JPH0349849Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a molding device used when molding a concrete product such as a box culvert.

[Conventional technology]

Traditionally, concrete products ranging from large box culverts to small domestic drainage basins, etc.
Manufactured by mold making. The molds used for this production, for example in the case of box culverts, are a combination of an outer mold for the outer shell and an inner mold for the inner shell, and the same is true for the molds for other products.

In mold making, since the mold functions as a temporary frame, it is necessary to release the mold after filling with concrete, shaping and curing. In order to release the mold, a method is used in which the mold is made up of a plurality of frame materials, some of which are pulled out first, and then the entire mold is dismantled.

In such mold release, the simplest structure is, for example, to make a part of the frame material a tapered material and use the tapered surface to pull it out from the adjacent member. For example, in the case of a box-shaped product such as a box culvert, the frame material at the corners of the product is tapered in the longitudinal direction, and when the product is released from the mold, the tapered frame material is tapered in the axial direction of the product. The process involves pulling out the frame, releasing the mutual restraints of the other frame materials, and dismantling it.

[Problem that the invention attempts to solve]

However, when a mold is made of a combination of a plurality of frame materials for mold release, the seams between the frame materials have an undesirable effect on the molded product. For example, if the degree of bonding between frame members is insufficient, concrete mortar may leak and cause burrs. Further, since the tapered frame material is frequently inserted and removed, the joint surface with the adjacent frame material is rapidly worn, and it is necessary to replace not only the tapered frame material but also the surrounding frame materials. In this case, since the frame material for the mold is generally expensive, it also affects the manufacturing cost.

Furthermore, in the case of a combination of a plurality of frame materials, if the molded product becomes large, the weight of the frame materials also increases, requiring work using a crane. Therefore, in order to manufacture one product, it was necessary to use heavy machinery in addition to multiple workers, and there was a limit to the improvement of productivity.

Therefore, an object of the present invention is to simplify the mold release work, reduce the frequency of replacing the mold itself, and manufacture a product without burrs.

[Means for solving problems]

The present invention uses an inner mold to create a hollow part such as a rectangular or circular cross section of a hollow concrete product at one part of the creation surface.
A mold device configured as a combination of a plurality of frame materials shorter than the width of a side or the circumference, each of the frame materials being connected by an elastically deformable joint,
The outer circumferential surface of the joint forms a production surface of the product together with the connected frame material, and the joint is hollow to provide an air chamber, and the air chamber is communicated with an external compressed air supply source. .

〔Example〕

Hereinafter, features of the present invention will be specifically explained with reference to embodiments shown in the drawings.

FIG. 1 is a front view showing the production of molds for concrete products using the mold apparatus of the present invention, and in this embodiment, the production of box culvert A shown in FIG. 4 will be taken as an example.

The mold apparatus is composed of an outer mold 1 and an inner mold 2 for creating an outer wall B and an inner wall C of a box culvert A. These outer mold 1 and inner mold 2 are made of four-sided frame materials 1a to 1d and 2a to 2d so as to create an outer shell corresponding to outer wall B and inner wall C, respectively.
It is equipped with These frame materials 1a to 1d, 2a to
2d is a thick metal plate as in the conventional case, and as shown in FIG.
The hinge pin 3a connects the opening/closing mechanism to the hinge pin 3a.

Each of the frame members 2a to 2d of the inner mold 2 has a substantially similar structure with equal side lengths, and in FIG. The horizontal ribs 5 are formed at an appropriate pitch. And, as shown enlarged in Figure 2,
Edges 6 that protrude in the frontage direction are provided outside the vertical ribs 4. Furthermore, between the edges 6 of the mutually adjacent frame members 2a to 2d of the inner mold 2,
An elastically deformable joint 7 is joined. The joint 7 is made of an elastic material such as synthetic resin such as natural rubber, chloroprene rubber, nitrile rubber, rayon, vinylon, and nylon, or a synthetic resin containing thread or cloth, etc., and the inner mold 2
It is arranged over the entire longitudinal length of.

As shown in FIG. 2, both ends of the joint 7 are integrated with the edge 6 in a stepped manner, and a frame member 2a forming the inner wall C surface of the box culvert A is formed.
It is joined to the outer surface of ~2d without any unevenness. Further, the joint 7 is shaped like a bag with an air chamber 7a formed therein, and this air chamber 7a occupies almost the entire length of the joint 7, and a hose 7b for supplying compressed air from a compressor (not shown) is connected to the joint 7. Connected in place.

By providing such an air chamber 7a, when compressed air is supplied from the hose 7b, the air chamber 7a can be inflated as shown in FIG. 2a by utilizing the elastic deformation of the joint 7.
Further, when the air is discharged, the air chamber 7a contracts and becomes the state shown in FIG. 2b.

In the above configuration, the frame members 1a to 1d and 2a to 2d of the outer mold 1 and the inner mold 2 are placed in a vertical position as shown in Fig. 3a, and the creation space between the two molds is filled with concrete mortar. Make a mold.
When the inner mold 2 is in a vertical position, the width of each of the frame members 2a to 2d is adjusted so that the edges 6 of the adjacent frame members 2a to 2d are spaced apart from each other as shown in FIG. 2a. It is necessary to determine the dimensions.

In the mold manufacturing stage, the joint 7 joined between the edges 6 deforms due to its elasticity, and by supplying compressed air to the air chamber 7a, tension is also applied to the surface facing the creation space. can give. That is, if the mold is manufactured by simply joining an elastic body between the edges 6, it will not be able to withstand the filling pressure of concrete mortar, and the shape of the inner wall of the product will not be maintained in a predetermined shape. On the other hand, if compressed air is supplied to the air chamber 7a, the generating surface of the joint 7 can be supported by its internal pressure, and a linear generating surface can be obtained as shown in FIG. 2a. In order to always maintain such a linear generation surface, it is even more effective to use a joint 7 filled with wire.

The mold making process and mold release after curing are performed by separating the outer mold 1 and the inner mold 2 from the forming surface of the box culvert A, as shown in FIG. 3b. In this case, since the frame members 1a to 1d are each independently pivoted to the base 3, the outer mold 1 may be tilted without any interlocking relationship, and may be rotated around the hinge pin 3a.

On the other hand, since the inner mold 2 has the respective frame members 2a to 2d joined by the joint 7, the entire inner mold 2 tilts at the same time. That is, if the compressed air is discharged from the air chamber 7a and the tension of the joint 7 as a whole becomes zero, the adjacent joint portions of the frame members 2a to 2d become free ends due to the elasticity of the joint 7. At this stage, when the upper ends of each of the frame members 2a to 2d are pushed toward the center using a tool or the like, they are tilted away from the inner wall C of the box culvert A, as shown in FIG. 3b. That is, each frame material 2a-2
Since the width dimension of d is smaller than the dimension of the inner wall C of the box culvert A to be created, as shown in FIG.
a to 2d change their postures. Further, at this time, the air chamber 7a of each joint 7 comes to be embraced by the vertical ribs 4 and edges 6 of the adjacent frame members 2a and 2b, as shown in FIG. 2b.

As described above, each of the frame members 2a to 2d is tilted by the elastic deformation of the joint 7, and can be released from the mold by lifting the created box culvert A upward in FIG. 3b.

FIG. 5 shows another embodiment, in which a concrete product is produced in which the inner wall is circular and the outer wall is regular octagonal. Incidentally, since the outer mold is the same as the above example, detailed explanation and drawings are omitted.

The inner mold 2 is composed of two semicircular frame members 2a and 2b in order to obtain a circular generating surface, and each has three vertical ribs 4 running almost the entire length in the axial direction, and these vertical ribs 4 Horizontal ribs 5 connecting the ribs 4 are formed at a predetermined pitch. The frame members 2a and 2b are connected at their proximal ends by a solid hinge joint 8, and at their distal ends, the edge 6 is joined by a joint 7 similar to that of the previous embodiment. The joint 7 forms an air chamber 7a inside and is supplied with compressed air by a hose 7b.
The hinge joint 8 is an elastic body made of hard synthetic resin or the like, and functions as a hinge to reduce the diameter of the frame members 2a and 2b, as shown by the dashed line in the figure.

In the inner mold 2 for making this circular generating surface, compressed air is supplied to the air chamber 7a during mold manufacturing to inflate it and provide tension. Furthermore, when releasing the mold, compressed air is removed from the air chamber 7a to cause it to contract, and then the side near the joint 7 is pushed from the outside toward the center. By this operation, the frame members 2a and 2b change their posture as shown by the dashed line in the figure by utilizing the elastic deformation of the hinge joint 8, and can be separated from the product and released from the mold.

In addition, instead of using two frame members, the number may be increased according to the size of the product, and a joint may be arranged at the joining point of each frame member.

Further, in the above embodiments, molds for products having box culverts and circular cavities have been described, but it goes without saying that the mold apparatus of the present invention can be applied to various other concrete products.

[Effect of idea]

In this invention, the plurality of frame materials constituting the inner mold are connected by elastically deformable joints, so when the mold is released, each frame material is folded using the contraction of the joints. This makes the work easier and reduces the burden. If compressed air is sent into the air chamber of the joint, the internal pressure of the air chamber will rise and it will be able to withstand the filling pressure of concrete. Therefore, even if the joint is elastically deformed, the creation surface can be made into an appropriate shape during molding, and a good concrete product can be obtained.

[Brief explanation of drawings]

Fig. 1 is a diagram showing the production of a box culvert using the molding device of the present invention, Fig. 2 is a sectional view showing an enlarged main part, and Fig. 3 is a diagram showing the operation of the inner mold and the outer mold.
FIG. 4 is a perspective view of the box culvert. Further, FIG. 5 shows another embodiment. 1...Outer mold, 1a to 1d...Frame material, 2...Inner mold, 2a to 2d...Frame material, 3...Base, 3a...
...Hinge pin, 4...Vertical rib, 5...Horizontal rib, 6
...Edge, 7...Joint, 7a...Air chamber, 7b...Hose, 8...Hinge joint, A...Box culvert, B...Outer wall,
C...Inner wall.

Claims (1)

[Scope of utility model registration request] A mold device in which an inner mold for creating a hollow part such as a rectangular or circular cross section of a hollow concrete product is configured as a combination of a plurality of frame materials shorter than the width of one side or the circumference of the creation surface, the mold device comprising: are connected by elastically deformable joints, the outer circumferential surface of the joint forms the creation surface of the product together with the connected frame material, and the inside of the joint is hollow to provide an air chamber, and the air chamber is connected to the outside. A molding device for concrete products, characterized in that the device is connected to a compressed air supply source.