JP3805784B2 - Power terminal block - Google Patents

Description

  The present invention relates to a power supply terminal block capable of completely preventing an accident due to overcurrent and / or abnormal heat generation at an early stage.

  2. Description of the Related Art Conventionally, there is a device in which a current fuse is provided in a circuit in order to prevent a device connected due to overcurrent from being damaged, and the current fuse element is blown by its Joule heat against a steep overcurrent. Also, for abnormal heating that occurs when the external conductor is incompletely inserted into the power supply terminal block, a temperature switch using shape memory alloy or bimetal is provided in the circuit, and this temperature switch is activated to short circuit. There is a device that melts the fuse with its Joule heat by applying a steep overcurrent to the current fuse element.

  In order to detect an abnormal current earlier than in the conventional apparatus, when the conductive fusible body that is the material of the current fuse is a single material, the length of the conductive fusible body 50 shown in FIG. The length L is long, the width w of the cross-sectional area perpendicular to the current direction is thin, and the thickness t needs to be thin.

  On the other hand, in order to avoid a malfunction of the temperature switch due to a temperature rise factor, the switch does not operate at 90 ° C. or less, and at the time of temperature rise at 100 ° C. or more which occurs when the external conductor is incompletely inserted into the power terminal block. In order to cut off the current reliably, when a shape memory alloy or bimetal is used, a part for suppressing deformation at 90 ° C. or lower must be newly provided. In addition, the method of stopping the energization of the load circuit by the operation of the shape memory alloy or bimetal, forming a short circuit including a current fuse, and fusing the current fuse at the time of abnormal temperature rise causes the current supply to the load side to be cut off The primary power line of the thing is not interrupted. Furthermore, the use of expensive shape memory alloys and bimetals is costly.

  In view of the above circumstances, the present invention provides a power supply terminal block having a current fuse that can be stored in a space-saving manner while lowering the fusing set current value, and cuts off the power supply to the load circuit in the event of abnormal heat generation. An object of the present invention is to provide a power terminal block that can also cut off the power supply to the side.

  In the power supply terminal block according to claim 1 of the present invention, the insulating resin that is softened and liquefied by the heat generated when the contact between the external conductive wire from the power supply and the electrode plate of the power supply terminal block is incomplete, It is fixed in the vicinity of the insertion portion and the electrode plate, and at least one of the insulating resins is located above the contact portion between the outer conductor and the electrode plate.

  A power supply terminal block according to claim 2 is the power supply terminal block according to claim 1, characterized in that a flame retardant material is added to the insulating resin.

  The power supply terminal block according to claim 3 is the power supply terminal block according to claim 1 or 2, wherein the insulating resin is in contact with either the conductive wire or the electrode plate in a solid state. .

  A power supply terminal block according to claim 4 is the power supply terminal block according to any one of claims 1, 2, or 3, wherein the insulating resin has a viscosity of 100 cp or less at 100 ° C. or more. To do.

  According to the first aspect of the present invention, the insulating resin that is softened by the heat generated when the contact between the external conductor from the power source and the electrode plate of the power terminal block is incomplete is the insertion portion of the external conductor. Or since it is fixed in the vicinity of the electrode plate, the insulating resin flows between the external conductor and the electrode plate when the insertion of the external conductor is incomplete, thereby forming an insulating film, thereby energizing the primary power supply line. Can be cut off.

  According to the invention relating to claim 2, since the flame-retardant material is added to the insulating resin, the reliability can be improved.

  According to the invention of claim 3, since the insulating resin is in contact with either the conductive wire or the electrode plate in the solid state, the insulating resin is external when the insertion of the external conductive wire is incomplete. By flowing in between the conducting wire and the electrode plate to form an insulating film, it is possible to cut off the energization of the primary power supply line.

  According to the invention of claim 4, since the insulating resin has a viscosity of 100 cp or less at 100 ° C. or higher, the insulating resin is transmitted to the conductive wire or the electrode plate during softening and poured between the conductive wire and the electrode plate, An insulating film can be formed reliably.

  Hereinafter, the power supply terminal block of the present invention will be described with reference to the accompanying drawings.

Embodiment 1
FIG. 1 is a development view of a circuit showing an embodiment of a power terminal block according to the present invention, showing an example of a configuration of a power terminal block capable of completely preventing an accident due to overcurrent and abnormal heat generation at an early stage, and FIG. FIG. 3 is a perspective view showing an insulating resin fixed in the vicinity of an electrode plate and an insertion portion of an external conductor in the power supply terminal block in FIG. 1, and FIG. 4 is a diagram showing a current fuse in the power supply terminal block in FIG. 2 is a perspective view showing a temperature switch in a power terminal block in FIG.

  In the power supply terminal block of the present invention, the conductive fusible body of the current fuse has at least four substantially U-shaped portions, the temperature at the center is the highest, and the temperature gradient at the substantially U-shaped portion is increased. Yes. Further, the substantially U-shaped portion prevents the heat deformation direction from being only one direction.

  1 to 4 are circuit diagrams using a power supply terminal block 1 according to an embodiment of the present invention. The terminal block 1 has one end of two power supply lines from a power supply 2 facing each other with a gap therebetween. An insulating resin 5 is fixed between the electrode plates 4a and 4b connected to the two external conductors (conductors) 3a and 3b so as to be softened and flown by heat generated at the time of defective connection. A current fuse 6 is connected to 4a and 4b, and a circuit of a temperature switch 10 comprising a conductor 7 which is insulated in a normal state and a heat-meltable insulator 9 sandwiched between the conductors 8 is provided at the tip of the current fuse 6. Is formed. Reference numeral 1a denotes a cover of the power terminal block 1.

  Conventionally, as shown in FIG. 5, a current fuse in a power supply terminal block is a load that operates with a power supply and power supplied from the power supply, such as a lighting fixture S1. ~ S4 is installed in a power supply terminal block provided between S4 and the like, and when an excessive current flows due to a load abnormality or the like, this is heated, softened by Joule heat in the conductive soluble body, The current path is cut by the physical phenomenon of fusing.

  However, in order to prevent an accident due to overcurrent at an early stage, a fuse that can be blown at a low set current value is necessary. For this reason, the length L in the current direction of the current fuse is long and perpendicular to the direction in which the current flows. In such a cross-sectional area, the width w must be thin and the thickness t must be thin, but these all greatly reduce the rigidity of the conductive fusible body immediately before fusing, and the softened conductive fusible body contacts the power terminal block. Therefore, the power terminal block could not be made compact.

  Therefore, in the present invention, the shape of the conductive fusible body of the current fuse is configured to have at least four substantially U-shaped portions. Here, according to FIG. 2, the details of the operation will be described in the case where there are four substantially U-shaped portions.

  When an excessive current flows, the middle of the second and third substantially U-shaped portions U2 and U3 becomes the central portion of the conductive soluble body, and the temperature rises most by Joule heat. If the softening temperature of the conductive fusible body is exceeded, if the second substantially U-shaped portion U2 is deformed in the direction perpendicular to the paper surface due to symmetry, the third substantially U-shaped portion U3 is deformed in the depth direction. Since there are two substantially U-shaped parts from the central part of the conductive fusible body to the conductor connecting parts 5a1, 5a2, the first substantially U-shaped part U1 from the conductor connecting part 5a1 or the fourth substantially U-shaped part The fusible body from U4 to the other conductor connection portion 5a2 does not rise in temperature enough to soften, and acts to apply a force to pull back or prevent the deformation. For this reason, until the deformed portion is melted, the sagging is suppressed by the action of the force, and the melting is completed. In addition, by having approximately four U-shaped parts, even when the temperature of the central portion of the conductive fusible body is abnormally increased due to Joule heat due to overcurrent, the conductor connecting portions 5a1, 5a2 can hold | maintain the temperature which a soluble body does not deform | transform. For this reason, in this Embodiment, the soluble body from a conductor connection part (current fuse edge part) to a substantially U-shaped part can further lengthen a full length, suppressing the thermal deformation of a center part. Thereby, while being able to make a setting fusing current value low, it can form in a small size.

  In addition, when a tensile stress is applied to the conductive fusible body in advance, the substantially U-shaped portion is pulled by the two conductor connecting portions, so that sagging is further suppressed. As a result, the substantially U-shaped portion may open at a wide angle. Alternatively, by forming at least one location where the substantially U-shaped portion of the conductive fusible body is opened at a wide angle in advance, contact between the conductive fusible members during thermal deformation can be prevented. Can be suppressed. Further, the distance L23 between the substantially U-shaped parts U2 and U3 is made smaller than the distance L12 between the substantially U-shaped parts U1 and U2 and the distance L34 between the substantially U-shaped parts U3 and U4, thereby reducing the region where the temperature rises until softening. The rigidity of the substantially U-shaped portions U1 and U2 can suppress the rotational moment generated during the thermal deformation of the substantially U-shaped portions U2 and U3, and can minimize the deformation.

Embodiment 2
In the present invention, in order to cut off the power supply to the primary current supply line arranged in series, an insulating resin whose viscosity is drastically lowered at 100 ° C. or higher is fixed to the insertion part of the external conductor or the vicinity of the electrode plate. When the insulating resin is softened at this set temperature, it flows between the external conductor and the electrode plate to form a complete insulating layer. As shown in FIG. 3, an insulating resin 5 whose viscosity rapidly decreases at 100 ° C. or higher is fixed to the external conductor insertion portion 11 to the power terminal block 1 and the electrode plate 4 a in the power terminal block 1. Examples of the insulating resin 5 having such properties include pine-based wax. The viscosity of the insulating resin 5 is preferably 100 ° C. or higher and 100 cp or lower in order to ensure optimum fluidity.

  Here, in accordance with FIG. 3, when the insulating resin 5 is fixed to two locations of the power supply terminal block 1 or the external conductor insertion portion 11 to the device body and the electrode terminal 4a of the power supply terminal block 1 or the device body. Details of the operation will be described.

  The insulating resin 5 fixed to the external conductor insertion portion 11 of the power terminal block 1 is softened and liquefied when, for example, an arc is generated between the external conductor 3a and the electrode plate 4a and the temperature of the external conductor 3a rises. In FIG. 3, it flows into the slight gap of the electrode plate 4a through the external conductor 3a in the gravity drop direction (arrow K direction). As a result, the energization is immediately stopped because the insulating layer is formed. When the direction of gravity action is opposite, the insulating resin fixed to the electrode plate similarly flows through the electrode plate into the slight gap between the external conductor and the electrode plate.

  In the present embodiment, the energization of the primary power supply line is stopped when an insulating resin, such as wax, fixed in the vicinity of the electrode plate of the power supply terminal block is conducted when the external conductor and the electrode plate are in an incomplete contact state. As the temperature of the external conductor and the electrode plate rises due to the arc being blown, the viscosity rapidly decreases, so that the wax flows into the incompletely contacted state portion and forms an insulating layer. As a result, energization of the load side as well as the primary power supply line can be stopped.

Embodiment 3
In the present embodiment, as a temperature switch that operates at the time of abnormal temperature rise, a heat-meltable insulator having a softening start temperature higher than 90 ° C. is disposed between the metal plates, and between the metal plates in order to provide immediate response. It is configured by applying a compressive stress to the heat-meltable insulator. At this time, it is possible to control the response time by providing a protrusion on one of the metal plates so that the distance from the other metal plate can be adjusted arbitrarily.

  As shown in FIGS. 1 and 4, the temperature switch 10 using the heat-meltable insulator 9 provided in the power supply terminal block 1 will be described in detail with respect to the action of cutting off the energization from other circuits when an arc is generated. explain.

  First, if there is no abnormality in the power terminal block 1, the external conductor 3 a is connected to the electrode plate 4 a and energizes the load circuit via the current fuse 6. However, if the insertion of the external conductor into the power terminal block 1 is incomplete, the temperature of the external conductor 3a and the electrode plate 4a, for example, increases during the energization, and the temperature in the power terminal block 1 increases and the conductor The heat-meltable insulator 9 which is a flame-retardant material having a melting point of 90 ° C. or more sandwiched between 7 and the conductor 8 or to which the flame-retardant material is added softens. At this time, the conductor 8 is set to be on the heat source side, and the heat-meltable insulator 9 in contact with the conductor 8 side is softened and liquefied, and enters the hole 12 having a smaller diameter than the insulator 9. The conductor 7 and the conductor 8 come into contact with each other at the conductive protrusion 13 which is the same member. As a result, a short circuit that does not include a load is formed, so that an excessive current flows through the current fuse 6 and the current supply to the load is instantaneously stopped. Therefore, since no short-circuit current is supplied to the load, it is possible to prevent an accident from spreading.

  The conductors 7 and 8 are preferably arranged so that compressive stress is applied to the heat-meltable insulator 9. Since such compressive stress acts, the heat-meltable insulator does not leave due to vibration during transportation or installation work.

  In the present embodiment, the temperature switch of the power supply terminal block is configured such that a heat-meltable insulator having a softening temperature of 90 ° C. or higher is applied with compressive stress by two metal plates, and the heat-meltable insulator is softened. In this case, the insulator is pushed out into a small hole provided in the metal plate and the interval between the metal plates is narrowed, and the two metal plates can be reliably brought into contact with each other by the protrusion provided on one metal plate.

  In the present embodiment, the temperature switch composed of the heat-meltable insulator sandwiched between the conductor having only the protrusion and the conductor having only the hole has been described. However, the temperature switch having the protrusion and the hole in the same conductor is described. Even the switch has the same effect as the present embodiment. Of course, the same effect can be obtained when there are a plurality of protrusions, holes, and hot-melt insulators. Furthermore, in the present embodiment, an example in which a conductor having a hole is arranged on the heat source side has been described. However, since the power terminal block has an almost uniform temperature as the temperature becomes higher, the hole is not formed on the heat source side. The same effect can be obtained even if a conductor provided with is provided.

Embodiment 4
In the above-described embodiment, the current fuse made of the conductive fusible body having the equal line width has been described. However, by increasing the resistance partially by narrowing the line width at the central part of the conductive fusible body, Heat can be generated locally to accelerate fusing. For example, the same effect can be obtained even if notches are provided.

Embodiment 5
In the above embodiment, a current fuse made of a single conductive fusible body has been described. However, a low thermal conductive material is coated in the vicinity of the central part of the conductive fusible body to suppress the dissipation of Joule heat and locally. It can also be blown out early by raising the temperature.

  In the case of the power supply terminal block in which the current fuse 6 and the temperature switch 10 are arranged, when the melting point of the insulating resin set in advance for some reason is reached, the heat-meltable insulator 9 of the temperature switch 10 is melted. The heat-meltable insulator 9 cannot contact the distance between the two conductors 7 and 8 and is in contact therewith, so that an excessive current flows instantaneously. The current fuse 6 is blown by this excessive current, and the load circuit is opened. For this reason, a load device, for example, a luminaire, is suddenly turned off, and an abnormality can be noticed.

  Also, in the case of the power supply terminal block in which the current fuse 6, the temperature switch 10 and the insulating resin 5 are arranged, the load device, for example, the lighting fixture, etc. suddenly turns off and an abnormality may be noticed as in the above embodiment. it can.

  In the above-described embodiment, the current fuse installed on the load side has been described. However, the current fuse may be installed on the primary side of the power source. Also in this case, the same effects as those of the above embodiment can be obtained.

It is an expanded view of the circuit which shows one Embodiment of the power supply terminal block of this invention. It is a shape figure which shows the current fuse in the power supply terminal block in FIG. It is a perspective view which shows the insulating resin fixed to the insertion part of an external conducting wire in the power supply terminal block in FIG. 1, and an electrode plate vicinity. It is a perspective view which shows the temperature switch in the power supply terminal block in FIG. It is a perspective view which shows one example of the conventional current fuse.

Explanation of symbols

  1 Power supply terminal block, 1a Power supply terminal block cover, 2 Power supply, 3a, 3b External conductor, 4 Temperature switch, 4a, 4b Electrode plate, 5 Insulating resin, 5a1, 5a2 Conductor connection, 6 Current fuse, 7, 8 Conductor, 9 heat-meltable insulator, 10 temperature switch, 11 outer conductor insertion portion, 12 holes, 13 protrusion.

Claims (4)

An insulating resin that is softened and liquefied by heat generated when the contact between the external conductor from the power source and the electrode plate of the power terminal block is imperfectly fixed to the insertion portion of the external conductor and the vicinity of the electrode plate, at least one of them The insulating resin is positioned above the contact portion between the outer conductor and the electrode plate. 2. The power terminal block according to claim 1, wherein a flame retardant material is added to the insulating resin. The power supply terminal block according to claim 1 or 2, wherein the insulating resin is in contact with either the insertion portion of the external conductor or the electrode plate in a solid state. The power terminal block according to claim 1, 2, or 3, wherein the insulating resin has a viscosity of 100 cp or less at 100 ° C or higher.

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