Terminal design for adjusting wire harness protection time

Abstract

The invention relates to a terminal design for adjusting wire harness protection time, in particular to a terminal assembly arranged for an automotive wire harness, comprising: a substrate; an improved terminal arranged in a plate structure, the plate structure being arranged on the substrate and extending perpendicularly with respect to a plane of the substrate; and a resettable fuse component comprising a polymer positive temperature coefficient (PPTC) material and coupled in series with the improved terminal.

Description

Technical Field

[0001] Embodiments relate to the field of circuit protection devices, and more particularly to circuit protection devices in automotive wiring harnesses. Background Art

[0002] Today, automobiles, including electric vehicles (EVs), use complex wiring harnesses that must be protected from damage caused by different faults, such as when a short circuit occurs in the vehicle wiring. Some types of wiring harnesses use polymer positive temperature coefficient (PPTC) devices as protection, which can act as resettable fuses. When a fault occurs, the driving temperature exceeds a certain trip temperature of the PPTC device, which will lock the device in a high resistance state. Once the fault is eliminated and power is restored, the PPTC device will automatically reset and the protected system will resume normal operation. However, for different applications, it may be desirable to control the time required for the protection device to trip (trip time). Control of the trip time may be important so that the protection device does not trip too quickly on the one hand, or too slowly on the other hand.

[0003] With regard to the above and other considerations, the present disclosure is provided. Summary of the invention

[0004] In one embodiment, a terminal assembly arranged for use in an automotive wiring harness is provided. The terminal assembly may include a substrate; an improved terminal including a plate structure arranged on the substrate and extending perpendicularly relative to the plane of the substrate; and a resettable fuse component including a polymer positive temperature coefficient (PPTC) material and coupled in series with the improved terminal.

[0005] In another embodiment, a terminal assembly for an automotive wiring harness is provided, which includes a substrate and an improved terminal, the improved terminal including a plate structure arranged on the substrate and extending perpendicularly relative to the plane of the substrate. The terminal assembly may include a wiring assembly coupled to the substrate; and a resettable fuse component including a polymer positive temperature coefficient (PPTC) material and coupled in series with the wiring assembly and the improved terminal.

[0006] In another embodiment, a terminal assembly of an automotive wiring harness may include a substrate arranged as a printed circuit board, and a wiring assembly including a pair of wires coupled to the substrate. The terminal assembly may also include an improved terminal, the improved terminal including a plate structure arranged as a pair of plates on the substrate and extending vertically relative to the plane of the substrate. The terminal assembly may further include a polymer positive temperature coefficient (PPTC) structure arranged between the pair of plates, wherein the PPTC structure is coupled in series with the improved terminal, and wherein the PPTC structure extends to the outside of the pair of plates. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1A A known terminal design is shown;

[0008] Figure 1B shows a terminal design for use with embodiments of the present disclosure;

[0009] Figure 1C Another terminal design for use with other embodiments of the present disclosure is shown;

[0010] Figure 1D Another terminal design for use with additional embodiments of the present disclosure is shown;

[0011] Figure 1E shows an additional terminal design according to a further embodiment of the present disclosure; and

[0012] Figure 2 The trip time as a function of current of a resettable fuse is shown for various terminal designs. DETAILED DESCRIPTION

[0013] The present embodiment will be described more fully below with reference to the accompanying drawings, in which exemplary embodiments are shown. These embodiments should not be construed as being limited to the embodiments set forth herein. On the contrary, these embodiments are provided to make the present disclosure thorough and complete and to fully convey its scope to those skilled in the art. In the accompanying drawings, the same numbers always refer to the same elements.

[0014] In the following description and / or claims, the terms "on ... ", "overlying", "disposed on ... ", and "above ... " may be used in the following description and claims. "On ... ", "overlying", "disposed on ... ", and "above ... " may be used to indicate that two or more elements are in direct physical contact with each other. In addition, the terms "on ... ", "overlying", "disposed on ... ", and "above ... " may indicate that two or more elements are not in direct contact with each other. For example, "above ... " may indicate that an element is above another element, but does not contact each other, and there may be another or more elements between the two elements. In addition, although the scope of the claimed subject matter is not limited in this regard, the term "and / or" may mean "and", may mean "or", may mean "exclusive or", may mean "one", may mean "some, but not all", may mean "neither", and / or may mean "both".

[0015] In various embodiments, a novel harness protection arrangement for an automotive wiring harness is shown. The harness protection arrangement is based on a terminal assembly that can employ a resettable fuse component. According to an embodiment of the present disclosure, the resettable fuse component is based on a PPTC device that can be electrically coupled in series with a wiring assembly and a given terminal of a wiring harness. Some terminal designs can be based on copper-plated steel.

[0016] The inventors have discovered that certain components of a terminal assembly for an automotive wiring harness can be improved in a manner that adjusts the protective characteristics of the terminal assembly. As used herein, a "terminal assembly" may refer to a circuit including a terminal, a resettable fuse (particularly a PPTC device), and wiring connected to the terminal. Specifically, by improving the design of the terminal, the type of wiring, and / or the use of a cap in a resettable fuse, the trip time of the resettable fuse can be substantially or precisely adjusted according to the desired application.

[0017] As background, known PPTC devices are characterized by a transition between a relatively low resistance state (the term "resistance" may be used herein to refer to resistance) to a relatively high resistance state, wherein the transition occurs at a given temperature, generally referred to as a trip temperature. As is known in the art, the absolute resistance of a PPTC device and the relative change in resistance and trip temperature can be adjusted by selecting an appropriate polymer matrix, an appropriate conductive filler, and a suitable composition for the PPTC device. In a temperature range below the trip temperature, the PPTC device will maintain a relatively low resistance, while in a temperature range above the trip temperature, the PPTC device will have a relatively high resistance. In some examples, the resistance above the trip temperature may be 10 times, 100 times, 1000 times, or 10,000 times the resistance of the PPTC device below the trip temperature. In various non-limiting embodiments, the PPTC device may be formed of a polyvinylidene fluoride (PVDF) matrix and a carbon filler.

[0018] Turning to the attached figure, Figure 1A shows a known terminal design, while Figure 1B shows a terminal design for use with embodiments of the present disclosure, Figure 1C Another terminal design for use with other embodiments of the present disclosure is shown, and Figure 1D Another terminal design for use with additional embodiments of the present disclosure is shown. The terminal arrangement 100 includes a terminal 102, which can be formed of copper plates as shown, and is designated as a standard terminal design. In this example, a PPTC structure 103 (which can be a plate-like layer) is disposed between the copper plates forming the terminal 102.

[0019] exist Figure 1B, an improved terminal design is shown as terminal arrangement 120 and is designated as a 3 / 4 standard design. In this configuration, the terminal 102 extends just over about 3 / 4 of the body of the PPTC structure 103, leaving an exposed portion 104. In this example, the exposed portion 104 extends horizontally above the terminal 102. In other words, about 1 / 4 of the PPTC structure extends outside of the pair of plates that form the terminal 102.

[0020] exist Figure 1C , an improved terminal design is shown as terminal arrangement 130 and is designated as a 1 / 2 standard design. In this configuration, the terminal 102 extends just over about 1 / 2 of the body of the PPTC structure 103, leaving an exposed portion 104. In this example, the exposed portion 104 also extends horizontally above the terminal 102.

[0021] Finally, in Figure 1D , an improved terminal design is shown as terminal arrangement 140 and is based on the TD0917 terminal. In this configuration, the terminal 102 only extends to less than 1 / 2 of the body of the PPTC structure 103, leaving an exposed portion 104. In this example, the exposed portion 104 extends vertically adjacent to the terminal 102.

[0022] exist Figures 1A-1D In each design, the terminal 102 can be connected to the external lead 106 using a substrate 108 (such as a printed circuit board as shown). For example, the external lead 106 can form part of a wiring assembly of an automotive wiring harness. Figures 1A-1D In all designs, the terminal 102 is provided as a plate on the substrate 108 and extends perpendicularly relative to the substrate 108 .

[0023] It should be noted that Figure 1B-1D In each design, the exposed portion 104 may include a thin metal foil disposed on the PPTC body (not visible) to serve as an internal electrode in contact with the terminal 102. Figures 1A-1D In the design of , different sizes and configurations of the terminals 102 may result in different tripping times for the same fault current. These results will be discussed below.

[0024] Figure 1E 1 shows an additional terminal design according to a further embodiment of the present disclosure. The terminal design 150 may be similar to the aforementioned Figures 1A-1D 105, wherein similar elements are labeled the same. In this case, the PPTC component (not visible) can be arranged as a blade-type fuse device enclosed in a cap 105, the role of which will be discussed further below.

[0025] According to various embodiments of the present disclosure, Table I gives a summary of the measurements of the tripping times of different terminal assemblies. The different columns in Table I are organized to illustrate the tripping times according to different current levels from 25 amperes (A) to 150A. The different rows in Table I are organized according to different terminal designs and different wire cross-sectional areas of two different wires. The minimum tripping time and the maximum tripping time at different current levels are also shown in Table I. As shown in Table I, when using AWG9 wire, the tripping time produced by the standard terminal design exceeds the specifications of all current levels, which means that the tripping time in this case is always greater than the maximum value of the specifications at any given current. It should be noted that the use of 3 / 4 standard terminals, 1 / 2 standard terminals or TD0917 terminals at all current levels reduces the tripping time relative to the use of standard terminals. In addition, the change from AWG9 wire to AWG13 wire (with a smaller cross-section) reduces the tripping time in all cases, and the effect is more obvious at currents of 50A or less. In the example shown, for current values ​​in the range of 34A to 50A, using the 1 / 2 standard terminals or TD0917 results in trip times within specification in all cases, while using the 3 / 4 standard terminals results in trip times within specification at 34A and 40A.

[0026] Turning to Table II, it shows the trip times for different PPTC device terminal assembly arrangements for blade type fuses BD280-25 configurations BD1, BD2, and BD3 with and without caps, again showing a variety of different current levels. In various embodiments, for example, the cap material may be PBT or nylon.

[0027] In all samples shown, AWG9 wire was used. In this set of examples, all devices were configured to provide trip times within specification limits at currents up to 50A. The use of the cap can be seen to increase the trip time to some extent compared to samples without the cap, and this difference can be attributed to the fact that the cap provides better thermal conduction, so the PPTC device takes longer to exceed the trip temperature.

[0028]

[0029]

[0030] Form I

[0031]

[0032] Form II

[0033] Turning to Table III, a comparison of the trip times for the same set of PPTC devices without caps as in Table II is shown, this time comparing the effect of changing the wire size from AWG9 to AWG13. These results show that the smaller area wire (AWG13) produces a shorter trip time than the larger area wire (AWG9).

[0034]

[0035] Form III

[0036] Turning to Table IV, a comparison of the trip times of PPTC devices with caps is shown, this time comparing the effect of changing the wire size from AWG9 to AWG13. These results show that the smaller area wire (AWG13) also produces a shorter trip time compared to the larger area wire (AWG9).

[0037]

[0038] Form IV

[0039] Figure 2 A graph of the trip time of a resettable fuse as a function of the current for various terminal designs is shown. In the figure, the two dashed lines represent the boundaries of the specification minimum and specification maximum values ​​according to the current. It should be noted that the trip time is expressed in a logarithmic scale. As shown, the terminal assembly based on the standard terminal and AWG9 wire produces excessive trip times for currents above 34A, which does not meet the requirements (i.e., is between the specification minimum and specification maximum). By changing the combination of wire size and / or changing the terminal design, the terminal assembly design according to the present embodiment can generally meet requirements up to 50A.

[0040] In particular, AWG13 wire can be adopted to meet the operating time requirements of the ISO10924-3 standard, while for a device rated at 25A, changes in wire diameter and terminal design can result in significant changes in trip time at currents ranging from 34A to 50A. In addition, the use of a cap can help to significantly increase the trip time at current levels between 34A and 50A by providing better thermal conduction. Finally, at higher current levels, such as 87.5A to 150A, the trip time will be almost entirely determined by the PPTC core characteristics of the PPTC device and will not depend on the presence of the cap.

[0041] Although the present embodiment has been disclosed with reference to certain embodiments, many improvements, changes and variations may be made to the described embodiments without departing from the field and scope of the present disclosure as defined in the appended claims. Therefore, the present embodiment is not limited to the described embodiments and may have the full scope defined by the language of the appended claims and their equivalents.

Claims

1. A terminal assembly arranged for use in an automotive wiring harness, the terminal assembly comprising: substrate; An improved terminal comprising a plate structure disposed on a substrate and extending perpendicularly relative to the plane of the substrate; as well as A resettable fuse component includes a polymer positive temperature coefficient (PPTC) material and is coupled in series with the improved terminal.

2. The terminal assembly according to claim 1, wherein: The improved terminal includes a 3 / 4 standard design.

3. The terminal assembly according to claim 1, wherein: The improved terminal comprises a 1 / 2 standard design.

4. The terminal assembly according to claim 1, wherein: The improved terminal includes the TD0917 design.

5. The terminal assembly according to claim 1, wherein: The terminal assembly further includes AWG13 wire.

6. The terminal assembly according to claim 1, wherein: The resettable fuse component includes a cap.

7. The terminal assembly according to claim 1, wherein: The improved terminal includes a set of copper plates, and wherein the resettable fuse component includes a PPTC body disposed between the set of copper plates.

8. The terminal assembly according to claim 1, further comprising a substrate, wherein The improved terminal is provided as a plate on a substrate and extends perpendicularly with respect to the substrate.

9. The terminal assembly according to claim 8, wherein: The substrate is a printed circuit board.

10. The terminal assembly according to claim 1, wherein: The resettable fuse component is provided with a cap.

11. A terminal assembly for an automobile wiring harness, comprising: substrate; An improved terminal comprising a plate structure disposed on a substrate and extending perpendicularly relative to the plane of the substrate; a wiring assembly coupled to the substrate; as well as A resettable fuse component includes a polymer positive temperature coefficient (PPTC) material and is coupled in series with the wiring assembly and the improved terminal.

12. The terminal assembly according to claim 11, wherein: The improved terminal includes a 3 / 4 standard design.

13. The terminal assembly according to claim 11, wherein: The improved terminal comprises a 1 / 2 standard design.

14. The terminal assembly according to claim 11, wherein: The improved terminal includes the TD0917 design.

15. The terminal assembly according to claim 11, wherein: The wiring assembly includes AWG13 wire.

16. The terminal assembly according to claim 11, wherein: The resettable fuse component includes a cap.

17. The terminal assembly according to claim 11, wherein: The improved terminal includes a set of copper plates, and wherein the resettable fuse component includes a PPTC body disposed between the set of copper plates.

18. The terminal assembly according to claim 11, further comprising a substrate, wherein: The improved terminal is provided as a plate on a substrate and extends perpendicularly with respect to the substrate.

19. The terminal assembly according to claim 18, wherein: The substrate is a printed circuit board.

20. A terminal assembly for an automobile wiring harness, comprising: a substrate arranged as a printed circuit board; a wiring assembly coupled to the substrate, comprising a pair of wires; An improved terminal comprising a plate structure arranged as a pair of plates on a substrate and extending perpendicularly relative to the plane of the substrate; as well as A polymer positive temperature coefficient (PPTC) structure is disposed between the pair of plates, wherein the PPTC structure is coupled in series with the improved terminal, and wherein the PPTC structure extends outside of the pair of plates.

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