JPH0346105Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Industrial application field]

This invention is a bottom cover material that closes one open end of the hard paper tube and becomes the bottom of the cutting die when a hard paper tube is used as a cutting die for forming a vertical hole during concrete pouring work. It is related to.

[Prior art]

Generally, when installing guardrails on roads, stone guards to protect against falling rocks on mountain roads, etc., or fences, etc.
Drill a vertical hole in the concrete foundation in advance, set a support such as a guardrail leg support, an H-shaped steel beam, or a fence that will serve as a stone guard support in the hole, and fill the void of the hole with mortar or concrete. to secure these. The conventional method of forming this vertical hole in a concrete foundation is to cut a long tube made of hard paper to an appropriate length before pouring the concrete into the formwork, and then cut one opening into an appropriate length. A closed cutting die is created, and this cutting die is placed in a concrete formwork with the closed part as the bottom, and the other opening is placed above the concrete formwork and fixed to the formwork. The desired vertical hole can be formed by setting the concrete in place, pouring concrete around the cutting die in the formwork, and removing the formwork after the concrete has hardened. In addition to the above-mentioned hard paper tube, a wooden frame can also be used as the cutting die, but in general, hard paper tubes called voids are commercially available and are convenient and frequently used. In addition, this hard paper tube is
It is manufactured by winding hard paper material in a spiral around a drum with a diameter of standard dimensions, and there is no negative error in the inner diameter due to differences in manufacturing company, manufacturing method, or specifications, but there is a slight positive error. There are often cases where this occurs. Although very rare, hard paper tubes with a rectangular cross section are sometimes used.

[Problem that the invention attempts to solve]

By the way, the methods actually used in the field to close one opening of the hard paper tube used in the above-mentioned construction method are, for example, pasting multiple layers of highly adhesive cloth tape, or The only "off-the-shelf" methods were to cut the open end of the tube, fold it inward, and secure it with tape to close it off. Therefore, the work is time-consuming, and it is difficult to completely close the bottom of the cutting die, or the tube may become deformed, so the concrete poured into the formwork may leak from the bottom. There were problems such as it getting into the cutting die. In addition, in order to standardize a member that closes an opening in a lid-like manner as a product, it is necessary to standardize it so that it can easily deal with the above-mentioned errors, and to be able to withstand the concrete pouring pressure that is quite impactful. The challenge was to make it strong enough to be used. The present invention has been devised in view of the above-mentioned problems and to effectively solve them. Therefore, the purpose is to simply close the opening of the hard paper tube and use it as the bottom of the cutting die, without worrying about deforming the tube, and almost completely preventing concrete from entering the tube. To provide a bottom cover material for a vertically punched tube for concrete pouring work, which can easily cope with errors in the inner dimensions or inner diameter dimensions of the tube and can sufficiently withstand concrete pouring pressure.

[Means to solve the problem]

The bottom cover material of the vertical hole punched tube for concrete pouring work according to the present invention has the following characteristic configuration in order to solve the problems of the prior art and achieve the purpose. That is, with a disc-shaped bottom portion having an outer dimension slightly smaller than the standard inner dimension of the hard paper tube, and the disc-shaped bottom portion being fitted into the opening of the hard paper tube, the lower edge of the periphery of the opening is a holding part having a bent piece that abuts, and a saw blade-shaped claw protruding outward and obliquely downward so as to have a dimension slightly larger than the standard inner dimension of the tube, on the peripheral edge of the plate-like bottom part. A section is formed. In particular, when the hard paper tube is cylindrical, the disk-shaped bottom portion has an outer diameter slightly smaller than its standard inner diameter dimension. This disc-shaped bottom is gently curved from the center to the outside so that the center protrudes downward or upward, and an annular groove is formed in the outer periphery to form a recess along the periphery. It's good to have one. Further, the holding portion not only abuts the lower end of the peripheral edge of the opening of the hard paper tube when the disc-shaped bottom portion is fitted into the opening, but also clamps and clamps the inner and outer surfaces of the peripheral edge. It is preferable to construct it from a bent piece having a U-shaped cross section as shown in FIG. A first claw is a saw blade-shaped claw formed on the peripheral edge of the disc-shaped bottom and projects radially outward and diagonally downward so as to have a dimension slightly larger than the standard inner diameter of the tube; It is further preferable that the bent piece of the holding portion corresponding to the outer surface of the opening periphery of the tube is provided with a saw-blade-shaped second claw portion that bites into the outer surface of the tube. The material of the bottom cover material is preferably made of thin steel plate, but it is also possible to use a molded product made of hard plastic material.

[Effect]

In order to solve the problems of the prior art and achieve the purpose, each constituent means of the bottom cover material of the vertical hole punched tube for concrete pouring work according to the present invention operates as follows. The dimensions of the disk-shaped bottom are slightly smaller than the standard inside dimensions of hard paper tubes, so even if there is an error in the inside dimensions or inside diameter of the tube, it is easy to insert into the tube and there is no concrete inside the tube. Intrusion can be almost completely prevented. In the holding part, when the disc-shaped bottom part is fitted into the opening of the tube, the bent piece comes into contact with the end face of the opening edge of the tube and is locked, so that even if the disc-shaped bottom part receives pressure from the concrete from below, It does not enter the tube any further. In particular, when the holding part, which has a U-shaped cross section and has a second claw part, engages with the edge of the tube and tightens it so as to clamp it, the second claw part bites into the outer peripheral surface of the tube. The disk-shaped bottom part is maintained in a fitted state with the tube even under concrete pouring pressure. The claw portion (first claw portion) formed on the peripheral edge of the disc-shaped bottom protrudes outward so that the dimension is slightly larger than the standard inner dimension of the tube, and the protrusion direction is diagonally downward. Therefore, it is easy to insert the disc-shaped bottom into the tube, and once the disc-shaped bottom is inserted into the tube, it is not easy to resist the force that tries to pull it out in the opposite direction because it bites into the inner surface of the tube. It does not come off, and even errors in the positive inner dimension or inner diameter dimension of the tube can be easily accommodated because the dimensions of the claw portion are larger than the standard inner dimension and the claws bite into it. The disk-shaped bottom is effective in preventing tube deformation just by being installed inside the tube.
In particular, the curved shape and grooves of the disc-shaped bottom further increase the bending rigidity and more effectively prevent deformation against forces acting in the radial direction of the tube. When the material of the bottom cover material is made of a thin steel plate, it is relatively easy to form a complicated shape, and it conforms well to concrete.

[Effect of the idea]

As is clear from the above description, the present invention provides the following excellent effects. In other words, the bottom cover material of a vertical hole punching type tube for concrete pouring work is convenient because it can be used as the bottom of the punching die by closing the opening of the hard paper tube, and there is no risk of deforming the tube, and it can be used almost completely. It is possible to prevent concrete from entering the tube, and it can easily accommodate errors in the inner diameter of the tube, and can sufficiently withstand concrete pouring pressure.

【Example】

A preferred embodiment of the present invention will be described below with reference to FIGS. 1 and 2. FIG. 1 is a plan view showing the holding portion of the bottom cover material of the vertical hole punching type tube for concrete pouring work according to the present invention developed. Moreover, FIG. 2 is a cross-sectional view showing the bottom cover material of the vertical hole punching type tube for concrete pouring work according to the present invention, cut in the axial direction thereof. As shown in Fig. 1, the bottom cover material includes a disc-shaped bottom part 1 which becomes the main body part, and bent pieces arranged at four equal parts from the peripheral edge of the disc-shaped bottom part 1 and extending radially outward. Holding part 5 formed by 2, 3, 4
It is mainly composed of. They are also made of thin steel plates, and the bottom cover material may be left in the concrete, for example, when removing the cut-out hard paper tube from the hardened concrete. In addition, the above-mentioned bent pieces 2, 3, and 4 are
Depending on the required strength, it is possible to configure the holding portion 5 with only the bent pieces 2 and 3, and furthermore, the holding portions 5, which are arranged equally at four locations, may be arranged equally at three locations. The outer diameter D ₁ of the disc-shaped bottom portion 1 is slightly smaller than the standard inner diameter dimension of the hard paper tube. For example, when the standard inner diameter dimension is 150 mm, in this example,
Let D ₁ be 148mm. On the peripheral edge of the disc-shaped bottom part 1, between each holding part 5, there is a saw-blade-shaped first claw part that protrudes radially outward and diagonally downward so that the diameter is slightly larger than the standard inner diameter dimension of the tube. 6 is formed. Assuming that the first claw diameter is D ₂ , if the standard inner diameter is 150 mm, in this embodiment D ₂ is set to 152 mm in consideration of the positive error in the standard inner diameter. The protruding dimension and protruding direction of the first claw portion 6 can accommodate a certain degree of inner diameter error of the tube without impairing the insertability of the disc-shaped bottom portion 1. Further, as shown in FIG. 2, the cross-sectional shape of the disc-shaped bottom 1 is gently curved from the center to the outer periphery so that the center protrudes downward, and the outer periphery has a curved shape along the periphery. An annular groove 7 is formed to constitute a recess. This curved bottom surface is formed by a bent piece 3 that forms the bottom surface portion of the holding portion 5.
Therefore, the depth inside the cutting die can be ensured to be approximately the same as the depth of the tube. Furthermore, by forming the groove portion 7, together with the curved shape, the bending rigidity of the disc-shaped bottom portion 1 can be increased, and by attaching this bottom cover material, crushing of the tube in the radial direction can be prevented. can. The holding portion 5 has a substantially U-shaped cross section by bending the bent pieces 2, 3, and 4, and is fitted onto the periphery of the opening of the tube. Cutting edge bending 4
A second claw portion 8 in the shape of a saw blade is formed on the tube to bite into the outer circumferential surface of the tube by tightening the holding portion 5 in the fitted state. Also, the second
The bent piece 4 on which the claw part 8 is formed is formed flat so as to have as little resistance as possible to the pressure of the poured concrete, and
When the claw part 8 bites into the tube, the tip of the bent piece 4 should be set lower than the upper end surface of the outermost periphery of the disc-shaped bottom part 1, as shown in FIG. The claws are made taller (indicated by h in the figure), and the size of the claws is also made larger toward the tip, as shown in FIG.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing the holding portion of the bottom cover material of the vertical hole punching type tube for concrete pouring work according to the present invention developed. FIG. 2 is a sectional view showing the bottom cover material of the vertical hole punching type tube for concrete pouring work according to the present invention, cut in the axial direction thereof. FIG. 3 is a sectional view showing a state in which the tube is locked to the holding part of the bottom cover material according to the present invention. 1... Disc-shaped bottom, 2, 3, 4... Bent piece, 5
...Holding part, 6...First claw part, 7...Groove part, 8...Second claw part.

Claims (1)

[Claims for Utility Model Registration] (1) A disc-shaped bottom 1 having an outer dimension D ₁ slightly smaller than the standard inner dimension of the hard paper tube, and fitting the disc-shaped bottom 1 into the opening of the hard paper tube. A holding part 5 having bent pieces 2 and 3 that abuts the lower edge of the periphery of the opening in the open state.
A saw blade-shaped claw part 6 is formed on the peripheral edge of the disc-shaped bottom part 1 and projects outward and obliquely downward so that the dimension _D2 is slightly larger than the standard inner dimension of the tube. A bottom cover material for vertical hole punching type tubes for concrete pouring work. (2) The disc-shaped bottom part 1 is a disc-shaped bottom part 1 having an outer diameter _D1 slightly smaller than the standard inner diameter dimension of a hard paper tube, and the holding part 5 holds the disc-shaped bottom part 1 of the hard paper tube. It consists of bent pieces 2, 3, and 4 each having a U-shaped cross section, which abut the lower end of the periphery of the opening and clamp and clamp the inner and outer peripheral surfaces of the periphery when fitted into the opening; The disc-shaped bottom 1 is gently curved from the center to the outer periphery so that the center protrudes downward or upward, and has an annular groove 7 on the outer periphery to form a recess along the periphery. The claw portion 6 is formed on the peripheral edge of the disc-shaped bottom portion 1 and protrudes radially outward and obliquely downward so as to have a diameter _D2 slightly larger than the standard inner diameter dimension of the tube. The bent piece 4 of the holding part 5 corresponding to the outer circumferential surface of the opening of the tube has a saw-blade-shaped second claw part 6 that bites into the outer circumferential surface of the tube. 8 is formed. The bottom cover material of a vertical hole punch type tube for concrete pouring work according to claim 1 of the registered utility model claim, characterized in that: 8 is formed. (3) The disc-shaped bottom part 1 and the holding part 5 are made of thin steel plates.
Bottom cover material for vertical hole punched tube for concrete pouring work as described in Section 1.