Deterioration diagnosis method for plastic parts

Abstract

[Problem] To provide a method for diagnosing degradation of a resin-made component, whereby the degree of progression of degradation of a resin-made component used in a vehicle such as an automobile can be precisely ascertained. [Solution] The present invention has: a degradation detection component fabrication step for fabricating a degradation detection component 10 by adding, to a resin-made component, a detection additional member 15 that has faster progression of degradation than the resin-made component and in which progression of degradation is easier to detect; a degradation detection component incorporation step for incorporating the degradation detection component 10 in a part of a vehicle where the resin-made component is incorporated; a detection additional member 15 degradation degree detection step for detecting the degree of progression of degradation in the added detection additional member 15 after a prescribed period has elapsed; and a degradation progression degree estimation step for estimating the degree of progression of degradation in the resin-made component using information obtained in advance as to a correlation in degradation between the degradation diagnostic member 15 and the resin-made component. [Selected drawing] FIG.1

Description

[Technical field]

[0001] The present invention relates to a deterioration diagnosis method for a resin part, and more particularly to a deterioration diagnosis method for a resin part assembled in a vehicle. [Background technology]

[0002] Automobiles and other vehicles that are required to be driven in various regions and environments are required to have durability to withstand harsh conditions. The same applies to the various parts that are incorporated into the vehicles. Vehicle parts, particularly plastic parts, deteriorate due to heat and humidity, and this deterioration causes changes in physical properties, which may result in them being unable to perform their original functions. Therefore, it is advocated that such plastic parts be designed to withstand the environmental loads they will be subjected to from production to disposal (for example, 25 years).

[0003] As a method for estimating the environmental load of a resin part, a method has been known in which the part is collected from a used vehicle and infrared spectroscopy or chemical luminescence measurement is performed. These methods can estimate the environmental load to a certain extent, for example, the amount of heat added. However, the measurement may involve destruction of the part, and the results are not always reliable, and it has been difficult to feed back the data to vehicles currently in use.

[0004] In the technology of Patent Document 1, a protrusion for detecting deterioration is provided on a plastic part used in an automobile, and the progress of deterioration is detected from the displacement when a predetermined load is applied to this protrusion, or the change in natural frequency when a predetermined displacement is given, and the associated change in rigidity or strength of this part is grasped. By continuing such measurements for a predetermined period of time, the progress of deterioration can be grasped, and it is possible, for example, to encourage the replacement of this plastic part during regular inspection. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 11-132909 Summary of the Invention [Problem to be solved by the invention]

[0006] In the method of Patent Document 1, a protrusion for detecting deterioration is provided on a plastic part, and the degree of deterioration of the part is grasped by periodically detecting changes in mechanical properties. However, depending on the type of plastic part, it may be difficult to obtain the above-mentioned displacement accurately, and in the case of such plastic parts, it is also difficult to detect the progress of deterioration from the displacement, and the progress of deterioration cannot be clearly and accurately grasped.

[0007] The present invention has been made in consideration of the above-mentioned problems, and its object is to provide a deterioration diagnosis method for plastic parts that can accurately grasp the degree of deterioration of plastic parts used in automobiles. [Means for solving the problem]

[0008] In order to achieve the above object, the deterioration diagnosis method for a resin part according to claim 1 comprises the steps of: A deterioration diagnosis method for a plastic part for estimating a degree of deterioration of a plastic part to be installed in a vehicle, comprising: a deterioration detection component fabrication step of fabricating a deterioration detection component by attaching a detection additional member, which deteriorates faster than the resin component and is easy to detect the deterioration of, to the resin component; a deterioration detection part installation process for installing the deterioration detection part at a location where the resin part of the vehicle is to be installed; a deterioration degree detection step of detecting a deterioration degree of the added detection member after a predetermined period of time has elapsed; and a deterioration progression estimation process for estimating the degree of deterioration of the resin part by using previously obtained information on the correlation between deterioration between the deterioration diagnosis component and the resin part.

[0009] According to this method, the degree of deterioration of the resin part is estimated by detecting the degree of deterioration of the additional member for detection, which is made of a material that deteriorates quickly and whose deterioration is easy to detect, and using the detection result. That is, even if it is difficult to directly estimate the degree of deterioration of the resin part, the degree of deterioration of the resin part to be inspected can be easily estimated by detecting the degree of deterioration of the additional member for detection and using correlation information between the detection result and the deterioration of the resin part. The correlation between the deterioration of the resin part and the additional member for detection can be grasped in advance based on the materials of each, and based on this correlation information, it is possible to estimate the degree of deterioration of the resin part from the degree of deterioration of the additional member for detection, which is easier to detect. Effect of the Invention

[0010] According to the deterioration diagnosis method for a plastic part of the present invention, deterioration of the plastic part can be diagnosed by detecting deterioration of the additional member for detection, the correlation of which is understood with the plastic part, and the progress of deterioration of the plastic part can be grasped more easily and clearly. Therefore, deterioration of the plastic part is prevented from being overlooked, and the management ability of the durability of the vehicle is improved. This also improves the long-term reliability of the vehicle user. [Brief description of the drawings]

[0011] [Figure 1] 1 is a flow chart of an embodiment of a deterioration diagnosis method for a resin part according to the present invention; [Diagram 2] 1 is a diagram illustrating the configuration of a deterioration detection part manufactured from a resin part that is a diagnosis target of a deterioration diagnosis method according to an embodiment of the present invention; [Diagram 3] 3 is an explanatory diagram of a manufacturing procedure for the deterioration detection part shown in FIG. 2. [Figure 4] FIG. 2 is an explanatory diagram showing an example of a change over time in the measured surface resistance of an additional member for detection according to one embodiment of the deterioration diagnosis method for a resin part of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a deterioration diagnosis method for a resin part according to the present invention will be described in detail below with reference to the drawings.

[0013] 1 is a flow diagram showing an embodiment of the deterioration diagnosis method for a resin part according to the present invention, and an intake pipe of an engine of an automobile is used as an example of a resin part to be diagnosed by the deterioration diagnosis method for a resin part according to the present invention.

[0014] 2 shows an example of the configuration of the deterioration detection part 10 produced in the deterioration detection part production process (step S31), which is the first process, based on this intake pipe 14. As a schematic configuration, as shown in the figure, an additional member for detection 15 is added to the surface of the intake pipe 14, and a surface resistance meter 21 for measuring the surface resistance of the additional member for detection 15 is attached around the intake pipe 14. The production procedure for this deterioration detection part 10 will be described below.

[0015] 3(a) to (c) show the steps of manufacturing the deterioration detection component 10. As shown in Fig. 3(a), first, the intake pipe 14 is manufactured, for example, by one-piece molding. The intake pipe 14 is made of a common material, nylon (polyamide). Fixing parts 13-1 and 13-2 are provided at predetermined locations on the intake pipe 14 for fixing the intake pipe 14 to a predetermined position on the automobile.

[0016] Next, the additional member for detection 15 is added to the surface of the intake pipe 14 (see FIG. 3(b)). This addition is performed, for example, by adhering the additional member for detection 15 cut into chips of a predetermined size to the surface of the intake pipe 14. Also, when the intake pipe 14 is integrally molded, the additional member for detection 15 may be inserted so as to be positioned at a predetermined surface position and molded as an integral part (insert molding). In this embodiment, the additional member for detection 15 is made of polycarbonate or polyester, which has low moisture absorption.

[0017] Next, a surface resistance measuring device 21 for measuring the surface resistance of the additional member for detection 15 is attached (see FIG. 3(c)). The surface resistance measuring device 21 is composed of a main body 20 and a measuring probe 16. The measuring probe 16 has two needle electrodes (not shown) and is provided so that these needle electrodes are in contact with the additional member for detection 15. The main body 20 and the measuring probe 16 are connected by lead wires 18-1 and 18-2 and are configured so that, for example, the surface resistance value is measured by the current that flows when a voltage is applied between the needle electrodes. The measurement result is transmitted by a harness 22 to an engine control unit (ECU), which is one of the control units mounted on the vehicle, and the ECU is configured so that the measured value can be monitored.

[0018] Here, if the additional member for detection 15 is hygroscopic, the measurement of the surface resistance value becomes unstable due to moisture. However, in this embodiment, the additional member for detection 15 is formed of polycarbonate or polyester with low hygroscopicity as described above, so that the surface resistance value can be measured stably and the reliability of the measurement result is improved. That is, even if the surface of the intake pipe 14, which is a resin part of the target part, is directly measured with the surface resistance measuring device 21, the surface resistance value cannot be measured stably if the intake pipe 14 is made of a resin with high hygroscopicity such as nylon, because nylon (polyamide), which is a resin material widely used in vehicles, has relatively high hygroscopicity. If the reliability of the measurement result of the surface resistance value is improved, the degree of deterioration of the resin part to be diagnosed, which will be described below, can be estimated with high accuracy.

[0019] Next, the deterioration detection part installation process (step S32) in the flow diagram of Fig. 1 will be described. The manufactured deterioration detection part 10 is installed in the location where the intake pipe 14, which is a resin part, should be installed. This installation is not particularly different from the installation process of a normal intake pipe 14. That is, the deterioration detection part 10 is attached to a predetermined location on the vehicle using the fixing parts 13-1, 13-2 of the intake pipe 14.

[0020] Next, a deterioration degree detection step (step S33) is performed to detect the degree of deterioration of the additional member for detection 15. The degree of deterioration is measured by measuring the surface resistance of the additional member for detection 15 using a surface resistance measuring device 21. This measurement can be performed continuously while the vehicle control unit is operating, for example, while the engine of the vehicle is running, and even if the intake pipe 14, which is a resin part, deteriorates in a shorter time than expected due to various causes, it can be detected without being overlooked. A case where deterioration occurs in a shorter time than expected may be a case where the deterioration detection part 10 is subjected to an excessive thermal load due to a special usage condition, such as not driving for a long period of time with the engine running under a hot, sunny day at high temperatures.

[0021] The surface resistance value of the additional member for detection 15 measured by the surface resistance measuring device 21 can be monitored via an engine control unit (ECU).

[0022] 4 shows an example of the change over time in the surface resistance value of the additional member for detection 15. The vertical axis of FIG. 4 represents the surface resistance (Ω / cm 2 ), and the horizontal axis is time (hr). There are various examples of surface resistance values, such as a linear decrease as shown in FIG. 4(a) and a nonlinear decrease as shown in FIG. 4(b). The important thing is that the surface resistance value decreases over time due to thermal degradation of the component. This is because the molecular structure of the surface of the additional component for detection 15 changes. That is, by measuring the surface resistance of the component using this phenomenon, the time when a degradation factor such as a thermal load was applied to the component can be known, and by conducting an experiment in which a degradation factor such as a thermal load is applied to the component for a predetermined time, the time when the degradation factor was applied to the component and the degree of degradation of the component can be known.

[0023] Next, the deterioration progress degree estimation step (step S34) will be described. This estimation step estimates the deterioration progress degree of the resin part by using previously obtained correlation information of deterioration between the additional member for detection 15 and the resin part. Here, the correlation information of deterioration between the additional member for detection 15 and the intake pipe 14 is used. That is, by using the measured surface resistance value of the additional member for detection 15, the deterioration degree of the additional member for detection 15 can be easily known from the relationship between the surface resistance value and time as described above, and further, by using the correlation information, the deterioration degree of the intake pipe 14, which is a resin part, can be estimated. This estimation may be automatically performed by inputting the measured surface resistance value of the additional member for detection 15 by programming a computer or the like.

[0024] Here, the correlation of deterioration can be obtained by, for example, determining the relationship between the surface resistance value of the detection additional member 15 prepared in advance and time, as described above, and knowing the time corresponding to the measured surface resistance value of the detection additional member 15, i.e., the time when a deterioration factor such as a thermal load was applied. Then, for both the detection additional member 15 and the resin part to be diagnosed, the deterioration factor is applied for that time, and infrared spectroscopy analysis, chemical luminescence analysis, and further measurement of the reaction force and displacement when a predetermined stress is applied are performed for each, thereby grasping the degree of deterioration of each and correlating them. By performing this operation for various corresponding times, deterioration correlation information can be obtained.

[0025] Next, in an estimation result transmission step (step S35), the estimation result is sent to a vehicle-related organization such as a vehicle manufacturer, a dealer, a repair shop, a factory, etc., using a mobile communication system. In this embodiment, the surface resistance value of the detection additional member 15 is measured, for example, every hour while the vehicle engine is running, and the result is sent to the vehicle-related organization from an engine control unit (ECU) or a power control unit (PCU), which is an on-board control unit, using the mobile communication system.

[0026] The data sent to vehicle-related organizations can more accurately gauge when plastic parts will deteriorate and begin to malfunction, giving users peace of mind that the durability of their vehicles is being managed.

[0027] According to the deterioration diagnosis method for resin parts of this embodiment, the surface resistance value of the additional member for detection 15, for which the correlation between the intake pipe 14 and deterioration has been grasped, is constantly monitored while the vehicle engine is running, and the result is sent to vehicle-related organizations. Therefore, the progress of deterioration of the intake pipe 14 can be easily and clearly grasped. In addition, the occurrence of a deterioration state is prevented from being overlooked, and the ability to manage the durability of the vehicle is improved. This also improves the long-term reliability of the vehicle for the vehicle user.

[0028] Furthermore, the addition of the detection additional member 15 to the resin part in the process of producing the deterioration detection part 10 is performed by adhering the detection additional member 15 to the surface of the resin part, and the process of detecting the deterioration degree of the detection additional member 15 is performed by measuring the surface resistance value of the detection additional member 15, so it is possible to easily produce the deterioration detection part 10 in a short time. Furthermore, the deterioration degree of the detection additional member 15 can be detected simply and easily by measuring the surface resistance value of the detection additional member 15.

[0029] In addition, since the additional detection member 15 is made of polycarbonate or polyester, which has low moisture absorption, the surface resistance can be measured stably, the reliability of the measurement results is improved, and the degree of deterioration of the resin parts can be estimated with high accuracy.

[0030] Moreover, the surface resistance value is measured by connecting a surface resistance measuring device 21 to the additional member for detection 15, constantly measuring the surface resistance value of the additional member for detection 15 while the engine of the vehicle is running, and monitoring the measurement results via an engine control unit (ECU) or a power control unit (PCU), so that the surface resistance value of the additional member for detection 15 is constantly measured while the engine is running, and therefore even if the resin parts deteriorate in a shorter time than expected due to various causes, this can be detected without being overlooked. Therefore, the reliability of the durability of the vehicle is improved.

[0031] In addition, the method includes an estimation result transmission process for sending the results of estimating the degree of deterioration to vehicle-related organizations such as the vehicle manufacturer, dealer, repair shop, factory, etc., using a mobile communication system. This allows vehicle-related organizations such as the vehicle manufacturer, dealer, repair shop, factory, etc. to more accurately measure the timing at which the plastic part will malfunction due to deterioration, thereby providing the user with peace of mind regarding the management of the vehicle's durability.

[0032] The present invention is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the present invention. For example, the engine intake pipe 14 is exemplified as a resin part, but the diagnosis target is not limited to this, and the present invention can be applied to various other resin parts. In addition, the surface resistance measuring device 21 has a main body 20 and a measuring probe 16, but the measuring device may be an integrated device.

[0033] In addition, the deterioration degree detection process has been described as being performed continuously while the vehicle engine is running, but it is also possible to perform detection at a required timing, in which case the estimation result transmission process will also be performed at a specified timing rather than being performed continuously. [Explanation of symbols]

[0034] 10. Deterioration detection parts 13-1, 13-2 Fixed part 14 Vehicle engine intake pipe 15 Additional parts for detection 16 Measuring probes 18-1, 18-2 Lead wires 20 Main body 21 Surface resistance measuring device 30 Flow diagram of deterioration diagnosis method

Claims

1. A deterioration diagnosis method for a plastic part for estimating a degree of deterioration of a plastic part to be installed in a vehicle, comprising: a deterioration detection component fabrication step of fabricating a deterioration detection component by attaching a detection additional member, which deteriorates faster than the resin component and is easy to detect the deterioration of, to the resin component; a deterioration detection part installation process for installing the deterioration detection part at a location where the resin part of the vehicle is to be installed; a deterioration degree detection step of detecting a deterioration degree of the added detection member after a predetermined period of time has elapsed; and a deterioration progression degree estimating step of estimating a deterioration progression degree of the resin part by using previously obtained correlation information of deterioration between the additional member for detection and the resin part, A deterioration diagnosis method for a resin part, characterized in that the addition of the detection additional member to the resin part during the process of manufacturing the deterioration detection part is performed by gluing or insert molding the detection additional member onto the surface of the resin part.

2. 2. The method for diagnosing deterioration of a resin part according to claim 1, wherein the step of detecting the degree of deterioration of the additional member for detection is carried out by measuring a surface resistance value of the additional member for detection.

3. 3. The deterioration diagnosis method for a resin part according to claim 1, wherein the additional member for detection is made of polycarbonate or polyester having low moisture absorption.

4. The deterioration diagnosis method for a resin part according to claim 2, characterized in that the measurement of the surface resistance value is performed by connecting a surface resistance measuring device to the detection additional member, constantly measuring the surface resistance value of the detection additional member while an on-vehicle control unit is operating, and monitoring the results of the measurement via the control unit.

5. 2. The deterioration diagnosis method for a resin part according to claim 1, further comprising an estimation result transmission step of transmitting the result of the estimation of the deterioration degree to a vehicle-related institution such as a manufacturer, a dealer, a repair shop, or a factory of the vehicle using a mobile communication system.

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