CN112180115B

CN112180115B - Magnetoelectric wheel speed sensor

Info

Publication number: CN112180115B
Application number: CN201910588995.0A
Authority: CN
Inventors: 胡兴伟; 刘金龙
Original assignee: Lubo Automotive Electronics Qufu Co ltd
Current assignee: Lubo Automotive Electronics Qufu Co ltd
Priority date: 2019-07-02
Filing date: 2019-07-02
Publication date: 2023-06-30
Anticipated expiration: 2039-07-02
Also published as: CN112180115A

Abstract

The invention relates to a magnetoelectric wheel speed sensor, which comprises magnetic steel, a magnetizer, a choke plug, a winding shaft assembly, a coil, an inserting sheet and the like. Two positioning columns are arranged on the inserting sheet, and a boss is arranged at one end, far away from the positioning columns, of the wire winding shaft assembly. The raised cylindrical hole structure and the cylindrical boss structure in the bobbin assembly are used as three-way positioning in the die cavity, so that the stability is good.

Description

Magnetoelectric wheel speed sensor

Technical Field

The invention belongs to the technical field of sensors, and particularly relates to a magnetoelectric wheel speed sensor.

Background

Wheel speed sensors are an important component on vehicles. The wheel speed sensor used on the heavy vehicles such as trucks and vans at present is mainly a magnetoelectric wheel speed sensor, and generally comprises a sensor head body, an insert shell and a cable. The sensor head body consists of parts such as a wire reel assembly, a coil, a choke plug, a permanent magnet, a magnetizer, an injection molding body, a stainless steel protective cover and the like.

In the current magnetoelectric wheel speed sensor, there are the following problems:

1. the structure design of the wire reel assembly is complex, the positioning in the die cavity is poor, the wire winding area is limited, the combination stability of the built-in inserting sheet and the injection molding material is poor, and the cost of the head injection molding die is increased; while not facilitating the versatility of the parts in similar items.

2. Under the normal condition, the circumference surface of the choke plug main body is fixed by friction, and the injection molding piece is small and has poor roundness controllability, so that the injection molding piece is easy to be separated from a wire reel mounting hole, thereby reducing the production efficiency and even stopping wires; in addition, the fusion property with the choke plug and the injection molding material is poor, so that the overall tightness of the product is poor, and the life cycle is greatly reduced.

3. At present, the magnetic steel mostly adopts weak magnetic profile materials (such as AlNiCO 5), and has larger volume, so that the design of a winding shaft is heavy. The magnetizer is generally 08AL and X6Cr17 materials, and the magnetic permeability is weak as a whole.

4. The protection casing is generally fixed on the head body of moulding plastics through three-point riveting mode, and product leakproofness is relatively poor, and through the high low temperature alternating environment influence of the certain periodically of automobile body chassis, the easy production is rocked and is even dropped, leads to the product performance unstable to product life cycle reduces.

Disclosure of Invention

The following improved technical solutions are proposed herein in combination with the research and practical experience of the inventors in this field.

A magneto-electric wheel speed sensor comprising:

magnetic steel;

the magnetizer is connected with the magnetic steel;

a choke plug arranged on one side of the magnetic steel opposite to the magnetizer;

the bobbin assembly is of a hollow structure, and the magnetic steel, the magnetizer and the choke plug are arranged in the bobbin assembly;

a coil wound on the outside of the bobbin assembly and axially corresponding to a portion of the magnetizer;

the inserting piece is arranged on the radial outer side of the winding shaft assembly;

two positioning columns are arranged on the inserting sheet, and a boss is arranged at one end, far away from the positioning columns, of the wire winding shaft assembly.

The raised cylindrical hole structure and the cylindrical boss structure in the bobbin assembly are used as three-way positioning in the die cavity, so that the stability is good.

Furthermore, the sensor of the present invention may also include one or more of the following features:

-providing a sealing rib on said bulkhead;

-providing a groove on said bulkhead adapted to receive a sealing ring.

-providing a sealing bead at an end of the spool assembly remote from the locating post, the sealing bead being located on a portion extending radially of the spool assembly;

preferably, the sealing ribs are longitudinally and transversely staggered sealing ribs.

-a groove is provided outside the insert sheet;

preferably, the grooves are wavy.

-further comprising a shield surrounding the coil, bobbin assembly and magnetizer;

preferably, the protective cover is integrally molded with the coil and wire reel assembly by injection molding.

-the magnetic steel is N35UH strong magnetic mark, and the magnetizer is made of DT4C material.

Through the technical scheme, compared with the prior art, the invention has the following advantages:

1. the combination degree between the built-in inserting piece and the injection molding material is enhanced, the positioning stability of the winding shaft in the mold cavity is improved, the design of a winding area (comprising the wire inlet end and the wire outlet end) is humanized, and the production operation is easy.

2. The overall sealing performance of the product is improved.

3. And parts with high cost performance are accurately selected, the output performance of the product is improved, and the standardization and the universalization of the parts are realized.

4. The stainless steel protective cover, the winding shaft component and the injection molding material are integrated into a whole, so that the high temperature resistance, the product stability and the life cycle are greatly improved, the production efficiency is improved, and the production cost is reduced.

Drawings

Exemplary embodiments of the present invention are described with reference to the accompanying drawings, in which:

fig. 1 is an overall schematic view of a wheel speed sensor according to the present invention with a wire connected thereto.

Fig. 2 is a cross-sectional view of a wheel speed sensor according to the present invention.

Fig. 3 is a schematic view of a bulkhead of a wheel speed sensor according to the invention.

Fig. 4 is a front view of a spool assembly and tab according to the present invention.

Fig. 5 is a left side view of a spool assembly and tab according to the present invention.

Fig. 6 is a cross-sectional view taken along the direction C-C in fig. 5.

The figures are merely schematic and not necessarily to scale, and they show only those parts which are necessary in order to elucidate the invention, other parts being omitted or merely mentioned. That is, the present invention may include other components in addition to those shown in the drawings.

Detailed Description

The following describes the technical scheme of the present invention in detail with reference to the accompanying drawings.

Fig. 1 is an overall schematic view of a wheel speed sensor according to the present invention with a wire connected thereto. The sensor is generally indicated at 100 and is connected to a cable 200 for outputting a signal.

Fig. 2 is a cross-sectional view of the wheel speed sensor according to the present invention, which shows a specific structure of the wheel speed sensor 100. As shown in fig. 2, the sensor 100 includes a magnetic steel 101, a magnetizer 102, a choke plug 103, a coil 104, a bobbin assembly 105, and a plug 106.

The magnetic steel 101 is connected with the magnetizer 102, and the magnetizer are penetrated in the winding shaft assembly 105. A coil 104 is provided in a portion of a bobbin assembly 105 located radially outward of the magnetic conductor 102. The tab 106 is disposed radially outward of a portion of the spool assembly 105 located radially outward of the magnetic steel 101, and a wire clamping support 1061 and a connecting frame 1062 are provided on the tab 106. The wire clamping support 1061 is used for connecting with copper wires in the cable 200 in a riveting or soldering manner, and the connecting frame 1062 is used for winding a coil, so that a conductive loop is formed and a performance signal is generated.

The choke plug 103 is provided on the opposite side of the magnetic steel 101 from the magnetizer 102, and seals the magnetic steel 101 and the magnetizer 102, and the specific structure is shown in fig. 3. The bulkhead 103 has a sealing rib 1031 so as to be in interference fit with the inner hole of the bobbin assembly during assembly and easy to install, has good melting degree effect with injection molding materials, has good sealing performance, and ensures the air tightness of products after injection molding. The bulkhead 103 also has an annular groove 1032 as a spare structure for installing a seal ring for sealing protection in case the sealing performance does not meet the product requirements.

As the preferred implementation mode, the magnetic steel 101 adopts N35UH in a strong magnetic series to realize the performances of small volume and strong magnetism, and has low demagnetizing rate and high cost performance.

Preferably, the magnetizer 102 is made of DT4C material, and after proper heat treatment, the magnetizer has good magnetic conductivity. In addition, the upper end of the magnetizer 102 is further designed with a boss structure, so that the gathering and the conduction of the surface magnetism are facilitated, as shown in fig. 2.

FIG. 4 is a front view of a spool assembly and tab according to the present invention; fig. 5 is a left side view of a spool assembly and tab according to the present invention. As can be seen in fig. 4 and 5, two cylindrical hole-type positioning posts 1063 are provided on the insert 106 for lateral positioning during injection molding; a cylindrical boss 1051 is provided at the end of the spool assembly 105, also for positioning during injection molding. The positioning column 1063 and the boss 1051 form three-way positioning, and have extremely high stability.

Preferably, 3-4 circles of welding rib structures are designed on the periphery of the positioning column 1063, so that the welding rib structures can be better fused with injection molding materials during injection molding, and the sealing performance of products is guaranteed.

In fig. 4, two boss structures 1064 are further provided, which serve as attachment points for bending the insert after winding is completed, and share the stress of the root of the insert. Also shown in fig. 4 is the wire inlet end 107 of the wire wrap. Accordingly, the wire outlet end 108 of the wire is shown in fig. 5. Generally, the depth of the slot at the wire inlet end 107 is significantly higher than that at the wire outlet end 108, so as to facilitate smooth wire winding.

As can also be seen from fig. 6, the insert 106 is provided with a groove, so that the insert is easily combined with the injection molding material during injection molding, and the bonding force is enhanced. The sealing rib 1052 is arranged at the tail end of the winding shaft assembly 105, is designed into a sealing rib structure which is longitudinally and transversely staggered, has high melting degree with injection molding materials during injection molding, and has good sealing performance. After winding is completed, the protective cover is sleeved into the coil and the winding shaft assembly and then injection molding is carried out, so that the risk of product performance and service life reduction caused by falling of the protective cover under severe conditions of long-term high temperature can be avoided, and the produced product has the advantages of high temperature resistance, low cost, long product service life and the like.

What has been described above is merely illustrative of the embodiments of the present invention with respect to the spirit and principles of the invention. It will be apparent to those skilled in the art that various changes may be made to the described examples and equivalents thereof without departing from the spirit and principles of the invention, which are intended to be within the scope of the invention as defined in the following claims.

Claims

1. A magneto-electric wheel speed sensor comprising:

a magnetic steel (101);

a magnetizer (102) connected with the magnetic steel;

a choke plug (103) arranged on the opposite side of the magnetic steel from the magnetizer (102);

the winding shaft assembly (105) is of a hollow structure, and the magnetic steel, the magnetizer and the choke plug are arranged in the winding shaft assembly;

a coil (104) wound on the outside of the spool assembly and corresponding to a part of the magnetizer in the axial direction;

a blade (106) provided radially outward of the spool assembly;

it is characterized in that the method comprises the steps of,

two positioning columns (1063) are arranged on the inserting sheet, a boss (1051) is arranged at one end, far away from the positioning columns, of the winding shaft assembly, a sealing rib (1031) and a groove (1032) suitable for installing a sealing ring are arranged on the choke plug, a groove is formed in the outer side of the inserting sheet, and the groove is wave-shaped.

2. The magneto-electric wheel speed sensor of claim 1, wherein a sealing rib (1052) is provided at an end of the spool assembly remote from the positioning post, the sealing rib being located on a portion extending radially of the spool assembly.

3. The magneto-electric wheel speed sensor of claim 2, wherein the sealing ribs are longitudinally and transversely staggered sealing ribs.

4. The magneto-electric wheel speed sensor of any one of claims 1-3, further comprising a shield that is sleeved outside the coil, spool assembly, and magnetizer.

5. The magneto-electric wheel speed sensor of claim 4, wherein the shield is injection molded integrally with the coil, spool assembly by injection molding.

6. A magneto-electric wheel speed sensor according to any one of claims 1 to 3, wherein the magnetic steel is of the type N35UH strong magnetic brand, and the magnetizer is made of DT4C material.