JPS62257024A - Mounting structure of liquid level meter - Google Patents

Abstract

PURPOSE:To accurately detect a liquid level without generating an error, by always energizing the liquid level meter supported on the bottom surface of a container downwardly by the repulsive force of the bellows member provided to the upper end of said level meter. CONSTITUTION:A bellows member 8 formed in an elastically expansible and contractible manner is provided to the upper end of a liquid level meter 10 and mounted on a fuel tank 1 so as to be always brought to a compressed state and the lower end thereof is supported on the bottom surface 11 of the fuel tank 1. If the fuel tank 1 contracts or expands by the change in temp., the lower member 3 forming the bottom surface 11 rises or falls and a liquid level rises or falls but, because the liquid level meter 10 is always energized downwardly by the repulsive force of the bellows member 18, the liquid level meter 10 also moves upwardly and downwardly in maching relation to the rising or falling. Therefore, even if the fuel tank 1 contracts or expands, the liquid level can be accurately detected without generating an error.

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Field of Industrial Application) The present invention relates to a structure for mounting a liquid level meter to a liquid storage container provided in a vehicle, industrial machine/appliance, or the like.

(Prior Art) Conventionally, various structures have been known as liquid level meters for detecting the liquid level of oil, water, various chemicals, etc. stored in containers such as tanks. Among them, for example, there is a liquid level meter described in Japanese Patent Application Laid-Open No. 60-253922.

As shown in FIG. 8, this liquid level it 50 is determined by a casing 54, a core 56 inserted therein, a coil 57 wound around the core 56, and a vertical movement around the outer periphery of the casing 54. Conductor ring 58 that can be fitted loosely
It is composed of.

The casing 54 has a fuel tank 51 in its upper part.
The conductor ring 58 is attached to a float 59 so as to float on the fuel 53 along the periphery of the casing 54.

In this liquid level meter 50, the conductor ring 58 moves up and down in response to changes in the liquid level due to increases and decreases in the fuel 53 in the fuel tank 51, so the inductance of the coil 57 changes, and the change in inductance is The liquid level can be detected with high precision using a meter or the like.

(Problems to be Solved by the Invention) However, the internal pressure of the fuel tank 51 increases from normal pressure to a higher pressure due to a rise in temperature, for example.
As shown by the two-dot chain line, the lower member 55 of the fuel tank 5]
If the fuel tank 51 expands downward, the liquid level will drop as shown by the two-dot chain line even if the storage m of the fuel 53 is constant, and the upper member 52 of the fuel tank 51 will also swell as shown by the two-dot chain line. Also, the mounting position of the liquid level gauge 50 fixed to the upper member 52 is higher than when the pressure is normal. Therefore, there is a problem in that an error occurs in the liquid level detected by the liquid level meter 50.

The internal pressure of the fuel tank 51 changes from normal pressure to lower pressure (
Even if corrected, the same problem as above will occur.

Therefore, the present invention and others considered the structure of mounting the liquid level meter 50 that can minimize the error, and found that the lower end of the liquid level meter 50 is supported on the bottom surface of the fuel tank 51,
It was discovered that it is sufficient to install the liquid level meter 50 in the fuel tank 51 so that it moves up and down in accordance with the relative up and down movement of the bottom surface of the lower member 55 with respect to the upper member 52.
Additionally, there was the following problem.

The first problem is how to structure the liquid level if 50 to constantly force it toward the bottom of the fuel tank 51. The second problem is how to move the liquid level meter 50, especially its upper end, toward the fuel tank 51. The question is whether they will support it internally.

Therefore, an object of the present invention is to provide a mounting structure for attaching a liquid level cutter to a liquid storage container in a state in which it is constantly urged against the bottom side of the liquid storage container and can be moved up and down. It's about doing.

Structure of the Invention (Means for Solving the Problems) In order to achieve the above-mentioned object, the present invention includes a bellows member formed to be elastically expandable and contractible at 3Ω at the upper end of the liquid level meter, and a bellows member that is A technical measure is adopted in which the liquid level gauge is attached to a liquid storage container so as to be in a compressed state at all times, and the lower end of the liquid level gauge is supported by the liquid storage container.

(Function) A liquid level meter is set in a liquid storage container, and the lower end of the liquid level gauge is supported on the bottom surface of the liquid storage container.

The liquid level meter is attached to the liquid storage container so that the bellows member provided at the upper end of the liquid level meter is constantly compressed.

Then, the liquid level gauge is constantly pushed downward (=J) by the repulsive force of the bellows part material. At the same time, the bellows part material itself prevents the upper part of the liquid level gauge from wobbling in the horizontal direction, and also prevents the liquid level It also exerts a guiding action to smoothly move S1 in the vertical direction.

Under this condition, when the liquid storage container expands due to temperature rise and its lower member expands downward and moves downward, the liquid level immediately follows the movement of the bottom surface and smoothly moves downward. Moving. Therefore, even if the lower portion t4 swells downward and the liquid level decreases, this will not cause an error in detecting the liquid level.

On the other hand, when the liquid storage container contracts, the liquid level rises together with the lower member through the reverse process to reduce the detection error. The same applies to the case where either the upper member or the lower member is fixed and only the lower member moves up and down as the liquid storage container expands or contracts.

(First Embodiment) Next, a first embodiment in which the present invention is embodied in a vehicle fuel tank will be described with reference to FIG.

A fuel tank 1, which is a storage container for storing fuel such as liquid gasoline or diesel oil, is a substantially flat structure in which a metal upper member 2 forming the upper part and a lower member 3 forming the lower part are welded together. It is a closed type container. Therefore, a flange 4, which is a joint between the upper and lower members 2.3, protrudes from the center of the side surface of the fuel tank 1 over the entire circumference.

The upper member 2 is provided with a removable recessed or flat mounting plate 23, which forms a part of the upper member 2. For this mounting, a circular mounting hole 23b and a circular insertion hole 23a smaller than the mounting hole 23b are formed in the plate 23, and a bellows member can be attached to the former, A vent tube 5 for discharging fuel is inserted through the latter.

A covered cylindrical protector 7 is provided on the mounting plate 23 to cover the mounting opening 23b from above, and a lead wire drawer lower a is formed at the center of the upper part of the protector 7.

The upper part of the Ben L-tube 5 is fixed by a gripping member 6 provided on the plate 23, and its lower end extends to the bottom of the fuel tank 1. The gripping member 6 is fixed to the plate 23 by, for example, welding, and seals between the vent tube 5 and the insertion hole 23a.

A base end portion of an elongated support member 8 extending substantially laterally is fixed to the lower portion of the vent tube 5 in the fuel tank 1 by fixing means 9 such as screws or heat fusion.

The lower part of a liquid level meter 10 for detecting the liquid level of the fuel tank is held at the tip of the support member 8. The support member 8 is made of an elastic member such as synthetic resin, urges the liquid level gauge 10 downward, and the lower end of the liquid level gauge 10 is supported on the bottom surface 11 of the lower member 3.

The liquid level meter 10 uses a cylindrical synthetic resin casing 12 having an enlarged diameter portion 12a at the top,
An annular groove 17 for locking the tip of the support member 8 is formed at its lower end.

On the other hand, a bellows member 18 made of synthetic resin and having elasticity extends in one direction from the upper end of the casing 12, and its upper end 18a is inserted into the mounting opening 23b of the mounting plate 23. The flange portion 18X formed on the outer peripheral side of the upper end portion 18a is fixed to the plate 23, and the bellows member 18 is always in a compressed state.

The bellows member 18 is integrally formed with the casing 12 by injection blow molding.

Inside the casing 12 is a rod-shaped core 15 of ferrite.
is inserted, and a coil 16 is wound around this core 15. The coil 16 is formed of a densely wound portion 13 wound tightly within the enlarged diameter portion 12a and a coarsely wound portion 14 similarly wound loosely within the enlarged diameter portion 12a, and electrical conduction is conducted continuously between the two. It looks like this.

One lead wire 19 is connected from the densely wound portion 13 and coarsely wound portion 14.
extends upward and is drawn out from the lead wire drawer lower a of the protector 7.

Note that the lead wire drawer lower a is sealed by the IT member 26 at t=1 after the lead wire 19 is drawn out.

A conductor ring 22 made of aluminum, conductive resin, or the like having a low specific gravity is loosely fitted on the outer periphery of the casing 12 so as to be movable up and down, and is electromagnetically connected to the tightly wound portion 13 and coarsely wound portion 14 of the coil 16. It is meant to be combined. A donut-shaped float 20 made of foamed resin or the like is attached to the conductor ring 22, allowing the conductor ring 22 to float on the fuel.

Next, the functions and effects of this embodiment configured as described above will be explained.

First, the pens 1 to tubes 5 and the liquid level meter 10 are set in advance on the plate 23 for mounting the upper member 2, and the protector 7 is fixed on the plate 23 for mounting. Fixed to 2.

Then, the vent tube 5 and the liquid level gauge 10 will be attached to the fuel tank 1, and the fuel tank 1 will be sealed at the same time. Therefore, in this embodiment, the liquid level gauge 10 and the vent tube 5 can be easily attached to the fuel tank 1, there are few sealing points, and the sealing performance of the fuel tank 1 is good.

Next, the pressure inside the fuel tank 1 increases due to the temperature rise,
When the upper member 2 and lower member 3 of the fuel tank 1 expand and bulge in the vertical direction as shown by the two-dot chain line, even if the six chains of the fuel tank remain constant, the liquid level of the fuel tank will also be 2. It decreases as shown by the dotted chain line.

At this time, since the bellows member 18 is always compressed and attached to the plate 23 at the upper part of the liquid level meter 10, it exerts an elastic action and the liquid level meter 10
0 is constantly biased downward. Therefore, when the lower member 3 swells downward, the liquid level gauge 10 also moves downward. The bellows member 18 attempts to maintain the upper part of the liquid level gauge 10 at its center while allowing the liquid level gauge 10 to move downward, thus exerting a kind of kite effect. Therefore, in the fuel tank 1 of this embodiment, a guide member for the upper part of the curved liquid level gauge 10 is provided as a separate part.
There is no need to

Further, since the lower end of the liquid level gauge 10 is fixed to the tip of the support member 8 so as not to move horizontally on the bottom surface 11, vertical movement of the liquid level gauge 10 is prevented by the bellows member. Coupled with the action of No. 18, this process is carried out even more smoothly.

Therefore, when the lower member 3 of the fuel tank 1 swells downward, the liquid level gauge 10 smoothly moves downward as the lower member 3 swells, so that the liquid level gauge The liquid level of the fuel tank detected by the sensor 10 has almost no error.

Since the upper part of the liquid level meter 10 is supported by the bellows member 18, the lead wire 19 can be protected by the bellows member 18, and as a result, there is no possibility that the lead wire 19 will become entangled with other members.

The above-mentioned functions and effects are exhibited in the same manner as described above even when the fuel tank 1 contracts. Further, either one of the upper member 2 or the lower member 3 is fixed, and when the upper member 2 is attached due to expansion or contraction of the fuel tank 1, only the plate 23 or the bottom surface 11 of the lower member 3 moves up and down. In this case, the same effect as described above can be obtained.

(Second Embodiment) Next, a second embodiment in which the mounting structure of the present invention is embodied in a different manner will be described based on FIG. 2.

In this embodiment, as in the first embodiment, a bellows member is provided above the liquid level gauge, and a coil spring is provided in the bellows member to actively force the liquid level gauge downward. It is configured as follows.

To explain its main structure, an elastic synthetic resin bellows member 1 is provided at the upper end of the enlarged diameter portion 12a of the casing 12.
8 is formed integrally with the casing 12 and extends upward.

The upper part of the bellows member 18 is attached to the plate 23 through the opening 23.
b, the flange portion 18X of the upper end portion 18a is fixed to the plate 23, and the bellows member 1B is always in a compressed state.

Inside the casing 12, a spring bearing member 21 is provided on the enlarged diameter portion 12a, and a plug-shaped spring bearing member 25 is screwed inside the upper end of the casing 18 above the spring bearing member 21. The coil spring 24 is attached between the members 21 and 25 in a compressed state, and urges the liquid level meter 10 downward.

A lead wire 19 extending upward from the upper end of the tightly wound portion 13 of the coil 16 is inserted into the coil spring 24, and is drawn out from the lead wire drawer lower a of the PRODECTUF.

The other configurations are the same as those of the first embodiment.

This embodiment also exhibits the same functions and effects as the first embodiment, but there is a coil 24 inside the bellows member 18.
Since the liquid level gauge 10 is actively urged downward by providing the fuel tank 1, the internal pressure of the fuel tank 1 increases and the lower member 3 swells downward, causing the bottom surface supporting the liquid level Ki 10 to rise. When the bottom surface 11 moves downward, the liquid level meter 10 also moves immediately following the bottom surface 11. Therefore, in addition to the effect of the first embodiment, the effect of responding reliably and quickly to a drop in the liquid level is achieved.

(Third Embodiment) A third embodiment in which the mounting structure of the present invention is embodied in a different manner will be described based on FIG. 3.

In this embodiment, the bellows member is made of synthetic rubber, and
It is intended to be formed separately from the casing and attached to the upper part of the enlarged diameter section.

To explain the main structure of this embodiment, the casing 12
A flange portion 12b is formed at the upper end of the enlarged diameter portion 12a. A bellows member 18 made of elastically expandable synthetic rubber is connected to this flange portion 12b, and its lower end portion 18b holds the flange portion 12b.

The upper end 18a of the bellows member 18 extends upward, and the plate 23 is attached by vulcanization bonding to the inner end of the opening 23b. In this embodiment as well, the bellows member 18 is always attached in a compressed state between the enlarged diameter portion 12a and the mounting plate 23.

The other configurations are the same as those of the first embodiment.

In this embodiment, the same effect as in the first embodiment is exhibited, but in addition to the roughness, since the bellows part material 18 is made of synthetic rubber, the bellows part material 18 utilizes its elasticity to The effect that the plate 23 can be easily attached to the opening 23b is exhibited.

The present invention is not limited to the configurations of the embodiments described above, and can be implemented, for example, in the following manner.

(1) In each of the first, second, and third embodiments, as shown in FIGS. 4 and 5, a recess 3a into which the lower end of the liquid level meter 10 can be fitted is provided in the lower member. 3 itself, the lower end of the liquid level meter 10 may be dropped into the recessed portion 3a, and the lower end of the liquid level meter 10 may be supported on the bottom surface 11. In this case, the lower member 3 is
The recess 3a may be formed by forming an annular bent portion 3b (FIG. 5).

In this way, the liquid level meter 10 can be brought closer to the bottom surface 11, thereby expanding the measurement range of the liquid level.

(2) As shown in FIG. 6, the concave member 27 is fixed to the lower member 3 by welding means or the like to form a concave portion 3a, and the lower end of the liquid level meter 10 is dropped into the concave portion 3a to measure the liquid level. 10 can be positioned so that its lower end does not wobble in the horizontal direction. Forming the concave portion 3a in this manner has the effect that machining of the lower member 3 is not required.

(3) Furthermore, as shown in FIG. 7, a support member 8 is fixed to the lower end of the vent tube 5 in the first embodiment.
It is also possible to integrate the tip end of the casing 12 with a bottom member 28 that closes the lower end of the casing 12. In this case, if the support member 8 is made of an elastic material such as a synthetic resin so that the bottom member 28 presses the bottom surface 11 of the fuel tank 1, the liquid level meter 10 will be configured so that the lower member 3 bulges downward. At this time, the liquid level meter 10 can easily follow the expansion quickly and reliably.

(4)] The spring 24 may be provided on the outer peripheral side of the bellows member 18, or may be formed integrally with the bellows member 18.

(5) The liquid level meter 10 of the present invention can be attached to the pond of the fuel tank 1 in various liquid storage containers, such as a water storage tank, a drug tank, etc.

(6) A supply port for supplying liquid can be provided at an appropriate location of these liquid storage containers 1, and this supply port can be sealed tightly.

Effects of the Invention As detailed above, the present invention has an elastic action that constantly urges the liquid level gauge downward by attaching a bellows member formed to be elastically expandable and contractible to the liquid level gauge; The upper part of the liquid level meter has a guiding effect that guides it vertically, so even if the liquid storage container contracts or expands due to temperature changes, the liquid level can be accurately detected with almost no errors. It shows excellent results.

Further, in the present invention, there is no need to form the upper part of the liquid level gauge with a separate member that acts as a guide in addition to the bellows member.

Further, since the lead wire of the liquid level meter is taken out through the bellows member, there is no risk of the lead wire getting tangled with other members. Furthermore, since the number of sealing parts of the liquid storage container can be reduced, the sealing properties thereof are good.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view of the first embodiment, Fig. 2 is a longitudinal sectional view of the second embodiment, Fig. 3 is a longitudinal sectional view of the third embodiment, and Fig. 4 is the lower end of the liquid level meter. FIG. 5 is a cross-sectional view of a main part showing another aspect of the support structure; FIG. 6 is a cross-sectional view of a main part showing another aspect of the support structure; FIG. FIG. 7 is a sectional view of a main part showing still another aspect of the support structure, and FIG. 8 is a longitudinal sectional view of the prior art. Liquid storage container 1, upper member 2, protector 7, liquid level gauge 10, bottom 11, casing 12, core 15, coil 16, bellows member 18, conductor ring 22, mounting plate 23, coil spring 24, liquid Patent applicant: Toyoda Gosei Co., Ltd. Horie Metal Industry Co., Ltd.

Claims (1)

[Claims] 1. A bellows member (18) formed to be elastically expandable is provided at the upper end of the liquid level meter (10), and the bellows member (18)
A liquid storage container (1
), and the lower end of the liquid level meter (10) is supported on the bottom surface (11) of the liquid storage container (1). 2. The liquid level meter mounting structure according to claim 1, wherein the bellows member (18) is integrally formed with the casing (12) of the liquid level meter (10). 3. The mounting structure for a liquid level gauge according to claim 1, wherein the bellows member (18) is formed separately from the casing (12) of the liquid level gauge (10). 4. The bellows member (18) is attached to the mounting plate (23) on the upper member (2) of the liquid storage container (1), and a protector is attached to the mounting plate (23) to cover the bellows member (18) from above. The mounting structure for a liquid level meter according to claim 1, wherein (7) is provided. 5. The liquid level meter (10) includes a casing (12) containing a core (15) around which a coil (16) is wound, and a conductor ring (22) loosely fitted around the outer periphery of the casing (12). ) A mounting structure for a liquid level meter according to claim 1, comprising: 6. The liquid level meter (10) is
) and the liquid storage container (1) and is biased downward by a coil spring (24).