Oil level sensor

Abstract

The utility model provides an oil level sensor which solves the problem that an existing sensor is short in service life. The oil level sensor comprises a support and a floating ball assembly, the floating ball assembly comprises a swing arm and a magnetic block fixed to one end of the swing arm, the swing arm is hinged to the support through a rotating shaft, and a sensing assembly is fixed to the support and arranged on the front side of the swing arm; the sensing assembly comprises a ceramic circuit board and a housing fixed on the front side of the ceramic circuit board, and a closed cavity is formed between the housing and the ceramic circuit board; comb-tooth-shaped spring pieces are vertically fixed in the closed cavity, the spring pieces are arranged right in front of the ceramic circuit board, and the spring pieces and the ceramic circuit board are distributed at intervals; the two ends of the spring piece are a comb tooth part and a solid part respectively, two sets of conductive strips are arranged on the ceramic circuit board, one ends of the two sets of conductive strips extend to the rear side face of the ceramic circuit board, and the other ends of the two sets of conductive strips are electrically connected with the solid part and right face the comb tooth part respectively. The swing arm swings to enable the magnetic block to be close to or away from the comb tooth part. The oil level sensor is long in service life.

Description

Technical Field

[0001] The utility model relates to a sensor, in particular to an oil level sensor. Background Art

[0002] The oil level sensor, also known as the fuel (Oil) Level Sensor, is a part used to detect the position (height) of oil in a container.

[0003] Existing oil level sensors, such as a float magnetic reed water level switch disclosed in the China Patent Library (application number: 201020631902.2), are mainly composed of a body, a rotating plate, a rotating frame, a movable rod, a magnet, a limit ring, a bracket, a wiring pin, a float, and a limit pin; the bracket and the wiring pin are both installed in the inner cavity of the body; the magnet is fixedly connected to the upper end of the movable rod, the float is sleeved in the middle of the movable rod, the limit ring is detachably connected to the lower part of the movable rod, the upper end of the movable rod is inserted into the guide groove of the body, and a notch of the guide groove is fixed to prevent the movable rod from moving. The upper end of the limit pin is released from the body; the rotating piece has a door-shaped channel for the upper end of the movable rod equipped with a magnet to pass through, and a notch is provided in the middle of the two side walls of the channel to divide the two side walls into upper and lower parts; one end of the rotating frame is fixed to the outer wall of the rotating piece door-shaped channel, a moving contact piece is installed on the free end of the rotating frame, a rotating shaft is provided in the middle of the rotating frame, the rotating shaft can be rotatably abutted on the bracket and can swing around the abutment, a fixed contact piece is installed on the bracket, the position of the fixed contact piece is located on the swinging trajectory of the moving contact piece on the rotating frame and can contact the moving contact piece on the rotating frame when swinging.

[0004] When the water level switch is used, the magnetic block drives the rotating frame to rotate around the rotating shaft to make the moving contact piece and the fixed contact piece slide in contact or separate to realize liquid level detection. However, the swing of the rotating frame and the sliding contact between the moving and fixed contact pieces will cause effective wear, affecting the life of the entire water level switch. Utility Model Content

[0005] The utility model aims to solve the above problems in the prior art and proposes an oil level sensor with a long service life.

[0006] The purpose of the utility model can be achieved through the following technical solutions: an oil level sensor, comprising a bracket and a float assembly, the float assembly comprising a swing arm and a magnetic block fixed at one end of the swing arm, the swing arm is hinged on the bracket through a horizontally arranged rotating shaft, characterized in that a sensor assembly is fixed on the bracket, and the sensor assembly is arranged on the front side of the swing arm; the sensor assembly comprises a vertically arranged ceramic circuit board and a cover shell fixed on the front side of the ceramic circuit board, and a closed cavity is formed between the cover shell and the ceramic circuit board; a spring sheet in the shape of comb teeth and made of magnetic conductive material is vertically fixed in the closed cavity, the spring sheet is arranged in front of the ceramic circuit board and the two are spaced apart; the two ends of the spring sheet are respectively a comb tooth part and a solid part, the ceramic circuit board has two groups of conductive strips, one end of the two groups of conductive strips extends to the rear side of the ceramic circuit board, and the other ends of the two groups of conductive strips are respectively electrically connected to the solid part and arranged opposite to the comb tooth part; the axes of the spring sheet and the rotating shaft are arranged in parallel, and the swing of the swing arm can make the magnetic block approach or move away from the comb tooth part.

[0007] When in use, the float of the float assembly is in the oil and drives the swing arm to swing through the change in liquid level. When the magnetic block gradually approaches the comb teeth, the comb teeth will deform backward and contact with the corresponding conductive strip to form a loop, thereby changing the effective resistance value of the ceramic circuit board. In actual use, the oil level condition is judged by detecting the above resistance value change.

[0008] The present application utilizes non-contact cooperation between a magnetic block and a spring sheet to realize oil level detection. Meanwhile, the front side of the ceramic circuit board and the spring sheet are both arranged in a closed cavity and do not contact the fuel. This can effectively avoid relative sliding wear of the components and fuel corrosion, thereby greatly improving the service life of the oil level sensor.

[0009] In the above oil level sensor, an insulating sheet is vertically arranged between the above ceramic circuit board and the spring sheet, and the front and rear sides of the insulating sheet are respectively attached to the solid part and the ceramic circuit board. The insulating sheet is used to support the spring sheet to stably separate the ceramic circuit board and the spring sheet to ensure stable operation of the sensor.

[0010] In the above-mentioned oil level sensor, the insulating sheet and the ceramic circuit board have the same length extension direction, so as to increase the contact area between the insulating sheet and the spring sheet and form better support.

[0011] In the above-mentioned oil level sensor, the solid part is fixed on the ceramic circuit board through the insulating sheet to facilitate the assembly of the spring sheet, and has the advantages of simple structure and convenient installation.

[0012] In the above-mentioned oil level sensor, the closed cavity is filled with an inert gas to isolate the air from the outside, prevent the conductive strip, spring sheet and other components from being oxidized, and further extend the service life of the oil level sensor.

[0013] In the above-mentioned oil level sensor, the front end of the housing is closed and the rear end is open. The ceramic circuit board is pressed on the rear end surface of the housing to close the rear port of the housing, so that a closed cavity is stably formed between the ceramic circuit board and the housing, and the structure is relatively simple.

[0014] In the above oil level sensor, the cover shell and the ceramic circuit board are sealed and fixedly connected by brazing.

[0015] In the above-mentioned oil level sensor, both sides of the insulating sheet are fixedly connected to the ceramic circuit board and the spring sheet respectively by bonding.

[0016] In the above oil level sensor, a connecting strip is integrally formed on one side of the solid part, the length of the connecting strip extends along the length direction of the ceramic circuit board, and the solid part is electrically connected to the corresponding conductive strip through the connecting strip to facilitate design and assembly.

[0017] In the above-mentioned oil level sensor, the thickness of the insulating sheet is 0.3 mm to 0.5 mm, so as to ensure that the spring sheet can be deformed to stably contact with the corresponding conductive sheet.

[0018] Compared with the existing technology, this oil level sensor has the following advantages:

[0019] 1. The present application utilizes non-contact cooperation between a magnetic block and a spring sheet to realize oil level detection. At the same time, the front side of the ceramic circuit board and the spring sheet are both arranged in a closed cavity and do not contact the fuel. This can effectively avoid relative sliding wear of various components and fuel corrosion, greatly improving the service life of the oil level sensor.

[0020] 2. The insulating sheet is used to support the spring sheet to stably separate the ceramic circuit board and the spring sheet to ensure stable operation of the sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a three-dimensional schematic diagram of the oil level sensor.

[0022] Figure 2 Figure 2 is a schematic diagram of the location of the swing arm and sensor components.

[0023] Figure 3 It is a schematic diagram of the structure of the sensor component after removing the cover.

[0024] Figure 4 is a cross-sectional schematic diagram of the sensor assembly.

[0025] Figure 5 It is a schematic diagram of the structure of the spring sheet.

[0026] In the figure, 1, bracket; 2, swing arm; 3, float; 4, connecting rod; 5, magnet; 6, rotating shaft; 7, ceramic circuit board; 7a, conductive strip; 8, cover; 9, spring sheet; 9a, comb tooth part; 9b, solid part; 9c, connecting strip; 10, insulating sheet. DETAILED DESCRIPTION

[0027] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0028] like Figure 1 As shown, the oil level sensor includes a bracket 1 and a float assembly, wherein the float assembly includes a swing arm 2, a float 3, and a connecting rod 4 for connecting one end of the swing arm 2 and the float 3. The swing arm 2 is made of a non-magnetic material, and a magnetic block 5 is fixed to the other end of the swing arm 2. In the actual product, a notch matching the magnetic block 5 is provided on the other end of the swing arm 2, and the magnetic block 5 is embedded in the notch.

[0029] Specifically,

[0030] like Figures 2 to 5 As shown, the swing arm 2 is hinged to the bracket 1 through a horizontally arranged shaft 6, and in the actual product, the swing arm 2 and the shaft 6 are an integrated structure and are a plastic one-piece. A sensor component is fixed to the bracket 1, and the sensor component is arranged on the front side of the swing arm 2. Figure 1 As shown, the sensor assembly includes a vertically arranged ceramic circuit board 7 and a cover 8 fixed on the front side of the ceramic circuit board 7, and a closed cavity is formed between the cover 8 and the ceramic circuit board 7. A spring sheet 9 in the shape of comb teeth and made of magnetic conductive material is vertically fixed in the closed cavity. The spring sheet 9 is arranged in front of the ceramic circuit board 7 and the two are spaced apart. The spring sheet 9 is an integrated structure, and the two ends of the spring sheet 9 are respectively a comb tooth portion 9a and a solid portion 9b. There are two groups of conductive strips 7a on the ceramic circuit board 7, one end of the two groups of conductive strips 7a extends to the rear side of the ceramic circuit board 7, and the other ends of the two groups of conductive strips 7a are respectively electrically connected to the solid portion 9b and arranged opposite to the comb tooth portion 9a. The axes of the spring sheet 9 and the rotating shaft 6 are arranged in parallel, and the swing of the swing arm 2 can make the magnetic block 5 approach or move away from the comb tooth portion 9a.

[0031] When in use, the float 3 of the float assembly is in the oil and drives the swing arm 2 to swing through the change in liquid level. When the magnetic block 5 gradually approaches the comb tooth portion 9a, the comb tooth portion 9a will deform backward and contact with the corresponding conductive strip 7a to form a loop, thereby changing the effective resistance value of the ceramic circuit board 7. In actual use, the oil level condition is judged by detecting the above-mentioned resistance value change.

[0032] The present application utilizes non-contact cooperation between the magnetic block 5 and the spring sheet 9 to realize oil level detection. Meanwhile, the front side of the ceramic circuit board 7 and the spring sheet 9 are both arranged in a closed cavity and do not contact the fuel. This can effectively avoid relative sliding wear of the components and fuel corrosion, thereby greatly improving the service life of the oil level sensor.

[0033] Further explanation, such as Figure 4As shown, an insulating sheet 10 is vertically arranged between the ceramic circuit board 7 and the spring sheet 9, and the front and rear sides of the insulating sheet 10 are respectively attached to the solid portion 9b and the ceramic circuit board 7. The insulating sheet 10 is used to support the spring sheet 9 to stably separate the ceramic circuit board 7 and the spring sheet 9 to ensure stable operation of the sensor. Preferably, the insulating sheet 10 and the ceramic circuit board 7 have the same length extension direction to increase the contact area between the insulating sheet 10 and the spring sheet 9 to form a better support.

[0034] In this embodiment,

[0035] The cover 8 is made of hot-rolled steel plate.

[0036] The spring sheet 9 is made of an iron-nickel alloy sheet, and the thickness is controlled to be 0.04 mm to 0.06 mm, so that it can be stably deformed under the attraction of the magnetic block 5 .

[0037] The solid part 9b is fixed on the ceramic circuit board 7 through the insulating sheet 10 to facilitate the assembly of the spring sheet 9, which has the advantages of simple structure and convenient installation. Preferably, both sides of the insulating sheet 10 are respectively fixed to the ceramic circuit board 7 and the spring sheet 9 by bonding.

[0038] The insulating sheet 10 is made of plastic material, and the thickness is controlled to be 0.3 mm to 0.5 mm.

[0039] The closed cavity is formed as follows: the front end of the housing 8 is closed and the rear end is open, and the ceramic circuit board 7 is pressed on the rear end surface of the housing 8 to close the rear port of the housing 8, so that a closed cavity is stably formed between the ceramic circuit board 7 and the housing 8. Preferably, the housing 8 and the ceramic circuit board 7 are sealed and fixedly connected by brazing.

[0040] like Figure 3 and Figure 5 As shown, a connecting strip 9c is integrally formed on one side of the solid portion 9b, and the length of the connecting strip 9c extends along the length direction of the ceramic circuit board 7. The solid portion 9b is electrically connected to the corresponding conductive strip 7a through the connecting strip 9c to facilitate design and assembly.

[0041] In actual products, the closed cavity is filled with inert gas to isolate the air from the outside, prevent the conductive strip 7a, spring sheet 9 and other components from being oxidized, and further extend the life of the oil level sensor. The inert gas is generally nitrogen, and during actual assembly, the lid is sealed with the circuit board by brazing in a nitrogen environment to achieve nitrogen filling in the closed cavity.

[0042] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. An oil level sensor, comprising a bracket (1) and a float assembly, wherein the float assembly comprises a swing arm (2) and a magnetic block (5) fixed to one end of the swing arm (2), wherein the swing arm (2) is hinged to the bracket (1) via a horizontally arranged rotating shaft (6), and wherein: A sensor assembly is fixed on the bracket (1), and the sensor assembly is arranged on the front side of the swing arm (2); the sensor assembly comprises a vertically arranged ceramic circuit board (7) and a cover shell (8) fixed on the front side of the ceramic circuit board (7), and a closed cavity is formed between the cover shell (8) and the ceramic circuit board (7); a comb-tooth-shaped spring sheet (9) made of a magnetic conductive material is vertically fixed in the closed cavity, and the spring sheet (9) is arranged in front of the ceramic circuit board (7) and the two are spaced apart; two ends of the spring sheet (9) are respectively a comb-tooth portion (9a) and a solid portion (9b); the ceramic circuit board (7) has two groups of conductive strips (7a), one end of the two groups of conductive strips (7a) extends to the rear side of the ceramic circuit board (7), and the other ends of the two groups of conductive strips (7a) are respectively electrically connected to the solid portion (9b) and arranged opposite to the comb-tooth portion (9a); the axes of the spring sheet (9) and the rotating shaft (6) are arranged in parallel, and the swing of the swing arm (2) can make the magnetic block (5) approach or move away from the comb-tooth portion (9a).

2. The oil level sensor according to claim 1, characterized in that: An insulating sheet (10) is vertically arranged between the ceramic circuit board (7) and the spring sheet (9), and the front and rear sides of the insulating sheet (10) are respectively attached to the solid portion (9b) and the ceramic circuit board (7).

3. The oil level sensor according to claim 2, characterized in that: The insulating sheet (10) and the ceramic circuit board (7) have the same length extension direction.

4. The oil level sensor according to claim 2 or 3, characterized in that: The solid portion (9b) is fixed on the ceramic circuit board (7) via an insulating sheet (10).

5. The oil level sensor according to claim 1, characterized in that: The closed cavity is filled with inert gas.

6. The oil level sensor according to claim 1, characterized in that: The front end of the cover shell (8) is closed and the rear end is open, and the ceramic circuit board (7) is pressed onto the rear end surface of the cover shell (8) to close the rear port of the cover shell (8).

7. The oil level sensor according to claim 6, characterized in that: The cover shell (8) and the ceramic circuit board (7) are sealed and fixedly connected by brazing.

8. The oil level sensor according to claim 4, characterized in that: Both sides of the insulating sheet (10) are respectively fixedly connected to the ceramic circuit board (7) and the spring sheet (9) by bonding.

9. The oil level sensor according to claim 1, characterized in that: A connecting strip (9c) is integrally formed on one side of the solid portion (9b); the length of the connecting strip (9c) extends along the length direction of the ceramic circuit board (7); and the solid portion (9b) is electrically connected to the corresponding conductive strip (7a) via the connecting strip (9c).

10. The oil level sensor according to claim 2 or 3, characterized in that: The thickness of the insulating sheet (10) is 0.3 mm to 0.5 mm.

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