Electrostatic coating apparatus for electrically conductive coating material

Abstract

In an electrostatic coating apparatus ( 1 ), an electrically conductive coating material is supplied through a coating material supplying path ( 11 ) to a coating gun ( 13 ) to which a high voltage is applied. The electrostatic coating apparatus ( 1 ) is provided with an insulating and separating valve ( 32 ) capable of electrically insulating and separating the coating material supplying path ( 11 ) into an application side in which the high voltage is applied and a non-application side. The insulating and separating valve ( 32 ) is provided with a female coupling member ( 32 U) having a first connecting portion ( 54 ) and a male coupling member ( 32 D) having a second connecting portion ( 64 ). A supplying hole ( 55 ) for supplying a cleaning fluid to the first connecting portion ( 54 ) and the second connecting portion ( 64 ) and a discharging hole ( 56 ) for discharging the cleaning fluid supplied to the first connecting portion and the second connecting portion are provided on one of the female coupling member ( 32 U) disposed on the non-application side and the male coupling member ( 32 D).

1 . An electrostatic coating apparatus for an electrically conductive coating material which supplies the electrically conductive coating material through a coating material supplying path to a coating gun to which a high voltage is applied, the apparatus comprising:
 an insulating and separating valve capable of electrically insulating and separating the coating material supplying path into an application side in which the high voltage is applied and a non-application side,   wherein the insulating and separating valve include:
 a female coupling member having a concave portion serving as one of coupling portions and a first connecting portion provided on a bottom face of the concave portion and serving as a connecting portion of the coating material supplying path; and 
 a male coupling member having a convex portion serving as the other of the coupling portions to be coupled to the concave portion and a second connecting portion provided on a tip of the convex portion and serving as a connecting portion of a passage to be connected to the first connecting portion, 
   wherein one of the female coupling member and the male coupling member being provided on the non-application side and including a supplying hole for supplying a cleaning fluid to the first connecting portion and the second connecting portion when the first connecting portion and the second connecting portion are disposed apart from a position for a connecting state by a predetermined distance, and a discharging hole for discharging the cleaning fluid supplied to the first connecting portion and the second connecting portion, and   wherein the other of the female coupling member and the male coupling member being provided on the application side.   
     
     
         2 . The electrostatic coating apparatus according to  claim 1 , the apparatus further comprising:
 a seal member provided on one of an outer peripheral part of the convex portion and an inner peripheral part of the concave portion and fitted in the other of the outer peripheral part of the convex portion and the inner peripheral part of the concave portion; and   a separating mechanism for moving at least one of the female coupling member and the male coupling member to be stopped in a position placed apart from the position for the connecting state of the first connecting portion and the second connecting portion by the predetermined distance within a range in which the seal member is fitted in the other of the outer peripheral part of the convex portion and the inner peripheral part of the concave portion.   
     
     
         3 . The electrostatic coating apparatus according to  claim 1 , wherein the cleaning fluid is deionized water. 
     
     
         4 . The electrostatic coating apparatus according to  claim 1 , wherein the male coupling member further includes a guide portion taking such a shape as to externally cover a part having the concave portion formed thereon when the first connecting portion and the second connecting portion are connected to each other. 
     
     
         5 . A connecting device for a fluid passage comprising:
 a female coupling member having a first connecting portion on one end side thereof;   a male coupling member having, on one end side thereof, a second connecting portion to be connected to the first connecting portion a passage formed in the female coupling member and a passage formed in the male coupling member being connected to each other through a connection of the first connecting portion and the second connecting portion;   a first operating mechanism for driving at least one of the female coupling member and the male coupling member to cause the first connecting portion and the second connecting portion to approach each other;   a second operating mechanism for driving at least one of the female coupling member and the male coupling member to separate the first connecting portion and the second connecting portion from each other; and   a controller for controlling a thrust generated in each of the first operating mechanism and the second operating mechanism,   wherein one of the female coupling member and the male coupling member includes a supplying hole for supplying a cleaning fluid toward the first connecting portion and the second connecting portion, and a discharging hole for discharging the cleaning fluid from the first connecting portion and the second connecting portion,   wherein one of the female coupling member and the male coupling member is provided with a seal member for closely coming in contact with the other coupling member, and   wherein the controller controls the thrust generated in the first operating mechanism to be greater than a force acting in such a direction as to separate the first connecting portion and the second connecting portion from each other against the thrust generated in the first operating mechanism in the supply of the cleaning fluid and to be equal to or smaller than the thrust generated in the second operating mechanism in a work for cleaning the first connecting portion and the second connecting portion with the cleaning fluid, and separates the first connecting portion and the second connecting portion from each other within a range in which the seal member closely comes in contact with the other coupling member.   
     
     
         6 . The connecting device for a fluid passage according to  claim 5 , wherein each of the first operating mechanism and the second operating mechanism is constituted by an air cylinder for generating a thrust through a supply of compressed air, and
 wherein a cylinder diameter of the air cylinder of the second operating mechanism is larger than that of the air cylinder of the first operating mechanism.   
     
     
         7 . The connecting device for a fluid passage according to  claim 5 , wherein the cleaning fluid is deionized water. 
     
     
         8 . An electrostatic coating apparatus for an electrically conductive coating material which supplies the electrically conductive coating material through a coating material supplying path to a coating gun to which a high voltage is applied, the apparatus comprising:
 an insulating mechanism provided in the coating material supplying path for dividing the coating material supplying path into an application side which is conducted to the coating gun and a non-application side which is insulated from the coating gun;   a fluid supplying path which is grounded and conducted to a part on the application side of the coating material supplying path; and   a fluid supplying device for supplying an electrically conductive fluid to the fluid supplying path.   
     
     
         9 . The electrostatic coating apparatus according to  claim 8  further comprising a controller for controlling the fluid supplying device,
 the controller starting to supply the electrically conductive fluid to the fluid supplying path after the application of the high voltage to the coating gun is ended. 
 
     
     
         10 . The electrostatic coating apparatus according to  claim 8 , wherein the electrically conductive fluid is deionized water. 
     
     
         11 . The electrostatic coating apparatus according to  claim 8  further comprising a gas supplying device for supplying a gas to the fluid supplying path.