EP3662294A1

EP3662294A1 - Rotational speed sensor for a vehicle, particularly commercial vehicle, and to a method for the production thereof

Info

Publication number: EP3662294A1
Application number: EP18729071.3A
Authority: EP
Inventors: Jürgen Dalisdas; Sebastian DUENSING; Oliver Gründker; Thilo Klostermann; Florian SCHWAGMEYER
Original assignee: Wabco GmbH
Current assignee: ZF CV Systems Hannover GmbH
Priority date: 2017-08-04
Filing date: 2018-05-29
Publication date: 2020-06-10
Also published as: DE102017007399A1; WO2019025050A1

Abstract

The invention relates to a rotational speed sensor (1) for a motor vehicle, particularly a commercial vehicle. The rotational speed sensor (1) comprises: a sensor carrier (4) and a magnetic sensor (5) which is housed in the sensor carrier (4) and which has a defined sensing system for measuring magnetic impulses of a signal wheel provided on the vehicle wheel, a securing flange (2) having a securing device (12) for securing on a vehicle-sided receiving element, electric lines (8a, 8b) for contacting of the magnetic sensor (5), a sensor housing (3) which surroundingly seals the sensor support (4), the magnetic sensor (5) and the electric lines (8a, 8b). According to the invention, in order to provide a compact and safe embodiment, the sensor housing (3) and the securing flange (2) are designed as an injection-moulding body (14), the sensor carrier (4) accommodating the magnetic sensor (5) on the front end area (4a) thereof and comprises a receiving region towards the back, e.g. a wall which is surrounded at least on the outer side thereof by the injection-moulding body (14), preferably also from inside. In order to produce a plurality of different sensors from few initial components in a simple manner, the sensor carrier can be inserted between two first tool halves. Two second tool halves rotatable to the first rotatable halves can determine the mounting flange in a desired angular position with respect to the sensing direction of the magnetic sensor. All components are connected together in a permanent and in a defined position in relation to each by means of the injection-moulding process. With the aid of a stamp which is inserted between the tool halves and on which the sensor carrier is applied, the length of the sensor can be determined.

Description

Speed sensor for a vehicle, in particular a commercial vehicle, and a method for its production

The invention relates to a speed sensor for a vehicle, in particular a commercial vehicle, and a method for its production.

Speed sensors are used, inter alia, as wheel speed sensors for determining a wheel speed of a respective wheel. Furthermore, speed sensors z. B. used in transmissions to determine the speeds of transmission shafts. For this purpose, the speed sensor on a magnetic sensor and a mounting flange, with which it on a component, eg. B. on the wheel arch, is firmly mounted. On the rotating wheel is generally a signal wheel, z. As incremental or pole provided, which generates a changing magnetic field in its rotation at the magnet position sensor positioned close. The magnetic sensor acts as an induction transmitter, which measures and counts the magnetic pulses.

The speed sensor generally includes a mounting flange for engaging the wheel housing side member, generally with a mounting sleeve for receiving a fastener, e.g. B. a screw or a bolt. Furthermore, the speed sensor has a sensor housing in which the magnetic sensor, for. B. a Hall IC, is recorded on a sensor carrier.

Since the rotational speed sensor is positioned directly on the pole wheel or signal wheel and thus exposed to significant environmental stresses such as temperature, water spray, etc., the sensor housing is sealing, so that the sensor carrier is sealed and secured against the environmental influences in its interior with recorded magnetic sensor , Depending on the installation conditions, in particular the position and orientation of the wheel-box-side attachment relative to the pulse wheel and the cable guide provided, the speed sensor is to be formed with different geometry and orientation. Here, different housing lengths of the sensor housing are provided to bridge the distance from the mounting flange to the pulse wheel. Furthermore, depending on the installation conditions and the angular position of the magnetic sensor relative to the mounting flange to adjust. Also, the electrical leads for contacting and powering the magnetic sensor are generally routed away by the speed sensor and exit at a suitable exit angle.

Thus, a plurality of different speed sensors is provided, which correspond to the respective installation conditions. For this purpose, the speed sensors generally have a complex construction with a protective cap receiving the sensor holder and further sealing caps and sealing rings, and in particular also springs for axial clamping of this arrangement in order to allow a secure, sealing hold.

The invention has for its object to provide a speed sensor and a method for its production, which allow a safe, the loads corresponding training with relatively little effort.

This object is achieved by a speed sensor according to claim 1 and a method for producing the speed sensor. The dependent claims describe preferred developments.

Thus, the sensor housing and the mounting flange are wholly or largely as a one-piece injection molded body of an injection molding material educated. The injection-molded body thus also surrounds a receiving region, in particular a wall, which is formed in a rear region of the sensor carrier; This safely accommodates the sensor carrier.

The sensor carrier may in particular be closed at its front end region and receive the magnetic sensor here, wherein the front end region is preferably not surrounded by the injection molding material. The rear area with the wall, however, is injected into the injection molded body and thus firmly and tightly received.

The sensor carrier is preferably not rotationally symmetrical; Thus, the angle between the Sensierungsrichtung and the departure of the flange or the lines can be adjusted already in the production.

Thus, the advantage is already achieved that the magnetic sensor is not thermally loaded during injection of the injection molding material and surrounded only by the preferably made of plastic, not affecting the magnetic measurement sensor carrier, so that the magnetic sensor is arranged close to the position of the pulse disc can be. The wall can be open to the rear, so that from there the magnetic sensor is used and this open rear end is subsequently closed and sealed by the injection molding material.

Furthermore, the advantages are achieved that a high density and firm recording, and in particular a cost-effective production is made possible by the one-piece injection molded body. In particular, it is no longer a complicated task to seal a separate sensor housing with respect to the mounting flange. The position of the components is securely determined by the one-piece injection molded body. By mounting the sensor carrier as a carrier clamp or carrier tube with the front end closed and behind Rear extending wall, in particular pipe wall, is formed, a high density is ensured.

Advantageously, the sensor housing is also filled in its interior with the injection-molded material, whereby the magnetic sensor is additionally sealed. The contacted with the magnetic sensor lines are preferably led away by the sensor carrier, in particular within the wall, to the rear. You can thus run through the injection molded body, so that a tightness of the cable guide is ensured.

Different housing lengths can be formed according to a preferred embodiment by means of a uniform sensor carrier by the sensor carrier is inserted in different length positions in the injection mold.

Alternatively, the sensor carrier can also be formed from an output sensor carrier by suitably cutting the rear end of its wall with adjustable longitudinal extension or housing length and are inserted into the injection molding tool after the appropriate cutting.

In both variants, the advantage of a flexible, cost-effective production of different lengths is made possible with uniform starting materials.

A secure attachment of the sensor carrier can by a melting area on its outside, z. As melting fins are ensured, which are partially melted during the injection process and thus can subsequently enter into a cohesive and / or positive connection with the injection molded body. A fastening device of the mounting flange, z. As a mounting bush, is advantageously made of a stronger material than the injection molding material, in particular made of metal, for. B. as a brass bushing, and is injected with. For this purpose, the mounting bushing can be inserted into the injection molding tool and subsequently encapsulated with and thus forms part of the mounting flange.

Another advantage of the invention lies in the free adjustability of a sensor angle:

For this purpose, first and second tool parts can be used, which are rotated relative to each other before the injection molding process. Thus, the mounting flange can be formed by first tool halves, in which preferably the fastening bush is inserted, and the sensor housing by second tool halves, in which the sensor carrier is inserted with magnetic sensor, wherein the first tool halves with respect to the second tool halves adjusted in its angular position before the injection molding process, d. H. can be rotated relative to each other to set a sensor angle or angle of the sensor relative to the mounting flange. The longitudinal extent of the sensor housing can be adjusted by a slide introduced in the longitudinal direction (axial direction). In the space or space between the first and second tool halves and the slide then the injection molding material is injected.

The entire speed sensor can thus be made of few parts and inexpensive, fast and safe, especially with a high number of different lengths and angular settings. By adjusting the angular position of the tool halves of the injection molding tool any adjustment angle can be formed with the same injection mold tool, further by adjusting the slide position and setting a suitable length position of the sensor carrier, or by suitable cutting to length from the output sensor carrier, any housing lengths can be set. Different attachments can preferably be achieved by choosing a suitable mounting bushing.

The lines run backwards through the injection molding body and exit at the rear end. Here, a cable outlet cap with appropriate cable routing or outlet angle placed on the back of the injection-molded body, z. B. engaged or plugged, which sets a cable outlet guide in a suitable direction.

The invention will be explained in more detail below with reference to the accompanying drawings of some embodiments. Show it:

1 is a perspective view of a speed sensor for mounting in a commercial vehicle.

Fig. 2 is a sectional side view of the speed sensor

Fig. 1;

3 is a partial view of the speed sensor in the injection molding tool.

4 is a flowchart of a manufacturing method according to a

Embodiment of the invention;

Fig. 5 sectional views of speed sensors with different lengths.

A speed sensor 1 is provided for mounting in a vehicle, in particular commercial vehicle, wherein it z. B. as a wheel speed sensor with a Signal wheel, which is provided on the wheel side or wheel firmly and thus rotatably cooperates.

The speed sensor 1 has the rear (in Fig. 1 right) a mounting flange 2 and the front (in Fig. 1 left) a substantially cylindrical, forward z. B. slightly tapered sensor housing 3 on. Furthermore, a sensor carrier 4 is provided made of plastic, in which a magnetic sensor 5, in particular Hall IC 5, recorded, for. B. glued or locked.

At the rear end of the mounting flange 2, a cable outlet cap (cable guide cap) 6 is provided with an outlet opening 7, from which two (or more) indicated here lines 8a, 8b, emerge, with which the Hall IC 5 is contacted. Furthermore, a sealing ring (O-ring) 9 is provided on a housing shoulder 10 between the mounting flange 2 and the sensor housing 3.

The mounting flange 2 is used for attachment to the vehicle, eg. B. a suspension. For this purpose, the mounting flange 2 and the housing shoulder 10 can be applied to the suspension, in which case an attachment via a provided in the mounting flange 2 mounting sleeve 12, z. B. made of brass and is used for insertion of a bolt or a screw.

2, an injection molded body 14 is formed, which integrally forms the sensor housing 3 and the fastening flange 2, wherein the metallic fastening bushing 12 is injected in the region of the fastening flange 2 and thus by the injection molding material 14a of the injection molded body 14 is surrounded. The sensor carrier 4 has a front end area 4a, in which the magnetic sensor 5 is arranged, and to the rear as a receiving area a cylindrical wall 1 6, which is received in the sensor housing 3, that is surrounded on its outer side 16a of the injection molding material 14a of the injection molded body 14 ; Preferably, the interior 4b of the sensor carrier 4 is filled by the injection molding material 14a.

Thus, the sensor carrier 4 z. B. as a support tube with the cylindrical wall 1 6 and the cylindrical wall 16 forwards final, closed end portion 4 a formed and is thus close to the front and open to the rear for receiving the Hall IC 5 and the Hall IC 5 contacting Lines 8a, 8b, wherein the tightness is ensured by the back of the injection molded body 14.

The two lines 8a and 8b extend from the Hall IC 5 back through the injection molding material 14a of the sensor housing 3 and the mounting flange 2 and exit into the cable outlet cap 6, the outlet opening 7 defines a discharge direction.

As can be seen in particular in the perspective view of FIG. 1, the Hall IC 5 is aligned in the non-rotationally symmetrical front end region 4 a in a sensing direction. Also, the mounting flange 2 is not rotationally symmetric due to the position of the mounting sleeve 12. Thus, a sensor angle α between the Hall IC 5 and the mounting flange 2 is set.

The cable outlet cap 6 is generally not rotationally symmetrical; according to the embodiment of Figure 1, the outlet opening 7 perpendicular to the longitudinal axis A, ie, extend to one side; However, the outlet opening 7 can also be with appropriate cable routing in the driving tool to the rear of the cable outlet cap 6 and thus extend in the longitudinal axis A.

On the outer side 16a of the wall 16 are connecting means, here melting fins 20, formed to form a cohesive and / or positive connection of the wall 1 6 and thus the entire sensor carrier 4 with the injection molded body 14 during the injection process.

A length L of the rotational speed sensor in its sensing direction can be adjusted in particular according to FIG. 5 by inserting the sensor carrier 4 in a suitable longitudinal position into the injection molding tool, which forms the injection-molded body 14; Fig. 5 shows three speed sensors which can be formed by such different length positions.

The manufacture is shown in more detail with reference to FIG. 3: an injection molding tool 22 has

- To form the mounting flange 2 first, rear tool halves 23 a and 23 b, in which the brass bushing formed mounting sleeve 12 is inserted, and

to form the sensor housing 3, second, front tool halves 24a and 24b and a punch inserted in the axial direction from the front 25th

The punch 25 can be inserted with variable insertion length and thereby determines the length L of the speed sensor 1 in its sense direction. The sensor carrier 4 with recorded sensor 5 can be placed directly on the punch 25. The first and second tool parts 23a, b and 24a, b can be rotated against each other, whereby the sensor angle α is already set in the injection mold 22. Between the first and second tool parts 23a, b and 24a, b and the star tool Pel 25 thus a space is formed, in which then the injection molding material is entered.

The production of the rotational speed sensor 1 can thus be carried out in particular according to the embodiment of the flowchart of FIG. 4, with the following steps:

After the start in step StO, the starting materials are subsequently provided in step St1, here thus the sensor carrier 4 as standardized, closed at the front end cylinder tube made of a partially fusible plastic with its melting fins 20,

Furthermore, the mounting bushing 12 made of brass, the cable outlet cap 6, the sealing ring 9 and serving as a magnetic sensor Hall IC 5, which is contacted with the lines 8a, 8b and positioned in the sensor carrier 4.

In step St2, the injection molding tool 22 is provided.

In step St3, the sensor carrier 4 with the magnetic sensor 5 and the lines 8a, 8b is placed between the second tool halves 24a, 24b of the injection molding tool 22. For this purpose, the sensor carrier 4 with the recorded Hall IC 5, can advantageously be added to the stamp 25, which ensures thermal protection of the Hall IC 5 during the subsequent injection process. Furthermore, the fastening bushing 12 is received between the first mold halves 23a, 23b. The cables 8a, 8b contacted at the Hall IC 5 extend rearwardly through the gap between the second tool halves 24a, 24b and the first tool halves 23a, 23b.

In step St4, the sensor angle a, or the relative angular position of the mounting flange 2 relative to the Hall IC 5 and the sensor carrier 4th set by the first tool halves 23a, 23b relative to the second tool halves 24a, 24b in a suitable angular position, ie the sensor angle a, are set. Also, the length L is adjusted by the position of the slider 25.

In step St5, the actual injection process is carried out, i. H. the injection-molded material 14a of the injection-molded body 14 is injected into the continuous clearance between the tool halves 23a, 23b, 24a, 24b and the slider 25, so that the injection-molded body 14 formed thereby surrounds the inserted fastening sleeve 12, and the cylinder tube 1 6 of the sensor carrier 4 inside and outside with the injection-molded material surrounds 14a, wherein the Aufschmelzrippen 20 are melted, thereby forming a cohesive connection, preferably or possibly also complementary with a positive connection. The outgoing from the Hall IC 5 cables 8a, 8b are covered accordingly by the injection molded body 14 and extend rearwardly from the injection molded body 14 thus formed out.

Subsequently, in step St6, the cable outlet cap 6 is placed on the rear portion of the injection molded body 14 in the desired position and orientation to provide the desired cable routing of the cables 8a, 8b, d. H. z. B. angled backwards or sideways to ensure. As an alternative to a placement process, an attachment by means of ultrasonic welding can also take place.

Thus, a speed sensor 1 in a few steps, with a large number of variants by the parameters to be set the length L, the sensor angle α and the position and orientation of the cable outlet cap 6, are set. Furthermore, different Hall IC 5 can be used, if desired. List of Reference Numerals (part of the description)

1 speed sensor

2 mounting flange

3 sensor housing

4 sensor carriers

4a front end portion of the sensor carrier 4th

4b Interior of the sensor carrier 4

5 magnetic sensor, in particular Hall IC

6 cable outlet cap

7 outlet opening in the cable outlet cap 6

8a, 8b lines

9 sealing ring

10 housing shoulder of the sensor housing 3

12 mounting bush made of metal

14 injection molded body

14a injection molding material of the injection molded body 14

16 receiving area, preferably wall of the sensor carrier 4th

16a outside of the wall 1 6

20 melting ribs

22 injection molding tool

23 a, 23 b first tool halves for forming the mounting flange. 2

24a, 24b second tool halves to form the sensor housing 3 25 punch α sensor angle

L length (longitudinal extent) of the sensor housing 3, housing length A longitudinal axis, symmetry axis

StO to St6 steps of the manufacturing process

Claims

claims

1 . Speed sensor (1) for a motor vehicle, in particular a commercial vehicle, wherein the rotational speed sensor (1) comprises:

a sensor carrier (4) and a magnetic sensor (5) accommodated in the sensor carrier (4) for measuring magnetic impulses of a rotating body,

a fastening flange (2) with a fastening device (12) for

Attachment to a vehicle-side recording,

electrical leads (8a, 8b) for contacting the magnetic sensor (5), a sensor housing (3) sealingly surrounding the sensor support (4), the magnetic sensor (5) and the electrical leads (8a, 8b),

characterized in that

the sensor housing (3) and the fastening flange (2) are designed as injection molded bodies (14),

the sensor carrier (4) receives the magnetic sensor (5) at its front end region (4a) and has a receiving region (16) towards the rear, which is surrounded by the injection-molded body (14) at least on its outer side (16a).

Second speed sensor (1) according to claim 1, characterized in that receiving area is a rearwardly extending wall (1 6) which surrounds an interior space (4b), in which the magnetic sensor (5) is inserted.

Third speed sensor (1) according to claim 2, characterized in that the electrical lines (8a, 8b) of the magnetic sensor (5) within the wall (1 6) of the sensor carrier (16) to the rear and through the mounting flange (2) exit to the back,

wherein the lines (8a, 8b) at least partially in the spray Cast body (14) are injected.

4. speed sensor (1) according to claim 2 or 3, characterized in that the interior (4b) of the sensor housing (3) with the injection molding material (14a) of the injection molded body (14) is filled.

5. speed sensor (1) according to one of the preceding claims, characterized in that on the outer side (16 a) of the receiving area (1 6) a melting area, for. B. melting fins (20) is formed for melting and cohesive and / or positive connection with the injection molding material (14 a) of the injection molded body (14).

6. speed sensor (1) according to one of the preceding claims, characterized in that as fastening means (12) of the mounting flange (2) has a fastening bushing (12) made of metal or plastic with a through hole (12 a) is provided for the use of a fastener, the the injection-molding material (14a) of the injection-molded body (14) is surrounded,

wherein a sensor angle (a) or an angular orientation of the rotational speed sensor (1) is defined as the angle of the fastening bushing (12) relative to the magnetic sensor (5).

7. speed sensor (1) according to one of the preceding claims, characterized in that the sensor housing (3), the mounting flange (2) and the sensor holder (4) by the injection molded body (14) are sealed and permanently indebted rigidly interconnected.

8. speed sensor (1) according to one of the preceding claims, characterized in that on the outside of the sensor housing (3) has a housing shoulder (10) with an applied sealing ring (9) for sealing is formed in the axial position on the vehicle-side recording.

9. speed sensor (1) according to one of the preceding claims, characterized in that behind the mounting flange (2) has a cable outlet cap (6) with an outlet opening (7) for guiding the electrical lines (8a, 8b) is provided, preferably on the injection molded body (14) set up, z. B. clipped or screwed, or welded.

10. Speed sensor (1) according to one of the preceding claims, characterized in that the sensor carrier (4) is designed non-rotationally symmetrical, laying down a Sensierungsrichtung relative to the mounting flange (2).

1 1. Method for producing a speed sensor (1) for a vehicle, in particular a speed sensor (1) according to one of the preceding claims, with at least the following steps:

Producing or providing a sensor carrier (4) and a magnetic sensor (5) attached to the sensor carrier with connected electrical lines (8a, 8b) (St1),

Providing an injection molding tool (22) with first tool halves (23a, 23b) for forming a mounting flange (2), second tool halves (24a, 24b) for forming a sensor housing (3) and a punch (25) for receiving and / or for positioning the sensor carrier (4) (St2),

Inserting the punch (25) with the sensor carrier (4) and the magnetic sensor (5) contacted with leads (8a, 8b) between the second tool halves (24a, 24b) of the injection mold (22) (St3), adjusting an angle between the first tool halves (23a, 23b) and the second tool halves (24a, 24b) or between the punch (25) and the tool halves (23a, 23b, 24a, 24b) for fixing the sensor angle (a) between the magnetic sensor (5) and the mounting flange (2), and

Adjusting a length of the speed sensor (1) by positioning the sensor carrier (4) (St4),

Injecting an injection molding material (14a) into a clearance formed between the first and second tool halves (23a, 23b, 24a, 24b) to form an injection molded body (14), (St5) through the first tool halves a mounting flange (2 ) and by the second tool halves a sensor carrier (4) with magnetic sensor (5) surrounding sensor housing (3) is formed, which surrounds the wall (1 6) of the sensor carrier (4) at least on its outer side (1 6a),

wherein the sensor angle (a) between the magnetic sensor (5) and the mounting flange is adjusted by the injection molded body (14).

12. The method according to claim 1 1, characterized in that the punch (25) receives the sensor carrier (4) such that the magnetic sensor (5) in the injection molding process is free of thermal stress by the injection-molded material (14a), preferably without attachment from

Injection molding material (14a) at the front end portion (4a) of the sensor carrier (4).

13. The method of claim 1 1 or 12, characterized in that prior to the injection process, a fastening device (12), for. B. a fastening bush (12) made of metal, ceramic or a plastic material, in the first tool halves (23a, 23b) is used (St4),

and the fastening device (12) is surrounded by the injection-molding material (14a) in the subsequent injection process to form the fastening flange (2) with injected fastening device (12) (St6).

14. The method according to any one of claims 1 1 to 13, characterized in that also an interior (4b) of the sensor housing (3) together with recorded lines (4a, 4b) of the injection molding material (14a) of the injection molded body (14) is filled (St4 , St5).

15. The method according to any one of claims 1 1 to 14, characterized in that subsequently at the rear end of the injection molded body (14) has a cable outlet cap (6) with a suitable shape and orientation, with an outlet opening (7), z. B. plugged, snapped or welded, laying down a departure direction of the electrical lines (8 a, 8 b) (St6).