JPH11132367A - Tip end hose for placing ready-mixed concrete and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure good flexuosity while lighten a weight of a hose tip end part by changing a wall thickness along an axial direction so as to enlarge an outer diameter of the inlet part side of ready-mixed concrete, and to form the outer diameter shorter toward an outlet part side continuously and intermittently. SOLUTION: A cylindrical liner surface rubber 1 is formed on a taper shape outer peripheral surface, whose inner diameter d1 is constantly formed along the total length of an axial direction, an outer diameter d2-1 of a joining side of a hose adapter is formed in a largest size in the outer peripheral surface, and the outer diameter d2-2 of an outlet part side is formed in a smallest size. The wall thickness of the inner surface rubber 1 is continuously changed along the axial direction so that the wall thickness 11 of the inlet part side is formed in a largest size and the thickness 12 of the outlet side is formed in a smallest size. Since the wall thickness is changed in order along the axial direction according to abrasion degree of each region A to E, the weight of a tip end part is reduced without reducing abrasion resistance, and a good flexuosity is ensured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tip hose for placing ready-mixed concrete and a method of manufacturing the same, and more particularly, to a ready-mixed concrete transported by a concrete mixer truck to a construction site through a concrete pump truck or the like. The present invention relates to a ready-concrete tipping hose that is used by being connected to the tip of a transport pipe when placing the hose at a predetermined location.

[0002]

2. Description of the Related Art In order to ensure the pressure resistance to withstand deformation due to bending, the rigidity to withstand the burden weight of ready-mixed concrete pumped inside, and the abrasion resistance, Generally, as shown in FIG. 7, a reinforcing layer 23 composed of a reinforcing fiber cord 21 and a spiral reinforcing wire 22 is laminated on the outer periphery of a cylindrical inner rubber 20, and the outer periphery of the reinforcing layer 23 is covered with a cylindrical outer rubber 24. A coated configuration is employed.

[0003] Conventionally, there has been proposed a structure having a general reinforcing structure, which is improved in consideration of special circumstances as a tip hose for placing ready-mixed concrete. One of them is that, as disclosed in Japanese Utility Model Publication No. 2-37346, a large pulsation is generated when fresh concrete is pumped into a hose used in a curved state, and this causes a discharge tip of the hose. Paying attention to the fact that the portion swings and hinders the placing operation, the helical pitch of the reinforcing wire rod 22 constituting the reinforcing layer 23 is changed, and the pulsating pressure absorption is performed by changing the ply of the reinforcing fiber cord 21. This is a pulsating pressure absorbing tip hose with characteristics. The other is that, as disclosed in Japanese Patent Publication No. 5-55656, for example, the hose expands greatly when pressurized, and twists along the axial direction when decompressed and returns to its original shape. In order to prevent the occurrence of the twist, the axial tension applied by the helical reinforcing wire 22 in one direction and the axial tension applied by the reinforcing fiber cord 21 in the other direction are balanced with each other, and the twisting factor This is a high elongation, non-twistable tip hose that eliminates the imbalance of the partial tension.

[0004]

As described above, in both the pulsating pressure absorbing tip hose and the high elongation and non-twistable tip hose which have been conventionally proposed, the cylindrical inner rubber 20 has an entire length in the axial direction. Since the wall thickness is constant or almost constant over the entire length, the degree of wear and damage on the inlet side where the internal pressure is the highest when the ready-mixed concrete is pumped increases. This was a factor in determining the service life to be short.

[0005] Further, if the thickness of the inner surface rubber is uniformly increased over the entire length in the axial direction in order to prolong the service life due to abrasion and damage on the inlet portion side, the weight of the entire hose increases, and the driving force is increased. There is a problem in that, when moving the ready-mixed concrete placement part by manual work such as the worker carrying the tip of the hose on the shoulder according to the situation of the place, the burden on the worker involved is extremely large. . Furthermore, it cannot be eliminated that uneven wear or damage on the inlet side is a factor that determines the service life of the hose.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and it is possible to reduce the weight of a hose end portion serving as a working portion at the time of a moving operation of a casting location without deteriorating wear resistance and pressure resistance and the like. It is a main object of the present invention to provide a ready-concrete tipping hose capable of securing flexibility and extending service life.

Another object of the present invention is to provide a hose which is excellent in abrasion resistance, pressure resistance, light weight and flexibility and has a long service life as described above, without using a special device, easily and inexpensively. The aim is to be able to manufacture at low cost.

[0008]

According to a first aspect of the present invention, there is provided a tipping hose for placing ready-mixed concrete, wherein the tipping hose is formed by a cylindrical hose. The inner diameter of the inner rubber is kept constant over the entire length, and the outer diameter is increased along the axial direction so that the inlet side of the ready-mixed concrete is larger on the inlet side and continuously or intermittently smaller toward the outlet side. It is characterized in that the thickness is varied.

According to the first aspect of the present invention, the thickness of the cylindrical inner surface rubber having a constant inner diameter over the entire length in the axial direction is determined by changing the thickness of one end in the axial direction depending on the degree of wear or damage. It is large and the exit side is changed to be small, so that the weight of the whole hose and the tip that will be the working part when placing ready-mixed concrete is reduced without deteriorating wear resistance, and excellent flexibility And the degree of wear and damage of the inner rubber is equalized or almost equalized over the entire length in the axial direction while ensuring a small bending reaction force, thereby extending the service life of the entire hose.

In the tip hose for placing ready-mixed concrete having the above-mentioned construction, a reinforcing layer comprising reinforcing fibers and / or a reinforcing wire and a cylindrical outer rubber are provided on the outer periphery of the cylindrical inner rubber as set forth in claim 2. With the laminated configuration, the pressure resistance and rigidity of the distal end hose can be sufficiently increased, and the service life can be further extended.

According to a third aspect of the present invention, there is provided a method for manufacturing a front end hose for placing ready-mixed concrete, wherein a cylindrical inner surface rubber is extruded from a tipping mandrel and an outer periphery thereof. A method for continuously manufacturing by extruding from between the extrusion die located in the above, continuously or intermittently toward the tapered small diameter portion of the extrusion mandrel with the start of the extrusion die. The inner diameter is constant by moving, and the outer diameter is changed along the axial direction so as to decrease continuously or intermittently from the entrance side to the exit side of the ready-mixed concrete. Is what you do.

According to the third aspect of the present invention, a conventionally-known general-purpose hose manufacturing apparatus is used as it is for manufacturing rubber hoses of various diameters, and the extrusion dies are continuously connected with the start of extrusion. The tip for casting fresh concrete, which has excellent wear resistance, light weight and flexibility, and has a long service life due to the change in thickness along the axial direction by a simple method of moving it intermittently or intermittently. The hose can be easily and continuously manufactured, and the manufacturing cost can be reduced.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a half-section longitudinal sectional view in which a part of a tip end hose A for placing ready-mixed concrete according to the present invention is partially cut away. In the same figure, reference numeral 1 denotes a cylindrical inner rubber. In addition, a reinforcing layer 2 is laminated, and the outer periphery of the reinforcing layer 2 is covered with a cylindrical outer rubber 3. A fixing reinforcing cord layer 4 and a fixing ring are provided at one end of the distal end hose A in the axial direction. As shown in FIG. 2, for example, as shown in FIG. 2, a mouthpiece 7 that can be connected to a tip of a docking hose 15 connected to a ready-mixed concrete transport pipe 6 attached to a boom tip or the like of a concrete mixer truck is subjected to heat treatment bonding. Have been.

The reinforcing layer 2 is formed between an inner reinforcing fiber cord 8 such as a synthetic fiber and an outer reinforcing fiber cord 9 such as a synthetic fiber, and has a spiral shape such as a hard steel wire embedded in a cylindrical intermediate rubber 10. The reinforcing wire 11 is interposed therebetween.

In the end hose A for placing ready-mixed concrete having the above-described configuration, the inner cylindrical rubber 1 has an inner diameter d1 formed to be constant over the entire length in the axial direction, as shown in FIG. The outer peripheral surface is formed in a tapered outer peripheral surface such that the outer diameter d2-1 on the joining side of the fitting 7 is the largest and the outer diameter d2-2 on the outlet side is the smallest, Thereby, the thickness of the inner rubber 1 is continuously changed along the axial direction so that the thickness t1 on the inlet side is the largest and the thickness t2 on the outlet side is the smallest.

FIGS. 4 and 5 show a tapered shape in which the inner diameter d1 is constant over the entire length and the outer diameter becomes gradually smaller as the outer diameter d2-2 on the outlet side as shown in FIG. It is a figure explaining the manufacturing method of the cylindrical inner surface rubber 1 which has an outer peripheral surface. It extrudes from the cylindrical clearance between the extrusion core 12 and the extrusion die 13 located in the outer periphery, and the extrusion molding is started. At this time, as shown in FIG. 4, the die 13 is separated from the tapered small diameter portion 12 a of the mandrel 12 via the hydraulic cylinder 14, and the inner rubber is removed from the small clearance between the extrusion mandrel 12 and the extrusion die 13. 1 is extruded to form a tip portion having a small thickness t2 (exit portion of ready-mixed concrete). Then, as shown in FIG. 5, the die 13 is continuously moved at a constant speed toward the tapered small-diameter portion 12a of the mandrel 12, as shown in FIG. As a result, the wall thickness gradually changes greatly along the axial direction, and the cylindrical inner rubber 1 as shown in FIG. 3 is continuously manufactured.

As shown in FIG. 2, for example, as shown in FIG. 2, the end hose A for fresh concrete pouring comprising the inner rubber 1 having the above-mentioned thickness change, the reinforcing layer 2 on the outer periphery thereof, and the outer rubber 3 covering the outer rubber. Is connected to the tip of a docking hose 15 connected to the ready-mixed concrete transport pipe 6 attached to the boom tip or the like via a mouthpiece 7, and the ready-mixed concrete pumped through the transport pipe 6 from a concrete pump truck or the like. It is used to discharge and place at a predetermined location.

When the ready-mixed concrete is pumped, the inner rubber 1 is most worn and damaged on the inlet side where the internal pressure is highest, and the wear damage is smaller toward the outlet side. For example, as shown in FIG. 3, when the entire length of the inner rubber 1 is divided into a plurality of regions A to E of the same length, and the degree of wear of the entrance region A is 1, a partial wear resistance is obtained. If no measures were taken to increase the wearability, the wear degree in the area B was 0.8 to 1.0, the wear degree in the area C was 0.7 to 0.9,
The degree of wear in the area D is about 0.6 to 0.8, and the degree of wear in the area E is about 0.5 to 0.7. By the way, in the end hose A having the above configuration, the thickness of the inner rubber 1 is sequentially changed along the axial direction in accordance with the degree of wear of each of the regions A to E, so that the wear resistance is not reduced. , While reducing the weight of the entire hose A and the tip portion serving as a working portion when placing ready-mixed concrete, while ensuring excellent flexibility, further partial reinforcement is not required, and the structure itself is simplified, The degree of wear and damage of the inner surface rubber 1 can be equalized or substantially equalized over the entire length in the axial direction, thereby extending the service life of the hose as a whole.

By the way, the present inventor has assumed that the inner diameter d1 = 100 m
m, the total length L = 10 m, the reinforcing layer makes the same end hose, and in the thickness ratio of the plurality of regions A to E of the inner rubber 1, A = 4.0, B = 3.5, C = 3 .0, d = 2.
5, the product of the present invention set to E = 2.0, and A to E =
Table 1 below shows the results of an experiment conducted by pumping ready-mixed concrete for each of Comparative Example 1 set to 4.0 and Comparative Example 2 set to A to E = 2.0. Such evaluation was obtained.

[0020]

[Table 1]

As is clear from Table 1 above, the product of the present invention not only reduces the weight of the hose tip, which is the work site, but also reduces the bending reaction force, and imposes a burden on the operator during the moving and placing operation. Can be reduced, and substantially uniform wear is observed over the entire length of the inner surface rubber 1, so that the service life can be extended.

In the above-described embodiment, the thickness of the cylindrical inner rubber 1 is continuously changed along the axial direction. However, as shown in FIG. 6, the thickness is changed along the axial direction. The same effect as described above can be obtained even if the thickness is changed intermittently so as to be thinner toward the outlet side, specifically, 3 to 5 steps including 4 steps as shown in the figure. It is.

[0023]

As described above, according to the first aspect of the present invention, the inner diameter of the cylindrical inner surface rubber is constant over the entire length in the axial direction, and one end in the axial direction according to the degree of wear and damage. The thickness of the hose is varied along the axial direction so that the wall thickness at the inlet side is the largest and the wall thickness at the outlet side is the smallest. In addition, while reducing the weight of the tip, which is the working part when placing fresh concrete, and ensuring excellent flexibility and reducing the bending reaction force, the degree of wear and damage of the inner rubber has been reduced over the entire length in the axial direction. Thus, the hose can be evenly or almost evenly distributed over the entire hose, and the service life of the hose as a whole can be extended.

In particular, by adopting the reinforcing structure as described in claim 2, the pressure resistance and rigidity of the distal end hose can be sufficiently increased, and the service life can be further extended.

According to the third aspect of the present invention, the extrusion dies are continuously or intermittently used for producing rubber hoses of various diameters by using a conventional general-purpose hose production apparatus as it is. A simple method of simply moving the hose makes it easy to produce the end hose for placing fresh concrete, which has excellent wear resistance, light weight and flexibility, and has a long service life due to the thickness change along the axial direction. The production cost can be reduced continuously.

[Brief description of the drawings]

FIG. 1 is a partially cut-away half-cut longitudinal sectional view showing a ready-mixed concrete tip hose according to the present invention.

FIG. 2 is a schematic side view showing a usage mode of the tip hose.

FIG. 3 is a vertical cross-sectional view of a cylindrical inner surface rubber in the same end hose.

FIG. 4 is an explanatory view showing a manufacturing state of a thin-walled tip portion in a method of manufacturing a cylindrical inner surface rubber in the same end hose.

FIG. 5 is an explanatory view showing a manufacturing state of a thick base end in the method of manufacturing the cylindrical inner surface rubber in the distal end hose.

FIG. 6 is a longitudinal sectional view showing another embodiment of the cylindrical inner surface rubber of the tip hose for placing ready-mixed concrete according to the present invention.

FIG. 7 is a longitudinal sectional view of a main part of a tip end hose for placing ready-mixed concrete having a reinforcing structure generally used conventionally.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cylindrical inner rubber 2 Reinforcement layer 3 Outer rubber 8, 9 Reinforcement fiber cord 11 Spiral reinforcing wire 12 Extrusion mandrel 12a Tapered small diameter portion 13 Extrusion die A Tip hose for placing ready-mixed concrete

Claims (3)

[Claims] In a tip hose for feeding and pouring ready-mixed concrete, the inner diameter of a cylindrical inner surface rubber is made constant over its entire length, and the outer diameter is larger on the inlet side of the ready-mixed concrete and the outlet portion. A hose for pouring ready-mixed concrete, characterized in that the thickness of the hose is varied along the axial direction so as to decrease continuously or intermittently toward the side. 2. The hose according to claim 1, wherein a reinforcing layer made of reinforcing fibers and / or a reinforcing wire and a cylindrical outer rubber are laminated on the outer periphery of the cylindrical inner rubber. 3. A method of continuously manufacturing by extruding a cylindrical inner surface rubber from a tipping mandrel and an extruding die located on an outer periphery of a tip end hose for pressure-feeding and pouring ready-mixed concrete. There is a constant inner diameter by moving the extrusion die continuously or intermittently toward the tapered small diameter portion of the extrusion mandrel with the start of extrusion, and the outer diameter is from the entrance side of the ready-mixed concrete. A method for manufacturing a tip end for placing fresh concrete, characterized in that the wall thickness is changed along the axial direction so as to decrease continuously or intermittently toward an outlet side.