JP7021777B2 - Pressure gauge - Google Patents

Description

The present invention relates to a pressure gauge that measures the pressure of a filling material in contact with the material to be filled in the space surrounded by one formwork and the other formwork.

A process of assembling one formwork and the other formwork, filling the space formed between them with an object to be filled, curing for a predetermined time, and then removing the formwork is performed. The pressure gauge of the present invention is premised on a pressure of about several to 200 kPa and a temperature of about 25 to 100 ° C. Typically, the material to be filled is cast concrete, but it can also be applied to resin or the like if conditions are met.

Now, in the management of cast concrete, measuring the pressure is one of the important points. This is due to the following reasons. That is, if the pressure is too high, it may lead to an accident of damaging the formwork or its supporting structure. On the other hand, if the pressure is too low, the coarse and dense state of the concrete may not be sufficiently saturated, and typically a nest may be formed in a part of the space. If this happens, the quality of the concrete to be constructed will be significantly deteriorated, such as insufficient strength.

There are various types of pressure gauges, but a piston type soil pressure gauge or a diaphragm type soil pressure gauge is generally used to measure the pressure of the cast concrete. Each of these has a built-in strain gauge equipped with an electric resistance wire, and uses a method of converting pressure from a measured value of strain.

What should be measured originally is the hydrostatic pressure of the cast concrete, not the dynamic pressure caused by the collision of an object or the like. However, the actual concrete also contains a component that is much harder than other components such as aggregate and has high kinetic energy.

In fact, the pressure gauge used when placing lining concrete has a specified number of cumulative uses, and its use beyond the specified range is prohibited. This is due to the following circumstances. That is, once the concrete is cast, the aggregate and other hard components will continue to hit the pressure gauge repeatedly. This is because it is assumed that the pressure gauge itself will be damaged by such repeated impacts and will eventually become unusable.

Further, as a result of the impact, the strain gauge becomes dysfunctional, and the reliability of the measured value itself is significantly reduced. In this case, it becomes impossible to know the pressure to be controlled accurately, and as described above, there is a possibility that the formwork or its supporting structure may be damaged or the quality may be deteriorated by the nest formed in the concrete.
Japanese Unexamined Patent Publication No. 2015-4585 Japanese Unexamined Patent Publication No. 4-52514 Japanese Unexamined Patent Publication No. 6-249724

In view of the above points, it is an object of the present invention to provide a pressure gauge which can be repeatedly used even for an object to be filled containing a hard component such as an aggregate and has high reliability of measured values.

The pressure gauge according to the first invention measures the pressure of the filling material in contact with the material to be filled in the space surrounded by one mold and the other mold, and the other mold has a pressure gauge. From the non-contact surface that does not come into contact with the object to be filled to the contact surface that comes into contact with the object to be filled, a through hole that penetrates the other mold is provided in the plate thickness direction, and is attached to the through hole. , A pressure gauge that measures pressure, and is connected to a head portion that is fitted into the through hole and is formed by an elastic body so that the top surface receives pressure and the side surface is in close contact with the through hole. A housing that is installed, fixed to the other mold, and has an internal space, a pressure receiving plate that is in close contact with the opposite side of the top surface of the head, a displacement sensor that is supported in the internal space, and an upper end that receives pressure. It is equipped with a follower that is in contact with the plate, the lower end is in contact with the displacement sensor, and the lower end is formed thinner than the upper end, so that the distributed load due to the pressure received by the top surface is converted into the centralized load received by the displacement sensor. ..

In this configuration, the pressure of the material to be filled acts directly on the top surface of the head portion. Even if the dynamic energy of a hard component such as aggregate acts, the action is alleviated by elastically deforming the head part made of an elastic body and converting it into strain energy, and it is directly applied to the sensor itself. The blow does not act on.

As a result, the sensor itself can be significantly protected from damage, can be used repeatedly, and the reliability of measured values can be improved.

Further, since the head portion is restrained by the through hole of the other mold, when pressure is applied to the top surface, the side surface of the head portion expands outward in the radial direction, and the liquidtightness of the filling becomes high. improves.

The distributed load applied to the top surface is transmitted in the order of the head portion, the pressure receiving plate, the upper end portion of the follower, and the lower end portion of the follower, becomes a concentrated load, and is received by the displacement sensor. As a result, the distributed load is efficiently transmitted to the displacement sensor as a concentrated load, and the displacement sensor can sharply capture the change in the distributed load, that is, the change in the pressure of the filling. As a result, preferable pressure control becomes possible.

Preferably, the pressure gauge further comprises a linear guide that constrains the displacement direction of the follower in the vertical direction.

With this configuration, the operation of the follower can be stabilized.

Preferably, the pressure receiving plate is curved so as to be convex downward when the head portion receives pressure.

With this configuration, the pressure receiving plate collects the distributed load received by the head part and transmits it to the upper end part of the follower, like a pressure lens, and the displacement sensor further improves the detection accuracy. The result is that the change in distributed load can be measured well.

Preferably, the displacement sensor is a load cell with a built-in strain gauge.

This configuration enables inexpensive and highly accurate measurement.

More preferably, the base end of the load cell is fixed to the housing, and the tip of the load cell is a free end and is in contact with the lower end of the follower.

With this configuration, the load cell is supported like a cantilever, the load cell is displaced sharply, and the displacement sensor can measure the change in the distributed load with good detection accuracy.

Preferably, one formwork has a bedrock, a mortar sprayed on the bedrock, and a tarpaulin attached to the mortar, and the other formwork is a formwork for lining concrete and is to be filled. Is a cast concrete containing aggregate.

With this configuration, it is possible to smoothly cope with the casting work of the secondary lining concrete of the tunnel.

Preferably, the elastic body consists of rubber, urethane resin or a blend thereof.

With this configuration, the head portion can be easily formed at low cost.

According to the present invention, even if the dynamic energy of a hard component such as an aggregate acts, the sensor can be protected from a direct impact, can be used repeatedly, and the reliability of the measured value can be improved. Further, since the distributed load applied to the top surface becomes a concentrated load and is received by the displacement sensor, the change in the pressure of the filling can be accurately captured. As described above, according to the present invention, it is possible to repeatedly use an object to be filled containing a hard component such as an aggregate, and a pressure gauge with high reliability of measured values can be obtained.

FIG. 1 is a cross-sectional view showing an installed state of a pressure gauge according to the present invention, and FIG. 2 is an enlarged view of a main part of FIG.

(Outline of the invention)
First, the outline of the pressure gauge according to the present invention will be described with reference to FIGS. 1 and 2. In the following, an example of the casting work of the secondary lining concrete of the tunnel will be described, but as already described in the section of "Background technology", the filling material is not limited to the casting concrete. As long as the conditions are met, it can be applied to resins and other objects to be filled, and even so, it is included in the protection scope of the present invention.

For example, in the case of injection molding a resin, the mold becomes a mold, and in this context, the concept of "form" as used herein may be broader than general ones. , Must be understood.

Further, as is clear from the following description, the pressure gauge of the present invention constructs a structure such as a bridge pier, a foundation, a harbor, etc., other than the concrete placing work for the secondary lining concrete of the tunnel. Needless to say, it can be suitably applied to civil engineering work, construction work to construct a concrete building, or similar work).

By the way, in the secondary lining concrete placing work of the tunnel, a special curved formwork called a centre formwork having a very large radius of curvature (a radius of about 5.5 m) is used.

Since the radius of curvature is very large, when observed close to the formwork, the curved surface looks as if it were a flat surface.

Therefore, in FIGS. 1 and 1 and below, the lines (accurately, arcs) constituting the tunnel are displayed as straight lines, but this is for convenience of display.

Secondary lining of the tunnel By the time concrete placement work is considered, the next primary lining has already been completed and the (one) formwork 4 has already been constructed. On the other hand, the formwork 4 is simply constructed as follows.

That is, first, the bedrock 1 to open the tunnel is excavated to secure a space for construction. Next, the exposed bedrock 1 is sprayed with mortar 2 to smooth the surface. Further, the waterproof sheet 3 is attached to the mortar 2 to finish the primary lining.

After the above is completed, the secondary lining concrete placing work will be started. That is, although not shown, the (other) formwork 5 is attached to the support mechanism while assembling the support mechanism that supports the center formwork.

The formwork 5 is a plate-shaped member having a non-contact surface 5b that does not come into contact with the cast concrete 30 and a contact surface 5a that comes into contact with the cast concrete 30, and the thickness thereof is usually about 6 to 9 mm.

However, the plate thickness is not related to the essence of the present invention, and the pressure gauge of the present invention can cope with various plate thicknesses by changing the height of the head portion 12, for example.

A space S exists between the two formwork 4 and 5, and the cast concrete 30 including the aggregate 31 fills this space S. At this time, as described above, the displacement sensor 16 is protected and is not directly damaged even if it is hit by the hard aggregate 31 or the like.

Further, the studs 5c project inward (downward in FIG. 1) at a predetermined pitch from the non-contact surface 5a of the formwork 5, and the plate of the formwork 5 is formed between the pair of stud groups 5c and 5c. A through hole 5d that penetrates the formwork 5 in the thickness direction is provided.

In the pressure gauge 10 of the present invention, the head portion 12 thereof is mounted in the through hole 5d to measure the pressure.

As shown enlarged in FIG. 2, the pressure gauge 10 of the present invention includes a head portion 12 and a housing 11.

The top surface 12a of the head portion 12 receives a distributed load 20 due to the pressure from the cast concrete 30, and the side surface 12b of the head portion 12 is fitted into the through hole 5d so as to be in close contact with the through hole 5d. ..

In this example, the entire head portion 12 is formed of an elastic body. The elastic body is preferably made of rubber, urethane resin or a blend thereof.

It is also possible to use an elastic body in the region from the top surface 12a of the head portion 12 to the pressure receiving plate 13, and to form the other portion with a non-elastic body (for example, a rigid body).

The housing 11 is a member that is continuously provided below the head portion 12 and is fixed to the formwork 5.

As shown in FIG. 1, in this example, the lid plate 6 is fixed to the lower end portion of the stud 5c of the formwork 5 by using the fixing screw 7, and further penetrates the central portion of the lid plate 5 up and down. The structure is such that the bottom portion of the housing 11 is supported by the tip portions of the pair of support bolt groups 8 and 8.

Here, the top surface 12a of the head portion 12 is preferably flush with the contact surface 5a of the formwork 5, and the screwing conditions of the support bolt groups 8 and 8 are adjusted so as to have such a positional relationship. ..

However, even if there is a slight height difference between the top surface 12a and the contact surface 5a, it does not pose a big problem in practice. That is, even if the top surface 12a is slightly higher or lower than the contact surface 5a, it is included in the protection range of the present invention.

As shown in FIG. 2, the housing 11 is a box-shaped member having an internal space 11a.

The displacement sensor 16 of this example is a load cell having a built-in strain gauge. According to this, inexpensive and highly accurate measurement becomes possible.

However, instead of this, it is also possible to use a capacitance type sensor, a pressure-sensitive conductive rubber sensor (for example, "Inastomer (trademark) SFR type" manufactured by Inaba Rubber Co., Ltd.), and thus. Is also included in the scope of protection of the present invention.

In this example, in order to secure the deflection allowance of the displacement sensor 16, an installation seat 11b that is slightly raised upward is formed from the bottom of the internal space 11a of the housing 11.

The base end portion 16a of the displacement sensor 16 is placed on the installation seat 11b, and the base end portion 16a is fixed to the installation seat 11b by the fixing screw groups 17 and 17. On the other hand, the tip portion 16b of the displacement sensor 16 has a free end, and the lower end portion 15b of the follower 15, which will be described later, presses against the tip portion 16b.

That is, the displacement sensor 16 is supported in the shape of a cantilever. By doing so, it is possible to smoothly follow the deformation of the displacement sensor 16 with respect to the vertical displacement of the follower 15, which is preferable.

However, the support structure of the displacement sensor 16 is not limited to this, and other well-known support structures such as double-sided beams may be adopted.

As shown in FIG. 2, a pressure receiving plate 13 is disposed on the opposite side (back side) of the top surface 12a of the head portion 12, and these members 12 and 13 are always in close contact with each other.

Although not shown in FIG. 2, it is preferable that the pressure receiving plate 13 is curved so as to be convex downward when the top surface 12a receives pressure. This is because the pressure receiving plate 13 aggregates the distributed load 12a received by the head portion 12 and transmits it to the upper end portion 15a of the follower 15.

Further, inside the head portion 12, a linear guide 14 is mounted below the pressure receiving plate 13, the upper end portion 15a is in contact with the pressure receiving plate 13 and the lower end portion 15b is the tip of the displacement sensor 16 in the linear guide 14. A follower 15 in contact with the portion 16b is attached.

The lower end portion 15b of the follower 15 is formed thinner than the upper end portion 15a, and the follower 15 concentrates the distributed load 20 due to the pressure received by the top surface 12a of the head portion 12 on the tip portion 16b of the displacement sensor 16. Convert to weight.

(Embodiment 1)
The outline of the present invention is as described above. Next, a more specific embodiment will be described with reference to FIGS. 3 to 5.

Here, FIG. 3 is a perspective view of the pressure gauge according to the embodiment of the present invention, FIG. 4 is a cross-sectional view of the pressure gauge, and FIG. 5 is an enlarged view of a main part of FIG.

In contrast to the outline shown in FIGS. 1 and 2, the following points are changed in this embodiment.

The major change is the shape of the follower 15, as shown enlarged in FIG. In this embodiment, the outer shape of the follower 15 is mushroom-shaped. That is, the upper end portion 15a is formed in an arc shape at the upper portion and is wide like a mushroom umbrella. Further, the lower end portion 15b is rounded and tapered, and the intermediate portion between the upper end portion 15a and the lower end portion 15b is formed in a barrel shape.

Further, although it may be difficult to read in FIG. 5, the pressure receiving plate 13 is formed in a downwardly convex shape, and the portion on the back side of the top surface 12a of the head portion 12 is also processed to match this convex shape. There is.

Due to these points, the function of collecting the distributed load received by the head portion and transmitting it to the upper end portion of the follower is further strengthened as compared with the above outline.

Further, as a minor change, the arrangement of the fixing screw group 17 is upside down as compared with the above outline. In addition, reinforcements and the like have been added due to strength problems, but it will be understood that these have nothing to do with the essence of the present invention.

The other points are the same as the outline.

Sectional drawing which shows the installation state of the pressure gauge which concerns on this invention. Enlarged view of the main part of FIG. Perspective view of the pressure gauge in one embodiment of the present invention Sectional drawing of pressure gauge in one Embodiment of this invention Enlarged view of the main part of FIG.

1 Bedrock 2 Mortar 3 Waterproof sheet 4 (one) formwork 5 (the other) formwork 5a Contact surface 5b Non-contact surface 5c Stud 5d Through hole 6 Lid plate 7 Fixing screw 8 Support bolt 10 Pressure gauge 11 Housing 11a Internal space 11b Installation seat 12 Head 13 Pressure receiving plate 14 Linear guide 15 Follower 15a Upper end 15b Lower end 16 Displacement sensor 16a Base 16b Tip 17 Fixing screw 20 Distributed load 30 Casting concrete 31 Aggregate

Claims (6)

The pressure of the filling material is measured in contact with the filling material to be filled in the space surrounded by one formwork and the other formwork.
The other formwork is provided with a through hole that penetrates the other formwork in the plate thickness direction from the non-contact surface that does not contact the material to be filled to the contact surface that comes into contact with the material to be filled. And moreover
A pressure gauge mounted in the through hole to measure the pressure.
A head portion having a substantially U-shaped cross section formed by an elastic body and fitted into the through hole so that the top surface receives the pressure and a part of the side surface is in close contact with the through hole.
A housing that is connected to the end of the side surface of the head portion, is fixed to the other formwork, and has an internal space.
A pressure receiving plate that is in close contact with the opposite side of the top surface of the head portion and is curved so as to be convex toward the non-contact surface side of the other mold when the top surface receives pressure .
The displacement sensor supported in the internal space and
The upper end portion is in contact with the pressure receiving plate, the lower end portion is in contact with the displacement sensor, and the lower end portion is formed thinner than the upper end portion, so that the distributed load due to the pressure received by the top surface is applied to the displacement sensor. A pressure gauge characterized by having a follower that converts to a centralized load that is received by the sensor. The pressure gauge according to claim 1, further comprising a linear guide that restrains the displacement direction of the follower in the vertical direction. The pressure gauge according to claim 1 , wherein the displacement sensor is a load cell having a built-in strain gauge. The pressure gauge according to claim 3 , wherein the base end portion of the load cell is fixed to the housing, and the tip end portion of the load cell is a free end and is in contact with the lower end portion of the follower. The one formwork has a bedrock, a mortar sprayed on the bedrock, and a waterproof sheet attached to the mortar.
The other formwork is a formwork for lining concrete.
The pressure gauge according to claim 1 , wherein the material to be filled is cast concrete containing an aggregate. The pressure gauge according to claim 1 , wherein the elastic body is made of rubber, urethane resin, or a blend thereof.

Images