JP5007900B2 - Demagnetization control method and demagnetization control system for electromagnet - Google Patents

Description

This invention adsorbs magnetic article, or concerning the degaussing leaving electromagnets instantaneously, and the degaussing control method and demagnetization control systems in the electromagnet for the purpose of reliably be performed.

  Conventional electromagnets that attract or desorb articles have a practical problem of demagnetization efficiency of residual magnetism that occurs when the articles are desorbed. Therefore, in general, when demagnetizing, a current in the direction opposite to the current for adsorption is applied, but it has been considered difficult to minimize the residual magnetism.

Therefore, there has been a proposal to set a time interval before applying a reverse current (Patent Document 1), thereby achieving a minimum Tesla.
Japanese Patent No. 2617146 Patent No. 2502451 JP-A-10-229014

  The demagnetization methods that have been proposed in the past are mainly methods in which a reverse current is applied, and in particular, the method of supplying a reverse current in a time interval (Patent Document 1) has a minimal residual magnetism. Although the superior point is known, since the demagnetization parameter setting is left to the user depending on the adsorption strength of the electromagnet, the condition of the work, and other conditions, the performance of the electromagnet varies depending on the ability of the user. There was a problem that occurred.

  It is known that the variation varies depending on the attractive force of the electromagnet, the shape and material of the workpiece, the allowable demagnetization time, etc., but the best parameter setting corresponding to this varies depending on the ability of the user. was there.

  In the present invention, when demagnetizing an electromagnet, the residual magnetism is measured every time the demagnetization operation is performed, and continues until the residual magnetism reaches a certain value (for example, 0.0005 Tesla or less), and the number of operations is stored in the degaussing circuit. By automatically setting parameters and then based on the set parameters, the conventional problems were solved.

That is, according to the present invention, in a demagnetization control method in an apparatus that energizes an electromagnet to attract a workpiece and cuts off electricity to detach the workpiece, the residual magnetism of the electromagnet is measured by a magnetic sensor and its output is connected to an interface Then, the exciting current is attenuated and then cut off, and then negative DC and / or alternating current demagnetizing current is applied. The DC demagnetizing current is separated by one square pulse at a time interval after the exciting current is cut off. Or, it is a single sawtooth pulse, the degaussing current of AC is a demagnetizing current with a time interval before the start of degaussing , and this demagnetizing operation is repeated until the residual magnetism reaches 0.0005 Tesla , By storing the output in the interface, the magnetic force parameter is automatically set and demagnetized based on this. A degaussing control how in the magnet.

In another aspect, the electromagnet, its power feeding circuit and demagnetization circuit, adsorption and demagnetization interface, electromagnet excitation pattern generator, demagnetization voltage preset, and work piece contact to detect the magnetic flux density of the electromagnet. It is characterized by combining a sensor probe, a magnetic sensor having green and red light emitting diodes (LEDs) and changing the light emission state by the residual magnetic quantity and the N pole and the S pole, and the magnetic force parameter obtained. A demagnetization control system for an electromagnet that implements the demagnetization control method according to claim 1 .

The next, and the Hall elements, and the electronic circuit, a voltage detector, a magnetic sensor for use in degaussing control system in you characterized electromagnets that a combination of a flux calculator.

Other magnetic sensors may include a sensor probe which contacts the workpiece, has a green and red light-emitting diode (LED), characterized in that so as to change the light emission state by the residual magnetic charge and N and S poles a degaussing control system in electromagnets.

  The adsorption of the work 1 (magnetic material) by an electromagnet that has been generally used conventionally is energized as shown in FIG. 2, lifted up by the electromagnet 2, and carried to a predetermined position as indicated by arrows 3 and 4. The air separation method was taken as shown by arrow 5. This has caused various problems due to the large amount of residual magnetism remaining on the attracted workpiece, and has prevented the expansion of electromagnetic utilization. The major factor is that it was difficult to demagnetize the residual magnetism to a minimum in a short time.

  However, the applicant has succeeded in minimizing the residual magnetism in a short time (Patent Document 1). That is, as shown in FIG. 1, the work 1 is lifted by the electromagnet 2 as indicated by an arrow 3, moved to a predetermined position as indicated by an arrow 6, and released at the set position. In this case, the residual magnetism became 0.0005 Tesla or less by appropriate demagnetization control. Moreover, since the demagnetization can be performed in a short time (for example, 5 seconds or less), the efficiency is also improved.

  In order to make it as shown in FIG. 1, it is necessary to set parameters for the demagnetization operation. However, the demagnetization operation varies depending on the conditions such as the adsorption strength of the electromagnet, the shape, material, and thickness of the workpiece. Depending on the quality, there was a risk of affecting the performance of the adsorption device using an electromagnet.

  Therefore, the present invention has succeeded in setting the best parameters by using a magnetic sensor and storing the output in an interface so that the parameters can be automatically set.

  The magnetic sensor can be used as a general magnetic sensor if used alone.

  Also, in order to realize reliable adsorption and separation, in the electromagnet demagnetization control method as described above, after releasing the attraction force, direct current and / or alternating current demagnetization current is applied at a time interval. Thus, rapid decay of the remanent magnetism was attempted.

  In order to confirm whether the workpiece is attracted or detached, a high-frequency current having a constant amplitude and a constant frequency is applied to the electromagnetic coil of the electromagnet to detect a change in the high-frequency current. This means is also used for detecting the disconnection of the electromagnetic coil constituting the electromagnet. It is possible to use a method in which the high-frequency current is applied to the electromagnetic coil for generating the magnet attracting it while being superposed on the exciting current, or a method in which the electromagnetic coil is supplied to an independent electromagnetic coil separate from the electromagnetic coil.

  The above-described means are selectively combined in accordance with the accuracy and other specifications required for workpiece shape, conveyance, and attitude control.

  Further, according to the means for realizing reliable detachment in the present invention, it is possible to eliminate the residual magnetism of the work and improve the working accuracy. Further, according to the means for confirming the adsorption and detachment of the workpiece and the means for detecting the disconnection of the electromagnetic coil, it is possible to detect the malfunction of the electromagnet in advance to improve the work accuracy and work efficiency.

  Since the present patent applicant is to set the pattern of the demagnetization control method which is the central technology of the development of the previously developed method for drastically reducing the remanence, the outline of the demagnetization control method already developed Will be explained.

  The demagnetization control method developed earlier will be described with reference to FIG. FIG. 3 shows several current patterns for an electromagnetic coil when a general electromagnet having an electromagnetic coil provided on a core made of an iron core is used. In FIG. 3, T1 is a start timing section, T2 is an adsorption section, T3 is a holding section, and T4 is a stop section.

  In any of the cases (a) to (e) of FIG. 3, when obtaining an attracting force, the attracting current is supplied to the electromagnetic coil as an exciting current in the attracting section T 2, that is, at the initial stage of attracting, and sufficient for attracting the workpiece. Generate magnetic attraction force. Next, after the adsorption of the workpiece is completed, the current is increased to an excitation current having a current value necessary and sufficient for maintaining the adsorption state of the workpiece, and the adsorption of the workpiece is held (T3). The time and current value at T2 and the time and current value at T3 are determined according to the characteristics of the electromagnet, the shape of the workpiece, and the size. The current value during T3 in the above is increased or decreased depending on the work, but in essence, it is determined in consideration that the adsorption is surely continued so that the work is not detached during the movement of the electromagnet.

  By doing so, the magnetic attraction force at the initial stage of the attracting operation can be sufficiently increased to reliably attract the work, and after the attracting is completed, the exciting current for the electromagnetic coil is set to a necessary and sufficient current value. Therefore, an appropriate current value is determined depending on the workpiece and its shape.

  After the workpiece is sucked and held as described above, the workpiece is detached and attached in the sections T4, T5, and T6 in FIG. T4 is a cut-off section of the excitation current energized to the electromagnetic coil, T5 is a time interval section, and T6 is a demagnetization section.

  The section from T5 to T6 has several patterns as described in (a) to (e) of FIG. In FIG. 3A, an AC attenuation current is applied at T6 after a time interval T5, and FIG. 3B shows a waveform of one square pulse at T6 after the time interval T5. In FIG. 3C, after a time interval T5, a direct current having a single sawtooth pulse waveform is applied at T6. In FIG. 3 (d), after passing through the time interval T5, a direct current consisting of a single sawtooth pulse waveform in which the relationship between the time and the current value is opposite to that in (c) is applied. In FIG. 3 (e), after a time interval T5, a rectangular pulse current similar to (b) and the AC decay current (a) are continuously energized at T6.

  When the above-described operation is performed to release the attraction force on the workpiece, residual magnetism can be eliminated from the attracted workpiece as well as the core constituting the electromagnet. This is because the residual magnetism is canceled by the magnetism generated by the negative DC current. In this case, it was experimentally observed that the time interval of T5 is effective in shortening the demagnetization section T6. For example, in FIG. 3B, it was recognized that the demagnetization interval of T6 could be 0.15 seconds when a time interval of 0.1 seconds was set as T5. In the above embodiment, there was almost no residual magnetism (5 gauss or less). In addition, when the demagnetizing current is AC and DC as in T6 of FIG. 3 (e), the DC current can be a pulse current having a sawtooth waveform as shown in FIGS. 3 (c) and 3 (d).

  This invention measures the residual magnetism of an electromagnet using a magnetic sensor, connects its output to an interface, and automatically stores the demagnetization pattern stored until the residual magnetism reaches a set value as a magnetic parameter. There is an effect that can be done.

  Therefore, if the user sets the residual magnetism, the parameters are automatically set so that the residual magnetism is obtained, and there is an effect that the best operation can be performed.

  Further, since it is determined by the output of the magnetic sensor, there is no possibility of being influenced by the ability of the user, and the set value can be satisfied.

  According to the present invention, the residual magnetism of an electromagnet to be demagnetized is measured by a magnetic sensor, the output is input to an interface and stored, and the demagnetizing operation is repeated until a predetermined residual magnetism amount is reached. When the residual magnetic quantity reaches the preset residual magnetic quantity in this way, the demagnetization operation is terminated.

  In this case, the degaussing operation sequentially stored in the interface automatically sets parameters.

  Therefore, if the demagnetization operation is repeated with this parameter after the turn, the set residual magnetism is always obtained. Therefore, the best demagnetization is always repeated, and the workpiece can be moved efficiently.

  The embodiment of the present invention will be described with reference to FIG. 4. The workpiece is attracted as the attracting voltage Va of the electromagnet, and then the workpiece is moved to the holding voltage Vb.

  Next, if it comes to the place which releases a workpiece | work, since electricity supply will be stopped, magnetic force will reduce rapidly in Tb (0.1-1.0 second).

Therefore, when the demagnetizing voltage Vc in the reverse direction is applied to the demagnetizing time Tc (0.2 sec to 1.0 sec) at the time interval T ₀ (0.1 sec to 1.0 sec), the residual magnetism rapidly decreases. Therefore, a demagnetizing voltage Vc having a negative polarity is applied by a separation command. There are various current patterns in this case, such as a triangular shape, a square shape, and an alternating attenuation (FIG. 3), and any of them can be adopted.

  As described above, when moving a work using an electromagnet (working), as shown in FIG. 4, the work is attracted by an adsorption command (ON, switching to input), and then a holding voltage is applied. In addition, the workpiece is moved from the suction position to the separation position by using a robot of another system. When it arrives at the disengagement position, the power is turned off by the disengagement command (OFF, power off, demagnetization), the magnetic force is suddenly reduced, and the residual magnetism between the work and the electromagnet is made close to 0 by the demagnetization current (For example, 5 gauss or less).

  The adsorption, desorption, and demagnetization are patterned. In the above, the demagnetization parameters differ depending on the characteristics of the electromagnet and the characteristics of the workpiece (for example, shape and material). Therefore, the initial parameter setting is performed, and after that, the best demagnetization is always performed by repeating the adsorption and desorption according to the parameters. The maximum efficiency can be maintained for relocation using

In the control pattern of FIG. 4, each parameter setting can be automatically generated by an excitation pattern set in the control unit by an adsorption command (ON) and a separation command (OFF). Attraction voltage Va in the holding voltage Vb, adsorption time Ta, demagnetizing time Tc and time interval T _0, since previously set in advance, can be automatically and smoothly transition.

  As described above, FIG. 4 shows that the automatic parameter setting is performed when the electromagnet control unit is set to the setting mode and the pen-shaped magnetic sensor is applied to the detection position (FIG. 5) and the positive polarity excitation current is turned off. For example, the excitation current is attenuated by a slope of 0.1 seconds and a time interval of 0.1 seconds is taken to automatically correct and control negative demagnetization time and demagnetization voltage, and the residual magnetism of the attracting surface is 0.0005 Tesla or less. Can be. Therefore, confirm the optimum value and set it with the setting button to complete the parameter setting.

As described above, according to the present invention, by setting the excitation parameter, the conventional separation parameter setting becomes unnecessary, and before use, the electromagnet control unit is set to the setting mode, and the pen-shaped magnet is set at the detection position in FIG. By applying the sensor and turning off the positive polarity excitation current, the optimum conditions for separation are automatically determined. In the figure, Va is an adsorption voltage (arbitrary setting), Vb is a holding voltage (MAX setting, arbitrary setting is possible), Vc is a negative demagnetizing voltage (0% to 99%, arbitrary setting), Ta is an adsorption time (0 second) In this case, external input switching is possible), Tb is the separation time (inclination 0.1 second to 1.0 second, arbitrary setting), Tc is the consumption time (reference value 0.2 second to 5 seconds, arbitrary setting), T ₀ is a time interval (reference value 0.1 second to 1.0 second, setting fixed).

  Further, before starting the automatic parameter adjustment algorithm shown in FIG. 5, the first release control is performed with the reference value of the negative demagnetizing voltage Vc.

Next, in FIG. 5, before starting the algorithm for automatic demagnetization parameter control, the negative demagnetization voltage Vc reference value is preset (Vc ₀ ) and at the same time the correction signal is cleared. Therefore, in FIG. 5, the magnetic sensor 15 is placed at a predetermined position to detect the residual magnetic flux density B, the output is input to the interface 12, data is captured, and the captured value Bn is input to the auxiliary signal generator 17. input. In this case, when the absolute value of the acquired value Bn is larger than the maximum value Bm of the allowable residual magnetic flux density shown in FIG. 7, a correction signal ΔVcn proportional to the acquired value Bn is transmitted by the auxiliary signal generator 17. A negative excitation voltage signal Vcn is generated and input to the pattern generator 18. An output corresponding to the pattern is output from the pattern generator 18 to the power amplifier 19, and the electromagnet 2 is excited by the output of the power amplifier 19.

  The reference value of the negative demagnetizing voltage Vc and the detected residual magnetic flux density B are corrected, and the minimum Vc value is stored.

Next, FIG. 6 is a diagram showing an automatic demagnetization parameter adjustment algorithm. That is, the magnetic flux density take-in value Bn generates the correction data correction signal ΔVen via the auxiliary signal generator 17 and transmits the correction signal ΔVcn together with the correction signal ΔVcn−1 from the correction signal data storage 20 to generate a negative polarity signal. An excitation voltage signal preset value Vc ₀ is obtained and a negative excitation voltage signal Vcn is generated.

  FIG. 7 is an input / output relationship graph of the auxiliary signal generator 17, and BM indicates a maximum allowable magnetic flux density. As shown in FIG. 7, if the magnetic flux density capture value Bn increases, the allowable residual magnetic flux density maximum value BM increases as the correction data correction signal ΔVen increases.

  The magnetic sensor 15 of the present invention will be described with reference to FIG. 9. Since the Hall element 8 is interposed in the constant current electronic circuit 9 and the magnetic flux passes through the Hall element 8, the voltage changes. The detected voltage is calculated by the magnetic flux calculation 11, and the output magnetic flux density is input to the interface 12 and stored. In the above, when the temperature of the Hall element 8 rises, the temperature detector 13 detects the raised temperature and inputs it to the magnetic flux calculation 11 to correct the temperature. When the temperature rise is small, there is no problem even if the temperature is not corrected.

  As shown in FIG. 8, the magnetic sensor 15 has LEDs that emit green g and red r, and the switch 14 is pressed to bring the tip of the sensor probe 15a into contact with the work 2 to be measured. If the magnetic strength is 5 gauss or more to 10 gauss, the green g and red r LEDs are lit, and if it is the N pole side, the green g and red r LEDs are lit flicker. If it is 10 gauss or more, red lights up, if it is on the N pole side, the red LED is lit, and if it is on the S pole side, the red LED flickers. Therefore, it is possible to immediately know the state of residual magnetism by turning on the green g and red r LEDs. In the figure, 16 is a latching piece.

  In the magnetic force parameter setting in the present invention, when the plug 23 of the cord 22 of the magnetic sensor 15 is connected to the outlet 25 of the electromagnet control unit 24 set in the demagnetization control system and demagnetization is started, the demagnetization operation is performed according to a predetermined pattern. Repeated. Therefore, if the switch 26 of the control unit 24 is pressed when the remanence becomes 5 gauss or less, the demagnetization recording becomes a parameter as it is and is automatically set. Therefore, after deactivation, automatic demagnetization is performed according to the parameters.

(A) The conceptual diagram which shows the magnetic adhesion movement of this invention and detachment | desorption demagnetization, (b) The graph which shows the change of the magnetic flux density in the case of demagnetization similarly. (A) Conceptual diagram showing normally used magnetic movement and separation demagnetization, (b) Graph showing the change in magnetic flux density during demagnetization. Similarly, (a), (b), (c), (d), and (e) are diagrams showing various demagnetization patterns, respectively. The figure which shows the exciting current waveform at the time of demagnetizing of this invention. The block diagram of the control unit of a demagnetization parameter automatic control similarly. The block diagram of a demagnetization parameter automatic adjustment algorithm similarly. The graph which similarly shows the input / output relationship of an auxiliary signal generator. (A) The conceptual diagram of parameter automatic setting similarly, (b) The figure of a magnetic sensor. The block diagram which similarly shows the structure of a magnetic sensor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Work 2 Electromagnet 8 Hall element 9 Constant current electronic circuit 10 Voltage detector 11 Magnetic flux calculation 12 Interface 15 Magnetic sensor

Claims (1)

An electromagnet,
The power supply circuit and the demagnetizing circuit;
A sensor probe that contacts the workpiece to detect the magnetic flux density of the electromagnet, and a magnetic sensor that has green and red light emitting diodes (LEDs) and changes the light emission state by the amount of residual magnetism and the N and S poles; ,
The magnetic sensor measures the magnetic flux density of the electromagnet, inputs the measured value to the interface, cuts off the exciting current applied to the electromagnet, and then sets the negative DC and / or alternating current at a time interval. An electromagnet excitation pattern generator for energizing a demagnetizing current until the residual magnetic flux density of the electromagnet reaches 0.0005 Tesla to demagnetize the electromagnet to form an electromagnet excitation pattern;
The DC demagnetizing current is one square pulse or one sawtooth pulse, the AC demagnetizing current is a decay current,
Demagnetizing voltage related to the demagnetizing current is determined by a preset value which is a reference value and a negative voltage value obtained by correcting the magnetic flux density of the electromagnet input to the interface,
A demagnetization control system for an electromagnet, wherein the excitation pattern is stored in the interface as a magnetic force parameter, and demagnetization of the electromagnet is repeated based on the memorized pattern .

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