EP-4739982-A1 - SENSOR UNIT WITH RIGID AND ELASTIC POSITIONING MEANS

Abstract

The present invention relates to a sensor unit, comprising a circuit board with capture means and at least one fixing element, a carrier unit, comprising a fixing portion, and a support portion for receiving and orienting the circuit board, and rigid and elastic positioning means, wherein the rigid positioning means are effectively connected to the fixing element of the circuit board and to the fixing portion of the carrier unit in such a manner that the circuit board is rigidly connected to the carrier unit in the region of the fixing element and the elastic positioning means press the circuit board onto the support portion in such a manner that the circuit board is connected movably relative to the support portion of the carrier unit in order to compensate thermally induced mechanical tensions.

Inventors

• TILLE, DIERK
• STALDER, MARTIN

Assignees

• Baumer Electric AG

Dates

Publication Date

20260513

Application Date

20240702

Claims (9)

1. 1. Sensor unit (1) comprising a circuit board (2) with detection means (3) and at least one fixing element (4), a carrier unit (5) comprising a fixing section (6) and a support section (7) for receiving and aligning the circuit board (2), rigid positioning means (8) and elastic positioning means (9), wherein the rigid positioning means (8) are operatively connected to the fixing element (4) of the circuit board (2) and the fixing section (6) of the carrier unit (5) such that the circuit board (2) is rigidly connected to the carrier unit (5) in the region of the fixing element (4) and the elastic positioning means (9) press the circuit board (2) onto the support section (7) such that the circuit board (2) is pressed against the support section (7) of the carrier unit (5) in order to compensate for thermally induced mechanical stresses, in particular within the plane of extension of the circuit board (2) and/or substantially transversely to the pressing force of the elastic positioning means (9). is movably connected.
2. 2. Sensor unit according to claim 1, characterized in that the fixing element (4) is designed as a recess (4a), in particular a bore (4b), which is closed in particular on the circumference.
3. 3. Sensor unit according to claim 1 or 2, characterized in that the rigid positioning means (8) are designed as a positive connection element (8a), preferably as a bolt and/or a retaining pin and/or a screw (8b).
4. 4. Sensor unit according to one of the preceding claims, characterized in that the elastic positioning means (9) are round and/or circular and/or annular, in particular as an O-ring (9a), and/or that the support section (7) is round and/or circular and/or annular.
5. 5. Sensor unit according to claim 4, characterized in that the fixing section (6) is arranged within or centrally to the annular support section (7).
6. 6. Sensor unit according to one of the preceding claims, characterized in that the circuit board (2) comprises at least one notch (10) on the edge, which preferably extends on the outside along a partial section, in particular a partial circle section.
7. 7. Sensor unit according to one of claims 1 to 6, characterized in that the carrier unit (5) is designed as a housing underside (11) of the sensor unit (1), in particular a housing underside of the inclination sensor.
8. 8. Sensor unit according to claim 7, characterized in that the sensor unit (1) comprises a housing top (12), wherein in a closed state of the sensor unit (1) the housing top (12) can be fixed to the housing bottom (11) in such a way that the elastic positioning means (9) can be subjected to force to produce a deformation in order to press the circuit board (2) onto the support section (7) by means of the elastic positioning means (9).
9. 9. Sensor unit according to one of the preceding claims, wherein the sensor unit (1) is designed as an inclination sensor (100) and the detection means (3) is designed as an inclination detection means (103).

Description

Sensor unit with rigid and elastic positioning means The present invention relates to a sensor unit according to claim 1. Sensor units having a circuit board with detection means for detecting objects and/or physical quantities are generally known from the prior art. In practice, a permissible temperature range must be taken into account when using sensor units. The manufacturer must guarantee the unrestricted functionality of the sensor unit within the permissible temperature range. In addition to the characteristic properties of the sensor unit, such as measurement result accuracy and/or detection speed, the thermal design of the sensor unit is therefore also of crucial importance. During thermal design, the different thermal expansion coefficients of critical components, such as a circuit board for accommodating and electrically connecting the detection means and the corresponding carrier unit of the sensor unit, which mechanically holds the circuit board, must be taken into account in such a way that they do not have a negative effect on the measurement result of the sensor unit. In this context, various solutions are known from the state of the art. On the one hand, it is known to select critical components from special materials with low or - in the case of materials that work together - with similar thermal expansion coefficients. In practice, this is usually not possible or leads to high material costs, although the use of the sensor unit is only permitted by the manufacturer for a small temperature range. Furthermore, it is also known from the state of the art that the influence of a temperature change on the measurement result is compensated by means of auxiliary electronics. Such auxiliary electronics determine the temperature directly or indirectly in order to determine a correction value depending on this temperature. Such a solution is not only complex and therefore costly, but can also lead to a falsification of the measurement result of the sensor unit. Consequently, the present invention is based on the object of solving the disadvantages known from the prior art. In particular, the object of the present invention is to provide a sensor unit with a circuit board, wherein the circuit board can be fixed to a carrier unit for positioning and/or aligning the detection center of the circuit board in such a way that a different thermal expansion between the circuit board and the carrier unit does not have a negative effect on the detection means and thus on the measurement result of the sensor unit. This object is achieved by a device according to the invention according to claim 1. Advantageous developments of the invention are described in the subclaims. The scope of the invention includes all combinations of at least two of the features disclosed in the description, the claims and/or the figures. The present invention relates to a sensor unit comprising a circuit board with detection means and at least one fixing element. The sensor unit according to the invention comprises a carrier unit for receiving and aligning the circuit board. The carrier unit has a fixing section and a support section. The support section preferably comprises a support surface with which the circuit board is in contact for alignment and/or positioning. Furthermore, the sensor unit according to the invention comprises rigid positioning means as well as elastic positioning means. The rigid positioning means are in active contact with the fixing element of the circuit board on the one hand and with the fixing section of the carrier unit on the other hand in order to rigidly connect the circuit board to the carrier unit. In other words, the rigid positioning means realize a positive and/or non-positive connection between the circuit board and the carrier unit, which is why a rigid coupling between the circuit board and the carrier unit occurs in the area of the rigid positioning means and/or around the rigid positioning means. The elastic positioning means are in active contact with the circuit board in such a way that the circuit board is pressed onto the support section of the carrier unit with a certain force. The pressing force acting on the circuit board, which is aligned transversely to the plane of extension of the circuit board, presses the circuit board onto the support section of the carrier unit. When the temperature changes, the circuit board and the carrier unit can expand independently of each other. A relative movement between the circuit board and the carrier unit is thus deliberately permitted to compensate for thermally induced stresses, whereby such an expansion does not have a negative effect on the detection means. Since the circuit board and the carrier unit are rigidly connected to one another via the fixing element and the fixing section as well as the rigid positioning means, such a relative movement will have an effect starting from this area. The elastic positioning means and the support sectio