JP3140582B2 - Pressure measuring device for continuous beams - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous beam pressure measuring device for measuring a pressure acting between arbitrary fulcrums of a structure including a continuous beam.

[0002]

2. Description of the Related Art A conventional continuous beam pressure measuring device comprises four strain sensors attached to both ends and a center portion of a continuous beam, sensors at both ends of the strain sensors, and sensors at a center portion. It has a Wheatstone bridge connected so as to form opposite sides, whereby it is possible to accurately measure the bending stress acting on the continuous beam without being affected by other strains.

FIGS. 8 and 9 show examples in which a conventional continuous beam pressure measuring device is applied to a hull structure. That is, the specific ribs 3, 3 of the longitudinal material 1 for reinforcing the double bottom inner bottom plate 2 of the hull.
In order to measure the distribution pressure during (interval L), four strain sensors A to D are attached to the face material 1a of the long material 1 which is a continuous beam. Strain sensors A and D are attached to both ends of the long material 1 near the rib 3, and strain sensors B and C are attached to the center of the long material 1,
As shown in FIG. 9, a Wheatstone bridge is configured such that the strain sensors A and D and the strain sensors B and C are on opposite sides, respectively. As a result, the influence of stress components other than bending stress is canceled out, and the distribution pressure in such a long material 1 can be measured (Japanese Patent Application Laid-Open No.
1-243335).

[0004]

However, in the conventional continuous beam pressure measuring device as described above, the length of the continuous beam is about 5 m when the wave fluctuating pressure is measured on a large ship. When four strain sensors are arranged in the longitudinal direction of the beam, the distance between the strain sensors becomes large, the cable becomes long, and separate waterproof protection is required for each strain sensor. There is a problem. The present invention seeks to solve such a problem. In this case, four strain sensors are centrally arranged at the center of the continuous beam, and the measurement system is reduced in size to reduce cost and improve reliability. It is an object of the present invention to provide a continuous beam pressure measuring device that can be used.

[0005]

In order to achieve the above-mentioned object, a continuous beam pressure measuring apparatus according to the present invention measures the pressure acting on a continuous beam in a structure including the continuous beam. And four Wheatstone bridges connecting the strain sensors to each other. The four strain sensors form two pairs of groups, and each pair of strain sensors has sensor it is disposed in the vicinity of and the transverse line symmetrically about a transverse line passing through the central portion of the continuous beam to each other. The pressure measuring device for a continuous beam according to the present invention is characterized in that the strain sensors of the pair of groups are arranged apart from each other in the depth direction of the continuous beam so as to sandwich the neutral axis of the continuous beam. Features. Further , the pressure measuring device for a continuous beam according to the present invention includes
The strain sensors of the paired groups are arranged so as to overlap with each other on the face material of the continuous beam.

[0006]

According to the pressure measuring device for a continuous beam of the present invention described above, 4
Strain sensors form two pairs of groups, each pair of strain sensors being affixed symmetrically with respect to a transverse line passing through the center of the continuous beam and in the vicinity of the transverse line. Since the sensors constitute a Wheatstone bridge so that the sensors symmetrical with respect to the above traverse line are opposite sides of the strain sensor, only the pressure acting on the continuous beam with the effect of the fluctuation strain cancelled The detection is performed as an output signal corresponding to the sum of the stresses.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIGS. 1 to 3 show a pressure measuring device for a continuous beam as a first embodiment of the present invention, and FIG. FIG. 2 is a cross-sectional view of the continuous beam portion, FIG. 3 is a distribution diagram of stress acting on the beam of FIG. 2, and FIGS. 4 to 7 are continuous diagrams as a second embodiment of the present invention. FIG. 4 shows a configuration of a continuous beam in the hull double bottom, FIG. 5 shows a cross-sectional view of the continuous beam, and FIG. 6 shows the stress acting on the beam shown in FIG. FIG. 7 is an enlarged view of a main part of FIG.

As shown in FIGS. 1 and 2, in the first embodiment of the present invention, the continuous beam pressure measuring device of the present invention is sandwiched between rib plates 3 for reinforcing the inner bottom plate 2 of the hull double bottom. This is an example applied to a long material 1. In the first embodiment, four strain sensors A, B, and 4 are attached to the long material 1 as a continuous beam.
C and D are divided into two pairs of strain sensors A and B and strain sensors D and C. Each pair of strain sensors A and B and strain sensors D and C It is arranged symmetrically with respect to the transverse line passing through the central portion and in the vicinity of the transverse line. Each of the strain sensors A and B or D and C of each pair of groups are arranged so as to be separated from each other in the depth direction of the long material 1 so as to sandwich the neutral axis na of the long material 1.

Further, each of the strain sensors is, as in the prior art, symmetrical with respect to the above-mentioned transverse line, that is, A and D.
And a Wheatstone bridge such that B and C are on opposite sides, respectively (see FIG. 9). A power supply (not shown) is connected to the input terminal (see FIG. 9) of the bridge configured as described above, and a voltmeter (not shown) is connected to the output terminal.

Since the continuous beam pressure measuring device according to the first embodiment of the present invention has the above-described configuration, the following operational effects can be obtained. First, as shown in FIG. 3, the bending stresses detected by the four strain sensors A to D are the stresses σ _A and σ _D in the sensors A to _D , and the stresses σ _B and σ _{C in the} sensors B and _C. Is detected. And, since each strain sensor constitutes a Wheatstone bridge such that A and D and B and C form opposite sides, each sensor A, B, C,
Let the output voltages at both ends of D be e _A , e _B , e _C , and e _D, and let the voltages due to only the distributed pressure acting on the continuous beam (longitude material 1) originally desired to be detected be e _A ', e _B ', e, respectively. _{Assuming that C} ′ and e _D ■, the output due to the fluctuation distortion is e _N and the output of the bridge is e _O , the following relational expression [Equation 1] holds.

[Number 1] _{e O = e B + e C} -e A -e D = (e B '+ e N) + (e C' + e N) - (- e A '+ e N) - (- e D' + e N ) = E _B '+ e _C ' + e _A '+ e _D '

Therefore, even when the strain caused by the hull fluctuation acts on the longitude material 1 and the output e _N resulting from this occurs in each of the strain sensors A to D, the component e _N is canceled by the bridge circuit, and the output e _N is output. As e _O , only the sum of the original distributed pressures is detected. Thus, according to the first embodiment, since the four strain sensors are arranged in a concentrated manner, the following effects or advantages can be obtained. (1) The length of the measuring cable can be reduced, and the quantity can be reduced. (2) The waterproofing of the four strain sensors can be performed collectively, so that the reliability of the measurement can be improved. (3) Since there is no need to attach an upward sensor, the workability is improved, and the reliability of the circuit is further improved.

Next, a second embodiment of the present invention will be described. The present embodiment is also an example in which the present measuring apparatus is applied to the long material 1 sandwiched between ribs 3 for reinforcing the inner bottom plate 2 of the hull double bottom. Also in this embodiment, as shown in FIGS. 4, 5, and 7, four strain sensors A, B, C, and D attached to the long material 1 as a continuous beam are divided into two pairs of groups A, B, and D. C, and a pair of strain sensors of groups A and B, and D and C are arranged symmetrically with respect to a transverse line passing through the center of the long material 1 and in the vicinity of the transverse line. Then, the strain sensor group 4-1 and the strain sensor group 4-
2 each of the strain sensors A and B or D and C is a long material 1
(See FIG. 7).

Further, as in the first embodiment, each of the strain sensors is arranged such that the sensors symmetrical with respect to the transverse line at the center of the beam 1, that is, A and D and B and C are opposite sides. Configured on Wheatstone Bridge. A power supply (not shown) is connected to the input terminal (see FIG. 9) of the bridge configured as described above, and a voltmeter (not shown) is connected to the output terminal. With such a configuration, substantially the same operation and effect as those of the above-described first embodiment can be obtained in the continuous beam pressure measuring device of the second embodiment.

First, the bending stresses detected by the four strain sensors A to D are, as shown in FIG.
In D, the stresses σ _A and σ _D are detected, and in the strain sensors B and C, the stresses σ _B and σ _C are detected. And, since each strain sensor constitutes a Wheatstone bridge such that A and D and B and C form opposite sides, each sensor A, B, C,
Let the output voltages at both ends of D be e _A , e _B , e _C , and e _D, and let the voltages due to only the distributed pressure acting on the continuous beam (longitude material 1) originally desired to be detected be e _A ', e _B ', e, respectively. _{Assuming that C} ′ and e _D ■, the output due to the fluctuation distortion is e _N , and the output of the bridge is e _O , the above relational expression [Equation 1] holds.

[0015] Accordingly, distortion due to the hull fluctuation acts on the longitudinals material 1, even when the output e _N due to the respective strain sensors A~D occurs, the component e _N by the bridge circuit is canceled, the output As e _O , only the sum of the original distributed pressures is detected. As described above, also in this embodiment, since the four strain sensors A to D are also arranged intensively in the central portion of the long material 1, the following effects or advantages can be obtained. (1) The length of the measuring cable can be reduced, and the quantity can be reduced. (2) The waterproofing of the four strain sensors can be performed collectively, so that the reliability of the measurement can be improved.

[0016]

As described above in detail, in the continuous beam pressure measuring device of the present invention, four strain sensors attached to the continuous beam to measure the pressure acting on the continuous beam are provided at the center of the beam. The following effects and advantages can be obtained because the components are intensively arranged. (1) Compared with the conventional technology, the length of a cable connecting between sensors or between a sensor and a measuring instrument can be significantly reduced, which can contribute to a reduction in the amount of material. (2) Since it is not necessary to disperse the sensors in a wide range, waterproofing can be performed on two or four sensors at a time. Therefore, the reliability of the measurement circuit can be improved. (3) The workability of the sensor attaching work is improved, which leads to the improvement of circuit reliability.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a continuous beam section inside a hull double bottom of a continuous beam pressure measuring device as a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of a continuous beam portion of the continuous beam pressure measuring device of FIG.

FIG. 3 is a distribution diagram of stress acting on the beam of FIG. 2;

FIG. 4 is a configuration diagram of a continuous beam portion inside a hull double bottom of a continuous beam pressure measuring device as a second embodiment of the present invention.

5 is a cross-sectional view of a continuous beam portion of the continuous beam pressure measuring device of FIG.

FIG. 6 is a distribution diagram of stress acting on the beam of FIG. 5;

FIG. 7 is an enlarged view of a main part of FIG.

FIG. 8 is a structural view of a conventional continuous beam pressure measuring device in a continuous beam portion inside a hull double bottom.

FIG. 9 is a configuration diagram of a strain sensor of a conventional continuous beam pressure measuring device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Longitude material 1a Face material 2 Double bottom inner bottom plate 3 Rib board A-D Strain sensor 4-1 and 4-2 Strain sensor group na neutral shaft

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G01L 1/00 G01L 5/00

Claims (2)

(57) [Claims] 1. A Wheatstone bridge connecting four strain sensors affixed to a continuous beam for measuring a pressure acting on the continuous beam for a structure including the continuous beam. The four strain sensors form two pairs of groups,
Each 1 strain sensor pair group is disposed in the vicinity of and the transverse line symmetrically about a transverse line passing through the central portion of the continuous beam to each other Rutotomoni, each strain sensor is the continuous beams of a group of the pair in
Separated from each other in the depth direction of the continuous beam across the vertical axis
A pressure measuring device for a continuous beam, wherein the pressure measuring device is disposed . 2. A structure including a continuous beam, the structure including the continuous beam.
4 pieces attached to the same continuous beam to measure the acting pressure
Between these strain sensors and these strain sensors.
With the following Wheatstone bridge, the four strain sensors form two pairs of groups,
Each pair of strain sensors is connected to each other
Symmetry with respect to the transverse line passing through the center and in the vicinity of the transverse line
And each strain sensor of the pair of groups is connected to the surface of the continuous beam.
Characterized in that they are arranged to overlap each other in the material
Pressure measuring device for continuous beams.