JPS589723B2 - Molded body manufacturing method using hydraulic kneaded material and its equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a molded body using a hydraulic kneaded material, and includes methods for producing molded bodies using hydraulic materials such as various cements or gypsum. When a kneaded material (including materials) is pumped through a pipe and injection molded, the pumping is performed using a pulsating pumping mechanism, and the molded product is smoothly formed without reducing the strength of the molded product by separating moisture. The present invention seeks to obtain a method and apparatus for manufacturing the same.

Conventionally, a hydraulic material mixture such as fresh concrete or mortar is press-fitted into a forming area such as a mold or a similar gap between parts using a pumping mechanism such as a concrete pump or a mortar pump. It has been implemented since.

By the way, there are two types of such pumping mechanisms: those that pump with pulsation, such as the general piston type, one-way roke type, or squeeze type, and those that use non-pulsation, such as the screw type. In the case of injection molding by force-feeding a hard kneaded material, if pulsations occur in the fluid injection, a separation phenomenon between the solid and liquid components will occur in the injection molding section and injection pipe, and this will cause This is particularly noticeable in cases such as the prepacked method, where coarse aggregate is prefilled into the molding area and injection molded, and the molded product cannot have sufficient strength and has poor surface properties. ).

In addition, it is common practice today to force-feed such a kneaded material under high-pressure conditions and perform spraying, but in such spraying, the above-mentioned pulsation in the feeding of the mixed material is not necessary. If there is, it will be expanded by being combined with the high-pressure air flow for blowing, causing significant vibration or bending action to the entire pressure feed pipe, and especially strong vibrations will occur at the blow nozzle area. , it requires a great deal of effort to fix the entire pressure-feeding pipeline, which is several tens of meters long or more than 100 meters long, and to suppress the spray nozzle, and it is always operated by multiple people as the nozzle man, who holds the spray nozzle and operates the spray to the target construction location. is required for smooth operation,
Not only is it impossible to carry out construction work, but it also becomes a major cause of occupational diseases and requires frequent replacement.

Furthermore, even if an attempt is made to specify the spraying direction, the spraying direction always fluctuates, making it impossible to perform stable work, and the spraying fluctuates intermittently, resulting in unfavorable construction conditions and poor workability.

Therefore, in such a case, a mechanism that can obtain high pressure in a completely continuous state without pulsation, such as the above-mentioned screw system, should be adopted; When press-fitting something, the load is heavy, and the solid components in the mixed material cause significant wear on the rotating parts. , it becomes impossible to perform the desired compression molding.

In particular, when trying to obtain this pressure injection under calculation control conditions, the rotation speed of such a pressure injection mechanism should be substituted for the injection volume, but the specific injection volume is gradually reduced by driving and is controlled by calculation. make it impossible.

The present invention was devised after repeated studies in view of the above-mentioned circumstances, and the embodiment thereof will be described with reference to the attached drawings. A hydraulic kneaded material such as mortar or fresh concrete or paste contained in a tank 2 is pumped through a pipe 3 by a pulsating pumping mechanism 1, and is injected into a molding area 4 to obtain a molded body. , a closed air chamber 5 is formed in the conduit 3 at a position above the pressure feeding line, the kneaded material is once press-fitted into this closed air chamber 5, and under the gas pressure operating condition in the closed air chamber 5, the forming area is 4
It is proposed that it be press-fitted into the

That is, the kneaded material fed under pressure by the above-mentioned pulsating pressure feeding mechanism 1 is pressurized into the closed air chamber 5, compressing the air and other gases in the closed air chamber 5, and increasing the gas pressure at the upper part of the chamber 5. The kneaded material is forced into or sprayed into the molding area by the increased gas pressure in the closed air chamber 5, and the gas pressure in the closed air chamber 5 is always within a considerable range. However, since the conduit leading from the sealed air chamber 5 to the forming area 4 has a predetermined diameter and the kneaded material itself has a certain viscosity, the flow to the forming area 4 is limited. The injection conditions become substantially uniform, making it possible to perform quiet injection or spraying without pulsation.

In the drawing, 6 is a pressure gauge provided immediately before the forming area 4, and 7 is an overflow tank provided in a position opposite to the injection pipe 3 in the forming area 4, and is set above the forming area 4. What is done is the same as the sealed air chamber 5, and this overflow tank 7 is connected to a decompression pipe 8 connected to a decompression mechanism such as a vacuum pump or a vacuum tank.
are connected to each other so that the pressure inside the tank 7 and the molding area 4 can be reduced.

Reference numeral 9 denotes a valve, which is provided before and after the molding area 4, as well as in the decompression pipe 8, and 10 is an atmosphere opening port provided in the overflow tank 7, which also includes a valve.

The airtight air chamber 5 is formed in a divided manner so that the inside thereof can be washed as appropriate and a diaphragm can be inserted therein as the case may be.

The squeeze pump illustrated as an example of the pulsating pumping mechanism 1 has a rubber-like flexible conduit 11 over its semicircular area.
A receiving plate 12 is provided to receive this, and trochanters 14 provided at both ends of a rotating member 13 that is pivoted and rotated at the center position of the flexible conduit 11 sequentially push the flexible conduit 11. It is generally known that the fluid in the pipe line 11 is pumped by compressing and rotating the pipe in the direction of the forming area 4.

Although the illustrated embodiment is applied to a closed molding area 4, the present invention can be applied to the above-mentioned spraying method to achieve remarkable characteristics.

That is, FIG. 2 shows an embodiment in such a case, in which high-pressure air is further supplied to the pipe line 3 from the pressure-feeding mechanism 1 as described above through the pipe 18 to the area around the kneaded material to be fed to the nozzle 15 on the machine side. Supplied in a state surrounding the side, the hose line 16
It is configured to be sprayed from the spray nozzle 17 through the spray nozzle 17.

By configuring the lid as shown in Fig. 2, a stable constant amount of the kneaded material is continuously supplied from the machine side nozzle 15 as a non-pulsating flow as described above, and this can be supplied with a flow of high pressure air. It is surrounded and blown along with the flow of high-pressure air, and even if the volume of the high-pressure air fluctuates depending on the pressure conditions, it is stable under conditions where there is no significant vibration or violent movement of the hose 16. Fully continuous spraying can be achieved.

Of course, the present invention can also be used as is for encasing construction, and this embodiment is as shown in FIG.

i.e. the segment 20 as in the excavated tunnel 19.
Under the conditions where
Various construction methods have been used in the past, such as enclosing the pipe, but stabilization can be achieved by inserting the end of the pipe 3 from a part of the segment 20 toward the cavity 21 as described above. The kneaded material can be supplied and the construction can be carried out accurately.

The specific structure of the sealed air chamber 5 described above is shown in FIG. 4 and subsequent figures.

That is, in the case shown in FIG. 4, a lid 23 is pivotally attached 25 to one side of a base 22 provided in the pipe 3 as described above, and is fastened with a tightening member 24 with a sealing material 26 interposed. A pressure gauge 31 is mounted on the top surface of the lid body 23.
A ring-shaped cleaning mechanism 27 is provided on the inner surface of the top of the lid 23, that is, a nozzle 28 thereof is connected to the lid 23.
The pressure water supply pipe 2 is opened toward the inner surface of the pressure water supply pipe 2.
9 are connected via a valve 30, so that the inside of the sealed air chamber 5 can be cleaned as appropriate, such as after the completion of the pressure-feeding operation.

Further preferred embodiments of the closed air chamber 5 are shown separately in FIGS. 5-8.

In the lid shown in FIG. 4, the structure of the lid 23 is the same as that in FIGS. As shown in the figure, symmetrical inclined walls 32 are provided on both sides of the connecting part of the pipe line 3,
Therefore, a sufficient space is formed in the upper part of the lid body 23 to effectively obtain the pumping effect of the increased gas pressure, but the kneaded material at the bottom is always concentrated in the pipe line 3. This eliminates the possibility that upper air, etc. may get mixed into the pipe line, minimizes the adhesion of the kneaded material in the closed air chamber 5, and further improves the cleaning effect of water washing by the cleaning mechanism 27 as described above. Furthermore, the washing water is effectively discharged.

Another more preferred sealed air chamber is shown in FIG.

That is, the shape and structure of the airtight air chamber 5 are the same as those described in the fourth section.
Although it is similar to the one shown in FIGS. 7 to 7, the one shown in FIG. It is attached below to provide the same cleaning effect as in the case described above, but at the same time, it also has a supporting function for the air bag 33 and is properly held within the lid 23.

The air sac body 33 has a valve part 34, and an injection pipe 35 connected to a needle-shaped high-pressure air source is bulged out in a hemispherical shape, and a cut 36 is provided only on the inside, similar to the air injection valve in a ball game. In the same way as a ball for a ball game, air can be released by inserting air into the valve part 34 and inserting a simple hollow pipe in place of the injection pipe 35. By adopting this, it is possible to form a predetermined air pressure in the portion in advance and to completely prevent the inner surface of the lid body 23 from being soiled.

Some examples of specific examples carried out by the present inventors using the above-mentioned apparatus are as follows.

Example 1 In the case of pre-packaged injection molding in a mold
Using the apparatus configured as shown in the figure, the molding area 4
A closed mold having an internal volume of 200 x 100 x 15 cr was used, No. 4 crushed stones were filled in advance in the closed mold, and mortar was injected between the filled crushed stones.

After filling with crushed stone, the upper mold plate is set airtight via a sealing material, and then the pressure inside the mold is reduced to -60 crHg by operating the pressure reduction system via the overflow tank 7, and such reduced pressure conditions are maintained during the injection molding process. It was also maintained and implemented.

Tank 2 has a sand-cement ratio of 1:1 and a water-cement ratio of 4.
0% mixed mortar is stored, this mortar is pumped using a squeeze pump as described above, and a sealed air chamber 5 with a diameter of 500 mm and a height of 240 mm is prepared, and the inner diameter of the pipe line 3 is A vinyl hose of about 5 mm was used.

Under the configuration conditions described above, the pumping speed of the pumping mechanism 1 was varied, and a diaphragm valve in the closed air chamber 5 was used (Group I), and a 0.0 mm valve was placed above the diaphragm valve.
A back pressure of 1 kg/cm2 was applied (Group ■), and the diaphragm valve was removed (Group ■).
The acrylic resin plate (
The following is a summary of the results of examining the injection situation through a transparent tube (which can be seen through), and measuring the pressure fluctuations in the closed air chamber 5 and the pressure value or its fluctuations using a pressure gauge installed just before the mold. As shown in Table 1, the reading on the pressure gauge just before the mold is almost constant in all cases, with almost no fluctuation during the pouring process, and the inside of the mold is quiet without pulsation. injection was obtained.

Note that the injection rate 1 is 110 l/min, the injection rate 2 is 601/niy, and the injection rate 3 is 231/miy.

However, one of the molded bodies obtained by such injection molding
The strength after weeks was 562 to 603 kg/cm2,
Also, the strength after 4 weeks is 628-695 kg/cI? The surface texture was smooth.

On the other hand, in the case where the closed air chamber 5 is not used, the pressure fluctuation cannot be measured with the pressure gauge immediately before the mold even if the injection rate is set to 1, and the resulting product
The strength after 8 days was 528-632k in each part.
It varied over a large range such as g/cm2, and the surface properties were not favorable.

Example 2 In the case of spraying construction, using the same equipment as in Example 1, instead of mortar, a mixture of 5 to 10 mm of river gravel was added as coarse aggregate to the mortar with the above composition at a ratio of 350 kg/m3 of the amount of cement. Using concrete, a machine-side nozzle 15 is attached to the tip of the pipe line 3 instead of the formwork, and a spraying mechanism as shown in Fig. 2 is formed, and the pumping speed in the pumping mechanism is increased to 47 kph.
g/Sec and 6kg/Sec for the machine side nozzle.
cyt's high-pressure air is supplied, the surrounding side of the ready-mixed concrete that is sequentially delivered to the center of the nozzle is surrounded by a flow of Takada air, and the inside of the spraying hose is forced to be fed, and the spraying nozzle provided at the tip of this spraying hose is It was sprayed onto a vertical wall.

The amount of air used for spraying was approximately 10% of the amount of sprayed mortar by weight, and the spraying work conditions were such that there was almost no pulsation in the spray nozzle and other areas, and there was little turbulence in the hose 16, making it possible to spray safely. Furthermore, the mixing relationship between air and fresh concrete was stable and smooth spraying was achieved.

Example 3 In the case of backfilling, as shown in Figure 3, after constructing shield segments as shoring in the excavated tunnel, cement 200 kg/m3 and sand 760 kg/m3 were applied to the gap between the segments and the excavated surface.
A mortar containing 100 kg/m3 of fly ash, 50 kg/m3 of bentonite, and 400 kg/m3 of water was injection molded at an injection pressure of 1.5 kg/ff2.

During the entire injection process, there is almost no pulsation in the conduit forming the pumping line, and the injection can be carried out smoothly without causing any uneven pressure on the shield segment, thereby sequentially forming a preferable backfilling process. I was able to do that.

Example 4 Ready-mixed concrete was pumped and constructed at a construction site of a building that was approximately 20 m in height and approximately 60 m horizontally from the pulsating pumping mechanism 1.

The pipe 3 used for this pumping has an inner diameter of 100 mm, and the pumped ready-mixed concrete has a W/C of 55%, a slump value of 21 Ct, 5 mm river sand and 25 mm gravel, and the mixing ratio is unit cement. Amount 369kg/m3,
Sand amount 824kg/m3, gravel 918kg/m3, water amount 2
It was 03 kg/m3.

When carrying out this pressure feeding, we measured the internal pressure at the part connected to the pumping mechanism 1 when the present invention was not used to carry out pressure feeding, and the maximum pulsating pressure was 23.4 kg/c.
It was m2.

On the other hand, when the above-described sealed air chamber 5 according to the present invention is employed, when the pressure inside the chamber 5 is set to about 6 kg/ff2, the air is pumped almost in a static state.
The pumping pressure was constant at approximately 15 kg/Cm2.

Furthermore, regarding the sample taken at the tip of the nozzle at this time, the amount of breathing was 0.04% for the sample not according to the present invention, whereas it was 0.019% for the sample according to the present invention. The compressive strength of the material according to the present invention at 28 days of age was 348 kg/cm2, while that of the comparative example was 325 kg/cm2, which indicates that the material according to the present invention is superior. I learned.

Example 5 This invention uses glass balls with a diameter of 20 mm in mortar for backfilling prepared by mixing 1 part of cement with 2 parts of fly ash, 0.5 parts of bentonite, 1.5 parts of river sand, and 0.4 parts of water. The fluidity test measurement results proposed by
/cm2, ΔFo is 0.059/cr4, λ is 5g/c
n4, and this mortar was injected into the gap formed between the inner surface of the excavated tunnel and the shield segment using the same squeeze-type pumping mechanism 1 as in Example 1.

A closed air chamber 5 as described above was used, and the inner diameter of the conduit 3 was 1 inch, and the injection pressure in this case was a constant pressure of approximately 8 kg/cy2, allowing smooth injection.

On the other hand, if the pipe line 3 is directly jointed and injected without using the closed air chamber 5, considerable pulsation will occur, that is, pressure fluctuations in the range of 5 to 15 kg/cm2 will be repeated in the pipe line. The pouring was unstable and there was a lot of breathing water in the pouring mortar.

That is, the amount of breathing water when using the closed air chamber according to the present invention was less than 5%, whereas the amount of breathing water in the comparative example which did not use the closed air chamber was around IO%.

However, the strength of the backfill injection layer formed in this way after 28 days of construction was 10% by the method of the present invention.
kg/ff2, whereas in the case of the comparative example it was 4k
g/er2, and it was confirmed that the strength of the product according to the present invention was considerably superior to that of the comparative example.

According to the present invention as explained above, a pumping line for the hydraulic kneaded material using a pulsating pumping mechanism is adopted to obtain a pulsation-free injection supply and to separate the liquid and solid components, or to add high-pressure air. Stable injection molding or spraying can be achieved without changing the ratio, and by adopting a pulsating pumping mechanism for pumping the hydraulic kneaded material, the durability of the pumping mechanism can be improved. It is sufficiently high that it can perform stable work smoothly without causing fluctuations in its pumping function, and it can also advantageously carry out industrial mass production operations to provide high-quality products or construction. Therefore, it is an invention with great industrial effects.

[BRIEF DESCRIPTION OF THE DRAWINGS] The drawings show embodiments of the present invention, and FIG. 1 is an explanatory diagram showing an outline of an apparatus for carrying out the present invention in the case of injection into a mold, and FIG. Figure 3 is an explanatory diagram of the spraying construction state, Figure 3 is an explanatory diagram of the backfilling construction state, Figure 4 is a sectional view of an example of the sealed air chamber, Figure 5 is its plan view, and Figure 6 is the sealed air chamber. FIG. 7 is a side view of another embodiment of the air chamber, FIG. 7 is a front view of the air chamber as seen from the direction of pipe connection, and FIG. 8 is a side view of still another sealed air chamber cut along the direction of the pipe. However, in these drawings, 1 indicates a pulsating pumping mechanism, and 2
is a tank, 3 is a pipe, 4 is a molding area, 5 is a sealed air chamber, 6 is a pressure gauge, 7 is an overflow tank, 8 is a reduction pipe, 9 is a valve, 10 is an air opening, 11 is a flexible 12 is a receiving plate, 13 is a rotating member, 14 is a trochanter, 15 is a machine side nozzle, 16 is a hose pipe, 17 is a spray nozzle, 19 is a tunnel, 20 is a segment, 21 is a cavity, 22 is the base, 2
3 is a lid body, 26 is a sealing material, 27 is a cleaning mechanism, 28 is its nozzle, 29 is a pressure water supply pipe, 30 is a valve, 31 is a pressure gauge, 32 is an inclined wall, 33 is an air blue body, 34 is a valve 35 indicates an injection tube.

Claims (1)

[Scope of Claims] 1. A hydraulic kneaded material such as fresh concrete, mortar, or paste is pumped by a pulsating pumping mechanism, and this pulsating pumping flow is sent into a closed air chamber with a space formed above the pumping line. A method for producing a molded body using a hydraulic kneaded material, characterized in that the gas pressure in a closed air chamber is increased, and the hydraulic kneaded material is supplied to a molding area and molded using the increased gas pressure. 2. The method for producing a molded body using a hydraulic kneaded material according to claim 1, wherein the lees aggregate is flapped in the molding area, and mortar is injected into the molding area through a conduit from a closed air chamber. 3 A nozzle configured to supply high-pressure air is connected to a conduit connected to a closed air chamber, and the hydraulic kneaded material is sprayed using the high-pressure air onto a molding area formed against the wall surface. A method for producing a molded body using a hydraulic kneaded material according to claim 1, which supplies the following: 4. A method for producing a molded body using a hydraulic kneaded material according to claim 1, wherein a shield segment is provided with a required gap on an excavated wall surface, and a kneaded material is injected into the gap. 5. A conduit in which a pulsating king-feeding mechanism is inserted is formed between a hydraulic kneaded material receiving mechanism such as ready-mixed concrete, mortar, or paste and a forming area, and furthermore, a conduit in which a pulsating king-feeding mechanism is connected to the forming area is formed. An apparatus for manufacturing a molded body using a hydraulic kneaded material, characterized by a closed air chamber with a space formed above the pipe pressure feeding line between the two. 6. An apparatus for producing a molded body using a hydraulic kneaded material according to claim 5, which uses a closed air chamber equipped with a cleaning mechanism inside the top. 7. An apparatus for producing a molded body using a hydraulic kneaded material according to claim 5, wherein the closed air chamber has an inclined wall with respect to the pressure feeding line formed by a conduit. 8. A sealed air chamber is constituted by a base body and a lid body, which are tightened with a sealing material interposed therebetween, and an air sac body is placed inside the lid body, and air is pressurized into the air sac body through a valve. An apparatus for producing a molded body using a hydraulic kneaded material according to claim 5.