JP2011092988A - Automatic diagnosis method and device for hot scarfing oxygen pressure control system in hot scarfing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an automatic diagnosis method for a hot scarfing oxygen pressure control system where, in a hot scarfing apparatus in which an electric signal output from a sequencer is converted into gas pressure by a plurality of converters, and the gas pressure is input into a main regulator so as to control hot scarfing oxygen pressure, in the case functional deterioration or the like is generated in the converter on the way, this can be easily detected even in the initial stage, and to provide a device therefor. <P>SOLUTION: The automatic device for a scarfing oxygen pressure control system is used in a hot scarfing apparatus in which an electric signal output from a sequencer 4 is converted into gas pressure by a plurality of converters 5, 6, and the gas pressure is inputted to a main regulator 3 so as to control hot scarfing oxygen pressure. The device includes: input value detection means of the respective converters 5, 6; an output value detection means; a conversion ratio calculation means 10 connected to them and calculating the conversion ratio of each converter; and a diagnosing apparatus 11 diagnosing the converter whose conversion ratio is made off from the set ratio as the abnormal one. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an automatic diagnosis method and apparatus for a cutting oxygen pressure control system in a hot scarf apparatus used for cutting a surface defect of a steel material such as a slab.

  A hot scarf device is a device that sprays cutting oxygen and LPG gas from a crater unit toward the surface of a steel material such as a slab to remove pinholes, cracks, and the like on the surface of the steel material. As shown in Patent Document 1, the pressure of the cutting oxygen is detected by a pressure sensor and controlled by a main regulator so as to be a set pressure instructed by a sequencer.

  However, it is not preferable to directly control the main regulator that determines the pressure of the cutting oxygen by the sequencer. This is because the output of the sequencer is an electrical signal, and when the main regulator is directly controlled by the sequencer, the electrical signal is input to the main regulator. However, if a spark occurs at the contact point when the electrical signal is turned on or off, there is a risk that a high pressure oxygen flowing through the main regulator may cause a fire.

  In order to avoid such danger, the electrical signal output from the sequencer is converted into gas pressure by a plurality of converters, and this gas pressure is input to the main regulator to control the cutting oxygen pressure. Specifically, first, an electric signal output from the sequencer is converted into nitrogen gas pressure by an electric / gas pressure converter, and further, nitrogen gas pressure is converted into oxygen gas pressure by a gas pressure / gas pressure converter. Gas pressure is input to the main regulator to control the cutting oxygen pressure. If the method of controlling the cutting oxygen pressure by the oxygen gas pressure is employed in this way, there is no risk of a fire, and even if a gas leak occurs in the main regulator, there is no serious trouble because oxygen is between them.

  However, if a plurality of converters are interposed between the sequencer and the main regulator, there is a problem that even if the function of any converter deteriorates or breaks down, it is not easy to find out. That is, if the function of the converter in the middle deteriorates and the output becomes lower, the cutting oxygen pressure will decrease as it is, but since the cutting oxygen pressure is feedback controlled, the sequencer will The output is changed to increase the oxygen pressure. For this reason, even if functional degradation occurs in the converter on the way, it is covered by the entire cutting oxygen pressure control system, and it is difficult for the functional degradation of the converter to be detected at the initial stage. There is a problem that it cannot be found. However, when a failure occurs and the hot scarf device is stopped, the subsequent process is greatly affected, leading to a decrease in productivity of the entire factory.

JP 2006-205206 A

  The present invention solves the above-described conventional problems, converts an electric signal output from a sequencer into a gas pressure by a plurality of converters, and inputs the gas pressure to a main regulator to control the cutting oxygen pressure. An object of the present invention is to provide an automatic diagnosis method and apparatus for a cutting oxygen pressure control system that can easily find out even in an initial stage when functional deterioration or the like occurs in a converter in the middle of a scarf device.

  The automatic diagnosis method of the present invention, which has been made to solve the above problems, converts an electrical signal output from a sequencer into a gas pressure by a plurality of converters, and inputs this gas pressure to a main regulator to perform cutting oxygen This is an automatic diagnosis method for a cutting oxygen pressure control system in a hot scarf device that controls pressure, and detects the input value and output value of each converter and constantly monitors the conversion ratio of each converter, In comparison, the presence or absence of abnormality is diagnosed.

  The automatic diagnostic apparatus of the present invention converts the electric signal output from the sequencer into a gas pressure by a plurality of converters, and inputs the gas pressure to the main regulator to control the cutting oxygen pressure. It is an automatic device for the cutting oxygen pressure control system, which is connected to the input value detection means, output value detection means, and these input value detection means and output value detection means of each converter, and calculates the conversion ratio of each converter. A conversion ratio calculating means for performing the conversion, and a diagnostic device for diagnosing that the converter having the conversion ratio deviated from the set ratio has an abnormality.

  The converter preferably includes an electric / gas pressure converter that converts an electric signal into nitrogen gas pressure and a gas pressure / gas pressure converter that converts nitrogen gas pressure into oxygen gas pressure.

  According to the present invention, the input value and the output value of each converter are detected, the conversion ratio of each converter is constantly monitored, and the presence or absence of abnormality is diagnosed by comparing with the set ratio. Even in a state where the feedback control is maintained constant, it is possible to detect an abnormality of each converter at an early stage and perform maintenance and repair before a failure occurs. For this reason, the fall of productivity by the stop of a hot scarf apparatus can be prevented. Moreover, since this diagnosis can be performed automatically, the operator is not required to take extra steps.

It is a block diagram which shows embodiment of this invention.

Hereinafter, a preferred embodiment of the present invention will be described with reference to FIG.
In FIG. 1, reference numeral 1 denotes a hot scarf device for cutting the surface of a slab or the like, and its structure and usage are well known. Reference numeral 2 denotes a cutting oxygen supply line to the hot scarf apparatus 1, and the cutting oxygen pressure is controlled by a known main regulator 3. In addition, although fuel gas, such as LPG, is also supplied to the hot scarf apparatus 1, it is abbreviate | omitted in FIG.

  Reference numeral 4 denotes a sequencer that controls the entire hot scarf apparatus, and controls the main regulator 3 according to the process to perform the cutting. However, since the output of the sequencer 4 is an electric signal, it is not preferable to control the main regulator 3 directly from the viewpoint of safety as described above. Therefore, the electrical signal output from the sequencer 4 is converted into a gas pressure by a plurality of converters, and this gas pressure is input to the main regulator 3 to control the cutting oxygen pressure.

  Specifically, first, an electric signal output from the sequencer 4 is input to the electric / gas pressure converter 5 and converted into a nitrogen gas pressure. Nitrogen gas was used because there is no risk of fire even if an electric spark occurs. In this embodiment, 0.21 MPa of nitrogen gas is supplied to the electric / gas pressure converter 5, and an electric signal of 0 to 20 mA outputted from the sequencer 4 is a nitrogen gas pressure of 18.6 to 186.1 kPa. Is converted to

  Although it is not impossible to control the main regulator 3 with this nitrogen gas pressure, it is not preferable that nitrogen gas is mixed into the cutting oxygen. Therefore, the nitrogen gas pressure is further converted into the oxygen gas pressure by the gas pressure / gas pressure converter 6. The gas pressure / gas pressure converter 6 is supplied with oxygen gas of 0.62 MPa, and the nitrogen gas pressure of 18.6 to 186.1 kPa output from the electric / gas pressure converter 5 is 55.8 to Converted to an oxygen pressure of 558.5 kPa. The main regulator 3 is controlled by this oxygen gas pressure. The cutting oxygen pressure controlled by the main regulator 3 is converted into an electric signal by the gas pressure / electric converter 7 and fed back to the sequencer 4.

  In the present invention, in order to detect abnormalities between the electric / gas pressure converter 5 and the gas pressure / gas pressure converter 6 which are a plurality of converters of the cutting oxygen pressure control system configured as described above, The input value detection means and the output value detection means of the devices 5 and 6 are provided and are constantly monitored. Since the input of the electric / gas pressure converter 5 is an electric signal from the sequencer 4, it is not necessary to separately provide a special input value detecting means, but the output of the electric / gas pressure converter 5 is the electric / gas pressure converter 5. And a first pressure sensor 8 installed between the gas pressure / gas pressure converter 6. The first pressure sensor 8 functions as an input value detecting means for the gas pressure / gas pressure converter 6. Further, a second pressure sensor 9 which is an output value detection means of the gas pressure / gas pressure converter 6 is provided between the gas pressure / gas pressure converter 6 and the main regulator 3.

  The input values and output values of the converters 5 and 6 detected by these detection means are input to the conversion ratio calculation means 10, and the conversion ratios of the converters 5 and 6 are calculated. Since it is known what conversion ratio each of the converters 5 and 6 has in the normal state, this is set as a set ratio, and the calculated conversion ratio is compared with the set ratio in the normal state to obtain a diagnostic apparatus. 11 diagnoses the presence or absence of abnormality. When a diagnosis that there is an abnormality is made, a warning as to which converter has an abnormality is displayed on the touch panel 12. The operator can perform maintenance of the corresponding part by this display.

  In addition, since it is common that the function deterioration has occurred before the converters 5 and 6 completely fail, by continuously sending data to the diagnostic device 10, the deterioration tendency can be detected at an early stage. You can also. As a result, maintenance at an early stage of deterioration becomes possible, and deterioration of the cutting quality due to troubles in the cutting oxygen pressure control system can be eliminated.

DESCRIPTION OF SYMBOLS 1 Hot scarf apparatus 2 Cutting oxygen supply line 3 Main regulator 4 Sequencer 5 Electricity / gas pressure converter 6 Gas pressure / gas pressure converter 7 Gas pressure / electricity converter 8 1st pressure sensor 9 2nd pressure sensor 10 Conversion ratio calculation means 11 diagnostic device 12 touch panel

Claims (3)

  An automatic diagnosis method for a cutting oxygen pressure control system in a hot scarf device that converts an electric signal output from a sequencer into a gas pressure by a plurality of converters and inputs the gas pressure to a main regulator to control the cutting oxygen pressure. In the hot scarf device, wherein the input value and the output value of each converter are detected, the conversion ratio of each converter is constantly monitored, and the presence or absence of abnormality is diagnosed by comparing with the set ratio. Automatic diagnosis method for the fusing oxygen pressure control system.   It is an automatic device of the cutting oxygen pressure control system in the hot scarf device that converts the electrical signal output from the sequencer into gas pressure by a plurality of converters and inputs this gas pressure to the main regulator to control the cutting oxygen pressure An input value detection means for each converter; an output value detection means; a conversion ratio calculation means for calculating the conversion ratio of each converter connected to these input value detection means and output value detection means; and a conversion ratio. An automatic diagnosis device for a cutting oxygen pressure control system in a hot scarf device, characterized in that it comprises a diagnosis device for diagnosing that there is an abnormality in a converter out of a set ratio.   3. The converter includes an electric / gas pressure converter that converts an electric signal into nitrogen gas pressure, and a gas pressure / gas pressure converter that converts nitrogen gas pressure into oxygen gas pressure. Automatic diagnosis device of the cutting oxygen pressure control system in the hot scarf equipment in Japan.

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