DE102023201896A1 - Method for producing a sensor assembly, sensor assembly and tank valve with sensor assembly - Google Patents

Abstract

The invention relates to a method for producing a sensor assembly (1), in particular a temperature sensor assembly, with a sensor element (3) having connecting wires (2) for insertion into a bore (4) of a valve block (5), comprising the steps of (a) connecting the connecting wires (2) in the region of their free ends to contact elements (6), for example in the form of conductor tracks, to form a plug-in, touch or sliding contact, (b) forming an overmolding (7) which encases the connecting wires (2) at least in sections and has a circumferential shoulder (8), so that a first overmolding section (7.1) with a defined length (L1) for insertion into a sensor sleeve (9) and a second overmolding section (7.2) with a defined length (L2) for insertion into the bore (4) of the valve block (5) are formed, (c) inserting the sensor element (3) and the first overmolding section (7.1) into the sensor sleeve (9), so that the shoulder (8) comes to rest on the sensor sleeve (9).The invention further relates to a sensor assembly (1) and a tank valve with a sensor assembly (1) according to the invention.

Description

The invention relates to a method for producing a sensor assembly, in particular a temperature sensor assembly. The invention further relates to a sensor assembly, in particular a temperature sensor assembly, for a tank valve and a tank valve with a sensor assembly according to the invention.

The preferred area of application is fuel gas tanks, for example hydrogen or natural gas tanks, in which a tank valve with a sensor, in particular with a temperature sensor, is inserted.

State of the art

A tank valve for a fuel gas tank is generally used to remove fuel gas from the fuel gas tank and to fill the fuel gas tank with fuel gas. For this purpose, several valves are integrated into the tank valve, so that the tank valve is not a single valve, but a valve assembly. A temperature sensor can also be integrated into the tank valve to record the temperature in the fuel gas tank. So that the temperature sensor is located inside the fuel gas tank, it is usually integrated into a connecting section of a valve block of the tank valve, which is inserted into the fuel gas tank to connect it. The electrical connections of the temperature sensor can then be led out of the fuel gas tank via the connecting section, so that they can be electrically contacted.

In the current state of the art, electrical contact is made using so-called Molex connectors, for example. A Molex connector has a female plug contact and a male plug contact. The Molex connector is connected to the sensor or its connection cables via the male plug contact, with the Molex connector and the temperature sensor within the valve block generally oriented at an angle of 90° to one another. The valve block has two holes at right angles to one another that are connected to one another via a hole intersection. During assembly, the sensor's connection cables are inserted into the hole for the sensor and pushed over the hole intersection into the hole for the Molex connector. The connection cables can then be pulled out via the hole for the Molex connector and connected to the male plug contact of the Molex connector. The male plug contact and the female plug contact are then connected and inserted into the hole for the Molex plug, whereby the sensor connection cable must be pushed back into the hole for the sensor - again over the hole intersection. When inserting the Molex plug, care must be taken that the sensor connection cable is not trapped between the plug and the valve block, as otherwise there is a risk of a short circuit or a line break.

This type of electrical contacting of a sensor, especially a temperature sensor, within a valve block of a tank valve is not only highly error-prone, but also very time-consuming, since many steps can only be carried out manually.

The general aim is therefore to achieve a high degree of automation by using a sensor assembly that is pre-assembled and can be inserted into the bore of the valve block as a pre-assembled unit. The use of identical parts should also reduce the costs of manufacturing the sensor assembly.

To solve the problem, the method with the features of claim 1 and the sensor assembly with the features of claim 7 are proposed. Advantageous further developments of the invention can be found in the respective subclaims. In addition, a tank valve with a sensor assembly according to the invention is specified.

Disclosure of the invention

1. (a) Verbinden der Anschlussdrähte im Bereich ihrer freien Enden mit Kontaktelementen, beispielsweise in Form von Leiterbahnen, zur Ausbildung eines Steck-, Streif- oder Schleifkontakts,
2. (b) Ausbilden einer die Anschlussdrähte zumindest abschnittsweise ummantelnden Umspritzung mit einem umlaufenden Absatz, so dass ein erster Umspritzungsabschnitt mit einer definierten Länge L₁ zum Einsetzen in eine Sensorhülse und ein zweiter Umspritzungsabschnitt mit einer definierten Länge L₂ zum Einsetzen in die Bohrung des Ventilblocks ausgebildet werden,
3. (c) Einsetzen des Sensorelements und des ersten Umspritzungsabschnitts in die Sensorhülse, so dass der Absatz zur Anlage an der Sensorhülse gelangt.

A method is proposed for producing a sensor assembly, in particular a temperature sensor assembly, with a sensor element having connecting wires for insertion into a bore of a valve block. The method comprises the following steps:

1. (a) Connecting the connecting wires in the area of their free ends to contact elements, for example in the form of conductor tracks, to form a plug-in, touch-contact or sliding contact,
2. (b) forming an overmolding which encloses the connecting wires at least in sections and has a circumferential shoulder, so that a first overmolding section with a defined length L ₁ for insertion into a sensor sleeve and a second overmolding section with a defined length L ₂ for insertion into the bore of the valve block are formed,
3. (c) Inserting the sensor element and the first overmolded section into the sensor sleeve, so that the heel comes into contact with the sensor sleeve.

The proposed steps lead to the formation of a sensor assembly which, due to the overmolding that encases the connecting wires and the contact elements connected to the connecting wires, has sufficient rigidity to be machine-assembled and inserted into the bore of the valve block. When inserted, the contact elements connected to the connecting wires can be pushed into an intersection area of the bore with another bore, so that the contact elements can be contacted via the other bore. This means that connecting wires no longer have to be routed over a bore intersection. Contact is made instead via a simple plug-in, touch-contact or sliding contact.

The joining of the sensor assembly, in particular the assembly of the sensor sleeve, is also simplified because the overmolding that encases the connecting wires forms a circumferential shoulder that serves as a stop during joining. The stop precisely defines the position of the sensor sleeve in the axial direction. The first overmolding section is therefore accommodated in the sensor sleeve up to the shoulder or stop. The further overmolding section extending from the shoulder to the contact elements forms the part of the sensor assembly that is later inserted into the bore of the valve block.

Given the dimensions of the valve block, in particular the bore formed therein to accommodate the sensor assembly, the length L ₂ of the overmolded section can be derived from this. If the sensor sleeve rests on the outside of the valve block when the sensor assembly is mounted, the length L ₂ of the overmolded section accommodated in the valve block essentially corresponds to the length of the bore formed in the valve block. If the sensor sleeve is accommodated in the bore in sections, the length L ₂ of the overmolded section is shorter than the length of the bore by this amount. Whether the sensor sleeve is accommodated in sections in the valve block is again determined by the valve block. The total length of the sensor sleeve can vary so that the valve block can be combined with sensor assemblies of different lengths without the length of the overmold changing. This in turn enables the use of identical parts, in particular when using injection molds and/or casting molds, which reduces manufacturing costs.

The sensor element used for the sensor assembly can already have a plastic or glass sheath that extends not only over the sensor element but also over the connecting wires in sections. If this sheath is not long enough so that the overmolding to be formed does not have an overlap area with the sheath, the sheath may have to be extended before the overmolding is formed. Overmolding can also be provided for the extension. This ensures that the connecting wires are overmolded and/or sheathed over their entire length.

Since not only the length of the sensor sleeve can vary, but also the length of the connecting wires of the sensor element, it is proposed in a further development of the invention that in step (a) the connecting wires are shortened before or after the connecting wires are connected to the contact elements. In this way, a length compensation can be achieved that ensures that the overmolding has the correct length and the contact elements are located in the area of the hole intersection.

Preferably, in step (a), the connecting wires of the sensor element are connected to the contact elements in a material and/or form-fitting manner, for example by soldering, welding, in particular resistance welding, or crimping. The material and/or form-fitting connection increases the robustness of the electrical contact between the connecting wires and the contact elements.

It is further proposed that in step (b) an overmolding is formed which at least partially encases the connecting wires and which has a circular cross-section at least in the second overmolding section. The circular cross-section of the second overmolding section enables centering when inserted into the bore of the valve block. The second overmolding section can also have a press fit relative to the bore so that the sensor assembly is held securely in the valve block by a press fit. If the first overmolding section also has a circular cross-section, the same applies when inserting the first overmolding section into the sensor sleeve. Alternatively or additionally, it is proposed that the overmolding formed in step (b) has at least one flattened area on the outer circumference in the first overmolding section. Advantageously, several flattened areas are provided, which are also preferably formed at the same angular distance from one another. The at least one flattened area makes it easier to insert the first overmolding section into the sensor sleeve, since it enables the sensor sleeve to be vented when inserted.

Given the dimensions of the valve block into which the sensor assembly is to be inserted, and given the length of the overmolding of the connecting wires, the length of the contact elements is also predetermined. It is therefore proposed that in step (b) when forming the overmolding, an end section of the contact elements with a defined length a is left free. This ensures that when the sensor assembly is inserted into the valve block, the free ends of the contact elements end in the intersection area and can be contacted via the further hole that ends in the intersection area.

According to a preferred embodiment of the invention, an NTC or PTC element, in particular an NTC or PTC element with a plastic or glass casing, is used as a sensor element. These are particularly small in volume and also very robust, so that they are particularly well suited for the intended application. The latter applies in particular if the NTC or PTC element has a plastic or glass casing.

• - ein Anschlussdrähte aufweisendes Sensorelement, insbesondere ein NTC- oder PTC-Element,
• - mit den freien Enden der Anschlussdrähten des Sensorelements verbundene Kontaktelemente, beispielsweise in Form von Leiterbahnen, zur Ausbildung eines Steck-, Streif- oder Schleifkontakts,
• - eine die Anschlussdrähte zumindest abschnittsweise ummantelnde Umspritzung mit einem umlaufenden Absatz, so dass ein erster Umspritzungsabschnitt mit einer definierten Länge L₁ und ein zweiter Umspritzungsabschnitt mit einer definierten Länge L₂ ausgebildet werden,
• - eine Sensorhülse, in welcher der erste Umspritzungsabschnitt der Umspritzung aufgenommen ist und an welcher der Absatz der Umspritzung anliegt.

Furthermore, a sensor assembly, in particular a temperature sensor assembly, for insertion into a bore of a valve block is proposed. The proposed sensor assembly comprises:

• - a sensor element having connecting wires, in particular an NTC or PTC element,
• - contact elements connected to the free ends of the connecting wires of the sensor element, for example in the form of conductor tracks, to form a plug-in, touch or sliding contact,
• - an overmolding which encases the connecting wires at least in sections and has a circumferential shoulder, so that a first overmolding section with a defined length L ₁ and a second overmolding section with a defined length L ₂ are formed,
• - a sensor sleeve in which the first overmolding section of the overmolding is accommodated and against which the shoulder of the overmolding rests.

The proposed sensor assembly can be manufactured in particular according to the method according to the invention described above, whereby the use of identical parts when using injection molds and/or casting molds and a high degree of automation reduce the manufacturing costs. This is because the stiffening overmolding makes the sensor assembly easy to handle, in particular to grip by machine, so that it can be joined and further processed automatically, for example inserted into the bore of the valve block. During the previous joining, the circumferential shoulder of the overmolding makes it easier to insert the sensor element into the sensor sleeve, since the shoulder can be used as a stop. When inserting the pre-assembled sensor assembly into the bore of the valve block, the sensor assembly can be easily electrically contacted via the "rigid" contact elements arranged at the end.

Preferably, the connecting wires of the sensor element are connected to the contact elements in a material and/or form-fitting manner, for example by soldering, welding, in particular resistance welding, or crimping. This measure can increase the robustness of the electrical contact between the connecting wires and the contact elements, which is particularly advantageous when automatically inserting the pre-assembled sensor module into the bore of the valve block and when subsequently contacting the contact elements.

Furthermore, the overmolding of the sensor assembly preferably has a circular cross-section at least in the second overmolding section. The circular shape makes it easier to insert into the bore of the valve block, since this usually also has a circular cross-section. The second overmolding section can have a press fit relative to the bore in order to enable a press fit that holds the sensor assembly securely in the valve block.

The first overmolding section can also have a circular cross-section, which in this case is adapted to the inner diameter of the sensor sleeve. Since the sensor sleeve is closed at the end, it must be ensured that air present in the sensor sleeve can escape when the sensor element is inserted. In a further development of the invention, it is therefore proposed that the overmolding in the first overmolding section has at least one flattened area on the outer circumference, via which the sensor sleeve can be vented when the sensor element is inserted.

Since the preferred application area is tank valves for fuel gas tanks, a tank valve with a valve block and a sensor assembly according to the invention is also proposed. The sensor assembly is inserted into a bore of the valve block, the bore being connected via an intersection area to another bore which is angled, in particular at right angles to the first hole. The sensor element can then be easily electrically contacted via the additional hole.

The use of a sensor assembly according to the invention enables a high degree of automation in the production of the tank valve, so that it can be manufactured easily and cost-effectively.

• 1 zwei erfindungsgemäße Sensorbaugruppen unterschiedlicher Länge, jeweils in einem Längsschnitt,
• 2 zwei erfindungsgemäße Sensorbaugruppen, jeweils in einem Querschnitt, a) mit kreisrundem Querschnitt und b) mit mehreren außenumfangseitigen Abflachungen,
• 3 eine Seitenansicht eines Sensorelements für eine erfindungsgemäße Sensorbaugruppe,
• 4 eine Seitenansicht eines weiteren Sensorelements für eine erfindungsgemäße Sensorbaugruppe nach dem Verbinden der Anschlussdrähte mit Kontaktelementen,
• 5 jeweils eine Seitenansicht der Sensorelemente der 3 und 4 nach dem Umspritzen und
• 6 einen Längsschnitt durch einen Ventilblock mit hierin eingesetzter erfindungsgemäßer Sensorbaugruppe.

Preferred embodiments of the invention are explained in more detail below with reference to the accompanying drawings, which show:

• 1 two sensor assemblies of different lengths according to the invention, each in a longitudinal section,
• 2 two sensor assemblies according to the invention, each in a cross-section, a) with a circular cross-section and b) with several flattened areas on the outer circumference,
• 3 a side view of a sensor element for a sensor assembly according to the invention,
• 4 a side view of another sensor element for a sensor assembly according to the invention after connecting the connecting wires to contact elements,
• 5 a side view of the sensor elements of the 3 and 4 after overmolding and
• 6 a longitudinal section through a valve block with a sensor assembly according to the invention inserted therein.

Detailed description of the drawings

The 1 Two sensor assemblies 1 according to the invention are shown, the upper one being longer than the lower one. Both sensor assemblies 1 can be pre-assembled with a high degree of automation and inserted as a pre-assembled unit into a bore 4 of a valve block 5 (see 6 ). This can be the same valve block 5, since the section of the sensor assembly 1 that is inserted into the bore 4 of the valve block 5 is essentially the same in design, in particular has the same dimensions.

Each of the two sensor assemblies 1 comprises a sensor element 3 provided with connecting wires 2 and a sheath 11, which in this case consists of plastic (see 3 ). The sheath 11 also extends in sections over the connecting wires 2. In the present case, the sheath 11 has a length l ₁ that is too short to connect the sheath 11 to an overmolding 7 that is still to be formed, the length L of which is predetermined by the dimensions of the valve block 5. Before overmolding, the sheath 11 is therefore extended (see 4 ), so that it has a new length l _2. The ends of the connecting wires 2 protruding from the sheath 11 can now be connected to contact elements 6, which are used for later contacting the sensor assembly 1. If the dimensions of the bore 4 formed in the valve block 5 to accommodate the sensor assembly 1 require length compensation, the connecting wires 2 can be shortened before or after being connected to the contact elements 6. The length compensation ensures that the contact elements 6 come to lie in an intersection area 12 with another bore 13 after the sensor assembly 1 has been inserted into the bore 4 of the valve block 5. The contact elements 6 can then be electrically contacted in a simple manner via the other bore 13 (see 6 ).

After connecting the connecting wires 2 with the contact elements 6, the overmolding 7 can be formed. As shown in the example in the 5 As shown, the overmolding 7 has the same dimensions regardless of the design of the sensor elements 3. In particular, the overmolding 7 has a circumferential shoulder 8, which serves as a stop for a sensor sleeve 9 that is still to be mounted. A first overmolding section 7.1, which has a smaller outer diameter than a second overmolding section 7.2 located beyond the shoulder 8, is inserted into the sensor sleeve 9. The pre-assembled sensor assembly 1 can then be inserted into the bore 4 of the valve block 5 via the second overmolding section 7.2. Since the dimensions of the valve block 5 and thus of the bore 4 are predetermined, the second overmolding section 7.2 must have a certain length L ₂ . The first overmolding section 7.1, on the other hand, has a length L ₁ . Furthermore, the contact elements 6 must each have an end section with a defined length a, which projects beyond the overmolding section 7.2.

For insertion into the bore 4 of the valve block 5, the second overmolding section 7.2 preferably has a circular cross-section. The first overmolding section 7.1 can - as shown by way of example in the 2a) shown - also have a circular cross-section, with the outer diameter being adapted to the inner diameter of the sensor sleeve 9. To facilitate insertion into the sensor sleeve 9, the first overmolding section 7.1 - as shown by way of example in the 2b) shown - also have at least one flattened area 10 so that the sensor sleeve 9 can be vented.

In the 6 is the upper of the two sensor assemblies of the 1 inserted into the bore 4 of the valve block 5. A stop surface 15 of an annular collar 14 of the sensor sleeve 9 comes to rest on a shoulder 17 of the valve block 5. The bore 4 is sealed by a sealing ring 16 arranged on the sensor sleeve 9. In the installation position shown, the sensor assembly 1 can be electrically contacted very easily via the further bore 13 and the intersection area 12.

Claims (10)

Method for producing a sensor assembly (1), in particular a temperature sensor assembly, with a sensor element (3) having connecting wires (2) for insertion into a bore (4) of a valve block (5), comprising the steps (a) connecting the connecting wires (2) in the region of their free ends to contact elements (6), for example in the form of conductor tracks, to form a plug-in, touch-contact or sliding contact, (b) forming an overmolding (7) which encases the connecting wires (2) at least in sections and has a circumferential shoulder (8), so that a first overmolding section (7.1) with a defined length (L ₁ ) for insertion into a sensor sleeve (9) and a second overmolding section (7.2) with a defined length (L ₂ ) for insertion into the bore (4) of the valve block (5) are formed, (c) inserting the sensor element (3) and the first overmolding section (7.1) into the sensor sleeve (9), so that the shoulder (8) comes into contact with the sensor sleeve (9). Procedure according to Claim 1 , characterized in that in step (a) before or after connecting the connecting wires to the contact elements (6) the connecting wires are shortened to compensate for length. Procedure according to Claim 1 or 2 , characterized in that in step (a) the connecting wires (2) of the sensor element (3) are materially and/or positively connected to the contact elements (6), for example by soldering, welding, in particular resistance welding, or crimping. Method according to one of the preceding claims, characterized in that in step (b) an overmolding (7) is formed which encases the connecting wires at least in sections and which has a circular cross-section at least in the second overmolding section (7.2) and/or at least one flattened area (10) on the outer circumference in the first overmolding section (7.1). Method according to one of the preceding claims, characterized in that in step (b) during the formation of the overmolding (7) an end section of the contact elements (6) with a defined length (a) is left free. Method according to one of the preceding claims, characterized in that an NTC or PTC element, in particular an NTC or PTC element with a sheath made of plastic or glass, is used as the sensor element (3). Sensor assembly (1), in particular a temperature sensor assembly, for insertion into a bore (2) of a valve block (3), comprising - a sensor element (5) having connecting wires (4), in particular an NTC or PTC element, - contact elements (6), for example in the form of conductor tracks, connected to the free ends of the connecting wires (4) of the sensor element (3) to form a plug-in, touch-contact or sliding contact, - an overmolding (7) which encases the connecting wires (2) at least in sections and has a circumferential shoulder (8), so that a first overmolding section (7.1) with a defined length (L ₁ ) and a second overmolding section (7.2) with a defined length (L ₂ ) are formed, - a sensor sleeve (9) in which the first overmolding section (7.1) of the overmolding (7) is received and against which the shoulder (8) of the overmolding (7) rests. Sensor assembly (1) according to Claim 7 , characterized in that the connecting wires (2) of the sensor element (3) are materially and/or positively connected to the contact elements (6), for example by soldering, welding, in particular resistance welding, or crimping. Sensor assembly (1) according to one of the preceding claims, characterized in that the overmolding (7) has a circular cross-section at least in the second overmolding section (7.2) and/or at least one outer peripheral flattening (10) in the first overmolding section (7.1). Tank valve with a valve block (5) and a sensor assembly (1) according to one of the preceding claims, which is inserted into a bore (4) of the valve block (5), wherein the bore (4) is connected via an intersection region (12) to a further bore (13) which is angled lig, in particular at right angles, to the first bore (4).

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