Sensor

Abstract

The invention relates to a sensor (1) comprising a housing (2) and a sensor element (3) arranged in the housing (2), which has a carrier body (6), a measuring component (4) arranged on the carrier body (6) and at least two measuring connections (5) contacted with the measuring component (4) and brought out of the housing (2), wherein the housing (2) is tubular with a closed end (2.1) and an open end (2.2), wherein at least one groove (7) extending in the longitudinal direction of the housing (2) and at least one guide web (8) engaging with the at least one groove (7) are arranged between an inner surface of the housing (2) and the carrier body (6), wherein the open end (2.2) of the housing (2) is closed with a plug (9) which has feedthroughs for the measuring connections (5), wherein a pairing of groove (7) and guide rib (8) is designed such that in an end position of the carrier body (6) in the housing (2) a joining gap between groove (7) and guide rib (8) is minimized.

Description

[0001] The invention relates to a sensor, in particular a temperature sensor.

[0002] The use of resistive sensors for temperature measurement is widespread. The clear relationship between resistance and temperature allows for the simple and accurate measurement of this physical quantity. A measuring current is applied to determine the resistance. This current must be designed to minimize self-heating, thus preventing inaccurate temperature readings. Equally important is the housing of such sensors, which protects the integrated, mechanically and electrically sensitive sensor elements from harsh environments. Material parameters, particularly thermal conductivity and mechanical tolerances, significantly influence the static-thermal measurement error.

[0003] DE 20 2014 102 022 U1 describes a capacitive sensor with a tubular housing and an electronic circuit board which is arranged inside the tubular housing, wherein a measuring electrode arrangement is arranged in the area of ​​an end face of the housing which is electrically connected to the circuit board, wherein the circuit board is arranged in a cylindrical pot element which itself is received by the tubular housing in the installed position.

[0004] DE 10 2019 129 521 A1 describes a sensor comprising a sensor element and electrical conductors, wherein the sensor element is connected to the electrical conductors. Furthermore, a housing is provided, the housing having an opening, and the sensor element is arranged in the housing such that the electrical conductors protrude from the opening. The housing is filled with epoxy resin, and the epoxy resin fixes the sensor element and the electrical conductors within the housing.

[0005] The invention is based on the objective of specifying a novel sensor.

[0006] The problem is solved according to the invention by a sensor having the features of claim 1.

[0007] Advantageous embodiments of the invention are the subject of the dependent claims.

[0008] A sensor, in particular a temperature sensor, is proposed, comprising a housing and a sensor element arranged in the housing. The sensor element has a carrier body, a measuring component arranged on the carrier body (for example, a measuring meander), and at least two measuring terminals that are in contact with the measuring component and extend out of the housing. The housing is tubular with a closed end and an open end. Between an inner surface of the housing and the carrier body, at least one longitudinal groove and at least one guide rib engaging with the groove are arranged. The open end of the housing is closed with a plug that has openings for the measuring terminals. The groove-guide rib pairing is designed such that, in an end position of the carrier body in the housing, the gap between the groove and the guide rib is minimized.

[0009] According to the invention, it is provided that either - at least one groove is arranged in the housing and at least one guide rib on the support body, the width of the at least one groove decreases from the open end to the closed end and the at least one guide rib has a shape complementary to the groove designed in this way over the length of the support body, - or that at least one guide web is arranged on the inside of the housing at least over part of its length and at least one groove is arranged in the support body, the width of the at least one guide web engaging with a groove increases from the open end to the closed end, and the at least one groove over the length of the support body has a shape complementary to the guide web thus designed.

[0010] In one embodiment, at least two grooves and guide ribs are arranged.

[0011] In one embodiment, at least one groove is arranged in the housing and at least one guide web on the support body, wherein an inner diameter of the housing measured in the at least one groove or between two grooves decreases in particular linearly from the open end to the closed end, wherein the guide web or guide webs of the support body have a shape complementary to the groove or grooves designed in this way over the length of the support body.

[0012] In one embodiment, at least one guide web is arranged on the inside of the housing at least over a part of its length, and at least one groove is arranged in the support body, wherein an inner diameter of the housing measured at the at least one guide web or between at least two guide webs decreases in particular linearly from the open end to the closed end, wherein the at least one groove of the support body has a shape complementary to the guide web thus designed over the length of the support body.

[0013] In one embodiment, the position of the grooves in the housing is asymmetrical or off-center, and the position of the guide webs on the support body is complementarily asymmetrical.

[0014] In one embodiment, two asymmetrically arranged guide webs are provided in the housing, wherein one of the guide webs extends over the entire length or a large part of the length of the housing and the other guide web extends from the closed end over a smaller part of the length of the housing, the shorter guide web being able to serve as a support for the carrier body on the side opposite the groove.

[0015] In one embodiment, a marking can be arranged on the housing that indicates how the sensor element should be installed in the correct position.

[0016] In one embodiment, the housing has a circular outer cross-section.

[0017] In one embodiment, the plug is designed as a separate part or as part of the carrier body.

[0018] In one embodiment, remaining gaps between the housing and the support body in the area of ​​the grooves and guide ribs are at least partially filled with a material of higher thermal conductivity, for example, thermal paste, a special glass (for example, composite glass, in particular a material containing a glass as a binder and aluminum oxide), or cement. The plug can also be sealed to the housing and / or in its feedthroughs with a material with good wettability, such as a special glass or cement.

[0019] The solution according to the invention enables cost-effective mass production of sensors with given mechanical tolerances, meeting the requirements for measurement accuracy and avoiding measurement errors due to positioning inaccuracies. At the same time, the sensors exhibit the highest possible mechanical and electrical stability, particularly under rapid temperature changes.

[0020] Exemplary embodiments of the invention are explained in more detail below with reference to drawings.

[0021] It shows: Fig. 1 A schematic view of a sensor with a housing and a sensor element, Fig. 2 another schematic view of the sensor, Fig. 3 a schematic cross-sectional view of the sensor element, Fig. 4 a schematic cross-sectional view of the housing, Fig. 5 a schematic view of another embodiment of a sensor comprising a housing and a sensor element, Fig. 6 schematic views of the sensor element, Fig. 7 schematic views of the housing, Fig. 8 schematic views of a plug, Fig. 9 schematic views of another embodiment of a sensor, Fig. 10 schematic views of another embodiment of a sensor, and Fig. 11 schematic views of another embodiment of a sensor.

[0022] Corresponding parts are marked with the same reference symbols in all figures.

[0023] The Fig. 1 and Fig. Figure 2 shows schematic views of a sensor 1, in particular a temperature sensor, comprising a housing 2 and a sensor element 3 arranged in the housing 2, which, for example, has a carrier body 6, a measuring component 4 arranged on the carrier body 6, for example a measuring meander 4, and at least two measuring terminals 5 contacted with the measuring component 4 and led out of the housing 2. Fig. Figure 3 is a schematic cross-sectional view of sensor element 3. Fig. Figure 4 is a schematic cross-sectional view of the housing 2.

[0024] The housing 2 is, for example, tubular, in particular with a circular outer cross-section, with a closed end 2.1, for example in the form of a hemispherical or dome-shaped cap, and an open end 2.2. The housing 2 has, in particular, an inner cross-section that deviates from a circular shape, for example with one, two, or more inwardly projecting grooves 7 in a longitudinal direction of the housing 2. The support body 6 of the sensor element 3 has a shape that is at least partially complementary to the inner cross-section of the housing 2, for example with one, two, or more outwardly projecting guide ribs 8 configured to engage in the grooves 7.

[0025] The open end 2.2 of the housing 2 can be closed with a plug 9, which has feedthroughs for the measuring connections 5. The plug 9 can be designed as a separate part or be part of the carrier body 6. The plug 9 can be sealed to the housing 2 and in its feedthroughs, for example by a material with good wettability, such as a special glass (e.g., composite glass) or cement, and can be designed as a preform.

[0026] The solution approach according to the invention makes it possible to choose constructive solutions for joining the components, i.e., the housing 2 and the sensor element 3, which, given manufacturing-related component tolerances due to mechanical influences and material-related parameters, ensure that the thermal contact resistance from the measuring meander 4 to the environment of the sensor 1 remains within the required tolerances for the measuring accuracy.

[0027] Based on the measurement accuracy, the solution according to the invention achieves that the thermal resistances influenced by the joining process amount to, for example, only 1 / 10 of the total thermal contact resistance from the measuring meander 4 to the environment or the temperature to be measured. This makes it possible to keep the static-thermal measurement error from component to component at least largely constant in series production.

[0028] According to the invention, it is proposed that complementary grooves 7 and guide ribs 8 be arranged between the housing 2 and the carrier body 6 of the sensor element 3. These grooves and guide ribs enable the joining gaps, which arise during manufacturing and which may be filled with a material of higher thermal conductivity for vibration-resistant construction, such as thermal paste, or with a special glass (e.g., composite glass) or cement for applications with higher operating temperatures, to be provided with a low and constant thermal resistance. The pairing of grooves 7 and guide ribs 8 is designed such that, firstly, there are no overlaps, as otherwise the sensor element 3 cannot be installed in the housing 2, and secondly, that mispositioning of the sensor element 3 within the housing 2 does not occur.For example, the design can be conical to achieve a minimized joining gap in an end position of the carrier body 6 in the housing 2. A conical design can mean, for example, that the inner diameter of the housing 2, measured in the grooves 7, decreases linearly from the open end 2.2 of the housing 2 to the closed end 2.1 of the housing 2, and that the guide webs 8 of the carrier body 6 have a shape complementary to the grooves 7 along the length of the carrier body 6.

[0029] Alternatively or additionally, it can be provided that the width of the grooves 7 decreases linearly from the open end 2.2 of the housing 2 to the closed end 2.1 of the housing 2, and that the guide webs 8 of the support body 6 have a shape complementary to the grooves 7 designed in this way over the length of the support body 6.

[0030] In this way, contact points are created where the materials of the housing 2 and the support body 6 directly touch. Furthermore, it can be provided that remaining joining gaps between the housing 2 and the support body 6 in the area of ​​the grooves 7 and guide ribs 8 are filled with a material of higher thermal conductivity, for example thermal paste, with a special glass (e.g. composite glass) or cement.

[0031] In the Fig. In the embodiment shown in Figure 4, two opposing grooves 7 are arranged in the housing 2, the position of which is asymmetrical or off-center, meaning that the two grooves 7 are not opposite each other with respect to the center point of the (outer) circular cross-section of the housing 2. The position of the guide webs 8 on the support body 6 can be chosen to be complementarily asymmetrical, so that when the sensor element 3 is correctly installed in the housing 2, the measuring connections 5, for example, are led out of the open end 2.2 of the housing 2 opposite each other with respect to the center point of the (outer) circular cross-section of the housing 2. A marking can be arranged on the housing 2 indicating how the sensor element 3 should be correctly installed.

[0032] Due to the asymmetrical design and the marking of the position of the sensor element 3 in the housing 2, the same thermal contact resistances are obtained in the applications, and thus the same measurement results are obtained in identical applications.

[0033] The design of the housing 2 can be such that the thermal resistance of the housing 2 and the heat capacity, through the choice of material, protect the sensitive sensor elements 3 while being as low as possible.

[0034] When using sensor 1, pulsed measuring currents can be employed to minimize the energy input into the measuring meander 4. The frequency of the pulsed measuring current should be matched to the heat capacity of the entire setup and / or a maximum permissible self-heating error.

[0035] The Fig. Figure 5 is a schematic view of a further embodiment of a sensor 1, in particular a temperature sensor, comprising a housing 2 and a sensor element 3 arranged in the housing 2, which, for example, has a carrier body 6, a measuring component 4 arranged on the carrier body 6, for example a measuring meander 4, and at least two measuring terminals 5 contacted with the measuring component 4 and brought out of the housing 2. Fig. Figure 6 shows schematic views of sensor element 3. Fig. Figure 7 shows schematic views of housing 2.

[0036] The wires or measuring terminals 5 can additionally be corrugated 12 (as in Fig. 10 and Fig. 11) be provided or bent by 180° along the sensor chip to increase mechanical stability and stress cycle stability, especially during rapid temperature changes.

[0037] The housing 2 is, for example, tubular, in particular with a circular outer cross-section, with a closed end 2.1, for example in the form of a hemispherical or dome-shaped cap, and an open end 2.2. The housing 2 has, in particular, an inner cross-section that deviates from a circular shape, for example with one, two, or more inwardly projecting guide webs 8 in a longitudinal direction of the housing 2, which extend over at least a portion of the length of the housing 2. In the embodiment shown, one of the guide webs 8 extends over the entire length of the housing 2, and the other guide web 8 extends from the closed end 2.1 over a portion, for example about one-third, of the length of the housing 2. The support body 6 of the sensor element 3 has a shape that is at least partially complementary to the inner cross-section of the housing 2, for example with one, two, or more grooves 7.In the embodiment shown, a groove 7 is arranged in one side of the carrier body 6 opposite the measuring component 4, which is configured to engage with one of the guide webs 8 of the housing 2, for example, the guide web 8 extending over the entire length of the housing 2.

[0038] The open end 2.2 of the housing 2 can be closed with a plug 9, which has feedthroughs for the measuring connections 5. The plug 9 can be designed as a separate part (preform) or be part of the carrier body 6. The plug 9 can be sealed to the housing 2 and in its feedthroughs, for example by a material with good wettability, such as a special glass (e.g., composite glass) or cement that can be melted in a single temperature step and thus wets and seals the walls of the housing.

[0039] Fig. Figure 8 shows schematic views of the plug 9, which may also be provided with a groove 7 for engagement with the longer guide rib 8.

[0040] The pairing of grooves 7 and guide ribs 8 is designed such that, firstly, there are no overlaps, as otherwise the sensor element 3 cannot be installed in the housing 2, and secondly, that mispositioning of the sensor element 3 within the housing 2 does not occur. For example, the design can be conical to achieve a minimized gap in an end position of the carrier body 6 within the housing 2. A conical design can mean, for example, that the inner diameter of the housing 2, measured between the guide ribs 8, decreases linearly from the open end 2.2 of the housing 2 to the closed end 2.1 of the housing 2, and that the at least one groove 7 of the carrier body 6 has a shape complementary to the guide rib 8 along the length of the carrier body 6.

[0041] Alternatively or additionally, it can be provided that the width of the guide webs 8 engaging with grooves 7 increases linearly from the open end 2.2 of the housing 2 to the closed end 2.1 of the housing 2, and that the at least one groove 7 of the support body 6 has a shape complementary to the guide web 8 designed in this way over the length of the support body 6.

[0042] The shorter guide web 8 can serve as a buttress for the support body 6 on the side opposite the groove 7.

[0043] In this way, contact points are created where the materials of the housing 2 and the support body 6 directly touch. Furthermore, it can be provided that remaining joining gaps between the housing 2 and the support body 6 in the area of ​​the grooves 7 and guide ribs 8 are filled with a material of higher thermal conductivity, for example thermal paste, with a special glass (e.g. composite glass) or cement.

[0044] The different lengths of the guide webs 8 result in an asymmetry of the housing 2. A marking can be arranged on the housing 2 that indicates how the sensor element 3 should be installed in the correct position.

[0045] Due to the asymmetrical design and the marking of the position of the sensor element 3 in the housing 2, the same thermal contact resistances are obtained in the applications, and thus the same measurement results are obtained in identical applications.

[0046] The design of the housing 2 can be such that the thermal resistance of the housing 2 and the heat capacity, through the choice of material, protect the sensitive sensor elements 3 while being as low as possible.

[0047] When using sensor 1, pulsed measuring currents can be employed to minimize the energy input into the measuring meander 4. The frequency of the pulsed measuring current should be matched to the heat capacity of the entire setup and / or a maximum permissible self-heating error.

[0048] Fig. Figure 9 shows schematic views of another embodiment of a sensor 1, which is described in the Fig. 1, Fig. 2, Fig. 3 to Fig. The embodiment shown in section 4 is largely similar or identical. Fig. 1, Fig. 2, Fig. 3 to Fig. 4 are the measuring connections 5 or connecting wires leading from the measuring component 4 out of and away from one end of the carrier body 6. In contrast, in Fig. 9. The measuring connections 5 or connecting wires extend from the measuring component 4 out of one end of the carrier body 6, in a 180° arc around this end of the carrier body 6, and are guided back on the side opposite the measuring component 4 and beyond the opposite end of the carrier body 6. The side of the carrier body 6 opposite the measuring component 4 may have groove-shaped channels 10 in which the measuring connections 5 are guided. The channels 10 may be filled with glass. A web 11 may be formed in the closed end 2.1 of the housing, which engages between the two 180° arcs of the measuring connections 5 when the sensor element 3 is inserted in the housing 2.

[0049] Fig. Figure 10 shows schematic views of another embodiment of a sensor 1, which is described in the Fig. 1, Fig. 2, Fig. 3 to Fig. The embodiment shown in section 4 is largely similar or identical. Fig. 1, Fig. 2, Fig. 3 to Fig. 4 are the measuring connections 5 or connecting wires originating from the measuring component 4, emerging from one end of the carrier body 6 and leading straight away from it. In contrast, in Fig. 10 The measuring terminals 5 or connecting wires leading from the measuring component 4 out of the carrier body 6 at one end of the carrier body then have a corrugation 12 in the direction in which the measuring component 4 also points and are subsequently led straight away from the carrier body 6.

[0050] Fig. Figure 11 shows schematic views of another embodiment of a sensor 1, which detects the [missing information] in the Fig. The embodiments shown in Figures 1 to 4 and 10 are largely similar or identical. In contrast, in Fig. 11 the measuring terminals 5 or connecting wires leading from the measuring component 4 out of the carrier body 6 at one end of the carrier body, then have a corrugation 12 in the direction opposite to the direction in which the measuring component 4 points, and are then led straight away from the carrier body 6. REFERENCE MARK LIST 1 sensor 2 cases 2.1 Closed End 2.2 open end 3 Sensor element 4 measuring component, measuring meander 5 measuring connection 6 carrier bodies 7 Nut 8 Guide bridge 9 plugs 10-channel 11 Bridge 12 ripple

Claims

[1] Sensor (1) comprising a housing (2) and a sensor element (3) arranged in the housing (2), which has a carrier body (6), a measuring component (4) arranged on the carrier body (6) and at least two measuring terminals (5) contacted with the measuring component (4) and extending out of the housing (2), wherein the housing (2) is tubular with a closed end (2.1) and an open end (2.2), wherein at least one groove (7) extending in the longitudinal direction of the housing (2) and at least one guide web (8) engaging with the at least one groove (7) is arranged between an inner surface of the housing (2) and the carrier body (6), wherein the open end (2.2) of the housing (2) is closed with a plug (9) which has feedthroughs for the measuring connections (5), wherein a pairing of groove (7) and guide rib (8) is designed such that in an end position of the carrier body (6) in the housing (2) a joining gap between groove (7) and guide rib (8) is minimized, wherein either. - the at least one groove (7) in the housing (2) and the at least one guide web (8) on the support body (6) is arranged, wherein the width of the at least one groove (7) decreases from the open end (2.2) to the closed end (2.1) and the at least one guide web (8) has a shape complementary to the groove (7) as designed over the length of the support body (6), or - the at least one guide web (8) is arranged on the inside of the housing (2) at least over part of the length of the housing (2) and the at least one groove (7) is arranged in the support body (6), wherein the width of the at least one guide web (8) engaging with a groove (7) increases from the open end (2.2) to the closed end (2.1) and the at least one groove (7) has a shape complementary to the guide web (8) thus designed over the length of the support body (6). [2] Sensor (1) according to claim 1, wherein at least two grooves (7) and guide ribs (8) are arranged. [3] Sensor (1) according to claim 1 or 2, wherein the at least one groove (7) is arranged in the housing (2) and the at least one guide web (8) is arranged on the carrier body (6), wherein an inner diameter of the housing (2) measured in the at least one groove (7) decreases from the open end (2.2) to the closed end (2.1), wherein the guide web (8) of the carrier body (6) has a shape complementary to the groove (7) thus designed over the length of the carrier body (6). [4] Sensor (1) according to claim 1 or 2, wherein the at least one guide web (8) is arranged on the inside of the housing (2) at least over a part of the length of the housing (2) and the at least one groove (7) is arranged in the support body (6), wherein an inner diameter of the housing (2) measured at the at least one guide web (8) or between at least two guide webs (8) decreases from the open end (2.2) to the closed end (2.1), wherein the at least one groove (7) of the support body (6) has a shape complementary to the guide web (8) thus designed over the length of the support body (6). [5] Sensor (1) according to one of claims 2 or 3, wherein the position of the grooves (7) in the housing (2) is asymmetric or off-center and the position of the guide webs (8) on the carrier body (6) is complementarily asymmetric. [6] Sensor (1) according to claim 4, with two asymmetrically arranged guide webs (8), wherein one of the guide webs (8) extends over the entire length or a large part of the length of the housing (2) and the other guide web (8) extends from the closed end (2.1) over a smaller part of the length of the housing (2), wherein the shorter guide web (8) serves as a support for the carrier body (6) on the side opposite the groove (7). [7] Sensor (1) according to claim 5 or 6, wherein a marking is arranged on the housing (2) indicating how the sensor element (3) should be installed in the correct position. [8] Sensor (1) according to one of the preceding claims, wherein the housing (2) has a circular outer cross-section. [9] Sensor (1) according to one of the preceding claims, wherein the plug (9) is designed as a separate part or is part of the carrier body (6). [10] Sensor (1) according to one of the preceding claims, wherein remaining joining gaps between the housing (2) and the support body (6) in the area of ​​the grooves (7) and guide webs (8) are at least partially filled with a material of higher thermal conductivity, with a special glass, in particular composite glass, or cement and / or wherein the plug (9) to the housing (2) and / or in its passages is sealed by a material with good wettability, a special glass or cement, wherein this material can be designed as a preform and can be remelted in a temperature step and thus wets and seals the walls of the housing (2).

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