KR100768699B1 - Vehicle wheel speed sensor and method manufacturing its - Google Patents

Abstract

A wheel speed sensor for a vehicle and a method for manufacturing the same are provided to improve reliability and reduce manufacturing cost by forming a first sub assembly having a sensing element and a cable, and over-molding the first sub assembly. A wheel speed sensor for a vehicle includes a first sub assembly(100) and an over-mold housing(300). The first sub assembly body(100) is installed on a carrier(120) by connecting a sensing element(110) with a cable(130). The first sub assembly body(100) is inserted into an over-mold(200). The over-mold housing(300) is injection-molded in the over-mold(200), and is installed outside the first sub assembly body(100). The sensing element(110) and the cable(130) are connected by compacting an end of a conductive unit of the cable(130) through direct electric resistance welding.

Description

Wheel speed sensor for automobile and its manufacturing method {VEHICLE WHEEL SPEED SENSOR AND METHOD MANUFACTURING ITS}

1 is a longitudinal sectional perspective view of a wheel speed sensor for an automobile according to an embodiment of the present invention;

Figure 2 is a perspective view showing the assembled state of the sensing element and the cable according to an embodiment of the present invention,

3 is a plan view of a primary subassembly according to an exemplary embodiment of the present invention;

4 is an explanatory view showing a state in which a primary subassembly is inserted into a mold according to an embodiment of the present invention;

5 (A) and 5 (B) are explanatory diagrams showing a state before and after the cable of the present invention is compacted,

6 is an explanatory view showing a state in which the cable of the present invention is welded to a sensing element in a compact state;

7 is a cross-sectional view showing an annular protrusion formed on a carrier constituting the wheel speed sensor for automobiles of the present invention.

8 is a cross-sectional view showing a wheel speed sensor for a conventional vehicle.

<Description of Symbols for Main Parts of Drawings>

100: primary sub-assembly 110: sensing element

120: carrier 121: annular projection

123: magnet receiving portion 124: through hole

130: cable 131: lead portion

200: mold (core) 300: overmolded housing

400: magnet

The present invention relates to a wheel speed sensor for automobiles and a method for manufacturing the same. More specifically, cost reduction is achieved due to a reduction in material costs, and process defects are reduced due to a reduction in the number of parts. The present invention relates to a vehicle wheel speed sensor and a method of manufacturing the same, which can shorten the time and reduce the content of heavy metals.

In general, a brake device of a vehicle is classified into a foot brake and a parking brake. The foot brake generates a braking force of a vehicle by controlling a disc brake or a drum brake mounted on four wheels using hydraulic pressure in a passenger car. will be.

That is, in the case of the disc brake, the braking force is generated by holding and fixing the disc caliper assembly which rotates in the same manner as the drive shaft at a predetermined pressure.

The brake device as described above is connected to the brake pedal and the brake pedal as well as a booster installed so that the negative pressure of the intake air is communicated, and the master connected to the front and rear brakes as well as connected to the booster. It consists of a cylinder.

In particular, in order to prevent slip during braking of the brake device, an anti-lock brake device (ABS) has been developed, which controls the brake oil pressure so as not to be locked while checking the rotational speed of the wheel with a wheel speed sensor.

Conventionally, such a wheel speed sensor for automobiles has a bobbin assembly (3) mounted with a printed circuit board assembly (1) and a sensing element (2) mounted therein, housed in the housing cup (4). In addition, an epoxy potting (6; epoxy potting) in the interior of the housing cup (4) while the terminal (5) connected to the cable is assembled to the printed circuit board assembly (1), the housing cup (4) The upper part and the cable side are overmolded (7).

In addition, depending on the sensing method, the magnet 8 may or may not be mounted where the sensing element 2 is installed.

However, such a wheel speed sensor for automobiles is difficult to reduce costs due to the large number of parts, high manufacturing cost, high process, many causes of process defects, long working time, and heavy metals because the connection is performed when soldering the terminal 5. There is a problem of increasing the content of the back.

Accordingly, the present invention has been made to solve the above problems, and by compacting the end of the lead portion of the cable enables direct electrical resistance welding with the sensing element, without the use of solder, product structure and manufacturing process It is a first object to provide a wheel speed sensor for an automobile that can simplify the operation.

The present invention is to provide a wheel speed sensor for an automobile designed to align the cable and having a through hole so that the cable and the sensing element is semi-fixed to the carrier to facilitate the operation such as electric resistance welding. There are two purposes.

The present invention provides a method of manufacturing a wheel speed sensor for an automobile, in which a conductor end of a cable is compacted to enable direct electrical resistance welding with a sensing element, thereby simplifying a product structure and a manufacturing process without using solder. There is a third purpose to provide.

In order to achieve the above object, a wheel speed sensor for an automobile mounted on a wheel shaft to detect a wheel speed by a sensing element of the present invention includes a primary sub-assembly mounted on a carrier by connecting a sensing element and a cable; And an overmolded housing which is overmolded in the state in which the primary subassembly is inserted into the overmolded mold and provided outside the primary subassembly. In this case, the connection between the sensing element and the cable is made by directly electric resistance welding with the sensing element by compacting the end of the lead portion of the cable. A magnet accommodating part is formed in the carrier, and a magnet is mounted on the magnet accommodating part to sense the same. The carrier is provided with a through hole formed through the upper and lower portions so that the welding rod can be introduced into the upper and lower portions so as to easily weld the end of the lead portion of the cable to the sensing element. The carrier is formed to protrude to a certain height of the annular projection having a constant diameter on the site where the pin of the mold is operated.

The method of manufacturing a wheel speed sensor for an automobile according to the present invention includes the steps of connecting a sensing element and a cable, mounting the first sub assembly by mounting the sensing element and a cable on a carrier, and the primary sub assembly. Injection molding of the overmolded housing to the outside of the primary subassembly by inserting the mold into the overmolded mold, wherein the connection between the sensing element and the cable is made to compact the lead end of the cable. And a step of directly electric resistance welding the compacted portion of the sensing element and the lead end of the cable, and cutting the end of the lead to a predetermined length, and a magnet formed in the carrier. The method further includes the step of seating the magnet to the receiving portion.

Hereinafter, with reference to the accompanying drawings will be described in detail an embodiment of the present invention.

1 is a longitudinal cross-sectional perspective view of a wheel speed sensor for a vehicle according to an embodiment of the present invention, Figure 2 is a perspective view showing the assembled state of the sensing element and the cable according to an embodiment of the present invention, Figure 3 is an embodiment of the present invention 4 is an explanatory view showing a state in which a primary subassembly is inserted into a mold according to an embodiment of the present invention, and FIGS. 5 (A) and (B) are cables of the present invention. 6 is an explanatory diagram showing a state before and after compacting, and FIG. 6 is an explanatory diagram showing a state in which the cable of the present invention is welded to a sensing element in a compact state, and FIG. It is sectional drawing which shows the annular processus | protrusion formed in the carrier which comprises.

A wheel speed sensor for an automobile mounted on a wheel shaft to detect a speed of a wheel by the sensing element of the present invention includes a primary sub-wire mounted on the carrier 120 by connecting the sensing element 110 and a cable 130. The assembly 100 and the overmolded housing 300 which is overmolded and injection molded while the primary subassembly 100 is inserted into the overmolded mold 200 to be provided outside of the primary subassembly 100. It includes.

The connection between the sensing element 110 and the cable 130 is made by direct electric resistance welding with the sensing element 110 by compacting the end of the lead 131 of the cable 130.

Therefore, by simply overmolding the primary subassembly 100, the manufacturing process is simple, and the number of parts is high, so that the manufacturing process is highly reliable, manufacturing costs are reduced, and the working time is shortened and heavy metals are not included (lead, etc.). do.

In addition, since the electrical resistance welding is possible directly with the sensing element 110 by compacting the copper wire strand, which is the conductive portion 131 of the cable 130, which corresponds to the gist of the present invention, Thereby simplifying the product structure.

And the magnet receiving portion 123 is formed on the carrier 120, the magnet 400 is mounted on the magnet receiving portion 123 may be of course to be sensed.

In addition, the carrier 120 prepared by molding plastic in advance so as to easily weld the end of the conductive portion 131 of the cable 130 to the sensing element 110 is formed through the top and bottom through the welding rod to the top and bottom It is provided with a through hole 124 to be introduced.

Therefore, a welding rod flows into the lower portion of the through hole 124 and a welding rod flows into the upper portion of the through hole 124 to facilitate welding by the electrical resistance of the end of the conductive portion 131 of the cable 130 and the sensing element 110.

On the other hand, the carrier 120 is formed to protrude to a certain height in the annular protrusion 121 having a constant diameter on the site where the mill pin of the mold 200 is operated.

The annular protrusion 121 inserts the carrier 120 into the mold and then ejects pins (milpins) of the mold when it is difficult to secure a space for separately ejecting a molded product because the size of the product is small when overmolding injection. After inserting into the mold, it is formed to be easily removed after overmolding.

In addition, the protrusion 121 of the carrier 120 may be installed at any position in a suitable position among the cavities formed in the core on the mold according to the customer's requirements without inserting the eject pin (mill pin) of the mold. It will only need to be suitable for fixing and taking out the product after injection.

Hereinafter, a method of manufacturing a wheel speed sensor for a vehicle mounted on a wheel shaft in order to detect a speed of a wheel by a sensing element will be described.

Method for manufacturing a wheel speed sensor for a vehicle of the present invention, the step of connecting the sensing element 110 and the cable 130 (S1), and the seating on the carrier 120 while the sensing element and the cable is connected 1 Comprising a step (S2) constituting the secondary sub-assembly 100, the primary sub-assembly 100 is overmolded in the state of being inserted into the overmolded mold 200 to the outside of the primary sub-assembly 100 It characterized in that it comprises a step (S3) of molding the overmolded housing (300).

Therefore, by forming the primary subassembly 100 and then overmolding injection molding, it is possible to simply manufacture a wheel speed sensor for an automobile.

The state in which the sensing device and the cable are connected to be described in more detail, in the connection of the sensing device 110 and the cable 130, compacting an end of the conductive part 131 of the cable 130 (S4). And a step of directly electric resistance welding the portion of the sensing element 110 and the end of the conductive part 131 of the cable 130 with the compacted portion.

It further includes the step (S6) of cutting the end of the conductive wire portion 131 to a predetermined length.

The gist configuration of the present invention enables direct electric resistance welding with the sensing element 100 (Hall IC) by aligning the lead portion 131 of the cable 130 and aggregating the ends thereof during the manufacturing process. Therefore, the electric resistance welded directly to the end of the lead portion 131 and the sensing element 110, the product is compact, thereby reducing the number of parts, thereby reducing the manufacturing cost, and improves reliability. Of course, the cable 130 and the sensing element 110 (Hall IC) is assembled to a pre-made plastic carrier to create a semi-assembled state, then the electrical resistance welding between the terminal of the cable 130 and the sensing element (Hall IC) Direct connection.

In addition, the step of mounting the magnet 400 to the magnet receiving portion 123 formed in the carrier 120 (S7) further.

Therefore, it is possible to apply various kinds of wheel speed sensors for automobiles in the state in which the magnet 400 is accommodated and in the non-accommodated state.

An embodiment of the present invention described above should not be construed as limiting the technical spirit of the present invention. The scope of protection of the present invention is limited only by the matters described in the claims, and those skilled in the art can change and change the technical idea of the present invention in various forms. Therefore, such improvements and modifications will fall within the protection scope of the present invention, as will be apparent to those skilled in the art.

According to the present invention as described above, the wheel speed sensor for an automobile can be configured by forming the primary subassembly in which the sensing element and the cable are fixed to the carrier and then overmolding, thereby improving the reliability and reducing the manufacturing cost. It is effective.

According to the present invention, the conductor end of the cable is compacted to enable direct electrical resistance welding with the sensing element, thereby simplifying the product structure and manufacturing process without using solder.

According to the present invention, the through hole is provided in the carrier, the cable and the sensing element is in the semi-fixed state in the carrier there is an effect that can be easily performed such as electric resistance welding.

Claims (9)

delete In a wheel speed sensor for an automobile mounted on the wheel shaft for detecting the speed of the wheel by the sensing element, The first sub-assembly 100 and the sensing element 110 and the cable 130 is connected to the carrier 120, The primary subassembly 100 includes an overmolded housing 300 which is overmolded in an injection molded state inserted into the overmolded mold 200 and provided to the outside of the primary subassembly 100. The sensing element 110 and the cable 130 is connected to the end of the lead portion 131 of the cable 130 by compacting the wheel for the automobile, characterized in that made of direct electrical resistance welding with the sensing element 110 Speed sensor. The method of claim 2, A magnet accommodating part 123 is formed in the carrier 120, The wheel receiving sensor for the automobile, characterized in that the magnet 400 is seated and sensed in the magnet receiving portion (123). The method of claim 3, wherein Through hole formed in the upper and lower portions of the carrier 120 so as to easily weld the end of the conductive portion 131 of the cable 130 to the sensing element 110, the welding rod can be introduced into the upper and lower portions Wheel speed sensor for a vehicle, characterized in that provided (124). The method of claim 4, wherein The carrier 120 is a wheel speed sensor for a vehicle, characterized in that formed in the projecting to a certain height of the annular protrusion 121 having a predetermined diameter on the site of the operation of the pin of the mold (200). delete In the manufacturing method of a wheel speed sensor for an automobile mounted on the wheel shaft for detecting the speed of the wheel by the sensing element, Connecting the sensing device 110 and the cable 130 (S1); (S2) configuring the primary subassembly 100 by seating on the carrier 120 while the sensing device and the cable are connected to each other; (S3) forming the overmolded housing 300 outside the primary subassembly 100 by overmolding injection molding while the primary subassembly 100 is inserted into the overmolded mold 200. , The connection between the sensing element 110 and the cable 130 is a step of compacting the end of the lead portion 131 of the cable 130 (S4), Method for manufacturing a wheel speed sensor for a vehicle, characterized in that it comprises a step (S5) of the sensing element 110 and the end of the lead portion 131 of the cable 130 to the compacted portion and direct electric resistance welding. . The method of claim 7, wherein Method of manufacturing a wheel speed sensor for a vehicle, characterized in that it further comprises the step (S6) of cutting the end of the lead portion (131) to a predetermined length. The method according to claim 7 and 8, Method of manufacturing a wheel speed sensor for a vehicle, characterized in that further comprising the step (S7) of seating the magnet 400 to the magnet receiving portion (123) formed in the carrier (120).

Images