JP3242383B2 - Magnetic plate overlap detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to die breakage caused by setting two metal plates such as iron plates in a stacked state in a die punching process of a press machine and a printing process of a printing machine, etc. The present invention relates to a detection device for preventing printing failure due to overlap printing.

[0002]

2. Description of the Related Art When a thin iron plate is set one by one on a press machine to perform die punching, or when a thin iron plate is sent one by one to a printing machine to print on the surface of the iron plate, for example, a thin plate of a standard size is used. The iron plates are stacked and arranged on a pallet (carrier), placed in a fixed position, and taken one by one from the top by a robot, and set in the above-described machine.

In order to reduce the cost of materials,
For the iron plate to be processed, a second-class product will be used.
It is inevitable that graded products vary in material and wall thickness.

[0004] For example, when an iron plate having a thickness of “0.8” mm is used, a second-class product has a thickness of “1.2” mm to “0.
It is said that up to about 6 ″ are mixed. Such thin iron plates having different thicknesses are laminated by vacuum suction using a funnel-shaped rubber vacuum cup (adsorber), for example. The sheet is picked up one by one from a pile of thin iron plates, carried to, for example, a press fitting position and pressed.
Even if it is a thin iron plate with a thickness of about 1 mm, for example, in a material having a side of about 40 to 50 cm, if oil or moisture adheres to the iron plate surface, the iron plates do not come off and adhere to each other,
Often, two items that are supposed to be taken out are stuck together.

[0005] When the iron plates are set on the press machine in such a state that the two plates are stacked and processed, a heavy load is applied to the die of the press machine, and as a result, the die is also damaged. Molds are expensive, so this must be avoided.

In the case of a printing machine, if iron plates are set in a state of two sheets stacked, the upper and lower iron plates are displaced at the time of printing, causing a shift in printing and causing printing failure. Also in this case, the yield is reduced and the material is wasted, so that the cost reduction effect is lost.

Therefore, various techniques have been devised for detecting when an iron plate is taken out in a state where two iron plates are taken out. Taking a press machine as an example, in a process of moving a press die position where a laminated thin iron plate is sucked from above by a vacuum cup and taken out, a magnetic sensor of an opposed type is used to detect the overlap of two sheets. At present, detection is performed by sandwiching an iron plate between the opposed sensors. However, in the case of this configuration, a step of sandwiching an iron plate between sensors is required for detection.

[0008]

When a thin iron plate arranged in a stack is sucked from above with a vacuum cup and moved one by one onto a press die or the like to perform processing, a press machine is exemplified as follows. In the process of moving the stacked thin iron plate to the press fitting position where it is sucked and taken out by the suction cup from above, a magnetic sensor having an opposed arrangement is used to detect the overlap between the two, and between the opposed sensors, At present, detection is performed with an iron plate interposed.

However, in the case of this configuration, a step of once measuring the thin iron plate taken out between the sensors is required for detecting the overlap of two sheets, and as a result, the detection step becomes complicated, In addition to causing a failure, there are problems such as a long process time.

[0010] Therefore, there is a demand for an urgent realization of an apparatus for detecting an overlap of magnetic plates, which can simplify the detection process and shorten the process time. Therefore, an object of the present invention
Rollers are designed to simplify the detection process and shorten the process time.
It is an object of the present invention to provide a device for detecting an overlap of magnetic plate materials.

[0011]

In order to achieve the above object, the present invention is configured as follows. That is, a sensor having a core wound with a coil, a core element to be attracted to the magnetic material to be measured by excitation of the coil and a Hall element arranged in a magnetic flux path in the core, and a thickness corresponding to the thickness of the magnetic material to be measured. Storage means for holding the Hall element output voltage and the voltage value data to be added to the Hall element output voltage at the time of coil excitation prepared in advance, and at the time of measurement, referring to the data of the storage means, the The output voltage of the Hall element obtained by exciting the coil is known, the additional voltage value determined by the output voltage data is obtained, and the output voltage of the Hall element is corrected by adding the additional voltage value. And a control means for obtaining a detection signal corresponding to the thickness of the plate material to be measured.

As described above, according to the present invention, a coil is wound around an iron core constituting a sensor, and the core is turned into an electromagnet when the coil is excited. When a plate (for example, a thin iron plate or the like) is taken out as a magnetic material to be measured by a suction means such as a vacuum cup, the core is magnetically attracted to the plate by exciting the coil. And make it adhere. Thus, a magnetic circuit is formed by the sucked plate and the iron core, and the magnetic flux in this magnetic circuit passes directly through the Hall element provided on the iron core. Thus, a voltage corresponding to the magnetic flux is generated in the Hall element.

Further, in response to the variation of the thickness of the magnetic plate material which is overlapped on two sheets, a voltage generated from the sensor (detection output) for each thickness and a bias voltage value for raising the generated voltage value to a predetermined voltage are provided. Are stored in the storage means, and their memory numbers (identification information corresponding to the group to which the magnetic plate material to be measured belongs) are stored, and the memory number which is the identification number corresponding to the group to which the plate material to be measured belongs is designated. In other words, of the data having the memory number,
Using data having a value close to the voltage generated from the sensor, a bias voltage value corresponding to the data is increased with respect to the voltage generated from the sensor to obtain a corrected detection output. Therefore, if a memory number, which is the identification number of a group of plate materials to be measured, is input, the detection voltage of one plate material is always the voltage level when one sheet is taken out of the plate materials of that group. Since the detection voltage of the plate material of the number of sheets always reaches the voltage level in the case of taking out two sheets, the detection of taking out two sheets can be surely performed. Therefore, according to the present invention, it is possible to provide an apparatus for detecting the overlap of the magnetic plate members, which can simplify the detection process, shorten the process time, and have high detection accuracy.

At a manufacturing site, an iron plate having a slight variation in thickness is often used as a thin magnetic material to be processed. In a pressing process, such thin iron plates are stacked and arranged in a fixed position, and this is, for example, used. An industrial robot having an arm with a vacuum cup suctions one by one from above with a vacuum cup, moves to a press die or the like, and performs processing. In such a case, in the present invention, the coil wound on the iron core of the sensor is excited to operate as a magnet, and the iron core is completely adhered to the iron plate including the Hall element of the sensor, whereby the coil,
A highly sensitive magnetic circuit composed of an iron core, a Hall element, and an iron plate to be processed can be instantaneously formed. At that time, since the generated magnetic flux passes through the Hall element arranged on the magnetic circuit, the Hall element generates a Hall voltage proportional to the amount of the magnetic flux. At this time, if the magnetic flux is made to pass at right angles to the Hall element arranged on the magnetic circuit, a Hall voltage proportional to the amount of the magnetic flux can be generated with higher accuracy.

In the case of the present system, the iron plate taken out by the vacuum cup constitutes a part of the magnetic circuit. Therefore, as the number of iron plates increases, the amount of magnetic flux passing through the Hall element increases, and the Hall voltage also increases. And the iron plate is 1
Whether the number is two or more can be identified. Therefore, this makes it possible to fully automate the pressing process and the printing process with high reliability.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a configuration used in the apparatus of the present invention.
In the figure, reference numeral 1 denotes a controller, which is a DC stabilized power supply 2, a synchronization circuit 3, a position detector 6, a display 7, an amplifier 8, a control circuit 9, a memory circuit 10, a Schmitt unit 11,
An output unit 12 is provided. 4 is an iron plate to be measured, and 5 is a sensor unit.

The sensor unit 5 includes a Hall element, a coil for forming an electromagnet, and an iron core. The sensor unit 5 receives DC power of a required voltage supplied from the controller unit 1 to excite the coil. A sensor for attracting the iron core to the iron plate 4 to be measured and generating a voltage signal corresponding to the magnetic flux at that time.

The stabilized DC power supply 2 is a power supply for converting a commercial power supply to DC and supplying a required DC voltage. The position detector 6 is a workpiece made of a magnetic material taken out from a vacuum cup. A detector for detecting when a certain thin iron plate 4 reaches a predetermined position, using an optical detection means such as a photoelectric detector, a proximity switch, or an image such as a CCD (individual imaging device). Non-contact position detecting means is used, such as a method of detecting a position by performing image recognition processing from an image obtained by a sensor.

In recent years, in the case of dangerous work or heavy labor, an industrial robot is often provided instead of human labor, and the industrial robot is often instructed to perform the procedure.
In this case, since the vacuum cup is configured to be held by the arm of the industrial robot, the vacuum cup is used based on the coordinate information of each joint of the robot arm necessary for controlling the movement of the robot arm. Various detection methods are conceivable, such as a configuration in which when the taken-out thin iron plate 4 reaches a predetermined position, this can be detected. Therefore, as the position detector 6, the best detection means may be adopted in consideration of various conditions as a system.

The synchronizing circuit 3 obtains the detection output of the position detector 6 and synchronizes the system. When the detection output of the position detector 6 is received, the DC stabilized power supply 2 has a predetermined time width. Supplies a required DC voltage to the sensor unit 5, and causes the control circuit 9 to perform a control operation for a period corresponding to the predetermined time width.

The amplifier 8 is a circuit for amplifying the output of the sensor unit 5. The memory circuit 10 is provided with a control circuit for detecting the output voltage of the sensor unit 5 when the detected output voltage corresponds to two iron plates overlapping each other. This is a circuit for raising the voltage or storing the required voltage and storing the memory together with the memory number for the thickness of the thin plate.

That is, when the thickness of the iron plate is 0.8 mm, when two 0.8 mm iron plates are stacked, for example, in order to turn on the red lamp 4 of the display 7, the voltage to be raised must be several volts. Whether it is necessary or not is stored in the memory circuit 10 together with a memory number to be called an identification number. Further, when one iron plate is used, it is confirmed how many green lamps of the indicator 7 are lit, and it is tested whether one or two sheets can be reliably determined, and the lighting level is adjusted. .

In the test mode, the control circuit 9
It has a function of creating the above-described table in the memory circuit 10, and in the normal operation mode, when the user determines which of the memory contents stored in the memory circuit 10 to use by specifying the memory number, With respect to the output of the sensor unit 5 obtained through the amplifier 8, a voltage corresponding to the stored content of the memory circuit 10 is raised and adjusted to correct the output, and the corrected voltage is output to the Schmitt circuit 7. is there.

The table creation on the memory circuit 10 is performed as follows. In the test mode, the control circuit 9
When the user adjusts the voltage level of the output of the sensor unit 5 obtained via the amplifier 8 in a state where two iron plates 4 to be measured are superimposed on each other so that a red lamp is lit on the display unit 7, the adjusted raising voltage is adjusted. This is achieved by storing the minute in the memory circuit 10 together with the memory number. The memory number is assigned to the group to which the iron plate to be measured belongs, that is, in this case, it is assigned according to the thickness of the iron plate to be measured. Therefore, such adjustment is performed for each measurement object, and a table is created. In the normal operation mode, when the user designates a memory number corresponding to the thickness of the iron plate to be machined, the control circuit 9 refers to information corresponding to the memory number in the memory contents stored in the memory circuit 10. , The detected output of the sensor unit 5, actually, the detected output of the sensor unit 5 obtained via the amplifier 8, by using the bias voltage value corresponding to the voltage value, and detecting the bias voltage value by the bias voltage value. The output is raised, and the corrected detected output voltage corrected by raising the output is output to the Schmitt circuit 7. The control circuit 9 is configured to output the corrected detected output voltage to the Schmitt circuit 7 when the level of the corrected detected output voltage has reached the level in the case where two iron plates are stacked. In addition, the configuration of the output stage of the abnormality detection signal can be simplified.

The display unit 7 is a simple display device for thickness presetting. For example, for the thickness presetting, 15 light emitting diodes whose lighting levels are distinguished for each voltage level for an indicator are prepared, and input is performed. In response to the signal voltage level to be displayed, whether or not one image is detected or two images are detected is displayed by lighting. The fifteen light-emitting diodes constituting the display unit 7 correspond to fifteen voltage levels, and are arranged in order from “No. 1” to “No. 15”, which are given via the control circuit 9. The lighting control is performed according to the level of the detection voltage of the sensor unit 5.

The fifteen light-emitting diodes constituting the display section 7 are numbered "1" to "15" in ascending order of voltage, and among these, the "1" to "10" light-emitting diodes Are set to, for example, green, so that they are lit in accordance with the detection level in the case of one iron plate 4 to be measured, and the light emitting diodes of “No. 11” to “No. 15” are set to red, Is lit, the measured iron plate 4
In the control circuit 9, the bias can be adjusted so that the lighting is controlled so as to correspond to the detection level when two are overlapped.

That is, the control circuit 9 has a calibration function, and in the test mode, the sensor section 5 is formed by overlapping the measured iron plate 4 of the sample to be machined from now on in all thickness variations.
DC stabilized power supply 2 so that any one of the “11th” to “15th” red light-emitting diodes always emits light when the display unit 7 performs the display operation based on the detection value obtained by the detection. The required voltage is more forcibly supplied, and the bias is adjusted to adjust the signal level from the amplifier 8 input to the control circuit 9. Therefore, when the calibration is completed in the test mode, in the normal operation mode, the iron plate 4 to be measured is combined with the combination over all the thickness variations in accordance with the signal level from the amplifier 8 input to the control circuit 9 by two. In the case of stacking, it is possible to control so that the red light-emitting diode of No. 11 is turned on in the thinnest combination and the red light-emitting diode of No. 15 is turned on in the thickest combination. Is the thinnest green light-emitting diode,
The bias level of the detection output of the iron plate 4 applied to the display unit 7 can be preset so that the green light-emitting diodes up to the "10th" light up even in the thickest case. In the test mode, the control circuit 9 controls such that the preset value is stored in the memory circuit 10 as a correction voltage value.

The Schmitt unit 11 receives a signal of a voltage obtained by adding the correction to the detection output of the sensor unit 5 obtained through the amplifier 8 and output from the control circuit 9, and cuts the signal to a predetermined level or more. The output circuit 12 receives the signal whose waveform has been shaped and outputs an abnormality detection signal.

FIG. 2 shows the structure of the sensor section 5. 2A is a plan view, and FIG. 2B is a cross-sectional view taken along the line AA. As shown in FIG. 2, the sensor unit 5 uses a laminated core 51 having an E-shaped cross section, and a central pillar 5 of the laminated core 51.
A coil 52 is wound so as to surround 1a.

As an example, the center pillar 51a of the laminated core 51 is slightly lower than the pillars 51b and 51c on both sides, and the end face of the central pillar 51a of the laminated core 51 or the detection sensitivity is good. A hall element (or hall IC) 53 is attached to an arbitrary part of the iron core. Note that an insulator 54 is provided on both end surfaces of the Hall element (or Hall IC) 53.
a and 54b are provided for insulation. In addition, the laminated core 51
Is filled with an epoxy resin 55 so as to cover the Hall element (or Hall IC) 53 and fill the central recess of the laminated core 51, whereby the laminated core 51 is arranged with the Hall element (or Hall IC) 53. The side surfaces are flush with the end surfaces of the pillar portions 51b and 51c on both sides, and are flattened.

The sensor unit 5 having such a configuration is provided with a coil 5
When a direct current is applied to 2, the laminated iron core 51 functions as an electromagnet. At this time, it is assumed that the epoxy resin-filled surface is used as an adsorption surface of the iron plate 4 to be measured. Further, by providing a configuration in which the magnetic flux passes through the Hall element at right angles, a sensor that can generate a Hall voltage that is accurately proportional to the amount of the magnetic flux can be provided.

FIG. 3 is an example of a work material feeding system equipped with the system of the present invention, and is a perspective view of a system using an industrial robot. This processing material feeding system uses the multi-joint arm 6 of the industrial robot 60 to move the iron plate 40 to be processed, which is stacked and arranged on the pallet 31.
1 is an apparatus that automatically performs an operation such as taking out and setting in a mold of a press machine.

The holder 62 attached to the tip of the articulated arm 61 of the industrial robot 60 has the sensor unit 5 described above.
Is attached, for example. Vacuum cup 63 for taking out one iron plate 4 by vacuum suction from the pile of thin iron plates 40 to be processed stacked on pallet 31 in holder 62
The tip of the articulated arm 61, which can freely move in a three-dimensional space under the control of a control device (not shown) for the industrial robot, is attached to the upper surface of the mountain of the iron plate 40 on the pallet 31. When the vacuum cup 63 is brought into close contact with the iron plate 40 and sucked by performing a vacuum suction operation, the sensor portion 5 held by the holder 62 is moved closer to the plate surface of the iron plate 4 on which the attraction surface side of the electromagnet is attracted. The mounting position has been adjusted so that it comes to.

Since the suction cup of the vacuum cup 63 has a funnel shape and is made of an elastic material such as rubber, which can be kept airtight, the coil 52 is energized and the sensor 5 is energized.
When the iron core 51 is an electromagnet, the magnetic force
Means to apply an adsorption force to the iron plate 4, and at this time,
When the vacuum cup 63 bends, the iron core 51 of the sensor unit 5 comes into close contact with the plate surface of the iron plate 4.

The position detector 6 is a detector that detects when the thin iron plate 4 which is a workpiece made of a magnetic material taken out of the vacuum cup reaches a predetermined position. A detection point is set at a desired position on the arm movement locus at the fixed position above the peak of the iron plate 40, and when the iron plate 4 picked up by the arm 61 by the vacuum cup 63 reaches this position, a detection output is set. Good.

Reference numeral 32 denotes a collection pallet for collecting the iron plates 4 taken out of the stack of two sheets. When the iron sheets in the state of two sheets are taken out, the arm 61 is moved by the vacuum cup 63 here. The pickup 2
The stacked iron plates are carried and lowered to a fixed position, and the vacuum cup 63 is used to recover the defective product by releasing the vacuum.

Next, the operation of the present system having such a configuration will be described. The system of the present invention has a test mode for performing calibration and a normal operation mode for performing actual two-sheet detection processing. In this system, the test mode is first executed, and after that, the mode is switched to the normal operation mode.

<Operation in Test Mode> The operation in the test mode is as follows. This system takes into account the variation in the thickness of the second-grade iron plate used for processing, and first detects the second-grade iron plate while changing the thickness by the variation in thickness when two sheets are overlapped. The control circuit 9 is preset so that the two-sheet overlap can be identified with certainty in response to the detection output.

On the other hand, the industrial robot 60 repeats such an operation as teaching in advance, picking up an iron plate from the pallet 31, moving along a predetermined trajectory to the mold portion of the press machine, and setting. It is.
Therefore, the material is removed by moving the tip of the articulated arm 61 of the industrial robot 60 onto the pallet 31 and holding the holder 62 attached to the tip of the articulated arm 61.
Of the vacuum cup 63 is lowered onto the pile of the iron plate 40 to be processed stacked on the pallet 31. Then, the vacuum cup 63 is brought into close contact with the iron plate 40 and a vacuum suction operation is performed to take out the topmost iron plate 4.

After the suction, the articulated arm 61
Is driven to move the iron plate 4 while following a predetermined movement locus.
Is transported to the press machine. At this time, since the iron plate 4 taken out by the vacuum cup is always taught so as to pass through a predetermined position, and the articulated arm 61 is driven and moved accordingly, , The position detector 6 generates a detection output at a stage passing through a specific point.

Then, the detection output is given to the synchronizing circuit 3, and upon receiving the detection output, the synchronizing circuit 3 supplies a required DC voltage from the DC stabilized power supply 2 to the sensor unit 5 for a predetermined time width. The control circuit 9 is controlled to operate for a period corresponding to the predetermined time width.

As a result, a DC voltage is applied to the coil 52 of the sensor unit 5, and the iron core 51 of the sensor unit 5 is excited for the predetermined time period.

The sensor portion 5 is held by the holder 62 together with the vacuum cup 63. When the vacuum plate 63 sucks the iron plate 4, the sensor portion 5 held by the holder 62 is attached to the iron plate 4 on which the attraction side of the electromagnet is attracted. The mounting position is adjusted so that it comes close to the board surface.

Since the vacuum cup 63 has a funnel shape at the tip end of the suction cup and is made of an elastic material such as rubber, the coil 52 is energized so that the iron core 51 of the sensor unit 5 is electromagnetized. Then, the magnetic force exerts an attraction force on the iron plate 4. At this time, the vacuum cup 63 bends, and the iron core 51 of the sensor unit 5
Adhere to the plate surface.

Here, the iron plate 4 to be measured and the iron core 51 of the sensor section 5 are brought into close contact with each other in order to eliminate the instability that the magnetic flux passing through the magnetic circuit formed by these variously changes depending on conditions. This is to prevent erroneous detection.

A voltage is applied to the coil 52 and the sensor unit 5
When the iron plate 51 to be measured is excited and the iron plate 4 to be measured is attracted to the iron core 51 of the sensor unit 5, the magnetic circuit including the iron core 51 of the sensor unit 5 is closed, and a magnetic circuit is formed. A magnetic flux as shown by an arrow φ is generated.

The iron core 51 of the sensor section 5 has a leg portion 51a at a central portion (or at an arbitrary position where magnetic flux is easily converged).
The Hall element (or Hall IC) 53 includes insulating portions 54a,
4b. Therefore, the leg 51a
Due to the magnetic flux in the direction of arrow φ flowing through
A Hall voltage is generated in the Hall element 53.

As is well known, the Hall element (or Hall I)
C), when placed in a magnetic field, generates a voltage corresponding to the magnetic flux at that time, and generates a voltage proportional to the magnetic flux. In the case, the magnetic resistance is lower and the amount of magnetic flux passing through is larger, so that when two iron plates 4 are used, the generated voltage is higher than when one iron plate 4 is used. The Hall voltage generated in the Hall element (or Hall IC) 53 due to the passage of the magnetic flux further enters the amplifier 8, where the voltage and current are amplified and then supplied to the control circuit 9.

On the other hand, the memory circuit 10 has an iron plate 4 on a pallet 31 which is a material to be processed at present.
It is necessary to prepare the generated voltage and the bias voltage value for correction in the case of two sheets based on the iron plate thickness corresponding to the combination of the thicknesses of the zero peaks.

In the normal operation mode, the control circuit 9 uses the stored contents (table) for the iron plate to be processed from the memory circuit 10 and obtains the sensor unit 5 obtained through the amplifier 8. Is compared with the value in the table, and a voltage corresponding to the correction voltage value is supplied from the stabilized DC power supply 2 using the correction voltage value paired with the data indicating the similar value, and the sensor unit 5 This is because the control is performed such that it is added to the detected output and corrected and then sent to the Schmitt circuit 11.

Therefore, in the test mode,
The control circuit 9 performs a process for setting table data on the memory circuit 10.

That is, the table data of the memory circuit 10 is prepared based on actual measurement under the control of the control circuit 9 in the test mode. In the test mode, a sample of an iron plate to be processed is used, and is sucked by the vacuum cup 63. At this time, the sensor unit 5 is excited to form a magnetic circuit with the sample of the iron plate. Hall element 5 corresponding to the magnetic flux passing through this magnetic circuit
The voltage generated at 3 is obtained as a detection output.

The system of the present invention is provided with a display 7 having 15 light-emitting diodes for indicators for presetting the thickness of the iron plate to be processed. The display 7 is used as a guide for presetting of the control circuit 9 for indicating whether the detection result is appropriate or not and always detecting the overlap when two sheets are overlapped.

The fifteen light-emitting diodes constituting the display unit 7 function as an indicator that lights up in accordance with the voltage level, and the voltage at the stage when the detection output voltage generated by the sensor unit 5 is corrected by the control circuit 9. This is a mechanism for controlling the lighting so that the light emitting diode is lit corresponding to (corrected detected output voltage).

The display section 7 indicates that the "first" to "10th" diodes corresponding to the minimum generated voltage are green, and during that time, they are lit in accordance with the generated voltage when there is only one iron plate 4 to be measured. As described above, the diodes from the "11th" to "15th" corresponding to the one having a large generated voltage are red, and when these are lit, the diodes correspond to the generated voltage at the time of detecting two sheets. In addition, the user operates the control circuit 9 so as to obtain the required bias voltage from the stabilized DC power supply 2.
Adjust the preset.

Then, the bias voltage at the stage when the adjustment is completed is converted into the data of the detected output voltage value (actually, the amplified detected output voltage value obtained via the amplifier 8) from the sensor unit 5 at that time. The control circuit 9 causes the memory circuit 10 to store the information in a table together with a memory number corresponding to the thickness of the iron plate to be measured (processed). This bias voltage value is referred to as the above-described correction voltage value.

A sample of an iron plate to be processed is actually measured as described above for variations of all combinations of the thickness of the iron plate.
So that one of the green diodes up to the number "
And when there are two iron plates, from the "11th" to the "15th"
The calibration is completed when the bias voltage is adjusted so that any of the red light emitting diodes up to the eye shines, and those values are stored in a table together with the memory number corresponding to the plate thickness. As a result, it is possible to obtain correction voltage values for all combinations of the thickness of the iron plate to be processed.

The memory number is assigned to the thickness of the iron plate to be processed.

When a plate material having a different material and a different plate thickness is to be processed in another processing lot, the table is prepared as described above, and the material and the plate thickness of the magnetic plate material to be detected are prepared. If a memory number determined in accordance with is specified, the data of that memory number can be used.

In the test mode, when the calibration for creating the table is completed, the mode is set to the normal operation mode, and the double-sheet overlap detection is started.

<Operation in Normal Operation Mode> The operation in the normal operation mode is as follows. The industrial robot 60 is set to repeat the operation of teaching in advance, picking up the iron plate from the pallet 31, moving along a predetermined trajectory to the die of the press machine, and setting it. Accordingly, the material removal operation is performed by moving the tip of the articulated arm 61 of the industrial robot 60 to the pallet 31.
The vacuum cup 63 at the tip of the holder 62 attached to the tip of the multi-joint arm 61 is moved upward.
This is performed by lowering the vacuum cup 63 on the iron plate 40, lowering the vacuum cup 63 on the iron plate 40, and performing a vacuum suction operation.

The vacuum cup 63 is processed into an iron plate 4 to be processed.
When the iron plate 4 is lowered on the mountain of 0 and the uppermost iron plate 4 is sucked, the articulated arm 61 is driven and moved, and the iron plate 4 is carried to the press machine while following a predetermined movement trajectory. At this time, since the articulated arm 61 is driven and moved so that the iron plate 4 taken out by the vacuum cup always passes through a predetermined position, the position detector 6 generates a detection output at a stage where it passes a specific point.

Then, this detection output is given to the synchronization circuit 3, and upon receiving the detection output, the synchronization circuit 3 supplies a required DC voltage from the DC stabilized power supply 2 to the sensor unit 5 for a predetermined time width. The control circuit 9 is controlled to operate for a period corresponding to the predetermined time width.

As a result, a DC voltage is applied to the coil 52 of the sensor unit 5, and the iron core 51 of the sensor unit 5 is excited.

The sensor unit 5 is held by the holder 62 together with the vacuum cup 63. When the vacuum plate 63 sucks the iron plate 4, the sensor unit 5 held by the holder 62 is attached to the iron plate 4 on which the attraction side of the electromagnet is sucked. The mounting position is adjusted so that it comes close to the board surface. Since the vacuum cup 63 has a funnel shape at the tip sucker and is made of an elastic material such as rubber, which can be kept airtight, when the coil 52 is energized to make the iron core 51 of the sensor unit 5 an electromagnet, the magnetic force The suction force acts on the iron plate 4 by this, and at this time, the vacuum cup 63 bends,
The iron core 51 of the sensor unit 5 comes into close contact with the plate surface of the iron plate 4.

A voltage is applied to the coil 52 and the sensor unit 5
When the iron plate 51 to be measured is excited and the iron plate 4 to be measured is attracted to the iron core 51 of the sensor unit 5, the magnetic circuit including the iron core 51 of the sensor unit 5 is closed, and a magnetic circuit is formed. A magnetic flux as shown by an arrow φ is generated.

For example, a Hall element (or Hall IC) 53 is provided on the iron core 51 of the sensor section 5 at the center leg section 51a.
Are arranged via insulating portions 54a and 54b. Therefore, a Hall voltage is generated in the Hall element 53 by the magnetic flux in the direction of the arrow (or the reverse) flowing through the leg 51a.

Since the Hall element (or Hall IC) generates a voltage corresponding to the magnetic flux, the passage of the magnetic flux is larger when two iron plates 4 are measured than when one iron plate 4 is measured. When two iron plates 4 are used, the generated voltage is higher than when one iron plate 4 is used. The Hall voltage generated in the Hall element 53 by the passage of the magnetic flux further enters the amplifier 8, where the voltage and current are amplified and then supplied to the control circuit 9.

On the other hand, the iron plate 4 on the pallet 31 which is the material currently being processed is stored in the memory circuit 10.
For the peak 0, the generated voltage and the bias voltage value (correction voltage value) for correcting the rise in the case of two sheets overlapping based on the thickness of the iron plate are prepared for each combination of the thicknesses.

The control circuit 9 uses the memory table for the iron plate, which is the current processing target, from the memory circuit 10 and outputs the detection output of the sensor unit 5 obtained through the amplifier 8 to the value of the memory table. DC stabilized power supply 2
Further, a voltage supply corresponding to the correction voltage value is received, and the detection output of the sensor unit 5 is corrected by adding to the detection output of the sensor unit 5.

The control circuit 9 controls the lighting of the light emitting diode of the display unit 7 in accordance with the voltage of the corrected detection output, and when the voltage of the corrected detection output is equal to or higher than a predetermined level corresponding to the superposition of two iron plates. In some cases, the corrected detection output is output to the Schmitt circuit 11.

The Schmitt circuit 11 shapes the waveform so that the output signal does not exceed a certain voltage level and provides the output signal to the output circuit 12. The output circuit 12 receives the signal from the Schmitt circuit 11. At that time, a signal is output. The output signal at this time is the abnormality detection signal. Then, when the abnormality detection signal is output,
A control device (not shown) for the industrial robot 60 executes a material collecting operation.

Up to this stage, since the voltage supply from the stabilized DC power supply 2 to the sensor unit 5 has been completed, the excitation of the coil 52 is released and the iron core 51 of the sensor unit 5 loses the magnetic force. The iron core 51 of the sensor unit 5 that has been in close contact with the plate surface of the iron plate 4 is also separated from the iron plate 4. Then, in this state, the iron plate 4 is brought into a state of only suction holding by the vacuum cup 63.

In this state, the Hall element 5 in the center leg 51a of the iron core 51 of the sensor section 5 is provided.
In No. 3, the Hall voltage output is also eliminated due to the disappearance of the magnetic flux flowing through the iron core 51.

In the material collecting operation, the arm 61 of the industrial robot 60 is controlled so that the iron plate 4 sucked and taken out by the vacuum cup 63 comes to the position of the collecting pallet 32, and is sucked by the vacuum cup 63. When the iron plate 4 reaches a fixed position on the collection pallet 32, the vacuum is released and the iron plate 4 is removed from the vacuum cup 63.
2 Place it in place.

Then, in order to move the vacuum cup 63 to the position of the pile of the laminated iron plate 40 on the pallet 31 again,
The arm 61 of the industrial robot 60 is controlled, and the operation moves on to pick up a new iron plate 4.

On the other hand, at the stage of detecting the overlap of two iron plates by exciting the coil of the sensor unit 5, the control circuit 9 determines that the corrected detection output is at a low level which does not correspond to the overlap of the two iron plates. The completed detection output is not output to the Schmitt circuit 11. Therefore, since the output circuit 12 does not receive the signal from the Schmitt circuit 11, no abnormality detection signal is output.

Since the supply of the voltage from the stabilized DC power supply 2 to the sensor unit 5 has been completed up to this stage,
Since the excitation of the coil 52 is released and the iron core 51 of the sensor unit 5 loses the magnetic force, the iron core 51 of the sensor unit 5 that has been in close contact with the plate surface of the iron plate 4 also moves away from the iron plate 4. Then, in this state, the iron plate 4 is brought into a state of only suction holding by the vacuum cup 63.

In this state, the Hall element 5 in the center leg 51a of the iron core 51 of the sensor section 5 is located.
In No. 3, the Hall voltage output is also eliminated due to the disappearance of the magnetic flux flowing through the iron core 51.

Since there is no abnormality detection signal, the industrial robot 60 is controlled so that the tip of the arm 61 is carried to the die position of the press machine, and the iron plate adsorbed by the vacuum cup 63 at the tip of the arm 61. After the position of the iron plate 4 is adjusted to a fixed position by controlling the position so that the iron plate 4 comes to the mold position of the press machine, the vacuum plate is released and the iron plate 4 is placed at a fixed position on the mold from the vacuum cup 63.

Then, in order to move the vacuum cup 63 again to the position of the pile of the laminated iron plate 40 on the pallet 31,
The arm 61 of the industrial robot 60 is controlled to start an operation of picking up a new iron plate 4.

In the above-described embodiment, the detection target is an iron plate. However, the present invention is not necessarily limited to the detection target of the iron plate, but can detect any magnetic material that allows a magnetic flux.

Further, in the memory circuit 10, by storing the generated voltage and the number according to the material and the plate thickness for each table, the preset corresponding to the plate thickness can be performed by selecting the table, so that the automatic operation by the table designation can be performed. It becomes possible. Therefore, it is possible to provide a system that can automatically adjust the apparatus to an optimum detection state in response to a call of a program.
It can be fully automated with reliability.

Although the above description is an example in the case of DC detection, AC detection can also be performed, and even in this case, it can be realized with the same reason as in DC detection.

As described above, according to the present invention, the iron core 5
1, a core element 51 is formed into an electromagnet when the coil is excited, and a hole element is provided in the iron core 51 in a magnetic flux passage.
When the iron plate is attracted at 3 and the coil is excited, the iron core 51 is magnetically attracted to and adheres to the iron plate 4, and when the coil is excited, a magnetic circuit is formed by the iron core 51 of the sensor unit 5 and the attracted iron plate 4. Each time the iron plate 4 is sucked by the vacuum cup 63, taken out and moved to a predetermined position, the position is detected by the position detector 6, whereby the synchronization circuit 3 synchronizes for a predetermined time width. A signal is output, and a DC current is applied from the stabilized DC power supply 2 to the coil 52 of the sensor unit 5 for a period corresponding to the time width of the synchronization signal.
By being excited, a magnetic circuit is formed by the iron plate 4 and the iron core 51 of the sensor unit 5, and the magnetic flux in the magnetic circuit directly passes through the Hall element 53 provided on the iron core 51 of the sensor unit 5, thereby forming a hole. Utilizing the fact that a voltage corresponding to the magnetic flux is generated in the element 53, the detection of the overlap of two iron plates is performed from the level of the generated voltage.

For this reason, the iron plate is attracted by the vacuum cup 63 and the core 51 of the sensor unit 5 is magnetically attracted and adheres to the iron plate 4 only by exciting the coil, and a magnetic circuit is formed by the iron core 51 and the attracted iron plate 4. In addition to the formation, it is possible to obtain a detection output of the number of iron plates by generating a voltage corresponding to the magnetic flux by the Hall element arranged in this magnetic circuit, so that the detection of the number of iron plates does not require a special detection process. Therefore, it is not necessary to take time for the detection.

Further, a voltage generated from the sensor unit and a bias voltage value (correction voltage value) for raising the generated voltage value are checked for each thickness in advance in correspondence with the variation of the thickness of the two iron plates. These are stored in a memory unit in correspondence with a memory number which is an identification code assigned to a group to which a magnetic plate material to be processed (a magnetic plate material to be measured) belongs (here, for example, a standard plate thickness of the magnetic plate material to be processed). If a memory number corresponding to the plate thickness corresponding to the standard plate thickness of the target magnetic plate material is input to the control circuit, the voltage in the data having the input memory number with respect to the voltage generated from the sensor unit is generated. Since the bias voltage value in the data corresponding to the voltage is raised and corrected, a magnetic plate material to be processed, for example, one iron plate to be processed is taken. The level of the corrected voltage of the detection voltage signal (generated voltage) from the sensor unit can be clearly different between when the iron plate is taken out and when two iron plates are taken out. Can be reliably detected.

Therefore, according to the present invention, it is possible to provide an apparatus for detecting the overlap of magnetic plate materials which has a simple detection step, can speed up the process, and has a high detection accuracy.

[0090]

As described above, according to the present invention, it is possible to provide an apparatus for detecting the overlap of magnetic plate members which has a simple detection process, can shorten the process time, and has high detection accuracy.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an overall configuration as a specific example of the present invention.

FIGS. 2A and 2B show a structure of a sensor unit 5 used in the system of the present invention, wherein FIG. 2A is a plan view and FIG.

FIG. 3 is an example of a work material feeding system equipped with the system of the present invention, and is a perspective view of a system using an industrial robot.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Controller part, 2 ... DC stabilized power supply, 3 ... Synchronous circuit, 4 ... Iron plate to be measured (thin plate material to be processed by magnetic material), 5 ... Sensor part, 6 ... Position detector, 7 ... Display, 8
... Amplifier, 9 ... Control circuit, 10 ... Memory circuit, 51 ... Iron core, 51a ... Iron leg, 52 ... Coil, 53 ... Hall element (or Hall IC), 54a, 54b ... Insulation part, 6
0: industrial robot, 61: articulated arm, 62: holder, 63: vacuum cup.

Claims (3)

(57) [Claims] A sensor having a core wound with a coil, attracted to the magnetic material to be measured by excitation of the coil, and a Hall element disposed in a magnetic flux path in the iron core; Storage means for holding data of the Hall element output voltage and the voltage value to be added to the Hall element output voltage at the time of the coil excitation prepared in advance corresponding to the thickness of the sheet material; Knowing data having a value approximating the output voltage of the Hall element obtained by exciting the coil, obtaining the added voltage value determined by this data, and adding the added voltage value to the output voltage of the Hall element. Control means for obtaining a detection signal corresponding to the thickness of the plate material to be measured by adding and correcting, and an overlap detection device for a magnetic plate material. A sensor provided with a core wound with a coil and attracted to the magnetic material to be measured by excitation of the coil, and a Hall element arranged in a magnetic flux path in the iron core; A storage means for holding data of a voltage value to be added to the Hall element output voltage at the time of exciting the coil prepared in advance corresponding to the plate material thickness together with identification information corresponding to the group to which the magnetic material to be measured belongs, and specifying the identification information, At the time of measurement, an additional voltage value corresponding to the generated voltage in the data corresponding to the identification information was added to the output voltage of the Hall element in the data corresponding to the identification information with respect to the generated voltage of the Hall element in the sensor. Control means for obtaining a detection signal; and means for waveform-shaping and outputting the corrected detection signal of the control means. Nari detection device. 3. The sensor according to claim 1, wherein an iron core has a shape in which a magnetic path is opened, and a Hall element is disposed in a magnetic circuit of the iron core, and a magnetic material to be measured is attracted to an open portion of the magnetic path. 3. The apparatus according to claim 1, wherein the magnetic plate is closed.