CA1122670A - Apparatus for detecting the presence of a moving rolled product - Google Patents
Apparatus for detecting the presence of a moving rolled productInfo
- Publication number
- CA1122670A CA1122670A CA318,589A CA318589A CA1122670A CA 1122670 A CA1122670 A CA 1122670A CA 318589 A CA318589 A CA 318589A CA 1122670 A CA1122670 A CA 1122670A
- Authority
- CA
- Canada
- Prior art keywords
- signal
- product
- sensor
- frequency
- resonance frequency
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B38/00—Methods or devices for measuring, detecting or monitoring specially adapted for metal-rolling mills, e.g. position detection, inspection of the product
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01V—GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS
- G01V3/00—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation
- G01V3/08—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation operating with magnetic or electric fields produced or modified by objects or geological structures or by detecting devices
- G01V3/10—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation operating with magnetic or electric fields produced or modified by objects or geological structures or by detecting devices using induction coils
- G01V3/101—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation operating with magnetic or electric fields produced or modified by objects or geological structures or by detecting devices using induction coils by measuring the impedance of the search coil; by measuring features of a resonant circuit comprising the search coil
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B1/00—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations
- B21B1/16—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling wire rods, bars, merchant bars, rounds wire or material of like small cross-section
- B21B1/18—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling wire rods, bars, merchant bars, rounds wire or material of like small cross-section in a continuous process
Landscapes
- Engineering & Computer Science (AREA)
- Remote Sensing (AREA)
- Physics & Mathematics (AREA)
- Life Sciences & Earth Sciences (AREA)
- Environmental & Geological Engineering (AREA)
- Electromagnetism (AREA)
- Mechanical Engineering (AREA)
- Geology (AREA)
- General Life Sciences & Earth Sciences (AREA)
- General Physics & Mathematics (AREA)
- Geophysics (AREA)
- Geophysics And Detection Of Objects (AREA)
- Investigating Or Analyzing Materials By The Use Of Magnetic Means (AREA)
Abstract
A B S T R A C T:
The presence of a magnetic rolled metal product moving longitudinally past a sensor, comprising an oscillatory circuit whose resonance frequency depends on the presence or absence of the product, is detected by measuring the resonance frequency or variation in the resonance frequency. An oscillator produces a square-wave signal having the resonance frequency. The signal is filtered and converted into a signal whose voltage is a function of the frequency. The latter signal is compared with a reference signal.
The presence of a magnetic rolled metal product moving longitudinally past a sensor, comprising an oscillatory circuit whose resonance frequency depends on the presence or absence of the product, is detected by measuring the resonance frequency or variation in the resonance frequency. An oscillator produces a square-wave signal having the resonance frequency. The signal is filtered and converted into a signal whose voltage is a function of the frequency. The latter signal is compared with a reference signal.
Description
APPARA'~IJ~ ~?OR Dl~:~EC~IN`G ~I-E PRESF,NCE OIIl A MOVI~ ROL~J~D
PRODUC'r ~ he present invention relates to apparatus ~or detecting, without contact, the presence of a longitudinally-moving rolled metal product, which is magnetic (e-ven if only slightly), the apparatus being capable of functioning at high tempera-tures and in an aggressive environment.-~he problem of detecting the pre~ence of a product is generally fairly easily solved by utilising: -- photoelectric cells, in the case of products at sufficiently high temperatures Cfor example higher than 800C) and in the absence of water, steam, and other opaque media; or - electromagnetic devices, in the case of products at sufficiently low temperatures (for example ~5 temperatures lower than 650C) and in the absence of magnetic parts in the immediate vicinity O L the capture element.
What is desired is de-tection apparatus which is able to function, without restriction, under the following conditions:
- temperature of the product to be detected: any met in practice (for example 20 to 1200C), - in the presence of water, steam,dust, or scale, - in an assembly with magnetic par-ts (on which it can also be ~olln~ed).
1.
l~Z;~:6~
According to the present invention there is provided an apparatus for detecting, without contact, the presence of a magnetic rolled metal product moving longitudinally, the apparatus comprising: (a) a sensor through which the product is to travel, the sensor comprising a winding which constitutes an inductor forming part of an oscillatory electrical circuit whose resonance frequency depends on the presence or absence of the product in the sensor, ~b) means for producing a first electrical signal having a frequency directly related to the resonance fre~uency of the oscillatory circuit, (c) means for filtering the said first signal, (d) means for converting the filtered first signal into a second signal whose amplitude is a function of the frequency of the first signal, (e) means for obtaining from the second signal a reference signal whose amplitude corresponds to th~ condition of the apparatus immediately before the presence of the product, and (f) means for comparing the second signal and the reference signal and for emitting a third signal which is a function of the comparison.
According to a preferred embodiment, the sensor comprises a set of turns of conducting wire disposed to form a winding having an internal diameter such that the product may pass through the winding.
According to another preferred embodiment, the sensor comprises a substantially ring-shaped magnetic core having a conducting wire wound around its surface, the core defining a gap through which the product may pass. The subst'antially ring-shaped core may be U-shaped. In the presence of the product the inductance of the assembly formed by the magnetic circuit and its winding is modifi`ed.
The apparatus preferably comprises means for monitoring the correct operation of the detection apparatus.
The apparatus also preferably comprises one or several 1~2~67~:) of the following accessories:
- a water chamber which protects the apparatus (at least the sensor) against possible overheating;
- a monitoring unit providing a water f]ow which is adequate for protecting the apparatus against overheating;
- a guide means ~or guiding the product past the sensor during its passing through the apparatus.
-~2Z67(~
l'he invention will be described further, by way of example, with reference -to the accompanying drawings, in which:
~ igu1~e 1 diagrammatically illus-trates apparatus for detecting the presence of a rolled steel product, showing a sensor and guide means in section, electronic components being omitted for clarity; and ~ igure 2 diagrammatically shows the electronic components of the apparatus.
Figure 1 shows a guide tube 1 for a steel product ~ - being discharged from a hot rolling mill and passing ~` through the tube 1 and other similar tubes arranged successively. A conducting wire winding 2 cast in a non-magnetic material, is arranged just beyond the exit end of the tube 1 and is coaxial with the tube. A water chamber 3 surrounding the exit end of the tube 1 is fed with water by a flexible pipe 4 through a monitoring unit 5 for a water flow supply 6. A main water chamber 8 surrounding the body of the tube 1 is fed by the conduit 7. ~e parts which are shown hatched may or may not be made from a magnetic material, without affecting operation of the detection apparatus.
In a preferred embodiment of the apparatus, the oscillatory circuit comprising the winding 2 has a resonance frequency which is from 5 to 40 kilohertz.
The electronic components of the apparatus comprise: -; 4-.
Z6~0 - ~1 osci.llator providing a squ~re-wave signal whose frequency is equal to the resonance frequency of the osci]latory circuit, - a band-pass fi]ter having a band width of 10 kHz centred on the resonance frequency of the oscillatory circui-t, - a converter which converts the frequency into voltage and which supplies a voltage at the output, : the voltage having a value which is a function of the 1 10 frequency, f, of the input signal, i - a reference assembly which enables a reference signal corresponding to a reference frequency fO to be ! obtained, which corresponds to the absence of a I ~ rolled product, - a comparator which provides an "all or nothing"
. electrical signal from the two electrical signals received (frequency f and fO), the said signal being a function of the variation between the input signals corresponding to frequencies f and fO, ~d . . .
:. 20 thus of the variation in freguency measured, B - optionally an interference suppress~Sr 'he reference assembly preferably comprises a measuring loop which enables the temperature variation and the shift of the frequency fO to be corrected.
: Figure 2 shows, by way of example, a block diagral~
of the apparatus. An oscillatory ~C circuit 11, including ~267(~
an inductor constitued by the winding 2, sends a signal to an oscillator 12 which, in its turn, provides a square-wave signal of the same frequency as the input signal. The sauare-wave signal, after passing through a band-pass filter 13 (band width 10 kHz centered on resonance frequency of the circuit 11), passes into a fre~uency-voltage converter 14. Then signals coming from a reference assembly 15 and from the converter 14 are compared in a comparator 17 emitting an "all or nothing"
electrical signal which, after passing through an interference suppressor 18 is sent to an optical coupling output stage 19.
The operation of the oscillator 12 i`s monitored by a moni~oring system 16 which is e~uipped with an alarm 10.
In an alternative embodiment, the winding 2 may be replaced by a substantially ring-shaped magnetic core having a ~ conducting wire around its surface. The core defines a gap through which the tube passes. In the presence of the tube, the inductance of the assembly is changed. The substantially ring-shaped core may be U-shaped.
PRODUC'r ~ he present invention relates to apparatus ~or detecting, without contact, the presence of a longitudinally-moving rolled metal product, which is magnetic (e-ven if only slightly), the apparatus being capable of functioning at high tempera-tures and in an aggressive environment.-~he problem of detecting the pre~ence of a product is generally fairly easily solved by utilising: -- photoelectric cells, in the case of products at sufficiently high temperatures Cfor example higher than 800C) and in the absence of water, steam, and other opaque media; or - electromagnetic devices, in the case of products at sufficiently low temperatures (for example ~5 temperatures lower than 650C) and in the absence of magnetic parts in the immediate vicinity O L the capture element.
What is desired is de-tection apparatus which is able to function, without restriction, under the following conditions:
- temperature of the product to be detected: any met in practice (for example 20 to 1200C), - in the presence of water, steam,dust, or scale, - in an assembly with magnetic par-ts (on which it can also be ~olln~ed).
1.
l~Z;~:6~
According to the present invention there is provided an apparatus for detecting, without contact, the presence of a magnetic rolled metal product moving longitudinally, the apparatus comprising: (a) a sensor through which the product is to travel, the sensor comprising a winding which constitutes an inductor forming part of an oscillatory electrical circuit whose resonance frequency depends on the presence or absence of the product in the sensor, ~b) means for producing a first electrical signal having a frequency directly related to the resonance fre~uency of the oscillatory circuit, (c) means for filtering the said first signal, (d) means for converting the filtered first signal into a second signal whose amplitude is a function of the frequency of the first signal, (e) means for obtaining from the second signal a reference signal whose amplitude corresponds to th~ condition of the apparatus immediately before the presence of the product, and (f) means for comparing the second signal and the reference signal and for emitting a third signal which is a function of the comparison.
According to a preferred embodiment, the sensor comprises a set of turns of conducting wire disposed to form a winding having an internal diameter such that the product may pass through the winding.
According to another preferred embodiment, the sensor comprises a substantially ring-shaped magnetic core having a conducting wire wound around its surface, the core defining a gap through which the product may pass. The subst'antially ring-shaped core may be U-shaped. In the presence of the product the inductance of the assembly formed by the magnetic circuit and its winding is modifi`ed.
The apparatus preferably comprises means for monitoring the correct operation of the detection apparatus.
The apparatus also preferably comprises one or several 1~2~67~:) of the following accessories:
- a water chamber which protects the apparatus (at least the sensor) against possible overheating;
- a monitoring unit providing a water f]ow which is adequate for protecting the apparatus against overheating;
- a guide means ~or guiding the product past the sensor during its passing through the apparatus.
-~2Z67(~
l'he invention will be described further, by way of example, with reference -to the accompanying drawings, in which:
~ igu1~e 1 diagrammatically illus-trates apparatus for detecting the presence of a rolled steel product, showing a sensor and guide means in section, electronic components being omitted for clarity; and ~ igure 2 diagrammatically shows the electronic components of the apparatus.
Figure 1 shows a guide tube 1 for a steel product ~ - being discharged from a hot rolling mill and passing ~` through the tube 1 and other similar tubes arranged successively. A conducting wire winding 2 cast in a non-magnetic material, is arranged just beyond the exit end of the tube 1 and is coaxial with the tube. A water chamber 3 surrounding the exit end of the tube 1 is fed with water by a flexible pipe 4 through a monitoring unit 5 for a water flow supply 6. A main water chamber 8 surrounding the body of the tube 1 is fed by the conduit 7. ~e parts which are shown hatched may or may not be made from a magnetic material, without affecting operation of the detection apparatus.
In a preferred embodiment of the apparatus, the oscillatory circuit comprising the winding 2 has a resonance frequency which is from 5 to 40 kilohertz.
The electronic components of the apparatus comprise: -; 4-.
Z6~0 - ~1 osci.llator providing a squ~re-wave signal whose frequency is equal to the resonance frequency of the osci]latory circuit, - a band-pass fi]ter having a band width of 10 kHz centred on the resonance frequency of the oscillatory circui-t, - a converter which converts the frequency into voltage and which supplies a voltage at the output, : the voltage having a value which is a function of the 1 10 frequency, f, of the input signal, i - a reference assembly which enables a reference signal corresponding to a reference frequency fO to be ! obtained, which corresponds to the absence of a I ~ rolled product, - a comparator which provides an "all or nothing"
. electrical signal from the two electrical signals received (frequency f and fO), the said signal being a function of the variation between the input signals corresponding to frequencies f and fO, ~d . . .
:. 20 thus of the variation in freguency measured, B - optionally an interference suppress~Sr 'he reference assembly preferably comprises a measuring loop which enables the temperature variation and the shift of the frequency fO to be corrected.
: Figure 2 shows, by way of example, a block diagral~
of the apparatus. An oscillatory ~C circuit 11, including ~267(~
an inductor constitued by the winding 2, sends a signal to an oscillator 12 which, in its turn, provides a square-wave signal of the same frequency as the input signal. The sauare-wave signal, after passing through a band-pass filter 13 (band width 10 kHz centered on resonance frequency of the circuit 11), passes into a fre~uency-voltage converter 14. Then signals coming from a reference assembly 15 and from the converter 14 are compared in a comparator 17 emitting an "all or nothing"
electrical signal which, after passing through an interference suppressor 18 is sent to an optical coupling output stage 19.
The operation of the oscillator 12 i`s monitored by a moni~oring system 16 which is e~uipped with an alarm 10.
In an alternative embodiment, the winding 2 may be replaced by a substantially ring-shaped magnetic core having a ~ conducting wire around its surface. The core defines a gap through which the tube passes. In the presence of the tube, the inductance of the assembly is changed. The substantially ring-shaped core may be U-shaped.
Claims (16)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. Apparatus for detecting, without contact, the presence of a magnetic rolled metal product moving longitudinally, the apparatus comprising:
(a) a sensor through which the product is to travel, the sensor comprising a winding which constitutes an inductor forming part of an oscillatory electrical circuit whose resonance frequency depends on the presence or absence of the product in the sensor, (b) means for producing a first electrical signal having a frequency directly related to the resonance frequency of the oscillatory circuit, (c) means for filtering the said first signal, (d) means for converting the filtered first signal into a second signal whose amplitude is a function of the frequency of the first signal, (e) means for obtaining from the second sig-nal a reference signal whose amplitude corres-ponds to the condition of the apparatus imme-diately before the presence of the product, and (f) means for comparing the second signal and the reference signal and for emitting a third signal which is a function of the comparison.
(a) a sensor through which the product is to travel, the sensor comprising a winding which constitutes an inductor forming part of an oscillatory electrical circuit whose resonance frequency depends on the presence or absence of the product in the sensor, (b) means for producing a first electrical signal having a frequency directly related to the resonance frequency of the oscillatory circuit, (c) means for filtering the said first signal, (d) means for converting the filtered first signal into a second signal whose amplitude is a function of the frequency of the first signal, (e) means for obtaining from the second sig-nal a reference signal whose amplitude corres-ponds to the condition of the apparatus imme-diately before the presence of the product, and (f) means for comparing the second signal and the reference signal and for emitting a third signal which is a function of the comparison.
2. Apparatus as claimed in claim 1 in which the winding comprises turns of conducting wire through which the product is to pass.
3. Apparatus as claimed in claim 1, in which the sensor comprises a substantially ring-shaped magnetic core having a gas through which the product is to pass, the winding being disposed around the core.
4. Apparatus as claimed in claim 3, in which the core is U-shaped.
5. Apparatus as claimed in claim 1, including means for monitoring the operation of the remainder of the apparatus.
6. Apparatus as claimed in claim 1, in which the oscillatory circuit has a resonance frequency of 5 to 40 kHz, in the absence of the product.
7. Apparatus as claimed in claim 1, in which the first signal producing means comprises an oscillator arranged to produce a square-wave signal.
8. Apparatus as claimed in claim 7, including means for monitoring the operation of the oscillator.
9. Apparatus as claimed in claim 1, in which the filtering means comprises a band-pass filter whose band has a width of 10 kHz and is centred on the resonance frequency of the oscillatory circuit in the absence of the product.
10. Apparatus as claimed in claim 1, in which the converting means comprises a frequency-voltage conver-ter whose output is a voltage which is a function of the frequency of an input signal.
11. Apparatus as claimed in claim1, in which the means for obtaining the reference signal includes a measuring loop which compensates for the effects of temperature variation on the reference signal.
12. Apparatus as claimed in claim 1, in which the comparing means comprises a comparator which emits an "all or nothing" signal as a function of the comparison between the second signal and the reference signal.
13. Apparatus as claimed in claim 1, including a suppressor arranged to suppress electrical interference.
14. Apparatus as claimed in claim 1, further compri-sing a water chamber which protects the sensor from over-heating.
15. Apparatus as claimed in claim 14, further com-prising a monitoring unit for maintaining a water flow adequate for protection against overheating.
16. Apparatus as claimed in claim 1, further compri-sing guide means for guiding the product through the sensor.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| BE862,377 | 1977-12-27 | ||
| BE6046287A BE862377A (en) | 1977-12-27 | 1977-12-27 | DEVICE FOR DETECTING THE PRESENCE OF A MOVING ROLLED METAL PRODUCT |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1122670A true CA1122670A (en) | 1982-04-27 |
Family
ID=3874761
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA318,589A Expired CA1122670A (en) | 1977-12-27 | 1978-12-22 | Apparatus for detecting the presence of a moving rolled product |
Country Status (7)
| Country | Link |
|---|---|
| JP (1) | JPS54100764A (en) |
| BE (1) | BE862377A (en) |
| CA (1) | CA1122670A (en) |
| DE (1) | DE2855081A1 (en) |
| FR (1) | FR2413673A1 (en) |
| GB (1) | GB2011082B (en) |
| LU (1) | LU80722A1 (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4334604A (en) * | 1979-03-15 | 1982-06-15 | Casino Investment Limited | Coin detecting apparatus for distinguishing genuine coins from slugs, spurious coins and the like |
| GB8424096D0 (en) * | 1984-09-24 | 1984-10-31 | Buttemer D A | Inductive loop detector |
| DE3526916A1 (en) * | 1985-07-24 | 1987-02-05 | Mannesmann Ag | ROLLER GEAR FOR FLAT MATERIAL ROLLING MILL |
| FR2683748A1 (en) * | 1991-11-19 | 1993-05-21 | Unimetall Sa | Method and device for detecting the presence of ferrous-metal (steel or iron) semifinished products on a hot rolling mill |
| GB2280802A (en) * | 1993-07-17 | 1995-02-08 | Sabed Ltd | An improved detector circuit |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3148563A (en) * | 1959-06-15 | 1964-09-15 | South African Iron & Steel | Detection of the arrival of material at a point in a rolling mill |
| CH421237A (en) * | 1964-02-05 | 1966-09-30 | Ebauches Sa | Proximity detector |
| US3397364A (en) * | 1967-05-24 | 1968-08-13 | Small Business Administ | Inductive loop metallic object detector |
| DE2220944C2 (en) * | 1972-04-28 | 1974-02-14 | Guenther Dipl.-Ing. 2209 Sushoern Weber | Electronic, contactless switching device |
| JPS5326972B2 (en) * | 1973-11-19 | 1978-08-05 | ||
| GB1482976A (en) * | 1975-06-09 | 1977-08-17 | Spencer P | Metal detectors |
-
1977
- 1977-12-27 BE BE6046287A patent/BE862377A/en not_active IP Right Cessation
-
1978
- 1978-12-20 FR FR7836404A patent/FR2413673A1/en active Granted
- 1978-12-20 DE DE19782855081 patent/DE2855081A1/en not_active Withdrawn
- 1978-12-22 LU LU80722A patent/LU80722A1/en unknown
- 1978-12-22 CA CA318,589A patent/CA1122670A/en not_active Expired
- 1978-12-26 JP JP16458378A patent/JPS54100764A/en active Pending
- 1978-12-27 GB GB7850028A patent/GB2011082B/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| LU80722A1 (en) | 1979-04-13 |
| JPS54100764A (en) | 1979-08-08 |
| BE862377A (en) | 1978-06-27 |
| GB2011082B (en) | 1982-10-06 |
| FR2413673A1 (en) | 1979-07-27 |
| DE2855081A1 (en) | 1979-07-05 |
| FR2413673B1 (en) | 1985-03-15 |
| GB2011082A (en) | 1979-07-04 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |