JP3179959B2 - Liquid level detector and liquid level detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid level detecting device and a liquid level detecting device for detecting a liquid level for judging an amount of lubricating oil for an engine or a transmission, for example.

[0002]

2. Description of the Related Art Conventionally, as a liquid level detecting device for detecting a liquid level for judging an amount of lubricating oil of an engine or a transmission of an automobile, for example, those shown in FIGS. 8 and 9 are known.

The liquid level detecting device shown in FIGS. 8 and 9 has a resilient metal wire connected to the other end of a metal wire gripping portion 41 bent in a ring shape so that a finger can be hooked on one end. A connecting section 42 is attached, and a connecting section 42 has a detecting section 43 provided at the tip of the connecting section 42 in the form of a flat metal plate with a scale 43a on one surface.

The liquid level detecting device 44 has a positioning means 45 between the grip portion 41 and the connection portion 42. The positioning means 45 is provided on one end surface of the substantially cylindrical shape in the axial direction of the grip portion 41. A body part 47 having a contact surface 46 substantially perpendicular to the body part 47;
A seal portion 48 having a wavy cross section is integrally formed on the contact surface 46 thereof with rubber, and is fitted and fixed to the grip portion 41.

[0005] On the other hand, reference numeral 50 denotes an oil pan.
Has an outlet 51 for accommodating an oil 51 for an engine or an automatic transmission therein, and is bent upward from one side and led out.The outlet 52 has an inspection port 53 at an upper end, and a lower end. Are formed in a continuous tubular shape in the oil pan 50.

[0006] Then, the liquid level detecting device 44 is inserted into the oil pan 50 from the inspection port 53 through the outlet pipe 52 through the inspection port 53 to immerse the tip portion in the oil 51, and the seal part 48 is connected to the outlet pipe 52. A liquid-tight abutment on the inner peripheral surface near the upper end of the body, abutting the abutment surface 46 of the body 47 against the periphery of the inspection port 53 at the upper end of the outlet pipe 52,
It is supported by the outlet pipe 52.

When measuring the amount of oil 51,
The liquid level detection device 44 supported by the outlet pipe 52 is pulled out by hooking a finger on the annular portion of the grip portion 41, and the extracted detection portion 43 wet with the oil 51 is wiped off once with a piece of cloth,
The liquid level detecting device 44 is again moved to the oil pan 50 until the contact surface 46 of the positioning means 45 contacts the upper end edge of the outlet pipe 52.
Insert into. Then, the liquid level detection device 44 is pulled out again, and the boundary line of the detection unit 43 wet with the oil 51 is detected by the detection unit 43.
The amount of oil 51 is determined by comparing the level of oil 51 in oil pan 50 with the scale 43a provided in 43.

[0008]

By the way, for example, when an automobile is shipped, when measuring the amount of the oil 51, the position of the boundary line wetted by the oil 51 of the detecting unit 43 is provided with a scale of mm unit. Confirmed by measuring with a measuring instrument such as a ruler.

For this reason, when measuring the amount of oil 51 with the above-mentioned conventional liquid level detecting device 44, the liquid level detecting device 44 must be inserted and removed twice, which makes the measuring operation complicated and reduces the oil level. When measuring the boundary line wet with 51 with a ruler, the boundary line is not clear because the oil 51 has a relatively small surface tension, and the detection unit 43 is derived when the liquid level detection device 44 is pulled out There is a problem that the boundary line bleeds due to contact with the inside of the tube 52, and an error easily occurs in the measurement in the unit of mm.

Further, since the length of the outlet pipe 52 differs depending on the type of vehicle, the liquid level detecting device 44 corresponding to each outlet pipe 52 is provided.
However, there is a problem that versatility is low.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a liquid level detecting device and a liquid level detecting device which can easily measure the liquid level and have high versatility. is there.

[0012]

According to a first aspect of the present invention, there is provided a liquid level detecting device capable of storing a liquid having a dielectric property, and having a front-end flow hole and a base-end flow hole for gas-liquid exchange at a front end and a base end. A liquid surface to be inserted into the liquid, comprising: a formed cylindrical external electrode; and a long internal electrode provided along the axial direction in the external electrode via an insulating gap with respect to the external electrode. A sensor, a longitudinal grip connected to the liquid level sensor, and sliding on the grip along the longitudinal direction of the grip.
Capable provided is obtained by and a positioning means for setting a position of the liquid level sensor to a predetermined position.

According to a second aspect of the present invention, there is provided a liquid level detecting device.
In the liquid level detecting apparatus according grip portion is for the liquid level sensor is connected via a connecting portion of the tubular having <br/> elasticity.

According to a third aspect of the present invention, there is provided a liquid level detecting device.
Or a power supply means for applying an AC voltage between an external electrode and an internal electrode of the liquid level sensor, and a static electricity between the external electrode and the internal electrode based on the voltage applied by the power supply means. The apparatus comprises a capacitance detecting means for detecting a capacitance, and a liquid level detecting means for detecting a liquid level based on the capacitance detected by the capacitance detecting means.

The liquid level detecting apparatus according to claim 4, wherein the claim 3
In the liquid level detecting device described in the above, a temperature detecting means attached near the liquid level sensor for detecting the temperature of the liquid, and a liquid level detected by the liquid level detecting means based on the temperature of the liquid level detected by the temperature detecting means And temperature correction means for correcting

[0016]

[Action] fluid level sensing apparatus of claim 1, wherein the longitudinal direction of the grip portion of the liquid surface sensor connected to the elongated gripping portion in the liquid
The liquid is inserted into a predetermined position by positioning means slidably moving along , and the liquid flows in the axial direction in the cylindrical external electrode by the gas-liquid exchange front and rear circulation holes provided in the cylindrical external electrode. It is housed in an insulating gap with the longitudinal internal electrode provided along, and the capacitance changes according to the position of the liquid between the external electrode and the internal electrode, and the potential changes. By measuring this potential, Since the liquid level can be detected, the liquid level sensor can be easily detected in a short time and with high accuracy simply by inserting the liquid level sensor into the liquid so as to be at a predetermined position by the positioning means. In addition, the positioning means may be a long grip.
The positioning means is slidable along the hand direction.
Just slide and move the liquid level regardless of the liquid level detection point.
Detection can be performed easily and with high accuracy, and versatility is improved.

According to a second aspect of the present invention, there is provided a liquid level detecting device according to the first aspect.
In the liquid level detection device according to the above, since the liquid level sensor is connected to the grip portion via a tubular connection having elasticity, for example, even when the liquid level detection portion is bent, the connection portion is bent at the liquid level detection portion. And the liquid level sensor can be easily detected in a short time with high accuracy by simply inserting the liquid level sensor into the liquid so as to be at a predetermined position by the positioning means. In addition, since the connecting portion is tubular, for example, when processing the lead wire of the liquid level sensor, the lead wire can be arranged in the connecting portion, and the lead wire is not exposed, such as friction or bending of the liquid level detecting portion. damage of the lead wire due to the Ru is prevented.

According to a third aspect of the present invention, there is provided a liquid level detecting device according to the first or second aspect, wherein the liquid level sensor is inserted into the liquid, and a power supply means is provided between the external electrode and the internal electrode of the liquid level sensor. AC voltage is applied to the power supply, and the capacitance between the external electrode and the internal electrode is detected by the capacitance detection means based on the voltage applied by the power supply means, and the capacitance detected by the capacitance detection means is applied. The liquid level is detected by the liquid level detection means based on the sensor, so the liquid level sensor can be detected easily and in a short time with high accuracy simply by inserting the liquid level sensor into the liquid so that it is at the predetermined position by the positioning means. Becomes

According to a fourth aspect of the present invention, there is provided a liquid level detecting apparatus according to the third aspect.
In the liquid level detection device described above, the temperature of the liquid is detected by temperature detection means attached near the liquid level sensor, and based on the temperature of the liquid surface detected by the temperature detection means, the temperature is corrected by the liquid level detection means. Since the detected liquid level is corrected, even if the dielectric constant of the liquid changes depending on the temperature, the liquid level position can be easily detected with high accuracy in a short time.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The construction of an embodiment of the liquid level detecting device of the present invention will be described below with reference to the drawings.

In FIG. 5, reference numeral 1 denotes an oil pan provided at a lower portion of, for example, an engine of an automobile.
Is made of metal and is formed in a substantially box shape, and accommodates therein a liquid oil 2 having a dielectric property for an engine or an automatic transmission. On one side surface of the oil pan 1, a lead-out pipe 3 is formed so as to be bent obliquely upward so as not to interfere with other parts of the engine compartment of the automobile (not shown). The outlet pipe 3 is formed in a tubular shape in which an inspection port 4 is opened at an upper end and a lower end is continuous in the oil pan 1.

On the other hand, reference numeral 6 denotes a main body of the liquid level detecting device. As shown in FIGS. 1 to 5, the main body 6 of the liquid level detecting device is made of, for example, synthetic resin or hard rubber and has an insertion hole (not shown) at the center axis. It has a cylindrical grip 7 provided. And
Position scales 8 are provided at predetermined intervals along the axial direction on the outer peripheral surface of the grip portion 7.

A cylindrical positioning means 10 made of, for example, a synthetic resin or rubber is slidably fitted to the grip portion 7. The positioning means 10 has one end face in the axial direction. A contact surface 11 substantially perpendicular to the axial direction is formed.

Further, an elastic tubular connecting portion 12 such as a metal spiral flexible tube or a heat-resistant synthetic resin flexible tube is fitted in the holding portion 7, and one end of the connecting portion 12 is fitted into an insertion hole of the holding portion 7. Fixed and connected.

Further, a liquid level sensor 13 is provided at the tip end of the connection portion 12.

The liquid level sensor 13 is shown in FIGS.
As shown in FIG. 3, the external electrode 15 is formed in an elongated cylindrical shape with a conductive material such as brass or an aluminum alloy. The external electrode 15 has a plurality of base end flow holes 16a and a plurality of front end flow holes 16b in the vicinity of the base end and the end in the axial direction, each having a circular shape having a diameter of, for example, about 2 mm, through which the oil 2 can flow. Note that these distal flow holes 16b and proximal flow holes 16b
In 16a, the oil 2 can flow and gas-liquid exchange is possible, and the oil 2 enters the external electrode 15.

On the other hand, on the outer peripheral surface of the external electrode 15, there are provided liquid level inspection visual scales 17 on which scales are marked at substantially equal intervals along the axial direction. Further, on the inner peripheral surface side of the external electrode 15, annular fixing portions 18a, 18b made of a material such as insulating synthetic resin or rubber are provided near both ends in the axial direction.

Reference numeral 20 denotes an internal electrode.
Is formed of the same material as the external electrode 15 in the shape of an elongated cylinder smaller in diameter than the external electrode 15. And this internal electrode 20
Both ends are fitted and fixed to the inner periphery of the fixing portions 18a and 18b provided on the outer electrode 15, and the outer peripheral surface is coaxially positioned within the outer electrode 15 through the insulating gap 21 with the inner peripheral surface of the outer electrode 15. Fixed.

Further, a connecting member 22 made of an insulating material such as a synthetic resin or hard rubber and formed in a cylindrical shape is provided on the fixing portion 18a on the base end side. The connection portion 12 is fitted and fixed to the inner peripheral surface side of the connection member 22, and the liquid level sensor 13 is provided at the tip of the connection portion 12 via the connection member 22.

At the tip of the liquid level sensor 13, a temperature detecting means 24 such as a thermocouple or a thermistor is provided on the outer surface of the fixed portion 18b on the tip side. Around the temperature detecting means 24, a protective cap 25 formed in a hemispherical shape with a synthetic resin, hard rubber, or the like is mixed and fixed to the peripheral edge of the external electrode 15 so as to cover the temperature detecting means 24. Is provided. The protective cap 25 has a diameter of, for example, 2 mm.
A plurality of inflow holes 26 having a circular shape into which the oil 2 can flow and gas-liquid exchange can be performed.

The inner peripheral surface of the end of the liquid level sensor 13 on the side of the connection portion 12 of the external electrode 15 and the outer peripheral surface of the end of the internal electrode 20 on the side of the connection portion 12 are provided with through holes for the grip portion 7. Lead wires 27 each composed of a pair of shield wires 28 wired through the inside of the connection portion 12 are connected by soldering or the like. Further, an electric wire 29 wired through the insertion hole of the grip part 7, the connection part 12, and the inside of the internal electrode 20 is connected to the temperature detection means 24.

Further, the grip 7 of the lead wire 27 and the electric wire 29
Connectors (not shown) are provided at the ends on the side extending from the ends of the connectors, and these connectors are connected to the control device 31. Then, the liquid level detecting device 30 is configured by connecting the liquid level detecting device body 6 to the control device 31.

On the other hand, the control device 31 has functions as a power supply unit, a capacitance detection unit, a liquid level detection unit, and a temperature correction unit, and as shown in FIG.
singUnit), and the control circuit 3
2 and an A / D converter 33 (analog-digital converter).

A display unit 34 is connected to the control circuit 32. The display unit 34, as shown in FIGS.
The control circuit 32 displays the result of processing the electric potential of the capacitance between the external electrode 15 and the internal electrode 20 and the electric signal from the temperature detecting means 24 by the control circuit 32 connected through the connector. The display unit 34 is, for example, a bar display type liquid level display unit 34a composed of a plurality of light emitting diodes, and a numerical display type liquid level display unit using liquid crystal.
34b, and a temperature display section 34c for numerically displaying the temperature of the oil 2 by liquid crystal is provided. The processed data may be processed / stored by the arithmetic storage device 36 such as a personal computer connected via the interface 35 (RS232C) to process and store a plurality of results measured by the liquid level detecting device body 6. It is possible.

Next, the operation of the above embodiment will be described.

For example, when inspecting the amount of oil 2 in various inspections before shipment of a car (not shown), first, the fixing means (not shown) is operated to move the positioning means 10 along the axial direction of the grip portion 7, and the inspection is performed. Gripper 7 corresponding to the type of vehicle
The abutment surface 11 is aligned with a predetermined position scale 8 provided on the outer peripheral surface of. That is, the positioning means 10 is slid by operating the fixing means so that the length from the contact surface 11 to the tip of the protective cap 25 becomes a predetermined length, and the positioning means 10 is positioned and fixed at a predetermined position.

Then, the liquid level detecting device main body 6 is connected to the control device 31 to which the commercial AC power supply 37 is supplied, and a power switch (not shown) of the control device 31 is closed. When the power switch is closed, a constant frequency AC voltage is applied from the control device 31 to the external electrode 15 via the lead wire 27.

Next, the liquid level sensor main body 6 connected to the control device 31 is inserted with the liquid level sensor 13 from the inspection port 4 through the outlet pipe 3, and the contact surface 11 is formed on the periphery of the inspection port 4. Insert it until it comes into contact with the upper end of the outlet pipe 3. During this insertion, since the connecting portion 12 has elasticity, the connecting portion 12 bends in accordance with the bending of the bent outgoing pipe 3, and the liquid level sensor 13 is inserted into the oil pan 1 and immersed in the oil 2.

The immersion of the liquid level sensor 13 causes the air or the like in the insulating gap 21 between the external electrode 15 and the internal electrode 20 to pass through the proximal end communication hole 16a on the proximal side with the connection portion 12 of the external electrode 15. Is discharged, and the oil 2 penetrates into the insulating gap 21 through the distal end flow hole 16b on the distal end side of the external electrode 15. Further, the oil 2 flows into the protection cap 25 provided at the tip of the liquid level sensor 13 through the inflow hole 26.

Then, the temperature of the oil 2 is detected by the temperature detecting means 24 provided in the protective cap 25, and the detected predetermined electric signal is transmitted via the electric wire 29 to the control device 31.
Is transmitted to Furthermore, the oil 2 that has entered between the external electrode 15 and the internal electrode 20 causes the external electrode 15 and the internal electrode 20 to move.
The potential of the capacitance due to the dielectric constant therebetween is transmitted to the control device 31 via the lead wire 27.

The potential of the capacitance from the liquid level sensor 13 is temperature-corrected by the control circuit 32 of the control device 31 by the electric signal from the temperature detecting means 24, and the electric signal of the temperature detecting means 24 and the temperature correction The displayed potential of the capacitance is displayed on the display unit 34, is converted into a digital signal by the A / D converter 33, and is transmitted to the operation storage device 36 via the interface 35. Make a record.

Since the dielectric constant of the oil 2 changes due to the temperature change, the potential of the capacitance changes. For this reason,
The potential of the capacitance is corrected for temperature.

Next, the result of measuring the liquid level using the liquid level detecting device main body 6 in which the flow hole 16 having a diameter of about 2 mm is provided in the liquid level sensor 13 will be described with reference to FIG. .

In FIG. 7, the vertical axis indicates the potential of the capacitance, and the horizontal axis indicates the liquid level position in the oil pan 1. The measurement was performed at an outside air temperature of about 23 ° C.

Then, the measurement is performed by checking the liquid level sensor 13 with the inspection port 4.
Inserted from the liquid level position at the time the contact surface 11 is in contact with the upper edge of the outlet pipe 3, the liquid level position after 3 seconds from the contact surface 11 abuts the upper edge of the outlet pipe 3 And the liquid surface position 10 seconds after the contact surface 11 came into contact with the upper end edge of the outlet pipe 3 was measured and compared.

From the results shown in FIG. 7, it can be seen that the liquid level can be measured immediately if the flow hole is an opening having a diameter of about 2 mm, and that the measurement can be easily performed in a short time. Furthermore, the measurement result after 3 seconds and the measurement result after 10 seconds are almost the same, and it is understood that the liquid level position can be measured with high accuracy down to the millimeter unit by immersing the liquid level sensor 13 in the oil 2 for 3 seconds or more. . In order to efficiently and easily obtain a highly accurate measurement result of the liquid surface position in a short time in an inspection at the time of shipping of an automobile or the like, the diameter of the opening of the front end circulation hole 16b may be further increased.

In the above embodiment, an elastic tubular connecting portion 12 protrudes from the gripping portion 7 provided with the positioning means 10 slidably in the axial direction from the contact surface 11 provided on the end face of the positioning means 10. A liquid level sensor 13 is provided at the tip of the connecting portion 12, and the connecting portion 12 corresponding to the bending of the outlet pipe 3 is kept until the contact surface 11 of the positioning means 10 contacts the inspection port 4 of the outlet pipe 3. The liquid level sensor 13 is inserted into the oil pan 1 from the inspection port 4 through the outlet pipe 3 while being bent, and is immersed in the oil 2 stored in the oil pan 1.

Then, by immersing the liquid level sensor 13,
Oil 2 penetrates into the insulating gap 21 between the external electrode 15 and the cylindrical internal electrode 20 housed coaxially with the external electrode 15 through the front end circulation hole 16b of the cylindrical external electrode 15 of the liquid level sensor 13. The potential changes because the capacitance changes due to the amount of oil between the external electrode 15 and the internal electrode 20 due to the constant frequency AC voltage applied to the external electrode 15, and the potential changes from the internal electrode 20 to the connection portion 12. It is detected through the provided lead wire 27. Further, the temperature of the oil 2 is detected by the temperature detecting means 24 provided at the tip of the liquid level sensor 13 via the electric wire 29 disposed inside the connecting portion 12 and the internal electrode 20. The change in the capacitance due to the change in the dielectric constant caused by the above is corrected by the control device 31, and the corrected potential is displayed on the display unit 34 as the liquid level in the oil pan 1 so that the liquid level can be measured.

That is, for example, the dielectric constant of the oil 2 changes due to a change in temperature, the capacitance changes, and the potential changes. Therefore, the potential of the capacitance is corrected by the temperature detected by the temperature detecting means 24. By doing so, a highly accurate liquid level position can be detected.

On the other hand, since the connecting tube 12 is tubular with elasticity, the lead wire 27 and the electric wire 29 can be accommodated inside and the appearance is not impaired by being exposed to the outside of the connecting portion 12.
Lead wire due to friction when connecting part 12 is inserted into outlet pipe 3
27 and the electric wire 29 can be prevented from being damaged. Furthermore, the outflow pipe 3
Since the connecting portion 12 bends in accordance with the bending of the lead tube 3, the measurement can be performed regardless of the bending state of the outlet tube 3. Further, only by inserting the liquid level sensor 13, it is possible to easily measure the liquid level position with high accuracy in a short time by the electric potential of the capacitance of the liquid level sensor 13.

Further, the positioning means 10 is provided with an abutment surface 11, and this positioning means 10
Slidable along the axial direction of the
The liquid level can be easily measured with high accuracy even when the shapes of the oil pan 1 and the outlet pipe 3 are different by simply sliding the 10, so that the versatility can be improved.

In the above embodiment, the positioning means
A switch is provided on the contact surface 11 of 10 so that when the liquid surface is detected, the switch is closed when the contact surface 11 comes into contact with the upper edge of the outlet pipe 3 so that the liquid surface is detected. Is also good. By providing the switch in this manner, the contact surface 11 serving as the reference surface surely comes into contact with the upper end edge of the outlet pipe 3 that opens the inspection port 4, and the position of the liquid surface can be easily measured with high accuracy.

A hose through which compressed air is introduced is connected to the end of the grip 7 on the side opposite to the side where the connecting portion 12 protrudes, and the operation means provided on the grip 7 allows the hose to enter the grip 7. Opening the disposed valve element, blowing compressed air into the insulating gap 21 between the external electrode 15 and the internal electrode 20 of the liquid level sensor 13, and blowing out a conductive liquid such as oil 2 remaining in the insulating gap 21. ,
It may be possible to promptly move to the detection of the next liquid level.

Further, the control device 31 is arranged on the vehicle so that the display unit 34 is located on the panel surface of the driver's seat so that the user can always confirm the position of the liquid level from the driver's seat. In order to check the state of the oil 2 at the time of maintenance and inspection, the liquid level detection device main body 6 is pulled out of the discharge tube 3 when the product is shipped with the liquid level detection device main body 6 attached to the discharge pipe 3.
Oil 2 adhering to the outer peripheral surface of the external electrode 15 of the liquid level sensor 13
May be observed.

When the liquid level detecting device main body 6 is mounted on the automobile as described above, the diameter of the front end flow hole 16b is reduced because the liquid level changes due to the vibration of the liquid level of the oil 2 in the external electrode 15. Then, the flow resistance of the oil 2 is increased to stabilize the liquid level of the oil 2, and the oil level is prevented from fluctuating rapidly due to the liquid level moving up and down due to vibrations during driving of the automobile. 2 is preferably formed so as to have a small diameter such that it can flow into the insulating gap 21, for example, a diameter of 2 mm or less.

[0056]

According to the liquid level detecting device of the first aspect,
The liquid level sensor is inserted in place in the liquid by slidable positioning means along the longitudinal direction of the elongate gripping portion,
The liquid is stored in an insulating gap between the internal electrode and the internal electrode in the external electrode, and the liquid level sensor is positioned at a predetermined position by the positioning means to detect the liquid level by measuring the capacitance between the external electrode and the internal electrode. The liquid surface position can be easily detected in a short time with high accuracy simply by inserting the liquid level into the liquid. In addition, long positioning means
Slidable along the longitudinal direction of the hand-shaped grip
Only by sliding the positioning means.
The liquid level can be detected easily and with high accuracy regardless of the location.
Usability can be improved.

According to the liquid level detecting device of the second aspect, in the liquid level detecting device of the first aspect, the liquid level sensor is connected to the grip portion via the elastic tubular connecting portion.
For example, even when the detection part of the liquid level is bent, the connection part is bent in correspondence with the bending of the detection part of the liquid level, and the liquid level sensor is simply inserted into the liquid so as to be at a predetermined position by the positioning means. Thus, the liquid level can be easily detected in a short time with high accuracy. In addition, since the connection portion is tubular, a lead wire for transmitting the potential of the capacitance between the external electrode and the internal electrode can be disposed in the connection portion, and the lead wire is not exposed, so that the friction at the liquid level detection point can be reduced. Ru prevents <br/> damage leads due bending.

According to a third aspect of the present invention, there is provided a liquid level detecting apparatus according to the first or second aspect, wherein the liquid level sensor is inserted into the liquid. An AC voltage is applied between the electrodes, and the capacitance between the external electrode and the internal electrode is detected by the capacitance detecting means based on the voltage applied by the power supply means. Since the liquid level is detected by the liquid level detecting means based on the electric capacity, the liquid level sensor can be easily and accurately detected in a short time simply by inserting the liquid level sensor into the liquid so as to be at a predetermined position by the positioning means. Can be detected.

According to a fourth aspect of the present invention, there is provided a liquid level detecting apparatus according to the third aspect.
In the liquid level detecting device described above, the temperature of the liquid is detected by the temperature detecting means, and the liquid level detected by the liquid level detecting means is corrected by the temperature correcting means based on the temperature of the liquid level detected by the temperature detecting means. The liquid surface position can be detected easily and in a short time with high accuracy.

[Brief description of the drawings]

FIG. 1 is a plan view showing a liquid level detecting device according to an embodiment of the present invention, with a part thereof being omitted.

FIG. 2 is a plan view showing the vicinity of a liquid level sensor according to the first embodiment.

FIG. 3 is a sectional view of the same.

FIG. 4 is a front view of the same.

FIG. 5 is an explanatory diagram showing a usage state of the liquid level detection device main body.

FIG. 6 is a block diagram showing a control device of the same.

FIG. 7 is a graph showing the results of the measurement.

FIG. 8 is a partially cutaway plan view showing one embodiment of a conventional liquid level detection device.

FIG. 9 is an explanatory diagram showing a usage state of the liquid level detection device main body.

[Explanation of symbols]

 2 Liquid oil 6 Liquid level detector main body 7 Grasping part 10 Positioning means 12 Connecting part 13 Liquid level sensor 15 External electrode 16a Base flow hole 16b Tip flow hole 20 Internal electrode 21 Insulation gap 24 Temperature detection means 30 Liquid level detection apparatus

Continued on the front page (72) Inventor Masato Omura 300 Takatsukacho, Hamamatsu-shi, Shizuoka Suzuki Co., Ltd. (72) Inventor Mamoru Itoh 300 Takatsukacho, Hamamatsu-shi, Shizuoka Suzuki Co., Ltd. (72) Inventor Kurita Ryosuke 300 Takatsukacho, Hamamatsu-shi, Shizuoka Suzuki Corporation (72) Inventor Masataka Tsuboi 1195 Kanda-cho, Hamamatsu-shi, Shizuoka Hamamatsu Trading Co., Ltd. (72) Mitsuo Yamamoto 500 Furukawacho, Hamamatsu-shi, Shizuoka Co., Ltd. Somic Ishikawa Hamamatsu Plant (56) References JP-A-63-157018 (JP, A) JP-A-56-64619 (JP, A) Fully open 57-166128 (JP, U) Really open 63-93519 (JP, U) JP, U) Hikaru Hei 4-102435 (JP, U) (58) Fields surveyed (Int. Cl. ⁷ , DB name) G01F 23/04 G01F 23/26

Claims (4)

(57) [Claims] 1. A cylindrical external electrode capable of accommodating a liquid having a dielectric property and having a front end and a base end formed with a front end flow hole and a base end flow hole for gas-liquid exchange, and A liquid level sensor provided with a longitudinal internal electrode provided along the axial direction in the external electrode via an insulating gap, and a liquid level sensor inserted into the liquid; and a longitudinal grip connected to the liquid level sensor And a positioning means provided on the gripper so as to be slidable along the longitudinal direction of the gripper and for setting the position of the liquid level sensor at a predetermined position. Liquid level detection device. Wherein gripper, the liquid level sensor is a liquid level sensing apparatus according to claim 1, characterized in that it is connected via the connection portion of the tubular having elasticity. 3. A liquid level detecting device according to claim 1 or 2, a power supply means for applying an AC voltage between an external electrode and an internal electrode of the liquid level sensor, and said external device based on a voltage applied by said power supply means. Capacitance detecting means for detecting a capacitance between an electrode and the internal electrode, and liquid level detecting means for detecting a liquid level based on the capacitance detected by the capacitance detecting means. Characteristic liquid level detection device. 4. A temperature detecting means mounted near the liquid level sensor for detecting the temperature of the liquid, and correcting the liquid level detected by the liquid level detecting means based on the temperature of the liquid level detected by the temperature detecting means. 4. The liquid level detecting device according to claim 3 , further comprising a temperature correcting unit.