JPH11118077A - Fitting for freshly mixed concrete feeding pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lengthen the life of a fitting for a freshly mixed concrete feeding pipe. SOLUTION: A fitting for a freshly mixed concrete feeding pipe is constituted of metallic ring 41 to be fitted to the outer peripheral surfaces of flanges 31, 31 formed by thickening the ends of pipes 3, 3 faced to each other with a space; a thick cylindrical seal rubber 42 to be fitted outside the ring; and a clamp fitting 43 for surrounding and holding the seal rubber 42 and the flanges 31, 31. Many small holes are provided on the ring 41, the seal rubber 42 is made of hard rubber, and V-shaped grooves are formed on a recessed part to be fitted with the ring 41 to the inner peripheral side, and in the central part of the recessed part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used in a ready-mixed concrete pipe for pumping a slurry-like concrete (hereinafter referred to as "mixed concrete") obtained by mixing cement, sand, aggregate and the like with water to a casting position. Related to pipe fittings.

[0002]

2. Description of the Related Art Conventionally, at the work site of civil engineering, construction, and the like for constructing a structure using concrete, in order to cast concrete, particularly at a high place or inside a cavity, a "cat wheel" has conventionally been used.
Although concrete was mainly fed manually using a hand cart, concrete tower, elevator, etc., recently, a slurry pump provided in a concrete pump truck was used, and piping with a large number of universal rotary joints was used. Is used to directly feed ready-mixed concrete.

FIG. 3 is a front view showing an example of a concrete pump truck. 1 is a concrete pump truck main body, 2 is a bendable and stretchable arm mounted thereon, and 3 is a concrete pumping machine arranged along the arm 2. Reference numeral 4 denotes a rotatable joint provided at a key point of the pipe 3 such as a bent portion, and reference numeral 5 denotes a flexible hose attached to a distal end portion of the pipe 3.

FIG. 4 is a perspective view showing an example of the vicinity of the bent portion of the arm (the position of the pipe relative to the arm does not necessarily correspond to FIG. 3). For example, when the arm 2a is bent as shown by the arrow a, the connection at the joint 4a is made. The pipes 3 on both sides are relatively rotated as shown by the arrow b. An example of a conventional joint 4 used at a key point of such a pipe 3 will be described with reference to the drawings. FIG. 5 is a partial cross-sectional view showing a part of the joint 4 in cross section, 31 is a thick portion (hereinafter, referred to as a flange) provided at an end of the pipe 3, and 42 is an inner peripheral lip portion provided on both sides of the pipe flange. Seal rubber that is lightly contacted and fitted to the outside,
Reference numeral 43 denotes a clamp fitting which further wraps and holds them from the outside, and FIG. 6 is a perspective view showing an example of the clamp fitting 43.

[0005] The seal rubber 42 has a continuous ring shape.
It has a lip that is folded inward at both ends in the longitudinal direction, and a space is formed therein. Further, the clamp metal 43 has a structure in which one end of a ring divided into a semicircle is connected by a hinge, and is formed into a ring shape by bolting an open end. When at least one of the flanges 31 of the pipes 3 on both sides slides on the inner circumference of the seal rubber 42, the pipe 3 can be rotated.

The pipe 3 has a gap of about 4 mm at the joint. When the ready-mixed concrete is fed under pressure, the ready-mixed concrete enters the space inside the seal rubber 42 from this gap. The lip portion is pressed against the flange 31 by the pressure, so that the ready-mixed concrete does not leak to the outside of the joint. Most remain without being. Since the concrete hardens soon, there is a problem that the seal rubber 42 is damaged by the solidified concrete when the arm 2 is used next time, for example, when the arm 2 bends and stretches, and the life of the joint portion is short.

As a countermeasure, it has been attempted to extend the life of the entire joint by inserting a ring-shaped rubber sheet called an inner packing into a space portion of the seal rubber and replacing the inner packing. The effect of only extending the two-month life to twice was recognized.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to solve such a problem and to realize a pipe joint for raw concrete pressure-feeding piping which can be used for a long time.

[0009]

According to the present invention, there is provided a metal ring which is fitted on the outer peripheral surface of a flange formed with a thick wall at the end of a pipe which is abutted with a gap, and further fitted on the outside thereof. Thick rubber seal, and a clamp metal which wraps and holds the seal rubber and the flange from the outside. Preferably, the metal ring is a metal plate having a ring shape and provided with a number of small holes. In addition, a concave portion for fitting the ring and a groove at the center of the concave portion are formed on the inner peripheral surface of the seal rubber, and the seal rubber is made of hard rubber.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The pipe joint for pressurized concrete piping of the present invention has a metal ring interposed between a seal rubber and a flange, so that concrete adhered and solidified on the outer peripheral surface of the flange when the pipe is rotated. The seal rubber is prevented from being damaged, and the seal rubber is made of hard rubber which is hardly damaged. Therefore, the life of the joint can be drastically extended to about 6 to 10 times that of the conventional product.

[0011]

An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a partial cross-sectional view showing a pipe joint for raw concrete pressure feeding piping of this embodiment, and the same reference numerals are used for the same parts as before. 41 is a metal ring. The pipe joint for raw concrete pressure feeding piping includes a metal ring 41 fitted on the outer peripheral surface of a flange 31 having thick ends formed on the ends of the pipes 3 and 3, which are abutted with a slight gap, and A seal rubber 42 fitted on the outside thereof, and a clamp hardware 43 wrapping and holding the seal rubber 42 and the flange 31 from outside.
It is composed of FIG. 2 is a partial perspective view showing a part of the ring 41. That is, the ring 41 is a ring-shaped metal plate such as a stainless steel plate and has a diameter of 1 m at an appropriate interval.
Many holes of about m are provided so that the pressure of the ready-mixed concrete is transmitted to the back surface of the ring 41 to push open the seal rubber, but the aggregate does not enter the back surface of the ring 41.
Also, since the ring 41 is interposed between the flange 31 and a seal rubber 42 described later, when the pipe 3 rotates, the seal rubber made of concrete adhered and solidified on the outer peripheral surface of the flange 31 is used.
42 damage can be prevented.

The seal rubber 42 is a thick cylinder made of hard rubber and has a concave portion for fitting the ring 41 on the inner peripheral surface thereof. Further, a central portion of the concave portion has a width of 2 to 3 mm. A V-shaped groove having a depth of 4 to 5 mm is formed. The pressure at the time of pressurizing the raw concrete acts on the V-shaped groove, which reduces the inner diameter of the portion in contact with the flange and improves the sealing performance. In the embodiment, the shape of the groove formed in the central portion of the concave portion is described as a V-shape, but any shape such as a U-shape or a semicircle may be used as long as the object of the present invention can be achieved. I do not care.

As the hard rubber, vulcanized natural rubber or synthetic rubber used for a tread portion of an automobile tire,
It is preferable to use a material such as plastic which has moderate elasticity and high damage resistance and high wear resistance. The clamp hardware 43 is the same as the conventional one.

[0014]

According to the present invention, there is an excellent effect that the life of the joint for the pressure-conveying pipe for the ready-mixed concrete can be greatly extended and the cost of the construction work can be reduced.

[Brief description of the drawings]

FIG. 1 is a partial sectional view of a pipe joint according to an embodiment of the present invention.

FIG. 2 is a partial perspective view showing a metal ring according to the embodiment of the present invention.

FIG. 3 is a front view showing an example of a concrete pump truck according to the present invention.

FIG. 4 is a perspective view showing an example of the vicinity of an arm bending portion of the concrete pump truck according to the present invention.

FIG. 5 is a partial sectional view of a pipe joint showing a conventional technique.

FIG. 6 is a plan view showing a clamp hardware according to the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Concrete pump car main body 2 Arm 3 Piping 4 Joint 5 Flexible hose 21 Node 31 Flange (thick part) 41 Ring 42 Seal rubber 43 Clamp hardware

Claims (4)

[Claims] The pipes (3,
A metal ring (41) fitted to the outer peripheral surface of the flange (31, 31) having a thick end at the end of (3), and a thick cylindrical seal rubber (42) fitted to the outside thereof. And a clamp fitting (43) for enclosing the seal rubber (42) and the flanges (31, 31) from outside and holding the same. 2. The pipe joint according to claim 1, wherein the metal ring has a ring shape formed of a metal plate and is provided with a large number of small holes. 3. The pipe joint for raw concrete pressure feed piping according to claim 1, wherein a concave portion for fitting said ring (41) and a groove at the center of the concave portion are formed on an inner peripheral surface of the seal rubber (42). 4. The pipe joint for fresh concrete pressure-feeding piping according to claim 1, wherein the seal rubber (42) is made of hard rubber.