JPH04111404U - Core formwork for precast parts with U-shaped cross section - Google Patents

Abstract

(57) [Summary] [Purpose] To enable core formwork to be demolded reliably and easily. [Structure] A plurality of turnbuckles 7 are formed with a U-shaped cross section from a steel plate with an uneven surface, and a plurality of turnbuckles 7 are installed at a predetermined interval in the longitudinal direction between the side frames 6a, 6a facing left and right, and each turnbuckle 7 is expanded and contracted. Rotation operating member 7c that performs
It is characterized in that a rotation operation member 8 for rotating the rotation operation member 8 is connected in series.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This idea is suitable for forming U-shaped precast members such as beams. This invention relates to a core formwork for forming a recessed portion of a precast member.

0002

[Conventional technology]

Conventionally, a precast member having a U-shaped cross section with a groove-shaped recess in the center becomes a recess. A core formwork that can be dismantled into multiple plates is installed at the location, concrete is poured, and it is cured. After that, the formwork was dismantled and removed from the mold, but the core formwork was removed. Even if it can be dismantled, pouring concrete will strengthen the formwork and concrete. It is very difficult to dismantle because it is firmly stuck, and sometimes it is impossible to dismantle it. There was also.

0003

[Problem that the idea aims to solve]

This idea solves the problem that demolding is difficult with a core formwork that can be easily disassembled. It is to decide.

0004

[Means to solve the problem]

In order to solve the above-mentioned conventional problems, this idea was created by forming a steel plate into a U-shaped cross section. The turnback is placed at a predetermined interval in the longitudinal direction between the left and right side frames 6a, 6a facing each other. A plurality of turnbuckles 7 are attached to the rotation operating member 7c that performs the expansion and contraction operation of each turnbuckle 7. , a U-shaped cross-sectional plate formed by a series of rotation operation members 8 for rotating the plate. A core formwork 6 for a cast member 1 is proposed.

[0005]

[Effect]

After molding and curing the U-shaped precast member 1 using the formwork, each turnbuckle 7 is When the rotary operating member 7c is simultaneously rotated and contracted by the rotary operating member 8, the core The side frame of the formwork 6 is bent inward and separated from the inner surface of the recess of the U-shaped precast member 1. In this state, the core form 6 is moved in the longitudinal direction of the recess to remove the mold.

[0006] Also, when assembling the formwork, each turnbuckle 7 is rotated by its rotation operating member 7c. When the operating member 8 simultaneously rotates and extends in the opposite direction to the above, the side frame of the core formwork 6 6a is pushed out and returns to its normal molded form.

[0007] If a striped steel plate with an uneven surface is used as the material for the core formwork 6, forming Irregularities are formed on the inner surface of the recessed part of the U-shaped precast member 1, The adhesion force with the post-cast concrete is increased, and the integrity is strengthened.

[0008]

【Example】

Figure 1 shows the forming state of a precast beam 1 with a U-shaped cross section. The side formworks 3, 3 are placed oppositely on the formwork base plate 2, and the reinforcing bars 4 and the lower end single-stage reinforcing bars 5 are arranged inside them. At the same time, a core formwork 6 is installed in the center, and the front and rear ends and lower ends of the core formwork 6 are placed in front of the single-stage reinforcement 5. The rear end is supported on the end formwork.

[0009] As shown in FIGS. 1 to 3, the core formwork 6 is made of a steel plate with an uneven surface, such as a striped steel plate. downward to the left and right side frames 6a, 6a, the bottom frame 6b, and the mutual intersection. It is formed into a U-shaped cross section by the chamfered frames 6c, 6c which are inclined so as to taper off. , a turnback is performed with a predetermined interval in the longitudinal direction between the left and right opposing side frames 6a, 6a. A plurality of cables 7 are installed.

0010 As shown in Fig. 4, the turnbuckle 7 has a threaded lock with reverse threads formed on the left and right ends. Screw the ends of the door 7a into the nuts 7b fixed to the left and right side frames 6a, 6a. , one or two rotation operating members 7c consisting of gears are attached to the center of the threaded rod 7a. It is being

[0011] The rotation operating members 7c, 7c made of adjacent gears have a rotary member for rotating them. A rotary operation member 8 consisting of an endless chain is wound around each turnbuckle 7. They are linked together so that they can expand and contract in unison.

0012 In the above configuration, when demolding the U-shaped precast beam 1 after molding and curing In this case, the threaded rod 7a of the turnbuckle 7 located at the end of the core formwork 6 is It is rotated by a handle 9, and its rotational force is transmitted through a rotation operation member 8 consisting of an endless chain. and is simultaneously transmitted to the rotational actuating member 7c consisting of gears of each turnbuckle 7. The threaded rods 7a are rotated in the direction of contraction operation.

[0013] As a result, the left and right side frames 6a, 6a are drawn together together with the nuts 7b, 7b. It is bent inward at the intersection of the bottom frame 6b and the chamfered frame 6c to form a U-shaped precast. It is peeled off from the inner surface of the recess of the beam 1, and in this state, the core formwork 6 is moved in the longitudinal direction of the recess. The mold can be removed by doing this.

[0014] The inner surface of the recess of the U-shaped precast beam 1 after demolding is caused by the unevenness of the surface of the side frame 6a. Irregularities are formed.

[0015] In addition, the turnbuckle 7 uses its rotation operating member 7c as a lever, and its tip Various cooperative operations, such as being configured to be pivotally attached to the forward/backward rod as the rotational operation member 8. A moving mechanism can be adopted.

[0016]

[Effect of the idea]

As described above, according to this invention, each turnbuckle is connected to its rotating member as a rotating operation section. The side frames of the core formwork bend inward as the materials rotate and contract at the same time. The U-shaped precast member is mechanically peeled off from the inner surface of the recess, making it easy to dismantle it. The core formwork can be reliably and easily demolded without the need for.

[0017] In addition, when reassembling the formwork after demolding, each turnbuckle should be rotated by its rotating member. Assembling work is facilitated by rotating the rotating operation member in the opposite direction and simultaneously extending it. The core form can be returned to its normal molding form without the need for

[0018] In addition, when using a striped steel plate with an uneven surface as the material for the core formwork, In this method, unevenness is formed on the inner surface of the recessed part of the molded U-shaped precast member, and the inside The adhesion force with the post-cast concrete that is poured on the concrete is increased, and the integrity is strengthened. can.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional front view showing a state of molding using the core formwork of this invention.

FIG. 2 is a vertical sectional side view of the core formwork of this invention.

FIG. 3 is a plan view of the core formwork of this invention.

FIG. 4 is a longitudinal sectional front view of the turnbuckle according to the invention.

[Explanation of symbols]

1 U-shaped precast beam 2 Formwork base plate 3 Side formwork 4 Rib muscles 5 Single-stage strip at the bottom end 6 Core formwork 6a side frame 6b Bottom frame 6c Chamfer frame 7a Threaded rod 7b nut 7c Rotation operating member 8 Rotation operation member 9 Rotating handle

Claims (4)

[Scope of utility model registration request] Claim 1: A plurality of turnbuckles formed from a steel plate into a U-shape in cross section are attached at a predetermined interval in the longitudinal direction between left and right opposing side frames, and each turnbuckle is attached to a rotary actuating member that extends and contracts the turnbuckles. A core formwork for a precast member having a U-shaped cross section, characterized in that the core formwork is formed by a series of cooperating rotation operation members for rotating the precast member. 2. A core formwork for a precast member having a U-shaped cross section as claimed in claim 1, wherein the steel plate has an uneven surface. [Claim 3] The rotary actuating member is a gear fixed to the center of a bolt having opposite threads on the left and right sides screwed into nuts mounted oppositely on the left and right side frames. A core formwork for a precast member having a U-shaped cross section according to claim 1. 4. A core formwork for a precast member having a U-shaped cross section as claimed in claim 3, wherein the rotation operating member is an endless chain wound around a gear of an adjacent turnbuckle.