WO2016024500A1

WO2016024500A1 - Sensor

Info

Publication number: WO2016024500A1
Application number: PCT/JP2015/072128
Authority: WO
Inventors: 伸幸向井
Original assignee: ナブテスコ株式会社
Priority date: 2014-08-11
Filing date: 2015-08-04
Publication date: 2016-02-18
Also published as: JP2016038351A

Abstract

A sensor for detecting the amount of water in oil is provided with a detecting element (20) and a cylindrical cover (12) accommodating the detecting element (20) therein. The cover (12) has a plurality of second introducing holes (26) which are smaller in size than the detecting element (20). The second introducing holes (26) are formed at positions where the second introducing holes do not face each other around the central axis of the cover (12).

Description

Sensor

The present invention relates to a sensor for detecting a characteristic of a fluid.

The sensor for detecting the characteristics of the fluid is not limited to detecting the collected sample at a predetermined sample position. For example, a sensor mounted on an attachment body such as a conduit or a tank through which the fluid flows, There are portable types that can be inserted into roads and tanks. This type of sensor is often required to be responsive to changes in the fluid state.

For example, a fluid temperature detection sensor described in Patent Document 1 has a sensor housing that is mounted on a mounted body. The sensor housing has a protection cylinder, and the temperature detection element is accommodated in the protection cylinder via a heat conductive paste. A male screw is formed on the outer periphery of the sensor housing. When mounting the sensor for detecting fluid temperature on the mounted body, the male screw of the sensor housing is inserted into the insertion hole of the mounted body with the protective cylinder facing the measurement medium (fluid for temperature detection) Threaded onto.

JP 2002-48654 A

In the fluid temperature detection sensor described above, the temperature detection element does not contact the measurement medium, but there is also a sensor in which the temperature detection element or other detection unit contacts the fluid. In such a sensor, if the detection unit unexpectedly drops due to factors such as a severe usage situation, the detection unit may be mixed into the fluid as a foreign substance. For this reason, it is preferable to cover the detection unit with a protective member such as a protective cylinder while keeping the detection unit in contact with the fluid.

However, when the detection unit is covered with the protective member, it is undeniable that the fluidity of the fluid around the detection unit is lower than when the detection unit is not covered with the protective member. For this reason, since the change in the state of the fluid to be detected is not immediately reflected in the state of the fluid in the protective cylinder, the responsiveness of the sensor may be reduced.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a sensor capable of improving responsiveness while protecting a detection unit.

In order to solve the above problems, according to one aspect of the present invention, there is provided a sensor including a detection unit that detects a characteristic of a fluid and a cylindrical cover that houses the detection unit inside. The cover has a plurality of introduction holes smaller than the size of the detection unit. The plurality of introduction holes are formed around the central axis of the cover at positions that do not face each other with the central axis in between.

According to the above configuration, since the plurality of holes smaller than the size of the detection unit are formed in the cover, the detection target fluid is brought into contact with the detection unit while suppressing the detection unit from dropping out of the cover. be able to. Further, since the plurality of holes in the cover are formed at positions that do not face each other, the response of the sensor can be improved by improving the fluidity of the fluid in the cover.

In this sensor, it is preferable that at least a part of the plurality of introduction holes is provided at a position facing the detection unit.
According to the above configuration, since at least a part of the plurality of introduction holes is provided at a position facing the detection unit, the time until the fluid that has flowed into the cover through the introduction hole reaches the detection unit is shortened. Can do.

With respect to this sensor, the cover has a plurality of introduction hole rows each consisting of a plurality of introduction holes that are a part of the introduction holes, and the introduction holes of each introduction hole row are introduced to adjacent introduction hole rows. It is preferable that the arrangement of the cover in the circumferential direction is different from the hole.

According to the above configuration, since the circumferential positions of the introduction holes are different between the two introduction hole rows adjacent to each other, the fluidity of the fluid in the cover can be improved.
With respect to this sensor, the cover has a plurality of introduction hole rows each composed of a plurality of introduction holes that are a part of the introduction holes, and the introduction holes of each introduction hole row are introduced to other introduction hole rows. It is preferable that the arrangement of the cover in the circumferential direction is different from the hole.

According to the above configuration, the introduction hole of each introduction hole row differs from the introduction hole of the other introduction hole row in the circumferential direction of the cover, so that the fluidity of the fluid in the cover can be improved.
In this sensor, it is preferable that the introduction holes are arranged in a spiral from one end portion to the other end portion in the axial direction of the cover.

According to the above configuration, since the introduction holes are arranged spirally in the cover, the fluidity of the fluid in the cover can be improved.
In this sensor, the cover has a plurality of introduction hole rows each including a plurality of introduction holes that are a part of the introduction holes, and between the adjacent pairs of the introduction holes in each introduction hole row. Are preferably different from each other.

According to the above configuration, since the intervals between adjacent pairs of the introduction holes in each introduction hole row are different from each other, the fluidity of the fluid in the cover can be improved.
With respect to this sensor, it is preferable that a wall portion is provided at one end portion in the axial direction of the cover, and an end portion introduction hole for taking a fluid into the inside of the cover is formed in the wall portion. .

According to the above configuration, the cover has the introduction hole located around the central axis of the cover and the end introduction hole located at one end in the axial direction of the cover. Improvements can be made.

In this sensor, the detection unit includes a first electrode, a second electrode that is disposed opposite to the first electrode and transmits water molecules, and a sensor sandwiched between the first electrode and the second electrode. And the detection unit detects the amount of water contained in the fluid based on a change in capacitance caused by the sensitive film adsorbing and desorbing water molecules that have passed through the second electrode. preferable.

According to the above configuration, since the detection unit is a capacitance-type element, the responsiveness of the detection unit itself can be improved as compared to a resistance-type sensor that detects a resistance change due to the amount of moisture between the electrodes.
In order to solve the above problems, another aspect of the present invention provides a sensor including a detection unit that detects a characteristic of a fluid and a cylindrical cover that houses the detection unit. The cover has a plurality of introduction holes smaller than the size of the detection unit, each of the introduction holes being located around the central axis of the cover and another one of the introduction holes. The two introduction holes facing each other have different inner diameters.

According to the above configuration, since the plurality of holes smaller than the size of the detection unit are formed in the cover, the detection target fluid is brought into contact with the detection unit while suppressing the detection unit from dropping out of the cover. be able to. Further, since the introduction holes facing each other have different inner diameters, the response of the sensor can be improved by improving the fluidity of the fluid in the cover.

ADVANTAGE OF THE INVENTION According to this invention, the response of a sensor can be improved, protecting the detection part of a sensor.
Other aspects and advantages of the present invention will become apparent from the following description taken in conjunction with the drawings which illustrate examples of the technical idea of the present invention.

The perspective view of the sensor of 1st Embodiment of this invention. The top view of the sensor of the embodiment. The perspective view of the detection element provided in the sensor in the embodiment. The perspective view which looked at the sensor of the embodiment from the angle different from FIG. The front view of the cover of the sensor of the embodiment. 5A is a sectional view taken along line 6a-6a in FIG. 5, FIG. 5B is a sectional view taken along line 6b-6b in FIG. 5, and FIG. 5C is a sectional view taken along line 6c-6c in FIG. The schematic diagram of the detection element of the embodiment. FIG. 8 is a cross-sectional view taken along line 8-8 in FIG. The figure which shows the attachment state of the sensor of the embodiment. The front view of the cover in the sensor of 2nd Embodiment of this invention. 10A is a sectional view taken along line 11a-11a in FIG. 10, FIG. 10B is a sectional view taken along line 11b-11b in FIG. 10, and FIG. 10C is a sectional view taken along line 11c-11c in FIG. The front view of the cover in the sensor of 3rd Embodiment of this invention. 12A is a sectional view taken along line 13a-13a in FIG. 12, FIG. 12B is a sectional view taken along line 13b-13b in FIG. 12, and FIG. 13C is a sectional view taken along line 13c-13c in FIG. The front view of the cover in the sensor of 4th Embodiment of this invention. 14A is a sectional view taken along line 15a-15a in FIG. 14, FIG. 14B is a sectional view taken along line 15b-15b in FIG. 14, and FIG. 14C is a sectional view taken along line 15c-15c in FIG. The front view of the cover in the sensor of 5th Embodiment of this invention. 16A is a cross-sectional view taken along line 17a-17a in FIG. 16, FIG. 16B is a cross-sectional view taken along line 17b-17b in FIG. 16, and FIG. 16C is a cross-sectional view taken along line 17c-17c in FIG. The front view of the cover in the sensor of 5th Embodiment of this invention. 18A is a cross-sectional view taken along a line 19a-19a in FIG. 18, FIG. 18B is a cross-sectional view taken along a line 19b-19b in FIG. 18, and FIG. 18C is a cross-sectional view taken along a line 19c-19c in FIG. The figure which shows the responsiveness of the sensor of Example 1 of this invention and Comparative Examples 1-2. The front view of the cover in the sensor of the modification of this invention. The front view of the cover in the sensor of the modification of this invention. Sectional drawing of the cover in the sensor of the modification of this invention.

(First embodiment)
A sensor according to a first embodiment of the present invention will be described with reference to FIGS. In the present embodiment, the sensor will be specifically described as a sensor that detects the amount of moisture contained in oil as a fluid, such as lubricating oil for a machine. The sensor is mounted on a mounted body such as a conduit through which oil flows or a tank in which oil is stored.

First, a schematic configuration of the sensor 10 will be described with reference to FIGS.
As shown in FIG. 1, the sensor 10 includes a housing 11 and a cover 12. The housing 11 has a large diameter portion 13 and a small diameter portion 14. The large diameter portion 13 and the small diameter portion 14 are fastened by a fastening portion 15 such as a nut.

Inside the cover 12, a detection element 20 as a detection part provided at the tip of the small diameter part 14 is accommodated. The cover 12 is formed of a metal material having corrosion resistance against oil to be detected such as mineral oil or insulating oil, and has a cylindrical shape. A side wall 22 is provided at one end of the cover 12 along the axial direction, and the other end is open. One first introduction hole 24 is formed through the side wall portion 22 of the cover 12. A plurality of second introduction holes 26 are formed through the peripheral wall portion 25 of the cover 12. The first introduction hole 24 and the second introduction hole 26 are through holes for introducing oil into the cover 12 and have the same shape and inner diameter. The first introduction hole 24 is formed in the central portion of the side wall portion 22.

As shown in FIG. 2, the small-diameter portion 14 of the housing 11 includes a first screwing portion 16 and a second screwing portion 17 in which male screws are respectively formed. A pair of pins 21 is fixed to the tip of the second screwing portion 17. The pin 21 is firmly fixed to the second screwing portion 17 by soldering or the like. At the tips of these pins 21, a detection element 20 that is electrically connected to the pins 21 is provided.

As shown in FIG. 3, the inner diameter D (see FIG. 2) of the first introduction hole 24 and the second introduction hole 26 described above is smaller than the width W, height H, and thickness T of the detection element 20.
A cover screw portion 27 is formed on the inner peripheral surface of the opening end 23 of the cover 12. When the cover screw portion 27 is screwed with the second screw portion 17 of the small diameter portion 14, the cover 12 is attached to the small diameter portion 14 in a state where the detection element 20 is accommodated inside. The relative position in the circumferential direction between the cover 12 and the detection element 20 is not particularly limited.

Of the peripheral wall portion 25 of the cover 12, a region Z <b> 1 in which the second introduction hole 26 is formed is located at a position where the detection element 20 is disposed in the axial direction of the cover 12 with the cover 12 being attached to the small diameter portion 14. Overlap. That is, at least a part of the second introduction hole 26 faces the detection element 20. For this reason, the oil that has flowed into the cover 12 from the second introduction hole 26 easily reaches the detection element 20. Here, the region Z1 is a region including from the second introduction hole 26 closest to the opening end 23 to the second introduction hole 26 closest to the side wall portion 22 in the axial direction of the cover 12.

As shown in FIG. 4, a connection portion 18 and a notification portion 19 are provided on the end surface 18 a on the opposite side of the small diameter portion 14 among the end surfaces of the large diameter portion 13. A power supply line and a signal line are connected to the connection unit 18. The power supply line connected to the connection unit 18 supplies power to the drive circuit accommodated in the large-diameter portion 13 and the notification unit 19. The signal line connected to the connection unit 18 transmits the detection signal output from the detection element 20 to an external output device or the like.

The notification unit 19 includes three

lamps

19a, 19b, and 19c. The lamps 19a to 19c are controlled to be lit by the drive circuit accommodated in the large diameter portion 13. In addition, each of the lamps 19a to 19c may emit light of different colors when turned on.

For example, when the amount of water contained in the detection target oil is within a preset low range, the back lamp 19a in FIG. 9 is turned on. Further, when the amount of water in the oil is within a preset medium range, the central lamp 19b is turned on. Further, when the amount of water in the oil is within a preset high range, the lamp 19c in front of FIG. 9 is turned on. That is, the notification unit 19 notifies the user of the approximate amount of water contained in the detection target oil. The measured value of the amount of moisture detected by the detection element 20 can be confirmed by the output device connected via the signal line. Further, when an abnormality occurs in the sensor 10 itself, the failure is notified by turning on all the lamps 19a to 19c.

Next, the formation pattern of the second introduction holes 26 will be described with reference to FIGS.
As shown in FIG. 5, the cover 12 is formed with a plurality of introduction hole arrays each including a plurality of second introduction holes 26 having the same position in the axial direction of the cover 12. In the present embodiment, four introduction hole rows L 1, L 2, L 3, and L 4 are arranged in the axial direction of the cover 12. Each of the introduction hole rows L1 to L4 has three second introduction holes 26.

Each second introduction hole 26 constituting each introduction hole row L1 to L4 is different in position in the circumferential direction of the cover 12 from any second introduction hole 26 in the adjacent introduction hole row. That is, the circumferential position of each second introduction hole 26 that constitutes the first introduction hole row L1 is different from the circumferential position of any second introduction hole 26 that constitutes the second introduction hole row L2. Further, the circumferential position of each second introduction hole 26 constituting the second introduction hole row L2 is different from the circumferential position of any second introduction hole 26 constituting the first introduction hole row L1, and the third introduction hole is arranged. It is different from the circumferential position of any second introduction hole 26 constituting the hole row L3. The circumferential position of each second introduction hole 26 constituting the first introduction hole row L1 is the same as the circumferential position of one of the second introduction holes 26 constituting the third introduction hole row L3. Further, the circumferential position of each second introduction hole 26 constituting the second introduction hole row L2 is the same as the circumferential position of one of the second introduction holes 26 constituting the fourth introduction hole row L4.

As shown in FIGS. 6A to 6C, the second introduction holes 26 constituting each of the introduction hole rows L1 to L4 are located at positions that do not face each other with the central axis X1 of the cover 12 in between, that is, the front faces Each is formed at a position that does not become. The central axis X1 passes through the center of the first introduction hole 24. The second introduction holes 26 of the second introduction hole row L2 shown in FIG. 6A are clockwise with respect to the position of the upper second introduction hole 26 in the figure, “0 °”, “120 °”, Each is formed at a position of “240 °”. The second introduction holes 26 of the third introduction hole row L3 shown in FIG. 6B are formed at positions of “60 °”, “180 °”, and “300 °”, respectively. The second introduction holes 26 of the fourth introduction hole row L4 shown in FIG. 6C are formed at positions of “0 °”, “120 °”, and “240 °”, respectively. Although illustration is omitted, the second introduction hole 26 of the first introduction hole row L1 is “60 °”, “180 °”, “300 °” similarly to the second introduction hole 26 of the third introduction hole row L3. It is formed at each position.

Next, the configuration of the detection element 20 will be described with reference to FIGS. The detection element 20 detects the amount of water contained in the oil to be detected based on the capacitance.
As shown in FIG. 7, the detection element 20 includes a substrate 30 and a first electrode 31 installed on the substrate 30. A sensitive film 33 is formed on the first electrode 31, and a second electrode 32 is formed on the sensitive film 33.

The first electrode 31 is made of a metal material such as chromium containing gold. A first electrode terminal 34 is connected to the first electrode 31. The 2nd electrode 32 consists of metal materials, such as chromium, and a water molecule can permeate | transmit. The second electrode 32 is connected to the second electrode 32. The first electrode terminal 34 and the second electrode terminal 35 are drawn from one side of the substrate 30 and are connected to the drive circuit accommodated in the large-diameter portion 13 through the pin 21. The sensitive film 33 is made of an organic insulator such as polyimide that can adsorb and desorb water molecules. The sensitive film 33 is formed to be slightly larger than the first electrode 31 and the second electrode 32, and is laminated so that end portions thereof protrude from the first electrode 31 and the second electrode 32.

As shown in FIG. 8, the first electrode 31 is covered with a sensitive film 33. The first electrode 31 and the second electrode 32 face each other with the sensitive film 33 interposed therebetween. Adsorption and desorption of water molecules to the sensitive film 33 are performed directly at the exposed portion protruding from the second electrode 32 and also through the second electrode 32.

When the moisture content in the detection target oil around the detection element 20 is stabilized, the adsorption of water molecules to the sensitive film 33 is balanced with the oil. For example, if the amount of water molecules contained in the oil increases, the amount of water molecules adsorbed on the sensitive membrane 33 also increases, and if the amount of water molecules contained in the oil decreases, the amount of water molecules adsorbed on the sensitive membrane 33 also increases. Decrease.

The capacitance between the first electrode 31 and the second electrode 32 changes due to the adsorption and desorption of water molecules on the sensitive film 33. The amount of moisture contained in the oil is detected by calculating a change in capacitance between the first electrode 31 and the second electrode 32 by a drive circuit connected to the first electrode terminal 34 and the second electrode terminal 35. Is done. As described above, in order to detect the amount of water contained in the oil, the time required for equilibration of the adsorption of water molecules to the sensitive membrane 33 is required to be minimal.

Next, the mounting state of the sensor 10 on the mounted body 100 will be described with reference to FIG. An insertion hole 101 for mounting the sensor 10 is formed in a wall such as a pipe line or a tank that is the mounted body 100. A female screw is formed on the inner peripheral surface of the insertion hole 101. The sensor 10 is mounted by inserting the cover 12 into the mounted body 100 and screwing the first screwing portion 16 into the female screw of the insertion hole 101.

The sensor 10 preferably detects the amount of water contained in the oil 102 in a state where the oil 102 is flowing in the mounted body 100. This is to make the water content of the oil 102 uniform in the mounted body 100, but the water content of the oil 102 is made uniform or needs to be made uniform before detection by the sensor 10. If there is not (for example, when the detection is in a biased state), the oil 102 does not need to flow during the detection.

The oil 102 flows into the cover 12 via the second introduction hole 26 and the first introduction hole 24 and contacts the detection element 20. The detection element 20 outputs an electrical signal corresponding to the amount of water molecules adsorbed to the drive circuit. The drive circuit transmits a signal corresponding to the moisture content to the above-described output device via a signal line connected to the sensor 10. Further, the drive circuit turns on a lamp corresponding to the moisture content among the lamps 19a to 19c to notify the user of the level of the moisture content.

Next, the operation of the cover 12 of the sensor 10 will be described with reference to FIG. The detection element 20 is covered with the cover 12 and is larger than the inner diameters of the first introduction hole 24 and the second introduction hole 26 formed in the cover 12. For this reason, even if the detection element 20 is unintentionally detached from the second screwing portion 17 due to factors such as the use environment, the detection element 20 does not fall out of the cover 12. For this reason, it is prevented that the detection element 20 mixes in the pipe line and tank in which oil flows.

It has been found through experiments and the like by the inventors that the sensor 10 has improved responsiveness compared to the case where the second introduction holes 26 are provided at positions where they are not opposed to each other. . The improvement of the responsiveness here is not the responsiveness of the detection element 20 itself, but when the water content of the oil 102 flowing through the mounted body 100 changes due to some factor, the change from the time of the change is detected by the sensor 10. This means shortening the delay time until it is detected by.

The reason for improving the responsiveness of the sensor 10 has not yet been clarified, but is estimated as follows.
When the second introduction holes 26 formed in the cover 12 are formed at positions facing each other, the oil 102 introduced into the cover 12 from one of the pair of opposed second introduction holes 26 is the other. The second introduction hole 26 is easily discharged out of the cover 12.

On the other hand, when the second introduction holes 26 are not formed at positions facing each other as in this embodiment, the oil 102 introduced into the cover 12 from the second introduction holes 26 faces the second introduction holes 26 facing each other. Therefore, it is not discharged out of the cover 12 as it is, but collides with the inner peripheral surface of the cover 12. In addition, since the inflow of the oil 102 from the first introduction hole 24 is also added, for example, shear force or turbulent flow is applied to the oil 102 in the cover 12 as compared with the case where the second introduction holes 26 are formed at positions facing each other. As a result, the flow of the oil 102 in the cover 12 is complicated.

Further, each second introduction hole 26 in each introduction hole row L1 to L4 is different in position in the circumferential direction of the cover 12 from any second introduction hole 26 in the adjacent introduction hole row. For this reason, the direction of the flow of the oil 102 introduced into the cover 12 is diversified as compared with the case where the circumferential position of the second introduction hole 26 is the same between the two introduction hole rows adjacent to each other. For this reason, the oil flow in the cover 12 can be made a more complicated flow. As a result, the oil in the cover 12 does not stay in the corners of the cover 12 and is mixed well in a short time, and then the oil in the cover 12 passes through either the second introduction hole 26 or the first introduction hole 24. Discharged to the outside. For this reason, the moisture content of the oil 102 existing inside the cover 12 is the same as the moisture content of the oil 102 existing outside the cover 12 in a short time.

As described above, according to the present embodiment, the following effects can be obtained.
(1) Since the plurality of second introduction holes 26 smaller than the size of the detection element 20 are formed in the cover 12, it is possible to prevent the detection element 20 from dropping out of the cover 12 and to detect the oil to be detected. It can be brought into contact with the detection element 20. Moreover, since the 2nd introduction hole 26 is formed in the position which is not mutually opposed, the responsiveness of the sensor 10 can be improved.

(2) Since a part of the second introduction hole 26 is provided at a position facing the detection element 20, the time until oil that has flowed into the cover 12 through the second introduction hole 26 reaches the detection element 20 is reduced. Can be shortened.

(3) The cover 12 has a second introduction hole 26 formed in the peripheral wall portion 25 and a first introduction hole 24 formed in the side wall portion 22. For this reason, the detection target oil can flow into the cover 12 not only in the direction from the peripheral wall portion 25 of the cover 12 toward the center in the radial direction but also in the axial direction from the side wall portion 22 toward the opening end 23. For this reason, the oil flow in the cover 12 is complicated, so that oil can be prevented from staying in the corners of the cover 12.

(4) The detection element 20 is a capacitive element, and detects a change in capacitance based on a change in the amount of moisture between the first electrode 31 and the second electrode 32. For this reason, the responsiveness of the detection element 20 itself can be improved compared with the resistance type sensor which detects the resistance change by the moisture content between electrodes.

(5) The circumferential position of the second introduction hole 26 is different between the two introduction hole rows L1 to L4 adjacent to each other. For this reason, the flow direction of the oil in the cover 12 can be diversified, and the fluidity of the oil in the cover 12 can be improved.

(Second Embodiment)
Next, with reference to FIG. 10 and FIG. 11, the sensor of 2nd Embodiment of this invention is demonstrated centering on difference with 1st Embodiment. The sensor of this embodiment is different from the first embodiment in that the circumferential position of the second introduction hole of each introduction hole row coincides with the circumferential position of the second introduction hole of another introduction hole row. Yes. The basic configuration of the sensor according to this embodiment is the same as that of the first embodiment, and in the drawings, substantially the same elements as those of the first embodiment are denoted by the same reference numerals. , I will omit the duplicate explanation.

As shown in FIG. 10, the cover 12 of the sensor 10 of the present embodiment has three introduction hole rows L1, L2, and L3. The region Z2 in which the introduction hole rows L1 to L3 are formed overlaps with the position of the detection element 20 in the axial direction of the cover 12 as in the first embodiment.

As shown in FIGS. 11A to 11C, each of the introduction hole arrays L1 to L3 has three second introduction holes 26 formed every 120 °. The second introduction holes 26 in each of the introduction hole rows L1 to L3 have the same circumferential position as the second introduction holes 26 of the other two introduction hole rows L1 to L3. The second introduction holes 26 of the introduction hole rows L1 to L3 are arranged at positions that do not face each other with the central axis X1 interposed therebetween.

For this reason, the stay of the oil in the cover 12 can be suppressed, and the fluidity of the oil in the cover 12 can be improved.
As described above, according to this embodiment, the same effects as the effects (1) to (4) of the first embodiment can be obtained.

(Third embodiment)
Next, with reference to FIGS. 12 and 13, a sensor according to a third embodiment of the present invention will be described focusing on differences from the first embodiment. The basic configuration of the sensor according to this embodiment is the same as that of the first embodiment, and in the drawings, substantially the same elements as those of the first embodiment are denoted by the same reference numerals. , I will omit the duplicate explanation.

As shown in FIG. 12, the cover 12 of the sensor 10 of this embodiment has four introduction hole rows L1, L2, L3, and L4. The region Z3 in which the introduction hole rows L1 to L4 are formed overlaps with the position of the detection element 20 in the axial direction of the cover 12 as in the first embodiment.

As shown in FIGS. 13A to 13C, each of the introduction hole rows L1 to L4 has five second introduction holes 26 formed every 72 °. The second introduction holes 26 of the introduction hole rows L1 to L4 are arranged at positions that do not face each other with the central axis X1 interposed therebetween. Further, each second introduction hole 26 of each introduction hole row L1 to L4 has a circumferential position different from the second introduction hole 26 of any other introduction hole row L1 to L4. That is, the second introduction holes 26 of the introduction hole rows L1 to L4 are different in the position in the axial direction and the circumferential direction of the cover 12 from the second introduction holes 26 of any other introduction hole rows L1 to L4. Further, in the present embodiment, the circumferential positions of the second introduction holes 26 of the introduction hole rows L1 to L4 are shifted by 18 ° with respect to the closest second introduction hole 26 among the adjacent introduction hole rows.

For example, as shown in FIG. 13C, the five second introduction holes 26 of the fourth introduction hole row L4 are “0 °”, “72 °”, “144 °”, “216 °” in the clockwise direction. ”And“ 288 ° ”.

As shown in FIG. 13B, at this time, the five second introduction holes 26 of the third introduction hole row L3 are “54 °”, “126 °”, “198 °”, “270 °”, “342”. It is formed at each position of “°”.

As shown in FIG. 13A, at this time, the five second introduction holes 26 of the second introduction hole row L2 are “36 °”, “108 °”, “180 °”, “252 °”, “324”. It is formed at each position of “°”.

Since each of the introduction hole rows L1 to L4 has the five second introduction holes 26, the opening ratio of the cover 12 can be increased. Further, the direction in which the detection target oil is introduced into the cover 12 can be further diversified as compared with the cover 12 of the first embodiment.

As described above, according to the present embodiment, the same effects as the effects (1) to (4) of the first embodiment can be obtained, and the following effects can be obtained.
(6) The circumferential positions of the second introduction holes 26 constituting the introduction hole rows L1 to L4 are different from the circumferential positions of the second introduction holes 26 of any other introduction hole rows L1 to L4. For this reason, the flow of oil in the cover 12 can be complicated, and the fluidity of the oil in the cover 12 can be improved.

(Fourth embodiment)
Next, with reference to FIGS. 14 and 15, a sensor according to a fourth embodiment of the present invention will be described focusing on differences from the first embodiment. The basic configuration of the sensor according to this embodiment is the same as that of the first embodiment, and in the drawings, substantially the same elements as those of the first embodiment are denoted by the same reference numerals. , I will omit the duplicate explanation.

As shown in FIG. 14, the second introduction holes 26 are arranged in a spiral from the side wall portion 22 to the opening end 23 in the cover 12 of the sensor of the present embodiment. That is, the position of the second introduction hole 26 in the axial direction and the position in the circumferential direction of the cover 12 are shifted from each other. The region Z4 in which the second introduction holes 26 are formed overlaps with the position of the detection element 20 in the axial direction of the cover 12 as in the first embodiment.

As shown in FIGS. 15A to 15C, the second introduction holes 26 are arranged at positions that do not face each other with the central axis X1 interposed therebetween. Further, each second introduction hole 26 is not opposed to any other second introduction hole 26 because the position of the cover 12 in the axial direction is shifted from any other second introduction hole 26. For this reason, the fluidity | liquidity of the oil in the cover 12 can be aimed at.

As described above, according to the present embodiment, the same effects as the effects (1) to (4) of the first embodiment can be obtained, and the following effects can be obtained.
(7) Since the second introduction holes 26 are arranged in a spiral on the cover 12, the fluidity of oil in the cover 12 can be improved.

(Fifth embodiment)
Next, a sensor according to a fifth embodiment of the present invention will be described with reference to FIGS. 16 and 17 focusing on differences from the first embodiment. The basic configuration of the sensor according to this embodiment is the same as that of the first embodiment, and in the drawings, substantially the same elements as those of the first embodiment are denoted by the same reference numerals. , I will omit the duplicate explanation.

As shown in FIG. 16, the cover 12 of the sensor 10 of this embodiment has three introduction hole rows L1, L2, and L3. The region Z5 in which the introduction hole rows L1 to L3 are formed overlaps with the position of the detection element 20 in the axial direction of the cover 12 as in the first embodiment.

As shown in FIGS. 17A to 17C, the second introduction holes 26 constituting each of the introduction hole rows L1 to L3 are arranged at positions that do not face each other with the central axis X1 interposed therebetween. The intervals between adjacent two of the second introduction holes 26 constituting each of the introduction hole rows L1 to L3 are different from each other.

As shown in FIG. 17 (a), the intervals θ11, θ12, θ13 between two adjacent second introduction holes 26 in the first introduction hole row L1 are, for example, “134 °”, “120 °”, “ 106 ° ". Further, as shown in FIG. 17B, the intervals θ21, θ22, θ23 between two adjacent second introduction holes 26 in the second introduction hole row L2 are “133 °”, “115 °”, It is different from each other like “112 °”. Further, as shown in FIG. 17C, the intervals θ31, θ32, and θ33 of the second introduction holes 26 in the third introduction hole row L3 are “115 °”, “123 °”, and “122 °”. Each is different. These intervals are merely examples, and other intervals may be used.

Thus, each second introduction hole 26 is not opposed to any other second introduction hole 26. Further, since the intervals between the second introduction holes 26 in each of the introduction hole arrays L1 to L3 are different from each other, for example, a large number of second introduction holes 26 are provided at positions corresponding to locations in the cover 12 where oil is likely to stay. You can also. For this reason, the fluidity | liquidity of the oil in the cover 12 can be aimed at.

As described above, according to the present embodiment, in addition to the same effects as the effects (1) to (4) of the first embodiment, the following effects can be obtained.
(8) Since the intervals between the second introduction holes 26 constituting each of the introduction hole rows L1 to L3 are different from each other, the flow direction of the oil introduced into the cover 12 is diversified. For this reason, the fluidity | liquidity of the oil in the cover 12 can be aimed at.

(Sixth embodiment)
Next, a sensor according to a fifth embodiment of the present invention will be described with reference to FIGS. 18 and 19 focusing on differences from the first embodiment. The basic configuration of the sensor according to this embodiment is the same as that of the first embodiment, and in the drawings, substantially the same elements as those of the first embodiment are denoted by the same reference numerals. , I will omit the duplicate explanation.

As shown in FIG. 18, the cover 12 of the sensor 10 of this embodiment has three introduction hole rows L1, L2, and L3. The regions where the introduction hole rows L1 to L3 are formed overlap with the position of the detection element 20 in the axial direction of the cover 12 as in the first embodiment. In FIG. 17, the position of the detection element 20 is not shown for convenience.

As shown in FIGS. 19A to 19C, each of the introduction hole rows L1 to L3 has four second introduction holes 26 formed every 90 °. Each second introduction hole 26 of each introduction hole row L1 to L3 faces one of the other second introduction holes 26 of the same introduction hole row L1 to L3. Each introduction hole row L1 to L3 includes two second introduction holes 26a having a relatively small inner diameter, and two second introduction holes 26b having a relatively large inner diameter. Two second introduction holes 26 facing each other across the central axis X1 are configured by a pair of 26a and the second introduction hole 26b.

Next, the operation of the sensor 10 of this embodiment will be described. The pair of second introduction holes 26 facing the cover 12 have different inner diameters. When the detection target oil flows into the inside of the cover 12 through the second introduction hole 26, the oil contracts in the cover 12. For example, a part of the contracted flow of oil that has passed through the large-diameter second introduction hole 26 b is easily discharged from the opposing second small-diameter second introduction hole 26 b, but the remaining portion of the contracted flow is within the cover 12. Easy to collide with the surrounding surface. For this reason, it is possible to prevent oil from staying in the cover 12 by complicating the flow of oil in the cover 12.

As described above, according to this embodiment, in addition to the same effects as the effects (2) to (4) of the first embodiment, the following effects can be obtained.
(9) Since a plurality of second introduction holes 26 smaller than the size of the detection element 20 are formed in the cover 12, it is possible to prevent the detection element 20 from dropping out of the cover 12 and Oil can be brought into contact with the detection element 20. Further, since the second introduction holes 26 facing each other have different inner diameters, the responsiveness of the sensor can be improved by improving the fluidity of the oil in the cover 12.

(Example)
Hereinafter, the relationship between the position of the second introduction hole 26 of the cover 12 and the responsiveness of the sensor 10 will be described with reference to FIG.

(Example 1)
Using the sensor 10 having the cover 12 of the first embodiment, the amount of water contained in the oil was detected. The first introduction hole 24 and the second introduction hole 26 were formed in a circular shape having a diameter of 5.5 mm.

Also, the test tank was filled with mineral oil and adjusted to a temperature of 70 degrees. Furthermore, the detection element 20 covered with the cover 12 of the sensor 10 was immersed in the oil in a state where the oil was stirred at a constant speed by a stirrer and a flow along the inner peripheral surface of the test tank was generated.

Next, in order to confirm the responsiveness of the sensor 10 when the amount of water contained in the oil changes, the water activity value in the oil is changed from 0.1 aw to 1 aw from a specific portion of the test tank while stirring the oil. Drops of water were added until 0.0 aw or more. The dropping speed was made not to greatly exceed the minimum required response speed of the sensor 10. In addition, a tester was connected to the sensor 10, and the output value (V) of the sensor 10 was detected.

(Comparative Example 1)
The output value (V) of the sensor 10 was detected under the same conditions as in Example 1 except that the cover 12 of the sensor 10 of Example 1 was removed.

(Comparative Example 2)
The number, shape, and diameter of the second introduction holes 26 of the sensor 10 are the same as those in the first embodiment, and only the formation positions are different from those in the first embodiment. The cover 12 of Comparative Example 2 was formed with three introduction hole arrays each including four second introduction holes 26 formed every 90 ° so that a pair of second introduction holes 26 face each other. That is, the aperture ratio of Example 1 and the cover 12 is the same.

FIG. 20 shows a graph of changes in the output values of Example 1, Comparative Example 1 and Comparative Example 2 with changes in the amount of water in the oil. In the sensor 10, the output value of the sensor 10 becomes “5V” and constant after the water activity value reaches 1.0 aw under the above-described test conditions.

In the sensor 10 of Comparative Example 1 without the cover 12, the time required to reach the output value (5V) when the water activity value reaches 1.0 aw is 52 seconds. This time is based on the response of the detection element 20 itself.

On the other hand, in the sensor 10 of Example 1, the time required to reach the output value (5 V) when the water activity value reaches 1.0 aw is 95 seconds. In the sensor 10 of Comparative Example 2, the time required to reach the output value (5 V) when the water activity value reaches 1.0 aw is 115 seconds. That is, the response time of the sensor 10 of Example 1 is shortened by 17% or more with respect to the response time of Comparative Example 3, and it can be said that the sensor 10 of Example 1 is more responsive than Comparative Example 2. .

(Other embodiments)
In addition, each said embodiment can also be implemented with the following forms.
-As shown in FIG. 21, the 2nd introduction hole 26 may be formed in the rectangular shape. In this case, the second introduction holes 26 constituting each introduction hole row may be formed at positions that do not face each other. Or each 2nd introduction hole 26 which constitutes each introduction hole line is located in opposition to one of the other 2nd introduction holes 26 of the same introduction hole line, and two 2nd which is located opposite to each other. The introduction holes 26 may have different inner diameters.

As shown in FIG. 22, the second introduction hole 26 may be formed in an elongated shape (slit shape) extending in the circumferential direction of the cover 12 as long as it is smaller than the length, width, and thickness of the detection element 20. . For example, the second introduction holes 26 are formed at different positions in the axial direction of the cover 12 and extend, for example, in the range of 45 ° along the circumferential direction of the cover 12. For this reason, the 2nd introduction hole 26 is provided in the position which does not oppose mutually.

As shown in FIG. 23, a rectifying unit 40 that rectifies oil may be provided on the inner peripheral surface of the cover 12 and in the vicinity of each second introduction hole 26. The rectifying unit 40 can also cause the oil at the corners of the cover 12 to flow.

In the first to fifth embodiments, the second introduction holes 26 formed in the cover 12 have the same inner diameter, but the inner diameters of the second introduction holes 26 may be two or more different inner diameters. . Moreover, although the internal diameter of the 2nd introduction hole 26 and the internal diameter of the 1st introduction hole 24 were made into the same internal diameter, you may make it a different internal diameter.

In the fourth embodiment, the second introduction holes 26 are arranged in one spiral, but a plurality of rows of the spiral second introduction holes 26 may be provided. At this time, even if the second introduction holes 26 are located at the same position in the axial direction of the cover 12, the second introduction holes 26 are preferably formed at positions that do not face each other.

The configuration of the detection element 20 may be other than the configuration described above. For example, the sensitive film 33 is made of an organic insulator, but may be made of an inorganic material having an insulating property.
In each of the above embodiments, the number and size of the second introduction holes 26 can be increased to the extent that the detection element 20 does not drop out of the cover 12, and the aperture ratio of the cover 12 is not particularly limited.

In each of the above embodiments, the number of introduction hole rows made up of a plurality of introduction holes can be appropriately changed according to the size of the detection unit, the size of the cover, the required response of the sensor, and the like. That is, the introduction hole row may be one row. The introduction hole row may be a plurality of two or more rows.

In each of the embodiments described above, the detection unit is a capacitive element, but it may be one that detects the amount of water in the fluid by other methods. For example, it may be a detection unit having an optical element or a heat conduction type detection element.

In each of the embodiments described above, the sensor 10 is a type of sensor that is mounted on the mounted body 100, but may be used in other methods. For example, the sensor 10 may be inserted into oil through a tank opening or the like while supporting the sensor 10 by hand. Further, the method is not limited to the method of mounting on the mounted body 100 or being inserted into a pipe or tank, and a sample collected from the pipe or tank may be a detection target.

In each of the above embodiments, the detection target of the sensor is the amount of water in the oil used in the machine, but it may be a fluid other than oil, or the characteristics of a fluid other than the amount of water may be detected. For example, the detection target may be a liquid other than oil. The liquid material is a liquid, a sol using a liquid as a medium, and is, for example, drainage, food or drink, medicine, river water, seawater, ink, detergent, or optical modeling agent. Further, the detection target may be gas. Furthermore, the sensor may measure the pressure, temperature, flow rate, liquid level, flow rate, etc. of the fluid, may measure the presence or absence of a specific contained substance, and the concentration of the contained substance. The substance may be specified. The detection method of the sensor may be a method other than the capacitance type, and is selected depending on the measurement object or the like. Moreover, the material of the member which comprises a sensor is selected according to a measuring object.

The above explanation is intended to be illustrative and not restrictive. For example, the above-described embodiments (or one or more aspects thereof) may be used in combination with each other. Other embodiments may be used by those skilled in the art, etc. by reviewing the above description. Also, in the above detailed description, various features may be grouped together to simplify the disclosure. This should not be interpreted as intending that an unclaimed disclosed feature is essential to any claim. Rather, the subject matter of the invention may reside in fewer than all features of a particular disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment. The scope of the invention should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

DESCRIPTION OF SYMBOLS 10 ... Sensor, 11 ... Housing, 12 ... Cover, 13 ... Large diameter part, 14 ... Small diameter part, 15 ... Fastening part, 16 ... 1st screwing part, 17 ... 2nd screwing part, 18 ... Connection part, 18a DESCRIPTION OF SYMBOLS ... End face, 19 ... Notification part, 19a-19c ... Lamp, 20 ... Detection element as detection part, 21 ... Pin, 22 ... Side wall part as wall part in which end part introduction hole was formed, 23 ... Open end, 24 ... 1st introduction hole as end part introduction hole, 25 ... Perimeter wall part, 26 ... 2nd introduction hole, 26a ... 2nd introduction hole, 26b ... 2nd introduction hole, 27 ... Cover screwing part, 30 ... Substrate, 31 ... 1st electrode, 32 ... 2nd electrode, 33 ... Sensitive membrane, 34 ... 1st electrode terminal, 35 ... 2nd electrode terminal, 40 ... Rectification part, 100 ... Mounted object, 101 ... Insertion hole, 102 ... As fluid Oil, L1 ... first introduction hole row, L2 ... second introduction hole row, L3 ... third introduction hole row, L4 ... fourth guide Row of holes.

Claims

A detector for detecting the characteristics of the fluid;
A cylindrical cover that houses the detection unit inside,
The cover has a plurality of introduction holes smaller than the size of the detection unit, and the introduction holes are formed around the central axis of the cover at positions that do not face each other with the central axis in between. Sensor.
The sensor according to claim 1, wherein at least a part of the plurality of introduction holes is provided at a position facing the detection unit.
The cover has a plurality of introduction hole rows each consisting of a plurality of introduction holes that are a part of the introduction holes,
The sensor according to claim 1 or 2, wherein the introduction hole of each introduction hole row is different in arrangement in the circumferential direction of the cover from the introduction hole of the adjacent introduction hole row.
The cover has a plurality of introduction hole rows each consisting of a plurality of introduction holes that are a part of the introduction holes,
The sensor according to claim 1 or 2, wherein the introduction hole of each introduction hole row is different in arrangement in the circumferential direction of the cover from introduction holes of other introduction hole rows.
The sensor according to claim 1 or 2, wherein the introduction holes are arranged in a spiral from one end portion to the other end portion in the axial direction of the cover.
The cover has a plurality of introduction hole rows each consisting of a plurality of introduction holes that are a part of the introduction holes,
The sensor according to any one of claims 1 to 5, wherein an interval between adjacent pairs of the introduction holes of each introduction hole row is different from each other.
A wall portion is provided at one end portion in the axial direction of the cover, and an end portion introduction hole for taking a fluid into the inside of the cover is formed in the wall portion. The sensor according to claim 1.
The detection unit includes a first electrode, a second electrode disposed opposite to the first electrode and transmitting water molecules, and a sensitive film sandwiched between the first electrode and the second electrode. The detection unit detects the amount of water contained in the fluid based on a change in capacitance caused by the sensitive film adsorbing and desorbing water molecules that have passed through the second electrode. The sensor according to any one of claims.
A detector for detecting the characteristics of the fluid;
A cylindrical cover that houses the detection unit;
The cover has a plurality of introduction holes smaller than the size of the detection unit, and each of the introduction holes is located around the central axis of the cover and is provided in another one of the introduction holes. The two introduction holes facing each other have different inner diameters.