CN110865222A

CN110865222A - Current sensor

Info

Publication number: CN110865222A
Application number: CN201810990043.7A
Authority: CN
Inventors: 刘双; 陆翠兴; 高洪良; 杨伟; 唐新颖
Original assignee: BYD Co Ltd
Current assignee: BYD Semiconductor Co Ltd
Priority date: 2018-08-28
Filing date: 2018-08-28
Publication date: 2020-03-06

Abstract

The utility model relates to a current sensor, wherein, including casing, magnetic core subassembly, magnetic induction chip, circuit board and circular telegram conductor, the magnetic core subassembly with the circuit board all sets up in the casing, the magnetic core subassembly is including the magnetic core that has the air gap and twine the compensation coil of establishing on this magnetic core surface, magnetic core integrated into one piece just is formed with closed cavity, be constructed in the closed cavity the air gap, the magnetic induction chip with the adjacent setting of air gap is in the closed cavity, the circular telegram conductor passes closed cavity and fixed to on the casing, just compensation coil draw forth the end with the output of magnetic induction chip all is connected to on the circuit board. The magnetic core formed integrally is high in structural strength and does not influence magnetic field precision, an air gap is formed in the closed cavity, the magnetic field of aggregation can be prevented from leaking, and therefore the precision of the current sensor can be improved.

Description

Current sensor

Technical Field

The present disclosure relates to the field of sensor technology, and in particular, to a current sensor.

Background

With the development of power electronic technology, the demand of high-performance current sensors is increasing, and the requirements of the current sensors on precision, temperature drift and linearity are also high. The Hall sensor is wide in engineering application at present due to simple principle and convenient control, but the Hall sensor has the defects of low sensitivity to a magnetic field and large temperature drift and null drift. The current sensor based on the fluxgate principle has the characteristics of unique magnetic induction capability, high sensitivity and high precision to an applied magnetic field and miniaturization, however, a magnetic core used by the current sensor based on the fluxgate principle in the current market is complex in forming, complex in assembly, very labor-wasting, high in assembly cost and inconvenient to realize.

Disclosure of Invention

An object of the present disclosure is to provide a current sensor having a simple structure and high accuracy.

In order to achieve the above object, the present disclosure provides a current sensor, including casing, magnetic core assembly, magnetic induction chip, circuit board and circular telegram conductor, the magnetic core assembly with the circuit board all sets up in the casing, the magnetic core assembly includes the magnetic core that has the air gap and twines the compensation coil of establishing on this magnetic core surface, magnetic core integrated into one piece just is formed with closed cavity, be constructed in the closed cavity the air gap, the magnetic induction chip with the air gap is adjacent to be set up in the closed cavity, the circular telegram conductor passes closed cavity and fixed to on the casing, just compensation coil's the end of drawing forth with the output of magnetic induction chip all is connected to on the circuit board.

Optionally, the closed cavity comprises a first cavity for the current-carrying conductor to pass through and a second cavity for accommodating the magnetic induction chip, and the first cavity and the second cavity are communicated through the air gap.

Optionally, the cross-sectional area of the first cavity is greater than the cross-sectional area of the second cavity.

Optionally, the first cavity includes a first main body portion and a first connecting portion, the second cavity includes a second main body portion and a second connecting portion, the first main body portion is formed into an inverted U shape and has two first sides and a first bottom side connected between the two first sides, one ends of the two first sides far away from the first bottom side respectively extend in opposite directions to form two first connecting sides arranged at intervals, the first connecting sides define the first connecting portion, correspondingly, the second main body portion is formed into a regular U shape matching with the inverted U shape and has two second sides and a second bottom side connected between the two second sides, one ends of the two second sides far away from the second bottom side extend in opposite directions to form two second connecting sides arranged at intervals, the second connecting sides define the second connecting portion, the adjacent first connecting edge and the second connecting edge are transited through a fillet, and a gap between the two fillets forms the air gap.

Optionally, the compensation coil is uniformly wound on the first body portion.

Optionally, an insulating protective sleeve is disposed on an outer surface of the first main body part.

Optionally, the housing includes an outer housing and an inner housing disposed inside the outer housing, the inner housing and the outer housing are disposed at an interval to form an accommodating space, and the magnetic core assembly and the circuit board are fixed in the accommodating space.

Optionally, the accommodating space has a spacing zone and is used for accommodating the zone that holds of first main part, hold the zone with first main part is isomorphic, spacing zone with second cavity isomorphism, and inside is provided with a plurality ofly and is used for connecting interior casing with the splice bar of shell body, and every the splice bar epirelief is provided with two first spacing muscle and the spacing muscle of second that set up by outer to interior interval in proper order, correspond on the circuit board and set up a plurality of draw-in grooves, every the draw-in groove inserts first spacing muscle with the joint arrives between the spacing muscle of second on the splice bar, just second base cartridge arrives the shell body with between the first spacing muscle, first joint limit with the second joint limit cartridge arrives between the second spacing muscle and the interior casing.

Optionally, the top of the first limiting rib has a first guide inclined plane facing the outer shell and a second guide inclined plane facing the second limiting rib, the first guide inclined plane and the second guide inclined plane extend obliquely in opposite directions along a direction away from the connecting rib, correspondingly, the top of the second limiting rib has a third guide inclined plane facing the inner shell and a fourth guide inclined plane facing the second guide inclined plane, and the third guide inclined plane and the fourth guide inclined plane extend obliquely in opposite directions along a direction away from the connecting rib.

Optionally, be provided with a plurality of contact pins that are used for being connected with the power on the circuit board, the contact pin has stiff end and pin output, a plurality of via holes have been seted up on the circuit board, the stiff end passes the via hole is in order to weld on the circuit board, the protrusion of pin output sets up the outside of casing.

The beneficial effect of this technique is: through providing a current sensor based on fluxgate principle to combine integrated into one piece's magnetic core, compare the form of assembling in a plurality of magnetic cores stack among the prior art, on the one hand, this magnetic core does not have the problem of assembly precision, saves installation time, another especially important one side, integrated into one piece structural strength is high, the joint strength's that produces when a plurality of magnetic cores splice problem can not appear, just so can not influence magnetic field accuracy yet, has further guaranteed this current sensor's precision. Meanwhile, a plurality of mounting parts can be saved in the integrated forming mode, so that the structure of the magnetic core is simpler. And the air gap forms in closed cavity, can avoid the magnetic field of gathering to leak, can further improve current sensor's precision.

Additional features and advantages of the disclosure will be set forth in the detailed description which follows.

Drawings

The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the description serve to explain the disclosure without limiting the disclosure. In the drawings:

FIG. 1 is an assembly view (unpackaged) of a current sensor provided by the present disclosure;

FIG. 2 is an internal block diagram of a current sensor provided by the present disclosure;

FIG. 3 is an enlarged view of portion A of FIG. 2;

FIG. 4 is an exploded view of a current sensor provided by the present disclosure;

FIG. 5 is a block diagram of a magnetic core provided by the present disclosure;

FIG. 6 is a block diagram of a magnetic core assembly provided by the present disclosure;

FIG. 7 is an internal block diagram of a housing provided by the present disclosure;

FIG. 8 is a block diagram of a circuit board provided by the present disclosure;

fig. 9 is an assembly view of the packaged current sensor.

Description of the reference numerals

1 casing 11 outer casing 12 inner casing

2 magnetic core assembly 21 magnetic core 22 compensation coil

3 magnetic induction chip 4 circuit board 41 card slot

42 via 5 through conductor 6 air gap

7 first body part of first cavity 711 of closed cavity 71

712 first connecting portion 7111 first side 7112 first bottom edge

72 second cavity 721 second body portion 722 second connecting portion

7211 the secondary side edge 7212 the secondary bottom edge 73 is rounded

8 accommodating space 81 limiting area 82 accommodating area

9 connecting rib 10, first limiting rib 20 and second limiting rib

30 pin 301 fixed end 302 pin output

101 first guiding incline 102 second guiding incline 201 third guiding incline

202 fourth guide slope 221 leading-out end 411 side wall

412 bottom wall 413 is rounded

Detailed Description

The following detailed description of specific embodiments of the present disclosure is provided in connection with the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the present disclosure, are given by way of illustration and explanation only, not limitation.

In the present disclosure, the use of directional words such as "inner and outer" means that the inner and outer definitions of the contours of the housing are meant, unless stated to the contrary.

As shown in fig. 1 to 9, the present disclosure provides a current sensor based on the fluxgate principle, which can improve parameters of the current sensor, such as accuracy, linearity, and temperature drift. Specifically including casing 1, magnetic core subassembly 2, magnetic induction chip 3, circuit board 4 and circular telegram conductor 5, magnetic core subassembly 2 and circuit board 4 all set up in casing 1, magnetic core subassembly 2 is including the magnetic core 21 that has air gap 6 and twine the compensation coil 22 of establishing on this magnetic core 21 surface, magnetic core 21 integrated into one piece just is formed with closed cavity 7, it has air gap 6 to construct in the closed cavity 7, magnetic induction chip 3 sets up in closed cavity 7 with air gap 6 is adjacent, circular telegram conductor 5 passes closed cavity 7 and fixes on casing 1, and compensation coil 22 draw forth end 221 and magnetic induction chip 3's output all be connected to on the circuit board 4.

Firstly, in this embodiment, the magnetic core 21 is integrally formed, and compared with a form of stacking and assembling a plurality of magnetic cores in the prior art, on one hand, the magnetic core has no problem of assembling precision, so that the installation time is saved, on the other hand, the magnetic core is particularly important, the integrally formed structural strength is high, and the problem of connection strength generated when the plurality of magnetic cores are spliced, for example, does not occur, so that the magnetic field precision is not affected, and the precision of the current sensor is further ensured. Meanwhile, the integral molding mode saves a plurality of installation parts, so that the structure of the magnetic core 21 is simpler. And air gap 6 forms in closed cavity 7, compares hall principle, can avoid the magnetic field of gathering to leak, can further improve current sensor's precision.

The specific working process is as follows: when the magnetic field generated by the electrifying conductor 5 (such as a copper bar) after being electrified is gathered by the magnetic core 21 and is induced to the magnetic induction chip 3 arranged in the closed cavity 7, the magnetic induction chip 3 converts the generated magnetic signal into an electric signal to be output, so that a compensation current is obtained, the compensation current generates a compensation magnetic field through the multi-turn compensation coil 22, the compensation magnetic field is just opposite to the magnetic field generated by the detected current (the magnetic field generated by the electrifying conductor 5), so that the original magnetic field is compensated, at the moment, the magnetic induction chip 3 plays a role of zero magnetic flux, and at the moment, the electrifying current of the electrifying conductor 5 can be measured and calculated through the compensation current. Once the magnetic field is out of balance, the magnetic induction chip 3 can output signals, and after power amplification, corresponding compensation current flows through the compensation coil to compensate the unbalanced magnetic field, so that a dynamic balance process is realized.

Specifically, as shown in fig. 5, in the present embodiment, the closed cavity 7 includes a first cavity 71 for passing the current conductor 5 therethrough and a second cavity 72 for accommodating the magnetic induction chip 3, and the first cavity 71 and the second cavity 72 communicate through the air gap 6. That is, by the arrangement of the two cavities, the air gap 6 is formed. At the same time, in order to reduce the volume of the current sensor, the circuit board 4 is also accommodated in the second cavity 72 at the same time in the present embodiment.

The present magnetic core may be constructed in any suitable manner, as shown in fig. 5 and 6, as an embodiment, the first cavity 71 includes a first main body 711 and a first connecting portion 712, the second cavity 72 includes a second main body 721 and a second connecting portion 722, the first main body 711 is formed in an inverted U-shape and has two first sides 7111 and a first bottom 7112 connected between the two first sides 7111, ends of the two first sides 7111 far from the first bottom 7112 respectively extend toward each other to form two first connecting sides disposed at intervals, the first connecting sides define the first connecting portions 712, correspondingly, the second main body 721 is formed in a regular U-shape matching the inverted U-shape and has two second sides 7211 and a second bottom 7212 connected between the two second sides 7211, ends of the two second sides 7211 far from the second bottom 7212 extend toward each other to form two second connecting sides disposed at intervals, the second connecting edge defines a second connecting portion 722, adjacent first and second connecting edges transition by rounded corners 73, and a gap between two rounded corners 73 forms an air gap 6. Wherein, there is not the clearance between first connection limit and the second connection limit, can play the effect that reduces current sensor volume.

And in order to further reduce the volume of the current sensor, in the present embodiment, the cross-sectional area of the first cavity 71 is larger than that of the second cavity 72. That is, the second cavity 72 only needs to be able to satisfy the space for accommodating the magnetic induction chip 3, so as to avoid occupying an excessive area.

As shown in fig. 6, the compensation coil 22 is uniformly wound on the first body 711, and the coil rotates in the direction of c01 toward c02 as shown in fig. 4, and is wound from one of the first sides 7111 to the other first side 7111 through the first bottom 7112. And the thickness of the coil is uniform, so that the uniformity of the magnetic flux density in the magnetic core is ensured, and the precision of the current sensor is improved.

In order to avoid the conduction between the compensation coil and the magnetic core 21 when the compensation coil 22 is wound, in the present embodiment, an insulating protective sleeve is disposed on the outer surface of the first body 711 to protect the coating layer of the compensation coil from being damaged, thereby preventing the conduction phenomenon.

Further, as shown in fig. 7, in the present embodiment, the case 1 includes an outer case 11 and an inner case 12 disposed inside the outer case 11, the inner case 12 is disposed at a distance from the outer case 11 to form the housing space 8, and the magnetic core assembly 2 and the circuit board 4 are fixed in the housing space 8. That is, the magnetic core assembly 2 and the circuit board 4 are accommodated by the housing 1, and the magnetic core assembly and the circuit board are protected and fixed. As shown in fig. 9, the housing 1 is a plastic part formed by injection molding, and after accommodating the circuit board 4 and the magnetic core assembly 2, the housing is sealed by glue filling and packaging, so that the sealing effect is good, specifically, the housing can be packaged by pouring insulating polyurethane, the polyurethane material has excellent elasticity, is resistant to aging and weathering, dustproof and shock-resistant, has good sealing performance of the overall structure, and can protect the internal structure of the current sensor from being damaged.

Specifically, as shown in fig. 2, 3 and 7, in the present embodiment, the accommodating space 8 has a limiting area 81 and an accommodating area 82 for accommodating the first main body 711, the accommodating area is shaped like the first main body 711, the limiting area 81 is shaped like the second cavity 72, and a plurality of connecting ribs 9 for connecting the inner housing 12 and the outer housing 11 are arranged inside the accommodating area, and each connecting rib 9 is protrudingly provided with two first limiting ribs 10 and two second limiting ribs 20 arranged at intervals from outside to inside, the circuit board 4 is correspondingly provided with a plurality of slots 41, each slot 41 is inserted between the first limiting rib 10 and the second limiting rib 20 to be clamped to the connecting rib 9, the second bottom edge 7212 is inserted between the outer housing 11 and the first limiting rib 10, and the first connecting edge and the second connecting edge are inserted between the second limiting rib 20 and the inner housing 12.

Wherein, first spacing muscle 10 and the spacing muscle 20 of second are used for fixing a position circuit board 4 after on the splice bar 9 is connected to circuit board 4 joint, make circuit board 4 can not swing, make its firm being connected to on the splice bar 9, on the other hand simultaneously, first spacing muscle 10 and shell body 11 have restricted the activity of second base 7212 of second cavity 72 jointly, correspondingly, the activity on first connection limit and second connection limit has then been restricted jointly to spacing muscle 20 of second and interior casing 12, thereby finally make magnetic core assembly 2 fixed in accommodating space 8. Meanwhile, for convenient installation, the accommodating space 8 is in clearance fit with the magnetic core assembly 2. And the corner of shell body 11 forms respectively into the fillet structure, avoids exposing the shell body in outside and produces sharp portion, injures the user.

Moreover, as shown in fig. 8, the above-mentioned card slot 41 is formed in a U shape and has two side walls 411 and a bottom wall 412, the end of the side wall 411 far from the bottom wall 412 is formed into a rounded corner 413, and the transition of the rounded corner structure makes the installation process more convenient and the operation easier.

To further facilitate the installation of the magnetic core assembly 2 and the circuit board 4, as shown in fig. 7, in the present embodiment, the top of the first limiting rib 10 has a first guiding inclined surface 101 facing the outer housing 11 and a second guiding inclined surface 102 facing the second limiting rib 20, the first guiding inclined surface 101 and the second guiding inclined surface 102 extend obliquely toward each other in a direction away from the connecting rib 9, correspondingly, the top of the second limiting rib 20 has a third guiding inclined surface 201 facing the inner housing 12 and a fourth guiding inclined surface 202 facing the second guiding inclined surface 102, and the third guiding inclined surface 201 and the fourth guiding inclined surface 202 extend obliquely toward each other in a direction away from the connecting rib 9.

Above each direction inclined plane homoenergetic plays the effect of direction in the installation, convenient quick installation. The second guiding inclined surface 102 and the fourth guiding inclined surface 202 are cooperatively formed into a substantially bell mouth shape, which facilitates the installation of the guiding circuit board 4. And the inclination of each guide inclined plane can be inconsistent and is determined according to the actual installation requirement.

In order to realize connection with an external power supply, as shown in fig. 8, a plurality of pins 30 for connection with the power supply are disposed on the circuit board 4, each pin 30 has a fixed end 301 and a pin output end 302, a plurality of via holes 42 are disposed on the circuit board 4, the fixed end 301 passes through the via hole 42 to be soldered to the circuit board 4, and the pin output end 302 protrudes out of the housing 1 to be connected with the external power supply.

The preferred embodiments of the present disclosure are described in detail with reference to the accompanying drawings, however, the present disclosure is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present disclosure within the technical idea of the present disclosure, and these simple modifications all belong to the protection scope of the present disclosure.

It should be noted that, in the foregoing embodiments, various features described in the above embodiments may be combined in any suitable manner, and in order to avoid unnecessary repetition, various combinations that are possible in the present disclosure are not described again.

In addition, any combination of various embodiments of the present disclosure may be made, and the same should be considered as the disclosure of the present disclosure, as long as it does not depart from the spirit of the present disclosure.

Claims

1. The utility model provides a current sensor, characterized in that, includes casing (1), magnetic core subassembly (2), magnetic induction chip (3), circuit board (4) and circular telegram conductor (5), magnetic core subassembly (2) with circuit board (4) all set up in casing (1), magnetic core subassembly (2) including magnetic core (21) that have air gap (6) with twine and establish compensation coil (22) on this magnetic core (21) surface, magnetic core (21) integrated into one piece and be formed with closed cavity (7), be constructed in closed cavity (7) air gap (6), magnetic induction chip (3) with air gap (6) adjacent setting is in closed cavity (7), circular telegram conductor (5) pass closed cavity (7) and fix on casing (1), just the end of drawing forth (221) of compensation coil (22) with the output of magnetic induction chip (3) all is connected to on circuit board (4).

2. The current sensor according to claim 1, characterized in that said closed cavity (7) comprises a first cavity (71) for passing said current conductor (5) and a second cavity (72) for housing said magnetic induction chip (3), said first cavity (71) and said second cavity (72) communicating through said air gap (6).

3. The current sensor according to claim 2, characterized in that the cross-sectional area of the first cavity (71) is larger than the cross-sectional area of the second cavity (72).

4. The current sensor according to claim 2 or 3, wherein the first cavity (71) comprises a first main body portion (711) and a first connecting portion (712), the second cavity (72) comprises a second main body portion (721) and a second connecting portion (722), the first main body portion (711) is formed in an inverted U shape and has two first sides (7111) and a first bottom side (7112) connected between the two first sides (7111), ends of the two first sides (7111) far away from the first bottom side (7112) respectively extend toward each other to form two first connecting sides arranged at intervals, the first connecting sides define the first connecting portion (712), and correspondingly, the second main body portion (721) is formed in a regular U shape matching the inverted U shape and has two second sides (7211) and a second bottom side (7212) connected between the two second sides (7211), one end, far away from the second bottom edge (7212), of the two second side edges (7211) extends towards each other to form two second connecting edges arranged at intervals, the second connecting edges define the second connecting parts (722), the adjacent first connecting edges and the second connecting edges are transited through round corners (73), and gaps between the two round corners (73) form the air gaps (6).

5. The current sensor according to claim 4, wherein the compensation coil (22) is uniformly wound on the first body portion (711).

6. The current sensor according to claim 5, characterized in that the outer surface of the first body part (711) is provided with an insulating protective sheath.

7. The current sensor according to claim 4, wherein the housing (1) comprises an outer housing (11) and an inner housing (12) arranged inside the outer housing (11), the inner housing (12) being arranged at a distance from the outer housing (11) to form a receiving space (8), the magnetic core assembly (2) and the circuit board (4) being fixed in the receiving space (8).

8. The current sensor according to claim 7, wherein the accommodating space (8) has a limiting region (81) and an accommodating region (82) for accommodating the first main body part (711), the accommodating region (82) is conformal to the first main body part (711), the limiting region (81) is conformal to the second cavity (72), and a plurality of connecting ribs (9) for connecting the inner housing (12) and the outer housing (11) are arranged inside the accommodating region, each connecting rib (9) protrudes and is provided with two first limiting ribs (10) and two second limiting ribs (20) which are sequentially arranged from outside to inside at intervals, the circuit board (4) is correspondingly provided with a plurality of clamping grooves (41), and each clamping groove (41) is inserted between the first limiting ribs (10) and the second limiting ribs (20) to be clamped on the connecting ribs (9), and the second bottom edge (7212) is inserted between the outer shell (11) and the first limiting rib (10), and the first connecting edge and the second connecting edge are inserted between the second limiting rib (20) and the inner shell (12).

9. The current sensor according to claim 8, wherein the top of the first stopper rib (10) has a first guide slope (101) facing the outer housing (11) and a second guide slope (102) facing the second stopper rib (20), the first guide slope (101) and the second guide slope (102) extend obliquely toward each other in a direction away from the connecting rib (9), and correspondingly, the top of the second stopper rib (20) has a third guide slope (201) facing the inner housing (12) and a fourth guide slope (202) facing the second guide slope (102), and the third guide slope (201) and the fourth guide slope (202) extend obliquely toward each other in a direction away from the connecting rib (9).

10. The current sensor according to claim 1, wherein a plurality of pins (30) for connecting with a power supply are disposed on the circuit board (4), the pins (30) have a fixing end (301) and a pin output end (302), a plurality of through holes (42) are disposed on the circuit board (4), the fixing end (301) passes through the through holes (42) to be soldered on the circuit board (4), and the pin output end (302) is protruded to the outside of the housing (1).