JP2019035648A - Control device and, high-voltage power supply device for electrostatic coating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To predict a disconnection of a cable connecting an electrostatic coating machine and a control unit, and to perform planned cable exchange. SOLUTION: A composite cable 40 connecting a high voltage generation unit 20 and a high voltage control unit 30 includes a detection line 401a using a plurality of coated wires, and a reference line 401b connected to the detection line 401a. The high voltage control unit 30 detects the first voltage across the detection line and the reference voltage generation circuit 51 that supplies the reference voltage to the detection path including the detection line 401a and the reference line 401b via a resistor. And an amplifier circuit 502 that detects the second voltage across the reference line. The high voltage controller 30 uses the ratio of the first voltage and the second voltage to disconnect the wire. To calculate. [Selection diagram] Figure 1

Description

  The present invention relates to a control device having a function of predicting disconnection of a cable, and a high voltage power supply device including the control device, which is used in an electrostatic coating device that disperses electrostatically charged coating material particles. For example, the present invention relates to a high-voltage power supply apparatus that can predict a cable break that connects a high-voltage generating unit included in an electrostatic coating machine disposed in a painting booth and a control unit installed outside the painting booth.

  A high voltage power supply device in a conventional electrostatic coating apparatus switches a high voltage generating module including a high voltage transformer and a voltage multiplying circuit (for example, a voltage doubler rectifier circuit) on its secondary side, and a current flowing to the primary side of the high voltage transformer. And a high voltage controller including a controller for supplying a drive signal thereto. As the coating material, a liquid paint material or the like is used.

  In car body painting systems, etc., an electrostatic coating machine with a built-in high voltage generation module is installed at the tip of the arm of the painting robot. This electrostatic coating machine is connected to a high voltage control unit installed outside the coating booth through a cable. The controller included in the high voltage control unit supplies a drive signal to the drive circuit, and generates a periodic or oscillating drive voltage on the primary side of the high-voltage transformer via a cable having a maximum length of about 30 m. As a result, a high voltage is generated on the secondary side of the high-voltage transformer, which is applied to the voltage multiplication circuit, and the output high voltage of the voltage multiplication circuit is supplied to the electrostatic coating machine using electrostatic potential. Yes. Also, a voltage proportional to the current flowing through the secondary side of the high-voltage transformer and a voltage proportional to the high voltage are input to the high voltage control unit via the cable, and the high voltage control unit generates a constant high voltage. There is known a high voltage power supply device that performs control to stop a high voltage when the current flowing through the secondary side of the high voltage transformer is abnormal.

  Depending on the painting operation, the robot moves the electrostatic coating machine along the shape of the object to be coated. At this time, the connection cable may be bent and the cable may be deteriorated. The cable is generally a multi-core cabtire cable having a shield configuration. It is known that disconnection occurs due to brittle deterioration of the copper wire constituting the cable.

As conventional disconnection or deterioration detection methods, the following methods are known.
(1) As shown in Patent Document 1, a signal that also serves as a detection purpose is used as one of signals of a multicore cable.
(2) As shown in Patent Document 2, a disconnection detection signal is used as one of the signals of a multicore cable, and the disconnection detection signal is applied to a detection line having a short mechanical life of the multicore cable.
(3) As shown in Patent Documents 3 and 4, the resistance value of the cable is observed, and the resistance value change and the voltage change due to the breakage of the stranded wire are detected.
(4) As shown in Patent Document 5, as a method for detecting a partial disconnection of a plurality of covered strands, a method for detecting a disconnection rate of a line whose length is determined as a component is known.

  However, the above-mentioned Patent Document 1 is a method of performing detection after a cable is in a state of advanced disconnection, and there is a problem that the progress of disconnection, that is, a sign cannot be found. In Patent Document 2, it is necessary to use a multi-core cable structure or a cable having a special structure with a different bending life. In general, it is difficult to predict the bending life of the detection wire with respect to the diameter and material of the wire, and there is a problem that the prediction wire may be broken too late or too early depending on the installation environment. In Patent Documents 3 and 4 described above, although continuous deterioration detection is attempted by resistance value change, since the resistivity of the copper wire is low, a high-accuracy circuit is required to detect a voltage drop due to the disconnection section. The change in the resistance value due to the disconnection that occurred in one section of the cable is very small compared to the resistance value due to the total length of the cable. In addition, a relatively large current may flow for detection. However, when the wire constituting the cable is broken, overheating occurs in the broken portion, which is not preferable from the viewpoint of preventing ignition of the coating solvent. . Further, Patent Document 5 is a technique mainly for extracting a manufacturing defect such as a coil, and the cables actually used in the high voltage power supply device have different cable lengths depending on the layout of the installation place. Because it is difficult to obtain the standard resistance value due to variations in cable manufacturing, such as variations in electrical conductivity and cross-sectional area, it is easy to install at the installation site while measuring the resistance values of these cables with high accuracy. It is inappropriate as a way to do it.

JP 2010-252465 A JP 2011-4004 A JP 2001-208783 A JP 2012-68171 A JP-A-6-292243

  The present invention has been made in view of such a situation, and its purpose is to predict the disconnection of a cable connecting two devices, for example, a cable connecting an electrostatic coating machine and a control unit, and systematically. An object of the present invention is to provide a control device and a high-voltage power supply device for an electrostatic coating device that can shorten the maintenance time of the equipment by performing a simple cable replacement.

The first aspect of the present invention is a control device. In the configuration using a composite cable including at least two cable wires,
At least one of the cable lines is a detection line using a plurality of coated strands,
Means for detecting a voltage of a detection path including the detection line, a reference voltage generation source, and a current limiting resistor for supplying a reference voltage of the reference voltage generation source to the detection path, and at both ends of the detection path An increase in the disconnection rate is detected by a change in the detection voltage value.

The second aspect of the present invention is also a control device. In the configuration using a composite cable including at least two cable wires,
One of the cable lines is a detection line using a plurality of coated strands, the detection line is connected to a shield portion of the composite cable on one side of the composite cable, and The shield part is connected to the ground on the other side of the composite cable,
Means for detecting a voltage of a detection path including the detection line, a reference voltage generation source, and a current limiting resistor for supplying a reference voltage of the reference voltage generation source to the detection path, and at both ends of the detection path An increase in the disconnection rate is detected by a change in the detection voltage value.

  In the first or second aspect, the number of strands of the detection line may be in the range of 30 to 150.

  In the first or second aspect, it has means for holding the detected voltage value at the initial time when the disconnection rate is 0% and means for holding the ambient temperature value at the initial time, and calculates the disconnection rate. The disconnection rate is calculated using the voltage of the detection path during operation, the ambient temperature, the held detection voltage value, and the held ambient temperature value, and the current limiting resistor has the disconnection rate of the reference line The resistance value at 0% is 5 to 15 times larger, and the disconnection rate may be calculated by correcting the influence of the line length of the composite cable and the temperature change.

A third aspect of the present invention is a high-voltage power supply device for an electrostatic coating apparatus that disperses electrostatically charged coating material particles. The high-voltage power supply device for an electrostatic coating apparatus includes a high-voltage transformer having a primary winding and a secondary winding, and a high-voltage rectifier that rectifies an induced voltage of the secondary winding. A high voltage generator that supplies an output voltage to a coating device using an electrostatic potential, a high voltage controller that switches a current flowing through the primary winding, and the high voltage generator and the high voltage controller are connected. With a composite cable
The composite cable has a detection line using a plurality of coated strands, and a reference line connected to the detection line in the high voltage generation unit,
The high voltage control unit detects a first voltage that supplies a voltage to the primary winding, means for detecting a first voltage at both ends of the detection line, and a second voltage at both ends of the reference line. Means, a second power source for generating a reference voltage, and a current limiting resistor for supplying the reference voltage to the detection line,
The high voltage control unit calculates a disconnection rate using a ratio between the first voltage and the second voltage.

In the third aspect, the detection line and the reference line are connected to a center tap of the primary winding, and one of the other terminals of the primary winding detects the first voltage. Connecting to means and means for detecting said second voltage;
With the switching means, the first power output and the second power output are switched and supplied to the detection line, and the detection line and the reference line serve as a power supply line to the primary winding. Good.

A fourth aspect of the present invention is a high-voltage power supply device for an electrostatic coating apparatus that disperses electrostatically charged coating material particles. This high voltage power supply for electrostatic coating equipment is
A high voltage power supply device used in an electrostatic coating apparatus for spraying electrostatically charged coating material particles,
A high-voltage transformer having a primary winding and a secondary winding, and a high-voltage rectifier that rectifies the induced voltage of the secondary winding, and the output voltage of the high-voltage rectifier is applied to a coating device using an electrostatic potential. A high voltage generator to be supplied;
A high voltage control unit for switching a current flowing through the primary winding;
Comprising a composite cable connecting the high voltage generator and the high voltage controller;
The composite cable has a detection line using a plurality of coated strands,
The high voltage control unit includes: a power source that supplies a voltage to the primary winding; a unit that detects a voltage of a detection path including the detection line; a reference voltage generation source that generates a reference voltage; and the reference voltage generation source And a current limiting resistor for supplying the reference voltage to the detection path, and detecting an increase in the disconnection rate by a change in the detection voltage value of the detection path.

  In the fourth aspect, the number of strands of the detection line may be in the range of 30 to 150.

  According to the present invention, at least one of the cable lines of the composite cable connecting two devices to each other is set as a detection line using a plurality of coated strands, and the voltage of the detection path including the detection line By detecting the disconnection rate of the detection line with higher accuracy than the conventional method, the disconnection of the cable can be predicted. As a result, the maintenance time of the equipment can be shortened by performing planned cable replacement.

1 is a block diagram illustrating a high-voltage power supply device for an electrostatic coating apparatus that is Embodiment 1 of the present invention and has a disconnection prediction function. FIG. The graph which shows the detection voltage Vd with respect to the disconnection rate Kd. The table | surface which shows the detection voltage Vd with respect to the disconnection rate Kd, and the resistance change of a detection line. It is Embodiment 2 of this invention, Comprising: The block diagram which shows the high voltage power supply device for electrostatic coating apparatuses which has a disconnection prediction function. It is Embodiment 3 of this invention, Comprising: The block diagram which shows the high voltage power supply device for electrostatic coating apparatuses which has a disconnection prediction function.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In addition, the same code | symbol is attached | subjected to the same or equivalent component, member, process, etc. which are shown by each drawing, and the overlapping description is abbreviate | omitted suitably. In addition, the embodiments do not limit the invention but are exemplifications, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention.

<Embodiment 1>
A high voltage power supply device for an electrostatic coating apparatus according to Embodiment 1 of the present invention will be described with reference to FIGS. A high voltage power supply device for an electrostatic coating apparatus shown in FIG. 1 generates a high voltage and supplies it to an injector (gun) 10 as a high voltage generation module 20 and an output of the high voltage generation module 20. And a high voltage control unit 30 for optimizing the efficiency and a cable 40 for connecting the two. The injector 10 is a coating device that uses electrostatic potential, and is for spraying charged coating material particles on an object. Since the high voltage generation module 20 is usually housed in the casing of the injector 10, The cable 40 is electrically connected to the high voltage control unit 30.

  The high voltage generation module 20 includes a high voltage transformer 21 having a primary winding 21a and a secondary winding 21b, and a voltage multiplication circuit 22 (for example, a voltage doubler rectification circuit) that rectifies and multiplies the induced voltage of the secondary winding 21b. The high voltage output of the voltage multiplication circuit 22 is supplied to the injector 10. One end of the series circuit of the resistors R21 and R22 for detecting high voltage output is connected to the output terminal of the voltage multiplication circuit 22, and the other end is connected to the voltage common terminal 201f. A connection point between the resistors R21 and R22 is connected to a terminal 201g for detecting a high voltage output. The high voltage current detection resistor R23 is connected to the secondary winding 21b, one end of which is connected to the terminal 201e for detecting the high voltage current, and the other end is connected to the voltage common terminal 201f.

  The high voltage control unit 30 includes drive circuits 31 and 32, input circuits 33 and 34, a variable control stabilization power supply 35, a microcontroller (abbreviation: microcomputer) 50, a reference voltage generation circuit 51, a switch 52 as a switching unit, a current limiter. The resistor RL and amplification circuits 501 and 502 (for example, operational amplifiers) as voltage detection means are included. The drive circuits 31 and 32 switch the current flowing through the primary winding 21a of the high-voltage transformer 21 in response to a drive signal from the microcomputer 50.

The cable 40 is a multi-core aggregated cable (also referred to as a composite cable) in which a large number of cable wires are bundled, and its length is about 30 m to 40 m at maximum. Cable 401e~401g is a signal line for control signal lines are used mainly with the cross-sectional area of about 0.2 mm ² 0.4 mm ² for the specification and workability of the connector and terminals. In contrast, the power supply signal line 401a~401d, in consideration of the efficiency of the high voltage generating module 20 uses the signal line having the cross-sectional area of about 0.5mm ² ~0.9mm ^2. Reference numeral 401h denotes a shield part of the cable, which is connected to the voltage common terminal 301h of the high voltage control unit 30 and grounded (connected to the ground).

  A terminal 201e for detecting a high voltage current and a terminal 201g for detecting a high voltage output of the high voltage generating module 20 are respectively connected to the input circuit 33 by cables 301e and 401g via terminals 301e and 301g of the high voltage control unit 30. , 34. The voltage common terminal 201f of the high voltage generation module 20 is connected to the voltage common terminal 301f of the high voltage control unit 30 by the cable line 401f.

  The primary winding 21 a of the high-voltage transformer 21 has a center tap, which is connected to the center tap terminals 201 a and 201 b of the high voltage generation module 20. The center tap terminal 201a is connected to the variable control stabilization power source 35 via the cable line 401a, the center tap terminal 301a of the high voltage control unit 30 and the switch 52, and the center tap terminal 201b is connected to the cable line 401b and the high voltage control unit 30. Is connected to the variable control stabilization power supply 35 via the center tap terminal 301b. That is, the output voltage of the variable control stabilization power supply 35 can be supplied to the center tap terminals 201a and 201b via the cables 401a and 401b as the drive voltage of the high-voltage transformer 21. Both ends of the primary winding 21a are connected to the drive signal terminals 201c and 201d of the high voltage generating module 20, respectively, and are further driven by the cable lines 401c and 401d via the drive signal terminals 301c and 301d of the high voltage control unit 30. Connected to circuits 31 and 32. These drive circuits 31 and 32 are driven by a complementary two-phase drive signal from the microcomputer 50 by a known technique.

In the first embodiment, the ratio of the disconnection of the cable line 401a serving as a detection line, which is a part of the cable 40, is determined based on the reference voltage generation circuit 51, the switch 52, the current limiting resistor RL, the amplification circuits 501, 502, and the length. Can be detected using the cable lines 401a and 401b having the same value. The cable wire 401a as the detection wire uses a wire using a plurality of covered strands such as a litz wire. On the other hand, the other cable lines including the cable line 401b serving as the reference line do not use a plurality of covered strands such as a litz wire, but an insulation-covered cable wire that bundles the strands without insulating each other. It is. However, the diameter and the number of the strands constituting the cable line 401a as the detection line may be the same as those of the other power signal lines so that the deterioration speed is not significantly different from that of the other signal lines. preferable. For example, when the line length of the cable 40 is about 30 m, a configuration in which strands having a diameter of 0.1 mm that are generally available and 100 strands are used is used. The cross-sectional area is about 0.785 mm ² .

  The current flowing through the center tap of the primary winding 21a is twice as large as the current flowing through the drive signal terminals 201c and 201d by the method of the drive circuits 31 and 32 according to a known technique. For this reason, the cable wires 401a and 401b are connected to the center tap terminals 201a and 201b, respectively, and the drive current is supplied by the two signal lines. In other words, during operation, the switch 52 connects the output of the variable control stabilization power supply 35 to the terminal 301a, and the microcomputer 50 instructs the variable control stabilization power supply 35 about the center tap voltage value corresponding to the output high voltage value. The output of the variable control stabilization power supply 35 is supplied to the high voltage generation module 20 through the cable line 401b and the cable line 401a via the switch 52.

  When the injector 10 attached to the painting robot is moved by the painting operation, when the assembly cable 40 is repeatedly bent, the strands constituting the signal lines in the cable are disconnected, and the ratio of the disconnection depends on the number of times of bending. Will go on.

The reference voltage generation circuit 51 generates a reference voltage Vc with reference to the output of the variable control stabilization power supply 35. An insulating power supply device is used to generate, for example, a reference voltage Vc = 2V. The current limiting resistor RL is inserted in series with the output of the reference voltage generation circuit 51. When observing the cable state, the switch 52 applies a reference voltage to the terminal 301a via the resistor RL. In addition, the drive circuits 31 and 32 are both turned off at the time of measurement, so that no current flows through the drive circuits 31 and 32.

In this state, the voltage Vd between the terminals 301a and 301c is measured by the amplifier circuit 501. This is a voltage drop of the detection line 401a. Subsequently, the voltage Vm between the terminals 301 c and 301 b is measured by the amplifier circuit 502. This is a voltage drop of the reference line 401b having the same strand configuration as the detection line 401a.

ここで、Ｋａは銅の抵抗値の温度係数＝０.００３９３、Ｋｒは基準温度Ｔ１＝２０℃のときのケーブルの単位長さあたりの抵抗値である。前記記載のケーブル構成では、断面積０.７８５ｍｍ^２ 程度であるので、Ｋｒ＝０.０２２Ω／ｍ程度である。
続く計算のため、基準となる係数Ｒｒｅｆを求める。Ｋｄ＝０％、Ｌ１＝３０ｍ、Ｔ２＝２０℃として、式１に代入し、Ｒｒｅｆ＝０.６６Ω となる。 According to the first embodiment of the present invention, it will be described that the disconnection rate of the cable line 401a as the detection line can be detected regardless of the length of the cable 40 using the voltages Vd and Vm. The resistance value R1 of the cable wire 401a can be expressed as in Equation 1 when the cable length L, the disconnection rate Kd, and the temperature T2.

Here, Ka is a temperature coefficient of resistance value of copper = 0.00393, and Kr is a resistance value per unit length of the cable when the reference temperature T1 = 20 ° C. In the cable configuration described above, since the cross-sectional area is about 0.785 mm ² , Kr = about 0.022 Ω / m.
For the subsequent calculation, a reference coefficient Rref is obtained. Assuming Kd = 0%, L1 = 30 m, and T2 = 20 ° C., it is substituted into Equation 1, and Rref = 0.66Ω.

In the first embodiment of the present invention, by using a wire using a plurality of covered strands such as a litz wire as the detection wire 401a, a large resistance change can be obtained as follows according to the disconnection rate. it can. In the case of the disconnection rate Kd = 50% and 99%, it is easily understood that the resistivity changes as follows according to the disconnection rate Kd under the same temperature T2 = 20 ° C.
R1 = 1 / (1-0.5) × Rref = 2 × 0.66Ω when Kd is 50%
R1 = 1 / (1-0.99) × Rref = 100 × 0.66Ω when Kd is 99%

On the other hand, the simple resistance value change includes the influence of the cable line length L and the resistance value change due to the temperature. Therefore, the resistance value R2 of the reference line 401b is used to influence the relationship from the expressions 2 and 3. Try to negate.

Since the resistance value of the reference line 401b does not change unless the disconnection is significantly advanced, R2 may be a constant value. For example, as in the case of the detection line 401a, in the configuration of 100 strands having a diameter of 0.1 mm, it is clear from the following calculation that 5 mm in the total length 30 m of the reference line has a disconnection rate of 99%.
The resistance value per unit length of the cable is 0.022Ω at a temperature of 20 ° C. as an example.
Resistance value in 30m section = 0.022Ω x 30m = 0.66Ω
Resistance value in 5 mm section = 2.2 Ω x 0.005 m = 0.011 Ω
Thus, even if there is a section with a very high disconnection rate, the above calculation shows a resistance change of 0.011Ω ÷ 0.66Ω = 1.67%.

  Further, as a feature of the first embodiment of the present invention, the cable line 401a as the detection line and the cable line 401b as the reference line run in parallel with other cable lines in the aggregate cable 40. By adopting the same cable element configuration as the cable line, the rate of change in resistance value with respect to temperature can be made the same. This can be compensated for the case where there is a temperature change in a part of the entire length of the cable 40.

式５を、Ｋｄを求める式に変形して式６を得る。

From Equation 2 and Equation 3, when R2 is approximated to R1 with a disconnection rate of 0%, and the variation with respect to temperature is described using the coefficient Rref, Equation 4 and Equation 5 are obtained.

Equation 5 is transformed into an equation for obtaining Kd to obtain Equation 6.

An example is shown below. When the above-described wire configuration is used for the cable wires 401a and 401b, when a configuration of Vc = 2V, RL = 2Ω, and cable length L = 30m is used at a temperature of 20 ° C., Vd = 0.85V, Vm = 0. At 28V, Kd = 0.67. This corresponds to a resistance value of 1.98Ω for the cable 401a and a resistance value of 0.66Ω for the cable 401b.

The current limiting resistor RL is determined in consideration of the accuracy of the A / D converter in the microcomputer 50 and the accuracy of the resistor RL. The procedure is described below. FIG. 2 is a graph plotting the disconnection rate Kd versus the detection voltage Vd against resistance values 1Ω, 2Ω, and 10Ω of the current limiting resistor RL. Vc = 2.0V, cable wire 401a as detection line, cable wire 401b as reference line, using the above-described wire configuration, temperature 20 ° C., cable length is the minimum value for a maximum of 30m Is 10m.

FIG. 3 is a table in which the value of Vd for each disconnection rate Kd in FIG. 2 and the resistance (R1) value of the detection line 401a corresponding to the disconnection rate Kd are described.

When the resistance value between the terminals 301a and 301b, that is, the sum of the resistance values of the cable wires 401a and 401b is equal to the resistance RL, Vd + Vm = Vc × 0.5. The RL is obtained in the range of the length of the cable to be connected and the range in which the change amount of the voltage Vd with respect to the disconnection rate Kd of 0 to 50% is at least 5% to 10% or more of Vc. In addition, the measurement current at this time is set to about 1 A or less.

  The change in the resistance value of R1 when the disconnection rate is 0% to 50% is 0.22Ω from FIG. 3, and when RL = 2Ω is used, the voltage change when the disconnection rate is 0% to 50% is 0.33V. -0.18V = 0.15V and 7.5% of Vc = 2.0V. The maximum current measured at this time is Vc ÷ (RL + R1 + R2) = 2V ÷ (2Ω + 0.22Ω + 0.22Ω) = 0.82A.

When RL = 1Ω is used, the voltage change when the disconnection rate is 0% to 50% is 0.53V−0.18V = 0.35V and 11% of Vc = 2.0V. The maximum current measured at this time is Vc / (RL + R1 + R2) = 2.0 V / (1Ω + 0.22Ω + 0.22Ω) = 1.39A.
From the change in the Vc voltage when the disconnection rate is 0% to 50%, it is understood that RL is preferably 2Ω or less. From this point, even when RL is 1Ω, although it is suitable from the viewpoint of the resolution of the AD converter, the circuit configuration of the reference voltage generation circuit 51 is increased when the output current of the reference voltage generation circuit 51 exceeds 1A. Therefore, 2Ω is suitable for RL.

From the above, the reference voltage Vc for detection is 2 to 4 V, and RL is about 5 to 15 times the resistance value of 0% disconnection of the cable wire to be measured, and the measurement current is If possible, Vc and RL should be adjusted so as not to exceed 1A and to be 2A or less in consideration of overheating of the disconnected portion.

  According to the first embodiment of the present invention, the following effects can be obtained.

(1) One of the cable wires constituting the multi-core assembly cable 40 is a detection wire 401a using a plurality of insulated wires, and the voltage of the detection wire 401a and the wires are individually insulated. It is possible to detect the disconnection rate of the detection line with higher accuracy than the conventional method by correcting the influence of the ambient temperature and the cable length by using the voltage of the reference line 401b that is not performed. The disconnection rate can be obtained continuously by setting the number of strands to about 30 to 150, and by checking the disconnection status, the cable can be quickly replaced before the cable assembly 40 breaks. it can. If the number of strands is less than 30, the number of wires is insufficient to change the disconnection rate stepwise, and if the number of strands exceeds 150, the cable tends to be too thick.
(2) The collective cable 40 used as the movable cable differs greatly in the maintainability at the time of laying and replacement of the cable depending on the thickness and weight thereof. The cable lines constituting the detection line 401a and the reference line 401b use a power line connected to the high voltage generation module 20, and can be implemented without increasing the diameter of the cable 40. Since there is no addition to the signal configuration of the cable 40, the cable 40 is not routed at the time of laying or maintainability at the time of replacement is not impaired.
(3) Although the cable length varies depending on the arrangement in the installed factory, the cable length is not required to be measured in this embodiment. That is, initial setting at the time of introducing the apparatus is easy.

  In the configuration of FIG. 1, the part that functions as a control device that calculates the disconnection rate and detects the increase is the detection line 401a, the reference line 401b, the microcomputer 50, the reference voltage generation circuit 51, the switching means 52, and the amplification. Computations of Formulas 1 to 6 including the circuits 501 and 502 are performed by the microcomputer 50.

<Embodiment 2>
The present invention can also be realized with a more simplified circuit configuration, and this case is shown as Embodiment 2 in FIG. FIG. 4 shows a configuration in which a plurality of covered strands such as litz wires are used for the cable wires 401a and 401b and used as dedicated detection wires. Only the part where the configuration of the detection line is different from FIG. 1 is shown. The cable lines 401a and 401b are connected to the terminals 211a and 211b on the high voltage generation module 20 side, so that the reference voltage Vc generated by the reference voltage generation circuit 51 causes the current limiting resistor RL and the terminal on the high voltage control unit 30 side. Current flows through a path of 311a, cable line 401a, internally connected terminals 211a and 211b on the high voltage generation module 20 side, cable line 401b, and terminal 311b on the high voltage control unit 30 side.

  In order to effectively detect the disconnection that occurs in the collective cable 40, the cable wires 401a and 401b formed by the two covered strands are arranged adjacent to each other in the collective cable without being adjacent to each other in the collective cable. good.

７式に対して、Ｒ１とＲ２の平均値をＲｃとすると式８となり、変形により式９を得る。

ケーブル線４０１ａ、４０１ｂの基準温度Ｔ１、断線率０％における抵抗値をＲｒｅｆとし、その時のＶｄをＶｄ０として、ＲＬ／Ｒｒｅｆの定数を式１０により求める。

式９、式１０は、後述で使用するので、次に所定の温度Ｔ２でのＲｃと、基準温度Ｔ１でのＲｒｅｆに対する断線率Ｋｄの関係式を使用すると、式１１及び変形した式１２のように表記することができる。

Even in this configuration, it is possible to detect the disconnection rate regardless of the influence of the cable length and temperature change. Hereinafter, description will be made using Equations 7 to 12.
The detection voltage Vd is expressed by Equation 7. As the disconnection progresses, the resistance value R1 of the cable line 401a and the resistance value R2 of the reference line 401b in Equation 7 change, respectively, so that the voltage Vd changes according to the disconnection rate of R1 and R2. When the disconnection rate of each of the cables 401a and 401b is 40% or less, it can be approximated by an average value of the disconnection rates.

If the average value of R1 and R2 is Rc with respect to Equation 7, Equation 8 is obtained, and Equation 9 is obtained by modification.

The resistance value of the cable wires 401a and 401b at the reference temperature T1 and the disconnection rate of 0% is Rref, the Vd at that time is Vd0, and the constant of RL / Rref is obtained by Equation 10.

Since Equations 9 and 10 will be used later, using the relational expression of Rc at a predetermined temperature T2 and the disconnection rate Kd with respect to Rref at the reference temperature T1, Equation 11 and a modified Equation 12 are obtained. Can be written as

When the electrostatic coating apparatus is installed or when the cable 40 is replaced, Vd0 serving as a reference is measured with a disconnection rate of 0% and a reference temperature T1, and a coefficient KRref = RL / (2Rref) is obtained from Equation 10. For example, as a trial calculation example, using a cable having a temperature T1 = 20 ° C., a strand having a diameter of 0.1 mm, and 100 strands, Vc = 3.3V, RL = 2Ω, and cable length L = 30 m In this case, Vd0 = 1.31V and KRref = 1.52. The microcomputer 50 holds the reference temperatures T1 and Vd0 in the temperature value holding means 53 and the voltage value holding means 54, respectively. The ambient temperature is measured by the temperature sensor 55.
During operation, the value of RL / (2Rc) is obtained from the ratio of Vc and Vd using Equation 9, and this is defined as KRc.
Temperature T2 = 40 ° C., Vd = 1.55 V is measured, and KRc = 1.13.
KRc ÷ KRref = RC / Rref, and further using the known cable temperature coefficient Ka (= 0.00393),
Kd = 1− (KRc / KRref) × (1 + Ka (40 ° C.-20 ° C.))
= 1-1.13 / 1.52 x (1 + Ka (40 ° C-20 ° C)) = 0.20
This corresponds to a resistance value of R1 of 0.66Ω at the temperature T1 = 20 ° C. and disconnection when the cable 40 is replaced, and 0.89Ω at the temperature T2 = 40 ° C.

  According to the second embodiment of the present invention, the following effects can be obtained.

(1) Two of the cable wires constituting the multicore cable 40 are configured as detection lines 401a and 401b using a plurality of coated strands, and the detection lines 401a and 401b By connecting the high-voltage control unit 30 back, the influence of the ambient temperature and cable length is corrected using the voltage of the detection path including the detection lines 401a and 401b and the ambient temperature, and higher accuracy than the conventional method. Thus, the disconnection rate of the detection lines 401a and 401b can be detected. The disconnection rate can be obtained continuously by setting the number of strands of the detection lines to about 30 to 150. By checking the disconnection status, the cable can be quickly replaced before the aggregate cable 40 breaks. It can be carried out.
(2) The number of detection lines is two, and it is possible to suppress the increase in the diameter of the cable 40 by reducing the addition of cable lines, and the influence of maintainability at the time of laying and replacement of the cable 40 is small.
(3) The initial set values necessary for detecting the disconnection rate are set to the detection voltage and temperature at the time of installation, and an easy and short-time setup is possible without obtaining the cable length in advance.
(4) The electrostatic coating apparatus is installed in a large factory premises, and the resistance value of the cable 40 tends to be easily affected by temperature changes. However, considering the ambient temperature (by detecting the temperature with the temperature sensor 55) ) The accuracy of disconnection prediction can be improved.

<Embodiment 3>
Embodiment 3 according to the present invention will be described with reference to FIG. In the third embodiment, one cable line composed of a plurality of covered strands is used as a detection line, and the signal addition of the cable 40 is minimized. A cable line 401a in FIG. 5 is a plurality of covered strands such as a litz wire, and connects the terminal 211a on the high voltage generation module 20 side and the terminal 311a on the high voltage control unit 30 side. The shield portion 401h of the collective cable 40 connects the terminal 211h on the high voltage generation module 20 side and the voltage common terminal 311h (earth terminal) on the high voltage control unit 30 side. Therefore, depending on the reference voltage Vc generated by the reference voltage generation circuit 51, the current limiting resistor RL, the terminal 311a on the high voltage control unit 30 side, the cable line 401a, and the internally connected terminals 211a, 211h on the high voltage generation module 20 side, A current flows through the path of the shield part 401h and the terminal 312h on the high voltage control unit 30 side.

また、シールド部分４０１ｈの抵抗値Ｒ２は、断線率０％における検出線４０１ａの抵抗値の１／Ｎとすると、Ｒ１の基準となる抵抗値Ｒｒｅｆを用いて、式１４のように記載できる。
シールド部分４０１ｈの断線率が極めて大きくない限り、Ｒ２は温度係数Ｋａにのみ依存する条件は、前記実施の形態１、２と同様である。

Ｒ２＝Ｒｒｅｆ×(１＋Ｋａ(Ｔ２−Ｔ１))／Ｎ ・・・式１４
式簡略化のため基準温度のときの係数ＫＴ０（＝ＲＬ÷Ｒｒｅｆ÷Ｎ）を用いて式１３を変形すると式１５となる。

Even in this configuration, it is possible to detect the disconnection rate regardless of the influence of the cable length and temperature change. This will be described below using Equations 13 to 17.
The above equation 7 is modified to obtain the following equation 13.

Further, if the resistance value R2 of the shield portion 401h is 1 / N of the resistance value of the detection line 401a when the disconnection rate is 0%, the resistance value Rref that is the reference of R1 can be used to describe the resistance value R2.
Unless the disconnection rate of the shield part 401h is very large, the condition that R2 depends only on the temperature coefficient Ka is the same as in the first and second embodiments.

R2 = Rref × (1 + Ka (T2−T1)) / N (14)
For simplifying the equation, Equation 15 is obtained by transforming Equation 13 using the coefficient KT0 (= RL / Rref / N) at the reference temperature.

Subsequently, a calculation procedure of the disconnection rate Kd by the microcomputer 50 will be described. The resistance ratio between the detection line 401a and the shield portion 401h is obtained in advance by design specifications or measurement. In addition, the constant part KT0 · N in Expression 15 is (1 + Ka (T2−T1)) = 1 at the reference temperature T1, and R1 / R2 = N, so that the reference voltage Vd0 is used. 16 can be described.
KT0 · N = (Vc / Vd0-1) · (N + 1) Equation 16
From Equations 15 and 16, R1 / R2 is calculated from the temperature T2 measured during operation and the detected voltage Vd, and is substituted into Equation 17 to obtain Kd.

A calculation example is shown below. When the electrostatic coating apparatus is installed or when the cable 40 is replaced, Vd0 serving as a reference is measured with a disconnection rate of 0% and a reference temperature T1, and a coefficient KT0 · N is obtained from Equation 15.
As a trial calculation example, when a wire having a diameter of 0.1 mm is used as the detection wire 401a and a cable wire having 100 stranded wires each coated with insulation is used, the temperature T1 = 20 ° C., Vc = 3.3V, RL = In the case of 2Ω and the cable length L = 30 m, Vd0 = 1.01V and KT0 · N = 9.07. N = 3 is used according to the specifications of the shield part.
During operation, the temperatures T2 and Vd are measured, and R1 / R2 is determined by Equation 15.
Assuming that the temperature T2 = 40 ° C., Vd = 1.80 V, and R1 / R2 = 9.09, Kd = 0.67 from Equation 17.
This corresponds to a resistance value of R1 of 0.66Ω at the temperature T1 = 20 ° C. and disconnection when the cable 40 is replaced, and 2.16Ω at the temperature T2 = 40 ° C.

  According to the third embodiment of the present invention, the following effects can be obtained.

(1) One of the cable wires constituting the multicore cable 40 is set as a detection wire 401a using a plurality of coated strands, and the voltage of the detection path including the detection wire 401a and the ambient temperature are used. By correcting the influence of ambient temperature and cable length, the disconnection rate of the detection line can be detected with higher accuracy than the conventional method. The disconnection rate can be obtained continuously by setting the number of strands to about 30 to 150, and by checking the disconnection status, the cable can be quickly replaced before the cable assembly 40 breaks. it can.
(2) Since there is one detection line and the shield portion 401h of the collective cable 40 is used as a return current path, an increase in the diameter of the cable 40 can be suppressed, and when the cable is routed or replaced during laying The effect of maintainability is small.
(3) The initial set values necessary for detection are the detection voltage and temperature at the time of installation, and easy and short setup is possible without obtaining the cable length in advance.
(4) The electrostatic coating apparatus is installed in a large factory premises, and the resistance value of the cable 40 tends to be easily affected by temperature changes. However, considering the ambient temperature (by detecting the temperature with the temperature sensor 55) ) The accuracy of disconnection prediction can be improved.

  As described above, in the first and third embodiments, as a feature of the present invention, a change in the detection voltage with respect to the disconnection rate is increased by using a line using a plurality of covered strands as the detection line 401a. Since the temperature distribution with respect to the remaining connected wires is the same as that of the reference line 401b, assuming that the detection line 401a is disconnected, the resistance value change with respect to the temperature is independent of the disconnection rate Kd. . In other words, it is also effective when a part of the cable 40 passes through the robot and there is a temperature rise in a part of the cable 40. Originally, since the disconnection position on the cable cannot be predicted, in the conventional method, the series connection of different resistance values has a temperature distribution, and fluctuations that are difficult to detect have occurred. By using a plurality of coated strands as detection lines, this influence can be removed and the accuracy of detection results can be improved.

  In the second embodiment, the detection is approximate from the above point of view, but it can be said that the two detection lines are the same under the condition that the same level of disconnection occurs.

  In each of the embodiments, for the cable lines 401a to 401g and the shield part 401h, the breakage progress rate (speed) is determined from the diameter of the cable line and the cable line constituting the aggregated cable 40 from the center of the aggregated cable cross-sectional area. Although it depends on where it is arranged and the covering to be used, the disconnection rate of the detection line can be used as a guide indicating the replacement time of the aggregate cable 40. According to each embodiment, since the continuous disconnection rate is known, if the disconnection of the cable line as the other signal line proceeds faster than the detection line depending on the installation environment and the operation situation, the cable 40 It is preferable to set the disconnection rate for replacement determination to 5%, 10%, or the like.

  The present invention has been described above by taking the embodiment as an example. However, it is understood by those skilled in the art that various modifications can be made to each component and each processing process of the embodiment within the scope of the claims. By the way.

As an embodiment of the present invention, a high-voltage power supply device for an electrostatic coating device has been described. However, the present invention can be applied to a device using a multicore cable of about 10 m or more and 30 m or less, and particularly a cross-sectional area of 0.5 mm ^2. It is suitable for applications in which two devices are connected to each other using a cable of ˜1.0 mm ² .

  In each embodiment, a relatively thick signal line having a configuration in which a strand having a diameter of 0.1 mm is used as a detection line and 100 strands are used is used, but a thinner configuration is also possible. On the other hand, since the number of states of change in the resistivity of the detection line is equal to the number of strands constituting the detection line, 30 or more strands are suitable for obtaining a stepwise disconnection rate.

DESCRIPTION OF SYMBOLS 10 Injector 20 High voltage generation module 21 High voltage transformer 22 Voltage multiplication circuit 30 High voltage control part 31, 32 Drive circuit 33, 34 Input circuit 35 Variable control stabilization power supply 40 Cable 401a-401g Cable line 401h Shield part 50 Microcomputer 51 Reference voltage generating circuit 52 Switching means 53 Temperature value holding means 54 Voltage value holding means 55 Temperature sensor 501 Amplifying circuit 502 Amplifying circuit

Claims (8)

In a control device using a composite cable including at least two cable wires,
At least one of the cable lines is a detection line using a plurality of coated strands,
Means for detecting a voltage of a detection path including the detection line, a reference voltage generation source, and a current limiting resistor for supplying a reference voltage of the reference voltage generation source to the detection path, the detection voltage of the detection path A control device that detects an increase in the disconnection rate by a change in value. In a control device using a composite cable including at least two cable wires,
One of the cable lines is a detection line using a plurality of coated strands, the detection line is connected to a shield portion of the composite cable on one side of the composite cable, and The shield part is connected to the ground on the other side of the composite cable,
Means for detecting a voltage of a detection path including the detection line, a reference voltage generation source, and a current limiting resistor for supplying a reference voltage of the reference voltage generation source to the detection path, and at both ends of the detection path A control device that detects an increase in the disconnection rate based on a change in a detected voltage value.   The control device according to claim 1, wherein the number of strands of the detection lines is in a range of 30 to 150. It has means for holding the detected voltage value at the initial stage of the disconnection rate of 0% and means for holding the ambient temperature value at the initial stage, and the voltage of the detection path during operation is calculated for calculating the disconnection rate. The disconnection rate is calculated using the ambient temperature, the held detection voltage value, and the held ambient temperature value, and the current limiting resistance is compared to the resistance value when the reference line has a disconnection rate of 0%. 5 to 15 times the value,
4. The control device according to claim 1, wherein the calculation of the disconnection rate corrects an influence of a line length of the composite cable and a temperature change. 5. A high voltage power supply device used in an electrostatic coating apparatus for spraying electrostatically charged coating material particles,
A high-voltage transformer having a primary winding and a secondary winding, and a high-voltage rectifier that rectifies the induced voltage of the secondary winding, and the output voltage of the high-voltage rectifier is applied to a coating device using an electrostatic potential. A high voltage generator to be supplied;
A high voltage control unit for switching a current flowing through the primary winding;
Comprising a composite cable connecting the high voltage generator and the high voltage controller;
The composite cable has a detection line using a plurality of coated strands, and a reference line connected to the detection line in the high voltage generation unit,
The high voltage control unit detects a first voltage that supplies a voltage to the primary winding, means for detecting a first voltage at both ends of the detection line, and a second voltage at both ends of the reference line. Means, a second power source for generating a reference voltage, and a current limiting resistor for supplying the reference voltage to the detection line,
The high-voltage power supply unit for an electrostatic coating apparatus, wherein the high-voltage control unit calculates a disconnection rate using a ratio between the first voltage and the second voltage. The detection line and the reference line are connected to a center tap of the primary winding, and one of the other terminals of the primary winding includes means for detecting the first voltage and the second voltage. Connected to the means to detect,
By switching means, the first power output and the second power output are switched and supplied to the detection line, and the detection line and the reference line also serve as a power supply line to the primary winding. The high voltage power supply device for an electrostatic coating apparatus according to claim 5. A high voltage power supply device used in an electrostatic coating apparatus for spraying electrostatically charged coating material particles,
A high-voltage transformer having a primary winding and a secondary winding, and a high-voltage rectifier that rectifies the induced voltage of the secondary winding, and the output voltage of the high-voltage rectifier is applied to a coating device using an electrostatic potential. A high voltage generator to be supplied;
A high voltage control unit for switching a current flowing through the primary winding;
Comprising a composite cable connecting the high voltage generator and the high voltage controller;
The composite cable has a detection line using a plurality of coated strands,
The high voltage control unit includes: a power source that supplies a voltage to the primary winding; a unit that detects a voltage of a detection path including the detection line; a reference voltage generation source that generates a reference voltage; and the reference voltage generation source A high-voltage power supply device for an electrostatic coating apparatus, comprising: a current limiting resistor for supplying a reference voltage to the detection path; and detecting an increase in the disconnection rate by a change in a detection voltage value of the detection path.   8. The high-voltage power supply device for an electrostatic coating apparatus according to claim 5, wherein the number of strands of the detection line is in a range of 30 to 150. 9.

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