JP7531985B2 - Ground terminal block - Google Patents

Description

The present invention relates to an earth terminal block that is placed inside a distribution board.

As described in Patent Document 1, it is known to install an earth bar on a distribution board. The earth bar is used for grounding purposes, and the ground wire of the load device is connected to the earth bar.

JP 2019-103317 A

However, workers need to adjust the length of the earth bar depending on the number of load devices to be installed on the distribution board. This requires either preparing earth bars of the appropriate length depending on the number of load devices, or cutting the earth bar, making on-site work difficult.

The inventor of this case has thoroughly investigated this issue and attempted to solve it. The problem that this invention aims to solve is to provide an earth terminal block that is easily adjustable according to the number of load devices.

In order to solve the above problems, the present invention provides an earth terminal block that is connected to an earth wire within a distribution board, and that includes a ground wire connection portion to which a ground wire for connecting to a load device is connected, and a strip terminal portion that is electrically connected to the ground wire connection portion, and the coating of the earth wire is stripped by the strip terminal portion, and the strip terminal portion and the earth wire are electrically connected to the earth terminal block.

It is also preferable that the strip terminal section has a clamping section for clamping the earth wire and an inlet for introducing the earth wire into the clamping section, and the earth terminal block 1 has a cover section for covering the inlet, a pressing section is formed on the cover section, and the pressing section is capable of pressing the earth wire into the clamping section in conjunction with the movement of the cover section.

It is also preferable that the cover be rotated so that the earth wire can be pushed into the clamping portion.

It is also preferable that the ground wire insertion port for inserting the ground wire into the ground wire connection portion opens upward, and the inlet opens in a direction other than upward.

It is also preferable that the cover be rotated upward so that the earth wire can be pushed into the clamping portion.

The present invention makes it possible to provide an earth terminal block that can be easily adjusted to accommodate the number of load devices.

FIG. 2 is a front perspective view of the earth terminal block. This is a cross-sectional view taken along the line II-II in Fig. 1, with the ground wire and the ground electric wire connected to the ground terminal block. This is a cross-sectional view taken along the line III-III in Fig. 1, with the earth wire connected to the earth terminal block. 1 is a front view of an earth terminal block to which a ground wire is connected and an earth wire introduced into a strip terminal portion, as viewed from the front side. FIG. 2 is a front view of the earth terminal block to which a ground wire and an earth electric wire are connected, as viewed from the front side. FIG. 2 is a partially enlarged view of a distribution board in which an earth terminal block and a branch breaker are installed. FIG. 2 is a front view of a distribution board in which a ground wire and an earth wire are connected to an earth terminal block and a branch breaker. FIG. 2 is an enlarged view of an earth terminal block and a branch breaker installed on a distribution board. FIG. 11 is a front view of the earth terminal block of the second embodiment as viewed from the front side. FIG. 11 is a front view of the ground terminal block of the third embodiment as viewed from the front side.

The following describes an embodiment of the invention. The earth terminal block 1 of the embodiment is installed in a distribution board 9 and is used to ground a load device connected to a branch breaker 91. In this specification, as shown in FIG. 1, the direction of the mounting surface attached to the distribution board 9 is defined as the downward direction, and the opposite side is defined as the upward direction. The earth terminal block 1 includes a ground wire connection portion 2 to which a ground wire 3 connected to a load device is connected, and a strip terminal portion 51 electrically connected to the ground wire connection portion 2. In the embodiment, as can be understood from FIG. 2 and FIG. 3, the strip terminal portion 51 is formed at the bottom of the metal strip terminal fitting 5, and a terminal plate portion 57 constituting the ground wire connection portion 2 is provided at the top. When the ground wire 3 is connected to the ground wire connection portion 2, the strip terminal fitting 5 becomes conductive and an electric path is connected to the strip terminal portion 51.

The strip terminal portion 51 strips the coating 41 of the earth wire 4 and is electrically connected to the earth wire 4. As can be seen from FIG. 2, in this embodiment, an upper blade 54 and a lower blade 55 provided on the strip terminal portion 51 strip the coating 41 of the earth wire 4. The coating 41 of the earth wire 4 is stripped and the earth conductor 42 inside the earth wire 4 comes into contact with the strip terminal portion 51, thereby electrically connecting the earth wire 4 and the strip terminal portion 51. As shown in FIG. 7, one earth wire 4 is connected to the housing side of the distribution board 9 and is wired across multiple branch breakers 91 on the load terminal side of the branch breakers 91.

The earth terminal block 1 of the above structure uses an earth wire 4, which is easy to adjust in length, for grounding, rather than an earth bar, whose length is difficult to adjust, so that the length can be easily adjusted to match the number of load devices connected. When the number of load devices increases, if the length of the earth bar is insufficient, it becomes necessary to replace it with an earth bar of an appropriate length, but the earth terminal block 1 of the present invention can easily adjust its length without being limited by the length of the earth bar.

The earth terminal block 1 of the embodiment includes a main body 11 having a ground wire connection portion 2 and a strip terminal portion 51 therein, and a cover portion 6 that covers at least a part of the strip terminal portion 51. In this specification, as shown in FIG. 1, the direction in which the upper blade 54 and the lower blade 55 provided on the strip terminal portion 51 extend is defined as the left-right direction, and the direction that forms 90 degrees with both the up-down direction and the left-right direction is defined as the front-rear direction. As can be understood from FIG. 1 and FIG. 2, the main body 11 of the embodiment includes cases 11a and 11b and can be divided into two in the front-rear direction. The cases 11a and 11b are connected by a connecting portion 14. The connecting portion 14 includes a hole 12 that penetrates the cases 11a and 11b, and the cases 11a and 11b are connected by passing a screw 13 or the like through the hole 12. As can be seen from FIG. 2 and FIG. 3, the space S for assembling the spring 22, which is a component of the ground wire connection portion 2, is formed to straddle the boundary between the case 11a and the case 11b. If the main body 11 is structured to be separable into the case 11a and the case 11b, the space S can be exposed, making it easier to assemble the spring 22. In addition, the strip terminal fitting 5 of the embodiment is assembled so that the strip terminal portion 51 is located at the boundary between the case 11a and the case 11b. If it becomes necessary to change to an earth electric wire 4 of a different thickness and replace the strip terminal fitting 5 with one corresponding to the thickness of the earth electric wire 4, the replacement work is easy if the main body 11 is structured to be separable in the front-rear direction.

The ground wire connection part 2 will be described. As can be understood from FIG. 2 and FIG. 3, the ground wire connection part 2 of the embodiment includes a terminal plate part 57 provided on the upper part of the strip terminal metal fitting 5, and a spring 22 that electrically connects the terminal plate part 57 and the ground wire 3. The spring 22 includes a locking spring 22a whose tip bites into the ground wire 3 to prevent the ground wire 3 from coming off, and a pressing spring 22b that presses the ground wire 3 and electrically connects it while a part of the spring 22 is in contact with the terminal plate part 57. The ground wire 3 is inserted from the ground wire insertion port 21 provided in the main body part 11 into the space S in which the ground wire connection part 2 is assembled. When the ground wire 3 is inserted from the ground wire insertion port 21, the ground wire 3 and the spring 22 come into contact with each other and the spring 22 is deformed. The deformed spring 22 presses and fixes the ground wire 3, and the spring 22 and the ground wire 3 are electrically connected. When removing the ground wire 3, the release button 8, the tip of which is exposed outside the main body 11, is pressed down to bend the locking spring 22a downward, loosening the grip on the ground wire 3, making it possible to remove the ground wire 3. The structure of the ground wire connection part 2 described above is a known quick-connect terminal mechanism. If the ground wire connection part 2 is not configured with a quick-connect terminal mechanism, the ground wire 3 may be connected by a screw or the like. However, using a quick-connect terminal mechanism as in the embodiment allows the earth terminal block 1 to be made more compact.

The strip terminal portion 51 will be described in detail. As can be seen from FIG. 3, the upper portion of the strip terminal fitting 5 of the embodiment has an L-shaped cross section, and a part of the terminal plate portion 57 contacts the spring 22 and is a component of the ground wire connection portion 2. When the ground wire 3 is connected to the ground wire connection portion 2, the ground wire 3 and the strip terminal portion 51 are electrically connected. Furthermore, as can be seen from FIG. 4, it is preferable to form a notch 52 in the strip terminal portion 51 for sandwiching the earth electric wire 4 and electrically connecting it. The notch 52 of the embodiment includes a clamping portion 53 for clamping the earth electric wire 4, an introduction port 56 for introducing the earth electric wire 4, and inclined portions 54a, 55a for forming a space that expands in a tapered shape from the clamping portion 53 toward the introduction port 56. Such a shape makes it easier to guide the earth electric wire 4 into the clamping portion 53. The clamping portion 53 and the inclined portions 54a, 55a of the embodiment are provided with an upper blade 54 and a lower blade 55 facing each other vertically. The distance between the upper blade 54 and the lower blade 55 in the clamping portion 53 is set to be narrower than the diameter of the earth electric wire 4 provided in the distribution board 9 , and is set so that the upper blade 54 and the lower blade 55 come into contact with the earth conductor 42 when the earth conductor 42 is clamped from above and below.

As can be seen from FIG. 4, when the strip terminal portion 51 is assembled to the main body portion 11, the notch 52 is exposed from the concave opening 15 provided in the main body portion 11. The earth wire 4 introduced from the inlet 56 into the clamping portion 53 comes into contact with the upper blade 54 and the lower blade 55, causing the coating 41 to be stripped off, and the earth conductor 42 is clamped in contact with the upper blade 54 and the lower blade 55, thereby electrically connecting to the strip terminal portion 51. Due to this structure, the earth wire 4 can be connected to the earth terminal block 1 without using a tool to strip off the coating 41.

The earth terminal block 1 of the embodiment includes a cover portion 6 that covers the inlet 56. The earth terminal block 1 preferably has a pressing portion 61 formed on the cover portion 6, and the pressing portion 61 can push the earth electric wire 4 into the clamping portion 53 in conjunction with the movement of the cover portion 6. As can be understood from FIG. 4 and FIG. 5, the pressing portion 61 of the embodiment is formed in a convex shape on the surface facing the main body portion 11 when the cover portion 6 is closed, and can press the earth electric wire 4 and push it into the clamping portion 53 in conjunction with the movement of the cover portion 6 to close. With this structure, the cover portion 6 covers and protects the strip terminal portion 51 and the earth conductor 42, which are conductive portions, while at the same time ensuring contact between the earth electric wire 4 and the strip terminal portion 51.

It is also preferable to have a structure in which the cover part 6 can be rotated. As can be understood from FIG. 4 and FIG. 5, the cover part 6 in the embodiment is supported rotatably by a rotation shaft 62 provided at a position below the notch 52. The cover part 6 is fixed to the main body part 11 by hooking a claw part 63 formed in a convex shape at the upper end to a locking part 64 formed at the upper part of the main body part 11. By holding the upper end of the cover part 6 and moving it, the cover part 6 rotates with the rotation shaft 62 at the lower end as a fulcrum. In conjunction with the movement of the cover part 6 rotating and closing, the pressing part 61 presses the earth electric wire 4 and can push it into the clamping part 53. With this configuration, the earth electric wire 4 can be pushed into the clamping part 53 with less force by the principle of leverage. Instead of rotating the cover 6, the cover 6 can be slid linearly in the direction of pushing the earth wire 4 into the clamping portion 53, so that the cover 6 can push the earth wire 4 into the clamping portion 53. Alternatively, the cover 6 can be a lid-shaped cover that is separate from the main body 11 and can be fixed to the main body 11 by a claw or the like, and the cover 6 can be attached to push the earth wire 4 into the clamping portion 53.

As can be seen from Figs. 6 and 7, the earth terminal block 1 of the embodiment is installed on the equipment mounting plate 93 of the distribution board 9, and one end of the earth wire 4 electrically connected to the ground wire 3 via the strip terminal portion 51 is electrically connected to the distribution board 9, thereby performing grounding. As can be seen from Figs. 1 and 6, the earth terminal block 1 of the embodiment has a fixing portion 7 for installation on the equipment mounting plate 93. The fixing portion 7 of the embodiment is provided in the opposite direction to the opening direction of the inlet 56 through which the earth wire 4 is introduced, has a mounting screw insertion hole penetrating in the vertical direction, and is fixed to the equipment mounting plate 93 by a screw or the like.

As can be seen from FIG. 6, the earth terminal block 1 of the embodiment is installed on the load terminal side of the branch breaker 91 of the distribution board 9. In this case, it is preferable to install the earth terminal block 1 in an orientation such that the cover portion 6 is located away from the branch breaker 91. In the embodiment, the earth terminal block 1 is installed so that the fixing portion 7 provided on the opposite side of the cover portion 6 is located between the strip terminal portion 51 and the branch breaker 91. There are two advantages to this arrangement. The first advantage is that when connecting the earth wire 4 to the strip terminal portion 51, the work can be performed as far away as possible from the branch breaker 91, improving safety.

The second point is that since the ground wire insertion port 21 is located close to the branch breaker 91, the wiring work of the ground wire 3 and the power wire 92 can be performed efficiently. The wiring worker brings the power wire 92 and the ground wire 3 connected to the load device to the position of the load terminal and the ground wire insertion port 21 of the branch breaker 91, cuts the power wire 92 and the ground wire 3 to an appropriate length, strips off the coating, and connects them to the load terminal and the ground wire insertion port 21 of the branch breaker 91. As can be understood from Figures 7 and 8, when the earth terminal block 1 is installed in the above-mentioned orientation, the position of the ground wire insertion port 21 can be brought closer to the load terminal of the branch breaker 91, so the wiring worker can cut the power wire 92 and the ground wire 3 at the same time, improving workability. If the ground wire insertion port 21 and the branch breaker 91 are located at a distance, the lengths of the power wire 92 and the ground wire 3 must be adjusted separately, which increases the work load.

In addition, it is preferable to form the front-to-rear width of the earth terminal block 1 to be equal to or smaller than the width of the adjacent branch breaker 91. By forming it to the above size, the earth terminal block 1 can be installed within the width of the branch breaker 91.

In the embodiment, the ground wire 3 is inserted from the ground wire insertion port 21 provided in the main body 11 and connected to the ground wire connection portion 2. It is preferable that the ground wire insertion port 21 opens upward and the inlet 56 for introducing the earth wire 4 opens in a direction other than the top. In the earth terminal block 1 of the embodiment, the ground wire insertion port 21 opens upward and the inlet 56 opens leftward. By distributing the two opening directions to the top and a direction other than the top, space can be saved and the limited installation space in the distribution board 9 can be effectively used. Note that both the ground wire insertion port 21 and the inlet 56 can also be opened upward. In this case, the ground wire 3 and the earth wire 4 can be connected from the front side of the distribution board 9, which improves workability.

It is also preferable that the cover part 6 has a pivot shaft 62 on the lower side, and that the pressing part 61 moves upwards when the cover part 6 is pivoted. When the earth terminal block 1 is installed on the load terminal side of the branch breaker 91 as in the embodiment, the cover part 6 is pivoted upwards to push the earth wire 4 into the clamping part 53, so that the cover part 6 can be pivoted in a state where the earth wire 4 is easily visible, which improves workability.

The second embodiment will be described. When a distribution board contains a mixture of earth leakage circuit breakers with a leakage current protection function and a circuit breaker without a leakage current protection function, the ground wires of the load devices connected to those circuit breakers should not be connected to a common circuit and grounded in principle. Therefore, the earth terminal block 1 of the second embodiment is provided with a ground wire connection portion and a strip terminal portion for a molded-case circuit breaker (MCB), and a ground wire connection portion and a strip terminal portion for an earth leakage circuit breaker (ELB). As can be understood from FIG. 9, the MCB ground wire 3M is connected to the MCB ground wire connection portion (not shown) and is connected to the earth wire 4M via the strip terminal portion 51M. The ground circuit for the ELB is also connected in the same manner, and independent ground circuits can be formed for the MCB and the ELB. Furthermore, it is preferable to form a structure in which a plurality of pressing portions are formed on the cover portion 6, and the work of pressing the MCB earth wire 4M against the strip terminal portion 51M and the work of pressing the ELB earth wire 4E against the strip terminal portion 51E can be performed simultaneously. With this structure, the earth wires 4M and 4E can be connected simultaneously by a single action of closing the cover part 6.

A third embodiment will be described. When it is not possible to provide space in the distribution board 9 for rotating the cover portion 6, an earth terminal block 1 without a cover portion 6 as in the third embodiment can be used. As can be seen from FIG. 10, the earth terminal block 1 of the third embodiment does not have a cover portion 6, and the inlet 56 for introducing the earth electric wire 4 opens downward. In the third embodiment, the earth electric wire 4 is pushed into the clamping portion 53 by hand or with any tool, and then the earth terminal block 1 is installed on the distribution board 9. Note that the opening direction of the inlet 56 does not have to be downward.

The present invention has been described above using the embodiments as examples, but the present invention is not limited to the above embodiments and can be implemented in various forms. For example, the earth conductor 42 may be a single wire as in the embodiment, or a stranded wire consisting of multiple wires.

REFERENCE SIGNS LIST 1 Earth terminal block 11 Main body 15 Opening 2 Ground wire connection section 21 Ground wire insertion port 22 Spring 3 Ground wire 3M MCB ground wire 3E ELB ground wire 4 Earth wire 41 Cover 42 Earth conductor 4M MCB ground wire 4E ELB ground wire 5 Strip terminal metal fitting 51 Strip terminal section 52 Notch 53 Clamping section 54 Upper blade 55 Lower blade 56 Introduction port 57 Terminal board section 6 Cover section 61 Pressing section 62 Rotating shaft 7 Fixing section 8 Release button 9 Distribution board 91 Branch breaker 92 Power line

Claims (5)

An earth terminal block that is connected to an earth wire in a distribution board,
a ground wire connection portion to which a ground wire for connecting to a load device is connected;
a strip terminal portion electrically connected to the ground wire connection portion;
An earth terminal block in which the insulation of an earth wire is stripped by a strip terminal portion, and the strip terminal portion and the earth wire are electrically connected to each other. The strip terminal portion includes a clamping portion for clamping the earth wire and an inlet for introducing the earth wire into the clamping portion,
A cover portion for covering the inlet is provided,
2. The earth terminal block according to claim 1, wherein a pressing portion is formed on the cover portion, and the pressing portion is capable of pressing the earth wire into the clamping portion in conjunction with the movement of the cover portion. The earth terminal block according to claim 2, in which the earth wire can be pushed into the clamping portion by rotating the cover portion. The earth terminal block according to claim 2 or 3, in which the ground wire insertion port for inserting the ground wire into the ground wire connection portion opens upward, and the inlet opens in a direction other than upward. An earth terminal block according to any one of claims 2 to 4, in which the earth wire can be pushed into the clamping portion by rotating the cover portion upward.

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