JPH0310485B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a formwork device for forming a concrete pile having a shaft portion and a protrusion portion surrounding the shaft portion and having a top surface of a predetermined width; especially,
The present invention relates to a formwork device suitable for manufacturing concrete piles whose protrusions include spiral ribs.

(Prior Art) Conventionally, as a centrifugal forming formwork device for a concrete pile with a spiral brim having a top surface of a predetermined width dimension, a cylindrical outer frame consisting of a pair of halves and a cylindrical outer frame consisting of a pair of halves, There is a formwork device that includes an inner frame held within an outer frame (Utility Model Publication No. 59-17612).

According to this formwork device, the inner frame consists of a plurality of segments arranged at regular intervals in the axial direction on the inner surface of the outer frame, and the outer frame is arranged at the top of the brim of the concrete pile to be formed. The plurality of segments also define both side surfaces continuous to the top surface of the collar and the circumferential surface of the shaft portion.

By the way, when assembling the conventional formwork device, the segments are arranged in the axial direction at intervals equal to the width dimension of the brim of the concrete pile and fixed to the outer frame. Careful work was required to accurately arrange and fix the molds, which had the disadvantage of requiring a great deal of time and effort to assemble the molds.

(Object of the Invention) Therefore, an object of the present invention is to provide a formwork device that is easy to assemble.

(Structure of the Invention) The present invention comprises an inner frame that is held within an outer frame and defines the shaft and protrusions of the concrete pile, and is composed of a plurality of segments that are divided in the circumferential direction and the axial direction and abutted against each other, The basic feature is that each segment is provided with a flange portion that defines a half width of the top surface of the projection.

Further, the present invention is characterized in that segments adjacent in the circumferential direction are butted together via a packing provided on one of them.

(Operations and Effects of the Invention) In the present invention, there are cases where the flange portion is a pair and cases where there is a single flange portion. In either case, when the flanges of the pair of segments are abutted against each other in the axial direction, the abutted flanges define the top surface of the protrusion of the concrete pile. Therefore, when assembling the formwork device, a plurality of segments can be aligned in the axial direction by abutting against each other, without providing intervals between the segments as in the prior art. Therefore, compared to the conventional case of arranging segments at intervals, it is possible to arrange a plurality of segments more accurately, and the time and effort required for arranging the segments can be significantly reduced. can.

In addition, during centrifugal force forming of concrete piles, if there is a manufacturing error in the segments, the centrifugal force will create a small gap between the circumferential abutting surfaces of the segments, and cement paste may leak from this gap, which may affect the quality of the molded product. There is a risk of deterioration. This is also caused by the non-uniformity of the inner diameter of the outer frame.

According to the present invention, such leakage of cement paste can be reliably prevented by interposing a packing between circumferentially adjacent segments.

(Embodiments) The features of the present invention will become clearer from the following description of the illustrated embodiments.

Referring to FIG. 1, a formwork apparatus for forming concrete piles is indicated generally at 10.

A concrete pile 12 that is centrifugally formed by rotating the formwork device 10 around its longitudinal axis.
As shown by the imaginary line, has a shaft portion 14 and a protrusion 16 that extends to and surrounds the shaft portion, and the protrusion has a top surface 16a having a predetermined width l set appropriately.
has. The projection 16 of the illustrated concrete pile 12 consists of a collar that spirally surrounds the shaft 14 from one end to the other. Note that it is also possible to form a concrete pile (not shown) in which the protrusions include a plurality of endless flanges, that is, ring-shaped flanges, which are spaced apart from each other in the axial direction.

The formwork apparatus 10 includes an outer frame 18 and an inner frame 20 held by the outer frame and defining the shaft 14 and projections 16 of the concrete pile.

The outer frame 18 can be composed of a pair of half bodies 18a and 18b that are butted against each other to form a cylindrical body. An angle member 22a is provided on the side of both halves for fixing the abutted halves to each other.
22b (see FIG. 2).
Angle members 22a and 22b arranged opposite to each other
can be secured to each other using fasteners such as bolt and nut assemblies. Further, a plurality of tires 24 that transmit rotational force to the formwork device 10 for centrifugal force forming are arranged on the outer circumferential surface of the outer frame 18 at intervals from each other in the axial direction. Each ring-shaped tire 24 is divided into two parts and fixed to the outer peripheral surface of each half body.

The inner frame 20 is composed of a plurality of segments 26 that are divided in the circumferential direction and the axial direction, and the segments are abutted against each other in the circumferential direction (see FIG. 2) and the axial direction.

As is clear from FIG.
a and the other side surface 16c opposite to the side surface 16b
The angles formed by the two are different from each other. When forming the concrete pile 12 having such a protrusion 16, the number of divisions of the inner frame 26 in the circumferential direction, that is, the number of segments in the circumferential direction, is set to four or five or more, as in the illustrated example. It will be divided equally. Thereby, it is possible to eliminate the interference or catch that occurs between the segment 26 and the protrusion 16 of the molded product 12 at a position where the rotation angle is 180 degrees and makes demolding impossible. Depending on the shape of the protrusion, the number of divisions is two or three, and
It can also be divided into unequal parts. For example,
For example, when the side surfaces of the protrusion are parallel to each other, the angles formed by the top surface of the protrusion and each side surface may be equal.

As shown in FIGS. 1 and 3, each segment 26 has a flange portion 26a that defines a half width of the top surface 16a of the protrusion 16 of the molded product.

In the illustrated example, the segments other than some of the segments located near both ends of the outer frame 18 have lengths of uniaxial pitches, and both ends of the segments in the axial direction constitute the flange portions 26a. are doing. These segments are integrally formed by press working, and are connected to one flange part and one side surface 1 of the protrusion of the concrete pile.
6b, a side portion 26c that is connected to the other flange portion and defines the other side surface 16c of the protrusion, and a side portion 26c that is connected to both side portions 26b, 26c and defines the circumferential surface of the shaft portion 14 of the molded product. Peripheral part 26
d. The segments located near both ends of the outer frame 18 have a single flange portion 26a. Each segment can also be formed by interconnecting a plurality of plate materials without using the above-mentioned press working.

The plurality of segments 26 are arranged in the axial direction by bringing the flange portions of the segments into contact with the inner peripheral surface of the outer frame 18 and by abutting the flange portions of the segments against each other. A flange portion 26a continuous to the side portion 26b of one segment and a flange portion 26 continuous to the side portion 26c of the other segment
By butting both flange portions 26
a will cooperate to define the top surface 16a of the protrusion of the concrete pile. By arranging the segments in the axial direction on the entire inner circumferential surface of the outer frame 18 and aligning the end faces in the axial direction of a plurality of (four in the illustrated example) segment rows that are butted against each other in the axial direction. , the segments are butted against each other in the circumferential direction. In this way, the plurality of segments constituting the inner frame 20 are positioned, but in this positioning,
To eliminate the need for extremely careful and long-time work as in the past.

The plurality of segments 26 arranged in this manner can be fixed to the outer frame 18 via the fasteners, but as shown in FIGS. 1 and 2, a plate 28 having an arcuate cross section is A plurality of segments 26 are formed by bringing the flange portion 26a into contact with the inner circumferential surface.
After arranging and fixing as described above, the plate 28 may be placed and fixed with its outer circumferential surface in contact with the inner circumferential surface of the outer frame 18. In the plate 28 shown in the figure, the length of the circular arc is set to one quarter of the circumference.

The segments 26 fixed to the outer frame 18 can be only the segment 26A located above and the segment 26B located below. When using the plate 28, an outer frame made of a single cylindrical body can be used, and the inner frame 20 can be constructed by inserting the plate 28 from one of the open ends of the cylindrical body. Further, the outer frame 18 can be constructed of a hoop-like strip.

When the four plates 28 are arranged along the inner peripheral surface of the outer frame 18 with their ends aligned, the four plates 28 have a cylindrical shape, and the plates 28
As in the case where the concrete pile 12 is not used, the plurality of segments 26 on the circumferentially adjacent plates 28 are butted against each other in the circumferential direction so as to have the same external shape as the concrete pile 12, as shown in FIG.

By the way, when there is a manufacturing error in the segments 26, a slight gap is created between the mutually abutted segments 26 due to the centrifugal force exerted during the forming of the concrete pile 12, and cement paste leaks from this gap. Product quality may be impaired.

In order to prevent this, a packing 30 is attached to either one of the segments 26 adjacent in the circumferential direction.
is provided, and liquid tightness between the segments is maintained through the packing.

The packing 30 can be provided only on both end surfaces in the circumferential direction of the segments 26 arranged on the upper and lower plates 28 as seen in FIG. 2 (hereinafter, to distinguish the positions of the segments in FIG. 2, The segments located on the top and bottom are respectively 26A and 26B, and the segments located on the left and right are 26C and 26D, respectively.)

As shown in detail in FIGS. 4 and 5, the segment 26 on which the packing 30 is provided has both side portions 26b, 26 near the end surface in the circumferential direction.
A plate member 32 that occupies a space defined by c and the circumferential surface portion 26d is fixed, and a holding member 34 that holds the packing 30 in cooperation with the plate member and the circumferential surface portion 26d is fixed to the plate member 32. The holding member 34 has a chevron-shaped cross-sectional shape, and has both side portions 26
b, 26c and the circumferential surface portion 26d and are arranged at a predetermined interval therebetween.

Further, at both ends in the circumferential direction of the left and right segments 26C and 26D where the packing 30 is not provided,
A plate member 36 (FIG. 2) having the same shape as the plate member 32 is attached to which the gasket 30 is in close contact.

As shown in FIG. 6, on the outer surface of the segment 26, both sides 26b, 26c and the peripheral surface
It is desirable to attach reinforcing ribs 38 to the peripheral surface portion 26d and the pair of plate members 32.

The gasket 30 can be placed at one end of each of the upper, lower, left, and right segments 26A to 26D;
It is desirable to provide only 6A and 26B. Prior to forming the concrete pile 12, the upper half 18a of the outer frame and the upper segment 26 are
In some cases, concrete is poured from above into the space surrounded by segments 26B, 26C, and 26D without arranging concrete and plate 28.
This is to prevent the concrete from adhering to the packing at this time, and although it is difficult to completely remove the concrete attached to the packing, conversely, the plate member of the segment where the packing 30 is not provided Concrete adhering to 36 can be easily removed.

In addition, as shown in FIG.
By forming the intersections b with c to be curved, these intersections can be completely filled with concrete during forming, and when the concrete pile is used as a product, the shaft 14 and the protrusion 16 can be It is possible to alleviate the stress concentration on the boundary between the Further, by forming the segment 26 so that the intersection c between the side portion 26b and the peripheral surface portion 26d and the intersection d between the side portion 26c and the peripheral surface portion 26d are curved, the molded product of the segment 26 can be removed. It becomes easy to peel off the molded product from the mold, and it is possible to prevent the protrusions 16 of the molded product from partially falling off during demolding.

The concrete pile 12 has a plurality of holes extending in the axial direction within the shaft portion 14 in order to increase its strength.
PC steel material 40 is embedded. The PC steel material 40 is kept under tension during the forming of the concrete pile 12, and is released after forming.

Both ends of the prestressed steel material 40 subjected to the hedging process are fitted into one end of the outer frame 18 and have a cylindrical shape against which one ends of the plurality of plates 28 and the plurality of segments 26 fixed thereto abut. An annular joint fitting 44 is fitted to the spacer 42 so as to be movable in the axial direction, and the other end of the plate 28 and the plurality of segments 26 is fitted to the other end of the outer frame 18. It is locked to an annular joint metal fitting 48 that is fitted into an annular spacer 46 that is in contact with it. A connecting plate 52 made of an annular plate is fixed to the joint hardware 44 via bolts 50.
A tension plate 54 is disposed within the spacer 42 at a distance from the connecting plate toward the open end of the outer frame 18 . A tension bar 56 extending in the axial direction is screwed into the tension plate 54 at its central portion. The connecting plate 52 and the tension plate 54 are connected to each other via a two-piece joint ring 58 that is fitted into the spacer 42 so as to be movable in the axial direction thereof. The tension bar 56 is connected to the outside through holes provided in each of a support plate 60 fitted to the outer frame while in contact with one end of the spacer 42 and a fixing plate 62 fixed to an end surface of one end of the outer frame 18. It stands out. On the other hand, the joint hardware 48 disposed at the other end of the outer frame 18 is fixed to the end face of the other end of the outer frame 18 via an annular connecting plate 66 fixed thereto via bolts 64. It is held in place by a cap 68.

While applying a tensile force to the tension bar 56, by bringing the nut 70 screwed into the tension bar into contact with the fixing plate via the washer 62,
The PC steel material 40 can be kept under tension. During demolding, when the upper half 18a is removed, the row of segments 26A and the plate 28 fixed thereto are removed together with the half 18a and peeled off from the molded product 12.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of a formwork device according to the present invention, FIG. 2 is a side view of the inside of the outer frame as seen from one end surface, and FIG. Front view of the combined segments, 4th
5 is a partial cross-sectional view taken along line 5--5 in FIG. 4, and FIG. 6 is a rear view showing the outer surface of the segment. 10: Formwork equipment, 12: Concrete pile,
14, 16: Shaft and projection of concrete pile, 18: Outer frame, 20: Inner frame, 26: Segment, 26a: Flange of segment, 28: Plate, 30: Packing, 32, 36: Plate member,
34: Holding member.

Claims (1)

[Scope of Claims] 1. A formwork device for forming a concrete pile having a shaft portion and a projection portion surrounding the shaft portion and having a top surface of a predetermined width, which comprises: an outer frame; an inner frame held by an outer frame and defining the shaft and the protrusion of the concrete pile to be formed, the inner frame being made up of a plurality of segments divided in the circumferential direction and the axial direction; A formwork device comprising: each segment having a flange portion defining a half width of the top surface of the protrusion. 2. The segment has a side portion that defines a side surface that is continuous with the top surface of the protrusion, and a peripheral surface that defines the peripheral surface of the shaft, and includes an intersection between the flange portion and the side portion, and a peripheral surface that defines the peripheral surface of the shaft portion. The formwork device according to claim 1, wherein intersections between the side portions and the peripheral surface portion are each curved. 3. The formwork device according to claim 1, wherein the protrusion includes a collar spirally surrounding the shaft. 4. The formwork device according to claim 1, wherein the protrusion comprises a plurality of endless flanges spaced apart from each other in the axial direction. 5. The formwork device according to claim 1, wherein the segment is equally divided into four in the circumferential direction. 6. A formwork device for forming a concrete pile having a shaft portion, a protrusion surrounding the shaft portion, and having a top surface of a predetermined width, the device comprising an outer frame and a projection portion held by the outer frame. The inner frame includes a plurality of segments that are divided in the circumferential direction and the axial direction, and each segment is divided into a plurality of segments in the circumferential direction and in the axial direction. The segment has a flange portion defining a half width of the top surface of the protrusion, and the segments adjacent in the circumferential direction are butted against each other via a packing provided on one of the segments. Device.