Circuit connection abnormality detection sensor and power outlet

Abstract

To provide a circuit connection abnormality detection sensor capable of detecting both tracking discharge and heat generation with a single sensor member.SOLUTION: A rod-shaped first electrode member 2 for detecting tracking discharge is arranged on an inner central axis M of a cylindrical housing 10 having a top surface 10b and a bottom surface 10c, and a through hole 11 is provided at a center of the top surface which a tip of a first electrode member 2 faces, such that the first electrode member 2 can detect the tracking discharge generated on the top surface 10b. One end of a bimetal member 4 arranged in the housing 10 is connected to the first electrode member 2. A second electrode member 3 that can come into contact with the other end being a free end made by the thermally deformed bimetal member 4, is arranged inside the housing 10. The second electrode member 3 and the first electrode member 2 extend from the bottom surface 10c of the housing 10 to form a pair of electrodes 2a and 3a.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a circuit connection abnormality detection sensor that detects an abnormality occurring in a circuit connection part in an electrical device such as a power outlet.

Background Art

[0002] For example, in a power outlet, tracking discharge may occur when minute dust or the like adheres between the plug blades of a connected plug. Regarding this tracking discharge, there is, for example, a power outlet for which countermeasures have been taken as disclosed in Patent Document 1. On the other hand, there is a problem that the circuit connection part generates heat due to loosening of the screw in the terminal part or the like, and regarding this problem, it is possible to cope with it by arranging a bimetal or a temperature sensor.

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 for detecting tracking discharge provides a minute hole between two holes of a power outlet into which the plug blades of a power plug are inserted, and an electrode is arranged therein to detect the current of the tracking discharge occurring between the plug blades. However, heat generation in a power outlet may occur due to a poor connection of an electric wire or the like in addition to tracking discharge, and since this cannot be detected by an electrode or the like for detecting tracking discharge, it was necessary to separately attach a temperature sensor or the like.

[0005] Therefore, in view of such problems, an object of the present invention is to provide a circuit connection abnormality detection sensor that can detect both tracking discharge and heat generation with one sensor member.

Means for Solving the Problems

[0006] In order to solve the above problems, the circuit connection abnormality detection sensor according to the invention of claim 1 arranges a rod-shaped conductor for detecting tracking discharge on the inner central axis of a cylindrical housing having a top surface and a bottom surface. A through hole is provided at the center of the top surface facing the tip of the rod-shaped conductor so that the rod-shaped conductor can detect the tracking discharge generated on the top surface. One end of a bimetal member arranged in the housing is connected to the rod-shaped conductor. On the other hand, an electrode member that can be contacted by the other end, which is the free end, when the bimetal member is thermally deformed is arranged in the housing. The electrode member and the rod-shaped conductor are sent out from the bottom surface of the housing to form a pair of electrodes. According to this configuration, by connecting a detection circuit to the pair of electrodes sent out from the housing, both tracking discharge and heat generation can be detected by one sensor member, which can be used for detecting abnormalities occurring in the circuit connection part.

[0007] The invention of claim 2 is characterized in that, in the configuration according to claim 1, the bimetal member is formed by at least one of a spiral shape and a helical shape being processed. According to this configuration, a sensor with excellent heat sensitivity can be obtained with a small space.

[0008] The invention of claim 3 is characterized in that, in the configuration according to claim 1 or 2, the housing has a cylindrical shape or a prismatic shape with a diameter or width of 2 to 4 mm and a length of 6 to 12 mm. According to this configuration, since the housing is small, it can be easily attached to, for example, a power outlet without significantly changing the size.

[0009] The invention of claim 4 is a power outlet for connecting a power plug, in which the circuit connection abnormality detection sensor according to any one of claims 1 to 3 is arranged in the case of the power outlet, and a hole is drilled between the receiving blades that form a pair for inserting the power plug of the case. The circuit connection abnormality detection sensor is arranged such that the through hole provided on the top surface communicates with the hole. According to this configuration, it is possible to detect both tracking discharge and heat generation without providing two types of sensors and without increasing the size of the case.

Advantages of the Invention

[0010] According to the circuit connection abnormality detection sensor of the present invention, by connecting a detection circuit to a pair of electrodes sent out from the housing, both tracking discharge and heat generation can be detected by one sensor member, and it can be used for detecting abnormalities in the circuit connection part. Moreover, according to the power outlet of the present invention, it is possible to detect both tracking discharge and heat generation without providing two types of sensors and without increasing the size of the case.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Embodiments for Carrying Out the Invention

[0012] Hereinafter, embodiments embodying the present invention will be described in detail with reference to the drawings. FIGS. 1 and 2 are explanatory diagrams showing an example of the circuit connection abnormality detection sensor according to the present invention. FIG. 1(a) is a perspective view, (b) is a side view, and FIG. 2 is a perspective view showing the internal structure with a part of the housing removed (a view cut along the line A-A in FIG. 1). The circuit connection abnormality detection sensor 1 is formed by accommodating two electrode members (a first electrode member 2 and a second electrode member 3) and a bimetal member 4 in a housing 10 made of synthetic resin. The housing 10 has a cylindrical side surface 10a, a top surface 10b, and a bottom surface 10c, and the dimensions are, for example, a diameter W of 3 mm and a length L of 10 mm. Note that the upper surface shown in the figure is the top surface and the lower surface is the bottom surface.

[0013] The first electrode member 2 is a rod-shaped conductor, which is arranged along the entire length on the central axis M of the housing 10. A through hole 11 is formed in the center of the top surface 10b of the housing 10 where the tips face each other. On the other hand, the other end of the first electrode member 2 is sent downward from the bottom surface 10c of the housing 10, forms an electrode 2a, and is connected to a detection circuit (not shown) provided outside. The second electrode member 3 is formed by an electrode member 3b that is arranged in the housing 10 and contacts when the bimetal member 4 thermally deforms, and an electrode 3a that is sent downward from the bottom surface 10c and connected to the detection circuit.

[0014] The bimetal member 4 has a spiral portion 41 having a spiral shape and a chordal portion 42 having a chord-wound shape, and both are connected. The center 41a of the spiral portion 41 is connected to the tip of the first electrode 2, and the tip 41b of its outermost circumference is arranged near the side surface 10a and is arranged parallel to the top surface 10b. One end 42a of the chordal portion 42 is connected to the tip 41b of the spiral portion 41 and is housed in the housing 10 so as to hang down. The other end of the chordal portion 42 is arranged below the housing 10, is a free end, and forms an electrode 42b. When the bimetal member 4 thermally deforms, this free end moves in the direction indicated by the arrow Y in FIG. 2 and contacts the electrode member 3b of the second electrode member 3. By forming the bimetal member 4 by connecting these two types of shapes, namely the spiral portion 41 and the chordal portion 42, the heat generated above (above the top surface 10b) is detected by the spiral portion 41 and thermally deformed, and the heat generated on the side of the housing 10 is detected by the chordal portion 42 and thermally deformed. Therefore, heat generation occurring in the surroundings can be detected well.

[0015] In this way, if a detection circuit is connected to the pair of electrodes 2a and 3a sent out from the housing 10, both tracking discharge and heat generation can be detected by one sensor member, and it can be used for detecting abnormalities in the circuit connection part. In addition, since the bimetal member 4 has two shapes, namely the spiral portion 41 and the chordal portion 42, without being formed in a linear shape, a sensor with excellent heat sensitivity can be obtained with a space-saving design. Furthermore, by making the housing 10 smaller, it can be easily accommodated, for example, in a power outlet without significantly changing the size of the case.

[0016] Incidentally, the smaller the dimensions of the housing 10, the easier it is to assemble. However, if the diameter is 2 to 4 mm and the length is 6 to 12 mm, it can be accommodated and manufactured in a power outlet case or the like. Also, the shape of the housing 10 may be a prismatic shape such as a quadrangular prism or a hexagonal prism.

[0017] Figure 3 is a cross-sectional explanatory view of a power outlet, showing a configuration incorporating the above-described circuit connection abnormality detection sensor 1. In Figure 3, 51 is a receiving blade that holds the plug blade of a power plug (not shown) accommodated and inserted in the case 50 of the power outlet 5, 52 is a hole formed in the case 50 into which the power plug is inserted, 53 is a circuit board assembled with a determination circuit that receives detection information from the circuit connection abnormality detection sensor 1 and determines the occurrence of an abnormality, and 54 is a hole for detecting tracking discharge. Also, 7 is an electric wire connected to the power outlet 5.

[0018] As shown in Figure 3, the circuit connection abnormality detection sensor 1 is disposed with its top surface 10b facing the front surface of the power outlet 5 between a pair of receiving blades 51. Then, a through hole 11 provided in the top surface 10b of the housing 10 coincides and communicates with the hole 54 of the case 50, and the tracking discharge current is configured to enter the circuit connection abnormality detection sensor 1. Then, by connecting the electrodes 2a and 3a of the circuit connection part abnormality detection sensor 1 to a connector 55 disposed in the case 50, the detected discharge current flows through a contact point 56 formed on the circuit board 53 to the determination circuit, and the presence or absence of an abnormality is determined. Also, if the temperature around or inside the case 50 rises due to tracking discharge or heat generation inside the case 50, the circuit connection abnormality detection sensor 1 detects it.

[0019] By arranging the circuit connection abnormality detection sensor 1 in this way, it is possible to detect tracking discharge occurring between the power plug and the power outlet 5, and also to detect heat generation caused by overcurrent or poor contact. In addition, without providing two types of sensors and without increasing the size of the case 50, it becomes possible to detect both tracking discharge and heat generation.

[0020] In addition, the circuit connection abnormality detection sensor 1 of the above embodiment has a shape in which the bimetal member 4 includes both the spiral portion 41 and the chordal winding portion 42, but only one of the shapes may be sufficient. Also, although the case where it is installed in the power outlet 5 to detect an abnormality of the outlet has been described, the circuit connection abnormality detection sensor 1 of the present invention can be widely used as a sensor for detecting heat generation. Furthermore, the power outlet 5 is provided with a hole 54 communicating with the through hole 11 of the circuit connection abnormality detection sensor 1 on the front surface of the case 50, but the entire top surface 10b of the circuit connection abnormality detection sensor 1 may be exposed from the case 50.

Explanation of reference numerals

[0021] 1 ··· Circuit connection abnormality detection sensor, 2 ··· First electrode member (rod-shaped conductor), 2a ··· Electrode, 3 ··· Second electrode member (electrode member), 3a ··· Electrode, 4 ··· Bimetal member, 5 ··· Power outlet, 10 ··· Housing, 10a ··· Side surface, 10b ··· Top surface, 10c ··· Bottom surface, 11 ··· Through hole, 41 ··· Spiral portion, 42 ··· Chordal winding portion, 51 ··· Receiving blade, M ··· Central axis, W ··· Diameter, L ··· Length.

Claims

1. A rod-shaped conductor for detecting tracking discharge is arranged on the inner central axis of a cylindrical housing having a top surface and a bottom surface. A through hole is provided at the center of the top surface facing the tip of the rod-shaped conductor, enabling the rod-shaped conductor to detect the tracking discharge occurring on the top surface. One end of a bimetal member arranged in the housing is connected to the rod-shaped conductor. An electrode member is arranged in the housing such that when the bimetal member thermally deforms, the other end, which is the free end, can come into contact with it. An abnormal circuit connection detection sensor, characterized in that the electrode member and the rod-shaped conductor form a pair of electrodes sent out from the bottom surface of the housing.

2. The abnormal circuit connection detection sensor according to Claim 1, wherein the bimetal member has at least one of a spiral shape and a helical shape.

3. The abnormal circuit connection detection sensor according to Claim 1 or 2, wherein the housing has a cylindrical shape or a prismatic shape with a diameter or width of 2 to 4 mm and a length of 6 to 12 mm.

4. A power outlet for connecting a power plug, wherein the abnormal circuit connection detection sensor according to any one of Claims 1 to 3 is arranged inside the case of the power outlet. A hole is formed between a pair of receiving blades into which the power plug of the case is inserted. The power outlet is characterized in that the abnormal circuit connection detection sensor is arranged such that the through hole provided on the top surface communicates with the hole.

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