JPS5916823B2 - Rotary atomization electrostatic coating method - Google Patents

Description

【発明の詳細な説明】 本発明は、静電塗装装置に対し相対的に変位す ヨる被
塗物に対し静電塗装する時に発生する静電クレータ、花
咲き現象等の静電気に起因する塗装不良の発生を防止す
る方法に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention is intended to prevent coatings caused by static electricity, such as electrostatic craters and flower blooming phenomena, which occur when electrostatically coating an object that moves relative to an electrostatic coating device. Concerning a method for preventing the occurrence of defects.

従来、自動車の塗装ラインでコンベアによつて被塗物の
自動車ボディを搬送して塗装する場合、自動車ボディが
塗装プースに設置された回転霧化； 静電塗装装置の前
を通過する時、常時−６０ｋＶ〜−１２０ｋＶの一定高
電圧を印加することにより、塗装を行つていた。Conventionally, when painting an automobile body to be coated by conveying it by a conveyor on an automobile painting line, a rotary atomizer is installed in the painting booth; when the automobile body passes in front of an electrostatic coating device, Painting was performed by applying a constant high voltage of -60 kV to -120 kV.

このため、自動車ボディのうち塗装装置に向つて出張つ
たホィールハウス周りは、塗装装置と被塗物間の距離が
近くなるため、０高電圧による暗電流が増大して被塗装
面に２コート１ベークメタリックのクリャ塗装時は静電
クレータが、またメタリックベース塗装時は花咲き現象
等、静電気に起因する塗装欠陥が発生すること。がしば
しばあつた。この塗装欠陥は、とくに自動５ 車ボディ
の半開されたドアのエッジ部近傍で塗面の塗料流れの塗
装不具合をさけるため、塗料吐出を一時的に中断した場
合暗電流が非常に大きくなつて著しく多く起こり、これ
を防ぐための何らかの方策が望まれていた。ｏ 本発明
は、回転霧化静電塗装における上記の静電クレータ、花
咲き現象等の塗装欠陥の発生を防止する静電塗装方法を
提供することを目的とするものである。For this reason, the distance between the coating equipment and the object to be coated becomes shorter in the area around the wheel house that extends toward the coating equipment in the automobile body, and the dark current due to the high voltage increases, causing two coats to be applied to the surface to be painted. Painting defects caused by static electricity may occur, such as electrostatic craters when applying baked metallic clear paint, and flower blooming when applying metallic base paint. was often hot. This paint defect occurs especially when the paint discharge is temporarily interrupted near the edge of a half-open door on the body of an automobile to avoid paint defects due to paint flow on the paint surface, and the dark current becomes extremely large. This happens often, and some kind of measure to prevent this is desired. o An object of the present invention is to provide an electrostatic coating method that prevents the occurrence of coating defects such as electrostatic craters and blooming phenomena in rotary atomization electrostatic coating.

そして、この目的に沿う本発明の回転霧化静電５ 塗装
方法は、回転霧化静電塗装装置の印加高電圧、噴霧頭位
置などを、各々独立にまたは同時に、回転霧化装置噴霧
頭からの距離が経済的に変化する被塗物に対し予じめ定
められたプログラムにより制御することによつて、暗電
流を被塗物の部位にｏ応じた適正値以下に制限し、２コ
ート１ベークメタリックのクリャおよびメタリックベー
ス塗装時の静電時の静電クレータ、花咲き現象等の塗装
不良の発生を防止するようにしたものである。The rotary atomization electrostatic 5 coating method of the present invention that meets this objective is to control the applied high voltage, spray head position, etc. of the rotary atomization electrostatic coating device independently or simultaneously from the rotary atomization device spray head. By controlling the dark current according to a predetermined program for objects whose distance varies economically, the dark current is limited to an appropriate value depending on the part of the object to be coated, and two coats and one coat are applied. This is intended to prevent the occurrence of coating defects such as electrostatic craters and flower blooming phenomenon caused by static electricity during baking metallic clearing and metallic base coating.

以下に、本発明の実施例を図に従つて説明する。５ 第
１図は、自動車ボディ用の回転霧化静電塗装装置のレイ
アウトの一例を示している。Embodiments of the present invention will be described below with reference to the drawings. 5 FIG. 1 shows an example of the layout of a rotary atomization electrostatic coating device for automobile bodies.

自動車ボディ１は、図示しない搬送装置にのつてｄ方向
に進行し、この搬送装置の両側に対向して設置されたロ
ーサイド噴霧頭２およびハイサイド噴霧頭３の前を通過
する間にボデイ側面が塗装され、また上方に設置された
トツプ噴霧頭４によつてボデイ上面が塗装される。トツ
プ噴霧頭４は門型レシプロケータ５に付随し、左右に２
０〜５０ｃｍレジプロ動作でき、かつボディ１の上面の
形状に応じてボディ１の上面と常時所定間隔を保つよう
にシリンダにより上下動できる構造をもつている。ボデ
イ１のうち１ａはドアを示し、塗装時にはこれらのドア
１ａは半開きの状態で搬送される。また、１ｂはホィー
ルハウス周辺の外方への張り出し部位を示す。ローサイ
ド噴霧頭２はボデイ側面の下方部位を塗装し、ハイサイ
ド噴霧頭３はボデイ側面の上方部位を塗装するために用
いられ、噴霧頭２，３はシリンダにより前後動できる構
造をもつている。つぎに、ローサイド噴霧頭２を例にと
つて第２図に基づき塗装操作状態の制御を説明する。The automobile body 1 moves in the direction d along a conveyance device (not shown), and while passing in front of a low side spray head 2 and a high side spray head 3 installed oppositely on both sides of the conveyance device, the side surface of the body is The upper surface of the body is painted by a top spray head 4 installed above. The top spray head 4 is attached to the portal reciprocator 5, and there are two on the left and right.
It has a structure in which it can perform a register operation from 0 to 50 cm and can be moved up and down by a cylinder so as to always maintain a predetermined distance from the top surface of the body 1 according to the shape of the top surface of the body 1. 1a of the body 1 represents a door, and during painting, these doors 1a are transported in a half-open state. Further, 1b indicates an outwardly projecting portion around the wheel house. The low side spray head 2 is used to paint the lower part of the side of the body, and the high side spray head 3 is used to paint the upper part of the side of the body.The spray heads 2 and 3 have a structure that can be moved back and forth by a cylinder. Next, control of the coating operation state will be explained based on FIG. 2, taking the low side spray head 2 as an example.

図中Ｐはローサイド噴霧頭２の軌跡を示す。図示のＢと
Ｅの間およびＪとＭの間は、ホイールハウス周辺１ｂで
側面外方へ張り出しているため暗電流６が流れやすい部
位であり、同様にＦとＩの間は半開きのドア１ａのエツ
ジ部があるため電気力線が集中し、暗電流が流れやすい
部位である。第２図中、ローサイド噴霧頭２から被塗物
の自動車ボデイ１に流れ戻る暗電流６の制御は、高電圧
７の増減および噴霧頭位置８の前後動による噴霧頭一被
塗吻間距離変動によつて行われる。In the figure, P indicates the locus of the low side spray head 2. The areas between B and E and between J and M shown in the figure are areas where the dark current 6 tends to flow because they protrude outward from the sides around the wheel house 1b, and similarly between F and I is the area where the door 1a is half open. Because there is an edge in the area, electric lines of force are concentrated in this area, making it easy for dark current to flow. In FIG. 2, the dark current 6 flowing back from the low side spray head 2 to the object to be coated, the automobile body 1, is controlled by changing the distance between the spray head and the object to be coated by increasing/decreasing the high voltage 7 and moving the spray head position 8 back and forth. It is carried out by.

なお、暗電流は塗料吐出量９のオン−オフの影響が大き
いため高電圧７および噴霧頭位置８とタイミングをとつ
て制御される。図中、７′は高電圧の制御を行うタイム
チヤート、８′は噴霧頭位置の制御を行うタイムチヤー
ト、９／は塗料吐出量の制御を行うタイムチヤート、６
′は暗電流の変化を示すタイムチヤートである。自動車
ボデイ１がｄ方向に搬送されてきて、サイド噴霧頭２，
３の前を進行すると、ＡとＢの間は高電圧が高、噴霧頭
位置が前方、塗料吐出量が小、ＢとＣの間は高電圧が低
、噴霧頭位置が後方、塗料吐出量が小、ＣとＤの間は高
電圧が低、噴霧頭位置が後方、塗料吐出がオフ状態にな
る。Incidentally, since the dark current is greatly influenced by the on/off state of the paint discharge amount 9, it is controlled in accordance with the timing of the high voltage 7 and the spray head position 8. In the figure, 7' is a time chart that controls the high voltage, 8' is a time chart that controls the spray head position, 9/ is a time chart that controls the amount of paint discharged, and 6
' is a time chart showing changes in dark current. The automobile body 1 is transported in the d direction, and the side spray head 2,
When moving in front of 3, the high voltage is high between A and B, the spray head position is forward, and the amount of paint discharged is small; between B and C, the high voltage is low, the spray head position is backward, and the amount of paint discharged. is small, the high voltage is low between C and D, the spray head position is backward, and paint discharge is off.

以下、ＣないしＮ間は、自動車ボディ１が進行するにつ
れて上記動作に準じて、第２図に示した動作を行なう。
上記動作中、コンベアが停止した場合は、高電圧はオフ
される。これら、高電圧、噴霧頭位置、吐出量の制御に
より暗電流は塗装開始から塗装終了まで全ての時間で１
００μＡ以下望ましくは２０ＩｔＡ以下に保持される。
上記操作は第３図に示す装置によつて行われる。Thereafter, from C to N, as the automobile body 1 advances, the operation shown in FIG. 2 is performed in accordance with the above operation.
During the above operation, if the conveyor stops, the high voltage is turned off. By controlling the high voltage, spray head position, and discharge amount, the dark current is 1 from the start of painting to the end of painting.
It is maintained at 00 μA or less, preferably 20 ItA or less.
The above operation is performed by the apparatus shown in FIG.

回転噴霧頭１０はシリンダ１１によつてＸの方向に前後
に移動する構造をもち、高電圧発生装置１２から高電圧
ケーブル１３を介して高電圧が印加される構成を持つ。
そしてコンピユータ１４からタイムチヤートにしたがつ
て、あらかじめ設定された高電圧の高低変化および噴霧
頭位置の前後動指示が出され、暗電流を一定値以下に制
御する。この場合は、１５はエアモータ、１６は、絶縁
支持棒、１７はガイドバー、１８はスラスト軸受、１９
は支持体、２０は連結棒であり、コンピユータ１４の指
令により、シリンダ１１が作動し、回転噴霧頭１０．エ
アモータ１５を自動車ボデイ１に対して最適量に前後さ
せるようになつている。上記タイムチヤートによる高電
圧および噴霧頭位置の制御はボディ形状および塗料種類
各々に応じた電圧値、噴霧頭位置およびタイミングのプ
ログラムを設定して行う。The rotating spray head 10 has a structure in which it moves back and forth in the X direction by a cylinder 11, and has a structure in which a high voltage is applied from a high voltage generator 12 via a high voltage cable 13.
Then, according to the time chart, the computer 14 issues instructions to change the level of the high voltage set in advance and to move the spray head position back and forth, thereby controlling the dark current below a certain value. In this case, 15 is an air motor, 16 is an insulating support rod, 17 is a guide bar, 18 is a thrust bearing, 19
20 is a support body, 20 is a connecting rod, and the cylinder 11 is operated according to a command from the computer 14, and the rotating spray head 10. The air motor 15 is moved back and forth by an optimum amount with respect to the automobile body 1. Control of the high voltage and the spray head position using the time chart is performed by setting programs for the voltage value, spray head position, and timing depending on the body shape and paint type.

これらプログラムの設定は塗装室の温、湿度や自動車ボ
デイの搬送速度の変化によつても調整が行われる。本発
明の回転霧化静電塗装方法によれば、あらかじめ設定さ
れたプログラムにより塗装部位に応じて高電圧および噴
霧頭位置を変化させることによつて暗電流を設定値以下
に保持でき、静電クレータ、花咲き現象等の塗装欠陥の
発生を防止できる他、静電塗装本来の目的である高い塗
着効率を維持することができるこという効果を得る。The settings of these programs are also adjusted according to changes in the temperature and humidity of the painting room and the conveyance speed of the automobile body. According to the rotary atomization electrostatic coating method of the present invention, the dark current can be maintained below the set value by changing the high voltage and the spray head position according to the area to be coated according to a preset program, and the electrostatic In addition to being able to prevent the occurrence of coating defects such as craters and blooming phenomena, it is also possible to maintain high coating efficiency, which is the original purpose of electrostatic coating.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図は本発明の回転霧化静電塗装方法を実施する装置
の概略平面図、第２図は本発明の方法における挙動状態
を示すタイムテャート図、第３図は本発明の方法におけ
る噴霧頭位置を変化させる装置の概略構成図である。 図中の符号の意味はつぎの通りである。 １ ・・迫動車ボデイ、１ａ・・・ドア、１ｂ・゜゜張り出
し部位、２・・・ローサイド噴霧頭、３・・・ハイサイ
ド噴霧頭、４・・・トツプ噴霧頭、５・・・門型レシプ
ロケータ、６・・・暗電流、６′・・・暗電流の変化を
示すタィムート、７・・・高電圧、７′・・・高電圧の
制御を行うタイムチヤート、８・・・噴霧頭位置、８′
・・・噴霧頭位置の制御を行うタイムチヤート、９・・
・塗料吐出量、９′・・・塗料吐出量の制御を行うタイ
ムチヤート、１０・・・回転噴霧頭、１１・・・シリン
ダ、１２・・・高電圧発生装置 １３・・・高電圧ケー
ブル、１４・・・コンピユータ、１５・・・エアモータ
、１６・・・絶縁支持棒、１７・・・ガイドバー、１８
・・・スラスト軸受、１９・・・支持体、２０・・・連
結棒、Ｐ・・・ローサイド噴霧頭の軌跡。Fig. 1 is a schematic plan view of an apparatus for carrying out the rotary atomization electrostatic coating method of the present invention, Fig. 2 is a time chart showing the behavior state in the method of the present invention, and Fig. 3 is a spray head in the method of the present invention. It is a schematic block diagram of the apparatus which changes a position. The meanings of the symbols in the figure are as follows. 1...Motor vehicle body, 1a...Door, 1b・゜゜projection part, 2...Low side spray head, 3...High side spray head, 4...Top spray head, 5...Gate type Reciprocator, 6...Dark current, 6'...Timeout indicating changes in dark current, 7...High voltage, 7'...Time chart for controlling high voltage, 8...Spray head position, 8'
...Time chart for controlling the spray head position, 9...
- Paint discharge amount, 9'... Time chart for controlling the paint discharge amount, 10... Rotating spray head, 11... Cylinder, 12... High voltage generator 13... High voltage cable, 14... Computer, 15... Air motor, 16... Insulating support rod, 17... Guide bar, 18
... Thrust bearing, 19... Support body, 20... Connecting rod, P... Locus of low side spray head.

Claims (1)

【特許請求の範囲】 １ 被塗物の回転霧化装置噴霧頭からの距離が経済的に
変化する被塗物に対して、あらかじめ定められた操作量
により回転霧化静電塗装装置から被塗物に流れる暗電流
を一定値以下に制御することを特徴とする回転霧化静電
塗装方法。 ２ 前記操作量が印加高電圧であり、暗電流の制御を該
印加高電圧を制御することにより行なう特許請求の範囲
第１項記載の回転霧化静電塗装方法。 ３ 前記操作量が噴霧頭位置であり、暗電流の制御を該
噴霧頭位置を制御することにより行なう特許請求の範囲
第１項記載の回転霧化静電塗装方法。 ４ 前記操作量が印加高電圧と噴霧頭位置であり、暗電
流制御を印加高電圧と噴霧頭位置の両者を同時に制御す
ることにより行なう特許請求の範囲第１項記載の回転霧
化静電塗装方法。[Scope of Claims] 1. For a workpiece whose distance from the rotary atomizer spray head of the workpiece varies economically, the workpiece can be coated from a rotary atomizer electrostatic coating equipment by a predetermined operation amount. A rotary atomization electrostatic coating method characterized by controlling the dark current flowing through objects to below a certain value. 2. The rotary atomization electrostatic coating method according to claim 1, wherein the manipulated variable is an applied high voltage, and dark current is controlled by controlling the applied high voltage. 3. The rotary atomization electrostatic coating method according to claim 1, wherein the manipulated variable is a spray head position, and dark current is controlled by controlling the spray head position. 4. The rotary atomization electrostatic coating according to claim 1, wherein the manipulated variables are an applied high voltage and a spray head position, and the dark current control is performed by simultaneously controlling both the applied high voltage and the spray head position. Method.