JP2006167660A

JP2006167660A - Rotary atomization coating apparatus and bell type atomizing head for coating

Info

Publication number: JP2006167660A
Application number: JP2004366431A
Authority: JP
Inventors: Tomoshi Nakamura; 知志中村
Original assignee: Daihatsu Motor Co Ltd
Current assignee: Daihatsu Motor Co Ltd
Priority date: 2004-12-17
Filing date: 2004-12-17
Publication date: 2006-06-29

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotary atomization type coating apparatus capable of forming into a liquid filament and atomizing even a coating material such as water paint of a type to be applied with the increase of shearing stress and the decrease of viscoelasticity. <P>SOLUTION: A groove 108 formed on the inner peripheral surface 107 of a bell type atomizing head 101 is formed so that the depth in the center of the groove 108 in the width direction is deeper than that in the rear side of the groove 108 in the rotation direction in the peripheral directional cross-section. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

本発明は回転霧化塗装装置及び回転霧化式塗装装置に用いるベル型霧化ヘッドに関するものである。 The present invention relates to a bell type atomizing head used in a rotary atomizing coating apparatus and a rotary atomizing coating apparatus.

回転霧化式塗装装置１００は、例えば、図１に示すように、ベル型霧化ヘッド１０１と、ベル型霧化ヘッド１０１を回転させる回転機構１０２と、回転霧化式塗装装置１００と被塗装物（図示省略）との間に高電圧を印加する電圧付与装置１０３と、ベル型霧化ヘッド１０１内に塗料を供給する塗料供給部１０４とで主に構成されている。 For example, as shown in FIG. 1, the rotary atomizing coating apparatus 100 includes a bell-type atomizing head 101, a rotating mechanism 102 that rotates the bell-type atomizing head 101, the rotary atomizing-type coating apparatus 100, and the object to be coated. A voltage applying device 103 that applies a high voltage to an object (not shown) and a paint supply unit 104 that supplies the paint into the bell-type atomizing head 101 are mainly configured.

回転機構１０２はベル型霧化ヘッド１０１を高速で回転させる。ベル型霧化ヘッド１０１は、底部から開口部に向かうにつれて開口径が大きくなったベル形状を有し、開口端部に形成された円錐面１０７に、複数の溝１０８が放射状に形成されている。塗料供給部１０４から供給された塗料は、ベル型霧化ヘッド１０１の内周面の底部に環状に穿設された多数の塗料流出孔１０９を通って内周面に沿って流れ出し、高速で回転するベル型霧化ヘッド１０１から遠心力を受けて、ベル型霧化ヘッド１０１の開口端部の円錐面１０７に達する。そして、図２に示すように、円錐面１０７に形成された溝１０８に沿ってヘッドの外径方向に塗料１１０を液糸状に放出するようになっている。ベル型霧化ヘッド１０１から放出された塗料は、その後、直ちにちぎれて粒子状になり、微細な塗料噴霧になる。 The rotating mechanism 102 rotates the bell type atomizing head 101 at a high speed. The bell-type atomizing head 101 has a bell shape whose opening diameter increases from the bottom toward the opening, and a plurality of grooves 108 are formed radially on a conical surface 107 formed at the opening end. . The paint supplied from the paint supply unit 104 flows out along the inner peripheral surface through a large number of paint outflow holes 109 formed in an annular shape at the bottom of the inner peripheral surface of the bell-type atomizing head 101, and rotates at high speed. The bell type atomizing head 101 receives a centrifugal force and reaches the conical surface 107 at the opening end of the bell type atomizing head 101. As shown in FIG. 2, the coating material 110 is discharged in the form of liquid yarn in the outer diameter direction of the head along the groove 108 formed on the conical surface 107. The paint discharged from the bell-type atomizing head 101 is then immediately torn into particles and becomes a fine paint spray.

斯かる回転霧化式塗装装置を用いた静電塗装では、塗料がベル型霧化ヘッド１０１から放出されるまでの間に、電圧付与装置１０３により塗料に負の電荷を付与し、他方、被塗装物（図示省略）に正の電荷を付与し、ベル型霧化ヘッド１０１から噴霧される微細な霧状の塗料を電気的な作用により均一に被塗装物に付着させる。 In electrostatic coating using such a rotary atomizing coating device, a negative charge is applied to the coating material by the voltage applying device 103 until the coating material is discharged from the bell-type atomizing head 101, while A positive charge is applied to the coated object (not shown), and the fine mist paint sprayed from the bell-type atomizing head 101 is uniformly attached to the object to be coated by an electrical action.

斯かる回転霧化式塗装装置及びベル型霧化ヘッドについては、例えば、特開平８−２４７１９号公報や特開２００４−６６０８０号公報に記載されている。
特開平８−２４７１９号公報、第６図〜第８図特開２００４−６６０８０号公報、第２図 Such a rotary atomizing coating apparatus and a bell type atomizing head are described in, for example, Japanese Patent Application Laid-Open Nos. 8-24719 and 2004-66080.
JP-A-8-24719, FIGS. 6-8 Japanese Patent Laid-Open No. 2004-66080, FIG.

近年、環境問題からシンナーを含む溶剤系塗料からシンナーを含まない水性塗料へ変更するケースが増えてきている。上述した回転霧化式静電塗装に、水性塗料を用いる場合、溶剤系塗料と水性塗料とでは、ベル回転数に対する塗料粘性が異なるため、溶剤系塗料の場合と同等の粘度を得るため、ベル型霧化ヘッドの回転数をより大きくしなければならない。 In recent years, due to environmental problems, there are increasing cases of changing from solvent-based paints containing thinner to water-based paints not containing thinner. When water-based paint is used for the above-mentioned rotary atomizing electrostatic coating, the solvent-based paint and water-based paint have different paint viscosities with respect to the number of rotations of the bell. The rotational speed of the mold atomizing head must be increased.

具体的には、溶剤系塗料と水性塗料のベル回転数に対する塗料粘性は、従来、溶剤系塗料で２７０００〜３５０００ｒｐｍの回転数で得られていた塗料粘度と同等の塗料粘度を得るには、水性塗料では４５０００〜５５０００ｒｐｍの回転数を与えなければならなかった。しかし、水性塗料で、ベル型霧化ヘッドの回転数を高くすると、遠心力が高くなるため、塗料がベル型霧化ヘッドの内周面に形成した溝を越えて、ベル型霧化ヘッドの開口端部で膜を張ったようになり、塗料が液糸化されず、噴霧させることができない場合があった。また、水性塗料と同様に、せん断応力を大きくし、粘弾性を下げて塗装するタイプの塗料でも同様に液糸化させて霧化させることが難しかった。 Specifically, the paint viscosity with respect to the bell rotation speed of the solvent-based paint and the water-based paint is water-based in order to obtain a paint viscosity equivalent to the paint viscosity conventionally obtained at a rotation speed of 27000-35000 rpm with the solvent-based paint. The paint had to give a rotational speed of 45000-55000 rpm. However, if the rotational speed of the bell-type atomizing head is increased with water-based paint, the centrifugal force increases, so that the paint passes over the groove formed on the inner peripheral surface of the bell-type atomizing head and the bell-type atomizing head In some cases, a film is stretched at the opening end, and the paint is not liquefied and cannot be sprayed. In addition, as with water-based paints, it is difficult to make liquid yarns atomized in the same manner even with paints of a type in which shear stress is increased and viscoelasticity is lowered.

本発明に係る回転霧化式塗装装置は、ベル型霧化ヘッドの内周面に形成した溝を、その周方向断面において、溝の幅方向の中心よりも回転方向の後方側を深く形成したことを特徴とする。 In the rotary atomizing type coating apparatus according to the present invention, the groove formed on the inner peripheral surface of the bell type atomizing head is formed deeper in the circumferential cross section at the rear side in the rotational direction than the center in the width direction of the groove. It is characterized by that.

このベル型霧化ヘッドを用いた回転霧化式塗装装置では、ベル型霧化ヘッドの内周面に形成した溝を、その周方向断面において、溝の幅方向の中心よりも回転方向の後方側を深く形成したので、高い回転数で運転した場合でも、各溝毎に塗料を保持し、塗料を液糸化して噴霧することができる。これにより、静電塗装に使用可能な塗料の種類を増すことができ、また塗料の霧化を安定させ、塗装品質の向上を図ることができる。 In the rotary atomizing coating apparatus using the bell-type atomizing head, the groove formed on the inner peripheral surface of the bell-type atomizing head is rearward in the rotational direction from the center in the width direction of the groove in the circumferential section. Since the side is formed deeply, the paint can be held in each groove, and the paint can be liquefied and sprayed even when operated at a high rotational speed. Thereby, the kind of coating material which can be used for electrostatic coating can be increased, the atomization of coating material can be stabilized, and the coating quality can be improved.

以下、本発明の一実施形態に係る回転霧化式塗装装置及びベル型霧化ヘッドを図面に基づいて説明する。なお、回転霧化式塗装装置１００の基本構成は、図１に示す通りであり、ここでは、ベル型霧化ヘッド１０１を中心に説明する。 Hereinafter, a rotary atomizing coating apparatus and a bell type atomizing head according to an embodiment of the present invention will be described with reference to the drawings. The basic configuration of the rotary atomizing coating apparatus 100 is as shown in FIG. 1, and here, the bell type atomizing head 101 will be mainly described.

ベル型霧化ヘッド１０１は、図１及び図３に示すように、開口端部の円錐面１０７に形成される溝１０８を、その周方向断面において、溝１０８の幅方向の中心よりも回転方向の後方側を深く形成している。 As shown in FIGS. 1 and 3, the bell-type atomizing head 101 has a groove 108 formed in the conical surface 107 at the opening end in the rotational direction of the circumferential cross section of the groove 108 relative to the center in the width direction. The back side is deeply formed.

例えば、この図示例では、周方向断面においてＶ字状に形成し、溝１０８の回転方向前方側の斜面１０８ａを緩やかにし、溝１０８の回転方向後方側の斜面１０８ｂの傾斜をきつくして、溝１０８の幅方向の中心ａよりも回転方向後方側にＶ字の最深部１０８ｃを形成している。 For example, in this illustrated example, the groove 108 is formed in a V shape in the circumferential cross section, the slope 108a on the front side in the rotational direction of the groove 108 is made gentle, and the slope of the slope 108b on the rear side in the rotational direction of the groove 108 is tightened. A V-shaped deepest portion 108c is formed on the rear side in the rotational direction from the center a in the width direction 108.

このベル型霧化ヘッド１０１を用いれば、回転数を高くしたときに、塗料は慣性力を受けて溝１０８の回転方向後方側の斜面１０８ｂに沿って外径方向に流れるが、このとき溝１０８の幅方向の中心ａよりも回転方向後方側を深く形成し、溝１０８の回転方向後方側の斜面１０８ｂの傾斜をきつくしたので、塗料を確実に溝１０８内に保持することができる。これにより、水性塗料のように、せん断応力を大きくし、粘弾性を下げて塗装するタイプの塗料を用い、例えば４５０００〜５５０００ｒｐｍの高い回転数で運転した場合でも、各溝１０８毎に塗料を保持させることができる。 When the bell type atomizing head 101 is used, when the rotational speed is increased, the paint receives an inertial force and flows in the outer diameter direction along the inclined surface 108b on the rear side in the rotation direction of the groove 108. At this time, the groove 108 Since the rear side in the rotational direction is formed deeper than the center a in the width direction and the slope 108b on the rear side in the rotational direction of the groove 108 is tightened, the paint can be reliably held in the groove 108. This makes it possible to maintain a paint for each groove 108 even when operating at a high rotational speed of 45,000 to 55000 rpm, for example, using a paint of a type in which the shear stress is increased and the viscoelasticity is lowered, such as an aqueous paint. Can be made.

従って、このベル型霧化ヘッド１０１を回転霧化式塗装装置１００に用いれば、水性塗料を用いた場合でも、塗料をベル型霧化ヘッド１０１の各溝１０８毎に液糸化させて放出し、塗料を霧化することができる。 Therefore, if the bell-type atomizing head 101 is used in the rotary atomizing-type coating apparatus 100, even when a water-based paint is used, the paint is liquefied and discharged for each groove 108 of the bell-type atomizing head 101. Can atomize paint.

以上、本発明の一実施形態に係る回転霧化式塗装装置及びベル型霧化ヘッドを説明したが、本発明に係る回転霧化式塗装装置及びベル型霧化ヘッドは、これに限定されず、種々の変形が可能である。 The rotary atomizing coating apparatus and the bell type atomizing head according to one embodiment of the present invention have been described above, but the rotary atomizing coating apparatus and the bell type atomizing head according to the present invention are not limited thereto. Various modifications are possible.

例えば、溝１０８の断面形状は、上記に限定されず、種々の変更が可能である。図４に示すものは、溝１０８の回転方向後方側の斜面１０８ｂの傾斜をよりきつくして、略垂直にしたものであり、図５に示すものは、溝１０８を滑らかな曲面で形成し、溝１０８の幅方向の中心ａよりも回転方向の後方側に最深部１０８ｃを形成したものである。さらに、図６に示すものは、溝１０８の回転方向後方側の斜面１０８ｂを表面からオーバーハングさせて形成したものである。 For example, the cross-sectional shape of the groove 108 is not limited to the above, and various changes can be made. 4 shows that the inclination of the inclined surface 108b on the rear side in the rotational direction of the groove 108 is made tighter and substantially vertical. In FIG. 5, the groove 108 is formed with a smooth curved surface. The deepest portion 108c is formed on the rear side in the rotational direction from the center a in the width direction of the groove 108. Furthermore, what is shown in FIG. 6 is formed by overhanging a slope 108b on the rear side in the rotational direction of the groove 108 from the surface.

また、溝１０８の表面形状は、ベル型霧化ヘッド１０１の開口端部において、半径方向に延在させたものを、放射状に複数設けたものを例示したが、これに限らず、ベル型霧化ヘッドの開口端部に放射方向に形成されていれば良い。例えば、図７に示すように、ベル型霧化ヘッド１０１の内周面上を、外径方向に向かうにつれて回転方向後方に曲がった曲線状に形成してもよい。これにより、塗料が慣性力を受けて回転方向の後方側に流れるのを許容できるので、さらにベル型霧化ヘッド１０１の回転数を高くした場合でも、塗料が溝１０８の回転方向後方の斜面を越えるのを防止することができ、より確実に塗料を各溝１０８内に保持することができる。 In addition, the surface shape of the groove 108 is illustrated by providing a plurality of radially extending portions extending in the radial direction at the opening end portion of the bell-type atomizing head 101. It suffices if it is formed in the radial direction at the opening end of the conversion head. For example, as shown in FIG. 7, the inner peripheral surface of the bell-type atomizing head 101 may be formed in a curved shape that curves backward in the rotational direction as it goes in the outer diameter direction. As a result, the paint can be allowed to flow to the rear side in the rotation direction due to the inertial force, so that even when the rotation speed of the bell-type atomizing head 101 is further increased, the paint moves on the inclined surface at the rear of the groove 108 in the rotation direction. Therefore, the paint can be held in each groove 108 more reliably.

また、溝１０８は、図８に示すように、ベル型霧化ヘッド１０１の内周面において、ベル型霧化ヘッドの開口端に到達せずに、ベル型霧化ヘッド１０１の内周面の中間部位に形成してもよい。この場合、図９に示すように、ベル型霧化ヘッドの開口端部１０９を溝１０８の最深部１０８ｃと同じか又は最深部１０８よりも低く形成し、開口端部１０９が最深部１０８ｃから液糸状に放出される塗料の流れを阻害しないようにするとよい。また、溝１０８は、全体に渡って、幅方向の中心よりも回転方向の後方側を深くした断面形状にしてもよいが、図７及び図８に破線Ａで示すように、溝１０８の外径側の部分を、部分的に、幅方向の中心よりも回転方向の後方側を深くした断面形状にしてもよい。 Further, as shown in FIG. 8, the groove 108 does not reach the opening end of the bell-type atomizing head 101 on the inner peripheral surface of the bell-type atomizing head 101, and is formed on the inner peripheral surface of the bell-type atomizing head 101. You may form in an intermediate part. In this case, as shown in FIG. 9, the opening end 109 of the bell-type atomizing head is formed to be the same as or lower than the deepest portion 108c of the groove 108, and the opening end 109 extends from the deepest portion 108c. It is preferable not to obstruct the flow of the paint released in the form of threads. Further, the groove 108 may have a cross-sectional shape that is deeper on the rear side in the rotational direction than the center in the width direction, but as shown by a broken line A in FIGS. You may make the diameter side part into the cross-sectional shape which deepened the back side of the rotation direction partially rather than the center of the width direction.

また、本発明に係る回転霧化式静電塗装装置及びベル型霧化ヘッドは、水性塗料を液糸化させて霧化させる場合に有益なものであるが、溶剤系塗料を霧化させる場合にベル型霧化ヘッドをより高い回転数で運転することができ、塗料の霧化を安定化させ、塗装品質の安定性を確保するのに有益である。 In addition, the rotary atomizing electrostatic coating apparatus and the bell type atomizing head according to the present invention are useful when the aqueous paint is made into liquid yarn and atomized, but when the solvent-based paint is atomized. In addition, the bell type atomizing head can be operated at a higher rotational speed, which is useful for stabilizing the atomization of the paint and ensuring the stability of the coating quality.

回転霧化式塗装装置の基本構成を示す図。The figure which shows the basic composition of a rotary atomization type coating device. ベル型霧化ヘッドの円錐面から塗料が放出される状態を示す図。The figure which shows the state from which a coating material is discharge | released from the conical surface of a bell type atomization head. 本発明の一実施形態に係るベル型霧化ヘッドの溝の形状を示す断面図。Sectional drawing which shows the shape of the groove | channel of the bell type atomization head which concerns on one Embodiment of this invention. 本発明の一実施形態に係るベル型霧化ヘッドの溝の変形例を示す断面図。Sectional drawing which shows the modification of the groove | channel of the bell type atomization head which concerns on one Embodiment of this invention. 本発明の一実施形態に係るベル型霧化ヘッドの溝の変形例を示す断面図。Sectional drawing which shows the modification of the groove | channel of the bell type atomization head which concerns on one Embodiment of this invention. 本発明の一実施形態に係るベル型霧化ヘッドの溝の変形例を示す断面図。Sectional drawing which shows the modification of the groove | channel of the bell type atomization head which concerns on one Embodiment of this invention. 本発明の一実施形態に係るベル型霧化ヘッドの溝の変形例を示す図。The figure which shows the modification of the groove | channel of the bell type atomization head which concerns on one Embodiment of this invention. 本発明の一実施形態に係るベル型霧化ヘッドの溝の変形例を示す図。The figure which shows the modification of the groove | channel of the bell type atomization head which concerns on one Embodiment of this invention. 図８のベル型霧化ヘッドの開口端部を示す斜視図。The perspective view which shows the opening edge part of the bell-type atomization head of FIG.

符号の説明Explanation of symbols

１００回転霧化式塗装装置
１０１ベル型霧化ヘッド
１０２回転機構
１０３電圧付与装置
１０４塗料供給部
１０７円錐面
１０８溝
１０８ａ溝の回転方向前方側の斜面
１０８ｂ溝の回転方向後方側の斜面
１０８ｃ溝の最深部
１０９塗料流出孔 DESCRIPTION OF SYMBOLS 100 Rotating atomizing type coating apparatus 101 Bell type atomizing head 102 Rotating mechanism 103 Voltage applying apparatus 104 Paint supply part 107 Conical surface 108 Groove 108a Slope 108b on the front side in the rotational direction of the groove Slope 108c on the rear side in the rotational direction on the groove Deepest part 109 Paint outflow hole

Claims

底部から開口部に向かうにつれて開口径が大きくなったベル形状を有し、内周面に放射方向に溝が形成されたベル型霧化ヘッドを備え、前記ベル型霧化ヘッドを回転させつつ、ベル型霧化ヘッドの溝から塗料を液糸化させて放出する回転霧化塗装装置において、
前記ベル型霧化ヘッドは、内周面に形成した溝を、その周方向断面において、溝の幅方向の中心よりも回転方向の後方側を深く形成したことを特徴とする回転霧化塗装装置。 The bell-shaped atomizing head has a bell shape with an opening diameter that increases from the bottom toward the opening, and includes a bell-shaped atomizing head in which grooves are formed in the radial direction on the inner peripheral surface, while rotating the bell-shaped atomizing head, In a rotary atomizing coating device that disperses paint from the groove of a bell-type atomizing head and discharges it,
The bell-type atomizing head is characterized in that the groove formed on the inner peripheral surface is formed deeper on the rear side in the rotational direction than the center in the width direction of the groove in the circumferential cross section. .

底部から開口部に向かうにつれて開口径が大きくなったベル形状を有し、内周面に放射状に溝を形成した塗装用ベル型霧化ヘッドにおいて、
前記内周面に形成した溝を、その周方向断面において、溝の幅方向の中心よりも回転方向の後方側を深く形成したことを特徴とする塗装用ベル型霧化ヘッド。 In the bell-type atomizing head for painting, which has a bell shape with an opening diameter increasing from the bottom to the opening, and radially formed grooves on the inner peripheral surface,
A bell-type atomizing head for coating, wherein the groove formed on the inner peripheral surface is formed deeper in the circumferential cross section in the rotational direction than the center in the width direction of the groove.