JPH0133904Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a high-pressure reel hose for reel winding used in construction machinery and industrial machinery.
Especially when winding a high-pressure reel hose onto a reel or unwinding it, it is used in places where a large tension is applied to the high-pressure reel hose in the longitudinal direction or where the hose is repeatedly bent. Regarding high pressure reel hoses.

The hoses conventionally used as high-pressure reel hoses for reel winding are shown in Figure 1.
It has a structure in which a first metal wire braided reinforcing layer 11, an intermediate rubber 12, a second metal wire braided reinforcing layer 13, and an outer rubber 14 are sequentially formed on the outer peripheral surface of a cylindrical inner rubber 10 that forms a fluid passage. Both the first metal wire braided reinforcing layer 11 and the second metal wire braided reinforcing layer 13 are formed at an angle close to the theoretical resting angle of 109.5 degrees. Usually, it is often knitted at an angle larger than the theoretical resting angle, but the range is about 105 degrees to 120 degrees. The braiding angle herein means the angle at which the metal wires intersect when several metal wires in the metal wire braid reinforcing layer are braided. The theoretical rest angle is also called the theoretical center braid angle. When high pressure is applied to the inside of a hose provided with a metal wire braided reinforcement layer, the wires are oriented in a direction that opposes both the force that attempts to expand the diameter due to the high pressure and the force that attempts to extend it in the axial direction. Regardless of the diameter of the wires or the initial braiding angle of the wires, the wires intersect and rest at a constant angle, close to 109.5 degrees. This angle is called the theoretical static angle.
Volume 5 Rubber Hose, pages 16 and 17). Such high-pressure reel hoses are often used in short lengths (for example, 2 to 3 m for forklifts, etc.) and have almost no elongation in the longitudinal direction. ) are applied. Therefore,
150kgf/cm ² in the high pressure reel hose,
Even if a high pressure of 210 kgf/cm ² is repeatedly applied, the elongation of the high pressure reel hose in the longitudinal direction is a few percent (10% at most).
(less than) and no problems occurred.

However, the hoses used as high-pressure reel hoses for reel winding are 50m, 70m,
Since the hose is long (100 m), it is often subjected to repeated winding and unwinding while hanging vertically, and the total weight or pulling force of the high-pressure reel hose is over 100 kgf. Because tension may be applied, when a high-pressure reel hose is stretched in the longitudinal direction (the diameter becomes smaller in the radial direction), it may be stretched by 30 to 50% of the initial total length of the high-pressure reel hose.

In this state, 150kgf/cm ² inside the hose,
When a high pressure of 200 kgf/cm ² is applied, the high pressure reel hose becomes larger in the radial direction (shrinks in the longitudinal direction), and in the case of a 100 m item, it actually shrinks in the longitudinal direction to 30 to 40 m. This shrinking action (radial expansion) of the high-pressure reel hose may cause damage to the take-up reel, resulting in the disadvantage that a take-up reel with a rigid framework must be used.

In addition, repeated expansion and contraction in the longitudinal direction of this high-pressure reel hose has the disadvantage that the metal wire reinforcing layer is disturbed and the rubber layer is separated, making it unusable at an early stage.

The present invention overcomes the above problems and provides a high-pressure reel hose that has high tensile strength and excellent flexibility.

In other words, the high-pressure reel hose of the present invention includes a cylindrical inner rubber and a first braided hose on the outer peripheral surface of the inner rubber with a braid angle close to the theoretical static angle of 109.5 degrees.
a metal wire braided reinforcing layer and the outer peripheral surface of the first metal wire braided reinforcing layer via an intermediate rubber, or
The second part was directly applied with a braid angle of 80 degrees to 100 degrees.
It is characterized by comprising a metal wire braided reinforcing layer and an outer surface rubber provided on the outer peripheral surface of the second metal wire braided reinforcing layer.

In the high pressure reel hose of the present invention, the first
The metal wire braid reinforcement layer is applied with a braid angle close to the theoretical rest angle, and this first metal wire braid reinforcement layer provides high pressure resistance. Further, the material of the second metal wire braid reinforcing layer of the second layer is metal wire, and the braid angle thereof is 80 degrees to 100 degrees. Since the material of the second metal wire braided reinforcing layer of the second layer is the same metal wire as the first metal wire braided reinforcing layer of the first layer, the elongation is 1 for the same load compared to thread.
An order of magnitude smaller. Therefore, even if a large tension is applied, the elongation is small and there is little risk of disturbing the first metal wire braided reinforcing layer of the first layer. For this reason, normally when several 10 meters
Can be used as a long high pressure reel hose over 100m. In addition, since the braid angle is relatively large at 80 degrees to 100 degrees, the flexibility of the high-pressure reel hose does not deteriorate due to the second metal wire braid reinforcing layer of the second layer. Therefore, it has great flexibility during use and can be wound up on a reel. A more preferable braid angle of the second metal wire braid reinforcing layer of the present invention is greater than 90 degrees and less than 100 degrees.

Further, the diameter of the metal wire of the second metal wire braided reinforcing layer is preferably larger than the diameter of the metal wire of the first metal wire braided reinforcing layer. This further increases high tensile strength and flexibility. The metal wire is preferably a hard wire such as a piano wire. Furthermore, the term "braided" does not refer to a single metal wire wound in a spiral, but rather a braided arrangement of several metal wires.

The high pressure reel hose of the present invention may or may not be provided with an intermediate rubber. Further, each of the first metal wire braided reinforcing layer and the second metal wire braided reinforcing layer only needs to have at least one layer, and depending on the application, either one of them can be made up of two or more layers, or both can be made up of two or more layers.

Further, the inner rubber, intermediate rubber, and outer rubber constituting the high-pressure reel hose of the present invention may be the same as those used in conventional high-pressure reel hoses.

As described above, the high-pressure reel hose of the present invention has high pressure resistance with the first metal wire braided reinforcing layer, and can obtain high tensile strength without sacrificing flexibility with the second metal wire braided reinforcing layer. In particular, high-pressure reel hoses are used with heavy caps attached and various heavy equipment connected to them, and are constantly subjected to large loads, but the rate of change in elongation is extremely low. This is a highly durable and reliable high-pressure reel hose with little risk of disturbing the theoretical resting angle.

Examples will be explained below.

Example 1 A mandrel having an outer diameter of 12.2 mm was coated with inner rubber using a rubber extrusion device. Next, attach the inner rubber to the diameter
6 x 24 0.32mm piano wires close to the theoretical resting angle
The first metal wire braided reinforcing layer was braided at 110 degrees.
Furthermore, on this first metal wire braided reinforcing layer,
The intermediate rubber was coated using a rubber extrusion device. Next, the same diameter as the first metal wire braided reinforcing layer is 0.32 mm.
7 x 24 piano wires were braided at a braiding angle of 99 degrees to form a second metal wire braid reinforcing layer. Finally, the second metal wire braided reinforcing layer was coated with outer rubber, vulcanized in a conventional manner, and the mandrel was pulled out to produce the high-pressure reel hose of this example. A partially cutaway perspective view of this high pressure reel hose is shown in FIG. In the figure, reference numeral 1 denotes an inner rubber, 2 a first metal wire braided reinforcing layer, 3 an intermediate rubber, 4 a second metal wire braided reinforcing layer, and 5 an outer rubber. This high-pressure reel hose had an inner diameter of 12.7 mm, an outer diameter of 22.5 mm, and a weight of 770 g/m. Next, in order to see the elongation of this high-pressure reel hose under load, we tested the high-pressure reel hose in a state in which no internal pressure is applied (no pressure) and in a state in which an internal pressure of 210 kg/cm ² is applied (pressurized) using hydraulic pressure. Loads of 50, 100, 150, and 200 kg were applied in the axial direction of the hose, and the rate of change in elongation (%) and rate of change in outer diameter of the high-pressure reel hose were investigated. The elongation change rate of the high pressure reel hose is the difference between the length of the high pressure reel hose when each load is applied and the length of the high pressure reel hose without a load. The diameter change rate of the outer diameter is the difference between the outer diameter of the high pressure reel hose when each load is applied and the outer diameter of the high pressure reel hose with no load. It is divided by the outside diameter of the hose. The results are shown by the solid line A in FIGS. 3 to 6. In addition,
Figure 3 is a diagram of load vs. elongation change rate under no pressure, Figure 4 is a diagram of load vs. diameter change rate under no pressure, and Figure 5 is a diagram of load under pressure. - A diagram of elongation change rate, and Fig. 6 shows a load-diameter change rate diagram in a pressurized state.

The tensile strength of the high-pressure reel hose of this example is extremely small, with an elongation change rate of +2.8% under a 200 kg load in a non-pressurized state and an elongation change rate of +1.7% under a 200 kg load in a pressurized state. Furthermore, the diameter change rate of the high-pressure reel hose in the unpressurized state with a load of 200 kg was -1.6%, and the diameter change rate in the pressurized state with a load of 200 kg was -1.4%. As will be discussed later, conventional high-pressure reel hoses exhibit an elongation change rate of 18% under an unpressurized load of 50 kg.
Disturbance occurred in the wire reinforcement layer braided at the theoretical rest angle under a load of 50Kg.

In order to examine the flexibility of the high-pressure reel hose of this example, the minimum radius of curvature was determined. The critical minimum radius of curvature in this case refers to the minimum radius of the bent portion of the high-pressure reel hose that can be bent without buckling or breaking. As a result, the critical minimum radius of curvature was 100 mm.

Example 2 A high-pressure reel hose of this example was manufactured in the same manner as in Example 1, except that the braid angle of the second metal wire braided reinforcing layer of the high-pressure reel hose of Example 1 was set to 91 degrees. This high pressure reel hose has an inner diameter of 12.7mm, an outer diameter of 22.5mm, and a weight of
It was 760g/m. The elongation change rate and diameter change rate in the pressurized state and non-pressurized state of the high-pressure reel hose of this example are shown by reference numeral B in FIGS. 3 to 6. Elongation change rate is +1.6 at 200Kg load in no-pressure state
%, +0.5% in pressurized state, diameter change rate in non-pressurized state
It was -0.4% under a load of 200 kg and -0.4% under pressure. Moreover, the critical minimum radius of curvature was 103 mm.

As a reference example, the braid angle of the second metal wire braid reinforcing layer of the high pressure reel hose in Example 1 is
A high-pressure reel hose was manufactured in the same manner as in Example 1 except that the temperature was 113 degrees. This high-pressure reel hose had an inner diameter of 12.7 mm, an outer diameter of 22.5 mm, and a weight of 780 g/m. Further, the elongation change rate and diameter change rate of this high-pressure reel hose in the pressurized state and in the non-pressurized state are indicated by the symbol R in FIGS. 3 to 6. The minimum radius of curvature of this high-pressure reel hose was 100 mm.

In addition, the relationship between the rate of change in elongation of the high-pressure reel hose in a non-pressurized state was investigated when the braiding angle of the second metal wire braided reinforcing layer was different. High-pressure reel hoses with braid angles of 80 degrees, 91 degrees, 99 degrees, and 113 degrees were used, and a constant load of 200 kg was applied to each high-pressure reel hose. The high-pressure reel hoses were all manufactured under the same conditions except for the different braid angles. The elongation change rate under a constant load of 200Kg is 1% when the braid angle is 80 degrees, 1.6% when it is 91 degrees, 2.8% when it is 99 degrees, and 2.8% when it is 113 degrees.
It was 18%. The results are shown in FIG.

As is clear from this result, the elongation rate of the high-pressure reel hose was small when the braid angle was 90 degrees or less, and the change in the elongation rate was moderate. However, when the braid angle exceeded 90 degrees, the change in elongation rate gradually became larger. When the braiding angle exceeded 110 degrees (theoretical resting angle), the elongation rate increased rapidly and its changes also became steeper.

Furthermore, the bending stress of each of the high-pressure reel hoses in an unpressurized state was also investigated. Braid angle is 80
3.6Kg/cm at 91 degrees, 1.8Kg/cm at 91 degrees,
1.3Kg/cm at 99 degrees, 0.9Kg/cm at 113 degrees
It was cm. The results are shown in FIG.

As is clear from this result, when the braid angle was small, the bending stress was extremely large, and as the braid angle became larger, the bending stress decreased in a decelerating manner. Moreover, when the braid angle became larger than 110 degrees, the bending stress value remained unchanged.

From the above, as the braid angle of the metal wire braided reinforcing layer increases, the tensile strength decreases.
On the contrary, bending stress becomes smaller. However, the braid angle
Those in the range of 80 degrees to 100 degrees are both sufficiently satisfactory for use as high-pressure reel hoses. Therefore, when the braid angle is set to 80 degrees to 100 degrees, the second metal wire braided reinforcing layer of the high-pressure reel hose has sufficient tensile strength without impairing its flexibility.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway perspective view of a conventional high pressure reel hose, Fig. 2 is a partially cutaway perspective view of a high pressure reel hose in Embodiment 1 of the present invention, and Fig. 3 is a rubber hose in an unpressurized state. Fig. 4 is a diagram showing the load - elongation change rate of the rubber hose in the non-pressurized state, and Fig. 5 is a diagram showing the load - elongation change rate of the rubber hose in the pressurized state. Fig. 6 is a graph showing the load-diameter change rate of the rubber hose in a pressurized state, and Fig. 7 is a graph showing the braid angle of the second metal wire braided reinforcing layer in a constant load state in an unpressurized state. FIG. 8 is a diagram showing the elongation rate of the rubber hose, and FIG. 8 is a diagram showing the braid angle-bending stress of the second metal wire braid reinforcing layer of the rubber hose in a non-pressurized state. In the figure, reference numeral 1 indicates inner rubber, 2 indicates first metal wire braided reinforcing layer, 3 indicates intermediate rubber, 4 indicates second metal wire braided reinforcing layer, and 5 indicates outer rubber.

Claims (1)

[Claims for Utility Model Registration] (1) A cylindrical inner rubber, and a first metal wire braided reinforcing layer provided on the outer peripheral surface of the inner rubber with a braiding angle close to the theoretical static angle of 109.5 degrees; a second metal wire braided reinforcing layer with a braiding angle of 80 degrees to 100 degrees, which is applied directly or via an intermediate rubber to the outer peripheral surface of the first metal wire braided reinforcing layer; and the second metal wire braided reinforcing layer. A high-pressure reel hose characterized by an outer rubber provided on the outer peripheral surface of the hose. (2) The high-pressure reel hose according to claim 1, wherein the diameter of the wire constituting the second braided metal wire reinforcing layer is larger than the diameter of the wire constituting the first braided metal wire reinforcing layer. (3) The high-pressure reel hose according to claim 1, wherein the braid angle of the second metal wire braid reinforcing layer is greater than 90 degrees and smaller than 100 degrees.