JPH04106657U - Switching valve for conductive paint - Google Patents

Abstract

(57) [Summary] [Purpose] When applying a high voltage directly to conductive paint, it is possible to prevent electrical communication between paths, and effectively prevent electric leakage and sparks. [Structure] Plane 7 of passage body 64 constituting directional control valve 54
0, the passage body 64 and the valve body 66 are made of an insulating material, and the flat surface 70
The shortest distance between the passages 56 to 62 and the rod 86 at the part where they come into close contact with the valve body 66, the shortest distance between the arcuate passages 72 and 74 and the second coupling member 84, and the shortest distance between each passage 56 to 62 are , the voltage (kV) directly applied to the conductive paint is expressed as the dielectric breakdown strength (kV) of the insulating material.
/mm).

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention is an electrostatic coating method that uses conductive paint to which high voltage is directly applied. This invention relates to a switching valve for conductive paint used in equipment.

0002

[Conventional technology]

Electrostatic painting is applied to objects such as automobile bodies by directly applying high voltage to conductive paint. For example, a voltage block method is known as a method. In this method, conductive Once the neutral paint is introduced into an intermediate reservoir, which is insulated from ground potential, The channels connecting the reservoir and the paint supply are cleaned and dried and voltage-blocked. The conductive paint to which a high voltage is directly applied is transferred to the intermediate storage tank with a Electrostatic painting work is performed on the object to be painted by supplying it to the painting gun from Ru.

0003 In this case, in order to change the conductive paint color efficiently and quickly, the paint supply The desired conductive paint is selectively supplied via a supply means connected to a supply source. intermediate storage tanks are arranged, and while one intermediate storage tank is being cleaned, the other one is being cleaned. A painting device is proposed that can perform painting work in a desired color through an intermediate storage tank. (See Japanese Patent Application Laid-Open No. 2-2885).

0004 This coating equipment uses a manifold to selectively supply and discharge paint, cleaning fluid, etc. A device has been devised to provide a plurality of ON-OFF switching valves in the field. However, this With conventional technology, ON/OFF switching control is complicated and the manifold There is a problem that cleaning inside the door is poor. Moreover, it effectively maintains electrical insulation. The problem of not being able to do so has also been pointed out.

[0005] Therefore, the applicant selectively connects each intermediate storage tank to the coating gun and the waste liquid tank. In order to achieve this, we are considering using a four-way switching valve, for example, a relatively rotatable passage body and a valve body. selectively establishes communication between the plurality of passages under rotation of the passage body and the valve body. A paint switching valve that can be switched to form a pair of inflow passages and a pair of outflow passages. (See Utility Model Application Publication No. 144870/1983).

[0006]

[Problem that the idea aims to solve]

However, when trying to use the above switching valve in an electrostatic coating device, the When applying high voltage directly, there is a risk that each path may be electrically connected to each other, causing electrical leakage. There is. For this purpose, blocks forming electrical insulation along the path for conductive paint It is necessary to install a circuit so that while electrostatic painting is being carried out in one passage, It is not possible to clean the other passage or fill it with paint, resulting in long cycle times. Therefore, there is a problem that an efficient color change painting operation cannot be performed.

[0007] Moreover, since the switching valve is electrically connected to the conductive paint, this switching If a conductor comes close to the valve, it will leak, making it impossible to maintain high voltage and causing sparks. There is also a risk that this may occur.

[0008] This invention solves this type of problem by applying high voltage directly to the conductive paint. When adding electricity, it can prevent electrical communication between each path and prevent electrical leakage and sparks. The purpose is to provide a switching valve for conductive paint that can effectively prevent the occurrence of do.

[0009]

[Means to solve the problem]

In order to achieve the above object, the present invention provides a conductive paint to which high voltage is directly applied. It is used in electrostatic painting equipment that supplies electrostatic paint to a painting gun to perform electrostatic painting. In a switching valve that can selectively switch communication, One opening of each passage is arranged on the same virtual circumference and on one plane side. a passage body made of an insulating material; A passageway is formed that connects at least one pair of openings adjacent to each other on the circumference. and an insulating material that engages with the plane so as to be rotatable relative to the passageway body. Equipped with a valve body made of stainless steel, The shortest distance between the passage and the conductor at the part where the plane and the valve body are in close contact with each other, the passage of the valve body The shortest distance between paths and conductors and the shortest distance between each path is applied directly to the conductive paint. The distance should be selected to be greater than or equal to the high voltage applied divided by the dielectric breakdown strength of the insulating material. It is characterized by.

0010

[Effect]

In the above switching valve for conductive paint according to the present invention, the passage body and the valve body are in close contact with a flat surface. is relatively rotated by a predetermined angle in a state in which the passage is opened through the passage of the valve body. Desired openings adjacent to each other in the body are communicated with each other. Here, the passage body and the valve body are The passage and the conductor are formed of an insulating material, and the passage and the conductor are formed of an insulating material and the shortest distance between the valve body passage and the conductor, and the shortest distance between each passage However, the high voltage applied directly to the conductive paint is The selected distance is greater than or equal to the distance divided by the edge resistance). For this reason, the It can effectively prevent electrical leakage when high voltage is directly applied to conductive paint. Supplying conductive paint to one passage while cleaning the other passage. becomes possible.

[0011]

【Example】

Examples of the switching valve for conductive paint according to the present invention are given below, and the attached drawings are referred to. This will be explained in detail below.

0012 In FIG. 2, reference numeral 10 incorporates a conductive paint switching valve according to the present invention. An electrostatic coating device is shown. This electrostatic coating device 10 uses conductive paint of different colors and air. , first and second blocks to which water and a cleaning fluid such as a cleaning solution are selectively supplied. The first and second block valve mechanisms 12 and 14 are provided with Each electrically insulating conduit 1 made of resin such as polytetrafluoroethylene (PTFE) 6 and switching valves 18a, 18b, each switching valve 18b on the outlet side is connected to a supply path 20. , 22, the first and second intermediate storage tanks 24, 26 are connected.

[0013] The first and second intermediate storage tanks 24 and 26 are connected to each other via a piston 28. A divided first cylinder chamber 30 for injecting conductive paint and cleaning liquid, and a first cylinder chamber 30 for supplying air. A second cylinder chamber 32 is provided with an air supply source (not shown) in the second cylinder chamber 32. communicate. This air supply source is also connected to a conductive paint flow regulator 33, which The flow rate regulator 33 controls the discharge amount of the conductive paint. The switching valve 18b is , are connected to a tank 36 via a discharge path 34.

[0014] The first cylinder chambers 30, 30 of the first and second intermediate storage tanks 24, 26 include a first The first and second delivery paths 40 and 46 communicate with each other, and the first and second delivery paths 40 and 46 communicate with each other. A directional control valve (for conductive paint) according to this embodiment is installed between 0, 46 and the paint gun 38. A switching valve) 54 is connected.

[0015] As shown in FIG. 1, this directional control valve 54 has four passages 56 to 62. It includes a passage body 64 and a valve body 66 that is rotatably engaged with the passage body 64. Ru. The passage body 64 is made of an insulating material such as ultra-high molecular weight polyethylene. One opening of each passage 56 to 62 is located in one plane 70 of the passage body 64 and in the same plane. They are arranged on one virtual circumference (see FIG. 3). The valve body 66 is also made of ultra-high molecular weight It is formed of an insulating material such as polyethylene, and is arranged alternately on the virtual circumference of the passages 56 to 62. The circular arc passages 72 and 74 are provided to connect two pairs of adjacent openings to each other.

[0016] A rotary drive source 78 is fixed to the passage body 64 via a casing 76, and this rotary drive source 78 is fixed to the passage body 64 via a casing 76. When the first coupling member 82 is fixed to the rotating shaft 80 extending from the power source 78, Then, a lock is inserted into the second coupling member 84 that engages with the first coupling member 82. head 86 is inserted. This rod 86 extends outside through the passage body 64. A spring 88 is disposed at the end of this rod 86, and the rod is A door 86 connects the valve body 66 to the plane 70 of the passage body 64 via the second coupling member 84. Press.

[0017] The casing 76, the first and second coupling members 82, 84 and the rod The board 86 is made of a conductive material such as stainless steel, and is connected to the flat surface 70 of the passage body 64. The openings of the passages 56 to 62 in the close contact area with the valve body 66 and the rod 8 which is the conductor. 6, the arcuate passages 72 and 74, and the second coupling member that is a conductor. 84 and the shortest distance L3 between each passage 56 to 62 are conductive. The dielectric breakdown strength (kV) of this type of insulating material is kV/mm) divided by the distance (mm) (see Figures 1 and 3). ).

[0018] A tank is connected to the outlet side of the directional control valve 54 configured in this manner via the discharge path 51. The paint guns 38 are connected to the tanks 52 and 38 through the flow rate regulators 33, respectively. The coating gun 38 includes a dump valve 90 and a trigger valve 92, not shown. It is connected to high voltage application means.

[0019] Next, the operation of the electrostatic coating apparatus 10 configured as described above will be explained. First, when a conductive paint of a predetermined color is supplied to the first block valve mechanism 12, the conductive paint is supplied with a predetermined color. The electrically conductive paint is filled into the first cylinder chamber 30 of the first intermediate storage tank 24 from the supply path 20. At the same time, the coating gun 38 is also filled via the first delivery path 40. that time In addition, in the direction control valve 54, the first delivery path 40 is communicated by the passage body 64 and the valve body 66. It communicates with the coating gun 38 via the passage 56, the arcuate passage 72, and the passage 60, while the second The outlet passage 46 communicates with the discharge passage 51 via a passage 58, an arcuate passage 74, and a passage 62. ing. During this filling, the trigger valve 92 is in a closed state, and the dump valve 90 is in an open state. After filling, the dump valve 90 is closed.

[0020] Therefore, the switching valves 18a and 18b of the first block valve mechanism 12 are driven and This first block valve mechanism 12 is cleaned under the driving action of the cleansing valve, and the cleaning liquid is removed. is discharged into tank 36. Further, the first block valve mechanism 12 is dried, and the first block valve mechanism 12 is dried. The conductive paint supply source (not shown) and the first intermediate storage tank 24 are electrically insulated by the It will be done.

[0021] Next, driving air is supplied from the air supply source to the second cylinder chamber 32 of the first intermediate storage tank 24. is supplied, and the conductive paint is passed through the piston 28 while a high voltage is directly applied. and sprayed onto a workpiece (not shown). Here, the trigger valve 92 is opened.

[0022] When using a conductive paint of a different color from the above-mentioned conductive paint, the above-mentioned painting process should be carried out. In parallel with the operation, the second intermediate storage tank 26 and the second delivery path 4 are opened under the action of a cleaning valve (not shown). 6 and the direction control valve 54 are cleaned, and the cleaning liquid is discharged from the tank through the discharge path 51. The water is discharged to the tank 52. After the painting work is completed, the direction control valve 54 is configured. The rotation drive source 78 is driven, and the rotation shaft 80, the first and second coupling members 82 , 84, the valve body 66 is rotated by a predetermined angle (actually 90°), and the second delivery path is opened. 46 communicates with the coating gun 38. Next, from the directional control valve 54 to the painting gun 38 After being cleaned, conductive paints of different colors are deposited in the first cylinder chamber of the second intermediate reservoir 26. 30, and the conductive paint in this second intermediate storage tank 26 is The coating gun 38 is filled via the second delivery path 46.

[0023] Therefore, the switching valves 18a and 18b of the second block valve mechanism 14 are driven, and this The two-block valve mechanism 14 is cleaned and the cleaning fluid is discharged into the tank 36. stop The second block valve mechanism 14 is then dried, which allows the conductive paint source (not shown) to dry. ) and the second intermediate storage tank 26 are electrically insulated.

[0024] Further, driving air is supplied to this second intermediate storage tank 26, and the first cylinder chamber 30 The conductive paint inside is activated under the action of the trigger valve 92 under the direct application of high voltage. (not shown).

[0025] In this case, in the direction control valve 54 according to this embodiment, the passage body 64 and the valve body 66 are , is formed of an insulating material, and has a close contact portion between the flat surface 70 of the passage body 64 and the valve body 66. The shortest distance L1 between the openings of the passages 56 to 62 and the rod 86 at the position, the arcuate passage The shortest distance L2 between 72, 74 and the second coupling member 84, and each passage 56 The shortest distance L3 between the The distance is selected to be greater than or equal to the distance divided by the dielectric breakdown strength of the insulating material. For this reason, the passage 56, a high voltage is applied to the conductive paint flowing through the arcuate passage 72 and the passage 60. In this case, electrical leakage may occur through the cleaning liquid flowing through the passage 58, the arcuate passage 74, and the passage 62. It is possible to carry out high-precision electrostatic painting work while cleaning. It becomes possible. Further, the painting operation is performed through the passage 56, the arcuate passage 72, and the passage 60. While performing the work, apply new conductive paint to passage 58, arcuate passage 74, and passage 62. Even if the conductive paint is filled with The effect is that efficiency of the entire electrostatic coating operation can be easily achieved.

[0026] Moreover, electrical leakage to the rod 86 and the second coupling member 84 is effectively prevented. Therefore, even if a conductor such as a robot arm approaches the directional control valve 54, current will not flow through this conductor. There is no problem of leakage and generation of sparks between conductors. stomach.

[0027] Furthermore, the valve body 66 is connected to the flat surface of the passage body 64 via the rod 86 and the spring 88. Since it is pressed against the surface 70, it prevents the conductive paint from stagnation and improves electrical insulation. can be done.

[0028]

[Effect of the idea]

According to the conductive paint switching valve according to the present invention, the following effects can be obtained.

[0029] The passage body and valve body constituting the switching valve are made of insulating material, and each passage The shortest distance between the conductor and the path is applied directly to the conductive paint. The distance is selected to be greater than or equal to the high voltage divided by the dielectric breakdown strength of the insulating material. child Therefore, when applying high voltage to conductive paint flowing in a passage, it is possible to effectively prevent electrical leakage. It is possible to supply conductive paint to one passage while cleaning the other passage, etc. This makes it possible to easily improve the efficiency of the entire electrostatic coating work.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of a conductive paint switching valve according to an embodiment of the present invention.

FIG. 2 is a schematic configuration explanatory diagram of an electrostatic coating device incorporating the switching valve.

FIG. 3 is an exploded perspective view of essential parts of the switching valve.

[Explanation of symbols]

10...Electrostatic coating device 12, 14...Block valve mechanism 24, 26...Intermediate storage tank 38...painting gun 40, 46...Sending path 54... Directional control valve 56-62...Aisle 64...Passway body 66...Valve body 70...Plane 72, 74...Circular passageway

Claims (1)

[Scope of utility model registration request] 1. A switching valve that is used in an electrostatic coating device that applies electrostatic coating by supplying conductive paint to which a high voltage is directly applied to a coating gun, and that is capable of selectively switching communication between a plurality of passages. wherein one opening of each passage communicates with a passage body made of an insulating material arranged on the same virtual circumference and provided on one plane side, and at least one pair of openings adjacent to each other on the circumference. a valve body made of an insulating material that engages with the flat surface in a rotatable manner relative to the passage body; , the shortest distance between the passage of the valve body and the conductor, and the shortest distance between each passage are equal to or greater than the distance obtained by dividing the high voltage directly applied to the conductive paint by the dielectric breakdown strength of the insulating material. A switching valve for conductive paint, characterized in that it is selected for use in conductive paints.