JPS6217732Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a transducer having a gimbal mechanism used in sounding work.

Conventionally, when measuring the depth of a harbor, etc., the method shown in Figure 1 was used. In the figure, 1 is a ship conventionally used for sounding work, 2 is an ultrasonic transducer, and the outer periphery of the vibrator 3 is watertightly molded with a molding material 4 whose acoustic impedance is close to that of water, such as urethane rubber. This is what I did. To measure depth, the transducer 2 is fixed to the side of the ship 1, etc., in the water near the water surface with its direction toward the bottom, and the transducer 2 transmits and receives ultrasonic signals, from wave transmission to wave reception. The water depth is measured based on the time. When the transducer 2 is fixed to the side of the ship 1 in this way, the rolling of the ship 1 or the like causes the transducer 2 to move as shown in FIG.
Since the wave transmission direction is oblique, high sounding accuracy cannot be obtained, and sounding work is impossible on rough seas.

The present invention eliminates these drawbacks by supporting the transducer with a gimbal, and will be described in detail below.

FIG. 2 is a partially cutaway sectional view showing an embodiment of the present invention, in which a shows a normal state and b shows a rolling state. In the figure, 2 is a transducer with a molded vibrator as described above, and 5 is this transducer 2.
The gimbal that supports the 6
A case with a watertight structure closed with a bottom case 7 made of the same material as the molding material, 8 is oil filled inside the case, 9 is an air chamber for pressure adjustment,
10 is a very flexible signal line.

FIG. 3 is a diagram showing the detailed structure of the gimbal 5, in which a ring 11 is rotatably supported by a fulcrum 12 attached to the inner wall of the case 6;
3 is a cylinder rotatably supported by a fulcrum 14 attached to this ring 11; 15 is a mounting portion for the transducer 2; FIG. 4 is a diagram showing the detailed structure of the air chamber 9.
It has a pressure receiving plate 18 that is airtight with a ring 17, and this movable plate is moved by external pressure.

The transducer 2 is supported in the case 6 by a gimbal 5 having the above-described structure so that it can swing freely in both the X and Y directions, regardless of the direction of the case 6 due to the action of gravity. It looks like it's facing straight down. Therefore, as the signal line 10, an extremely flexible material such as a spiral cord is used so as not to adversely affect the operation of the gimbal 5. Inside this case 6 is oil 8 as mentioned above.
This is to prevent the function of the gimbal 5 from being inhibited by rust caused by exposure to seawater. Therefore, the density of the filled oil 8 is made close to the density of the water, seawater, etc. to be surveyed, and the acoustic impedance is matched so that there is no difference in the sound wave propagation speed. Here, this oil 8 also functions as a damper for the transducer 2. In addition, the bottom case 7 that closes the bottom of the case 6 is also made of the same material as the molding material of the transducer of the transducer 2, as described above, so that there is no change in the sound wave propagation velocity in this part as well. I'm trying to prevent it from happening. moreover,
The case 6 is provided with the above-mentioned air chamber in its upper part, and the thermal expansion of the oil 8 due to temperature changes is absorbed by the movement of the pressure receiving plate 18. That is, when the pressure corresponding to the thermal expansion of the oil 8 is applied to the pressure receiving plate 18, the pressure receiving plate 18 moves inside the outer casing 16, which is made airtight by the O-ring 17, and absorbs the pressure. This makes it possible to create an easy-to-handle transducer that can be placed anywhere, such as outdoors or underwater.

As described above, if the transducer with the gimbal mechanism of the present invention is used, even if the case 6 is fixed to the side of the ship 1, the case 6 will be damaged by the rolling of the ship 1, etc., as shown in FIG. 2b. Regardless of which direction it is facing, the transducer/receiver 2 is always facing straight down, so the wave transmission direction will never be diagonal. Therefore, the accuracy of sounding is extremely high, and sounding work can be carried out even on rough seas.

Here, the transducer having the gimbal mechanism configured in this manner has the natural frequency of the system itself sufficiently higher than the oscillation period of the ship 1, and the center of gravity relationship between the gimbal 5 and the transducer 2 is set appropriately. It goes without saying that consideration must be given to avoid resonance with the hull motion of the vessel 1 when selecting the appropriate one.

Furthermore, by stacking an accelerometer on the transducer and integrating the obtained data twice, it is also possible to measure the displacement of the oscillation.

[Brief explanation of the drawing]

Figure 1 is a diagram for explaining the conventional sounding method.
FIG. 2 is a partially cutaway sectional view showing an embodiment of the present invention, FIG. 3 is a view showing an example of a gimbal used therein, and FIG. 4 is a view showing an example of an air chamber. 1... ship, 2... transducer, 5... gimbal, 6... case, 7... bottom case, 8... oil, 9... air chamber.

Claims (1)

[Scope of utility model registration request] A transducer that is housed in a case and transmits and receives ultrasonic signals;
A gimbal that supports the gimbal so that it can swing freely in both Y directions, a bottom case that is made of a material whose acoustic impedance is close to that of water and that closes the bottom of the case, and an airtight system that is installed inside the case and moves between the outer casing and the inside thereof. A transducer having a gimbal mechanism including an air chamber consisting of a pressure receiving plate and a case filled with oil.