JPH06270127A - Method and apparatus for centrifugally molding concrete pipe - Google Patents

Abstract

PURPOSE:To automate a process developing and leveling ready mixed concrete in a centrifugal molding method and a process finishing the inner surface of a molded concrete pipe. CONSTITUTION:Ready mixed concrete 100 is charged in the cylindrical form 3 rotated on a rotary wheel 2 and a vibration wheel to be developed and levelled and compacted by centrifugal force and the inner peripheral surface of a concrete pipe is finished while the form 3 is rotated. An auger shaft 50 is provided to the form 3 so as to pierce the form 3 in parallel to the center axis of the form 3 and reversibly rotated by a motor 57 to be made movable in the diameter direction and rotary shaft direction of the form 3 corresponding to the position of a moving stand 55. This auger shaft 50 is reversibly rotated to develop and level the ready mixed concrete 100 charged in the form 3. In a finish process, the form 3 is rotated in the direction reverse to the rotary direction thereof to cut and finish the inner peripheral surface of the concrete pipe molded on the outer peripheral part of the form.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for centrifugally forming a concrete pipe body for forming a concrete product such as a concrete pipe by utilizing centrifugal force.

[0002]

2. Description of the Related Art Centrifugal molding method utilizing centrifugal force is widely known as a method for producing various concrete products such as centrifugal force reinforced concrete pipe (fume pipe) and centrifugal force concrete pile. In this conventional centrifugal force forming method, for example, a cylindrical form frame, in which reinforcing bars are assembled in advance, is placed on a wheel rotated by a motor or the like, and this is rotated. And, first, while rotating the mold at a low speed, raw concrete is put into the inside of the mold to spread and level it, and then the mold is rotated at a medium speed and a high speed, and the centrifugal force generated by this is applied. Fresh concrete is dehydrated and compacted into a cylindrical shape. Finally, the inner circumference is finished smooth.

After that, the concrete is hardened by steam curing or the like, then the mold is separated and demolded, and further cured to complete a centrifugal reinforced concrete product.

By the way, in the above-mentioned method for forming a concrete pipe according to the prior art, in order to spread and level the fresh concrete in the mold when the fresh concrete is initially put, a long rod-shaped body is passed through the mold and the end thereof is inserted. It has been practiced that the part is manually held and the tip end portion of this long rod-shaped body is brought into contact with the poured concrete to uniformly level it. Further, the final finishing of the inner peripheral surface is also performed by using a long rod-shaped body which holds the end portion manually as in the above.

[0005]

As described above, in the conventional method for centrifugally forming a concrete pipe body, it is necessary to manually deploy the fresh concrete in the formwork at the initial stage of the injection of the ready-mixed concrete. As a result, quick concrete development and leveling cannot be performed. Further, there is a problem in that the finishing work of the inner peripheral surface of the pipe body requires skill and it is impossible to quickly and accurately finish the inner peripheral surface.

Therefore, in the present invention, in view of the above-mentioned problems in the prior art, it is possible to automatically perform the unfolding and leveling of the fresh concrete and the finishing work of the inner peripheral surface without manual labor. A method for centrifugally molding a concrete pipe,
It is an object of the present invention to provide a device therefor.

[0007]

[Means for Solving the Problems] That is, in order to achieve the above-mentioned object, a method for centrifugally molding a concrete pipe is proposed by the present invention, in which ready-mixed concrete is placed in a rotating cylindrical formwork. The steps of throwing in and spreading the fresh concrete into the formwork and leveling it, compacting the concrete by centrifugal force, and finishing the inner circumference of the concrete tube formed by rotating the formwork. After stopping the rotation of the frame, in the centrifugal molding method of the concrete pipe having a step of taking out concrete products from the same frame, in the hollow part of the frame, pass the auger shaft parallel to the central axis of the frame, While rotating the auger shaft in the normal and reverse directions, the step of developing and leveling the ready-mixed concrete in the form is performed, and while rotating the auger shaft in the direction opposite to the form, the outer periphery of the auger shaft is molded. Cutting the inner peripheral surface of the concrete tube, a centrifugal molding method of the concrete pipe body by a step of finishing the inner circumferential surface.

Further, in order to achieve the above-mentioned object, it is proposed by the present invention in a centrifugal forming apparatus for a concrete pipe body, which comprises a cylindrical formwork and a foil supporting and rotating the formwork. , An auger shaft whose one end is rotatably supported at a position parallel to the center axis of the mold supported on the wheel, a rotating mechanism for rotating the auger shaft forward and backward, and the auger shaft for the mold. A centrifugal molding apparatus for a concrete pipe, comprising: a radial movement mechanism that moves in the radial direction of the frame; and an axial movement mechanism that moves the auger shaft in the central axis direction of the mold.

[0009]

According to the method and apparatus for centrifugally forming a concrete pipe according to the present invention described above, in order to form a concrete pipe, fresh concrete is put into the inside of the form. The rotating auger shaft evenly spreads and leveles the inside of the mold. In the unfolding process of this ready-mixed concrete, by rotating the auger shaft forward and backward, the peripheral part of the ready-mixed concrete is pushed forwards and backwards to be leveled, so that it can be unfolded uniformly without being biased to one side. is there.

Further, in the inner surface finishing step after compaction by high speed rotation, the finishing step is completed by finishing the inner peripheral surface of the concrete pipe body while rotating the auger shaft in the direction opposite to the form. Done. In this finishing process, the sludge floating on the inner peripheral surface of the concrete pipe body can be cut at the tip portion of the auger shaft to finish the inner surface smoothly.

[0011]

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. FIG. 2 shows an example of a centrifugal force molding device for carrying out the method for centrifugally molding a concrete pipe of the present invention. In this device, as shown in the figure,
A fixed base 6 is installed on the base 5, and a vibration base 7 is installed on the left side of the fixed base 6 via a hinge 9. The end of the vibration base 7 opposite to the hinge 9 is
It is supported on the base 5 via a damper 8 such as an anti-vibration rubber. The rotary wheel 2 is rotatably installed on the fixed base 6, while the vibration wheel 2 ′ is rotatably supported on the vibration base 7.

Frames 10, 1 attached to the base 5
The driven pulleys 11 and 13 are rotatably supported by the respective two. A motor 1 is installed on the right side of the base 5, and the rotation of the motor 1 is transmitted to the rotating wheel 2 via the pulleys 11 and 13 and the belts 14, 15 and 16. The vibrator 4 is installed on the vibration base 7,
By vibrating this, vibration is applied to the vibrating wheel 2 ′ via the vibrating base 7.

FIG. 1 is a side view of this centrifugal force molding apparatus. In the figure, substantially annular flange portions 30, 30 are provided at both ends of a mold 3, for example, bolts and nuts (indicated by dotted lines in the figure). (Shown) and the like, and the flange portions 30 and 30 are placed on the rotating wheels 2 and 2 and are rotationally driven. In the drawing, the rotation directions of the rotating wheels 2 and 2 are indicated by arrows. Reference numeral 21 in the drawing denotes a rotating shaft connecting the rotating wheels 2 and 2, and reference numerals 22 and 22 allow the rotating shaft 21 to rotate freely. Bearings to be supported by
Indicates a fixed base.

Further, in FIG. 1, an auger shaft 50 and a drive mechanism for driving the auger shaft 50 are shown. The drive mechanism is located on the side of the rotary wheels 2 and 2 on which the mold 3 is placed (see FIG. In the left). This auger shaft 50
Is a rotary shaft 5 rotatably supported at one end (left side in the figure).
1. A spiral screw 52 is fixed around the rotary shaft 5
A cylindrical roller 53 is attached to the other end (the right end in the figure) of No. 1. Reference numerals 54 and 54 denote bearings for rotatably supporting the rotary shaft 51 on the moving base 55. A pulley 56 is fixed in the middle of the rotary shaft 51, and the rotation of a motor 57 provided inside the moving base 55 is transmitted to the rotary shaft 51 via a belt 58.

The moving base 55 is mounted on a moving vehicle body 70 movably arranged on a rail 60. That is, the screw jack 7 is mounted on the moving body 70.
1, 71 are installed, these screw jacks 7
The movable table 55 is arranged on the first and the first units 71. These screw jacks 71, 71 are still the moving body 7
It is moved up and down by the rotation of the motor 75 arranged above 0, so that the height of the moving base 55, in other words,
The height of the auger shaft 50 can be freely adjusted. A part of the wheels 72, 72 ... Of the moving vehicle body 70 is rotatably driven by a motor or the like not shown in the figure, so that the rail 60 can freely move in the left-right direction in the figure. There is.

The operation of the centrifugal force forming apparatus of the present invention described above will be described with reference to FIGS. 1 and 2 above. First, in this apparatus, on the rotating wheel 2 and the vibrating wheel 2 ', Place the flange part of the formwork 3 assembled in advance. Then, by rotating the rotating wheel 2 with the motor 1, the rotation of the rotating wheel 2 is transmitted to the mold 3 and the mold 3 rotates in the arrow direction. At this time, by driving the vibrator 4, the vibration is transmitted to the mold 3 via the vibrating wheel 2 ', whereby the mold 3
Vibrates.

As described above, the flange portion of the mold 3 in which the reinforcing bars are preassembled is placed on the rotary wheel 2 and the vibration wheel 2 ', and the rotary wheel 2 is rotated by the motor 1. Then, while rotating the form 3 at a relatively low speed, the ready-mixed concrete 100 is put therein, and this is developed and leveled. At this time, the moving vehicle body 70 of FIG. 1 is moved to the right, the auger shaft 50 is passed through the hollow portion of the mold 3 in parallel with the rotation center axis thereof, and the auger shaft 50 is moved into the mold 3 by the screw jacks 71, 71. Added fresh concrete 10
Move to the position where it touches 0. After that, while rotating the auger shaft 50 alternately in both forward and reverse directions (clockwise is the forward direction), the ready-mixed concrete 10 put into the form 3 is rotated.
Expand 0 and level. That is, as shown in FIG. 3, the spiral screw 52 is rotated by the rotation of the auger shaft 50.
While being rotated, the poured ready-mixed concrete 100 is moved and expanded while being pushed out to the left and right in the figure by the tip edge of the screw 52, and is uniformly leveled in the mold 3.

The auger shaft 50 is alternately rotated in both the forward and reverse directions because the ready-mixed concrete 100 put into the mold 3 when the auger shaft 50 is rotated only in the forward or reverse direction is This is because the mold 3 is moved only in one direction (for example, rightward or leftward in the drawing) and is biased in one direction.

Following this, the rotating wheels 2 and 2 are rotated at high speed, the mold 3 is rotated at a medium speed and a high speed, and the raw concrete introduced and expanded by centrifugal force is compacted. Finish the inner surface. In addition,
At this time, the inner peripheral surface is finished using the auger shaft 50 again. That is, the auger shaft 50 is rotated in the direction opposite to the rotating direction of the mold 3 to finish the inner peripheral surface of the concrete pipe while cutting. In this way, when finishing the inner peripheral surface of the concrete pipe, rotating the auger shaft 50 in the direction opposite to the rotating direction of the mold 3 is performed by the centrifugal force in the compaction process by the high speed rotation. Sludge-like concrete floating on the inner surface of the pipe,
This is for scraping off with the tip of the spiral screw 52 of the auger shaft 50 (see FIG. 3). Then, the scraped sludge-like concrete is poured out of the mold 3 from one end of the mold 3.

Thereafter, while gradually pulling out the auger shaft 50 (that is, while moving the moving vehicle body 70 in FIG. 1 to the left in the drawing), the outer peripheral surface of the cylindrical roller 53 attached to the tip of the auger shaft 50 is reinforced with a concrete pipe. The inner peripheral surface of the concrete pipe is finished to be smooth while being pressed against the inner peripheral surface of, thereby completing the finishing process.

After the above steps are completed, concrete is further hardened, for example, by steam curing, the mold is separated and demolded, and further curing is performed to complete the centrifugal reinforced concrete product. It is similar to the method of. When molding a long reinforced concrete product, it is desirable that the roller 53 at the tip of the auger shaft 50 be supported by a removable bearing or the like.

FIG. 4 shows the cross-sectional shape of the spiral screw 52 of the auger shaft 50. That is, FIG.
4A shows a spiral screw 52 having an acute-angled triangular cross-section, FIG. 4B shows a plate-shaped spiral screw 52 with a rounded tip, and FIG. Shows a spiral screw 52 having a plate-like tip to which a semicircular edge portion is attached. Among the cross-sectional shapes of the above spiral screw 52, in particular, the screw having the shape shown in FIG. 4 (C) has an edge extending on both sides thereof for leveling by extruding fresh concrete and the inner peripheral surface of the molded concrete pipe. Since the above cutting is performed, the shape is optimum among the above-mentioned modified examples.

[0023]

As is apparent from the above detailed description, according to the method and the apparatus for centrifugally forming a concrete pipe of the present invention, the method for centrifugally forming a concrete pipe, which could not be conventionally done manually. It is possible to automate the unfolding and leveling work of the ready-mixed concrete in the formwork and the finishing work of the inner peripheral surface, which does not require the skill of the worker, and enables quick and accurate finishing of the inner peripheral surface. It is possible and has the technical effect of improving workability.

[Brief description of drawings]

FIG. 1 is a side view showing an example of an apparatus for carrying out the method for centrifugally molding a concrete pipe of the present invention.

FIG. 2 is a front view showing the overall configuration of the centrifugal molding apparatus for concrete pipe of FIG.

FIG. 3 is a cross-sectional view for explaining the action and operation of the auger shaft according to the method for centrifugally molding the concrete pipe body.

FIG. 4 is a partially enlarged cross-sectional view showing various modified examples of the auger shaft.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Motor 2 Rotation wheel 2'Vibration wheel 3 Formwork 30 Flange part 50 Auger shaft 51 Rotation shaft 52 Spiral screw 53 Roller 55 Moving stand 57 Motor 100 Ready-mixed concrete

Claims (2)

[Reference number] 0930014-02 [Claims] 1. A step of pouring fresh concrete into a rotating cylindrical formwork to spread and level the ready-mixed concrete in the formwork, a step of compacting concrete by centrifugal force, and a formwork In a centrifugal molding method for a concrete pipe having a step of finishing the inner circumference of a concrete pipe molded while rotating and a step of taking out concrete products from the mold after stopping the rotation of the form, Pass the auger shaft through the hollow part of the mold in parallel with the center axis of the mold, and rotate the auger shaft forward and backward to expand and level the fresh concrete put into the mold. Centrifugal forming of concrete pipe body, characterized in that the inner peripheral surface of the formed concrete pipe body is cut at the outer peripheral portion of the auger shaft while rotating in the opposite direction to finish the inner peripheral face. Method. 2. A centrifugal forming apparatus for a concrete pipe body, comprising a cylindrical mold and a foil supporting and rotating the mold, the centrifugal mold being parallel to the central axis of the mold supported on the foil. An auger shaft whose one end is rotatably supported at a position, a rotating mechanism for rotating the auger shaft, a radial moving mechanism for moving the auger shaft in the radial direction of the mold, and the auger shaft for the mold. An apparatus for centrifugally forming a concrete pipe, comprising: an axial movement mechanism that moves in a central axis direction of a frame.