JP5999838B2 - Formwork for molding specimens of concrete or mortar - Google Patents

Description

  The present invention relates to a technical field of a mold for molding concrete or mortar specimens for molding a cylindrical specimen used for a concrete or mortar strength test.

Conventionally, as a mold for molding a specimen of concrete or mortar, a cylindrical body that can be divided into two in the vertical direction for molding a peripheral surface portion of a columnar specimen, a bottom plate for molding a bottom surface portion, a bolt nut, etc. What was fastened together and assembled was generally used. However, the mold having such a structure is troublesome and troublesome because the mold must be assembled and disassembled every time the specimen is molded and removed. Further, the cylindrical body divided into two in the vertical direction has a problem that distortion may occur during assembly or with time, which may affect the accuracy of the specimen.
Therefore, the cylindrical part of the specimen molding mold is made into a non-split type, and the molded specimen is demolded using compressed air, thereby facilitating the preparation of the specimen. In addition, a device that can ensure the accuracy of the specimen is known (for example, see Patent Document 1).

Japanese Patent No. 3669199

By the way, in what was made to demold using compressed air like the said patent document 1, although the air supply hole for sending compressed air into a mold is opened, raw concrete or mortar is formed in a mold It is necessary to prevent water from leaking from the air supply holes when filling the air.
Therefore, in Patent Document 1, a technique is disclosed in which packing is provided on the peripheral surface of the bottom plate and the lower end of the cylindrical body, and the packing is deformed by compressed air so that compressed air is fed into the mold. In addition, as the packing, a U-shaped or hollow special structure or an O-ring is used. However, the U-shaped and hollow special-structured packing is not manufactured for general use, and thus has a problem that it is custom-made and the cost is increased. On the other hand, although an O-ring can be obtained at a low cost, the one disclosed in Patent Document 1 has a configuration in which the O-ring is extended with compressed air to enter a corrugated or comb-shaped gap. In this case, since the O-ring has a relatively high hardness, the cross-sectional shape is almost deformed and enters the gap portion so that it extends in a bowl shape. However, if this is repeated several times, the O-ring becomes a bowl shape. There is a concern that it will remain in an extended state and will not escape from the corrugated or comb-shaped gap, and will not function as a packing at an early stage, which is a problem to be solved by the present invention.

The present invention was created in view of the above-described circumstances in order to solve these problems, and the invention of claim 1 is a cylinder for molding a cylindrical concrete or mortar specimen. A cylindrical mold body that molds the peripheral surface portion of the specimen, and a bottom plate that is removably fitted in the mold body and molds the bottom surface portion of the specimen; In a mold for molding a concrete or mortar specimen configured by using an annular groove formed on the outer peripheral surface of the bottom plate, and an O-ring that is in close contact with the inner peripheral surface of the mold body is attached to the annular groove. An air supply hole for sending compressed air to the annular groove is opened in the mold body, and the compressed air sent from the air supply hole separates the O-ring from the inner peripheral surface of the mold body and jets the compressed air to the upper side of the bottom plate. Specimen molded by letting The configuration in which the mold, the annular groove has an inclined surface where the groove width of the annular groove is inclined to become narrower groove depth side, while the O-ring is compressed by the inclined surface at the time of supply of compressed air Mizooku while moving to the side, there is the supply of compressed air has a configuration in which when stopping the O-ring is in close contact with the inner peripheral surface of the return to the mold body to the original state while being guided by the inclined surface, the The annular groove to which the O-ring is mounted is located above the air supply hole established in the mold body, and forms a second annular groove located below the air supply hole on the outer peripheral surface of the bottom plate, A concrete or mortar made of concrete or mortar, wherein a sealing O-ring that is pressure-bonded to the inner peripheral surface of the mold body is attached to the second annular groove to prevent compressed air from leaking to the lower side of the bottom plate . This is a mold for molding a specimen.

With the invention of claim 1, it is possible to reduce the cost by using an inexpensive and easily obtainable O-ring, while ensuring the function of opening and closing the flow path of the compressed air over a long period of time. it can. In addition, it is possible to reliably prevent the compressed air from leaking to the lower side of the bottom plate, and the demolding can be performed efficiently.

It is a longitudinal cross-sectional view of a sample molding mold. (A), (B), (C), (D) is a perspective view, a plan view, a front view, and a longitudinal sectional view of a bottom plate. (A) is a principal part enlarged view in the state where compressed air is not supplied, (B) is a principal part enlarged view at the time of compressed air supply.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the figure, reference numeral 1 denotes a specimen molding mold for molding a columnar specimen 2 used for a strength test of concrete or mortar. The specimen molding mold 1 is a mold body to be described later. 3 and the bottom plate 4. The specimen 2 is molded by filling and solidifying the concrete molding mold 1 with raw concrete or mortar. On the other hand, the molded specimen 2 is supplied with compressed air as described later. It is designed to be demolded from the specimen molding form 1 by using it. In this embodiment, the mold body 3 and the bottom plate 4 are made of FRP (fiber reinforced plastic). However, the material of the mold body 3 and the bottom plate 4 is not limited to this, and various plastics are used. Or metal can be used.

  The mold body 3 is a cylindrical body that molds the peripheral surface portion of the columnar specimen 2, and an inner flange portion 3 a for supporting the bottom plate 4 is provided at the lower part of the mold body 3. Projecting toward the inner diameter side.

  Further, the bottom plate 4 is a low-profile cylindrical member that molds the bottom surface portion of the specimen 2, and is fitted in the mold body 3 so as to be freely inserted and removed, and the bottom surface of the bottom plate 4 is the mold frame. The main body 3 is attached to the lower part of the mold body 3 while being supported by the upper surface of the inner flange portion 3a.

  On the outer peripheral surface of the bottom plate 4, annular first and second annular grooves 5, 6 are provided over the entire circumference of the outer peripheral surface. A first O-ring 7 is fitted, and a second O-ring 8 is fitted in a second annular groove located on the lower side. Further, the bottom plate 4 is set such that the outer diameter dimension of the bottom plate upper portion 4A above the first annular groove 5 is set slightly smaller than the inner diameter dimension of the mold body 3, and the first annular groove 5 and the second annular groove 5 The outer diameter dimension of the bottom plate intermediate portion 4B between the annular grooves 6 is larger than the inner diameter dimension of the mold body 3 so that a compressed air flow path 9 to be described later is formed between the inner peripheral surface of the mold body 3. The outer diameter dimension of the bottom plate lower portion 4C below the second annular groove 6 is set smaller than the bottom plate middle portion 4B but smaller than the bottom plate upper portion 4A. Has been. The first annular groove 5 and the first O-ring 7 correspond to the annular groove and O-ring of the present invention, respectively, but do not correspond to the second annular groove and sealing O-ring of the present invention. The second annular groove 6 and the second O-ring 8 correspond to the second annular groove and the sealing O-ring of the present invention, respectively, but do not correspond to the annular groove and O-ring of the present invention. Further, general-purpose O-rings are used for the first and second O-rings 7 and 8, but in the present embodiment, the first O-ring 7 is made of silicon rubber having high compressibility. .

  On the other hand, the mold body 3 has a portion between the first annular groove 5 and the second annular groove 6 facing the bottom plate intermediate portion 4B, and the bottom plate intermediate portion 4B and the inner peripheral surface of the mold body 3 An air supply hole 10 for supplying compressed air to the flow path 9 formed between is formed. The air supply hole 10 is connected to a compressed air supply source (not shown) such as an air compressor via a pipe (not shown) such as a hose, and the molded specimen 2 is molded. When compressed air is supplied from the air supply hole 10 when the mold is removed, the compressed air is sent into the flow path 9 from the air supply hole.

  Here, the first annular groove 5 formed in the bottom plate 4 includes upper and lower groove side surfaces 5a and 5b extending from the outer peripheral surface of the bottom plate 4 to the inner diameter side, and inner diameter side ends of the upper and lower groove side surfaces 5a and 5b. In this case, the upper groove side surface 5a is formed by an orthogonal surface orthogonal to the outer peripheral surface of the bottom plate 4, while the lower groove side surface 5b is formed as a groove. The groove inlet side portion is formed by an orthogonal surface orthogonal to the outer peripheral surface of the bottom plate 4. The portion extending to the inner diameter side continuously to the groove inlet side portion is on the upper side of the groove back side (groove bottom surface 5c side). This is formed by an inclined surface 5d that is close to the groove side surface 5a and whose groove width (the distance between the upper groove side surface 5a and the lower groove side surface 5b) becomes narrow. Furthermore, the groove width of the groove inlet side portion of the first annular groove 5 is the diameter of the first O-ring 7 fitted in the first annular groove 5 (the first O-ring 7 before being attached to the first annular groove 5). Thus, the groove width of the first annular groove 5 is substantially equal to the diameter of the first O-ring 7 at the groove inlet side portion, but closer to the groove back side. It is formed to be narrower than the diameter of the first O-ring 7. The groove depth of the first annular groove 5 (the distance from the groove inlet to the groove bottom surface 5 c) is set longer than the diameter of the first O-ring 7. The first O-ring 7 fitted in the first annular groove 5 is located at the groove inlet side portion of the first annular groove 5 in a state where compressed air is not fed into the flow path 9. Although it is in close contact with the inner peripheral surface of the mold body 3, the compressed air is pressed by the compressed air by being sent from the flow path 9 to the groove inlet side of the first annular groove 5 when the specimen 2 is demolded. Then, the first annular groove 5 moves to the rear side of the groove. In this case, since the groove side surface 5b on the lower side of the first annular groove 5 is formed by the inclined surface 5d whose groove width becomes narrower toward the groove depth side as described above, the first O-ring 7 is inclined. While being compressed by the surface 5 d, it moves to the inner side of the groove and is separated from the inner peripheral surface of the mold body 3. Then, the compressed air that has flowed upward as the first O-ring 7 is separated from the inner peripheral surface of the mold body 3 passes through the gap between the bottom plate upper portion 4A and the inner peripheral surface of the mold body 3 to the bottom plate 4. The specimen 2 is demolded by ejecting upward. On the other hand, when the supply of compressed air is stopped after the specimen 2 is removed from the mold, the pressing force for compressing the first O-ring 7 disappears and the first O-ring 7 returns to the original state. 7 is returned to its original state while being guided by the inclined surface 5d, and is brought into close contact with the inner peripheral surface of the mold body.

  On the other hand, the second annular groove 6 formed in the bottom plate 4 is formed in a U-shaped cross section equal to the groove width between the groove inlet side and the groove back side, and the groove depth of the second annular groove 6 is. Is set narrower than the diameter of the second O-ring 8 fitted in the second annular groove 6 (the diameter of the second O-ring 8 before being attached to the second annular groove 6). The second O-ring 8 is compressed in a state in which the bottom plate 4 is attached to the mold body 3 and is crimped to the inner peripheral surface of the mold body 3. The compressed air sent to the bottom plate 4 is prevented from leaking to the lower side of the bottom plate 4.

  The bottom plate 4 is attached to the mold body 3 with the first and second O-rings 7 and 8 fitted in the first and second annular grooves 5 and 6. By applying the agent, it can be easily mounted on the mold body 3.

  In the present embodiment configured as described, the specimen forming mold 1 is a cylindrical container for molding a columnar concrete or mortar specimen 2, and is a peripheral surface portion of the specimen 2 Is formed by using a cylindrical mold body 3 for molding the base plate 4 and a bottom plate 4 that is removably fitted in the mold main body 3 and molds the bottom surface portion of the specimen 2. A first annular groove 5 is formed on the outer peripheral surface, and a first O-ring 7 that is in close contact with the inner peripheral surface of the mold body 3 is attached to the first annular groove 5, while An air supply hole 10 for supplying compressed air to the first annular groove 5 is provided. Then, the first O-ring 7 is separated from the inner peripheral surface of the mold body 3 by the compressed air sent from the air supply hole 10 and the compressed air is ejected to the upper side of the bottom plate 4 to remove the molded specimen 2. In this structure, the first annular groove 5 has an inclined surface 5d that is inclined so that the groove width of the first annular groove 5 becomes narrower toward the back of the groove. While the first O-ring 7 is compressed by the inclined surface 5d when it is supplied, the first O-ring 7 moves to the deep side of the groove, while when the supply of compressed air is stopped, the first O-ring 7 is guided to the inclined surface 5d and is in its original state. It returns to and adheres to the inner peripheral surface of the mold body 3.

  Thus, the first O-ring 7 fitted in the first annular groove 5 of the bottom plate 4 is in close contact with the inner peripheral surface of the mold body 3 in a state where compressed air is not supplied, thereby forming the specimen. While it is possible to prevent water leaking from the air supply holes 10 when the concrete 1 is filled with raw concrete or mortar, the inclined surface is inclined so that the groove width becomes narrower toward the back of the groove when compressed air is supplied. While being compressed by 5d, it moves to the back side of the groove and moves away from the inner peripheral surface of the mold main body 3, thereby ejecting compressed air to the upper side of the bottom plate 4 to demold the specimen 2. In this case, the first O-ring 7 does not extend to move toward the groove back side of the annular first annular groove 5 while being compressed, and further moves to the groove back side while being compressed. The compressed air supply is stopped and the first O-ring 7 is Reliably restored to the original state by being guided by the inclined surface 5d and the compression force is not necessary to, it will be in close contact with the inner peripheral surface of the mold body 3. As a result, it is possible to achieve a cost reduction by using a general-purpose first O-ring 7 that is inexpensive and easily available, but the function of opening and closing the flow path of the compressed air, that is, when supplying the compressed air, 3, the flow path of the compressed air from the air supply hole 10 to the upper side of the bottom plate 4 is opened by separating from the inner peripheral surface of the mold 3, and in close contact with the inner peripheral surface of the mold body 3 in a state where the compressed air is not supplied. Thus, the function of closing the flow path can be reliably ensured over a long period of time.

  Further, in this structure, the first annular groove 5 in which the first O-ring 7 is mounted is located above the air supply hole 10 formed in the mold body 3 and the outer peripheral surface of the bottom plate 4 A second annular groove 6 is formed on the lower side of the pore 10, and a second O-ring 8 that is pressure-bonded to the inner peripheral surface of the mold body 3 is attached to the second annular groove 6. Thus, the second O-ring 8 can surely prevent the compressed air from leaking to the lower side of the bottom plate 4, and the demolding can be performed efficiently.

  Further, the bottom plate 4 is fitted into the mold body 3 so as to be freely inserted and removed, and the bottom surface 4 is supported on the upper surface of the inner flange portion 3 a formed on the mold body 3. Thus, the bottom surface of the bottom plate 4 is exposed to the outside from the opening portion on the inner peripheral side of the inner flange portion 3a in a state where the bottom plate 4 is mounted on the mold body 3. It is in the state to do. As a result, when the first and second O-rings 7 and 8 fitted in the first and second annular grooves 5 and 6 of the bottom plate 4 need to be replaced over time, the inner flange By hitting the bottom plate 4 upward from the opening portion on the inner peripheral side of the portion 3a, the bottom plate 4 can be easily pulled out from the mold body 3, and the first and second O-rings 7 and 8 can be replaced. There is an advantage that can be easily performed.

Of course, the present invention is not limited to the above-described embodiment, and the annular groove formed on the outer peripheral surface of the bottom plate is provided with an inclined surface that is inclined so that the groove width becomes narrower toward the back of the groove. In the above embodiment, the inclined surface 5d is provided on the lower groove side surface 5b of the first annular groove 5, but the inclined surface may be provided on the upper groove side surface 5a, and both the upper and lower groove side surfaces 5a, An inclined surface can also be provided on 5b.
In the above embodiment, the first and second O-rings 7 and 8 have the same diameter, but the present invention is not limited to this, and those having different diameters can also be used.

  INDUSTRIAL APPLICABILITY The present invention can be used for a specimen molding form for molding a cylindrical specimen used for a concrete or mortar strength test.

DESCRIPTION OF SYMBOLS 1 Specimen forming mold 2 Specimen 3 Mold body 4 Bottom plate 5 First annular groove 5d Inclined surface 6 Second annular groove 7 First O-ring 8 Second O-ring 10 Air supply hole

Claims (1)

Cylindrical container-shaped molds for molding cylindrical concrete or mortar specimens can be inserted into and removed from the cylindrical mold body that molds the peripheral surface of the specimen. In a concrete or mortar molding mold for concrete or mortar formed by using a bottom plate that is fitted in and molded from the bottom portion of the specimen, an annular groove is formed on the outer peripheral surface of the bottom plate, and a mold is formed in the annular groove. An O-ring that is in close contact with the inner peripheral surface of the frame main body is mounted, while an air supply hole for sending compressed air to the annular groove is opened in the mold main body, and the O-ring is attached to the mold main body by the compressed air sent from the air supply hole. The molded specimen is removed from the inner peripheral surface by ejecting compressed air to the upper side of the bottom plate , and the annular groove is configured such that the groove width of the annular groove becomes narrower toward the back of the groove. Supplying compressed air with an inclined surface While the O-ring is compressed by the inclined surface, the O-ring moves to the back of the groove. On the other hand, when the supply of compressed air is stopped, the O-ring returns to the original state while being guided by the inclined surface, and the inside of the mold body The annular groove in which the O-ring is mounted is positioned above the air supply hole established in the mold body, and is formed on the outer peripheral surface of the bottom plate. A second annular groove located on the lower side is formed, and the second annular groove is sealed to the inner peripheral surface of the mold body in order to prevent compressed air from leaking to the lower side of the bottom plate. A concrete or mortar mold for molding a specimen characterized by mounting an O-ring .

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