JPH01203887A - Detector for passing material in continuous heat treating furnace - Google Patents

Abstract

PURPOSE:To minimize operation trouble by giving an alarm when a time interval between signals made by existence detectors for detecting material existence found in consistent with a standard time obtained by dividing a distance between the detectors by a running speed of revolving rollers. CONSTITUTION:Flag switches 5a-5d as existence detectors are situated respectively between revolving rollers 3. When materials 1 are transferred on the rollers 3 in furnace and kick the flag face 51 of one of the switches 5a-5d, a flag switch pin 52 turns to close a limit switch 53, and this lights one of material detection indicator lamps 11 in alarm indicator 8, which respectively correspond to positions in the furnace. When a prescribed time has elapsed, lamps 13 for indicating load existence in zones go on to show load existence of material 1. Repeating this operation enables us to recognize passing of materials. In addition, a time from ON to OFF of the flag switch 5, or that from ON to ON of the next flag switch is measured and compared with a standard time, and when difference is larger than a specified allowance, occurrence of an abnormal situation is indicated by lighting of trouble indicator lamp 12 or by its flashing.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention constantly monitors the presence or absence of material conveyance abnormalities in a roller hearth type continuous heat treatment furnace to monitor operating conditions and detect troubles at an early stage. The present invention relates to a method for monitoring material passage in a continuous heat treatment furnace.

[Prior art] There is a method for transporting materials in a continuous heat treatment furnace, such as loading the materials on a non-powered cart and pushing the carts one after another in a beading style. However, when the materials are of different sizes, The rotating roller bed (roller hearth) method is often adopted because the material charging interval is free and there are few restrictions on the preceding and following processes.

FIG. 5 is a side sectional view of an example of a roller hearth type continuous heat treatment furnace, in which 1 is a material, 2 is a heat treatment furnace, 3 is a rotating roller, and 4 is a drive device.

The material 1 is placed on a rotating roller 3 on the left side of the figure, and the rotating roller 3 is rotated and opened by a drive device 4 to move the material 1 to the right side of the figure. The material 1 heated to a high temperature in the center of the furnace 2 and heat-treated for a predetermined distance (predetermined time) is extracted and discharged from the right end of the furnace 2. During this period, the material 1 is moved by the instant rotating rollers 3 disposed over the entire length of the passage inside the furnace 2.

[Problems to be solved] However, when processing materials shorter than the furnace length in a roller hearth type continuous heat treatment furnace, the condition inside the furnace cannot be seen, so the position inside the furnace and the All I had to do was calculate the extraction time. In addition, even if abnormalities such as overlapping or catching of materials occur in the furnace, they are not detected and the trouble increases.

The present invention aims to solve the above problems.

The purpose of the present invention is to obtain a method for monitoring the passage of material in a continuous heat treatment furnace, which detects conveyance abnormalities at an early stage and provides warnings to minimize operational troubles.

[Means to solve the problem] A method for monitoring material passage through a continuous heat treatment furnace according to the present invention.

A plurality of presence detection devices for detecting the presence of material are installed at intermediate positions of the material passage in the furnace, and the signal intervals emitted by the presence detection devices are compared with the scheduled time obtained by dividing the distance between the presence detection devices by the rotating roller drive speed. Alternatively, a presence detection device for detecting the presence of material may be provided at an intermediate position of the material passage in the furnace, and the signal interval emitted by the presence detection device and the length of the material may be adjusted by the rotation. It is characterized by comparing the scheduled time divided by the roller drive speed and issuing an alarm if they do not match.

[Operation] In the present invention, in order to grasp the conveyance situation in the furnace, a presence detection means for detecting whether or not the material is located at a specific position is provided in the furnace. To do this, a method that can withstand heat and reliably detect the material is required. Alternatively, it is practical to detect optical path interruption using a phototube.

In the furnace, 1. For example, the time interval from the time when the signal of the presence detection device installed at point A turns ON to the time when the signal of the presence detection device installed at point B turns ON is the time interval from the point A to point B of the material. If the expected arrival time is not within the range of plus or minus a predetermined value, the in-furnace conveyance situation is determined to be abnormal and an alarm is issued.

The estimated arrival time is determined by dividing the distance between points A and B by the rotating roller drive speed.

Alternatively, if the time from ON to OFF of the signal of the presence detection device installed at point A is not within the predetermined range of the scheduled time calculated by dividing the length of the material or tray by the rotating roller drive speed, the furnace The system determines that the internal transportation situation is abnormal and issues an alarm.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings. Note that the reference numerals already mentioned indicate the same parts, and a description thereof will be omitted.

FIG. 1 is a block diagram of a monitoring device according to a material passage monitoring method in a continuous heat treatment furnace as an example, and shows 58 to 58.
5d is installed between the rotating rollers 3, and the material 1 is placed between the rotating rollers 3.
It is a flag switch that serves as a presence detection device that sends an ON signal when it is present on the ground, and is installed in multiple cylinders. 6 is a pulse generator that measures the amount of rotation of the rotating roller 3;
7 is an arithmetic and monitoring device, and 8 is an alarm display panel.

FIG. 2 is a schematic longitudinal cross-sectional view showing the structure of one of the flag switches 5a to 5d (reference numeral 5).
1 is a flag surface that protrudes from the conveying surface of the rotary roller 3 if the material 1 is not present, and is pushed down to the conveying surface of the rotary roller 3 if the material 1 is present, and 52 is a flag surface 51 whose length spans the entire width of the furnace. The flag switch shaft 53, which rotates as the flag switch shaft 52 operates, is a limit switch that is installed close to the flag switch shaft 52 outside the furnace and is turned on by the rotation of the same shaft 52.

In FIG. 2, when the material 1 moves to the right, the flag surface 51 is pushed down to the lower right, the flag switch shaft 52 is rotated clockwise, and the limit switch 53 is turned on.

FIG. 3 is a flowchart showing the operation of the arithmetic monitoring device 7. In FIG. 3(a), in step 31, the length of the material 1 or the length of the tray Lt, the installation point of the flag switch 5a, and the sinking position are determined. The distance Lab from the installation point of the flag switch 5b is input, and in step 32, the flag switch 5a is set ONL.

It is checked whether the ON state has changed from the OF state to the ON state, and if it is not ON, the process goes to step 34.
ONL, after a timer (not shown) is reset in step 33, timing is started, and the process goes to step 38.

In step 34, the flag switch 5a is turned off (
It is checked whether the ON state has changed to the OFF state), and if it is 0FFL, the process goes to step 36, and ○F
If FL, the material length or tray length is checked and alarm processing is performed in step 35, and the process proceeds to step 38. Here, A and B are the exits of the subprogram.

In step 36, it is checked whether the next stage flag switch 5b is turned ON (changed from OFF state to ON state).
L, if you were there.

In step 37, the distance between materials or trays is checked and an alarm process is performed. Here, C and D are the input/exit of the subprogram.

In step 38, it is determined whether or not to continue the calculation by referring to the operation switch on the operation panel, and if it is to be continued, step 32
Return to , and stop if finished.

In FIG. 3(b), in step 39, the time measured by the timer started in step 33 is read and set as T□, and the conveyance speed of the rotating roll is read by the pulse generator 6 and set as V.

In step 40, the scheduled tray passage time Taa is calculated.

Taa=v0Lt In step 41, the above T1 and Taa are compared. In this case, a mismatch within a predetermined value, for example, ±20% is allowed. If they match, the process goes to exit B; if they do not match, in step 42, a tray contact warning is output to the alarm display panel 8 and the abnormality display lamp 12 is turned on. After that, go to exit B and end this subprogram.

In FIG. 3(Q), in step 43, the time measured by the timer started in step 33 is read as T2, and the conveyance speed of the rotary roll 3 is read by the pulse generator 6 and is set as V.

In step 44, the scheduled tray interval time Tab is calculated.

Tab=v-Lab In step 45, the T2 and Tab are compared. In this case, a mismatch within a predetermined value, for example, ±20% is allowed. If they match, the process goes to the exit, and if they do not match, in step 46, a warning that the tray interval is abnormal is output to the alarm display panel 8 and the abnormality display lamp 12 is made to blink. After that, go to the exit and end this subprogram.

FIG. 4 is an external view of the alarm display panel 8 that displays information of the monitoring device 7, in which 11 is a presence detection display lamp that lights up when the flag switch 5 is turned on, and 12 is a presence detection display lamp that is detected as being abnormal in steps 42 and 46. An abnormality indicator lamp 13 lights up when the presence detection indicator lamp 11 lights up, and an in-zone load indicator lamp 13 lights up a predetermined time after the presence detection indicator lamp 11 lights up.

The monitoring device according to the method of this embodiment is configured as described above and operates as follows.

In FIG. 1, when the material 1 is fed on the rotary roller 3 in the furnace and the flag face 51 of one of the flag switches 58 to 5d is kicked, the flag switch shaft 52 rotates and the limit switch 53 is turned on. .

When the limit switch 53 is turned on, one of the material detection display lamps 11 corresponding to the relevant position of the alarm indicator 8 lights up. After a predetermined period of time has elapsed, the in-zone inventory display lamp 13, which indicates the inventory of material 1, lights up. By repeating this process, the state of material passage can be determined.

On the other hand, the flag switch 5 is turned from ON to OFF, or
The time from N to ON of the flag switch at the next position is measured and compared with the scheduled time. If there is a difference of more than a predetermined value, the abnormality indicator lamp 12 is turned on (for example, in step 42) or blinks (for example, in step 46). ) to indicate the occurrence of an abnormality. The operator looks at the display and takes predetermined measures to prevent the failure from spreading.

In this way, the method for monitoring the passage of material in a continuous heat treatment furnace according to this embodiment makes it possible to grasp the conveyance status inside the furnace, which cannot be seen visually, by means of the lamp display, and it is possible to detect material snags and take early countermeasures. It is possible to prevent damage from becoming serious.

[Effects of the Invention] The method for monitoring the passage of material in a continuous heat treatment furnace of the present invention includes providing a plurality of presence detection devices for detecting the presence of material at intermediate positions of the material passage in the furnace, and determining the interval between signals emitted by the presence detection devices and the presence of the material. Compare the distance between the detection devices with the scheduled time divided by the rotating roller drive speed and issue an alarm if they do not match, or install a presence detection device that detects the presence of material in the middle of the material passage in the furnace. The signal interval emitted by the presence detection device is compared with the scheduled time obtained by dividing the length of the material by the immediate speed of the rotating roller, and an alarm is issued when they do not match. By monitoring the load (load), it is possible to increase the charging amount without fear of overlapping materials.

(2) By preventing long-term failures through early detection of troubles within the furnace, the downtime of the heat treatment furnace can be reduced, the annual heat treatment capacity can be significantly improved, and large economic benefits can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a monitoring device according to a method for monitoring material passage in a continuous heat treatment furnace as an embodiment. Fig. 2 is a schematic vertical sectional view showing the structure of the flag switch of the same embodiment, Fig. 3 is a flowchart showing the operation of the arithmetic and monitoring device of the same embodiment, and Fig. 4 is an alarm display panel of the same embodiment. FIG. 5 is a side sectional view of a conventional roller hearth type continuous heat treatment furnace. 1... Material, 2... Heat treatment furnace, 3...
... Rotating roller, 4 ... Drive device, 5, 5
a to 5d...Flag switch as a presence detection device, 6...Pulse generator, 7...
...Arithmetic monitoring device, 8...Alarm display panel, 11.
...Presence detection indicator lamp, 12... Abnormality indicator lamp, 13... Load in zone indicator lamp. 51...Flag surface, 52...Flag switch shaft, 53...Limit switch. Patent applicant: Kobe Steel, Ltd. Representative: Patent attorney Fu Kobayashi Figure 1 Figure 2 Figure 3 (G) Figure 3 (b) (C)

Claims (2)

[Claims] (1) In a continuous heat treatment furnace, the material to be heat treated is placed on a rotating roller and the rotating roller is driven to pass through the heat treatment furnace to heat treat the material. A plurality of presence detection devices are provided to detect presence, and the interval between signals emitted by the presence detection devices is compared with a scheduled time obtained by dividing the distance between the presence detection devices by the rotating roller drive speed, and an alarm is issued when they do not match. A method for monitoring the passage of material in a continuous heat treatment furnace, characterized by emitting. (2) In a continuous heat treatment furnace, the material to be heat treated is placed on a rotating roller and the rotating roller is driven to pass through the heat treatment furnace to heat treat the material. A presence detection device for detecting the presence is provided, and a signal interval emitted by the presence detection device is compared with a scheduled time obtained by dividing the length of the material by the rotation roller drive speed, and an alarm is issued when they do not match. Features: A method for monitoring material passage in a continuous heat treatment furnace.