JP7506552B2 - Concrete pouring pipe - Google Patents

Description

The present invention relates to a concrete pouring pipe.

A conventional technique in this field is a concrete pouring pipe described in Patent Document 1 below. This pouring pipe is equipped with a connection pipe that is connected to the supply pipe of a pump truck that supplies concrete, and a filling pipe that is connected to the connection pipe and fills a specified pouring area with concrete, and the filling pipe is connected to the connection pipe so that it can rotate freely around the pipe axis. By rotating the filling pipe in this way, it becomes easier to operate the concrete discharge port to move to the desired position.

JP 2019-183526 A

However, there is still room for improvement in the rotation mechanism of this filling pipe. For example, if the rotational resistance of the filling pipe could be reduced, the workload of pouring concrete would be reduced and the range of applications for this type of concrete pouring pipe would be expanded. The present invention aims to provide a concrete pouring pipe that reduces the rotational resistance of the filling pipe relative to the connecting pipe.

The concrete pouring pipe of the present invention comprises a connecting pipe connected to a concrete supply source, and a filling pipe connected coaxially to the connecting pipe so as to be rotatable around the pipe axis and discharging concrete from the connecting pipe into a pouring area. When one of the connecting pipe and the filling pipe is the first pipe and the other is the second pipe, the end of the first pipe on the second pipe side has a stopper surface that wraps around to the back side of the second pipe flange formed at the end of the second pipe on the first pipe side and faces the back side, and a flange holding portion is provided that restricts the displacement of the second pipe flange in the pipe axis direction away from the first pipe by the stopper surface, and a friction reducing material is sandwiched between the back side of the second pipe flange and the stopper surface.

The section of the filling pipe on the concrete discharge port side may be formed in a flat shape. Also, at least a portion of the filling pipe may be made of a flexible material.

The flange holding portion may also have a second stopper surface that faces the end face of the second pipe flange on the first pipe side and restricts the displacement of the second pipe flange in the opposite direction to the displacement restricted by the stopper surface, and an annular seal material that seals the inside of the first pipe and the second pipe from the outside of the pipes is provided between the end face of the second pipe flange and the second stopper surface.

The flange retaining portion may include a first pipe flange formed on the first pipe so as to be abutted against the second pipe flange, and a flange retaining member attached to the outer periphery of the end face of the first pipe flange and having a stopper surface.

The present invention provides a concrete pouring pipe that reduces the rotational resistance of the filling pipe relative to the connecting pipe.

1A is a front view showing a concrete pouring pipe of an embodiment, and FIG. 1B is a cross-sectional view taken along the line Ib-Ib. FIG. 2 is an exploded perspective view showing the main parts of a concrete pouring pipe. FIG. 2 is a cross-sectional view showing a concrete pouring pipe. FIG. 2 is a diagram showing the use of a concrete pouring pipe. A cross-sectional view showing a modified example of a concrete pouring pipe.

Below, an embodiment of the concrete pouring pipe according to the present invention will be described in detail with reference to the drawings. The concrete pouring pipe 1 shown in Figures 1 and 2 is a pipe that transports concrete delivered from a concrete supply pipe 3 of a concrete pump truck (not shown) to a pouring area T. This concrete pouring pipe 1 is connected to the downstream side of the concrete supply pipe 3, and is mainly used in a position where it hangs vertically from the concrete supply pipe 3 (see Figure 3). In the following description, when terms such as "above/below" and "top/bottom" are used, they correspond to the up-down direction of the concrete pouring pipe 1 in the above-mentioned usage state.

The concrete pouring pipe 1 comprises a steel connecting pipe 5 (first pipe) and a filling pipe 7 (second pipe) connected vertically. The connecting pipe 5 is coaxially connected to the lower end of the concrete supply pipe 3 (concrete supply source), and the filling pipe 7 is further coaxially connected to the lower end of the connecting pipe 5. A concrete discharge port 7b is provided at the lower end of the filling pipe 7. A joint part 9 is provided at the connection between the connecting pipe 5 and the filling pipe 7, allowing the filling pipe 7 to rotate around the pipe axis relative to the connecting pipe 5. Details of the joint part 9 will be described later.

The filling tube 7 has three components: a filling tube upper part 11, a hose attachment part 13, and a rubber hose 15. The filling tube upper part 11 is a steel tube member, and is connected to the lower end of the connection tube 5 via a joint part 9. The rubber hose 15 is a tube member made of a flexible rubber material, and the aforementioned discharge port 7b is formed at the lower end. Examples of this rubber material include natural rubber, isoprene rubber, butadiene rubber, styrene butadiene rubber, acrylonitrile butadiene rubber, chloroprene rubber, isobutylene-isoprene rubber (butyl rubber), ethylene propylene rubber, etc.

The hose attachment part 13 is a steel member for attaching the rubber hose 15. The upper end of the rubber hose 15 is fitted around the outer periphery of the lower end of the hose attachment part 13 and a cable tie 17 is wrapped around it, thereby attaching the rubber hose 15 to the hose attachment part 13. The upper end of the hose attachment part 13 and the lower end of the upper filling pipe part 11 are connected by a suitable predetermined connecting member 19. The same connecting member 19 is also used to connect the concrete supply pipe 3 and the connecting pipe 5.

The upper hose portion 15a of the rubber hose 15 has a circular cross section, but the lower hose portion 15b has a flat shape, as shown in the cross section in FIG. 1(b). When concrete is not being supplied from the concrete supply pipe 3 to the rubber hose 15, the opposing pipe walls of the lower hose portion 15b are in close contact with each other due to the elasticity of the rubber material, and the lower hose portion 15b is closed. In this case, the lower hose portion 15b does not deform under the load of the concrete remaining in the upper hose portion 15a, and the closed state of the lower hose portion 15b is maintained. Then, when concrete is being supplied from the concrete pump vehicle to the rubber hose 15, the internal pressure of the concrete pushes the lower hose portion 15b from the inside, and the concrete is discharged from the discharge port 7b. The presence of the flat lower hose portion 15b reduces the falling speed of the concrete in the concrete pouring pipe 1, and suppresses the separation of the concrete material.

Because the filling pipe 7 of the concrete pouring pipe 1 has the flexible rubber hose 15 as described above, even if the concrete supply pipe 3 is almost fixed to the boom of the concrete pump vehicle, the worker P can bend the rubber hose 15 to move the discharge port 7b to the desired position, as shown in FIG. 3. In addition, because the filling pipe 7 can rotate around the pipe axis due to the presence of the joint part 9 described above, the rotation direction of the flat discharge port 7b can be adjusted to the desired direction. In this way, the worker P can freely adjust the position and direction of the discharge port 7b, so that the hose lower part 15b can be quickly inserted into narrow places (for example, gaps between reinforcing bars and formwork or gaps between reinforcing bars) without moving the boom of the concrete pump vehicle, and concrete can be sent to the pouring area T.

The structure of the joint 9 that enables the filling pipe 7 to rotate as described above will now be explained. During concrete pouring work, it is thought that the worker P will often operate the concrete pouring pipe 1 by holding the rubber hose 15 of the concrete pouring pipe 1 in his or her hand, as shown in Figure 3. When it is desired to rotate the direction of the discharge port 7b of the filling pipe 7, the worker P will perform an operation such as twisting the rubber hose 15 around the pipe axis.

Here, if the entire filling pipe 7 were made of steel, as in the above-mentioned Patent Document 1, when the worker P twists the lower part of the filling pipe 7 around the pipe axis, the torsional force would be transmitted to the upper end of the filling pipe 7, and the filling pipe 7 would rotate smoothly around the pipe axis relative to the connecting pipe 5. However, in this concrete pouring pipe 1, because the torsional rigidity of the rubber hose 15 is low, when the worker P twists the rubber hose 15, the torsional force would not be easily transmitted to the upper end of the filling pipe 7, and the filling pipe 7 might not easily rotate.

Therefore, particularly in a concrete pouring pipe 1 in which a flexible member such as a rubber hose 15 is used for the filling pipe 7, it is preferable to reduce the rotational resistance of the filling pipe 7 at the joint 9 so that the upper part of the filling pipe 7 rotates with a small torsional force. In particular, when the discharge port 7b of the filling pipe 7 has a non-circular cross-sectional shape (flat shape in this embodiment), there are many opportunities to rotate the discharge port 7b in a direction that makes it easier to insert when inserting the tip of the rubber hose 15 into a narrow space, so there is a high need to reduce the rotational resistance of the filling pipe 7. Therefore, the joint 9 of the concrete pouring pipe 1 has the following structure.

Figure 4 is an exploded perspective view showing the joint portion 9. As shown in Figures 4 and 2, a flange 21 (hereinafter referred to as the "connection pipe flange 21") is formed at the lower end of the connection pipe 5. In contrast, a flange 23 (hereinafter referred to as the "filling pipe flange 23") having a smaller diameter than the connection pipe flange 21 is formed at the upper end of the filling pipe upper portion 11. The connection pipe flange 21 (first pipe flange) and the filling pipe flange 23 (second pipe flange) are butted together in the pipe axial direction to connect the connection pipe 5 and the filling pipe 7. In addition, an O-ring 27 (sealing material) that annularly surrounds the concrete flow path is installed on the lower surface 21b of the connection pipe flange 21, and this O-ring 27 is sandwiched between the upper surface 23a of the filling pipe flange 23, thereby sealing the inside of the concrete pouring pipe 1 from the outside of the pipe, preventing concrete leakage.

Below the connecting pipe flange 21, a filling pipe receiving ring 29 (flange hooking member) is bolted to the bottom of the connecting pipe flange 21. The ring-shaped ring has an outer diameter approximately the same as that of the connecting pipe flange 21, and is used to hook and hold the filling pipe flange 23. The reference numeral 30 in FIG. 4 denotes a bolt hole for the bolting. The lower part of the inner circumferential surface of the filling pipe receiving ring 29 is provided with a flange receiving portion 31 that protrudes to the inner circumferential side so as to wrap around the lower surface 23b of the filling pipe flange 23. The filling pipe upper portion 11 is inserted from above into the filling pipe receiving ring 29 together with a thrust washer 33 described later, and the filling pipe flange 23 is hooked on the upper surface 31a of the flange receiving portion 31, so that the filling pipe 7 is supported by the flange receiving portion 31. The upper surface 31a (stopper surface) of the flange receiving portion 31 faces the lower surface 23b of the filling pipe flange 23 and regulates the downward displacement of the filling pipe flange 23. On the other hand, the upward displacement of the filling pipe flange 23 is restricted by the lower surface 21b (second stopper surface) of the connection pipe flange 21.

In this way, the connection pipe flange 21 and the filling pipe receiving ring 29 provided at the lower end of the connection pipe 5 form a flange holding portion 47 that has a stopper surface (upper surface 31a of the flange receiving portion 31) that wraps around the back side (lower surface 23b side) of the filling pipe flange 23 and faces the lower surface 23b, and that restricts the downward displacement of the filling pipe flange 23 with the stopper surface. In other words, the flange holding portion 47 comprises the connection pipe flange 21 formed on the connection pipe 5 so as to abut against the filling pipe flange 23, and the filling pipe receiving ring 29 that is attached to the outer periphery of the lower surface 21b of the connection pipe flange 21 and has a stopper surface (upper surface 31a).

The filling pipe flange 23 is stored in the space surrounded by the inner peripheral surface of the upper part of the filling pipe receiving ring 29, the upper surface 31a of the flange receiving portion 31, and the lower surface 21b of the connection pipe flange 21 with a radial clearance that allows rotation. This clearance allows the filling pipe upper part 11 to rotate around the pipe axis relative to the connection pipe 5, and thus allows the filling pipe 7 to rotate around the pipe axis relative to the concrete supply pipe 3 and the connection pipe 5. In addition, a pair of screw holes 41 that penetrate radially from the outer peripheral surface to the inner peripheral surface are formed at symmetrical positions on the upper part of the filling pipe receiving ring 29. A thumbscrew 43 is attached to this screw hole 41, and the thumbscrew 43 is tightened so that the tip of the thumbscrew 43 abuts against the outer peripheral surface of the filling pipe flange 23, thereby prohibiting the rotation of the filling pipe 7 as described above.

Furthermore, a thrust washer 33 (friction reducing material) is sandwiched between the lower surface 23b of the filled pipe flange 23 and the upper surface 31a of the flange receiving portion 31. The thrust washer 33 has a circular thin plate shape that is almost the same shape as the lower surface 23b of the filled pipe flange 23 when viewed from the pipe axis direction. The thrust washer 33 achieves low friction against the smooth surfaces of the steel material (the lower surface 23b of the filled pipe flange 23, the upper surface 31a of the flange receiving portion 31) due to its material and surface condition. The upper end surface 33a of the thrust washer 33 adheres to the lower surface 23b of the filled pipe flange 23 and slides smoothly on the lower surface 23b. In addition, the lower end surface 33b of the thrust washer 33 adheres to the upper surface 31a of the flange receiving portion 31 and slides smoothly on the upper surface 31a. The material of the thrust washer 33 is, for example, high-strength brass casting. A commercially available thrust washer may be used as the thrust washer 33.

The effects of the concrete pouring pipe 1 as described above will be explained. In this concrete pouring pipe 1, the load due to the weight of the filling pipe 7 acts vertically from the lower surface 23b of the filling pipe flange 23 to the upper surface 31a of the flange receiving portion 31, so the friction between the lower surface 23b and the upper surface 31a can hinder the smooth rotation of the filling pipe 7. In contrast, according to the concrete pouring pipe 1, the presence of the thrust washer 33 reduces the friction between the lower surface 23b of the filling pipe flange 23 and the upper surface 31a of the flange receiving portion 31. As a result, at the joint portion 9, the rotational resistance of the filling pipe 7 relative to the connecting pipe 5 is reduced, and the filling pipe 7 can be rotated by a small twisting force. Then, when the worker works by holding the flexible and low-rigidity portion of the filling pipe 7 (the rubber hose 15 in this embodiment), the filling pipe 7 can be rotated by twisting the portion.

The present invention can be implemented in various forms, including the above-described embodiment, with various modifications and improvements based on the knowledge of those skilled in the art. In addition, the following modified examples can be constructed by utilizing the technical matters described in the above-described embodiment. The configurations of each embodiment may be used in appropriate combination.

For example, in the concrete pouring pipe 1 of the embodiment, the O-ring 27 may be omitted. Omitting the O-ring 27 is preferable in terms of reducing the rotational resistance of the filling pipe 7 caused by the friction of the O-ring 27. In addition, instead of the thrust washer 33, another type of friction reducing material that can reduce friction in the rotational direction may be sandwiched between the lower surface 23b of the filling pipe flange 23 and the upper surface 31a of the flange receiving portion 31. In addition, the material of the thrust washer 33 is not limited to high-strength brass casting, and thrust washers made of various materials such as metal, resin, and ceramic can be applied. In addition, as the material of the thrust washer 33, a material that not only has a small friction coefficient but is more easily worn than the connecting pipe 5 and the filling pipe 7 may be selected. If the thrust washer 33 is more easily worn than the connecting pipe 5 and the filling pipe 7, the wear of the connecting pipe 5 and the filling pipe 7 is suppressed, and only the worn thrust washer 33 needs to be replaced during maintenance.

For example, FIG. 5 is a cross-sectional view showing a concrete pouring pipe 51 according to a modified example. In addition to the configuration of the concrete pouring pipe 1, the concrete pouring pipe 51 also has a thrust washer 33 sandwiched between the lower surface 21b of the connection pipe flange 21 and the upper surface 23a of the filling pipe flange 23. With this configuration, the friction in the rotational direction between the lower surface 21b and the upper surface 23a is further reduced, and as a result, the rotational resistance of the filling pipe 7 relative to the connection pipe 5 at the joint portion 9 is further reduced. Note that the O-ring 27 and the thumbscrew 43 (see FIG. 2) are omitted from the concrete pouring pipe 51. The components of the concrete pouring pipe 51 that are the same or equivalent to those of the concrete pouring pipe 1 described above are given the same reference numerals in the drawings and will not be described again.

In addition, in the embodiment, the flange holding portion 47 is formed by the bolted connection pipe flange 21 and the filling pipe receiving ring 29, but the flange holding portion 47 may be formed integrally or may be formed by three or more parts.

In addition, in the embodiment, the flange holder 47 as described above is provided at the lower end of the connecting pipe 5 (first pipe), and the flange holder 47 holds the filling pipe flange 23 of the filling pipe 7 (second pipe) on the inside. However, the relationship between the connecting pipe 5 and the filling pipe 7 may be reversed. That is, the flange holder 47 may be provided at the upper end of the filling pipe 7 (first pipe), and the flange holder 47 may hold the connecting pipe flange 21 of the connecting pipe 5 (second pipe) on the inside. In this case, the cross-sectional view of the joint part will be the cross-sectional view of the joint part 9 in FIG. 2 or FIG. 5 flipped upside down.

1, 51...concrete pouring pipe, 3...concrete supply pipe (supply source), 5...connecting pipe, 7...filling pipe, 7b...discharge port, 15...rubber hose, 15b...lower part of hose (section on discharge port side), 21...connecting pipe flange (first pipe flange), 21b...lower surface (second stopper surface), 23...filling pipe flange (second pipe flange), 23a...upper surface, 23b...lower surface (reverse surface), 27...O-ring (sealing material), 29...filling pipe receiving ring (flange retaining member), 31a...upper surface (stopper surface), 33...thrust washer (friction reducing material), 47...flange retaining portion, T...pouring area.

Claims (3)

a connecting pipe connected to a source of concrete;
a filling pipe that is coaxially connected to the connecting pipe so as to be rotatable about a pipe axis and that discharges concrete from the connecting pipe to a pouring area;
When one of the connecting pipe and the filling pipe is a first pipe and the other is a second pipe,
a flange holding portion is provided at an end portion of the first pipe on the second pipe side, the flange holding portion having a stopper surface that wraps around to a back surface side of a second pipe flange formed at the end portion of the second pipe on the first pipe side and faces the back surface, the stopper surface restricting displacement of the second pipe flange in the pipe axis direction in a direction away from the first pipe,
a friction reducing material is sandwiched between the back surface of the second pipe flange and the stopper surface,
the first pipe is provided with an operating portion capable of prohibiting rotation of the second pipe relative to the first pipe about the pipe axis by tightening a screw that radially penetrates the flange holding portion from the outer peripheral surface to the inner peripheral surface so that a tip of the screw abuts against the outer peripheral surface of the second pipe flange ,
The section of the filling pipe on the concrete discharge port side is formed in a flat shape,
At least a portion of the filling tube is made of a flexible material;
The flange holding portion is
a second stopper surface provided opposite to an end surface of the second pipe flange on the first pipe side and configured to restrict displacement of the second pipe flange in a direction opposite to the displacement restricted by the stopper surface;
A concrete pouring pipe , wherein an annular sealing material is installed between the end face of the second pipe flange and the second stopper surface to seal the inside of the first pipe and the second pipe from the outside . a connecting pipe connected to a source of concrete;
a filling pipe that is coaxially connected to the connecting pipe so as to be rotatable about a pipe axis and that discharges concrete from the connecting pipe to a pouring area;
When one of the connecting pipe and the filling pipe is a first pipe and the other is a second pipe,
a flange holding portion is provided at an end portion of the first pipe on the second pipe side, the flange holding portion having a stopper surface that wraps around to a back surface side of a second pipe flange formed at the end portion of the second pipe on the first pipe side and faces the back surface, the stopper surface restricting displacement of the second pipe flange in the pipe axis direction in a direction away from the first pipe,
a friction reducing material is sandwiched between the back surface of the second pipe flange and the stopper surface,
the first pipe is provided with an operating portion capable of prohibiting rotation of the second pipe relative to the first pipe about the pipe axis by tightening a screw that radially penetrates the flange holding portion from the outer peripheral surface to the inner peripheral surface so that a tip of the screw abuts against the outer peripheral surface of the second pipe flange,
A section of the filling pipe on the concrete discharge port side is formed in a flat shape,
The flange holding portion is
a second stopper surface provided opposite to an end surface of the second pipe flange on the first pipe side and configured to restrict displacement of the second pipe flange in a direction opposite to the displacement restricted by the stopper surface;
A concrete pouring pipe, wherein an annular sealing material is installed between the end face of the second pipe flange and the second stopper surface to seal the inside of the first pipe and the second pipe from the outside. The flange holding portion is
3. The concrete pouring pipe according to claim 1, further comprising: a first pipe flange formed on the first pipe so as to be abutted against the second pipe flange; and a flange hooking member attached to the outer circumferential side of an end face of the first pipe flange, the flange hooking member having the stopper surface.

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