JPS5888059A - Method for intercepting high voltage in electrostatic coater - Google Patents

Abstract

PURPOSE:To prevent accidents such as a fire caused by a short circuit of a load or the like, by detecting an overcurrent at the secondary side of a high voltage- generating circuit, immediately intercepting a power source at its primary side and conurrently discharging the residual electricity, etc. between the high voltage-generating circuit and a coater. CONSTITUTION:By detecting an overcurrent, the abnormal change or voltage or the like at the secondary side of a high voltage-generating circuit 2 with an overvoltage-detecting circuit 5, a power source at the primary side of the high voltage-generating circuit 2 is intercepted, residual electricity remaining between the high voltage-generating circuit 2 and a coater 1 is discharged through an ionizing means 21, and the still-remaining electricity is discharged by the contact of a movable contact rod 18 with a main electrode 14. By these discharges, accidents such as spark discharge caused by the abnormal approach of the coater 1 to a workpiece 4 to be coated are prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION In this invention, a voltage from a high voltage generating circuit is supplied to the mW7e machine via a voltage line metal to charge paint particles.
1! This article relates to a high-voltage AI1#T method in an electrostatic W& device that detonates one coat onto a painted object.

Is it possible to use a device in which the paint particles are fully charged with a coating machine and applied to the iron object?
Since the paint particles are flammable, if the coating machine gets too close to the object to be coated and a spark discharge occurs between the two, it can cause an explosion or fire.

For this reason, conventionally, when an I11-equipped machine and a steel object come abnormally close to each other, a detector is used to detect abnormal current or voltage fluctuations that occur on the secondary side of the high voltage generating circuit. At the same time, the primary power supply is cut off, and the residual charge in the high voltage line between the high voltage generation circuit and the TII machine is discharged by a movable contact T-shoulder cutoff switch operated by a drive mechanism.

However, when air cylinders, electromagnetic cylinders, etc. are used as a drive mechanism to activate and detonate the movable contact, there is a limit to the operation time, and the operation time can be as long as several islands at most. This is rare because the residual charge cannot be removed from the discharge field.

The present invention aims to provide a method for connecting a high voltage in a novel electrocoating ij device that can shorten the discharge operation time of the conventional device, and if! If there is an overcurrent on the secondary side of the high voltage generation circuit or an abnormality in the voltage quality, please contact us! In order to detect the voltage, the residual charge between the voltage generation circuit and the iron machine is removed by ionizing means to remove the residual charge between the high voltage I [WII and the ground]. A discharge is induced between the main electrode and the ground electrode, which is instantaneously reduced, and the remaining charge is discharged by short-circuiting the main electrode and the ground electrode.

An example of the present invention will be explained below with reference to the drawings.

Figure 1 shows a schematic diagram of the electrostatic coating equipment.The high voltage from the high voltage generating circuit (2), which is supplied by Komatsu and connects the high voltage generating coil to the 9m express plane (1), is shown by the shielded voltage cable. (
3) Apply it through the internet, II! In the coating machine (1), charged atomized paint particles are applied to a grounded object (41).

An overcurrent detection circuit (5) is connected to the secondary side of the high voltage generation coil of the high voltage generation circuit (2).
The detection output of 5) is connected to the high voltage cable (3) and the darkness of Honji! The switch is supplied to the WIr switch (6), which operates the switching switch (2) and also activates the high voltage generation circuit (2).
For this reason, the pressure generating coil (HL) - next side power supply is turned off.

In the present invention, a switch shown in Fig. M2 is applied as an example of the faIil'r switch (6).

That is, (3) is a cylindrical electric body that is rarely an insulator (material) (
9), the lower surface is closed by an insulating end @uci (6), and a QIJ-type sealing material (b) is placed at the connecting position of these. .

The end plate (G) has a hemispherical end surface Q under the stile 1ilI1111
The main electrode α~ having 1 is vertically disposed, and its upper end is connected to the end plate (6
) is extended to form a terminal portion (2).

゛End plate (11, IK with main electrode (b) and 12 on its upper surface
A truncated hemispherical ground electrode (G) facing each other while maintaining the JT support interval (Ll) is disposed, and a central opening extending vertically is provided in the center of the ground electrode (G). A movable contact rod that can freely slide up and down is disposed within the center opening.

This movable contact rod has a holding bag attached to the end plate αυ at its lower end.
#The piston rod of the single-acting electromagnetic cylinder (6) having a spring is connected and raised against the return spring by the bias of the 11L magnetic cylinder 0I, and comes into contact with the tip of the main electrode (14). (1) is a grounding terminal that is arranged on the lower surface side of the end plate (6) and connected to the dormitory ground electricity & (G) via a conductive support piece 651.

Further, the ground electrode (G) is provided with ionization means (product) for forming an ionization layer on the surface facing the main electrode (◆).

An example of this ionization means is a through hole c parallel to the center opening aη at a symmetrical position between the center of the grounded IIL pole (g) and the opening a7)t. 4 (2) are drilled, and a U-shaped insulator (E) inserted into and held by the needle-shaped conductor (to) is placed in these through-holes (4), and the needle-shaped conductor is The protruding upper layer of N■ is closely opposed to the edge of the ground electrode, and the other end is electrically connected by a conductive ring, which extends through the end plate αυ to form the lower end. Conductive material with MV shadow formed on the terminal area
Shoulder the configuration connected to the terminal section - 8~12KV0:
)? By applying the voltage Ii + nozers, the gas in the vicinity of the discharge is ionized between the needle-like body mold □ and the ground electrode (T).

In addition, sulfur hexafluoride (SF'6) gas is sealed in the housing (8) at a pressure of, for example, 2 to 5 atmospheres, thereby reducing the distance (L) between the main electrode C1 and the ground electrode 0#. You can narrow it down compared to when you have 9 ki.

Next, the electromagnetic cylinder (6) No. 811 and the ionization means (2)
) Control @ circuit that controls the shaft drive (2) The five factors of t-silver will be explained.

(s2a) (32blt'X[fi power terminal,
An excess a1iL detection circuit (5) is interposed between these terminals to detect an overcurrent of the high voltage generation circuit (2). An example of this overcurrent detection is the power supply terminal (51).
2a) <52b) Between the reset normally closed transistor, the collector and emitter of the amplification transistor, and the WJ
The i-resistance (7) and the fixed resistance tube are interposed in the column and connected to the transistor pace tube voltage reproducing circuit (2) and the power supply terminal (!52b), respectively. The movable element of the resistor is connected to the base of the switching transistor, and the collector of this transistor is connected to the power supply terminal (52b) via the reset switch and the capacitor through the resistor and the emitter. A power supply terminal (52b) is connected to the power source terminal (52b). Also, the connection between the resistor tube and transistor collector is unijunction transistor j1-
The emitter of this transistor is connected to the reset switch through the resistor Wt, and the other base is connected to the power supply terminal (32b) through the pulse transformer primary winding edge (21). ing.

- This is a diode for preventing back electromotive force inserted in parallel with the pulse transformer -〇 primary winding @ (Ax).

In addition, a thyristor and an excitation coil (6) of the Xa cylinder (6) are connected in series between the reset switch and the power supply terminal (52b).
L) is inserted, and one secondary s-line (tsl) of the nose transformer is inserted between the gate of the thyristor and the power sword.

Furthermore, connect 1 between the reset switch and the power supply terminal (52b).
A thyristor and a light emitting diode are inserted in the U.
The other secondary winding fil (/a) of the nose transformer is inserted between the gate and cathode of the thyristor.

A phototransistor (49) that constitutes a photowig together with a light emitting diode (to emit light from this diode)
When the light is received, the high voltage pulse generating circuit is driven [2] and a high voltage nose (8T) is obtained.

Also, a switching transistor (51) is connected to the anode side of the diode, and the collector of this transistor (51) is connected to the reset switch and the high voltage generating coil (HL) of the high voltage generating circuit (2). The emitter of the transistor (52) inserted in J is connected to the power supply terminal (32bl).

Next, the method of the present invention based on the above configuration will be explained.
In a blockage state, the connection switch (8) will not operate and the high voltage from the voltage generation circuit (2) or the cable (3) will be applied 71
The object to be coated (41) is charged with m'I#+ particles which are applied to the solid iron machine (1) and the object to be coated (4). If the distance becomes abnormally narrow,
The secondary current value of the high voltage generation circuit (2) increases, and as a result, the emitter current of the amplification transistor of the overcurrent detection circuit increases, and as a result, the pace potential of the switching transistor increases, so this transistor When the light turned on, the photoelectric charge or discharge field of the capacitor (2), which was turned on and the light flashed.

In response to this, the unijunction transistor is turned on, and the primary winding (tI) of the nose transformer is energized for a while.

Therefore, pulse transformer -〇2nd volume ml (4x) (A
Since the trigger pulse is induced every minute, the thyristor
The excitation coil of the electromagnetic cylinder α9 is energized and the movable contact rod starts to rise, and the transistor (51) turns on and the transistor (52)
9 high voltage generation circuits (21 high voltage generation coils (H
The primary spinal cord power source of L) is obtained from the mIIT and a high voltage pulse (8T) is obtained from the high voltage pulse generation circuit and is supplied to the needle conductor g4 of the connection switch (8).
A discharge occurs between the needle-like conductor 94c# and the ground electrode (6), and the enclosed gas in the vicinity is ionized, which induces a discharge between the main electrode α4 and the ground electrode (7), and the high voltage cable ( 3) About 5ON of the residual % load is instantaneously created in the discharge field,
After that, the movable contact rod □□□, which was lifted up by the electromagnetic cylinder (6), returns to the main electrode (b), and this contact rod Qal
The remaining charge is discharged over time.

1m after that! To restore the voltage applied to the FC machine (1), press the reset switch of the overcurrent detection circuit (■) to turn off the thyristor @R(e)1.
The energization of the electromagnetic cylinder 40 is released, and the piston rond 4 (combined with the force of the tawarabata spring) is lowered to the original position (delta), and the high voltage pulse generation circuit 111J, etc. The generation of the vortex pressure pulse (8T) is stopped.

By releasing the suppression of the reset switch, the transistor (52) becomes high potential and turns on, causing the primary side of the high voltage generation 1gJw6 (21) to be replaced.

According to the present invention, by detecting the high voltage generation t2J (approximately secondary overcurrent), the primary source of the overcurrent is continuously cut off, and at the same time, the residual charge in the high voltage path is removed. By operating the ionization means provided near the ground electrode, the remaining 'a' load is brought into contact with the contact rod and discharged into the discharge field, resulting in quick response and safe operation. It is possible to provide a method for connecting voltages, to prevent accidents caused by short-circuiting of the load, and to develop a practically excellent wheel image that can improve MS performance.

In the same example, the stile, iA voltage! ! A#4 describes the case where a high voltage nocellus is supplied to the needle-like conductor as the ionization means (b) of the cut-off switch (6) to form an ionized layer around the ML pole of the writing area. It is also possible to form ionized mt by irradiating with a laser source or the like.

Also, instead of providing the ground electrode <11119 on the movable contact rod (to), a live electrode (14) may be provided, and the driving means thereof is not limited to an electromagnetic cylinder but may also be an air cylinder or other linear actuator. It's very striking, and even more so.
(to) It may be moved forward and backward in the direction of the five cypress stones to contact both the main electrode (b) and the margin electrode.

Even higher? In 11, the case where the overcurrent detection circuit is applied to detect rX abnormality was explained in 1i52, but it is not limited to this, but it can also be used to detect voltage, or to detect primary or secondary fine molecules rL in 1L flow. However, if it is possible to obtain an abnormality detection output, it is acceptable. Moreover, the configuration a of the overcurrent detection circuit is not limited to the above example, and various known circuits can be applied, as long as it is possible to obtain an overcurrent detection output of 1gk.

[Brief explanation of drawings]

Fig. 1 is a schematic explanatory diagram of the frame separator folding device, Fig. 2 is a sectional view showing an example of a high voltage disconnection switch, and Fig. 5 is a circuit diagram showing its drive control circuit. (1)...Kiteem +21...High voltage generation circuit, (31...High voltage cable, (4)...IIl fungus, (5)...Overcurrent detection circuit. (6 )... Voltage 3111T switch, (b)...
Main electrode, light...ground electrode, (to)...movable contact,
αTaku...electromagnetic cylinder? v... Ionization means. Output 1 person Trinity Industries Co., Ltd. 4 tons

Claims (1)

[Claims] High voltage is supplied from the high voltage generation (b) path to the coating machine via the high voltage line 1, and the high voltage By detecting an abnormality in the secondary overcurrent or voltage fluctuation of the generating circuit, the primary working current 5t-lII! In addition to l'r, the high voltage generation circuit and 1M! The residual electric charge of the installed engine is ionized into the ground electrodes of the main electrode and the ground electrode, which are interposed between the high voltage line and the ground and are opposed to each other with a distance between them. It induces discharge in other ears and instantly decreases it,
In addition, the method for shutting off high voltage in a silent tm* device is to short-circuit the main electrode and the image area electrode to discharge the remaining charge.