JP4850334B2 - Flow sensor for piping - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily detect the flow of fluid even when the flow of the fluid is trace, and surely detect the flow of the fluid without receiving their influence by making non-contact with air mixing the fluid itself. SOLUTION: In the method for detecting fluid to flow in a pipe provided in the route of the piping, a resin-made detection pipe 10, a strain gage 11 attached to the detection pipe and for detecting that the detection pipe 10 expands by the pressure increase of the fluid, a connector 14 provided on both the ends of the detection pipe 10 respectively and connecting the pipe and a case 20 held by covering the detection pipe 10 are provided.

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is, for example, used lubricating oil as a fluid to various machine tools or the like and supplies centralized lubrication system, etc. through a pipe, in particular, to flow sensor piping that detect the fluid in the pipe flows.
[0002]
[Prior art]
In general, for example, in a centralized lubrication system that supplies grease, which is lubricating oil as a fluid, to various machine tools, a main piping pipe 2 is connected to a pump 1 and a joint 3 is connected to the main piping pipe 2 as shown in FIG. A plurality of plunger-type metering dispensing valves 4 are provided via the valve, and a terminal pipe pipe 6 made of resin is provided from the dispensing valve 4 to the oiling point 5 to intermittently meter the grease.
In such a lubrication system, in recent years, there has been a demand for ensuring safety by detecting whether or not refueling has been performed at a refueling point 5, and in particular, terminal piping pipes that are the end of refueling. Attempts have been made to check the lubrication by detecting the flow of grease every 6th.
[0003]
[Problems to be solved by the invention]
By the way, in such a lubrication system, the pressure in the terminal pipe pipe 6 is about 0.3 to 1 MP, but the discharge amount of the distribution valve 4 is, for example, 0.3 to 1.5 cc / shot (0 .3 to 1.5 ml / shot), the amount of oil supply is extremely small. Therefore, there is a problem that the flow in the terminal piping pipe 6 is slow and its detection is extremely difficult.
In addition, although a mechanically configured detector such as a pressure gauge is also used, the grease that has entered the detector may solidify or the operation may be uncertain due to air contamination, etc. These detectors are large and require a lot of installation space.
The present invention has been made in view of such problems, and makes it possible to easily detect the flow of the fluid even if the flow of the fluid is very small, and to make it non-contact with the fluid itself and the air to be mixed. and to provide a flow sensor distribution pipe was set to the flow of fluid can be reliably detected without receiving these influences Te.
[0004]
[Means for Solving the Problems]
The method for detecting the flow of fluid in a pipe realized by the flow sensor for piping according to the present invention is a method for detecting the flow of fluid in a resin pipe, wherein a strain gauge is attached to the pipe, and the pipe is fluid. It is configured to detect that the fluid has flowed into the pipe by detecting the expansion due to the pressure increase by the strain gauge.
Thus, since the pipe is made of resin, when the fluid flows and the pressure in the pipe rises, the pipe expands. This expansion is detected by the strain gauge, and it is detected that the fluid has flowed into the pipe. Therefore, the flow of the fluid in the pipe is extremely small, and the flow of the fluid in the pipe is slow, so that the flow of the fluid can be easily detected even if the flow of the fluid is very small. In addition, since the strain gauge is attached to the pipe, it is not in contact with the fluid itself or the air to be mixed, so it is not directly affected by this, so that the fluid flow can be reliably detected. Become.
If necessary, a correlation is obtained between the strain amount of the strain gauge and the pressure of the fluid in the pipe, and the pressure of the fluid in the pipe can be calculated based on the correlation. As a result, not only the presence or absence of flow but also a pressure abnormality can be detected, and it can also function as a pressure gauge, increasing versatility.
[0005]
Moreover, the flow sensor for piping of the present invention for solving such a problem is a flow sensor for piping provided in a path of a piped pipe that detects that a fluid has flowed into the pipe. Connected to the detection pipe, a strain gauge attached to the detection pipe and detecting that the detection pipe has expanded due to an increase in the pressure of the fluid, and the piping pipe provided at both ends of the detection pipe. And a connector to be configured.
Accordingly, when a fluid flows in the pipe pipe path, the fluid also flows in the pipe of the pipe flow sensor. In this case, since the pipe is made of resin, when the fluid flows and the pressure in the pipe rises, the pipe expands. This expansion is detected by the strain gauge, and it is detected that the fluid has flowed into the pipe. Therefore, the flow of the fluid in the pipe is extremely small, and the flow of the fluid in the pipe is slow, so that the flow of the fluid can be easily detected even if the flow of the fluid is very small. In addition, since the strain gauge is attached to the pipe, it is not in contact with the fluid itself or the air to be mixed, so it is not directly affected by this, so that the fluid flow can be reliably detected. Become.
[0006]
And if necessary, the strain gauge is configured to be provided on a cylindrical tube made of a thin film resin that is attached to the detection pipe. The strain gauge can be attached by an easy operation of attaching the cylindrical tube to the pipe, and the fixing thereof can be ensured.
Further, if necessary, the cylindrical tube is provided in a double manner, and the strain gauge is interposed between the double cylindrical tubes. The strain gauge can be protected by the cylindrical tube, and the durability can be improved.
Furthermore, a case body that covers and holds the detection pipe is provided as necessary. The detection pipe can be protected and durability can be improved.
Furthermore, if necessary, the case body is provided with a recess that faces a portion of the detection pipe provided with a strain gauge, and a holding portion that holds connectors provided at both ends of the detection pipe. And a lid that covers the recess of the main body. Removing the lid allows maintenance of the strain gauge on the detection pipe, making it extremely convenient.
If necessary, either one of the main body and the lid is provided with a passage hole through which the lead wire of the strain gauge passes, and a grommet for protecting the lead wire is provided in the passage hole. Lead wire can be protected and durability can be improved.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, that describes the flow sensor piping engaging Ru to the embodiment of the present invention with reference to the accompanying drawings. In addition, the same code | symbol is attached | subjected and demonstrated to the same thing as the above.
The piping flow sensor S according to the embodiment shown in FIG. 1 is used, for example, in a centralized lubrication system that supplies grease, which is lubricating oil as the fluid, to various machine tools. In this centralized lubrication system, as shown in FIG. 4, a main piping pipe 2 is connected to a pump 1, and a plurality of plunger-type metering distribution valves 4 are provided on the main piping pipe 2 via joints 3. A terminal pipe pipe 6 made of resin is provided at the oil supply point 5 and the grease is intermittently supplied in a fixed quantity. The pipe flow sensor S is provided, for example, in the path of the piped terminal pipe pipe 6 and detects that a fluid has flowed through the pipe pipe 6.
[0008]
In the flow sensor S for piping according to the embodiment, 10 is a resin detection pipe such as a flexible nylon tube that can be elastically deformed, and has a diameter of, for example, about 4 mm and a length of, for example, about 50 mm. .
A strain gauge 11 is attached to the detection pipe 10 and detects that the detection pipe 10 has expanded due to an increase in the pressure of grease. As shown in FIGS. 2 and 3, the strain gauge 11 is formed by meandering fine metal wires, and is provided with a double-walled cylindrical tube 12, 12 made of thin film resin that is attached to the detection pipe 10. Is provided. The strain gauge 11 is interposed between the double cylindrical tubes 12 and bonded to the cylindrical tube 12. The cylindrical tube 12 is attached to the detection pipe 10 and attached with an adhesive. Therefore, the cylindrical tube 12 can be attached by an easy operation of attaching the tubular tube 12 to the pipe, and since the cylindrical tube 12 is in a ring shape, its fixing is ensured. Furthermore, since the strain gauge 11 is interposed between the double tubular tubes 12, the strain gauge 11 can be protected by the tubular tube 12, and the durability is improved.
Reference numeral 13 denotes a lead wire connected to the strain gauge 11. When strain occurs in the strain gauge 11, the resistance value changes and the flowing current value changes.
[0009]
Reference numerals 14 are connectors provided at both ends of the detection pipe 10 to which the terminal piping pipe 6 is connected. One connector 14 (A) has a connection port 15 to which the piping pipe 6 is connected at the outer end, and an insertion port 16 into which one end of the detection pipe 10 is inserted at the inner end. The insertion port 16 is provided with an O-ring 17 that seals the detection pipe 10. The other connector 14 (B) has a connection port 15 to which the piping pipe 6 is connected at the outer end, and an insertion port 16 in which a female screw 18 into which the other end of the detection pipe 10 is inserted is formed at the inner end. Have. A cone 19a is fitted into the other end of the detection pipe 10, and the bushing 19 is screwed into the female screw 18 of the insertion port 16 so that the cone 19a is crushed, whereby the other end of the detection pipe 10 is inserted into the insertion port 16. It is fixed to.
[0010]
Reference numeral 20 denotes a case body that covers and holds the detection pipe 10. The case body 20 is formed of a metal block such as aluminum, and a connector 21 provided at both end portions of the detection pipe 10 and the recess 21 facing the portion to which the strain gauge 11 of the detection pipe 10 is attached is screwed. The main body 23 provided with the holding part 22 to hold by and the lid body 24 covering the recess 21 of the main body 23 are provided. For this reason, since the case body 20 that covers and holds the detection pipe 10 is provided, the detection pipe 10 can be protected and durability can be improved. Furthermore, the lid 24 can be removed to maintain the strain gauge 11 of the detection pipe 10, which is extremely convenient.
In addition, a passage hole 25 through which the lead wire 13 of the strain gauge 11 passes is provided in one of the main body 23 and the lid body 24 (the lid body 24 in the embodiment). A grommet 26 is provided for protection. The lead wire 13 can be protected and durability is improved.
[0011]
Further, in the centralized lubrication system using the piping flow sensor S according to this embodiment, the correlation between the strain amount (current value) of the strain gauge 11 and the pressure of the fluid in the detection pipe 10 is taken in advance. This correlation makes it possible to calculate the pressure of the fluid in the pipe 10. Then, after the pump 1 is operated and the distribution valve 4 is operated, the current value flowing through the strain gauge 11 is detected, and when this current value is an appropriate value, the grease flows and the oil is supplied with the appropriate pressure. To do. On the other hand, when this current value does not change, an abnormal signal is issued to indicate that there is no grease flow, and a warning is given by a lamp or buzzer. Alternatively, when this current value exceeds a predetermined value, the distribution valve 4, piping or oiling point When the pressure in the pipe becomes high due to a problem such as clogging of No. 5, an abnormal signal is issued and a warning is issued with a lamp or buzzer.
[0012]
Therefore, in the centralized lubrication system using the piping flow sensor S according to this embodiment, when the pump 1 is operated and the distribution valve 4 is operated, the terminal piping pipe 6 and the detection pipe 10 of the piping flow sensor S are connected. The grease flows through and is supplied to the oil supply point 5. At this time, since the pressure in the terminal piping pipe 6 is, for example, about 0.3 to 1 MP, the detection pipe 10 is made of resin, so that it expands due to an increase in grease pressure. Thereby, this expansion is detected by the strain gauge 11, the current value is changed, and it is detected that grease has flowed into the pipe.
In this case, the discharge amount of the distribution valve 4 is, for example, about 0.3 to 1.5 cc / shot (0.3 to 1.5 ml / shot), and the amount of oil supply is extremely small. Although the flow is slow, since the expansion of the detection pipe 10 is detected by the strain gauge 11, the flow of the grease can be easily detected even if the flow of the grease is very small.
In addition, since the strain gauge 11 is attached to the detection pipe 10, it is not in contact with the grease itself or the air to be mixed, so that it is not directly affected by this, and the grease flow can be reliably ensured. Can be detected.
[0013]
Also, if the value of the current flowing through the strain gauge 11 does not change, an abnormal signal is generated and a warning is issued with a lamp or buzzer because there is no grease flow. Furthermore, if the current value exceeds a predetermined value, an abnormal signal is generated to indicate that the pressure in the piping has increased due to a problem such as clogging of the distribution valve 4, piping, or oiling point 5, and a lamp or buzzer. A warning is issued. Therefore, not only the presence / absence of a flow but also a pressure abnormality can be detected, so that the function of the flow sensor S for piping is greatly increased.
[0014]
Note that piping flow sensor S according to the above Symbol implementation has been provided in path of the terminal pipe pipe 6, which is a pipe, not necessarily limited to such a pipe, for example, the main pipe pipes 2 It may be changed as appropriate, such as being provided in the path of.
Further, in the above-described embodiment, the case where grease is used as the fluid has been described. However, the present invention is not necessarily limited to this. In the case of oil other than grease as the fluid, or a so-called air mix in which air and oil are mixed. Of course, the present invention can be applied to any pipe through which a fluid flows. Of course, the present invention is not limited to a centralized lubrication system, and can be applied to any system.
Furthermore, in the fluid flow detection method in the pipe of the present invention, not only the above-described flow sensor S for piping, but also a strain gauge 11 is directly attached to the main piping pipe 2 and the terminal piping pipe 6. Of course, it can also be realized.
[0015]
【The invention's effect】
As described above, according to the piping for the flow sensor of the present invention, since the pipe is a resin since it expands by the pressure rise of the fluid, the fluid flows in the pipe to detect the expansion in strain gauge Can be detected. Therefore, the flow of the fluid in the pipe is extremely small, and the flow of the fluid in the pipe is slow, so that the flow of the fluid can be easily detected even if the flow of the fluid is very small. In addition, since the strain gauge is attached to the pipe, it is not in contact with the fluid itself or the air to be mixed, so it is not directly affected by this, so that the fluid flow can be reliably detected. Become.
In the fluid flow detection by the flow sensor for piping of the present invention, when the strain amount of the strain gauge and the pressure of the fluid in the pipe are correlated, the pressure of the fluid in the pipe can be calculated by this correlation Can detect not only the presence or absence of flow but also abnormal pressure, and can also function as a pressure gauge, increasing versatility.
[0016]
Furthermore, in the flow sensor for piping according to the present invention, when the strain gauge is provided on a cylindrical tube made of a thin film resin that is attached to the pipe, it can be attached by an easy operation of attaching the strain gauge to the pipe. Fixing can also be ensured.
Furthermore, when a cylindrical tube is provided twice and a strain gauge is interposed between the double cylindrical tubes, the strain gauge can be protected by the cylindrical tube and durability can be improved.
Moreover, when it comprises and comprises the case body which covers and hold | maintains the detection pipe, a detection pipe can be protected and durability can be improved.
Further, the case body covers a main body having a recess where a portion of the detection pipe provided with a strain gauge and a holding portion for holding connectors provided at both ends of the detection pipe, and a recess of the main body. In the case of being configured with a lid, the lid can be removed to maintain the strain gauge of the detection pipe, which is extremely convenient.
In addition, if a passage hole through which the strain gauge lead wire passes is provided in either the main body or the lid, and a grommet that protects the lead wire is provided in the passage hole, the lead wire can be protected and durability is improved. Can be made.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a flow sensor for piping according to an embodiment of the present invention.
2A and 2B are diagrams showing a main part of a flow sensor for piping according to an embodiment of the present invention, wherein FIG. 2A is a perspective view showing a state before a strain gauge is attached to a detection pipe, and FIG. It is a perspective view which shows the state which mounted | wore the detection pipe with the strain gauge.
FIG. 3 is a cross-sectional view showing a state in which a strain gauge is attached to a detection pipe in the piping flow sensor according to the embodiment of the present invention.
FIG. 4 is a diagram showing an example of a centralized lubrication system in which a flow sensor for piping according to an embodiment of the present invention is used.
[Explanation of symbols]
S Pipe Flow Sensor 1 Pump 2 Main Piping Pipe 4 Distribution Valve 5 Refueling Point 6 Terminal Piping Pipe 10 Detection Pipe 11 Strain Gauge 12 Tubular Pipe 13 Lead Wire 14 Connector 20 Case Body 21 Recess 22 Holding Portion 23 Main Body 24 Lid Body 25 Passing hole 26 Grommet

Claims (4)

In the flow sensor for piping, which is provided in the path of the pipe that has been piped and detects that a fluid has flowed through the pipe,
A detection pipe made of resin, a strain gauge attached to the detection pipe and detecting that the detection pipe has expanded due to an increase in the pressure of the fluid, and the pipe pipe provided at both ends of the detection pipe. With a connector to be connected,
The strain gauge, set in the cylindrical tube made thin resins ring wear to the sensing pipe,
A flow sensor for piping , wherein the cylindrical pipe is provided in a double manner, and the strain gauge is interposed between the double cylindrical pipes . The flow sensor for piping according to claim 1 , comprising a case body that covers and holds the pipe for detection. A body provided with a recess that faces the portion of the detection pipe provided with a strain gauge and a holding portion that holds connectors provided at both ends of the detection pipe; and a recess in the body The flow sensor for piping according to claim 2, further comprising a lid that covers the pipe. 4. The piping for piping according to claim 3 , wherein a passage hole through which the lead wire of the strain gauge passes is provided in one of the main body and the lid, and a grommet for protecting the lead wire is provided in the passage hole. Flow sensor.

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