JPS5910882B2 - Rotating device for centrifugal concrete molding - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotating device for centrifugal concrete pipe forming.

Concrete pipes have traditionally been manufactured by centrifugal molding or rotation methods, and various attempts have been made in the meantime to reduce the time that the centrifugal formwork used to form the pipe is rotated on equipment to harden and dewater the concrete fed to the formwork. It has been done.

Centrifugally formed concrete pipes are often manufactured with a rotating device in which a centrifugal formwork is supported by two pairs of wheels, which wheels are most often made of steel.

However, other configurations have also been used to support the formwork, one of which uses a belt hanging method,
Others use wheels with pneumatic tires to carry the formwork.

For rotating machines in which the formwork is carried by two pairs of wheels made of steel, the pair of axially spaced wheels are actively rotated by a drive mechanism at the drive wheels, and likewise axially spaced. The other pair of wheels spaced apart from each other are idle wheels and are rotated only by the formwork itself which is rotated by the drive wheel.

To manufacture pipes using such equipment, the formwork is supported by two pairs of wheels and rotated by a drive wheel.

The concrete is then introduced into the formwork with a rotation that provides sufficient centrifugal force to grip the concrete against the inner surface of the formwork.Once enough concrete has been fed into the formwork to form a pipe, the The rotation speed of the frame is increased to harden the concrete along the inner surface of the formwork.

Conventional practice has been to harden concrete solely by centrifugal force while the formwork rotates.
For this reason, the walkability of concrete needs to be high.

In order for the concrete to flow into the rotating formwork to the desired shape and uniform wall thickness, the concrete is made with a relatively high water-to-cement ratio such that the sufficient walkability of Funkrete is 0.5. This is usually achieved by:

Under the very high formwork rotational speeds used, the concrete is 20 to 40 f? This centrifugal force causes the concrete to coagulate, and excess water in the concrete is discharged to the inner surface of the concrete pipe, and the water flows out from the end of the formwork.

In order to produce high quality and good strength concrete, as much excess water as possible needs to be expelled from the concrete during rolling, thereby creating a remaining water-to-cement ratio sufficient to hydrate the cement and water. is only 0.26.

Because the initial water-to-cement ratio is large at 0.5 and the final water-to-cement ratio is small at 0.26, very large volumes of water have to be squeezed out of the concrete, which requires considerable rotation time. The time required is 7 5 for the inner diameter.
It takes about 20 minutes for a 0-1000mm pipe.

To increase the production of pipes using rotating equipment,
There is a need to reduce the rotation time, and this can only be done effectively by reducing the volume of water that has to be dewatered from the concrete.

This can only be achieved by reducing the initial water-to-cement ratio, but of course without neglecting to fully harden the concrete.

Various attempts have been made to make centrifugally formed concrete pipes with concrete having an initial water-to-cement ratio lower than 0.5; A configuration that vibrates is often used.

To date, however, these techniques have not been entirely satisfactory; none have significantly reduced the initial water-to-cement ratio and therefore have not been able to significantly reduce the rotation time.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a rotating device for centrifugal concrete pipe forming, which assists in compacting the concrete in the formwork and forms the concrete at a lower water-to-cement ratio than has hitherto been practiced. The purpose is to efficiently vibrate the formwork during its rotation in order to make it possible to feed the formwork.

In this way, the rotation time of the formwork for setting the concrete to a satisfactory hardness can be substantially reduced.

The rotating device for centrifugal concrete pipe forming according to the present invention has two pairs of wheels supporting the formwork to be rotated supported on the base, and these pairs of wheels are driven by driving wheels spaced apart from each other in the axial direction. Yes, 5 One of the wheels is also an idle wheel, although it is spaced apart from each other in the axial direction, and further comprises a drive mechanism for rotating the drive wheel, and the idle wheel forms a part of the base and has an elastic The apparatus is operated by rotatably supported on a sub-frame attached to a vibration-absorbing table, and an electrically driven vibrator is attached to this sub-frame to vibrate these sub-frames and the idle wheel. This device vibrates the equipment when the concrete is placed in the formwork to help solidify the concrete in the formwork.

Preferably, the subframe is pivotally connected to the rest of the base by one or more resilient vibration-absorbing pushers.

Preferably, two electrically driven vibrators are mounted on the subframe, which vibrators are rotary and rotate in opposite directions.

In a further preferred embodiment, a Tsingya variable speed linear vibrator is attached to the subframe;
The frequency can be varied according to the size and weight of the formwork and the concrete in the formwork to improve the speed and efficiency of compacting the concrete in the formwork.

With the device of the invention it is possible to reduce the initial ratio of water to cement feeding the formwork from 0.3 to 0.35 when the subframe is matched with the twin gear variable speed vibrator, from an internal diameter of 750 The time required to harden and dewater the concrete for a 1000 mm pipe is reduced from the 20 minutes required for conventional equipment using concrete with an initial water-to-cement ratio of approximately 0.5 to 6,7 due to the above-mentioned ratio. It has been found that it can be reduced to minutes.

Even allowing for the time required to change formwork from one form to the next in a continuous pipe forming process, 1
The output from one machine can be approximately doubled.

The device according to the invention not only significantly reduces rotation time, but in its preferred configuration also exhibits less wear and lower maintenance costs than conventional devices.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a rotating device for centrifugal concrete pipe forming according to the present invention will be described below with reference to the accompanying drawings.

The rotating device of the present invention shown in the diagram of FIG. 1 consists of a base formed by a steel main frame 1 and a steel subframe 2, and the subframe 2 is pivotally connected to the main frame 1 by a pivot connecting member. , one of the connecting members is indicated at 3 and each includes a resilient rubber vibration absorbing push.

The main frame 1 is carried directly on the foundation 4 and the subframe 2
is supported on the main frame 1 by a pivot connection member 3 and attached to the foundation 4 by an elastic rubber vibration-absorbing mount.
Supported by

One of the mounts is indicated at 5.

In this way, the subframe 2 performs a pivoting vibration movement about the pivot axis of the pusher 3, and can vibrate upward and downward relative to the main frame 1.

The pushers 3 and the mounting bases 5 substantially prevent vibrations from being transmitted from the subframe 2 to the main frame 1 and the foundation 4.

A pair of drive wheels, one of which is designated by the numeral 6, are rotatably mounted on a bearing I of the main frame 1, and a pair of idle wheels 8 are similarly mounted on a bearing 9 of the subframe 2.

When the rotating device is in operation, the centrifugal concrete pipe form 10 is supported by these pairs of wheels 6 and 8.

The drive wheel 6 is fixed to an axle 11 which is driven via a belt or chain 13 by an electric drive motor 12 mounted on the main frame 1 .

Drive wheel 6 is rotated counterclockwise by motor 12 and formwork 10 is rotated clockwise as indicated by arrow 14.

Next, the idle wheel 8 is rotated counterclockwise by 100 revolutions of the formwork.

A pair of electrically driven variable speed pibrators 15 are attached to subframe 2 by support members 16 .

As shown in the figure, the pibrator 15 is located in the subframe 2 on a side remote from the pivoting side of the subframe 2 and the main frame 1.

The pair of bipolar plates 15 are interlocked and rotate synchronously with each other, but in opposite directions as shown by arrows 17.

The pair of pibrators 15 are of the linear type and both generate vibrations in the vertical direction, and the vibrations are along a line of action tangential to the axis of the connection 3 between the main frame 1 and the subframe 2, and this axis line is extends perpendicular to the plane of the paper.

Therefore, when the pair of interlocking linear vibrators 15 are activated, the subframe 2 vibrates upward and downward, and these vibrations are transmitted to the foundation 4 and the main frame 1 by the vibration absorbing mount 5 and the pusher. 3, the vibrations are transmitted via the idle wheels 8 to the formwork 10 and thereby to the concrete formed in the formwork 10.

Since the linear vibrator 15 is driven at variable speed,
The frequency of vibration of the formwork 10 can be adjusted by the size and thickness of the form and thus by the weight of the concrete to be formed in the formwork.

Therefore, the frequency can be set to produce maximum consolidation and hydration efficiency by the concrete in the formwork.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a rotating device for a centrifugal concrete forming frame according to the present invention. DESCRIPTION OF SYMBOLS 1...Main frame, 2...Subframe, 3...Connection member, 5...Mounting stand, 6...Drive wheel, 8...Idle wheel, 1
0...--Formwork, 15... Vibrator.

Claims (1)

[Claims] 1. Two pairs of wheels supporting the rotating formwork are supported on the base, and these one pair of wheels are drive wheels spaced apart from each other in the axial direction, and the other pair Although the wheels are spaced apart from each other in the axial direction, they are idling wheels, and in a rotating device for centrifugal concrete pipe forming comprising a drive mechanism for rotating the driving wheels, the idling wheels form a part of the base. and is rotatably supported on a subframe attached to an elastic vibration absorbing table, and an electrically driven vibrator is attached to the subframe to vibrate the subframe and the idle wheel, and the device is activated. A rotating device for centrifugal concrete pipe forming, which is characterized by vibrating the device to help solidify the concrete in the formwork. 2. The rotating device for centrifugal concrete pipe forming according to claim 1, characterized in that the subframe is pivotally connected to the rest of the base by one or more elastic vibration-absorbing pushers. 3. According to claim 1 or 2, two rotary electrically driven vibrators are attached to the subframe, and these vibrators rotate in opposite directions to each other. Rotating equipment for centrifugal concrete pipe forming. 4. Rotation for centrifugal concrete pipe forming according to any one of Claims 1 or 2, characterized in that linear variable speed vibrators linked in pairs are attached to the subframe. Device. 5. When the subframe is pivotally connected to the rest of the base, the linear vibrator generates vibration along a line of action that is substantially tangential to the pivot axis between the subframe and the rest of the base. A rotating device for centrifugal concrete molding according to claim 4.