Temperature sensor, hydrogen tank valve, and end plug

Abstract

The invention relates to a temperature sensor (1) comprising: - a sensor element (3), preferably an NTC element, having connection wires (2), - conducting tracks (4) for contacting the connection wires (2) of the sensor element (3), - a plastic part (5) for accommodating the sensor element (3) and the conducting tracks (4), and - a sensor sleeve (6) for at least partly accommodating the plastic part (5) including the sensor element (3) accommodated in the plastic part, wherein the plastic part (5) has ◦ longitudinal grooves (7) for guiding and electrically insulating the connection wires (2) of the sensor element (3), ◦ longitudinal grooves (8) for guiding and electrically insulating the conducting tracks (4), and ◦ at least one window-type opening (9) extending through the plastic part (5), for exposing the connection wires (2) and conducting tracks (4) accommodated in the longitudinal grooves (7, 8), and wherein the longitudinal grooves (7, 8) for the connection wires (2) and the conducting tracks (4) mutually overlap in the region of the at least one window-type opening (9). The invention also relates to a hydrogen tank valve and an end plug having a temperature sensor (1) according to the invention.

Description

[0001] Description hydrogen tank valve as well as

[0002] The invention relates to a temperature sensor, in particular a temperature sensor for a hydrogen tank valve, with which the temperature in a hydrogen tank can be measured. Furthermore, the invention relates to a hydrogen tank valve and an end cap, each with a temperature sensor according to the invention.

[0003] State of the art

[0004] Hydrogen tank valves are known for both withdrawing hydrogen from and filling a hydrogen tank. Such a hydrogen tank valve incorporates at least one controllable shut-off valve. In addition, further valves and / or sensors, particularly a temperature sensor for monitoring the temperature inside the hydrogen tank, are typically integrated.

[0005] A temperature sensor for a hydrogen tank valve comprises a sensor element, for example, an NTC element, which is placed in the hydrogen tank via the hydrogen tank valve. A sensor sleeve protects the sensor element from contact with the hydrogen stored in the tank. The electrical connections of the sensor element, for example, in the form of connecting wires, must be routed to the outside via a bore in the hydrogen tank valve or contacted externally. This contact can be achieved, for example, by means of conductive traces that are electrically connected to the sensor element's connecting wires, in particular by welding.

[0006] When mounting the sensor element and connecting its electrical terminals, care must be taken to ensure that these terminals are adequately electrically insulated from each other and from the surrounding sensor sleeve, as otherwise there is a risk of a short circuit and / or ground fault. If conductive traces are used for contact, these must also be electrically insulated from each other and from the sensor sleeve. The necessary electrical insulation can be achieved, for example, with a plastic component that surrounds the connecting wires and conductive traces, at least partially. However, when joining the plastic component to the sensor sleeve, there is a risk that the thin connecting wires will be bent upwards, compressed, and / or kinked, causing them to contact either each other or the sensor sleeve, resulting in a short circuit or ground fault.

[0007] The present invention is concerned with the objective of providing a short-circuit and / or mass-circuit optimized temperature sensor for a hydrogen tank valve.

[0008] To solve the problem, a temperature sensor with the features of claim 1 is proposed. Advantageous embodiments of the invention are described in the dependent claims. Furthermore, a hydrogen tank valve and an end cap, each with a temperature sensor according to the invention, are specified.

[0009] Disclosure of the invention

[0010] The proposed temperature sensor comprises: a sensor element having connecting wires, preferably an NTC element,

[0011] Conductive traces for contacting the connecting wires of the sensor element, a plastic part for receiving the sensor element and the conductive traces, and a sensor sleeve for receiving at least part of the plastic part including the sensor element received therein.

[0012] The plastic part exhibits:

[0013] Longitudinal grooves for guiding and electrically insulating the connecting wires of the sensor element,

[0014] Longitudinal grooves for guiding and electrically insulating the conductor tracks, and at least one window-like opening penetrating the plastic part to expose the connecting wires and conductor tracks received in the longitudinal grooves, wherein the longitudinal grooves for the connecting wires and the conductor tracks overlap each other in the area of ​​the at least one window-like opening.

[0015] The plastic part of the temperature sensor not only provides electrical insulation but also guides the connecting wires and conductor tracks. This guidance facilitates the installation of the temperature sensor, particularly the insertion of the sensor element into the plastic part and the insertion of the assembly into the sensor housing. Both the electrical insulation and the guidance are achieved via longitudinal grooves formed in the plastic part. The plastic part features first longitudinal grooves for the connecting wires and second longitudinal grooves for the conductor tracks. Since the first and second longitudinal grooves overlap, the connecting wires and conductor tracks can also be arranged in an overlapping configuration. The connecting wires can be welded to the conductor tracks through at least one window-like opening provided in this area of ​​the plastic part.Preferably, two window-like openings are provided in the plastic part, so that each opening exposes a connecting wire and a conductor track. Thus, a separate welding window is provided for each weld connection. This prevents a short circuit caused by the welding material introduced into the opening.

[0016] Guiding the sensor element's connecting wires through the longitudinal grooves ensures correct and reproducible positioning of the wires. Since the plastic part simultaneously supports the connecting wires held in the longitudinal grooves, the risk of bending, compression, and / or kinking is minimized.

[0017] In a further development of the invention, it is proposed that the longitudinal grooves for guiding and electrically insulating the connecting wires extend from an end section of the plastic part to behind the at least one window-like opening. When the sensor element is inserted into the plastic part, the free ends of the connecting wires can thus be pushed behind the at least one window-like opening, so that they are trapped. This reliably prevents the free ends of the connecting wires from bending open when the pre-assembled unit, consisting at least of the sensor element, plastic part, and conductor tracks, is inserted into the sensor sleeve.

[0018] Since the connecting wires are typically very thin, it is proposed, for further optimization of their guidance, that the longitudinal grooves for guiding and electrically insulating the connecting wires have a narrower width than the longitudinal grooves for guiding and electrically insulating the conductor tracks. Preferably, the width of the longitudinal grooves for the connecting wires is adapted to the diameter of the connecting wires. This largely prevents the connecting wires from being compressed or kinked. This, in turn, ensures precise positioning of the free ends of the connecting wires relative to the conductor tracks.

[0019] Furthermore, it is proposed that in an overlap area of ​​the longitudinal grooves for the connecting wires and the conductor tracks, the longitudinal grooves for guiding and electrically insulating the connecting wires are designed as bottom-side recesses in the longitudinal grooves for guiding and electrically insulating the conductor tracks. This allows the connecting wires and conductor tracks to lie on top of each other in the overlap area. Ideally, the sensor element is first inserted into the plastic part so that the free ends of the connecting wires lie in the bottom-side recesses of the longitudinal grooves for the conductor tracks. Subsequently, the conductor tracks can be inserted into the longitudinal grooves provided for this purpose, so that the conductor tracks lie on the connecting wires. Welding can then be carried out through the at least one window-like opening that exposes the connecting wires and the conductor tracks behind them.

[0020] The longitudinal grooves for guiding and electrically insulating the conductor tracks preferably run parallel to each other at a distance, forming a central rib. This rib separates the two conductor tracks and thus prevents a short circuit. The longitudinal grooves for the connecting wires can be designed analogously, at least in sections. If the plastic part tapers towards the end section that accommodates the sensor element, the longitudinal grooves for the connecting wires can also be separated, at least in sections, by a tapered central rib. Preferably, the longitudinal grooves for guiding and electrically insulating the conductor tracks have a depth greater than the height of the conductor tracks themselves. This means that the conductor tracks are neither flush with the surface of the plastic part nor protrude beyond it, but are recessed.This increases the ground connection distance of the conductor tracks to adjacent components, such as the sensor sleeve. To simplify the insertion of the conductor tracks into the deep longitudinal slots, it is proposed as a further improvement that at least one longitudinal edge of each slot be chamfered. Alternatively or additionally, it is proposed that the longitudinal slots have a certain amount of play relative to the conductor tracks to facilitate insertion. However, this requires additional securing of the conductor tracks within the longitudinal slots.

[0021] According to a preferred embodiment of the invention, the longitudinal grooves for guiding and electrically insulating the conductor tracks have clamping lugs that are arranged offset from one another on opposite sides. The conductor tracks are held clamped in the longitudinal grooves by means of these clamping lugs.

[0022] Alternatively or additionally, it is proposed that the plastic part has several pins arranged along the longitudinal grooves, oriented perpendicular to them and deformable under the influence of temperature. Under the influence of temperature, the pins can then be deformed so that they rest on the conductor tracks and secure them against falling out of the longitudinal grooves. Appropriate recesses in the conductor tracks – if provided – can also create a positive fit between the deformed pins and the conductor tracks, preventing longitudinal displacement of the conductor tracks relative to the plastic part. The deformation of the pins can be achieved, for example, by hot or warm riveting. To fix two conductor tracks with the aid of one pin, the pins are preferably arranged along the longitudinal grooves on the central rib separating the longitudinal grooves.

[0023] The connecting wires of the sensor element can be fixed in the longitudinal grooves using temperature-deformable pins, similar to the conductor tracks. Alternatively or additionally, the connecting wires can be bonded to the plastic part. In an advantageous embodiment, the plastic part has a circular cross-section, at least in sections, and is provided with at least one flattened area on its outer circumference, serving as a bearing surface and / or gripping surface. The circular cross-section facilitates insertion of the plastic part into the sensor sleeve, as the angular position of the plastic part relative to the sensor sleeve is irrelevant. The at least one flattened area on the outer circumference, serving as a bearing surface and / or gripping surface, enables a high degree of automation in the manufacturing of the temperature sensor, thus saving time and costs.

[0024] Furthermore, it is proposed that the sensor sleeve have a stepped axial bore to accommodate the sensor element and the plastic part. This means that the axial bore has a reduced inner diameter in one end section, where the sensor element will be located after assembly. This minimizes the clearance between the sensor sleeve and the sensor element, thus enabling the most efficient heat transfer possible from the sensor sleeve to the sensor element. Consequently, the measurement accuracy of the temperature sensor is increased.

[0025] Since the temperature sensor according to the invention is preferably used in a hydrogen tank valve, a hydrogen tank valve with a temperature sensor according to the invention is further proposed. The temperature sensor is preferably partially housed in a bore of a valve block of the hydrogen tank valve. The connection of the temperature sensor to an external power source can be realized via the bore. The sensor element, enclosed by the sensor sleeve, projects into the water tank to detect the temperature of the hydrogen stored therein.

[0026] Furthermore, an end plug for a hydrogen tank with a temperature sensor according to the invention is provided. The end plug is preferably integrated into one end of the hydrogen tank, more preferably into the end opposite a hydrogen tank valve. Preferably, a temperature sensor according to the invention is integrated into both the end plug and the hydrogen tank valve to detect the temperature in the hydrogen tank. The invention and its advantages are explained in more detail below with reference to the accompanying drawings. These show:

[0027] Fig. 1 a) to c) each shows a top view of a temperature sensor according to the invention during assembly, wherein a) shows the plastic part, b) the plastic part with inserted sensor element and c) the plastic part with inserted sensor element and inserted conductor tracks,

[0028] Fig. 2 a) to c) each shows a side view of the plastic part of the temperature sensor of figure 1 ,

[0029] Fig. 3 shows a cross-section through the plastic part of the temperature sensor of Figure 1 ,

[0030] Fig. 4 shows a perspective view of a section of the plastic part with embedded conductor tracks,

[0031] Fig. 5 shows a sectional view through a temperature sensor according to the invention in the area of ​​the sensor sleeve,

[0032] Fig. 6 shows a half longitudinal section through the temperature sensor of Figure 5 in the area of ​​the sensor sleeve and

[0033] Fig. 7 shows a longitudinal section through a sensor sleeve of a temperature sensor according to the invention.

[0034] Detailed description of the drawings

[0035] A temperature sensor 1 according to the invention comprises a sensor element 3 having connecting wires, for example an NTC element, conductive tracks 4 for contacting the connecting wires 2 of the sensor element 3, and a plastic part 5 for guiding and electrically insulating both the connecting wires 2 and the conductive tracks 4. These components are pre-assembled and then inserted into a sensor sleeve 6 to complete the temperature sensor 1. Figures 1a) to 1c) show the pre-assembly steps. In a first step, the plastic part 5 is provided. This part is elongated and has a tapered end section. First longitudinal grooves 7 are formed in this section for receiving the connecting wires 2 of the sensor element 3. These extend to and beyond window-like openings 9 formed in the plastic part 5. Furthermore, the plastic part 5 has second longitudinal grooves 8 for receiving the conductive tracks 4.These are led from the other side to the window-like openings 9 and beyond, so that an overlap area 16 with the first longitudinal grooves 7 is created (see Figure 1 a)).

[0036] First, the sensor element 3 is inserted into the plastic part 5, with the connecting wires 2 being placed in the longitudinal grooves 7. The actual measuring probe of the sensor element 3 protrudes beyond the plastic part 5 (see Figure 1b)).

[0037] The conductive traces 4 are then inserted into the longitudinal grooves 8 of the plastic part 5 so that they partially rest on the connecting wires 2 of the sensor element 3 (see Figure 1c). In this arrangement, the connecting wires 2 and the conductive traces 4 can now be electrically connected, preferably by welding. Welding is carried out via the window-like openings 9. The pre-assembled unit then simply needs to be inserted into the sensor sleeve 6. The longitudinal grooves 7 guide and electrically insulate the connecting wires, preventing short circuits and / or ground faults. Furthermore, the free ends of the connecting wires 2 are held in the longitudinal channels 7, thus preventing bending, compression, and / or kinking of the connecting wires 2 when the pre-assembled unit is inserted into the sensor sleeve 6.

[0038] As can be seen in Figure 3, the plastic part 5 has very deep longitudinal grooves 7 and 8. The connecting wires 2 and conductor tracks 4 inserted therein are thus spaced from the outer circumferential surface of the plastic part 5. This space corresponds to the ground fault distance, so that the risk of a ground fault decreases with the size of the distance. The short-circuit distance is defined by a central web 10, which electrically insulates the two connecting wires 2 from each other and the two conductor tracks 4 from each other. As can also be seen in Figure 3, the longitudinal grooves 7 are designed as bottom-side recesses in the area of ​​the longitudinal grooves 8, so that the connecting wires 2 and the conductor tracks 4 lie on top of each other in the overlap area 16. Furthermore, clamping lugs 12 projecting into the longitudinal grooves 8 are provided for clamping the conductor tracks 4 in the longitudinal grooves 8.Additional fixation is achieved by means of several pins 13 arranged along the central web 10 (see also Figures 2a) and 2b)), which are deformed under the influence of heat. The pin material is thereby pressed into the longitudinal grooves 8, thus preventing the conductor tracks 4 from falling out. The underlying connecting wires 2 are held by the conductor tracks 4. To achieve a positive fit between the pin material and the conductor tracks 4, the conductor tracks 4 can have recesses 17 in the area of ​​the pins 10 (see Figure 4), into which the pin material is then pressed.

[0039] The insertion and fixing of the connecting wires 2 and the conductor tracks 4 in the longitudinal grooves 7, 8 can be carried out fully automatically. For this purpose, the plastic part 5 has flattened areas 14 on its outer circumference (see Figures 2b) and 2c)), which serve as a contact surface and / or as a gripping surface.

[0040] To facilitate the insertion of the connecting wires 2 and the conductor tracks 4, the longitudinal grooves 7, 8 can have chamfered longitudinal edges 11 (see Figures 4 and 5).

[0041] Inserting the pre-assembled module into the sensor sleeve 6 can also be automated. Preferably, the sensor sleeve 6 has a stepped axial bore 15 for receiving the pre-assembled module (see Figures 6 and 7). This improves heat transfer from the sensor sleeve 6 to the sensor element 3. The risk of the thin connecting wires 2 of the sensor element 3 being bent, compressed, and / or kinked in the area of ​​the step during insertion into the sensor sleeve 6 is eliminated, since the connecting wires are guided over the plastic element and their free ends are secured in the longitudinal grooves 7.

Claims

Claims 1. Temperature sensor (1) comprising a sensor element (3) having connecting wires (2), preferably an NTC element, Conductive traces (4) for contacting the connecting wires (2) of the sensor element (3), a plastic part (5) for receiving the sensor element (3) and the conductor tracks (4) and a sensor sleeve (6) for receiving at least part of the plastic part (5) including the sensor element (3) incorporated therein, wherein the plastic part (5) has longitudinal grooves (7) for guiding and electrically insulating the connecting wires (2) of the sensor element (3), longitudinal grooves (8) for guiding and electrically insulating the conductor tracks (4), and at least one window-like opening (9) through the plastic part (5) for exposing the connecting wires (2) and conductor tracks (4) incorporated in the longitudinal grooves (7, 8), wherein the longitudinal grooves (7, 8) for the connecting wires (2) and the conductor tracks (4) overlap each other in the area of ​​the at least one window-like opening (9).

2. Temperature sensor (1) according to claim 1 , characterized in that the longitudinal grooves (7) for guiding and electrically insulating the connecting wires (2) extend from an end section of the plastic part (5) to behind the at least one window-like opening (9).

3. Temperature sensor (1) according to claim 1 or 2, characterized in that the longitudinal grooves (7) for guiding and electrically insulating the connecting wires (2) have a smaller width than the longitudinal grooves (8) for guiding and electrically insulating the conductor tracks (4).

4. Temperature sensor (1) according to one of the preceding claims, characterized in that in an overlap area (16) of the longitudinal grooves (7, 8) the longitudinal grooves (7) for guiding and electrically insulating the connecting wires (2) are designed as bottom-side recesses in the longitudinal grooves (8) for guiding and electrically insulating the conductor tracks (4).

5. Temperature sensor (1) according to one of the preceding claims, characterized in that the longitudinal grooves (8) for guiding and electrically insulating the conductor tracks (4) run parallel to each other at a distance, so that a central web (10) is formed.

6. Temperature sensor (1) according to one of the preceding claims, characterized in that the longitudinal grooves (8) for guiding and electrically insulating the conductor tracks (4) have a depth exceeding the height of the conductor tracks (4), wherein preferably at least one longitudinal edge (11) of the longitudinal grooves (8) is chamfered.

7. Temperature sensor (1) according to one of the preceding claims, characterized in that the longitudinal grooves (8) for guiding and electrically insulating the conductor tracks (4) have clamping lugs (12) which are arranged offset from each other on opposite sides.

8. Temperature sensor (1) according to one of the preceding claims, characterized in that the plastic part (5) has several pins (13) oriented perpendicular to the longitudinal grooves (7, 8) and deformable under the influence of temperature, which are arranged, preferably on the central web (10), along the longitudinal grooves (7, 8).

9. Temperature sensor (1) according to one of the preceding claims, characterized in that the plastic part (5) has at least a circular cross-section in sections and is provided on its outer circumference with at least one flattening (14) as a bearing surface and / or gripping surface.

10. Temperature sensor (1) according to one of the preceding claims, characterized in that the sensor sleeve (6) has a stepped axial bore (15) for receiving the sensor element (3) and the plastic part (5).

11. Hydrogen tank valve with a temperature sensor (1) according to one of the preceding claims, wherein preferably the temperature sensor (1) is received section by section in a bore of a valve block of the hydrogen tank valve.

12. End plug for a hydrogen tank with a temperature sensor (1) according to one of the preceding claims.

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