KR20200108201A - Vehicle hose - Google Patents

Abstract

An embodiment of the present invention relates to a vehicle hose. The vehicle hose includes: a thermoplastic rubber component; and a vulcanized rubber component that is crosslinked by a crosslinking agent so that its strength increases when the temperature rises. The vehicle hose is formed in a shape of the hose, and the content of the crosslinking agent is adjusted to compensate for the decrease in strength due to the thermoplastic rubber component when the temperature rises with the increase in strength due to the vulcanized rubber component, or increase the strength due to the vulcanized rubber component.

Description

Vehicle hose {VEHICLE HOSE}

The present invention relates to a vehicle hose, and more particularly, to a vehicle hose that maintains or increases strength even when the temperature rises.

Next-generation vehicles such as hybrid vehicles (HEVs), electric vehicles (EVs), and fuel cell vehicles (FCVs) are driven by electricity, so some or all of them are driven by electricity. In such a next-generation automobile, weight reduction of various parts is a problem.

On the other hand, the brake device of the vehicle inevitably includes a hose or a pipe in order to deliver pressure oil by hydraulic pressure. A hydraulic hose (brake hose) made of a flexible material is connected to the hydraulic supply pipe of the brake system used to slow down and stop the vehicle and maintain the parking state to smoothly distribute the hydraulic oil to each wheel. In addition, high-pressure hoses that transmit high-pressure oil are also used in the power steering system. Such a hose may cause a problem in the reliability of the hose in the long term due to thermal expansion or the like in a high temperature environment.

In addition, a vehicle hose installed near the engine is placed in a high temperature environment due to heat from the engine. As the temperature increases, the hose may sag, and in particular, in a high-temperature environment near the engine, such sagging of the hose or deformation of the hose may further occur.

Since the hose or brake hose near the engine is directly connected to the safety of the driver, a vehicle hose having high reliability is required even in a high temperature and high pressure use environment.

While securing safety and reliability for such a vehicle hose, various materials have been studied to achieve weight reduction as described above.

For example, carbon fiber reinforced polymer (CFRP) has been recently used because it is light and can increase its rigidity. However, since CFRP is an anisotropic material, it is difficult to design.

Meanwhile, in the case of a generally used vehicle hose, as a rubber hose, a rubber material is widely used in various industrial fields due to its unique property of elasticity. However, the physical properties of the rubber material such as hardness may change due to temperature change during use, and the performance or efficiency of the product may decrease.

In particular, a vehicle hose used in the vicinity of an engine and exposed to a high temperature environment may sag or decrease in strength when the temperature increases as described above, and thus a more specific response to heat is required.

The technical problem to be achieved by the present invention is to provide a vehicle hose capable of achieving weight reduction without reducing rigidity even in a high temperature environment.

The technical problem to be achieved by the present invention is not limited to the technical problems mentioned above, and other technical problems that are not mentioned can be clearly understood by those of ordinary skill in the technical field to which the present invention belongs from the following description. There will be.

In order to achieve the above technical problem, an embodiment of the present invention provides a vehicle hose. Vehicle hoses are thermoplastic (Thermoplastic) rubber component; And a vulcanized rubber component that is crosslinked by a crosslinking agent to increase strength when the temperature is increased, and is formed in a shape of a hose, and when the temperature is increased, the strength decrease due to the thermoplastic rubber component is reduced due to the vulcanized rubber component. The content of the crosslinking agent is adjusted to offset by increase or to increase the strength.

In an embodiment of the present invention, the crosslinking agent may contain at least one of sulfur and dicumyl peroxide (DCP).

In an embodiment of the present invention, the thermoplastic rubber component may include at least one of NR, SBR, and acrylic rubber.

In an embodiment of the present invention, the vulcanized rubber component may be of the same type of rubber as the thermoplastic rubber component except for the crosslinking agent.

In an embodiment of the present invention, when the vulcanized rubber component is NR, the content of the crosslinking agent is 2.0 phr or more of sulfur, or 3.0 phr or more of DCP, and when the vulcanized rubber component is SBR, the content of the crosslinking agent is 1.75 sulfur. It may be greater than or equal to phr, or greater than or equal to 1.0 phr of DCP.

In an embodiment of the present invention, the vehicle hose includes: a first hose layer comprising the crosslinked vulcanized rubber component and the non-crosslinked thermoplastic rubber component by adding the crosslinked material to unvulcanized rubber, kneading and then heating; And a second hose layer surrounding the outer surface of the first hose layer or formed on the inner surface of the first hose layer.

In an embodiment of the present invention, when the temperature rises, in addition to the increase in thermal stiffness of the first hose layer, due to the pressure applied to the first hose layer by the thermally expanded second hose layer, the first hose layer The thermal stiffness can be further increased.

In an embodiment of the present invention, the vehicle hose may be formed in the shape of the hose by further mixing carbon fiber.

In an embodiment of the present invention, the second hose layer may include a vulcanized rubber component crosslinked by a crosslinking agent different from the first hose layer.

In an embodiment of the present invention, at least one of the first hose layer and the second hose layer may include carbon fiber.

According to an embodiment of the present invention, a vehicle hose is composed of a vulcanized rubber component added with a crosslinking agent and a thermoplastic rubber component, providing flexibility and elasticity due to the thermoplastic rubber component, while maintaining stiffness when the temperature increases by the vulcanized rubber component. Therefore, it is possible to prevent sagging and secure safety even with a vehicle hose having a reduced thickness than before, thereby reducing weight and providing a vehicle hose suitable for high temperature environments.

The effects of the present invention are not limited to the above effects, and should be understood to include all effects that can be inferred from the configuration of the invention described in the detailed description or claims of the present invention.

1 is a view showing a vehicle hose according to an embodiment of the present invention.
FIG. 2 is a partially enlarged view of FIG. 1.
3 is a diagram for explaining crosslinking of rubber and properties of thermoplastic rubber.
4 is a view for explaining the characteristics of a vehicle hose consisting of a thermoplastic rubber component and a vulcanized rubber component.
5 is a view for explaining the characteristics of a vehicle hose according to an embodiment of the present invention consisting of a thermoplastic rubber component and a vulcanized rubber component.
6 is a view for explaining the strength of a vehicle hose according to an embodiment of the present invention.
7 is a view for explaining the hardness change according to the temperature of the vehicle hose according to an embodiment of the present invention.
8 is a view for explaining the thermal stiffness according to the temperature of a vehicle hose according to an embodiment of the present invention.
9 is a view showing a vehicle hose according to another embodiment of the present invention.
10 is a view showing a vehicle hose according to another embodiment of the present invention.
11 is a view for explaining an example of a method of manufacturing a vehicle hose according to an embodiment of the present invention.

Hereinafter, the present invention will be described with reference to the accompanying drawings. However, the present invention may be implemented in various different forms, and therefore is not limited to the embodiments described herein. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and similar reference numerals are assigned to similar parts throughout the specification.

Throughout the specification, when a part is said to be "connected (connected, contacted, coupled)" with another part, it is not only "directly connected", but also "indirectly connected" with another member interposed therebetween. "Including the case. In addition, when a part "includes" a certain component, it means that other components may be further provided, rather than excluding other components unless specifically stated to the contrary.

The terms used in the present specification are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as "comprise" or "have" are intended to designate the presence of features, numbers, steps, actions, components, parts, or a combination thereof described in the specification, but one or more other features. It is to be understood that the presence or addition of elements or numbers, steps, actions, components, parts, or combinations thereof, does not preclude in advance.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a view showing a vehicle hose 100 according to an embodiment of the present invention. FIG. 2 is a partially enlarged view of FIG. 1.

The vehicle hose 100 may be a high-temperature environment, such as a brake hose installed near an engine and a power steering hose, or a vehicle hose used for a pressure transmission mechanism. The vehicle hose is not limited to the above hoses.

The vehicle hose 100 according to an embodiment of the present invention has a characteristic that, when the temperature increases, the temperature stress (thermal stiffness) is maintained without being lowered or further increases. Therefore, it has better safety and reliability than the existing hose, and in particular, since sufficient rigidity is secured even if the hose is formed with a smaller thickness than the existing hose (refer to the lower figure of Fig. 2), weight reduction can be achieved, It is also reduced in cost.

The vehicle hose 100 according to the present embodiment includes a thermoplastic rubber component and a vulcanized rubber component to which a crosslinking agent is added. The vehicle hose 100 may be formed to be made of a crosslinked vulcanized rubber component and a non-crosslinked thermoplastic rubber component by adding a crosslinking agent to the unvulcanized rubber, kneading, and crosslinking by heating.

Due to the thermoplastic rubber component, the vehicle hose 100 may have very good flexibility, processability and moldability during manufacture, but the thermoplastic rubber component tends to decrease strength when the temperature rises. On the other hand, the strength of the vulcanized rubber component crosslinked by the crosslinking agent may be maintained even when the temperature increases, or the strength may rather increase.

In this embodiment, the flexibility and processability of the thermoplastic rubber component are taken, but the problem of the increase in temperature, that is, the strength decrease due to heat, is offset by the increase in strength due to the vulcanized rubber component, or rather, the strength of the crosslinking agent is increased. The content is adjusted so that the vehicle hose 100 may be formed.

3 is a diagram for explaining crosslinking of rubber.

A chain-shaped polymer material that exhibits rubbery elasticity at room temperature or a polymer material that is a raw material for it is called rubber. There are natural rubber and synthetic rubber for rubber.

Rubber materials show various physical properties depending on the crosslinking type. Among the crosslinking methods of rubber materials, a crosslinking method using sulfur and peroxide is known.

Crosslinking by vulcanization refers to a strong bond between rubber molecules by heating (or irradiating with radiation, etc.) sulfur or other vulcanizing agent (organic peroxide, etc.) to the raw rubber to form crosslinking points (refer to the upper right figure in Fig. 3). It means to increase the elasticity and tensile strength, and to reduce the plastic flow. By infiltrating the solvent into the rubber, the crosslinking degree can be analyzed using the difference in weight, density, and Flory-Rehner equation before and after.

Rubber materials may have an increase in hardness due to an additional crosslinking reaction with an increase in temperature or an increase in crosslinking density due to the exchange of polysulfide chains to a lower order.

On the other hand, the uncrosslinked part of the vehicle hose 100 may have a thermoplastic (See the lower figure of FIG. 3). That is, the thermoplastic rubber component may change into a crystalline phase at low temperatures and into an amorphous phase at high temperatures.

At room temperature, the movement of molecular chains decreases and the distance between molecular chains becomes closer. When a thermoplastic rubber component is heated at a high temperature and becomes an amorphous phase, the molecular chains move irregularly and the packing distance between the molecular chains becomes farther.

The closer the molecular chains are to each other, the greater the van der waals force, and as the molecular chains move away from each other, the attractive force weakens and the stiffness of the rubber may decrease.

4 is a view for explaining the characteristics of a vehicle hose made of a thermoplastic rubber component and a vulcanized rubber component. 5 is a view for explaining the characteristics of the vehicle hose 100 according to an embodiment of the present invention comprising a thermoplastic rubber component and a vulcanized rubber component. 6 is a view for explaining the strength of the vehicle hose 100 according to an embodiment of the present invention.

As described above, the vehicle hose 100 of the present embodiment may have a hose shape made of a vulcanized rubber component crosslinked by a thermoplastic rubber component and a crosslinking agent.

As illustrated in the upper figure of FIGS. 4 and 6, when the temperature increases, the strength may tend to decrease due to the thermoplastic rubber component. However, the vehicle hose 100 of the present embodiment also has a tendency to increase its strength when the temperature rises due to a vulcanized rubber component to which a crosslinking agent such as sulfur is added (refer to the lower figures of FIGS. 5 and 6 ).

These tendencies may cancel each other out, and the resulting strength may decrease or increase depending on the magnitude of the tendencies.

The example shown in FIG. 5 shows that the vulcanized rubber component with an increased degree of crosslinking (crosslinking density) can offset the decrease in strength due to temperature rise due to the thermoplastic rubber component, which is an uncrosslinked part, or rather increase the strength as a result.

As illustrated in FIG. 5, the vehicle hose 100 according to the present embodiment may be formed such that the vulcanized rubber component has a sufficiently large crosslinking density to maintain or increase the strength when the temperature increases.

At least one of sulfur and peroxide may be used as the crosslinking agent, and dicumyl peroxide (DCP) may be used as peroxide. The crosslinking agent is not limited thereto.

The rubber component to which the crosslinking agent is added, that is, the vulcanized rubber component may include at least one of NR, SBR, and acrylic rubber. Except that the uncrosslinked part of the vehicle hose 100 is also not crosslinked, it may be of the same type of rubber as the vulcanized rubber component.

The vehicle hose 100 may be manufactured for a vehicle by an injection molding method.

7 is a view for explaining a change in hardness of the vehicle hose according to the embodiment according to the temperature.

7(a) shows the results of measuring the hardness of natural rubber (NR) crosslinked with various amounts of sulfur or DCP at various temperatures.

As can be seen from Fig. 7(a), the hardness of NR tends to increase with increasing temperature. This change can be interpreted as being related to the increase in the mobility of the rubber molecular chain or the change in the crosslinking density with an increase in temperature.

In the case of NR, it is composed of long chains intermingled with each other with cis-1,4-polyisoprene structure, and due to this chain structure, NR is affected by the increase in entropy due to the increase in molecular motility as the temperature increases above the glass transition temperature. The hardness or modulus of can be increased.

In the case of a rubber specimen crosslinked with sulfur, a change in the order of sulfur bonds may occur as the temperature increases, resulting in a change in crosslinking density. A change in crosslinking density according to an increase in temperature may also affect a change in hardness or modulus of the vehicle hose 100.

When the vulcanized rubber component of the vehicle hose 100 according to the present embodiment is NR, the content of the crosslinking agent may be 2.0 phr or more of sulfur or 3.0 phr or more of DCP for a hardness increase effect according to temperature increase.

Figure 7(b) shows the results of hardness measurement of SBR (Styrene Butadiene Rubber) specimens crosslinked with various amounts of sulfur and DCP.

SBR also tends to increase in hardness with increasing temperature. In the case of crosslinking with sulfur, it can be seen that the hardness of both NR and SBR increases at a similar rate as the sulfur content increases.

On the other hand, SBR crosslinked with DCP shows a large change in hardness even with a small amount of DCP compared to NR crosslinked with DCP. This is because SBR can exhibit a large crosslinking effect even with a small amount of DCP.

The cause of the increase in hardness of the rubber specimen according to the increase in temperature can be considered the effect of temperature stress due to the change in crosslinking density or the increase in entropy.

When the vulcanized rubber component of the vehicle hose 100 according to the present embodiment is SBR, the content of the crosslinking agent is 1.75 phr or more of sulfur, or 1.0 phr of DCP for the effect of increasing the hardness according to temperature increase, that is, increasing the strength. It can be more than that.

8 is a view for explaining the thermal stiffness of the vehicle hose according to the embodiment according to the temperature. 8(a) and 8(b) are experimental results of measuring temperature stress according to temperature change of NR and SBR specimens to find out the effect of entropy, which is one of the causes of hardness increase according to temperature increase.

When a certain strain is applied to the specimen, the randomly arranged chains are oriented in a certain direction, resulting in a low entropy state. When heat is applied to this, the kinetic energy of the molecule increases, and stress is generated due to the property of going to a high entropy state. The temperature stress generated at this time is caused by the occurrence of stress and thermal expansion due to entropy, and it slightly decreases due to the stress relaxation phenomenon over time.

When a specimen pressed with a constant pressure increases in entropy due to a change in temperature or a temperature stress occurs due to thermal expansion, the hardness increases. As shown in the graph, as the temperature increases, the temperature stress generated in the rubber specimen increases.

From this result, it is interpreted that the increase in hardness with increasing temperature above the glass transition temperature of the crosslinked rubber specimen is mainly due to the occurrence of temperature stress.

In addition to the thermoplastic rubber component and the vulcanized rubber component, the vehicle hose 100 according to the present embodiment may be formed to have carbon fiber reinforced polymer properties by further mixing carbon fibers.

9 is a view showing a vehicle hose 100 according to another embodiment of the present invention.

The vehicle hose 100 of the embodiment shown in FIG. 9 includes a first hose layer 110 and a second hose layer 130.

The first hose layer 110 may be made of a thermoplastic rubber component and a vulcanized rubber component. Since the configuration of the first hose layer 110 is substantially the same as or similar to those described in FIGS. 1 to 8, a detailed description will be omitted.

The second hose layer 130 may be formed to surround the outer surface of the first hose layer 110. The second hose layer 130 may be a simple rubber layer or a vulcanized rubber layer whose hardness increases when the temperature increases by increasing crosslinking by a crosslinking agent. Alternatively, the second hose layer 130 may include carbon fiber.

Alternatively, the second hose layer 130 includes a rubber component crosslinked by a crosslinking agent different from the first hose layer 110, and in terms of expansion rate or hardness reinforcing properties when the temperature rises, the first hose layer 110 and the second There may be a difference between the hose layer 130.

When the rubber chain is elongated or oriented by external stress and is in a low entropy state, when it receives heat energy, the mobility of the molecule increases and the entropy increases, and the rubber chain changes into a disordered coil shape. Such entropy elastic behavior can provide a decisive cause for changes in hardness or elastic modulus of rubber materials according to changes in temperature.

In addition, the hardness of the rubber material may increase due to an additional crosslinking reaction with an increase in temperature or an increase in crosslinking density due to the exchange of polysulfide chains to a lower order.

In this embodiment, when there is a difference between the first hose layer 110 and the second hose layer 130 in the expansion rate or hardness reinforcing characteristics when the temperature rises, the second hose layer 130 is the first hose layer ( 110). Accordingly, the first hose layer 110 is in a state of receiving a kind of external pressure by the second hose layer 130, and the effect of receiving such external pressure by thermal expansion when the temperature is increased may be further increased.

Therefore, when the temperature rises, in addition to the increase in the thermal stiffness of the first hose layer 110, due to the pressure applied to the first hose layer by the thermally expanded second hose layer 130, the first hose layer ( 110) can be further increased.

That is, due to the increase in the rigidity of the first hose layer 110, it is possible to provide a vehicle hose 100 that is more durable in environments such as high temperature and high pressure.

In particular, when the rubber component of the second hose layer 130 is a rubber crosslinked by a crosslinking agent, and the crosslinking agent is different from the first hose layer 110, the first hose layer 110 and the second hose layer 130 Since there is a difference in the behavior according to the temperature increase, the first hose layer 110 may be constrained by the second hose layer 130 to receive an external force, and as a result, the first hose layer 110 when the temperature rises The stiffness of can be further increased.

At least one of the first hose layer 110 and the second hose layer 130 may be reinforced with carbon fiber. In this case, at least one carbon fiber of the first hose layer 110 and the second hose layer 130 may form a braided braided layer.

10 is a view showing a vehicle hose 100 according to another embodiment of the present invention.

The vehicle hose 100 of the embodiment shown in FIG. 10 includes a first hose layer 110 and a second hose layer 130.

The first hose layer 110 is similar to the first hose layer 110 of the embodiment shown in FIG. 9 and thus a detailed description thereof will be omitted.

2 The hose layer 130 may be formed on the inner surface of the first hose layer 110. When the second hose layer 130 is expanded, it acts as an external force on the first hose layer 110 to help increase the hardness or strength of the first hose layer 110 according to the temperature increase. Since the second hose layer 130 is similar to the second hose layer 130 of the embodiment shown in FIG. 9, further detailed description will be omitted.

11 is a view for explaining an example of a method of manufacturing a vehicle hose 100 according to an embodiment of the present invention.

In the case of manufacturing the vehicle hose 100 shown in FIG. 9, for example, first, the amount of the unvulcanized rubber has the characteristics described in FIGS. 5 and 6, that is, strength maintenance or increasing characteristics when the temperature rises. The adjusted crosslinking agent is added and kneaded to make raw materials.

Thereafter, this raw material provided from the raw material tank is extruded by the extruder 2 to extrude the first hose layer 110, and the first hose layer 110 may be cooled by the cooler 4.

Thereafter, the first hose layer 110 may be subjected to a predetermined heat treatment through the heat treatment unit 10. At this time, a crosslinking reaction occurs in the first hose layer 110, so that a part of the vulcanized rubber component and a part of the first hose layer 110 may not be crosslinked, and thus a thermoplastic rubber component may be obtained.

On the other hand, before extruding the first hose layer 110, a process of forming the first hose layer 110 by extruding a raw material subjected to a partial crosslinking process and further performing crosslinking by heat treatment is also possible.

Thereafter, the raw material for forming the second hose layer 130 is stored in the raw material feeder 6, and the raw material for forming the second hose layer 130 is supplied to the extruder 12, and the extruder 12 is 1 The second hose layer 130 may be formed on the outer surface of the hose layer 110 and additional heat treatment may be performed, and accordingly, the vehicle hose 100 may be manufactured.

The above description of the present invention is for illustrative purposes only, and those of ordinary skill in the art to which the present invention pertains will be able to understand that it can be easily modified into other specific forms without changing the technical spirit or essential features of the present invention. will be. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not limiting. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as being distributed may also be implemented in a combined form.

The scope of the present invention is indicated by the claims to be described later, and all changes or modified forms derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present invention.

100: vehicle hose
110: first hose layer
130: second hose layer

Claims (10)

In the vehicle hose,
Thermoplastic rubber component; And
A vulcanization rubber component that is crosslinked by a crosslinking agent to increase strength when the temperature increases, and is formed in a hose shape,
A vehicle hose in which the content of the crosslinking agent is adjusted to compensate for the decrease in strength due to the thermoplastic rubber component when the temperature rises, or increase the strength due to the vulcanized rubber component.
The method of claim 1,
The crosslinking agent is a vehicle hose, characterized in that it contains at least one of sulfur and DCP (dicumyl peroxide).
The method of claim 1,
The thermoplastic rubber component comprises at least one of NR, SBR, and acrylic rubber.
The method of claim 1,
The vulcanized rubber component is a vehicle hose, characterized in that the rubber of the same type as the thermoplastic rubber component except for a crosslinking agent.
The method of claim 4,
When the vulcanized rubber component is NR, the content of the crosslinking agent is sulfur 2.0 phr or higher, or DCP 3.0 phr or higher,
When the vulcanized rubber component is SBR, the content of the crosslinking agent is sulfur 1.75 phr or more, or DCP 1.0 phr or more.
The method of claim 1,
The vehicle hose,
A first hose layer made of the crosslinked vulcanized rubber component and the non-crosslinked thermoplastic rubber component by adding the crosslinking agent to the unvulcanized rubber, kneading and heating it; And
And a second hose layer surrounding the outer surface of the first hose layer or formed on the inner surface of the first hose layer.
The method of claim 6,
When the temperature rises, the thermal stiffness of the first hose layer further increases due to the pressure exerted on the first hose layer by the second hose layer to be thermally expanded in addition to the increase in the thermal stiffness of the first hose layer. Vehicle hose.
The method of claim 1,
A vehicle hose, characterized in that the carbon fiber is further mixed to form the hose shape.
The method of claim 6,
The second hose layer is a vehicle hose, characterized in that it comprises a vulcanized rubber component crosslinked by a crosslinking agent different from the first hose layer.
The method of claim 6,
At least one of the first hose layer and the second hose layer comprises carbon fiber.

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