JPH0210874Y2 - - Google Patents

Description

[Detailed explanation of the idea]

[Technical Field of the Invention] The present invention relates to a hose having two reinforcing layers made of spirally wound steel wire. [Prior art] Conventionally, in a durability test by twisting attachment, a hose having two reinforcing layers like this has been shown to not break if the steel wire of the outer spiral reinforcing layer is twisted in the direction in which it unravels. This causes the rubber layer to break and eventually leads to structural failure, so it has the disadvantage that it is weak against impact pressure and the steel wire does not play the role of a reinforcing layer. In addition, a hose with three reinforcing layers of steel wire has a binding property even when subjected to repeated shocks, so the distance between the wires does not widen, so it functions satisfactorily, but the manufacturing process is complex and requires advanced technology. There are drawbacks such as the need for additional hoses and the weight of the hose itself. [Purpose of the invention] An object of the invention is to provide a hose having two reinforcing layers made of spirally wound steel wire and having excellent impact resistance. [Structure of the invention] For this reason, the present invention provides a hose formed by winding two spiral reinforcing layers of steel wire on an inner rubber layer and covering this with an outer layer of rubber. The method is characterized in that one or more threads per lead are spirally wound with a cutting elongation of 5% or less at equal intervals only on the reinforcing layer in a direction crossing the wire winding direction of the reinforcing layer. This article focuses on hoses that can be used. Hereinafter, the configuration of the present invention will be explained in detail with reference to the drawings. FIG. 1 is a partially cutaway perspective view of an example of the hose of the present invention. In this figure, reference numeral 1 denotes a rubber inner layer, on which a steel wire is spirally wound to form a first spiral reinforcing layer 2. A second spiral reinforcing layer 4 is disposed on the outside of the first spiral reinforcing layer 2 with an intermediate rubber layer 3 interposed therebetween. In the present invention, only on this second spiral reinforcing layer 4, in a direction intersecting the wire winding direction (that is, in the opposite direction), a thread material 5 having a small elongation with a cutting elongation of 5% or less is applied. One or more wires per lead are wound spirally at equal intervals. here,
The reason why the elongation at break of the thread material 5 is set to be 5% or less is because the minimum elongation at break of current fibers is around 5%, which is the closest value to the elongation at break of hard wire. Examples of the thread material 5 include rubber-coated wire and aramid (aromatic polyamide fiber). The reason why one or more threads 5 are wound spirally at equal intervals per lead is to cover at least one hard wire of the second spiral reinforcing layer 4. In addition, 6 is a rubber outer layer. The rubber inner layer 1 is preferably made of a rubber material having high oil resistance and water resistance, such as NBR rubber material. The first spiral reinforcing layer 2 and the second spiral reinforcing layer 4 are formed by winding steel wires of appropriate thickness in opposite directions at a desired angle. For the intermediate rubber layer 3, a rubber material that can prevent contact wear of the steel wires of the first spiral reinforcing layer 2 and the second spiral reinforcing layer 4 and has good adhesion to the wires may be used. modulus is
It is preferable to use a rubber material with a weight of 20 kg/cm ² or more. The rubber outer layer 6 is preferably made of a rubber material that is highly weather resistant and wear resistant, and for this reason, for example, a CR rubber material may be used. In this way, in the present invention, the thread material is wound only on the second spiral reinforcing layer 4, and only on the inner spiral reinforcing layer, that is, the first spiral reinforcing layer 2. In addition, the thread material is not wound around both the first spiral reinforcing layer 2 and the second spiral reinforcing layer 4. In the case where the thread material is wound only on the first spiral reinforcing layer 2, when the second spiral reinforcing layer 4 is twisted in the direction of unraveling, the reinforcing layer is not destroyed, but the rubber layer is destroyed, and eventually This will lead to structural destruction, resulting in a decrease in impact resistance. Also,
When thread material is wound on both the first spiral reinforcing layer 2 and the second spiral reinforcing layer 4, force due to internal pressure is unevenly applied to both of these reinforcing layers, and the spiral is subjected to a strong force. The wire will break and the impact resistance will decrease. Furthermore, wrapping the reinforcing layer over both reinforcing layers increases the number of manufacturing steps. [Effects of the invention] As explained above, according to the invention, since the thread material is wound on the spiral reinforcing layer (second spiral reinforcing layer 4) of the outer steel wire, the durability test by twisting attachment is not possible. Since the reinforcing layer can withstand the impact even if it is repeatedly subjected to impact, it is possible to improve the impact resistance. Compared to hoses, the structure is simpler and lighter and more flexible.
The hose of the present invention is particularly useful as a high pressure hose. The effects of the present invention will be specifically explained below with reference to Examples. Example (1) Highly oil-resistant NBR with a wall thickness of 1.8 mm and an inner diameter of 12.7 mm.
A first spiral reinforcing layer is formed by winding a steel wire with a wire diameter of 0.4 mm at an angle of 54 degrees to the left with respect to the central axis of the hose, around the inner rubber layer made of rubber material, and on this reinforcing layer, 50% modulus is 90
An intermediate rubber layer with a thickness of 0.3 mm is provided using NBR rubber material that has good contact with the Kg/cm ² steel wire.
Wrap a steel wire with a wire diameter of 0.4 mm on top of it at an angle of 55° to the right with respect to the center axis of the hose.
A spiral reinforcing layer is formed, and on top of this second spiral reinforcing layer, aromatic polyamide fiber threads with a cutting elongation of 5% are arranged at equal intervals, one per lead, in the left direction with respect to the center axis of the hose. After winding it in a spiral shape at an angle of 100 degrees, the hose was covered with a 1.2 mm thick rubber outer layer made of CR rubber material, which is highly weather resistant and abrasion resistant (the hose of the present invention). (2) For comparison, a hose was produced in the same manner as in the hose of the present invention in (1) above, except that the thread material was not wound on the second spiral reinforcing layer (comparison hose). Impact pressure tests were conducted on these hoses in accordance with JIS K6365. This result is shown in the first section below.
Shown in the table. The test conditions are pressure: 175Kgf/
cm ² trapezoidal wave, oil temperature: 100℃, installation: U-shape, minimum bending radius: 110mm.

【table】

[Table] As is clear from Table 1 above, it can be seen that the hose of the present invention has excellent impact resistance.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view of an example of the hose of the present invention. DESCRIPTION OF SYMBOLS 1... Rubber inner layer, 2... First spiral reinforcing layer, 3... Intermediate rubber layer, 4... Second spiral reinforcing layer, 5... Thread material, 6... Rubber outer layer.

Claims (1)

[Scope of utility model registration request] In a hose formed by winding two spiral reinforcing layers of steel wire on an inner rubber layer and covering this with a rubber layer, the reinforcing layer is coated only on the outer spiral reinforcing layer of steel wire. A hose characterized in that one or more threads per lead are spirally wound at equal intervals in a direction intersecting the wire winding direction with a cutting elongation of 5% or less.