KR102304112B1 - A sound emitter - Google Patents

Abstract

The sound wave generator for the sound emitter 10 has an electric motor with a rotating shaft. The axis of rotation comprises or is connected to a drive, which drive is eccentric with respect to the axis of rotation. The sound wave generator 30 further includes a sound wave element connected to the driving unit and extending in a direction substantially perpendicular to the driving unit, whereby the sound wave element is configured to perform a reciprocating motion when the driving unit rotates about the rotation axis. .

Description

A SOUND EMITTER

The present invention relates to a sound emitter provided with a sound wave generator arranged on a ship, factory, or the like.

A basic structure of a sound emitter provided with a horn is disclosed in GB-A-871,097. This kind of sound emitter has been widely used in large ships and the like since the 1960s.

The sound wave is produced, for example, by a piston in a cylinder that is connected to a horn. The subassembly comprising the piston and cylinder may also include a motor with a gearbox, which may also be referred to as a sonic generator.

There are many different sound emitters on the market today, which are, for example, electronic motor driven, but most of them are sensitive to adverse air temperature changes. Because the speed of sound is dependent on the ambient air temperature, the resonant frequency of a horn with a fixed length is not stable, and the resonant frequency decreases with decreasing temperature, which leads to a mismatch between the speed and resonance of the motor, and with increasing temperature. increase and then the sound level may substantially decrease. Designers have attempted to alleviate this problem caused by air temperature changes in other ways. A specific motor was used, a heating coil was arranged within the horn to heat the air within the horn, and the horn was modified to suit the characteristics of the horn, for example the length of the horn to suit the specific weather conditions. These solutions are unreliable and require costly adjustments and can lead to unwanted leaks resulting in a lower quality sound.

이다.Another issue with today's sound emitters is that the sound emitters typically require a gear transmission that operates as a shift so that the sound emitter's sonic generator can be provided with the correct frequency to achieve a sound wave that matches the resonant frequency of the horn. . Gear transmissions are cumbersome and add cost to the structure. Also, the gear transmission is made of steel and therefore often requires lubrication with liquid oil, or the gear transmission can be made of plastics. One plastic material used is Bakelite, which has a greater adverse effect on the environment.

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Other examples of prior art are disclosed in GB-A-1,312,747 and US-A-4,805,732. However, none of these known sound emitters provides a complete solution to the above-mentioned problem.

It is an object of the present invention to provide a novel sound generating arrangement which improves upon the prior art. This object is achieved by a technology defined in the appended independent claims and specific embodiments are set forth in the relevant dependent claims.

According to one aspect of the present invention, there is provided a sound wave generator for a sound emitter, comprising an electric motor having a rotating shaft, the rotating shaft comprising or connected to a driving part eccentric with respect to the rotating shaft do. In addition, the sound emitter is connected to the driving unit and configured to perform a reciprocating motion when the driving unit rotates about the rotating axis of the sound wave element extending in a direction substantially perpendicular to the driving unit. . The present invention is advantageous because the electric motor drives the sonic element by means of an axis of rotation and a drive but without any gear transmission, meaning that said sound emitter is not more complex and therefore less expensive than the sound emitters used today.

In one embodiment, the sonic element is arranged in a chamber and within the chamber the sonic element is able to move reciprocally and slightly laterally, such that the sonic element is relatively free without causing any wear on the chamber. allow to move

In another embodiment, the sonic generator further comprises a bearing, the bearing being arranged at least partially around the drive to allow the drive to rotate within the bearing and the bearing being coupled to the sonic element. This is advantageous because it provides a sonic element with controlled reciprocating motion as the drive rotates.

In another embodiment, the sonic generator further comprises a casing that receives the bearing and at least partially the drive and is connected to the sonic element. Such a casing is advantageous because it maintains lubrication for the parts it receives and ensures that the lubrication does not leak into any nearby parts.

In one embodiment of the invention, the electric motor is an induction motor with a three-phase delta connection. By having a delta-connection in the electric motor it is possible to operate the rotating shaft at the same frequency that is fed into the motor and thereby develops with maximum torque. Also, it is not necessary that an expensive special motor be used, but it is economically advantageous.

In another embodiment, the electric motor is connected to a frequency converter for providing a desired frequency to the rotating shaft. The frequency converter can be connected to any available electrical outlet, which converts the voltage from the electrical source to the desired frequency, eg 130 Hz, and supplies it to the three-phase connection of the motor. Another advantageous feature is that the converter from the frequency converter can be varied so that it can be applied to horns having different sizes and shapes.

In another aspect of the present invention, there is provided a resonant horn and a sound wave generator provided thereon, whereby the sound wave generator is configured to deliver an air pressure pulse to the resonant horn to generate sound.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below, and reference is made to the accompanying drawings which illustrate non-limiting examples which may actually reduce the inventive concept.
1 shows a sound emitter mounted on a ship;
2 is a perspective view of a sound emitter according to an embodiment;
Fig. 3 is a cross-sectional view of the sound emitter of Fig. 2, including a sound wave generator according to one embodiment;
Fig. 4 is a cross-sectional view of the sound wave generator of Fig. 3;
Fig. 5A is a diagram showing the relationship between the torque developed by the motor of the sound wave generator of the prior art solution and the acoustic load;
5B is a diagram showing a relationship between a torque of a motor and an acoustic load according to an embodiment of the present invention.

Referring to FIG. 1 , a first application of a sound emitter 10 is shown, wherein the sound emitter is mounted on a vessel V . The sound emitter 10 is arranged to generate a sound, for example, as a warning or a signal notifying an intended action in case of bad weather. Preferably, the sound emitter 10 is positioned relatively high on the vessel V so as to radiate the sound as far as possible.

2 is a perspective view of a sound generator 10 comprising a hollow horn 20 , ie a resonant horn and a sound wave generator 30 . The sound wave generator 30 is described in more detail in FIGS. 3 and 4 . The horn 20 is rigidly coupled to the sound wave generator and is arranged to produce a desired sound when receiving a sound wave from the sound wave generator 30 capable of propagating in the horn 20 . The horn 20 has two or more acoustic purposes to generate a load on the sound wave generator 30 and match the acoustic impedance of the sound wave generator 30 to that of air. The maximum load on the sound wave generator 30 occurs at the resonance frequency of the horn 20, and the greater the resonance, the greater the load. Impedance matching determines the sound pressure level and spectrum. Accordingly, the size and shape of the horn may be different depending on the purpose and location of the sound emitter 10 .

3 shows a cross section of a sound generator 10 with a horn 20 and a sound wave generator 30 . The sound wave generator 30 and its components are shown in more detail in FIG. 4 .

The sound wave generator 30 is a motor 31 , preferably three-phase, with a stator 32 , a rotor 33 , two motor bearings 34a , 34b and a rotating shaft 35 , also referred to as an engine shaft. Includes an induction motor. In addition, the rotating shaft 35 includes a driving unit 36 eccentric with respect to the rotating shaft 35 . The rotating shaft 35 and the driving unit 36 rotate about the central axis A as the motor 31 operates. In an alternative embodiment (not shown), the rotating shaft and the drive may be two separate parts mounted to each other.

A bearing 37 is mounted on a drive 36 and follows the drive 36 as it rotates about the axis A and allows the drive 36 to rotate within the bearing 37 . Said baileung 37 and at least partially driving part 36 are arranged in a hollow casing 38 comprising a container part 39 , a cover 40 and a lubricant (not shown), wherein the container part 39 and The cover 40 is connected to each other by screws 41a and 41b. The bearing 37 is attached to the container portion 39 of the casing 38 so that the axle 36 can rotate within the casing 38 about the axis A. This is possible because, together with the drive part 36 and the bearing 37 , the casing 38 is arranged in the chamber 42 of the sound wave generator 30 . Since the bearing 37 is mounted eccentrically on the axis 36 , the casing 38 moves along a circular path when viewed in the direction of the arrow B. The chamber 42 is surrounded by a housing 43 which also surrounds the entire sound wave generator 30 .

A sonic element 44 is connected to the outside of the casing 38 by a first end portion 46 thereof. The sonic element 44 includes a piston rod 45, and a piston 47, which are preferably manufactured in one piece, although the two parts may be separable from each other in an alternative embodiment (not shown). The sonic element 44 preferably has a partially varying circular cross-section and extends away from the casing 38 , perpendicular to the extension of the axis of rotation 35 and the drive 36 . Preferably, the piston 47 has a changing cross-section, a frusto-conical shape that increases with distance from the piston rod 45, whereas the piston rod 45 is elongate with a circular or other shape, cross-section that does not change. . The sonic element 44 is hollow between the closed first end portion 46 and the closed second end portion 48 to keep the weight of the sonic element 44 as low as possible. The sonic element 44 can be open but has a closed end 48 for greater acoustic efficiency.

As the sonic element 44 is attached to the casing 38 , the sonic element follows the motion of the casing resulting in the creation of a reciprocating motion of the sonic element 44 . As the sonic element 44 moves back and forth within the chamber 42 , the sonic element creates a sonic, i.e., air pressure change, which propagates and travels into the horn 20 to produce the desired sound. .

The chamber 42 may be configured in an alternative embodiment (not shown) to allow the sonic element to move even slightly laterally and avoid possible friction wear.

By having a direct drive between the motor 31 and the rest of the sound generator 30 , i.e. no gears or meshing wheels, the sound emitter 10 operates more reliably and has fewer components and less complex manufacturing processes. made cheaper by

In order to obtain the correct frequency of rotation of the rotating shaft 35, the motor 31 is connected to a frequency converter 50 which can be connected to any available electrical outlet and is schematically shown in FIGS. 3 and 4 . do. The frequency converter 50 converts the voltage from the electrical source to a desired frequency, for example 130 Hz, and supplies this frequency to the three-phase connection of the motor 31 . Standard induction motors have a Y-connection and are designed for standard voltages (3x380V/50Hz or 3x440V/60Hz). When the standard voltage is supplied as a three-phase voltage, 130 Hz, it will not develop to full torque. However, by having a delta-connection in the standard induction motor 31 , it is possible to operate the rotating shaft 35 with the same frequency that is supplied into the motor 31 and develops with maximum torque. In the embodiment described, 130 Hz is a preferred value of the frequency as this results in the best possible sound by this particular design of the horn. It is also advantageously economical, since expensive special motors do not need to be used. In other embodiments, different designs may require different frequencies.

An advantageous feature of the sound generator 10 described above is that it is adjustable to different types and types of horn 20 , by changing the frequency from the frequency converter 50 into the motor 31 . The horns with the described sound generator 10, in which horns of different sizes and shapes have different resonant frequencies and only generate frequencies into the motor 31, have adapters for specific features of the horns 20 to achieve different frequencies. It is known to have. This means that the components within the sound generator 10 do not change to be able to change between different frequencies.

The sound generated by the sound emitter 10 depends on the torque of the motor 31 , the rotational speed of the motor 31 and the ambient air temperature. A problem with sound emitters known today is that they are sensitive to changes in ambient air temperature, in particular to temperature drops. Usually expensive and/or unreliable equipment must be used to regulate the ambient air temperature.

5A and 5B show the torque (vertical axis) of the motor of each sound emitter 10 of the prior art sound emitter according to an embodiment of the present invention, the operating speed of the motor 31, that is, the motor 31 ) shows a graph of how it changes with the frequency (horizontal axis). The torque corresponds to a sound level where the desired sound level is between the values y1 and y2. The diagram shows the values of the motor torque curve (A') versus the operating speed, and three acoustic load curves (B', C, D'), all three acoustic load curves at a given point (b', c). ', d'), the motor torque curve (A') is distinguished. The acoustic load is dependent on the ambient air temperature and curves B', C, D' are such that at some point between the values y1 and y2 the motor torque curve A' is should be distinguished The three acoustic load curves (B', C, D') illustrate three different temperature states, eg B'=-20°, C'=0°, D'=±20°.

5A, which is shown in the prior art, it is clearly shown how difficult it is to achieve the correct sound level when the air temperature changes, especially when the air temperature drops to a lower value. One curve B' will never separate the motor torque curve A' at the desired point and thus will never produce the desired sound in the horn.

5B illustrates an overview of a motor torque curve A" according to an embodiment of the present invention and illustrates the same acoustic load curves B", C", D" as in FIG. 5A. The motor torque curve A" is in this case flattened and controlled so that the desired sound level is such that the air temperature surrounds the sound generator, ie all three cut-off points b", c", d" are all within y1 and y2. achieved irrespective of whether This is achieved by using a frequency converter to provide voltage and power to the motor, which in turn allows the user to control the frequency provided to the rotating shaft and thereby control the motor torque curve A'. The motor torque curve A' shown in FIG. 5B may appear to be essentially straight, but the example is only relevant to using the range of interest.

The components of the sound emitter may preferably be made of an anticorrosive material to withstand all types of environments.

Although various features and advantages of the present invention, together with details of structure and function thereof, are set forth in the foregoing description, the foregoing description is illustrative only and, in particular, variations in shape, size and arrangement of parts are governed by the appended claims. It should be acknowledged that the indicated detail can be made to a sufficient degree.

Claims (11)

A sound wave generator for a sound emitter (10), comprising:
an electric motor (31) having a rotating shaft (35), the rotating shaft (35) being directly connected to a drive (36) arranged eccentric with respect to the rotating shaft (35);
comprising a sonic element (44) connected to the drive (36) and extending in a direction perpendicular to the drive (36),
the sonic element (44) is configured to perform a reciprocating motion when the drive (36) rotates about the axis of rotation (35);
The electric motor 31 is connected to a frequency converter 50 for providing a desired frequency to the rotation shaft 35 , and the frequency converter 50 has a torque curve with respect to the rotation speed of the electric motor 31 . providing the frequency to be straight and horizontal,
Sound generator for sound emitter. The method of claim 1,
The sonic element 44 is connected to the drive unit 36 by an end portion 46 , which causes a circular motion as the drive unit 36 rotates about the axis of rotation 35 . configured to perform,
Sound generator for sound emitter. The method of claim 1,
the sonic element (44) is arranged in a chamber (42), in which the sonic element (44) is reciprocally and laterally movable;
Sound generator for sound emitter. The method of claim 1,
further comprising a bearing (37), said bearing being arranged at least partially around said drive (36) to allow said drive (36) to rotate within said bearing (37), said bearing being said sonic element ( 44) connected to,
Sound generator for sound emitter. 5. The method of claim 4,
further comprising a casing (38), said casing receiving said bearing (37) and at least partially said drive (36) and at the same time being connected to said sonic element (44);
Sound generator for sound emitter. The method of claim 1,
the sonic element (44) comprises a hollow element (44), the hollow element (44) comprising a piston rod (45) and a piston (47);
Sound generator for sound emitter. 7. The method of claim 6,
wherein the piston rod (45) is elongate and has a circular or elliptical cross-section, the piston (47) is frusto-conical and the piston (47) has a widest end surface spaced from the piston rod (45);
Sound generator for sound emitter. The method of claim 1,
The electric motor (31) is an induction motor with a three-phase delta connection (three-phase delta connection),
Sound generator for sound emitter. As a sound emitter,
resonant horn 20, and
9. A sound wave generator (30) according to any one of claims 1 to 8, comprising:
wherein the sound wave generator (30) is configured to deliver air pressure pulses into the resonant horn (20) to generate sound.
sound emitter. 10. The method of claim 9,
the end portion 22 of the resonant horn 20 facing the ambient air has a rectangular cross-section,
sound emitter. delete

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