JP5376980B2 - Liquid level detector - Google Patents

Description

  The present invention relates to a liquid level detection device that detects a liquid level of a fuel tank mounted on a vehicle, for example.

  For example, a liquid level detection device is used to detect the level of fuel remaining in a fuel tank mounted on a vehicle (see, for example, Patent Documents 1 and 2). A conventional liquid level detection device floats a float in a fuel tank and rotates a conductive sliding arm in conjunction with the vertical movement of the float. Further, the sliding arm is slid on the resistance substrate. Therefore, since the contact position on the resistance substrate changes according to the rotation angle of the sliding arm, the resistance value between the sliding arm and the reference point changes. By measuring this resistance value, Thus, the rotation angle of the sliding arm can be measured, so that the liquid level of the fuel tank can be detected.

  FIG. 14 is an explanatory view schematically showing a configuration of a resistance substrate used in a conventional liquid level detection device. As shown in the figure, the liquid level detecting device includes a resistance substrate 101 and a conductive sliding arm 106. The sliding arm is interlocked with the vertical movement of a float (not shown) provided in the fuel tank. 106 is displaced in the direction of arrow Yf or Ye in the drawing.

  The resistive substrate 101 has a plurality of strip-shaped conductive segments 102-1 to 102-n (hereinafter referred to as "102" with the suffix omitted if it is not necessary to distinguish) from each other at substantially predetermined intervals. Is provided. In addition, a resistance pattern 110 having a predetermined width is provided so as to straddle each conductive segment 102. Accordingly, a predetermined resistance value is generated between the conductive segments 102. The rightmost conductive segment 102-n is connected to the reference electrode 103 via a resistor R11.

  Further, a common electrode 104 is provided below each conductive segment 102, and the common electrode 104 is connected to the measurement electrode 105. Here, each conductive segment 102, resistance pattern 110, resistance R11, reference electrode 103, common electrode 104, and measurement electrode 105 can be printed on the resistance substrate 101 by screen printing or the like.

  The sliding arm 106 rotates in the direction of the arrow Yf as the liquid level increases, and rotates in the direction of the arrow Ye as the liquid level decreases. Therefore, the sliding arm 106 comes into contact with any one of the conductive segments 102 and the common electrode 104 according to the level of the fuel in the fuel tank.

  For this reason, the resistance value generated between the reference electrode 103 and the measurement electrode 105 is measured by the resistance measuring device 121, whereby the rotation angle of the sliding arm 106 can be measured. As a result, the liquid of the fuel in the fuel tank can be measured. The surface level can be detected.

  Here, the resistance substrate 101 configured as described above has a gap between the reference electrode 103 and the measurement electrode 105 according to the specifications of the host device provided upstream of the resistance substrate 101 or the shape of the fuel tank. The resulting resistance value needs to be set to a predetermined value. For this reason, the resistance value is changed by appropriately trimming the resistance pattern 110 provided between the conductive segments 102. Hereinafter, this process will be described with reference to FIG.

  FIG. 15 is an explanatory diagram of the conductive segment 102-1 and the conductive segment 102-2 adjacent thereto. 15A shows a state in which the resistor pattern 110 is not trimmed, FIG. 15B shows a state in which the resistor pattern 110 is trimmed to almost the center, and FIG. 15C shows a state in which the resistor pattern 110 is trimmed to the very end. ing.

  As an example, the resistance value between the conductive segments 102-1 and 102-2 is 4Ω in the case shown in FIG. 10A, 10Ω in the case shown in FIG. In the case shown, it is 40Ω. That is, the resistance value between the conductive segments 102 can be arbitrarily set in the range of 4Ω, which is the basic resistance value, to 40Ω, which is 10 times the resistance value by trimming.

JP 2003-257717 A JP 2003-254815 A

  However, in the above-described prior art, when the resistance pattern between the conductive segments 102 is trimmed, the limit is to change the resistance value from the basic resistance value to 10 times the resistance value, and a resistance value higher than that is set. It was difficult. Further, since the relationship between the length of the trimming process and the resistance value of the resistance pattern changes with a quadratic function curve as shown in FIG. 16, as the length of the trimming process increases, the resistance value with respect to the trimming length increases. There is a drawback that the amount of increase becomes large and fine adjustment of the resistance value in a region where the resistance value is large is not easy.

  As a result, the range of the resistance value generated between the reference electrode 103 and the measurement electrode 105 is limited, and a resistor board having a dedicated shape is prepared for each specification in order to cope with the specifications of various types of host devices. This has led to a problem of high costs.

  The present invention has been made to solve such a conventional problem, and an object of the present invention is to provide a liquid level detection device capable of setting a resistance value in a wider range with the same resistance substrate. There is to do.

In order to achieve the above object, the invention according to claim 1 of the present application detects the liquid level by changing the resistance value between two points according to the liquid level to be measured and measuring the resistance value. A liquid level detection device, which is displaced according to a change in the liquid level, and a conductive sliding arm which slides on the substrate in accordance with the displacement, and a strip shape which is provided on the substrate and spaced apart from each other A plurality of conductive segments disposed along the sliding direction of the sliding arm, a first resistance pattern disposed across the conductive segments and connecting the conductive segments, A second resistance pattern disposed at at least one location between the conductive segments to connect adjacent conductive segments and spaced apart from the first resistance pattern, the first between the conductive segments out of the resistance pattern At least one place and trimming or cutting, and, by trimming or cutting at least one portion of said second resistor pattern, arbitrarily setting the resistance value between each segment of the plurality of conductive segments One of them is a first measurement point, the sliding arm is a second measurement point, and the liquid level is detected based on a resistance value between the first measurement point and the second measurement point. And

  The invention according to claim 2 is characterized in that the first resistance pattern and the second resistance pattern have different resistance values between the conductive segments in a state before the trimming process.

  The invention according to claim 3 is characterized in that the second resistance pattern is disposed across the plurality of conductive segments.

The invention according to claim 4 is a liquid level detection device for detecting the liquid level by changing a resistance value between two points according to the liquid level to be measured , and measuring the resistance value, A conductive sliding arm that displaces according to the change in the liquid level and slides on the substrate in accordance with the displacement, and a strip shape provided on the substrate and spaced apart from each other. A plurality of conductive segments disposed along the sliding direction, and among the conductive segments, an end conductive segment disposed at an end, and an adjacent conductive adjacent to the end conductive segment Each of the segments has a main body portion and a tip portion that faces a direction bent by 180 degrees with respect to the main body portion, and is further disposed across the conductive segments, and a first resistor that connects the conductive segments. Pattern and said end conductive segment And a second resistance pattern disposed between the front end portion of the adjacent conductive segment and the first resistance pattern between the conductive segments, and the second resistance pattern. Trimming at least one of them, or setting the resistance value between the conductive segments and between the tip portions without trimming, and when setting the resistance value, the second resistance pattern If unnecessary, the end conductive segment and the adjacent conductive segment are cut between the main body portion and the tip portion, and one of the plurality of conductive segments is used as a first measurement point, The sliding arm is a second measurement point, and the liquid level is detected based on a resistance value between the first measurement point and the second measurement point .

A liquid level detection device that detects the liquid level by measuring a resistance value by changing a resistance value between two points according to a liquid level to be measured, and is displaced according to the change in the liquid level A conductive sliding arm that slides on the substrate in accordance with this displacement and a strip shape that is provided on the substrate and spaced apart from each other, and is disposed along the sliding direction of the sliding arm. A plurality of conductive segments, and a first resistance pattern disposed across the conductive segments and connecting the conductive segments, and provided at at least one end of the plurality of conductive segments. The end conductive segment formed has a trunk portion and a branch portion branched to the outside thereof, and a second resistance pattern is disposed between the trunk portion and the branch portion, and the first conductive segment between the conductive segments is arranged. At least one portion in the resistor pattern And trimming or cutting, and the second arbitrarily setting the resistance value of the trunk and branch portions of the resistor pattern without or trimmed to trimming, and the end conductive segments, said stem A resistance value between the end conductive segment and an adjacent conductive segment is set depending on whether or not a proper position is cut, and one of the plurality of conductive segments is set as a first measurement point, and the sliding arm The liquid level is detected based on a resistance value between the first measurement point and the second measurement point.

  In the first aspect of the invention, the first resistance pattern is disposed between the plurality of conductive segments, and the second resistance pattern is disposed at least at one location between the conductive segments. Therefore, it is possible to widen the setting range when setting the resistance value between the conductive segments by trimming, and it becomes easy to standardize and share the resistance substrate, thereby reducing the cost as a whole.

  In the invention of claim 2, since the resistance values of the first resistance pattern and the second resistance pattern are different, a wider range of resistance values can be set.

  In the invention of claim 3, since the second resistance pattern is disposed between the plurality of conductive segments, the adjustment range of the resistance value between all the conductive segments can be widened, and the specifications of various types of host devices are provided. Can be flexibly dealt with.

  In the invention of claim 4, the end conductive segment and the tip of the adjacent conductive segment adjacent thereto are bent in the direction of 180 degrees, and the first resistance pattern is formed between the main body portions of the two conductive segments. A second resistance pattern is formed between the tips of the two conductive segments. For this reason, a space for disposing the second resistance pattern can be provided in the vicinity of the side portion of the end conductive segment, and there is no need to lengthen the conductive segment. Can be achieved.

  According to the fifth aspect of the present invention, the end conductive segment has a trunk portion and a branch portion branched from the trunk portion, and the second resistance pattern is disposed between the trunk portion and the branch portion. Therefore, by trimming at least one of the first resistance pattern and the second resistance pattern, the resistance value between the end conductive segment and the adjacent conductive segment can be arbitrarily set. Furthermore, if the trunk portion of the end conductive segment is cut at an appropriate position, a series connection circuit of the first resistance pattern and the second resistance pattern can be formed, and resistance setting using this series connection circuit becomes possible. If the trunk is not cut in place, the resistance setting using only the first resistance pattern is possible. As a result, the resistance value of the end conductive segment can be set wider.

It is the schematic which shows the structure of the liquid level detection apparatus which concerns on embodiment of this invention. It is a top view which shows a resistance board | substrate of the liquid level detection apparatus which concerns on 1st Embodiment of this invention. It is a side view which shows a resistance board | substrate of the liquid level detection apparatus which concerns on 1st Embodiment of this invention. It is explanatory drawing which shows the example which trims the resistance pattern used for the liquid level detection apparatus which concerns on 1st Embodiment of this invention. It is the equivalent circuit of the resistance board mounted in the liquid level detection apparatus which concerns on 1st Embodiment of this invention. It is a top view which shows a resistance board | substrate of the liquid level detection apparatus which concerns on the modification of 1st Embodiment of this invention. It is an equivalent circuit of the resistance board mounted in the liquid level detection apparatus which concerns on the modification of 1st Embodiment of this invention. It is a top view which shows a resistance board | substrate of the liquid level detection apparatus which concerns on 2nd Embodiment of this invention. It is explanatory drawing which shows the principal part of the resistance board | substrate shown in FIG. It is an equivalent circuit of the resistance board mounted in the liquid level detection apparatus which concerns on 2nd Embodiment of this invention. It is a top view which shows a resistance board | substrate of the liquid level detection apparatus which concerns on 3rd Embodiment of this invention. It is explanatory drawing which shows the principal part of the resistance board | substrate shown in FIG. In the liquid level detection device according to the present invention, it is an equivalent circuit when a resistance pattern is arranged in three stages. It is explanatory drawing which shows typically the resistance board | substrate used for the conventional liquid level detection apparatus. It is explanatory drawing which shows the example which trims the resistance pattern provided in the resistance board used for the conventional liquid level detection apparatus. It is a characteristic view which shows the length of a trimming process, and the change of resistance value.

[Description of First Embodiment]
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory diagram showing the overall configuration of the liquid level detection device according to the first embodiment of the present invention, FIG. 2 is a plan view showing the configuration of a resistance substrate (substrate) used in the liquid level detection device, and FIG. It is the same side view.

  As shown in FIG. 1, the liquid level detection device 10 according to this embodiment includes a detection device main body 13, a resistance substrate 21 provided in the detection device main body 13, and a liquid level L of a liquid to be detected. A float 11 that floats and a float arm 12 that connects the float 11 and the detection device main body 13 are provided. A sliding arm 14 is provided at the distal end of the float arm 12 on the fixed side, and is supported by the rotation axis P. Therefore, when the liquid level L changes and the float 11 moves up and down, the sliding arm 14 rotates around the rotation axis P within a predetermined angular range.

  As shown in FIG. 2, a resistance substrate 21, a sliding arm 14, and a resistance measuring device 29 are provided inside the detection device main body 13.

  A plurality of conductive segments 22-1 to 22-n are provided on the resistance substrate 21 along the rotation direction of the sliding arm 14 (hereinafter, the suffix is omitted if it is not necessary to distinguish between them). Is provided. Each conductive segment 22 is formed in a strip shape and is spaced apart from each other by a predetermined distance. Moreover, the 1st resistance pattern 51 and the 2nd resistance pattern 52 are arrange | positioned so that each conductive segment 22 may be straddled, and each resistance pattern 51 and 52 is provided mutually spaced apart. The second resistance pattern 52 is narrower than the first resistance pattern 51. Therefore, the resistance value between the conductive segments 22 (for example, between 22-1 and 22-2) is smaller in the first resistance pattern 51 than in the second resistance pattern 52. That is, the first resistance pattern 51 and the second resistance pattern 52 have different resistance values between the conductive segments 22 in a state before trimming. The rightmost conductive segment 22 -n (corresponding to the first measurement point) is connected to the reference electrode 26 via the resistor 53.

  A plurality of strip-shaped common electrodes 24 (corresponding to the second measurement points) are provided at appropriate positions on the rotation axis P side (lower side in the drawing) of each conductive segment 22. Each common electrode 24 is electrically connected to each other, and is connected to a measurement electrode 28 provided at the right end of the resistance substrate 21. The reference electrode 26 and the measurement electrode 28 are connected to a resistance measuring device 29.

  Here, each conductive segment 22, the first resistance pattern 51, the second resistance pattern 52, the resistance 53, the common electrode 24, the reference electrode 26, and the measurement electrode 28 are formed on the resistance substrate 21 by a method such as screen printing. Printed on.

  Then, the sliding arm 14 rotates around the rotation axis P in the range from the leftmost conductive segment 22-1 to the rightmost conductive segment 22-n (for example, in the range of 70 °), and any one conductive segment. 22 is contacted. As shown in FIG. 3, a first contact 14 a and a second contact 14 b are provided on the surface of the sliding arm 14 on the side of the resistance substrate 21, and the first contact 14 a is connected to one of the plurality of conductive segments 22. The second contact 14 b comes into contact with one of the plurality of common electrodes 24.

  Next, the operation of the liquid level detection device according to the first embodiment of the present invention will be described. The resistance substrate 21 used in this embodiment is provided with a first resistance pattern 51 and a second resistance pattern 52 between the conductive segments 22. Then, each resistance pattern 51, 52 provided between each conductive segment 22 is trimmed to set an arbitrary resistance value. Hereinafter, this will be described in detail with reference to FIG.

  FIG. 4 is an explanatory diagram showing a connection state of the conductive segment 22-1 and the conductive segment 22-2 adjacent thereto. As shown in FIG. 4A, a first resistance pattern 51 and a second resistance pattern 52 are provided between the conductive segments 22-1 and 22-2. The width N1 of the first resistance pattern 51 is larger than the width N2 of the second resistance pattern.

  The resistance value of the first resistance pattern 51 is 4Ω, for example, and the resistance value of the second resistance pattern is 8Ω, for example. Therefore, as shown in FIG. 4B, if the entire second resistance pattern 52 is cut by trimming and only the first resistance pattern 51 is left, the conductive segments 22-1 and 22-2 are separated. The resistance value is 4Ω. Further, as shown in FIG. 4C, when a part of the first resistance pattern 51 is trimmed to adjust the width of the first resistance pattern 51, the resistance value is set according to the trimming length N3. Can be arbitrarily adjusted within a range of 4 to 40Ω.

  On the other hand, as shown in FIG. 4D, if the entire first resistance pattern 51 is cut by trimming and only the second resistance pattern 52 is left, the conductive segments 22-1 and 22-2 are separated. The resistance value is 8Ω. Further, as shown in FIG. 4E, if a part of the second resistance pattern 52 is trimmed to adjust the width of the second resistance pattern 52, the resistance value is set according to the trimming length N4. Can be arbitrarily adjusted within the range of 8 to 80Ω.

  Further, by trimming at least one of each of the resistance patterns 51 and 52 without completely cutting any one of the first resistance pattern 51 and the second resistance pattern 52, or by not performing the trimming process, A wider range of resistance values can be set. For example, if both of the resistance patterns 51 and 52 are not trimmed (state shown in FIG. 4A), a parallel combined resistance of 4Ω and 8Ω is obtained, and a resistance value of 2.67Ω can be obtained.

  FIG. 5 is an equivalent circuit diagram of the resistor board 21 described above. As shown in the figure, between two adjacent conductive segments 22-1 and 22-2, a variable resistance VR1-1 whose resistance value can be changed within a range of 4 to 40Ω and a resistance within a range of 8 to 80Ω. A variable resistor VR2-1 that can change the value is provided, and a switch SW1-1 is connected in series with the variable resistor VR1-1, and a SW2-1 is connected in series with the variable resistor VR2-1. Has been. Then, turning off (opening) the switch SW1-1 means cutting the first resistance pattern 51, and turning off the switch SW2-1 means cutting the resistance pattern 52. Further, the adjustment of each of the variable resistors VR1-1 and VR2-1 corresponds to the trimming process of each of the resistance patterns 51 and 52.

  Then, by executing the above processing between the conductive segments 22 and setting the resistance value, a desired resistance value corresponding to the angle of the sliding arm 14 is generated between the reference electrode 26 and the measurement electrode 28. Can do. That is, when the first contact 14a (see FIG. 3) provided on the sliding arm 14 contacts any one of the plurality of conductive segments 22, the contact between the contacted conductive segment 22 and the rightmost conductive segment 22-n. Therefore, a resistance value corresponding to the angle of the sliding arm 14 is generated between the reference electrode 26 and the measurement electrode 28, and this resistance value is measured by the resistance measuring device 29. Thus, the angle of the sliding arm 14 can be detected, and consequently the liquid level L shown in FIG. 1 can be measured.

  In this way, in the liquid level detection device 10 according to the first embodiment of the present invention, the first resistance pattern 51 and the second resistance so as to straddle the plurality of conductive segments 22 provided on the resistance substrate 21. Since the pattern 52 is provided and the resistance value between the conductive segments 22 can be set without trimming or trimming at least one of the resistance patterns 51 and 52, the resistance value can be set in a wider range. Can be set. For this reason, it becomes possible to respond flexibly to the specifications of the host device of the liquid level detection device 10, and it is rich in versatility, can be easily standardized and shared, and the cost can be reduced as a whole.

[Description of modification]
Next, a modification of the first embodiment described above will be described. In the first embodiment, the second resistance pattern is provided so as to straddle each conductive segment 22, but in this modification, as shown in FIG. 6, the conductive segments 22-1 and 22- provided at the ends are provided. The second resistance pattern 52 is provided only between the two.

  As shown in FIG. 6, the resistance substrate 21a according to the modification is provided with the second resistance pattern 52 only between the conductive segments 22-1 and 22-2, and the first resistance pattern 51 is formed by the same method as described above. Alternatively, the resistance value can be set by trimming the second resistance pattern 52.

  As shown in FIG. 7, the equivalent circuit in this case has a configuration in which the variable resistor VR2-1 and the switch SW2-1 are provided only between the conductive segments 22-1 and 22-2. In this way, in the liquid level detection device 10 according to the modified example, when it is required to set only the resistance value at the end (the liquid level L is the lowest level or the resistance value near the highest level) widely. It is valid.

[Description of Second Embodiment]
Next, a second embodiment of the liquid level detection device 10 according to the present invention will be described. FIG. 8 is an explanatory diagram showing the configuration of the resistance substrate 21b according to the second embodiment. The resistance substrate 21b according to the second embodiment is different from the resistance substrate 21a shown in FIG. 6 in the configuration of the leftmost conductive segment 22-1. Hereinafter, this difference will be described in detail.

  FIG. 9 is an explanatory diagram showing a detailed configuration of the conductive segments 22-1 and 22-2 provided on the resistance substrate 21b shown in FIG. As shown in the figure, the conductive segment 22-1 provided at the end includes a trunk portion 22a and a branch portion 22b that branches outward from the trunk portion 22a. Between the trunk portion 22a and the conductive segment 22-2, A first resistance pattern 51 is provided. Further, a second resistance pattern 52 having a width (length in the vertical direction in the drawing) different from that of the first resistance pattern 51 is provided between the trunk portions 22a and 22b.

  In this state, since the conductive segments 22-1 and 22-2 are connected via the first resistance pattern 51, the resistance value can be adjusted in the range of 4 to 40Ω. On the other hand, when the trunk portion 22a is cut along the alternate long and short dash line α1 (appropriate position of the trunk portion 22a) shown in FIG. 9, the first resistance pattern 51 and the second resistance pattern are formed between the two conductive segments 22-1 and 22-2. 52 are connected by a series connection circuit. As a result, the resistance value can be adjusted in the range of 12 to 120Ω by trimming each of the resistance patterns 51 and 52.

  FIG. 10 is an equivalent circuit of each of the resistance patterns 51 and 52 shown in FIG. 9. When the trunk portion 22a is not cut, the switch SW3 is in an on (contact) state, and both ends of the variable resistor VR3 are short-circuited. Resistance adjustment using only the variable resistor VR4 becomes possible. On the other hand, when the trunk portion 22a is cut at α1 in FIG. 9, the switch SW3 is turned off (opened), so that the resistance can be adjusted by the two variable resistors VR3 and VR4 connected in series.

  In this way, in the liquid level detection device 10 according to the second embodiment, among the plurality of conductive segments 22, the branch portions 22b are formed outside the conductive segments (end conductive segments) 22-1 provided at the ends. In addition, since the second resistance pattern 52 is provided between the trunk portion 22a and the branch portion 22b, the resistance setting using only the first resistance pattern 51, and the first resistance pattern 51 and the second resistance pattern 52 are provided. Any one of the resistance settings using the series connection circuit of the resistance pattern 52 can be selected, and only the resistance value at the end (the resistance value at the liquid level L is the lowest level or near the highest level) is set widely. This is useful when

  Further, since the trunk portion 22a of the conductive segment 22-1 is branched to the branch portion 22b, it is not necessary to take a large space in the longitudinal direction of the conductive segment 22, and the resistance substrate 21 is reduced in size, weight and space. be able to.

[Description of Third Embodiment]
Next, a third embodiment of the liquid level detection device 10 according to the present invention will be described. FIG. 11 is an explanatory diagram illustrating a configuration of a resistance substrate 21c according to the third embodiment. The resistance substrate 21c according to the third embodiment is compared with the resistance substrate 21b of FIG. 8 described in the second embodiment, and the conductive segment (edge conductive segment) 22-1 at the left end and the conductive layer adjacent thereto. The configuration of the segment (adjacent conductive segment) 22-2 is different. Hereinafter, this difference will be described in detail.

  FIG. 12 is an explanatory diagram showing a detailed configuration of the conductive segments 22-1 and 22-2 provided on the resistance substrate 21c shown in FIG. As shown in the figure, the two conductive segments 22-1 and 22-2 provided at the end portions are bent into a “U” shape at a predetermined interval. That is, the conductive segment 22-1 includes three parts, a main body part 22-1a, a communication part 22-1b, and a tip part 22-1c. The directions of the main body 22-1a and the tip 22-1c are shifted by 180 degrees. Similarly, the conductive segment 22-2 includes three parts: a main body part 22-2a, a communication part 22-2b, and a tip part 22-2c. The main body 22-2a and the front end 22-2c are deviated by 180 degrees. Further, a first resistance pattern 51 is provided between the two main body portions 22-1a and 22-2a, and a second resistance pattern 52 is provided between the two tip portions 22-1c and 22-2c.

  When the resistance value between the two conductive segments 22-1 and 22-2 is set using the second resistance pattern 52, the first resistance pattern 51 is cut by trimming, The resistance pattern 52 is trimmed by a predetermined length and set to an arbitrary resistance value. When the resistance value is set using the first resistance pattern 51, the communication portions 22-1b and 22-2b are cut at the portion indicated by the alternate long and short dash line β1 in the figure, and the first resistance pattern An arbitrary resistance value is set by trimming 51 by a predetermined length. The equivalent circuit is the same circuit as that shown in FIG.

  In this manner, in the liquid level detection device 10 according to the third embodiment, the two conductive segments 22-1 and 22-2 provided at the end portions are bent into a “U” shape, and the main body portion 22-1a. And 22-2a, the first resistance pattern 51 is provided, and the second resistance pattern 52 is provided between the tip portions 22-1c and 22-2c. Similarly to the first embodiment described above, by trimming at least one of the first resistance pattern 51 and the second resistance pattern 52 or not trimming, the two conductive segments 22-1, Since the resistance value between 22-2 is set, a wide range of resistance values can be set. Therefore, it is effective when it is required to set only the resistance value of the end portion (the resistance value of the liquid level L at the lowest level or near the highest level).

  Further, since the two conductive segments 22-1 and 22-2 disposed at the end portions are formed by bending in a “U” shape, it is not necessary to take a large space in the longitudinal direction of the conductive segment 22. Thus, the resistance substrate 21 can be reduced in size, weight, and space.

  As mentioned above, although the liquid level detection apparatus of this invention was demonstrated based on embodiment of illustration, this invention is not limited to this, The structure of each part is replaced with the thing of the arbitrary structures which have the same function. be able to.

  For example, in each of the above-described embodiments, the example in which the two resistance patterns of the first resistance pattern 51 and the second resistance pattern are used has been described, but three or more resistance patterns may be used. In this case, for example, as shown in the equivalent circuit of FIG. 13, a resistance pattern that can be adjusted within a range of 1 to 3Ω, a resistance pattern that can be adjusted within a range of 8 to 80Ω, and a resistance pattern that can be adjusted within a range of 4 to 40Ω. By providing a simple resistance pattern, the resistance value can be set in a wider range.

  The present invention can be used, for example, for detecting the liquid level of a fuel tank mounted on a vehicle.

DESCRIPTION OF SYMBOLS 10 Liquid level detection apparatus 11 Float 12 Float arm 13 Detection apparatus main body 14 Sliding arm 14a 1st contact 14b 2nd contact 21, 21, 21a, 21b, 21c Resistance board 22 (22-1 to 22-n) Conductive segment 22a Trunk part 22b Branch part 22-1a, 22-2a Main body part 22-1b, 22-2b Communication part 22-1c, 22-2c Tip part 24 Common electrode 26 Reference electrode 28 Measurement electrode 29 Resistance measuring instrument 51 First resistance pattern 52 First 2 resistance pattern 53 Resistance P Rotating shaft

Claims (5)

A liquid level detection device for detecting the liquid level by changing a resistance value between two points according to a liquid level to be measured and measuring the resistance value,
A conductive sliding arm that is displaced according to the change in the liquid level and slides on the substrate in accordance with the displacement;
A plurality of conductive segments provided on the substrate, formed in a strip shape spaced apart from each other, and disposed along a sliding direction of the sliding arm;
A first resistance pattern disposed across the conductive segments and connecting the conductive segments;
A second resistance pattern disposed at at least one location between the conductive segments to connect adjacent conductive segments and spaced apart from the first resistance pattern;
Trimming or cutting at least one of the first resistance patterns between the conductive segments , and trimming or cutting at least one of the second resistance patterns . Set the resistance value arbitrarily,
One of the plurality of conductive segments is a first measurement point, the sliding arm is a second measurement point, and the liquid level is determined based on a resistance value between the first measurement point and the second measurement point. A liquid level detecting device characterized by detecting the above.   2. The liquid level detection device according to claim 1, wherein the first resistance pattern and the second resistance pattern have different resistance values between the conductive segments in a state before the trimming process.   The liquid level detection device according to claim 1, wherein the second resistance pattern is disposed across the plurality of conductive segments. A liquid level detection device for detecting the liquid level by changing a resistance value between two points according to a liquid level to be measured and measuring the resistance value,
A conductive sliding arm that is displaced according to the change in the liquid level and slides on the substrate in accordance with the displacement;
A plurality of conductive segments provided on the substrate, formed in a strip shape spaced apart from each other, and disposed along a sliding direction of the sliding arm;
Among the conductive segments, the end conductive segment disposed at the end and the adjacent conductive segment adjacent to the end conductive segment face the main body and the direction bent by 180 degrees with respect to the main body, respectively. Having a tip,
Furthermore, a first resistance pattern disposed across the conductive segments and connecting the conductive segments;
A second resistance pattern disposed between a tip portion of the end conductive segment and a tip portion of the adjacent conductive segment,
At least one of the first resistance pattern and the second resistance pattern between the conductive segments is trimmed, or the resistance value between the conductive segments and between the tip portions is arbitrarily set without trimming. Set to
Furthermore, when setting the resistance value, if the second resistance pattern is not necessary, the end conductive segment and the adjacent conductive segment, between the body portion and the tip portion, is cut,
One of the plurality of conductive segments is a first measurement point, the sliding arm is a second measurement point, and the liquid level is determined based on a resistance value between the first measurement point and the second measurement point. A liquid level detecting device characterized by detecting the above. A liquid level detection device for detecting the liquid level by changing a resistance value between two points according to a liquid level to be measured and measuring the resistance value,
A conductive sliding arm that is displaced according to the change in the liquid level and slides on the substrate in accordance with the displacement;
A plurality of conductive segments provided on the substrate, formed in a strip shape spaced apart from each other, and disposed along a sliding direction of the sliding arm;
A first resistance pattern disposed across the conductive segments and connecting the conductive segments; and
An end conductive segment provided at at least one end of the plurality of conductive segments has a trunk portion and a branch portion that branches to the outside thereof, and a second resistor is provided between the trunk portion and the branch portion. Arrange the pattern,
Trimming or cutting at least one of the first resistance patterns between the conductive segments , and the resistance of the trunk and the branch without trimming or trimming the second resistance pattern A value is arbitrarily set, and the end conductive segment sets a resistance value between the end conductive segment and an adjacent conductive segment according to whether or not to cut the appropriate portion of the trunk,
One of the plurality of conductive segments is a first measurement point, the sliding arm is a second measurement point, and the liquid level is determined based on a resistance value between the first measurement point and the second measurement point. A liquid level detecting device characterized by detecting the above.

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