JP6282473B2 - Concrete product manufacturing apparatus and concrete product manufacturing method - Google Patents

Description

  The present invention relates to a concrete product manufacturing apparatus and a concrete product manufacturing method.

  Conventionally, as a method of manufacturing a cylindrical concrete product, a mold frame in which joint fittings attached to both ends of a reinforcing steel bar are arranged on both sides is installed in a centrifugal molding machine, and the mold frame is rotated while the mold frame is rotated. A technique is known in which concrete is poured into a concrete product and a concrete product is formed while applying centrifugal force (see, for example, Patent Document 1).

JP-A-5-17938

  However, in the case of the above-described conventional technology, a factory facility for operating a large centrifugal molding machine is required, and the number of diversions is reduced due to the damage of the mold due to the centrifugal force load, or the centrifugal force can be resisted. The formwork designed in such a manner is expensive, which causes a problem that the cost of the concrete product increases. In addition, when concrete is put into a formwork, vibrations for promoting filling and noise for operating large machines have a great influence on the environment around the factory. Furthermore, there is a problem that the cost of transporting heavy concrete products from the factory to the construction site is increased, which increases the construction cost.

  An object of the present invention is to provide a concrete product manufacturing apparatus and a concrete product manufacturing method capable of manufacturing a concrete product at low cost.

In order to solve the above problems, the invention according to claim 1 is a concrete product manufacturing apparatus,
An outer mold or a steel pipe that houses therein a steel bar extending in a predetermined direction and a pair of fitting hardware fixed at both ends of the steel bar;
It has a tapered surface that reduces the diameter toward the tip along the axial direction of the steel rod, and is composed of a pair of cores that are arranged so that the tips face each other, and the tapered surface and the outer frame or the steel pipe An inner mold that forms a space between which concrete is poured,
A bowl-shaped frame that movably supports the rear ends of the pair of cores;
With
At least one of the cores of the steel rod is placed so that the space is compressed and the concrete is pressurized when the pair of cores are brought close to each other and the space is filled with concrete . A moving means for moving along the axial direction is provided.

The invention according to claim 2 is a concrete product manufacturing apparatus,
An outer mold or a steel pipe that houses therein a steel bar extending in a predetermined direction and a pair of fitting hardware fixed at both ends of the steel bar;
It has a tapered surface that reduces the diameter toward the tip along the axial direction of the steel rod, and is composed of a pair of cores that are arranged so that the tips face each other, and the tapered surface and the outer frame or the steel pipe An inner mold that forms a space between which concrete is poured,
A bowl-shaped frame that movably supports the rear ends of the pair of cores;
Moving means for moving at least one of the cores along the axial direction of the steel rod so as to bring the pair of cores close to and away from each other;
The pair of fitting hardware is in contact with the saddle frame on both ends of the steel bar via a cushioning material .

The invention according to claim 3 is the concrete product manufacturing apparatus according to claim 1 or 2,
Of the pair of cores, an opening is provided on the distal end side of one core, and the distal end side of the other core extends along the axial direction of the steel rod. The protrusion part penetrated is provided, It is characterized by the above-mentioned.

The invention according to claim 4
An outer mold or a steel pipe that houses therein a steel bar extending in a predetermined direction and a pair of fitting hardware fixed at both ends of the steel bar;
It has a tapered surface that reduces the diameter toward the tip along the axial direction of the steel rod, and is composed of a pair of cores that are arranged so that the tips face each other, and the tapered surface and the outer frame or the steel pipe An inner mold that forms a space between which concrete is poured,
A bowl-shaped frame that movably supports the rear ends of the pair of cores;
And a moving means for moving at least one of the cores along the axial direction of the steel bar so as to bring the pair of cores close to and away from each other. A method,
Putting concrete into the space between the pair of fittings;
A step of proximity to each other of the pair of core,
After holding for a predetermined time at a position in close proximity to said pair of core, the steps of demolding the inside formwork is moved to space the pair of core,
It is characterized by including.

  According to the present invention, a concrete product can be manufactured at low cost.

They are the side view (a) which shows the manufacturing apparatus of the concrete product in this embodiment in cross section, and sectional drawing in the BB line of Fig.1 (a). It is a side view which shows the manufacturing apparatus of the concrete product in this embodiment in cross section, and has shown the state which pulled a pair of cores in the center of the apparatus.

  Hereinafter, embodiments of a concrete product manufacturing apparatus and a concrete product manufacturing method according to the present invention will be described in detail with reference to the drawings.

  As shown in FIGS. 1A and 1B, the concrete product manufacturing apparatus 100 according to the present embodiment includes an outer mold frame 10 assembled in a substantially rectangular tube shape, and an inner frame disposed inside the outer mold frame 10. A mold 20 and a saddle mold 30 that closes the openings at both ends of the outer mold 10 are provided.

The outer mold 10 is assembled so that a steel bar 1 extending in a predetermined direction and a pair of fittings 2 fixed to both ends of the steel bar 1 can be accommodated therein.
The steel bar 1 is, for example, a PC steel bar, and is a core material that serves as a reinforcing bar for a concrete product such as a concrete pile.
The joint hardware 2 is a steel plate-like member having an opening formed in the center thereof, and is a member that becomes a joint end plate of a concrete product such as a concrete pile.
Both ends of the steel bar 1 are fixed to the joint hardware 2 by a fixing tool such as a bolt, and the steel bar 1 and the pair of joint hardware 2 are integrated. In the present embodiment, twelve steel bars 1 are bridged between a pair of fittings 2.

The inner mold 20 has a tapered surface that decreases in diameter toward the tips 21a and 22a along the direction in which the steel bar 1 accommodated in the outer mold 10 extends (the axial direction of the steel bar 1). It consists of a pair of cores 21 and 22 with their tips facing each other.
An opening 23 is provided on the tip 21 a side of one core 21, and a protrusion 24 inserted through the opening 23 is provided on the tip 22 a side of the other core 22.
The opening 23 provided at the tip 21a of the core 21 is a cylindrical member, and has a size such that the protruding portion 24 is in sliding contact with the inner peripheral surface thereof.
The protrusion 24 provided at the tip 22a of the core 22 is a cylindrical member extending along the axial direction of the steel rod 1, and its outer peripheral surface is in sliding contact with the opening 23 and moves in the tube axis direction. It has a possible shape. In addition, the inner surfaces of the inner molds 20 are prevented from being slackened by, for example, securing a considerable length on the sliding surfaces of the cores 21 and 22.
Therefore, a space S into which concrete is poured is formed between the tapered surface of the inner mold 20 and the outer mold 10 in a state where the inner mold 20 is provided in the outer mold 10.

The pair of cores 21 and 22 of the inner mold 20 has a hollow portion on the inside, and is a moving means for moving the cores 21 and 22 along the axial direction of the steel rod 1 in the hollow portion. A cylinder device 40 is provided.
The cylinder device 40 is, for example, a double-acting hydraulic cylinder, and includes a cylinder tube 41 and a piston rod 42. The cylinder tube 41 is connected to one core 21, and the piston rod 42 is connected to the other core 22. In particular, the cylinder tube 41 is connected to the core 21 via a connection pin 43 that can be opened and closed by remote operation to switch the attachment / detachment state.
By operating this cylinder device 40 and moving the piston rod 42 forward and backward with respect to the cylinder tube 41, the tip 21a of the one core 21 and the tip 22a of the other core 22 can be brought close to or separated from each other. . Then, the cylinder device 40 moves the pair of cores 21, 22 close to each other or separates them so that the opening 23 provided at the tip 21 a of one core 21 and the tip 22 a of the other core 22 The pair of cores 21 and 22 can be slid so that the provided protruding portion 24 moves in sliding contact.

The saddle mold 30 is disposed at both ends of the outer mold 10 in the longitudinal direction.
The saddle mold 30 is provided with a recess 30a that slidably supports the rear end portions 21b and 22b of the cores 21 and 22 constituting the inner mold 20.
In addition, a buffer material 50 having elasticity is provided on the inner surface of the saddle mold frame 30, and the pair of joint hardware 2 fixed to both ends of the steel rod 1 accommodated in the outer mold frame 10 includes a buffer material. 50 is in contact with the saddle form frame 30. The buffer material 50 is a plate-like member made of, for example, styrene foam or hard sponge, and has an opening formed on the center side in the same manner as the joint hardware 2.

  Next, a concrete product manufacturing method using the concrete product manufacturing apparatus 100 will be described.

First, a plurality of (for example, 12) steel rods 1 are attached so as to be bridged between a pair of fittings 2.
A rectangular tube-shaped outer mold frame 10 that is long in the extending direction of the steel bar 1 is assembled so that the steel bar 1 fixed between the pair of fittings 2 is housed inside.
Further, a haunch 60 is provided at the corner of the outer mold 10 (see FIG. 1B). The haunch 60 is a member made of a water-permeable material such as hard urethane.

Next, one core 21 is inserted from the opening of one joint hardware 2, and the other core 22 is inserted from the opening of the other joint hardware 2. A piston rod 42 is connected to the other core 22, and a cylinder device 40 is attached to the core 22 side.
Then, at approximately the center between the pair of fittings 2, the protrusion 24 provided at the tip 22 a of the other core 22 is inserted into the opening 23 provided at the tip 21 a of the one core 21. Then, the pair of cores 21 and 22 are assembled in a state where the protruding portion 24 is inserted into the opening 23.
Further, when the protruding portion 24 of the core 22 is inserted into the opening 23 of the core 21, the cylinder tube 41 of the cylinder device 40 attached to the other core 22 is inserted into the one core 21. . When the cylinder tube 41 reaches a predetermined position in the core 21, the connecting pin 43 is operated by remote control to connect the cylinder tube 41 to the core 21.
By connecting the pair of cores 21 and 22 via the cylinder device 40 in this way, when the cylinder device 40 is operated, the tip 21a of one core 21 and the tip 22a of the other core 22 are connected. The inner mold 20 that can be brought close to or separated from is assembled.

Next, the buffer material 50 is sandwiched between the joint hardware 2 and the saddle mold frame 30, and the saddle mold frame 30 is fixed to both ends of the outer mold frame 10. At this time, the rear end portions 21 b and 22 b of the cores 21 and 22 constituting the inner mold frame 20 are aligned with the recesses 30 a of the saddle mold frame 30, and the saddle mold frame 30 is assembled to the outer mold frame 10.
In this way, the concrete product manufacturing apparatus 100 shown in FIGS. 1A and 1B is completed.

Next, concrete is poured from an insertion port (not shown) provided in the outer mold 10, and the concrete is poured into a space S between the pair of joint hardware 2 and between the outer mold 10 and the inner mold 20. To do. At this time, it is preferable to fill the space S with the concrete while promoting the fluidity of the concrete by operating the cylinder device 40 and repeating the advancing and retreating to move the pair of cores 21 and 22 close to and away from each other. .
Then, after filling the space S with a predetermined amount of concrete, the inlet (not shown) is closed.

Next, as shown in FIG. 2, the cylinder device 40 is operated so as to draw the piston rod 42 into the cylinder tube 41, and the tip 21 a of one core 21 and the tip 22 a of the other core 22 are brought close to each other.
In this way, the pair of cores 21 and 22 that are tapered toward the tips 21a and 22a are drawn toward the center of the manufacturing apparatus 100 so that the tips 21a and 22a come close to each other, so that the concrete can be obtained. The filled space S comes to be compressed, the internal pressure in the space S rises, and the concrete is in a pressurized state.
Then, the concrete is hardened by holding the pair of cores 21 and 22 toward the center of the apparatus for a predetermined time so that the internal pressure of the concrete in the manufacturing apparatus 100 becomes a set value.
In addition, in FIG. 2, illustration of the concrete with which the space S was filled is abbreviate | omitted.

Here, the process of holding the state where the tips 21a and 22a of the pair of cores 21 and 22 are close to each other for a predetermined time will be described.
When the pair of cores 21 and 22 are drawn toward the center side of the manufacturing apparatus 100, the space S between the pair of fittings 2 is compressed, and the concrete filled in the space S is evenly pressurized. A pressing force acts on the joint hardware 2 facing S, and the pair of joint hardware 2 is pressed in a direction away from each other and pressed toward the vertical frame 30.
At this time, since the cushioning material 50 is interposed between the joint hardware 2 and the saddle mold frame 30, the elongation of the steel rod 1 when the pair of joint hardware 2 is pressed against the saddle mold 30 respectively. Is absorbed by the buffer material 50 and pretension is introduced into the steel rod 1.
By prepressing and holding the concrete filled in the space S in this way, pretension can be introduced into the steel rod 1, and further, the pretensioned steel is introduced by holding the concrete under pressure for a predetermined time and hardening it. The bar 1 introduces prestressed concrete into the concrete after the inner mold 20 has been removed.
In addition, since the moving amount | distance which draws a pair of cores 21 and 22 to the center side of the manufacturing apparatus 100 is dependent on the excess water and air in concrete, the correlation with a concrete mixing | blending, a concrete volume change, and an internal pressure change beforehand By taking this, the internal pressure of the concrete can be adjusted to a desired set value in a state where the tips of the cores 21 and 22 are in contact with each other.
Further, if the concrete is pressed and held in a state where the tips of the cores 21 and 22 are in contact with each other, the hardened concrete is in contact with the tapered surfaces of the cores 21 and 22. Demolding becomes easy.

Next, the state in which the pair of cores 21 and 22 are attracted toward the center of the manufacturing apparatus 100 is maintained, and the concrete in the manufacturing apparatus 100 is pressed and held for a predetermined time to harden the concrete, and then the piston is removed from the cylinder tube 41. The cylinder device 40 is operated so as to push out the rod 42, and the inner mold frame 20 is removed by moving the tip ends 21a, 22a of the pair of cores 21, 22 so as to be separated from each other.
In addition, after the saddle mold 30 is removed, the connecting pin 43 is operated by remote operation to remove the cylinder tube 41 from the core 21 and remove the one core 21 and the other core 22 respectively. Furthermore, the outer mold 10 is removed from the mold to obtain a concrete product.
The demolded concrete product is completed, for example, as a concrete pile after wet curing at high temperature, for example, by individually covering with a sheet and steam curing.
Thus, the prestressed concrete pile (PC pile) by which the prestressed is introduced into concrete with the steel bar 1 in which the pretension was introduced can be manufactured.

As described above, the concrete product manufacturing apparatus 100 of the present embodiment has a simple structure and can be easily installed and removed. Therefore, the manufacturing apparatus 100 is installed at a construction site. Thus, it becomes possible to manufacture concrete products using ready-mixed concrete and on-site kneaded concrete at each construction site.
And if concrete products can be manufactured at the construction site, large factory equipment will be unnecessary, and the cost of transporting heavy concrete products from the factory to the construction site can be reduced. Construction cost can be reduced.
In addition, the manufacturing method using the concrete product manufacturing apparatus 100 does not perform centrifugal force molding or vibration compaction as in the prior art, so there is no need to apply excessive reinforcement to the mold, and the mold Therefore, the maintenance cost of the manufacturing apparatus 100 can be reduced, and the product cost and the construction cost can be reduced. Furthermore, no noise or vibration is involved, so there is no impact on the environment around the site.
That is, according to the concrete product manufacturing method using the concrete product manufacturing apparatus 100 of the present embodiment, a concrete product such as a concrete pile can be manufactured at low cost, and construction at low cost becomes possible.

In addition, since the inner mold frame 20 constituted by the pair of cores 21 and 22 that are closely spaced by the cylinder device 40 is adopted in the manufacturing apparatus 100, the concrete filled in the space S in the manufacturing apparatus 100 is suitably added. Since the excess water and air contained in the concrete can be discharged well, it is possible to form a solid concrete without the need for compaction such as centrifugal force and vibration. Strong and high-quality concrete products can be manufactured.
Further, by providing the water-permeable haunch 60 at the corner of the outer mold 10 in the manufacturing apparatus 100, it is easy to drain the excess water of the concrete, and the W / C (water cement ratio) can be reduced. The strength of concrete products can be improved.

Further, when the concrete is hardened, the concrete is pressed by the cores 21 and 22 of the inner mold frame 20, so that a pressing force in a direction away from each other acts on the pair of fittings 2. Since pretension is introduced in the axial direction of the steel bar 1 fixed to the metal object 2, prestressed is introduced into the concrete after the inner mold 20 is removed.
Therefore, when manufacturing a concrete product, it is not necessary to separately prepare a special tool or device for introducing pretension into the steel bar 1, and it is possible to save time and labor for introducing pretension into the steel bar 1 in advance. Can do. That is, according to the concrete product manufacturing apparatus 100 including the inner mold frame 20 composed of the pair of cores 21 and 22 that are close to and separated from each other by the cylinder device 40, the concrete product into which prestressed is easily introduced can be manufactured. Can do.

In the above embodiment, the pair of cores 21 and 22 are moved together by the cylinder device 40 so as to be brought closer to the center of the manufacturing apparatus 100 so that the tips of the two are close to each other. However, the present invention is not limited to this. For example, one core 21 is fixed to the saddle type frame 30 side, and the other core 22 is moved by the operation of the cylinder device 40 so as to be close to the one core 21. You may make it make it.
In addition, the cylinder device 40 is not limited to the tip side of the cores 21 and 22, and for example, the cylinder device 40 is provided at the rear end portion 21 b of one core 21 and the piston rod 42 is connected to the rear end of the other core. The structure may be such that the portion 22b is penetrated and connected, or the cylinder devices are provided on the rear end portions 21b and 22b of the cores 21 and 22, respectively, and the cores 21 and 22 are pushed out toward the center of the device. It may be a configuration. Furthermore, the tips of the cores 21 and 22 may be brought into contact with each other in advance, and may be pressurized with the pump pressure when the concrete is charged.

  In the present embodiment, the pretension is introduced to the steel rod 1 by disposing the buffer material 50 between the joint hardware 2 and the vertical frame 30. When the cushioning material 50 is not disposed therebetween, the steel rod 1 may be tensioned before the inner mold 20 is removed, and prestressed may be introduced into the concrete after being removed.

In the present embodiment, the cross-sectional shape of the outer mold frame 10 is rectangular, but the present invention is not limited to this, and the cross-sectional shape is arbitrary. For example, the cross-sectional shape of the outer mold frame 10 May be circular. Similarly, the cross-sectional shapes of the cores 21 and 22 are arbitrary.
The technology of the present invention is not limited to manufacturing PC piles as concrete products, but can also be applied to the manufacture of RC piles, and can also be applied to products other than concrete piles.
In this embodiment, the outer mold is arranged, but it goes without saying that a steel pipe concrete pile can be produced by using a steel pipe instead.

  In addition, it is needless to say that other specific detailed structures can be appropriately changed.

DESCRIPTION OF SYMBOLS 1 Steel bar 2 Joint metal | frame 10 Outer mold frame 20 Inner mold frame 21 One core 21a Front end 21b Rear end part 22 Other core 22a Front end 22b Rear end part 23 Opening part 24 Projection part 30 Vertical mold frame 40 Cylinder apparatus ( transportation)
50 Buffer material 60 Haunch 100 Concrete product manufacturing equipment S Space

Claims (4)

An outer mold or a steel pipe that houses therein a steel bar extending in a predetermined direction and a pair of fitting hardware fixed at both ends of the steel bar;
It has a tapered surface that reduces the diameter toward the tip along the axial direction of the steel rod, and is composed of a pair of cores that are arranged so that the tips face each other, and the tapered surface and the outer frame or the steel pipe An inner mold that forms a space between which concrete is poured,
A bowl-shaped frame that movably supports the rear ends of the pair of cores;
With
At least one of the cores of the steel rod is placed so that the space is compressed and the concrete is pressurized when the pair of cores are brought close to each other and the space is filled with concrete . A concrete product manufacturing apparatus comprising a moving means for moving along an axial direction. An outer mold or a steel pipe that houses therein a steel bar extending in a predetermined direction and a pair of fitting hardware fixed at both ends of the steel bar;
It has a tapered surface that reduces the diameter toward the tip along the axial direction of the steel rod, and is composed of a pair of cores that are arranged so that the tips face each other, and the tapered surface and the outer frame or the steel pipe An inner mold that forms a space between which concrete is poured,
A bowl-shaped frame that movably supports the rear ends of the pair of cores ;
So as to close to or away from each other of said pair of core, comprising moving means for moving along at least one of the core in the axial direction of the steel bars, and
The pair of joint hardware is in contact with the vertical frame on both end sides of the steel bar via a cushioning material, and the concrete product manufacturing apparatus. Of the pair of cores, an opening is provided on the distal end side of one core, and the distal end side of the other core extends along the axial direction of the steel rod. concrete product manufacturing apparatus according to claim 1 or 2, characterized in that the projecting portion to be inserted. An outer mold or a steel pipe that houses therein a steel bar extending in a predetermined direction and a pair of fitting hardware fixed at both ends of the steel bar;
It has a tapered surface that reduces the diameter toward the tip along the axial direction of the steel rod, and is composed of a pair of cores that are arranged so that the tips face each other, and the tapered surface and the outer frame or the steel pipe An inner mold that forms a space between which concrete is poured,
A bowl-shaped frame that movably supports the rear ends of the pair of cores;
And a moving means for moving at least one of the cores along the axial direction of the steel bar so as to bring the pair of cores close to and away from each other. A method,
Putting concrete into the space between the pair of fittings;
A step of proximity to each other of the pair of core,
After holding for a predetermined time at a position in close proximity to said pair of core, the steps of demolding the inside formwork is moved to space the pair of core,
A method for producing a concrete product, comprising:

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