FI65145B - ALARMANORDNING MED HOEG EFFEKT - Google Patents

Description

65145

High power alarms in alarm mode with high effect

The invention relates to a high-power alarm, the alarm system of which comprises a fan driven by a motor for blowing air into an alarm part generating an alarm sound, comprising a concentrator, a second stator with apertures and a rotor with apertures.

In a high-power alarm, the alarm sound is produced by interrupting the pressurized air flow with a rotating rotor. Openings are formed in the rotor which move at high speed past the corresponding openings of the stator. The air flow flowing through the openings, interrupted by the rotor, then causes pressure and vacuum waves in the surrounding air, which sound like a loud alarm sound. The audibility of the alarm sound can be further increased by exponential horns connected to the stator openings. The required compressed air is obtained either from an air pump or from a compressed air tank which is filled by an air compressor.

Known high power alarms are usually arranged to operate by means of compressed air tanks. Due to the large amounts of air required, the compressed air tanks used must also be large and robust. Normally, the tanks are placed above or below ground and the actual sound head, i.e. the alarm part, is placed, for example, on the roof of a tall building, so that the alarm sound can be heard far away. In this case, a long compressed air-25 piping must be built from the tank to the alarm section. This becomes expensive and, in addition, the entire alarm equipment is very difficult to move from one place to another. Long pipelines are also prone to clogging and rupture. In addition, the condition of such an alarm cannot be tested other than by performing an alarm.

It is natural that such training alarms cannot be made 30 very often. Despite the large tanks, the number of consecutive alarms is also limited. Filling the tanks takes a considerable amount of time.

In known high power alarms, the perforated plate acting as a rotor 35 operates either under the influence of compressed air or rotated by an electric motor. Since the alarm part is located, for example, on the roof of a tall building in the open air space, it is clear that the rotor rotates more rigidly in winter frost than in summer. It follows that the rotational speed of the rotor is different under different conditions, and since the frequency of the alarm sound is directly proportional to the rotational speed of the rotor, the frequency of the alarm sound 5 is also different under different conditions. For example, an ascending and descending sound is usually produced by alternately switching on and off the electric power of the electric motor rotating the rotor. In summer conditions, the rotor speed, i.e. the frequency of the alarm sound, increases rapidly and decreases slowly as the root-10 market rotates for a long time even when the power is switched off. In winter conditions, on the other hand, the rotor starts to move slowly and stops quickly. As a result, it has not been possible with the known devices to implement the agreed-upon alarm tones very accurately.

15 The alarm signals currently in use are grouped into normal time signs and emergency conditions signs. Four different alarm signals have been established for the siren-type alarm, which have slightly different meanings in normal and emergency conditions. A long sound lasting about one minute means a fire and rescue sign or, in the event of an emergency, a "danger over" sign. The general alarm signal is always a signal lasting about a minute, with the alarm device on alternately for about seven seconds and off for about seven seconds. The resulting sound is ascending and descending in turn. To test the alarm devices, a symbol is used in which the alarm trigger is held on for about seven seconds. The fourth character is a general hazard symbol used in exceptional circumstances, with the alarm trigger on for approximately seven seconds and off for approximately 21 seconds. The alarm device is switched on five times during the signaling, ie the duration of the sound signal is about two minutes. When the alarm trigger is switched on 30 and switched off, the alarm sound increases or decreases in frequency depending on how fast the rotor of the alarm accelerates or decelerates. Due to this, the alarm signals are different for different alarm devices, even if the devices are used according to the instructions.

The distinctiveness of the different brands may then be impaired.

The object of the present invention is to eliminate the above-mentioned drawbacks and to provide an efficient, reliable and in all circumstances the same high-power alarm operating in accordance with the set program. The invention is characterized in that a speed measuring sensor is connected to the rotor, and that the alarm apparatus comprises a control device to which the sensor is connected and which adjusts the rotor speed to the desired value based on the feedback received from the sensor. line. According to the invention, since the rotational speed of the rotor of the alarm part is always exactly the desired value, the alarm sound produced by the alarm is also exactly in accordance with the desired alarm program. In this case, the alarm can always be repeated exactly the same, regardless of the circumstances, in which case the separability of the different 10 alarms is the best possible. In known alarm devices, ambiguities may arise from variations in operation. The high-power alarm according to the invention is therefore a versatile, accurate and programmable device with which all the alarm programs in use can be repeated.

The invention will now be described, by way of example, with reference to the accompanying drawings, in which

Figure 1 shows the equipment of a high-power alarm according to the invention mounted in a container.

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Fig. 2 shows an operation diagram of the main parts of the high power alarm of Fig. 1.

Fig. 3 shows an operation diagram of the high power alarm control device of Fig. 1.

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Figure 4 shows a vertical section of the alarm part of the high power alarm of Figure 1.

Fig. 5 shows a section taken along the line V-V in Fig. 4.

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Figure 1 shows a high-power alarm built into a container 15. Inside the container there is a fan 2 driven by an internal combustion engine 1 which draws air from an opening 16 in the wall of the container 15. In addition, the container has a fuel tank 14, a battery 12 and a control device 9.

Battery power is required to start the internal combustion engine 1, to operate the control device 9 and to rotate the rotor of the alarm part 3. From the fan 2, the air flow is led along the duct 17 to the alarm part 3 placed on the container. This alarm part, i.e. the sound end of the alarm, includes a stator 7, in the openings of which exponential horns 18 increasing the audible sound are placed. A bypass valve 11 is connected to the air duct 17 leading to the alarm part inside the container 15, by means of which the air flow 10 produced by the fan 2 can be directed either up to the alarm part 3 or directly out of the opening 19 formed in the container wall. The bypass valve 11 can be used to operate the fan 2 even when the alarm sound is not desired.

This valve also makes it possible to interrupt the alarm sound, i.e. to produce constant-frequency whistles. In addition to standard frequency sound, standard alarm tone diagrams use rising and falling frequency sounds. Various alarm signals can be programmed in the control device 9 controlling the alarm system.

Figure 2 schematically shows a functional diagram of the main parts of a high-power alarm according to the invention. It can be seen from the figure that the internal combustion engine 1 rotates a fan 2, the air produced by which is led to the alarm section 3. The rotor 5 inside the alarm section is driven by an electric motor 8 which receives electric current from the battery 12. 25 toon for adjusting the speed of the motor 8. The battery 12 is charged by the generator 13 driven by the internal combustion engine 1. The control device, i.e. the control center 9, controls the rotational speed of the internal combustion engine 1 and the electric motor 8. The rotational speed of the motor 1 of the fan 2 is kept essentially constant, but the rotational speed of the electric motor 8 rotating the rotor 5 is adjusted according to how the frequency of the alarm sound is to be changed. The internal combustion engine 1 provides feedback to the control center 9 so that pulses are passed from the tips of the breaker to the control center. The rotational speed of the rotor 5 is measured by an inductive sensor, the information provided by which is fed to the control center 9. Thanks to this feedback, the rotational speed of the rotor 5 of the alarm part 35 is always of the desired value.

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Figure 3 shows diagrammatically the operation of a control device included in the alarm system. Operating commands for the internal combustion engine and the electric motor are sent from the central unit, ie the time interruption service. When an alarm command is received, the central unit first starts the internal combustion engine.

5 When the specified speed of the motor is reached, the electric motor of the rotor, i.e. the DC motor, starts, the speed of which is adjusted according to a predetermined program. If, on the other hand, it is an experiment with alarm equipment, then the central unit does not start the internal combustion engine, but the alarm program is run through by rotating the electric motor of the rotor. 10 In this case, the alarm can be heard at a very low volume.

Fig. 4 is a simplified vertical section of the alarm part 3 at the top of Fig. 1. The body or stator 7 of the alarm part is most preferably cylindrical in this embodiment. Inside the stator 7 15 is also arranged concentrically a cylindrical rotating rotor 5, which is rotated by an electric motor 8. The compressed air required by the alarm part is led from the fan to the alarm part via a duct 17. In the alarm part, the air flow propagates from inside the rotating rotor 5 through openings 4 to openings 6 at the corresponding point of the stator 7. Interruption of compressed air 20 by means of rotating rotor 5 causes vacuum and overpressure waves propagating through exponential horns 18 to the surrounding space.

Figure 5 shows a horizontal section taken from Figure 4. Inside the stator 7 of the cylinder stack 25 there is a rotating cylinder stack rotor 5. Air is led from the inside of the rotor 5 through its openings 4 to the openings 6 of the stator 7 and further as pressure waves through exponential horns 18 to the outside air. It can be seen from the figure that the opening 4 of the rotor 5 is substantially larger in the direction of rotation than the opening 6 of the stator 7 30 at a corresponding point in this direction. In the case shown in the figure, this ratio is about 2: 1. According to the invention, this ratio can be as high as 3: 1, which gives a very advantageous efficiency over sound.

Various embodiments of the invention may vary within the scope of the claims set forth below. Thus, the air pressure produced by the fan 2 is at most 0.3 bar, but can also be changed as needed. The frequency of the alarm sound in the 6 65145 high power alarm according to the invention is 370 Hz, which is advantageous both in terms of sound propagation and the sensitivity of the human ear. Four different alarm signals have been programmed into the alarm according to the invention, but they can of course be added. An alarm command can be given to the alarm by cable 5 or by radio. The stator and rotor are cylindrical in the embodiments shown in the drawings, but may also have other shapes. The rotor can also be located outside the stator. It is essential that they are concentric and that their airflow openings are at corresponding points.

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Claims (7)

1. High power alarm device, to which the alarm system belongs a fan (2) driven by a motor (1) for blowing air to an alarm device part (3). which provides an alarm sound and associated with a stator (7) provided with apertures (6) and a rotor (5) provided with apertures (4) concentrically placed one inside the other, wherein a motor (8), most preferably an electric motor whose rotational speed is controllable is connected to the rotor for rotating it, characterized in that a sensor measuring the rotational speed is connected to the rotor (5) and that to the alarm system a control device 10 (9) , to which the sensor is connected and which control device controls the rotational speed of the rotor (5) to the desired size on the base of a free sensor obtained iter coupling, so that the frequency of the alarm sound can be controlled according to a set program. 2. A high power alarm device according to claim 1, characterized in that the control device (9) is arranged to control the motor (1) of the fan (2) so that the fan output is constant. High power alarm device according to claim 1 or 2, characterized in that the motor (8) of the rotor (5) is a direct current motor, whose rotational speed is controlled by a pulse mower (10). 4. High power alarm device according to claims 1-3, characterized in that the alarm system can be tested with a low noise level e, that the rotor (5) is rotated according to the alarm program di fan (2) is not functioning. 5. A high power alarm device according to claims 1-4, characterized in that the alarm system comprises a bypass flow valve (11), by means of which the air flow coming from the fan (2) can direct antigen to the alarm device part (3). ) or past it.