JPH052873Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a transducer mounted on the head of an underwater vehicle.

[Conventional technology]

As a conventional underwater vehicle transducer, the third,
There are devices like those shown in Figures 4 and 6. First, as shown in Figure 3, the head of the underwater vehicle T has a transmitter and receiver that emits and senses sound waves to detect underwater targets. Wave device N is attached.

This transducer N is shown in Fig. 4 or 6.
As shown in the figure, a transducer P' for transmitting and receiving waves is provided, and the transducer P' is laminated between a front mass member 10 and a rear mass member 12 for adjusting the natural frequency of longitudinal vibration. A piezoelectric element 11 is interposed therebetween. Note that the vibrator P' includes both the front mass member 10 and the rear mass member 12.

The acoustic rubber 1 is bonded to the front surface of the transducer P', and transmits the water pressure generated by the propulsion of the underwater vehicle T and depth pressure to the highly rigid back plate 4 via the grid plate 3. This prevents the acoustic rubber 1 from being excessively deformed.

The grid plates 3 are layered, and in addition to the gaps between the grid plates 3, the gaps with the head shell 5' of the underwater vehicle T and the gaps with the vibrator P' are filled with cork rubber, etc. A pad 9 is inserted for vibration prevention.

The back plate 4 is connected to the head shell 5' by bolts 6, and has a wiring hole 8 so that a lead wire 7 connected to the vibrator P' passes through the back plate 4.

The lead wire 7 is connected to a rear control section (not shown).

Since the transducers of conventional underwater vehicles are configured as described above, the sound waves propagating underwater are
The acoustic rubber 1 and the vibrator P' are vibrated.

Distortion caused by the vibration of the vibrator P' is detected as an electrical signal and transmitted to the rear control section via the lead wire 7.

This vibrator P' utilizes the piezo effect of the piezoelectric element 11, and is used for both transmission and reception, and a plurality of vibrators are provided so that the target object can be detected using each transmitted and received signal.

The vertical natural vibration mode of the vibrator P', which is used for signal transmission and reception, is as shown in Figure 5, and the amplitude is large at the front and rear ends of the vibrator P', and the antinodes of the vibration are large. However, vibration nodes are formed near the center.

The vibration of the vibrator P' is restrained by the pad 9 at the rear end (restriction point C') of the front mass member 10. Here, the restraint point C' is the front mass member 1
0 and the grid plate 3; when depth pressure acts on the acoustic rubber surface, the front mass member 10 moves through the pad 9 to the grid plate 3.
The longitudinal vibration of the vibrator P' is restrained at this point.

[Problem that the invention attempts to solve]

However, in the conventional transducer for an underwater vehicle, when high external water pressure acts on the outer surface of the acoustic rubber 1, the front mass member 10 of the vibrator P' is transferred to the grid plate 3 via the pad 9 to a restraining point. Since it is strongly pressed down by C′, the longitudinal vibration of the vibrator P′ is restrained,
There is a problem in that the natural frequency of longitudinal vibration changes or the amplitude is limited, impairing the function of the transducer.

In addition, vibrations caused by the propulsion device provided in the underwater vehicle T are caused by the head shell 5', the back plate 4,
It is transmitted to the oscillator P' through the grid plate 3 and the constraint point C', but since the constraint point C' is at a position where the amplitude of the longitudinal natural vibration mode 15 of the oscillator P' is large, the propulsion device The vibrator is damaged by disturbance vibration such as
There is a problem in that the longitudinal vibration of P' is excited, and this also impairs the original function of the transducer.

The present invention aims to solve these problems by preventing the longitudinal vibration of the vibrator from being excited by external vibrations, while also preventing depth pressure and shock pressure upon landing from affecting the piezoelectric element. An object of the present invention is to provide a transducer for an underwater vehicle that does not cause any interference.

[Means for solving problems]

Therefore, the transducer for the underwater vehicle of the present invention is
A hole opening forward is formed in the outer shell of the head of the underwater vehicle, and a vibrator is provided inside the hole, and the vibrator is attached to the inner circumference at the front end of the hole. A front mass member whose parts are held through an O-ring, a metal member whose front end is attached to the rear end of the front mass member, and a metal member whose front end is attached to the rear end of the metal member and whose outer peripheral portion is inserted into the hole. The front mass is composed of a central support member fixed to the periphery, a piezoelectric element whose front end is attached to the rear end of the central support member, and a rear mass member attached to the rear end of the piezoelectric element. The feature is that the front side of the member is placed in contact with the outside water.

[Effect]

In the above-mentioned transducer for an underwater vehicle according to the present invention, since the position of the node of the longitudinal vibration mode of the transducer is held in the outer shell by the central support member, the vertical vibration of the transducer is No vibrations are excited.

Furthermore, even if the hydrostatic pressure of an external fluid or impact pressure upon water landing is applied, these hydrostatic pressures and impact pressures will only be applied to the front mass member, the central support member, and the metal members interposed between these members. It has no effect and thus has no effect on the piezoelectric element interposed between the central support member and the rear mass member.

〔Example〕

Below, a transducer for an underwater vehicle as an embodiment of the present invention will be explained with reference to the drawings. FIG. 1 is a longitudinal cross-sectional view thereof, FIG. In Figures 1 and 2, the same reference numerals as in Figures 4, 5, and 6 indicate substantially similar parts.

As shown in FIG. 1, the head shell 5 of the underwater vehicle
A transducer P for transmitting and receiving waves is provided inside a hole 17 formed to open forward. , a metal member 16 interposed between the front mass member 10 and the central support member 13
A piezoelectric element 11 is interposed between a central support member 13 and a rear mass member 12. That is, the front end of the metal member 16 is attached to the rear end of the front mass member 10, and the metal member 16
The front end of the central support member 13 is attached to the rear end. The front end of the piezoelectric element 11 is attached to the rear end of the central support member 13, and the rear mass member 12 is attached to the rear end of the piezoelectric element 11.

Here, the front surface of the front mass member 10 is arranged so as to be in contact with the outside water, and the vibrator P has its approximately central portion connected to a central support member 13 having a threaded joint.
It is firmly held to the head shell 5 of the underwater vehicle via the head shell 5 of the underwater vehicle.

The reduced diameter portion of the hole 17 in the head shell 5 has a female threaded portion 1.
4 is formed, and the central support member 1 of the vibrator P
It is designed to be screwed together with 3.

Therefore, the depth pressure acting on the vibrator P and the impact pressure at the time of water landing are the front mass member 10, the metal member 16,
It is transmitted to the rigid head shell 5 via the central support member 13 .

Note that a watertight O-ring 18 is interposed between the front mass member 10 and the head shell 5. That is, the front mass member 10 is held at the inner circumference at the front end of the hole 17 via the O-ring 18 at the outer circumference.

Further, a lead wire 7 is provided from the rear of the vibrator P to connect the piezoelectric element 11 to a control section (not shown).

Since the transducer for the underwater vehicle as an embodiment of the present invention is configured as described above, when transmitting sound waves from this transducer, a transmission signal is input from the control section (not shown) through the lead wire 7. When it is done,
The piezoelectric element 11 expands and contracts via the rear mass member 12, and the longitudinal natural vibration of the vibrator P is excited.

Then, from the piezoelectric element 11 to the central support member 13,
Vibrations are transmitted to the metal member 16 and the front mass member 10, and sound waves are transmitted from the front surface of the front mass member 10 to the outside water in front of the underwater vehicle.

Also, when this transducer receives sound waves,
When the sound waves that have propagated through the open water in front of the underwater vehicle reach the head of the underwater vehicle, the vertical natural vibration of the transducer P is excited by exciting the transducer P from the front of the front mass member 10 of the transducer P. is excited. This natural vibration is sensed by the piezoelectric element 11 and inputted to a control section (not shown) through the lead wire 7.

In this way, the transducer of the underwater vehicle transmits and receives sound waves to detect underwater targets.

Further, this vertical natural vibration is transmitted to the head shell 5 via the front mass member 10, the metal member 16, and the central support member 13, but at this time, the central support member 13 This serves as a constraint point C (see FIG. 2) for the natural vibration in the direction, and holds the vibrator P firmly.

By the way, the vertical natural vibration mode 15 of the excited vibrator P has a node at its center, as shown in FIG. It's summery.

Therefore, since the node of the vertical natural vibration mode of the vibrator P coincides with the constraint point C in the head shell 5, the disturbance vibration transmitted from the constraint point C to the vibrator P is Do not excite natural vibration modes.

Further, since the depth pressure acting on the front surface of the front mass member 10 and the impact pressure at the time of water landing do not act on the piezoelectric element 11, damage to the piezoelectric element 11 and change in characteristics can be prevented.

The frequency of longitudinal vibration of the ultrasonic transducer P is 10K.
Hz or higher, the outer shell 5 does not appear to be a rigid body in this frequency range, and when a pressure wave is applied to the front mass member 10, an elastic stress wave is generated, which moves vertically inside the oscillator P. A portion of the vibration propagates in the direction, and a portion is reflected by the central support member 13, but most of it reaches the rear mass member 12 and is reflected, and then returns to the front mass member 10 and is reflected. This process is repeated, and the vibration A standing wave is formed within the child P. As a result, even if the vibrator P is fixed to the outer shell 5 at the central support member 13, the transmitting and receiving function of the vibrator P is not impaired.

In addition, the dimensions of the piezoelectric element 11 and the front and rear mass members 10 and 12 are adjusted so that a vibration node is formed at point C of the central support member 13 and the primary natural frequency of the vibrator P matches the target frequency. has been decided. This is based on a general resonator design method.

Note that the central support member 13 in the vibrator P is
The central support member 13 of the vibrator P may be fixed to the inner wall of the hole 17 of the underwater vehicle outer shell 5, either by fixing it with adhesive or by passing a locking pin through it. be done.

[Effects of the invention] As detailed above, according to the transducer for an underwater vehicle of the present invention, the hole 17 opening forward is formed in the head shell 5 of the underwater vehicle, and A vibrator P is provided inside the hole 17, and the vibrator P is connected to the front mass member 10 whose outer circumference is held at the inner circumference at the front end of the hole 17 via an O-ring 18. A metal member 16 whose front end is attached to the rear end of the front mass member 10, and a central support member 13 whose front end is attached to the rear end of the metal member 16 and whose outer circumference is fixed to the inner circumference of the hole 17.
, a piezoelectric element 11 whose front end is attached to the rear end of the central support member 13, and a rear mass member 12 attached to the rear end of the piezoelectric element 11, so that the front surface of the front mass member 10 is With a simple configuration in which it is placed in contact with outside water, the following effects and advantages can be obtained.

(1) Since the constraint point C is at the node of vibration mode 15, the longitudinal vibration of the vibrator P is not excited by disturbance vibration, and the function of the transducer is not impaired thereby.

(2) Since the depth pressure acting on the front surface of the front mass member 10 and the impact pressure at the time of water landing do not act on the piezoelectric element 11, damage to the piezoelectric element 11 and change in characteristics can be prevented.

[Brief explanation of drawings]

Figures 1 and 2 show a transducer for an underwater vehicle as an embodiment of the present invention. Figure 1 is a longitudinal cross-sectional view of the transducer, and Figure 2 is an explanatory diagram showing the characteristics of its oscillator. Figures 3 to 6 show a conventional transducer for an underwater vehicle. Figure 3 is a side view showing how it is attached to the head of an underwater vehicle, and Figure 4 is a longitudinal cross-section. figure,
FIG. 5 is an explanatory diagram showing the characteristics of the vibrator, and FIG. 6 is a longitudinal sectional view showing another example corresponding to FIG. 4. 5... Outer shell of head of underwater vehicle, 7... Lead wire, 10... Front mass member, 11... Piezoelectric element,
12... Rear mass member, 13... Central support member,
14... Female thread part, 15... Longitudinal natural vibration mode, 16... Metal member, 17... Hole, 18... O
Ring, C... restraint point, P... vibrator.

Claims (1)

[Scope of utility model registration request] Hole 1 opening forward in head shell 5 of underwater vehicle
7 is formed, and a vibrator P is provided inside this hole 17, and the vibrator P is held at its outer circumference at the inner circumference at the front end of the hole 17 via an O-ring 18. A front mass member 10, a metal member 16 whose front end is attached to the rear end of the front mass member 10, and a front end attached to the rear end of the metal member 16, and whose outer circumference is fixed to the inner circumference of the hole 17. the central support member 13 and the piezoelectric element 11 whose front end is attached to the rear end of the central support member 13.
and a rear mass member 12 attached to the rear end of the piezoelectric element 11.
1. A transducer for an underwater vehicle, characterized in that the front surface of the transducer is arranged so as to be in contact with open water.