JPH0650774Y2 - Underwater accelerometer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to the structure of an underwater accelerometer, particularly an underwater accelerometer for measuring the acceleration of an underwater structure such as a ship.

[Prior Art] FIG. 4 is a sectional view showing a conventional underwater accelerometer. In the figure, 1 is a cylindrical metal case with a bottom, 1a is a screw groove provided on the inner peripheral surface of the opening of the metal case 1, and 2 is a disk-shaped electrode arranged on the bottom of the metal case 1, the periphery of which is It has a step portion 2a on the inner surface of the portion. 3 has one surface as a plus pole surface 3a
, And a ring-shaped disc-shaped piezoelectric electron with the other surface being the negative pole surface 3b.
The positive electrode 3a sandwiches the peripheral portion of the electrode 2 disposed inside from both sides thereof. At this time, two piezoelectric electrons 3,3
Is positioned by the stepped portion 2a of the electrode 2, and the stepped portion of the stepped portion 2a is smaller than the thickness of the piezoelectric electron 3. Therefore, the negative pole surface 3b of the piezoelectric electron 3 located below the electrode 2 becomes Are in contact. Reference numeral 4 denotes a cylindrical additional mass member arranged on the negative pole surface 3b of the upper piezoelectric electron 3 which does not come into contact with the case bottom inner surface 1b in the metal case 1, and has a fitting convex portion at the upper end.
Have 4a. Reference numeral 5 denotes a disk-shaped cover pressing screw that closes the opening of the metal case 1, and has a fitting recess 5a on the inner surface of the central portion. When the lid holding screw 5 is screwed into the thread groove 1a of the metal case 1, the fitting convex portion 5a of the lid holding screw 5 and the fitting convex portion 4a of the additional mass member 4 are fitted to each other, and the additional mass member 4 Through
Electrode 2 and two piezoelectrics 3,3 sandwiching the electrode 2
Are fixed in the metal case 1 under a predetermined pressing force. 6 is a cable penetrating the cap screw 5 and 7
Is two lead wires of the cable 6, one lead wire 7 is connected to the electrode 2 through the inside of the mass addition member 4, and the other lead wire 7 is connected to the fitting recess 5a of the lid holding screw 5. There is.

Here, regarding the wiring system path between the piezoelectric electrons 3 and the lead wire 7, the positive pole surface 3a of the two piezoelectric electrons 3, 3 is changed from the electrode 2 sandwiched by these piezoelectric electrons 3 to one lead wire 7. One of the negative poles of the two piezoelectric electrons 3,3 comes into conduction, and one of the negative poles of the two piezoelectric electrons 3,3 comes into conduction with the lid holding screw 5 through the metal case 1 from the inner surface 1b of the case bottom portion. Through the additional mass member 4 which is in contact with this, it is conducted to the lid pressing screw 5. Therefore, the two piezoelectrics 3,3
The acceleration detection signal detected by the
It is transmitted to 7 and 7, respectively.

Reference numeral 8 is a waterproof molding material for molding the opening portion of the metal case 1 and the cable 6.

[Problems to be Solved by the Invention] However, in the underwater accelerometer configured as described above, of the two piezoelectric electrons 3, 3 arranged and fixed in the metal case 1, the negative electrode of one of the piezoelectric electrons 3 is the metal case 1. Since it is connected to the lead wire 7 of the cable 6 through the electric cable, electric noise is transmitted to the lead wire 7 when it is used in water, and electrical noise is transmitted to the lead wire 7. Therefore, accurate acceleration cannot be detected.

In addition, in order to make the metal case 1 as small as possible in terms of performance, the piezoelectric element 3,
It is difficult and time-consuming to assemble the electrode 2 and the additional mass member 4 in order, and pay attention to the displacement of these parts, and press and fix the piezoelectric electron 3 and the electrode 2 with the lid pressing screw 5 through the additional mass member 4. When it is applied and is pressed and fixed,
There is also a problem that the piezoelectric element 3 is cracked.

Among the problems that the above-mentioned conventional technology has, the present invention is
The present invention provides an underwater accelerometer that solves the problems of picking up electrical noise and difficulty in assembly.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention relates to an underwater accelerometer, which is an eyeglass including a conductive foil plated with solder on the surface of a thin film having flexibility and insulation. One of the sheet-shaped wiring sheets is interposed between the bottom of the case and the piezoelectric material so that the conductive foil comes into contact with the piezoelectric electrons, and the other of the wiring sheets is added so that the conductive foil comes into contact with the piezoelectric electrons. And one of the lead wires of the cable is connected to the electrode inside the case, and the other of the lead wires is connected to the conductive foil of the wiring sheet.

[Operation] According to the present invention, since the underwater accelerometer is configured as described above, the two ring-shaped disc-shaped piezoelectric electrons sandwiching the peripheral portion of the disc-shaped electrode have positive electrodes thereof. The surface is in contact with the electrode, and the surface of the negative electrode is sandwiched between the two piezoelectric electrons in a bent state and is provided on one surface of a spectacle-shaped wiring sheet made of a thin film having flexibility and insulation. The lead wires of the cable are connected to the electrodes and the conductive foil of the wiring sheet, respectively, and the lead wires of the cable are insulated from the metal case 1. Therefore, the lead wire of the cable does not pick up the electrical noise that is carried on the metal case.

In addition, since the conductive foil provided on one surface of the wiring sheet is solder-plated, it is necessary to sandwich the peripheral edge of the electrode before accommodating the piezoelectric and electrodes in the metal case. Solder the wiring sheet against the piezoelectric electrons, and assemble the electrodes, piezoelectric electrons, and wiring sheet together in advance.
The assembled product is stored in a metal case.
Therefore, when assembling, it is not necessary to consider the misalignment between the parts, the assembling work is simplified, and the misalignment between the parts is reduced.

[Embodiment] FIG. 1 is a sectional view showing an embodiment of the present invention, FIG. 2 is a plan view showing a state where a wiring sheet is developed, and FIG. 3 is a front view showing a state where the wiring sheet is bent. is there. In the figure,
The same components as those of the conventional example are designated by the same reference numerals, and the description of the duplicated configuration will be omitted. 10 is a wiring sheet, thickness 0.025mm
A polyimide film, which is a thin film having a degree of flexibility and insulation, is formed in the shape of glasses including two circular portions 11 and 11 and a connecting portion 12, and these circular portions 11 and the connecting portion 12 are formed.
A copper foil 13 is provided on one surface of the two circular parts 11, 11
It is formed by applying solder plating with a thickness of about 0.035 mm on the surface of. Reference numeral 14 is a cut-and-raised piece for connection provided in the center of one circular portion 11.

Next, the assembly of the underwater accelerometer of this invention will be described.

First, outside the metal case 1, the peripheral edge of the disk-shaped electrode 2 is sandwiched with two piezoelectric electrons 3, 3 from both sides thereof. At this time,
The positive pole surfaces 3a of the two piezoelectrics 3,3 are in contact with both sides of the peripheral edge of the electrode 2 and are positioned by the step 2a of the peripheral edge, and the two piezoelectrics 3,3 and the electrode 2 are momentarily bonded. It is temporarily fixed with a drug.

Next, two piezoelectric electrons 3, which sandwich the peripheral edge of the electrode 2,
Attach wiring sheet 10 to 3. Assembling is performed by bringing the negative electrode surface 3b of the two piezoelectric elements 3 and 3 into contact with the solder-plated copper foil 13 of the two circular portions 11 and 11 of the wiring sheet 10 which is folded in two. The two piezoelectric elements 3, 3 and the wiring sheet 10 are integrally assembled and heated at about 200 ° C. By such heating, the negative electrode surface 3b of the piezoelectric element 3 and the copper foil 13 of the wiring sheet 10 are joined, and the electrode 2, the two piezoelectric elements 3, 3 and the wiring sheet 10 are integrally assembled.

The cable 6 is attached to the copper foil 13 of the cut-and-raised piece 14 for connection of the circular portion 11 of the electrode 2 and the wiring sheet 10 which are integrally assembled in this way.
The lead wires 7 are connected and housed inside the metal case 1. The cylindrical additional mass member 4 having the cable 6 inserted therein is installed on the circular portion 11 of the wiring sheet 10 which is joined to the piezoelectric 3 located on the opening side in the metal case 1, and the cable 6 is further inserted. Attach the lid holding screw 5 to the metal case 1
The opening of the metal case 1 is closed with the lid holding screw 5 by being screwed into the thread groove 1a on the inner peripheral surface of the opening. At this time, the fitting concave portion 5a of the lid pressing screw 5 fits with the fitting convex portion 4a of the additional mass member 4, and the electrodes 2 in the metal case 1 and the two piezoelectric electrons 3, which sandwich the electrode 2, 3 is fixed by receiving a predetermined pressing force through the additional mass member 4 by the lid pressing screw 5. As described above, when assembling the underwater accelerometer, the one in which the electrode 2, the two piezoelectric electrons 3, 3 and the wiring torch 10 are integrally assembled is housed in the metal case 1, and the lid is pressed through the additional mass member 4. The electrode 5 and the piezoelectric element 3 in the metal case 1 are fixed by the screw 5.
Since the parts are fixed, there is no need to consider the misalignment between the parts, which facilitates the assembly work. In addition, since there is no deviation between each component, the piezoelectric
There is no longer a risk that the 3 will break.

Finally, the opening part of the metal case 1 and the cable 6 are molded with the waterproof molding material 8 to complete the assembly.

Here, regarding the wiring system path between the piezoelectric electrons 3 and the lead wire 7, the positive pole surface 3a of the two piezoelectric electrons 3, 3 conducts from the electrode 2 sandwiched by these piezoelectric electrons 3 to one lead wire 7. As a result, the negative pole surface 3b of the two piezoelectric electrons 3,3 is electrically connected to the other lead wire 7 via the wiring sheet 10 having the copper foil 14 in contact with the piezoelectric case 3 and the metal case 1. Since it is insulated, even if the metal case 1 picks up electrical noise during use in water, the electrical noise will not be picked up by the lead wire 7, and accurate acceleration can be detected.

Further, one piezoelectric element 3 is in contact with the inner surface 1b of the case bottom through the wiring sheet 10, but the thickness of the entire wiring sheet 10 is about
Since it is very thin at 0.06mm, there is no problem in terms of performance.

[Effects of the Invention] As described in detail above, according to the present invention, two ring-shaped disk-shaped piezoelectric electrons sandwiching the peripheral edge of the disk-shaped electrode have their positive pole surfaces as electrodes. The surface of the negative pole is in contact with and the two piezoelectric electrons are sandwiched in a bent state. Solder plating provided on one surface of a spectacle-shaped wiring sheet made of a thin film having flexibility and insulation. Since the cable lead wire is connected to this electrode and the conductive foil of the wiring sheet to insulate it from the metal case, the cable lead wire should be attached to the metal case when used in water. It is possible to expect the effect of being able to detect accurate acceleration without picking up the electric noise that has been riding.

Furthermore, the conductive foil provided on one surface of the wiring sheet is solder-plated, and the wiring sheet is soldered to the two piezoelectric electrons that have previously sandwiched the peripheral edge of the electrode. , The two piezoelectric and wiring sheets are assembled together, and they are housed in a metal case to assemble the underwater accelerometer, so there is no need to consider misalignment between the parts, and the assembly work is easy. Moreover, the deviation and the like are reduced, and the effect of preventing the breakage of piezoelectric electrons caused by the deviation and the like can be expected.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, FIG. 2 is a plan view showing a state in which a wiring sheet is developed, FIG. 3 is a front view showing a state in which the wiring sheet is bent, and FIG. It is sectional drawing which shows the conventional underwater accelerometer. 1 ... Metal case, 1a ... Thread groove, 2 ... Electrode, 2a ... Step, 3
… Piezoelectric, 3a… Positive pole surface, 3b… Negative pole surface, 4… Additional mass member, 5… Lid cap screw, 6… Cable, 7… Lead wire, 10… Wiring sheet, 13… Copper foil (conductive foil) .

Claims (1)

[Scope of utility model registration request] 1. A bottomed cylindrical metal case having a thread groove on the inner peripheral surface of the opening, a disk-shaped electrode having step portions on both sides of the peripheral edge, and a peripheral surface of the electrode having the same polarity from both sides thereof. And the ring-shaped piezoelectric electrons, which are positioned inside the metal case in contact with the inner surface of the bottom of the case, and are positioned by the step of the peripheral edge. The cylindrical mass addition member that is placed on the other piezoelectric element that does not come into contact with the inner surface of the bottom of the case is fitted with the free end of the mass addition member at the inner surface of the central part, and is screwed into the thread groove of the metal case. A submersible accelerometer comprising a combined cap holding screw and a cable penetrating the cap pressing screw and having lead wires respectively connected to two polarities of two piezoelectric electrons in a metal case. Solder on the surface of the insulating thin film One of the eyeglass-shaped wiring sheets provided with the conductive foil is placed between the bottom of the case and the piezoelectric electrons so that the conductive foil comes into contact with the piezoelectric electrons, and the other of the wiring sheets is electrically conductive. It is interposed between the additional mass member and the piezoelectric material so that the foil contacts the piezoelectric material, one of the cable lead wires is connected to the electrode inside the case, and the other of the lead wire is connected to the conductive foil of the wiring sheet. Underwater accelerometer characterized by doing