Sensor device

Abstract

To provide a generic sensor device which maintains measurement accuracy even in the presence of external forces such as vibration or impact.SOLUTION: A sensor device comprising a beaker-like sensor housing 1 and a wired sensor is provided, the beaker-like sensor housing having an introduction region 3 for the wired sensor. The sensor housing also has an orientation region 4 for the sensor and a placement region 5 for the sensor located near an end face thereof. The orientation region has an internal cross-sectional contour adapted to the cross-sectional contour of the sensor, and the sensor is introduced into a curable material in the placement region in the sensor housing.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a sensor device comprising a beaker-like sensor housing and a wired sensor, the beaker-like sensor housing having an introduction area for the wired sensor and also having an orientation area for the sensor and a placement area for the sensor near an end face of the sensor housing. [Background technology]

[0002] Sensor devices of this kind are used in particular on wheels or bicycles to detect, for example by means of magnetic pulses, the distance traveled, the speed and further parameters of the bicycle.

[0003] Known sensor devices suffer in particular from problems of accurate placement on the bicycle frame as well as inaccurate measurement detection, which problems arise from the sensor and its sensor housing, because the sensor and its sensor housing are not designed to be robust enough for various cycling purposes.

[0004] In particular, inaccuracies in the measurement data may result from the actual sensor not being securely and accurately positioned in the sensor housing and from changes in position due to the action of impact forces, which ultimately leads to inaccurate measurements.

[0005] The sensor device itself must also be easily and accurately positionable on the bicycle frame. Summary of the Invention [Problem to be solved by the invention]

[0006] Therefore, taking these disadvantages into consideration, the objective is to design a universal type of sensor device such that the measurement accuracy of the sensor device is maintained even in the presence of externally acting forces, such as vibration or impact forces. [Means for solving the problem]

[0007] This object is achieved by the features of the characterizing part of claim 1.

[0008] One essential core concept in such cases is to be able to introduce and position the wired sensor in the sensor housing very precisely, and maintain the positioning of the sensor in the sensor housing even when different forces are applied, thereby ensuring that the measurement accuracy of the sensor device is also not impaired even when sudden forces are applied.

[0009] On the other hand, the design contributes to high measurement accuracy in that, when the sensor is introduced into the beaker-like sensor housing, it must be guided through the internal cross-sectional contour of the orientation region, and the sensor itself has a corresponding cross-sectional contour that is adapted to the internal cross-sectional contour of the orientation region. Thus, the corresponding orientation of the sensor when introduced into the placement region close to the inside of the end face of the sensor housing and its embedding in the hardened material results in a fixed position of the sensor in the sensor housing.

[0010] In this case, the sensor is introduced into the sensor housing into a hardenable material, in particular a free-flowing plastic material or resin, which is introduced into the interior of the sensor housing, and the hardenable material is hardened by temperature or by radiation once the sensor is placed in the region of the inner surface of the end face of the sensor housing.

[0011] In the lead-in region of the sensor housing, elongated guide bars are provided, preferably distributed over the inner circumferential surface of the sensor housing, which guide bars allow the sensor to be led axially and centrally into the orientation region of the sensor housing, where, by means of an adapted contour, it can be oriented, for example in a specific angular arrangement, as required for high measurement accuracy. In particular, for this purpose, four guide bars are provided in the lead-in region, arranged at the same angular distance from each other.

[0012] When a sensor connected to a cable is introduced into the internal region of the sensor housing, a tapered section is provided in the orientation region after the introduction region or in front of the orientation region, which makes it possible to insert the sensor into the orientation region even more easily and accurately, and the tapered section can in particular have a cross section in the form of an ellipse.

[0013] After this orientation operation, the sensor, together with the cable, is guided through the free-flowing hardenable material into its appropriate placement area near the inside end face of the sensor housing.

[0014] This manufacturing operation is conveniently carried out in a vertical position of the beaker-like sensor housing, with the opening facing upwards and the end face at the bottom being closed in the base region.

[0015] One improvement of this sensor device is that a strain relief means is arranged on the cable connected to the sensor. This can be easily achieved by arranging an O-ring on the cable. In this case, the opening of the O-ring preferably provides a press fit on the cable sheath to absorb forces acting on the cable from the outside and transmit these forces to the entire sensor housing. Therefore, the O-ring is preferably fixed in a ring groove in the introduction area of the sensor housing. Advantageously, the fixation of the O-ring is carried out after the material introduced into the sensor housing has hardened.

[0016] The possibility of strain relief by an O-ring fixed to the sensor housing also has the advantage that different strain reliefs can be realized by different openings in the O-ring.

[0017] The O-ring closure also provides an aesthetic covering over the filled and hardened material.

[0018] The sensor housing is preferably made of a plastic material. In particular, the plastic material having the trade name "Lexan" is suitable for this purpose. Advantageously, a reed contact is used as the sensor or sensor element, which contact can be opened or closed under the influence of a magnetic field. For excellent detectability of the magnetic field generated close to the outer end face of the beaker-like sensor housing, the sensor is arranged very close to the inner end face region of the sensor housing.

[0019] Thus, a free-flowing plastic material or resin introduced into the interior of the sensor housing without air and bubbles ensures that the precise placement of the sensor within the sensor housing is maintained when the material hardens.

[0020] A somewhat modified manufacturing method can also be considered in which the wired sensor is introduced and placed in the beaker-like sensor housing before the introduction of the free-flowing material, and only then is the free-flowing embedding material introduced inside the beaker-like sensor housing.

[0021] The invention will be discussed in more detail below with reference to two schematic drawings. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 1 is a longitudinal cross-sectional view of the sensor housing without the sensor and cable but with strain relief at the end. [Figure 2]2 is a somewhat enlarged vertical cross-section of the sensor housing shown in FIG. 1 without strain relief at the end, seen from the left; the schematic cross-section according to FIG. 1 is indicated as AA in FIG. 2. DETAILED DESCRIPTION OF THE INVENTION

[0023] The sensor device according to the invention is shown schematically and will be considered in more detail below with respect to two schematic representations of the essential module, i.e. the sensor housing 1, without the actual sensor or sensor element and without the corresponding cable connections.

[0024] The longitudinal section of the beaker-like sensor housing 1 in Figure 1 shows in particular the beaker of the sensor housing 1, which is manufactured in one piece from a plastic material such as Lexan. The left end region of the sensor housing 1 shows an opening into which an O-ring 21 is inserted and fixed. The sensor housing 1 is closed at its right end face 7 like a beaker.

[0025] In the manufacturing process of the sensor device, the sensor housing 1 is normally placed in a vertical position with its left opening facing upwards.

[0026] A hardenable free-flowing material or resin is then introduced into the beaker 6 of the sensor housing 1. The actual sensor with its connected cable is then inserted into the top opening of the beaker 6 and guided or lowered by the guide rails 11 in the center from the introduction area 3 into the orientation area 4. The sensor is oriented by the conically tapered area 14 and by the internal contour configured as an elliptical section 16.

[0027] The sensor or sensor element in the illustrated example similarly has the external configuration of a corresponding oval portion 16, which allows the sensor to be guided through the oval portion 16 to fit accurately into the right or lower placement area 5.

[0028] As soon as the end position of the sensor in the region of the inner surface of the end face 7 is reached, a hardening operation of the hardenable material is subsequently carried out, which makes it possible to realize an air-free and bubble-free embedding and fixation of the sensor in the sensor housing 1.

[0029] Once the free-flowing material has hardened, or possibly even before hardening, an O-ring 21 for strain relief of the sensor and attached to the cable can be fixed in the ring groove on the opening side of the lead-in area 3, thus providing a closure also with respect to the potting and encapsulating material.

[0030] In this design, the sensor arrangement represents a very precisely positioned sensor, whose relative positioning inside the sensor housing is not adversely affected by acting impact forces, thus also ensuring high measurement accuracy.

[0031] An annular bead 25 in the middle region of the sensor housing 1 can also serve to accurately position the sensor housing 1 on the bicycle frame, with clamping holders providing further fastening to the bicycle frame on one or both sides of the annular bead 25.

Claims

1. A sensor device comprising a beaker-like sensor housing and a wired sensor, the beaker-like sensor housing comprising: an entrance area for the wired sensor; an orientation area for the sensor having an internal cross-sectional contour adapted to a cross-sectional contour of the sensor; a placement area of the sensor near an end surface of the sensor housing; and a curable material is provided within the sensor housing, the sensor within the sensor housing being introduced into the curable material within its placement area; and a tapered section for guiding the sensor into the placement area is provided in front of or at the orientation area of the sensor; the orientation region has a cross section in the form of an oval; four guide bars for the sensors are provided in the lead-in area, at the same angular distance from each other; A sensor device, wherein the curable material is cured with the sensor embedded therein.

2. 2. The sensor arrangement according to claim 1, wherein strain relief means for the cable and the sensor formed as an O-ring with a cable-accommodating opening is provided in the lead-in area of the sensor housing.

3. The sensor device of claim 1 , wherein the curable material is a free-flowing plastic material or resin.

4. The sensor apparatus of claim 1 , wherein the sensor housing is fabricated from Lexan, a plastic material.

5. 10. The sensor device of claim 1, wherein the beaker-like sensor housing has a closed end and a detection zone of the sensor formed as a reed contact is provided adjacent the closed end.

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