Sensor device for detecting rotational speed

Abstract

The invention relates to a sensor device for detecting a rotational speed. The sensor device comprises a housing and a sensor for detecting the rotational speed of a rotating body rotating about a rotational shaft. A base body of the housing extends in a base plane. The housing has an inner side and an opposite outer side. The sensor is provided with a lead frame, a sensing device arranged on the lead frame and an electric connecting device arranged on the sensor and used for supplying power to the sensor. The lead frame is disposed inside the housing at a defined distance from the rotation shaft. The lead frame is parallel to the rotating shaft and extends from one side, adjacent to the base plane, of the sensor to a direction away from the outer side. The electrical connection device is divided into a first portion, a second portion and a third portion. The first portion extends from the lead frame into the housing. The second portion extends from the first portion to the axis of rotation at an angle of 90 DEG. The third portion extends in a direction at an angle of between 0 DEG and 45 DEG with the second portion.

Description

Technical Field

[0001] This invention relates to a sensor device for detecting rotational speed. Background Technology

[0002] Modern vehicles are equipped with numerous sensors to make driving safer and more comfortable. Among these sensors are wheel speed sensors, which measure wheel rotation speed. The measured wheel speed is used, for example, in so-called anti-lock braking systems (ABS), designed to prevent wheel lock-up by reducing braking pressure. Here, the sensor device consists of a sensor and an encoding device. The encoding device is typically a disk with permanent magnets arranged around the circumference, alternating between north and south poles.

[0003] There are two main methods for installing wheel speed sensors in vehicles. One method involves placing the sensor in a hole in the steering knuckle and correspondingly installing an encoding device. The other method involves placing the sensor inside a housing and mounting it on the side of the wheel bearing. The encoding device is mounted on the axle or a similar device. Sensor manufacturing involves several steps, resulting in a ready-to-assemble sensor at the end of the manufacturing process. Summary of the Invention

[0004] The basic objective of this invention is to provide a sensor device for detecting rotational speed, which has low manufacturing complexity and / or enables the production of a more cost-effective sensor device.

[0005] To accomplish this task, the present invention provides a sensor device for detecting rotational speed. The sensor device includes a housing and a sensor for detecting the rotational speed of a rotating body about a rotational axis. The base of the housing extends in a base plane. The housing has an inner side and an oppositely disposed outer side. The sensor has a lead frame, a sensor element disposed on the lead frame, and an electrical connection device disposed on the sensor element for powering the sensor. The lead frame is disposed inside the housing and has a defined distance from the rotational axis. The lead frame extends parallel to the rotational axis from one side of the sensor adjacent to the base plane in a direction away from the outer side. This side of the sensor extends perpendicular to the rotational axis. The electrical connection device is divided into a first part, a second part, and a third part. The first part extends from the lead frame into the housing. The second part extends from the first part toward the rotational axis at a 90° angle. The third part extends in a direction at an angle between 0° and 45° to the second part.

[0006] The sensor device should be understood as a device comprising a sensor with a sensor element for detecting rotational speed and a housing in which the sensor is arranged.

[0007] The axis of rotation is understood to be the axis located at the center of the housing, which is circular, especially at the bottom, around which the rotating body rotates.

[0008] A rotating body is the main body that rotates around a rotation axis. The rotating body is preferably designed as an axis.

[0009] The substrate is the main body from which other components of the sensor device extend or surround. The substrate forms the base surface of the sensor device. The substrate is preferably circular or radially shaped. The substrate has an inner side and an outer side opposite to it. Electrical connection devices are disposed on the outer side. The sensor is disposed on the inner side. The substrate lies on a base plane extending substantially perpendicular to the axis of rotation.

[0010] A lead frame is a metal cable support consisting of two independent conductors. The lead frame serves as an electrical connection device for the sensor. A capacitor, particularly a coupling capacitor, may be placed between the two conductors. The lead frame is preferably made of copper.

[0011] A sensor is a device containing electronic circuitry configured to detect physical variables, particularly magnetic fields. The magnetic field is generated by a circular encoding device mounted on a rotating body. The encoding device has permanent magnets with alternating north and south poles of defined radii and defined spacing arranged on it. The electronic circuitry detects time-varying changes in the magnetic field and generates an analog output signal. The sensor is preferably an anisotropic magnetoresistive (AMR) sensor, a giant magnetoresistive (GMR) sensor, or a Hall effect sensor. The encoding device is preferably an encoder disk.

[0012] An electrical connection device is a connection device used to connect an electrical conductor that provides voltage to the sensor and facilitates data transmission. The electrical connection device extends from a lead frame, typically enclosed within a housing, to an external location. The electrical connection device is preferably made of copper.

[0013] The advantage of this invention is that it simplifies the manufacturing process of the sensor device, thereby reducing production costs. This is because the sensor device no longer requires a support element to surround and fix the sensor in the injection mold. This eliminates the manufacturing steps of the sensor device and the support element, thus reducing costs and simplifying production.

[0014] The sensor preferably has a sensor housing. The sensor housing at least partially surrounds the sensor element and the lead frame supporting the sensor element. On the side of the sensor housing adjacent to the base surface, the lead frame protrudes from the sensor housing in the form of two conductors. The sensor housing is preferably made of a polymer, especially polyurethane. This protects the sensor element from environmental influences such as dirt and / or moisture.

[0015] The sensor housing preferably has a recess on a first side, which is the base surface of the sensor housing. The first side extends perpendicularly to the base of the sensor device and extends outward from the inside. The recess on the first side of the sensor housing is configured such that a mold, for example, having a rectangular protrusion corresponding to the recess, is engaged into the recess during manufacturing. The base surface of the sensor housing is preferably rectangular, and in particular square. This has the advantage of allowing for easy fixing during the manufacturing process of the sensor device.

[0016] Furthermore, the sensor housing has a protrusion on a second side, which is positioned opposite the first side. The protrusion is, for example, rectangular and / or circular and / or X-shaped. The protrusion is configured to allow the mold to secure the sensor device during the manufacturing process. For example, the mold may have rectangular recesses corresponding to the protrusion. The advantage of this is that the sensor device can be easily secured during the manufacturing process.

[0017] The lead frame and the first part of the electrical connection device are preferably welded or crimped together. The electrical connection device can be arranged on the lead frame, for example, by means of a mold, especially by means of a gripper, such that a region of the lead frame and a region of the electrical connection device overlap each other. The lead frame and the electrical connection device are preferably welded together in the overlapping area, for example, by ultrasonic welding or laser welding. Alternatively, the overlapping area can be joined together by a joining process, by plastic deformation, especially crimping. The advantage of doing so is that a strong mechanical connection can be established between the lead frame and the electrical connection device.

[0018] Furthermore, the sensor has a plug placement space on the outside of the housing, into which a third part extends. The plug placement space is designed to receive a plug. The plug is provided with conductors for power supply and / or data transmission. Additionally, the plug placement space preferably has a first locking device that can lock with a second locking device on the plug, thereby forming a form-locked connection with the housing. The plug placement space offers the advantage of providing power to the sensor device and transmitting data, particularly to the control unit. The plug placement space constitutes a unified interface.

[0019] Preferably, the housing has at least a pre-formed groove for the sensor, wherein the groove at least partially surrounds the sensor housing. The groove is configured to securely mount the sensor within the housing. The groove preferably has an opening on a first side of the sensor housing, which is formed during the manufacturing process of the sensor device. This provides the advantage of firmly positioning the sensor within the housing and providing additional protection.

[0020] Furthermore, the housing is configured in a canister shape, with a structure extending from the inside of the housing to form a placement space, where the sensor is located inside the housing. The canister shape is achieved by extending a structure, specifically an edge, from the inside of the housing at intervals greater than the distance defined by the sensor, across the entire circumference of the housing. This structure thus creates a placement space for the rotating body. The advantage of this design is that the housing can be positioned within the freely accessible area of ​​the rotating body.

[0021] A fixing device is preferably included at the edge of the placement space. This fixing device secures the housing to a fixed point close to the rotating body, such as the outer ring of a bearing that supports the rotating body. The fixing device forms a force-locking connection and a form-locking connection on the surface of the fixed point. Furthermore, the fixing device prevents moisture and / or dirt from seeping in. Its advantages are that the sensor device can be securely mounted, and the sensor is protected from the influence of the surrounding environment.

[0022] To accomplish this task, a method for manufacturing the aforementioned sensor device is also provided, wherein the sensor device includes a sensor, a housing, a lead frame, and an electrical connection device, and the method includes the following steps:

[0023] • Use a mold to fix the sensor.

[0024] • The lead frame is connected to the electrical connection device by welding or crimping.

[0025] • Place the fixing device into the mold.

[0026] • Manufacture a housing that at least partially surrounds the sensor, electrical connection device, and fixing device. Attached Figure Description

[0027] Other features and advantages can be derived from the following description in conjunction with the accompanying drawings. Wherein:

[0028] Figure 1 A side view of the sensor device is shown;

[0029] Figure 2 Showing according to Figure 1 A perspective view of the sensor device; and

[0030] Figure 3 The process steps of the production process are shown. Detailed Implementation

[0031] Figure 1A sensor device 10 is shown. Here, the sensor device 10 includes a sensor 12, a lead frame 14, an electrical connection device 16, and a housing 18. A rotation axis 20 is located at the center of the housing. An encoding device is disposed on a rotating body (not shown) that rotates around the rotation axis 20. The encoding device includes multiple encoders. The encoding device is preferably a permanent magnet and is arranged on the rotating body in a circular orbit with alternating north and south poles. The sensor 12 is disposed on the inner side 24 of the housing. A plug placement space 22 is disposed on the outer side 26 of the housing.

[0032] Sensor 12 at the defined spacing R S The sensor 12 is disposed inside the housing 18, 24. Here, the sensor 12 includes a sensor element 44, a lead frame 14, and a sensor housing surrounding the sensor element 44 and the lead frame. The sensor housing protects the sensor element and the lead frame from environmental factors such as moisture and dirt. Furthermore, the sensor 12 is at least partially surrounded by the housing 18.

[0033] Sensor element 44 is mounted on lead frame 14. Lead frame 14 provides power to sensor element 44 and transmits signals to control unit (not shown). Lead frame 14 includes at least two separate conductors. A coupling capacitor, for example, is disposed between the two conductors for capacitive coupling. The lead frame connects the sensor to base surface G. V It extends to the adjacent side and from the outside into the shell.

[0034] Electrical connection device 16 is disposed on lead frame 14. Lead frame 14 and electrical connection device 16 partially overlap. In the overlapping area, lead frame 14 and electrical connection device 16 are welded or crimped together.

[0035] The electrical connection device 16 is divided into three parts. The first part 38 overlaps with the lead frame 14 in the overlapping area and further extends into the housing 18. The second part 40 extends from the first part 38 and bends 90° relative to the first part. The second part 40 extends vertically along the center direction of the housing. Between the first part 38 and the second part 40, the electrical connection device 16 bends in an arc. The third part 42 is located at the end of the second part 40, forming an angle between 15° and 45° with the longitudinal axis of the second part 40. The third part 42 extends from the housing 18 and serves as part of or extends into the plug placement space 22. The electrical connection device 16 is used for transmitting electrical energy and data transmission from the sensor 12 to the plug placement space 22.

[0036] A plug placement space 22 is located on the outer side 26 of the housing 18. The plug placement space 22 is part of the housing 18. The plug placement space 22 is used to hold a plug (not shown), which has conductors for supplying power to the sensor 12 and transmitting data from the sensor. To secure the plug in the plug placement space 22, at least two locking devices 28 are pre-installed on the plug placement space 22, wherein the locking devices on the plug can be engaged with the two locking devices.

[0037] A structure 30 begins from the inner side 24 of the housing 18, at a distance greater than the defined spacing R. S The radius extends outward from the inner side 24. The structure 30 extends over the entire circumference of the housing 18. The structure 30 and the base of the sensor device together form a placement space 32 for placing the rotating body (not shown) and the encoding device disposed thereon.

[0038] Structure 30 has end members. The end members of structure 30 are the areas furthest from the inner side 24. The end members of structure 30 have fixing devices 34 on their outer sides. The fixing devices 34 extend over the entire circumference of structure 30. The fixing devices 34 are partially connected to structure 30 and are designed to be more securely attached to housing 18. With the fixing devices 34, housing 18 can be fitted onto corresponding mating parts (not shown here) in a form-locking and force-locking manner, such as the outer ring of a bearing supporting a rotating body.

[0039] Sensor 44 is configured to detect changes in the magnetic field. Permanent magnets (not shown) pass over the end of sensor 12, opposite the lead frame 14 extending from the housing. These permanent magnets are mounted on a rotating body (not shown). The permanent magnets are arranged at fixed intervals around the periphery of the rotating body, thus causing the magnetic field to change at fixed intervals as well. The velocity can be determined by the change in the magnetic field over time and the known intervals between the permanent magnets.

[0040] Figure 2 As can be seen, the structure 30 of the housing 18 extends along the entire circumferential direction of the housing 18. The fixing device 34 provided at the end of the structure 30 also extends along the entire circumferential direction, just like the structure 30.

[0041] Sensor 12 is surrounded by a recess 36. The recess 36 at least partially surrounds sensor 12, thus revealing a recess 46, which is part of the housing of sensor 12. The recess 36 with sensor 12 extends from the inner side 24 of housing 18 to placement space 32. Recess 46 is used to secure the sensor during the manufacturing process of the sensor device by embedding a corresponding mold into recess 46 and securing sensor 12 using another mold or mold component disposed on the opposite side of recess 46.

[0042] Figure 3A method for manufacturing the sensor device 10 is shown. In a first step, a mold is used to fix the sensor 12. Here, the mold includes a core and a sliding core. The core is placed into the aforementioned recess 46 of the sensor housing. On the opposite side of the recess 46, there is a protrusion on the sensor housing. The sliding core moves over the protrusion, thereby fixing the sensor between the two mold components.

[0043] The second step is to connect the sensor 12 to the electrical connection device 16. Here, the electrical connection device is disposed on the lead frame 14 of the sensor 12, for example, using a gripping device. Then, the lead frame 14 and the electrical connection device 16 are preferably welded together by ultrasonic welding. However, other welding methods are also conceivable. Alternatively, the lead frame 14 and the electrical connection device 16 can be pressed together, i.e., connected together by plastic deformation.

[0044] During the connection between the lead frame 14 and the electrical connection device 16, the electrical connection device 16 provides spacer devices between the various conductors of the lead frame 14. These spacer devices are removed after connection, for example, by stamping.

[0045] In a subsequent step, the fixing device 34 is positioned around the sensor 12. This is accomplished, for example, by positioning the electrical connection device 16 onto the same gripping device on the lead frame 14.

[0046] The manufacturing process of housing 18 begins when the retaining element 34 is in the position pre-set in the manufacturing process. The position of the retaining element 34 can be determined and checked, for example, by a sensor. Housing 18 is produced by injection molding of polymer or plastic.

[0047] The final step is to remove the finished sensor device 10 from the mold or have it removed by an operator. Then, the process is restarted.

[0048] In another embodiment, sensor 12 can rotate 180° along an axis parallel to the rotation axis. Therefore, recess 46 is located on the outward-facing side. This arrangement of sensor 12 is related to the rotation direction of the encoding device.

[0049] List of reference numerals in the attached diagram:

[0050] 10 sensor devices

[0051] 12 sensors

[0052] 14-lead frame

[0053] 16 Electrical connection devices

[0054] 18 shell

[0055] 20 rotating axes

[0056] 22-plug device

[0057] 24 inner side

[0058] 26 outer

[0059] 28 locking devices

[0060] 30 structure

[0061] 32 storage spaces

[0062] 34 Fixing devices

[0063] 36 grooves

[0064] 38 Part 1

[0065] 40 Part Two

[0066] 42 Part Three

[0067] 44 sensor devices

[0068] 46 depressions

[0069] R S Define spacing

[0070] G V The base plane of the sensor device.

Claims

1. A sensor device (10) for detecting rotational speed, wherein, The sensor device (10) includes a housing (18) and a sensor (12) for detecting the rotational speed of a rotating body rotating about a rotation axis (20). Among them, the base of the shell (18) is on the base plane (G V Extending in, wherein the housing includes an inner side (24) and an outer side (26) oppositely disposed. The sensor (12) has a lead frame (14), a sensor element (44) disposed on the lead frame (14), and an electrical connection device (16) disposed on the lead frame for supplying power to the sensor. Among them, the lead frame (14) is spaced at a specified distance (R) from the rotation axis (20). S ) is set on the inner side (24) of the housing (18), Among them, the lead frame (14) is located adjacent to the base plane (G) of the sensor (12). V One side of the axis of rotation (20) extends outward from the outer side (26). The electrical connection device (16) is divided into a first part (38), a second part (40) and a third part (42). The first part (38) extends from the lead frame (14) to the housing (18). The second part (40) extends from the first part toward the rotation axis (20) at an angle of 90°. The third part (42) extends along a direction at an angle between 0° and 45° to the second part.

2. The sensor device according to claim 1, characterized in that, The sensor (12) has a sensor housing.

3. The sensor device according to claim 2, characterized in that, The sensor housing has a recess (46) on the first side, which is the bottom surface of the sensor housing.

4. The sensor device according to claim 3, characterized in that, The sensor housing has a protrusion on the second side, which is opposite to the first side.

5. The sensor device according to any one of the preceding claims, characterized in that, The lead frame (14) and the first part (38) of the electrical connection device (16) are welded or crimped together.

6. The sensor device according to any one of the preceding claims, characterized in that, The sensor (12) forms a plug placement space (22) on the outside (26) of the housing (18), and the third part (42) extends into the plug placement space.

7. The sensor device according to any one of the preceding claims, characterized in that, The housing (18) is provided with at least one groove (36) for the sensor, wherein the groove (36) at least partially surrounds the sensor housing.

8. The sensor device according to any one of the preceding claims, characterized in that, The housing (18) is constructed in the shape of a can, wherein a structure (30) is formed extending from the inner side (24) of the housing (18) and a placement space (32) is formed, wherein the sensor (12) is disposed on the inner side (24) of the housing (18).

9. The sensor device according to claim 8, characterized in that, A fixing device (34) is included at the edge of the placement space (32).

10. A method for producing a sensor device according to any one of the preceding claims, wherein, The sensor device includes a sensor, a housing, a lead frame, and an electrical connection device. The method includes the following steps: • Use a mold to fix the sensor. • The lead frame is connected to the electrical connection device by welding or crimping. • Place the fixing device into the mold. • Create a housing that at least partially surrounds the sensor, electrical connection device, and fixing device.

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