対応する作用効果）
▲３▼上クランパ２１を上型１３に支持した弾発体３１により最終拘束位置よりも突出する側に初期設定し、下クランパ２２を下型１４に支持した弾発体３２により最終拘束位置よりも突出する側に初期設定し、左右のクランパ２３、２４を上下型１３、１４の相対移動に連動して初期設定位置から最終拘束位置まで移動可能にした。従って、上型１３を下型１４に対して移動させるだけで、左右上下のクランパ２１〜２４による上述▲１▼の拘束動作を実行できる。
【００４４】
（請求項４に対応する作用効果）
▲４▼上型１３に設けたくさび部５１、５２により左右のクランパ２３、２４を初期設定位置から最終拘束位置に押動可能にする。即ち、左右のクランパ２３、２４による拘束動作を上型１３の移動に簡易に連動させることができる。
【００４５】
（請求項５に対応する作用効果）
▲５▼上下型１３、１４の型当たり面６１、６２が接した状態において、上クランパ２１を上型１３のストッパ面１３Ｃにより最終拘束位置に設定し、下クランパ２２を下型１４のストッパ面１４Ｃにより最終拘束位置に設定し、左右のクランパ２３、２４を上型１３に設けたくさび部５１、５２により最終拘束位置に設定可能にする。従って、上型１３を下型１４に型当りするまで移動することにより、上下左右の全てのクランパ２１〜２４を簡易確実に最終拘束位置に設定できる。
【００４６】
（請求項６に対応する作用効果）
▲６▼上下左右の全てのクランパ２１〜２４を最終拘束位置に設定した状態で、それら全てのクランパ２１〜２４の先端面２１Ａ〜２４Ａが互いに被焼入材１の断面形状と同一形状を区画形成する。従って、上下左右のクランパ２１〜２４の拘束領域が、被焼入材１の断面よりも狭小になることがなく、被焼入材１にクランパ２１〜２４による拘束変形を生じさせることがない。
【００４７】
（請求項７に対応する作用効果）
▲７▼上下型１３、１４に噴射口７１〜７４を設けることにより、クランパ２１〜２４に噴射口を設ける必要がない。被焼入材１の断面形状の変更によって交換する必要を生ずるクランパ２１〜２４の構造の簡素を図ることができる。
【００４８】
（請求項８に対応する作用効果）
▲８▼下クランパ２２は平面状の先端面２２Ａにより、被焼入材１のラック歯面２に広く当接し、被焼入材１を確実に拘束できる。下クランパ２２の先端面２２Ａと被焼入材１の間には、被焼入材１のラック歯面２の溝が焼入れ液を流通可能にする。上クランパ２１と左右のクランパ２３、２４の先端面２１Ａ、２３Ａ、２４Ａと被焼入材１の間には、それら各クランパ２１、２３、２４の先端面２１Ａ、２３Ａ、２４Ａに設けた液流通溝８１Ａ、８１Ｂ、８３Ａ、８３Ｂ、８４Ａ、８４Ｂが焼入れ液を流通可能にする。
【００４９】
以上、本発明の実施の形態を図面により記述したが、本発明の具体的な構成はこの実施の形態に限られるものではなく、本発明の要旨を逸脱しない範囲の設計の変更等があっても本発明に含まれる。
【００５０】
【発明の効果】
本発明によれば、加熱によって変形し易い中空ラックの被焼入材を焼入れするに際し、被焼入材の変形を容易に矯正して拘束し、冷却することができる。、また、本発明によれば、焼入装置の構成の簡素を図ることができる。
【図面の簡単な説明】
【図１】図１は焼入装置による被焼入材の加熱状態を示す正面図である。
【図２】図２は焼入装置による被焼入材の拘束冷却状態を示す正面図である。
【図３】図３は図１のＩＩＩ−ＩＩＩ線に沿う矢視図である。
【図４】図４は上型を示し、（Ａ）は断面図、（Ｂ）は下面図である。
【図５】図５は下型を示し、（Ａ）は断面図、（Ｂ）は上面図である。
【図６】図６は下クランパを示し、（Ａ）は側面図、（Ｂ）は平面図、（Ｃ）は（Ａ）のＣ−Ｃ線に沿う断面図である。
【図７】図７は下クランパを示し、（Ａ）は側面図、（Ｂ）は平面図、（Ｃ）は（Ａ）のＣ−Ｃ線に沿う断面図である。
【図８】図８は上クランパを示し、（Ａ）は側面図、（Ｂ）は平面図、（Ｃ）は（Ａ）のＣ−Ｃ線に沿う断面図である。
【図９】図９は左右のクランパを示し、（Ａ）は側面図、（Ｂ）は平面図、（Ｃ）は（Ｂ）のＣ−Ｃ線に沿う断面図である。
【符号の説明】
１被焼入材
２ラック歯面
１０焼入装置
１３、１４上下型
１３Ｃ、１４Ｃストッパ面
２１上クランパ
２１Ａ先端面
２２下クランパ
２２Ａ先端面
２３、２４左右のクランパ
２３Ａ、２４Ａ先端面
３１、３２弾発体
４５、４６弾発体
５１、５２くさび部
６１、６２型当たり面
７１〜７４噴射口
８１Ａ、８１Ｂ、８３Ａ、８３Ｂ、８４Ａ、８４Ｂ、８５Ａ、８５Ｂ液流通溝
８２平坦面[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method and an apparatus for quenching a hollow rack having a rack tooth surface on at least a part of a cylindrical rack bar in a longitudinal direction.
[0002]
[Prior art]
As a quenching apparatus for a hollow rack, as described in Patent Literature 1, there is an apparatus that injects a quenching liquid in a state where a material to be quenched in a hollow rack heated by an upper projection and a lower projection is restrained.
[0003]
As another quenching device for a hollow rack, as described in Patent Document 2, there is a device that injects a quenching liquid in a state where a material to be quenched in a hollow rack heated by four restraining jigs is restrained.
[0004]
[Patent Document 1]
Patent No. 3205412 (1 page, FIG. 1)
[0005]
[Patent Document 2]
JP-A-2001-11536 (4 pages, FIG. 1)
[0006]
[Problems to be solved by the invention]
The quenching device of Patent Document 1 has the following problems.
{Circle around (1)} The material to be quenched in the hollow rack is easily deformed by heating, and when the entire periphery of the cross section of the material to be quenched is to be constrained at once by the convex portion of the upper die and the convex portion of the lower die, the convex shape of the upper die is raised. In some cases, the deformed bent portion of the material to be quenched protrudes from the constrained region between the portion and the convex portion of the lower mold and cannot be constrained.
[0007]
{Circle around (2)} The upper and lower dies are integrally formed with the projections. If the cross-sectional shape of the material to be quenched changes, it is necessary to replace the entire upper and lower dies.
[0008]
The quenching device of Patent Document 2 has the following problems.
{Circle around (1)} The material to be quenched in the hollow rack is easily deformed by heating. If four constraining jigs are used to constrain the entire circumference of the cross section of the material to be hardened at once, the constrained areas of the four constraining jigs are used. In some cases, the deformed bent portion of the quenched material protrudes and cannot be restrained.
[0009]
{Circle around (2)} Each of the four restraining jigs must be individually advanced and retracted by hydraulic pressure or the like, and furthermore, must be advanced and retracted synchronously with each other, which complicates the configuration.
[0010]
SUMMARY OF THE INVENTION An object of the present invention is to easily correct deformation of a material to be quenched, restrain the material, and cool the material when quenching a material to be quenched in a hollow rack that is easily deformed by heating.
[0011]
Another object of the present invention is to simplify the configuration of a quenching device.
[0012]
[Means for Solving the Problems]
The invention according to claim 1 is a method of quenching a hollow rack in which a quenching liquid is injected after restraining the quenched material of the hollow rack by at least four upper, lower, left and right clampers. After being constrained in the vertical direction perpendicular to the tooth surface, the quenched material is constrained in the left and right directions by the left and right clampers.
[0013]
According to a second aspect of the present invention, an upper die and a lower die are provided so as to be relatively movable in a hollow rack quenching apparatus which injects a quenching liquid after restraining a material to be quenched in a hollow rack by at least four clamps of up, down, left and right. , An upper clamp is provided on the upper mold so that it can move up and down, a lower clamper is provided on the lower mold so that it can move up and down, and one of the lower mold and the upper mold has left and right clampers that can move left and right. The material can be restrained in the vertical direction perpendicular to the tooth surface of the rack, and the upper and lower clampers can restrain the material to be hardened before the left and right clampers.
[0014]
According to a third aspect of the present invention, in the second aspect of the present invention, the upper clamper is further initialized by a resilient body supported by the upper mold to a side protruding from a final restraint position, and is provided with a relative movement of the upper and lower molds. By the abutment with the quenched material, it is made possible to move to the final restraint position against the elastic body, and the lower clamper is initialized to the side protruding from the final restraint position by the elastic body supported by the lower mold, The movable body can be moved to the final restraint position against the elastic body by abutment with the quenched material due to the relative movement of the upper and lower molds, and the left and right clampers are supported by one of the lower mold and the upper mold Initially set to the retracted side than the final restraint position, the upper and lower clampers are interlocked with the relative movement of the upper and lower molds under the condition that the upper and lower clampers restrain the material to be quenched first by the relative movement of the upper and lower molds. Made it possible to move to the final restraint position against the projectile One in which the.
[0015]
According to a fourth aspect of the present invention, the left and right clampers are further provided by wedge portions provided on the other of the lower mold and the upper mold while the left and right clampers are supported by one of the lower mold and the upper mold. Can be pushed from the initial setting position to the final restraint position.
[0016]
According to a fifth aspect of the present invention, in the fourth aspect of the present invention, the upper clamper is set to the final restraint position by the upper mold stopper surface while the upper and lower mold contact surfaces are in contact with each other, and the lower clamper is set to the lower mold. The stopper surface is set to the final restraint position, and the left and right clampers can be set to the final restraint position by wedge portions provided on the other of the lower die and the upper die.
[0017]
According to a sixth aspect of the present invention, in the state of the fifth aspect, in a state where all of the upper, lower, left, and right clampers are set to the final restraint positions, the tip surfaces of all the clampers have the same sectional shape as the material to be quenched. The shape is sectioned.
[0018]
The invention according to claim 7 is the invention according to any one of claims 2 to 6, wherein the upper and lower molds are fired between adjacent clampers in a state in which all of the upper, lower, left and right clampers are set at final restraint positions. An injection port for injecting a quenching liquid into the material is provided.
[0019]
According to an eighth aspect of the present invention, in addition to any one of the second to seventh aspects, the tip surface of the lower clamper has a planar shape in a state where the tip surface of the lower clamper is brought into contact with the tooth surface of the rack of the material to be hardened. In this case, a liquid circulation groove is provided on the tip surfaces of the upper clamper and the left and right clampers.
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
1 is a front view showing a state of heating the material to be quenched by the quenching device, FIG. 2 is a front view showing a state of constrained cooling of the material to be quenched by the quenching device, and FIG. 3 is a line III-III in FIG. FIG. 4 shows an upper mold, (A) is a sectional view, (B) is a bottom view, and FIG. 5 shows a lower mold, (A) is a sectional view, (B) is a top view, and FIG. 6 shows a lower clamper, (A) is a side view, (B) is a plan view, (C) is a cross-sectional view along line CC of (A), FIG. 7 shows a lower clamper, (A) (B) is a side view, (B) is a plan view, (C) is a cross-sectional view along line CC of (A), FIG. 8 shows an upper clamper, (A) is a side view, (B) is a plan view, 9C is a cross-sectional view taken along line CC of FIG. 9A, FIG. 9 shows left and right clampers, FIG. 9A is a side view, FIG. 9B is a plan view, and FIG. 9C is CC of FIG. It is sectional drawing which follows a line.
[0021]
The quenching device 10 enables the quenched material 1 of the hollow rack to be quenched. The material to be quenched 1 has a circular tubular shape and forms a rack tooth surface 2 at a part in the circumferential direction within a certain length range in the longitudinal direction. The rack tooth surface 2 arranges the cutting edges of adjacent rack teeth in a single plane.
[0022]
As shown in FIGS. 1 to 3, the quenching device 10 guides the bases 15 and 16 of the upper and lower dies 13 and 14 to the left and right columns 11 and 12 so that the bases 15 and 16 can move up and down. , 14 can be opposed to each other.
[0023]
The quenching device 10 positions the material to be quenched 1 held by a rack holding device (not shown) at a quenching work position in the center in the vertical direction between the upper and lower dies 13 and 14.
[0024]
The quenching device 10 has a heating device 17. The heating device 17 includes a high-frequency induction heating device or the like, moves forward from the standby position toward the quenching operation position, heats the material 1 to be quenched held by the work holding device, and then returns to the standby position. . During the heating by the heating device 17, the material to be quenched 1 is rotated around its own axis by the work holding device.
[0025]
The quenching device 10 has at least four upper, lower, left and right clampers 21 to 24, an upper clamp 13 is provided with an upper clamper 21 so as to be movable up and down, and a lower clamp 14 is provided with a lower clamper 22 so as to be movable up and down. 14 are provided with left and right clampers 23 and 24 so as to be movable left and right. The quenching device 10 enables the quenched material 1 in a heated state by the upper and lower clampers 21 and 22 to be pinched and restrained from a vertical direction orthogonal to the rack tooth surface 2, and then to be clamped by the left and right clampers 23 and 24. The quenched material 1 is clamped from the left and right directions to be restrained, and the upper and lower clampers 21 and 22 can restrain the quenched material 1 before the left and right clampers 23 and 24.
[0026]
Here, the upper clamper 21 is vertically movably guided by a concave guide 13A provided on the center axis of the upper die 13, and is built in the spring storage hole 13B on the back side of the concave guide 13A and supported by the upper die 13. The upper clamper 21 is initially set to a side protruding from a final restraint position for finally restraining the quenched material 1 by a resilient body 31 such as a compression coil spring. The upper clamper 21 and the material to be quenched 1 make it possible to move to the final restraint position against the resilient body 31 due to the collision between the upper clamper 21 and the material 1 to be hardened. In the final restraint position, the upper clamper 21 abuts against a stopper surface 13C formed of a step surface between the concave guide 13A and the spring storage hole 13B, and is moved and locked. The final restraint position of the upper clamper 21 can be adjusted by a shim 13D laminated on the stopper surface 13C.
[0027]
The lower clamper 22 is vertically movably guided by a concave guide 14A provided on the center axis of the lower mold 14, and is built in a spring storage hole 14B on the back side of the concave guide 14A and supported by the lower mold 14. The lower clamper 22 is initially set by a resilient body 32 such as a spring on a side protruding from a final restraint position for finally restraining the material 1 to be quenched, and the lower clamper 22 is moved by approaching movement of the upper and lower dies 13 and 14. The abutment between the clamper 22 and the material 1 to be quenched makes it possible to move to the final restraint position against the resilient body 32. In the final restraint position, the lower clamper 22 abuts against a stopper surface 14C formed of a step surface between the concave guide 14A and the spring storage hole 14B and is locked and moved. The final restraint position of the lower clamper 22 can be adjusted by a shim 14D laminated on the stopper surface 14C.
[0028]
The right and left clampers 23 and 24 are guided by horizontal slide surfaces 41A and 42A of L-shaped guides 41 and 42 provided on the left and right sides of the lower die 14 so as to be movable left and right. The connecting rods 43, 44 connected to the rear surfaces of the clampers 23, 24 penetrate the vertical walls 41B, 42B of the L-shaped guides 41, 42, and are fixed to the penetrating ends with the stoppers 43A, 44A and the vertical walls 41B, 42B. The elastic bodies 45 and 46 such as rubber lumps are sandwiched and held between them. The resilient members 45 and 46 initially set the left and right clampers 23 and 24 on the retracted side from the final restraint position, in this embodiment, on the side in contact with the vertical walls 41B and 42B.
[0029]
The right and left clampers 23 and 24 are moved under the state in which the upper and lower clampers 21 and 22 first abut against the quenched material 1 by restraining the quenched material 1 by the approaching movement of the upper and lower dies 13 and 14 (up and down). May be in a state where the clampers 21 and 22 have reached the final restraint position and have completed the restraint, or may be in a state where they have not reached the final restraint position and are in the middle of restraint process), and are interlocked with the movement of the clampers 21 and 22. The elastic members 45 and 46 can be moved to the final restraint position while compressively deforming the elastic members 45 and 46 against the elastic members 45 and 46.
[0030]
In the present embodiment, the left and right clampers 23 and 24 can be pushed from the initial setting position to the final constraint position by wedge portions 51 and 52 projecting downward on both sides of the upper clamper 21 in the upper die 13. . The wedge portions 51 and 52 enter between the rear surfaces of the left and right clampers 23 and 24 and the vertical walls 41B and 42B of the L-shaped guides 41 and 42 by the approaching movement of the upper and lower dies 13 and 14, and move the clampers 23 and 24. It is pushed toward the final restraint position on the horizontal slide surfaces 41A and 42A.
[0031]
The quenching device 10 sets the upper clamper 21 to the final restraint position by the stopper surface 13C of the upper die 13 in a state where the upper and lower dies 13 and 14 move close to each other and their die contact surfaces 61 and 62 are in contact with each other. The clamper 22 is set to the final restraint position by the stopper surface 14C of the lower die 14, and the left and right clampers 23, 24 are set to the final restraint position by the wedge portions 51, 52 provided on the upper die 13.
[0032]
Then, in a state where all of the upper, lower, left, and right clampers 21 to 24 are set to the final restraint positions as described above, the tip surfaces 21A to 24A of all the clampers 21 to 24 are mutually cross-sectionally shaped. And the same shape as the above. The tip surfaces 21A to 24A of the clampers 21 to 24 surround the outer periphery of the quenched material 1 without a gap or with a small gap therebetween.
[0033]
In a state in which all the upper, lower, left, and right clampers 21 to 24 are set at the final restraint position, the quenching device 10 allows the upper and lower dies 13, 14 to pass through between the adjacent clampers 21 to 24 as shown in FIG. Injection ports 71, 72, 73, 74 for injecting the quenching liquid to the quenching material 1 are provided. As shown in FIG. 4, the upper die 13 has quench liquid supply paths 70A and 70B connected to the quench liquid supply source, and the injection ports 71 and 72 communicate with the quench liquid supply paths 70A and 70B, respectively. As shown in FIG. 5, the lower mold 14 has quenching liquid supply paths 70C and 70D connected to the quench liquid supply source, and the injection ports 73 and 74 communicate with the quench liquid supply paths 70C and 70D, respectively. The injection ports 71 to 74 are formed of a large number of hole rows (slits are also possible) along the longitudinal direction of the material 1 to be quenched. The injection ports 71 to 74 correspond to four equally spaced positions in the circumferential direction of the material 1 to be quenched (positions at 90-degree intervals), and the injection ports 73 and 74 correspond to the rack tooth surface 2 of the material 1 to be quenched. Corresponds to both sides.
[0034]
As shown in FIG. 6, the quenching device 10 puts the tip surface 22A of the lower clamper 22 on the rack tooth surface 2 of the material 1 to be quenched. The tooth surface 2 is made up of a flat surface 82 which is flat and extends along a single plane formed by the cutting edge of the tooth surface 2. Further, the quenching device 10 is configured so that the tip surfaces 21A, 23A, 24A of the upper clamper 21 and the left and right clampers 23, 24 are respectively arranged along the arc surface of the quenched material 1 as shown in FIGS. Each of the end faces 21A, 23A, 24A is provided with vertical and horizontal liquid flow grooves 81A, 81B, 83A, 83B, 84A, 84B.
[0035]
In addition, the quenching device 10 is configured to move the tip end surface 22A of the lower clamper 22, which corresponds to a portion other than the rack tooth surface 2 of the quenched material 1, into an arc along the arc surface of the quenched material 1 as shown in FIG. Surface 85, and vertical and horizontal liquid circulation grooves 85A and 85B are provided on each end surface 22A.
[0036]
The method of quenching the material to be quenched 1 by the quenching device 10 is performed in the following procedure.
(1) After forming the teeth to be hardened by forming rack teeth in a hollow tube to be a rack material, the entirety of the hardened material 1 including the rack tooth surface 2 is simultaneously heated by the heating device 17. The material to be quenched 1 caused a bending amount of, for example, 0.66 mm in a vertical direction orthogonal to the tooth surface 2 of the rack of the material to be quenched 1 as distortion due to heating.
[0037]
(2) The heated material to be quenched 1 is set at a quenching work position.
(3) The upper and lower dies 13 and 14 are moved close to each other, and the quenched material 1 is first restrained from the upper and lower directions by the upper and lower clampers 21 and 22.
[0038]
(4) At the final stage of the approach movement of the upper and lower dies 13, 14, the right and left clampers 23, 24 start restraining the quenched material 1 from the left and right directions.
[0039]
(5) In the state where the contact surfaces 61, 62 of the upper and lower dies 13, 14 are in contact with each other, the upper, lower, left, and right clampers 21 to 24 are set to their final restraint positions, and the quenched material 1 by the clampers 21 to 24 is set. Complete the restraint.
[0040]
(6) The quenching liquid is injected from the injection ports 71 to 74 of the upper and lower dies 13 and 14 to cool the entire quenched material 1 including the rack tooth surface 2. Since the entire material 1 to be quenched was cooled while being clamped by the clampers 21 to 24, the amount of bending of the material 1 to be quenched was reduced to 0.05 mm.
[0041]
According to the present embodiment, the following operational effects can be obtained.
(Operation and Effect Corresponding to Claims 1 and 2)
{Circle around (1)} The quenched material 1 of the hollow rack tends to be warped in the vertical direction perpendicular to the rack tooth surface 2 by heating. First, the quenched material 1 is restrained and corrected by the upper and lower clampers 21 and 22 in the vertical direction, and then the cross section of the quenched material 1 is formed by all the right and left upper and lower clampers 21 to 24 including the right and left clampers 23 and 24. , The deformation of the quenched material 1 can be easily corrected and restrained without causing the deformed bent portion of the quenched material 1 to protrude from the restraining regions of the left, right, upper and lower clampers 21 to 24.
[0042]
(2) Since the upper mold 13 is provided with the upper clamper 21 and the lower mold 14 is provided with the lower clamper 22 and the right and left clampers 23 and 24, even if the cross-sectional shape of the material 1 to be quenched changes, the left and right and upper and lower clampers 21 to 21 are provided. It is sufficient to replace only 24, and it is not necessary to replace the entire upper and lower dies 13, 14.
[0043]
(Operation and Effect Corresponding to Claim 3)
(3) The upper clamper 21 is initially set on the side protruding from the final restraint position by the resilient body 31 supported by the upper mold 13, and the lower clamper 22 is moved from the final restraint position by the resilient body 32 supported by the lower mold 14. Also, the right and left clampers 23 and 24 can be moved from the initial setting position to the final restraint position in conjunction with the relative movement of the upper and lower dies 13 and 14. Therefore, only by moving the upper die 13 with respect to the lower die 14, the above-mentioned (1) restraining operation by the left, right, upper and lower clampers 21 to 24 can be executed.
[0044]
(Operation and Effect Corresponding to Claim 4)
(4) The left and right clampers 23 and 24 can be pushed from the initial setting position to the final restraint position by the wedge portions 51 and 52 provided on the upper die 13. That is, the restraining operation by the right and left clampers 23 and 24 can be easily linked to the movement of the upper mold 13.
[0045]
(Operation and Effect Corresponding to Claim 5)
(5) When the upper and lower dies 13, 14 are in contact with the contact surfaces 61, 62, the upper clamper 21 is set to the final restraint position by the stopper surface 13C of the upper mold 13, and the lower clamper 22 is set to the stopper surface of the lower mold 14. 14C, it is possible to set the left and right clampers 23, 24 to the final restraint position by wedge portions 51, 52 provided on the upper die 13. Therefore, by moving the upper die 13 until it hits the lower die 14, all the upper, lower, left and right clampers 21 to 24 can be easily and reliably set to the final restraint position.
[0046]
(Operation and Effect Corresponding to Claim 6)
{Circle around (6)} With the upper, lower, left, and right clampers 21 to 24 set at the final restraint positions, the tip surfaces 21A to 24A of all the clampers 21 to 24 define the same shape as the cross-sectional shape of the material 1 to be quenched. Form. Therefore, the restrained regions of the upper, lower, left and right clampers 21 to 24 do not become narrower than the cross section of the material 1 to be quenched, and the material to be quenched 1 is not restricted by the clampers 21 to 24.
[0047]
(Operation and Effect Corresponding to Claim 7)
{Circle around (7)} By providing the injection ports 71 to 74 in the upper and lower dies 13 and 14, there is no need to provide the injection ports in the clampers 21 to 24. It is possible to simplify the structure of the clampers 21 to 24 that need to be replaced by changing the cross-sectional shape of the material 1 to be quenched.
[0048]
(Operation and Effect Corresponding to Claim 8)
{Circle around (8)} The lower clamper 22 is in wide contact with the rack tooth surface 2 of the material 1 to be quenched by the flat tip surface 22A, so that the material 1 to be quenched can be reliably restrained. Between the tip surface 22A of the lower clamper 22 and the material 1 to be quenched, the groove of the rack tooth surface 2 of the material 1 to be quenched allows the quenching liquid to flow. Between the upper clamper 21 and the tip surfaces 21A, 23A, 24A of the left and right clampers 23, 24 and the quenched material 1, the liquid circulation provided on the tip surfaces 21A, 23A, 24A of the respective clampers 21, 23, 24 is provided. The grooves 81A, 81B, 83A, 83B, 84A, 84B allow the quenching liquid to flow.
[0049]
As described above, the embodiment of the present invention has been described with reference to the drawings. However, the specific configuration of the present invention is not limited to this embodiment, and there are design changes and the like that do not depart from the gist of the present invention. Are also included in the present invention.
[0050]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, when quenching the quenched material of the hollow rack which is easily deformed by heating, the deformation of the quenched material can be easily corrected, restrained, and cooled. Further, according to the present invention, the configuration of the quenching apparatus can be simplified.
[Brief description of the drawings]
FIG. 1 is a front view showing a state of heating a material to be quenched by a quenching device.
FIG. 2 is a front view showing a constrained cooling state of a material to be quenched by a quenching device.
FIG. 3 is an arrow view along the line III-III in FIG. 1;
FIGS. 4A and 4B show an upper mold, in which FIG. 4A is a sectional view and FIG. 4B is a bottom view.
FIGS. 5A and 5B show a lower die, in which FIG. 5A is a sectional view and FIG. 5B is a top view.
FIGS. 6A and 6B show a lower clamper, wherein FIG. 6A is a side view, FIG. 6B is a plan view, and FIG. 6C is a cross-sectional view taken along line CC of FIG.
7A and 7B show a lower clamper, wherein FIG. 7A is a side view, FIG. 7B is a plan view, and FIG. 7C is a cross-sectional view taken along line CC of FIG.
8A and 8B show an upper clamper, wherein FIG. 8A is a side view, FIG. 8B is a plan view, and FIG. 8C is a cross-sectional view taken along line CC of FIG. 8A.
9A and 9B show left and right clampers, FIG. 9A is a side view, FIG. 9B is a plan view, and FIG. 9C is a cross-sectional view taken along line CC of FIG. 9B.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Hardened material 2 Rack tooth surface 10 Quenching device 13, 14 Upper and lower dies 13C, 14C Stopper surface 21 Upper clamper 21A Tip surface 22 Lower clamper 22A Tip surface 23, 24 Left and right clampers 23A, 24A Tip surface 31, 32 Bullet Ejectors 45, 46 Ejectors 51, 52 Wedge 61, 62 Mold contact surface 71-74 Injection ports 81A, 81B, 83A, 83B, 84A, 84B, 85A, 85B Liquid flow groove 82 Flat surface

Claims

In a method of quenching a hollow rack in which a quenching liquid is injected after restraining a quenched material of a hollow rack by at least four clampers of up, down, left and right, the quenched material is vertically moved perpendicular to a rack tooth surface by upper and lower clampers. Characterized in that the material to be quenched is constrained from the left and right directions by left and right clampers after the quenching of the hollow rack.

After constraining the material to be quenched in the hollow rack by at least four clampers on the upper, lower, left, and right sides, in a quenching device for a hollow rack that injects a quenching liquid,
The upper mold and the lower mold are provided so as to be relatively movable,
An upper clamper is provided on the upper die so that it can move up and down,
A lower clamper is provided on the lower mold so that it can move up and down,
Left and right clampers are provided on one of the lower mold and upper mold so that they can move left and right,
The hollow rack is characterized in that the material to be quenched can be restrained from the vertical direction perpendicular to the rack tooth surface by upper and lower clampers, and the material to be quenched can be restrained by the upper and lower clampers before the left and right clampers. Hardening equipment.

The upper clamper is initially set on the side protruding from the final restraint position by the resilient body supported by the upper mold, and is opposed to the resilient body by abutment with the material to be quenched due to the relative movement of the upper and lower molds. It can be moved to the final constraint position,
The lower clamper is initially set on the side protruding from the final restraint position by the lower body supported elastic body, and is finally opposed to the elastic body by abutment with the material to be hardened due to the relative movement of the upper and lower molds. It is possible to move to the constraint position,
The left and right clampers are initially set to the retracted side from the final restraint position by the elastic body supported by one of the lower mold and the upper mold, and the upper and lower clampers restrain the quenched material first by the relative movement of the upper and lower molds The quenching apparatus for a hollow rack according to claim 2, wherein the left and right clampers can be moved to a final restraint position against the resilient body in conjunction with the relative movement of the up and down dies under the state.

Under the condition that the left and right clampers are supported by one of the lower mold and the upper mold, the left and right clampers can be pushed from the initial setting position to the final restraint position by wedge portions provided on the other of the lower mold and the upper mold. Item 4. A quenching apparatus for a hollow rack according to Item 3.

When the upper and lower mold contact surfaces are in contact with each other, the upper clamper is set to the final constraint position by the upper mold stopper surface, the lower clamper is set to the final constraint position by the lower mold stopper surface, and the left and right clampers are lowered. 5. The quenching device for a hollow rack according to claim 4, wherein a wedge portion provided on the other of the mold and the upper mold enables the final constraint position to be set.

6. The quenching of the hollow rack according to claim 5, wherein in a state in which all of the upper, lower, left, and right clampers are set at the final restraint positions, the tip surfaces of all the clampers define the same cross-sectional shape as the material to be quenched. apparatus.

The upper and lower molds are provided with an injection port for injecting a quenching liquid into a material to be quenched through a space between adjacent clampers in a state in which all of the upper, lower, left, and right clampers are set at final constraint positions. The hardening device for a hollow rack according to item 1.

In a state in which the tip surface of the lower clamper is brought into contact with the tooth surface of the rack of the material to be quenched, the tip surface of the lower clamper has a planar shape, and a liquid circulation groove is provided on the tip surfaces of the upper clamper and the left and right clampers. Item 8. A hardening device for a hollow rack according to any one of Items 2 to 7.