Sensor device comprising a housing and a sensor element for detecting a gas and / or gas mixture

Abstract

The invention relates to a sensor device (10) with a housing (20) and a sensor element (30) for detecting a gas and / or gas mixture, wherein the sensor element (30) is arranged inside the housing (20), wherein the housing (20) is at least partially made of metal, ceramic, plastic and / or glass, and wherein the housing (20) has a media access (23) which allows the passage of a gas and / or gas mixture from an environment (100) of the sensor device (10) to the sensor element (30), wherein the media access (23) is designed as a perforated area (24) of the housing (20).

Description

Prior ArtGas sensors are safety sensors for detecting a gas or a gas mixture. Such a gas sensor can be designed, for example, as a hydrogen sensor which is used, for example, in hydrogen-operated vehicles and is operated there under ambient conditions and is placed, for example, in enclosed or partially enclosed spaces such as, for example, the engine compartment, trunk, or vehicle cabin. Such a sensor has the task of reliably measuring a hydrogen concentration and thereby detecting a possible leakage. For such hydrogen sensors, there are a large number of measurement principles or sensor configurations, including heat conduction, catalytic pellistor, electrochemical cell, semiconducting metal oxide, chemiresistor or else field effect transistor.In principle, when using such sensors, it is to be ensured that these are not an ignition source and, for example, cause a combustible or explosive air-hydrogen gas mixture to ignite, or even that a ignited gas mixture is reliably prevented from spreading out of the sensor. This is necessary in particular when the measurement principle used is based on high operating temperatures and / or exposed catalytic surfaces, such as, for example, in the case of the catalytic pellistor.Sensors from the prior art mostly have a mesh-wire-like grid structure which serves as a flame barrier. Flame arresters are elements which allow passage of a gas or gas mixture but interrupt or prevent passage of a flame. The mode of operation is typically based on absorbing the heat of the flame front, cooling the gas below the self-ignition temperature and thus achieving extinction of the flame. The geometric design depends substantially on the properties of the ignitable gas mixture.Disclosure of the InventionThe invention relates to a sensor device having a housing and a sensor element for detecting a gas and / or gas mixture, wherein the sensor element is arranged within the housing, wherein the housing is formed at least partially from metal, ceramic, plastic and / or glass, and wherein the housing has a medium access which enables the passage of a gas and / or gas mixture from a surrounding area of the sensor device to the sensor element, wherein the medium access is formed as a perforated region of the housing.It is advantageous here that the flame arrester is integrated directly into the sensor housing by means of the perforated region and is formed from this sensor housing. This makes it possible to dispense with the use of an additional grid, as used in the prior art. The sensor device can thus be produced more easily and economically, since in particular a component reduction and an assembly simplification are achieved. In addition, the configuration according to the invention makes it possible to achieve increased stability and durability compared to housings having an inserted grid structure.The sensor element can use in particular one of the following measurement principles for detecting the gas and / or gas mixture or can be configured as a corresponding sensor element: thermal conductivity sensor, catalytic pellistor, electrochemical cell, semiconducting metal oxide, chemiresistor, field effect transistor.The gas to be detected can be hydrogen, for example, or the gas mixture to be detected can contain hydrogen.The housing is typically a fixed casing which surrounds the sensor element in a protective manner from mechanical influences from outside the housing and additionally also protects the environment from a possible flame which could be triggered by the sensor element. Here, the arrangement of the sensor element within the housing means that the sensor element is arranged in a receiving space formed by the housing.The surroundings of the sensor device can in turn be understood to mean everything outside the housing. The media access serves to allow the gas to be detected to pass from the surroundings of the sensor device into the housing and thus to the sensor element, in order to be detected there accordingly.A perforated region is understood to be a region of the housing which has one or more recesses and / or apertures and / or holes which extend from the outer side of the housing to the inner side of the housing and function as a media access.The housing in the perforated region is here substantially made of metal, i.e. in particular completely made of metal, except for, for example, impurities or further additions for easier handling of the metal, and serves as a flame barrier in the region of the media access. The metal may be, for example, steel or stainless steel. Alternatively, the housing can be formed substantially from another stable material, for example ceramic, plastic or also glass.One embodiment of the invention provides that the housing has at least one hole, and in particular a plurality of holes, for forming the perforated region.It is advantageous here that this represents a simple possibility of forming a correspondingly perforated region.One embodiment of the invention provides that the at least one hole of the perforated region is produced by means of water jet cutting, erosion, punching, lasering and / or ultrasonic drilling.It is advantageous here that these represent simple possibilities for producing a corresponding hole in the housing.A further embodiment of the invention provides that all holes of the perforated region each have a diameter of less than 200 μm. It is advantageous here that a flame barrier can be formed by this maximum diameter of the holes, which reliably prevents a flame from being able to emerge from the housing through the media access.The diameter of a hole is understood here to mean the largest possible distance between two points which lie on the hole circumference.According to a further embodiment of the invention, it is provided that the perforated region has holes with a distance of less than 100 μm between adjacent holes.It is advantageous here that the perforated region enables good media access and thus the sensor device can achieve a good measurement result.According to a further embodiment of the invention, it is provided that adjacent holes in the perforated region are arranged offset with respect to one another and / or in series.It is advantageous here that the stability of the perforated housing can be influenced by the respective arrangement of the holes.According to a further embodiment of the invention, it is provided that a thickness of the housing, in particular in the perforated region, is at least 200 μm.It is advantageous here that a flame barrier can be formed by this minimum thickness of the housing, which reliably prevents a flame from being able to emerge from the housing through the media access.The thickness of the housing is understood here as the hole depth.According to a further embodiment of the invention, it is provided that the housing has a base plate and a cover, wherein the perforated region is arranged in the cover.It is advantageous here that the production and assembly of the corresponding sensor device is simplified, since the perforation can first be introduced into the cover and the cover is subsequently placed on the base plate in order to form a complete housing. In particular, at least the cover is made of metal or another stable material, for example glass, plastic or also ceramic, in order to be able to form a stable flame barrier.According to a further embodiment of the invention, it is provided that the sensor element is arranged on the base plate.It is advantageous here that the production and assembly of the corresponding sensor device is simplified, since the sensor element can be arranged on the base plate before the housing is assembled. In particular, the base plate can also represent a substrate of the sensor element, as a result of which a further process step can be avoided.The base plate can be designed, for example, as a printed circuit board, which serves, inter alia, as a carrier for the sensor element.DRAWINGSFIG. 1 shows a first exemplary embodiment of a sensor device according to the invention in a perspective view. FIG. 2 shows a second exemplary embodiment of a sensor device according to the invention in a perspective view. FIG. 3 shows the first exemplary embodiment of the sensor device according to the invention according to FIG. 2 in a lateral sectional view.DESCRIPTION OF EMBODIMENTSFIG. 1 shows a first exemplary embodiment of a sensor device according to the invention in a perspective view.A sensor device 10 is shown, The sensor device 10 has a housing 20 and a sensor element 30, which is not visible in the drawing, for detecting a gas and / or gas mixture. The sensor element 30 is not visible because the sensor element 30 is arranged inside the housing 20. The housing 20 is at least partially formed from metal, ceramic, plastic and / or glass and additionally has a medium access 23 which enables the passage of a gas and / or gas mixture from an environment 100 of the sensor device 10 to the sensor element 30. The media access 23 is formed as a perforated region 24 of the housing 20. The housing 20 has a base plate 21 and a cover 22, the perforated region 24 being arranged in the cover 22.The housing 20 has at least one plurality of holes 26 for forming the perforated region 24, which holes are produced, for example, by means of water jet cutting, erosion, punching, laser machining and / or ultrasonic drilling. Furthermore, the holes 26 of the perforated region each have a diameter 27 of less than 200 μm. In addition, the distance 28 between adjacent holes 26 is less than 100 μm. In addition, the adjacent holes 26 in the perforated area 24 are arranged in series with each other.FIG. 2 shows a second exemplary embodiment of a sensor device according to the invention in a perspective view.The sensor device 10 is again shown, which here only differs in the arrangement of the holes 26 from the first exemplary embodiment from FIG. 1. Thus, adjacent holes 26 in the perforated region 24 are arranged offset relative to one another.FIG. 3 shows the first exemplary embodiment of the sensor device according to the invention according to FIG. 1 in a lateral sectional view.The sensor device 10 from FIG. 2 is shown in a sectional view, wherein the section is through the plane A shown in FIG. 2. The sensor device 10 in turn comprises the housing 20, which is formed from the base plate 21 and the cover 22. In addition, the sensor device 10 comprises the sensor element 30, which is arranged inside the housing 20 on the base plate 21. In addition, a thickness 29 of the housing 20 is evident here, which is at least 200 μm.

Claims

Sensor device (10) having a housing (20) and a sensor element (30) for detecting a gas and / or gas mixture, wherein the sensor element (30) is arranged within the housing (20), wherein the housing (20) is formed at least partially from metal, ceramic, plastic and / or glass, and wherein the housing (20) has a medium access (23) which enables the passage of a gas and / or gas mixture from an environment (100) of the sensor device (10) to the sensor element (30), wherein the medium access (23) is formed as a perforated region (24) of the housing (20).Sensor device (10) according to Claim 1, characterized in that the housing (20) has at least one hole (26), and in particular a multiplicity of holes (26), for forming the perforated region (24).The sensor device (10) according to claim 2, wherein the at least one hole (26) of the perforated region (24) is produced by means of water jet cutting, erosion, punching, lasering and / or ultrasonic drilling.Sensor device (10) according to one of the preceding claims, characterized in that all the holes (26) of the perforated region each have a diameter (27) of less than 200 μm.Sensor device (10) according to one of the preceding claims, characterized in that the perforated region (24) has holes (26) with a spacing (28) of less than 100 μm between adjacent holes (26).Sensor device (10) according to one of the preceding claims, characterized in that adjacent holes (26) in the perforated region (24) are arranged offset with respect to one another and / or in series.Sensor device (10) according to one of the preceding claims, characterized in that a thickness (29) of the housing (20), in particular in the perforated region (24), is at least 200 μm.Sensor device (10) according to one of the preceding claims, characterized in that the housing (20) has a base plate (21) and a cover (22), the perforated region (24) being arranged in the cover (22).Sensor device (10) according to Claim 8, characterized in that the sensor element (30) is arranged on the base plate (21).

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