JP2001009824A - Prestressing device, and apparatus and method for manufacturing molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a very easy and simple prestressing device without inviting a fault such as a decrease in workability, an increase in a facility cost and the like, and an apparatus and a method for manufacturing a molding. SOLUTION: The prestressing device 1 comprises a base member 2 and compression beams 3 placed on the member 2. In this case, a pair of heads 4A, 4B are provided at both end sides of the beams 3, and PC steel wires 5 are stretched and bridged between the heads 4A and 4B. A member form 6 is placed between the heads 4A and 4B. The head 4B is mounted through rods 20 provided projectably and retractably by hydraulic jacks 19 fixed to an end face of the beams 3. In the case of manufacturing a molding, the jacks 19 are driven and the head 4B is moved in a direction for separating the head 4B from the beams 3. Thus, a tensile force is given to the PC materials 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a prestressing apparatus used for producing a molded product such as a prestressed concrete member. The present invention also relates to an apparatus and a method for manufacturing a molded product using a prestress apparatus.

[0002]

2. Description of the Related Art Conventionally, for example, a bridge girder 50 as shown in FIG.
Prestressed concrete members (hereinafter referred to as P
A pretension (precast) method, a posttension method, and the like are known as methods for manufacturing the C member. In a case where such a PC member is to be manufactured by a pretension method, a long-line type manufacturing facility is generally used. That is, as shown in FIG. 8, in a conventional long-line manufacturing facility, a plurality of member formwork 51 for placing concrete are placed on a large number of sleepers 52 arranged in parallel. Further, a pair of pretension abutments 53A,
53B is fixed by being embedded in the ground. Then, a plurality of prestressing materials (PC steel materials) 54
Are suspended from the pretensioning abutments 53 along the member formwork 51.

Further, each pretension abutment 53
A and 53B are provided with a mechanism for applying a tensile force to the PC steel 54. More specifically, a head 55A for fixing one end of the PC steel 54 and a fixing plate 56A are provided on one pretensioning abutment 53A (right side in the figure). A hydraulic jack 57 for pulling the other end of the PC steel 54 and a head 55B are provided on the other pretensioning abutment 53B (left side in the figure).
And a fixing plate 56B. Hydraulic jack 5
Reference numeral 7 is fixed to the pretension abutment 53B, and a head 55B is attached via a rod 58 provided to be able to protrude and retract from the jack 57. FIG.
As shown in FIG. 5, the heads 55A and 55B are provided with lattice-shaped ribs 59, and both ends of the PC steel 54 are inserted into the gaps of the ribs 59 so that the heads 55A and 55B are inserted.
The fixing plates 56A and 56B fixed to the end surface of the fixing member B are fixed so as not to be relatively movable by a fixing tool (not shown).

When manufacturing the PC member, the jack 57 is driven to move the head 55B in the direction away from the abutment 53B (to the left in the figure). Thereby, a tensile force is applied to the PC steel 54. In this state, concrete is poured into the member formwork 51. Then, after the concrete is hardened, it is taken out from the member form 51 and the PC steel material 54 is cut, so that the P
C member is obtained.

[0005]

However, in the above prior art, since the pretension abutments 53A and 53B buried in the ground are required, the equipment itself has to be large. Therefore, it was difficult to adopt the above method in a small factory. In particular, many PCs
If the members are to be manufactured at the same time, the equipment must be enlarged in the longitudinal direction, which has been exacerbated by the above-mentioned problem. Also, once the above equipment is installed, it is very difficult to move it. Therefore, there has been a problem that the inside of the factory cannot be effectively used other than the routine production of PC members, or that PC members cannot be produced at a desired place.

[0006] That is, with the installation of large equipment and the enlargement of the equipment, there are problems such as securing an installation place and increasing equipment cost.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problem, and has as its object to provide a simple and easy-to-use prestressing apparatus and molding without inviting an increase in the size and cost of equipment. An object of the present invention is to provide an apparatus for manufacturing a product and a method for manufacturing the same.

[0008]

Means effective to achieve the above object will be described below. The operation and the like will be described as necessary.

Means 1. A prestressing device for applying a tensile force to a long prestressing material and maintaining the state of applying the tensile force, wherein a plurality of tensioning devices arranged in parallel in a longitudinal direction of the prestressing material are provided. A force support means, and a pair of movable parts are provided at both ends of the tensile force support means for supporting and fixing a part of the prestressing material, at least one of which is relatively movable in the longitudinal direction with respect to the tensile force support means. A prestressing material supporting means, and a stress applying means for applying a stress in a direction away from the tensile force supporting means to at least one of the prestressing material supporting means to apply a tensile force to the prestressing material. A prestressing device, characterized in that:

According to the above means, of the pair of prestressing material supporting means provided at both ends of the tensile force supporting means,
At least one tends to move away from the tensile force support means based on the stress applied by the stress support means. Thus, the prestressing material is pulled while being supported by the prestressing material supporting means, and the plurality of tensile force supporting means arranged in parallel in the longitudinal direction of the prestressing material receive a compressive stress, and The state can be maintained. For this reason, it is possible to maintain the state of applying the tensile force of the prestress material without fixing the abutment in the ground at all, as compared with the related art in which the abutment needs to be fixed in the ground.

Means 2. The prestressing device according to the first aspect, wherein the tensile force supporting means is constituted by a plurality of units that can be joined and separated in a longitudinal direction.

According to the above-mentioned means, since the tensile force supporting means is constituted by a unit, during transport or the like,
Work can be performed in a state where they are separated from each other. In addition, the length can be adjusted as needed.

Means 3. The prestressing device according to claim 2, wherein a base member is provided at least below the tensile force supporting means.

According to the above-described means, the positioning is easily performed when the tensile force supporting means is installed due to the presence of the base member, and the displacement is hardly caused. In addition, the function as a sleeper is also exhibited.

Means 4. In the means 2 or 3, the base member is constituted by a plurality of units, and a joint portion of the base member and a joint portion of each unit of the tensile force supporting means are shifted.

According to the above means, since the base member is constituted by the unit, the work can be performed in a state of being separated from each other at the time of transportation or the like. Further, since the joint portion is displaced from the joint portion of each unit of the tensile force supporting means, the concentration of the compressive stress is avoided, and a larger tensile force can be applied.

Means 5. In any one of the means 2 to 4,
A prestressing device, wherein a cushioning material is interposed between the units of the tensile force supporting means.

According to the above means, the presence of the cushioning material allows
Concentration of stress on a part of the joint surface between the units can be avoided, and the compressive stress applied to the joint surface can be appropriately dispersed.

Means 6 In any one of the means 2 to 5,
A prestressing device, wherein each unit of the tensile force supporting means has a connecting tool.

According to the above-mentioned means, since each unit is already provided with a connecting member, the labor required for connecting each unit is simplified.

Means 7. In any one of the means 1 to 6,
A prestressing device, wherein the tensile force supporting means is superimposable in at least one of a width direction and a height direction.

According to the above means, it is possible to cope with an increase in the tensile force (an increase in the compressive stress) by appropriately overlapping the tensile force supporting means in at least one of the width direction and the height direction.

Means 8. In any one of the means 1 to 7,
The prestressing device, wherein the prestressing material supporting means is constituted by a plurality of plate-like units which are removably superimposed on each other with a gap for supporting the prestressing material.

According to the above means, since the prestressing material supporting means is constituted by a plurality of plate-like units,
If necessary, the work can be performed in a state of being separated from each other.
Further, the size of the prestressing material supporting means can be adjusted as needed. For this reason, the arrangement, number, etc. of the prestressing materials can be freely changed, and manufacturing according to needs can be performed.

Means 9 A prestressing device according to any one of means 1 to 7, and a molding device provided between the pair of prestressing material support means and configured to mold a molded product having a predetermined shape while the prestressing material is embedded. An apparatus for manufacturing a molded article, comprising:

According to the above-mentioned means, the state in which the elongate prestressing material is applied with the tensile force is maintained by the prestressing device, and then the prestressing material is formed by the molding device provided between the prestressing material supporting means. A molded article having a predetermined shape to be buried can be molded.

Means 10. Means for applying and maintaining a tensile force on the prestressed material by using a prestressing device of the manufacturing apparatus according to the means 9;
Forming a molded product having a predetermined shape with the prestressing material embedded therein.

According to the above means, a tensile force is applied to the prestressed material and the state is maintained by using the prestressed device. Then, by using the molding apparatus, a molded article having a predetermined shape is molded in a state where the prestressing material is embedded.

Means 11. In the means 9 or 10, the molded article is a concrete molded article.

Means 12. In the means 1 to 11, the prestressing material contains a steel material.

[0031]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a prestressing apparatus, an apparatus for manufacturing a molded article, and a method for manufacturing the same will be described below in detail with reference to the drawings.

In this embodiment, the molded product is P
A description will be given using the C member as an example. In particular, a snow shed 41 as shown in FIG. 6 is taken as an example of the PC member. The snow shed 41 is for preventing an avalanche or the like, and has a flat plate shape as a whole. The snowshed 41 is mainly made of concrete,
A plurality of PC steel wires 5 are buried in the inside along the longitudinal direction.

An apparatus for manufacturing the snow shed 41 includes a prestressing apparatus 1 for applying a tensile force to the PC steel wire 5 and maintaining the state, and a member forming a main part of a concrete forming apparatus. And a mold 6.

As shown in FIG. 1, a prestressing device 1 according to the present embodiment includes a base member 2 composed of a lower base H steel 7A and an upper base H steel 7B,
A compression beam 3 mounted and fixed on the steel 7B, and a pair of heads 4A and 4B provided at both ends of the compression beam 3 are provided, and a PC steel wire 5 is delivered between the heads 4A and 4B. Have been. Also, a member form 6 is provided between the heads 4A and 4B.
Is placed.

A plurality of lower base H steels 7A are arranged in a direction orthogonal to the PC steel wire 5, and a plurality of upper base H steels 7B are arranged on the lower base H steel 7A in parallel with the PC steel wire 5. It is fixed. As shown in FIG.
Joint holes 8A and 8B are provided in the upper part of the steel 7A and the lower part of the upper base H steel 7B, respectively. The base H steels 7A and 7B are fixed to each other by fastening with bolts and nuts in a state where the two 8A and 8B are aligned. Also, by removing the bolts and nuts, the upper and lower stage base H steels 7A and 7B can be detached separately. In other words, the base member 2 is constituted by a detachable base member unit.

The lower base member H steel 7A plays a role of a sleeper for positioning in the height direction when the member formwork 6 is installed, and the upper base H steel 7B serves as a stopper when the compression beam 3 is provided. Plays the role of positioning in the length and width directions.

The compression beam 3 is composed of a plurality of compression beam units 9 connected in the longitudinal direction. As shown in FIG. 3, the compression beam unit 9 has a substantially rectangular parallelepiped outer shape, and is formed of concrete. On each side of the both ends in the longitudinal direction of the compression beam unit 9, a concave connector 10 is fixedly provided. Recessed connector 1
0 is a pair of joining holes 1 drilled in the unit joining direction.
2 are formed so that the units 9 can be joined to each other. Note that a cushioning material 13 made of hard rubber is interposed on each joint surface.

Further, a concave connector 11 having a joint hole 14 similar to the concave connector 10 is fixedly provided at the lower left and right side surfaces of the compression beam unit 9. Then, in a state where the joint hole 14 of the connecting tool of the compression beam unit 9 and the pair of joint holes 15 formed in the upper portion of the upper base H steel 7B are aligned, they are fastened with bolts and nuts. The compression beam unit 9 is mounted and fixed to the upper base H steel 7B. However, as shown in FIG. 2, in the present embodiment, the position of the joint between the compression beam unit 9 and the upper base H steel 7B and the position of the joint between the upper and lower base H steels 7A and 7B are shifted. . For this reason, the concentration of the compressive stress at each joint is avoided, and a larger tensile force (stress) can be applied.

Further, the concave connecting member 11 may be fixed to the upper part of the left and right side surfaces of the compression beam unit 9. With such a configuration, the compression beams 3 can be stacked and connected in the height direction and the width direction. It can cope with stronger tensile force, and can also cope with molded products having various shapes.

Further, as shown in FIGS. 1, 4 and 5, the heads 4A and 4B are composed of a plurality of iron plates (plate-like units) 16. Each iron plate 16 is provided with a plurality of joining holes 17 pierced so as to penetrate in the vertical direction.
A bolt is inserted through the nut, and the tip is screwed with a nut and fixed. Further, a washer is interposed between the iron plates 16, thereby providing a gap 21 for inserting the PC steel wire 5.
Are formed. Thus, in the present embodiment, the heads 4A and 4B are also detachable for each plate-like unit 16.

At one end of the compression beam 3, a head 4A for fixing one end of the PC steel material 5 and a fixing plate 18A are provided. At the other end, a hydraulic jack 19 for pulling the other end of the PC steel material 5, a head 4B, and a fixing plate 18B are provided. The hydraulic jack 19 is fixed to the end face of the compression beam 3, and the head 4 </ b> B is connected via a rod 20 provided to be able to protrude and retract from the jack 19.
Is installed. As described above, the heads 4A, 4A
In B, a gap 21 is provided between the iron plates 16 and P
In a state where both ends of the C steel material 5 are inserted between the gaps 21,
Fixing plates 18A, 1 fixed to end faces of heads 4A, 4B
8B is fixed to a chuck (not shown).

When the PC member is manufactured, the jack 19 is driven to move the head 4B in a direction away from the compression beam 3. Thereby, a tensile force is applied to the PC steel material 5.

Next, a method of manufacturing the snowshed 41 and an operation at the time of manufacturing the snowshed 41 using the manufacturing apparatus including the prestressing device 1 and the member form 6 configured as described above will be described.

First, in order to introduce a predetermined prestress into the snowshed 41, the necessary number and positions of the PC steel wires 5 to be buried are determined, and then the PC steel wires 5 are placed between the heads 4A and 4B. hand over. At this time, both ends of the PC steel wire 5 are inserted through the gaps 21 provided between the plate units 16 of the heads 4A and 4B, and the fixing plate 18
A, 18B is fixed by the chuck.

Next, the hydraulic jack 19 is driven, concrete is poured into the member form 6 in a state where a tensile force is applied, and after the concrete is hardened, the hydraulic jack 19 is returned to the original state. Return and introduce prestress into the concrete by unloading the tensile force.

After the introduction of the prestress, the PC steel wire 5 projecting from the end face of the concrete is cut and taken out from the member form 6 to obtain the snow shed 41 as a product.

As described in detail above, according to the present embodiment, the two compression beams 3 arranged in parallel with the longitudinal direction of the PC steel wire 5 receive the compressive stress. For this reason, it is not necessary to fix the abutment underground, and it is possible to maintain the PC steel wire 5 in the state where the tensile force is applied. As a result, it is possible to apply the tensile force without causing problems such as an increase in the size of the equipment and an increase in the equipment cost.

In this embodiment, since the compression beam 3, the base member 2, and the heads 4A and 4B are each constituted by a unit, they can be moved and stored. In particular, at the time of storage or the like, the space can be effectively used. Further, when moving, transporting, or the like, the work can be performed in a state where they are separated from each other. As a result, dramatic improvement in workability can be achieved, and transport costs due to on-site production can be significantly reduced.

Further, by appropriately adjusting the compression beam unit 9 and the like, it is possible to cope with the size and shape of the product, and the length of the compression beam 3 can be adjusted. Can also be adjusted appropriately. Moreover, by adjusting the size of the plate-like unit 16 of the heads 4A and 4B, the arrangement and the number of the PC steel wires can be freely changed, and the compressive force introduced, the width and the length of the molded product can be changed. In terms of height, shape, etc., flexible manufacturing can be performed according to needs. At the same time, reassembly can be easily performed.

Further, in this embodiment, since the foundation work is not required, the initial cost can be significantly reduced. In addition, the degree to which the land and the factory building are also restrained by the facilities and the like is smaller than in the past, so that the initial cost can be further reduced in this sense.

Further, in this embodiment, since the base member 2 is provided at the lower portion, when the compression beam 3 is installed, the positioning is easily performed, and furthermore, the displacement is hard to occur, so that it can be used as a sleeper. Is also exerted. In addition, since the joint portion is displaced from the joint portion of each unit of the compression beam 3, the concentration of compressive stress is avoided, and a larger tensile force can be applied.

In addition, in the present embodiment, it is possible to cope with a further increase in tensile force (an increase in compressive stress) by appropriately overlapping the compression beam 3 in at least one of the width direction and the height direction. it can. Therefore, the above-described effects can be easily and reliably achieved.

In addition, the cushioning material 1 is provided between each compression beam unit 9.
Since the intervening member 3 is provided, it is possible to avoid concentration of stress on a part of the joint surface between the units 9, and the compressive stress applied to the joint surface can be appropriately dispersed.

Furthermore, in the present embodiment, since the connecting members 10 and 11 are already provided in each of the compression beam units 9, the labor required for connecting each unit and the base member is simplified. Workability can be improved.

It should be noted that the present invention is not limited to the contents described in the above embodiment, and may be implemented as follows, for example.

(A) In the above embodiment, the present invention has been embodied in the manufacture of the snowshed 41 as a PC member, but may be embodied in the manufacture of other products (bridge girders, panels, etc.).

(B) As a molded product, a material that can be cured with time, such as a resin, may be used instead of concrete.

(C) PC steel wire 5 as prestressing material
Instead, another prestress material such as a reinforcing fiber may be used.

(D) In the above embodiment, the base member 2
However, the base member may be omitted if the displacement does not occur only by the compression beam 3 (tensile force support means).

(E) As the base member 2, other materials such as concrete may be used instead of H steel.

(F) In the above embodiment, the base member 2
May be configured as a detachable unit, and may not be a unit.

(G) In the above embodiment, the compression beam 3 is constituted by the detachable compression beam unit 9, but the compression beam 3 may not be a unit.

(H) In the above embodiment, the compression beam 3 is
Although installed in the main parallel state, three or more compression beams may be used.

(I) As a material of the compression beam unit 9, instead of concrete, another material such as iron which can be easily fastened may be used.

(J) The joining position between the base members 2 and the joining position between the compression beam units 9 do not always need to be shifted.

(K) In the above embodiment, the heads 4A,
Although 4B is constituted by the detachable plate-like unit 16, the unit may not be a unit.

(L) In the above embodiment, the heads 4A,
4B is configured by stacking a plurality of the plate-shaped units 16 in the height direction, but may be configured to stack a plurality of the plate-shaped units 16 in the width direction.

(M) In the above embodiment, the jack 19
Is used as means for pressing the head 4B in the direction away from the compression beam 3, but may be used as means for pulling from the opposite direction. Further, a plurality of jacks may be provided.

(N) As the cushioning material 13, other materials such as plywood and plastic may be used instead of hard rubber. Further, the cushioning material 13 may be omitted.

[0070]

As described above in detail, according to the prestressing apparatus, the apparatus for manufacturing a molded article and the method for manufacturing the same according to the present invention, the equipment is not enlarged and the cost is not increased. It has an excellent effect of richness.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of an entire manufacturing apparatus including a prestress apparatus.

FIG. 2 is a partial plan view showing a base member.

FIG. 3 is a perspective view showing a compression beam unit.

FIG. 4 is a perspective view showing a head and the like.

FIG. 5 is a front view showing a head and the like.

FIG. 6 is a partial perspective view showing a snowshed.

FIG. 7 is a partial perspective view showing a bridge girder.

FIG. 8 is a schematic side view showing a long-line type manufacturing facility.

FIG. 9 is a perspective view showing a head for a long-line type manufacturing facility.

[Explanation of symbols]

1 ... prestressing device, 2 ... base member, 3 ... compression beam,
4A, 4B: Head, 5: PC steel, 6: Member formwork, 9
... compression beam unit, 16 ... plate unit, 19 ... hydraulic jack.

Claims (6)

[Claims] 1. A prestressing device for applying a tensile force to a long prestressing material and maintaining the state of applying the tensile force, wherein the prestressing device is disposed in parallel with a longitudinal direction of the prestressing material. A plurality of tensile force supporting means, provided at both ends of the tensile force supporting means to support and fix a part of the prestressing material, at least one of which is provided in the longitudinal direction relative to the tensile force supporting means. A pair of movable prestressing material supporting means, and a stress applying means for applying a stress in a direction separating at least one of the prestressing material supporting means from the tensile force supporting means in order to apply a tensile force to the prestressing material. And a means for prestressing. 2. The prestressing device according to claim 1, wherein said tensile force supporting means is constituted by a plurality of units which can be joined and separated in a longitudinal direction. 3. The prestressing device according to claim 1, wherein the tensile force supporting means is superimposable in at least one of a width direction and a height direction. 4. The prestressing material supporting means is composed of a plurality of plate-like units which are removably stacked on each other in a state capable of supporting the prestressing material. The prestressing device according to any one of claims 1 to 3. 5. A prestressing device according to claim 1, wherein said prestressing member is provided between said pair of prestressing material supporting means, and said prestressing material is buried to form a molded article having a predetermined shape. And a molding device for producing the molded product. 6. A step of applying and maintaining a tensile force to the prestressed material using the prestressing device of the manufacturing apparatus according to claim 5, and embedding the prestressed material using the molding device. Forming a molded product having a predetermined shape in a state.