JPS6139523Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a centrifugal forming formwork device for forming hollow concrete products.

Hollow concrete products, such as concrete piles and concrete pipes, can be formed using so-called centrifugal forming formwork, the end faces of the formwork containing the end faces of the hollow concrete product to be formed. An end plate is arranged that defines the.

By the way, in the manufacture of this type of concrete product, it is a challenge to improve the work efficiency in order to increase the rotation rate of the formwork and to reduce the manufacturing cost as much as possible.

Conventionally, a part of the bracket fixed to the end of the formwork was made to protrude from the end face of the formwork, and an end plate was housed between the protruding part and the end face of the formwork, and the fixation provided on the bracket was There is a formwork device (see Utility Model Application Publication No. 57-24012) that fixes by means of means.

The fixing means includes a spring member and a pawl member, which are held on the bracket via a fastening member that is supported by the bracket and extends in the axial direction of the formwork, and the pawl member is held by the spring force of the spring member. By rotating the fastening member around the axis against the force of the fastening member and engaging the end plate and the bracket, the end plate is fixed in contact with the end surface of the formwork, and the engagement is prevented. By unraveling, the fixation of the end plate is released.

According to this fixing means, it is possible to easily and quickly perform each operation of attaching the end plate to the end surface of the formwork and releasing the fixation of the end plate fixed to the formwork.

However, when the claw member is engaged with the end plate and is oriented in the radial direction of the formwork, the center of gravity of the claw member is located inwardly in the radial direction of the formwork with respect to the axis of the fastening member. has. For this reason, improper tightening of the fastening means during assembly of the formwork, loosening of the fastening means over time, etc. may occur, and the spring force of the spring means may increase due to the rotation of the formwork. If it is insufficient to prevent the rotation of the claw member, there is a risk that the claw member will rotate and be disengaged from the end plate. When such a phenomenon occurs during centrifugal force forming, a bonding failure occurs between the formwork and the end plate, and cement leaks between them, causing a decrease in the quality and strength of the hollow concrete product. Paste leakage may occur.

Measures applied to formwork equipment to improve work efficiency in the production of hollow concrete products include:
It must not itself impair the intended quality, strength, etc. of the resulting product. The conventional formwork apparatus is not sufficient in this respect.

In addition, when arranged and fixed as described above, it is very difficult to pull the end plate off from the hollow concrete product during demolding because the end plate is attached to the end face of the hollow concrete product. This is difficult, and this is one of the reasons that hinders the improvement of work efficiency in the production of concrete products.

An object of the present invention is to provide a formwork device for centrifugal force forming that can improve the efficiency of manufacturing hollow concrete products without impairing the expected quality or strength of the hollow concrete products.

The present invention includes a cylindrical formwork and a bracket disposed at an end of the formwork, which has an opening that substantially receives an end plate that abuts an end face of the formwork into the end face of the bracket. and,
It consists of a spring member and a pawl member that are held on the bracket via a fastening member that is supported by the bracket and extends in the axial direction of the formwork, the pawl member being engageable with the end plate and the bracket, and the spring member being able to engage with the end plate and the bracket. A formwork device for centrifugal force forming, comprising a plurality of end plate fixing means rotatable around the axis of the fastening member against the spring force of the member, wherein the claw member of the end plate fixing means is rotatable around the axis of the fastening member. , when the claw member is engaged with the end plate and oriented in the radial direction of the formwork, the center of gravity is on the outer side in the radial direction of the formwork with respect to the axis of the fastening member;
The bracket has a notch provided on an inner circumferential surface defining the opening and opening at an end face of the bracket, and a hollow portion connected to the notch.

According to the present invention, when the formwork is rotated for centrifugal force forming, a rotational force that rotates the claw member around the axis of the fastening member acts on the claw member. Since the center of gravity is located on the outer side in the radial direction of the formwork, a centrifugal force that substantially cancels out the rotational force acts on the claw member. That is, a centrifugal force acts on the pawl member that forces the pawl member to engage the end plate and face in the radial direction of the formwork.

Therefore, due to improper tightening of the fastening member during assembly of the formwork, loosening of the fastening member over time, etc., the spring force of the spring member against the pawl member may decrease as the formwork rotates. Even if it is insufficient to prevent the rotation of the claw member,
The claw member is maintained engaged with the end plate without substantially rotating due to the centrifugal force acting on the claw member. Thereby, it is possible to completely prevent leakage of cement paste from between the formwork and the end plates during centrifugal force forming, which is a cause of deterioration in quality, strength, etc. of hollow concrete products. As a result, it is possible to increase the work efficiency in the production of hollow concrete products without impairing the intended quality or strength of the obtained hollow concrete products. The work of fixing and the work of releasing the fixation between the end plate and the formwork can be easily and quickly performed.

Further, according to the present invention, when demolding, a highly rigid rod is inserted into the notch provided in the bracket from the outside of the formwork, and the tip thereof reaches the hollow part connected to the notch. By placing the tip of the rod against the outer peripheral surface of the end plate and applying rotational force to the rod using the open edge of the notch as a fulcrum, the adhesion between the end plate and the hollow concrete product is broken and the end plate is attached to the formwork. It can be easily and quickly removed from the end face of the hollow concrete product, further improving work efficiency in manufacturing hollow concrete products.

The features of the present invention will become clearer from the following example of a formwork apparatus for centrifugal force forming of a concrete pipe having a socket portion at one end and a spigot portion at the other end.

As shown in FIG. 1, the centrifugal force forming mold apparatus according to the present invention includes a mold having a body portion 10a made of a cylindrical body, and a socket portion 10b and a spigot portion 10c that abut on both ends of the body portion 10a. 10.

Socket part 10b and spigot part 10c
define the outer peripheral surfaces of one end and the other end of the concrete pipe 12, which is one of the hollow concrete products to be formed.

Socket part 10b and spigot part 10c
can be replaced by parts of the brackets 14, 16 formed to perform these functions, as in the illustrated example. Brackets 14, 16
are removably fixed to blocks 18 and 20, respectively, which are fixed by welding on the outer periphery of the body portion 10a. Further, the brackets 14 and 16 each have a tire portion 1 for rotating the formwork 10.
4a and 16a.

The bracket 14 has a cone 22, which is an end plate, disposed approximately midway between the tire portion 14a located near the outer periphery of the bracket and the socket portion 10b located on the inner periphery, and in contact with the end surface of the socket portion 10b. It includes protrusions 14b and 14c that form an opening 24 for receiving. Like the bracket 14, the bracket 16 also has protrusions 16b, 1
6c, the protrusion forming an opening 28 for receiving the end plate spigot ring 26. Socket portion 10b and protruding portions 14b, 1
4c defines a hollow part 25 connected to a notch 39 described later, and also defines a spigot part 10c and a protruding part 1.
6b and 16c are hollow parts 2 connected to the notches 38 described later
9.

Hereinafter, for convenience of explanation, the spigot portion 10c side will be representatively explained. Therefore, unless otherwise specified, what is said about the spigot portion 10c also applies to the socket portion 10b.

The diameter of the opening 28 is almost the same as the outer diameter of the spigot ring 26, and when the spigot ring 26 is accommodated in the opening 28 in contact with the end surface of the formwork 10, that is, the end surface of the spigot portion 10c, the end surface 26a of the spigot ring 26 protrudes. Part 16b,
It is placed in a state aligned with each end face of 16c. Further, the end surface 26a of the spigot ring 26 may protrude outward in the axial direction of the formwork 10 slightly more than the end surfaces of the protrusions 16b and 16c. It can be said that it is in a state of being substantially accepted within the country.

The protrusion 16b is formed to be thicker than the protrusion 16c;
This is to provide an internal thread extending inward from the end surface of the holder. An end plate fixing means 30 for fixing the spigot ring 26 to the formwork 10 is held on the bracket 16 via a bolt 31 which is a fastening member that can be screwed into this female thread. Similarly, on the side of the socket portion 10b, via a bolt 33 which is a fastening member supported by the bracket 14,
An end plate fixing means 32 for fixing the socket cone 22 to the formwork 10 is arranged and held on the protrusion 14b of the bracket 14. Both bolts 31 and 33 extend in the axial direction of the formwork 10.

The fixing means 30 includes a claw member 34 having an L-shaped cross section that can come into contact with the end surface of the protrusion 16b and the end surface 26a of the spigot ring 26, and a spring member 36 such as a coil spring or a spring washer. 31 is fitted. The claw member 34 is pressed against the protrusion 16b by the spring force of the spring member 36 due to the appropriate tightening of the bolt 31. Since the claw member 34 can be slightly displaced in the axial direction of the bolt 31 against the spring force, the claw member 34 is rotated around the axis and engaged with the end face of the spigot ring 26. , or by disengaging the spigot ring 26 from the formwork 10 in a short time and easily.
It can be fixed or unfixed. Usually, a plurality of fixing means 30 are arranged at intervals in the circumferential direction of the bracket 16 (FIG. 2).

Referring to FIG. 1, the pawl member 34 is attached to the bolt 3.
A contact part 34a having one insertion hole (not shown) and capable of contacting the protruding part 16b of the bracket 16 and the end surface 26a of the spigot ring is connected to the contact part 34a by being bent at approximately right angles to the corresponding contact part. and a bent portion 34b extending outward in the direction away from the protruding portion 16b of the bracket 16, that is, in the axial direction of the formwork 10. The claw member 34 is attached to the bolt 3
The length dimension from the central axis of the insertion hole through which 1 passes through to the tip of the bent portion 34b along the claw member 34 is from the central axis of the insertion hole to the abutting portion 34a.
It is larger than the length dimension to the tip of. That is,
The contact portion 34a of the claw member contacts both the bracket 16 and the spigot ring 26, and the claw member 3
4 is oriented in the radial direction of the formwork 10 (second
(see figure), the claw member 34 has a center of gravity on the outer side in the radial direction of the formwork 10 with respect to the axis of the bolt 31 that coincides with the central axis of the insertion hole.

From this, during the rotation of the formwork, the centrifugal force acting on the claw member 34 is caused by the centrifugal force acting on the claw member 34
and forces it to point in the radial direction of the formwork 10. Therefore, even if the spring force of the spring member 36 is insufficient due to an inappropriate tightening amount of the bolt 31 when assembling the formwork 10 or loosening of the bolt 31 over time, the claw member 34 will be able to tighten the spigot ring. Due to the action of said centrifugal force which engages 26 and forces it to point in the radial direction of the formwork 10, the pawl members 16 undergo almost no rotation. As a result, unless the pawl member 34 is intentionally rotated during demolding to release the fixation between the spigot ring 26 and the formwork 10, there will be poor bonding between the formwork 10 and the spigot ring 26 during centrifugal force forming. The formwork 10 and the spigot ring 2 during centrifugal force forming will cause a decrease in the quality, strength, etc. of the concrete pipe 12.
6. Leakage of cement paste from between the two is reliably prevented.

The protrusion 16c having a small wall thickness has an opening 2 therein.
A notch 38 is provided on the inner circumferential surface defining the bracket 8, and the notch 38 is open at the end face of the protruding portion 16c forming a part of the end face of the bracket 16. The cutout on the side of the socket cone 22 is designated by the reference numeral 39.

As shown in FIG. 2, the notches 38 can be arranged between the fixing means 30 in the circumferential direction of the bracket 16. In the illustrated example, a plurality of notches 38 are provided, but it can be reduced to one by increasing the arc length of the notch 38.

After releasing the fixation of the spigot ring 26 by the fixing means 30, a highly rigid metal rod (not shown) such as a crowbar is inserted into the notch 38, and the tip thereof reaches the hollow part 29 and the periphery of the spigot ring 26. When the metal rod is brought into contact with the metal rod and a rotational force is applied to the metal rod using the end edge 40 of the protruding portion 16c at the back of the notch 38 as a fulcrum, the adhesion between the spigot ring 26 and the molded concrete pipe 12 is broken and the spigot ring 26 is It can be easily and quickly removed from the formwork 10. Note that the spigot ring 26
When removing the spigot ring 26, the spigot ring 26 and the concrete pipe 12 are removed by applying vibration or impact force to the spigot ring 26 or the metal rod.
and can be peeled off even more easily.

When a plurality of notches 38 are arranged, a force for peeling off the spigot ring 26 can be applied from various angular positions on the end face of the formwork 10,
In addition, in the case of one notch 38 with a large arc length, the spigot ring 6 is within the range of the arc length.
This can be pried open by applying a peeling force to it.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a centrifugal force forming mold device according to the present invention, and FIG. 2 is a right side view of the mold device. 10: Formwork, 12: Concrete pipe (hollow concrete product), 14, 16: Bracket, 2
2: Socket cone (end plate), 24,
28: opening, 25, 29: hollow part, 26: spigot ring (end plate), 30, 32: fixing means, 31, 33: fastening member, 34: claw member,
36: Spring member, 38, 39: Notch.

Claims (1)

[Scope of utility model registration request] A cylindrical formwork, a bracket disposed at an end of the formwork and having an opening that substantially receives an end plate that abuts an end face of the formwork into the end face of the bracket, and the bracket It consists of a spring member and a pawl member that are held on the bracket via a fastening member that is supported by the mold and extends in the axial direction of the formwork, and the pawl member is engageable with the end plate and the bracket and the spring member is engaged with the end plate and the bracket. A formwork device for centrifugal force forming, comprising a plurality of end plate fixing means rotatable around the axis of the fastening member against spring force, wherein the claw members of the end plate fixing means are When the claw member is engaged with the end plate and is oriented in the radial direction of the formwork, the claw member has a center of gravity on the outer side in the radial direction of the formwork with respect to the axis of the fastening member, and the bracket A formwork device for centrifugal force forming of a hollow concrete product, comprising a notch provided in an inner circumferential surface defining the opening and opening at an end face of the bracket, and a hollow portion connected to the notch.