JPH07146233A - Oil deterioration degree sensor - Google Patents

Abstract

PURPOSE:To provide an oil deterioration degree sensor which has high sensitivity and in which clogging scarcely occurs. CONSTITUTION:The oil deterioration degree sensor comprises an entirely substantially U-shaped light propagating member 4 in which an intermediate part to be dipped in oil is bent, a holder 2 for supporting the member 4 in a state in contact with the intermediate part, a light emitting element 8 emitting light and guiding it to one end of the member 4, and a photodetector 9 for detecting the quantity of light emitted from the other end of the member 4, wherein an air gap 7 which the oil enters and is formed at the intermediate part of the member 4. The gap 7 is formed by cutting the intermediate part of the member 4 in a state that the intermediate part of the member 4 is brought into contact with a support surface 2a of the holder 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sensor for detecting the degree of deterioration of oil used in engines of automobiles and aircraft.

[0002]

2. Description of the Related Art Lubricating oil is used in automobile engines. If this oil deteriorates, it may cause a malfunction such as baking, so it is necessary to detect the degree of oil deterioration in advance and replace the oil. The following technology (J01) is known as an oil deterioration degree sensor of this type. (J01) (Technology described in Japanese Patent Application Laid-Open No. 1-214737) In this publication, a light emitting element and a light emitting element are directly opposed to each other with a gap of 40 to 170 μm, and the light enters into (flows into) this narrow gap. It is described that the degree of deterioration is determined by measuring the amount of light absorbed by oil.

(J02) (Technology described in Japanese Patent Application Laid-Open No. 1-245135) In this publication, light is made incident from one end of a light propagating member immersed in oil, and is repeatedly reflected and refracted in the light propagating member. The degree of deterioration is determined by measuring the amount of light reaching the other end side by utilizing the fact that the amount of light leaking from the light propagating member into the oil varies depending on the degree of oil deterioration when What is done is described.

[0004]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
1) has the following problems. Since a gap is provided to allow oil to enter, a spacer is sandwiched between the light emitting surface of the light emitting element and the light receiving surface of the light receiving element, and this is pressed into contact, so that the temperature of the oil rises due to vibration or the temperature of the oil rises and the sensor thermally expands. By doing so, the light emitting surface or the light receiving surface glass that comes into contact with the spacer may be damaged. If the gap through which the oil passes is too wide, the amount of light absorbed by the oil will be too large and the amount of light reaching the light receiving element will decrease too much, making measurement difficult.On the other hand, if the gap is too small, it will be included in the oil. It is set to about 40 to 170 μm because the carbon particles to be passed cannot pass and the oil flow deteriorates. However, when the light emitting surface and the light receiving surface are directly opposed to each other with such a narrow gap therebetween, Due to the large cross-sectional area of the light receiving element, the flow of oil into the gap was extremely poor and clogging occurred. That is, it is desired to reduce the cross-sectional area in order to improve the flow of oil, but there was no light-emitting element or light-receiving element having such a small cross-sectional area. In addition, since the light emitting element and the light receiving element are directly immersed in the oil in this oil deterioration sensor, the light emitting element decreases its emission intensity as the temperature of the oil increases, and the light receiving element increases the dark current to increase the sensor sensitivity. There was a problem that it got worse.

The conventional technique (J02) has the following problems. As in the technique of (J02), light is made to enter from one end of the light propagating member immersed in oil and is reflected and refracted repeatedly to progress through the light propagating member to the other end.
What determines the degree of deterioration from the amount of light that reaches the light receiving element provided on the other end side is not that which directly transmits light into the oil and measures the light absorption by the oil, but rather the change in the refractive index and reflectance. Measure the variation in light intensity. However, this fluctuation amount was too small, and it was difficult to judge the degree of deterioration.

In view of the above-mentioned prior art, the present invention has the following contents. (O01) To provide an oil deterioration degree sensor that has high sensitivity and is unlikely to cause clogging.

[0007]

The present invention devised to solve the above problems will now be described. The elements of the present invention are to facilitate correspondence with the elements of the embodiments described later. Note that the reference numerals of the elements of the embodiments are enclosed in parentheses. Further, the reason why the present invention is described in association with the reference numerals of the embodiments described later is to facilitate understanding of the present invention and not to limit the scope of the present invention to the embodiments.

(Invention) In order to solve the above-mentioned problems, an oil deterioration sensor of the present invention comprises a light propagation member (4) having a substantially U-shape as a whole by bending an intermediate portion immersed in oil. A holder (2) for supporting the light propagating member (4) in contact with the intermediate portion, and the light propagating member (4)
Of the light propagating member (4), which includes a light emitting element (8) for allowing light to enter one end of the light propagating member (4) and a light receiving element (9) for detecting the amount of light emitted from the other end of the light propagating member (4). An oil deterioration sensor having an oil entry space (7) formed in an intermediate portion is characterized by having the following requirements: (Y01) The oil entry space (7) is provided with the light propagation path. The intermediate portion of the member (4) is the support surface (2) of the holder (2).
The intermediate portion of the light propagating member (4) is cut and formed in a state where the light propagating member (4) abuts and is fixed.

(Supplementary Explanation of the Present Invention) It is preferable that the light propagation member (4), the holder (2) and the like are made of a material having a small coefficient of thermal expansion. Further, it is preferable that the light emitting element (8) and the light receiving element (9) are arranged at positions where there is little temperature change. In the present specification, the “substantially U-shaped” means a shape in which a rod-shaped member is bent at an intermediate portion and both ends are directed in the same direction, and a shape such as “V-shaped” or “arc-shaped” is used. It includes. Further, the "bending" means the "bending" in the case where the linear member is first manufactured and then the "bending" is performed thereafter, and when the one having the "bent" shape is manufactured from the beginning. Shall also be included.

(Embodiment 1 of the present invention) An oil deterioration sensor according to embodiment 1 of the present invention is characterized in that the oil deterioration sensor of the present invention has the following requirements: (Y001) The light emission A means for making most of the light emitted from the element (8) incident on one end of the light propagating member (4) (that is, a high-emission-rate incident means for emitting light) is provided.

(Embodiment 2 of the present invention) An oil deterioration sensor according to a second embodiment of the present invention is characterized in that the oil deterioration sensor of the present invention or the first embodiment has the following requirements. Y002) A means for causing most of the light emitted from the other end of the light propagating member (4) to enter the light receiving element (9) (that is, a detection light amount high-rate entrance means is provided.

(Third Embodiment of the Present Invention) An oil deterioration sensor according to a third embodiment of the present invention is characterized in that the oil deterioration sensor according to the first embodiment of the present invention has the following requirements. Y003) The high-intensity-incidence light emitting means sets the area of one end face of the light propagation member (4) arranged facing the light emitting area larger than the area of the light emitting area of the light emitting element (8). It is configured by the end face shape of the member (4).

(Fourth Embodiment of the Invention) An oil deterioration sensor according to a fourth embodiment of the present invention is characterized in that the oil deterioration sensor according to the third embodiment of the present invention has the following requirements. Y004) One end surface of the light propagating member (4) has a curved surface shape for condensing the light incident on the light propagating member (4).

(Embodiment 5 of the present invention) An oil deterioration degree sensor according to a fifth embodiment of the present invention is characterized in that the oil deterioration degree sensor according to the first embodiment of the present invention has the following requirements. Y005) The high-emission-intensity-incidence means is a condensing lens (provided between the light-emitting region of the light-emitting element (8) and one end face of the light-propagating member (4) arranged facing the light-emitting region. R1).

(Sixth Embodiment of the Present Invention) An oil deterioration sensor according to a sixth embodiment of the present invention is characterized in that the oil deterioration sensor according to the second embodiment of the present invention has the following requirements. Y006) The above-mentioned high-intensity-detection-light-incidence means sets the area of the other end surface of the light propagation member (4) arranged facing the light receiving area smaller than the area of the light receiving area of the light receiving element (9). It is configured by the end face shape of the member (4).

(Seventh Embodiment of the Present Invention) An oil deterioration degree sensor according to a seventh embodiment of the present invention is characterized in that the oil deterioration degree sensor according to the second embodiment of the present invention has the following requirements. Y007) The other end surface of the light propagating member (4) has a curved surface shape for condensing light emitted from the light propagating member (4).

(Embodiment 8 of the present invention) An oil deterioration degree sensor according to embodiment 8 of the present invention is characterized in that the oil deterioration degree sensor according to embodiment 2 of the present invention has the following requirements. Y008) The high-intensity-detection-light-incident means is a condenser lens (provided between the light-receiving region of the light-receiving element (9) and the other end face of the light-propagating member (4) arranged so as to face the light-receiving region. It was composed by R2).

(Embodiment 9 of the present invention) An oil deterioration sensor according to a ninth embodiment of the present invention is the same as the oil deterioration sensor according to the present invention or any of the first to eighth embodiments of the present invention. (Y009) The oil intrusion cavity (7) is formed by cutting with a dicing saw for cutting a silicon wafer.

(Embodiment 10 of the present invention) An oil deterioration degree sensor of embodiment 10 of the present invention has the following requirements in the oil deterioration degree sensor of the present invention or any of the embodiments 1 to 9 of the present invention. (Y0010) The supporting surface (2a) of the holder (2), to which the intermediate portion of the light propagating member (4) abuts and is fixed, has the oil intrusion void portion (7). The part where the oil is formed was partially removed to form the oil entry space (2b).

(Embodiment 11 of the present invention) An oil deterioration degree sensor according to embodiment 11 of the present invention has the following requirements in the oil deterioration degree sensor according to any one of the embodiments 1 to 10 of the present invention. (Y0011) The light emitting element (8) and the light receiving element (9)
Is disposed on the surface of the holder (2) opposite to the supporting surface (2a) and is oil-tightly sealed by the sealing means (15).

[0021]

Next, the operation of the present invention having the above features will be described. (Operation of the present invention) In the oil deterioration sensor of the present invention having the above-mentioned characteristics, the light emitted from the light emitting element (8) enters one end of the light propagation member (4). The incident light travels through the light propagating member (4) and reaches the oil penetration space (7) provided midway. Then, the light is absorbed by the oil when passing through the oil existing in the oil intrusion void portion (7). This oil entry space (7)
The light which has passed through travels through the light propagating member (4) further ahead and is emitted from the other end of the light propagating member (4). The amount of light emitted from the other end is detected by the light receiving element (9). That is, since the light receiving element (9) receives light according to the light absorption amount of oil (which has a correlation with the deterioration degree of oil), the oil deterioration degree can be determined by the received light amount.

Unlike the light emitting element (8) and the light receiving element (9), the cross-sectional area of the light propagating member (4) can be made sufficiently small. Therefore, even if the space for the oil intrusion (7) is narrow, It is possible to prevent the oil from easily entering the oil entry space (7). Further, the oil penetration space (7) formed in the intermediate portion of the light propagating member (4) is formed by cutting while the light propagating member (4) is in contact with and fixed to the holder (2). Therefore, even if the light propagating member (4) is a brittle material such as glass, it does not crack or chip,
It can be formed with high precision and high yield.

(Operation of Embodiment 1 of the Present Invention) In the oil deterioration degree sensor of Embodiment 1 of the present invention, most of the light emitted from the light emitting element (8) is applied to one end of the light propagation member (4). Since the means for making the light incident (that is, the means for injecting a high amount of emitted light) is provided, the light emitted from the light emitting element (8) can be used with high efficiency (without leaking to the outside).

(Operation of Embodiment 2 of the Present Invention) In the oil deterioration degree sensor of Embodiment 2 of the present invention, most of the light emitted from the other end of the light propagation member (4) is received by the light receiving element (9). Since the means for making the light incident on the light receiving area (namely, the means for injecting a high amount of detected light) is provided, the light emitted from the other end of the light propagating member (4) can be efficiently used without waste.

(Operation of Embodiment 3 of the Present Invention) In the oil deterioration degree sensor of Embodiment 3 of the present invention, the emitted light from the light emitting element (8) is larger than the area of the light emitting region of the light emitting element (8). Light enters the light propagating member (4) with high efficiency from one end face of the light propagating member (4) set to be large without waste (without leaking to the outside). Therefore, the light emitted from the light emitting element (8) can be efficiently used without waste.

(Operation of Embodiment 4 of the Present Invention) In the oil deterioration sensor of Embodiment 3 of the present invention, the emitted light from the light emitting element (8) is larger than the area of the light emitting region of the light emitting element (8). Light enters the light propagating member (4) with high efficiency from the one end surface of the curved shape of the light propagating member (4) that is set large without waste (without leaking to the outside). Therefore, the light emitted from the light emitting element (8) can be efficiently used without waste.

(Operation of Fifth Embodiment of the Present Invention) In the oil deterioration degree sensor of the fifth embodiment of the present invention, the light emitted from the light emitting element (8) is condensed by the condenser lens to be the light propagating member. It is incident on the light propagating member (4) from one end face of (4) with high efficiency and without waste. Therefore, the light emitted from the light emitting element (8) can be efficiently used without waste.

(Operation of Embodiment 6 of the Present Invention) In the oil deterioration sensor of Embodiment 6 of the present invention, the light propagating member (4) is used.
Light emitted from the other end surface (detection light) is incident on the light receiving region of the light receiving element (9) having a larger area than the other end surface with high efficiency without waste (without leakage). Therefore,
The emitted light (detection light) from the other end surface of the light propagating member (4) can be efficiently used without waste.

(Operation of Embodiment 7 of the Present Invention) In the oil deterioration sensor of Embodiment 7 of the present invention, the light propagating member (4) is used.
The emitted light (detection light) from the other end surface of the light enters the light receiving area of the light receiving element (9) with high efficiency while being collected from the other end surface of the curved surface shape. Therefore, the light emitted from the other end surface of the light propagating member (4) (detection light)
Can be used efficiently without waste.

(Embodiment 8 of the present invention) In the oil deterioration degree sensor of embodiment 8 of the present invention, the oil deterioration sensor from the other end surface of the light propagating member (4) arranged facing the light receiving area of the light receiving element (9). The emitted light (detection light) is condensed by a condenser lens and is efficiently incident on the light receiving area of the light receiving element (9) with high efficiency. Therefore, the emitted light (detection light) from the other end surface of the light propagating member (4) can be efficiently used without waste.

(Operation of Ninth Embodiment of the Present Invention) The oil deterioration sensor according to the ninth embodiment of the present invention is formed by cutting the oil intrusion void portion (7) with a dicing saw for cutting a silicon wafer. Therefore, the shape and interval of the oil intrusion void portion (7) can always be formed uniformly and with high precision.

(Operation of Embodiment 10 of the Present Invention) In the oil deterioration sensor according to Embodiment 10 of the present invention, the holder (2) fixed by abutting the intermediate portion of the light propagating member (4). The support surface (2a) has an oil entry space (2b) formed by partially removing the portion where the oil entry space (7) is formed, so that the oil entry space (7) is formed. It becomes easy for oil to flow into.

(Operation of Embodiment 11 of the Present Invention) The supporting surface (2a) of the holder (2) and the surface opposite to the supporting surface (2a) (that is, the light emitting element (8) and the light receiving element). The distance from the surface on which the element (9) is arranged) can be set appropriately. If the distance is set long enough,
The distance between the oil penetration space (7) fixed to the support surface (2a) of the holder (2) and the light emitting element (8) and the light receiving element (9) can be made sufficiently long. In this case, since the light emitting element (8) and the light receiving element (9) can be arranged at positions apart from the oil when the oil entry space (7) is immersed in the oil, the influence of the temperature of the oil is exerted. Can be reduced. Also,
The light emitting element (8) and the light receiving element (9) are sealed with a sealing means (1
Since it is oil-tightly sealed by 5), the light emitting element (8) and the light receiving element (9) are prevented from being contaminated with oil.

[0034]

EXAMPLES Examples of the present invention will now be described with reference to the drawings, but the present invention is not limited to the following examples. (Embodiment 1) FIG. 1 is a side sectional view of Embodiment 1 of the oil deterioration degree sensor of the present invention. FIG. 2 is a bottom view of the oil deterioration sensor of the embodiment, which is a view as seen from an arrow II in FIG. In FIGS. 1 and 2, a holder holding portion 1a formed of a large-diameter cylindrical surface is provided at the tip (lower end) of the case 1 having an inner cylindrical surface. A circuit accommodating portion 1b formed by a small diameter cylindrical surface is provided above the holder holding portion 1a. A large-diameter operation part (portion to be held and operated by hand) 1c on the outer periphery of the upper end of the case 1
And a screw 1d is provided on the outer periphery of the middle part of the case 1. The screw 1d is a screw for installing at a predetermined inspection position.

A metal holder 2 is held in the holder accommodating portion 1a. The holder 2 is held by inserting the metal holder 2 into the holder accommodating portion 1a with the tip of the case 1 not bent inward and then bending the tip of the case 1 inward. It is done by. An O-ring groove is formed on the outer peripheral surface of the holder 2, and an O-ring 3 is arranged in the O-ring groove.
The O-ring 3 is in close contact with the inner peripheral surface of the holder accommodating portion 1a, and when the tip (lower end) of the case is immersed in oil, the oil is between the inner peripheral surface of the holder accommodating portion 1a and the outer peripheral surface of the holder 2. It is prevented from invading the inside of the circuit accommodating portion 1b through the above. The tip surface (lower surface) of the holder 2 is used as a support surface 2 a that supports the light propagation member 4. A cutout portion 2b is provided at the center of the support surface 2a. The cutout portion 2b forms an oil entry space. Also,
A light emitting element accommodating hole 2d and a light receiving element accommodating hole 2e are formed on a surface opposite to the supporting surface (lower surface) 2a of the holder 2, that is, an upper surface 2c. In addition, the holder 2 has a pair of light propagation member insertion holes that communicate with the light emitting element housing hole 2d and the light receiving element housing hole 2e formed on the opposite surface (upper surface) 2c from the supporting surface (lower surface) 2a. 2f, 2f
(Only one is shown) are formed.

The light propagating member 4 is composed of a glass rod, and the middle portion thereof is bent to be formed in a substantially U shape as a whole. Both end portions of the light propagating member 4 are inserted into the light propagating member insertion holes 2f, 2f (only one is shown) of the holder 2, and the end faces thereof are placed in the light emitting element accommodation hole 2d and the light receiving element accommodation hole 2e. It is arranged. The light propagation member 4 is fixed to the support surface 2a of the holder 2 with an adhesive. Then, the support surface 2 at the intermediate portion of the light propagation member 4
A portion corresponding to the cut portion 2b at the center of a is cut by a dicing saw for cutting a silicon wafer, and an oil intrusion void portion 7 is formed at the cut portion. The oil penetration space 7 is provided in the holder 2 with an adhesive for the light propagation member 4.
It can be easily formed by cutting with a blade having a width that is the same as or slightly smaller than the required space between the oil intrusion gaps 7 in a state of being fixed to. In the present embodiment, the oil penetration space 7 is formed perpendicularly to the extending direction of the light propagation member 4, and is formed at a position corresponding to the cutout 2b. It should be noted that the oil entry space 7 may be formed by cutting it obliquely instead of forming it perpendicularly to the extending direction of the light propagation member 4.

Regarding the diameter of the light propagating member 4, if the diameter is too thick, it becomes difficult for the oil to enter the oil entry space 7, and conversely, if the diameter is too small, the amount of light propagating through the light propagating member 4 decreases and it is detected. It is set in consideration of both reduction in sensitivity. According to an experiment of automobile oil, the gap between the oil intrusion gaps 7 is optimally 40 to 100 μm, and the diameter of the glass rod forming the light propagation member 4 is optimally about 1 mm.

A light emitting element 8 composed of an infrared LED is housed in the light emitting element housing hole 2d, and a light receiving element 9 composed of a photodiode is housed in the light receiving element housing hole 2e. The light emitted from the light emitting element 8 enters from one end surface of the light propagating member 4, passes through the oil intrusion void portion 7, and further exits from the other end surface of the light propagating member 4. The light receiving element 9 is arranged at a position for detecting the light emitted from the other end surface of the light propagating member 4.

An electronic control circuit 11 is housed in the circuit housing portion 1b of the case 1. The electronic control circuit 11 has functions of driving the light emitting element 8, amplifying the output of the light receiving element 9, temperature correction, and the like, and further having a function of transmitting the light amount signal detected by the light receiving element 9 to the outside. . The periphery of the electronic control circuit 11 is covered with an insulating tape 12 for insulating the electronic control circuit 11 and the case 1.
The inside of the circuit housing portion 1b of the case 1 is connected to the female connector 14 by a connecting pipe 13. The upper end of the circuit housing portion 1b of the case 1 is filled with an epoxy adhesive 15 for vibration prevention and sealing. That is, the epoxy adhesive 15 constitutes the sealing means of this embodiment. A recess 14a is formed at the upper end of the female connector 14, and a plurality of terminals 14b are arranged in the recess 14a. The plurality of terminals 14b are connected to the electronic control circuit 11 by connection transmission lines (not shown) arranged in the connection pipe 13. The terminal 14b of the female connector 14 is connected to the socket terminal 16a of the male connector 16.

(Operation of Embodiment 1) Next, the operation of the oil deterioration degree sensor having the above-described structure will be described. Infrared LED
The light emitted from the light emitting element 8 configured by the above enters the light propagation member 4 configured by a glass rod and reaches the oil intrusion void portion 7. The light is absorbed by the oil when passing through the oil-entry void 7. The light that has passed through the oil intrusion gap 7 propagates again through the light propagation member 4 and is received by the light receiving element 9 formed of a photodiode, and the amount of light is detected. The light receiving amount (light receiving intensity) of the light receiving element 9 depends on the light absorbing amount of oil, and since the light absorbing amount of oil correlates with the oil deterioration degree, the deterioration degree of oil can be determined by measuring the light receiving amount. . The change in the amount of received light is theoretically shown as follows.

That is, as shown in FIG. 3, assuming that parallel light is incident on one surface of a sample having two unit parallel planes, the incident light i on a thin layer having a thickness dx therein is from x to x +.
If it changes to i + di by advancing to dx,
It is considered that the changed light amount di is proportional to i and the amount of the light absorbing substance in the thin layer. The concentration of the light absorbing substance is c
Then, since the amount of the light absorbing substance in the volume (1 × 1 × dx) of the thin layer is c × dx, the following differential equation is established with the proportional constant k ′. -Di = k'icdx ………………………………………………………… (1) The following equation is obtained from equation (1). -Di / i = k'cdx ………………………………………………………… (2) The incident light quantity is Io and the light quantity when it is transmitted through the layer of thickness L is It.
When the definite integral is performed as, the following equation is obtained. It = IoEXP (−cLk ′) ……………………………………………… (3) Converting it to the formula using common logarithm, It = Io × 10 (-cLk ′) ) Power ………………………………………… (4) However, k = 0.434k ′, which is called the molecular extinction coefficient. In this equation (4), the incident light is L or c as shown in FIG.
On the other hand, it shows that it decreases exponentially.

In the present invention, Io, It, c, L, k
Respectively correspond to the following: Io: Amount of light incident on the oil from the light propagating member 4 on the light emitting element 8 side in the oil intrusion void 7 It: Amount of light incident on the light propagating member 4 on the light receiving element 9 side from the oil in the oil intruding void 7 L: Interval of oil intrusion void 7 c: Insoluble matter concentration in oil, that is, oil deterioration degree k: Sensitivity of light receiving element 9 to insoluble matter in oil Here, L and k are known. Further, when the oil does not exist in the oil entry space 7, that is, Io can be easily obtained from the data when c = 0. Therefore, by measuring It, the concentration of insoluble matter in the oil, that is,
The deterioration degree c of oil can be measured.

When the oil deterioration sensor of the present embodiment is actually used, the detection signal from the light receiving element 9 is compared with a predetermined set value to determine whether or not it has exceeded an allowable level,
A normal comparison circuit and a display circuit that turn on the alarm lamp when the level is above the allowable level are provided to determine the degree of oil deterioration.

(Second Embodiment) Next, a second embodiment of the oil deterioration sensor of the present invention will be described with reference to FIG. FIG. 5 is an explanatory diagram of a second embodiment of the oil deterioration degree sensor. In addition,
In the description of the second embodiment, constituent elements corresponding to those of the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. The second embodiment differs from the first embodiment in the following points, but is configured similarly to the first embodiment in other points. (S01) The shape of the light propagating member 4 is different. That is,
As shown in FIG. 5, one end of the light propagating member 4, that is, the end face shape of the end portion facing the light emitting element 8 is formed to be larger than the area (light emitting area) of the light emitting region of the light emitting element 8. The other end, that is, the end face shape of the end portion facing the light receiving element 9 is formed smaller than the area (light receiving area) of the light receiving region of the light receiving element 9. The light propagating member 4 having the above-mentioned shape is
The molded product placed in a mold is cut with a dicing saw for cutting a silicon wafer as in the case of the first embodiment, and an oil-entry void 7 is formed at the cut portion. The shape of the one end face of the light propagating member 4 formed to be larger than the area of the light emitting area of the light emitting element 8 constitutes the high-emission-intensity-incidence means of the second embodiment, and the area of the light receiving area of the light receiving element 9 is formed. The shape of the other end surface of the light propagating member 4 formed to be smaller than the above constitutes the detection light amount high-rate incidence means.

(Operation of Second Embodiment) In the second embodiment, the light propagating member 4 does not leak most of the light emitted from the light emitting element 8.
Of the detection light that can be incident on one end of the light-transmitting member 4 and that does not leak most of the detection light emitted from the other end of the light-propagating member 4.
Can be incident on. Therefore, the light emitted from the light emitting element 8 can be used with high efficiency.

(Third Embodiment) Next, referring to FIG. 6, a third embodiment of the oil deterioration sensor of the present invention will be described. FIG. 6 is an explanatory diagram of a third embodiment of the oil deterioration sensor. In addition,
In the description of the third embodiment, constituent elements corresponding to those of the second embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. The third embodiment differs from the second embodiment in the following points, but is configured similarly to the second embodiment in other points. (S02) The shape of the light propagating member 4 is different. That is, as shown in FIG. 6, the light propagating member 4 has a large area of one end surface facing the light emitting element 8, the cross-sectional area decreases as the distance from the one end surface increases, and the light propagating member 4 faces the light receiving element 9. The point is such that the cross-sectional area becomes smaller toward the other end surface. Also in this third embodiment, the light emitted from the light emitting element 8 can be used with high efficiency as in the second embodiment.

(Fourth Embodiment) Next, a fourth embodiment of the oil deterioration sensor of the present invention will be described with reference to FIG. In addition,
In the description of the fourth embodiment, the third embodiment shown in FIG.
The same reference numerals are given to the constituent elements corresponding to those constituent elements, and detailed description thereof will be omitted. The fourth embodiment differs from the third embodiment in the following points, but is configured similarly to the third embodiment in other points. (S03) The shape of the light propagating member 4 is different. That is, in FIG. 7, the right edge of the portion of the light propagating member 4 extending upward from one end surface facing the light emitting element 8 and the right edge of the portion extending upward from the other end surface facing the light receiving element 9 are parallel to each other. It is arranged. When fixing the light propagation member 4 to the holder 2, it is possible to perform positioning with respect to the holder 2 with the right side edge as a reference. Also in the fourth embodiment, the light emitted from the light emitting element 8 can be used with high efficiency as in the second embodiment.

(Fifth Embodiment) Next, a fifth embodiment of the oil deterioration degree sensor of the present invention will be described with reference to FIG. FIG. 8 is an explanatory diagram of a fifth embodiment of the oil deterioration degree sensor. In addition,
In the description of the fifth embodiment, constituent elements corresponding to those of the second embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. The fifth embodiment differs from the second embodiment in the following points, but is configured similarly to the second embodiment in other points. (S04) The shape of the light propagating member 4 is different. That is, as shown in FIG. 8, the light propagating member 4 is formed such that the area of one end surface facing the light emitting element 8 and the area of the other end surface facing the light receiving element 9 are equal. (S05) The area of the light emitting area of the light emitting element 8 is set smaller than the area of one end surface of the light propagating member 4, and the area of the light receiving area of the light receiving element 9 is smaller than the area of the other end surface of the light propagating member 4. Is also set large. In this fifth embodiment, as in the second embodiment, the light emitted from the light emitting element 8 can be used with high efficiency.

(Sixth Embodiment) Next, a sixth embodiment of the oil deterioration sensor according to the present invention will be described with reference to FIG. FIG. 9 is an explanatory diagram of a sixth embodiment of the oil deterioration degree sensor. In addition,
In the description of the sixth embodiment, constituent elements corresponding to those of the second embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. The sixth embodiment is different from the second embodiment in the following points, but is configured similarly to the second embodiment in other points. (S06) The shape of the light propagating member 4 is different. That is, as shown in FIG. 9, the light propagating member 4 is formed such that the area of one end surface facing the light emitting element 8 and the area of the other end surface facing the light receiving element 9 are both equal. (S07) Area of light emitting region of light emitting element 8 and light receiving element 9
The areas of the light receiving regions are set to be the same and smaller than the areas of the one end surface and the other end surface of the light propagating member 4. (S08) The light emitting element 8 and the light propagating member 4 facing the light emitting element 8.
Between one end face of the light-emitting element 8 and the one end face of the light-propagating member 4 to be incident on the one end face of the light-propagating member 4.
1 is placed. The condenser lens R1 constitutes the high-emission-amount-incident-incidence means of the sixth embodiment. (S09) Between the other end surface of the light propagating member 4 and the light receiving element 9 facing the other end surface, the light emitted from the other end surface of the light propagating member 4 is collected and incident on the light receiving element 9. An optical lens R2 is arranged. The condenser lens R2 constitutes the high-intensity-detection-light-amount incidence means of the sixth embodiment. In Example 6 as well, as in Example 2, the light emitted from the light emitting element 8 can be used with high efficiency.

(Embodiment 7) Next, referring to FIG. 10, Embodiment 7 of the oil deterioration sensor of the present invention will be described. Figure 1
FIG. 0 is an explanatory diagram of Example 7 of the oil deterioration sensor. In the description of the seventh embodiment, constituent elements corresponding to those of the sixth embodiment shown in FIG. 9 are designated by the same reference numerals, and detailed description thereof will be omitted. The seventh embodiment differs from the sixth embodiment in the following points, but is configured similarly to the sixth embodiment shown in FIG. 9 in other points. (S010) Condensing lenses R1 and R of Example 6 shown in FIG.
The point that 2 is omitted and the shape of the light propagating member 4 is different. That is, as shown in FIG. 10, in the light propagating member 4, one end surface facing the light emitting element 8 and the other end surface facing the light receiving element 9 are formed into curved surfaces having a lens function. In Example 7 as well, as in Example 6, the light emitted from the light emitting element 8 can be used with high efficiency.

(Modifications) The embodiments of the present invention have been described in detail above, but the present invention is not limited to the above-mentioned embodiments, and is within the scope of the gist of the present invention described in the claims. Thus, various changes can be made. A modified embodiment of the present invention is illustrated below.

(H01) As the material of the light propagating member 4,
Various materials that propagate light, such as plastics and glass, can be used. In addition, as the light propagation member 4,
If fiber optic glass is used, it is easy to process. (H02) As the light propagating through the light propagating member 4, various kinds of light such as ultraviolet rays, visible light, far infrared rays and the like can be adopted.

[0053]

The oil deterioration sensor of the present invention described above is
The following effects can be achieved. (E01) Since the cross-sectional area of the detection portion is small and the flow of oil in the detection portion (oil entry space) is good, clogging is small and the degree of oil deterioration can be accurately measured. Therefore, it is possible to reliably know when to change the oil. Moreover, unlike the prior art, since the light emitting surface of the light emitting element and the light receiving surface of the light receiving element are not pressed against each other with the spacer interposed therebetween, there is little risk of damage and excellent vibration resistance. (E02) Further, by providing the emitted light amount high-rate incidence means and the detected light amount high-rate incidence means, the light emitted by the light emitting element can be used with high efficiency. Further, when a dicing saw is used for cutting the light propagating member, it is possible to form the oil intrusion void portion with high accuracy.

[Brief description of drawings]

FIG. 1 is a side sectional view of an oil deterioration sensor according to a first embodiment of the present invention.

FIG. 2 is a bottom view of the oil deterioration degree sensor of the embodiment, which is a view as seen from an arrow II in FIG.

FIG. 3 is an operation explanatory view of the same embodiment, and is an explanatory view of absorption of light passing through the oil intrusion void portion.

FIG. 4 is a diagram for explaining the operation of the same embodiment, and is a diagram showing the relationship between the distance between the oil intrusion gaps or the degree of oil deterioration and the detected light amount.

FIG. 5 is an explanatory diagram of a second embodiment of the oil deterioration sensor.

FIG. 6 is an explanatory diagram of a third embodiment of the oil deterioration sensor.

FIG. 7 is an explanatory diagram of a fourth embodiment of the oil deterioration sensor.

FIG. 8 is an explanatory diagram of a fifth embodiment of the oil deterioration sensor.

FIG. 9 is an explanatory diagram of a sixth embodiment of the oil deterioration sensor.

FIG. 10 is an explanatory diagram of an oil deterioration degree sensor according to a seventh embodiment.

[Explanation of symbols]

R1 ... Emitted light quantity high-rate incidence means (condenser lens), R2 ... Detected light quantity high-rate incidence means (condenser lens), 2 ... Holder, 2a ...
Supporting surface, 4 ... Light propagating member, 7 ... Void for oil entry, 8
... light emitting element, 9 ... light receiving element, 15 ... sealing means,

Claims (1)

[Claims] 1. A light propagating member having a substantially U shape as a whole by bending an intermediate part immersed in oil, a holder for supporting the light propagating member in contact with the intermediate part, and the light propagating member. A light emitting element that allows light to enter one end of the member and a light receiving element that detects the amount of light emitted from the other end of the light propagating member are provided, and an oil intrusion void is formed in the middle part of the light propagating member. In the oil deterioration sensor, the oil deterioration sensor is provided with the following requirements: (Y01) In the oil intrusion gap, the intermediate portion of the light propagating member is in contact with the supporting surface of the holder. The intermediate portion of the light propagating member is cut and formed in a state where the light propagating member is fixed.