JPS5844450B2 - Concrete formwork for underground pits - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mold for forming a box-shaped hand hole.

BACKGROUND ART Conventionally, in connection parts of ducts of underground cables such as underground electric wires and underground communication lines, a box-shaped hand hole is buried underground for connection.

When molding a hand hole, assemble the box-shaped inner frame in the opposite direction on the -L side of the plywood, and then attach the outer frame to the outside of the inner frame, fill it with concrete, and remove the mold. In this case, the outer frame must be removed and the inner frame must be removed by turning in the opposite direction, which requires time and effort to assemble and remove the molding frame.

Therefore, the applicant developed a mechanism for joining the inner frame at the four corners and removing the mold after the inner frame on each four sides was pushed inward by operating a lever, and filed an application (Patent Application No. 151539 of 1978). In this formwork, there is a difficulty in the joints on each of the four sides of the inner frame, and since the side frames on each four sides must be folded inward with a 1/1 lever operation, it is time consuming and the lever hinges may play, causing the joints to fall down. There was a drawback that it was difficult to adhere closely.

In order to solve the above-mentioned drawbacks, the present invention consists of (1)7 formworks in which the inner circumferential side frame is divided at the central position of the side faces, which are pivotally attached to the underframe so as to be able to fall inward, and wedges are formed in the gaps between the joints of each formwork. This is a concrete formwork in which the frame rods are guided back and forth from the inside, and four sets of wedge frames can be formed by rotating the screw shaft installed in the center without causing any rattling at the joints of the internal formwork. The feature is that the rods are guided back and forth to facilitate assembly and demolding of the formwork.

Hereinafter, the present invention will be explained in detail with reference to embodiment figures.

A base frame 2 is fixed to the lower surface of a square base plate 1 having a square hole in the center, a hinge 3 is provided at a position close to the upper center of the outer surface of the four sides of the base frame 2, and a receiving plate 4 is vertically attached to the lower edge of the outer surface. A front outer frame 6a, a rear outer frame 6b, a left outer frame 6c, and a right outer frame 6d, each of which is protruded and has a reinforcing plate 5 attached to its upper end, are placed on the soil surface at an intermediate position between the inner edge and outer edge of the rectangular base plate 1. The lower end outer side of the vertical reinforcing plate 7 attached to the outer surface of each outer frame is pivoted to each hinge 3, and the fastening metal fitting 8 is attached to the upper end of the joint part of each outer frame. , from the four corners of the rectangular base frame 2 toward the center, there are four sets of L-shaped first columns 9a, second columns 9b, and third columns.
A pillar 9c and a fourth pillar 9d are provided protrudingly, and the upper end of each pillar is lower than the upper end of the outer frame by the thickness of the bottom plate of the box, and a rectangular frame 10 is successively installed inside the upper end, and the four sides and four corners are Chamfer 1
Four sets of arm rods 13 that fit into the inner surfaces of the four corners of the rectangular frame 10 at the upper end of the column are provided diagonally projecting downward from the center on the lower surface of the upper pressure plate 12, and a screw bearing 14 is fixed to the tip. The arm rod 13 is fitted into the rectangular frame 10 and the upper pressure plate 12 is removably mounted at the end of each column, and the first inner frame is shaped like a planar view and fits into the four corners of the inner edge of the base plate 1. 15a1 Second inner frame 15b1 Third inner frame 15
c1 A vertical chamfer 16 is provided at the corner of the fourth inner frame 15d, and an inclined surface 17 is joined to the chamfer 11 of the upper pressure plate 12 at the upper end.
The L frame rods 19, whose upper ends are fixed to the horizontal support rods 18 fixed at the lower positions on the inner surface of each inner frame, are pivoted to the hinges 20 at the four corners of the inner surface of the base frame 2 to support each inner frame. , so that the inner edge of the plate 1 can be inclined from the four corners toward the center, and a tapered surface 21 that expands inward is provided on both opposing end surfaces of each inner frame, and at the center position of the four inner edges of the base plate 1. Four sets of first wedge-shaped rods 22a1 and second wedge-shaped rods 2 that fit into the model gaps at both ends of each inner frame.
2b1 Third wedge-shaped rod 22c1 Fourth wedge-shaped rod 22d are arranged, the lower ends of each wedge rod are bent in two directions of the base frame, and are pivotally connected, and the earth slab 12 is mounted on the upper ends of four sets of supports. Screw bearing 1 on the bottom of
The upper end of the screw shaft 23 is screwed into the screw shaft 23, and the spacer 24 loosely fitted to the lower shaft body of the screw shaft 23 is locked with the upper and lower flanges 25 and 25' fixed to the screw shaft 23. The concrete formwork 27 is constructed by having one end loosely attached to the inner center position of the telescopic adjustment arm 26 and the other end loosely attached to the spacer 24 in an inclined manner.

Note that 28 in the figure indicates concrete.

Next, the effects of the present invention will be explained with reference to embodiment figures.

When forming a concrete hand hole using the concrete formwork 27 according to the present invention, insert a monkey spanner or the like from the underside of the base frame 2 and rotate the screw shaft 23 in the forward direction so that it engages with the screw bearing 14 and rises. and telescopic adjustment arm rod 2
6 in a direction perpendicular to the screw shaft 23, each of the four sets of first to fourth wedge-shaped rods 22a, 22b, 22c
, 22d, four sets of first to fourth inner frames 15a, 15b, 15e,
While the tapered surfaces 21 at both ends of 15d are pressed by the wedge rods, each inner frame is guided to stand up toward the four corners around the hinge 20 of the L frame rod 19, and each inner frame stands up perpendicularly to the inner edges of the four corners of the base plate 1. - L end slope - j17 is chamfered 1 on all sides of upper pressure plate 12
1, and the outer surface of each proofing frame is the same as the outer surface of the inner frame, and the upper pressure plate 12 is also pulled downward and comes into close contact with the rectangular frame at the upper end of the column.

Next, each of the outer frames 6a, 6b, 6c, and 6d is vertically raised and rotated around the hinge 3 of the base frame 2, and each joint is connected with the fastening metal fittings 8 to complete the assembly. The concrete 28 is filled and solidified up to the -L end inside the outer frame.

The interval between each inner frame and the outer frame forms the side wall of the hand hole, and the upper part of the floor plate 12 forms the bottom plate.

Next, when demolding the solidified concrete 1,
Each outer frame 5a.

6b, 6c, and 6d are disengaged from each other, the hinge 3 of the base frame 2 is rotated outward in the upper position, and then the screw shaft 23 inside the inner frame is rotated in the opposite direction. When the screw shaft 23 is lowered, each telescopic adjustment arm rod 26 is lowered together, and each of the four sets of wedge rods 22a, 22b.

22c and 22d are pulled diagonally downward inward and operated backward, and with the lower part of each wedge rod partially remaining in the gap between the tapered surfaces 21 of each inner frame, the solidified concrete is moved to the ground with a winch or the like. When the mold is removed, the upper pressure plate 12 rises slightly due to the adhesive force of the concrete and is peeled off, and each inner frame 15
a, 15b, 15c.

The adhesion pressure of the concrete also acts outward on 15d, and each inner frame is tilted radially symmetrically in the direction of the screw around the hinge 20 of the L frame 19, and as it closes and contracts, the concrete can be easily demolded. .

Therefore, in the present invention, by rotating the screw shaft 23 in the forward direction and in the reverse direction, the internal frame can be efficiently assembled and closed and retracted with one touch, and each inner frame is mutually and -L The joint with the floor slab is also straight, making it easy to manufacture.
It has the remarkable effects mentioned above, such as making it possible to semi-automate the molding work of the box-shaped block manhole and achieve labor saving without causing backlash or the like in the joints.

[Brief Description of the Drawings] Fig. 1 is a partially cutaway plan view of a concrete form according to an embodiment of the present invention, Fig. 2 is a sectional view taken along the line A-A, and Fig. 3 is a partially cutaway plan view of a concrete form according to an embodiment of the present invention.
The figure is a partially enlarged sectional view taken along the line A-A, FIG. 4 is a partially enlarged sectional view taken along the line B-B of FIG. 2, FIG.
The figure is a cross-sectional view taken along the line D-D in Figure 3, Figure 7 is a cross-sectional view taken along the same line E-E, Figure 8 is a partially enlarged plan view showing the inner frame, and Figure 9 is a cross-sectional view taken in Figure 8 F. 10 is a plan view of the -L floor slab, and FIG. 11 is a perspective view of the concrete IJ formwork.

Claims (1)

[Claims] 1. A base frame 2 is attached to the lower surface of a base plate 1 with a square hole in the center, and four sets of four sets are attached to the upper surface of the base plate 1 at a position midway between the outer edge and the inner edge of the base plate 1 and pivoted to the outer surfaces of the four sides of the base plate. The outer frame is assembled and erected so as to be freely rotatable, and four sets of L-shaped supports are erected radially symmetrically from the four inner corners of the base frame toward the center of the base frame, with the top end of each support being attached to the top of the outer frame. A rectangular frame is connected to the upper end of the frame at a lower position corresponding to the thickness of the bottom plate of the rod, and an arbitrary number of arm rods are diagonally directed downward from the center on the lower surface of the upper pressure plate 12 whose four sides and four corners are chamfered. A screw bearing is fixed to the tip of the protruding arm, and each arm rod is fitted into a rectangular frame at the upper end of the strut, and an upper pressure plate 12 is attached to the upper end of the strut.
Four sets of inner frames 15a, 15b, each having a plan view shape, are removably mounted, fit into the four corners of the inner edge of the base plate 1, and have -L ends joined to the four corners of the upper pressure plate 12. , 15
c, 1sa are pivotally attached to the four corners of the inner surface of the base frame 2 via L frame rods, and tapered surfaces 21 expanding inward are provided on opposing surfaces at both ends of each inner frame, and gaps between opposing ends of each inner frame are provided. Four sets of wedge rods 22a, 22b, 22c, 22d that fit into the
The upper end of the screw shaft 23 is screwed into the screw bearing 14 on the lower surface of the upper pressure plate 12, and is loosely fitted into the lower shaft body of the screw shaft 23.
This concrete formwork for an underground trench is characterized in that a spacer 24 whose upper and lower surfaces are locked by flanges is connected to the inner center position of each wedge rod by a telescopic adjustment arm rod.