JP2013130283A - Air conditioner hose for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air conditioner hose with more excellent vibration absorption performance than a conventional one.SOLUTION: The air conditioner hose 10A for a vehicle is formed by laminating an inner rubber layer 12, a reinforcing yarn layer 14 formed by braiding reinforcing yarn on an outer circumference side of the inner rubber layer 12, and an outer rubber layer 16 on an outer circumference side of the reinforcing yarn layer 14. The inner rubber layer 12 and the outer rubber layer 16 are vulcanized integrally in an incorporated state to each other through a clearance between the reinforcing yarn and the reinforcing yarn of the reinforcing yarn layer 14. An area rate of the incorporated part is in a range of 30-72%.

Description

  The present invention relates to a vehicle air conditioner hose for transporting a refrigerant, and more particularly to a feature of technical means for enhancing vibration absorption performance.

The air conditioner hose for vehicles connects the compressor in the engine room to the condenser and evaporator fixed on the vehicle body, and plays a role of transporting refrigerant from the compressor to the condenser or from the evaporator to the compressor. At the same time, the condenser, evaporator and compressor It absorbs the vibration between the compressor and the compressor, and further suppresses the transmission of the compressor vibration and further the engine vibration that drives the compressor to the vehicle body.
If compressor vibration or engine vibration is transmitted to the vehicle body side, it will cause vehicle interior noise.

  This air-conditioner hose connects a hose connected to the outlet side of the compressor, that is, the compressor and the condenser, and a high-pressure side air-conditioning hose in which a pressure of about 1.5 MPa is applied inside, and a hose connected to the inlet side of the compressor, ie, the compressor And an evaporator, and is divided into a low-pressure air conditioner hose that applies a pressure of about 0.5 MPa inside.

FIG. 6A shows a conventional configuration example of the latter high-pressure side air-conditioning hose as a comparative example.
As shown in the figure, the conventional high-pressure side air conditioner hose 200A includes an inner rubber layer 201, a reinforcing yarn layer 202 formed on the outer peripheral side of the reinforcing yarn made of organic fibers by spiral braiding, Further, a laminated structure is formed with an outer rubber layer 204 formed on the outer peripheral side.
Here, the reinforcing yarn layer 202 includes a first reinforcing yarn layer 202-1 spirally wound around the outer peripheral surface of the inner rubber layer 201, and a first spiral yarn wound in the opposite direction on the outer peripheral side. 2 reinforcing yarn layers 202-2, and an intermediate rubber layer 206 is interposed between the first reinforcing yarn layer 202-1 and the second reinforcing yarn layer 202-2.
Further, on the inner side of the inner rubber layer 201, a resin inner layer 208 serving as a barrier layer against the refrigerant that is a transport fluid is laminated so as to cover the inner surface of the inner rubber layer 201.
Incidentally, this type of air conditioner hose 200A is disclosed in, for example, Patent Document 1 and Patent Document 2 below.

The reinforcing yarn layer 202 gives pressure resistance strength to the air conditioner hose 200A, and the high pressure air conditioner hose 200A is applied with a high pressure of 1.5 MPa as an internal pressure, and is used severely in the market environment. Conventionally, the reinforcing yarn layer 202 is braided at a high braid density of 100% together with the first reinforcing yarn layer 202-1 and the second reinforcing yarn layer 202-2.
Here, the braid density is the area ratio of the reinforcing yarn in the reinforcing yarn layer 202, and when the gap between the reinforcing yarns is zero, the braid density is 100%.
That is, the inner rubber layer 201 and the outer rubber layer 204 are completely blocked by the reinforcing yarn layer 202 interposed therebetween.

  Therefore, in the conventional high-pressure side air-conditioning hose 200A shown in FIG. 6 (a), it is indispensable to bond the reinforcing yarn with an adhesive, and the inner rubber layer 201 is bonded to the reinforcing yarn layer 202 by the adhesive. Similarly, the outer rubber layer 204 was bonded to the reinforcing yarn layer 202 with an adhesive, and the inner rubber layer 201 and the outer rubber layer 204 were integrated with each other through the reinforcing yarn layer 202.

  However, in this case, the air conditioner hose 200A is added to the hard and rigid resin inner layer 208 as the innermost layer (the resin inner layer 208 as the barrier layer is made of a hard and rigid resin such as polyamide), and further Since the structure has a rigid reinforcing yarn layer 202 having a high braid density in the middle part of the cross section, and further, the inner rubber layer 201 and the outer rubber layer 204 are blocked by the reinforcing yarn layer 202. This has been a hindrance to improving the vibration absorption performance, and has a problem that the vibration absorption performance is still insufficient.

FIG. 6B shows a conventional configuration example of a low-pressure air conditioning hose as a comparative example.
This low-pressure side air-conditioning hose 200B has basically the same configuration as the high-pressure side air-conditioning hose 200A shown in FIG. 6A except that the resin inner layer 208 is not provided.
However, in this low-pressure side air-conditioning hose 200B, the braid density of each of the first reinforcing yarn layer 202-1 and the second reinforcing yarn layer 202-2 does not reach 100%, for example, 82% here. A predetermined stitch or gap is formed between the reinforcing yarns.
And the inner rubber layer 201 and the outer rubber layer 204 are connected to each other through the intermediate rubber layer 206 through the gap, but because the gap is small, the adhesive treatment of the reinforcing yarn with an adhesive is indispensable like the high pressure hose, The inner rubber layer 201 is bonded to the reinforcing thread layer 202 by the adhesive, and the outer rubber layer 204 is also bonded to the reinforcing thread 202 by the adhesive, so that the inner rubber layer 201 and the outer rubber layer 204 are reinforced. They are integrated with each other via the thread layer 202.

  This low-pressure side air-conditioning hose 20B has the same basic structure as the high-pressure-side air-conditioning hose 200A, but does not include the resin inner layer 208, and the braid density of the reinforcing yarn layer 202 is higher than that of the high-pressure-side air-conditioning hose 200A. However, the braid density of the reinforcing yarn layer 202 is still high, and therefore the low-pressure side air-conditioning hose 200B is also reinforced. Since the yarn layer 202 is a rigid layer, the vibration absorbing performance is still insufficient.

  Under such circumstances, in order to further reduce vehicle interior noise caused by compressor vibration and engine vibration, further improvement in vibration absorption performance has been demanded for the air conditioner hose.

Japanese Patent No. 3396975 JP 2008-101709 A

  The present invention has been made for the purpose of providing an air conditioner hose which is more excellent in vibration absorbing performance than the conventional one against the background described above.

  Thus, according to the first aspect, the inner rubber layer, the reinforcing yarn layer formed by braiding the reinforcing yarn on the outer peripheral side of the inner rubber layer, and the outer rubber layer on the outer peripheral side of the reinforcing yarn layer are laminated. In the vehicular air conditioner hose, the inner rubber layer and the outer rubber layer are integrally vulcanized in a united state through a gap between the reinforcing yarn and the reinforcing yarn in the reinforcing yarn layer. The area ratio is in the range of 30 to 72%.

  According to a second aspect of the present invention, the hose on the high pressure side connected to the outlet side of the compressor according to the first aspect, wherein an inner resin layer is laminated so as to cover an inner surface of the inner rubber layer, and the combined portion The area ratio is in the range of 30 to 49%.

  A third aspect of the present invention is the low-pressure side hose connected to the inlet side of the compressor according to the first aspect, wherein the area ratio of the combined portion is in the range of 42 to 72%.

  According to a fourth aspect of the present invention, in any one of the first to third aspects, the base yarn in the reinforcing yarn has a tensile strength of 17 cN / decitex or more.

  According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the reinforcing yarn is configured using a spanned yarn.

  A sixth aspect is characterized in that, in the fifth aspect, the reinforcing yarn is an aramid yarn.

  According to a seventh aspect of the present invention, in any one of the first to sixth aspects, the inner rubber layer and the outer rubber layer are configured so that each of them includes a rubber material of the same material as at least a part of the rubber material. It is characterized by that.

Effects and effects of the invention

As described above, the present invention provides a vehicle air conditioner hose having a laminated structure of an inner rubber layer, a reinforcing yarn layer, and an outer rubber layer, and the inner rubber layer and the outer rubber layer are connected to the reinforcing yarn in the reinforcing yarn layer. These are integrally vulcanized in a combined state through a stitch gap between the reinforcing yarns, and the area ratio of the combined portion is in the range of 30 to 72%.
Here, the area ratio of the merged portion refers to an area ratio of the entire overlapping surface in the radial direction between the outer peripheral surface of the inner rubber layer and the inner peripheral surface of the outer rubber layer.
In the present invention, the reinforcing yarn layer naturally does not include a metal wire.

According to the present invention, the inner rubber layer and the outer rubber layer are integrally vulcanized into a combined state through a gap between the reinforcing yarn and the reinforcing yarn, and the area ratio of the combined portion is set to a high ratio of 30 to 72%. Therefore, the flexibility of the entire air conditioner hose can be increased compared to the conventional one, and the vibration absorption of the air conditioner hose can be achieved by making the inner rubber layer and the outer rubber layer an integrated structure in which the rubber materials are connected to each other. Performance can be increased.
As a result, the compressor vibration and engine vibration generated in the engine room can be further suppressed from propagating to the vehicle body via the air conditioner hose, and the vehicle interior noise caused by the vibration propagation can be effectively reduced. can do.

According to the present invention, the vibration absorption performance of the air conditioner hose is enhanced, and as a result, it is possible to make it shorter than the conventional air conditioner hose.
A conventional air conditioner hose has high rigidity and vibration absorption performance is not always sufficient. For example, even if the linear distance to be connected is 200 mm, a long hose having a length of 300 to 600 mm, for example, about 400 mm is used. In order to reduce the propagation of vibration, the length of the hose is increased, which inevitably increases the contact area with the refrigerant and increases the amount of refrigerant permeated.
In addition, the amount of moisture entering the hose from the outside also increases.
However, if the air-conditioning hose can be shortened, it can be expected that the amount of refrigerant permeation and moisture intrusion can be reduced by the shortening itself.

In the present invention, the area ratio of the combined portion is defined as 30% to 72% for the following reason.
That is, when the area ratio is lower than 30%, the integration of the inner rubber layer and the outer rubber layer by partial coalescence becomes insufficient, and the braid density of the reinforcing yarn is also increased, so that the air conditioner hose is increased. This is because the vibration absorption performance of the air conditioner hose cannot be sufficiently increased.
On the other hand, when the area ratio exceeds 72%, the flexibility and vibration absorption performance increase, but the braid density of the reinforcing yarn becomes too low and the pressure resistance strength as an air conditioner hose becomes insufficient.

As described above, the air conditioner hose includes the high pressure side air conditioner hose connected to the outlet side of the compressor and the low pressure side air conditioner hose connected to the inlet side of the compressor, particularly the former high pressure side air conditioner hose. Therefore, it is desirable to keep the area ratio of the combined portion in the range of 30 to 49% according to claim 2.
On the other hand, in the latter low-pressure side air-conditioning hose, it is desirable to keep the area ratio of the combined portion within the range of 42 to 72% higher than that of the former high-pressure-side air-conditioning hose according to claim 3.

In the present invention, it is desirable that the reinforcing yarn is constituted by using the spanned yarn according to the fifth aspect.
Here, configuring the reinforcing yarn using the spanned yarn means that the raw yarn that is a structural unit of the reinforcing yarn is a spanned yarn.

  When constructing a reinforcing yarn, if it is composed of one raw yarn, if it is composed by twisting two raw yarns (twisted yarn), or if it is composed by twisting three or more raw yarns The original yarn is a spanned yarn means that at least one original yarn is a spanned yarn.

Here, the original yarn is a twisted monofilament group consisting of a large number of monofilaments (short fibers), and the spanned yarn is a monofilament that is obtained by applying tension in a state where a large number of monofilaments are aligned and bundled. Is broken (checked out) at an arbitrary position with a length of about 60 cm, and is further twisted to form a yarn, which has a predetermined fluff due to the breaking.
When the reinforcing yarn is configured using such a spanned yarn, the integrity of the reinforcing yarn and the rubber is easily obtained due to the anchoring effect by fuzzing.
As a result, the reinforcing effect by the reinforcing yarn can be enhanced, and the displacement of the reinforcing yarn and the wear of the reinforcing yarn resulting therefrom can be effectively suppressed.

In the present invention, it is desirable to use a yarn having a tensile strength of 17 cN / decitex or more as the raw yarn of the reinforcing yarn.
In addition, the tensile strength said here means the tensile strength in the tensile test according to JIS L1013.
Even if the inner rubber layer and the outer rubber layer are combined at a high area ratio of 30 to 72% by configuring the reinforcing yarn using such high-strength raw yarn, it is required as an air conditioner hose. It is possible to obtain a withstand pressure strength.

  In this case, an aramid yarn can be suitably used as the raw yarn in the reinforcing yarn (claim 6).

In the present invention, it is desirable that each of the inner rubber layer and the outer rubber layer is configured to include the same rubber material as at least a part of the rubber material.
By doing in this way, it becomes easy to integrally vulcanize the inner rubber layer and the outer rubber layer in the combined portion.

It is the figure which showed the air-conditioner hose of the high voltage | pressure side which is one Embodiment of this invention. It is the figure which showed the measurement result of the vibration transmission characteristic and the softness | flexibility of the air-conditioner hose of FIG. It is the figure which showed the measuring method of a vibration transfer characteristic, and the measuring method of a flexibility measurement. It is the figure which showed the low pressure side air-conditioning hose which is other embodiment of this invention. It is the figure which showed the measurement result of the vibration transmission characteristic of the air-conditioner hose of FIG. It is the figure which showed an example of the conventional vehicle air conditioner hose.

Next, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 shows an example of a high-pressure side air-conditioning hose. A high-pressure side air-conditioning hose 10A in this example includes an inner rubber layer 12, a reinforcing yarn layer 14 formed on the outer peripheral side thereof, and an outer periphery thereof. A laminated structure with the outer rubber layer 16 formed on the side is formed.
Further, an inner resin layer 18 is laminated on the inner rubber layer 12 so as to cover the inner surface thereof.

The resin inner layer 18 serves as a barrier layer against a refrigerant as a transport fluid, and the resin inner layer 18 may be made of a polyamide resin, a polyester resin or other material which is stable against the refrigerant. Polyamide 6 resin is used.
The wall thickness is about 0.15 mm.

  On the other hand, the inner rubber layer 12 is made of butyl rubber, specifically butyl rubber (IIR), halogenated butyl rubber (Cl-IIR, Br-IIR), butyl rubber and halogenated from the viewpoint of weather resistance, chemical resistance, and low gas permeability. A copolymer of butyl rubber or the like can be suitably used. Here, halogenated butyl rubber is used as the inner rubber layer 12.

  On the other hand, as the outer rubber layer 16, the butyl rubber type, acrylic rubber type, ethylene-propylene copolymer (EPM, EPDM of ethylene-propylene-diene copolymer, etc.) can be preferably used. As the layer 16, a halogenated butyl rubber made of the same material as that of the inner rubber layer 12 is used.

However, EPDM can also be used as the outer rubber layer 16 from the viewpoint of better weather resistance.
In this case, when butyl rubber is used as the inner rubber layer 12, it is desirable to use a blend material of EPDM and butyl rubber which is the same material as the inner rubber layer 12 as the outer rubber layer 16.

  In this example, the reinforcing yarn layer 14 can also be constituted by braiding the reinforcing yarn with a blade braid or knitting braid, but here the spiral braiding, more specifically, the reinforcing yarn is spiraled in one direction on the outer peripheral surface of the inner rubber layer 12. A first layer 14-1 wound and a second layer 14-2 spirally wound in the opposite direction so that the same reinforcing yarn is directly crossed with the reinforcing yarn of the first layer 14-1 It has a laminated structure.

  That is, in the conventional air conditioner hose, the first reinforcing layer formed by spirally winding the reinforcing yarn and the second reinforcing layer formed by spirally winding the reinforcing yarn in the opposite direction are laminated with the intermediate rubber layer interposed therebetween. Although the reinforcing yarn layer is configured in the form, the reinforcing yarn layer 14 is configured by laminating the first layer 14-1 and the second layer 14-2 in direct contact with each other.

  Further, in the conventional air conditioner hose, the reinforcing yarn layer is configured by using the reinforcing yarn that has been subjected to DIP processing (adhesive application processing) in advance. Here, the reinforcing yarn is used by using the reinforcing yarn that has not been subjected to such DIP processing. Layer 14 is configured. However, the reinforcing yarn layer 14 can also be configured by using a reinforcing yarn that has been subjected to DIP processing in advance.

Furthermore, in this embodiment, the braid density of the reinforcing yarn in the reinforcing yarn layer 14 is as low as 59%, and a large stitch gap is formed between the reinforcing yarn and the reinforcing yarn. The rubber layer 12 and the outer rubber layer 16 are integrally vulcanized in a combined state.
The area ratio of the merged portion is 41% here.

但しこの実施形態では、補強糸層１４が第１層１４-１と第２層１４-２とから成っているため、第１層１４-１の編組密度をＸ１，第２層１４-２の編組密度（見かけの編組密度）をＸ２としたとき、補強糸層１４全体の編組密度を下記式(２)で求めている。

具体的にはこの実施形態では、（補強糸層のすぐ内側層）は内ゴム層１２となる。ここではその外径は１５．９ｍｍである。
尚、上記の式中糸幅，糸本数はそれぞれ補強糸の幅，本数である。
ここでは補強糸の幅（直径）は０．４ｍｍであり、また補強糸の本数（打ち込み本数）は第１層１４-１，第２層１４-２ともに２６本であり、また補強糸の編組角度θは５５°である。
本実施形態では、補強糸層１４として引張強度が１７ｃＮ／デシテックスの高強度のアラミド糸が用いられており、エアコンホースとしての所要の耐圧強度を有している。
また補強糸として毛羽立ちを有するスパナイズド糸が用いられており、その毛羽の投錨効果によって、補強糸と内ゴム層１２及び外ゴム層１６との一体性が確保されている。 In other words, here, the inner rubber layer 12 and the outer rubber layer 16 are integrated (a state in which they are integrally connected) over the overlapping surface in the radial direction, that is, 41% of the entire opposing surface.
In this embodiment, the area ratio [%] of the merged portion is 100 [%] − the braid density of the reinforcing yarn [%]
Is required.
Here, the braid density of the reinforcing yarn can be obtained by the following equation (1) when the reinforcing yarn layer is single (only one layer).

However, in this embodiment, since the reinforcing yarn layer 14 is composed of the first layer 14-1 and the second layer 14-2, the braid density of the first layer 14-1 is X1, the second layer 14-2. When the braid density (apparent braid density) is X2, the braid density of the entire reinforcing yarn layer 14 is obtained by the following equation (2).

Specifically, in this embodiment, the (immediately inner layer of the reinforcing yarn layer) is the inner rubber layer 12. Here, the outer diameter is 15.9 mm.
In the above formula, the middle thread width and the number of yarns are the width and number of reinforcing threads, respectively.
Here, the width (diameter) of the reinforcing yarn is 0.4 mm, the number of reinforcing yarns (the number of driven-in yarns) is 26 for both the first layer 14-1 and the second layer 14-2, and the braiding of the reinforcing yarn The angle θ is 55 °.
In the present embodiment, a high-strength aramid yarn having a tensile strength of 17 cN / dtex is used as the reinforcing yarn layer 14 and has a required pressure resistance strength as an air conditioner hose.
A spanned yarn having fluff is used as the reinforcing yarn, and the integrity of the reinforcing yarn and the inner rubber layer 12 and the outer rubber layer 16 is ensured by the throwing effect of the fluff.

In this example, the air conditioner hose 10A has an outer diameter d ₁ = φ19.0 mm, an inner diameter d ₂ = φ12.0 mm, and a wall thickness t = 3.5 mm.
The air conditioner hose 10A having the above configuration can be manufactured as follows.
That is, the reinforcing thread is wound around the outer peripheral surface of the extruded inner rubber layer 12 to first form the first layer 14-1, and then the second layer 14-2 is formed on the upper side thereof.
At this time, the reinforcing yarn in the reinforcing yarn layer 14 is in a state of being bitten into the inner rubber layer 12.

Thereafter, the outer rubber layer 16 is extruded on the outer peripheral side of the reinforcing yarn layer 14. At this time, the inner rubber layer 12 and the outer rubber layer 16 are in contact with each other through a gap between the reinforcing yarn and the reinforcing yarn in the reinforcing yarn layer 14.
At this time, even if there is a minute gap between the inner rubber layer 12 and the outer rubber layer 16, the outer rubber layer 16 is then coated with a resin and the outer rubber layer 16 is pressed in the direction of diameter reduction. When the vulcanization process is performed, the inner rubber layer 12 and the outer rubber layer 16 are reinforced with a reinforcing yarn and a reinforcing yarn by pressing the outer rubber layer 16 in a reduced diameter direction by the resin coating and expanding the rubber by heating during vulcanization. The portion of the stitch gap is fused in a sufficiently close contact state, that is, in a coalesced state, and in the coalesced state, a cross-linking reaction occurs across the inner rubber layer 12 and the outer rubber layer 16 so that they are integrally bonded.
Thereafter, the resin coating is removed and the molded body is cut into a predetermined size, whereby the high-pressure side air conditioner hose 10A shown in FIG. 1 is obtained.

About the above high-pressure side air conditioner hose 10A, vibration transmission measurement and flexibility measurement were performed to evaluate each characteristic of vibration absorption performance and flexibility.
For comparison, the same test and evaluation were performed for the conventional high-pressure air conditioner hose 200A shown in FIG.
The conventional air conditioner hose 200A has the same dimensional relationship as that of the present embodiment, but differs in the material, the configuration of the reinforcing yarn layer, the presence or absence of an intermediate rubber layer, and the like.
That is, the resin inner layer 200 </ b> A and the inner rubber layer 201 are the same as in the present embodiment, but EPDM is used as the intermediate rubber layer 206 and the outer rubber layer 204.

Further, a polyester yarn that has been DIP-treated in advance is used as the reinforcing yarn, and this is 100% in total including the first reinforcing yarn layer 202-1 and the second reinforcing yarn layer 202-2 (specifically, the first reinforcing yarn layer 202). The reinforcing yarn layer 202 was configured by braiding at a braiding density of 100% for both the -1 and the second reinforcing yarn layers 202-2.
In the case of the air conditioner hose 200A, the overall braid density is the braid density obtained by combining the braid density of the first reinforcing yarn layer 202-1 and the braid density of the second reinforcing yarn layer 202-2.
In this case, the inner layer of the reinforcing yarn layer that becomes the reference for calculating the braid density of the first reinforcing yarn layer 202-1 becomes the inner rubber layer 201, and the braid density of the second reinforcing yarn layer 202-2 is calculated. A layer immediately inside the reference reinforcing yarn layer is an intermediate rubber layer 206.
Therefore, the inner rubber layer 201 and the outer rubber layer 204 are completely cut off by the reinforcing yarn layer 202, and they are not combined, fused, or integrated with each other at all.
That is, the area ratio of the combined portion of the inner rubber layer 201 and the outer rubber layer 204 is 0%.

<Vibration transmission measurement>
The vibration transmission measurement was performed using a measuring apparatus 20 shown in FIG.
Specifically, a hose (air conditioner hose 10A, 200A) is set in the measuring device 20, and each end is fixed and supported by a fixed part 22 on the vibration side and a fixed part 24 on the vibration side. The vibration device 26 is applied with a constant acceleration of 29.4 m / s ² (3G) while receiving vibration at the other end side with the vibration device 26 applied at 0.5 MPa, and provided on the fixed portion 22 on the vibration side. The excitation-side acceleration sensor 28 measures the excitation-side acceleration A _0, and the vibration-receiving-side acceleration sensor 30 provided in the vibration-receiving-side fixing unit 24 measures the vibration-receiving acceleration A _1. Gain) was measured.
In FIG. 3A, reference numeral 32 denotes a rubber, and L denotes a hose free length.

<Flexibility measurement>
The flexible measurement was performed by the method shown in FIG.
Specifically, a spring gauge 34 is attached to one end of the hose, the hose is bent and deformed by 180 °, and the bending force of the hose when it is bent by 180 ° is measured to obtain a value indicating flexibility.
The hose free length L was set to 350 mm.
<Result>
The results of vibration transmission measurement are shown in FIGS. 2A and 2B, and the flexibility measurement result is shown in FIG.
FIG. 2A shows the vibration transfer characteristic (gain) by changing the excitation frequency. The horizontal axis indicates the excitation frequency, and the vertical axis indicates the gain = 20 Log ₁₀ (A ₁ / A ₀ ). It is.
Table 1 also shows the gain values at 100 Hz, 300 Hz, and 600 Hz and the average gain value from 100 to 600 Hz.

  As shown in FIG. 2A and Table 1, in the high-pressure-side air conditioner hose 10A of the present embodiment, 5.6 dB (under an excitation frequency of 100 Hz as compared with the conventional air conditioner hose 200A) 14%), 5.6 dB (14%) lower at an excitation frequency of 300 Hz, and 14.1 dB (29%) lower at 600 Hz, and an average gain of 100 to 600 Hz is 9. The air conditioner hose 10A of the present embodiment has a higher vibration absorption performance than the conventional air conditioner hose 200A.

  On the other hand, FIG. 2B shows an average gain of 100 to 600 Hz when the hose free length is changed to 250 mm, 300 mm, and 400 mm. As shown in the result of FIG. In the air conditioner hose 10A of the configuration, the hose free length 250 mm is 6.6 dB (15%) lower, the hose free length 300 mm is 7.3 dB (16%) lower than the conventional air conditioner hose 200 A, and the hose free length 400 mm is 9 mm. .8 dB (21%), and it can be seen from this result that the air conditioner hose 10A of the present embodiment has higher vibration absorption performance than the conventional air conditioner hose 200A.

Of particular note is that in the air conditioner hose 10A of the present embodiment, even when the hose free length is shortened to 250 mm, the average gain is greatly reduced as compared with the conventional air conditioner hose 200A, which is as long as 400 mm. Even if the length is reduced to 250 mm, the vibration absorbing performance is higher than that of the conventional air conditioner hose 200A. From this, it can be seen that the air conditioner hose 10A of the present embodiment can be shortened while maintaining high vibration absorption performance.
In the high-pressure side air conditioner hose 200A, the length is usually 400 mm or more.

  FIG. 2C shows the measurement result of the hose flexibility. In the conventional air conditioner hose 200A (conventional product), the force for bending by 180 ° is 7.4 N, whereas the air conditioner of this embodiment is shown in FIG. In the case of the hose 10A, the bending force is as small as 4.8N (reduction of 35%), and the flexibility of the hose is high.

Next, Table 2 shows the results of tests other than the above (pressure repetition test, air tightness test, dimensional change test, pressure resistance test, destructive test, permeation test, moisture permeation test).
Each test was performed as follows.

<Pressure repetition test>
Endurance is evaluated by bending the hose into a U-shape, repeatedly applying an internal pressure of 0 to 3.5 MPa to the hose at an atmospheric temperature of 130 ° C. at a repetition rate of 30 cpm, and examining the number of repetitions until the hose bursts. did.

<Airtight test>
After filling with nitrogen gas at a test pressure of 3.0 MPa, the hose was submerged in water and examined for leakage of nitrogen gas from the hose caulking portion.

<Dimensional change test>
A change in hose length and change in outer diameter due to the internal pressure after applying an internal pressure of 3.0 MPa and holding for 5 minutes were examined.

<Pressure resistance test>
A liquid pressure of 5.0 MPa was applied, and the occurrence of rupture, liquid leakage, and local blistering after 5 minutes was examined.

<Destructive testing>
The hydraulic pressure was applied at a pressing speed of 150 mPa / min, and the burst strength was measured.

<Transmission test>
The sample hose in which the refrigerant was sealed was left in a constant temperature bath at 90 ° C. for 72 hours, and the mass loss ratio was calculated.

<Moisture permeability test>
A hose containing a desiccant (a type of zeolite having a porous structure and adsorbing water molecules in the pores to dry, here using molecular sieve (trade name)), 60 ° C x 95% Place in a constant temperature and humidity chamber adjusted to RH, leave it for 168 hours, take out the hose after the lapse of specified time, take out the desiccant from the hose and measure the mass.
The water permeability was determined from the difference between the mass of the initial desiccant and the mass of the desiccant after leaving the test.

  As can be seen from the results in Table 2, the air conditioner hose 10A of the present embodiment has characteristics such as repeated pressure durability, airtightness, dimensional change, pressure resistance, breaking strength, permeation resistance, and moisture permeation resistance. It has the same performance as the conventional air conditioner hose 200A.

Next, FIG. 4 shows an example of a low-pressure air conditioner hose.
The low pressure side air conditioner hose 10B of this example has basically the same configuration as the high pressure side air conditioner hose 10A shown in FIG. 1 except that the resin inner layer 18 is not provided.
However, in this low-pressure side air-conditioning hose 10B, the braid density of the reinforcing yarn layer 14 is 48%, the area ratio of the combined portion of the inner rubber layer 12 and the outer rubber layer 16 is 52%, and the high-pressure side air-conditioning hose 10B. The area ratio is higher than that of the hose 10A.
In terms of dimensions, the low-pressure air conditioner hose 10B has an outer diameter d ₁ = φ24.5 mm, an inner diameter d ₂ = φ16 mm, and a wall thickness t = 4.25 mm.
The material of the reinforcing thread in the inner rubber layer 12, the outer rubber layer 16, and the reinforcing thread layer 14 is the same as that of the high-pressure side air conditioner hose 10A in FIG.

With respect to the low-pressure side air-conditioning hose 10B, vibration transmission measurement was performed in the same manner and under the same conditions as those for the high-pressure-side air-conditioning hose 10A.
For comparison, the same test and evaluation were performed for the conventional low-pressure air conditioner hose 200B shown in FIG.
The conventional air conditioner hose 200B has the same dimensional relationship as the low pressure side air conditioner hose 10B of the present embodiment, but differs in material and configuration of the reinforcing yarn layer.
That is, butyl rubber is used for the inner rubber layer 201 as in the present embodiment, but EPDM is used for the intermediate rubber layer 206 and the outer rubber layer 204.
Further, the reinforcing yarn layer 202 is configured by using a polyester yarn that has been DIP-treated in advance as a reinforcing yarn and braiding the first reinforcing yarn layer 202-1 and the second reinforcing yarn layer 202-2 with a braid density of 82%. doing.

The results are shown in FIGS. 5 (A) and (B).
FIG. 5A shows the vibration transfer characteristics (gain) examined by changing the excitation frequency. The horizontal axis indicates the excitation frequency and the vertical axis indicates gain = 20 Log ₁₀ (A ₁ / A ₀ ). It is.
In Table 3, gains at 100 Hz, 300 Hz, and 600 Hz and average gain values between 100 and 600 Hz are separately shown.
As shown in FIG. 5A and Table 3, the low-pressure air conditioner hose 10B of the present embodiment has 5.0 dB (under an excitation frequency of 100 Hz as compared with the conventional air conditioner hose 200B. 13%) low, 4.3 dB (9%) lower at an excitation frequency of 300 Hz, 7.4 dB (13%) lower at 600 Hz, and 5.7 dB at an average gain of 100-600 Hz. The air conditioning hose 10B of the present embodiment on the low pressure side also has higher vibration absorption performance than the conventional air conditioning hose 200B.

  On the other hand, FIG. 5B shows the average gain of 100 to 600 Hz when the hose free length is changed to 250, 300, and 400 mm. As shown in the result of FIG. Even if the air conditioner hose 10B of the embodiment is shortened within a range of up to 250 mm, the air conditioner hose 10B of the conventional low pressure side air conditioner hose 200B has a vibration absorbing performance equal to or higher than that of the hose length of 400 mm. Yes.

  Although the embodiment of the present invention has been described in detail above, this is merely an example, and the present invention can be configured in various forms without departing from the spirit of the present invention.

10A, 10B Air conditioning hose 12 Inner rubber layer 14 Reinforcement layer 16 Outer rubber layer 18 Resin inner layer

Claims (7)

In a vehicle air conditioner hose formed by laminating an inner rubber layer, a reinforcing yarn layer formed by braiding reinforcing yarn on the outer peripheral side of the inner rubber layer, and an outer rubber layer on the outer peripheral side of the reinforcing yarn layer,
The inner rubber layer and the outer rubber layer are integrally vulcanized in a combined state through a gap between the reinforcing yarn and the reinforcing yarn in the reinforcing yarn layer, and the area ratio of the combined portion is in the range of 30 to 72% An air conditioner hose for a vehicle characterized in that it is inside.   A hose on the high pressure side connected to the outlet side of the compressor, wherein the resin inner layer is laminated so as to cover the inner surface of the inner rubber layer, and the area ratio of the combined portion is in the range of 30 to 49% The vehicle air conditioner hose according to claim 1, wherein the vehicle air conditioner hose is provided.   The vehicle air conditioner hose according to claim 1, wherein the hose is a low pressure side hose connected to an inlet side of a compressor, and an area ratio of the combined portion is in a range of 42 to 72%.   The air conditioner hose for a vehicle according to any one of claims 1 to 3, wherein a raw yarn in the reinforcing yarn has a tensile strength of 17 cN / dtex or more.   The vehicle air conditioner hose according to any one of claims 1 to 4, wherein the reinforcing yarn is configured using a spanned yarn.   The vehicular air conditioning hose according to claim 5, wherein the reinforcing yarn is an aramid yarn.   The vehicle according to any one of claims 1 to 6, wherein the inner rubber layer and the outer rubber layer are configured so that each of them includes the same rubber material as at least a part of the rubber material. Air conditioner hose.

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