JPH07314428A - Fastening device for form - Google Patents

Abstract

PURPOSE:To prevent the deterioration of a bolt used for a fastening device and prevent the oscillation of the bolt when it is depressed in the fastening device used for centrifugally molding a hollow concrete product. CONSTITUTION:For joining a pair of half split bodies 3, 4 abutted to each other to form a cylindrical form 2, flanges 5, 6 with holes 5a, 6a matching with each other are respectively fixed on the side parts of the half split bodies 3, 4. Furthermore, a fastening device comprises a cylindrical body 8 fixed to the upper surface of the flange 5, a coil spring 14 the lower end of which is detachably fastened inside the cylindrical body 8, a bolt 7 wound with the coil spring 14, and a nut 10 unrotatably provided on the lower surface of the flange 6 to be helically fitted with the bolt 7 for fastening both the flanges 5, 6 to each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold fastening device, and in particular, it is used for connecting a pair of half halves forming a centrifugal force forming mold for hollow concrete products such as concrete piles. The present invention relates to a fastening device for a mold.

[0002]

2. Description of the Related Art As an example of a conventional fastening device for a mold of this type, one disclosed in Japanese Utility Model Publication No. 46-48882 is known. Thus, the mold fastening device described in the publication has a pair of flanges horizontally projecting from one side of the half body and abutted against each other and coupled, and On the upper surface of the flange of, the lower end peripheral portion of the inverted-cylinder-shaped tubular body is fixed, and a large-diameter round hole is opened in the upper plate of the tubular body. A coil spring wound around the side surface is inserted, and the lower end portion of the coil spring is configured to be locked by the lower surface of the upper plate of the tubular body. Further, a hole which is aligned with each other is formed in the pair of flanges, and a nut which is prevented from rotating is attached to the lower surface of the other flange and around the hole. There is. Therefore, the bolt is pushed down, and the bolt is screwed into the nut through the mutual holes to connect the flanges.
Then, when the centrifugal force forming operation of the hollow concrete product is completed, the mold is separated into each half and disassembled. In this disassembly, both halves can be easily separated by simply unscrewing the bolt from the nut. At this time, since the bolt is wound by the coil spring and the lower end portion of the coil spring is locked to the lower surface of the upper plate of the tubular body, the bolt and the coil spring are removed. You won't lose it.

[0003]

In the above-mentioned conventional example, the cement paste generated during the centrifugal forming of hollow concrete products reaches the hole through the joint of the flange and adheres to the bolt. In that case, the elastic force of the bolt deteriorates, and when the half body is separated, even if the bolt is unscrewed from the nut, the elastic restoring force of the bolt prevents the bolt from coming out of the hole in the lower flange. There is also.

Further, when the bolt is inserted into the hole and screwed into the nut, the bolt is inevitably swung due to the action of the elastic force of the coil spring. There is a defect that the alignment operation with the nut is not performed smoothly. Therefore, a technical problem to be solved in order to prevent the deterioration of the bolt and to allow the bolt to be vertically pressed during the pressing operation of the bolt to easily align the center with the hole of the flange and the nut. Therefore, the present invention aims to solve the problems.

[0005]

DISCLOSURE OF THE INVENTION The present invention has been proposed in order to achieve the above-mentioned object, and for connecting a pair of half halves abutted against each other to form a cylindrical form. , A cylindrical body fixed to each side of both the half halves and having holes aligned with each other, and further, a cylinder fixed to the upper surface of one of the flanges and a lower end of the cylinder can be freely attached and detached. To the coil spring, the bolt around which the coil spring is wound, and the bolts screwed together to fasten both flanges. In the fastening device according to the present invention, the cylindrical body has a bottom plate formed in a square cross section, and the bottom plate is formed with a through hole that is aligned with the hole formed in the one flange. , The steady-state pad extending from the inner wall surface of the through hole to the vicinity of the upper end of the cylinder. The coil spring is formed to have a smaller diameter in order from the lower part to the upper part, and the lower end of the coil spring is detachably locked in a recess provided near the bottom surface of the cylinder. Further, when the bolt is pushed down and the bolt is tightened to the lower nut, the coil spring is an outer portion of the steady rest pipe and can be housed in the cylindrical body. The present invention provides a fastening device for a configured mold.

[0006]

The lower end of the coil spring, into which the bolt is inserted, is fitted in the recess provided near the bottom surface of the cylindrical body. Then, the head of the bolt is gripped and the bolt is pressed against the elastic force of the coil spring. In that case, since the bolt descends along the hole surface of the steady rest pipe fixed to the hole wall of the through hole opened in the bottom plate of the cylindrical body, it is based on the action of the elastic force of the coil spring. Without swinging, it descends vertically, passes through the respective holes in the flanges that are butted up and down, and reaches the upper surface of the lower nut. Therefore, when the bolt is rotated, the bolt is screwed into the nut and the upper and lower flanges are coupled to each other to form a cylindrical form, and the hollow concrete product is centrifugally molded. At this time, since the coil spring is outside the steady pipe and is housed in the cylindrical body, the cement paste generated during the centrifugal force molding passes through the upper and lower flanges and the hole of the flange. Does not adhere to the coil spring. Therefore, since the elastic force of the coil spring is not deteriorated, if the bolt is unscrewed from the nut when the mold is disassembled, the elastic restoring force of the coil spring causes the bolt to move to the upper and lower flanges respectively. The coil spring can be detached from the hole, and the lower end portion of the coil spring is fitted into the recess of the cylindrical body, so that the coil spring and the bolt or other coil spring receiving body inserted into the coil spring are It does not fall off the cylinder.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to FIGS. In the figure, 1 is a fastening device. The fastening device 1 is used to join a pair of steel halves 3 and 4 forming a cylindrical form for centrifugally forming a hollow concrete product such as a concrete pile. Thus, one half-split body 3 has a flange 5, and the other half-split body 4 is provided with a flange 6 facing the front and rear flanges 5. In addition, each flange 5, 6 is a half body 3, 4
It is provided on both sides of so as to extend parallel to the axis of the form 2.

Further, holes 5a, 6a into which bolts 7 described later can be inserted are formed in the respective flanges 5, 6 so as to be aligned with each other. Further, a cylindrical body having a square cross section is fixedly mounted on the upper surface of the flange 5 by means of welding or the like with the hole 5a opened in one flange 5 as the center. In addition, a large-diameter through hole 8b is opened at the center of the bottom plate 8a of the cylindrical body 8, and a steady rest pipe 9 is fixed to the hole wall of the through hole 8b by means such as press fitting or welding. I am doing it. Moreover, the steady rest pipe 9 is provided so as to project into the cylindrical body 8, and its upper end portion is formed so as to be located slightly below the upper end portion of the cylindrical body 8. Further, the steady rest pipe 9 is aligned with the hole 5a opened in the one flange 5, and the inner diameter of the steady rest pipe 9 does not swing when the bolt 7 is pressed and lowered. It is formed with an inner diameter that can guide the bolt 7 to some extent.

Also, the bolt 7 is screwed into the lower surface of the flange 6 around the hole 6a which is opened in the other flange 6 and is aligned with the hole 5a provided in the one flange 5. Attach nut 10 that can be attached. Further, the nut 10
Is to receive the screwing of the bolt 7 in alignment with the holes 5a and 6a. Further, the nut 10 is housed in a sleeve 11 fixed to the lower surface of the flange 6 while being prevented from rotating, and the lower surface thereof is supported by a washer 12.

Further, the cylindrical body 8 is provided at the open upper surface of the cylindrical body 8.
A coil spring receiver 13 having the same diameter as that of the coil spring receiver 13 is releasably contacted with the coil spring receiver 13, and the coil spring receiver 13 is
A through hole 13a for inserting and removing the bolt 7 is provided at the center of the
Has been opened. Further, the bolt 7 is attached to the through hole 13a.
When the bolt 7 is inserted into, the head portion 7a of the bolt 7 contacts the upper surface of the coil spring receiver 13 around the through hole 13a.

Further, a recess 8c is formed near the bottom surface of the inner wall surface of the cylindrical body 8. Then, the lower end of the coil spring 14 is detachably locked in the recess 8c. Further, the coil spring 14 has a large diameter in the lower part, and is gradually formed in a smaller diameter as it goes upward, and is formed in exactly a mountain shape. Therefore, the upper end of the coil spring 14 is attached to the bolt 7
The bolt 7 is wound to the extent that it is crimped to and is supported by the coil spring receiver 13, but the present invention is not limited to this.

The elastic force of the coil spring 14 is
It is set so that when the bolt 7 is disengaged from the nut 10, a restoring force is applied to the bolt 7 so that the bolt 7 can be detached from the holes 5a, 6a opened in both flanges 5, 6 and the steady pipe 9. It Furthermore, the number of turns of the coil spring 14 is set by pressing the bolt 7 and lowering the nut 1 at the bottom.
When the coil spring receiver 13 that is screwed to 0 and is in contact with the lower surface of the head 7a of the bolt 7 is in contact with the open upper surface of the cylindrical body 8 to close the cylindrical body 8, The steady rest pipe 9 with the coil spring 14 contracted.
The outer surface of the cylindrical body 8 is set so that it can be accommodated in the inner surface of the cylindrical body 8.

Thus, when assembling the bolt 7 to the cylindrical body 8, first, the coil spring receiver 13 and the coil spring 14 are passed through the lower end of the bolt 7, and then the lower end of the coil spring 14 is inserted. The bolt 7 by engaging the bolt 7 with a recess 8c provided in the tubular body 8.
Can be set to. Therefore, the halves 3, 4
Holes 5a formed on the flanges 5 and 6 by butting each other,
6a is aligned, and the head 7a of the bolt 7 is gripped by using a member such as a spanner, and is pressed against the elastic force of the coil spring 14. If so, the coil spring 1
As described above, 4 is the outer surface of the steadying pipe 9 and is housed in the inner surface of the tubular body 8 in a contracted manner, and the lower end portion of the bolt 7 has the nut 1
0, and when the bolt 7 is rotated there, the bolt 7 is screwed onto the nut 10 so that both flanges 5 and 6 are connected.

When the bolt 7 is lowered, the elastic force of the coil spring 14 normally swings the head 7, and it is difficult to align the nut 7 with the nut 10. However, in the case of the present invention, the steadying pipe 9 is fixedly provided in the through hole 8b opened at the center of the tubular body 8, and the upper portion thereof is provided so as to project into the tubular body 8. Therefore, the lower end portion of the bolt 7 is almost always the steady pipe 9
Since it is stationary while being in contact with the hole surface of No. 3, if the bolt 7 is pushed down as described above, the lower end of the bolt 7 is inserted into the hole at the upper portion of the steady rest pipe 9, and further, When the bolt 7 is pushed down, the bolt 7 descends along the inner wall surface of the steadying pipe 9. Therefore, the bolt 7 can be accurately lowered onto the upper surface of the nut 10 and screwed onto the nut 10 without causing the swinging action as described above. Therefore, the centering operation of the bolt 7 and the nut 10 can be performed reliably and easily.

Further, when the halves 3 and 4 are joined to form the form 2, the hollow concrete product is centrifugally formed by the form 2. Thus, the cement paste generated during the centrifugal molding passes between the flanges 5 and 6 which are joined to each other and reaches the holes 5a and 6a provided in the flanges 5 and 6. However, since the bolt 7 is the outer surface of the steady pipe 9 and is housed in the cylindrical body 8, the cement paste is rarely attached to the bolt 7. In this way, the elastic force of the bolt 7 does not deteriorate.

Further, when the mold 2 is divided into the respective halves 3 and 4 after the centrifugal force forming is completed, the head 7a of the bolt 7 is fixed to the bolt 7 by using a member such as a spanner. By rotating in the reverse direction, the bolt 7 is unscrewed from the nut 10, and the elastic restoring force of the coil spring receiver 13 easily restores the state of FIGS. Thus, the half halves can also be easily separated.

The present invention can be modified in various ways without departing from the spirit of the present invention, and it goes without saying that the present invention extends to such modifications.

[0018]

As described in detail in the above-mentioned one embodiment of the present invention, the cylindrical body fixedly provided on the upper surface of one flange has a bottom plate formed in a square cross section, and the bottom plate has one of the above-mentioned ones. The coil spring has a through hole that matches the hole provided in the flange, a steady pipe is fixedly mounted on the inner wall surface of the through hole and is erected inside the cylinder, and the coil spring wound around the bolt is The lower end of the coil spring is detachably locked in a recess provided in the vicinity of the bottom surface of the tubular body, and the coil spring is formed to have a smaller diameter toward the upper part. The bolt inserted into the coil spring can now be locked. Therefore, when the bolt is unscrewed from the nut, the elastic restoring force of the coil spring pulls out the bolt from each hole of the mutual flange. It is possible to separate the halves easily But this time, the bolt will not be such as to fall off from the tube body to maintain a state of being accommodated inside the coil spring. Of course, when replacing the bolt, the bolt, the coil spring, and the coil spring receiver can be easily removed from the cylinder by an operation such as removing the lower end of the coil spring from a recess provided in the bottom of the cylinder. Therefore, the bolt can be replaced very easily.

Further, when the bolt assembled in the cylinder is pushed down and screwed into the lower nut to connect both flanges, the bolt is guided into the steady pipe and lowered. Therefore, unlike the conventional case, the bolt is vertically lowered without swinging, the centering of the hole of the flange and the nut is very smoothly performed, and the workability of assembling the mold is improved.

Furthermore, since cement paste produced during centrifugal molding does not adhere to the coil spring, it is possible to prevent deterioration of the coil spring as much as possible. It is an invention that plays.

[Brief description of drawings]

FIG. 1 is a front view of an embodiment of the present invention in a non-fastened state.

FIG. 2 is a vertical cross-sectional view of FIG.

FIG. 3 is a front view when the non-fastened state of FIG. 1 is changed to the fastened state.

FIG. 4 is a vertical sectional view of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fastening device 2 Formwork 3,4 Half body 5,6 Flange 5a, 6a Hole 7 Bolt 7a Head 8 Cylindrical body 8a Bottom plate 8b Through hole 8c Recessed 9 Steady stop pipe 10 Nut 11 Sleeve 12 Washer 13 Coil spring receiver Body 13a Through hole 14 Coil spring

Claims (1)

[Claims] 1. A pair of halves, which are butted against each other to form a cylindrical formwork, are joined together so that they are fixed to each side of the two halves and are aligned with each other. A cylindrical body fixed to the upper surface of one of the flanges, a coil spring having a lower end portion detachably locked in the cylindrical body, and a bolt around which the coil spring is wound. In order to fasten both flanges by screwing the bolts together, in the fastening device composed of a nut whose rotation is blocked on the lower surface of the other flange, the tubular body is formed in a square cross section and has a bottom plate. In addition, a through hole that matches the hole opened in the one flange is opened in the bottom plate, and a steady rest pipe is extended from the inner wall surface of the through hole to the vicinity of the upper end of the cylinder. While being fixed, the coil springs have a decreasing diameter from the bottom to the top. When the lower end of the coil spring is detachably locked in a recess provided in the vicinity of the bottom surface of the tubular body and the bolt is pushed down to tighten the bolt to the lower nut. The coil spring is an outer portion of the steady rest pipe, and
A mold fastening device, characterized in that it can be housed in the cylinder.