JPH081842Y2 - Formwork for concrete pipe molding - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold for molding a concrete pipe, and more particularly to a mold for molding a concrete pipe having a flat bottom surface.

[0002]

2. Description of the Related Art Conventionally, concrete pipes having a circular outer shape and inner shape, as represented by centrifugal force reinforced concrete pipes (so-called fume pipes), have been widely used. However, in order to facilitate the construction and to enable installation on soft ground, etc., a pipe with a non-circular outer shape having a flat bottom, such as a box culvert, has come to be used, and its molding technique has been developed. In the case of molding such a non-circular tubular conduit by, for example, a centrifugal molding method, conventionally, it is generally performed as follows. That is, the reinforcing bars are assembled in an outer peripheral mold member corresponding to the outer shape of the molded Nuclet tube, and ring-shaped foils are fixed to both ends thereof. Then, the wheel is placed on a drive wheel rotated by a motor or the like, and the mold is rotated. First, while rotating the formwork at a low speed, put the fresh concrete into the inside, then increase the rotation speed, rotate at a high speed, dehydrate the fresh concrete by centrifugal force, compact and compact the concrete pipe To do. Then, the concrete is cured through a process such as steam curing of the molded concrete pipe, the mold is separated and demolded, and further cured to complete the concrete pipe.

[0003]

In a conventional mold used for molding such a concrete pipe, an outer peripheral mold member is vertically divided into two parts. The procedure is to join in the longitudinal direction and then attach the foil. Further, when removing the mold, a procedure is adopted in which the foil is removed, the upper and lower split molds are separated in the longitudinal direction, and the molded concrete pipe is taken out from the mold. However, assembling and demolding such a formwork is a troublesome work, which is a major obstacle to increasing the productivity of concrete pipes.

In a mold for molding a concrete pipe having a circular outer shape, a taper is formed on the molding surface of the outer peripheral surface of the concrete pipe, and the molded concrete pipe is axially separated without separating the integral cylindrical mold. A so-called seamless mold, which is extruded and demolded, is used (for example, Japanese Patent Publication No.
No. 39208). However, in the case of the above-mentioned non-circular concrete with a flat bottom surface, if a slope is formed on the bottom surface, it will be difficult to install during construction. The principle is that no gradient is formed in. Therefore, it has been said that the above-mentioned seamless formwork cannot be applied to the above-mentioned non-circular concrete pipe whose bottom surface cannot be provided with a gradient. In view of such conventional problems, the present invention is a mold for molding a non-circular concrete pipe whose bottom surface is a flat surface, which can be molded without complicated assembly and disassembly of the mold. It is an object of the present invention to provide a concrete pipe molding form capable of extruding the formed concrete pipe in the axial direction and demolding.

[0005]

That is, in the present invention,
In order to achieve the above-mentioned object, in a formwork for molding a concrete pipe having a through hole at the center and at least a bottom surface made of a flat surface, it is made of an integral tubular member forming an outer peripheral surface of the concrete pipe, An outer peripheral mold member having a molding surface other than a bottom molding surface that forms the bottom surface of the concrete pipe having a gradient from one end side to the other end side, and an end surface type member detachably attached to both end surfaces of the peripheral mold member. Provided is a formwork for concrete pipe molding, which comprises:

[0006]

[Function] The inventors of the present invention, when molding a non-circular concrete pipe whose bottom surface is a flat surface, do not assemble and disassemble the formwork, and the molded concrete pipe is axially moved. We examined the possibility of pushing it out of the formwork and conducted an experiment.As a result, even if the entire outer circumference of the concrete pipe did not have a slope, it could be easily molded by providing a slope on a part of the surface. We have found that it is possible to extrude concrete pipes axially from the formwork. The present invention has been made as a result of such attention.
That is, by providing a gradient from one end side to the other end side on the other molding surface except the bottom molding surface that forms at least the bottom surface of the concrete pipe of the integral cylindrical outer peripheral member that forms the outer peripheral surface of the concrete pipe, It was confirmed that it is possible to separate the concrete pipe from the mold by removing the end face mold members attached to both ends of the outer peripheral mold member after the pipe is molded and extruding the concrete pipe in its axial direction.

[0007]

Embodiments of the present invention will now be described in detail with reference to the drawings. 1 to 6 show a mold according to a first embodiment of the present invention, in which an outer peripheral surface has an octagonal cross section and an inner peripheral surface has a circular cross section, as shown in FIGS. 7 and 8. A formwork for molding a concrete pipe is shown. This mold has an outer peripheral mold member 11 that forms the outer peripheral surface of a concrete pipe a to be molded, and end face mold members 21 and 31 that form the end surface of the concrete pipe a.

The molding surface forming the outer periphery of the concrete pipe a which is the inner surface of the outer peripheral die member 11 is the concrete pipe a.
It has an octagonal cross-section corresponding to the outer shape of. here,
FIG. 6 shows both end surfaces of the outer peripheral die member 11,
As shown here, the inner surface of the outer peripheral mold member 11 has a bottom molding surface 14 for forming a bottom surface, a top surface, both side surfaces of the concrete pipe a and a chamfered surface of about 45 ° connecting these surfaces to each other. It has an upper surface molding surface 15, side surface molding surfaces 16, 16 and chamfered surface molding surfaces 17, 18. Then, as is apparent from FIG. 6, the bottom surface molding surface 14 has no slope formed, but the other molding surface, that is, the top surface molding surface 1
5, the side surface molding surfaces 16 and 16 and the chamfered surface molding surfaces 18 and 18 therebetween have a constant gradient from one end portion to the other end portion. As a result, in FIG. 6 (a) side showing the left end surface of the outer peripheral die member 11 in FIG.
6 (b) showing the right end surface of the outer peripheral die member 11, the upper surface molding surface 15 is lower and the distance between the side surface molding surfaces 16 and 16 is narrower.

At both ends of the outer periphery of the outer peripheral die member 11, foil mounting members 12 and 13 are radially provided from the chamfered molding surfaces 17 and 18, respectively. As shown in FIGS. 1 and 3, a circular ring-shaped wheel ring 34 is attached to the wheel mounting member 13 on one end surface side of the outer peripheral die member 11 so that the central axis of the outer peripheral die member 11 coincides with the bolt 33. It is fixed with a nut fastened to it. The wheel ring 34 is for supporting the mold on the rotating drive wheel and for transmitting the rotation of the foil to the mold. The outer peripheral surface of the wheel ring 34 is in rolling contact with the rotary wheel. Has a circumferential surface of. Furthermore, this wheel ring 3
The inner peripheral side of 4 is led to the inner peripheral side from the end surface of the outer peripheral mold member 11, whereby the inner peripheral side of the wheel ring 34 is a mold for forming a part of the end surface of the concrete pipe a to be molded. Also has the function of. Specifically, the peripheral surface and the end surface of the step portion between the spigot portion b formed to project from the end surface of the concrete pipe a and the pipe body are formed.

As also shown in FIG. 4, the foil ring 34
On the inner peripheral side of the protrusions, protruding pieces 34a are formed which are folded back in a U shape outward at 90 ° intervals. A stopper 38 is attached to the protruding piece 34a with a bolt 35 and a nut 37. As shown in FIG. 3, this stopper 38 is 9
Although it is attached at 0 ° intervals, as is clear from FIG. 4 (b), the shape is an elliptical shape, and is attached rotatably around the bolt 35 penetrating one end side thereof as an axis.
The tip end side is projected from the protrusion 34a toward the inner peripheral side of the wheel ring 34. The bolt 35 applies a required tightening force to the stopper 38 via the coil spring 36, and the projection 39 provided on the tip side of the bolt 35 allows the tip side to rotate in the direction indicated by the arrow in FIG. 4B. It has become.

A circular ring-shaped end surface type member 31 is adapted to be brought into contact with the outer plate surface of the projection 34 a of the wheel ring 34. That is, the end surface type member 31 is
From the position shown in FIG.
In the state of being rotated by 90 ° around 5, it is applied to the central portion of the end face of the projecting piece 34a. Then, fix the stopper 38 to the bolt 3
5 by rotating 90 ° in the opposite direction to the above and returning to the position shown in FIG.
8 and the projecting piece 34a. The end surface molding member 31 functions as a mold member that forms the end surface of the concrete pipe a to be molded, and specifically forms the end surface of the spigot portion b formed to project from the end surface of the concrete pipe a.
The center of the end face forming member 31 is a circular opening 32, which serves as a concrete inlet into the mold.

As shown in FIGS. 1 and 2, the outer peripheral die member 1
A circular ring-shaped wheel ring 24 is attached to the wheel mounting member 12 on the other end surface side of 1 in such a manner that a bolt 25 ′ (see FIG. 2) and a nut fastened thereto are attached so that the central axis of the wheel ring 24 is aligned with the outer peripheral member 11. It is fixed at. Similar to the ring wheel 34, the wheel ring 24 serves to support the mold on a rotating foil and to transmit the rotation of the foil to the mold. A stopper 28 is attached to the wheel ring 24 by the bolt 25 ′, another bolt 25, and a nut 27 fastened thereto. This stopper 28 is similar to the stopper 38 described above, and as is apparent from FIG. 2, it is attached to the plate surface of the wheel ring 24 at 90 ° intervals, and the bolt 25 penetrating to one end side thereof is pivoted. Is rotatably attached, and the tip end side is projected to the inner peripheral side of the wheel ring 24. The bolt 25 applies a required tightening force to a stopper 28 via a coil spring 26, and a protrusion 29 provided on the tip side thereof allows the tip side to rotate.

A circular ring-shaped end surface type member 21 is fitted on the inner peripheral side of the wheel ring 24 so that it is brought into contact with the end surfaces of the outer peripheral type member 11 and the wheel mounting member 12. That is, the end surface type member 21 is
From the position shown in FIG.
In the state of being rotated by 90 ° around 5, it is fitted in the central portion surrounded by the wheel ring 24. Thereafter, the stopper 28 is rotated around the bolt 25 in the opposite direction to the above by 90 ° and returned to the position shown in FIG. 2 so that the flange portion 23 on the outer peripheral side of the end face molding member 21 is moved to the outer peripheral member 11. It is clamped between the end face and the stopper 28. The end face molding member 21 functions as a mold member that forms the end face of the concrete pipe a to be molded, and specifically, one end face of the concrete pipe a and the socket portion c formed in a concave shape on the end face.
Shape the inner surface of. The end face forming member 21 has a circular opening 22 at the center, which serves as a concrete inlet into the formwork.

When a concrete pipe is molded by using this mold, for example, by a centrifugal molding method, the mold is assembled as shown in FIGS. 1 to 3, and a reinforcing bar (not shown) is assembled therein. Then, the outer peripheral surfaces of the wheel rings 24 and 34 are placed on a drive wheel rotated by a motor or the like, and the mold is rotated. First, while rotating the mold at a low speed, a predetermined amount of fresh concrete is poured into the outer peripheral mold member 11 from the openings 22 and 23 of the end face molding members 21 and 31, and then the rotational speed of the mold is increased. Then, the concrete is dehydrated by the centrifugal force and is compacted to mold the concrete pipe a . After that, cure and concrete pipe a
After curing, the stops 28, 38 shown in FIGS.
By using those protrusions 29 and 39, for example, in FIG.
The end face molding members 21, 3 are rotated as indicated by arrows in FIG.
1 is removed from the end of the outer peripheral die member. Then,
Since both end faces of the outer peripheral die member 11 are opened as shown in FIG. 5, the molded concrete pipe a is pushed out from the spigot b side toward the socket c side as shown by the arrow in FIG. As described above, the bottom molding surface 14 that forms at least the bottom surface of the concrete pipe a of the integral cylindrical outer peripheral die member 11 that forms the outer peripheral surface of the concrete pipe a, and the chamfered surfaces 17 and 17 on both sides thereof (see FIG. 6). Except for the other molding surface having a slope from the spigot b side toward the socket c side, the concrete pipe a is extruded in the axial direction,
It is possible to release the mold.

FIG. 7 shows an example in which the concrete pipe a thus molded is joined. That is, the concrete pipe a is joined by fitting the spigot b and the socket c. In this case, since the bottom surface of the concrete pipe a is flat and no slope is formed, as shown in FIG. 8, the bottom surface of the series of concrete pipes a is relative to the central axis of the through hole of the concrete pipe a which serves as a water channel. Become parallel planes. Therefore, it can be installed and laid on a flat and level ground.

[0016]

[0017]

As described above, according to the present invention, it is a mold for molding a non-circular concrete pipe having a flat bottom surface, which does not require troublesome assembly and disassembly of the mold. In addition, it is possible to provide a concrete pipe molding frame capable of extruding a molded concrete pipe in the axial direction and demolding.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view of a mold according to a first embodiment of the present invention.

FIG. 2 is a front view showing an end surface on the socket side of the mold according to the first embodiment.

FIG. 3 is a rear view showing an end face on the spigot side of the mold according to the first embodiment.

FIG. 4 is an enlarged longitudinal side view of essential parts and an enlarged rear view of essential parts showing an example of a structure for fixing an end face mold member to a spigot side end face of a mold according to the first embodiment.

FIG. 5 is a vertical cross-sectional side view when demolding a concrete pipe molded from a mold according to an embodiment of the present invention.

FIG. 6 is a front view (a) showing the socket-side end face of the outer peripheral mold member of the mold according to the first embodiment and a rear view (b) showing the spigot-side end face thereof, both of which are shown in FIG. 3 is tilted by 45 ° from the state of FIG.

FIG. 7 is a perspective view showing a state in which concrete pipes molded by using the mold according to the first embodiment are connected to each other.

FIG. 8 is a side view showing a state in which concrete pipes molded by using the mold according to the first embodiment are connected to each other.

[Explanation of symbols]

 a concrete pipe 11 outer peripheral member 14 bottom molding surface of outer peripheral member 15 upper surface molding surface of outer peripheral member 15 'upper surface molding surface of outer peripheral member 16 side molding surface of outer peripheral member 14 chamfered surface molding surface of outer peripheral member 21 End face type member 31 End face type member

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Kazuya Aoyama 6236, Tatetsuka, Mimura, Ishioka, Ibaraki Prefecture 6236, Tomoe Works Co., Ltd. (72) Morio Kubota, 6236, Tatetsuka, Mimura, Ishioka, Ibaraki No. 6 at Tomoe Works Co., Ltd. (72) Creator Takashi Tasaka 1-1-13 Manabe, Tsuchiura-shi, Ibaraki Nakagawa Fumekan Kogyo Co., Ltd.

Claims (1)

[Scope of utility model registration request] 1. A formwork for molding a concrete pipe having a through hole in the center and at least a bottom surface formed of a flat surface, which is composed of an integral tubular member forming an outer peripheral surface of the concrete pipe, and at least the concrete pipe. Other peripheral surfaces except the bottom molding surface that forms the bottom surface of the outer peripheral mold member having an inclination from one end side to the other end side, and end face mold members detachably attached to both end faces of the peripheral mold member. A mold for concrete pipe molding characterized by.