[DESCRIPTION]

[Invention Title]

Automobile ABS ton wheel sensor and manufacture method

[Technical Field]

The present invention relates to an anti-lock brake system (ABS) tone wheel sensor for vehicles and a manufacturing method thereof, and more particularly, to an ABS tone wheel sensor for vehicles and a manufacturing method thereof, which can prevent that scales are formed on the ABS tone wheel sensor by foreign substances, and reduce its weight and the manufacturing cost.

[Background Art]

As well-known in the art, in general, an anti-lock brake system (ABS) for vehicles is a system, which ensures that the vehicle is not completely locked in bad conditions, such as on an icy road or a rainy road, to thereby allow a driver to stop the vehicle at the shortest distance while manipulating a steering wheel smoothly, and essentially includes a tone wheel sensor for sensing a rotational speed of a vehicle wheel.

As described above, the tone wheel sensor capable of sensing the speed of the vehicle wheel in the ABS system for the vehicle includes a small saw- toothed disk located in the proximity of a brake device mounted inside each of four wheels. When the vehicle wheel is rotated, the saw-toothed disk is also rotated at the same rotational frequency as the wheel. The sensor mounted in the proximity of the tone wheel reads the value of the rotational frequency of each of the four vehicle wheels and sends the value to an electronic control unit (ECU). Then, the ECU continuously reads the value, and independently controls the pressure of a brake pad, which holds the wheel, when the value drops strikingly or the rotation of the vehicle wheel is stopped, such that the tone wheel sensor can provide the optimum conditions during the braking of the vehicle.

In the ABS system for the vehicles having the above function, as shown in FIG. 1, the tone wheel sensor includes a disk 102 having small saw teeth

101 formed on the outer circumference thereof.

The ABS tone wheel sensor 100 is heavy and very high in the manufacturing cost since it is manufactured by sintering metal powder. Furthermore, the ABS tone wheel sensor 100 cannot always correctly sense information of the ABS system associated with the rotational speed of the wheel since foreign substances are accumulated on grooves formed between the saw teeth 101 to thereby form scales, and hence, cannot send correct information to the ECU to thereby deteriorate an ABS function when the vehicle brakes.

[Disclosure]

[Technical Problem]

Accordingly, the present invention has been made in an effort to solve the above-mentioned problems occurring in the prior arts, and it is an object of the present invention to provide an anti-lock brake system (ABS) tone wheel sensor, which is lightweight and includes metal pieces and grooves having the same outer diameter without any stepped portion to thereby prevent scales from being formed by foreign substances.

Another object of the present invention is to provide a method for manufacturing the ABS tone wheel sensor, which can produce and supply inexpensive ABS tone wheel sensors in a simple manner, thereby promoting lightweight and quality improvement of vehicles.

[Technical Solution]

[Advantageous Effects]

[Description of Drawings]

FIG. 1 is a cross-sectional view of a conventional tone wheel sensor.

FIG. 2 is a perspective view showing a manufacturing process of a tone wheel sensor according to the present invention.

FIG. 3 is a perspective view of the tone wheel sensor according to the present invention.

FIG. 4 is a cross-sectional view of the tone wheel sensor according to the present invention.

FIG. 5 is an exemplary view showing a used state of the tone wheel sensor according to the present invention.

Explanation of essential reference numerals in drawings>

1: tone wheel sensor

2: inner wheel

3: groove

4: metal piece

5: space part

6: outer wheel

T- synthetic resin layer [Best Mode]

[Mode for Invention]

To achieve the above objects, the present invention provides an anti- lock brake system (ABS) tone wheel sensor comprising an inner wheel, a space part, and an outer wheel having grooves and metal pieces alternately arranged with each other, the inner wheel, the space part and the outer wheel being constructed of a metal sheet, which is a magnetic substance, wherein the space part and the grooves formed between the metal pieces are filled with synthetic resin, which is a non-magnetic substance.

The ABS tone wheel sensor for the vehicle is manufactured by the steps

of blanking the metal sheet into a metal plate, forming the metal plate, and putting the metal plate into a mold and injecting synthetic resin thereto.

Reference will be now made in detail to the preferred embodiment of the present invention with reference to the attached drawings.

FIG. 2 is a diagram showing a manufacturing process of a tone wheel sensor according to the present invention, FIG. 3 is a perspective view of the tone wheel sensor, FIG. 4 is a cross-sectional view of the tone wheel sensor, and FIG. 5 is an exemplary view showing a used state of the tone wheel sensor.

An anti-lock brake system (ABS) tone wheel sensor 1 for vehicles according to the present invention includes: an inner wheel 2; a space part 5; an outer wheel having grooves 3 and metal pieces 4 alternately arranged with each other at predetermined intervals, the inner wheel 2 and the outer wheel 6 being formed of a metal sheet, which is a magnetic substance; and a synthetic resin layer 7 made of a non-magnetic substance formed integrally among the inner wheel 2, the space part 5 and the grooves 3 formed between the metal pieces 4.

A method for manufacturing the ABS tone wheel sensor for the vehicles will be described in detail.

First step: Blanking process

A circular metal sheet 11 is subjected to a blanking process to prepare an annular wheel sensor metal plate having an opening 10 penetrated at the center thereof;

Second step: Inner wheel forming process

An inner wheel 2 is formed around the opening 10 of the circular wheel sensor metal plate 11 obtained by the first step using a punch and a die.

Third step: Process for forming grooves and metal pieces

Grooves 3 and metal pieces 4 are formed on the outer circumference of

the annular wheel sensor metal plate 11 by blanking the circular wheel sensor metal plate 11 having the inner wheel obtained by the second step.

Fourth step: Outer wheel forming process

A forming work is performed on the grooves and the metal pieces of the circular wheel sensor metal plate 11 obtained by the third step using the punch and the die to thereby form an outer wheel.

Fifth step: Injection-molding & release process

The wheel sensor metal plate 11 obtained by the first to fourth steps, which includes the inner wheel 2, the outer wheel 6 having the grooves 3 and the metal pieces 4, and the space part 5, is put into an injection mold, injecting synthetic resin is injection-molded among the outer wheel 6, the space part 5 and the inner wheel 2 of the wheel sensor metal plate 11 to thereby form the synthetic resin layer 7 of a non-magnetic substance, and then the process is finished after releasing the mold from synthetic resin layer.

The ABS tone wheel sensor may be manufactured through another manufacturing method including the steps of subjecting a circular metal sheet to a single blanking process to produce an annular wheel sensor metal plate having an opening 10 penetrated at the center thereof and the metal pieces and grooves formed on the outer circumference thereof, forming the inner wheel and the outer wheel through a single forming process, and forming the ABS tone wheel sensor through the injection molding of the wheel sensor metal plate in the injection mold.

As described above, in the ABS tone wheel sensor 1 for the vehicles according to the present invention, since the inner wheel 2 is formed of the metal sheet, which is the magnetic substance, it can have a sufficient durability and keep the durability continuously when it is mounted inside a vehicle wheel .

Furthermore, since the space part 5 formed between the inner wheel 2 and

the outer wheel 6 is filled with the synthetic resin layer 7, which is the non-magnetic substance, a distance between the inner wheel 2 and the outer wheel 6 can always be kept at a predetermined interval without getting narrow.

Moreover, since the synthetic resin layer 7 fills the grooves 3 formed between the metal pieces 4 and it completely prevents that scales are formed on the grooves 3 by foreign substances accumulated on the grooves 3, the ABS tone wheel sensor can exactly sense information of an ABS system related with a rotational speed of the vehicle wheels and ensure the sensed information is sent to an electronic control unit (ECU).

[Industrial Applicability]

As described above, the ABS tone wheel sensor for the vehicles according to the present invention can contribute lightweight of the vehicles since it is constructed of the metal sheet and synthetic resin, solve an error action of the tone wheel sensor by foreign substances and provide reliable information of the rotational speed of the vehicle wheel to the ECU since the grooves formed between the metal pieces are filled with synthetic resin, and can be manufactured at low cost since it is manufactured through simple processes.

[Sequence List Text]