Electric connection part

Abstract

To provide an electric connection part capable of inhibiting a red heat part of an electric wire connection part, in which connection failure occurs, from proceeding to the electric wire side.SOLUTION: An electric connection part according to the disclosure includes: one or multiple electric wire connection parts; an electric wire connected to each electric wire connection part; a holding base which holds the electric wire connection part; small diameter conductors each of which has a conductor part having a cross sectional area smaller than that of the electric wire and is disposed in the electric connection part with one end side contacting with the electric wire; and a temperature detection element connected to the other end side of the small diameter conductor.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to an electrical connection part.

Background Art

[0002] A conventional electrical connection part disclosed in Patent Document 1 below includes a metal fitting having a plurality of wire connection parts and leg parts for supporting the leg parts, and a substrate having a copper foil pattern to which the leg parts are soldered. It is a board-mounted terminal block that electrically connects wires connected to the wire connection parts. The substrate is provided with a copper foil pattern for mounting a temperature detection element arranged to ensure an insulating creepage distance from the copper foil pattern, a temperature detection element soldered to the copper foil pattern, and a connector for outputting the measurement result of the temperature detection element. The temperature detection element detects an increase in temperature due to poor contact at the wire connection part.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The technique of Patent Document 1 is effective for detection by a temperature detection element because heat generation is large when a large current is used. However, in the case of a small current, a red-hot phenomenon occurs due to the formation of metal oxides such as cuprous oxide at the wire connection part where poor contact has occurred. In this case, since the temperature becomes locally high, it is difficult to detect the temperature with the configuration of the prior art. Therefore, a configuration capable of detecting the red-hot phenomenon caused by metal oxides generated by a small current is required.

[0005] The present disclosure has been made to solve the above-described problems. An object of the present disclosure is to provide an electrical connection part capable of suppressing the progression of the red-hot part of a wire connection part where poor contact has occurred to the wire side.

Means for Solving the Problems

[0006] The electrical connection part according to the present disclosure includes one or more wire connection parts, wires connected to each of the wire connection parts, a holding base for holding the wire connection parts, a thin-diameter conductor having a smaller cross-sectional area of the conductor part than the wire and arranged at the wire connection part in a state where one end side is in contact with the wire, and a temperature detection element connected to the other end side of the thin-diameter conductor. It is provided with an electrical connection part.

Effect of the Invention

[0007] According to the present disclosure, it is possible to provide an electrical connection part capable of suppressing the progress of the red-hot part of the wire connection part where poor contact has occurred to the wire side.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0009] Hereinafter, embodiments will be described with reference to the drawings. The same reference numerals are given to common or corresponding elements in each figure to simplify or omit the description. The configurations shown in the following embodiments are examples of the technical idea according to the present disclosure, and it is possible to combine them with other known technologies, and it is also possible to combine a plurality of technical ideas described in the present disclosure. Also, within the scope not departing from the gist of the present disclosure, it is possible to omit or change a part of the configuration.

[0010] Embodiment 1. FIG. 1 is a perspective view schematically showing an electrical connection part according to Embodiment 1. As shown in FIG. 1, a terminal block 10 which is the electrical connection part in Embodiment 1 includes a wire connection part 1 composed of a screw 2 and a holding base 4, a wire 3 connected to the wire connection part 1, a small-diameter conductor 5 having a smaller cross-sectional area of the conductor part than that of the wire 3, and a temperature detection element 6 connected to the small-diameter conductor 5. A screw hole into which the screw 2 is screwed is formed in the holding base 4. The wire connection part 1 is composed of the screw 2 and the holding base 4 around the screw hole. A plurality of wire connection parts 1 may be provided on one terminal block 10. One end side of the small-diameter conductor 5 is arranged in the wire connection part 1 in a state of being in contact with the wire 3. The temperature detection element 6 is connected to the other end side of the small-diameter conductor 5. The tip of the wire 3 may be wound around the shaft part of the screw 2. A fitting attached to the tip of the wire 3 may be in contact with the screw 2.

[0011] In Embodiment 1, the wire connection part 1 secures electrical continuity between the wire connection part 1 and the wire 3 by sandwiching and holding the wire 3 between the seating surface of the screw 2 and the holding base 4 by the fastening force of the screw 2. Here, in the wire connection part 1, if rotational looseness or non-rotational looseness of the screw 2 occurs due to poor mounting during wiring, external loads such as thermal cycles or vibrations, or aging effects such as deformation of the screw 2 or the holding base 4, the fastening force of the screw 2 decreases, and there is a concern that a contact failure may occur between the wire connection part 1 and the wire 3. When the operating current of the wire connection part 1 is small (generally 0.1 A to several A), a discharge occurs starting from the contact failure part and metal oxides are generated, and a red-hot phenomenon may occur where a locally high-temperature part of about 1000 °C is generated.

[0012] Here, the red-hot part generated by the red-hot phenomenon has a property of progressing and expanding toward the conductor side with a smaller cross-sectional area starting from between the conductors where the contact failure has occurred. For this reason, if no countermeasures are taken, there is a concern that the red-hot part will progress and expand along the wire 3 having a smaller cross-sectional area than the screw 2 or the holding base 4, causing ignition and burning of the coating of the wire 3 or components arranged near the wire 3.

[0013] In this way, the red-hot phenomenon caused by metal oxide is generated due to poor contact at the wire connection part 1, and the red-hot part expands over time. However, the red-hot part has the property of expanding in the direction where the cross-sectional area of the conductor is small. In the present embodiment, even if poor contact occurs at the wire connection part 1 and the red-hot phenomenon caused by metal oxide occurs, the red-hot part 5a progresses along the thin-diameter conductor 5 instead of the wire 3. Therefore, the risk of burning of the components connected to the other end of the wire 3 can be suppressed, and the detection accuracy of the temperature rise by the temperature detection element 6 connected to the other end of the thin-diameter conductor 5 can be improved.

[0014] In the present embodiment, thin-diameter conductors 5 are respectively installed at the upper end and the lower end of the wire connection part 1. The seat surface side of the screw 2 corresponds to the upper end of the wire connection part 1. The holding base 4 side corresponds to the lower end of the wire connection part 1.

[0015] Further, one end of the thin-diameter conductor 5 is circular so as to follow the shaft part of the screw 2. That is, the thin-diameter conductor 5 is installed around the wire connection part 1 over the entire circumference. Since the red-hot phenomenon occurs starting from the position where conduction cannot be finally ensured due to poor contact, it is difficult to predict at which position of the wire connection part 1 the red-hot phenomenon will occur. According to the configuration of Embodiment 1, since the thin-diameter conductor is circular so as to surround the outer shape of the shaft part of the screw 2, regardless of the starting position of the red-hot phenomenon, the red-hot part can be made to progress and expand toward the thin-diameter conductor 5 side. Also, since the thin-diameter conductors 5 are provided at both of the two places, i.e., the seat surface side of the screw 2 and the holding base 4 side, which are the contact positions sandwiching the wire 3 from above and below, regardless of whether the starting position of the red-hot phenomenon is on the seat surface side of the screw 2 or on the holding base 4 side, the red-hot part can be made to progress and expand toward the thin-diameter conductor 5 side.

[0016] The other end of the thin-diameter conductor 5 is connected to the temperature detection element 6 and also to a contact point 7 that is electrically conductive with the holding base 4. When the red-hot part progresses and expands along the thin-diameter conductor 5, the temperature near the temperature detection element 6 rises due to heat conduction within the thin-diameter conductor 5, so an abnormality can be detected. The reason for making the thin-diameter conductor 5 and the holding base 4 electrically conductive at the contact point 7 is to make the thin-diameter conductor 5 and the wire connection part 1 composed of the screw 2 and the holding base 4 at the same potential, so that the current continues to flow even after the red-hot phenomenon occurs. If the thin-diameter conductor 5 and the holding base 4 are not made electrically conductive, when a poor contact occurs at the wire connection part 1, the thin-diameter conductor 5 will be in an electrically floating state, and the red-hot part will progress and expand to the wire 3 or other unexpected paths, which may cause ignition and burning of combustibles in the vicinity.

[0017] The thin-diameter conductor 5 is preferably composed of a conductor material with high thermal conductivity. This is because the ease of heat transfer from the position where the red-hot phenomenon occurs to the temperature detection element 6 is determined by the thermal conductivity of the material. Also, the thin-diameter conductor 5 is preferably composed of a high melting point material. Specifically, as long as it is a material having a melting point exceeding about 1000°C, which is the highest temperature reached by the red-hot part, the thin-diameter conductor 5 will not melt even when the red-hot phenomenon occurs. If the thin-diameter conductor 5 melts, the red-hot part will progress and expand to the wire 3 or other unexpected paths, which may cause ignition and burning of combustibles in the vicinity.

[0018] In the illustrated example, thin-diameter conductors 5 are respectively installed at the upper end and the lower end of the wire connection part 1, and the two thin-diameter conductors 5 are connected to the temperature detection element 6. Thereby, it becomes possible to detect the red-hot phenomena at both the upper end and the lower end of the wire connection part 1 using one temperature detection element 6. Instead of the illustrated configuration, the thin-diameter conductor installed at the upper end of the wire connection part 1 and the thin-diameter conductor 5 installed at the lower end of the wire connection part 1 may be respectively connected to different temperature detection elements. By doing so, when the red-hot phenomenon occurs, the temperature rise of the temperature detection element 6 due to heat conduction becomes larger, and the accuracy of abnormality detection can be improved.

[0019] At the tip of the left end of the thin-diameter conductor 5 in FIG. 1, a similar wire connection portion 1 may be provided. By doing so, it becomes possible to detect the red-hot phenomenon of the wire connection portions 1 at a plurality of locations using one temperature detection element 6.

[0020] FIG. 2 is a functional block diagram of the electrical connection portion according to Embodiment 1. As shown in FIG. 2, the temperature detection element 6 is connected to the control unit 11. The switch 12 is connected to the control unit 11. The switch 12 is a switch capable of interrupting the energization to the wire connection portion 1. When the detected temperature of the temperature detection element 6 becomes a predetermined temperature or higher, the control unit 11 turns off the switch 12 to interrupt the energization to the wire connection portion 1. Thereby, it is possible to prevent current from continuously flowing through the contact failure portion. The control unit 11 and the switch 12 correspond to interruption means for interrupting the energization to the wire connection portion 1 when the detected temperature of the temperature detection element 6 becomes a predetermined temperature or higher in the above example.

[0021] Embodiment 2. Next, referring to FIGS. 3 and 4, Embodiment 2 will be described. The description will focus on the differences from Embodiment 1 described above, and the common descriptions will be simplified or omitted. Also, the same reference numerals will be given to the elements that are common or corresponding to the elements described above.

[0022] FIG. 3 is a front view schematically showing the electrical connection portion according to Embodiment 2. FIG. 4 is a front view schematically showing the electrical connection portion according to Embodiment 2.

[0023] In Embodiment 2, similar to Embodiment 1, in the wire connection portion 1, by sandwiching and holding the wire 3 and the thin-diameter conductor 5 between the seating surface of the screw 2 and the holding base 4 by the fastening force of the screw 2, the conductivity between the wire connection portion 1 and the wire 3 is ensured. As the thin-diameter conductor 5, thin-diameter conductors 5 having a smaller cross-sectional area than the wire 3 are provided at two locations on the seating surface side and the holding base 4 side of the screw 2 in the wire connection portion 1. Each thin-diameter conductor 5 has an air layer between it and the holding base 4 by the spacer 8, but is electrically connected to the holding base 4 via the contact point 7.

[0024] In the wire connection part 1, a schematic diagram of the case where the fastening force of the screw 2 acts and the wire 3 is correctly connected is shown in FIG. 3. In this case, since the thin-diameter conductor 5 is bent so as to be biased toward the holding base 4 by the fastening force of the screw 2, the thin-diameter conductor 5 on the seat surface side of the screw 2 contacts the seat surface of the screw 2, and the thin-diameter conductor 5 on the holding base 4 side contacts the holding base 4. Parts such as the thin-diameter conductor 5 and the spacer 8 are designed such that when the screw 2 is fastened, the deformation of the thin-diameter conductor 5 is within the elastic range. Therefore, if the screw 2 loosens and the fastening force is lost, the bending of the thin-diameter conductor 5 is eliminated.

[0025] In the wire connection part 1, a schematic diagram of the case where the screw 2 loosens and a red-hot phenomenon occurs is shown in FIG. 4. In this case, since the fastening force of the screw 2 is lost due to the loosening of the screw 2, the bending of the thin-diameter conductor 5 shown in FIG. 3 is eliminated. Therefore, an air layer exists between the seat surface of the screw 2 and the thin-diameter conductor 5 on the screw 2 side, and between the holding base 4 and the thin-diameter conductor 5 on the holding base 4 side, respectively. Thus, when the connection between the wire connection part 1 and the wire 3 becomes loose, the thin-diameter conductor 5 and the wire connection part 1 maintain a non-contact state between the wire connection part 1 and the contact point 7. Here, if the thin-diameter conductor 5 contacts the screw 2 or the holding base 4 when the red-hot phenomenon occurs, since the cross-sectional area of the screw 2 or the holding base 4 is larger than that of the wire 3, the red-hot part that has advanced along the thin-diameter conductor 5 to the contact part with the screw 2 or the holding base 4 does not advance further, and there is a concern that the red-hot part will advance toward the wire 3 side. On the other hand, according to the configuration of the second embodiment, when the screw 2 loosens, an air layer exists between the thin-diameter conductor 5 and the screw 2 or the holding base 4, so that the red-hot part does not advance toward the wire 3 side, and the red-hot part advances only along the thin-diameter conductor 5. Therefore, the risk of burning of the components connected to the other end of the wire 3 can be suppressed, and the accuracy of abnormality detection by the temperature detection element 6 connected to the other end of the thin-diameter conductor 5 can be improved.

[0026] Note that among the features of the above-described plurality of embodiments, two or more features that can be combined may be combined and implemented.

[0027] Hereinafter, aspects of the present disclosure will be collectively described as appendices.

[0028] (Appendix 1) One or more wire connection parts, Wires connected to each of the wire connection parts, A holding base for holding the wire connection parts, A small-diameter conductor having a smaller cross-sectional area of the conductor part than the wire and arranged in the wire connection part in a state where one end side is in contact with the wire, A temperature detection element connected to the other end side of the small-diameter conductor, An electrical connection part provided with the above. (Appendix 2) The electrical connection part according to Appendix 1, further comprising a cutoff means for cutting off the energization to the wire connection part when the detected temperature of the temperature detection element becomes a predetermined temperature or higher. (Appendix 3) The small-diameter conductor is installed over the entire circumference around the wire connection part in the electrical connection part according to Appendix 1 or Appendix 2. (Appendix 4) The small-diameter conductor is installed at the upper end and the lower end of the wire connection part respectively, The electrical connection part according to any one of Appendices 1 to 3, wherein two of the small-diameter conductors are connected to the temperature detection element. (Appendix 5) The small-diameter conductor is installed at the upper end and the lower end of the wire connection part respectively, The electrical connection part according to any one of Appendices 1 to 3, wherein two of the small-diameter conductors are connected to different temperature detection elements respectively. (Appendix 6) The electrical connection part according to any one of Appendices 1 to 5, wherein when the connection between the wire connection part and the wire becomes loose, the small-diameter conductor and the wire connection part maintain a non-contact state. (Appendix 7) The electrical connection part according to any one of Appendices 1 to 6, having a contact point for electrically connecting the other end side of the small-diameter conductor to the holding base.

Explanation of Reference Numerals

[0029] 1 wire connection part, 3 wires, 4 holding base, 5 fine-diameter conductor, 5a red-hot part, 6 temperature detection element, 7 contact, 8 spacer, 10 terminal block, 11 control unit, 12 switch

Claims

1. One or more wire connection parts, Wires connected to each of the wire connection parts, A holding base for holding the wire connection parts, A thin conductor having a smaller cross-sectional area of the conductor part than the wire and disposed at the wire connection part in a state where one end side is in contact with the wire, A temperature sensing element connected to the other end side of the thin conductor, An electrical connection part provided with the above.

2. The electrical connection part according to claim 1, further comprising a cutoff means for cutting off the energization to the wire connection part when the detected temperature of the temperature sensing element becomes a predetermined temperature or higher.

3. The electrical connection part according to claim 1 or claim 2, wherein the thin conductor is installed around the wire connection part over the entire circumference.

4. The thin conductor is installed at the upper end and the lower end of the wire connection part respectively, The electrical connection part according to claim 1 or claim 2, wherein two of the thin conductors are connected to the temperature sensing element.

5. The thin conductor is installed at the upper end and the lower end of the wire connection part respectively, The electrical connection part according to claim 1 or claim 2, wherein two of the thin conductors are connected to different temperature sensing elements respectively.

6. The electrical connection part according to claim 1 or claim 2, wherein when the connection between the wire connection part and the wire becomes loose, the thin conductor and the wire connection part maintain a non-contact state.

7. The electrical connection part according to claim 1 or claim 2, having a contact point for electrically connecting the other end side of the thin conductor to the holding base.

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