JP3414629B2 - Spiral die with spiral strip, method of manufacturing the pile, and centrifugal cast pile with spiral strip - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cast iron pile having a spiral line formed at its tip, a casting mold for the pile, and a method for manufacturing the pile.

[0002]

2. Description of the Related Art As a metal pile, there is known a steel pile 1S with a spiral strip in which a spiral strip 3S is formed on the outer circumference of a seamless steel tube 2S as shown in FIG.

When the piles 3S with spiral stripes are driven into the ground, they are embedded by the screwing operation by the rotational drive around the shaft, so that noise and vibration are very small and they can be driven to a sufficient depth. It is preferably used for foundation work in the ground and urban areas.

[0004]

By the way, in the case of forming the pile 3S with a spiral strip, conventionally, the spiral strip 3S is attached to the steel pipe 1S for the pile by welding and then formed.

Therefore, the manufacturing method requires a skilled welding technique, and it takes a lot of time and labor to prepare a steel sheet formed into a spiral shape.

[0006] Especially, the larger the diameter of the pile is, the more serious the above-mentioned drawback becomes. On the other hand, it is considered that if the above-mentioned pile with spiral stripes is formed by casting, it can be easily manufactured by saving the labor of welding, but it is very difficult or impossible to remove the spiral stripe 3S integrally formed at the tip of the straight pipe portion. Therefore, in general, the mold cannot be removed unless the casting mold is broken, and there is a problem that industrial implementation is extremely impossible.

The present invention has been made for the purpose of solving the above problems, and an object thereof is to make it possible to industrially manufacture a pile with spiral threads by centrifugal casting.

[0008]

Means for Solving the Problems The invention recited in claim 1 relates to a casting mold of a helical strip with piles, a casting mold for casting a tube by centrifugal force, the helical end surface the end face is not around the periphery shaft A straight pipe portion, a spiral surface portion extending in the radial direction on the same plane as the spiral end surface of the straight pipe portion, and a cylindrical edge coaxial with the straight pipe portion forming a peripheral edge of the spiral surface portion. And a section.

Since the spiral strip on the end face of the straight pipe is formed so as not to go around the axis, there is no overlap on the projection plane in the axial direction of the spiral strip. Therefore, when the pile is pulled out from the centrifugal forming die, the spiral strip is not overlapped. It is possible to pull out straight from the side where the is formed and remove from the mold.

The invention as set forth in claim 2 relates to a casting die for a pile with a spiral ridge, which has an outer diameter capable of being fitted into a tubular edge portion of the casting die for a pile with a spiral ridge according to claim 1, The present invention is characterized in that a spiral end face of a casting die of a spiral pile is provided with spiral end faces facing each other while being separated by a thickness of the spiral strip to be cast.

It is, so to speak, the core of the spiral strip portion of the pile with spiral strips. As described above, since the spiral line is set in the range of the rotation angle of 360 ° or less, this outer mold can also be pulled straight in the axial direction.

[0012] The invention of claim 3 relates to a casting die for centrifugally casting a pile with spiral stripes, wherein the spiral end surface of the casting die of the pile with spiral stripes according to claim 1 is provided with spiral stripes according to claim 2. The present invention is characterized in that a casting die for a pile is fitted with the end faces of the helical strips separated by the thickness of the helical strips.

The straight tubular pile body is formed by centrifugal force,
The spiral stripe portion of the tip portion is formed between the spiral surfaces facing each other. The invention as set forth in claim 4 relates to a method for manufacturing a pile with spiral stripes, wherein the casting die for the pile with spiral stripes according to claim 2 is provided on the tubular edge of the casting mold for the pile with spiral stripes according to claim 1. The centrifugal force casting mold for piles with spiral strips, which is fitted with, is rotatably supported with the pipe axis in a horizontal position, while the molten cast iron flows in while rotating and the straight pipe portion and the spiral strip portion are centrifugally generated. And are integrally molded.

According to the method of the present invention, a pile integrally having a spiral ridge can be easily and inexpensively manufactured by the centrifugal casting method. A fifth aspect of the present invention relates to a centrifugally cast spiral threaded pile obtained by the molds of the first to third aspects and the manufacturing method of the fourth aspect, wherein the pipe end face is the winding start point only at the tip of the straight pipe portion. It is characterized in that a spiral strip having a cross-sectional shape extending from the straight pipe portion in a blade shape in a radial direction is integrally formed with a winding angle of 360 ° or less.

Although the length of the spiral stripe is short, since the spiral stripe is integrally formed with the pile main body, the durability of the spiral stripe can be increased, and even such a small length enables sufficient excavation.

Further, the reason why the spiral winding angle is within 360 ° is to enable centrifugal casting.
If the angle is larger than 60 °, demolding becomes impossible unless the mold is broken.

Although the lower limit of the winding angle of the spiral strip 3 is not particularly specified, it is set to a minimum size that allows for excavation. The helix angle and lead angle of the spiral strip for excavation are set according to the application of the pile.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of the present invention will be described. FIG. 1 and subsequent drawings show an embodiment of a casting die for a pile with spiral stripes and a method for manufacturing a pile.

In FIG. 1, reference numeral 5 in the drawing denotes a casting die for a pile with a spiral ridge. The casting die 5 for a pile with a spiral ridge is a straight pipe portion 6 for casting a pipe by centrifugal force, and an end face 6A is shown in FIG. At θ, a spiral end surface 6A that does not go around the axis, a spiral surface portion 7 that extends in the radial direction on the same plane as the spiral end surface 6A of the straight pipe portion 6, and a peripheral edge of the spiral surface portion 7. And has a tubular edge portion 8 coaxial with the straight pipe portion.

Reference numeral 9 in the drawing denotes an extending cylindrical portion for fitting the casting mold 10 as a core. FIG. 3 is a perspective view of a casting mold 10 serving as a core fitted to the extending cylinder portion 9 of the casting mold 5 for the pile with spiral ridges according to claim 2.

The casting die 10 has an outer diameter d which can be fitted into the extension tube portion 9 of the casting die 5 of the pile with spiral stripes, and is provided on the spiral end surface 6A of the casting die 5 of the pile with spiral stripes. The spiral end surface 11 is formed to have a thickness corresponding to the thickness of the spiral strip 3 to be cast, that is, the spiral end surface 11 that faces the height of the edge of the tubular strip edge portion 8.

The casting mold 10 is formed of foundry sand or the like, but may be formed of a refractory material such as refractory clay or ceramic so that it can be used repeatedly.

FIG. 4 is a sectional view showing a state where a casting die for piles with a spiral thread is assembled, in which a casting die 10 is fitted to an extension tube portion 9 of a casting die 5 for piles with a spiral thread. In the figure, reference numeral 12 denotes a lid for fixing the casting mold 10 for reinforcing the flow pressure of the molten cast iron that has flowed in.

In this casting mold, as shown in FIG. 2, the spiral line has a winding angle of 360 ° or less, and therefore, when the mold is assembled and when the mold is released, as shown by the arrow, It suffices to make a straight moving direction S along the direction, and the work of assembling and disassembling the mold becomes easy despite the formation of the spiral line.

FIG. 5 and subsequent drawings are side views showing the steps of the method for manufacturing a pile with spiral stripes according to claim 4. In FIG.
The casting mold 5 is horizontally placed on the rotating rollers 13, 13,
As shown in the drawing, the casting die 10 and the lid 12 are fitted and fixed in this order to the extension tube portion 9 to be assembled.

Reference numeral 14 in the drawing denotes a guide trough for pouring the molten cast iron into the open end 5A of the casting mold 5, and guides the molten cast iron supplied from the pouring ladle 15 to the straight pipe portion 6 of the casting mold 5. For molding, the casting mold 5 assembled as shown in FIG. 6 is rotated at a predetermined rotation speed, and molten cast iron is poured therein.

The molten cast iron flows in the casting die 5 in the axial direction, collides with the casting die 10 and a part of the molten cast iron flows into the spiral ridge portion, and the other is centrifugally distributed evenly on the inner surface of the casting die 5 to form a tubular shape, and then cooled. It becomes a tube with a spiral strip.

When cooled and hardened to an extent that it can be handled, the lid 11 and the casting die 10 are removed in this order, and the formed pile 1 with a spiral strip is moved in the axial direction of the casting die 5 by a drawing machine 16 as shown in FIG. Pull straight out.

Since the projection planes in the axial direction do not overlap with each other, the spiral stripe can be pulled out straight in the axial direction. FIG. 8 is a side view of the main part of the above-mentioned casting mold and the pile with a spiral strip obtained by the manufacturing method, and FIG. 9 is a bottom view.

In the centrifugally cast spiral pile 1 having the pipe end face 2A as the winding start point only at the tip of the straight pipe portion 2, the cross-sectional shape extends from the straight pipe portion 2 in the radial direction into a spiral ridge 3 Is 36
It is integrally formed with a rotation angle θ (FIG. 8) within 0 °.

Reference numeral 4 in the drawing denotes a cap fitted to the tip of the pile 1 with spiral stripes. The straight pipe portion 2 and the spiral strip 3 are integrally formed of cast iron, and the cap 4 is attached by retrofitting.

Further, the case of the single-thread screw is shown as the above-mentioned embodiment, but even if the number of threads is two or more, the same operation is possible as long as the projection planes in the axial direction of the spiral threads 3 ... 3 do not overlap each other. Is.

As shown in FIG. 10, the pile 1 with spiral stripes is driven to rotate by the excavation drive machine A, and is excavated below the ground G by the screw pitch of the spiral stripes 3.

[0034]

As described above, in the spiral-shaped part of the casting die of the present invention, the winding angle of the spiral is within the range of 360 °. Therefore, the straight pipe part and the spiral-shaped part are formed by centrifugal casting. Even if both and are integrally molded, they can be pulled straight out in the axial direction of the straight pipe portion when they are released from the mold, and the pipe with a spiral line can be molded by the centrifugal casting method.

Further, according to the method for manufacturing a pile with a spiral strip of the present invention, the spiral strip can be integrally formed when the pipe is formed,
It has an effect that a pile with a spiral strip, which has been difficult in the past, can be formed very easily and inexpensively.

In the pile with spiral ridges of the present invention, since the straight pipe portion and the spiral ridge portion forming the pile are not welded but integrated, the attachment strength of the spiral ridge is remarkably strong, and the pile is used under severe operating conditions. It also has the effect of enduring.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a casting die for a pile with spiral threads according to claim 2.

FIG. 2 is a side view of a casting die for a pile with spiral threads according to claim 2;

FIG. 3 is a perspective view of a casting die for a pile with spiral stripes according to claim 3;

FIG. 4 is a cross-sectional view of a casting die for a pile with spiral stripes according to claim 4.

FIG. 5 is a side view showing the steps of the method for manufacturing a pile with spiral stripes according to claim 5;

FIG. 6 is a side view showing the steps of the method for manufacturing a pile with spiral threads according to claim 5;

FIG. 7 is a side view showing a demolded state in the method for manufacturing a pile with spiral threads according to claim 5;

FIG. 8 is a side view of a main portion of the spiral pile with claim 1;

FIG. 9 is a bottom view of the pile with spiral stripes according to claim 1.

FIG. 10 is a side view showing a usage state of the pile with spiral stripes according to claim 1.

FIG. 11 is an explanatory side view of a conventional pile with spiral stripes.

[Explanation of symbols]

1 Piles with spiral stripes 2 Straight pipe section 2A pipe end face 3 spiral θ rotation angle 4 cap A excavation drive machine G ground 5 Casting type of pile with spiral stripe 6 Straight pipe section 6A (spiral) end face 7 spiral surface 8 tubular edge 9 Extension tube part 10 casting mold 11 spiral end face 12 lid 13 rotating roller 14 Information gutter 15 pouring ladle 16 pulling machine

─────────────────────────────────────────────────── --- Continuation of the front page (56) References JP-A-8-134904 (JP, A) JP-A-7-11637 (JP, A) JP-A-62-296014 (JP, A) Actual development Sho-60- 104437 (JP, U) Actual development Sho 55-163343 (JP, U) International publication 97/017498 (WO, A1) (58) Fields investigated (Int.Cl. ⁷ , DB name) B22D 13/10 E02D 5 / 56

Claims (5)

(57) [Claims] 1. A casting die for casting a pipe by centrifugal force, which has a straight pipe portion whose end face is a spiral end face that does not make a round around the axis, and a radial direction on the same plane as the spiral end face of the straight pipe portion. A casting die for a pile with a spiral ridge, comprising: a spiral surface portion extending to an inner side of the spiral surface portion; and a cylindrical edge portion coaxial with the straight pipe portion forming a peripheral edge of the spiral surface portion. 2. A helix having an outer diameter capable of being fitted to the tubular edge portion of the casting die of the spiral thread pile according to claim 1, and being cast on the spiral end surface of the casting die of the helix thread pile. A casting die for a pile with a spiral stripe, which has spiral end surfaces facing each other with a thickness of the stripe. 3. A casting die for a spiral pile with a thread according to claim 2, wherein the spiral end surface of the casting die for the pile with a spiral thread according to claim 1 has the spiral strip end surface of the die with the thickness of the spiral strip. Casting mold for piles with spiral stripes, characterized in that they are fitted separately. 4. A centrifugal force of a pile with a spiral strip formed by fitting the casting die of the pile with a spiral strip according to claim 2 to the tubular edge of the casting die of the pile with a spiral strip according to claim 1. A spiral strip characterized in that the casting die is rotatably supported with the tube axis in a horizontal position, and while being rotated, molten cast iron flows into the casting die and a straight pipe portion and a spiral strip portion are integrally formed by centrifugal force. Manufacturing method of attached pile. 5. A spiral strip having a tube end surface as a winding start point and having a cross-sectional shape extending like a blade in the radial direction from the straight pipe section only at the tip of the straight pipe section has a winding start point. Than 360 °
It is characterized by being integrally formed with a winding angle within
Centrifugal casting spiral piles.