Sensor device
The sensor device with a ceramic housing and plastic overmolded insulation ensures high voltage resistance and fast response time by direct surface contact, addressing the challenges of existing sensor designs in electromobility.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-04-12
- Publication Date
- 2026-03-17
AI Technical Summary
Existing sensor designs for high voltage applications, such as in electromobility, face challenges in maintaining high voltage resistance while minimizing size and ensuring fast response times, as increased insulation materials hinder heat transfer and enlarge the design.
A sensor device with a ceramic housing containing a glass NTC thermistor, overmolded with plastic substrates and external housings for insulation, and a flexible mounting element, allowing direct contact with the surface for rapid temperature measurement.
The sensor device provides high voltage resistance up to 4300V DC, maintains a compact size, and achieves a fast response time of less than 10 seconds, suitable for automotive and electromobility applications.
Smart Images
Figure 2026509147000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a sensor device for measuring the temperature of a surface. Furthermore, the present invention relates to the use of the sensor device.
[0002] Current trends in electromobility require electronic components to have high voltage (HV) resistance. High voltage insulation can be ensured by increasing the creepage distance or air distance between conductors or by encapsulating the conductors with solid insulating materials.
[0003] However, this causes the sensor design to become larger and longer to meet the HV requirements, or the response time of the sensor design to become slower because the thick insulating material hinders heat transfer.
[0004] The objective of this disclosure is to describe a sensor device that solves the above problems.
[0005] This objective is solved by the sensor device and the use of the sensor device according to the independent claims.
[0006] According to a first aspect of the present disclosure, a sensor device is described. The sensor device is configured to measure the temperature of a surface. The sensor device consists of a temperature sensor device. The operating temperature range of the sensor device can be from -40°C to 180°C, and up to 200°C for short periods.
[0007] The sensor device is adapted for use in high voltage applications, for example, on an HV busbar. The sensor device is specifically adapted for use in automotive applications, particularly in electromobility applications.
[0008] 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.
[0009] The sensor device further comprises a ceramic housing. The term "ceramic housing" is understood to mean that the material of the ceramic housing includes ceramic. The sensor element is at least partially located within the interior / internal region of the ceramic housing. The sensor element is firmly fixed inside the ceramic housing, for example, by a potting material.
[0010] The sensor device further comprises a substrate. The ceramic housing is connected to the substrate. The ceramic housing can be clamped to the substrate. The substrate is fitted and positioned to at least partially surround the ceramic housing. For example, at least a portion of the top surface of the ceramic housing, as well as the sides and bottom surface of the ceramic housing, may be surrounded by the substrate. Preferably, the substrate includes plastic. The substrate may be an insulating component of the sensor device.
[0011] The sensor device further comprises an external housing. The external housing may constitute the outer shell of the sensor device. Preferably, the external housing includes plastic. The external housing may be an insulating component (i.e., an additional insulating component) of the sensor device.
[0012] The external housing and the substrate are understood to be different / independent parts of the sensor device, each performing a very specific function, such as insulation. The external housing is preferably irremovably connected to the substrate. The external housing encloses the substrate and the ceramic housing at least partially. The substrate, ceramic housing, and therefore the sensor element can be at least partially overmolded by the external housing. This means that the sensor device can be an overmolded component, i.e., it can be at least partially overmolded by the material of the external housing. Thus, a very stable and compact sensor device is provided.
[0013] The sensor device further comprises at least one mounting element, the mounting element being made of metal. The mounting element is adapted and positioned to mount the sensor device to its intended application (i.e., the application in which the sensor device will be used), for example, an HV application.
[0014] The mounting elements are fitted and positioned to ensure a pressing force against the surface of the object to be temperature measured. In other words, the mounting elements press the sensor device against the surface with a predetermined force. Furthermore, the mounting elements are fitted to provide mechanical strength at the mounting position so that the sensor device can withstand vibrations required, for example, in a gearbox (the maximum acceleration may be 10.5 g). Thus, a very robust and reliable sensor device is provided.
[0015] The mounting elements may be designed to removably attach the sensor device to the intended application. In other words, the mounting elements may ensure that the sensor device can be removed from one application and moved and incorporated into another. Thus, the sensor device is highly flexible in its application.
[0016] The sensor device is designed so that the ceramic housing has an open surface, or exposed surface. In particular, the components of the sensor device are interconnected, and the ceramic housing is specifically designed so that the surface of the ceramic housing is exposed.
[0017] This means that the ceramic housing has a surface that is in direct mechanical contact with the surface of the object whose temperature is being measured. In other words, the ceramic housing is placed at least partially directly on the surface of the object whose temperature is being measured, particularly on the measurement point on that surface. In this way, the sensor device can measure the temperature from the surface directly, quickly, and in complete isolation. As a result, the sensor device has a very fast response time, i.e., t63 < 10s (on the surface).
[0018] By integrating the sensor device into the application being monitored, it is possible to improve thermal contact with the HV surface and reduce thermal influences from the surroundings.
[0019] According to one embodiment, the ceramic housing includes a sensing region. The sensing region is understood as a region of the ceramic housing that directly transmits the surface temperature of the object to be measured to a sensor element. The sensor element may be located immediately adjacent to the sensing region. The sensing region may be located on the bottom surface of the ceramic housing. The sensing region may constitute a part of the bottom surface of the ceramic housing. The bottom surface may be the surface of the ceramic housing that faces the surface of the object to be temperature measured when the sensor device is mounted for the intended application.
[0020] The sensing area protrudes at least partially from the external housing. This means that the external housing completely encloses the substrate and ceramic housing, except for the sensing area. Therefore, when the sensor device is mounted for its intended application, the sensing area can be in direct mechanical contact with the surface. In this way, a highly efficient sensor device with a fast response time is provided.
[0021] According to one embodiment, the substrate and external housing constitute double or reinforced HV insulation for the sensor device. This means that the sensor device has two separate components (substrate and external housing) to ensure sufficient HV resistance, instead of just one insulating housing component.
[0022] Preferably, the sensor device has high voltage tolerance of 4300V or less to DC (direct current). In this way, the sensor device is particularly suitable for use in HV applications such as electromobility.
[0023] According to one embodiment, the sensor device comprises at least two connecting elements, preferably exactly two, for electrically connecting the sensor devices. Each connecting element may include a terminal and a metal wire. Each connecting element protrudes from the external housing to enable the electrical connection of the sensor devices.
[0024] Each connection element, in particular the wire, can be at least partially covered by an insulating material. The wires of the connection elements can be twisted.
[0025] According to one embodiment, the mounting element is clamped to the outer surface of the external housing. In this way, a quick and easy connection of the mounting element to the outer surface of the sensor device becomes possible.
[0026] According to one embodiment, the design of the mounting element can be adapted to the shape of the intended application. In other words, the shape of the mounting element can be adapted to the desired position / intended application where the sensor device is to be mounted. The mounting element can comprise, for example, a clip, a spring clip, or a screw. In this way, a sensor device that can be applied very flexibly is provided.
[0027] According to a further aspect, the use of the sensor device is described. The sensor device can be the sensor device described above. Accordingly, all features described in connection with the sensor device apply to the use of the sensor device and vice versa.
[0028] The sensor device is used for measuring the surface temperature in high-voltage applications, for example in electro-mobility applications. Preferably, the sensor device is clipped to the intended application.
[0029] By the introduction of the ceramic housing, the sensor device can be manufactured using a fully plastic overmolded (doubly insulated) glass NTC and can maintain HV resistance with a fast response time. The sensor device has a very high HV resistance of up to 4300 V for DC. In addition, the sensor device has a very small overall size.
[0030] Furthermore, by the introduction of a flexible mounting element (for example, a spring clip) and an exposed ceramic housing surface, the sensor device can measure the temperature directly, quickly, and in a fully insulated state from the bottom contact surface. Accordingly, the sensor device provides a very fast response time.
[0031] Further features, improvements, and advantageous methods will become apparent from the following description of the exemplary embodiments in relation to the drawings.
Brief Description of the Drawings
[0032] [Figure 1] A perspective view of the sensor device is schematically shown. [Figure 2] A bottom perspective view of the sensor device according to FIG. 1 is schematically shown. [Figure 3] A partial side perspective view of the sensor device according to FIG. 1 is schematically shown. [Figure 4] A partial perspective view of the sensor device according to FIG. 1 is schematically shown. [Figure 5] A side cross-sectional view of the sensor device attached to the target application is schematically shown. [Figure 6] A side cross-sectional view of the sensor device is schematically shown. [Figure 7] A perspective view of the sensor device is schematically shown. [Figure 8] A partial cross-sectional view of the sensor device is schematically shown.
[0033] In the figures, elements of the same structure and / or functionality may be referred to by the same reference numerals. It is understood that the embodiments shown in the figures are exemplary representations and are not necessarily drawn to scale.
[0034] FIGS. 1 to 8 show the sensor device 1 or a part thereof. The sensor device 1 is a temperature sensor device. In particular, the sensor device 1 is configured to measure the temperature of a surface, for example, the temperature of a plastic surface.
[0035] The sensor device 1 is adapted to be used in HV applications. The sensor device 1 has a very high HV resistance, as will be described in detail later. The HV resistance of the sensor device is preferably 4300 V for DC.
[0036] Sensor device 1 is specifically adapted for use in automotive applications, particularly in electromobility applications. For example, sensor device 1 can be used to measure the temperature of busbar surfaces for HV applications in the electromobility field. The operating temperature range of sensor device 1 is between -40°C and 180°C, with a maximum of 200°C for short periods.
[0037] The sensor device 1 comprises a sensor element 2 (see Figure 4 in particular). The sensor element 2 comprises an NTC thermistor, preferably a glass NTC thermistor. The sensor element 2 is connected to two connecting elements 4. Each connecting element 4 may comprise terminals and metal wires. The wires may be twisted together (see Figures 6 and 7). The wires are at least partially surrounded by an insulating material 4A.
[0038] The connection element 4 is adapted to electrically connect the sensor device 1. In particular, the connection element 4 electrically connects the sensor device 1 to the connector 10, as can be seen from Figures 6 and 7. The connector 10 is adapted and positioned to electrically connect the sensor device 1 to an external supply unit (not explicitly shown).
[0039] The sensor device 1 further comprises a ceramic housing 3. The ceramic housing 3 has a top surface 3A, a bottom surface 3B, and a hollow interior / hollow inner region 12 (Figure 8). The bottom surface 3B may be the surface of the ceramic housing 3 that faces the surface to be measured when the sensor device 1 is attached to the application 9 (see Figure 5 in this context).
[0040] The ceramic housing 3 has an open end 15 and a closed end 16. In the inner region 12, the closed end 16 has a rounded shape. The sensor element 2 is positioned in the inner region 12 near the rounded closed end 16 (see, for example, Figures 4 and 5). The sensor element 2 is firmly fixed to the inner region 12 of the ceramic housing 3 by a potting material 17 (Figure 5). The connecting element 4 partially protrudes from the open end 15 of the ceramic housing 3 to enable the electrical connection of the sensor device 1 as described above (see Figure 4).
[0041] The sensor device 1, in particular the ceramic housing 3, includes a sensing region 6. The sensing region 6 is understood as a region of the ceramic housing 3 that directly transmits the surface temperature of the object to be measured to the sensor element 2. The sensing region 6 is located on the bottom surface 3B of the ceramic housing 3. The sensing region 6 is a part of the bottom surface 3B.
[0042] The base surface 3B has a raised portion. Therefore, the base surface 3A is not smooth. In particular, the base surface 3A has an edge 11 (Figure 8). In other words, the base surface 3A has two parts that differ in height, i.e., in length perpendicular to the main longitudinal axis X of the ceramic housing 3 / sensor device 1. The sensing area 6 comprises a portion of the base surface 3B that has a greater height compared to the further / second portion of the base surface 3B. To put it another way, the sensing area 6 is thicker than the rest of the base surface 3B and consequently protrudes from the finished sensor device 1.
[0043] The sensing region 6 is located directly beneath the sensor element 2 when the sensor element 2 is placed inside the ceramic housing 3. Furthermore, when the sensor device 1 is attached to the target application, the sensing region 6 is placed directly on the surface 9A of the object whose temperature is to be measured (see Figure 5). This will be explained in detail later.
[0044] The total length l1 of the base surface 3A, and thus of the ceramic housing 3, may be between 6 mm and 8 mm, for example, 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 portion of the base surface 3A with a smaller height may be between 2 mm and 3 mm, for example, 2.5 mm or 2.8 mm. The length l2 of the inner region 12 of the ceramic housing 3 may be between 6 and 7 mm, for example, 6.5 mm or 6.2 mm.
[0045] The sensor device 1 further comprises a base 5. The base 5 is made of plastic. The base constitutes the first HV insulation of the sensor device 1. The base 5 is connected to the ceramic housing 3. In particular, the ceramic housing 3 is clamped to the base 5.
[0046] The base 5 partially surrounds the ceramic housing 3 and the connecting element 4, as can be seen, for example, in Figures 1-3 and 5. The connecting element 4 protrudes from the side of the base 5 to enable the electrical connection of the sensor device 1. Furthermore, the sensing area 6 (i.e., a portion of the bottom surface 3A of the ceramic housing 3) is also free of the material of the base 5.
[0047] The base body 5 comprises a plurality of alignment features 13 arranged on the outer surface of the base body 5. Each of the alignment features 13 may have a projection. The alignment features 13 are fitted and positioned to align the base body 5 with the external housing 8 of the sensor device.
[0048] The external housing 8 of the sensor device 1 constitutes further / secondary HV insulation of the sensor device 1. The external housing 8 includes plastic. The length L of the external housing 8 may be between 20 mm and 25 mm, for example, 22 mm or 23 mm (Figure 6). Furthermore, the height H1 of the external housing 8 may be between 5 mm and 6 mm, for example, 5.5 mm. The total height H2 of the sensor device 1, including the mounting element 7 described later, may be between 8 mm and 9 mm, for example, 8.5 mm or 8.8 mm (Figure 6).
[0049] The outer housing 8 encloses the base 5, the connecting element 4, and the ceramic housing 3 at least partially. The base 5, the ceramic housing 3, and the connecting element 4 are at least partially overmolded by the material of the outer housing 8. However, the portion of the bottom surface 3B of the ceramic housing 3, i.e., the sensing area 6, is not covered by the material of the outer housing 8. In other words, the sensing area 6 is exposed.
[0050] In this way, when the sensor device 1 is attached to the target application 9A, the sensing area 6 can be directly positioned on the surface 9A. Therefore, no further components, especially insulating materials, are placed between the surface 9A and the sensing area 6. Consequently, the sensor device 1 has a very fast response time. In particular, the response time t63 < 10s (on the surface).
[0051] Furthermore, the double insulation provided by the external housing 8 and the base 5 gives the sensor device 1 very high HV resistance. In particular, the HV resistance is 4300V relative to DC.
[0052] Finally, the sensor device 1 includes a mounting element 7. The mounting element 7 is made of metal. The mounting element 7 is adapted and positioned to mount the sensor device 1 to the application 9. In the illustrated embodiment, the mounting element 9 includes a spring clip. However, different embodiments of the mounting element 7 are possible, for example, a screw or a clip. In particular, the design of the mounting element 7 can be adapted to the shape of the application.
[0053] 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 elastic arms 7A having radially inward projections 18 that engage with a mating recess in the outer housing 8 (Figures 1 and 2).
[0054] The mounting element 7 is further designed to be clipped to the application 9. For this purpose, the mounting element 7 further comprises a spring arm 7B having a bulge 14. The spring arm 7B, in particular the bulge 14, is fitted and positioned to mechanically cooperate with the mating structure of the application 9, such as a notch, in order to securely and easily connect the sensor device 1 to the application 9.
[0055] When the sensor device 1 is attached to the target application 9, the mounting elements 7, particularly the spring arm 7B, provide a constant pressing force toward the bottom, i.e., the surface 9A, where the measurement point is located (Figure 5). Furthermore, the mounting elements 7 ensure mechanical strength at the mounting position to withstand vibrations required, for example, in a gearbox (maximum acceleration may be 10.5 g).
[0056] In addition, when the sensor device 1 is attached to the target application 9, as can be seen in Figure 5, the sensing area 6 of the ceramic housing 3 comes into direct mechanical contact with the surface 9A of the object whose temperature is to be measured. The exposed bottom surface 3B of the ceramic housing (i.e., direct contact with the measurement point) ensures a fast response time in addition to HV resistance.
[0057] The present invention is not limited to the embodiments described above. Rather, the present invention encompasses all new features and all combinations of features, including, in particular, all combinations of features in the claims, even if the feature or combination itself is not explicitly described in the claims or embodiments. [Explanation of symbols]
[0058] 1. Sensor device 2 Sensor elements 3. Ceramic Housing 3A Top 3B Bottom 4 connection elements 4A insulating material 5 Base 6 Sensing area 7 Mounting elements 7A Elastic Arm 7B Spring Arm 8. External Housing 9. Target Uses 10 connectors 11 Edge 12 Inner area 13 Alignment Features 14. Swelling 15 Open end 16 closed end 17 Potting material 18 protrusions H1 Height H2 Height L Length of the external housing l1 Total length of ceramic housing l2 Ceramic housing inner length l3 Ceramic housing portion length X Main longitudinal axis
Claims
1. A sensor device (1) for measuring the temperature of a surface (9A), wherein the sensor device (1) is At least one sensor element (2), A ceramic housing (3) wherein the sensor element (2) is at least partially disposed within the ceramic housing (3), A base (5) that at least partially surrounds the ceramic housing (3), An external housing (8) connected to the base body (5), wherein the external housing (8) at least partially encloses the base body (5) and the ceramic housing (3), The sensor device (1) comprises at least one mounting element (7) adapted and arranged to be attached to the target application (9), The ceramic housing (3) is fitted and positioned to be in direct mechanical contact with the surface (9A) of the object whose temperature is to be measured, and this is the sensor device (1).
2. The sensor device (1) according to claim 1, wherein the ceramic housing (3) comprises a sensing region (6), and the sensing region (6) protrudes at least partially from the external housing (8).
3. The sensor device (1) according to claim 2, wherein the external housing (8) completely surrounds the substrate (5) and the ceramic housing (3), except for the sensing area (6).
4. The sensor device (1) is at least partially overmolded by the material of the external housing (8) according to any one of claims 1 to 3.
5. The sensor device (1) according to any one of claims 1 to 4, wherein the sensor element (2) comprises a glass NTC thermistor.
6. The sensor device (1) according to any one of claims 1 to 5, wherein the base body (5) and the external housing (8) constitute double HV insulation of the sensor device (1).
7. The sensor device (1) according to any one of claims 1 to 6, wherein the base body (5) and the external housing (8) include plastic.
8. The sensor device (1) according to any one of claims 1 to 7, further comprising at least two connecting elements (4) for electrically connecting the sensor device (1), wherein the connecting elements (4) are at least partially covered with an insulating material (4A).
9. The sensor device (1) according to any one of claims 1 to 8, wherein the mounting element (7) is clamped to the outer surface of the external housing (8).
10. The design of the mounting element (7) is adaptable to the shape of the target application, as described in any one of claims 1 to 9.
11. The sensor device (1) according to any one of claims 1 to 10, wherein the mounting element (7) comprises a clip, a spring clip, or a screw.
12. The sensor device (1) is the sensor device (1) according to any one of claims 1 to 11, wherein the sensor device (1) is equipped with high voltage tolerance of 4300V DC or less.
13. Use of the sensor device (1) according to any one of claims 1 to 12 for measuring surface temperature in high-voltage applications (9).
14. The use according to claim 13, wherein the sensor device (1) is clipped to the target application (9).
15. The sensor device (1) is used in an electromobility application, as described in claim 13 or 14.