JPH074468A - Rubber belt inspection method - Google Patents

Abstract

(57) [Summary] [Purpose] To be able to accurately detect the degree of deterioration of a rubber belt in a non-destructive manner and make an accurate determination of the remaining life of the rubber belt. [Structure] A trapezoidal prism 11 is placed on the surface of a rubber material 7 on a timing belt 6 of an engine, and incident light 14 incident on the trapezoidal prism 11 is repeatedly reflected by the surface of the rubber material 7, and the reflected light 15 is red. The external absorption spectrum is measured, and the deterioration degree of the timing belt 6 is detected by the change in the absorbance of the infrared absorption spectrum.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for inspecting a deterioration condition of an engine timing belt or the like.

[0002]

2. Description of the Related Art Since a timing belt of a vehicle-mounted engine gradually deteriorates according to the traveling distance of the vehicle, etc., conventionally, the back rubber of the timing belt is hardened or cracked, the cloth is cracked or peeled, the bottom of the tooth is cracked, or the side surface is cracked. The presence or absence of cracks, abnormal wear, and abnormal wear on the teeth was inspected visually and by touch to determine the presence and extent of deterioration. It was difficult to determine the degree of chemical deterioration of the material and the remaining life. Further, the back surface hardness of the timing belt may be defined by the needle insertion depth to judge the presence or absence of belt deterioration, but the correlation with the degree of chemical deterioration is unclear, and accurate detection is not always possible. Not necessarily.

[0003]

DISCLOSURE OF THE INVENTION The present invention proposes a method capable of accurately detecting the degree of deterioration of a rubber belt such as a timing belt in a nondestructive manner and making an accurate determination of the remaining life of the rubber belt. It is a thing.

[0004]

Therefore, in the rubber belt inspection method according to the present invention, light is incident on the surface of the rubber belt, the infrared absorption spectrum of the light which is transmitted through the surface layer of the rubber belt and inverted, is detected. The degree of deterioration of the rubber belt is detected from the absorbance of the infrared absorption spectrum.

[0005]

In other words, since the degree of deterioration of the rubber belt is detected from the absorbance of the infrared absorption spectrum on the surface of the rubber belt, the degree of chemical deterioration of the rubber belt is always detected accurately without any damage to the remaining life of the rubber belt. It can be easily determined.

[0006]

Embodiments of the present invention shown in the drawings will be specifically described below. 1 and 2, the main body 2 of the infrared spectrophotometer 1 and the measuring unit 3 are connected by flexible optical fibers 4 and 4, and the measuring unit 3 can be freely moved away from the main body 2. It is configured to be able to.

The toothed timing belt 6 hung on the camshaft pulley 5 of the vehicle-mounted engine is twisted by the rubber material 7 made of hydrogenated acrylonitrile butylene and the glass fiber or the amirad fiber into the rubber material 7 in the longitudinal direction. A plurality of core wires 8 embedded in parallel with each other, and a canvas 9 woven of polyamide fiber and adhered to the tooth surface. The infrared ray transmittance of the measuring unit 3 is outside the timing belt 6. A high trapezoidal prism 11 is applied, a dummy belt 10 having the same structure is engaged with the inside of the timing belt 6, and the upper holder 12 of the measuring unit 3 is further engaged.
The light 14 which is pressed by sandwiching the above-mentioned parts from above and below by the lower holder 13 and which is incident on one side of the trapezoidal prism 11 from the light source in the main body 2 through one optical fiber 4 is appropriately reflected on the inner surface of the trapezoidal prism 11. Is totally reflected, and is repeatedly incident on the surface of the rubber material 7.
As a result of being shallowly entangled in the surface layer of and then being inverted, it is emitted as reflected light 15 from the other side of the trapezoidal prism 11, and is guided to the detection section in the main body 2 through the other optical fiber 4.

In the detection section of the infrared spectrophotometer 1,
From the light 15 that is transmitted through the surface layer of the rubber substance 7 and reversed
The infrared absorption spectrum is detected as shown in FIG. 3, and while the timing belt 6 is used for a relatively short period of time, the absorbance at the specific wavelength is large as shown by the curve A, but the As the usage period becomes longer, the infrared absorption characteristics of the rubber substance 7 change due to a chemical change such as the double bond portion of the butadiene group contained in the rubber substance 7 being gradually destroyed, and the above-mentioned absorbance. Decreases as shown by the curve B and further deteriorates as shown by the curve C as the deterioration of the rubber material 7 progresses.

Therefore, the absorption peak wavelength of the infrared absorption spectrum that correlates with the deterioration factor of the rubber substance 7 is found, and its absorbance or the area of the peak of the absorbance near that wavelength changes and the running of the vehicle. The relationship with the durability of the timing belt 6 using the distance and the like as an index is measured as shown in FIG. 4, and the management target of the timing belt 6, for example, the probability of breakage of the timing belt 6 when the vehicle is running 100,000 km is a certain percentage. Rubber quality 7 against durability X when reaching
If the absorbance Y, which is the criterion for determining the degree of deterioration, or the area of the peak of the absorbance is obtained in advance, the infrared spectrophotometer 1 keeps the timing belt rubber material 7 of The degree of deterioration of the timing belt 6 is obtained by measuring the infrared absorption spectrum and detecting the ratio of the absorbance at that time to the absorbance Y or the area ratio of these absorption spectra. Therefore, it is possible to easily and accurately determine whether the timing belt 6 needs to be replaced with a new one at that time.

As described above, the degree of deterioration of the timing belt 6 is not a conventional vague method such as visual observation or tactile sensation, but is converted into a numerical value by the absorbance of the infrared absorption spectrum of the rubber substance 7, and is always accurate without being destroyed. In addition to being able to detect, the remaining life of the timing belt 6 can be accurately and easily estimated. Further, since the degree of deterioration can be inspected in the vehicle mounted state without removing the timing belt 6 from the engine, the workability thereof can be easily enhanced and it is practically very convenient.

Needless to say, the present invention can be applied not only to the timing belt of the engine but also to a rubber belt which is liable to deteriorate due to use conditions such as ambient temperature and load. Depending on the degree of deterioration, the absorbance of the infrared absorption spectrum may change in a direction of increasing, and in this case also, similarly to the above, the rubber belt of the rubber belt is changed in accordance with the absorbance change of the infrared absorption spectrum. The degree of deterioration can be detected.

[0012]

According to the rubber belt inspection method of the present invention, the remaining life of the rubber belt can be easily determined by always accurately detecting the degree of chemical deterioration of the rubber belt without destroying it. The inspection work of the rubber belt is extremely simple, and it is possible to properly judge that the time to replace the rubber belt has come, and thus it is possible to surely avoid the damage accident of the rubber belt.

[Brief description of drawings]

FIG. 1 is a schematic layout diagram in an embodiment of the present invention.

FIG. 2 is an enlarged vertical sectional view of a main part of the above embodiment.

FIG. 3 is an explanatory view of the operation of the above embodiment.

FIG. 4 is an explanatory view of the operation of the above embodiment.

[Explanation of symbols]

 1 Infrared spectrophotometer 3 Measuring part 6 Timing belt 7 Rubber material 11 Trapezoidal prism 14 Incident light 15 Reflected light

Claims (1)

[Claims] 1. An infrared absorption spectrum of light that is incident on the surface of a rubber belt, transmitted through the surface layer of the rubber belt and inverted, and detects the degree of deterioration of the rubber belt from the absorbance of the infrared absorption spectrum. How to check the rubber belt.