JP2000193152A - Heat resistant hose - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a heat resistant hose with a high heat resistant temperature, excellent in a productivity and also hard to soak an engine oil onto its outer surface. SOLUTION: A heat resistant hose 20 connected to a turbo-charger is provided with an inner pipe rubber layer 22 forming a flow route 22a for flowing a high temperature gas fluid, a lower rubber layer 24 formed by a silicon piled on the inner pipe rubber layer 22, a reinforcement thread layer 26 formed by winding the reinforcement thread onto the lower rubber layer 24 and an upper rubber layer 28 consisting of a silicon rubber piled on the reinforcement layer 26. The inner pipe rubber layer 22 is formed by a fluorine compound system rubber or the blend rubber of fluorine compound system rubber/acrylic compound system rubber or their polymer. The inner pipe rubber layer 22 can maintain a cylindrical shape in a push out process and take a process for winding the reinforcement thread by inserting a mandrel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-resistant hose used for an automobile engine and the like for flowing a high-temperature gas, and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, as a heat-resistant hose of this type, for example, in an engine equipped with a turbocharger, it has been used as a hose for sending intake gas supplied by the turbocharger to an intake pipe side of the engine. FIG.
9 is a half sectional view showing the heat resistant hose 100, and FIG. 10 is a sectional view taken along line 10-10 in FIG. 9 and 10, the heat-resistant hose 100 has a pressure resistance up to 600 kPa by embedding a reinforcing thread layer 104 in a hose body 102 made of silicone rubber. Also,
The heat-resistant hose 100 is formed of silicon rubber so as to withstand high-temperature intake gas supplied by a turbocharger. Silicon rubber is excellent in heat resistance, but because of its low viscosity when unvulcanized, it is difficult to produce it by an extrusion process like a normal hose. For this reason, as shown in FIG. 11, it was manufactured by a manual winding process. That is, the cloth 112 for forming the reinforcing yarn layer 104 is formed on the unvulcanized silicon rubber plate 110.
Are superimposed, wound around a roll 114, and then vulcanized.

[0003]

However, since the conventional manufacturing process of the heat-resistant hose 100 is a winding operation by hand, the productivity is low and the cost of the product is increased. The silicone rubber forming the hose body 102 has a property that oil permeability is high. Therefore, when engine oil is mixed in a mist state with the intake gas sent from the turbocharger,
The oil may penetrate into the silicone rubber of the heat-resistant hose 100 and ooze out to the outer surface of the heat-resistant hose 100. Such an oil has a problem that the appearance is impaired because it becomes a pattern such as spots on the outer surface of the heat-resistant hose 100.

[0004] In another conventional technique, there is also known one formed of only an acrylic rubber material instead of silicone rubber. However, heat resistance up to about 120 ° C is obtained, and 160 Long-term heat resistance at temperatures up to about ° C has been required.

An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a heat-resistant hose which has a high heat-resistant temperature, is excellent in productivity, and in which engine oil and the like are hardly oozed on its outer surface. And

[0006]

Means for Solving the Problems and Action / Effect of the Invention According to a first aspect of the present invention, there is provided a heat-resistant hose for flowing a high-temperature gas fluid, wherein a flow path for the high-temperature gas fluid is formed. An inner pipe rubber layer, a lower rubber layer laminated on the inner pipe rubber layer and formed of silicon, a reinforcing thread layer formed by winding a reinforcing thread on the lower rubber layer, and a reinforcing thread layer on the lower thread layer. And an upper rubber layer made of silicone rubber or an acrylic compound rubber, wherein the inner tube rubber layer is made of a fluorine compound rubber or a blend rubber of a fluorine compound rubber / acryl compound rubber, or a rubber mixture thereof. It is characterized by being formed from a polymer.

[0007] In the heat-resistant hose according to the first invention, the outer peripheral side of the inner pipe rubber layer having the flow path for flowing the high-temperature gas fluid is provided.
A lower rubber layer, a reinforcing thread layer, and an upper rubber layer are sequentially laminated. The lower rubber layer is formed of silicon rubber, and has improved heat resistance to a high-temperature gas fluid. The inner tube rubber layer is made of a fluorine compound rubber or a fluorine compound rubber /
It is formed from a blend rubber of an acrylic compound rubber or a polymer thereof. Here, the fluorine compound rubber means vinylidene fluoride / hexafluoropropylene / tetrafluoroethylene copolymer: FKM or the like.
The acrylic compound rubber is a copolymer of an alkyl ester and 2-chloroethyl vinyl ester: AC
Refers to M. Fluorine compound rubber or a fluorine compound rubber / acrylic compound rubber blend rubber or a polymer thereof, which forms the inner tube rubber layer, has high resistance to oil penetration, and even if oil is mixed in a high-temperature fluid. It can be prevented from penetrating into the lower rubber layer, the reinforcing yarn layer, and the upper rubber layer. Therefore, the appearance such as spots does not appear on the outer surface of the heat-resistant hose to impair the appearance.

According to a second aspect of the present invention, there is provided a method of manufacturing a heat-resistant hose through which a high-temperature gas fluid flows, by extruding an inner tube rubber layer and a lower rubber layer made of silicone rubber so that the inner tube rubber layer is formed inside the inner tube rubber layer. A step of forming an extruded body having a flow path, a step of supporting the extruded body by inserting a mandrel into the flow path of the extruded body, and winding a reinforcing yarn around an outer peripheral portion of the extruded body supported by the mandrel Forming a reinforcing yarn layer, and laminating an upper rubber layer made of silicon rubber or an acrylic compound rubber on the reinforcing yarn layer, wherein the inner tube rubber layer is made of a fluorine compound rubber or fluorine. It is characterized by being formed from a compound rubber / acrylic compound rubber blend rubber or a polymer thereof.

The second invention relates to a method for manufacturing a heat-resistant hose, and extrudes a fluorine compound rubber, a blend rubber of a fluorine compound rubber / acrylic compound rubber, or a polymer thereof by using an extruder. An extrudate is formed. Since this extruded body is formed of an acrylic compound rubber or the like, the extruded body has a higher viscosity than silicone rubber, can be extruded, and is not crushed by its own weight, and maintains a tubular shape. Then, a mandrel is inserted into the flow path of the extruded body immediately after the extrusion, and the reinforcing yarn is wound around the outer periphery of the extruded body while being supported by the mandrel to form a reinforcing yarn layer. in this way,
Since the reinforcing yarn can be wound in a state where the extruded body is supported, the heat-resistant hose manufacturing process can take a process of forming a continuous reinforcing yarn layer following the extrusion process,
Excellent productivity.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to further clarify the configuration and operation of the present invention described above, a preferred embodiment of the present invention will be described below.

FIG. 1 is a half sectional view of a heat-resistant hose 20 according to an embodiment of the present invention cut in a longitudinal direction, and FIG. 2 is a sectional view taken along line 2-2 of FIG. 1 and 2, a heat-resistant hose 20 is a hose that connects a turbocharger of an automobile engine (not shown) and an intake pipe, and is formed to have heat resistance and pressure resistance by being laminated in four layers. Have been. That is, the heat-resistant hose 2
No. 0 includes an inner tube rubber layer 22 having a flow path 22a, a lower rubber layer 24, a reinforcing thread layer 26, and an upper rubber layer 28. The material of each layer of the heat resistant hose 20 is determined in order to obtain heat resistance of 10,000 hours or more at 160 ° C., pressure resistance up to 600 kPa, oil penetration resistance and shape retention.

That is, as described later, the inner tube rubber layer 22 is mainly used to obtain shape retention and oil penetration resistance.
It is formed from a fluorine compound rubber (FKM), a blend rubber of a fluorine compound rubber (FKM) / acryl compound rubber (ACM), or a polymer thereof. Here, the shape retention refers to the difficulty of crushing by its own weight when the extruded body is formed in a tubular shape. Also, the lower rubber layer 24
Is mainly made of silicone rubber to improve heat resistance. Further, the reinforcing thread layer 26 is formed to increase the pressure resistance, and is formed by braiding a fiber thread such as an aramid resin or an aromatic polyamide onto the lower rubber layer 24. Further, the upper rubber layer 28 is formed of a single layer of silicon rubber or a single layer of acrylic compound rubber in order to obtain environmental resistance. This upper rubber layer 2
The material 8 is preferably a material that can be vulcanized and bonded to the lower rubber layer 24. The upper rubber layer 28 does not require much heat resistance because the temperature rise is suppressed by the heat insulating action of the inner tube rubber layer 22 and the lower rubber layer 24.

The thickness of each layer of the heat-resistant hose 20 is also determined in consideration of heat resistance, oil penetration resistance, and the like. For example, the inner diameter φ of the heat-resistant hose 20 is 30 to 70 mm,
When the thickness t is 4 to 8 mm, the lower rubber layer 24
Can be determined in the range of 2 to 4 mm, the reinforcing thread layer 26 can be in the range of 0.1 to 1 mm, and the upper rubber layer 28 can be in the range of 2 to 4 mm. The thickness of the inner tube rubber layer 22 will be described later.

Next, a method of manufacturing the heat-resistant hose 20 will be described. The heat-resistant hose 20 is formed by a known method.
That is, it can be manufactured by performing a rubber extrusion step, a reinforcing yarn winding step, and a vulcanization step. FIG. 3 is an explanatory diagram illustrating the hose manufacturing device 30.

In FIG. 3, the hose manufacturing apparatus 30 includes a first extruder 40, a blade device 50, and a second extruder 60.
And The first extruder 40 is a device for forming an extruded body 20A (the inner tube rubber layer 22 and the lower rubber layer 24) by co-extruding a rubber material. The blade device 50 is a device for forming the reinforcing yarn layer 26 on the extruded body 20A, includes a bobbin carrier (not shown) mounted on a drum 52a, and feeds out the reinforcing yarn 26a from the bobbin carrier. This is an apparatus for forming a reinforcing yarn layer 26 by braiding on 20A. The second extruder 60 is a device for forming the upper rubber layer 28, and extrudes a rubber material from the outer tube extruding portion 61 to form the upper rubber layer 28.

Next, referring to FIG.
A series of manufacturing steps of the heat-resistant hose 20 will be described. The first extruder 40 coaxially extrudes a fluorine compound rubber or a rubber compound of a fluorine compound rubber / acrylic compound rubber, or a rubber material composed of these polymers, and silicone rubber to form a two-layered structure. A cylindrical extruded body 20A is formed. And the extruded body 2
When 0A is extruded, the mandrel Md is inserted into the space 20a forming the flow path of the extruded body 20A.

Subsequently, the extruded body 20A is connected to the blade device 5
The reinforcing yarn 26a is sent out from the bobbin by the rotation of the drum 52a of the blade device 50, whereby the reinforcing yarn layer 26 is formed on the extruded body 20A. That is, the extruded body 2 immediately after being extruded by the first extruder 40
The reinforcing yarn layer 26 is formed in a state where 0A is supported by the mandrel Md. At this time, the extruded body 20A does not collapse because it is supported by the mandrel Md. Next, the second extruder 60 uses a silicone rubber or an acrylic compound rubber (AC) for forming the upper rubber layer 28.
M) is laminated on the reinforcing yarn layer 26. That is, the rubber material for forming the upper rubber layer 28 is supplied directly onto the reinforcing yarn layer 26.

Subsequently, a vulcanization step is performed. The conditions of the vulcanization step are set at 140 to 170 ° C. for 20 to 60 minutes. By this vulcanization step, the inner tube rubber layer 22, the lower rubber layer 2
4 and the upper rubber layer 28 are joined by performing normal vulcanization adhesion. Thereby, the heat resistant hose 20 is formed integrally.

In the method of manufacturing the heat-resistant hose 20 according to the above embodiment, the inner rubber layer 22 of the extruded body 20A extruded by the first extruder 40 is made of a fluorine compound rubber or a fluorine compound rubber / acryl compound rubber. Is formed from a blended rubber or a polymer thereof, and has a higher mechanical strength than that formed from silicone rubber alone, so that it is not easily crushed by its own weight. Therefore, the mandrel Md can be inserted into the extruded body 20A immediately after extrusion, and the reinforcing yarn 26a can be wound by the blade device 50 in a state where the extruded body 20A is supported by the mandrel Md. Therefore, the manufacturing process of the heat-resistant hose 20 can take the process of forming the continuous reinforcing yarn layer 26 following the extrusion process, and is excellent in productivity.

Next, the thickness of the extruded body 20A will be described. The thickness of the extruded body 20A is determined in consideration of the shape retention and the oil permeation resistance at which the reinforcing yarn layer 26 can be formed. That is, first, the thickness of the extruded body 20A was determined from the flatness K (%) in consideration of the fact that the mandrel Md can be inserted to form the reinforcing yarn layer 26. FIG. 4 is an explanatory diagram for explaining the flatness K, wherein a indicates the distance in the vertical direction, b indicates the distance in the horizontal direction, and the flatness K (%)
K = (1−a / b) × 100. FIG. 5 is a graph showing the relationship between the flatness K and the thickness t of the inner tube rubber layer 22 of the extruded body 20A. The thickness of the extruded body 20A, that is, the total thickness of the inner tube rubber layer 22 and the lower rubber layer 24 is
2.5 mm. Here, when the flatness ratio K is 50% or less, since the mandrel Md can be inserted, it has been found that the thickness t of the inner tube rubber layer 22 needs to be 0.25 mm or more. By setting the thickness of the inner tube rubber layer 22 to such a value, the extruded body 20A can be improved in shape retention without being crushed, and the reinforcing thread 26a can be wound.

The inner tube rubber layer 22 has a thickness t of 0.5 mm for a fluorine compound rubber (FKM) and a fluorine compound rubber (FKM) / acryl compound rubber (ACM) in view of oil resistance. / FKM), FKM / ACM
When the blending ratio is 70/30, it is preferably set to 1.0 mm or more. Thereby, sufficient performance with respect to oil permeation resistance can be obtained.

On the other hand, if the thickness of the inner rubber layer 22 exceeds 2 mm, the amount of expensive materials such as fluorine compound rubber is increased, so that the inner rubber layer 2 is reduced from the viewpoint of cost reduction.
2 is preferably 2 mm or less.

Next, an experiment was conducted on the heat resistance of the material used for the heat-resistant hose 20. This heat resistance experiment
The test was performed by leaving a strip-shaped rubber piece formed of the following material left in an atmosphere at a predetermined temperature for a predetermined time and examining the time taken to break when stretched twice. FIG. 6 shows the result. In FIG. 6, the one-dot chain line indicates silicone rubber, the solid line indicates ACM, the two-dot chain line indicates FKM, and the dashed line indicates FKM / ACM.
Each shows a blend rubber (blend ratio 70/30). Here, the suitable range was 10,000 hours or more at a heat resistance of 160 ° C. or more. The applicable range is the temperature during normal running of the vehicle, 300,000 km (average speed 30 km / h).
/ H). From FIG. 6, FKM applied to the inner tube rubber layer 22 and the lower rubber layer 24, FKM / A
It was confirmed that the CM blend rubber and the silicone rubber satisfied the conformity standards.

Further, an experiment for examining the oil permeation amount of the heat-resistant hose was conducted. The experiment was performed for a total length of 200 m and an inner diameter of φ34.
Diesel oil was filled in a hose having a thickness of 5 mm and a thickness of 5 mm, and the amount of oil permeation in an atmosphere at 145 ° C. was examined. FIG. 7 shows the elapsed time when measured on the horizontal axis, and the ratio when the amount of transmission of silicon (first comparative example) after 24 hours is 1 on the vertical axis. FIG. 8 shows data of the thickness t of each sample. As shown in FIG. 7, in the case of the silicone rubber corresponding to the prior art, the oil permeation amount hardly decreases with the passage of time, whereas the oil permeation amount of the first and second embodiments increases with the passage of time. Was reduced and oil bleeding on the outer surface of the hose was visually observed. Even if the intake gas mixed with mist-like oil flows through the flow path 22a of the heat-resistant hose 20, since the inner pipe rubber layer 22 is made of a material having excellent oil permeability, the heat resistance is high. Hose 2
No pattern such as spots appeared on the outer peripheral surface of No. 0, and it was found that the effect of the oil resistance of the inner tube rubber layer 22 against oil penetration was obtained.

The present invention is not limited to the above embodiment, but can be implemented in various modes without departing from the gist of the present invention. For example, the following modifications are possible.

(1) The heat-resistant hose 20 is composed of the upper rubber layer 2
8 may be made of silicone rubber, but ACM may be used when the ambient temperature at which the heat-resistant hose is used is low. In this case, the ACM can be added with the features that it has excellent weldability to silicon rubber, high shape retention, and is hardly damaged.

[Brief description of the drawings]

FIG. 1 is a heat-resistant hose 2 according to one embodiment of the present invention.
FIG. 2 is a half cross-sectional view taken along the longitudinal direction of FIG.

FIG. 2 is a sectional view taken along line 2-2 of FIG.

FIG. 3 is an explanatory diagram illustrating a hose manufacturing device 30.

FIG. 4 is an explanatory diagram illustrating an oblateness ratio K.

FIG. 5 is a graph showing a relationship between an oblateness and a thickness t of an extruded body 20A.

FIG. 6 is a graph showing the results of a heat resistance test of a heat resistant hose.

FIG. 7 is a graph illustrating an oil permeation ratio based on silicon over time.

FIG. 8 is an explanatory diagram for explaining the material and thickness of each sample.

FIG. 9 is a half sectional view showing a conventional heat resistant hose 100.

FIG. 10 is a sectional view taken along the line 10-10 in FIG. 9;

FIG. 11 is an explanatory diagram illustrating a process of manufacturing a conventional heat-resistant hose 100.

[Explanation of symbols]

 Reference Signs List 20 heat-resistant hose 20A extruded body 20a space 22a flow path 22 inner tube rubber layer 24 lower rubber layer 26 reinforcing thread layer 26a reinforcing thread 28 upper rubber layer 30 hose manufacturing apparatus 40 first Extruder 50 ... Blade device 52a ... Drum 60 ... Second extruder 61 ... Outer tube extrusion unit

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takahiro Iwata 1 Ochiai Ogata, Kasuga-machi, Nishi-Kasugai-gun, Aichi Prefecture Inside Toyota Gosei Co., Ltd. F-term (reference) in Toyoda Gosei Co., Ltd. 3H111 AA02 BA12 CB05 CB11 CB14 CC03 DA09 DA11 DB11 DB20 EA04 EA17 4F207 AA16 AA21 AA33 AA45 AD16 AG03 AG08 AH16 KA01 KA17 KB11 KB22 KJ05 KL58 KL65

Claims (2)

[Claims] 1. A heat-resistant hose for flowing a high-temperature gas fluid, comprising: an inner pipe rubber layer forming a flow path for flowing the high-temperature gas fluid; and a lower rubber layer laminated on the inner pipe rubber layer and formed of silicon. A reinforcing yarn layer formed by winding a reinforcing yarn on the lower rubber layer, and an upper rubber layer laminated on the reinforcing yarn layer and made of silicon rubber or an acrylic compound rubber; The rubber layer is made of a fluorine compound rubber or a blend rubber of a fluorine compound rubber / acryl compound rubber,
Alternatively, a heat-resistant hose formed of these polymers. 2. A method for manufacturing a heat-resistant hose through which a high-temperature gas fluid flows, comprising: extruding an inner tube rubber layer and a lower rubber layer made of silicone rubber, thereby forming an extruded body having a flow path inside the inner tube rubber layer. Forming a mandrel in the flow path of the extruded body to support the extruded body, and forming a reinforcing yarn layer by winding a reinforcing yarn around the outer periphery of the extruded body supported by the mandrel. And a step of laminating an upper rubber layer made of silicon rubber or acrylic compound rubber on the reinforcing yarn layer, wherein the inner tube rubber layer is made of a fluorine compound rubber or a fluorine compound rubber / acryl compound System rubber blended rubber,
Alternatively, a method for producing a heat-resistant hose characterized by being formed from these polymers.