JPH0420577Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to formwork for manufacturing concrete products, and particularly relates to the inner frame thereof.

(Conventional technology and problems) Concrete formwork has an outer frame, an inner frame, and a gable board as its main parts, but it is not suitable for producing rectangular or cylindrical concrete products such as box-type culverts. In the case of formwork, the inner frame is independent, and the ready-mixed concrete covers the entire inner frame and hardens, so in order to remove it from the mold, a part of the inner frame or the side plates must be tilted inward, and the This was done by installing bolts or pantograph-type jacks inside and tilting the inner frame inward.

However, these screw-type systems have some inconveniences, such as the screw threads collapsing, the threads becoming clogged by leakage, which prevents them from functioning properly, and the operation takes a long time.

Another method is to fit a wedge-shaped plate into the crack in the inner frame in advance to hold the inner frame, and when demolding, remove this wedge-shaped plate and tilt the inner frame plate inward. There are disadvantages in that it takes time to assemble and the rubber member interposed on the contact surface is easily damaged.

(Means for solving the problems) The present invention was developed in view of the above-mentioned drawbacks, and it is easy to operate, does not take much time to assemble the mold, and is not affected by leakage. In addition, the aim is to provide an inner frame for concrete formwork that can withstand long-term use, and its gist is to provide a cylindrical inner frame with a separable joint that is cracked in the longitudinal direction on one side. The left and right openings of the inner frame are provided with support plates on both sides of the joint, and each support plate has a pair of elongated holes in an inverted V-shape extending from the bottom to the top and outward. A working plate is provided in which a hole is bored and protrusions protruding from both ends are inserted into the elongated hole, and a blocking plate connected to the working plate is installed along the joint, and this blocking plate is further installed. A clamping device that can be moved up and down is provided so as to be operable from the outside, and when the clamping device is in a released state, the action plate descends together with the blocking plate to push open the support plate, thereby opening the joint of the inner frame, and causing the inside of the opened joint to open. This is the inner frame of a concrete formwork characterized by a closing plate that lowers and seals the area.

First, the concrete formwork to which the present invention is applied is mainly a formwork for producing square tube or cylindrical concrete products, and the formwork consists of an outer frame that is open at the top and can be fanned out, and an outer frame that is open at the top and can be fanned out. The main components are an end plate that approaches and separates from both openings, and an inner frame that is suspended between the outer frame and the end plate. Of course, the formwork to which the present invention is applied is not limited to this, and can be applied to the inner frame of a concrete formwork for a U-shaped groove, for example, regardless of its form.

The inner frame of the present invention includes either a rectangular tube shape or a cylindrical shape, and one side thereof is split in the longitudinal direction.
The inner frame is usually made of iron plates, and the joints can be opened and closed in opposite directions. It is preferable that the side plate portion where this joint is provided be located on the lower side when the inner frame is mounted between the end plates.

Support plates are attached to the left and right openings of the inner frame on both sides of the joint, and elongated holes are provided in the support plates from the bottom to the outside and upward.
The pair of elongated holes are arranged in an inverted V shape.

On the other hand, a closing plate is arranged along the joint in the inner frame, and this closing plate is connected to the lower end of the clamp shaft which is rotatably connected to the operating shaft mounted longitudinally above the inner frame. The clamp shaft is connected to the top and bottom of the clamp shaft, and is moved toward and away from the joint in the direction of the joint.

Action plates are attached directly or indirectly to both ends of this blocking plate, and projections are formed at both ends of the action plate, and these projections fit into elongated holes formed in the support plate of the inner frame. There is. When the clamping device is released, the closing plate is lowered and sealed into the joint opened by the lowering of the action plate. When the clamp device is tightened, the joint is closed by the rising of the action plate, and the closing plate is positioned directly above the joint.

In order to make the lifting and lowering movement of the closing plate smooth and to ensure a better sealing condition, the closing plate is made wedge-shaped, and each edge of the joint has a symmetrical shape that comes in close contact with the side of the closing plate when closing. It is better to provide a sloped wall.

The operating shaft of the clamp device, which is provided in the longitudinal direction along the top plate of the inner frame, has at least one end extended outward from the opening edge of the inner frame so that it can be operated externally, and the operating shaft is connected there with a bar or the like. An engagement member for rotation is attached.

The clamp shafts are connected to and suspended from the operating shafts near the opening, and the number of clamp shafts is usually 2 to 4, but more may be provided depending on the depth of the inner frame. The clamp shaft has a jaw near the operating shaft, and when tightening, this jaw engages with the operating shaft to maintain the tightened state. At this time, the entire clamp shaft rises, and the closing plate at its lower end also rises. be. Note that it is desirable to be equipped with a means for adjusting the distance between the closing plate and the joint portion.

(Function) Since the present invention is constructed as described above, first, the inner frame according to the present invention is suspended between the outer frame and the end plate. In the case of an inner frame of a rectangular cylindrical concrete product such as a box-type culvert, the frame is removably suspended, leaving room for fresh concrete around the periphery.

At this time, the inner frame is prepared before it is suspended between the end boards or before the fresh concrete is poured in. That is, in order to release the device from the clamp housed within the inner frame, the operating rod is inserted into the engaging member formed at the end of the operating shaft protruding from one of the openings of the inner frame and rotated in the direction of releasing the clamp. do.

When the clamp is rotated in the release direction, the jaws of the clamp shaft are removed from the operating shaft, and the lower end gradually extends downward, and the closing plate connected thereto approaches the bottom of the inner frame.

Due to this action, since the action plate is connected to the closing plate, the action plate also descends, but the protrusions protruding from both ends of the action plate are connected to the pair of supports implanted on both sides of the inner frame opening. It fits into an oblong hole in the shape of an inverted C at the bottom of the plate, and the intervals between the protrusions are constant.The protrusions inside this elongate hole push the inner frame outward through the support plate, so It will descend while fanning out the joint at the bottom of the inner frame. The joint of the bottom plate is thus opened, and at the same time, the closing plate is lowered to close the inside of this joint.

In this state, pour fresh concrete into the formwork and wait for the concrete to harden.

Once solidification is complete, remove the end plate and release the bond between the outer frame and the concrete product using normal means, then insert the operating rod into the engaging part of the operating shaft and rotate until the jaws of the clamp shaft are clamped to the operating shaft. .

At this time, the closing plate attached to the lower end of the clamp shaft and the action plate connected thereto also rise. The joint part is not affected by the rise of the blocking plate, but the protrusion of the action plate, which rises in synchronization with this, moves upward within the elongated hole of the support plate, and the protrusion presses the elongated hole inward. As a result, both sides of the inner frame narrow inwardly, and the joint of the bottom plate is closed at the same time.

Due to such contractionary movement of the side and bottom surfaces of the inner frame, the inner frame is peeled off from the inner surface of the concrete product to which it has been adhered, and the mold can be removed.

(Example) An explanation will be given below according to the drawings shown as examples. 1 is a concrete form body for a box underdrain, and 2 is an outer frame. Reference numeral 3 denotes an inner frame, which has a rectangular cylindrical shape in the cross-sectional direction. Although the end plates are not shown, they are set in the openings 4 of the outer frame 2 and inner frame 3. A rubber plate is usually interposed on the contact surface to prevent leakage.

Figure 1 shows the state before ready-mixed concrete is poured, with the end plate removed and the inner frame 3 installed inside the outer frame 2. Although the inner frame 3 appears to be floating inside the outer frame 2, It is supported by the wife board and is not floating in the air. 5 is a space where fresh concrete is poured.

Reference numeral 6 indicates a plurality of clamp devices provided within the inner frame 3, and this device 6 includes an operating shaft 8 rotatably attached in the longitudinal direction along the inner surface of the top plate 7 of the inner frame 3; The main element is a clamp shaft 10, which is rotatably connected to the clamp shaft 10 via a connecting plate 9, and has a jaw 8' above and hangs down.A closing plate 11 is provided at the lower end of the clamp shaft 10, and a closing plate 11 is connected to the clamp shaft 10, which is rotatably connected to the clamp shaft 10 through a connecting plate 9, and has a jaw 8' above. In the previous state, the inner frame 3 is fitted into a joint 13 formed in the center of the bottom plate 12 in the longitudinal direction.

Reference numeral 14 designates a pair of support plates formed in the opening 4 of the inner frame, and reference numeral 15 designates a pair of elongated holes drilled below the support plate 14 at a slope similar to an inverted V-shape. 1
Reference numeral 6 denotes an action plate that is connected to the closure plate 11 and moves up and down in synchronization with the closure plate 11.Protrusions 17 are provided at both ends of the action plate 16, and the protrusions 17 are inserted into the elongated holes 15. I'm stuck in it.

Reference numeral 18 denotes an engaging portion formed at the outer end of the operating shaft 8 of the clamp device 6 and into which an operating rod is inserted. 19
is a contact plate erected in a wedge shape on the edge of the joint portion 13 in order to guide the closing plate 11 and ensure a close contact area therewith.

(Effects of the invention) As described above, the present invention effectively applies a clamp device to demolding the inner frame, and allows the inner frame to easily return to its original shape and perform contraction operations for demolding in almost one operation. It is possible to do this. That is, in the present invention, while an openable and closable joint is formed on one side of the inner frame,
The clamping device is installed inside the inner frame, and the joint is opened and closed using the vertical movement of the clamp shaft, and when the joint opens, it is closed with a closing plate.The clamping device is also effective for demolding the inner frame. It is a compact and practical application, and has great practical value in terms of operability, durability, and economy.

[Brief explanation of the drawing]

Figure 1 is a front view of the formwork with the end plate removed;
FIG. 2 is a perspective view of the inner frame, FIG. 3 is a partially enlarged perspective view of the inner frame showing the state at the time of demolding, and FIG. 4 is a diagram showing the operation of the clamp device. 1...Concrete form body, 2...Outer frame, 3
...Inner frame, 4...Opening, 5...Space, 6...
Clamp device, 7...Top plate, 8...Operation shaft, 9...
...Connection plate, 10... Clamp shaft, 11... Closure plate, 12... Bottom plate, 13... Joint portion, 14... Support plate, 15... Elongated hole, 16... Action plate, 17...
Projection, 18... engaging portion, 19... contact plate.

Claims (1)

[Scope of Claim for Utility Model Registration] 1 A cylindrical inner frame has a longitudinally split joint that can be separated and separated on one side, and the left and right openings of the inner frame have a joint on both sides with this joint as a border. A support plate is provided, and a pair of elongated holes are formed in each of the support plates in an inverted V-shape facing upward and outward from the bottom, and protrusions with both ends protruding are inserted into the elongated holes. While the plate is provided, a closing plate connected to the action plate is installed inside along the joint part, and a clamping device for moving the closing plate up and down is provided so as to be operable from the outside, and when the clamping device is released, An inner frame of a concrete form, characterized in that an action plate descends together with a closing plate to push open the support plate, thereby opening a joint of the inner frame, and the closing plate descends into the open joint to seal it. 2. An inner frame for a concrete form, characterized in that the inner frame has a substantially square cylindrical shape.