JPS5941133B2 - wall pressure detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a detector for pressure acting on a wall surface.

Conventional pressure detectors of this kind, as seen in almost all upper pressure gauges on the market, can become unable to detect the correct upper ball if the pressure-receiving surface becomes deformed or worn out, or the upper ball cannot be detected correctly. Since the stiffness of the pressure gauge and the wall surface on which it is mounted are not the same, there are fundamental drawbacks such as the inability to correctly detect the upper ball on the wall surface in principle.

However, in a very small number of cases, detectors have been developed that measure the upper ball by making both the stiffnesses the same and conforming to academic truth. Since it is configured to detect balls, the number of strain gauges that can be attached is limited, resulting in a small output signal, and pressure cannot be detected with high resolution, making it difficult to expand the specific pressure range required. However, the disadvantage was that the detection accuracy deteriorated. Also, when subjected to heavy pressure in harsh usage environments,
There were drawbacks such as plastic strain or breakage in the pressure detection plate, and the lack of a detection plate that would begin to deflect when pressure above a certain level was applied, making it impossible to obtain pressure information over a wide range. In order to eliminate such conventional drawbacks, the present invention increases the number of pressure detection plates and can be used in a wide pressure range.
It has high precision and high resolution, and has a flexible plate for rigidity adjustment to provide versatility and improve economic efficiency.It also has a pressure plate that starts to deflect when pressure above a certain level is applied. This system is designed to obtain pressure information at high pressures, and is also equipped with a mechanism to avoid plastic strain and damage to the pressure detection plate and flexible plate under high pressures, thereby improving reliability.

An embodiment of the present invention will be described in detail below with reference to the drawings. The figure is a sectional view showing one embodiment of the wall pressure detector of the present invention. In the figure, 1 is a wall surface, 2 is soil, 3 is an upper pressure, and 4 is a flexible plate for supporting a pressure receiving body, the end of which is inside the wall surface 1. A protrusion 5a having a step protruding from the center of the pressure receiving body 5 is inserted from above into a hole provided in the center of the casing 15 housed in the casing 15, and the flexible plate 4 and the pressure receiving body 5 are connected to each other. They are screwed together via the step.

Further, below the protrusion 5a, a plurality of first pressure detection plates 8 are provided.
(two plates in the figure) and the rigidity adjustment flexible plate 9 are in contact with each other via the pressure receiving body displacement transmission ball 6 provided in the center thereof,
In addition, second pressure detection plates 12 are assembled in a layered manner by pressure plate support washers 7, respectively, at a certain interval via pressure receiving body displacement transmission balls 11 in the lower central part thereof, and a mounting plate 15a.
It is fixed in the casing 15 by. Then, the total stiffness of the pressure receiving body 5, the pressure receiving body supporting flexible plate 4, the first pressure detection plate 8, and the stiffness adjustment flexible plate 9 in the vertical direction of the wall surface 1 is the same as the stiffness of the wall surface 1 in the vertical direction of the wall surface 1. so that it becomes Further, an appropriate gap 14 is provided between the casing 15 and the supporting flexible plate 4 to restrain the supporting flexible plate 4 from deflecting beyond all elastic limits. Reference numerals 10 and 13 denote strain gauges, each of which is attached to the first pressure plate 8 and second pressure plate 12 in the required number, and whose outputs are led to a lead wire 16 and collectively transmitted through an amplifier 17 for recording and display. It is designed to be read in section 18. Therefore, when the earth pressure 3 of the soil 2 in contact with the wall surface 1 acts on the pressure receiving body 5 supported by the pressure receiving body supporting flexible plate 4 and the pressure receiving body 5 is displaced in the direction perpendicular to the wall surface 1, the pressure receiving body displacement transmitting ball is generated. 6, the displacement of the pressure receiving body 5 is transmitted to all of the first pressure detection plates 8.

The outputs from a large number of strain gauges 10 mounted on the pressure plate 8 are displayed on a record display section 18. In addition, when soil pressure 3 of a certain magnitude or more acts, that soil pressure 3 becomes the second
The output from the strain gauge 13 mounted on the pressure plate 12 is obtained from the display section 18. However, if an extremely large earth pressure 3 such as an impact force acts on the pressure receiving body 5, the center portion of the pressure receiving body supporting flexible plate 4 will hit the casing 15 at the gap 14, and the pressure receiving body supporting flexible plate 4 and all the test pieces will be damaged. The pressure plates 8, 12 will not be damaged due to deflection only within their respective elastic limits, nor will plastic strain occur. In the embodiment, the target was soil, but the pressure on the wall surface 1 of general powder or granules can also be detected.

In addition, if the soil contains liquid such as water, it is necessary to seal it with an O-ring 19 or filler rubber 20 to prevent water from entering the pressure detection plate 8, and a drain hole must be provided in the casing 15. It may be attached to the Further, it is preferable that the O-ring 19 and the rubber filler 20 do not hinder the ease of movement of the pressure-receiving body 5. In addition, the material of the pressure receiving body 5 may be changed to the wall surface 1 as necessary.
The same material may be used. In addition, in order to match the stiffness of the wall surface 1 and the stiffness of the wall pressure detector, there is no problem in adjusting the stiffness using not only the stiffness adjustment deflection plate 9 but also the pressure detection plate 8. There is no problem in preparing in advance various types of integrated plates 9 and pressure plates 8 having a predetermined stiffness, and using the one that matches the stiffness of each wall surface 1 each time. No problem. As explained in detail above, according to the present invention, even if the pressure receiving surface is slightly deformed or worn, the detection accuracy is not affected, and when converting extremely small displacement into pressure using a strain gauge, the detection area can be made as wide as necessary, which not only makes it easier to measure the strain gauge, but also allows high output to be obtained over a wide pressure range and high resolution, improving detection performance. The stiffness can be easily adjusted by replacing the plates and pressure detection plates, which provides versatility, and if you prepare products with various stiffnesses in advance, this pressure detector can be mass-produced, which is a huge advantage.

In addition, we have introduced a pressure detection plate that begins to deflect when the pressure exceeds a certain level, so we can detect extremely high pressures with a certain level of accuracy, and at the same time, we can obtain information on unexpected pressures that act on the pressure-receiving surface. A mechanism is introduced to protect the pressure plate and deflection plate so that they deflect only within their elastic ranges, which has the effect of improving detection accuracy and reliability against damage. Therefore, the fields of application of the pressure detector of the present invention are as follows:
In civil engineering construction, which is used in harsh environments, it has great effects, particularly in tunneling in the earth pressure shielding method, and as a control detector in the transportation process of powder and granules.

[Brief explanation of drawings]

The figure is a sectional view showing an embodiment of the wall pressure detector of the present invention. 1...Wall, 2...Soil, 3...
・Earth pressure, 4...Flexible plate for supporting pressure receiving body, 5.
...Pressure receiving body, 5a...Protrusion, 6, 11
......Pressure body displacement transmission ball, 7...Pressure plate support washer, 8...First pressure test plate, 9...
- Flexible plate for stiffness adjustment, 10, 13...Strain gauge, 12...Second pressure plate, 14...
...Gap, 15...Casing, 15a...
...Mounting plate, 17...Amplifier, 18...
...Record display section, 19...O ring, 20...
...Filled rubber.

Claims (1)

[Claims] 1 Inside the casing housed within the wall, there is a supporting flexible plate held at the end, and a pressure receiving body with a stepped protrusion protruding from the center, with the protruding part inserted into the hole provided in the flexible plate. When inserted from above, the plurality of first pressure detection plates and stiffness adjustment flexible plates are arranged in a layered manner, and are screwed together via a stepped portion, and the protrusion portion simultaneously deflects by the same amount of displacement via a pressure receiving body displacement transmission ball. The stiffness in the vertical direction of the wall surface is the same as the stiffness of the wall surface in the vertical direction, and the pressure receiving body is disposed at a certain interval below the stiffness adjusting flexible plate. A second pressure detection plate is held in each of the casings, and the second pressure detection plate starts to deflect through the pressure receiving body displacement transmission ball when the displacement exceeds the amount, while the supporting deflection plate is prevented from deflecting beyond all elastic limits. A wall pressure detector characterized in that an appropriate gap is provided between a casing and a supporting flexible plate for restraint.