JP2001201389A - Liquid level detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the generation of an error in a detection indicating amount to enhance detection resolution. SOLUTION: A liquid surface position of an LPG 34 in a container 60 is detected based on an electromotive force generated by a magnetic flux passing through a Hall IC 51 based on a relative positional change between a detection side magnet 46 rotated in response to the liquid surface position of the LPG 34 filled in the container 60 and the Hall IC 51 fixed to a case 31 side. The first contact point 54 is provided in a circumferential face of a contact plate 53 rotated together with the magnet 46, and the second contact point 55 and the third contact point 56 are constituted to contact with the circumferential face of the plate 53 all the time.

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 more particularly, for example, to LPG (Liquefied Petrole).
The present invention relates to a liquid level detecting device for a high-pressure liquid that is filled and filled in a container such as um Gas (liquefied petroleum gas) under high-pressure conditions.

[0002]

2. Description of the Related Art Conventionally, a liquid level detecting device for LPG has been
Since the internal pressure of the container filled with is high, a pressure-resistant structure capable of withstanding this high pressure is employed. FIG. 6 and FIG.
1 shows an LPG liquid level detection device having a pressure resistance structure.

As shown in FIG. 6, a metal base 4 which is a constituent element of a detector unit 3 is air-tightly and liquid-tightly fixed in a unit mounting hole 2 formed in an upper wall of a container 1. I have. A recess 5 is formed outside (upper side) of the base 4, and a casing 6 is accommodated and fixed in the recess 5.

The base 4 has a partition 7 for isolating the inside and outside of the container 1. An internal magnet 9 provided at the upper end of a rotary shaft 8 that is rotated by converting a vertical movement of the float into a rotational movement by a gear mechanism is disposed near a lower portion of the partition wall 7.

The casing 6 has a lower cover 10 made of metal and an insulating body 11 made of synthetic resin. A holder 12 is formed in the center of the insulating body 11. An annular groove 13 formed in the holder 12
, An annular winding plate 14 in which a resistance winding 16 is provided on an insulating ring 15 made of synthetic resin is fitted and fixed. The winding plate 14 is set to protrude downward.

A bearing pin 17 is provided upright at the center of the bottom of the lower cover 10. This bearing pin 17 has
A tubular contact shaft 20 to which the detection-side magnet 18 and the contact 19 are fixed is rotatably fitted. The contact 21 of the contact 19 is connected to the above-described winding plate 14.
Is set so as to contact the contact surface 14a on the lower surface of the.

[0007] The lower cover 10 and the insulating body 11
The claws 2 of the case holder 22 are formed at the mating flanges.
3 are caulked and joined. As described above, the casing 6 in which the lower cover 10 and the insulating body 11 are integrally assembled by the case holder 22 accommodates the lower cover 10 in the concave portion 5 of the base 4, and the detection side magnet 18 is separated from the inner magnet by the partition wall 7 as a boundary. 9 and the case holder 22
Is fixed to the base 4 by fastening the bracket piece 24 to the upper surface of the base 4.

With this configuration, the LPG liquid level detection device operates as follows. That is, the container 1
When the float (not shown) moves in the vertical direction according to the displacement of the LPG liquid level in the inside, and the vertical movement is converted into a rotational movement, the rotation shaft 8 rotates. Due to the magnetic coupling, the contact shaft 20 also rotates integrally, and the contact 21 of the contact 19 slides on the contact surface 14 a on the lower surface of the winding plate 14. As a result, the liquid level that the float follows can be converted into an electric resistance value and detected. That is, the winding plate 14 functions as a variable resistor. This electrical detection signal is output to a meter (not shown), and the meter displays the remaining LPG (filling amount) in the container 1 based on the output signal.

In FIGS. 6 and 7, reference numeral 26 designates a contact shaft 2 provided on the upper surface of the detecting magnet 18.
0 indicates a stopper for restricting the rotation of 0, and reference numeral 2
Reference numerals 7 and 28 denote sealing packings interposed between the mating surface of the case holder 22 and the insulating body 11 and the mating surface of the insulating body 11 with the dial 25 and the lower cover 10.

[0010]

However, the above-described conventional LPG liquid level detecting device has an electric resistance value correlated with the liquid level due to the contact between the resistance winding 16 wound around the insulating ring 15 and the contact 21. Is a contact-type detection device for measuring the resistance, there is a possibility that the resistance value may change over time due to wear of the contact portion. For this reason, in the conventional LPG liquid level detecting device, inspection and management were necessary in long-term use. Further, in such an LPG liquid level detecting device, there is a problem that the use of the winding plate 14 limits downsizing, and the number of parts to be assembled is large, so that the assembling work becomes complicated. Such a problem is not limited to the liquid level detecting device for LPG, and there is a similar problem in detecting the liquid level of the liquid filled and stored under other high pressure conditions.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a liquid level detecting device capable of suppressing the occurrence of a detection instruction amount error and having a small number of parts and capable of being miniaturized.

[0012]

According to the first aspect of the present invention,
A detecting magnet having a two-pole configuration and a Hall IC that relatively rotates in accordance with a liquid surface position of the liquid filled in the container, and a Hall IC; A liquid level detection device for detecting a surface position, comprising a disk-shaped contact plate provided coaxially with the detection-side magnet and rotating integrally with the detection-side magnet, and a peripheral surface of the contact plate A first contact is provided along the second contact, and a second contact and a third contact arranged in close proximity to each other and slidably in contact with the peripheral surface of the contact plate are fixed to the case side, and the first contact is attached to the first contact. When the second contact and the third contact come into contact simultaneously, the hole I
It is characterized in that a predetermined voltage is applied to C.

According to the first aspect of the present invention, since the detection-side magnet and the Hall IC relatively rotate according to the liquid level of the liquid in the container, the relative rotation is accompanied by this relative rotation. Thus, the liquid surface position can be detected by detecting a change in the electromotive force generated in the Hall IC due to the change in the magnetic flux. Further, by applying a predetermined voltage to the Hall IC when the second contact and the third contact simultaneously contact the first contact provided on the peripheral surface of the contact plate, the relative rotation angle between the detection magnet and the Hall IC is increased. Exceeds 180 °, a voltage value obtained by adding the electromotive force due to the magnetic flux passing through the Hall IC and a predetermined voltage is detected, so that a voltage different from the detection voltage when the relative rotation angle is 0 to 180 ° is detected. Will be able to

Therefore, detection can be performed in a wide range where the relative rotation angle is from 0 to 360 °. As described above, when the range of the relative rotation angle is widened, the liquid level detection device has an operation that enables detection when the amount of change in the liquid surface position of the liquid in the container is large and an operation that improves the resolution. be able to. According to the first aspect of the present invention, since the liquid level can be detected in a non-contact manner, problems such as sensor deterioration due to abrasion can be eliminated, and a highly durable liquid level detecting device can be realized.

According to a second aspect of the present invention, in the liquid level detecting device according to the first aspect, the Hall IC is fixed to the case side, and the detection side magnet and the contact plate are disposed in the liquid level position. It is characterized in that it rotates in accordance with.

Therefore, in the second aspect of the invention, in addition to the operation of the first aspect, the Hall IC is fixed to the case side, and the detection-side magnet that does not require a wiring system rotates. , Relative rotation can be easily performed.

Further, the invention according to claim 3 is the invention according to claim 1.
Or the liquid level detecting device according to claim 2, wherein the second
The range in which the contact point or the third contact point contacts the first contact point is substantially half the circumference of the contact plate.

Therefore, according to the third aspect of the present invention, in addition to the effects of the first and second aspects of the present invention, the second aspect
By making the range in which the contact point or the third contact point comes into contact with the first contact point approximately half of the circumference of the contact plate, the detection-side magnet having a two-pole configuration rotates half a turn with respect to the Hall IC (180).
), A predetermined voltage can be applied to the Hall IC.

According to a fourth aspect of the present invention, there is provided the liquid level detecting device according to any one of the second to third aspects,
The detection-side magnet and the contact plate are separated by at least a base, and a rotating shaft in a container that rotates in accordance with a liquid level position of the liquid is disposed in the container, and a container is disposed at an end of the shaft in the container. The inner magnet is fixed, and the detection-side magnet rotates with the rotation of the inner magnet of the container.

Therefore, according to the fourth aspect of the invention, in addition to the effects of the second and third aspects of the invention, the liquid level can be detected without being affected by the liquid in the container.
For this reason, the detection accuracy of the liquid level detection device can be improved.

Further, the invention described in claim 5 is the same as claim 2
The liquid level detection device according to any one of claims 1 to 4, wherein the detection-side magnet is provided integrally on one end side of the detection-side rotary shaft, and on the other end side of the detection-side rotary shaft, A rotation transmitting magnet that transmits the rotation of the in-container magnet to the detection-side rotating shaft while being opposed to the in-container magnet through the base while holding a magnetic space is fixed, and the contact plate is It is characterized by being fixed to the detection-side rotating shaft.

Therefore, according to the fifth aspect of the present invention, the detection-side magnet provided at one end of the detection-side rotary shaft and the rotation transmitting magnet provided at the other end of the detection-side rotary shaft are separated from each other. Therefore, it is possible to prevent the Hall IC disposed inside the ring of the detection-side magnet from being affected by the in-container magnet and the rotation transmitting magnet.

According to a sixth aspect of the present invention, there is provided the liquid level detecting device according to any one of the first to fifth aspects, wherein:
A pair of cores are arranged apart from each other inside the ring of the detection-side magnet, and the Hall IC is arranged between opposing end faces of the core.

Therefore, according to the sixth aspect of the invention, in addition to the effects of the first to fifth aspects, the direction of the magnetic force lines between the pair of cores is changed by the rotation of the detection-side magnet, and this change is caused. As a result, the magnetic flux passing through the Hall IC changes. The change in magnetic flux makes it possible to detect the liquid level based on the electromotive force detected by the Hall IC. Since such a change in the magnetic flux has a linear correlation with the rotational position of the detection-side magnet, it is possible to detect the liquid level position with high accuracy. This is because the relative rotation angle between the detection side magnet and the Hall IC is 180 to 36.
The same applies to the range of 0 °.

Further, the invention described in claim 7 is the first invention.
The liquid level detecting device according to any one of claims 6 to 6, wherein the container is a pressure-resistant container, and the liquid is liquefied petroleum gas.

Therefore, according to the invention described in claim 7, in addition to the effects of the inventions described in claims 1 to 6, L
The liquid level position of the PG can be safely detected by a liquid level detecting device having a simple structure.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a liquid level detecting device according to the present invention will be described in detail based on an embodiment shown in the drawings.

FIGS. 1 to 5 show an embodiment in which the liquid level detecting device according to the present invention is applied to a liquid level detecting device for LPG. FIG. 1 is an exploded perspective view of a main part of a liquid level device 30 for LPG of the present embodiment, FIG. 2 is a longitudinal sectional view of the liquid level detecting device 30 for LPG, and FIG. FIG. 4 is a circuit diagram of the liquid level detecting device 30 for LPG of the present embodiment, and FIG. 5 is a graph showing the relationship between the relative rotation angle and the detected voltage.

The liquid level detecting device 30 for LPG of the present embodiment
As shown in FIG. 2, the device is generally constituted by a lower mechanism 32 disposed in a pressure-resistant container 60 and a detection unit 33 provided outside the upper portion of the container 60.

First, the configuration of the lower mechanism 32 will be described with reference to FIG. The lower mechanism 32 includes a float 35 composed of a hollow sphere floating following the liquid surface of an LPG 34 which is a liquid contained in the container 60, a float 35 fixed to a free end, and a first gear 36 at a base end. A fixed swing rod 37, a bearing cylinder 38 whose lower end supports a first gear 36 and is fixed to the container 60 side, and a bearing cylinder 3.
A rotatable shaft 41 in which a second gear 39 meshing with the first gear 36 is rotatably fitted to the lower end 8 and fixed to the first gear 36 and an inner magnet 40 is fixed to the upper end. . The in-container magnet 40 is disposed near the inner surface of the base 61 provided on the container 60.

In the lower mechanism 32 having such a structure, the rotation shaft 36A of the first gear 36 is disposed along the horizontal direction, and the rotation shaft of the second gear 39 is coaxial with the rotation shaft 41 and extends along the vertical direction. Are located. Therefore, the swing rod 37 moves with the movement of the float 35 following the liquid level.
Is moved up and down, the rotation of the first gear 36 is converted into the rotation of the second gear 39 in the horizontal plane.

Next, the configuration of the detection unit 33 will be described with reference to FIGS. The detection unit 33 includes a detection-side rotary shaft 42 rotatably disposed on a base 61 provided on the container 60 so as to be positioned on the same axis as the in-container shaft 41 of the lower mechanism 32 described above. ing.
A lower mechanism 32 is provided below the detection-side rotary shaft 42.
The rotation transmitting magnet 43 is fixed to the in-container magnet 40 fixed to the upper end of the in-container shaft 41 via the base 61 (partition wall). The lower end of the detection-side rotary shaft 42 is rotatably supported by a bearing 31B formed on the upper plate 31A of the case 31.

On the other hand, the upper end of the detection-side rotary shaft 42
It is rotatably supported by a cover 44 described later. A disk-shaped contact plate 53 having a larger diameter than the rotation transmitting magnet 43 is coaxially fixed above the rotation transmitting magnet 43. On the peripheral surface of the contact plate 53, a first contact 54 having a fan shape is provided over a substantially half range of the circumference of the contact plate 53. The first contact 54 functions as a switch that connects the two contacts 55 and 56 when the first contact 54 contacts a second contact 55 or a third contact 56 described later. The second contact 55 functions as a positive contact, and the third contact 56 functions as a negative contact. Power is supplied from the second contact 55 and output from the third contact 56 via the first contact 54. .

A substantially disc-shaped visual scale 45 is integrally provided above the detection-side rotary shaft 42. For this reason, the visual scale plate 45 rotates together with the detection-side rotary shaft 42. Further, the visual scale plate 45 includes a side plate 45 that hangs down along the periphery.
A. Then, as shown in FIGS. 1 and 2,
On an outer surface of the side plate 45A, a numerical display portion 45B indicating the remaining amount of the LPG 34 is written. Further, a ring-shaped two-pole detection-side magnet 46 is fixed inside the side plate 45A of the visual scale 45 as shown in FIGS. That is, when the rotation transmitting magnet 43 is rotated by the action of the magnet 40 in the container, the detection-side magnet 46 rotates the detection-side rotating shaft 42 and the scale 45 for visual observation.

By the way, a cylindrical support base 47 protrudes upward around a bearing 31B formed on the upper plate 31A of the case 31. The above-described rotation transmitting magnet 43 is accommodated in a concave portion 48 formed by the supporting base 47 and the upper plate 31A. As shown in FIGS. 1 and 3, the second contact 55 and the third contact 56 are disposed on the inner wall surface of the support base 47 such that the free end contacts the peripheral surface of the contact plate 53. The base ends are fixed by screws or the like so that the free ends are close to each other. The second contact 55 and the third contact 56 are respectively connected to a voltage application circuit 57 as shown in FIG.
It is connected to the.

A dish-shaped core base 49 is placed and fixed on the support base 47. On the core base 49, a pair of cores 50, 50 made of a ferromagnetic material having a fan shape are fixed at predetermined intervals.

A Hall IC 51 is arranged and fixed between the opposing end faces of the cores 50, 50. The Hall IC 51 is formed by integrating a Hall element, an amplifier, a processor, and the like into a silicon chip, and in this embodiment, a packaged one is used. The plurality of terminals 51A of the Hall IC 51 are led out below the core base 49, are appropriately wired, and are connected to a voltage detection circuit of a voltage detector 58 and a power supply circuit 59 as shown in FIG. The cores 50, 50 arranged and fixed in this way are connected to the ring-shaped detection-side magnet 46.
It is set to be located inside.

The core base 49 and the cores 50, 50
, The detection side rotating shaft 42 penetrates rotatably. That is, an opening 49 </ b> A having a diameter larger than the diameter of the shaft 42 is opened in the center of the core base 49.

Finally, these components are covered with a container-shaped cover 44 made of a transparent material as shown in FIGS. At the center of the lower surface of the top plate 44A of the cover 44, a bearing portion 44B that rotatably supports the upper end of the detection-side rotating shaft 42 is formed. Also,
The lower edge of the cover 44 is fixed to the upper plate 31 </ b> A of the case 31. Also, at a predetermined position on the side surface of the cover 44,
An outwardly swelling lens portion 44C is formed to make it easier to see the numerical value display portion 45B written on the outer surface of the side plate 45A of the visual scale 45. Also, the lens unit 44C
Below, a pointer sticker 52 is affixed, which serves as a reference when viewing the numerical value display portion 45B.

The configuration of the LPG liquid level detecting device 30 of the present embodiment has been described above. Next, the operation and operation of the device 30 will be described.

First, as shown in FIG. 2, when the float 35 floating on the surface of the LPG 34 filled in the container 60 moves up and down following the liquid level, the swing rod 37 moves the shaft 36A of the first gear 36. The first gear 36
Is rotated. At this time, the second gear meshing with the first gear 36
The rotation is transmitted to the gear 39, and the up-and-down movement is converted into a rotational movement. Then, as the second gear 39 rotates, the in-container rotation shaft 41 rotates in a predetermined rotation direction. Along with this, the in-container magnet 40 fixed to the upper end of the in-container rotation shaft 41 also rotates in the same rotation direction.

On the detection unit 33 side, the rotation transmitting magnet 43 facing the in-container magnet 40 via the base 61 with the rotation of the in-container magnet 40 described above.
Rotates integrally with the in-container magnet 40, and at the same time, the detection-side rotating shaft 42, the visual scale plate 45, and the detection-side magnet 46 rotate. For this reason, the numerical value display part 45B visually recognized from the lens part 44C of the cover 44 also rotates, and it becomes possible to recognize the remaining amount of the LPG 34 in the container 60.

The rotation of the detection magnet 46 causes a pair of cores 50, 5 fixed to the case 31 side.
The magnetic flux passing through 0 changes. Therefore, the cores 50, 50
The magnetic flux passing through the Hall IC 51 arranged and fixed between the end faces also changes, and the Hall electromotive force detected by the Hall IC 51 changes. The liquid level (liquid level) can be detected from the magnitude of the electromotive force output from the Hall IC 51, and the remaining amount of the LPG 34 can be known.

When the relative angle between the detection magnet 46 and the Hall IC 51 exceeds 180 °, the detected electromotive force normally changes in the opposite direction from the change from 0 ° to 180 ° (dotted line in FIG. 5). However, in the present embodiment, the second contact 55 and the third contact 56 are set to contact the first contact 54 when the relative angle exceeds 180 °. Therefore, as shown in FIG. 4, the voltage application circuit 57 is turned on, and a predetermined voltage V2 is applied to the Hall IC 51. As a result, in the voltage detector 58, the electromotive force V1 detected by the Hall IC 51 by the Hall effect and the voltage V2
And the voltage value (V1 + V2) is added (see FIG. 5). For this reason, the detection side magnet 46
Detection in a rotation range of less than 360 ° is possible, and detection accuracy is improved by improving resolution.

Although the embodiments have been described above, the present invention is not limited to the embodiments, and various changes accompanying the gist of the configuration are possible. For example, in the above-described embodiment, the present invention has been described as applied to the liquid level detecting device for LPG, but the present invention is applied to various liquid level detecting devices for detecting the liquid level of the liquid sealed and filled in the container under high pressure conditions. The invention can be applied.

In the above embodiment, the second contact 5
Although the fifth contact point and the third contact point are arranged to be shifted in the circumferential direction of the inner wall surface of the support base 47, a configuration may be employed in which they are electrically separated from each other vertically at the same position in the circumferential direction.

[0047]

As is apparent from the above description, according to the first aspect of the present invention, the detecting magnet and the Hall IC are provided.
When the relative rotation angle with respect to
Since the voltage value is obtained by adding the electromotive force due to the magnetic flux passing through C and the predetermined voltage, it is possible to detect a voltage different from the detection voltage when the relative rotation angle is from 0 to 180 °. Therefore, according to the first aspect of the present invention, there is an effect that detection can be performed in a wide range of relative rotation angles from 0 to 360 °. As described above, when the range of the relative rotation angle is widened, the liquid level detection device has an effect of enabling detection when the amount of change in the liquid level of the liquid in the container is large and an effect of improving the resolution. Can be done. Further, since non-contact detection can be performed by using a Hall IC, problems such as sensor deterioration due to wear can be eliminated, and a highly durable liquid level detection device can be realized.

According to the second aspect of the invention, in addition to the effect of the first aspect, the hall IC is fixed to the case side, and the detection side magnet which does not require a wiring system rotates. , Relative rotation can be easily performed.

According to the third aspect of the present invention, in addition to the effects of the first and second aspects of the present invention, after the detection side magnet having the two-pole configuration makes a half rotation with respect to the Hall IC, By applying a predetermined voltage to the Hall IC,
Detection can be performed in a wide range from 0 to 360 °.

According to the fourth aspect of the present invention,
In addition to the effect of the invention described in claim 3, the liquid level can be detected without being affected by the liquid in the container. For this reason, the detection accuracy of the liquid level detection device can be improved.

According to the fifth aspect of the present invention, the detection-side magnet provided at one end of the detection-side rotating shaft and the rotation transmitting magnet provided at the other end of the detection-side rotating shaft are separated from each other. Therefore, it is possible to prevent the Hall IC disposed inside the ring of the detection-side magnet from being affected by the in-container magnet and the rotation transmitting magnet.

According to the invention described in claim 6, claims 1 to 5
In addition to the effect of the invention described in claim 5, it is possible to accurately and reliably detect the liquid surface position based on the electromotive force detected by the Hall IC due to the change in magnetic flux.

According to the invention of claim 7, claims 1 to 1 are provided.
In addition to the effect of the invention described in claim 6, the liquid level position of LPG can be safely detected by a liquid level detecting device having a simple structure.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of an essential part showing an embodiment in which a liquid level detecting device according to the present invention is applied to a liquid level detecting device for LPG.

FIG. 2 is a longitudinal sectional view of the liquid level detecting device for LPG of the embodiment.

FIG. 3 is a diagram illustrating a first example of the LPG liquid level detecting device according to the embodiment.
It is a top view which shows a contact, a 2nd contact, and a 3rd contact.

FIG. 4 is a circuit diagram of the liquid level detection device for LPG of the embodiment.

FIG. 5 is a characteristic diagram illustrating a relationship between a detection voltage and a rotation angle of a detection-side magnet in the LPG liquid level detection device according to the embodiment.

FIG. 6 is a sectional view of a main part of a conventional liquid level detecting device for LPG.

FIG. 7 is an exploded perspective view of a conventional liquid level detecting device for LPG.

[Explanation of symbols]

 Reference Signs List 30 LPG liquid level detecting device 31 Case 31A Upper plate (partition) 34 LPG 40 Magnet in container 41 Rotating shaft in container 42 Detecting rotating shaft 43 Rotation transmitting magnet 45 Visual scale plate 46 Detecting magnet 50 Core 51 Hall IC 53 contact plate 54 first contact 55 second contact 56 third contact 60 container 61 base

Claims (7)

[Claims] A first magnet configured to rotate relative to a liquid level of a liquid filled in a container and a Hall IC, and the electromotive force generated by a magnetic flux passing through the Hall IC. A liquid level detection device for detecting the liquid level position in a container, comprising: a disk-shaped contact plate provided coaxially with the detection-side magnet and rotating integrally with the detection-side magnet; A first contact is provided along a peripheral surface of the plate, and a second contact and a third contact arranged in close proximity to each other and slidably contacting the peripheral surface of the contact plate are fixed to the case side, and A liquid level detection device, wherein a predetermined voltage is applied to the Hall IC when at least one of the second contact and the third contact contacts one contact. 2. The liquid level detecting device according to claim 1, wherein the Hall IC is fixed to the case side, and the detection side magnet and the contact plate rotate according to the liquid level position. Liquid level detecting device. 3. The liquid level detecting device according to claim 1, wherein a range in which the second contact or the third contact is in contact with the first contact is defined by a circumference of the contact plate. A liquid level detection device characterized in that the liquid level is approximately half. 4. The liquid level detection device according to claim 2, wherein the detection-side magnet and the contact plate are separated at least via a base, and the liquid is stored in the container. A rotating shaft in the container that rotates according to the liquid surface position of the container is disposed, and a magnet in the container is fixed to an end of the shaft in the container, and the detection-side magnet rotates with the rotation of the magnet in the container. Characteristic liquid level detection device. 5. The liquid level detection device according to claim 2, wherein the detection-side magnet is provided integrally with one end of a detection-side rotating shaft, and the detection-side rotation is performed. On the other end side of the shaft, a rotation transmitting magnet that transmits the rotation of the in-container magnet to the detection-side rotating shaft by opposing through the base while maintaining a magnetic space with respect to the in-container magnet. The liquid level detection device, wherein the contact plate is fixed to the detection-side rotating shaft. 6. The liquid level detecting device according to claim 1, wherein a pair of cores are disposed inside a ring of the detection-side magnet and are separated from each other. A liquid level detecting device, wherein the Hall IC is arranged between opposed end faces. 7. The liquid level detecting device according to claim 1, wherein the container is a pressure-resistant container, and the liquid is liquefied petroleum gas. apparatus.