Sensor device

Abstract

It is described a sensor device (1) for measuring the temperature of a surface (9A), the sensor device (1) comprising:-at least one sensor element (2); -a ceramic housing (3), the sensor element (2) being at least partially arranged in the ceramic housing (3); a base body (5) at least partially surrounding the ceramic housing (3); -an outer shell (8) connected to the base body (5) wherein the outer shell (8) at least partially surrounds the base body (5) and the ceramic shell (3); -at least one mounting element (7) adapted and arranged for mounting the sensor device (1) to a target application (9) wherein the ceramic housing (3) is adapted and arranged in direct mechanical contact with a surface (9A) of which the temperature is to be measured. Furthermore, the use of the sensor device (1) is described.

Description

TECHNICAL FIELD

[0001] The present invention relates to a sensor device for measuring a temperature of a surface. Furthermore, the present invention relates to a use of the sensor device. BACKGROUND

[0002] Current trends in electric vehicles require electronic components to have high voltage (HV) strength. High voltage insulation can be ensured by lengthening the creepage distance, the gap distance between conductors, or sealing the conductors with solid insulation material.

[0003] However, this results in the sensor being designed large and long to meet the HV requirements or having a slower response time due to the thick insulation material hindering heat transfer. SUMMARY

[0004] It is an object of the present disclosure to describe a sensor device solving the above-mentioned problems. This object is solved by the sensor device according to the independent claims and the use of the sensor device.

[0005] According to a first aspect of the present disclosure, a sensor device is described. The sensor device is configured for measuring a temperature of a surface. The sensor device comprises a temperature sensor device. The sensor device can have an operating temperature range of -40°C and 180°C, short-term up to 200°C.

[0006] The sensor device is suitable for use in high voltage applications, for example HV busbars. The sensor device is particularly suitable for use in automotive applications, in particular electric vehicle applications.

[0007] The sensor device comprises at least one sensor element, preferably exactly one sensor element. The sensor element can comprise an NTC (negative temperature coefficient) thermistor. In particular, the sensor element can comprise a glass NTC thermistor.

[0008] The sensor device further comprises a ceramic housing. The term "ceramic housing" is to be understood such that the material of the ceramic housing comprises ceramic. The sensor element is at least partially arranged in an inner region / interior region of the ceramic housing. The sensor element is fixedly secured in the interior of the ceramic housing, for example by a potting material.

[0009] The sensor device further comprises a base body. The ceramic housing is connected to the base body. The ceramic housing can be clamped into the base body. The base body is adapted and arranged to at least partially surround the ceramic housing. For example, a top surface of the ceramic housing as well as at least a part of a side surface and at least a part of a bottom surface of the ceramic housing can be surrounded by the base body. Preferably, the base body comprises plastic. The base body can be an insulating component of the sensor device.

[0010] The sensor device further comprises an outer housing. The outer housing can constitute the outer shell of the sensor device. Preferably, the outer housing comprises plastic. The outer housing can be an insulating component (i.e. a further insulating component) of the sensor device.

[0011] It is to be understood that the outer housing and the base body are different / independent components of the sensor device, each implementing a very specific function, e.g. an insulating function. The outer housing is connected to the base body, preferably in a non-releasable manner. The outer housing at least partially surrounds the base body and the ceramic housing. The base body, the ceramic housing and thus the sensor element can be at least partially overmoulded by the outer housing. This means that the sensor device can be an overmoulded component, i.e. it can be at least partially overmoulded by the material of the outer housing. Thus, a very stable and compact sensor device is provided.

[0012] The sensor device further comprises at least one mounting element. The mounting element comprises metal. The mounting element is adapted and arranged to mount the sensor device to a target application, i.e. an application in which the sensor device is to be used, e.g. a gear box.

[0013] HV application.

[0014] The mounting element is adapted and arranged to fix a downward pushing force to the surface whose temperature is to be measured. In other words, the mounting element pushes the sensor device onto the surface with a defined force. Furthermore, the mounting element is adapted to provide mechanical strength at the mounting position, so that the sensor device can withstand the vibrations required, e.g. by a gear box (the maximum acceleration can be 10.5g). Thus, a very robust and reliable sensor device is provided.

[0015] The mounting element can be designed to mount the sensor device to a target application in a releasable manner. In other words, the mounting element can ensure that the sensor device can be removed from one target application and can be moved into and combined in another target application. Thus, the sensor device can be applied very flexibly.

[0016] The sensor device is designed such that the ceramic housing has an open / exposed surface. In particular, the components of the sensor device are interrelated to each other and the ceramic housing is specifically designed such that a surface of the ceramic housing is exposed.

[0017] This means that the ceramic housing comprises a surface which is in direct mechanical contact with the surface whose temperature is to be measured. In other words, the ceramic housing rests at least partially directly on the surface whose temperature is to be measured, in particular on the measurement point of the surface. In this way, the sensor device can measure the temperature of the surface directly, quickly and completely insulated. Thus, the sensor device has a very fast response time: t63<10s (on the surface).

[0018] The sensor device can be incorporated within the application to be monitored to better make thermal contact with the HV surface while reducing the thermal influence of the surrounding environment.

[0019] According to one embodiment, the ceramic housing comprises a sensing area. The sensing area is to be understood as the area of the ceramic housing through which the surface temperature to be measured is directly transmitted to the sensor element. The sensor element can be positioned directly next to the sensing area. The sensing area can be arranged on the bottom surface of the ceramic housing. The sensing area can constitute a part of the bottom surface of the ceramic housing. The bottom surface can be the surface of the ceramic housing which, once the sensor device is installed to the target application, faces the surface whose temperature is to be measured.

[0020] The sensing area at least partially protrudes from the outer housing. This means that, in addition to the sensing area, the outer housing completely surrounds the base body and the ceramic housing. Thus, when the sensor device is installed to the target application, the sensing area can be in direct mechanical contact with the surface. In this way, a very effective sensor device with a fast response time is provided.

[0021] According to one embodiment, the base body and the outer housing constitute a double or reinforced HV insulation of the sensor device. This means that, instead of only one insulating housing part, the sensor device comprises two separate parts (base body and outer housing) to ensure sufficient HV resistance.

[0022] Preferably, the sensor device comprises a high voltage resistance of < 4300 V for DC (direct current). In this way, the sensor device is particularly suitable for use in HV applications such as electric cars.

[0023] According to one embodiment, the sensor device comprises at least two, preferably exactly two, connection elements for electrically connecting the sensor device. The respective connection element can comprise a terminal and a metal wire. The respective connection element protrudes from the outer housing to enable an electrical connection of the sensor device.

[0024] The respective connection element, in particular the wire, can be at least partially covered by an insulating material. The wires of the connection elements can be interwoven.

[0025] According to the embodiment, the mounting element is clamped to the outer surface of the outer housing. In this way, the mounting element can be quickly and easily connected to the outer surface of the sensor device.

[0026] According to the embodiment, the design of the mounting element can be adapted to the shape of the target application. In other words, the shape of the mounting element can be adapted to the desired location / target application to which the sensor device is to be installed. The mounting element can comprise, for example, a clip, a spring clip or a screw. In this way, a very flexible application of the sensor device is provided.

[0027] According to another aspect, a use of the sensor device is described. The sensor device can be the sensor device described above. Thus, all features described in connection with the sensor device apply to the use of the sensor device, and all features described in connection with the use of the sensor device apply to the sensor device.

[0028] The sensor device is used for measuring surface temperatures in high voltage target applications, for example electric car applications. Preferably, the sensor device is clamped to the target application.

[0029] Due to the introduction of the ceramic housing, the sensor device can be produced with a glass NTC having a full plastic overmolding (double insulation) but maintaining a fast response time and at the same time maintaining the HV strength. The sensor device comprises a very high HV resistance for DC of up to 4300 V. Furthermore, the sensor device comprises a very small overall size.

[0030] Furthermore, due to the introduction of the flexible mounting element (e.g. spring clip) and the exposed ceramic housing surface, the sensor device can measure the temperature directly, quickly and completely insulated from the bottom contact surface. Thus, the sensor device provides a very fast response time. BRIEF DESCRIPTION OF DRAWINGS

[0031] Further features, improvements and advantages become apparent from the following description of exemplary embodiments in conjunction with the attached drawings.

[0032] Figure 1 a perspective view of the sensor device is schematically shown,

[0033] Figure 2 a perspective bottom view of the sensor device according to Figure 1 is schematically shown,

[0034] Figure 3 a perspective side view of parts of the sensor device according to Figure 1 is schematically shown,

[0035] Figure 4 a perspective view of parts of the sensor device according to Figure 1 is schematically shown,

[0036] Figure 5 a cross-sectional side view of the sensor device mounted on a target application is schematically shown,

[0037] Figure 6 a cross-sectional side view of the sensor device is schematically shown,

[0038] Figure 7 a perspective view of the sensor device is schematically shown,

[0039] Figure 8 A cross-sectional view of a portion of the sensor device is schematically shown. DETAILED DESCRIPTION

[0040] In the drawings, elements having the same structure and / or function can be denoted by the same reference signs. It is understood that the embodiments shown in the drawings are representational and not necessarily drawn to scale.

[0041] Figures 1 to 8 A sensor device 1 or a portion thereof is shown. The sensor device 1 is a temperature sensor device. In particular, the sensor device 1 is configured for measuring a temperature of a surface, e.g. a temperature of a plastic surface.

[0042] The sensor device 1 is suitable for use in HV applications. The sensor device 1 has a very high HV resistance, as will be explained in detail later on. The HV resistance of the sensor device is preferably 4300 V for DC.

[0043] The sensor device 1 is particularly suitable for use in automotive applications, in particular electric vehicle applications. For example, the sensor device 1 can be used for temperature measurement on busbar surfaces of HV applications in the field of electric vehicles. The operating temperature range of the sensor device 1 is between -40°C and 180°C, short-term up to 200°C.

[0044] The sensor device 1 comprises a sensor element 2 (see in particular Figure 4 ). The sensor element 2 comprises an NTC thermistor, preferably a glass NTC thermistor. The sensor element 2 is connected with two connection elements 4. The respective connection element 4 can comprise a terminal and a metal wire. The wires can be twisted together (see Figure 6 and Figure 7 ). The wires are at least partially surrounded by an insulating material 4A.

[0045] The connection elements 4 are suitable for electrically connecting the sensor device 1. In particular, the connection elements 4 electrically connect the sensor device 1 with a connector 10, as can be gathered from Figure 6 and Figure 7 . The connector 10 is suitable and arranged to electrically connect the sensor device 1 with an external supply unit (not explicitly shown).

[0046] The sensor device 1 further comprises a ceramic housing 3. The ceramic housing 3 comprises a top surface 3A, a bottom surface 3B and a hollow interior / hollow inner area 12 (see Figure 8 ). The bottom surface 3B can be the surface of the ceramic housing 3 which, once the sensor device 1 is mounted to a target application 9, faces the surface whose temperature is to be measured (see in this context Figure 5 ).

[0047] The ceramic housing 3 has an open end 15 and a closed end 16. In the inner region 12, the closed end 16 comprises a rounded shape. The sensor element 2 is arranged in the inner region 12 close to the rounded closed end 16 (see e.g. Figure 4 and Figure 5 ). The sensor element 2 is firmly fixed in the inner region 12 of the ceramic housing 3 by means of a potting material 17 ( Figure 5 ). The connection element 4 partially protrudes from the open end 15 of the ceramic housing 3 for realizing the electrical connection of the sensor device 1 as described above (see Figure 4 ).

[0048] The sensor device 1 and in particular the ceramic housing 3 comprises a sensing region 6. The sensing region 6 is to be understood as the region of the ceramic housing 3 through which the surface temperature to be measured is directly transmitted to the sensor element 2. The sensing region 6 is arranged at the bottom surface 3B of the ceramic housing 3. The sensing region 6 is a part of the bottom surface 3B.

[0049] The bottom surface 3B comprises a protrusion. Thus, the bottom surface 3A is not smooth. In particular, the bottom surface 3A comprises an edge 11 ( Figure 8 ). In other words, the bottom surface 3A comprises two parts having different heights, i.e. an extension perpendicular to the main longitudinal axis X of the ceramic housing 3 / sensor device 1 with respect to each other. The sensing region 6 comprises the part of the bottom surface 3B having the greater height compared to the other part / second part of the bottom surface 3B. In other words, the sensing region 6 is thicker than the rest of the bottom surface 3B such that the sensing region 6 protrudes from the final sensor device 1.

[0050] Once the sensor element 2 is arranged within the ceramic housing 3, the sensing region 6 is directly below the sensor element 2. Moreover, once the sensor device 1 is installed to the target application, the sensing region 6 is directly seated on the surface 9A of which the temperature is to be measured (see Figure 5 ). This will be explained in detail later on.

[0051] The total length li of the bottom surface 3A and thus of the ceramic housing 3 can be between 6 mm and 8 mm, e.g. 7.2 mm, 7.0 mm or 6.8 mm ( Figure 8 ). In this context, the term length refers to the extension of the ceramic housing 3 along the main longitudinal axis X. The length l3 of the part of the bottom surface 3A having the smaller height can be between 2 mm and 3 mm, e.g. 2.5 mm or 2.8 mm. The length l2 of the inner region 12 of the ceramic housing 3 can be between 6 mm and 7 mm, e.g. 6.5 mm or 6.2 mm.

[0052] The sensor device 1 further comprises a base body 5. The base body 5 comprises plastic. The base body constitutes a first HV insulation of the sensor device 1. The base body 5 is connected to the ceramic housing 3. In particular, the ceramic housing 3 is clamped into the base body 5.

[0053] As can be seen, for example, from Figures 1 to 3 and Figure 5 the base body 5 partially surrounds the ceramic housing 3 and the connection element 4. The connection element 4 protrudes from a side surface of the base body 5 to enable an electrical connection of the sensor device 1. Furthermore, the sensing area 6, i.e. a part of the bottom surface 3A of the ceramic housing 3, is free of material of the base body 5.

[0054] The base body 5 comprises a plurality of alignment features 13 arranged at an outer surface of the base body 5. The alignment features 13 can each comprise a protrusion. The alignment features 13 are adapted and arranged to align the base body 5 with an outer housing 8 of the sensor device.

[0055] The outer housing 8 of the sensor device 1 constitutes a further HV insulation / second HV insulation of the sensor device 1. The outer housing 8 comprises plastic. A length L of the outer housing 8 can be between 20 mm and 25 mm, for example 22 mm or 23 mm Figure 6 . Furthermore, a height H1 of the outer housing 8 can be between 5 mm and 6 mm, for example 5.5 mm. A total height H2 of the sensor device 1 including the mounting element 7 described later can be between 8 mm and 9 mm, for example 8.5 mm or 8.8 mm Figure 6 .

[0056] The outer housing 8 at least partially encloses the base body 5, the connection element 4 and the ceramic housing 3. The base body 5, the ceramic housing 3 and the connection element 4 are at least partially overmolded by the material of the outer housing 8. However, a part of the bottom surface 3B of the ceramic housing 3, i.e. the sensing area 6, remains free of material of the housing 8. In other words, the sensing area 6 is exposed.

[0057] In this way, when the sensor device 1 is mounted to the target application 9A, the sensing area 6 can be directly placed onto the surface 9A. Thus, no further components, in particular no insulating material, are arranged between the surface 9A and the sensing area 6. Thus, the sensor device 1 has a very fast response time. In particular, the response time t63< 10 s (on the surface).

[0058] Furthermore, by the double insulation provided by the outer housing 8 and the base body 5, the sensor device 1 has a very high HV resistance. In particular, the HV resistance is 4300 V for DC.

[0059] Finally, the sensor device 1 comprises a mounting element 7. The mounting element 7 comprises metal. The mounting element 7 is adapted and arranged for mounting the sensor device 1 to the target application 9. In the shown embodiment, the mounting element 9 comprises a spring clip. However, different embodiments of the mounting element 7 are conceivable, e.g. a screw or a clip. In particular, the design of the mounting element 7 can be adapted to the shape of the target application.

[0060] In this embodiment, the mounting element 7 is clamped to the outer surface of the outer housing 8. For this purpose, the mounting element 7 comprises two spring arms 7A having radially inwardly pointing protrusions 18 which engage with mating notches of the outer housing 8. Figure 1 and Figure 2 ).

[0061] The mounting element 7 is also designed to be clamped to the target application 9. For this purpose, the mounting element 7 also comprises a spring arm 7B having a protrusion 14. The spring arm 7B and in particular the protrusion 14 is adapted and arranged to mechanically cooperate with mating structures, e.g. cutouts, of the target application 9 to firmly and easily connect the sensor device 1 to the target application 9.

[0062] Once the sensor device 1 is mounted to the target application 9, the mounting element 7 and in particular the spring arm 7B provides a certain downward pushing force towards the bottom, i.e. towards the surface 9A where the measuring point is located. Figure 5 ). Furthermore, the mounting element 7 guarantees mechanical strength at the mounting position to withstand the vibrations required, e.g. for a gear box (maximum acceleration can be 10.5 g).

[0063] In addition to this, once the sensor device 1 is mounted to the target application 9, the sensing area 6 of the ceramic housing 3 is in direct mechanical contact with the surface 9A whose temperature will be measured as Figure 5 can be learned. In addition to guaranteeing HV strength, the bottom surface 3B of the exposed ceramic housing, i.e. the direct contact with the measuring point, also guarantees a fast response time.

[0064] The present invention is not limited to the embodiments based on its description. On the contrary, the present invention comprises any novel feature and any combination of features, in particular any combination of features in the claims, even if that feature or combination itself is not explicitly stated in the claims or embodiments.

[0065] Reference signs

[0066] 1 sensor device

[0067] 2 sensor element

[0068] 3 ceramic housing

[0069] 3A top surface

[0070] 3B bottom surface

[0071] 4 connecting element

[0072] 4A insulating material

[0073] 5 base body

[0074] 6 induction area

[0075] 7 mounting element

[0076] 7A spring arm

[0077] 7B spring arm

[0078] 8 outer housing

[0079] 9 target application

[0080] 10 connector

[0081] 11 edge

[0082] 12 inner area

[0083] 13 alignment feature

[0084] 14 protrusion

[0085] 15 open end

[0086] 16 closed end

[0087] 17 potting material

[0088] 18 protrusion

[0089] H1 height

[0090] H2 height

[0091] L length of the outer housing

[0092] li total length of the ceramic housing

[0093] l2 inner length of the ceramic housing

[0094] l3 partial length of the ceramic housing

[0095] X main longitudinal axis

Claims

1. A sensor device (1) for measuring the temperature of a surface (9A), the sensor device (1) comprising: - at least one sensor element (2), a ceramic housing (3), wherein the sensor element (2) is at least partially arranged in the ceramic housing (3), a basic body (5) which at least partially surrounds the ceramic housing (3), an outer shell (8) connected to the basic body (5), wherein the outer shell (8) at least partially surrounds the basic body (5) and the ceramic housing (3), - at least one mounting element (7) adapted and arranged for mounting the sensor device (1) to a target application (9), The ceramic housing (3) is adapted and arranged to be in direct mechanical contact with the surface (9A) whose temperature is to be measured.

2. The sensor device (1) according to claim 1, in, The ceramic housing (3) comprises a sensing region (6), wherein the sensing region (6) at least partially protrudes from the outer housing (8).

3. The sensor device (1) according to claim 2, in, The outer housing (8) completely surrounds the basic body (5) and the ceramic housing (3) except for the sensing region (6).

4. The sensor device (1) according to any one of the preceding claims, in, The sensor device (1) is at least partially overmolded by the material of the outer housing (8).

5. Sensor device (1) according to any one of the preceding claims, in, The sensor element (2) comprises a glass NTC thermistor.

6. Sensor device (1) according to any one of the preceding claims, in, The basic body (5) and the outer housing (8) form a double high-voltage insulator of the sensor device (1).

7. Sensor device (1) according to any one of the preceding claims, in, The basic body (5) and the outer shell (8) comprise plastic.

8. Sensor device (1) according to any one of the preceding claims, It also comprises at least two connecting elements (4) for electrically connecting the sensor device (1), wherein The connecting element (4) is at least partially covered by an insulating material (4A).

9. Sensor device (1) according to any one of the preceding claims, in, The mounting element (7) is clamped to the outer surface of the outer shell (8).

10. The sensor device (1) according to any one of the preceding claims, in, The design of the mounting element (7) can be adapted to the shape of the target application.

11. Sensor device (1) according to any one of the preceding claims, in, The mounting element (7) comprises a clip, a spring clip or a screw.

12. Sensor device (1) according to any one of the preceding claims, in, The sensor device (1) comprises a high voltage resistor of direct current ≤4300V.

13. Use of a sensor device (1) according to any one of the preceding claims for measuring surface temperature in high voltage target applications (9).

14. The use according to claim 13, in, The sensor device (1) is clamped to the target application (9).

15. The use according to claim 13 or 14, in, The sensor device (1) is used in electric vehicle applications.

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