JP6343159B2 - Electrostatic coating machine - Google Patents

Description

  The present invention relates to an electrostatic coating machine provided with a shaft between a valve body that opens and closes a paint valve port and a drive unit.

  In an electrostatic coating machine, a paint valve port and a valve body for opening and closing the paint valve port are provided in the front part of the paint machine body so as to be movable in the front-rear direction, and a drive unit is provided at the rear part of the paint machine body The valve body and the drive unit are connected by a shaft. As the drive unit, a trigger operated by fingers is used in the case of a manual type, and an air cylinder using pressurized air is used in the case of an automatic type. When the valve body for the paint is opened by moving the valve body rearward through the shaft by the drive unit, the pressurized paint passes through the paint passage of the coating machine body from the paint valve mouth, and then the paint machine It is discharged to the outside from the paint outlet at the tip of the main body. At this time, the paint is atomized by pressurized air. The paint discharge port is provided with an electrode for applying a high voltage, and the paint particles discharged from the paint discharge port are charged by applying a high voltage.

  In the electrostatic coating machine having such a configuration, particularly in the case of an automatic type using an air cylinder as a drive unit, moisture is generated in the cylinder as the air supplied to the air cylinder is compressed and expanded, and the moisture is transferred to the shaft. , It reaches the tip of the coating machine main body through the valve body, and high-potential electricity applied to this part is transmitted to the rear part of the coating machine main body, which may cause electric discharge and leakage. In order to cope with this, the shaft connecting the valve body and the drive unit is made of non-conductive resin, and the length of the shaft is increased to ensure a large insulation distance between them. The structure to do is mainstream.

Japanese Patent No. 2556811 JP-A-6-335642

  However, in the conventional configuration, the valve body and the drive unit are connected via a shaft, and particularly when the length of the shaft is increased, the valve body and the shaft that opens and closes the paint valve port, and the rear drive unit It is difficult to perform maintenance, and their maintainability is reduced.

  The present invention has been made in view of the above circumstances, and its purpose is to secure an insulation distance between a valve body that opens and closes a paint valve port and a drive section, and then a valve body, a shaft, and a drive section. It is in providing the electrostatic coating machine which can aim at the improvement of maintainability.

In order to achieve the above-described object, an electrostatic coating machine of the present invention is provided with a coating machine main body, a front block detachably provided at the front part of the coating machine main body, and the front block. A paint valve port, a valve body that is movably provided on the front block and opens and closes the paint valve port with the movement, a drive unit provided in the main body of the coating machine, and the valve body and the drive unit A shaft that moves as the drive unit moves to move the valve body, a paint discharge port that discharges paint that has passed through the paint valve port, and paint particles discharged from the paint discharge port High voltage generating means for applying a voltage to charge, the shaft is divided into a front shaft connected to the valve body side and a rear shaft connected to the drive unit side, the front shaft is Housed in the front block and painted from the front block Provided extends into the machine body, the rear shaft is received in coating machine body is provided so as not to protrude to the front block side, out between a and paint passage of the front block and the front shaft An urging means is provided at the position, and the coating machine main body and the front block can be separated with the front shaft and the urging means exposed.

  In the above configuration, by increasing the length of the entire shaft, it is possible to ensure an insulation distance between the valve body that opens and closes the paint valve port and the drive unit. And if a front block is removed from a coating machine main body, a shaft can be isolate | separated into a front shaft and a rear shaft. For this reason, it becomes easy to perform maintenance of the valve body and the front shaft on the front block side, and the rear shaft and the drive unit on the rear coating machine main body side.

Sectional drawing of the electrostatic coating machine by one Embodiment of this invention FIG. 1 equivalent view in a state where the piston of the air cylinder is moved most backward.

  Hereinafter, an electrostatic coating machine according to an embodiment of the present invention will be described with reference to the drawings. First, in FIG. 1, the electrostatic coating machine 1 is roughly provided with two blocks in the front-rear direction. Specifically, the left front block 2 in FIG. 1 and the rear block 3 thereafter are detachably combined. A back plate 4 is detachably provided at the rear part of the rear block 3. In this case, the painting machine body 5 is constituted by the rear block 3 and the back plate 4. Therefore, the front block 2 is detachably provided at the front portion of the coating machine body 5.

  A cover 6 is detachably provided on the outside of the front block 2 and the rear block 3. This cover 6 covers the boundary between the front block 2 and the rear block 3 from the outside. In this case, the front block 2, the rear block 3, the back plate 4, and the cover 6 are made of non-conductive synthetic resin.

  An air cylinder 7 constituting a drive unit is provided at a predetermined portion of the back plate 4 in the coating machine body 5. The air cylinder 7 is provided in a cylinder 8 so that a piston 9 can move in the front-rear direction. The piston 9 is biased forward by the compression coil spring 10 (leftward in FIG. 1). When pressurized air is supplied between the front surface of the piston 9 and the inner surface of the cylinder 8, the piston 9 is moved backward against the urging force of the compression coil spring 10. A piston rod 11 is connected to the piston 9. A front portion of the piston rod 11 protrudes toward the rear block 3 through an insertion hole 12 formed in the back plate 4 and is connected to a rear portion of the rear shaft 13.

  The rear shaft 13 is provided so as to be slidable in the front-rear direction in an insertion hole 15 of a sleeve 14 fixed to the back plate 4 and a guide hole 16 formed in the rear block 3. A large-diameter portion 13 a having a larger diameter than other portions is integrally provided at the front end portion of the rear shaft 13, and the outer peripheral surface of the large-diameter portion 13 a slides on the inner surface of the guide hole 16. The large-diameter portion 13 a is located on the front side of the middle portion in the front-rear direction of the rear block 3.

  A shaft guide 17 is fixedly provided at the rear of the front block 2 so as to be positioned in front of the rear shaft 13. An insertion hole 18 is formed in the shaft guide 17, and the front shaft 20 is inserted into the insertion hole 18 so as to be slidable in the front-rear direction. A large-diameter portion 20 a having a larger diameter than other portions is integrally provided at the rear end portion of the front shaft 20, and the outer peripheral surface of the large-diameter portion 20 a slides on the inner surface of the guide hole 16. The front portion of the front shaft 20 is covered with a bellows 21. The bellows 21 has a proximal end portion 21a fixed to the shaft guide 17, a distal end portion 21b fixed to the front end portion of the front shaft 20, and an intermediate portion having a bellows shape. A proximal end portion of the valve body 22 is fixed to the distal end portion 21 b of the bellows 21.

  In the front block 2, a paint reservoir 23 is formed around the bellows 21. The paint reservoir 23 communicates with a paint supply path (not shown), and pressurized paint is supplied to the paint reservoir 23. In the front block 2, a valve seat 25 that is positioned on the front side of the valve body 22 and has a paint valve port 24 is provided in a fixed state. The distal end portion of the paint valve port 24 communicates with a communication passage 26 formed in the front portion of the front block 2. Accordingly, the paint reservoir 23 communicates with the communication passage 26 via the paint valve port 24. The valve body 22 is movable in the front-rear direction, and the paint valve port 24 is opened and closed by the movement.

  A compression coil spring 27 that constitutes an urging means is provided between the shaft guide 17 and the large-diameter portion 20 a of the front shaft 20, and the urging force of the compression coil spring 27 is the front shaft 20. Is biased toward the rear rear shaft 13 side. In the state of FIG. 1, the rear surface of the large-diameter portion 20 a of the front shaft 20 is in contact with the front surface of the large-diameter portion 13 a of the rear shaft 13 from the front. Here, the front shaft 20 and the rear shaft 13 constitute a shaft 28 provided between the valve body 22 for opening and closing the paint valve port 24 and the piston 9 of the air cylinder 7 constituting the drive unit. Yes. Therefore, the shaft 28 is divided into a front shaft 20 connected to the valve body 22 side and a rear shaft 13 connected to the piston 9 on the drive unit side. The spring force of the compression coil spring 27 on the front shaft 20 side is set to be smaller than the spring force of the compression coil spring 10 on the air cylinder 7 side.

  The compression coil spring 27 on the valve body 22 side is arranged behind the bellows 21 and at a position away from the paint passage. Here, the piston 9 of the air cylinder 7, the piston rod 11, the rear shaft 13, the front shaft 20, the bellows 21, the main body of the valve body 22, and the valve seat 25 are formed of a non-conductive synthetic resin.

  From the rear block 3 to the front end of the front block 2, high voltage generating means 30 is provided inside them. The high voltage generating means 30 includes a high voltage generating circuit 31, a conductive spring 32, a conductive metal electrode support 33, and a charge electrode 34. The high voltage generation circuit 31 has a main portion provided in the rear block 3 and a front portion inserted in the front block 2. The conductive spring 32 and the electrode support 33 are provided on the front block 2. A nozzle 35 is detachably attached to the tip of the front block 2. The nozzle 35 is provided with a paint discharge port 36, and a charge electrode 34 is disposed in the paint discharge port 36.

  In this case, the charge electrode 34 includes an electrode main body 34a and an electrode pin 34b provided at the tip of the electrode main body 34a. The electrode body 34a is formed of a conductive synthetic resin, for example, carbon-containing polyacetal or nylon, and has a configuration of integrally having a limiting resistance function. The volume resistance value of the electrode body 34a is set to 1 MΩ to 100 MΩ, and in this case, for example, 45 MΩ. The volume resistance value of the electrode body 34a can be controlled by the degree of carbon addition when the electrode body 34a is molded. The electrode pin 34b is made of a conductive metal, for example, an alloy of nickel and titanium, or stainless steel, and is integrally provided on the electrode body 34a by insert molding when the electrode body 34a is molded.

  A coiled spring portion 34 c is provided on the rear side of the electrode body 34 a by integral molding, and the rear end portion of the spring portion 34 c is in pressure contact with the electrode support 33. Therefore, the spring portion 34c is also made of conductive synthetic resin and has conductivity. A paint passage 39 is formed around the electrode support 33 and inside the electrode support 33 in the front block 2. The paint passage 39 communicates with the communication passage 26 and the paint discharge port 36.

  The nozzle 35 is provided with an atomizing air discharge port 40 and a pattern air discharge port 41 around the paint discharge port 36. Pressurized air is supplied to the atomizing air discharge port 40 and the pattern air discharge port 41 via an air passage (not shown).

Next, the operation of the above configuration will be described.
As shown in FIG. 1, in the air supply stop state where pressurized air is not supplied to the air cylinder 7, the piston 9 is moved forward by the spring force of the compression coil spring 10 on the air cylinder 7 side, The valve body 22 is moved forward via the shaft 28, and the paint valve port 24 is closed by the valve body 22. In this state, the paint is not discharged from the paint discharge port 36.

  When pressurized air is supplied between the front surface of the piston 9 and the inner surface of the cylinder 8 in this state, the piston 9 is moved rearward against the urging force of the compression coil spring 10 by the pressure. Along with this, the rear shaft 13 also moves rearward, the front shaft 20 also moves rearward by the urging force of the compression coil spring 27, the valve body 22 also moves rearward, and the paint valve port 24 is opened. The Then, the pressurized paint passes through the paint reservoir 23, the paint valve port 24, the communication passage 26, and the paint passage 39 in this order, and is discharged forward from the paint discharge port 36.

  At this time, the pressurized air is discharged from the atomizing air discharge port 40, whereby the paint is atomized. In addition, the spray pattern is flattened by the pressurized air being blown from the pattern air discharge port 41 to the paint flow discharged from the paint discharge port 36. Further, at this time, a high voltage (for example, −60 kV) is applied to the paint particles discharged from the paint discharge port 36 by the electrode pin 34 b of the charge electrode 34 in the high voltage generating means 30, thereby charging the paint particles. Is done. At this time, the electrode body 34a of the charge electrode 34 functions as a limiting resistor that suppresses discharge energy.

  Here, in the state where the piston 9 is moved most rearward, as shown in FIG. 2, a slight gap 43 is formed between the front end portion of the rear shaft 13 and the rear end portion of the front shaft 20. Thus, the length in the front-rear direction of the compression coil spring 27 on the front shaft 20 side is set.

  When the supply of pressurized air to the air cylinder 7 is stopped, the piston 9 is moved forward by the spring force of the compression coil spring 10 on the air cylinder 7 side, and the valve element 22 is connected via the shaft 28. Is moved forward, the valve body 24 is closed by the valve body 22, and the discharge of the paint from the paint discharge port 36 is stopped. Further, the supply of pressurized air to the atomizing air discharge port 40 and the pattern air discharge port 41 is stopped, and the application of a high voltage to the charge electrode 34 by the high voltage generating means 30 is also stopped.

In the embodiment described above, the following operational effects can be obtained.
A valve body 22 that opens and closes the paint valve port 24 is disposed in the front block 2, and an air cylinder 7 that constitutes a drive unit is disposed in the rear part of the coating machine body 5, and the valve body 22 and the air cylinder 7 are connected to each other. By setting the overall length of the shaft 28 between them long, it is possible to ensure an insulation distance between the valve body 22 and the air cylinder 7. When the front block 2 is removed from the coating machine main body 5 after removing the cover 6, the shaft 28 can be separated into the front shaft 20 and the rear shaft 13, and both the shafts 20 and 13 are exposed. be able to. Therefore, maintenance of the valve body 22 and the front shaft 20 on the front block 2 side and the rear shaft 13 and the air cylinder 7 on the rear coating machine body 5 side is facilitated. Furthermore, since the coating machine main body 5 can be divided into the rear block 3 and the back plate 4, maintenance of the air cylinder 7 that is a drive unit is further facilitated.

  A compression coil spring 27 constituting an urging means is provided between the shaft guide 17 provided in the front block 2 and the large diameter portion 20a of the front shaft 20 at a position outside the paint passage, and this compression coil spring 27, the front shaft 20 is biased toward the rear shaft 13. According to this configuration, even if the shaft 28 is divided into the front shaft 20 and the rear shaft 13, when the piston 9 moves rearward, the front shaft 20 also follows the rear shaft 13. Thus, the valve body 22 can be moved favorably and the valve body 22 can be favorably moved. Further, since the compression coil spring 27 is disposed at a position away from the paint passage, there is an advantage that the paint does not adhere and can be easily cleaned.

  A gap 43 is formed between the front shaft 20 and the rear shaft 13 with the rear shaft 13 moved most rearward by the piston 9 of the air cylinder 7. According to this configuration, it is possible to ensure electrical insulation between the valve body 22 and the air cylinder 7 more reliably.

  The present invention is not limited to the embodiments described above and shown in the drawings, and can be modified as follows, for example. In the above-described embodiment, the air cylinder 7 is exemplified as the drive unit that drives the valve body 22, but a manual trigger may be employed as the drive unit.

  In the drawings, 1 is an electrostatic coating machine, 2 is a front block, 3 is a rear block, 4 is a back plate, 5 is a coating machine body, 7 is an air cylinder (drive unit), 9 is a piston, 13 is a rear shaft, 20 is a front shaft, 21 is a bellows, 22 is a valve body, 23 is a paint reservoir, 24 is a paint valve port, 25 is a valve seat, 26 is a communication passage, 27 is a compression coil spring (biasing means), 28 Is a shaft, 30 is a high voltage generating means, 34 is a charge electrode, 35 is a nozzle, 36 is a paint discharge port, and 43 is a gap.

Claims (3)

The main body of the coating machine,
A front block detachably provided at the front of the main body of the coating machine;
A paint valve provided in the front block;
A valve body that is movably provided in the front block, and that opens and closes the paint valve port with the movement;
A drive unit provided in the main body of the coating machine;
A shaft that is provided between the valve body and the drive unit and moves with the drive of the drive unit to move the valve body;
A paint discharge port for discharging the paint that has passed through the paint valve port;
A high voltage generating means for applying a high voltage to the paint particles discharged from the paint discharge port for charging;
The shaft is divided into a front shaft connected to the valve body side and a rear shaft connected to the drive unit side,
The front shaft is housed in the front block and is provided to extend from the front block into the coating machine main body.
The rear shaft is accommodated in the coating machine body so as not to protrude toward the front block side,
A biasing means is provided at a position between the front block and the front shaft and out of the paint passage,
The electrostatic coating machine, wherein the coating machine main body and the front block are separable with the front shaft and the biasing means exposed. The electrostatic coating machine according to claim 1, wherein the biasing unit biases the front shaft toward the rear shaft. In a state of being moved to the most rearward the rear shaft by the driving unit, according to claim 1 or 2 electrostatic coater, wherein a gap is formed between the rear shaft and the front shaft .

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