JP4039516B2

JP4039516B2 - Coating film scraper

Info

Publication number: JP4039516B2
Application number: JP2002217965A
Authority: JP
Inventors: 政章宮城
Original assignee: 有限会社沖栄工業
Priority date: 2002-07-26
Filing date: 2002-07-26
Publication date: 2008-01-30
Anticipated expiration: 2022-07-26
Also published as: JP2003181824A

Description

【０００１】
【産業上の利用分野】
本発明は、回転駆動されるホイールの切削面でコンクリート（モルタル）の床または壁等の面に塗布された塗膜を削り取る塗膜削り取り装置に関するものである。
【０００２】
【従来の技術】
一般に、塗膜削り取り装置は、コンクリート床またはコンクリート壁等の硬質の面に塗布された塗膜を削り取るのに用いられる（例えば、特開２０００−２０２７７７号公報、特開２０００−３２６２３３号公報参照）。このような塗膜削り取り装置はグラインダやディスクサンダとして知られている。塗膜削り取り装置（ディスクサンダ）は、図１１に示されるように、持ち運び可能な本体２と、この本体２に取り付けられ本体２の駆動モータに接続され、回転駆動して切削面で塗膜を削り取るホイール３とを備えて構成される。このホイール３は図１２に示されるように、本体２の回転軸４にワッシャ５およびショックアブソーバ６を介してクランプナット（止めねじ）７により取り付けられるようになっている。
【０００３】
ホイール３は、鉄材からなり、図１２および図１３に示すように、中心に取り付け孔８が穿設された円板状部９と、この円板状部９外周から下方に延びる円筒状部１０と、この円筒状部１０下端から水平に延びる鍔部１１とを備えて構成される。鍔部１１の下面外周側には、厚肉でかつ下面が平坦に形成された切削部１２が形成される。切削部１２には、切削刃１３が周方向等間隔に所定の数（この例では６個）溶接されて設けられる。切削刃１３は、回転方向Ｒ１（図１３の反時計回り方向）前方側の鋼製刃部１３Ａと、この刃部１３Ａの回転方向後方側に形成され刃部１３Ａを支持するとともに切削部１２に溶接される鉄製の支持部１３Ｂとを備えて構成される。切削刃１３は厚さ１ないし２mm、径方向幅２ないし３mm、回転方向の前後長さ５ないし１３mmの直方体形状で、これら各寸法は、切削刃１３の数や径により適宜変更される。
【０００４】
切削刃１３は、図１３に示すように、円周の接線方向Ｌ１（径方向の直線Ｌ２に対し直交する線）に対し回転方向前方側が径方向外側に回転方向後方側が径方向内側に傾斜して設けられる（特開２０００−２０２７７７号公報参照）。
【０００５】
【発明が解決しようとする課題】
ところで、上記従来の塗膜削り取り装置では、コンクリート面に塗布された塗膜を削り取るのに、時間がかかるという問題があった。このため、作業時間に制約がある場合や、広い面積の塗膜を処理する場合、多数の作業員を配しそれぞれの作業員に塗膜削り取り装置を持たせて作業を行わなければならず、コストアップを招くという問題があった。さらに、上記従来の構成に係る塗膜削り取り装置では、切削刃のうち、鉄製の支持部１３Ｂの摩耗が激しく、使用時間が長くなると、支持部１３Ｂが薄肉化し切削刃１３の損傷を招くという問題があった。このため、所定の使用時間毎に切削刃の損耗度をチェックし、摩耗が進むと、高価なホイール３を交換しなければならず、コストアップを招くという問題があった。
【０００６】
本発明は上記課題を解決するためになされたもので、塗膜の削り取り性能を向上させることができるとともに、切削刃の損耗を抑制し、ホイールの長寿命化を図ることができる塗膜削り取り装置を提供するものである。
【０００７】
【課題を解決するための手段】
本発明に係る塗膜削り取り装置は、本体に取り付けられ回転駆動されるホイールと、このホイールの下面に下方に突出し周方向等間隔に設けられた切削刃とを備え、ホイールを回転駆動させて塗布面に塗布された塗膜を削り取る塗膜削り取り装置において、ホイールの外周面に、ホイール下面から下方に突出し切削刃の削り取りに先行して塗膜を傷つける刻み刃を設け、この刻み刃を、回転方向前方側の刃部とこの刃部の回転方向後方側に形成され刃部を支持するとともにホイール外周面に溶接される支持部とを備えて構成し、刃部をホイール下面から下方に突出させ、かつ、刃部の回転方向前面が斜め下方を向くようにし、刻み刃と切削刃とのホイール下面からの突出高さを同一にしたものである。
【０００８】
本発明に係る塗膜削り取り装置では、本体に取り付けられ回転駆動されるホイールと、このホイールの下面に下方に突出し周方向等間隔に設けられた切削刃とを備え、ホイールを回転駆動させて塗布面に塗布された塗膜を削り取る塗膜削り取り装置において、ホイールの外周面に、ホイール下面から下方に突出し切削刃の削り取りに先行して塗膜を傷つける刻み刃を設け、この刻み刃を、回転方向前方側の刃部とこの刃部の回転方向後方側に形成され刃部を支持するとともにホイール外周面に溶接される支持部とを備えて構成し、刃部をホイール下面から下方に突出させ、かつ、刃部の回転方向前面が斜め下方を向くようにし、刻み刃と切削刃とのホイール下面からの突出高さを同一にしたことにより、塗膜削り取り時、回転するホイールの移動方向すなわち進行方向では、ホイール外周面に設けられた刻み刃が、まず初めに塗膜を切り刻み削りほぐして剥離し易くし、続いてこの削りほぐされた塗膜をホイール下面に設けられた切削刃が削り取るので、塗膜が確実に削り取られ、塗膜の削り残しが少なくなり、削り取り効率が向上する。このため、回転するホイールを何度も往復させて削り残りを取り除く作業が必要なくなり、作業効率が向上する。
【０００９】
また、請求項２に係る塗膜削り取り装置は、ホイール下面に設けられた切削刃を、回転方向前方側の刃部とこの刃部の回転方向後方側に形成され刃部を支持するとともにホイールに溶接される支持部とを備えて構成するとともに、この支持部を回転方向に対し前方側が径方向内側に後方側が径方向外側にそれぞれ位置するよう傾斜させて設けたものである。
【００１０】
請求項２に係る塗膜削り取り装置では、ホイール下面に設けられた切削刃を、回転方向前方側の刃部とこの刃部の回転方向後方側に形成され刃部を支持するとともにホイールに溶接される支持部とを備えて構成するとともに、この支持部を回転方向に対し前方側が径方向内側に後方側が径方向外側にそれぞれ位置するよう傾斜させて設けたことにより、塗膜削り取り時、支持部の径方向内側には、削り取られた塗膜が当たりにくくなり支持部径方向内側の損耗を抑えることができる。また、支持部の径方向外側は、回転方向前方側の刃部により塗膜が径方向外方にはじき飛ばされるので、塗膜が当たりにくくなる。このため、支持部径方向外側の損耗も抑えることができるので、支持部は摩耗しにくくホイールを長期にわたり使用することができる。
【００１７】
【発明の実施の形態】
以下、図面に示す実施の形態により本発明を説明する。図１は本発明のうち第１の発明の一実施の形態に係る塗膜削り取り装置の要部を示す底面図、図２は図１の側面図である。この実施の形態に係る塗膜削り取り装置は、図１１ないし１３に示す上記従来のものとホイールの構成が異なる点を除いてほぼ同一の構成を備えている。すなわち、上記実施の形態に係る塗膜削り取り装置は、持ち運び可能な本体２（図１１参照）と、図１に示すように、この本体２に取り付けられ本体２の駆動モータに接続され、回転駆動して切削面で塗膜を削り取るホイール２０とを備えて構成される。
【００１８】
このホイール２０は、鉄材からなり、図１および図２に示すように、中心に取り付け孔２８が穿設された円板状部２９と、この円板状部２９外周から下方に延びる円筒状部３０と、この円筒状部３０から円錐状に下方に拡がる円錐状部３１と、この円錐状部３１下端から水平に外方に延びる鍔部３２とを備えて成型される。鍔部３２の下面外周側には、厚肉でかつ下面が平坦に形成された切削部３３が設けられる。切削部３３は、径方向に所定の幅寸法Ｗ１（図２参照、本実施の形態では、およそ５〜６mm）を有している。
【００１９】
成型されたホイール２０の切削部３３には、図３の（Ａ）、（Ｂ）に示すように、下面３３Ａと外周面３３Ｂとにそれぞれ、切削刃溶接用の凹陥部３４と刻み刃溶接用の凹陥部３５が穿設される。切削刃溶接用の凹陥部３４は、周方向等間隔に所定の数（この例では６個）設けられ、回転方向Ｒ２（図１および図３（Ａ）の反時計回り方向）に対し前方側が浅く後方側が深くなるように傾斜して形成される。刻み刃溶接用の凹陥部３５は、周方向等間隔に所定の数（この例では６個）設けられ、回転方向Ｒ２（図１および図３（Ａ）の反時計回り方向）に対し前方側が径方向中心側に向かって浅く後方側が径方向中心側に向かって深くなるように傾斜して形成される。
【００２０】
切削部３３の凹陥部３４には、図１および図２に示すように、切削刃４０が溶接されて設けられる。切削刃４０は、図４に示すように、回転方向Ｒ２（図１の反時計回り方向）前方側に配置された硬質の鋼製刃部４０Ａと、この刃部４０Ａの回転方向後方側に形成され刃部４０Ａを支持するとともに凹陥部３４に溶接される鉄製の支持部４０Ｂとを備えたチップにより構成される。刃部４０Ａは、厚さおよそ０．３から１．０mmの薄片からなり、支持部４０Ｂは、厚さ１ないし２mm、径方向幅２ないし３mm、回転方向前後長さ５ないし１３mmの直方体形状で、これら各寸法は、切削刃４０の数や径により適宜変更される。切削刃４０は、図５に示すように、支持部４０Ｂの幅広の一面４０Ｃ（図４参照）が凹陥部３４の傾斜面に溶接され、刃部４０Ａが切削部下面３３Ａから下方（図５では上方）に突出し、支持部４０Ｂの回転方向後方側が凹陥部３４内に沈み込むようになっている。このため、切削刃４０は切削部下面３３Ａに対して傾斜して設けられる。
【００２１】
ところで、本実施の形態に係る塗膜削り取り装置では、切削刃４０の直方体状支持部４０Ｂは、図１および図５に示すように、回転方向前方側の刃部４０Ａの前面が、回転方向に対し径方向内側に傾斜して向くように、支持部４０Ｂの回転方向前方側を径方向内側に、回転方向後方側を径方向外側にそれぞれ位置させ回転方向に対して内側に傾斜させて溶接される。しかも、切削刃４０は、図５に示すように、切削部下面３３Ａに対して支持部４０Ｂの回転方向前方側が下方に突出し、支持部４０Ｂの回転方向後方側が凹陥部３４の内部に沈み込むように傾斜して設けられている。このため、塗膜削り取り時、支持部４０Ｂの径方向内側には、削り取られた塗膜が当たりにくくなり支持部４０Ｂ径方向内側の損耗を抑えることができる。また支持部４０Ｂの径方向外側には、回転方向前方側の刃部４０Ａにより塗膜が径方向外方にはじき飛ばされるので、塗膜が当たりにくくなる。このため、支持部４０Ｂ径方向外側の損耗も抑えることができるので、支持部４０Ｂは摩耗しにくく高価なホイールを長期にわたり使用することができる。
【００２２】
さらに、本実施の形態に係る塗膜削り取り装置では、上記切削刃４０と略同一の構成を有する刻み刃（刃）４１を、図１、図２、図６および図７（Ａ）ないし（Ｃ）に示すように、刃部４０Ａを切削部下面３３Ａにより形成される平面より下方（図２では下方向、図６では上方向）に突出させて刃部４０Ａの前面が切削部外周面３３Ｂの接線方向に対し斜め下方を向くように、支持部４０Ｂを傾斜させ幅広の一面４０Ｃを凹陥部３５の傾斜面に溶接している。すなわち、直方体状の刻み刃４１の幅広の一面４０Ｃを凹陥部３５の傾斜面に溶接する際、刃部４０Ａが切削部下面３３Ａから下方に突出し、かつ、刃部４０Ａの前面が斜め下方を向くように傾斜させて溶接するようにしている。刻み刃４１は、刃部４０Ａの長手方向が刃幅となる切削刃４０に比べて、刃部４０Ａの短寸方向が刃幅となる鋭利な刃となっており、切削刃４０の削り取りに先行して塗膜を傷つけ剥離しやすくさせるようになっている。
【００２３】
刻み刃４１の刃部４０Ａ下端と切削刃４０の刃部４０Ａ下端とは、いずれも同一の寸法Ｗ３（図２参照）で切削部下面３３Ａから下方に突出するようになっている。なお、刃部４０Ａの傾斜角度や突出寸法は、ホイール２０の大きさや形状、刻み刃４１の数により変わることがあるのはいうまでもない。本実施の形態では、刻み刃４１を周方向等間隔に６個設けているがこれに限られるものではなく、２個、３個、４個というように、性能とコストを勘案して個数の増減を図ってもよいことはいうまでもない。
【００２４】
この塗膜削り取り装置では、切削部３３の外周側に、切削部下面３３Ａにより形成される平面より下方に突出した刻み刃４１を設けるようにしているので、塗膜削り取り時、回転するホイールの進行方向前方側では、ホイールの外周側に設けられた刻み刃４１が塗膜を傷つけ削りほぐして剥離しやすくし、続いてこの削りほぐされた塗膜をホイール下面に設けられた切削刃４０が削り取るようになっている。
【００２５】
次に、上記実施の形態に係る塗膜削り取り装置の作用について説明する。上記実施の形態に係る塗膜削り取り装置では、ホイール２０が回転駆動され、切削部３３がコンクリート（モルタル）の塗膜に押し当てられて塗膜を削り取る際、回転するホイール２０の移動方向すなわち進行方向では、ホイール２０の外周面３３Ｂに設けられた刻み刃４１がまず塗膜を切り刻んで削りほぐし、塗膜を軟化させて剥離しやすくし、続いてこの削りほぐされた塗膜を切削部下面３３Ａの切削刃４０が削り取るので、塗膜が確実に削り取られ、塗膜の削り残しが少なくなり、削り取り効率が向上する。このため、回転するホイールを何度も往復させて削り残りを取り除く作業が必要なくなり、作業効率が向上する。また、上記実施の形態に係る塗膜削り取り装置では、切削刃４０の支持部４０Ｂは、回転方向に対して前方側が径方向内側に傾斜して溶接され、支持部４０Ｂの回転方向後方側が凹陥部３４の内部に沈み込むように切削部下面３３Ａに対して傾斜して設けられている。このため、塗膜削り取り時、切削刃４０の支持部４０Ｂの径方向内側には、削り取られた塗膜が当たりにくくなり支持部４０Ｂ径方向内側の損耗を抑えることができる。また切削刃４０の支持部４０Ｂの径方向外側には、回転方向前方側の刃部４０Ａにより塗膜が径方向外方にはじき飛ばされるので、塗膜が当たりにくくなる。このため、支持部４０Ｂ径方向外側の損耗も抑えることができるので、切削刃４０の支持部４０Ｂは摩耗しにくく高価なホイールを長期にわたり使用することができる。
【００２６】
なお、上記実施の形態では、刻み刃４１を、切削部外周面３３Ｂの凹陥部３５に設けるようにしているがこれに限られるものではなく、刻み刃４１は切削刃４０の外周側に設けられていればよく、切削部下面３３Ａの外周縁に設けるようにしてもよいことはいうまでもない。
【００２７】
次に、本発明の参考例に係る塗膜削り取り装置の一実施の形態について、図８および図９を参照して説明する。参考例に係る塗膜削り取り装置は、第１の発明に係る塗膜削り取り装置が、ホイール２０の切削部３３に切削刃４０を溶接して設けるようにしているのに対し、図８ないし図１０に示すように、ホイール５０の切削部５３に上下面を貫通する貫通孔６０を穿設し、この貫通孔６０に切削刃６１を取り換え可能に取り付けた点が異なっている。
【００２８】
ホイール５０は、鉄材からなり、図８および図９に示すように、中心に取り付け孔２８が穿設された円板状部２９と、この円板状部２９外周から下方に延びる円筒状部３０と、この円筒状部３０から円錐状に下方に拡がる円錐状部３１と、この円錐状部３１下端から水平に延びる鍔状の切削部５３とを備えて成型される。切削部５３は、所定の厚肉を有しかつ下面が平坦に形成され、径方向に所定の幅寸法Ｗ２（本実施の形態では、およそ１０〜１２mm、Ｗ２＞Ｗ１）を有している。
【００２９】
成型されたホイール５０の切削部５３には、図１０に示すように、上下面を貫通する貫通孔６０が穿設される。貫通孔６０は、切削部５３下面に形成され回転方向Ｒ３（図８の反時計回り方向）前方側に開口する四角形状開口部６０Ａと、この四角形状開口部６０Ａと同じ形状で、切削部５３上面に形成され回転方向Ｒ３後方側に開口する四角形状開口部６０Ｂとを結ぶ傾斜した貫通孔として形成される。すなわち、貫通孔６０は傾斜した四角柱状の空間が切削部５３を貫通するように形成され、この傾斜した四角柱状の空間６０は回転方向前方側の延長空間が切削部５３下面から斜め下方に向かって延び、回転方向後方側の延長空間が切削部５３上面から斜め上方に向かって延びるようになっている。
【００３０】
この貫通孔６０には、図１０に示すように、回転方向後方側の傾斜した壁面５４に、板状の切削刃６１がねじ６２により取り付けられる。切削刃６１は、下端の硬質の鋼製刃部６１Ａが貫通孔６０の切削部下面開口部６０Ａから、上端６１Ｂが貫通孔６０の切削部上面開口６０Ｂからそれぞれ突出し、鉋刃のように切削部５３に取り付けられる。ねじ６２は、切削部上面開口６０Ｂから工具により取り付けられる。このため、切削刃６１の着脱が容易にできるようになっている。
【００３１】
切削刃６１の前面６１Ｃと貫通孔６０の前方側傾斜壁面５５との間には、図１０に示すように、ガイド孔（空隙）Ｓ１が形成される。このガイド孔Ｓ１は、塗膜削り取り時、削り取られた塗膜を下面開口部６０Ａから上面開口部６０Ｂに導いて外部に排出するようになっている。
【００３２】
切削部５３の下面には、図８および図１０に示すように、下面開口部６０Ａの回転方向前方側と後方側とにそれぞれ鋭利な刻み刃（刃）６３、６４が設けられる。回転方向前方側の刻み刃６３は、下面開口部６０Ａより径方向外側に、回転方向後方側の刻み刃６４は、下面開口部６０Ａより径方向内側にそれぞれ設けられるようになっている。刻み刃６３、６４は、刃幅の長い切削刃６１に比べて、刃幅が短寸の鋭利な刃となっており、切削刃６１の削り取りに先行して塗膜を傷つけ剥離しやすくさせるとともに、切削刃６１により削り取られた削りかすをより細かく切断して削り取り性能を向上させるようになっている。なお、これら刻み刃６３、６４の径方向位置は逆でもよい。
【００３３】
次に、上記参考例に係る塗膜削り取り装置の作用について説明する。上記参考例に係る塗膜削り取り装置では、ホイール５０が回転駆動され、切削部５３がコンクリート（モルタル）の塗膜に押し当てられて塗膜を削り取る際、回転するホイール５０の移動方向すなわち進行方向では、切削部５３下面の刻み刃６３、６４がまず塗膜を切り刻んで帯状に削りほぐし、塗膜を軟化させて剥離し易くし、続いてこの削りほぐされた塗膜を切削部５３下面の切削刃６１が削り取るので、塗膜が確実に削り取られ、塗膜の削り残しが少なくなり、削り取り効率が向上する。切削刃６１により削り取られた塗膜は、切削刃６１の傾斜した前面に当たって下面開口部６０Ａからガイド孔Ｓ１内に導かれ、上面開口部６０Ｂから外部に排出される。このため、塗膜削り取り時、切削部５３下面に削りかすが滞留しにくくなり、削り取り効率がより向上する。切削刃６１が損耗した場合、ねじ６２を外して新たな切削刃６１に交換することができるので、高価なホイールを取り換える必要がなく、コストダウンを図ることができる。さらに、切削刃６１はホイール５０の切削部５３上面からねじ６２により取り外しができるようになっているので、切削刃６１の交換時、交換作業を容易に行うことができる。
【００３４】
なお、上記実施例および参考例に係る塗膜削り取り装置では、図１１に示すように、手で持って作業する持ち運び可能なものを一例に挙げているがこれに限られるものではなく、車輪を有する重量のある大型のものにも適用可能であることはいうまでもない。また、回転駆動されるホイールは単一のものに限られるものではなく、複数のホイールを備えたものにも適用可能であることはいうまでもない。さらに、上記参考例に係る実施の形態では、切削刃６１の取り付けをねじ６２により行っているがこれに限られるものではなく、切削刃６１を貫通孔６０内に確実にかつ交換可能に取り付けることができるものであれば、他の締結具や締結機構を用いてもよいことはいうまでない。また、貫通孔６０は傾斜した四角柱状空間に限られるものではなく、切削刃の形状や種類に応じて適宜変更してもよいことはいうまでもない。また、ホイール２０、５０は、強度上、円筒状部３０や円錐状部３１を設けているがこれに限られるものではなく、下面が平坦で外周部を有する切削部を有するものであればよいことはいうまでもなく、円盤状でも円板状でもよい。さらに、参考例に係るホイール５０について、刻み刃６３、６４に代えて、第１の発明の構成に係る刻み刃４１をホイール５０の外周側に設けるようにしてもよい。
【００３５】
【発明の効果】
以上述べたように、本発明に係る塗膜削り取り装置によれば、本体に取り付けられ回転駆動されるホイールと、このホイールの下面に下方に突出し周方向等間隔に設けられた切削刃とを備え、ホイールを回転駆動させて塗布面に塗布された塗膜を削り取る塗膜削り取り装置において、ホイールの外周面に、ホイール下面から下方に突出し切削刃の削り取りに先行して塗膜を傷つける刻み刃を設け、この刻み刃を、回転方向前方側の刃部とこの刃部の回転方向後方側に形成され刃部を支持するとともにホイール外周面に溶接される支持部とを備えて構成し、刃部をホイール下面から下方に突出させ、かつ、刃部の回転方向前面が斜め下方を向くようにし、刻み刃と切削刃とのホイール下面からの突出高さを同一にしたことにより、塗膜削り取り時、回転するホイールの移動方向すなわち進行方向では、ホイール外周面に設けられた刻み刃が、まず初めに塗膜を切り刻み削りほぐして剥離し易くし、続いてこの削りほぐされた塗膜をホイール下面に設けられた切削刃が削り取るので、塗膜の削り取り性能を向上させることができ、作業効率が向上するとともに、切削刃の損耗を抑制し、ホイールの長寿命化を実現しコストダウンを図ることができる効果がある。
【図面の簡単な説明】
【図１】第１の発明の一実施の形態に係る塗膜削り取り装置のホイールを示す底面図である。
【図２】図１のホイールのII-II線から見た一部破断側面図である。
【図３】（Ａ）、（Ｂ）はそれぞれ、図１のホイールに切削刃および刻み刃を溶接する前の凹陥部を形成した状態を示す底面図およびその側面図である。
【図４】切削刃および刻み刃を構成するチップを示す斜視図である。
【図５】図１のホイールに溶接された切削刃を示す説明図である。
【図６】図１のホイールに溶接された刻み刃を示す説明図である。
【図７】（Ａ）ないし（Ｃ）はそれぞれ、刻み刃がホイールの切削部に溶接された状態を下方から見た説明図、側方からみた説明図および上方から見た説明図である。
【図８】第２の発明の一実施の形態に係る塗膜削り取り装置のホイールを示す底面図である。
【図９】図８のホイールのIX-IX線から見た一部破断側面図である。
【図１０】図８のホイールの要部を拡大して示す断面図である。
【図１１】塗膜削り取り装置を示す斜視図である。
【図１２】塗膜削り取り装置の回転軸にホイールを取り付ける際の説明図である。
【図１３】従来のホイールを示す底面図である。
【符号の説明】
２塗膜削り取り装置本体
２０ホイール
３３Ａホイール下面
３３Ｂホイール外周面
４０切削刃
４１刻み刃[0001]
[Industrial application fields]
The present invention relates to a coating film scraping device that scrapes off a coating film applied to a surface of a concrete (mortar) floor or wall with a cutting surface of a wheel that is driven to rotate.
[0002]
[Prior art]
In general, the coating film scraping device is used to scrape a coating film applied to a hard surface such as a concrete floor or a concrete wall (see, for example, JP 2000-202777 A, JP 2000-326233 A). . Such a coating film scraping apparatus is known as a grinder or a disk sander. As shown in FIG. 11, the coating film scraping device (disc sander) is connected to a portable main body 2 and a driving motor of the main body 2 and is rotated to drive the coating film on the cutting surface. It comprises a wheel 3 for scraping. As shown in FIG. 12, the wheel 3 is attached to a rotating shaft 4 of the main body 2 by a clamp nut (set screw) 7 via a washer 5 and a shock absorber 6.
[0003]
The wheel 3 is made of an iron material, and as shown in FIGS. 12 and 13, a disk-shaped part 9 having a mounting hole 8 formed in the center and a cylindrical part 10 extending downward from the outer periphery of the disk-shaped part 9. And a flange portion 11 extending horizontally from the lower end of the cylindrical portion 10. On the outer peripheral side of the lower surface of the flange portion 11, a cutting portion 12 having a thick wall and a flat lower surface is formed. A predetermined number (six in this example) of cutting blades 13 are welded to the cutting portion 12 at equal intervals in the circumferential direction. The cutting blade 13 is formed on a steel blade portion 13A on the front side in the rotation direction R1 (counterclockwise direction in FIG. 13) and on the rear side in the rotation direction of the blade portion 13A, and supports the blade portion 13A. And an iron support portion 13B to be welded. The cutting blade 13 has a rectangular parallelepiped shape with a thickness of 1 to 2 mm, a radial width of 2 to 3 mm, and a longitudinal length of 5 to 13 mm, and these dimensions are appropriately changed depending on the number and diameter of the cutting blades 13.
[0004]
As shown in FIG. 13, the cutting blade 13 is inclined with respect to the tangential direction L1 of the circumference (a line perpendicular to the radial straight line L2) with the front side in the rotational direction radially outward and the rear side in the rotational direction radially inward. (See JP 2000-202777 A).
[0005]
[Problems to be solved by the invention]
By the way, in the said conventional coating-film scraping apparatus, there existed a problem that it took time to scrape off the coating film apply | coated to the concrete surface. For this reason, when there is a restriction on the work time or when processing a large area of the coating film, a large number of workers must be arranged and each worker must have a coating film scraping device to perform the work, There was a problem of incurring a cost increase. Furthermore, in the coating film scraping device according to the above-described conventional configuration, when the wear of the iron support portion 13B is severe among the cutting blades and the usage time becomes long, the support portion 13B becomes thin and causes damage to the cutting blade 13. was there. For this reason, the degree of wear of the cutting blade is checked every predetermined usage time, and if the wear progresses, the expensive wheel 3 must be replaced, resulting in an increase in cost.
[0006]
The present invention has been made to solve the above problems, and can improve the coating performance of the coating film, suppress wear of the cutting blade, and extend the service life of the wheel. it is intended to provide.
[0007]
[Means for Solving the Problems]
A coating film scraping apparatus according to the present invention includes a wheel that is attached to a main body and is rotationally driven, and a cutting blade that protrudes downward on the lower surface of the wheel and is provided at equal intervals in the circumferential direction, and is applied by rotating the wheel and applying it. in coating scraping device scraping a coating film applied to a surface, on the outer peripheral surface of the wheel is provided with a knurled edge hurt coating from the wheel bottom surface prior to the chipping of the projecting cutting edge downward, the increment blade, rotary A blade portion on the front side in the direction and a support portion formed on the rear side in the rotation direction of the blade portion to support the blade portion and welded to the outer peripheral surface of the wheel, and the blade portion protrudes downward from the lower surface of the wheel. In addition, the front surface in the rotational direction of the blade portion faces obliquely downward, and the protruding heights of the knitting blade and the cutting blade from the lower surface of the wheel are the same .
[0008]
The coating film scraping device according to the present invention includes a wheel that is attached to the main body and is rotationally driven, and a cutting blade that protrudes downward on the lower surface of the wheel and is provided at equal intervals in the circumferential direction. in coating scraping device scraping a coating film applied to a surface, on the outer peripheral surface of the wheel is provided with a knurled edge hurt coating from the wheel bottom surface prior to the chipping of the projecting cutting edge downward, the increment blade, rotary A blade portion on the front side in the direction and a support portion formed on the rear side in the rotation direction of the blade portion to support the blade portion and welded to the outer peripheral surface of the wheel, and the blade portion protrudes downward from the lower surface of the wheel. and the rotation direction front of the blade portion so as to face obliquely downward, by which the projection height from the wheel bottom surface of the increments blade and the cutting edge in the same, when scraping the coating, the wheel rotates The dynamic direction, i.e. travel direction, increments blades provided on the wheel outer peripheral surface, and easily removed by loosening cutting minced First coating, followed by provided the shaving loosened paint film to the wheel bottom surface cutting Since the blade is scraped off, the coating film is surely scraped off, and the uncut portion of the coating film is reduced, and the scraping efficiency is improved. For this reason, the work which reciprocates the rotating wheel many times and removes a shaving residue becomes unnecessary, and work efficiency improves.
[0009]
Further, the coating film scraping device according to claim 2 is configured such that the cutting blade provided on the lower surface of the wheel is formed on the blade portion on the front side in the rotational direction and on the rear side in the rotational direction of the blade portion, and supports the blade portion. And a support portion to be welded. The support portion is provided so as to be inclined with respect to the rotation direction so that the front side is positioned radially inward and the rear side is positioned radially outward.
[0010]
In the coating film scraping device according to claim 2, the cutting blade provided on the lower surface of the wheel is formed on the blade portion on the front side in the rotational direction and on the rear side in the rotational direction of the blade portion, and is welded to the wheel while supporting the blade portion. The support portion is provided with an inclination so that the front side is located radially inward and the rear side is located radially outward with respect to the rotational direction. It is difficult for the scraped paint film to hit the inner side in the radial direction of the steel plate, and wear on the inner side in the radial direction of the support portion can be suppressed. Moreover, since the coating film is repelled radially outward by the blade part on the front side in the rotation direction, the coating film is less likely to hit the radially outer side of the support part. For this reason, since wear on the outer side in the radial direction of the support portion can be suppressed, the support portion is less likely to be worn and the wheel can be used for a long period of time.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described below with reference to embodiments shown in the drawings. FIG. 1 is a bottom view showing a main part of a coating film scraping apparatus according to an embodiment of the first invention of the present invention, and FIG. 2 is a side view of FIG. The coating film scraping apparatus according to this embodiment has substantially the same configuration except that the configuration of the wheel is different from that of the conventional apparatus shown in FIGS. That is, the coating film scraping device according to the above embodiment includes a portable main body 2 (see FIG. 11) and, as shown in FIG. 1, is attached to the main body 2 and connected to a drive motor of the main body 2, and is rotationally driven. And a wheel 20 that scrapes off the coating film on the cutting surface.
[0018]
The wheel 20 is made of an iron material, and as shown in FIGS. 1 and 2, a disk-shaped part 29 having a mounting hole 28 formed in the center and a cylindrical part extending downward from the outer periphery of the disk-shaped part 29. 30, a conical portion 31 that extends downward in a conical shape from the cylindrical portion 30, and a collar portion 32 that extends horizontally outward from the lower end of the conical portion 31. A cutting portion 33 having a thick wall and a flat bottom surface is provided on the outer peripheral side of the bottom surface of the collar portion 32. The cutting part 33 has a predetermined width dimension W1 (see FIG. 2, approximately 5 to 6 mm in this embodiment) in the radial direction.
[0019]
As shown in FIGS. 3A and 3B, the cutting portion 33 of the molded wheel 20 has a concave portion 34 for cutting blade welding and a cutting blade welding for a lower surface 33A and an outer peripheral surface 33B, respectively. The recessed portion 35 is drilled. A predetermined number (six in this example) of recesses 34 for cutting blade welding are provided at equal intervals in the circumferential direction, and the front side with respect to the rotation direction R2 (counterclockwise direction in FIGS. 1 and 3A) is It is shallow and formed so that the rear side is deep. A predetermined number (six in this example) of recesses 35 for knives blade welding are provided at equal intervals in the circumferential direction, and the front side is in the rotational direction R2 (the counterclockwise direction in FIGS. 1 and 3A). It is formed so as to incline so that the rear side is shallower toward the radial center side and the rear side is deeper toward the radial center side.
[0020]
As shown in FIGS. 1 and 2, a cutting blade 40 is welded to the recessed portion 34 of the cutting portion 33. As shown in FIG. 4, the cutting blade 40 is formed on a hard steel blade portion 40A disposed on the front side in the rotational direction R2 (counterclockwise direction in FIG. 1), and on the rear side in the rotational direction of the blade portion 40A. The blade portion 40A is supported by a chip having an iron support portion 40B welded to the recessed portion 34. The blade portion 40A is a thin piece having a thickness of about 0.3 to 1.0 mm, and the support portion 40B is a rectangular parallelepiped shape having a thickness of 1 to 2 mm, a radial width of 2 to 3 mm, and a longitudinal length of 5 to 13 mm in the rotational direction. These dimensions are appropriately changed depending on the number and diameter of the cutting blades 40. In the cutting blade 40, as shown in FIG. 5, one wide surface 40C (see FIG. 4) of the support portion 40B is welded to the inclined surface of the recessed portion 34, and the blade portion 40A is below the cutting portion lower surface 33A (in FIG. 5). It protrudes upward), and the rear side in the rotation direction of the support portion 40B sinks into the recessed portion 34. For this reason, the cutting blade 40 is inclined with respect to the lower surface 33A of the cutting part.
[0021]
By the way, in the coating-film scraping apparatus which concerns on this Embodiment, as shown to FIG. 1 and FIG. 5, as for the rectangular parallelepiped support part 40B of the cutting blade 40, the front surface of the blade part 40A of the rotation direction front side is a rotation direction. The support portion 40B is welded so that the front side in the rotational direction of the support portion 40B is positioned inward in the radial direction and the rear side in the rotational direction is radially inward so that the support portion 40B is inclined inward with respect to the rotational direction. The In addition, as shown in FIG. 5, the cutting blade 40 protrudes downward in the rotational direction of the support portion 40 B with respect to the lower surface 33 A of the cutting portion, and the rear side in the rotational direction of the support portion 40 B sinks into the recessed portion 34. It is provided with an inclination. For this reason, at the time of coating film scraping, the scraped coating film is less likely to hit the radially inner side of the support portion 40B, and wear on the radially inner side of the support portion 40B can be suppressed. Further, since the coating film is repelled radially outward by the blade part 40A on the front side in the rotational direction on the radially outer side of the support portion 40B, the coating film is difficult to hit. For this reason, since the wear on the outer side in the radial direction of the support portion 40B can be suppressed, the support portion 40B can be used with an expensive wheel that is hard to wear over a long period of time.
[0022]
Furthermore, in the coating film scraping apparatus according to the present embodiment, a cutting blade (blade) 41 having substantially the same configuration as that of the cutting blade 40 is replaced with FIGS. 1, 2, 6, and 7 (A) to (C). ), The blade portion 40A protrudes downward (downward in FIG. 2, upward in FIG. 6) from the plane formed by the cutting portion lower surface 33A, and the front surface of the cutting portion 40A is the cutting portion outer peripheral surface 33B. The support portion 40B is inclined so as to face obliquely downward with respect to the tangential direction, and the wide one surface 40C is welded to the inclined surface of the recessed portion 35. That is, when welding one wide surface 40C of the rectangular cutting blade 41 to the inclined surface of the recessed portion 35, the blade portion 40A protrudes downward from the cutting portion lower surface 33A, and the front surface of the blade portion 40A faces obliquely downward. It is made to incline and weld. The cutting blade 41 is a sharp blade in which the short direction of the blade portion 40A is the blade width compared to the cutting blade 40 in which the longitudinal direction of the blade portion 40A is the blade width, and precedes the cutting of the cutting blade 40. Thus, the coating film is damaged and easily peeled off.
[0023]
The lower end 40A of the cutting blade 41 and the lower end 40A of the cutting blade 40 both protrude downward from the lower surface 33A of the cutting portion with the same dimension W3 (see FIG. 2). In addition, it cannot be overemphasized that the inclination-angle and protrusion dimension of 40 A of blade parts may change with the magnitude | size and shape of the wheel 20, and the number of the cutting blades 41. FIG. In the present embodiment, six cutting blades 41 are provided at equal intervals in the circumferential direction. However, the number of cutting blades 41 is not limited to this, and the number of cutting blades 41 is considered in consideration of performance and cost, such as two, three, and four. Needless to say, it may be increased or decreased.
[0024]
In this coating film scraping device, the cutting blade 41 projecting downward from the plane formed by the lower surface 33A of the cutting portion is provided on the outer peripheral side of the cutting portion 33. Therefore, the progress of the rotating wheel during coating film scraping is provided. On the front side in the direction, the cutting blade 41 provided on the outer peripheral side of the wheel damages the coating film to make it easy to peel off, and then the cutting blade 40 provided on the lower surface of the wheel scrapes off the scraped coating film. It is like that.
[0025]
Next, the effect | action of the coating-film scraping apparatus which concerns on the said embodiment is demonstrated. In the coating film scraping apparatus according to the above-described embodiment, when the wheel 20 is driven to rotate and the cutting portion 33 is pressed against the concrete (mortar) coating film to scrape the coating film, the moving direction of the rotating wheel 20, that is, the progress. In the direction, the cutting blade 41 provided on the outer peripheral surface 33B of the wheel 20 first cuts and tears the coating film, softens the coating film to make it easy to peel, and subsequently removes the shaved coating film on the lower surface of the cutting portion. Since the 33A cutting blade 40 is scraped off, the coating film is reliably scraped off, and the uncut portion of the coating film is reduced, and the scraping efficiency is improved. For this reason, the work which reciprocates the rotating wheel many times and removes a shaving residue becomes unnecessary, and work efficiency improves. Further, in the coating film scraping device according to the above-described embodiment, the support portion 40B of the cutting blade 40 is welded such that the front side is inclined radially inward with respect to the rotation direction, and the rotation direction rear side of the support portion 40B is a recessed portion. 34 is provided so as to be inclined with respect to the lower surface 33A of the cutting portion so as to sink into the inside. For this reason, at the time of coating film scraping, the scraped coating film is less likely to hit the inside in the radial direction of the support portion 40B of the cutting blade 40, and wear on the inside in the radial direction of the support portion 40B can be suppressed. Further, the coating film is hardly hit on the radially outer side of the support portion 40B of the cutting blade 40 because the coating portion is repelled radially outward by the blade portion 40A on the front side in the rotation direction. For this reason, since the wear on the radially outer side of the support portion 40B can be suppressed, the support portion 40B of the cutting blade 40 is less likely to be worn and an expensive wheel can be used for a long time.
[0026]
In the above embodiment, the cutting blade 41 is provided in the recessed portion 35 of the cutting portion outer peripheral surface 33B. However, the present invention is not limited to this, and the cutting blade 41 is provided on the outer peripheral side of the cutting blade 40. Needless to say, it may be provided on the outer peripheral edge of the lower surface 33A of the cutting portion.
[0027]
Next, an embodiment of a paint film scraping apparatus according to a reference example of the present invention will be described with reference to FIGS. The coating film scraping apparatus according to the reference example is such that the coating film scraping apparatus according to the first invention is provided by welding the cutting blade 40 to the cutting portion 33 of the wheel 20, whereas FIGS. As shown in FIG. 4, a through hole 60 penetrating the upper and lower surfaces is formed in the cutting portion 53 of the wheel 50, and the cutting blade 61 is attached to the through hole 60 so as to be replaceable.
[0028]
The wheel 50 is made of an iron material, and as shown in FIGS. 8 and 9, a disc-like portion 29 having a mounting hole 28 formed in the center and a cylindrical portion 30 extending downward from the outer periphery of the disc-like portion 29. And a conical portion 31 that extends downward in a conical shape from the cylindrical portion 30, and a bowl-shaped cutting portion 53 that extends horizontally from the lower end of the conical portion 31. The cutting portion 53 has a predetermined thickness and a flat bottom surface, and has a predetermined width dimension W2 in the radial direction (in the present embodiment, approximately 10 to 12 mm, W2> W1).
[0029]
As shown in FIG. 10, a through hole 60 penetrating the upper and lower surfaces is formed in the molded cutting portion 53 of the wheel 50. The through hole 60 is formed on the lower surface of the cutting portion 53 and has a rectangular opening 60A that opens to the front side in the rotation direction R3 (counterclockwise direction in FIG. 8). The cutting hole 53 has the same shape as the rectangular opening 60A. It is formed as an inclined through-hole that connects to the rectangular opening 60B that is formed on the upper surface and opens to the rear side in the rotation direction R3. That is, the through hole 60 is formed so that an inclined square columnar space penetrates the cutting part 53, and the inclined square columnar space 60 has an extended space on the front side in the rotation direction obliquely downward from the lower surface of the cutting part 53. The extension space on the rear side in the rotation direction extends obliquely upward from the upper surface of the cutting portion 53.
[0030]
As shown in FIG. 10, a plate-like cutting blade 61 is attached to the through-hole 60 with a screw 62 on an inclined wall surface 54 on the rear side in the rotational direction. In the cutting blade 61, a hard steel blade portion 61A at the lower end protrudes from the lower surface opening portion 60A of the cutting portion of the through hole 60, and an upper end 61B protrudes from the upper surface opening 60B of the cutting portion of the through hole 60, respectively. 53. The screw 62 is attached by a tool from the upper surface opening 60B of the cutting part. For this reason, the cutting blade 61 can be easily attached and detached.
[0031]
As shown in FIG. 10, a guide hole (gap) S 1 is formed between the front surface 61 C of the cutting blade 61 and the front inclined wall surface 55 of the through hole 60. The guide hole S1 guides the scraped coating film from the lower surface opening 60A to the upper surface opening 60B and discharges it to the outside when the coating film is scraped.
[0032]
As shown in FIGS. 8 and 10, sharp cutting blades (blades) 63 and 64 are provided on the lower surface of the cutting portion 53 on the front and rear sides in the rotational direction of the lower surface opening 60 A, respectively. The cutting blade 63 on the front side in the rotational direction is provided radially outward from the lower surface opening 60A, and the cutting blade 64 on the rear side in the rotational direction is provided radially inward from the lower surface opening 60A. The cutting blades 63 and 64 are sharp blades having a short blade width compared to the cutting blade 61 having a long blade width, and are easy to damage and peel off the coating film prior to the cutting of the cutting blade 61. The shavings shaved off by the cutting blade 61 are cut more finely to improve the shaving performance. The radial positions of the knive blades 63 and 64 may be reversed.
[0033]
Next, the operation of the coating film scraping device according to the reference example will be described. In the coating film scraping device according to the above reference example , when the wheel 50 is driven to rotate and the cutting portion 53 is pressed against the concrete (mortar) coating film to scrape the coating film, the moving direction of the rotating wheel 50, that is, the traveling direction. Then, the cutting blades 63 and 64 on the lower surface of the cutting part 53 first cut the coating film to scrape it into a strip shape, soften the coating film to make it easy to peel off, and subsequently remove the shaved coating film on the lower surface of the cutting part 53. Since the cutting blade 61 is scraped off, the coating film is surely scraped off, and the uncut portion of the coating film is reduced, and the scraping efficiency is improved. The coating film scraped off by the cutting blade 61 strikes the inclined front surface of the cutting blade 61, is guided into the guide hole S1 from the lower surface opening 60A, and is discharged to the outside from the upper surface opening 60B. For this reason, at the time of coating film scraping, the shavings are less likely to stay on the lower surface of the cutting portion 53, and the shaving efficiency is further improved. When the cutting blade 61 is worn out, the screw 62 can be removed and replaced with a new cutting blade 61. Therefore, it is not necessary to replace an expensive wheel, and the cost can be reduced. Furthermore, since the cutting blade 61 can be removed from the upper surface of the cutting portion 53 of the wheel 50 with the screw 62, the replacement work can be easily performed when the cutting blade 61 is replaced.
[0034]
In coating scraping device according to the above you施例and the reference example, as shown in FIG. 11, but the present invention is cited what portable working by hand in one example is not limited to this, Needless to say, the present invention can also be applied to a large-sized one having wheels. Needless to say, the rotationally driven wheel is not limited to a single wheel, and can be applied to a wheel having a plurality of wheels. Furthermore, in the embodiment according to the above reference example , the cutting blade 61 is attached by the screw 62, but the present invention is not limited to this, and the cutting blade 61 is securely and replaceably attached in the through hole 60. It goes without saying that other fasteners and fastening mechanisms may be used as long as they can be used. Needless to say, the through hole 60 is not limited to the inclined square columnar space, and may be appropriately changed according to the shape and type of the cutting blade. Further, the wheels 20 and 50 are provided with the cylindrical portion 30 and the conical portion 31 in terms of strength, but are not limited thereto, and may be any as long as the lower surface is flat and has a cutting portion having an outer peripheral portion. Needless to say, it may be disk-shaped or disk-shaped. Further, with respect to the wheel 50 according to the reference example , the cutting blade 41 according to the configuration of the first invention may be provided on the outer peripheral side of the wheel 50 in place of the cutting blades 63 and 64.
[0035]
【The invention's effect】
As described above, the coating film scraping apparatus according to the present invention includes a wheel that is attached to the main body and is driven to rotate, and a cutting blade that protrudes downward on the lower surface of the wheel and is provided at equal intervals in the circumferential direction. In the coating film scraping device that drives the wheel to scrape off the coating film applied to the coating surface, the outer peripheral surface of the wheel protrudes downward from the lower surface of the wheel and has a notch blade that damages the coating film prior to scraping the cutting blade. The cutting blade is configured to include a blade portion on the front side in the rotational direction and a support portion formed on the rear side in the rotational direction of the blade portion to support the blade portion and welded to the outer peripheral surface of the wheel. the protruding from the wheel bottom surface downwardly, and, by the rotation direction front of the blade portion so as to face obliquely downward, and a protrusion height from the wheel bottom surface of the increments blade and the cutting edge in the same, the coating scraped In the moving direction of the rotating wheel, that is, the traveling direction, the cutting blade provided on the outer peripheral surface of the wheel first chops up the coating to make it easy to peel off, and then removes the crushed coating on the lower surface of the wheel. since scraped cutting edge provided on, it can improve the scraping performance of the coating film, thereby improving work efficiency, to suppress the wear of the cutting edge, to reduce the cost and achieve a long life of the wheel There is an effect that can.
[Brief description of the drawings]
FIG. 1 is a bottom view showing a wheel of a paint film scraping device according to an embodiment of the first invention.
2 is a partially broken side view of the wheel of FIG. 1 as seen from the line II-II.
FIGS. 3A and 3B are a bottom view and a side view, respectively, illustrating a state in which a recess is formed on the wheel of FIG. 1 before welding a cutting blade and a cutting blade.
FIG. 4 is a perspective view showing chips constituting a cutting blade and a knitting blade.
5 is an explanatory view showing a cutting blade welded to the wheel of FIG. 1. FIG.
6 is an explanatory view showing a knitting blade welded to the wheel of FIG. 1; FIG.
7A to 7C are an explanatory diagram viewed from below, an explanatory diagram viewed from the side, and an explanatory diagram viewed from above, respectively, in a state in which the cutting blade is welded to the cutting part of the wheel.
FIG. 8 is a bottom view showing a wheel of a paint film scraping device according to an embodiment of the second invention.
9 is a partially cutaway side view of the wheel of FIG. 8 as seen from line IX-IX.
10 is an enlarged cross-sectional view showing a main part of the wheel of FIG. 8. FIG.
FIG. 11 is a perspective view showing a coating film scraping device.
FIG. 12 is an explanatory diagram when a wheel is attached to the rotating shaft of the coating film scraping device.
FIG. 13 is a bottom view showing a conventional wheel.
[Explanation of symbols]
2 Coating film scraping device main body 20 Wheel 33A Wheel lower surface 33B Wheel outer peripheral surface 40 Cutting blade 41 Knitting blade

Claims

A wheel that is attached to the main body and is rotationally driven, and a cutting blade that protrudes downwardly on the lower surface of the wheel and is provided at equal intervals in the circumferential direction. The coating applied on the coating surface is scraped off by rotating the wheel. In the film scraper,
On the outer peripheral surface of the wheel, a cutting blade that protrudes downward from the lower surface of the wheel and damages the coating film prior to scraping of the cutting blade is provided ,
The notching blade is configured to include a blade portion on the front side in the rotation direction and a support portion formed on the rear side in the rotation direction of the blade portion to support the blade portion and welded to the outer peripheral surface of the wheel. A coating film scraping device characterized by projecting downward from the lower surface and having the blade surface in the rotational direction face obliquely downward, so that the projecting height from the lower surface of the wheel of the knitting blade and the cutting blade is the same. .

The cutting blade provided on the lower surface of the wheel comprises a blade portion on the front side in the rotational direction and a support portion formed on the rear side in the rotational direction of the blade portion to support the blade portion and welded to the wheel, 2. The coating film scraping device according to claim 1, wherein the support portion is provided so as to be inclined with respect to the rotational direction such that the front side is located radially inside and the back side is located radially outside.