SU1610268A1 - Inductive-optical pickup of position and for checking - Google Patents

Abstract

This invention relates to a measurement technique and can be used to recognize heated metallic and non-metallic products. The purpose of the invention is to increase the reliability of the sensor by eliminating false alarms from unheated metal objects. When moving heated metal objects relative to an inductive optical sensor made in the form of an inductor placed in the annular groove of a cup of ferrite core 3 with a central hole, and an infrared photodetector 8 installed coaxially with the central hole of the core core 3 on the side opposite to the arrangement of the inductance, a successive intersection of the electromagnetic field of the sensor occurs, the light of the photodetector 8 is illuminated. In this case, a signal appears on the output bus 7 eskoy 1, carrying information about the contact in a zone of action of the heated metal object sensor. On the output bus 12, there is a logical "0" signal. When a heated non-metallic object enters the zone of action of the sensor, the information signal appears only from the photodetector 8, which passes to the bus 12, while the bus 7 has a logical signal "0". When an unheated metal object enters the zone of action of the sensor, a zero signal is present on tires 7 and 12. The sensor detects heated metallic and non-metallic objects and eliminates false positives from unheated metallic objects. 2 Il.

Description

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The invention relates to a measurement technique and can be used to recognize heated metal and non-metal products and their differentiated counting, as well as as a position sensor and control of heated products in process lines and complexes.

The purpose of the invention is to increase the reliability of the sensor by eliminating its false positives from unheated metal objects.

Figure 1 shows the block diagram of the sensor; Fig. 2 is a diagram of the mutual arrangement of the photodetector and the product under test relative to the ferrite core.

The sensor contains an inductive sensing element 1, made in the form of an inductance coil 2, placed in the annular groove of a cup of ferrite core 3 with a central hole, a high-frequency electric oscillator 4, made, for example, according to the inductive three-point circuit, and the outputs of the inductive sensing element are connected to its oscillating circuit, the threshold element 5, the input of which is connected to the output of the high-frequency generator of electrical oscillations, the logic element 2I 6, the first input to second, connected to the output of the threshold element, the first output terminal 7 connected to the output of logic element 2I and the first sensor output, infrared photodetector 8, driver 9, to the input of which the photodetector is connected, and the output connected to the second input of logic element 2I, inverter 10 whose input is connected to the output of the driver, the logical element 2IL-NOT 11. The first input of which is connected to the output of the inverter 10, and the second input to the output of the logical element 2И, and the second output terminal 12 connected to the output of the log chemical elements 2or-NO is yuschuyus and the second sensor output.

The photodetector 8 is installed (figure 2) with the central opening of the cup of the ferrite core 3 on the side opposite to the arrangement of the inductance. Such a mutual arrangement of the inductive sensing element 1 and the photodetector 8 always ensures the intersection of the controlled product moving relative to the open end of the cup of the ferrite core 3 and within the limits of its electromagnetic field, first the electromagnetic field and then illuminating the photodetector 8.

0

five

0

The sensor works as follows.

When the supply voltage is applied and the magnetic field of the monitored product is absent, the generator 4 goes into high-frequency oscillation generation mode, the constant component of which at its output creates a voltage drop exceeding the trigger threshold value of the threshold element 5. At the same time, the threshold element 5 switches to such a stable state, in which a voltage is set at its output with a level O, which is applied to one of the inputs of logic element 2I 6. As a result, the output is logical The CEI element and the output terminal 7 is set to the voltage level O applied to the first input of the logic element 2OR-HE11.

0

0

five

0

The photodetector 8 is in a darkened state, and the output of the imaging unit 9 is set to the voltage level O, and the output of the inverter 10-voltage

5 with level 1. This voltage is applied to the second input of the logic element 2IL- NOT 11, inverted by it, since its first input is supplied with a permitting zero voltage level from the output of the logic element 2I, and as a result, the second output terminal 12 is set to - prjenyaz level O. From the output of the shaper 9 to the second input of the logic element 6 receives a voltage from

Level 5 O.

In the mode of recognition of heated metal and non-metal products, in which the test product moves relative to the open end of the sensing element 1 within the electromagnetic field, the sensor works as follows.

When the heated metal product is introduced in the direction of the arrow into the zone of action of the electromagnetic field, the generator 4 is disconnected due to the attenuation of its oscillating circuit. As a result, the constant component of the output voltage of the generator a is sharply reduced, and, when its value is below the trigger threshold of the threshold element 5, the latter switches to another steady state at which its output and the first input of the logic element 2I 6 voltage is set to level 1. After a certain period of time, the controlled heated metal product overlaps the central bore of the ferrite core 3 and illuminates with its infrared light flux topriemnik 8.

At the output of the shaper 9, the input of the inverter 10 and the second input of the logic element 2И 6 are set to voltage with level 1, and at the output of the inverter 10 - voltage with level O. At the moment of appearance at both inputs of the element 2 and voltage with levels 1 at its output, and, therefore, at the first input of the logic element 2IL-HE 11 and the first output bus 7, a voltage is set to level 1.

While continuing to move the controlled heated metal product, it remains in the zone of action of the electromagnetic field and opens the center hole of the ferrite core cup 3. At the same time, the photodetector darkens again and the output of the generator 9 and the second input of element 2I 6 is set to O, and the output of the inverter 10 - level P. At the moment of appearance at the second input of the element 2I O, it switches and on the first output bus 7 and the first input of the element .2 OR-NO 11 it is set to O.

Then, at the moment the monitored product leaves the electromagnetic field, the generator 4 again goes into the mode of oscillation generation, i.e. in the initial state, as a result of which the threshold element 5 also switches to the initial state, in which at its output and the first input of the element 2I,

Consequently, when a monitored heated metal product passes through the end of the inductive sensing element, a voltage pulse with a level 1 is generated at the first output terminal 7, and a voltage pulse with a level O which at the second output terminal 12 through the logical element 2OR-NOT 11 does not pass, since a voltage pulse with level 1 prevents its passage from the output of a logical element 2I 6 to the first input of a 2IL-NOT 11 logic element.

In the case of movement along the arrow of a heated non-metallic product relative to the open end of the inductive sensing element 1, it does not introduce significant damping into the oscillatory circuit of the generator 4. In this case, the change in the mode of the generator 4 and the operation of the threshold device 5 does not occur, as a result of which the output of the threshold element 5 and the first output terminal 7

five

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10, the formation of voltage pulses does not occur. In this case, only a voltage pulse with a level 1 at the output of the driver 9 and a voltage pulse with a level O at the output of the inverter 10, which is inverted by the logic element 2OR-NE 11 and passes to the output terminal 12, are formed, because at this moment The first input of the logic element 2IL- NOT 11 from the output of the logic element 2И 6 20 receives the enabling zero logic level of the voltage.

Thus, in the described sensor operation mode, the signal at its first output terminal 7 unambiguously corresponds to the 25th passage relative to the end of the sensitive element 1 of the heated metal product, and the signal at the second output terminal 12 to the passage of the heated non-metallic product that provides 30 recognition of the heated metal and non-metallic products.

When moving a controlled heated product outside the zone of action of an electromagnetic field, the proposed 35 sensor does not respond differentially to heated metal and non-metallic products. In this case, it works as a non-contact photoelectric position sensor, equally functioning from 40 heated metal and heated non-metallic products.

When an extraneous non-heated metal object enters the zone of action of the electromagnetic field, a voltage pulse with a level 1 is generated at the 45 output of the threshold element, which is fed to the first input of the logic element 2I 6. However, this false pulse to the output of the logic element 2I 6 output 0 terminal 7 is not it passes, since simultaneously a prohibiting zero voltage level is fed to the second input of the logic element 2I 6 from the output of the imaging unit 9. Thus, the sensor allows the implementation of a differential response mode to heated metallic and non-metallic products, i.e. recognize metallic and non-metallic {transparent and opaque) products with regard to their thermal state.

Claims (1)

Inductive-optical position and control sensor, containing a series-connected electrical oscillator with an inductive sensing element included in its oscillating circuit, and a threshold element, a series-connected infrared photodetector, pulse shaper, inverter and logic element 2IL-HE, whose output is the second output of the sensor, the inductive sensing element is made in the form of an inductance coil placed in the annular groove of the ferrite se dechnika with a central opening, which is situated coaxially with the infrared light detector on the side opposite the placement 0 inductance coils are different and so that, in order to increase the reliability of the sensor operation by eliminating false alarms from unheated metal objects, it is equipped with logic element 2I, the first input of which is connected to the output of the threshold element, and the second input the output, which is the first output of the sensor, is connected to the second input of the logic element 2OR-NOT, 2