JPH0623953Y2 - Pressure sensor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a pressure sensor, and more particularly to a pressure sensor used in an excavator or the like.

[Prior art and its problems]

Conventionally, the soil pressure is measured in order to transport a predetermined amount of soil out of the excavated soil in an excavator etc. that is supposed to be transported after excavating the soil. A pressure sensor is attached to.

This pressure sensor has a mechanical type that mainly uses springs and the like, and it measures the pressure of the soil that is being excavated by the excavator and conveys the amount of soil that corresponds to the specified pressure value. Was.

However, the conventional pressure sensor cannot measure only the earth pressure, and the pressure of the liquid such as water excavated together with the soil is measured. There was a problem that a liquid such as water was transported together with the soil.

It is an object of the present invention to solve the above-mentioned problems and to provide a pressure sensor that can measure only earth pressure without adding pressure of water or the like, particularly in a pressure sensor used in a drilling machine or the like. It is a thing.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention is a pressure sensor attached to an excavator or the like, wherein a case is provided with a fixing member having a communication hole to form two compartments and both compartments. Through the communication hole,
One of the compartments is closed by a first pressure receiving member that receives earth pressure and water pressure, and the other compartment is closed by a second pressure receiving member that receives only water pressure, and a pressure transmitting fluid is sealed inside the case. A pressure detecting member is arranged in the communication hole, and the pressure detecting member has means for receiving earth pressure and water pressure on one side and only water pressure on the other side.

[Action]

The present invention adopts the above means, and when earth pressure and water pressure are applied to the pressure sensor, the first pressure receiving member that closes one of the compartments inside the case is via the pressure transmitting fluid,
A second pressure receiving member that transmits earth pressure and water pressure to one side of the pressure detecting member through a communication hole formed in a fixing member that divides the inside of the case into two compartments, and closes the other compartment inside the case The member transmits only the water pressure to the other side of the pressure detection member via the pressure transmission fluid, and the pressure detection member relatively balances out the water pressure to detect only the earth pressure.

〔Example〕

Hereinafter, a pressure sensor according to the present invention will be described with reference to the drawings.

FIG. 1 shows a sectional view of a pressure sensor according to the present invention. The pressure sensor has a case 1 having a cylindrical shape, an upper end closed and a lower end opened. In addition, a cylindrical fixing member 2 having a central portion closed by a base portion 2b and a communication hole 2a formed in the base portion 2b.
Is provided in the center with the lower end of the opening coinciding with the lower end of the opening of the case 1.

Then, the communication hole 2a of the fixing member 2 has the pressure detecting member 3
And the lower end of the opening is closed by the first pressure receiving member 4,
Further, the lower end of the case 1 and the lower end of the fixing member 2 form an annular shape and are closed by a second pressure receiving member 5 provided on the outer peripheral portion of the first pressure receiving member 4, and further, the inside of the case 1 Oil 6, which is a pressure transmitting fluid, is sealed in.

Therefore, inside the case,
It is formed into two compartments, a compartment A formed by the pressure receiving member 4 and a compartment B formed inside the other case 1.

The pressure detection member 3 provided on the fixing member 2
Is formed of a substrate 7 which is provided on the base portion 2b to close the communication hole 2a and a gauge resistor 8 which is embedded on the substrate 7 so as to match the upper surface thereof. Are connected.

In addition, the first pressure receiving member 4 is a disc-shaped pressure receiving plate 1.
0, an elastic member 11 provided on the upper surface of the pressure receiving plate 10 and having a disc shape and having a matching outer periphery, and a metal diaphragm 12 provided on the upper surface of the elastic member 11 and having a disc shape and an outer peripheral portion protruding. The outer peripheral portion of the metal diaphragm 12 is joined to the lower end of the opening of the fixing member 2 to close the lower end of the opening.

The second pressure-receiving member 5 has an annular plate shape and a fixed platen 14 having a plurality of holes 13 formed therein, and an annular plate provided on the upper surface of the fixed platen 14 and having inner and outer circumferences. And the outer peripheral portion of the elastic material 15 is joined to the lower end of the opening of the case 1, and the inner peripheral portion is joined to the lower end of the opening of the fixing member 2 via the metal diaphragm 12. The lower end of the case 1 and the lower end of the fixing member 2 are closed.

Next, the above pressure sensor is attached to the excavator etc.,
The action of measuring the pressure when transporting the excavated soil will be described.

First, the lower surface of the case 1 is a surface that receives earth pressure and water pressure.

Then, when earth pressure and water pressure are applied to the first pressure receiving member 4 and the second pressure receiving member 5, earth pressure and water pressure are applied to the first pressure receiving member 4, pushing up the pressure receiving plate 10 and pressing the pressure receiving plate 10
Pushes up the metal diaphragm 12 via the elastic material 11 located on the upper part, the metal diaphragm 12 displaces the oil 6 existing in the upper compartment A, and the oil 6 is placed on the base of the fixing member 2 via the communication hole 2a. Earth pressure and water pressure are applied to the lower surface of the substrate 7 provided on the portion 2b.

On the other hand, although earth pressure and water pressure are also applied to the second pressure receiving member 5, as shown in the enlarged view of the main part of FIG.
Is blocked by the fixed platen 14, and only the water pressure b is fixed to the fixed platen 1.
The elastic material 1 on the fixed platen 14 through the hole 13 formed in
5, the elastic material 15 displaces the oil 6 existing in the compartment B above the elastic material 15.

Since this oil 6 is continuous to the upper surface of the substrate 7 as shown in FIG. 1, only water pressure is applied to the upper surface of the substrate 7.

3 shows an enlarged view of the periphery of the substrate 7, in which the earth pressure and the water pressure are applied to the substrate 7 from the arrow C, and only the water pressure is applied from the arrow D, and the pressure applied to the substrate 7 is applied. The water pressure is relatively canceled out and only the earth pressure is generated.
Is deformed by earth pressure, and the gauge resistance 8 provided on the substrate 7
The resistance value of is displaced according to the deformation, therefore, by reading the change in the resistance value as an electrical signal, it becomes possible to detect the change in the substrate, that is, the earth pressure, and by mounting this pressure sensor on the excavator, etc. The excavator can accurately convey a predetermined amount of excavated soil.

In the present invention, the case has a cylindrical shape. However, the case is not limited to this, and may have a square shape, and the fixing member is not limited to a cylindrical shape. What is necessary is just to divide the inside into two compartments.

[Effect of device]

As described above, the present invention is a pressure sensor mounted on an excavator or the like, wherein a case is provided with a fixing member having a communication hole to form two compartments, and both compartments are connected to the communication hole. Through one side, one compartment is closed by a first pressure receiving member that receives earth pressure and water pressure, and the other compartment is closed by a second pressure receiving member that receives only water pressure. The pressure transmitting fluid is sealed and a pressure detecting member is provided in the communication hole. This pressure detecting member receives earth pressure and water pressure on one side and receives water pressure only on the other side. Also, when receiving water pressure, it is possible to detect only the earth pressure, and since the pressure transmitting fluid exists between the pressure detecting member and the first pressure receiving member and the second pressure receiving member, the pressure detecting member is damaged. Durability is low Those having excellent effects such as the above.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of a pressure sensor according to the present invention, FIG. 2 is an enlarged view of a main part of FIG. 1, and FIG. 3 is an enlarged view of the periphery of a substrate of FIG. 1 ... Case 2 ... Fixing member 2a ... Communication hole 2b ... Table part 3 ... Pressure detecting member 4 ... First pressure receiving member 5 ... Second pressure receiving member 6 ... Oil 7 ... Substrate 8 …… Gauge resistance 9 …… Conductor wire 10 …… Pressure receiving plate 11, 15 …… Elastic material 12 …… Metal diaphragm 13 …… Hole 14 …… Fixing board a …… Soil pressure b …… Water pressure A, B …… compartment

Claims (1)

[Scope of utility model registration request] 1. A pressure sensor mounted on an excavator or the like, wherein a case is provided with a fixing member having a communication hole to form two compartments, and both compartments are communicated via the communication hole. One of the compartments is closed by a first pressure receiving member that receives earth pressure and water pressure, and the other compartment is closed by a second pressure receiving member that receives only water pressure. A pressure sensor characterized in that it is enclosed and a pressure detecting member is arranged in the communication hole, and the pressure detecting member receives earth pressure and water pressure on one side and only water pressure on the other side.