JPS6331925Y2 - - Google Patents

Description

[Detailed explanation of the idea]

[Technical Field] The present invention relates to a rubber mold for forming holes in concrete blocks and the like. [Prior Art] Holes are often formed in concrete blocks, concrete walls, etc. For example, vertically stackable T-shirts have been developed in recent years to make effective use of land.
In the molded concrete block, a hole is formed for inserting the core rod. By the way, when forming holes in this concrete block, conventionally an iron pipe is assembled into a main mold having a cavity part of the same size as the concrete block, and then concrete is poured into the cavity part of the main mold. The iron pipe is then removed from the main mold when the concrete in the cavity is semi-solidified. The reason why iron pipes are removed when they are in a semi-solidified state is that if you try to remove the iron pipe when the concrete is almost solidified, the solidified concrete will cover the iron pipe and stick to it, making it difficult to remove it. This is because the work becomes extremely difficult or virtually impossible. As described above, in the past, since the iron pipe had to be extracted while the concrete block was in a semi-solidified state, there was a problem that various defects would occur in the concrete block if the timing of extraction was incorrect. For example, if the iron pipe is removed too quickly, unsolidified concrete will flow into the hole from which the iron pipe was removed, deforming the shape of the hole and possibly clogging the hole. On the other hand, if the removal is too slow, the concrete will harden and the concrete block will have to be destroyed in order to remove the iron pipe. [Purpose of the invention] The present invention has been made against the background of the above-mentioned prior art. An object of the present invention is to provide a rubber mold for forming holes that facilitates the extraction work. [Structure of the invention] As a result of intensive research, the inventor of the present invention has developed a tape-like body having a fiber cord into a spiral shape in two directions, at an angle of 47 degrees to 53 degrees with respect to the direction parallel to the axis of the mold part. The diameter of the rubber mold for hole forming can be reduced or increased by forming a mold part in which a reinforcing layer is embedded and lowering or increasing the pressure in the internal space. It has been found that if this is done, the work of removing the rubber mold for forming the hole becomes easier. The present invention was completed based on this knowledge. That is, the rubber mold for forming a hole of the present invention includes a cylindrical rubber mold part with both ends open, a pair of sealing devices airtightly fixed to the openings of the mold part, and at least one of the sealing parts. The opening/closing member is provided on the tool and allows fluid to enter and exit the internal space formed by the mold section and the sealing tool. 47 for direction
It is formed by embedding a reinforcing layer that is spirally wound in two directions, in the forward and reverse directions at an angle of 53 degrees or more.
The mold part maintains a cylindrical shape when the fluid pressure in the internal space is at normal pressure, and by increasing the fluid pressure in the internal space, the diameter of the mold part increases and the length of the mold part contracts. It is characterized by being configured as follows. The hole-forming rubber mold of the present invention can be used not only when forming holes in concrete blocks, but also when forming holes in structures made of other types of concrete. It can also be used when The mold part is a member that expands when fluid such as air is introduced. Therefore, the mold part is made of rubber and has a cylindrical shape. Although air is preferred as the fluid, other gases may be used, and liquids such as oil and water may also be used depending on the circumstances. The mold section is usually cylindrical. The diameter and length of the mold part are set depending on the inner diameter and length of the hole to be formed. It is desirable that the mold part has a tapered shape. If formed into a tapered shape,
The work of extracting a rubber mold for forming holes from a concrete block or the like becomes easier. Therefore, the taper portion may be formed over the entire length of the mold portion, or may be formed only at one end portion of the mold portion. The sealing device seals the openings at both ends of the mold part so that the fluid inside the mold part does not leak outward. Therefore, the sealing tool is airtightly fixed to the opening of the mold section. The closure is usually cylindrical with a bottom. The closure may be provided with a handle. If a handle is provided, it will be easier to remove the rubber mold for forming holes. Further, a pressure gauge may be attached to the sealing device.
If a pressure gauge is attached, it is convenient to be able to immediately check the fluid pressure in the internal space of the mold section. The opening/closing member is for letting fluid in and out of the internal space formed by the mold part and the sealing member. Therefore, the opening/closing member has a structure capable of opening and closing the fluid inlet/outlet hole formed in the sealing device. An air coupler can be used as a typical opening/closing member. As other opening/closing members, manual valves, electromagnetic valves, etc. can be used. By the way, in the case of the present invention, the mold part described above is
The mold portion is configured to increase in diameter by increasing the fluid pressure within the internal space. Further, the mold section is configured to maintain a cylindrical shape when the fluid pressure is at normal pressure. Here, the normal pressure state is
It means under atmospheric pressure. In the above configuration, the mold part includes a reinforcing layer formed by winding a tape-like body having a fiber cord in a spiral shape in two directions, forward and reverse. Here, the fiber cord refers to each fiber, such as polyester thread. Further, the tape-shaped body forming the reinforcing layer refers to a tape-shaped body in which the fiber cords are aligned in the longitudinal direction and rubber is topped on a blind canvas bound with leno threads, and the tape-shaped body is It has strength in the longitudinal direction. The tape-like body having the fiber cord is wound spirally at an angle of 53 degrees or less with respect to a direction parallel to the axis of the cylindrical mold part. The axis is
It means the center line in the longitudinal direction of the cylindrical mold part. The reason for winding at an angle of 53 degrees or less is as follows. That is, if the cylindrical mold part includes a reinforcing layer made of a tape-shaped body spirally wound in two directions, as described above, and the above angle is 54 degrees and 44 minutes, the radial direction of the mold part It has been theoretically clarified that the strength in the longitudinal direction is equal to the strength in the longitudinal direction. If the above angle is set smaller than 54 degrees 44 minutes, the strength in the radial direction of the mold section is weaker than the strength in the length direction, so when air is introduced into the mold section, the angle becomes 54 degrees 44 minutes. Trying to go back. Therefore, the mold section expands in the radial direction and contracts in the length direction. Furthermore, if the above angle is set larger than 54 degrees and 44 minutes, the angle tends to return to 54 degrees and 44 minutes when air is introduced into the mold section. For this reason,
The mold section extends in the length direction and contracts in the radial direction. Therefore,
If you set the above angle to a value of 53 degrees or less in advance,
When air is sent out, the above angle expands from a value of 53 degrees or less back to 54 degrees and 44 minutes. Therefore, the diameter of the mold part can be increased efficiently. However, if the above-mentioned angle is set too small, the diameter of the mold part increases too much, and therefore the length of the mold part shrinks too much. Therefore, it is desirable that the angle is within the range of 53 to 47 degrees. Note that the reinforcing layer is made of heat-resistant rubber. Now, a typical method of using the hole-forming rubber mold of the present invention will be explained using the manufacturing process of concrete blocks as an example. First, the diameter of the mold section is increased by opening the opening/closing member and introducing fluid, for example, air, into the mold section. When the diameter increases to a predetermined size, the opening/closing member is closed. Thereafter, a rubber mold for forming holes with an increased diameter of the mold part is assembled into the main mold.
Note that the fluid may be introduced into the mold section after the hole-forming rubber mold is assembled into the main mold before being filled with fluid. Next, concrete is poured into the cavity of the main mold using a vibrator and allowed to harden. In this case, the main mold may be stored in a steam room kept at a temperature of 70 to 80°C to cure the concrete. When the concrete has solidified after a predetermined period of time has elapsed, the opening/closing member is opened to discharge the fluid from the mold section and reduce the pressure in the internal space of the mold section. This reduces the diameter of the mold section. Then, a gap corresponding to the diameter reduction is created between the outer surface of the mold part and the periphery of the hole in the concrete. Using this gap, the rubber mold for forming the hole is removed from the concrete block. [Effects of the invention] As described above, according to the rubber mold for forming holes of the present invention, by opening the opening/closing member and discharging the fluid in the internal space, the diameter of the mold part is reduced and the outer surface of the mold part is reduced. Since a gap can be created around the hole, it becomes easier to remove the hole-forming rubber mold from a concrete block, concrete wall, etc. In addition, by using the above-mentioned gap, the rubber mold for forming the holes can be removed even after the concrete or concrete wall has solidified, which eliminates the conventional method of removing the rubber mold when it is half-hardened. In contrast, defects such as hole deformation and clogging can be prevented. By the way, if the mold part becomes flat when the fluid filled in the mold part is discharged,
When the rubber mold for forming the hole is removed after the concrete or the like has solidified, the flat end of the mold is likely to rub against the periphery of the hole and be damaged. This is because the mold part is flat and widens laterally, so that the width of the mold part is larger than the inner diameter of the hole. In this regard, in the present invention, the mold part is formed by embedding a reinforcing layer in which a tape-like body having a fiber cord is spirally wound in two directions, so that the fluid pressure in the internal space of the mold part is reduced. Even when the pressure is normal, the mold part is not flat but maintains a cylindrical shape. Therefore, even when the fluid filled in the mold part is discharged, the mold part maintains its cylindrical shape and does not bend. Therefore, damage to the mold part can be suppressed. [Embodiment] FIGS. 1 to 4 show a rubber mold for forming a hole according to an embodiment of the present invention. FIG. 1 is a side view of a hole-forming rubber mold showing the upper half in cross section. In FIG. 1, reference numeral 1 denotes a mold part having a long cylindrical shape. A tapered part 2 is formed as a draft on one end 1a side of the mold part 1. Tapered part 2
is inclined so that the diameter becomes smaller toward the tip of one end portion 1a of the mold portion. The draft angle of the tapered portion 2 is about 8 degrees. One end 1a of this mold part 1
A first sealing member 3 in the shape of a metal cylinder with a bottom is fitted into the opening, and a sealing plate 6 is fitted into the opening at the other end 1b of the mold part 1 near the center. A second metal sealing member 4 having a cylindrical shape is fitted therein. Two tightening bands 5 are fixed around the outer periphery of one end 1a and the other end 1b of the mold part 1, thereby creating an airtight state between the mold part 1 and the sealing devices 3 and 4. is maintained. A through hole 7 is formed in the sealing plate 6 constituting the second sealing device 4 . An air coupler 8, which is an opening/closing member, is attached to the sealing plate 6 so as to face the through hole 7. Although not shown, the air coupler 8 has an internal spring and a valve that opens and closes by the elastic force of the spring. When the air supply hose is connected to the air coupler 8, the valve opens and the hose communicates with the mold section 1, allowing air to be introduced into the mold section 1. Further, when the hose is removed from the air coupler 8, the valve of the air coupler 8 is automatically closed by the elastic force of the spring, and the supply of air into the mold section 1 is stopped. By the way, the mold part 1 of this example includes a reinforcing layer 9 in which tape-like bodies 9a and 9b are spirally wound in two directions, and an inner surface rubber layer 10 inside this reinforcing layer 9.
and an outer rubber layer 11 outside the reinforcing layer 9. The tape-shaped bodies 9a and 9b forming the reinforcing layer 9 are made of polyester fiber cords stretched in the longitudinal direction and bound with leno threads, and topped with rubber. The inner rubber layer 10 is made of styrene-butadiene rubber, and the outer rubber layer 11 is made of chloroprene rubber. The thickness of each tape-like body 9a and 9b is 0.5 mm.
The thickness of the reinforcing layer 9 formed by laminating two layers is 1 mm. Further, the thickness of the inner rubber layer 10 and the outer rubber layer 11 is 1 mm. The layer thickness of mold part 1 is therefore 3 mm. Now, a description will be given of how the hole-forming rubber mold of this example having the mold part 1 having the above-mentioned configuration was manufactured. First, as shown in FIG. 3, a cylindrical mandrel 13 having a tapered portion 12 was fitted onto the main mandrel 14. Next, the outer peripheral surface of the mandrel 13 was wiped with a mold release agent, and a rubber sheet having a thickness of 1 mm and a width of 270 mm was wrapped in a sushi roll shape over the entire length of the mandrels 13 and 14 to form the inner rubber layer 10. Next, as shown in FIG.
It was attached to the recess at the front of the. This rubber pile 16 is used to fill the depression and prevent the area from thinning after vulcanization. Next, a tape-shaped body 9a having a thickness of 0.5 mm and a width of 170 mm was wound around the outer peripheral surface of the inner rubber layer 10 in a spiral shape as shown in FIG. At this time, mandrel 13
It was wound at an angle of 50 degrees with respect to the axis 15 of. Thereafter, another same tape-like body 9b was layered on the tape-like body 9a and spirally wound in the opposite direction. At this time, the tape-like body 9b is attached to the mandrel 13.
The wire was wound at an angle of 50 degrees with respect to the axis 15 of the wire. Specifically, these tape-like bodies 9a and 9b are made by topping a wide (usually 1.3 m) blind canvas made of polyester fiber cords drawn in the longitudinal direction and bound with twine using a calender roll or the like, and then topping the canvas with rubber using a calendar roll or the like. , and was formed by cutting it along the longitudinal direction to the required width (170 mm in this example). As described above, the reinforcing layer 9 was constituted by the tape-like bodies 9a and 9b wound on top of each other in the forward and reverse directions. Next, a rubber sheet having a thickness of 0.5 mm and a width of 280 mm was wrapped around the outer periphery of the reinforcing layer 9 to form an outer rubber layer 11. Thereafter, a wrapping cloth was wound around the outer periphery of the outer rubber layer 11, and vulcanization was performed in that state. Vulcanization treatment is 60% under pressure of 3.5Kg/ ^cm2
I did it for a minute. After that, the wrapping cloth was removed. Next, it was cut into a predetermined length to form a cylindrical mold part 1. Thereafter, the mandrel 13 and the mandrel 14 were extracted from the mold part 1. In this case, the cylindrical shape of the mold part 1 was maintained. Thereafter, the first sealing member 3 and the second sealing member 4 were fitted into the openings at both ends of the mold section 1 and fixed with the tightening bands 5. The total length of the rubber mold for hole forming manufactured as above is
The outer diameter of one end 1a of the mold part 1 was 83 mm, and the outer diameter of the other end 1b of the mold part 1 was 100 mm. Air was sent into the inner space of the mold part 1 of such a rubber mold for forming holes, and changes in outer diameter and length were tested. The exam is
This was carried out by connecting an air supply hose to an air coupler 8 to feed air into the internal space of the mold section 1. The table shows the relationship between the pressure in the internal space of the mold part 1 and the outer diameter of the rubber mold for forming holes, and the relationship between the pressure and the length. The outside diameter measurement location is a location 650 mm from the tip of one end 1a of the mold section 1 toward the center. As shown in the table, when no air is introduced and the pressure inside the internal space is normal pressure, the outer diameter is 87.6
mm, and the length was 1350 mm. this

[Table] At this time, the cylindrical shape of mold part 1 was maintained. When the gauge pressure in the internal space was 2 Kg/cm ² , the outer diameter expanded to 90.1 mm and the length contracted to 1312 mm. When the gauge pressure in the internal space was 4 Kg/cm ² , the outer diameter expanded to 91.7 mm and the length contracted to 1302 mm. Therefore, in a hole-forming rubber mold with a gauge pressure of 4 kg/cm ² in the internal space, if the air coupler 8 is opened to exhaust the air in the internal space of the mold part 1 after the concrete hardens, the outside of the mold part 1 can be removed. The diameter is 4.1mm (91.7mm−
87.6mm=4.1mm) decrease. A gap corresponding to this reduction is created between the mold part 1 and the hole.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and Fig. 1 is a side view of the entire rubber mold for forming holes, showing the upper half in cross section, and Fig. 2 is a state in the middle of spirally winding a tape-like material around a mandrel. FIG. 3 is an enlarged cross-sectional view of the main parts showing the manufacturing process of the rubber mold for forming holes. In the figure, 1 is a mold part, 3 and 4 are sealing devices, 9 is a reinforcing layer, 9a and 9b are tape-like bodies, 10 is an inner rubber layer, 11 is an outer rubber layer, and 12 is a tapered part.

Claims (1)

[Claims for Utility Model Registration] (1) A cylindrical rubber mold with open ends, a pair of sealing devices securely fixed to the openings of the mold, and at least one of the sealing devices. an opening/closing member provided in the mold part and an opening/closing member for letting fluid in and out of an internal space formed by the mold part and the sealing device, and the mold part is configured to hold a tape-shaped body having at least a fiber cord parallel to the axis of the mold part. The reinforcing layer is formed by embedding a reinforcing layer spirally wound in two directions, forward and reverse, at an angle of 47 degrees or more and 53 degrees or less with respect to the direction of When the mold part is in the state, it maintains a cylindrical shape, and by increasing the fluid pressure in the internal space, the diameter of the mold part increases and the length of the mold part contracts. Rubber mold for hole forming. (2) The rubber mold for forming holes according to claim 1, wherein the reinforcing layer is constructed such that the fiber cord is polyester yarn and the rubber component is heat-resistant rubber. (3) The rubber mold for forming a hole according to claim 1, wherein the mold part has a tapered shape in which the diameter of one end is smaller than the diameter of the central part. (4) The rubber mold for forming a hole according to claim 1, wherein the opening/closing member is provided only on the sealing member at the end opposite to the tapered end. (5) A rubber mold for forming holes according to claim 1 of the utility model registration, which is used for forming holes in concrete blocks.