JPS6294243A - Method for detecting fire - Google Patents

Abstract

PURPOSE:To improve the reliability of a fire detector which is set in a polluted atmosphere and the safety of an unmanned operation by periodically inspecting said fire detector by means of a pseudo-fire generator and restricting the external output of a fire signal during a pseudo-fire and during the dead time of detection due to the signal of said pseudo-fire. CONSTITUTION:A pseudo-fire generation command is given by a control unit, light is emitted from a pseudo-fire generator 6 for 2min, and a fire-detection effective signal is outputted in the control unit. Whereas, if fire is not detected and to minutes has passed after the command is given, judgement is made that there is a trouble in a fire detector 4 or that a detecting surface is polluted and the detecting capacity is deteriorated. However, even if a 2min timer is operated and a pseudo-fire is outputted, when the signal of the fire detector is not outputted due to a pulse signal at every 5sec which is operated by a fire detector ready signal as a set signal, a detection-normal signal is outputted, confirming the function of the detector 4. When a pseudo-fire is outputted and its detection is confirmed by means of the pulse signal at every 5sec which is operated by the fire detector ready signal as a set signal, a fire detecting signal is outputted.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a fire detection method, and particularly to a method that is effective when the detection surface is installed in an atmosphere where there is a possibility of contamination.

BACKGROUND OF THE INVENTION In recent years, automated and unmanned operations such as FMS have been introduced to production lines, and various safety measures have become an urgent need. When machining is performed using cutting oil, the heat of the chips causes the chips to turn red, especially in heavy cutting, and the cutting oil evaporates. Machining in such an atmosphere poses a potential risk of fires caused by red-hot chips igniting vaporized oil, which is a problem for automation and unmanned processing.

For this reason, in recent years, machine tools have been equipped with fire detectors and fire extinguishers to prevent fires from occurring.

Problems to be Solved by the Invention There are various types of fire detectors, and heat detectors have a delay in response and are difficult to detect if the location of the fire and the location of the sensor are far apart. Another problem with smoke detectors is that it is difficult to distinguish smoke from vaporized oil during cutting. Furthermore, infrared detectors, ultraviolet detectors, and the above-mentioned detectors detect the infrared rays and ultraviolet rays characteristic of flames, as well as the above-mentioned detectors, which detect chips during cutting.

There is a problem that the sensing surface may be contaminated by cutting oil dust, especially casting dust, etc., resulting in unstable factors such as a decrease or loss of sensing ability, resulting in the inability to sense in an emergency.

Means for Solving the Problem: A simulated fire is generated periodically using a simulated fire generator 6, and the operation of the fire detector 4 is confirmed. This suppresses the output of the time fire signal to the outside.

Example Embodiments of the present invention will be described below based on the drawings.

In machine tools, especially FMS, and machining centers, where there is a risk of a fire occurring due to the vaporization and atomization of cutting oil and the heat of chips, a location with good visibility and easy fire detection, such as the sliding of cross rail 2 moving above column 1. The above-mentioned commercially available fire detector 4 is installed in the oil hydraulic section 3, and the fire detector 4 is installed at a position where it can be detected without interfering with the detection of the fire, for example, in the oil section 5 on the opposite side of the cross rail 2. A pseudo fire generator 6 capable of projecting light onto the sensing surface of the device 4 is provided. The type of lamp and filter are selected and installed so that the light from this pseudo fire generator 6 emits light that matches the sensing characteristics of the attached fire outbreak detector 4.

The light is emitted in response to a regular light emission command from the control device.

This will be explained with reference to FIG. 2 showing the flow of the action detection method, FIG. 3 showing the signal time chart, FIG. 4 showing the connection with the control device, and FIG. 5 showing the calculation in the control device. When the control 'rS source of the machine control device is turned on (Fig. 3 A), the fire detection system is activated at the same time, and in step Sl, it is determined whether the detector is ready by checking whether the time has elapsed until the fire detector becomes stable. If no, the judgment is repeated until it becomes YES (Figure 3). If YES, a pseudo fire occurrence command is issued from the control device in step S2, and the pseudo fire generator 6 emits light for, for example, two minutes.

In the control device, a pseudo fire signal (FIG. 3C) and a pseudo fire signal, that is, a fire detection valid signal (FIG. 3C) are output. In step S3, it is determined whether a fire has been detected, and if no, in step S4, it is determined whether two minutes have elapsed since the command of the fire. The fire detector 4 has a slight detection delay time of less than 2 minutes, and during this time it will naturally not be detected and the result will be No. If 2 minutes have not passed, the result will be No.
In step S5, it is determined whether 5 seconds have elapsed. If 5 seconds have not elapsed, the process returns to step S5 and it is again determined that 5 seconds have elapsed. If 5 seconds have elapsed, return to step S3 and repeat this process. If YES in step S4, there is an abnormality in the fire detector 4, or the detection ability has decreased due to a loss of detection surface force < 2η. It's for a reason. This is because in the control device, even if the 2-minute timer is activated and a pseudo fire is output, the fire detection signal is not output due to the pulse signal every 5 seconds (see Figure 5) which operates using the fire detector ready signal as the cent signal. As a result, the negative of the detector normal signal, that is, the detection normal signal (FIG. 3) is output.

The 2-minute timer is turned off while maintaining this state. Next, in step S6, in the hardware circuit, the 120 minute timer is activated by the OFF signal of the 2 minute timer, and the fire detection valid signal (Figure 5) is output based on the AND condition with the fire detector ready signal (Figure 5). A detector abnormal alarm signal (third diagram) is output as a result of the AND condition of the normal detector signal in step S4. Based on this signal, the operator investigates the cause and repairs or 't'l: Cleans the jU surface to remove the cause (If YES in step S3, a two-minute timer is activated in the control device in step S7. A suspected fire is output, and the fire detection is confirmed by a pulse signal every 5 seconds (Figure 5) that activates with the fire detector ready signal as a set signal, and a fire detection signal (Figure 3) is activated. is output.Furthermore, when the pseudo fire signal rises from the fire detector ready signal (exit in Figure 3), 0 is output.
FFL outputs a detector normal signal (see Figure 3) that turns ON when the fire detection signal just obtained rises. This detector normal signal is output when it is determined that the function of the fire detector 4 can sufficiently function against a fire. In step S8, it is determined whether two minutes have elapsed since the pseudo fire outbreak command.
If O, the process returns to step S3 and repeats.The control device detects a pseudo fire (Fig. 5 C) - Fire detection (Fig. 5 E) - Detector normal signal output (Fig. 5 E) until the 2-minute timer turns OFF.
) will be repeated. Y in step S8
If YES, A=O is set in step S9, and it is determined in step SIO whether a true fire (Fig. 3) has been detected. If YES, a fire signal (Fig. 3) is output in step Sll. . In the control '4'B device, the 120 minute timer is activated by the OFF signal of the 2 minute timer, and this ON signal is ANDed with the fire detector ready signal (Figure 3, exit).
Based on the conditions, a fire detection signal (Fig. 3, h) (l) is output.

-5 The fire detection signal (Fig. 3 E) (2) is output due to a real fire (Fig. 3 E), which has already been output, and the detector normal signal (Fig. 3) which is updated and output every 5 seconds. to)(3)(
A fire signal (No. 3 in FIG. 3) is output by the three signals 11 to (3). If No in step SIO, 1 is added to A in step 512. In step S13, it is determined whether A>1440. This increases fire detection to 5
It is said that the detectors will be checked once every second, and the detectors will also be checked every two hours with simulated fires.
The time is 7200 seconds, so dividing it by 5 seconds gives 144.
Since it will count 0 times, let it be determined whether 2 hours have passed. If YES, the process returns to step S2, outputs the pseudo fire generator command again, and repeats the steps.

If No, a fire check is performed every 5 seconds in step 314, so it is determined whether 5 seconds have elapsed, and if No, this step is repeated. If YES, step 310
and repeat the subsequent steps. The control device combines a 2-minute timer and a 120-minute timer, and the 2-minute timer operates at the same time as the fire detector ready signal (Figure 3 Exit) and outputs a pseudo fire signal (Figure 3 C). When the 2-minute timer turns off after 2 minutes, the 120-minute timer is activated by this OFF signal, and a fire detection enable signal (Fig. 3-1) is output. After another 120 minutes, the 120 minute timer will turn off! ,, With this OFF signal, the 2-minute timer is activated again. Further, regardless of whether the fire detection signal is output or not, the current state of the fire detector signal is updated by a pulse signal every 5 seconds after the fire detector ready signal is output.

In this embodiment, the control device, fire detector, and pseudo fire generator are connected as shown in Fig. 4, but if a soft timer is installed in the NC and the control operation is performed as shown in Fig. 2, this is not necessarily the case. There is no need to provide a new control device.

Effects As detailed above, the present invention has a system that includes a fire detector and a pseudo fire generator and periodically checks the detection ability of the fire detector, so that the fire detector installed in an atmosphere that is easily contaminated can be used as a fire detector. This has the effect of improving the reliability of the vehicle and greatly contributing to the safety of automated and unmanned driving.

[Brief explanation of drawings]

Figure 1 shows the case where a fire detector and pseudo fire generator are installed on a machining center, Figure 2 shows the flow of the fire detection system, and Figure 3 shows the operation time chart. Time of occurrence. (b) is a diagram showing when a detector abnormality alarm occurs, Figure 4 is a diagram showing the connection between the hardware circuit, fire detector, and pseudo fire generator, and Figure 5 is a diagram showing the calculations in the hardware circuit. .

Claims (1)

[Claims] (1) Periodically generate a simulated fire using a simulated fire generator installed within the detection range of a fire detector installed in an atmosphere where the detection surface may be contaminated, and confirm the operation of the fire detector. , A fire detection method characterized by suppressing output of a fire signal to the outside during a fire detection dead zone during a pseudo fire outbreak and by using a pseudo fire signal.