CN106404124B - liquid level sensor - Google Patents

Abstract

The present invention provides a liquid level sensor, comprising: a resistance plate base; a resistance plate fixedly installed on the resistance plate base; a bracket provided with a sliding contact piece, and the sliding contact piece can slide on the resistance plate The lever arm is installed on the bracket; the float is installed on the lever arm; the cover is used to form an enclosed space, and the enclosed space has an opening relative to the liquid surface, and the opening is used to make the lever The arm is free to move, and the resistive piece and the sliding contact piece are at least partially located within the enclosed space. The liquid level sensor of the invention can still maintain the accuracy of measurement after a long time of use.

Description

liquid level sensor

technical field

The invention relates to a liquid level sensor, in particular to a liquid level sensor for measuring the oil level in a vehicle fuel tank.

Background technique

Among automobile instruments, the indication of oil quantity is very important, and the indication of oil quantity depends on the liquid level sensor. In the prior art, there is a liquid level sensor that drives a lever arm through a float, and the lever arm then drives a sliding contact piece set on the bracket to slide on the resistance piece to convert the liquid level change information into resistance change information, and then pass the signal The circuit and the output interface output the liquid level signal to the instrument, so that people can obtain the liquid level information.

However, the sliding contact piece and the resistor piece have been in contact with gasoline for a long time, and due to the influence of factors such as oil composition differences and impurities, after the liquid level sensor has been used for a long time, the contact between the sliding contact piece and the resistance piece has changed, so that The output resistance value deviates from the standard resistance value, and the output electrical signal representing the liquid level value changes, and finally the pointer cannot accurately reflect the change of the liquid level.

Contents of the invention

In order to overcome the above difficulties, the present invention aims to provide a liquid level sensor that can reduce or avoid the impact of gasoline on the sliding contact piece and the resistor plate, so that the liquid level sensor can still maintain the accuracy of measurement after a long time of use.

The present invention provides a liquid level sensor, comprising: a resistance plate base; a resistance plate fixedly installed on the resistance plate base; a bracket provided with a sliding contact piece, and the sliding contact piece can slide on the resistance plate The lever arm is installed on the bracket; the float is installed on the lever arm; the cover is used to form an enclosed space, and the enclosed space has an opening relative to the liquid surface, and the opening is used to make the lever The arm is free to move, and the resistive piece and the sliding contact piece are at least partially located within the enclosed space.

Preferably, the cover body is integrally formed.

Preferably, the liquid level sensor further includes a cover, a connecting arm and a housing, the connecting arm is connected to the cover and the housing, and the cover is installed on the cover.

Preferably, it further includes a cover, a connecting arm and a housing, the connecting arm is connected to the cover and the housing, the cover is installed on the housing, the housing and the housing The cover jointly forms the enclosed space.

Preferably, the cover is detachably mounted on the housing.

Preferably, the cover body is integrally formed with the casing.

Preferably, the cover body has a top body, a side body and a front body; the resistor sheet and the sliding contact sheet are close to the top body.

Preferably, the base of the resistive sheet is bent to form a first horizontal portion and a first vertical portion, and the bracket is bent to form a second horizontal portion and a second vertical portion corresponding to the resistive sheet, and the resistive sheet is located at the On the first horizontal part, the sliding contact piece is arranged on the second horizontal part.

Preferably, the liquid level sensor further includes a guide rail for assisting the installation and positioning of the resistor plate base.

The liquid level sensor of the present invention reduces the contact time between the resistance sheet and the sliding contact sheet and gasoline by means of the cover to form an enclosed space, and even prevents the resistance sheet and the sliding contact sheet from contacting gasoline. Compared with the existing solutions, the contact between the slider and the resistance sheet in the prior art will change so that the output resistance value deviates from the standard resistance value. The liquid level sensor of the present invention can still measure the accuracy.

Description of drawings

Fig. 1 is the schematic diagram that the liquid level sensor of the first embodiment of the present invention is installed in the gasoline tank;

Fig. 2 is an exploded view of the liquid level sensor shown in Fig. 1;

Fig. 3 is a sectional view of the liquid level sensor shown in Fig. 1;

Fig. 4 is the schematic diagram of the liquid level sensor of the second embodiment of the present invention;

Fig. 5 is an exploded view of the liquid level sensor shown in Fig. 4;

Fig. 6 is a schematic diagram of the cover body shown in Fig. 4;

Fig. 7 is an exploded view of a liquid level sensor according to a third embodiment of the present invention;

Fig. 8 is a schematic diagram of the internal structure of the cover assembly shown in Fig. 7;

Fig. 9 is a schematic diagram of the combination of the resistance sheet, the resistance sheet base, the sliding contact sheet, the bracket and the lever arm of the liquid level sensor shown in Fig. 7 .

Explanation of reference numbers

Cover 10 connecting arm 20

Lever arm 3 free section 31 middle section 32

The front flat wall surface 41 of the indicator section 33 housing 4

Guide rail 5, 5' blocking block 6, 6' slope surface 61

Resistor base 7 Resistor 15 First horizontal part 71

The first vertical part 72 bracket 8 sliding contact piece 9

Fixed clamping block 80 second horizontal part 81 second vertical part 82

Cover body 2 front body 21 rear body 22

Side body 23 Top body 24

Float 12 enclosed space 13

specific embodiment

The liquid level sensor of the present invention will be described in detail below with reference to the accompanying drawings.

1 to 3 are schematic diagrams of the first embodiment.

As shown in FIG. 1 , the liquid level sensor of the present invention is installed in a gasoline tank, and the liquid level sensor has a float 12 fixed on a lever arm 3 . The position of the float 12 changes with the change of the gasoline level, and then drives the lever arm 3 to deflect. The deflection of the lever arm 3 causes the resistance to change, which is reflected on the instrument, so that people can obtain the liquid level information.

As shown in Figure 2, the liquid level sensor includes a cover body 10, a connecting arm 20 and a roughly cylindrical housing 4 from top to bottom, the cover body 10 is used for fixing on the top of the gasoline tank, and the connecting arm 20 is used for fixed connection Cover 10 and housing 4 . The housing 4 has a front flat wall surface 41 . A pair of guide rails 5 and a blocking block 6 are arranged on the front flat wall 41 , and the blocking block 6 is located between the guide rails 5 .

The liquid level sensor also includes a resistor base 7 , a resistor 15 , a sliding contact 9 , a bracket 8 , a lever arm 3 , a cover 2 and a float 12 .

The resistor sheet 15 is fixedly mounted on the resistor sheet base 7, and the bracket 8 is rotatably mounted on the resistor sheet base 7, as shown in Fig. 3 , the rotation of the lever arm 3 drives the bracket 8 to rotate around the central axis I-I. The bracket 8 is provided with a sliding contact piece 9 , and the sliding contact piece 9 elastically abuts against the resistance piece 15 . When the support 8 rotates relative to the base 7 of the resistor sheet, the sliding contact piece 9 slides on the resistor sheet 15, so that the resistance changes.

The bracket 8 is provided with two pairs of fixed clamping blocks 80 for clamping and fixing the lever arm 3 in a cylindrical state, whereby the lever arm 3 is detachably mounted on the bracket 8 . The lever arm 3 is composed of three sections, namely a free section 31 fixedly connected to the float 12, an indicating section 33 extending in the same direction as the support 8, and an intermediate section 32 connecting the former two. The indicating segment 33 cooperates with the fixed clamping block 80 .

When assembling, the resistance sheet base 7, the resistance sheet 15, the sliding contact piece 9, the bracket 8 and the lever arm 3 form an assembly, and the assembly slides from bottom to top to the top of the front flat wall surface 41 through the guide rail 5, due to the blocking block 6 There is a slope surface 61 (referring to Fig. 3), therefore, the assembly can gradually transition until being positioned at the top of the blocking block 6, but the top surface of the blocking block 6 is perpendicular to the front flat wall surface 41, so that the assembly cannot fall down.

The cover body 2 is installed on the front flat wall surface 41 of the housing 4 , so that an enclosed space 13 is formed between the cover body 2 and the front flat wall surface 41 . In this embodiment, the cover body 2 is composed of four faces, which are respectively a top body 24, two side bodies 23 and a front body 21, which are shaped like a cuboid, and the rear body corresponding to the front flat wall surface 41 does not exist, and the bottom body Nor does it exist. When the cover body 2 is installed on the front flat wall 41 , only the bottom end of the enclosed space 13 formed correspondingly is not sealed for the flexible movement of the lever arm 3 .

When refueling in the gasoline tank, because there is gas in the enclosed space 13 formed inside the cover body 2, and the cover body 2 only has an opening at the bottom end, and the position of the opening at the bottom end is blocked by oil, so the gas cannot be discharged. At this time, although the liquid level of the gasoline tank gradually rises, the liquid level inside the cover body 2 remains unchanged, so that the gas is sealed in the enclosed space 13 jointly enclosed by the cover body 2 and the front flat wall surface 41, and the resistor sheet 15 and the sliding contact piece 9 are located in the enclosed space 13 full of air, thereby avoiding the possibility that the resistance piece 15 and the sliding contact piece 9 are soaked in gasoline, thus preventing the resistance piece 15 and the sliding contact piece 9 from being subjected to gasoline. Corrosion prevents the resistance sheet 15 and the sliding contact sheet 9 from being affected by impurities in the oil, so that the sliding of the sliding contact sheet 9 on the resistance sheet 15 is not affected by gasoline, so as to keep the contact sensitive and accurate.

Of course, in other embodiments, if the opening position of the bottom end of the cover body 2 is too upward, the enclosed space 13 formed between the cover body 2 and the front flat wall surface 41 is not large enough, so that the resistance sheet 15 and the sliding contact sheet 9 Part is located in enclosed space 13, like this, when refueling in gasoline tank, resistor plate 15 and sliding contact sheet 9 still may make lower part be located in gasoline immersion, and this still belongs within the essential spirit of the present invention. Like this, the setting of enclosing space, plays the degree that reduces resistive sheet 15 and sliding contact sheet 9 to be soaked in gasoline, has reduced resistive sheet 15 and sliding contact sheet 9 to be subjected to the impact of impurity in oil, makes sliding contact sheet 9 in The sliding on the resistance sheet 15 is affected by gasoline as little as possible, so as to keep contact sensitive and accurate as much as possible.

Therefore, in this embodiment, the position of the top surface body 24 of the cover body 2 is as close as possible to the upper end of the housing 4, so that the installation of the resistance sheet 15 and the sliding contact sheet 9 is as close as possible upward. In this way, it can be ensured that the enclosed space 13 formed in the cover body 2 is more reliable, and when the gasoline starts to be consumed, the resistance sheet 15 and the sliding contact sheet 9 are less likely to contact gasoline. In this way, the application function of the enclosed space 13 is more guaranteed.

4 to 6 are schematic diagrams of the second embodiment.

The main difference between the second embodiment and the first embodiment is the structure and position of the cover. As shown in Figures 5 and 6, in the second embodiment, the cover body 2' is composed of five faces, including a front body 21, a rear body 22, two side faces 23 and a top face body 24, similar to a cuboid , only the bottom body does not exist, so as to form an opening relative to the liquid surface, which is suitable for the free movement of the lever arm 3 . The rear body is attached to the front flat wall surface 41 .

The guide rail 5' and the blocking block 6' are not arranged on the front flat wall surface 41 of the housing 4, but the guide rail 5' and the blocking block 6' are arranged on the inner wall surface of the cover body 2'. In this embodiment, they are arranged on the rear body 22 on the wall facing the enclosed space. As shown in Figure 4, the whole cover body 2' is fixedly installed on the cover body 10. As shown in FIG. 6 , the arrow A indicates the sliding direction of the resistor base 7 .

In the first embodiment, since the front flat wall 41 of the cover body 2 needs to cooperate with the housing to form an enclosed space 13 with a common wall, this cooperative installation needs to pay attention to sealing; however, the cover body 2 of the second embodiment It is not necessary to form an enclosed space together with the front flat wall surface 41 of the housing, and the cover body 2 ′ in the second embodiment is integrally formed, which avoids the trouble of installation with the housing 4 . In addition, the cover body 2' is directly installed on the cover body 10, and the installation position of the cover body 10 is the top surface of the fuel tank. Therefore, the enclosed space formed inside the cover body 2' is almost located at the highest position inside the fuel tank, so that the resistor sheet 15 and the sliding contact piece 9 have avoided or reduced the possibility of being immersed in gasoline to the greatest extent.

7 to 9 are schematic diagrams of the third embodiment.

As shown in Figure 7, the liquid level sensor includes a cover body 10, a connecting arm 20 and a substantially cylindrical housing 4 from top to bottom, the cover body 10 is used for fixing on the top of the gasoline tank, and the connecting arm 20 is used for fixing The cover 10 and the casing 4 are connected. The liquid level sensor also includes a resistor base, a resistor 15 , a sliding contact 9 , a bracket, a lever arm 3 , a cover 2 and a float 12 .

As shown in Figures 8 and 9, the cover body 2 has a top body 24, two side bodies 23 and a front body 21; the base of the resistance sheet is bent to form a first horizontal portion 71 and a first vertical portion 72, and the bracket corresponds to the resistance The sheet base is bent to form a second horizontal portion 81 and a second vertical portion 82, the resistor sheet 15 is located on the first horizontal portion 71, and the sliding contact sheet 9 is arranged on the second horizontal portion 81; the first horizontal portion 71 and the second The horizontal parts 81 are all attached to the top surface body 24, in other words, the first horizontal part 71 and the second horizontal part 81 are all parallel to the top surface body 24; the second vertical part 82 corresponding to the bracket is correspondingly installed on the resistor base On the first vertical portion 72 of the seat. It can be understood that the rotation axis of the bracket relative to the base of the resistive sheet is located on the second vertical portion 82 .

When the lever arm 3 rotates, it drives the second vertical part 82 of the bracket to rotate, and the second vertical part 82 and the second horizontal part 81 are integrally formed, and the rotation of the second vertical part 82 inevitably drives the rotation of the second horizontal part 81; The first horizontal portion 71 of the resistor base is fixedly mounted on the top body 24 of the cover 2, and the first horizontal portion 71 of the resistor base is integrally formed with the first vertical portion 72, therefore, the first horizontal portion 71 and the first vertical portion 72 are integrally formed. The first vertical portion 72 remains stationary. Like this, resistor sheet 15 belongs to static, and slider 9 belongs to dynamic.

In summary, the liquid level sensor of the present invention adopts a cover body to form an enclosed space. This enclosed space is opposite to the opening of the liquid surface. When the liquid level rises during the refueling process, the opening is blocked by oil, and the enclosed space The gas is enclosed inside, so that the relative movement of the sliding contact piece and the resistance piece occurs in the enclosed space filled with gas, therefore, it is not soaked by gasoline, which can reduce the influence of gasoline, thereby maintaining sensitive contact to obtain accurate measurement value.

It should be understood that the cover body can not only be integrally formed with the shell body, but also can be detachably mounted on the shell body; or the cover body can be formed independently as a single-opening enclosed object.

It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the present invention can be The technical solution of the invention shall be modified or equivalently replaced without departing from the spirit and scope of the technical solution of the present invention.

Claims (5)

1. A liquid level sensor, characterized in that, comprising: Resistor base; The resistance sheet is fixedly installed on the base of the resistance sheet; The bracket is provided with a sliding contact piece, and the sliding contact piece slides on the resistance piece; a lever arm mounted on the bracket; a float mounted on said lever arm; Wherein, the base of the resistor sheet, the resistor sheet, the slider, the bracket and the lever arm form a combination; and The cover body is used to form an enclosed space, and the enclosed space has an opening relative to the liquid surface, and the opening is used to allow the lever arm to move freely, and the resistance sheet and the sliding contact sheet are at least partially located in the enclosure within the space; The housing, which is connected with the cover, has a front flat wall surface, a pair of guide rails and a blocking block are arranged on the front flat wall surface, and the blocking block is located between the guide rails; the blocking block has a slope surface; the The assembly slides to the upper part of the front flat wall through the guide rail, and the assembly is located above the blocking block. 2. The liquid level sensor according to claim 1, further comprising a cover and a connecting arm, the connecting arm is connected to the cover and the housing, and the cover is installed on the housing Generally, the housing and the cover together form the enclosed space. 3. The liquid level sensor according to claim 1, wherein the cover is detachably mounted on the housing. 4. The liquid level sensor according to claim 1, characterized in that, the cover is integrally formed with the housing. 5 . The liquid level sensor according to claim 1 , wherein the cover body has a top body, a side body and a front body; the resistor sheet and the sliding contact sheet are close to the top body. 6 .

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