JPH074810B2 - Concrete pipe for manhole and its forming method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a concrete pipe for a manhole having a step fitting fixed thereto, and a molding method thereof.

(Prior art) A pair of left and right insertion holes are formed in the side block, both ends of the step metal fittings are inserted into these, nuts are screwed into both ends, and the gap between the insertion holes is sealed with a sealant and mortar. By attaching the step metal fittings (for example, No. Sho 60-369), or by embedding an insert member in the side block and fixing both ends of the step metal member to this insert member (for example, No. Sho 60-369). 151942), a step temporary structure in a concrete formwork for integrally fixing the step metal fittings at the same time as forming the side block (Jitsuko Sho 59-42445).
No.) is known.

In addition, in automatic molding using a solid concrete material with a low water content, as a method of fixing the step metal fittings at the same time as molding the side block, an opening is formed on the outer surface of the inner mold and the inner mold is formed in the opening. The auxiliary mold provided in the frame is fitted so that it can move back and forth, the step metal fittings are held in the auxiliary mold, and both ends of the step metal fitting are projected between the inner mold and the outer mold, and then the two molds are There is a method in which a hardened concrete material is added, the material is vibrated to be compacted, and then immediately removed from the mold.

(Problems to be solved by the invention) However, in the case of the above-mentioned Japanese Utility Model Publication No. 60-369, it is necessary to spend a lot of time on filling the sealing material and the mortar and carefully perform work in order to completely prevent water leakage from the insertion hole. Therefore, the workability is extremely poor, and when embedding an insert member as in Japanese Utility Model Laid-Open No. 60-151942, the molding block for the side block becomes complicated and the step fitting work is troublesome. There was a problem that it hangs.

In addition, when fixing the step metal fittings at the same time as forming the side block, as in Japanese Utility Model Publication No. 59-42445, a device with a complicated structure that holds the step metal fittings in the inner mold and separates from the step metal fittings when demolding is required. Is.

Furthermore, in the case of automatic molding by so-called immediate demolding, in which side blocks are molded using a hardened concrete material with a reduced water content, the same step metal fitting holding device as in the above case is required, In addition, the step fittings sometimes tilt downward due to their own weight or vibration when the mold is removed or when the side block immediately after molding is moved to a curing place. Further, due to the inclination of the step fitting, there is a problem that concrete around the step fitting is damaged and the step fitting is loosened, or the step fitting falls off.

(Means for Solving the Problems) The present invention was developed to solve the above problems, and at least two metal columns are embedded in the side blocks with a space therebetween, and the step metal fittings are embedded in the columns. Fix both left and right ends of
The step metal fittings are fixed to the concrete pipes for manholes protruding from the inner wall surface of the side block, and at least two metal pillars arranged at intervals, and the right and left ends of the step metal fittings are fixed to the outer mold. A lid that is inserted into a molding space formed by a frame and an inner mold, and a step fitting is inserted into a lateral hole of a movable auxiliary mold that forms a part of the inner mold, and is attached to the step fitting. The present invention relates to a method for molding a concrete pipe for a manhole, in which a horizontal hole is sealed by a body, a concrete material is put into a molding space, vibration is applied to the concrete material to perform compaction, and then the mold is released.

The auxiliary mold may be provided so as to be movable back and forth in the inner mold, or may be formed so as to be separated from the inner mold and movable as shown in the following embodiments.

Also, if one step metal fitting is provided on the side block or if a plurality of step metal fittings are provided in a line in the vertical direction, 2
Although three columns are used, three or four columns are used when a plurality of step fittings are provided in a zigzag pattern in the vertical direction.

(Operation) Fix both ends of the step metal fittings to the left and right columns, establish these pillars in the molding space, insert the step metal fittings into the lateral holes of the auxiliary mold, seal the lateral holes with the lid, and then in the molding space. When the hardened concrete material is put in and is solidified to the extent that it does not deform even if it is removed from the mold by vibration and compaction, the outer mold, the inner mold and the auxiliary mold are separated and moved to a curing place to cure. However, as described above, since the step fitting is fixed to the support pillar, it does not tilt downward, loosen, or fall off due to its own weight or vibration.

(Example) An example of the concrete pipe for manholes according to the present invention will be described with reference to Fig. 1. Reference numeral 1 is a side block of the concrete pipe. Reference numeral 2 designates a pair of left and right metal columns that are opposed to each other in the side block, and the upper and lower sides of the column 2 are welded to ring reinforcements 3 embedded in the upper part and the lower part of the side block 1. Reference numeral 4 denotes a step metal fitting 4 having a U-shaped planar shape, both ends of which are welded to the upper and lower sides of the column 2 and project from the inner surface of the side block 1. The step fitting 4 is not limited to the U-shape, but may be a straight shape, for example. However, in this case, it goes without saying that it is necessary to increase the distance between the columns 2.

An arcuate connecting bar may be used instead of the ring reinforcing bar 3, and the upper and lower ends of the left and right columns 2 may be connected by the connecting bar. Further, when the cage-shaped reinforcing bar is embedded in the side block 1, the vertical bar can be used as a pillar.

Next, an embodiment of the method for forming a concrete pipe for a manhole according to the present invention will be described with reference to FIGS. 2 and 3, and 5 is an inner formwork, which is a base plate horizontally supported by a vibration isolator. 6 is detachably attached. A vibrator is provided in the inner formwork 5. A recess 7 is formed on one side of the inner mold form 5 from the upper end to the lower end.

Reference numeral 8 denotes a ring-shaped pallet that is fitted and inserted into the outer side of the inner mold 5, and is supported on a support portion that is provided around the lower outer side of the inner mold 5.

Reference numeral 9 denotes an outer frame, the lower end of which is supported by the pallet 8.

An auxiliary mold 10 is fitted in the concave portion 7 of the inner mold frame 5, and the lower end is placed inside the pallet 8 as shown in FIG. Further, the outer surface thereof forms a part of the outer surface of the inner formwork 5. Further, lateral holes 11 into which the step fittings 4 are inserted are formed on the outer side surface of the auxiliary mold 10 at intervals vertically. Although the lateral hole 11 is a through hole, it may be formed as a groove having a depth capable of accommodating the step fitting 4. The lateral hole 11 is closed by a lid 12 provided on the step fitting 4. The lid 12 may be fixed to the step fitting 4 in advance, or may be formed by a member that is divided into upper and lower parts, and the both ends of the step fitting 4 may be attached by this member.

13 is a molding space formed by the inner mold 5 and the outer mold 9. In this molding space 13, support pins 14 provided at intervals outside the upper and lower parts of the outer frame 9 project in a retractable manner, hold the upper and lower ring streaks 3, and press the column 2 inward. The lid 12 is configured to be in pressure contact with the inner frame 5. The support 2 may be held by a conventionally known spacer for holding the reinforcing bars.

In this molding apparatus, the step fitting 4 is inserted into the lateral hole 11 and the lateral hole 11 is sealed by the lid 12, and then the support 2 and the auxiliary mold
10 is inserted into the molding space 13 and the recess 7 of the inner mold 5, and support pins 14 provided at intervals on the upper outer side of the outer mold 9 are projected into the molding space 13 so that the upper ring stirrup 3 is formed. Holding the stanchion 2
Is stabilized at a predetermined position in the molding space 13. Then, the inner mold 5, the auxiliary mold 10, and the outer mold 9 are vibrated, and the solid concrete material is put into the molding space 13, and after vibrating this, the upper end of the concrete is pressed with a pressure plate to remove the mold. To do.

The molded concrete pipe is moved to the curing place together with the auxiliary mold 10 and the pallet 8, and the auxiliary mold 10 is immediately removed and cured.

The above example is based on the patent application No. 1 of 1991 related to the applicant's application.
Like the molding mold of No. 300998, the auxiliary mold 10 was separated from the inner mold 5 and used as a movable mold, but a mold for retracting the auxiliary mold into the inner mold and removing it was also used. It goes without saying that you can do it.

(Effect) As described above, the concrete pipe for a manhole according to the present invention,
Also, according to the molding method, since both ends of the step fitting are fixed to the left and right struts embedded in the side block, the step fitting does not tilt downward or fall off due to the load.
In addition, it is not necessary to provide a complicated holding device for the step metal fittings in the inner mold or the auxiliary mold both in general concrete molding by pouring and in molding by immediate demolding using solid concrete material. Has the advantage that it is easier and the workability is improved.

Particularly, in the molding method according to the present invention, even when the concrete material is not sufficiently hardened, the step fittings are supported by the pillars embedded in the side blocks as described above, so that the inner mold and the inner mold are not supported. Not only the mold but also the auxiliary mold can be immediately removed. Therefore, while moving the molded product to the curing place, a new pallet can be set with an inner mold, an outer mold, and an auxiliary mold, and the next molding can be performed continuously, so that the production efficiency can be further improved. Is.

In addition, in the molding method in which the auxiliary mold is separated from the inner mold and transferred to the curing place together with the molded product, this auxiliary mold can be immediately recovered and prepared for the next molding, so it is necessary to prepare many auxiliary molds. There is no effect.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view showing an embodiment of a concrete pipe for manholes according to the present invention, FIG. 2 is a plan view showing an embodiment of a method for forming the concrete pipe, and FIG.
Sectional drawing of the XX line in a figure. 1; Side block, 2; Posts 3; Ring reinforcement, 4; Step metal fittings 5; Inner formwork, 6; Base plate 7; Recesses, 8; Pallet 9; Outer formwork, 10; Auxiliary mold 11; Lateral hole, 12; Lid 13; Molding space, 14; Support pin

Claims (2)

[Claims] 1. At least two metal columns are embedded in the side block with a space therebetween, and the left and right ends of the step fitting are fixed to the columns, and the step bracket is projected from the inner wall surface of the side block. A concrete pipe for manholes characterized by. 2. The right and left ends of the step metal fitting are fixed to at least two metal columns arranged at intervals, and the columns are placed in a molding space formed by an outer mold and an inner mold. After inserting the step metal fittings into the lateral holes of the movable auxiliary mold forming a part of the inner mold, and closing the lateral holes with the lid attached to the step metal fittings, the concrete material is placed in the molding space. A method for forming a concrete pipe for a manhole, which comprises: