JPS58153123A - Electrostatic capacitance type liquid gage - Google Patents

Abstract

PURPOSE:To perform highly accurate measurement without the effect of the stray capacity of lead wires, by directly connecting electrode plates and a detecting circuit. CONSTITUTION:In assembling a fuel tank 1, the first electrode plate 4b is welded to an upper shell 2. The second electrode plate 5b is attached to the first electrode plates 4b, which also serves as a baffle, by a distance keeping material 13. Then a detector part 10 is arranged at a specified position of the upper shell 2. Flanges 24a and 24b of a case 16 are connected to the back surface of the upper shell 2 by a spot welding. A connecting terminal 11 of the detector part 10 is electrically connected to a connecting terminal 12 of the second electrode plate 5b by the spot welding. Connecting terminals 17-19 of the detector part 10 are electrically connected to the connecting terminals 21-23 of a panel part 20 by the spot welding. Finally, the upper shell 2 is connected to a lower shell 3 by seam welding. Since the measurement errors are not yielded by the stray capacity of the lead wires, the highly accurate measurement is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a capacitance type liquid meter that detects the amount of liquid contained in a container based on capacitance.

Since then, as this type of capacitance m liquid meter, the first capacitance m liquid meter 6 used in automobile O fuel tank 1 has been introduced as shown in Fig. 1 and Fig. 2. For example,
This species 0III-nk 1 consists of an upper shell 2 and a lower shell 6 that are joined together by seam welding or the like.
A good steel plate 11 (11 is installed on the J-buff) prevents the liquid fuel stored inside the tank from being transferred during driving, etc., and preventing the generation of noise and changes in the liquid level.
4m, 4b has an upper shell of 2 kills.

In addition, when the shape of the fuel tank 1 is flat or asymmetrical, the capacitance m liquid level meter 6
In order to avoid frequent errors such as + or liquid level tol 14 movement, multiple pairs of electrode plates are used.Generally, one of the pair of electrode plates is replaced with the full plate 4 above as the first plate, and the other is used as the first plate. A two-wire electrode plate 5 is installed in an insulated manner by interlayering the TSM 11th Kfi plate. Second electrode plate 5m, 5b
, 5c between...-Ness plate 7m, 7bK! The leads 88 are electrically connected to each other and are fixed to the upper part of the second electrode plate 5b by soldering. It is connected to a detection circuit section 10 for detecting capacitance via a terminal 11'.

However, in such a conventional capacitive layer liquid level meter for a fuel tank 1, the detection circuit section 10 is placed outside the fuel tank 1 for serviceability and credibility reasons, and the connection of the llll12 electronic false board 5 is Because the structure was such that the lead 81 extending from the terminal 12 was connected to the connecting terminal 11 of the detection circuit section 10, the lead 81 was hanging loosely inside the fuel tank 1 at 15 shown in FIG. .

Therefore, although the capacitance m liquid meter measures the capacitance by the level of the liquid immersed between the pair of electric currents, the constant value of the column O is small, ranging from several tens to hundreds of PF. Changes due to the rise of the liquid level K and L, and stray capacitance due to the swinging of the lead a, also affect it as an error, causing the problem that the definition accuracy is not sufficient.

The present invention has been made in view of the above-mentioned conventional point-of-contact point, and eliminates the electrical follow-up by the conventional lead 41. The purpose is to provide a liquid meter. That is, the gist of the present invention is to provide an electrode plate OI which is installed in an insulated state from at least the container among the pair of electrode plates. A detection circuit section is arranged near the connection terminal, and this detection path IIO connection terminal is directly connected to the connection terminal Wt of the electrode plate at point 90.

Hereinafter, the present invention will be described in detail based on embodiments shown in the accompanying drawings. It should be noted that members or parts that are the same or equivalent to those in the prior art are designated by the same reference numerals, and redundant explanations will be omitted.

Figures 3 to 1115 show the first embodiment of the present invention.
The fuel tank 1 of the car is shown by the ffllK ball 9.

In this implementation row, the electrode plate pair is the same as the conventional one, and the ttm plates 4m and 4b substitute the baffle plate welded to the upper shell 2, and this! 181 Electrical board 4a, 4b and facing each other, and installed insulated from the wall of fuel tank 1. 2den [i1E5m.

It is composed of 5b and 5c. and the first t of these
The interleaving between the 4i plate 4 and the $1!2 electrode plate 5 is provided by a plurality of spacing holding members 16K, as shown in FIGS.
The second electrode 1115m,
5b and 5c are... - Ness plate 7m + 7bK machined electrically**. In this embodiment, the connection between the two is as shown in FIG. 4 and FIG.
Bent portion 14m formed at the lower end 11 of one side of m, 5b, 5c
, 14b, 14c and this 1R111111114
m, 14b, formed at the side end so as to engage with 14c...bent portions 15m, 1 of one splat 7m, 7b
111 with 5b and 15c, each joint t spot fI
This caused a delay in engineering 9 due to the I-contact. Therefore, the first electrode plate 4m is 7m and 7b is sprayed one by one for 15 times.
, 4b, it is possible to provide a large distance between the two parts, and to prevent contact between the two parts due to vibrations of the fuel tank 1, tremors, etc. Moreover, the second electrode plate 5 and the
The joint with the Nesbu V-door can be easily connected by spot welding, which improves ease of assembly.
Even if a change 4 occurs, the main body of the second electric plate 5 and the second plate 7 does not deform, so there is no risk that the capacitance will change due to the deformation.

In this way, one @2 electrode plate 50 connected by one splatter 1&, 1bK has a hook-shaped connecting terminal 12 protruding from its upper end for connecting the detection circuit S.

On the other hand, in this embodiment, the detection circuit [11G is -wJ2
A storage case 16 with a built-in detection circuit is fixed to the front side of the upper shell 2 in the vicinity of the connection terminal 12 of the electric panel 5b. 1 is negatively connected to the connecting terminal 12 of the two-electrode plate 5b! A connecting end hole 11 is formed in a protruding manner so as to overlap the connection terminal 12 on the second electrode plate 5b side, and a power source 17 and a ground terminal 18sP are provided on the other side of the storage case 16.
and an output terminal 19 are formed protrudingly in the shape of a hook.

These are formed on the other side of the storage case 16. At the tip of the terminal group, there are external S* connection terminals (electrical connection terminal 21, earth connection terminal n2, output connection terminal 23) arranged on the connection panel dl120 fixed to the upper surface of the upper shell 20. ) is connected to the p1 power supply connection terminal 21 and the output connection terminal 26 is insulated from the upper shell 2 and panel section 20 by means of a sealing member.

To assemble such a fuel tank 1, first, the second electrode plate 5 is attached to the upper shell 2 by welding means to the buckled first TFL plate 4t upper shell 2 to which the second electrode plate 5 is attached in advance, and then the upper shell 2 is attached to the upper shell 2. Body earth. Incidentally, above the upper shell 2, a panel 420 having the above-mentioned connection terminal group inserted therein is fixed. Next, the detection circuit section 10't is placed at an optimum position on the back surface side of the upper shell 2, and spot welded to the back surface of the flange 24L24b t upper/el 2 formed on both sides of the storage case 16. In this state, the light overlapping portions of the ma-conductor 11 of the detection circuit section 10 and the connection terminals 12 of the second electrode plate 5b overlap with each other, so that they are electrically connected by spot welding the overlapping portions. In addition, the hook-shaped tips of the connection terminal #(1) of the detection circuit section 10 are overlapped with the tips of the connection terminals from the panel section 20, and the overlapped portions are spot welded. Electrical connection with the outside is made. Finally, the fuel tank 1, which is sealed by the upper shell 2, the upper shell 6, and the seam S*°r, is completed. Therefore, even if the liquid in the fuel tank 1 moves or the liquid level changes, the second electrode plate 5
and Yokoide field fill O and r to each other connection terminal 12.11
Since the wires are connected in series, highly accurate measurement results can be obtained without the measurement error caused by the bursting of the lead as in the conventional method.

FIG. 8 shows the second embodiment of the present invention.
The earth' in the detection circuit section 1o is connected to the a-contact upper shell 2 through the storage case 16', and the side output circuit 8tl is connected to the ground'.
Earth connection for IO's first child and panel club! ff1
4! This differs from the first implementation in that the children are omitted, but in other respects it has the same structure as 111j.

Incidentally, the earthing to the upper shell 2 is reliably carried out through the storage case 1607 lungies 24m and 24b which are placed on the surface of the upper shell 20a.

? If L is used in this embodiment, there is no need for a terminal for earthing, and therefore, the manual inspection required for welding can be omitted.

Figure 9 shows a third embodiment of the present invention, which is different from any of the previous embodiments. However, the other points are the same as the vote 20 @ example,
The ground of the detection circuit section is connected to the upper shell 2 via the 7-lunge 24L24b. Therefore, according to the embodiment C, since it has a molding structure, it is possible to reduce the size and weight of the lateral circuit 810.

FIG. 110 shows a fourth embodiment of the present invention, which basically has the same configuration as any of the above embodiments, but in the vicinity of the upper end of the detection circuit section 10t and the second electrode plate 5b. , is different from the previous embodiment in that it is directly fixed to the first electrode plate 4b.

That is, in this example #1, the detection circuit section 10t is assembled by welding the 7 flange 4124, 24b of the storage case 16 to the first electrode plate 4bK! 0112 is placed near the electrode plate 5b, and is directly welded to the main body of the electrode plate 5b. The terminal 19 and the panel 1120 arranged on the upper surface of the upper shell 2 also include the electric S* connection terminal 21 inserted into the fuel tank 1, the earth connection M4 terminal 22, and the output connection terminal 2s.
The tips 4Il and 4Il are welded and electrically connected to each other.

This embodiment has the advantage that the detection circuit section 10 is disposed near the second electrode plate 5b, and a part of the main body of the second electrode plate 5b can be used as a connecting piece.

FIG. 11 shows a fifth embodiment of the present invention.
The ground in the detection circuit 810 is directly connected to the first electrode plate 4bK through the storage case 16t by the edge 1 of the first electrode plate 4b, the ground 1 of the detection circuit section 10, and the ground connection terminal of the panel 1120. However, in other respects, the configuration is similar to that of the fourth embodiment.

Fig. 1112 shows a sixth embodiment of the present invention, which differs from the fifth embodiment in that the detection circuit section is a molded tube integrally molded with 10 tons of plastic and resin.
@This is an attempt at quantification.

Ground of detection circuit s10 is flange 24L 24b
The first electrode plate 4bK is grounded via t. Incidentally, in any of the above-mentioned embodiments, the detection circuit section 10t is fixed on the reverse side of the upper shell 2 or on the first electrode plate 4b, and the proportion is explained, but in the present invention, instead of being fixed at these locations, Of course, it can be placed at an appropriate position as long as it is near the II series 12 of the tII and 2-electron 4ii board 5b.

The distance between the 111E41i plate 4 and the second electrode plate 5 is -
As described above, it is held constant by the sleeping area holding member 13 of 11111. This interlayer holding member 13 includes, for example, as shown in FIG. A collar 27 made of an insulating material press-fitted from the 111th pole 141m to the second electrode plate 5 side at the center 'kA of -1i26;
In this actual JNML, when the flanged collar 27 is compressed, four parts of the spacer 26 are secured by the flanged collar 27. In order to prevent burrs from occurring, a notch Wt is provided in a part of the spacer 26 in the construction shown in FIG. A notch 85 in the longitudinal direction is made in the shaft part 1 of the collar 21 shown in Fig. 14.
Two wells are provided to prevent burrs from forming in the notch [2 spaces] when press-fitting the flanged collar 27. When a concave portion 34.34'' is formed on the periphery of the center opening 66 of the spacer 26 and the collar 27 is press-fitted, the burr formed on the periphery of the opening 55 of the spacer 260 is formed on the electrode plate 4.
．． 5, the distance between both electrode plates 4.5 may be kept constant.

In addition, as shown in FIG. 17, when caulking the tip of the rivet 29tv, in order to prevent creases from occurring on the first tli plate 4 and insufficient caulking, the outer side of the second electrode plate 5 is Placed on the ring-shaped washer 55, this washer! The second electrode plate 50 may be crimped onto the rivet 29 through the rivet 50. In this case, the second electrode plate 50 is
Rivets 29 can prevent warping and deformation, etc.
is fixed at 1IjI, and the distance between the electrode plate pairs is maintained constant.

In history, in the holding member 16 between 2#IiI on the top, there is a rivet 29
Although the method of fixing by caulking is adopted, as shown in FIGS. 18 and 19, a fixing member 66t made of plastic may be used instead of the rivet. The moth is instantaneously melted by sonic welding (not shown) at the tip of the fixing member 66 inserted from the outside of the first XM slope 4, and heat caulked to the outside of the second electrode plate 5. The first electrode plate 4, the second electrode plate 5, and the t-spar 926k can be maintained at a constant distance.

In addition, in the embodiment shown in FIG. 19, the distal end of the fixing member 66 protruding outwardly from the second sleeve Ii plate 5 is fitted into a locking member 57 in the shape of a ring. The fixing member 66 and the locking member 67 are joined #kJt by ultrasonic welding by applying ultrasonic waves, or the joint Ii is joined to Australian steel or the like. According to these examples, the construction cost is the flange collar, so the number of parts can be reduced, and since plastic parts are used instead of metal rivets, corrosion resistance and insulation during assembly are improved. 1-* There is no need to take into account, and there is no need to swage #, so workability and reliability are excellent, and the cost of the device can be reduced. As for the material of the fixing member 66 and the work retaining member 67t), thermoplastic resins such as Boliabad, polyethylene, polyacetal, etc. are suitable from the viewpoint of ultrasonic welding and oil resistance. 'Also, in the above embodiment, the rivet 29 or the fixing member S6
Although the case has been described in which the electrode plate is inserted from the 4th direction and caulked or thermally welded at the second electrode plate 5, it is of course possible to insert the electrode plate in the opposite direction.

As explained above, according to the static capacitance liquid meter according to the present invention, it is possible to conduct electricity without using a lead me as in the conventional case.
Since the i-board and the detection circuit section are directly connected, the influence of stray capacitance due to the lead can be eliminated, and a constant value with a high degree of n can be obtained with a simple device.

First, the capacitance type liquid level needle of the present invention can be easily attached and used not only as a fuel needle for automobiles as in the above-mentioned example, but also to other horizontally opening fuel tanks for transportation. Furthermore, it has the advantage that it can be widely applied as a liquid level meter when attached to a container other than a fuel tank.

[Brief explanation of drawings]

Figure 1 is a plan view a@ of a fuel tank to which a conventional capacitive liquid level needle is applied, figure wJ2 is a vertical cross-sectional explanatory diagram of the fuel tank,
Figure 3 shows the capacitive liquid volume needle according to the present invention! 111
f! Figure 5 is an enlarged view of the supporting part of Figure 4. Figure 6 is a fresh example of the Ichinoseki holding member. [The cross-sectional explanatory diagram, Figure 7, shows the joint shape of the IT electrode plate 11! Figures 8 to 12 are explanatory diagrams showing the capacitance ffi liquid volume measurement second embodiment to the sixth fruit lllAl1 according to the present invention, respectively, and Figure 13 shows f4 of Subena. Perspective view, Figure 14 is a perspective view showing one side of the collar with flange, fg 151
i1 is a perspective view showing other details of the spacer, and series 16#A is the spacer tv! shown in FIG. 15. Figure 17 shows the mounting structure of the spacing member when a washer is used.
The explanatory drawing, FIG. 18, and FIG. 19 are cross-sectional views showing mounting structures for different spacing members. 1...Fuel tank 4...File 1tIi plate (・baffle plate) 5...Hunger 2 electric 4j board 10...Detection circuit trowel 11.12...Connection terminal patent applicant Nissan Motor Co., Ltd. Figure 1/1 Figure 2 0 93 Figure 1, Rod 4 Figure 5 WI Sha 6 Sen Figure 7 Figure 8 v! J Figure 10 Figure 1 Figure 12 jI! 13Figure 6 Current collector 5Figure 16Figure-7Figure 18Figure 19

Claims (1)

[Claims] A pair of electrode plates arranged facing each other at a distance from each other in a container, and a detection circuit that is electrically connected to the pair of electrode plates and detects the capacitance of the pair of electrode plates that changes in response to the amount of liquid in the container. In a liquid meter with a capacitance m having a part and a t- part, a detection circuit s is arranged in the vicinity of a connection terminal of a tangential electrode plate which is attached in an insulated state from at least the container among the above-mentioned electrode plates. death,
The connection terminal of this detection circuit section and the **terminal of the electrode plate and t
The capacitance ms amount needle is directly connected to the % image.