Actuator arrangement with a sensor module for an actuator with a movable armature

Abstract

Actuator arrangement (18) comprising an actuator (17) with • a magnet housing (19), • a magnetic coil (20) arranged within the magnet housing (19), • a magnetic yoke (22) for supporting the magnetic coil (20), • an armature (23) which is axially movable in the magnet housing (19), and further comprising a sensor module (01) with a sensor (11) for detecting the movement of the armature (23), wherein the sensor module (01) is fastened to an end face of the actuator (17) and wherein the sensor module comprises: • a carrier plate (02) with a top side (03) and a bottom side (04); • a plug (05) arranged on the top side (03) of the carrier plate (02) and mechanically connected to the carrier plate (02) with a plug housing (07) and at least two plug contacts (08) arranged in the plug housing (07) for electrically connecting the sensor module (01) to an external control device; • a sensor (11) arranged on the underside (04) of the carrier plate (02) and mechanically connected to the carrier plate (02) for detecting an armature movement of the displaceable armature (23), wherein the sensor (11) is electrically connected to the plug contacts (08).

Description

[0001] The invention relates to an actuator assembly comprising a sensor module for an actuator with a movable armature. The sensor module serves to detect the armature movement.

[0002] A preferred application area for the sensor module according to the invention is automotive engineering. The sensor module can be used, for example, in actuators for sliding cam systems. However, other applications, particularly those involving switching magnets, are also possible.

[0003] Actuators that convert electrical signals from an electromagnet into a mechanical armature movement are known from the prior art. The armature movement can be transmitted to machine components, such as the sliding cams of a sliding cam system, which are thereby adjusted or shifted. Such actuators are known from DE 10 2008 020 892 A1, DE 10 2011 078 525 A1, and WO 2014 / 198 264 A1.

[0004] DE 10 2008 020 892 A1 shows an adjusting device with a housing and an actuator pin mounted in the housing for adjusting a machine part interacting with the adjusting device, such as a sliding cam.

[0005] DE 10 2011 078 525 A1 describes a sliding cam system with a bistable actuator unit with an actuator pin for moving sliding cam units.

[0006] WO 2014 / 198 264 A1 describes an actuator comprising at least one electromagnet, a magnet housing, a pressure pin, and at least one movable armature, each with a plunger movable in an axial direction. A lever, which is operatively connected to the plunger and the pressure pin, is pivotably mounted on one side of the magnet housing and serves to transmit force.

[0007] DE 102 01 000 A1 discloses a sensor module, particularly for use in motor vehicles. The sensor module comprises an electrical sensor component enclosed in a sensor housing. A connector housing is firmly connected to the sensor housing, which serves to accommodate active and / or passive electronic components. Contact terminals protrude from the connector housing for electrically connecting the sensor module to a circuit peripheral via plug contacts.

[0008] Also known are so-called on-board diagnostic (OBD) systems. These are vehicle diagnostic systems that monitor all systems affecting exhaust emissions, as well as other important control units, while the vehicle is in operation. Any errors that occur are indicated to the driver via an indicator light and permanently stored in the respective control unit. Error messages can later be retrieved by a specialist workshop via standardized interfaces. Actuator diagnostics, for example, check whether an actuator is responding appropriately to a control signal. For example, an armature movement can be detected using a sensor. The recorded sensor values ​​are transmitted to the corresponding control unit for further processing.

[0009] Further sensor modules are known from DE 10 2014 210 977 A1, US 2009 / 0 026 860 A1, JP 2009- 33 850 A, JP 2009- 33 847 A, DE 10 2013 206 897 A1 and DE 102 28 689 A1.

[0010] An object of the present invention is to provide an actuator arrangement with a sensor module for an actuator with a movable armature, which can be mounted on an actuator or integrated into an actuator with little effort and has a compact design.

[0011] To achieve the object of the invention, an actuator arrangement according to claim 1 serves.

[0012] The sensor module according to the invention is used in actuators with a movable armature. It initially comprises a carrier plate with a top and a bottom made of an electrically non-conductive material, preferably plastic. The carrier plate can, for example, have a circular base. The top of the carrier plate carries a connector with a connector housing and at least two connector contacts arranged in the connector housing. There is a mechanical connection between the connector and the carrier plate. The connector housing and carrier plate can be designed as a single piece. An electrical connection between the sensor module and a control device can be established by means of a connector. A sensor is arranged on the underside of the carrier plate and is mechanically connected to the carrier plate. The sensor is electrically connected to the connector contacts.

[0013] A key advantage of the sensor module according to the invention is its extremely compact design, requiring relatively little installation space. The sensor module is suitable for both mounting on an actuator and for installation in an actuator. The sensor module is immediately ready for operation after installation. To communicate with a control unit, only a corresponding connecting cable needs to be connected to the connector contacts. Using a sensor module, actuators can be easily equipped with sensors to monitor their functionality, which particularly enables actuator diagnostics in OBD systems.

[0014] According to an advantageous embodiment, the sensor is arranged on a printed circuit board. A fixed connection exists between the printed circuit board and the carrier plate. To secure the printed circuit board, the carrier plate, which is preferably made of plastic, has plastic domes that protrude through holes in the printed circuit board. These plastic domes are securely fixed to the carrier plate by hot or ultrasonic riveting. The printed circuit board is then electrically connected to the connector contacts, which is usually done by soldering or solderless using a press fit. Further electronic components required for the operation of the sensor are preferably arranged on the printed circuit board; these components can vary depending on the sensor type.According to an advantageous embodiment, the circuit board is embedded in a media-tight potting compound after it has been mounted on the carrier plate in order to protect the sensitive components from moisture and dirt.

[0015] Alternatively, the sensor module according to the invention can also be manufactured by equipping the circuit board with the connector contacts and then overmolding the circuit board, for example, with plastic, whereby the carrier plate and connector housing are produced by the overmolding process.

[0016] Alternatively, a lead frame made of a material with good electrical conductivity can be used instead of the circuit board. The lead frame serves both as the carrier material and as an electrical conductor, eliminating the need for the usual application of contacts and conductor tracks on circuit boards. The sensor and any other required electronic components are attached to the lead frame, for example, via welded connections. The connector contacts are preferably formed integrally with the lead frame, which further simplifies production. The unit consisting of the lead frame, connector contacts, and sensor is overmolded to form the carrier plate and connector housing. However, it is also possible to overmold only the lead frame to create the carrier plate and connector housing, and then assemble the sensor and electronic components.

[0017] According to an advantageous embodiment, the sensor is a magnetic field sensor, such as a Hall sensor or a magnetoresistive sensor, although this is not intended to be limited to the sensors mentioned. Other sensors suitable for position determination are certainly possible.

[0018] The actuator assembly according to the invention initially comprises an actuator. The actuator includes a magnet housing, a magnet coil arranged within the magnet housing, a magnet yoke for supporting the magnet coil, and an armature axially movable within the magnet housing. The actuator assembly further comprises a sensor module with a sensor for detecting the movement of the armature. The sensor module can be attached to the actuator, preferably attached to an end face of the actuator, or it can be integrated into the actuator.

[0019] To secure the sensor module, plastic domes can be attached to the front of the overmolding of the magnet coil, which protrude through holes in the magnet yoke and the sensor module. These plastic domes are hot-stitched or ultrasonic riveted to secure the sensor module to the actuator. However, the sensor module can also be attached to the actuator using screws, clamps, snap hooks attached to the sensor module, adhesive bonding, or crimping tabs located on the magnet housing or the magnet yoke. These mounting methods are merely examples; other suitable mounting methods are of course possible.

[0020] The sensor module can be integrated into the actuator in various ways. According to a first variant, the carrier plate and connector housing are created during the coil overmolding process. The assembled circuit board is then assembled. In a second variant, the circuit board or lead frame located in the actuator is also overmolded during the coil overmolding process, forming the carrier plate and connector housing. The sensor module connector can be combined with a coil connector to form a single connector.

[0021] According to an advantageous embodiment, the sensor is a magnetic field sensor. In this embodiment, a permanent magnet is preferably attached to the end face of the armature. When the actuator's magnetic coil is de-energized, the armature and thus the permanent magnet are in a position close to the sensor. Due to the magnetic field of the permanent magnet, the sensor sends a signal to a control unit connected to the sensor, which detects in the control unit that the armature is in the de-energized end position. A digital Hall sensor, for example, would transmit a "high" or "low" signal to the control unit. When the coil is energized, the armature moves from the de-energized end position to the energized end position and thus moves away from the sensor module. As the distance between the permanent magnet and the sensor module increases, the magnetic field of the permanent magnet in the area of ​​the sensor decreases.If the magnetic field falls below a specified value, the sensor sends a modified signal to the control unit. A digital Hall sensor would switch from "high" to "low" or from "low" to "high." The control unit would then detect that the permanent magnet is no longer near the sensor. The control unit would interpret this as the actuator switching. By subsequently de-energizing the coil, the armature with the permanent magnet moves from the energized to the de-energized position, and the sensor returns the original signal to the control unit.

[0022] Sintered or plastic-bonded rare earth magnets, ferrite magnets or AlNiCo magnets can preferably be used as permanent magnets.

[0023] Depending on the sensor type used and the associated measuring principle, a permanent magnet may be required or not required. Depending on the sensor type, design adjustments to the armature may be necessary.

[0024] A preferred embodiment of the invention, as well as its advantages and details, are explained in more detail below with reference to the accompanying figures. They show: Fig. 1 a top view of a sensor module according to the invention; Fig. 2 a bottom view of the sensor module; Fig. 3 a perspective view of an actuator arrangement according to the invention; Fig. 4 a partially sectioned view of the actuator arrangement.

[0025] Fig. 1 shows a sensor module 01 according to the invention in a view from above, while Fig. 2 shows a bottom view. The sensor module 01 comprises a carrier plate 02, which in the illustrated embodiment has a circular cross-section. The carrier plate 02 is made of an electrically non-conductive material, preferably plastic. It has a top side 03 and a bottom side 04.

[0026] On the Fig. A connector 05 is arranged on the top side 03 of the carrier plate 02, shown in Figure 1, which connector is mechanically connected to the carrier plate 02. The connector 05 consists of a connector housing 07 and two connector contacts 08 arranged in the connector housing 07. In alternative embodiments, more than two connector contacts 08 are also possible. The carrier plate 02 and connector housing 07 can be designed as a single piece. They can be manufactured, for example, using an injection molding process. The orientation of the connector 05 can be adapted to the respective application. A connecting cable can be connected to the connector 05 in order to connect the sensor module 01 to a control device. The control device evaluates the data supplied by the sensor module 01.

[0027] On the Fig. A printed circuit board 09 is arranged on the underside 04 of the carrier plate 02, shown in Figure 2. The carrier plate 02 and the printed circuit board 09 are firmly connected to one another. To secure the printed circuit board 09, plastic domes 10 are molded onto the carrier plate 02. The plastic domes 10 extend through corresponding holes in the printed circuit board 09. The mechanical connection between the carrier plate 02 and the printed circuit board 09 is established by preferably hot or ultrasonic riveting of the plastic domes 10.

[0028] A sensor 11 is arranged on the circuit board 09 and is designed, for example, as a magnetic field sensor, preferably as a Hall sensor. The circuit board 09 also carries further electronic components 12 which are required for the operation of the sensor 11. The electronic components 12 can vary depending on the type of sensor used. The circuit board 09 is electrically connected to the plug contacts 08 via contact points 13. The connection between the circuit board 09 and the plug contacts 08 is realized, for example, by soldering or solder-free using a press fit. To protect the circuit board 09 from moisture and dirt, the circuit board 09 can be potted with a potting compound (not shown) after it has been mounted on the carrier plate 02. Alternatively, the circuit board 09 can be populated with the plug contacts 08 and then the circuit board 09 can be overmolded, whereby the carrier plate 02 and the plug housing 07 are created.

[0029] The carrier plate 02 has three recesses 14 distributed around its circumference, which serve to receive fastening elements 15 for holding actuator components, such as a magnetic coil 20 and a magnetic yoke 22 on an actuator 17 (see Fig. 4).

[0030] Fig. 3 shows a perspective view of an actuator arrangement 18 according to the invention, while Fig. 4 shows a partially sectioned view of the actuator assembly 18. The actuator assembly 18 according to the invention comprises an actuator 17 and the previously described sensor module 01, which is attached to an end face of the actuator 17. The top side 03 of the carrier plate 02, which has the connector 05, faces outward. The underside 04 of the carrier plate 02, which carries the printed circuit board 09, faces toward the actuator 17. A cable (not shown) can be connected to the connector 05 to connect the sensor module 01 to a control device.

[0031] In the embodiment shown, the actuator 17 is designed as a sliding cam actuator. It initially includes a cylindrical magnet housing 19. Arranged within the magnet housing 19 is a magnetic coil 20, which is held by a magnetic yoke 22. The magnetic yoke 22 forms the magnetic return path. An armature 23 is arranged axially movable within the magnet housing 19. The actuator 17 further includes a coil connector 24 for connecting a connecting cable for the magnetic coil 20.

[0032] Plastic domes 25 are arranged on the front side of the overmolding of the magnetic coil 20, which extend through holes in the magnetic yoke 22 and through holes 27 in the carrier plate 02. The sensor module 01 is fastened to the actuator 17 by hot or ultrasonic riveting of these plastic domes 25. Fastening elements 15 are arranged on the magnet housing 19, which engage in the recesses 14 of the carrier plate 02 and ensure the fixation of actuator components, such as the magnetic coil 20 and the magnetic yoke 22, to the actuator 17.

[0033] The sensor 11 is designed as a magnetic field sensor. A permanent magnet 28 is arranged on the front end of the armature 23 facing the sensor module 01. Fig.In the de-energized state of the magnetic coil 20 shown in Figure 4, the armature 23 with the permanent magnet 28 is in the position close to the sensor. Due to the magnetic field of the permanent magnet 28, the sensor 11 delivers a signal which signals to a connected control unit that the armature 23 is in the de-energized end position. When the magnetic coil 20 is energized, the armature 23 moves from the de-energized end position to the energized end position and thus moves away from the sensor module 01. As the distance of the permanent magnet 28 from the sensor module 01 increases, the measurable magnetic field decreases. If the magnetic field at the sensor module falls below a predetermined limit, the sensor 11 sends a modified signal to the control unit, which signals that the permanent magnet 28 is no longer near the sensor 11 and thus a switching operation of the actuator 17 has taken place. List of reference symbols 01 Sensor module 02 Carrier plate 03 Top of the carrier plate 04 Underside of the carrier plate 05 Plug 06 - 07 Connector housing 08 Plug contacts 09 Circuit board 10 plastic domes of the carrier plate 11 Sensor 12 electronic components 13 contact points 14 recesses in carrier plate 15 fasteners 16 - 17 Actuator 18 Actuator arrangement 19 magnet housings 20 solenoid coil 21 - 22 Magnetic yoke 23 anchors 24 coil connectors 25 plastic domes of the actuator 26 - 27 holes in carrier plate 28 permanent magnet

Claims

[1] Actuator arrangement (18) comprising an actuator (17) with • a magnetic housing (19), • a magnetic coil (20) arranged inside the magnet housing (19), • a magnetic yoke (22) for supporting the magnetic coil (20), • an armature (23) axially movable in the magnet housing (19), and further comprising a sensor module (01) with a sensor (11) for detecting the movement of the armature (23), wherein the sensor module (01) is attached to an end face of the actuator (17) and wherein the sensor module comprises: • a carrier plate (02) with a top (03) and a bottom (04); • a plug (05) arranged on the top (03) of the carrier plate (02) and mechanically connected to the carrier plate (02) with a plug housing (07) and at least two plug contacts (08) arranged in the plug housing (07) for electrical connection of the sensor module (01) to an external control device; • a sensor (11) arranged on the underside (04) of the carrier plate (02) and mechanically connected to the carrier plate (02) for detecting an armature movement of the movable armature (23), wherein the sensor (11) is electrically connected to the plug contacts (08). [2] Actuator arrangement (18) according to claim 1, characterized by , that the sensor (11) is arranged on a circuit board (09), wherein the circuit board (09) is firmly connected to the carrier board (02). [3] Actuator arrangement (18) according to claim 2, characterized by , that the circuit board (09) is embedded in a media-tight potting compound. [4] Actuator arrangement (18) according to claim 1, characterized by , that it has a die-cut grid made of an electrically conductive material firmly connected to the carrier plate (02), wherein the sensor (11) is attached to the die-cut grid and wherein the plug contacts (08) are formed integrally with the die-cut grid. [5] Actuator arrangement (18) according to one of claims 1 to 4, characterized by , that the sensor (11) is a magnetic field sensor. [6] Actuator arrangement (18) according to one of claims 1 to 5, characterized by , that the carrier plate (02) is made of plastic. [7] Actuator arrangement (18) according to claim 6, characterized by , that the carrier plate (02) has plastic domes (10) for fastening the circuit board (09) or the stamped grid. [8] Actuator arrangement (18) according to any of the preceding claims, characterized by , that the sensor (11) is a magnetic field sensor, and that a permanent magnet (28) is attached to one end face of the armature (23).

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