SU834635A2

SU834635A2 - Attached ferromagnetic coercimeter

Info

Publication number: SU834635A2
Application number: SU792731508A
Authority: SU
Inventors: Иршат Лутфуллович Аитов; Масхут Маликович Валиев
Original assignee: Уфимский Авиационный Институтим. Орджоникидзе
Priority date: 1979-03-01
Filing date: 1979-03-01
Publication date: 1981-05-30

Description

(54) ПРИСТАВНОЙ ФЕРРОМАГНИТНЫЙ КОЭР ЦИТИМЕТР(54) BEFORE FERROMAGNETIC COER CYTIMETER

II

Изобретение относитс к магнитным измерени м, используемым дл неразрушающего контрол качества локальных участков издели по остаточной индукции и коэрцитивной силе.The invention relates to magnetic measurements used for non-destructive quality control of local areas of a product by residual induction and coercive force.

По основному авт. св. № 744395 известен приставной ферромагнитный коэрцитиметр , используемый дл измерени коэрцитивной силы локальных участков ферромагнитных изделий. Это устройство выполнено в виде П-образного сердечника с расположенными на его, стержн х намагничивающей и размагничивающей обмотками и индикаторного элемента, выполненного в виде ферромагнитного накопительного счетчика с переменным коэффициентом накоплени . Индикаторный элемент установлен на среднем стержне П-образного сердечника. П-об-, разный сердечник и изделие образуют замкнутую магнитную цепь 1.According to the main author. St. No. 744395 is known for adding a ferromagnetic coercimeter used to measure the coercivity of local portions of ferromagnetic products. This device is made in the form of a U-shaped core with magnetizing and demagnetizing windings located on its rods and an indicator element made in the form of a ferromagnetic storage counter with a variable accumulation factor. The indicator element is mounted on the middle rod of the U-shaped core. P-ob-, different core and product form a closed magnetic circuit 1.

Измерение коэрцитивной силы с помощью этого устройства производитс следующим образом. Остаточна индукци издели , намагниченного приставным- электромагнитом , создает в цепи коэрцитиметра магнитный поток. Это приводит к изменению коэффициента накоплени индикаторного ферромагнитного накопительного счетчика . Причем в зависимости от накоплени намагничивающего пол коэффициент накоплени может быть больше или меньше на некоторую величину п первоначально установленного коэффициента К |. В результате выходна частота счетчика становитс равной. ..The measurement of the coercive force using this device is made as follows. The residual induction of a product magnetized by an attachment electromagnet creates a magnetic flux in the coercimeter circuit. This leads to a change in the accumulation coefficient of the indicator ferromagnetic storage counter. Moreover, depending on the accumulation of the magnetizing field, the accumulation coefficient may be more or less by some value n of the initially established coefficient K |. As a result, the output frequency of the counter becomes equal. ..

, (1), (one)

где f I - частота выходного сигнала счетчика до намагничивани ;where f I is the frequency of the output signal of the counter before magnetization;

Ха-коэффициент накоплени ферромагнитного счетчика после намагничивани издели .Xa is the accumulation coefficient of the ferromagnetic counter after magnetization of the product.

Claims

With an increase in the demagnetization current in the magnetic circuit of the coercimeter, a magnetic flux is created in the opposite direction. At the same time, the accumulation factor of the indicator counter changes, approaching the K value. The frequency at the output of the counter also changes accordingly. p The value of the demagnetization current, at which the frequency of the output signal with: it is the initial value, is taken as a measure of the coercive force. A disadvantage of the known device is the presence in the output signal of the initial frequency, which limits the functionality of the coercimeter and reduces the speed of the recording device. To clarify this, we expand expression (1), substituting its value for the ferromagnetic indicator counter, instead of the accumulation factor, after magnetizing Ik to it. then we get equality. (2) where A- / 5 J j-value, is proportional to the residual induction of the magnetized product. From expression (2) it follows that the first term does not carry information on the magnetic state of the monitored product, but increases the time required to read the frequency of the output signal. The purpose of the invention is to increase accuracy and speed. The goal is achieved by adding a ferromagnetic coercimeter containing a U-shaped core with magnetizing and demagnetizing windings located on its rods and an indicator element in the form of a ferromagnetic storage counter with a variable accumulation factor installed on the middle rod of the U-shaped core, an additional ferromagnetic storage meter with a trimmer magnet and a comparison element, one input of which is connected to the output of the indicator counter, and The second input is with the output of an additional counter. The drawing shows a block diagram of the proposed device. The attached ferromagnetic coercimeter includes an indicator accumulative ferromagnetic counter 1 with a variable accumulation factor located on the middle rod of an U-shaped core 2, windings 3 and 4 of magnetization and demagnetization installed on the terminals of the U-shaped core 2, a ferromagnetic accumulator counter 5c with a trimmer. comparing element 6. The device operates as follows. When the product (not shown) is not magnetized, the accumulation factor of the counter 5 is set equal to the accumulation factor of the counter 1 of the attached coercimeter. In this case, the accumulation factors of counters 1 and 5 correspond to their maximum value. Signals with the same frequency are recorded from the reading windings of counters 1 and 5, and at the output of the matching element 6, the signal corresponds to zero frequency. The product is magnetized by the current pulse flowing through the magnetize windings 3. In this case, the direction of magnetization is chosen in such a way that the residual induction of the product changes the accumulation factor of the indicator counter in the direction of decreasing. The frequency of the signal from the output of the indicator counter 1 after magnetization of the product increases by a certain amount. Since the accumulation factor of counter 5 does not change, a signal appears at the output of comparing element 6, whose frequency is proportional to the magnitude of the residual induction. Further, the pass current in the opposite direction along the demagnetization winding, the accumulation factor of the indicator ferromagnetic storage counter 1 of the coercimeter is reduced to the initial value. The demagnetization current at which the signal at the output of the comparison element 6 corresponds to zero frequency is taken as a measure of the coercivity. The use of the invention allows quality control of ferromagnetic products by two parameters: by magnetic induction and coercive force. This increases the speed and accuracy of reading the coercimeter signal by the recording device. Moreover, setting the initial accumulation factor of the indicator counter to its maximum value and choosing the magnetisation direction of the product makes it possible to use the entire range of variation of the accumulation coefficient of the indicator counter, which makes it possible to increase the limits of measurement of the magnetic induction and coercive force of the product. Claims of the invention Add-on ferromagnetic coercimeter according to ed. St. No. 744395, characterized in that, in order to increase accuracy and speed, an additional ferromagnetic storage counter with a trimmer magnet and a comparison element are introduced in it, one input of which is connected to the output of the indicator counter. and the second input with the output of an additional counter. Sources of information taken into account during the examination 1. USSR Author's Certificate No. 744395, cl. G01 R 33/12.