JPH0137246B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a centrifugally formed concrete product manufacturing apparatus for the purpose of filling relatively hard concrete in a fixed quantity with low resistance during centrifugal forming.

Conventionally, when centrifugally forming long concrete products such as pulses or poles, if the formwork is closed in the circumferential direction, a concrete transfer pipe that should be inserted into the formwork at the tip of the concrete injection pipe. In this method, concrete is poured into the formwork from the end of the concrete transfer pipe, and a predetermined amount of concrete is poured into the formwork in the axial direction by moving the formwork, but the concrete transfer pipe becomes long. Not only this, but the diameter of the concrete transfer pipe is made smaller toward the tip, and consideration is given to preventing deformation as much as possible when pouring the pipe into a cantilever shape. Therefore, the transfer resistance becomes large and the injection must be carried out under a high pressure, which not only requires a large amount of power but also causes problems such as severe damage to equipment and transfer pipes.

However, in this invention, the core is inserted into the formwork, and the concrete is poured between the core and the inner wall of the formwork, so the connecting pipe that replaces the conventional concrete transfer pipe becomes extremely short. Since there is no restriction on the inner diameter, there is little friction loss in this part, and there is also a sufficient gap between the inner wall of the formwork and the outer wall of the core, so the friction loss in this part is also small, and it is extremely low after all. This allows the injection to be performed at a specified level using pressure, thus solving the problems of the conventional method. It is known that the strength of the product is higher when concrete is hard mixed, but when using a long transfer pipe as has been done in the past, the slump value
15cm or more, the pump pressure needed to be 100Kg/cm2 ^or more. Therefore, pump failure was likely to occur. In contrast, according to the present invention, the pressure can be injected with less than half of the conventional pressure, and the work can be performed with a slump value of about 10 cm, improving workability.
It was found to be superior in all aspects, including increased product strength and a drastic reduction in pump failures. Moreover, since the formwork is placed on the truck and the core is supported by support legs that are collapsible in the direction of movement of the truck, the core can be installed in the formwork extremely easily.

Next, the present invention will be described with reference to an embodiment shown in FIG. That is, a hopper 1 equipped with a stirring device inside.
Extrusion cylinders 3, 3 equipped with pistons 2, 2 are connected to the lower part of the cylinder via a drop tube 29, and the tip sides of the extrusion cylinders 3, 3 are connected to one end of an injection pipe 5 via branch pipes 4, 4. , the other end of the injection pipe 5 is connected to one end of a connecting pipe 6. Each device up to the injection tube 5 is the same as a conventionally known device. A support pipe 8 of a core 7 is firmly fixed to the center of the inside of the connecting pipe 6 by a support plate 9 provided radially, and a support pipe 8 outside the connecting pipe is provided with a hole diameter of the concrete assembly taken into consideration. A core 7 having an outer diameter is fitted and fixed. Said core 7
is tubular (FIG. 4), and is supported and fixed by support plates 10 arranged radially between the support tube 8 and the support tube 8.
Both ends 7a and 7b are conically constricted to facilitate insertion and removal. The core 7 is supported, for example, at an appropriate interval from the support rods 11, 11, and
1 and 11 are pins 1 to brackets 13 and 13 on the floor.
2 and 12, and is held vertically by springs 14 and 14.
Therefore, the carriage 16 of the formwork 15 moves in the direction of the arrow 17 (FIG. 5), and the tip of the carriage 16 touches the support rod 11,
11, the support rod falls in the direction of the arrow support 18 against the springs 14, 14, and the core 7 falls against the formwork 1.
5 without any trouble. So Nakako 7 is the first
When the hopper is completely inserted into the formwork as shown in the figure, the pistons 2 and 2 are reciprocated alternately in the directions of arrows 19 and 20, so that the concrete in the hopper is transferred to the branch pipes 4 and 4. The concrete in the left and right branch pipes is combined in the injection pipe 5 as shown by arrows 21 and 22, and is continuously fed as shown in the arrow 23, and is then fed into the gap S between the formwork 15 and the core 7. is injected as shown by arrow 24. Once the gap S has been filled with concrete as described above, the formwork 15 is moved in the direction of the arrow 25 (the formwork 15 is placed on the trolley 16, so it can be easily moved), Pull out the core. In this case, if the formwork 15 can be slightly rotated, the concrete will move toward the inner wall of the formwork 15, making it easier to remove the core. In addition, a support piece 26 is attached to the lower side of the tip of the core to provide a specified support when the core is inserted, and when the core is removed, the support piece 26
If the height of 6 is reduced, it will provide support when inserting the core, and will have the effect of reducing resistance as much as possible when removing the core. In the above case, even if the formwork is rotated, the core does not rotate and friction occurs between the outer wall of the core and the concrete, but for example, as shown in Fig. 6, the support plate of the core is fixed to the ring 27, and the ring 27 is rotatably fitted into the support tube 8, the core can be rotated when the mold is rotated.
Next, in the above embodiment, the core is supported by a support rod, and the support rod automatically rotates when the cart enters the vehicle, but the device of the present invention is limited to such a specific structure. It's not a thing. FIG. 7 also shows the flange of the connecting pipe 6 when the formwork 15 is fixed to the connecting pipe 6.
Although this embodiment uses a connecting bolt 28 rotatably attached to the collar 15a of the formwork 15, the connecting structure is not limited to this.

As mentioned above, according to the method of the present invention, the core is inserted into the formwork and concrete is injected into the gap between the core and the inner wall of the formwork, making it possible to produce long concrete products. Even in the case of manufacturing, the injection pipe can be short, and since the concrete is filled sequentially, there is no risk of aggregate separation, and the concrete movement path within the formwork should have a larger cross-sectional area than the injection pipe. Therefore, there are various effects such as being able to reduce the concrete injection pressure as much as possible and suppressing the slump value to a small value. Therefore, it has the effect of improving the strength of concrete products and drastically reducing wear and tear on pumps, other equipment, injection pipes, etc. Further, according to the device of the present invention, a support tube for the core (not necessarily a pipe, for example, a support rod having a cross-shaped cross section may be used) is fixed concentrically within the connecting tube, and the core is fitted into the support tube. Therefore, the core can be held firmly and concentrically, and can be easily inserted and set into the center of the mold. Therefore, by replacing the connecting pipe, the core can be easily replaced, and the concrete passing cross section in the connecting pipe can be freely designed, so the increase in concrete passing resistance caused by fixing the support pipe can be avoided. can be prevented. Moreover, since the formwork is installed on a truck and the core is supported by support legs that are collapsible in the moving direction of the truck, the core can be easily and automatically installed.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway front view of the apparatus for implementing this invention during use, Fig. 2 is a partial plan view of the concrete pouring apparatus, and Fig. 3 is A in Fig. 1.
- An enlarged sectional view of part A, FIG. 4 is an enlarged sectional view of part B-B in FIG. FIG. 7 is a partially enlarged cross-sectional view showing another example of the child, and FIG. 7 is a partially front view showing an example of the connecting portion between the connecting pipe and the formwork. 1... hopper, 5... injection pipe, 6... connecting pipe, 7... core, 8... support pipe, 15... formwork,
16...Dolly.

Claims (1)

[Scope of Claims] 1. An apparatus for manufacturing centrifugally formed concrete products by inserting a core into the center of a centrifugal forming form, which comprises: installing the form on a cart, and supplying the concrete within the form; The proximal end of the connecting pipe is connected to the tip of the concrete injection pipe, and one end of the core is connected to the inside of the connecting pipe, and the core is removably inserted into the formwork for centrifugal molding. An apparatus for manufacturing a centrifugally formed concrete product, characterized in that the core is disposed protruding horizontally along the moving direction of the cart, and the core is supported by support legs that are collapsible in the moving direction.