JP7787664B2 - Method and system for predicting remaining hose life - Google Patents

Description

The present invention relates to a method for predicting the remaining life of a hose and a system for predicting the remaining life of a hose.

Hoses with an inner rubber layer are commonly used in construction machinery, factory equipment, etc. to transmit pressure using a fluid (oil, etc.). Even when used within the range specified by the hose's specifications, the rubber layer of such hoses gradually deteriorates over long periods of use.
When the rubber layer deteriorates and the hose is used beyond its lifespan, problems such as leakage of fluid present inside the hose from the vicinity of the deteriorated portion may occur.
To prevent such problems, it has been proposed to predict the remaining usable period of a hose based on the length of time the hose has been in use, so as to prevent the hose from exceeding its lifespan (see, for example, Patent Document 1).

Japanese Patent Application Laid-Open No. 2020-186983

The inventors conducted extensive research into hoses used to handle fluids and discovered that additives added to the fluid affect the hose's lifespan.

In light of these problems, the present invention aims to provide a method and system for predicting the remaining life of a hose that uses a fluid containing an additive, which can easily predict the remaining life of the hose.

The hose remaining life prediction method described in claim 1 predicts the remaining life of a hose currently in use, the hose having at least an inner tube rubber layer containing rubber that comes into contact with a fluid containing an additive and whose physical property values are affected by the additive over time, and a reinforcing layer disposed more radially outward than the inner tube rubber layer. The method includes: a degradation model creation step for determining the relationship between the usage time of the inner tube rubber layer and the physical property values of the rubber for a hose of the same type as the currently in use hose, using the fluid, and creating a degradation model of the inner tube rubber layer; a usage time calculation step for calculating the usage time of the inner tube rubber layer from the start of use to the time the prediction is made; and a remaining life prediction step for predicting the remaining life of the currently in use hose based on the usage time calculated in the usage time calculation step and the degradation model created in the degradation model creation step.

The method for predicting the remaining life of a hose described in claim 1 predicts the remaining life of a hose currently in use, which has at least an inner rubber layer that is internally in contact with a fluid containing an additive and that contains rubber that is affected by the additive in terms of changes in physical properties over time, and a reinforcing layer that is positioned outer than the inner rubber layer.

First, in the degradation model creation process, the relationship between usage time and the rubber physical properties of the inner tube rubber layer is determined for a hose of the same type as the hose currently in use, using the fluid used in the hose, and a degradation model of the inner tube rubber layer is created.

In the usage time calculation process, the usage time of the inner tube rubber layer of the hose in use from the start of use to the predicted time is calculated.

In the remaining life prediction process, the remaining life of the hose in use is predicted based on the usage time calculation process, the usage time calculated in the usage time calculation process, and the deterioration model created in the deterioration model creation process.

The hose remaining life prediction system described in claim 2 predicts the remaining life of a hose currently in use, the hose having at least an inner rubber layer containing rubber that comes into contact with a fluid containing an additive and that is affected by the additive in terms of changes in physical properties over time, and a reinforcing layer disposed more radially outward than the inner rubber layer. The system includes: a degradation model creation means that, for a hose of the same type as the currently in use hose, determines the relationship between the usage time of the inner rubber layer and the physical properties of the rubber, and creates a degradation model of the inner rubber layer; a usage time calculation means that calculates the usage time of the inner rubber layer of the currently in use hose from the start of use to the time the prediction is made; and a remaining life prediction means that predicts the remaining life of the currently in use hose based on the usage time calculated by the usage time calculation means and the degradation model created by the degradation model creation means.

The hose remaining life prediction system described in claim 2 predicts the remaining life of a hose currently in use, which has at least an inner rubber layer that is internally in contact with a fluid containing additives and that contains rubber that is affected by the additives in terms of changes in physical properties over time, and a reinforcing layer that is positioned outer than the inner rubber layer.

The degradation model creation means determines the relationship between usage time and the rubber physical properties of the inner tube rubber layer for a hose of the same type as the hose currently in use, using the fluid used in the hose, and creates a degradation model for the inner tube rubber layer.

The usage time calculation means calculates the usage time of the inner tube rubber layer of a hose currently in use from the start of use to the predicted time.

The remaining life prediction means predicts the remaining life of the hose in use based on the usage time calculated by the usage time calculation means and the deterioration model created by the deterioration model creation means.

As described above, the hose remaining life prediction method of the present invention has the excellent effect of easily predicting the remaining life of a hose that uses a fluid containing an additive.

Furthermore, the hose remaining life prediction system of the present invention has the excellent effect of easily predicting the remaining life of a hose that uses a fluid containing an additive.

FIG. 1 is an overall perspective view illustrating an example of a hose to be predicted by a method for predicting the remaining life of a hose according to an embodiment of the present invention and a system for predicting the remaining life of a hose according to an embodiment of the present invention, the hose being attached to a machine or the like. 2A and 2B are partially exploded perspective views illustrating the internal configuration of the hose shown in FIG. 1 . 1 is a flowchart illustrating a method for predicting the remaining life of a hose according to an embodiment of the present invention. FIG. 2 is a conceptual diagram illustrating an example of a deterioration model according to an embodiment of the present invention. FIG. 2 is a conceptual diagram showing an example of the relationship between breaking elongation of rubber and usage time. 1 is a diagram for explaining a hose remaining life prediction system according to an embodiment of the present invention; FIG. 2 is a functional block diagram showing a control configuration of the system according to the embodiment of the present invention. FIG. 2 is a conceptual diagram showing an example of the relationship between breaking elongation of rubber and usage time. FIG. 2 is a conceptual diagram showing an example of the relationship between breaking elongation of rubber and usage time. 1A and 1B are conceptual diagrams showing an example of the relationship between breaking elongation of rubber and usage time. 10A and 10B are side views of a hose showing an example of a bent state. FIG. 2 is a conceptual diagram showing an example of the relationship between breaking elongation of rubber and usage time. 10A and 10B are side views of a hose showing an example of a bent state. FIG. 2 is a conceptual diagram showing an example of the relationship between breaking elongation of rubber and usage time. 10A and 10B are side views of a hose showing an example of a bent state. FIG. 2 is a conceptual diagram showing an example of the relationship between breaking elongation of rubber and usage time.

[Embodiment]
A method for predicting the remaining life of a hose and a system 100 for predicting the remaining life of a hose according to one embodiment of the present invention will be described with reference to FIGS. 1 to 8. FIG.

<Method for predicting remaining life of hose according to embodiment>
First, with reference to FIG. 1, a hose 1 to which the hose remaining life prediction method according to this embodiment and the hose remaining life prediction system 100 (see FIG. 7) according to this embodiment can be applied will be described.

As shown in Figure 1, the hose 1 is attached to, for example, a machine 3 (for example, construction machinery as shown in the illustration, or factory equipment) and is used to transmit pressure using, for example, a high-pressure fluid (oil, etc.).

As an example, as shown in Figure 11, a hose 1 may have fittings 2 with couplings attached to both ends thereof for connection to a machine or the like 3, which are inserted into and crimped onto the hose 1. The hose 1 can then be attached to the machine or the like 3 via the fittings 2 with couplings.

As shown in Figure 2(A) or 2(B), the hose 1 has at least an inner tube rubber layer 11, a reinforcing layer 12 disposed radially outward of the inner tube rubber layer 11, and an outer skin layer 13 disposed radially outward of the reinforcing layer 12.

The inner tube rubber layer 11 is the innermost rubber layer and has heat resistance and other resistance to the fluid flowing inside.

The reinforcing layer 12 is provided in one or more layers (one layer in the example of Figure 2(A) and four layers in the example of Figure 2(B)) and serves to ensure the pressure resistance of the hose 1. The reinforcing layer 12 is formed by wrapping a reinforcing material such as fiber or metal wire around the outer surface of the inner tube rubber layer 11 or further outward in a spiral or braided form (braided form in the example of Figure 2(A) and spiral form in the example of Figure 2(B)).

The outer skin layer 13 forms the outermost layer of the hose 1 and is made of a material that is abrasion-resistant, weather-resistant, and capable of protecting the hose 1 from the external environment. There are no particular restrictions on the material of the outer skin layer 13, but it can be made of rubber, for example.

Also, as shown in Figure 2(B), one or more intermediate rubber layers 14 (three layers in the example of Figure 2(B)) may be disposed between the inner tube rubber layer 11 and the outer skin layer 13.

Next, we will first explain how the hose remaining life prediction method and the hose remaining life prediction system of this embodiment were developed.

In the hose 1 shown in Figure 1, the inner rubber layer 11 gradually deteriorates even when used within the range specified in the hose 1's specifications. After extensive research into the causes of deterioration of the inner rubber layer 11, the inventors discovered that the inner rubber layer 11 of the hose 1 deteriorates due to the effects of additives contained in the fluid used. The inventors therefore considered it possible to predict the remaining life of the hose 1 by using the same type (same) fluid containing additives as the fluid that comes into contact with the inner rubber layer 11 of the hose 1 during use. This embodiment is based on this idea. The degree of deterioration of the inner rubber layer 11 over time may vary depending on the effects of the additives.

In this embodiment, the fluid used in the machine 3 is, for example, oil used in hydraulic equipment, but may be a fluid other than oil. An example of the additive is an antioxidant, but it may also be something other than an antioxidant. Examples of antioxidants include chain terminators, peroxide decomposers, and metal deactivators.

(Method for predicting remaining life of hose)
First, a method for predicting the remaining life of a hose according to an embodiment of the present invention will be described with reference to FIGS.
The method for predicting the remaining life of a hose according to this embodiment predicts the remaining life of a hose 1 in use, which has at least an inner tube rubber layer 11, a reinforcing layer 12 arranged radially outward from the inner tube rubber layer 11, and an outer skin layer 13 arranged radially outward from the reinforcing layer 12.

Here, the term "hose 1 in use" can be defined arbitrarily depending on the operating mode of the machine, etc., but in this embodiment it refers to a hose 1 that is attached to a machine 3, etc. and in use.

As shown in Figure 3, the method for predicting the remaining life of a hose according to this embodiment involves first determining the relationship between the usage time of the inner rubber layer and the physical properties of the rubber that makes up the inner rubber layer for a hose (not shown) of the same type as the hose 1 currently in use, and creating a deterioration model for the inner rubber layer (deterioration model creation process). The usage time of the inner rubber layer 11 of the hose 1 currently in use up to the time of prediction is calculated (usage time calculation process). The remaining life of the hose 1 currently in use is then predicted based on a comparison between the usage time calculated in the usage time calculation process and the deterioration model created in the degradation model creation process (remaining life prediction process), thereby predicting the remaining life of the hose 1 currently in use.

(Deterioration model creation process)
In the deterioration model creation process, a hose (not shown; in other words, a hose for creating a deterioration model) of the same type as the hose currently in use (in other words, a hose attached to a machine or the like) 1 is prepared in advance, and for this hose, the relationship between the usage time of the inner tube rubber and the physical property values of the rubber constituting the inner tube rubber layer is determined, and a deterioration model of the inner tube rubber layer is created.

Here, a hose of the same type as the hose 1 currently in use (hereinafter simply referred to as "the same type of hose") refers to a hose whose inner rubber layer is made of the same type of rubber as the hose 1 currently in use. Note that "the same type of rubber" means that the rubber compounding is the same.

The physical property values of the rubber making up the inner tube rubber layer used in the deterioration model of the inner tube rubber layer are not particularly limited, but are preferably, for example, elongation at break, strength at break, and hardness. This is because these are commonly used indicators of rubber physical property values and can be measured accurately. However, the physical property values of the rubber used in the deterioration model are not limited to these indicators, and multiple indicators may be used. In this embodiment, an example using elongation at break will be described.

Figure 4 is a conceptual diagram showing an example of a deterioration model in this embodiment. Figure 4 shows the relationship between the usage time (h) of the same type of hose and the elongation at break (%) of the rubber that makes up the inner tube rubber layer. In this embodiment, the deterioration model is a graph, as shown in Figure 4, that shows the relationship between usage time and the physical property value of the rubber (in this example, the elongation at break of the rubber). Hereinafter, this graph will be referred to as the deterioration curve, as appropriate.

The deterioration model can be created, for example, by conducting a test in which a fluid containing additives (the same type (same) fluid as the fluid used in hose 1 currently in use) is continuously circulated through the same type of hose, and the elongation at break of the rubber that makes up the inner tube rubber layer is measured over multiple periods of use, and then a graph showing the progress of the rubber elongation at break is created based on the results obtained.

The elongation at break of rubber can be measured, for example, by a tensile test based on JIS K6251. Furthermore, when the strength at break of rubber is used as the physical property of rubber, testing can be performed, for example, based on JIS K6251, and when rubber hardness is used, testing can be performed, for example, based on JIS K6253.

If multiple indicators of elongation at break, strength at break, and hardness are used as rubber property values, a degradation model will be created for each property value.

(Use time calculation process)
In the usage time calculation step, the usage time of the inner tube rubber layer 11 of the hose 1 currently in use from the start of use to the predicted time is calculated.

The usage time calculation process, for example, calculates the cumulative time of the inner rubber layer 11 of a hose 1 in use from the time it is attached to a machine, etc. 3 and begins use until the predicted time.

(Remaining life prediction process)
In the remaining life prediction step, the remaining life of the hose 1 in use is predicted based on a comparison between the usage time calculated in the usage time calculation step and the deterioration model created in the deterioration model creation step.

More specifically, for example, as shown in FIG. 5 , the service limit of the inner tube rubber layer 11 can be determined by setting a threshold value for the physical property value of the rubber constituting the inner tube rubber layer 11, and predicting the remaining life as the time from the time of use (point A) to the time of use (point B) at which the physical property value becomes the threshold value in the deterioration model.
According to the above method, the remaining life of the hose can be predicted more simply and accurately.

Here, the method for setting the threshold value for the rubber's physical properties is not particularly limited, but for example, the physical properties of a faulty hose of the same type as the hose currently in use can be measured and the threshold value can be set based on that value.

When setting the threshold value for the rubber's physical properties, it is preferable to set it to a value before the actual service limit of the inner tube rubber layer 11 is reached, so that the hose 1 can be replaced before a malfunction such as a fluid leak or hose breakage occurs.

In the remaining life prediction process, for example, as shown in Figure 5, the usage time can be plotted on a degradation model to estimate the elongation at break of the rubber that makes up the inner tube rubber layer 11 of the hose 1 at the time of usage (A). The time from the time of usage (A) to the time of usage (B) at which the physical property value reaches a threshold value can then be predicted as the remaining life of the hose 1. Note that to predict the remaining life, it is not necessary to estimate the value of the elongation at break of the rubber at the time of usage (A); it is sufficient to know the time from the time of usage (A) to the time of usage (B).

The method for predicting the remaining life of a hose according to this embodiment eliminates the need to monitor pressure and other factors in a hose 1 currently in use, which has an inner rubber layer 11 that is affected by additives contained in a fluid. The remaining life of the hose can be easily predicted simply by obtaining the usage time (cumulative usage time) in the machine 3.

<Hose remaining life prediction system according to the embodiment>
Next, a hose remaining life prediction system 100 according to an embodiment of the present invention will be described.
(System configuration)
6 is a configuration diagram of a hose remaining life prediction system 100 according to one embodiment of the present invention. In the description of the remaining life prediction system 100 according to this embodiment, the term "user" refers to a person who operates a terminal to check the remaining life of the hose 1, such as a user of the machine 3 (e.g., construction machinery, factory equipment, etc.) to which the hose 1 is attached, a seller of the machine 3, a seller of the hose 1, etc.

The remaining life prediction system 100 for a hose 1 is composed of a machine, etc. 3 (construction machine in the illustrated example) to which the hose 1 is attached, a server 40, and one or more terminals 50, and the server 40 is connected to each of the machine, etc. 3 and the terminals 50 so that they can communicate with each other via a network 60.
The machine 3 transmits data such as usage time to the server 40. Examples of the network 60 connecting the machine 3 and the server 40 include a wireless line and a satellite line.
The server 40 is a server that predicts the remaining life of the hose 1 based on data received from the machine 3 and data stored in a database, and transmits the prediction result to the terminal 50 .
As examples of the terminal 50, various devices such as a PC, a PDA, a mobile phone, etc. can be used.
Furthermore, the server 40 and the terminal 50 may belong to different users, or may be integrated.
The interface between the server 40 and the terminal 50 can be realized by, for example, the server 40 launching a web server, the terminal 50 being provided with a web browser, and communication via HTTP or HTTPS.

(machines, etc.)
The machine or the like 3 is configured to wirelessly transmit data on the usage time of the inner tube rubber layer 11 of the hose 1 currently in use up to the predicted time to the server 40 .
6 and 7, the machine 3 includes a usage time measuring means (clock or the like) 31, which is made up of a recorder or the like that measures and records the usage time of the inner tube rubber layer 11, and an information communication means 32 that transmits the usage time. Note that these devices are merely examples, and the machine 3 may include any device as the usage time measuring means.

(server)
As shown in FIG. 7, the server 40 includes a database 41 , a deterioration model creating means 42 , a usage time calculating means 43 , a remaining life predicting means 44 , and an information communicating means 45 .
The database 41 stores various information used to predict the remaining life of the hose 1. The database 41 can receive information from the deterioration model creating means .
The usage time calculation means 43 calculates the usage time of the hose 1 currently in use up to the time of prediction.
The usage time calculation means 43 preferably includes a data acquisition means (not shown; for example, a terminal with a receiving device) that acquires time data of the inner tube rubber layer 11 up to the prediction time for the hose 1 in use.

The information communication means 45 transmits the predicted remaining life of the hose 1 currently in use to the terminal 50. The information communication means 45 allows the server 40 to communicate with the machine 3 and the terminal 50 via the network 60. The contents of the server 40 can also be incorporated into the machine 3. The terminal 50 can also be incorporated into the machine 3.

(Deterioration model creation means)
The deterioration model creation means 42 creates information used to predict the remaining life of the hose 1 and can transmit the information to the database 41. The deterioration model creation means 42 obtains the relationship between the usage time of the inner tube rubber layer and the physical property values of the rubber that makes up the inner tube rubber layer for a hose of the same type as the hose 1 currently in use, and creates a deterioration model of the inner tube rubber layer.

The physical property values of the rubber making up the inner tube rubber layer used in the deterioration model of the inner tube rubber layer are not particularly limited, but are preferably, for example, elongation at break, strength at break, and hardness. This is because these are commonly used indicators of rubber physical property values and can be measured accurately. However, the physical property values of the rubber used in the deterioration model are not limited to these indicators, and multiple indicators may be used. In this embodiment, an example using elongation at break will be described.

In addition, in this embodiment, an example of a deterioration model can be a graph showing the relationship between usage time and the physical property value of the rubber (in this example, the rubber's elongation at break), as shown in Figure 4 above.

If multiple indicators of elongation at break, strength at break, and hardness are used as rubber property values, a degradation model will be created for each property value.

(Means for calculating usage time)
The usage time calculation means 43 calculates (obtains) the cumulative usage time of the inner tube rubber layer 11 of the hose 1 in use from the start of use to the predicted time.

It is preferable that the usage time calculation means 43 (data acquisition means) acquires the data transmitted from the machine etc. 3 via the network 60.

(Remaining life prediction means)
The remaining life prediction means 44 predicts the remaining life of the hose 1 in use based on a comparison between the usage time of the inner tube rubber layer 11 calculated by the usage time calculation means 43 and the deterioration model created by the deterioration model creation means 42 and stored in the database 41.

More specifically, as shown in Figure 5, for example, the remaining life can be predicted by setting a threshold value for the physical property value of the rubber that makes up the inner tube rubber layer 11 as the service limit for the inner tube rubber layer 11, and then estimating the time from the time of use (point A) in the degradation model until the time of use (point B) at which the physical property value reaches the threshold value. This method makes it possible to more easily and accurately predict the remaining life of the hose.

The threshold value may be preset in the remaining life prediction means 44, or it may be input or changed manually by the user.

Here, the method for setting the threshold value for the rubber's physical properties is not particularly limited, but for example, the physical properties of a faulty hose of the same type as the hose 1 currently in use can be measured and the threshold value can be set based on that value.

It is preferable to set the threshold value of the rubber's physical properties to a value before the inner tube rubber layer 11 actually reaches its service limit, so that the hose 1 can be replaced before it fails.

The remaining life prediction means can be configured to plot the usage time on a degradation model as shown in Figure 5, similar to the remaining life prediction process described above, and estimate the elongation at break of the rubber constituting the inner tube rubber layer 11 of the hose 1 after the usage time has elapsed (A).

When setting the degradation model and threshold, it is preferable to use the index that causes the fastest degradation of physical property values among multiple indexes.

(Terminal)
The terminal 50 receives the remaining life of the hose 1 predicted by the remaining life prediction means 44 and can display the remaining life of the hose 1 on a display screen, for example.

By using the hose remaining life prediction system of this embodiment, the remaining life of a hose 1 in use that has an inner rubber layer 11 that is affected by additives contained in the fluid can be easily predicted simply by obtaining the usage time (cumulative usage time) without the need to monitor pressure, etc., in the machine, etc. 3.

As shown in Figure 8, the deterioration model (deterioration curve) changes depending on the type of additive. For example, deterioration curve A is for when an additive that easily deteriorates rubber is used, and deterioration curve B is for when an additive that does not easily deteriorate rubber is used.

Furthermore, rubber may deteriorate due to high temperatures, shortening its lifespan. For example, continuous use of the machine 3 may cause the fluid flowing through the hose 1 to become hot. When the hot fluid comes into contact with the rubber, the rubber is heated, which may accelerate the deterioration of the rubber.
In this way, in the case of a usage pattern in which temperature accelerates the deterioration of rubber, it is preferable to create a deterioration model using a fluid at the same temperature as that of the hose 1 in use.

[Reference example 1]
Next, a description will be given of a method and system for predicting the remaining life of a hose according to Reference Example 1. Note that the same components as those in the above-described embodiment are given the same reference numerals, and descriptions thereof will be omitted.
In this Reference Example 1, the life of the hose 1 is predicted when the physical properties of the inner tube rubber layer 11 change depending on the physical properties of the fluid itself.

<Method for predicting remaining life of hose according to Reference Example 1>
The inventors conducted extensive research into the use patterns of the hose and the factors that cause deterioration of the inner rubber layer 11. They discovered that machines 3 and the like sometimes use fluids that do not contain additives, and that the physical properties of the inner rubber layer 11 change over time due to the physical properties of the fluid itself, leading to deterioration over time, for example. Therefore, the inventors considered that it would be possible to predict the remaining life of the hose 1 by using the same type (same) fluid as the fluid that comes into contact with the inner rubber layer 11 of the hose 1 during use. This reference example was developed based on this idea. Note that the degree of change (deterioration) over time of the inner rubber layer 11 may also vary due to the influence of the fluid itself.

In this reference example, the same components as those in the previously described embodiment are designated by the same reference numerals, and their description will be omitted. Similar to the hose 1 in the previously described embodiment, the hose 1 in this reference example is also intended to be attached to a machine or the like 3 for use.

In this reference example, the remaining life prediction method for a hose 1 in use involves: determining the relationship between the usage time of the inner rubber layer and the physical properties of the rubber constituting the inner rubber layer using the same type of fluid as the fluid that contacts the inner rubber layer 11 of the hose 1 in use; creating a deterioration model for the inner rubber layer (deterioration model creation process); calculating the usage time of the inner rubber layer 11 of the hose 1 in use up to the time of prediction (usage time calculation process); and predicting the remaining life of the hose 1 in use based on a comparison between the usage time calculated in the usage time calculation process and the deterioration model created in the degradation model creation process (remaining life prediction process), thereby predicting the remaining life of the hose 1 in use (similar to the previously described embodiment; see Figure 3).

(Deterioration model creation process)
As in the above-described embodiment, in the deterioration model creation process, a hose of the same type as the hose 1 currently in use is prepared in advance, and for this hose, the relationship between the usage time of the inner tube rubber and the physical property values of the rubber that makes up the inner tube rubber layer is determined, and a deterioration model of the inner tube rubber layer is created.

As in the previously described embodiment, the degradation model can be created by, for example, conducting a test in which a fluid (the same type of fluid as that in hose 1 currently in use) is continuously circulated through the same type of hose and measuring the elongation at break of the rubber that makes up the inner tube rubber layer over multiple periods of use, and then creating a graph based on the results obtained that shows the progression of the rubber elongation at break over time.

(Use time calculation process)
As in the above-described embodiment, the usage time calculation step calculates, for example, the cumulative time of the inner tube rubber layer 11 of the hose 1 currently in use from the start of use to the predicted time.

(Remaining life prediction process)
As in the previously described embodiment, in the remaining life prediction process, the remaining life of the hose 1 in use is predicted based on a comparison between the usage time calculated in the usage time calculation process and the deterioration model created in the deterioration model creation process (similar to the previously described embodiment; see Figure 6).

The method for predicting the remaining life of a hose in this reference example eliminates the need to monitor pressure, etc., in a hose 1 currently in use that has an inner rubber layer 11 that is affected by the physical properties of the fluid. The remaining life of the hose can be easily predicted simply by obtaining the usage time (cumulative usage time) in the machine, etc. 3.

<System for predicting remaining life of a hose according to Reference Example 1>
Next, a description will be given of a hose remaining life prediction system according to Reference Example 1. The hose remaining life prediction system according to Reference Example 1 has the same device configuration (hardware) as the above-described embodiment, so a description of the device configuration will be omitted and only the differences will be described below.

The deterioration model creation means 42 of the remaining life prediction system 100 of this reference example uses a hose of the same type as the hose 1 currently in use and a fluid containing no additives used in the hose 1 to determine the relationship between the usage time of the inner tube rubber layer and the physical properties of the rubber that makes up the inner tube rubber layer, and creates a deterioration model of the inner tube rubber layer.

As a result, with the hose remaining life prediction system 100 according to Reference Example 1, for a hose 1 currently in use that has an inner rubber layer 11 that is affected by the physical properties of the fluid, there is no need to monitor pressure, etc., in the machine, etc. 3; the remaining life of the hose can be easily predicted simply by obtaining the usage time (cumulative usage time).

If the fluid is oil, the rubber of the inner tube rubber layer 11 may swell and become more elongated when it comes into contact with the oil, resulting in improved elongation at break and possibly extending the life of the hose 1.

In addition, using oil with a low aniline point makes the rubber more likely to swell and stretch, which suppresses deterioration (for example, deterioration in elongation at break). Therefore, hose 1 using oil with a low aniline point tends to have a longer lifespan than hoses using oil with a high aniline point.

Figure 9 shows, as an example, a deterioration curve C when an oil with a high aniline point is used, and a deterioration curve D when an oil with a low aniline point is used.

(Appendix 1)
A method for predicting the remaining life of a hose in use, the hose having at least an inner tube rubber layer that is made up of rubber that comes into contact with a fluid inside and is affected by the physical properties of the fluid with respect to changes in physical properties over time, a reinforcing layer that is disposed outer peripherally of the inner tube rubber layer, and an outer skin layer that is disposed outer peripherally of the reinforcing layer, comprising:
a deterioration model creation step of determining in advance, using the fluid, a relationship between the usage time of the inner tube rubber layer and a physical property value of the rubber for a hose of the same type as the hose currently in use, and creating a deterioration model of the inner tube rubber layer;
a usage time calculation step of calculating a usage time of the inner tube rubber layer of the hose in use from the start of use to the time when the prediction is made;
a remaining life prediction step of predicting a remaining life of the hose in use based on the usage time calculated in the usage time calculation step and the deterioration model created in the deterioration model creation step;
A method for predicting the remaining life of a hose, comprising:

(Appendix 2)
A hose remaining life prediction system for predicting the remaining life of a hose currently in use, the hose having at least an inner tube rubber layer that is made up of rubber that comes into contact with a fluid and whose physical property values are affected by the physical properties of the fluid with respect to changes over time, a reinforcing layer that is disposed on the outer periphery of the inner tube rubber layer, and an outer skin layer that is disposed on the outer periphery of the reinforcing layer,
a deterioration model creation means for determining a relationship between a usage time of the inner tube rubber layer and a physical property value of the rubber using the fluid for a hose of the same type as the hose currently in use, and creating a deterioration model of the inner tube rubber layer;
a usage time calculation means for calculating a usage time of the inner tube rubber layer of the hose in use from the start of use to the time when the prediction is made;
a remaining life prediction means for predicting a remaining life of the hose in use based on the usage time calculated by the usage time calculation means and the deterioration model created by the deterioration model creation means;
A hose remaining life prediction system including:

[Reference example 2]
Next, a description will be given of a method and system for predicting the remaining life of a hose according to Example 2. Note that the same components as those in the above-described embodiment are given the same reference numerals, and descriptions thereof will be omitted.
In this reference example 2, the life of a hose 1 in which the inner tube rubber layer 11 deteriorates due to deterioration of the fluid is predicted.

<Method for predicting remaining life of hose according to Reference Example 2>
The inventors conducted extensive research into the use patterns of the hose and the factors that cause deterioration of the inner tube rubber layer 11. They discovered that machines 3 and the like may continue to use deteriorated fluids, and that the physical properties of the inner tube rubber layer 11 may change over time due to the influence of the deteriorated fluid. For example, the inner tube rubber layer 11 may deteriorate over time. Therefore, the inventors considered that it would be possible to predict the remaining life of the hose 1 by using the same type (same) fluid as the fluid that comes into contact with the inner tube rubber layer 11 of the hose 1 during use. This reference example was developed based on this idea. The degree of deterioration (deterioration) of the inner tube rubber layer 11 over time may also change due to the influence of the deteriorated fluid.

In this reference example, the same components as those in the previously described embodiment are designated by the same reference numerals, and their description will be omitted. Similar to the hose 1 in the previously described embodiment, the hose 1 in this reference example is also intended to be attached to a machine or the like 3 for use.

In the hose remaining life prediction method according to this reference example, the relationship between the usage time of the inner tube rubber layer and the physical properties of the rubber making up the inner tube rubber layer is determined in advance for a hose of the same type as the hose 1 currently in use, and a deterioration model of the inner tube rubber layer is created (deterioration model creation process). The usage time of the inner tube rubber layer 11 of the hose 1 currently in use up to the time of prediction is calculated (usage time calculation process). The remaining life of the hose 1 currently in use is predicted based on a comparison between the usage time calculated in the usage time calculation process and the deterioration model created in the deterioration model creation process (remaining life prediction process), thereby predicting the remaining life of the hose 1 currently in use (similar to the embodiment shown in Figure 3).

(Deterioration model creation process)
As in the above-described embodiment, in the deterioration model creation process, a hose of the same type as the hose currently in use (in other words, a hose attached to a machine or the like and in use) 1 is prepared in advance, and for this hose, the relationship between the usage time of the inner tube rubber and the physical property values of the rubber constituting the inner tube rubber layer is determined, and a deterioration model of the inner tube rubber layer is created.

As in the previously described embodiment, the deterioration model can be created by, for example, conducting a test in which a fluid (a deteriorated fluid of the same type (same) as that of the hose 1 currently in use) is continuously circulated through the same type of hose, measuring the elongation at break of the rubber that makes up the inner tube rubber layer over multiple periods of use, and then creating a graph based on the results obtained that shows the progression of the value of the rubber elongation at break.

(Use time calculation process)
As in the above-described embodiment, the usage time calculation step calculates, for example, the cumulative time of the inner tube rubber layer 11 of the hose 1 currently in use from the start of use to the predicted time.

(Remaining life prediction process)
As in the previously described embodiment, in the remaining life prediction process, the remaining life of the hose 1 in use is predicted based on a comparison between the usage time calculated in the usage time calculation process and the deterioration model created in the deterioration model creation process.

More specifically, as shown in Figure 5, for example, the service limit of the inner tube rubber layer 11 can be determined by setting a threshold value for the physical property values of the rubber that makes up the inner tube rubber layer 11, and predicting the remaining life as the time from the time of use in the deterioration model until the time of use at which the physical property value reaches the threshold value.

The method for predicting the remaining life of a hose in this reference example makes it possible to easily predict the remaining life of a hose 1 in use that has an inner rubber layer 11 that is susceptible to fluid deterioration, by simply obtaining the usage time (cumulative usage time) without the need to monitor pressure, etc., in the machine, etc. 3.

<System for predicting remaining life of a hose according to Reference Example 2>
Next, a description will be given of a hose remaining life prediction system according to Reference Example 2. The hose remaining life prediction system according to Reference Example 2 has the same device configuration (hardware) as the above-described embodiment, so a description of the device configuration will be omitted and only the differences will be described below.

The deterioration model creation means 42 of the remaining life prediction system in this reference example uses a hose of the same type as the hose 1 currently in use and the fluid used in the hose 1 to determine the relationship between the usage time of the inner tube rubber layer and the physical properties of the rubber that makes up the inner tube rubber layer, and creates a deterioration model of the inner tube rubber layer.

As a result, with the hose remaining life prediction system according to this reference example, for a hose 1 currently in use that has an inner rubber layer 11 that is affected by the physical properties of the fluid, there is no need to monitor pressure, etc., in the machine, etc. 3; the remaining life of the hose can be easily predicted simply by obtaining the usage time (cumulative usage time).

Note that Figures 10(A) and (B) show, as examples, a deterioration curve when the fluid deterioration is small and a deterioration curve when the fluid deterioration is large.

(Appendix 3)
A method for predicting the remaining life of a hose in use, the hose having at least an inner tube rubber layer that is in contact with an interior of the hose and that includes rubber that is affected by the deterioration of the fluid over time in terms of changes in physical properties over time, a reinforcing layer that is disposed more outer than the inner tube rubber layer, and an outer skin layer that is disposed more outer than the reinforcing layer, the method comprising:
a deterioration model creation step of determining a relationship between usage time and physical property values of the rubber of the inner tube rubber layer using the fluid for a hose of the same type as the hose currently in use, and creating a deterioration model of the inner tube rubber layer;
a usage time calculation step of calculating a usage time of the inner tube rubber layer of the hose in use from the start of use to the time when the prediction is made;
a remaining life prediction step of predicting a remaining life of the hose in use based on the usage time calculated in the usage time calculation step and the deterioration model created in the deterioration model creation step;
A method for predicting the remaining life of a hose, comprising:

(Appendix 4)
A system for predicting the remaining life of a hose in use, the hose having at least an inner tube rubber layer through which a fluid that deteriorates over time passes and which is made up of rubber that is affected by the deterioration of the fluid in terms of changes in physical properties over time, a reinforcing layer disposed on the outer periphery of the inner tube rubber layer, and an outer skin layer disposed on the outer periphery of the reinforcing layer,
a deterioration model creation means for determining a relationship between a usage time of the inner tube rubber layer and a physical property value of the rubber using the fluid for a hose of the same type as the hose currently in use, and creating a deterioration model of the inner tube rubber layer;
a usage time calculation means for calculating a usage time of the inner tube rubber layer of the hose in use from the start of use to the time when the prediction is made;
a remaining life prediction means for predicting a remaining life of the hose in use based on the usage time calculated by the usage time calculation means and the deterioration model created by the deterioration model creation means;
A hose remaining life prediction system including:

[Reference example 3]
Next, a description will be given of a method and system for predicting the remaining life of a hose according to Reference Example 3. Note that the same components as those in the above-described embodiment are given the same reference numerals, and descriptions thereof will be omitted.
In this reference example 3, the threshold value is changed depending on the usage pattern of the hose (degree of distortion, for example, degree of bending).

<Method and system for predicting remaining life of a hose according to Reference Example 3>
When comparing general rubber subjected to a large tensile force (tensile strain) with rubber subjected to a small tensile force (or no tensile force), the rubber subjected to a large tensile force tends to be more susceptible to failure (for example, cracks occurring, cracks propagating, etc.).
That is, rubber subjected to a large tensile force (tensile strain) has a shorter lifespan than rubber subjected to a small tensile force (or no tensile force).

For example, as shown in FIG. 11(A), the hose 1 may be used in a state where the radius of curvature R is relatively large (in other words, the hose 1 is little bent (including a straight state)), or in a state where the hose 1 is used in a state where the radius of curvature R is relatively small (in other words, the hose 1 is greatly bent) as shown in FIG. 11(B). The strain acting on the rubber of the hose 1 in the latter case (FIG. 11(B)) is greater than that of the hose 1 in the former case (FIG. 11(A)).
For this reason, even if the physical properties (elongation at break) of rubber are the same, rubber with a larger strain will have a shorter lifespan.
When the hose 1 is bent and deformed, the rubber on the outside of the curvature radius is pulled (the rubber on the inside of the curvature radius is compressed), causing tensile strain. The smaller the curvature radius of the hose 1, the greater the tensile strain that occurs in the rubber of the hose 1.

Therefore, even when the same fluid is used, it is preferable to change the threshold value of the physical property value depending on the magnitude of the strain generated in the inner tube rubber layer 11 (especially in the case of rubber, the magnitude of the strain due to tension).
The strain referred to here is, for example, the maximum strain acting on the hose 1.

Specifically, as shown in FIG. 12, the threshold value is shifted upward as the distortion increases.
The amount by which the threshold value is shifted can be determined by using the same type of hose as the hose 1 currently in use, bending the hose in the same way as the hose 1 currently in use, creating a deterioration model, setting a threshold value as the usage limit for the amount of time the hose in the deterioration model has been in use at the time it has failed (for example, when a crack has developed and fluid has leaked), and storing the threshold value in the remaining life prediction means 44.

(Appendix 5)
A method for predicting a remaining life of a hose in use, the method comprising: predicting a remaining life of the hose having at least an inner tube rubber layer and a reinforcing layer disposed on an outer peripheral side of the inner tube rubber layer;
a deterioration model creation step of determining in advance, using the fluid, a relationship between the usage time of the inner tube rubber layer and a physical property value of the rubber for a hose of the same type and usage pattern as the hose currently in use, and creating a deterioration model of the inner tube rubber layer;
a usage time calculation step of calculating a usage time of the inner tube rubber layer of the hose in use from the start of use to the time when the prediction is made;
a threshold value setting step of setting a threshold value of the physical property value according to the magnitude of strain occurring in the inner tube rubber layer as a use limit of the inner tube rubber layer;
a remaining life prediction step of predicting the remaining life of the hose in use as the time from when the usage time calculated in the usage time calculation step and the deterioration model created in the deterioration model creation step have elapsed until when the usage time at which the physical property value reaches the threshold value is reached, based on the usage time calculated in the usage time calculation step and the deterioration model created in the deterioration model creation step;
A method for predicting the remaining life of a hose, comprising:

(Appendix 6)
The strain is the maximum strain acting on the hose.
6. A method for predicting the remaining life of a hose according to claim 5.

(Appendix 7)
A hose remaining life prediction system that predicts the remaining life of a hose in use, the hose having at least an inner tube rubber layer and a reinforcing layer disposed on an outer peripheral side of the inner tube rubber layer, comprising:
a deterioration model creation means for determining, using the fluid, the relationship between the usage time of the inner tube rubber layer and the physical property values of the rubber for a hose of the same type and in the same usage pattern as the hose currently in use, and creating a deterioration model of the inner tube rubber layer;
a usage time calculation means for calculating a usage time of the inner tube rubber layer of the hose in use from the start of use to the time when the prediction is made;
a threshold value setting means for setting a threshold value of the physical property value according to the magnitude of strain occurring in the inner tube rubber layer as a use limit of the inner tube rubber layer;
a remaining life prediction means for predicting the remaining life of the hose in use as the time from when the usage time calculated by the usage time calculation means and the deterioration model created by the deterioration model creation means have elapsed until when the usage time at which the physical property value reaches the threshold value is reached, in consideration of the usage time calculated by the usage time calculation means and the deterioration model created by the deterioration model creation means;
A hose remaining life prediction system including:

(Appendix 8)
The strain is the maximum strain acting on the hose.
8. A hose remaining life prediction system as described in appendix 7.

[Reference example 4]
Next, a method and system for predicting the remaining life of a hose according to Example 4 will be described. Note that the same components as those in the above-described embodiment are designated by the same reference numerals, and their description will be omitted.
In the fourth embodiment, the threshold value is changed depending on the manner in which the hose is used (for example, how it is bent), but the manner in which the hose is used is different from that in the third embodiment.

<Method and system for predicting remaining life of a hose according to Reference Example 4>
When comparing typical rubber when strain is repeatedly applied (for example, when strain changes from large to small) with when strain is not repeatedly applied, rubber when strain is repeatedly applied tends to be more susceptible to failure (for example, cracks occurring, cracks growing, etc.).
That is, rubber subjected to a large tensile force (tensile strain) has a shorter lifespan than rubber subjected to a small tensile force (or no tensile force).

As shown in Figures 13(A) and 13(B), the hose 1 used in a machine 3 or the like may be used in one case where the distance L between one end and the other end in the longitudinal direction varies to form a convex shape in one direction (the direction of arrow A), and in another case where the distance L between one end and the other end in the longitudinal direction does not change (not shown; in other words, when the hose 1 does not move). It can be said that the lifespan of the rubber is shorter in the former case than in the latter case.
It can be said that the greater the amplitude of the hose 1 and the more times it is repeated, the shorter the life of the rubber.

Therefore, even when using the same fluid, it is preferable to change the threshold values of the physical properties depending on how the hose 1 is used.

Specifically, the larger the amplitude of the hose 1 is and the greater the number of repetitions, the higher the threshold value is shifted, as shown in FIG.
The amount by which the threshold value is shifted can be determined by using the same type of hose as the hose 1 currently in use, moving the hose in the same way as the hose 1 currently in use to create a deterioration model, setting the threshold value as the usage limit for the time period at which the hose in the deterioration model breaks down (for example, when a crack occurs and fluid leaks), and storing the threshold value in the remaining life prediction means 44.

(Appendix 9)
A method for predicting the remaining life of a hose in use, the hose having at least an inner tube rubber layer that is used with a distance between one end and the other end in a longitudinal direction varying so that a fluid comes into contact with the inside of the hose and the distance between one end and the other end in a longitudinal direction varies so as to form a convex shape in one direction, and a reinforcing layer that is disposed on the outer circumferential side of the inner tube rubber layer, comprising:
a deterioration model creation step of determining in advance, using the fluid, a relationship between the usage time of the inner tube rubber layer and a physical property value of the rubber for a hose of the same type and usage pattern as the hose currently in use, and creating a deterioration model of the inner tube rubber layer;
a usage time calculation step of calculating a usage time of the inner tube rubber layer of the hose in use from the start of use to the time when the prediction is made;
a threshold value setting step of setting a threshold value of the physical property value as a use limit of the inner tube rubber layer in accordance with an amount of change in the distance of the inner tube rubber layer and a number of repetitions of bending the inner tube rubber layer due to the change in distance;
a remaining life prediction step of predicting the remaining life of the hose in use as the time from when the usage time calculated by the usage time calculation means and the deterioration model created by the deterioration model creation means have elapsed until when the usage time at which the physical property value reaches the threshold value is reached, in consideration of the usage time calculated by the usage time calculation means and the deterioration model created by the deterioration model creation means;
A method for predicting the remaining life of a hose, comprising:

(Appendix 10)
A system for predicting the remaining life of a hose in use, the system comprising at least an inner tube rubber layer that is used with a distance between one end and the other end in a longitudinal direction varying so that a fluid comes into contact with the inside of the hose and the distance between one end and the other end in a longitudinal direction varies so as to form a convex shape in one direction, and a reinforcing layer that is disposed on the outer circumferential side of the inner tube rubber layer, the system comprising:
a deterioration model creation means for determining, using the fluid, the relationship between the usage time of the inner tube rubber layer and the physical property values of the rubber for a hose of the same type and in the same usage pattern as the hose currently in use, and creating a deterioration model of the inner tube rubber layer;
a usage time calculation means for calculating a usage time of the inner tube rubber layer of the hose in use up to the time when the prediction is made;
a threshold value setting means for setting a threshold value of the physical property value as a use limit of the inner tube rubber layer in accordance with an amount of change in the distance of the inner tube rubber layer and a number of repetitions of bending the inner tube rubber layer due to the change in distance;
a remaining life prediction means for predicting the remaining life of the hose in use as the time from when the usage time calculated by the usage time calculation means and the deterioration model created by the deterioration model creation means have elapsed until when the usage time at which the physical property value reaches the threshold value is reached, in consideration of the usage time calculated by the usage time calculation means and the deterioration model created by the deterioration model creation means;
A hose remaining life prediction system including:

[Reference example 5]
Next, a method and system for predicting the remaining life of a hose according to Example 5 will be described. Note that the same components as those in the above-described embodiment are designated by the same reference numerals, and descriptions thereof will be omitted.
In the fifth embodiment, the threshold value is changed depending on the manner in which the hose is used (for example, how it is bent), but the manner in which the hose is used is different from that in the third and fourth embodiments.

<Method and system for predicting remaining life of a hose according to Reference Example 5>
15(A) and 15(B), the hose 1 used in a machine 3 or the like may be used in one case where the distance between one end and the other end in the longitudinal direction changes so that the hose deforms alternately in one direction and the other in a convex shape, and in another case where the distance L between one end and the other end in the longitudinal direction does not change (not shown; in other words, the hose 1 does not move). Therefore, it can be said that the life of the rubber is shorter in the former case than in the latter case.
In the hose 1 that deforms alternately in a convex shape in one direction and the other direction as in Reference Example 5, tension and compression act alternately on the rubber of the inner tube rubber layer 11 .

Therefore, in the case of Reference Example 5, as in Reference Example 4, it is preferable to change the threshold values of the physical properties depending on the usage pattern of the hose 1.

Specifically, when hose 1 is used with the distance between one end and the other end in the longitudinal direction varying in magnitude so that it deforms alternately in a convex shape in one direction and the other, the threshold value is shifted upward as the amplitude of hose 1 increases and the number of repetitions increases, as shown in Figure 16.

To determine the amount by which the threshold value is shifted, a deterioration model can be created by using the same type of hose as the hose 1 currently in use and moving the hose in the same way as the hose 1 currently in use. The threshold value can then be set as the usage limit, based on the usage time at which the hose in the deterioration model fails (for example, when a crack develops and fluid leaks), and the threshold value can be stored in the remaining life prediction means 44.

(Appendix 11)
A method for predicting the remaining life of a hose in use, the hose having at least an inner tube rubber layer that is in contact with the inside of the hose and that changes in distance between one end and the other end in a longitudinal direction so as to be deformed alternately in one direction and the other direction in a convex shape when a fluid comes into contact with the inside of the hose, and a reinforcing layer that is disposed on the outer circumferential side of the inner tube rubber layer, the method comprising:
a deterioration model creation step of determining, in advance, a relationship between the usage time of the inner tube rubber layer and the physical property values of the rubber constituting the inner tube rubber layer using the fluid for a hose of the same type and usage pattern as the hose currently in use, and creating a deterioration model of the inner tube rubber layer;
a usage time calculation step of calculating a usage time of the inner tube rubber layer of the hose in use from the start of use to the time when the prediction is made;
a threshold value setting step of setting a threshold value of the physical property value according to the number of repetitions of bending the inner tube rubber layer due to the change in the distance as a use limit of the inner tube rubber layer;
a remaining life prediction step of predicting the remaining life of the hose in use as the time from when the usage time calculated by the usage time calculation means and the deterioration model created by the deterioration model creation means have elapsed until when the usage time at which the physical property value reaches a threshold value is reached, based on the usage time calculated by the usage time calculation means and the deterioration model created by the deterioration model creation means;
A method for predicting the remaining life of a hose, comprising:

(Appendix 12)
The remaining life of a hose in use is predicted, the hose having at least an inner tube rubber layer that is used with a distance between one end and the other end in the longitudinal direction varying in magnitude so that a fluid comes into contact with the inside and the hose is deformed alternately in one direction and the other in a convex shape, and a reinforcing layer disposed on the outer periphery of the inner tube rubber layer.
A hose remaining life prediction system, comprising:
a deterioration model creation means for determining, using the fluid, the relationship between the usage time of the inner tube rubber layer and the physical property values of the rubber constituting the inner tube rubber layer for a hose of the same type and in the same usage pattern as the hose currently in use, and creating a deterioration model of the inner tube rubber layer;
a usage time calculation means for calculating a usage time of the inner tube rubber layer of the hose in use up to the time when the prediction is made;
a threshold value setting step of setting a threshold value of the physical property value according to the number of repetitions of bending the inner tube rubber layer due to the change in the distance as a use limit of the inner tube rubber layer;
a remaining life prediction means for predicting the remaining life of the hose in use as the time from when the usage time calculated by the usage time calculation means and the deterioration model created by the deterioration model creation means have elapsed until when the usage time at which the physical property value reaches a threshold value is reached, in consideration of the usage time calculated by the usage time calculation means and the deterioration model created by the deterioration model creation means;
A hose remaining life prediction system including:

[Other embodiments]
The above describes one embodiment of the present invention, but the present invention is not limited to the above, and it goes without saying that the present invention can be implemented in various modified forms within the scope of the gist of the present invention.

In the embodiment, it was explained that in a usage scenario where temperature accelerates rubber degradation, it is preferable to create a degradation model using a fluid at a temperature similar to that of the hose 1 in use, and the same applies to Reference Examples 1 to 5 above.

Furthermore, the hose remaining life prediction method and hose remaining life prediction system of this embodiment can be combined with the hose remaining life prediction methods and hose remaining life prediction systems of Reference Examples 1 to 5, as necessary.

1... Hose, 11... Inner tube rubber layer, 12... Reinforcement layer, 42... Deterioration model creation means, 43... Usage time calculation means, 44... Remaining life prediction means, 100... Hose remaining life prediction system

Claims (4)

A method for predicting the remaining life of a hose in use, the method comprising: an inner tube rubber layer that is in contact with an interior of the hose and that includes a rubber that is affected by a fluid containing an additive and whose physical property values change over time due to the additive; and a reinforcing layer that is disposed more outer than the inner tube rubber layer, the method comprising:
a deterioration model creation step of creating a deterioration model of the inner tube rubber layer by previously determining a relationship between the deterioration of the rubber and the time of use based on a hose of the same type as the hose currently in use and a fluid, and correcting the relationship based on the type of additive that changes the physical property value of the fluid ;
a usage time calculation step of calculating a usage time of the inner tube rubber layer of the hose in use from the start of use to the time when the prediction is made;
a remaining life prediction step of predicting a remaining life of the hose in use based on the usage time calculated in the usage time calculation step and the deterioration model created in the deterioration model creation step;
A method for predicting the remaining life of a hose, comprising: In the degradation model creation step, if the additive is likely to degrade the rubber, the relationship is corrected to shorten the remaining life, and if the additive is unlikely to degrade the rubber, the relationship is corrected to lengthen the remaining life.
The method for predicting the remaining life of a hose according to claim 1. A system for predicting the remaining life of a hose in use, the system comprising at least an inner tube rubber layer containing rubber that comes into contact with an interior of the hose with an additive added thereto and that is affected by the additive in terms of changes in physical properties over time, and a reinforcing layer disposed on the outer periphery of the inner tube rubber layer, the system comprising:
a deterioration model creation means for creating a deterioration model of the inner tube rubber layer by previously determining a relationship between the deterioration of the rubber and the time of use based on a hose of the same type as the hose currently in use and a fluid, and correcting the relationship based on the type of additive that changes the physical property value of the fluid ;
a usage time calculation means for calculating a usage time of the inner tube rubber layer of the hose in use from the start of use to the time when the prediction is made;
a remaining life prediction means for predicting a remaining life of the hose in use based on the usage time calculated by the usage time calculation means and the deterioration model created by the deterioration model creation means;
A hose remaining life prediction system including: the deterioration model creation means corrects the relationship to shorten the remaining life when the additive is likely to deteriorate the rubber, and corrects the relationship to lengthen the remaining life when the additive is unlikely to deteriorate the rubber.
The system for predicting the remaining life of a hose according to claim 3.