JP2001227996A - Detection method for oil flowing through pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To certainly detect oil flowing through a pipe to improve detection precision by increasing a detection amount of the oil and making the oil flow along a constant track to equalize reflection and absorption of light. SOLUTION: In a system letting the oil L run along a translucent inner wall surface 6 having a circular cross section of the pipe P by air, a light emission part 2 emitting light into the pipe P and a light reception part 3 receiving the light emitted from the light emission part 2 passing through the pipe P are provided outside the pipe P on a circumference with the center of the circular cross section as the center. When detecting the oil L flowing through the pipe P on the basis of light reception of the light reception part 3, a portion of the pipe P facing the light emission part 2 and the light reception part 3 is bent in an arc shape, and the oil L is detected such that the oil L mainly flows along the track A of the inner wall face 6 of the bent pipe P having a smallest curvature radius.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting oil flowing through a pipe in a system for flowing oil through a light-transmitting pipe by air.

[0002]

2. Description of the Related Art In general, as a system for flowing oil through a light-transmitting pipe by air, for example, an oil supply unit for supplying oil to the pipe using air supplied from an air source, and an oil supply unit for supplying oil to the pipe from the air source An air supply unit that supplies air to the pipe is provided.The oil supplied from the oil supply unit flows through the pipe with the air supplied from the air supply unit, and the mixed oil is discharged from the nozzle provided at the pipe tip. Known lubrication systems are known. In such a system, detection of oil flowing through a pipe may be performed. As a detection method, conventionally, as shown in FIG. 6, for example, as shown in FIG. 6, a light emitting section 2 that irradiates light from a light emitting surface 4 into the pipe P outside the pipe P and a pipe P that is irradiated from the light emitting surface 4 of the light emitting section 2 A light receiving portion 3 for receiving the light passing through the light receiving surface 5, and the oil L flowing through the pipe P based on a change in the amount of light received by the light receiving portion 3.
There is a known method for detecting the In the method of detecting oil flowing through the pipe, light is constantly emitted from the light emitting surface 4. Therefore, when the oil L flowing through the pipe P does not exist, the light receiving surface 5 responds to the light emitted from the light emitting surface 4. While receiving a predetermined amount of light, the oil L flowing through the pipe P
Is present, the light emitted from the light emitting surface 4 passes through the oil L, and at this time, the light path is refracted or the light is absorbed, so that the light receiving surface 5 receives a predetermined amount of light. Therefore, the detection of the oil L flowing through the pipe P is determined by sensing a change in the amount of light received by the light receiving surface 5.

[0003]

According to this conventional method for detecting oil flowing through a pipe, as shown in FIG. 7, oil L flowing through a pipe P blows air on the inner wall surface of the pipe P. Depending on the applied pressure, the oil L flows in a granular or rippled shape, and the trajectory of the oil L becomes indefinite. Therefore, the reflection or absorption of light to the oil L varies, or the oil L spreads over the entire inner wall surface. In the case of ripples flowing over the light receiving surface 5, a desired change in the amount of light may not be given to the light receiving surface 5.
In some cases, this flow cannot be detected despite the flow of the oil L, and there has been a problem that the detection accuracy is poor and the detection accuracy is poor.

The present invention has been made in view of such a problem, and when a very small amount of oil flows in a pipe together with air, the oil flows on a fixed orbit so that the amount of the detected oil increases. Thus, it is possible to provide a method of detecting oil flowing through a pipe so that the reflection and absorption of light can be made constant, and the detection of oil flowing through the pipe can be reliably performed to improve the detection accuracy. Aim.

[0005]

The technical means of the present invention for solving the above-mentioned problem is that oil is applied to a pipe having an inner wall surface which is translucent and has a circular cross section by air. A method for detecting oil flowing through a pipe for detecting oil flowing through the pipe in a system flowing along an inner wall surface, wherein the oil is located on a circumference centered on the center of one cross-sectional circle outside the pipe. A light emitting unit for irradiating light in a pipe and a light receiving unit for receiving light emitted from the light emitting unit and passing through the pipe, and a pipe for detecting oil flowing through the pipe based on light reception of the light receiving unit In the method for detecting oil flowing through the pipe, a portion of the pipe where the light-emitting portion and the light-receiving portion are located is bent in an arc shape, and the oil follows the orbit of the bent inner pipe on the inner wall surface having the smallest radius of curvature. Te and configured to detect as the main flows. According to this configuration, in the pipe, the portion where the light emitting unit and the light receiving unit are located is bent in an arc shape,
The oil mainly flows along the trajectory of the inner wall surface of the bent pipe having the smallest radius of curvature. The main reason why this flowing oil flows along the orbit of the inner wall surface with the smallest radius of curvature of the pipe is that when the air passes through the place where the pipe is bent in an arc shape, the wind pressure of the air is outside the bending of the inner wall surface This is considered to be caused by the fact that oil cannot adhere to the outside of the bend and the oil concentrates inside the bend having a small wind pressure. From this, the trajectory of the oil is specified in the pipe where the light-emitting part and the light-receiving part are provided, so that the oil particles combine to increase the volume of the oil particles, and the light emitted from the light-emitting surface The degree of passage through the oil particles is increased, and the effects of light refraction, reflection, absorption and the like by the oil particles become constant. As a result, the change in the amount of light received by the light receiving surface when the oil is flowing is substantially constant, the oil flowing through the pipe is reliably detected, and the detection accuracy is improved. In addition, since the threshold value for detecting oil can be increased, it becomes easier to detect a change in the amount of received light when the threshold value is increased.

If necessary, the light emitting surface of the light emitting portion is perpendicular to the light emitting surface passing through the center of the sectional circle, and the light emitting surface of the light receiving portion is perpendicular to the light receiving surface. Angle θ with the light-receiving surface perpendicular passing through the center of the cross-section circle
The angle of the orbit of the orbit on the cross-sectional circle is located between the inner angle range between the light emitting surface normal and the light receiving surface normal while the inner angle range of 60 ° to 110 ° is set. The light emitting section and the light receiving section were arranged.
By arranging the light emitting unit and the light receiving unit in this manner, the change in the amount of light received by the light receiving surface can be reliably increased, and the threshold value can be further increased. In other words, the threshold value for detecting the change in the amount of received light increases, so that it is easy to detect the change in the amount of received light.

Further, if necessary, the angle θ between the perpendicular to the light emitting surface and the perpendicular to the light receiving surface is set to 90 °, and a line connecting the center of the cross section circle and the orbit point of the orbit on the cross section circle. , And the angle α between the reference line and the perpendicular to the light emitting surface is set to 20 ° to 80 °. Angle θ is 9
If the angle is set to 0 °, the ratio of the light passing through the oil to the light receiving surface is substantially halved, and the amount of light received on the light receiving surface becomes large depending on the presence or absence of the oil flowing through the pipe. Angle θ is 90 °
If it is smaller, the amount of received light increases, but the ratio of light passing through the oil to the light receiving surface becomes too large, and the change in the amount of light received on the light receiving surface due to the presence or absence of oil becomes small. Also,
If the angle θ is larger than 90 °, the amount of received light decreases and the rate of light passing through the oil reaching the light receiving surface decreases, so that the change in the amount of light received on the light receiving surface due to the presence or absence of oil also decreases. That is, when the angle θ at which an appropriate amount of received light can be obtained and the change in the amount of received light on the light receiving surface due to the presence or absence of oil is 90 ° is 90 °, the light receiving unit can easily sense the change in the amount of received light, and Detection accuracy is improved. At this time, if the angle α is set to 20 ° to 80 °, the change in the amount of received light on the light receiving surface due to the presence or absence of oil can be made larger, and the threshold value for sensing the change in the amount of received light becomes larger. Therefore, it becomes easy to detect a change in the amount of received light. Furthermore, if necessary, the light emitting surface of the light emitting section has a configuration having a width smaller than the diameter of the pipe. As the width of the light-emitting surface decreases, the degree of light emitted from the light-emitting surface passing through the oil increases, and the change in the amount of light received on the light-receiving surface greatly depends on the presence or absence of oil. As the threshold value for detecting the change in the amount of received light increases, it becomes easy to detect the change in the amount of received light.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for detecting oil flowing through a pipe according to an embodiment of the present invention will be described below with reference to the accompanying drawings. Note that the same components as described above are denoted by the same reference numerals and described. The method of detecting oil flowing through a pipe according to the embodiment of the present invention shown in FIG. 1 is performed, for example, in an oil supply system S that supplies a small amount of oil L to a supply unit 17 using air as shown in FIG. , Using the detection device 1. The lubrication system S is driven by air supplied from an air source 10 to a passage pipe 12 via a regulator 11, and the plunger pump 1 discharges a fixed amount of oil L.
An oil supply section 13 having an oil supply section 3a, an air supply pipe 14 branched from an air pipe leading to the oil supply section 13 and supplying air from an air source 10 through another regulator 11; Oil line 15 and air supply line 1 for oil discharged from plunger pump 13a
A three-way joint-like mixing block 16 which is connected to the mixing block 4 to allow oil and air to be mixed and supplied; and a pipe P through which the mixed oil flows from the mixing block 16 to the oil supply section 17. , A nozzle 18 connected to the tip of the pipe P and ejecting the oil L to the supply unit 17
It is comprised including. In the refueling system S, the plunger pump 13a is operated intermittently with a single oil supply amount of, for example, 0.01 to 0.05 cc and a downtime of 1 minute to 10 minutes. The air pressure is, for example,
It is set to 0.1 MPa to 0.5 MPa. Further, as shown in FIGS. 1, 3 to 5, the pipe P has a light-transmitting inner wall surface 6 forming a cross-section circle Q.
It is composed of a resin pipe such as a 5 mm (outer diameter 4 mm) nylon tube.

The detecting device 1 is provided at a predetermined position of the pipe P of the refueling system S. As shown in FIGS. 3 to 5, the detecting device 1 emits light into the pipe P on the circumference around the center O of one cross-section circle Q outside the pipe P. 2 and a light receiving unit 3 for receiving light emitted from the light emitting unit 2 and passing through the pipe P, and detects the oil L flowing through the pipe P based on the light received by the light receiving unit 3. As shown in FIG. 1, the light emitting unit 2 includes a light source such as a light emitting diode (not shown) therein, and keeps irradiating light into the pipe P via the light emitting surface 4 while the refueling system S is operating. . The light receiving unit 3
A light-sensitive element is provided inside and light is sensed through a light-receiving surface 5.
In the light receiving unit 3, a light amount received when the oil L is not flowing in the pipe P is set as a reference value (for example, 100), and a threshold value (for example, 100 ± 30) is set for this reference value. By setting this threshold value, the light receiving unit 3
Is configured such that the oil L can be detected when the amount of received light is 130 or more or less than 70. Also,
The light emitting surface 4 of the light emitting unit 2 is configured to have a width smaller than the diameter of the pipe P. 3 to 5, the light emitting surface 4 of the light emitting unit 2 is larger than the diameter of the pipe P for convenience of explanation.

Next, a method of detecting oil flowing through a pipe according to an embodiment of the present invention, which is realized by using the detection device 1, will be described in detail. The detection method according to the embodiment is an oil detection method for detecting oil L flowing through a pipe P. In this detection method, as shown in FIG. The bent portion is bent in an arc shape so that the oil L flows mainly along the trajectory A of the inner wall surface 6 on the inner side having the smallest radius of curvature of the bent pipe P. In this case, the radius of curvature may be appropriately determined, and is not limited to the direction of gravity, and the bending direction may be any direction of up, down, left, and right. The reason that the flowing oil L flows mainly along the trajectory A of the inner inner wall surface 6 having the smallest radius of curvature of the pipe P is that when the air passes through a place where the pipe P is bent in an arc shape, the wind pressure of the air is It is considered that the oil L strongly adheres to the outside of the bend of the wall surface 6 so that the oil L cannot adhere to the outside of the bend, and the oil L concentrates on the inside of the bend having a small wind pressure.

In the detection method according to the embodiment of the present invention, the positional relationship between the light emitting unit 2 and the light receiving unit 3 is determined as follows. As shown in FIGS. 3 to 5, the light emitting unit 2 and the light receiving unit 3 are perpendicular to the light emitting surface 4 of the light emitting unit 2 and pass through the center O of the cross-section circle Q of the inner wall surface 6. The angle θ between N and the light receiving surface perpendicular M that is perpendicular to the light receiving surface 5 of the light receiving portion 3 and that passes through the center O of the cross-section circle Q of the inner wall surface 6 is within the range of 60 ° to 110 °. In addition, the trajectory point a of the trajectory A on the cross-sectional circle Q is arranged within the range of the inner angle θ between the light-emitting surface perpendicular N and the light-receiving surface perpendicular M. FIG. 3 shows a case where the angle θ is 60 °, and FIG. 4 shows a case where the angle θ is 110 °. FIG. 5 shows a case where the angle θ is 90 °.

As shown in FIG. 5, when the angle θ between the light emitting surface normal N and the light receiving surface normal M is set to 90 °, the center O of the sectional circle Q and the orbital point of the orbit A on the sectional circle Q It is more preferable to set the angle α between the reference line X and the light-emitting surface perpendicular N to 20 ° to 80 °, with the line connecting “a” as the reference line X. In addition, as shown in FIGS. 3 to 5, in particular, the positional relationship between the light emitting unit 2 and the light receiving unit 3 is such that the light emitting surface 4 and the light receiving surface 5 abut on the pipe P.

Therefore, according to the oil supply system S, when the air is supplied from the air source 10 and the oil is discharged from the plunger pump 13a of the oil supply section 13, the oil and the air are mixed by the mixing block 16, and The oil mixed with the air passes through the pipe P and is supplied to the oil supply unit 17.
And is ejected from the nozzle 18. In this state, the detection device 1 always detects the oil L flowing through the pipe P, and this detection allows the abnormality of the system to be recognized. According to the oil detecting method using the detecting device 1, as shown in FIG. 1, the portion where the light emitting unit 2 and the light receiving unit 3 are located is bent in an arc shape in the pipe P, so that the oil L is bent. Since the flow mainly flows along the trajectory A of the inner wall surface 6 having the smallest radius of curvature of the pipe P, the trajectory A of the oil L is specified, and the trajectory A is specified. By
The oil L particles are combined with each other to increase the volume of the oil L particles, so that the light emitted from the light-emitting surface 4 passes through the oil L particles, and the refraction, reflection, absorption, etc. of the light by the oil L particles. Of the oil L flowing through the pipe P can be reliably detected, and the detection accuracy is improved.

That is, the positional relationship between the light-emitting portion 2 and the light-receiving portion 3 is set so that the angle θ is within the range of 60 ° to 110 ° and the internal angle θ between the light-emitting surface normal N and the light-receiving surface normal M.
By locating the trajectory point a of the trajectory A on the cross-section circle Q within the range, the degree of light emitted from the light emitting surface 4 passing through the oil L increases, and the light received when the oil L does not flow is received. A large difference (a change in the received light amount) occurs between the amount and the received light amount when the oil L is flowing. By increasing the change in the amount of received light, the threshold value for sensing the change in the amount of received light can be increased, and the oil L can be easily detected. In other words, since the threshold value becomes large, a change in the amount of received light can be sensed using a light-receiving element having low sensitivity.

In this case, the light emitting surface 4 of the light emitting section 2 is
Since it is configured to have a width smaller than the diameter of the pipe P, the light emitted from the light emitting surface 4 is
The light emitting surface 4 was positioned so as to pass through. As the light emitting surface 4 becomes smaller, the degree of light emitted from the light emitting surface 4 passing through the oil L increases, and the change in the amount of light on the light receiving surface 5 greatly depends on the presence or absence of the oil L. As a result, the change in the amount of received light increases, so that the light receiving unit 3 can easily detect the change, and the accuracy of detecting the oil L can be improved. Further, when the area of the light emitting surface 4 is reduced, the amount of heat consumed is reduced at the same illuminance ratio, so that the economy is excellent. Further, as shown in FIGS. 3 to 5, the light emitting surface 4 of the light emitting unit 2 is in contact with the pipe P, and the light receiving surface 5 of the light receiving unit 3 is also in contact with the pipe P.
Therefore, the degree of passage of the light irradiated from the oil L through the oil L increases, and the change in the amount of light received on the light receiving surface 5 increases, so that the detection accuracy of the oil L can be improved.

As shown in FIG. 5, when the angle θ between the light emitting surface normal N and the light receiving surface normal M is set to 90 °, the center O of the cross-section circle Q and the trajectory of the trajectory A on the cross-section circle If the angle α between the reference line X and the light-emitting surface normal N is set to 20 ° to 80 ° with the line connecting the point a as the reference line X, since the angle θ is 90 °, the pipe P It can be seen that the change in the amount of received light depending on the presence or absence of the oil L flowing through the can be increased. If the angle θ is smaller than 90 °, the amount of received light increases, but the ratio of light passing through the oil L to the light receiving surface 5 becomes too large, and the change in the amount of received light due to the presence or absence of the oil L decreases. If the angle θ is larger than 90 °, the amount of received light decreases, and the ratio of light passing through the oil L to the light receiving surface 5 decreases, so that the change in the amount of received light due to the presence or absence of the oil L also decreases. As described above, the change in the amount of received light on the light receiving surface 5 can be maximized when the angle θ is 90 °. Further, when the angle θ is 90 °, by setting the angle α to 20 ° to 80 °, the change in the amount of light received by the light receiving surface 5 of the light emitted from the light emitting surface 4 that has passed through the oil L becomes larger. .
With such an arrangement condition, it is possible to cause a large difference in the amount of light received by the light receiving surface 5 when the oil L is flowing and when the oil L is not flowing, so that the threshold value for sensing is increased. Thus, the oil L can be reliably detected using a normal photosensitive element without using a sensitive and expensive photosensitive element.

In the method of detecting oil flowing through a pipe according to the above-described embodiment, the amount of light received by the light receiving section 3 when the oil L flows through the pipe P is changed.
Is detected, but the positional relationship between the light emitting unit 2 and the light receiving unit 3 is adjusted so that the amount of light received by the light receiving unit 3 when the oil L flows through the pipe P is increased or decreased. The oil L can be detected from an increase or a decrease in the amount of light.

[0018]

As described above, according to the method for detecting oil flowing through a pipe according to the present invention, the portion where the light emitting portion and the light receiving portion of the pipe are located is bent in an arc shape, and the radius of curvature of the bent pipe is the largest. A small amount of oil mainly flows along the trajectory of the small inner wall surface, and the light is irradiated on the trajectory of the inner wall surface through which the oil flows, and the light received by the light receiving unit Since a constant change is given to the amount, the change can be sensed to reliably detect the oil flowing through the pipe. In addition, the light emitting surface perpendicular to the light emitting surface of the light emitting portion and passing through the center of the cross section circle of the inner wall surface, and the vertical relationship to the light receiving surface of the light receiving portion and the center of the cross sectional circle of the inner wall surface are The angle θ formed by the perpendicular to the light-receiving surface passing therethrough is set to be within the inner angle range of 60 ° to 110 °, and the orbit point of the trajectory on the cross-sectional circle is located between the inner angles of the perpendicular to the light-emitting surface and the light-receiving surface perpendicular When the light emitting unit and the light receiving unit are arranged, the change in the amount of light received by the light receiving surface can be reliably increased, and the threshold value can be further increased. This makes it easier to carry out, so that the oil detection accuracy can be improved.

Further, the angle θ between the perpendicular to the light-emitting surface and the perpendicular to the light-receiving surface is set to 90 °, and the line connecting the center of the cross-sectional circle and the orbital point of the orbit on the cross-sectional circle is used as the reference line, and When the angle α formed with the surface perpendicular is set to 20 ° to 80 °, an appropriate amount of received light that can further increase the change in the amount of received light on the light receiving surface due to the presence or absence of oil is obtained. Since the change can be easily sensed, the accuracy of oil detection can be improved. Furthermore, if the light emitting surface of the light emitting section is made smaller in width than the diameter of the pipe, the degree of light passing through the oil from the light emitting surface increases, so that the change in the amount of light on the light receiving surface depends on the presence or absence of oil. , And the light receiving unit can easily detect the change, so that the oil detection accuracy can be improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing a method for detecting oil flowing through a pipe according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating an example of an oil supply system in which a method for detecting oil flowing through a pipe according to an embodiment of the present invention is used.

FIG. 3 is a cross-sectional view showing a method for detecting oil flowing through a pipe according to the embodiment of the present invention, showing a case where θ is 60 °.

FIG. 4 is a cross-sectional view showing a method for detecting oil flowing through a pipe according to the embodiment of the present invention, showing a case where θ is 110 °.

FIG. 5 is a cross-sectional view illustrating a method for detecting oil flowing through a pipe according to the embodiment of the present invention.

FIG. 6 is a sectional view showing an example of a conventional method for detecting oil flowing through a pipe.

FIG. 7 is a sectional view showing a state of oil flowing through a straight pipe.

[Explanation of symbols]

 P pipe L oil N perpendicular to light emitting surface M perpendicular to light receiving surface Q section circle O center α angle θ angle X reference line A orbit a orbit point 1 detector 2 light emitting unit 3 light receiving unit 4 light emitting surface 5 light receiving surface 6 inner wall surface

Claims (4)

[Claims] An oil flowing through a pipe for detecting oil flowing through a pipe in a system in which oil flows along the inner wall of the pipe by air through a pipe having an inner wall surface that forms a circular cross section and is transparent. A light-emitting unit that irradiates light into the pipe on a circumference around the center of one cross-section circle outside the pipe and a light-emitting unit that is irradiated from the light-emitting unit and passes through the pipe. A light receiving unit for receiving light; a method for detecting oil flowing through the pipe based on light reception of the light from the light receiving unit, wherein a portion of the pipe where the light emitting unit and the light receiving unit are located; An oil flowing through the pipe, wherein the oil is detected by flowing the oil mainly along the trajectory of the inner wall surface having the smallest radius of curvature of the bent pipe. The method of detection. 2. A light emitting surface perpendicular to the light emitting surface of the light emitting portion and passing through the center of the cross section circle, and perpendicular to the light receiving surface of the light receiving portion and the center of the cross sectional circle. Between the light receiving surface perpendicular passing through and
°, and the orbital point of the orbit on the cross-sectional circle is located between the inner angle range between the light-emitting surface normal and the light-receiving surface normal, and The method for detecting oil flowing through a pipe according to claim 1, wherein a portion is disposed. 3. An angle θ between the perpendicular to the light emitting surface and the perpendicular to the light receiving surface is set to 90 °, and a line connecting the center of the sectional circle and the orbital point of the orbit on the sectional circle is used as a reference line. 3. The method for detecting oil flowing through a pipe according to claim 2, wherein an angle α between the reference line and the perpendicular to the light emitting surface is set to 20 ° to 80 °. 4. A light-emitting surface of said light-emitting portion has a width smaller than a diameter of a pipe.
Or the method for detecting oil flowing through a pipe according to 3.