Charging inlet with thermal sensor

Abstract

A charging inlet (110) includes a power terminal (204) and a thermal sensor (312) for monitoring the temperature of the power terminal. The power terminal is configured to releasably engage a mating contact of an external power source (104). The power terminal includes a cylindrical shaft (304). The thermal sensor includes a substrate (320) and a sensing element (322) mounted on the substrate. The substrate is flexible and bends along at least a portion of an outer surface (314) of the cylindrical shaft.

Description

Technical Field

[0001] The subject matter of this document relates to a charging system having an electrical connector for establishing an electrical conduction path for supplying current from a power source to a battery. Background Art

[0002] Electric vehicles (including all-electric and plug-in hybrid vehicles) have a charging system for charging a battery that provides current for propelling the vehicle. The charging system includes a charging inlet on the vehicle that is releasably coupled to a mating connector connected to an external power source. Since the vehicle is stationary during the charging operation, it is desirable to reduce the duration of the charging operation to reduce the amount of time the vehicle is stationary. The charging duration can be reduced by increasing the rate of power (e.g., current) transfer. At high currents, components of the vehicle charging system (such as the charging inlet) can become hot due to electrical contact resistance. If allowed to develop, the heat can damage components of the charging system, such as melting these components and potentially causing a fire.

[0003] To prevent heat-related damage, some known charging systems have sensors for monitoring the temperature inside or around the charging inlet. If the measured temperature exceeds a threshold, the charging system reduces the power transfer rate and / or takes other measures to maintain the temperature at a safe level where damage is unlikely to occur. However, temperature sensing in known charging systems can be inaccurate and / or have a delayed response time. For example, to provide electrical isolation for the sensing circuit from the high current conducted through the power contacts, the temperature sensor can be positioned relatively far from the power contacts and / or placed behind a wall or other structure. However, the separation distance and intervening structure can result in a significant temperature difference between the power contacts and the temperature sensor, reducing accuracy and slowing the response time of the sensor. Due to the low accuracy and slow response time, the control of known charging systems for the charging operation is limited.

[0004] The problem to be solved is to provide a charging inlet having a thermal sensor that can more accurately and quickly monitor the temperature of the power contacts during the charging operation than known charging systems, thereby allowing a greater power transfer rate during the charging operation to reduce the charging duration without concern for heat-related damage. Summary of the Invention

[0005] In one or more embodiments of the present disclosure, the problem is solved by a charging inlet that includes a power terminal and a thermal sensor for monitoring the temperature of the power terminal. The power terminal is configured to releasably engage a mating contact of an external power source. The power terminal includes a cylindrical shaft. The thermal sensor includes a substrate and a sensing element mounted on the substrate. The substrate is flexible and bends along at least a portion of the outer surface of the cylindrical shaft.

[0006] In one or more embodiments, a charging inlet is provided, which includes a housing, a power terminal, and a thermal sensor for monitoring the temperature of the power terminal. The housing defines a cavity. The power terminal is held by the housing and extends into the cavity. The power terminal is configured to releasably engage a mating contact of an external power source. The thermal sensor includes a substrate and a sensing element. The substrate has a component side and a mounting side opposite to the component side. The sensing element is mounted on the component side of the substrate. The mounting side of the substrate is mounted to an outer surface of the power terminal. The substrate is flexible and bends along a contour of at least a portion of the periphery of the power terminal.

[0007] In one or more embodiments, a charging inlet is provided, comprising first and second power terminals and a thermal sensor for monitoring the temperature of the first power terminal. The first and second power terminals are configured to releasably engage corresponding mating contacts of an external power source. The first and second power terminals are spaced apart from each other within a housing. The first power terminal comprises a cylindrical shaft. The thermal sensor comprises a substrate and a sensing element mounted on the substrate. The substrate is flexible and is mounted to the cylindrical shaft of the first power terminal so that the substrate bends along at least a portion of an outer surface of the cylindrical shaft. The sensing element of the thermal sensor is located between the first and second power terminals. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The present invention will now be described by way of example with reference to the accompanying drawings:

[0009] Figure 1 A charging system according to an embodiment is shown including an electric vehicle parked next to a charging station.

[0010] Figure 2 is a top view of a charging inlet according to an embodiment.

[0011] Figure 3 is a perspective view of a portion of a charging inlet according to an embodiment.

[0012] Figure 4 is based on Figure 3 An isometric perspective view of a power terminal and a thermal sensor associated with the power terminal of the illustrated embodiment.

[0013] Figure 5 is along Figure 3 A cross-sectional view of a portion of the charging inlet taken along line 5-5 in FIG.

[0014] Figure 6 is a top cross-sectional view of a thermal sensor bent along an outer surface of one of power terminals of a charging inlet according to an embodiment.

[0015] Figure 7 is a top cross-sectional view of a thermal sensor bent along an outer surface of a power terminal according to another embodiment.

[0016] Figure 8 is an isometric view of one of the thermal sensors in an unassembled state according to another embodiment.

[0017] Fig. 9 is a top cross-sectional view of two thermal sensors bent along an outer surface of a power terminal according to yet another embodiment.

[0018] Fig.10 According to an alternative embodiment, Figure 3 A cross-sectional view of a portion of the charging inlet taken along line 5-5 in FIG.

[0019] Fig.11 is an enlarged perspective view of a portion of a charging inlet according to another alternative embodiment. DETAILED DESCRIPTION

[0020] Figure 1 A charging system 100 according to an embodiment is shown, including an electric vehicle 102 parked next to a charging station 104. The electric vehicle 102 includes an onboard battery pack 106 electrically connected to an onboard charging inlet 110. Figure 1 The battery pack 106 is shown in dashed lines in FIG. The vehicle 102 may be an all-electric vehicle without an internal combustion engine, a plug-in hybrid vehicle including the battery pack 106 and an internal combustion engine, etc. The battery pack 106 supplies power (e.g., current) for powering a traction motor (not shown) of the vehicle 102 to provide traction to the powertrain and wheels 116 to propel the vehicle 102. Optionally, when traction is not needed, such as when traveling downhill, the traction motor may selectively be used as a generator to generate electrical energy using regenerative braking to charge the battery pack 106. The battery pack 106 may represent an array of batteries and / or battery cells. Although in Figure 1 Although the electric vehicle 102 is shown as a passenger car, the embodiments of the charging inlet 110 described herein are not limited to use with passenger cars, but may be installed on other types of vehicles, such as buses, trucks, rail vehicles, ships, etc.

[0021] The charging inlet 110 is configured to connect to a mating connector of an external power source to charge the battery pack 106. In the illustrated embodiment, the charging station 104 represents the external power source and the plug connector 112 represents the mating connector. When the vehicle 102 is not near the charging station 104, other external power sources that can be used to connect to the charging inlet 110 to charge the battery pack 106 include a household electrical outlet, an external generator, etc. The mating plug connector 112 is coupled to the charging station 104 via a power cable 114.

[0022] In the illustrated embodiment, the charging inlet 110 is mounted to a side 118 of the vehicle 102. The charging inlet 110 has a mating interface that is releasably coupled directly to a mating plug connector 112 to establish an electrical connection for conducting current from the charging station 104 to the battery pack 106. The charging inlet 110 may have a locking device (not shown) that releasably secures the mating connector 112 in a mated position with the charging inlet 110 to prevent the mating plug connector 112 from being prematurely disconnected from the charging inlet 110.

[0023] Figure 2 1 is a top view of the charging inlet 110 according to an embodiment. The charging inlet 110 includes a housing 202 and a power terminal 204 held by the housing 202. The housing 202 has a mating side 206 that is coupled to the mating connector 112 ( Figure 1 For example, the mating side 206 has an interface that is complementary to the interface of the mating connector 112. The housing 202 may include a connector for mounting the charging inlet 110 to the vehicle 102 ( Figure 1 The housing 202 may include a mounting flange 208 (shown in FIG. 1 ). For example, the mounting flange 208 may define a hole 210 that receives a fastener therethrough to secure the charging inlet 110 to a panel of the vehicle 102, such as a body panel or a chassis wall. The housing 202 extends from the mating side 206 to a rear side 212 opposite the mating side 206. The housing 202 defines a cavity 214 that extends from the rear side 212 to the mating side 206.

[0024] In the illustrated embodiment, the charging inlet 110 has two power terminals 204 (e.g., a first power terminal 204A and a second power terminal 204B), but may have a different number of power terminals 204 in other embodiments. The power terminals 204 extend into different corresponding cavities 214 of the housing 202. Portions of the power terminals 204 protrude beyond the rear side 212 of the housing 202 outside the cavities 214. Each power terminal 204 is mechanically fixed to a different corresponding power cable 216 to electrically connect the corresponding power terminal 204 to the corresponding power cable 216. The power cable 216 extends from the power terminal 204 to the battery pack 106 ( Figure 1 106 ) and is configured to deliver current to charge the battery pack 106. The power terminal 204 engages one or more conductors 218 of a power cable 216 at an interface located at Figure 2 In an embodiment, the charging inlet 110 includes a cover (not shown) that covers and surrounds the exposed interface when the cover is assembled to the housing 202 .

[0025] Figure 32 is a perspective view of a portion of the charging inlet 110 according to an embodiment. The power terminal 204 is configured to transmit high power electrical energy (e.g., high voltage, high current, etc.). The power terminal 204 may be a direct current (DC) fast charging terminal for transmitting direct current at a high current rate of up to or exceeding 1000A. In addition to the two power terminals 204, the charging inlet 110 may also include other power terminals retained within the housing 202. For example, although not shown Figure 3 , but the charging inlet 110 may include power terminals for delivering alternating current (AC) at a reduced power level relative to the power level delivered along the power terminals 204 .

[0026] Each power terminal 204 has a head 302 that is terminated to one or more conductors 218 of a corresponding power cable 216, and also includes a cylindrical shaft 304 protruding from the head 302. The head 302 is exposed outside the housing 202, and the shaft 304 extends into the corresponding cavity 214 of the housing 202.

[0027] In the illustrated embodiment, the head 302 has a termination region 306 that engages one or more conductors 218 and is mechanically coupled to the conductors 218 by chemical bonding means such as welding, soldering, etc. In a non-limiting example, the conductors 218 of the power cable 216 are ultrasonically welded to the termination region 306 to non-removably couple the power cable 216 mechanically and electrically to the power terminal 204. The termination region 306 can be a flat planar surface along a rear side 308 of the corresponding head 302 that faces away from the cylindrical shaft 304. As used herein, relative or spatial terms such as "front", "rear", "back", "top", "bottom", "inner" and "outer" are only used to identify and distinguish reference elements shown in the drawings along the illustrated orientation, and do not necessarily require a specific position or orientation relative to gravity and / or the surrounding environment of the charging inlet 110. In the illustrated embodiment, each head 302 of the power terminal 204 includes an elongated appendage 310 or tab that protrudes outward from the location where the head 302 is connected to the shaft 304. The termination region 306 is located along the appendage 310 .

[0028] The charging inlet 110 includes at least one thermal sensor 312 that measures and monitors the temperature of one or both of the power terminals 204. In the illustrated embodiment, the charging inlet 110 includes two thermal sensors 312. Each of the thermal sensors 312 is disposed on or near a different one of the two power terminals 204A, 204B. The thermal sensors 312 may have the same size, shape, and components as one another. The following description of one of the thermal sensors 312 may apply to both thermal sensors 312.

[0029] The thermal sensor 312 includes a substrate 320 and at least one sensing element 322 ( Figure 4). The substrate 320 is flexible. The substrate 320 is bent along the contour of at least a portion of the periphery of the corresponding power terminal 204 on which the substrate 320 is mounted or adjacent thereto. For example, Figure 3 The front side thermal sensor 312 is bent along at least a portion of the outer surface 314 of the cylindrical shaft 304 of the second power terminal 204B. In the illustrated embodiment, the thermal sensor 312 is mounted to the outer surface 314 of the cylindrical shaft 304. Figure 3 Most of it is shielded, but another thermal sensor 312 is bent along the outer surface 314 of the cylindrical shaft 304 of the first power terminal 204A.

[0030] The thermal sensor 312 is electrically connected to the control device 316 via wires 318. The wires 318 are electrically terminated to the substrate 320 by soldering, through-hole mounting, discrete connectors, etc. The thermal sensor 312 can generate temperature data, which is transmitted to the control device 316 as an electrical signal along the wires 318. The wires 318 can be insulated to separate the electrical signal from the power supply terminals 204 for controlling the battery pack 106 ( Figure 1 The control device 316 may include one or more processors that analyze the temperature data received from the thermal sensor 312 to monitor the temperature of the power terminal 204. The temperature of the power terminal 204 may be monitored during the charging operation to ensure that the power terminal 204 and other components of the charging inlet 110 do not overheat. For example, if the temperature data indicates that the temperature of the power terminal 204 exceeds a first specified threshold, the control device 316 may be programmed to automatically reduce the current transfer rate during the charging operation to reduce the temperature within the charging inlet 110. Conversely, if it is determined that the temperature is below a second specified threshold (which is a temperature lower than the first threshold), the control device 316 may be programmed to automatically increase the current transfer rate during the charging operation, which advantageously reduces the length of time that the battery pack 106 is charged. Although the control device 316 is shown within the housing 202 in the illustrated embodiment, in alternative embodiments, the control device 316 may be disposed along the exterior of the housing 202 or spaced apart from the housing 202.

[0031] In an alternative embodiment, instead of wires 318, thermal sensor 312 may include passive or active communication circuitry for wirelessly transmitting temperature data to control device 316. For example, the communication circuitry may receive an activation signal to communicate (e.g., transmit or broadcast) from control device 316, and may utilize energy from the activation signal to obtain an updated temperature measurement and generate a wireless response signal including the updated temperature measurement to control device 316. The communication circuitry may be embedded within substrate 320.

[0032] Figure 4 is based on Figure 31 and 12. The embodiment shown is an isometric perspective view of the first power terminal 204A and the thermal sensor 312 associated with the first power terminal 204A. The following description of the first power terminal 204A and the thermal sensor 312 can also be applied to the second power terminal 204B ( Figure 3 as shown) and a thermal sensor 312 bent along the second power terminal 204B.

[0033] The cylindrical shaft 304 extends from the head 302 to the mating end 402 of the power terminal 204A. Due to the various features of the shaft 304 and the housing 202 ( Figure 3 The shaft 304 may optionally have a varying diameter along its length to allow for spacing tolerances within the range shown. For example, the shaft 304 in the illustrated embodiment has a radially outwardly extending flange 406 that has a larger diameter than portions of the shaft 304 on either side of the flange 406. The shaft 304 defines a pin-shaped contact 404 in the illustrated embodiment. The contact pin 404 extends to the mating end 402 and is configured to engage the mating connector 112 ( Figure 1 In an alternative embodiment, the shaft 304 may have other types of contacts at the mating end 402, such as blades, spring beams, sockets, etc.

[0034] In the illustrated embodiment, the head 302 of the power terminal 204A is a separate component from the shaft 304. The shaft 304 is received in the opening 408 in the head 302 to mechanically couple the two components together. The shaft 304 can be threadedly connected to the threads in the opening 408, or connected via an interference fit, adhesive, welding or other chemical bonding methods. In an alternative embodiment, the power terminal 204A can be a single-piece, integral structure so that the shaft 304 is integrated with the head 302 without the need for a joining operation to couple the two components. The power terminal 204A is composed of one or more metals.

[0035] In the illustrated embodiment, the thermal sensor 312 is disposed proximate to the head 302 and does not interfere with the mating of the pin contact 404 with the complementary mating contact. In alternative embodiments, the thermal sensor 312 may be positioned away from the head 302 (e.g., closer to the mating end 402). The substrate 320 of the thermal sensor 312 is flexible and bends along at least a portion of the outer surface 314 of the cylindrical shaft 304. In an embodiment, the substrate 320 wraps around the entire perimeter (e.g., circumference) of the shaft 304, although it is recognized that in Figure 4 Only about half of the circumference of the shaft 304 is visible in the figure. Alternatively, the substrate 320 may be curved along only a sub-portion of the circumference of the shaft 304, such as along half or less than half of the circumference. The substrate 320 may be or include a polymer film, such as a polyimide film. The substrate 320 may have material properties that enable the substrate 320 to provide electrical insulation between the sensing element 322 and the power supply terminal 204A.

[0036] The sensing element 322 is mounted on the substrate 320. The sensing element 322 can be configured to measure the temperature of the power terminal 204A based on the resistance of the sensing element 322. The sensing element 322 can be or include a thermistor, a thermocouple, a resistance temperature detector (RTD), a conductive film trace or electrode, etc. In a non-limiting example embodiment, the sensing element 322 can be a conductive film formed directly on the substrate 320 by screen printing. For example, the conductive film can be composed of conductive ink, and the resistance of the conductive film can change according to the temperature. The sensing element 322 can have a relatively thin thickness. In an embodiment where the sensing element is a conductive film, the thickness of the sensing element 322 on the substrate 320 can be on the order of microns. In the illustrated embodiment, the sensing element 322 is positioned relative to the power terminal 204A so that the sensing element 322 is aligned with the axis 304 that generally faces the second power terminal 204B ( Figure 3 Although the sensing element 322 is Figure 4 The sensing element 322 may have a generally square shape, but the sensing element 322 may be more elongated along the length of the substrate 320 so that the ratio of the sensing element 322 to the axis 304 is Figure 4 The sensing element 322 may have a relatively large surface area to density (e.g., thickness) ratio, which enables the sensing element 322 to quickly adjust to temperature changes on or around the shaft 304. The rapid temperature adjustment of the sensing element 322 advantageously allows for a shorter sensor response time (e.g., less hysteresis). In an alternative embodiment, the thermal sensor 312 may include multiple sensing elements 322 on the substrate 320, rather than just one. In an alternative embodiment, the multiple sensing elements 322 may be spaced apart from each other around the circumference of the shaft 304.

[0037] The thermal sensor 312 may include a conductive element 410, such as a trace, embedded in the substrate 320. The conductive element 410 may be exposed along a surface of the substrate 320 or recessed relative to the surface and encapsulated within the material of the substrate 320. The conductive element 410 is electrically connected to the sensing element 322 and extends from the sensing element 322 to the wire 318. The conductive element 410 transmits an electrical signal representing temperature data from the sensing element 322 to the wire 318 to communicate with the control device 316 ( Figure 3 In an alternative embodiment without wire 318 , conductive element 410 may be connected to wireless communication circuitry embedded on substrate 320 .

[0038] Figure 5 is along Figure 35. The cross section extends through the first and second power terminals 204A, 204B and the two thermal sensors 312. More specifically, the cross section extends through each substrate 320 of the two thermal sensors 312 at two different locations along opposite sides of the corresponding cylindrical axis 304.

[0039] The substrate 320 of each thermal sensor 312 is a film, plate or sheet having a component side 502 and a mounting side 504 opposite the component side 502. The corresponding sensing element 322 is mounted on the component side 502 of the substrate 320. For the purpose of illustration, Figure 5 The thickness of the sensing element 322 protruding from the corresponding substrate 320 is exaggerated in FIG, because the sensing element 322 can be as thin as a few microns in one or more embodiments. The mounting side 504 of the substrate 320 is mounted to the outer surface 314 of the corresponding cylindrical shaft 304. The mounting side 504 can be directly engaged with the outer surface 314, and / or can be indirectly engaged with the outer surface 314 via an intermediate adhesive layer (not shown) that bonds the substrate 320 to the shaft 304. The adhesive can be an epoxy or other adhesive material having heat-resistant properties to withstand the high temperature of the shaft 304 during charging operations. For example, one or more areas of the substrate 320 can directly engage the outer surface 314, and one or more other areas of the substrate 320 can indirectly engage the outer surface 314 through the adhesive. The adhesive can fix the thermal sensor 312 in a fixed position on the corresponding shaft 304 of the power terminal 204.

[0040] Because the sensing element 322 is mounted on the component side 502 of the substrate 320, the substrate 320 extends between the axis 304 of the corresponding power terminal 204 and the sensing element 322. The substrate 320 can provide electrical insulation between the power terminal 204 and the sensing element 322 to reduce the negative effects of electromagnetic interference on the sensing element 322 and the associated temperature sensing circuit. Due to the insulation provided by the substrate 320, the sensing element 322 can be positioned close to the power terminal 204, such as Figure 5 For example, the sensing element 322 may be separated from the outer surface 314 of the shaft 304 only by the relatively thin thickness of the substrate 320 .

[0041] The sensing element 322 of the thermal sensor 312 according to the embodiments described herein can be positioned closer to the power terminal 204 than the thermal sensors of the known charging inlet, and the thermal gradient between the outer surface 314 of the power terminal 204 and the sensing element 322 can be smaller than the known thermal sensors. As a result, the thermal sensor 312 described herein can provide more accurate temperature measurements with faster response times (e.g., less lag time) than the known thermal sensors.

[0042] In the illustrated embodiment, the sensing element 322 of the thermal sensor 312 is disposed between the two power terminals 204A, 204B. For example, the sensing element 322 of the first thermal sensor 312A mounted to the first power terminal 204A is positioned on the substrate 320 along the inner region 512 of its cylindrical axis 304 that generally faces the second power terminal 204B. Similarly, the sensing element 322 of the second thermal sensor 312B mounted to the second power terminal 204B is positioned on the substrate 320 along the inner region 512 of its cylindrical axis 304 that generally faces the first power terminal 204A. The sensing element 322 may be located in the space between the two power terminals 204A, 204B because the space may absorb heat from the two power terminals 204A, 204B, thereby making the space one of the hottest areas (if not the hottest) of the charging inlet 110.

[0043] In the illustrated embodiment, the charging inlet 110 further includes a secondary lock 514 configured to secure the power terminals 204A, 204B to the housing 202 ( Figure 3 The secondary lock 514 includes two inner edges 516 that extend into an annular groove 518 of the shaft 304 of the power terminals 204A, 204B. Each annular groove 518 is defined between the flange 406 of the corresponding shaft 304 and the shoulder 520 of the shaft 304. The shoulder 520 is axially located between the flange 406 and the head 302. The inner edge 516 is configured to engage the flange 406 and / or the shoulder 520 of the shaft 304 to inhibit axial movement of the shaft 304 relative to the secondary lock 514. The thermal sensor 312 is axially disposed between the inner edge 516 of the secondary lock 514 and the head 302 of the power terminals 204A, 204B. In an embodiment where the thermal sensor 312 is mounted to the shaft 304 without using an adhesive, the axial movement of the thermal sensor 312 can be limited to the gap distance between the head 302 and the secondary lock 514. For example, the base plate 320 may be wrapped around the shaft 304 and may be allowed to rotate and / or slide axially relative to the shaft 304 in the space between the head 302 and the secondary lock 514 .

[0044] Figure 6 FIG. 2 is a top cross-sectional view of one of the thermal sensors 312 bent along an outer surface 314 of one of the power terminals 204 according to an embodiment. The cross section extends through the cylindrical axis 314 of the power terminal 204. The power terminal 204 may represent Figure 5Any one of the two power terminals 204A, 204B of the charging inlet 110 shown. The substrate 320 of the thermal sensor 312 is elongated to extend from a first end 602 of the substrate 320 to a second end 604 opposite the first end 602. In the embodiment shown, the substrate 320 wraps around almost the entire circumference of the shaft 304. The first end 602 of the substrate 320 is close to the second end 604, but the two ends 602, 604 do not overlap. The substrate 320 can be mounted on the outer surface 314 of the shaft 304 by an adhesive.

[0045] Figure 7 is a top cross-sectional view of one of the thermal sensors 312 bent along the outer surface 314 of one of the power terminals 204 according to another embodiment. In the illustrated embodiment, the first end 602 and the second end 604 of the substrate 320 overlap each other. The first section 608 of the substrate 320 at the first end 602 overlaps the second section 610 of the substrate 320 at the second end 604. The first section 608 can be attached to the second section 610 to fix the substrate 320 in an annular or ring shape around the shaft 304 of the power terminal 204. The first section 608 can be attached to the second section 610 by an adhesive, a fastener, a clamp, etc. In the illustrated embodiment, the substrate 320 may not require an adhesive layer between the substrate 320 and the shaft 304 to mount the substrate 320 to the shaft 304. For example, the substrate 320 is fixed in an annular shape around the shaft 304 by the engagement between the first section 608 and the second section 610, and the axial movement of the substrate 320 relative to the shaft 304 is limited by the head 302 and the secondary lock 514, as described above with reference to Figure 5 described.

[0046] Figure 8 is an isometric view of one of the thermal sensors 312 in an uninstalled and unassembled state according to another embodiment. Figure 8 The embodiment shown is similar to Figure 7 The embodiment shown, except that the first segment 608 is configured to be attached to the second segment 610 by structural features to define an annular shape without the use of discrete fasteners or adhesives. For example, the substrate 320 is formed so that the first segment 608 includes a tab 614, and the substrate 320 defines a hole 616 along the second segment 610. The hole 616 is sized to accommodate the tab 614. The tab 614 has two ears 618 that protrude laterally outward away from each other. The sensing element 322 is disposed on the substrate 320 spaced apart from the first segment 608 and the second segment 610. In one embodiment, the thermal sensor 312 is mounted to one of the power terminals 204 by wrapping the substrate 320 around the cylindrical shaft 304 of the terminal 204. Similar to Figure 7In the illustrated embodiment, the base plate 320 is long enough so that the tab 614 overlaps the second section 610. The tab 614 is inserted into the hole 616. The ears 618 engage and snap onto the area of ​​the base plate 320 around the hole 616 to secure the base plate 320 in an annular shape around the shaft 304.

[0047] In the illustrated embodiment, the sensing element 322 includes a conductive film trace that can be mounted to the substrate 320 via in-situ screen printing or other deposition process. The conductive film trace can have conductive particles embedded in a polymer binder. The sensing element 322 also has two electrode leads 323 that can also be screen printed. The leads 323 can have pads for termination to wires (e.g., Figure 4 Wire 318 shown). Figure 8 As shown, sensing element 322 is elongated along the length of substrate 320, which allows sensing element 322 to overlap a greater amount of the circumference of cylindrical shaft 304 than if sensing element 322 were more compact.

[0048] Fig. 9 is a top cross-sectional view of two thermal sensors 312 bent along outer surfaces 314 of respective power terminals 204A, 204B according to yet another embodiment. Fig. 9 The embodiment shown is Figure 6 The illustrated embodiment is similar except that the substrates 320 of the thermal sensors 312 wrap around less than half of the circumference of the respective cylindrical shaft 304. For example, each substrate 320 is bent along a sub-portion of the circumference that includes the inner region 512 of the respective cylindrical shaft 304 that faces the adjacent power terminals. The substrates 320 may be mounted to the shaft 304 by using an adhesive.

[0049] Fig.10 According to an alternative embodiment, Figure 3 5-5 in FIG. 5 is a cross-sectional view of a portion of the charging inlet 110. The substrate 320 of the thermal sensor 312 in the illustrated embodiment is flexible and bends around the outer surface 314 of the cylindrical shaft 304 of the power terminals 204A, 204B, similar to Figures 3 to 9 However, with Figures 3 to 9Unlike the illustrated embodiment, the substrate 320 of the thermal sensor 312 in the illustrated embodiment is not mounted to the shaft 304 or any other portion of the power terminals 204A, 204B. The substrate 320 is mounted to the secondary lock 514. For example, the substrate 320 is mounted along the curved surface 802 of the secondary lock 514. Each curved surface 802 faces and surrounds at least a portion of the outer surface 314 of the shaft 304 of the corresponding power terminal 204A, 204B. The substrate 320 can be mounted to the curved surface 802 by an adhesive or an interference fit. When mounted, the substrate 320 is disposed between the curved surface 802 of the secondary lock 514 and the outer surface 314 of the shaft 304. The secondary lock 514 does not extend between the thermal sensor 312 and the shaft 304, and therefore does not interfere with the accuracy or response time of the thermal sensor 312. In the illustrated embodiment, the component side 502 of the substrate 320 on which the sensing element 322 is disposed faces the cylindrical shaft 304. In alternative embodiments, the orientation of substrate 320 may be flipped such that substrate 320 is located between sensing element 322 and corresponding shaft 304 to provide electrical insulation for sensing element 322 .

[0050] Fig.11 is an enlarged perspective view of a portion of a charging inlet 110 according to another alternative embodiment. Fig.11 , one thermal sensor 312 is visible. The thermal sensor 312 is mounted to the second power terminal 204B. Similar to the above embodiment, the substrate 320 of the thermal sensor 312 is bent along the contour of a portion of the periphery of the power terminal 204B. Another thermal sensor 312 may be mounted on the first power terminal 204A, but Fig.11 Unlike the above embodiment, Fig.11 The thermal sensor 312 in the embodiment is mounted to the outer surface 902 of the head 302 of the power terminal 204B. The substrate 320 is bent along the contour of the outer surface 902 of the head 302. The substrate 320 is spaced apart from the cylindrical axis 304 of the power terminal 204B. The outer surface 902 can be along the edge of the head 302 facing the first power terminal 204A. For example, the sensing element 322 can be positioned along an area near the first power terminal 204A. The substrate 320 on the outer surface 902 is spaced apart from the termination area 306 of the head 302.

Claims

1. A charging inlet (110), include: a power terminal (204) configured to releasably engage a mating contact of an external power source (104), the power terminal comprising a cylindrical shaft (304); and A thermal sensor (312) for monitoring the temperature of a power terminal, the thermal sensor comprising a substrate (320) and a sensing element (322) mounted on the substrate and extending along the length of the substrate, wherein the substrate is flexible and bends along at least a portion of an outer surface (314) of a cylindrical shaft; wherein the substrate (320) is wrapped around the entire circumference of the cylindrical shaft (304), and wherein the substrate (320) extends from a first end (602) of the substrate to a second end (604) of the substrate opposite the first end, wherein a first section (608) of the substrate at or near the first end is secured to a second section (610) of the substrate at or near the second end to secure the thermal sensor (312) around the cylindrical shaft (304).

2. The charging inlet (110) according to claim 1, in, The substrate (320) has a component side (502) and a mounting side (504) opposite to the component side, the sensing element (322) is mounted on the component side of the substrate, wherein the mounting side of the substrate is mounted to the outer surface (314) of the cylindrical shaft (304).

3. The charging inlet (110) according to claim 2, in, The mounting side (504) of the base plate (320) is mounted to the outer surface (314) of the cylindrical shaft (304) by adhesive.

4. The charging inlet (110) according to claim 1, in, The substrate (320) is a polyimide film.

5. The charging inlet (110) according to claim 1, in, The first section (608) of the base plate (320) includes a tab (614), and the second section (610) of the base plate defines a hole (616) through which the tab is inserted and engages the base plate around the hole to secure the first section to the second section.

6. The charging inlet (110) according to claim 1, in, The power terminal (204) is a first power terminal (204A), and the charging inlet includes a second power terminal (204B) disposed adjacent to the first power terminal, wherein the sensing element (322) of the thermal sensor (312) is located between the first and second power terminals.

7. The charging inlet (110) of claim 1, further comprising a secondary lock (514) overlapping and supporting a flange (406) of the power terminal (204) to secure the power terminal in a fixed position, the secondary lock having a curved surface (802) facing and surrounding at least a portion of an outer surface (314) of the cylindrical shaft (304), in, The base plate (320) is mounted to the curved surface of the secondary lock adjacent to the outer surface of the cylindrical shaft.

8. The charging inlet (110) according to claim 1, in, The sensing element (322) is a thermistor or a thermocouple.

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