JPH06280831A - Tightening device for molding flask - Google Patents

Abstract

PURPOSE:To prevent a foreign matter from mixing inside a sleeve by fixing a nut to the back of the first protrusive piece of a molding flask, arrangedly providing a bolt threadedly engaging with the nut on the second protrusive piece, energizing the bolt toward its head through a spring, fixing the one end of the sleeve on the back of the second protrusive piece, and providing a sleeve cover through which the bolt can be inserted at the other end of the sleeve. CONSTITUTION:In a molding flask tightening device for tightening the first and the second protrusive piece 3, 4 which are individually provided on molds 1, 2 forming a molding flask and mutually opposite, a nut 5 is nonrotatably supported on the back of the first protrusive piece 3, and on the other hand, the second protrusive piece 4 is arrangedly provided with a bolt 8 which passes through both the protrusive pieces 3, 4 and threadedly engages with the nut 5. The shaft part 8a of the bolt 8 is provided with a spring 15 for energizing the bolt 8 toward its head 8b, and in addition, the one end of a sleeve 11 surrounding the all sides of the bolt 8 is fixed to the back of the second protrusive piece 4, and a sleeve cover 13 through which the shaft part 8a can be inserted is attached to the other end of the sleeve 11. Thus a foreign matter can be prevented from mixing inside the sleeve.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold clamping device for clamping a mold used for centrifugal forming of concrete piles, fume pipes and other concrete products.

[0002]

2. Description of the Related Art Conventionally, as a mold tightening device of this type, for example, there is a mold tightening device disclosed in Japanese Utility Model Publication No. 1-156308 by the present applicant. In the tightening device according to the present invention, the first and second projecting pieces are individually welded to the edges of the upper and lower molds of the mold so as to face each other, and the nut is rotated on the back surface of the first projecting piece. Welded a fixed cylinder that was impossible to fit inside, and on the second protruding piece, install a flanged bolt that is screwed with the nut and tightens the upper mold and the lower mold, and at the back side of the second protruding piece. And a sleeve (bolt holding member) for holding the bolt is welded. Further, the above-mentioned publication also discloses the one in which a spring is interposed between the bearing surface of the flange of the bolt and the bottom of the sleeve, and the bolt is biased so as to hit a stopper fitted in the upper part of the sleeve. .

In the tightening device of such a form, the bolt does not fall while always maintaining the same posture, the position and direction of the head of the bolt are specified, and the bolt is not screwed with the nut. However, there is an effect that the spring pushes against the stopper to position it, and by doing so, each work of tightening and loosening the bolt with the wrench can be performed smoothly.

[0004]

However, the following inconveniences have been pointed out regarding the above-mentioned conventional tightening device. That is, the upper portion of the sleeve is always open regardless of the tightened or loosened state of the bolt, and foreign matter may enter the inside of the sleeve from the outside. In particular, when the tightening device is applied to a mold used for centrifugal force molding of concrete products, if the concrete filling this mold accidentally enters the inside of the sleeve and hardens as it is, the bolt rises and falls. There is a risk of being unable to move. Even if this situation does not occur,
When concrete adheres to bolts or springs, they are significantly consumed. Further, for example, if a needle-shaped body or the like enters the inside of the sleeve and is caught by a spring interposed inside the sleeve, the spring may come off and a functional disorder may occur.

Further, when the concrete filled in the mold is undergoing a hardening process, the strength of the concrete is
For the purpose of exhibiting various properties such as durability and watertightness, curing is performed by providing sufficient moisture and an appropriate temperature to create conditions suitable for the hydration reaction of cement. In particular, a concrete product produced by centrifugal force molding is subjected to high temperature and high pressure steam curing, which has advantages such as quick shipment as a finished product, high strength, little shrinkage and high resistance to chemical erosion. Then, in order to prevent the reliability of the tightening device from being deteriorated due to the high temperature at the time of curing, it is necessary to appropriately supply the lubricating oil to the bolts and nuts, but in the conventional tightening device, consideration is given to this lubricating oil. However, there was also the inconvenience of having to refuel frequently.

The present invention is capable of solving the above-mentioned problems, and an object thereof is to prevent foreign matter from entering the inside of the sleeve from the outside and to supply lubricating oil to the bolts and nuts suitably. The purpose of the present invention is to provide a tightening device for molds that can be used.

[0007]

Among the mold tightening devices of the present invention, the one described in claim 1 is the first and the first, which are provided separately for the two molds forming the mold and which face each other. In a mold tightening device for tightening the second projecting piece, a nut is held non-rotatably on the back surface of the first projecting piece while the second projecting piece is penetrated through both projecting pieces. And a spring for biasing the bolt toward the head thereof is provided on the shaft portion of the bolt, and a sleeve surrounding the four sides of the bolt on the back surface of the second projecting piece. Is fixed, and a sleeve lid through which the shaft portion of the bolt can be inserted is attached to the other end of the sleeve.

According to the second aspect, the first aspect is the first aspect.
The lubricating oil is filled in the annular space between the inner surface of the sleeve and the outer surface of the shaft portion of the bolt.

[0009]

According to the mold tightening device of the present invention as set forth in claim 1, a sleeve lid through which the shaft portion of the bolt can be inserted is attached to the other end of the sleeve surrounding the four sides of the bolt. This prevents foreign matter from entering the inside of the sleeve from the outside, prevents functional failures of the bolts and springs arranged inside the sleeve, and reduces wear of these bolts and springs.

Further, according to the second aspect of the invention, the lubricating oil in the annular space is pushed out due to the bending of the spring when the bolt is tightened, and this lubricating oil preferably lubricates the shaft portion and the nut of the bolt. Therefore, it is possible to improve the durability of the bolts and nuts without the need for special refueling work.

[0011]

Embodiments of the present invention will now be described in detail with reference to the drawings. 1 to 3 are views showing an embodiment of a mold clamping device of the present invention, in which a lower mold 1 having a semicircular cross section and an upper mold 2 having the same shape are opposed to each other to form a cylindrical mold. I am configuring. The first protruding piece 3 of the plate-like body is fixed to the edge of the lower mold 1 by welding, and the second protruding piece 4 of the plate-like body is similarly fixed to the edge of the upper mold 4 by welding. , The mold is tightened by tightening both projecting pieces 3 and 4 in a direction approaching each other.

The two protruding pieces 3 and 4 are opposed to each other, and their opposing surfaces are in close proximity to each other. On the back surface of the first protruding piece 3, a nut 5 is provided with a nut case 6 and a C-shaped ring 7. It is held non-rotatably by. The nut case 6 is welded to the first projecting piece 3 and has the same shape as the outer peripheral surface of the nut 5 to fit the nut 5 therein, and also engages with the groove on the inner periphery of the nut case 6. The ring 5 prevents the nut 5 from coming off.

The second projecting piece 4 holds a bolt 8 which penetrates both projecting pieces 3 and 4 and is screwed into the nut 5.
The shaft portion 8a of the bolt 8 has a C-shaped stop ring 9
Is attached, and a tapered surface is formed on the head portion 8b. A sleeve 11 holds the bolt 8 on the second protruding piece 4. The sleeve 11 is a bottomed tubular body that surrounds the bolt 8 on all sides, has a circular cross section, and its inner diameter is slightly larger than the outer diameter of the stop ring 9 attached to the bolt 8. Also, the sleeve 11
A through hole 12a that is slightly larger than the outer diameter of the shaft portion 8a of the bolt 8 is formed in the bottom portion 12, and the bottom portion 12 is fixed to the rear surface side of the second protruding piece 4 by welding.

On the other hand, a sleeve lid 13 is attached to the upper portion of the sleeve 11. This sleeve lid 13
The inner diameter of the sleeve 11 is slightly larger than the outer diameter of the sleeve 11, and the inner peripheral surface of the sleeve 11 is formed with a screw groove to be screwed into a screw thread formed on the outer peripheral surface of the sleeve 11. Is blocking. Further, the sleeve lid 13 is formed with a through hole 13a slightly larger than the outer diameter of the shaft portion 8a of the bolt 8 so that the stop ring 9 attached to the bolt 8 abuts the sleeve lid 13.
It is designed to prevent it from slipping upward. The sleeve lid 1
Between the upper surface of 3 and the head 8b of the bolt 8, a washer 1
4 is interposed.

The bolt 8 is urged by a spring 15 having a rectangular cross section interposed between the stop ring 9 and the bottom portion 12 of the sleeve 11 so that the stop ring 9 contacts the sleeve lid 13. Therefore, when the bolt 8 is released from the screw engagement with the nut 5,
The bolt 8 is in contact with the sleeve lid 13 by the spring 15. At this time, the tip of the shaft portion 8a of the bolt 8 is located between the through holes 3a and 4a formed in the projecting pieces 3 and 4 or in the through hole 4a. In any of these cases, the shaft portion 8a of the bolt 8 is held at its periphery by the through holes 12a and 13a and is fixed in the position intersecting the axis.

Further, the inner surface of the sleeve 11 and the bolt 8
The annular space between the outer surface of the shaft portion 8a and the outer surface of the shaft portion 8a is filled with the lubricating oil 16. The lubricating oil 16 is semi-solid and has a higher viscosity than ordinary grease,
In particular, those that do not liquefy even at high temperatures are used. Next, an example of use of the mold tightening device configured as described above will be described. In this example, the case where the mold clamping device according to the present invention is applied to a mold used for centrifugal force molding of concrete piles, fume pipes and other concrete products will be described.

The bolt 8 is initially in an open state as shown in FIG. 2 and is axially positioned by the spring 15, the stop ring 9 and the sleeve lid 13. Further, the shaft portion 8a of the bolt 8 has the through holes 12a, 13
The periphery of the bolt 8 is held by a, and the bolt 8 is positioned by these in a direction intersecting the axis. Here, when the upper mold 2 is lowered and the mold is closed in a state where the reinforcing material such as the reinforcing bar is arranged in the lower mold 1 and the concrete which is not yet hardened is put in, the head 8b of the bolt 8 is A wrench (not shown) is engaged and the bolt 8 is rotated. At this time, even if concrete that has not yet hardened is accidentally thrown into the outside of the lower mold 1, since the sleeve lid 13 is attached to the upper portion of the sleeve 11, it does not enter the inside of the sleeve 11.

When the wrench engages with the head portion 8b of the bolt 8, the head portion 8b of the bolt 8 is guided by the taper surface of the head portion 8b even if there is some deviation in the lowered position of the wrench.
Securely engage b. The wrench rotates the bolt 8 and pushes it down, and the bolt 8 flexes the spring 15 and descends while rotating. At this time, the shaft portion 8a of the bolt 8 is guided to the inner surfaces of the through holes 12a and 13a, and is rotated and lowered while keeping the axis line and screwed into the nut 5.

In the opened state of the bolt 8, the lubricating oil 16 filled in the annular space in the sleeve 11 is attached to the shaft portion 8a, and the spring 15 is bent when the bolt 8 is pushed down, so that the lubricating oil 16 is released. Are extruded from the annular space toward the slight gaps between the shaft portion 8a and the through holes 12a and 4a. At this time, the spring 15
Has a rectangular cross section, the lubricating oil 16
Extrudes satisfactorily.

As described above, while the lubricating oil 16 is pushed out by the flexure of the spring 15, the screwing of the bolt 8 and the nut 5 is continued until a predetermined torque is reached, and then stopped. When this state is reached, as shown in FIG.
And the upper die 2 are firmly tightened. Further, the wrench rises and comes off the head 8b of the bolt 8. On the other hand, when the mold is finished and the mold is released, the screwing of the bolt 8 is released. At this time, the bolt 8 is loosened by re-engaging the wrench with the head portion 8b of the bolt 8 and rotating it in the opposite direction. Even when the bolt 8 rises due to this loosening, the shaft portion 8a is always held in the same posture because the periphery thereof is held by the through holes 12a and 13a.

When the engagement with the nut 5 is released by the wrench, the bolt 11 is pushed up by the urging force of the spring 15, and the elevation is stopped at the position where the stop ring 9 contacts the sleeve lid 13. Bolt 8 at this time
Since the tip of the shaft portion 8a is located between the through holes 3a and 4a formed in both the protruding pieces 3 and 4 or in the through hole 4a, the shaft portion 8a may hit the first protruding piece 3. Therefore, the upper mold 2 can be smoothly raised.

Even during these series of operations, the upper end of the sleeve 11 is closed by the sleeve lid 13, so that concrete and other foreign matters which have not yet hardened do not enter from the outside. Further, since the lubricating oil 16 is pushed out by the bending of the spring 15 accompanying the tightening of the bolt 8, and the shaft portion 8a of the bolt 8 and the nut 5 are lubricated, the labor for special oil supply work can be saved.

After that, even when the concrete in the formwork is cured, the bolts 8 and the nuts 5 are well lubricated, so that the life of the bolts 8 and the nuts 5 is maintained against the high temperature during curing. It does not lower. Also,
4 and 5 show another example different from the above. As shown in these drawings, when the plate thicknesses of both the protruding pieces 3 and 4 are large, the nut 5 including the tubular portion 5a and the flange portion 5b is used, and the diameter of the through hole 3a of the first protruding piece 3 is used. The cylindrical portion 5a may be fitted in the through hole 3a, and the flange portion 5b may be fitted in the nut case 6 internally. In the nut 5 having such a configuration, since the end of the tubular portion 5a is flush with the abdominal surface of the first projecting piece 3, the bolt 8 and the nut 5 start to be screwed simultaneously with the rotation of the wrench. Therefore, the force for pushing down the bolt 8 is unnecessary, and the bolt 8 and the nut 5 can be easily screwed together.

[0024]

As is apparent from the above description, the following effects can be obtained according to the mold clamping device of the present invention. According to the first aspect, the sleeve lid is attached to the upper part of the sleeve surrounding the four sides of the bolt,
Foreign matter does not enter the inside of the sleeve from the outside,
Therefore, foreign matters do not come into contact with the shaft portion and the spring of the bolt arranged inside the sleeve, so that the functional failure of the bolt and the spring can be prevented and the consumption of them can be reduced.

Further, according to the second aspect of the invention, the lubricating oil inside the sleeve is pushed out by the bending of the spring when the bolt is tightened, and this lubricating oil suitably lubricates the shaft portion and the nut of the bolt. Therefore, the durability of the bolts and nuts can be improved, and since there is no need to perform special lubrication work, smooth work can be realized.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of essential parts showing a tightened state of a mold tightening device according to the present invention.

FIG. 2 is a main-portion cross-sectional view showing the opened state.

FIG. 3 is a side view of the same appearance.

FIG. 4 is a cross-sectional view of essential parts showing a tightened state of another example of the mold tightening device according to the present invention.

FIG. 5 is a sectional view of an essential part showing the opened state.

[Explanation of symbols]

 1 Lower Mold 2 Upper Mold 3 First Projecting Piece 4 Second Projecting Piece 5 Nut 8 Bolt 8a Shaft 8b Head 11 Sleeve 13 Sleeve Lid 15 Spring 16 Lubricating Oil

Claims (2)

[Claims] 1. A mold frame tightening device for tightening mutually opposing first and second projecting pieces individually provided in two molds forming a mold, wherein a rear surface of the first projecting piece is provided. While holding the nut non-rotatable, the second projecting piece, a bolt that penetrates both projecting pieces and is screwed into the nut is provided,
A spring for urging the bolt in the head direction thereof is provided on the shaft portion of the bolt, and one end of a sleeve surrounding the four sides of the bolt is fixedly provided on the back surface of the second projecting piece.
A mold tightening device characterized in that a sleeve lid into which the shaft portion of the bolt can be inserted is attached to the other end of the sleeve. 2. The mold clamping device according to claim 1, wherein the annular space between the inner surface of the sleeve and the outer surface of the shaft portion of the bolt is filled with lubricating oil.