JPH0651286B2 - Core structure of centrifugal molding machine - Google Patents

Description

TECHNICAL FIELD The present invention relates to the core structure of a centrifugal molding machine.

(B) Conventional technology Conventionally, the hollow cylindrical part is attached to a centrifugal molding machine and casts kneaded concrete by using centrifugal force to produce a hollow cylindrical concrete molded product. A core was used to form the core, and the core was formed into a taper shape and a longitudinal draft was provided in order to extract it from the concrete after molding the concrete. .

Further, as seen in Japanese Utility Model Publication No. 52-55488, a core for molding a concrete cylinder by utilizing centrifugal force is provided over the entire length in the axial direction of the hollow cylinder core. An open opening is formed, and a tapered guide edge formed inside this opening is closed by a hollow elongated fitting type with a tapered cross section, and both ends of the fitting type are supported by an engaging body. As shown in Japanese Utility Model Publication No. 35-5542 and Japanese Utility Model Publication No. 14-18137, a notch opening in the longitudinal direction is provided in the outer peripheral wall of the core, and a wedge-shaped member is fitted into the opening. However, there is a structure in which a supporting member for supporting a wedge-shaped member formed in a taper shape is inserted into the inside of the core to hold the outer shape.

(C) Problems to be solved by the invention However, since the concrete molded by centrifugal molding is compacted with a pressure of several tens of times that of gravity, the core and the molded concrete adhere to each other, resulting in high friction resistance. , The core became difficult to pull out, and the molded concrete was sometimes broken during the core pulling out work.

In addition, the core described in Japanese Utility Model Publication No. 52-55488 supports the hollow fitting type with a tapered cross-section even though a strong centrifugal force and concrete pressure are applied to both ends of the same type. Since only the engaged body is engaged, the center portion of the same mold is bent inward by the above pressure and cannot maintain a predetermined shape, and the function as the core may be lost.

Further, when a gap is created at the joint surface between the wedge type and the core type, and concrete milk enters the core type through the gap and solidifies, the contraction operation of the core type is hindered.

In addition, in Japanese Utility Model Publication No. 35-5542 and Japanese Utility Model Publication No. 14-18137, each member constituting the core is not connected,
Therefore, when the core is taken out, each member is disjointed, and when reassembling the core, much labor is required for positioning and fixing each member.

(D) Means for Solving the Problems In the present invention, the core is formed into a substantially cylindrical shape, and a notch opening in the longitudinal direction is provided on the outer peripheral wall of the core, and the opening is provided from the inside of the core. Insert the wedge body to complement the outer shape of the core at the notch opening at the tip surface of the wedge body, insert the tapered support rod inside the core, and insert the side surface of the rod body. In order to support the wedge body from the inside of the core to hold the outer shape of the core, the inside of the core is fixed to the back surface of the wedge body at a predetermined distance to fix the support material, (EN) Provided is a core structure of a centrifugal molding machine for hollow cylindrical concrete molding which is configured to limit the amount of depression of the wedge body when the support rod is pulled out from the core.

(E) Action / Effect According to the present invention, the wedge body is fitted from the inside into the notch opening of the core, and the wedge body is supported from the inside by the side surface of the tapered support rod body. The outer shape is slightly expanded compared to the core alone.When removing the core from the molded concrete after centrifugal molding, if the tapered support rod is removed and the wedge body is depressed inside the core. The outer shape of the core shrinks, the adhesion between the molded concrete and the outer peripheral surface of the core is peeled off, the core can be easily removed, and damage to the product during the same work is prevented.

Further, since the wedge body is entirely supported by the support rod body from the inside, it can withstand a strong pressure during centrifugal molding.

Further, since the outer shape of the core is contracted and the core is extracted as described above, it is not necessary to make a draft in the outer shape of the core, and a hollow cylindrical concrete molded product having a constant wall thickness can be manufactured.

It should be noted that the withdrawal of the support rod is performed very easily because the cores are slid by the metal members and the taper is provided.

In addition, since the wedge body is not distorted, no gap is generated between the notched opening portion of the core and the wedge body, and it is possible to prevent the problem that concrete milk enters the core.

In addition, when the support rod is pulled out during core removal, the wedge body collapses inside the core, but the inside of the core has a substantially L-shaped cross section secured to the back surface of the wedge body at a predetermined distance. Since the amount of depression is limited by the support material, it is not completely separated, and the core and the wedge body can be integrally directed from the molded product.

In this way, when the core is pulled out, it is only divided into two members, the core and the wedge body, which are half-integral with the support rod, so that when the core is reassembled, the support rod is re-inserted in the core. Reinsertion of the core is easy and easy, just inserting the body.

(F) Example To explain the example of the present invention in detail with reference to the drawings, (A) shows a centrifugal molding machine, in which a star-shaped hydraulic motor (2) is driven by hydraulic pressure from a hydraulic pump (1) connected to the motor. The rotation operation of the motor (2) is transmitted to one end of the rotary spindle (4) via the interlocking mechanism (3), and the rotary disc (5) is connected to the other end of the spindle (4). Installed on the outer surface of the disk (5) with multiple arms (6).
The base ends (7) of the arm (6) are continuously arranged at equal radial intervals, and are bent forward in a substantially L-shape at the middle part (8) of the arm (6) to make the tip part (9) of the arm (6). Is forming. The inner surface (10) of the tip (9) is flat and set parallel to the axis of the rotating spindle (4), and the rotating frame is formed by the inner surface (10) of the tips of the plurality of arms (6). It is in contact with the outer peripheral surface (12) of the body (11).

The rotating frame body (11) is a staircase block made of concrete and having a substantially triangular cross section between a substantially disk-shaped inner frame (13) having a circular hole in the center and an outer frame (14). Formwork for forming (B)
(15) A large number of them are arranged in a erected form to form a substantially cylindrical rotating body as a whole, and the block (B) of the formwork (15) is used.
Open the part that hits one end of the rotary frame body (11) inward, and the kneaded concrete injected into the frame body (11) flows into the formwork (15) through this open portion, Rotating spindle (4)
The kneading concrete is pressed into the formwork (15) by the centrifugal force generated by the rotation of the rotating frame body (11) transmitted from
It is for molding dense and strong concrete products.

The formwork (15) is formed into a substantially triangular tubular shape in cross section, and one triangular corner of the formwork (15) is cut off to form an opening (15a) inside the rotary frame body (11). The core (16) having a substantially triangular tubular outer shape is housed inside the mold (15).

The core (16) has a substantially triangular tubular outer shape, and is inserted through the inside of the mold (15) over the entire length of the mold (15).
On the outer peripheral wall (16b) in the central part, which is one side of the triangular shape of 6),
A cutout opening (16a) having a dovetail-shaped cross-section with the cross-section gradually widening toward the inside is formed in the longitudinal direction, and a wedge body (17) is inserted into the cutout opening end (16a) from the inside. .

The wedge body (17) has a substantially trapezoidal cross-section, and the wedge body (1
The tip surface (17a) of 7) complements the outer shape of the core (16) in the cutout opening (16a).

The outer shape of the core (16) before the wedge body (17) is inserted is the core (16).
Due to its elasticity, the core is slightly contracted from the defined outer shape, and the outer shape is expanded by the insertion of the wedge body (17) to form the core (16) of the defined outer shape.

The support rod (18) is in contact with the inner end surface (17b) of the wedge body (17), and the wedge body (17) is supported by the rod body (18) while being pressed outward.

The support rod (18) has a substantially rhombic cross-section tubular shape, and a tapered taper is formed from the base end (18a) to the tip (18b), and the contact portion with the wedge body (17) is substantially formed. A support base (18c) having a rectangular cross section is formed.

In order to support the wedge body (17) from the inside by inserting the support rod (18) and the rod (18), the support rod (18) is provided inside the core (16). A rod insertion hole (19) having a shape that matches the tapered shape of the rhombic cross section is formed, and the hole (19) is
The support material (19a) (19b) (19c) (19d) having a substantially L-shaped cross section is
It is fixedly formed on the inner peripheral surface of (16).

In particular, the support material (19c) is arranged so as to maintain a predetermined gap between one surface of the support material (19c) and the back surface of the wedge body (17).

And a formwork incorporating the core (16) configured as described above.
(15) A large number of them are connected to form a substantially cylindrical rotating frame body (11) with the opening (15a) of the mold (15) inside.

In the figure, (20) is a spacer for maintaining a constant space between adjacent rotary molds when the rotary frame body (11) is assembled, (21)
Is a recess for positioning when constructing stairs in the block (B), and (22) is a recess for making the core (16) easy to expand and contract.

The rotating frame body (11) configured as described above is attached to the centrifugal molding machine (A) to mold the stair block (B),
The demolding work of the molded product is performed as follows.

First, remove the rotating frame (11) from the centrifugal molding machine (A),
The support bar (18) of (16) is placed on the ground so that the base end (18a) of the support bar (18) faces upward.

Next, the support rod (18) is pulled out upward from the rod insertion hole (19) in the core (16) with a crane or the like. The rod (18) and the supporting members (19a) (19b) (19c) (19d) of the insertion hole (19) are in the same metal contact, and the rod (18) is tapered. Since it has been added, it can be easily pulled out.

Next, when the wedge body (17) is recessed inside the core (16) to contract the outer shape of the core (16), the outer peripheral surface of the core (16) and the inner peripheral surface of the stair block (B). The adhesion between the
(16) becomes free, and the free core (16) is pulled out upward. Especially this pulling out work is free
Since (16) is pulled out, there is no difficulty in working and no damage to the product occurs.

Further, the amount of depression of the wedge body (17) is the support material (19c)
Since the core (16) and the wedge body (16) are not completely separated, the core (16) and the wedge body (17) may be integrally pulled out from the molded product. it can.

Therefore, at the time of reassembling the core, it suffices to insert the support rod body (18) into the core (16), and the labor for reassembling the core is minimized.

In addition, when the wedge body (17) is liable to be depressed, it is advisable to lightly impact the wedge body (17) with a hammer or the like.

The rotating frame body (11) from which the core (16) has been pulled out as described above is disassembled, and the formwork (15) is disassembled to take out the internal stair block (B).

FIG. 5 and FIG. 6 show cores of other examples for making the hollow cross-sectional shape of hollow concrete into a rectangular tubular shape and a circular tubular shape, respectively. The outer shape that has contracted somewhat due to the elasticity of (23) is expanded by fitting it into the notch opening (25) of the wedge body (24) so that it has the specified outer shape, and the wedge body (24) is tapered. Support rod
The core (23) is supported from the inside, and the core (23) can be extracted very easily as in the case of the present embodiment.

[Brief description of drawings]

FIG. 1 is an overall side view of a centrifugal molding machine having a core structure according to the present invention. FIG. 2 is a front view of the same. FIG. 3 is an enlarged cross-sectional view of a mold and a core. I-I sectional view FIGS. 5 and 6 show another embodiment (16): core (16a): notch opening (16b): outer peripheral wall (17): wedge body (17a): tip surface (18): Support rod (19c): Support material

Claims (1)

[Claims] 1. The core (16) is formed in a substantially cylindrical shape, and the core (16) is formed.
The outer peripheral wall (16b) is provided with a notch opening (16a) in the longitudinal direction, and the wedge body (17) is fitted into the opening (16a) from the inside of the core (16) to remove the wedge body (17). Notch opening (16a) at the tip surface (17a)
Complementing the outer shape of the core (16) in, insert a tapered support rod (18) inside the core (16), at the side of the rod (18) wedge ( The core (16) is supported from the inside of the core (16) so as to retain the outer shape of the core (16), and the inside of the core (16) has a predetermined distance from the back surface of the wedge body (17). The hollow cylindrical shape that holds the support member (19c) and limits the amount of depression of the wedge body (17) when the support rod (18) is pulled out from the core (16). Core structure of centrifugal molding machine for concrete molding.