Residual current detection device and ammeter

Abstract

The utility model relates to the technical field of electronic control devices, in particular to a residual current detection device and an electric meter. The residual current detection device comprises a relay, a mutual inductor, a live wire connecting piece and a null line connecting piece, the relay and the mutual inductor are arranged in the direction perpendicular to the height direction of the meter shell, the relay comprises a first leading-out end and a second leading-out end, the mutual inductor comprises a magnetic core, the magnetic core is provided with a through hole, and the axis of the through hole is perpendicular to the height direction. The through hole corresponds to the end part of the second leading-out end; the live wire connecting piece comprises a penetrating section and a turning-back section, one end of the penetrating section is fixedly connected with the second leading-out end, and the penetrating section penetrates through the magnetic core; the null line connecting piece is arranged in the through hole in a penetrating manner; an isolation part is arranged between the null line connecting piece and the penetrating section; the live wire connecting piece and the zero wire connecting piece are both metal rods which can be bent and shaped at will, so that the occupied space of the meter shell in the height direction can be reduced, the meter shell can be shaped after being bent correspondingly, and the safety distance can be ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of electronic control devices, in particular to a residual current detection device and an electric meter. Background Art

[0002] A relay is an electronic control device with a control circuit (also known as an input circuit) and a controlled system (also known as an output circuit). It is commonly used in automatic control circuits. A relay is essentially an "automatic switch" that uses a smaller current to control a larger one. Therefore, it plays a role in automatic regulation, safety protection, and circuit switching.

[0003] Magnetic latching relays are widely used in smart meters. They are used in combination with current transformers to form residual current detection devices to detect residual current and thus determine whether there is electricity theft or leakage.

[0004] In the related art, the current transformer is located below the magnetic latching relay so that the live wire lead on the magnetic latching relay passes directly through the current transformer from top to bottom. However, this layout will occupy the space in the height direction of the case. Utility Model Content

[0005] The embodiment of the utility model provides a residual current detection device to reduce the space occupied in the height direction of the watch case.

[0006] The residual current detection device provided in an embodiment of the present utility model is used to be installed in a meter case of an electric meter, the meter case having a height direction, the residual current detection device comprising a relay, a mutual inductor, a live wire connector, and a neutral wire connector, the relay and the mutual inductor being arranged in a direction perpendicular to the height direction, the relay comprising a first lead end and a second lead end; the mutual inductor comprising a magnetic core, the magnetic core having a through hole, the axis of the through hole being perpendicular to the height direction, the through hole corresponding to an end of the second lead end;

[0007] The live wire connector includes a passing section and a folded-back section, one end of the passing section is fixedly connected to the second lead-out end, the passing section passes through the magnetic core, and the folded-back section is located outside the mutual inductor;

[0008] The neutral line connector is passed through the through hole, and an isolation portion is provided between the neutral line connector and the passing section;

[0009] Wherein, the live wire connector and the neutral wire connector are both metal rods that can be bent and shaped arbitrarily.

[0010] According to some embodiments of the present invention, in the height direction, the upper surface of the folded segment is lower than the upper surface of the mutual inductor.

[0011] According to some embodiments of the present invention, the second lead-out end is plate-shaped, and the second lead-out end has a width direction, which is perpendicular to the height direction of the case and the axis of the magnetic core; an avoidance space is provided on one side of the width direction of the second lead-out end so that at least part of the projection of the folded section in the set plane is located within the side wall of the relay close to the transformer, and an extension portion is provided on the other side of the width direction of the second lead-out end, wherein the set plane is the plane where the side wall of the relay close to the transformer is located.

[0012] According to some embodiments of the present invention, in the width direction of the second lead-out end, the size of the extension portion is not less than the size of the avoidance space.

[0013] According to some embodiments of the present invention, the folding section includes a first sub-segment, a second sub-segment and a third sub-segment, one end of the first sub-segment is connected to the passing section, the other end of the first sub-segment is connected to one end of the second sub-segment, the second sub-segment extends toward the direction close to the relay, the other end of the second sub-segment is connected to one end of the third sub-segment, and the other end of the third sub-segment is used to be connected to the live wire output end of the electric meter.

[0014] According to some embodiments of the present invention, the projections of the first subsegment and the third subsegment within the set plane are both located within the side wall of the relay close to the transformer, and at least part of the projection of the second subsegment within the set plane is located within the side wall of the relay close to the transformer.

[0015] According to some embodiments of the present invention, the mutual inductor further includes a shell, the magnetic core is installed in the shell, and the shell is provided with a positioning structure, and the positioning structure is used to position the first sub-segment.

[0016] According to some embodiments of the present invention, the positioning structure includes two positioning protrusions, which are spaced apart to form a positioning groove, and a portion of the first sub-segment close to the second sub-segment is limited to the positioning groove.

[0017] According to some embodiments of the present invention, the mutual inductor further includes a shell, the magnetic core is installed in the shell, the shell is provided with a guide structure, the guide structure has a guide surface, and the extension direction of the second sub-segment is parallel to the guide surface.

[0018] According to some embodiments of the present invention, the neutral wire connector is U-shaped, and the neutral wire connector includes a first connecting section, a second connecting section and a third connecting section connected in sequence, the second connecting section is passed through the through hole, the first connecting section is located on the side of the mutual inductor close to the relay, and the third connecting section is located on the side of the mutual inductor away from the relay. The first connecting section is used to connect to the neutral wire output end of the electric meter, and the third connecting section is used to connect to the neutral wire input end of the electric meter.

[0019] According to some embodiments of the present invention, the isolation portion includes an isolation plate, which is detachably connected to the mutual inductor, and the isolation plate is located between the passing section and the neutral line connector.

[0020] According to some embodiments of the present invention, a first positioning groove is provided on the surface of the isolation plate close to the passing section, and the passing section is limited to the first positioning groove; a second positioning groove is provided on the surface of the isolation plate close to the neutral wire connector, and the neutral wire connector is limited to the second positioning groove.

[0021] According to some embodiments of the present invention, the end of the passing section has a connecting piece, the connecting piece is provided with a limiting portion, the second lead-out end is provided with a limiting matching portion, the limiting matching portion cooperates with the limiting portion to align the connecting piece with the second lead-out end, and the connecting piece is welded to the second lead-out end.

[0022] According to some embodiments of the present invention, one of the limiting portion and the limiting matching portion is a limiting notch, and the other is a limiting protrusion.

[0023] According to some embodiments of the present invention, the residual current detection device further includes a neutral line detection pin and a live line detection pin, the neutral line detection pin is connected to the neutral line connector, and the live line detection pin is connected to the first lead-out end.

[0024] The electric meter provided by the embodiment of the utility model includes a meter case, a terminal block and the residual current detection device, wherein the meter case includes a back plate, and the back plate is installed with a circuit board; the terminal block is installed on the meter case, and the terminal block is provided with a first wiring terminal, a second wiring terminal, a third wiring terminal and a fourth wiring terminal;

[0025] The first lead-out end is connected to the first terminal, the free end of the folded-back section is connected to the second terminal, the end of the neutral wire connector close to the relay is connected to the third terminal, and the end of the neutral wire connector away from the relay is connected to the fourth terminal.

[0026] After long-term observation, testing and research, the inventor of the utility model found that the reason why the residual current detection device in the prior art occupies a large space in the height direction inside the meter case is mainly that the prior art uses broadband welding pieces or soft wires as the lead-out pieces of the live wire and the neutral wire, which are respectively connected to the various terminals on the terminal block of the electric meter. Since the broadband welding pieces are rigid and not easy to bend, in order to make the lead-out pieces of the live wire and the neutral wire as close as possible to the terminals to be connected, it is usually necessary to place the current transformer below the magnetic latching relay. This layout will occupy the space in the height direction inside the meter case; if the current transformer and the magnetic latching relay are arranged in a direction perpendicular to the height direction of the meter case, the broadband welding piece needs to be bent and welded multiple times. For example, after the lead-out piece of the live wire passes through the through hole of the transformer, it is necessary to weld a right-angle bent plate-shaped welding piece to change its extension direction so that it extends to the top of the corresponding terminal, and then weld a welding piece extending vertically downward to connect to the corresponding terminal of the electric meter. This method of multiple bending and welding is inconvenient to operate and has low installation efficiency. When using soft wires for connection, although soft wires do not require welding, they are not easy to shape, resulting in the inability to ensure a safe distance between the neutral wire connector and the live wire connector.

[0027] Based on this, one embodiment of the above utility model has at least the following advantages or beneficial effects:

[0028] (1) The residual current detection device provided by the embodiment of the present invention can be installed in the case of an electric meter. The height direction of the residual current detection device is consistent with the height direction of the case. Since the relay and the mutual inductor are arranged in a direction perpendicular to the height direction of the case, the space occupied by the residual current detection device in the height direction of the case can be reduced. At the same time, since the live wire connector and the neutral wire connector are both metal rods that can be bent and shaped arbitrarily, the live wire connector and the neutral wire connector can be bent accordingly as needed. There is no need to weld the live wire connector and the neutral wire connector multiple times, which makes the operation easier. Moreover, the shape after bending can be fixed, and the safe distance between the neutral wire connector and the live wire connector can be guaranteed.

[0029] When detecting residual current, the live current flows through the live connector, and the neutral current flows through the neutral connector. Both currents flow through the transformer's magnetic core through-hole simultaneously, with equal magnitude and opposite directions. That is, the current in the through-hole section is opposite to the current in the portion of the neutral connector located within the through-hole. The neutral connector and the through-hole section are insulated and isolated by an isolation section. If an imbalance in the live and neutral currents occurs, the transformer's secondary side will sense a corresponding secondary current. This current, flowing through the meter's metering chip circuitry, can be used to analyze whether there are electrical safety issues, such as leaking wires or power theft.

[0030] (2) In the height direction, since the upper surface of the folded section is lower than the upper surface of the transformer, it can ensure that the portion between the top of the relay and the top of the transformer will not be blocked by the folded section, so that more components can be arranged in the space between the top of the relay and the top of the transformer.

[0031] (3) By providing an escape space on one side of the width direction of the second lead end, the folded section can be tilted and moved closer to the second lead end when bending, so that at least part of the projection of the folded section in the set plane is located inside the side wall of the relay close to the transformer, and only a small part of the folded section protrudes outside the side wall, which is conducive to reducing the size of the residual current detection device in the width direction. At the same time, by providing an extension portion on the side of the second lead end corresponding to the escape space, it can be ensured that the current-carrying area of the second lead end does not change significantly, thereby ensuring that the temperature of the second lead end is within a reasonable range and does not cause significant heating. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 The figure shows a schematic structural diagram of a residual current detection device provided by an embodiment of the present utility model;

[0033] Figure 2 Shown is a top view of a residual current detection device provided by an embodiment of the present utility model;

[0034] Figure 3 Shown is a left side view of the residual current detection device provided by an embodiment of the present utility model;

[0035] Figure 4 Shown is a front view of a residual current detection device provided by an embodiment of the utility model;

[0036] Figure 5 The figure shows a front view of a relay in a residual current detection device provided by an embodiment of the present utility model;

[0037] Figure 6 Shown is a bottom view of a relay in a residual current detection device provided by an embodiment of the present utility model;

[0038] Figure 7 FIG2 shows a schematic structural diagram of a mutual inductor in a residual current detection device provided by an embodiment of the present utility model;

[0039] Figure 8 FIG2 shows a schematic diagram of the structure of a mutual inductor in a residual current detection device provided by an embodiment of the present utility model;

[0040] Figure 9 Shown is a schematic structural diagram of a live wire connector in an embodiment of the present utility model;

[0041] Figure 10 Shown is a schematic structural diagram of a neutral line connector in an embodiment of the present utility model;

[0042] Figure 11 Shown is a schematic structural diagram of the isolation portion in an embodiment of the present utility model;

[0043] Figure 12 Shown is a schematic structural diagram of an electric meter provided by an embodiment of the utility model.

[0044] The following are the descriptions of the reference numerals:

[0045] 1-relay; 11-first lead-out terminal; 12-second lead-out terminal; 121-avoidance space; 122-extension portion; 123-limiting protrusion; 13-side wall; 14-coil lead-out pin; 15-auxiliary lead-out pin; 16-live detection pin; 2-transformer; 21-housing; 22-neutral detection pin; 211-positioning protrusion; 212-guide structure; 3-live connector; 31-through section; 311-connecting piece; 3111-limiting notch; 32-fold Return section; 321-first subsection; 322-second subsection; 323-third subsection; 4-neutral line connector; 41-first connecting section; 42-second connecting section; 43-third connecting section; 5-isolating portion; 51-isolating plate; 511-first positioning groove; 512-second positioning groove; 52-supporting portion; 6-case; 7-circuit board; 8-terminal block; 81-first terminal block; 82-second terminal block; 83-third terminal block; 84-fourth terminal block. DETAILED DESCRIPTION

[0046] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the concepts of the example embodiments to those skilled in the art. Like reference numerals in the figures represent like or similar structures, and thus their detailed description will be omitted.

[0047] See also Figures 1 to 12 As shown, this embodiment provides a residual current detection device, which is used to be installed in a meter case 6 of an electric meter. The meter case 6 has a height direction (in terms of Figure 12 The residual current detection device includes a relay 1, a mutual inductor 2, a live wire connector 3 and a neutral wire connector 4. The relay 1 and the mutual inductor 2 are arranged in a direction perpendicular to the height direction. In this embodiment, the relay 1 and the mutual inductor 2 are arranged in a direction perpendicular to the height direction. Figure 12Arranged in the direction of arrow X in the figure; the relay 1 includes a first lead-out terminal 11 and a second lead-out terminal 12; the mutual inductor 2 includes a magnetic core, the magnetic core has a through hole, the axis of the through hole is perpendicular to the height direction, and the through hole corresponds to the end of the second lead-out terminal 12; the live wire connector 3 includes a passing section 31 and a folded section 32, one end of the passing section 31 is fixedly connected to the second lead-out terminal 12, the passing section 31 passes through the magnetic core, and the folded section 32 is located outside the mutual inductor 2; the neutral wire connector 4 is passed through the through hole, and an isolation portion 5 is provided between the neutral wire connector 4 and the passing section 31; wherein, the live wire connector 3 and the neutral wire connector 4 are both metal rods that can be bent and shaped arbitrarily.

[0048] The residual current detection device provided in this embodiment can be installed in the case of an electric meter. The height direction of the residual current detection device is consistent with the height direction of the case. Since the relay and the mutual inductor are arranged in a direction perpendicular to the height direction of the case, the space occupied by the residual current detection device in the height direction of the case can be reduced. At the same time, since the live wire connector and the neutral wire connector are both metal rods that can be bent and shaped arbitrarily, the live wire connector and the neutral wire connector can be bent accordingly as needed. There is no need to weld the live wire connector and the neutral wire connector multiple times, which makes the operation easier. The shape after bending can be fixed, and the safe distance between the neutral wire connector and the live wire connector can be guaranteed.

[0049] When detecting residual current, the live current flows through live connector 3, and the neutral current flows through neutral connector 4. Both the live and neutral currents pass through the magnetic core through-hole of transformer 2 simultaneously, with equal magnitude and opposite directions. That is, the direction of the current in through-section 31 is opposite to the direction of the current in the portion of neutral connector 4 located within the through-hole. Neutral connector 4 is insulated from through-section 31 by isolation 5. If an imbalance in the live and neutral currents occurs, a corresponding secondary current will be sensed on the secondary side of transformer 2. This secondary current, flowing through the metering chip circuit in the electric meter, can be used to analyze whether there is an electrical safety issue, such as a broken wire leak or power theft.

[0050] For example, the relay 1 in this embodiment may be a magnetic latching relay, and the transformer 2 may be a current transformer.

[0051] It should be understood that the cross-section of the metal rod in this embodiment may be, but is not limited to, circular or elliptical. The material of the metal rod may be pure copper, brass, or red copper, which has strong conductivity and plasticity.

[0052] Exemplarily, the live wire connector 3 is formed by bending a copper rod. To facilitate welding, both ends of the live wire connector 3 are pressed into a flat shape so as to be respectively attached to and welded with the second lead-out terminal 12 and the live wire output terminal of the electric meter.

[0053] The copper rod has great flexibility during the bending process. In addition to being able to bend in the vertical and horizontal directions, it can also be bent in an inclined direction, which helps to make the overall structure of the residual current detection device more compact and the external dimensions smaller, thereby allowing more space to be arranged for other components.

[0054] In this embodiment, the live wire connector 3 is an integrally formed structure.

[0055] In one embodiment, the neutral wire connector 4 can also be formed by bending a copper rod. The two ends of the neutral wire connector 4 are also pressed into a flat shape to facilitate adhesion and welding to the neutral wire input and output terminals of the meter. In this embodiment, the neutral wire connector 4 is an integrally formed structure.

[0056] For example, see Figure 10 As shown, the neutral wire connector 4 is U-shaped, and the neutral wire connector 4 includes a first connecting section 41, a second connecting section 42 and a third connecting section 43 connected in sequence. The second connecting section 42 is passed through the through hole. The first connecting section 41 is located on the side of the mutual inductor 2 close to the relay 1, and the third connecting section 43 is located on the side of the mutual inductor 2 away from the relay 1. The first connecting section 41 is used to connect to the neutral wire output terminal of the electric meter, and the third connecting section 43 is used to connect to the neutral wire input terminal of the electric meter.

[0057] See also Figure 10 As shown, the end of the first connecting section 41 is flat, so as to be connected to the neutral line output terminal of the electric meter; the end of the third connecting section 43 is flat, so as to be connected to the neutral line input terminal of the electric meter.

[0058] In some embodiments, along the height direction, the top of the relay 1 may be higher than the top of the transformer 2 .

[0059] In some embodiments, the upper surface of the folded section 32 is lower than the upper surface of the transformer 2 in the height direction. This ensures that the space between the top of the relay and the top of the transformer is not obstructed by the folded section, allowing for the placement of more components in the space between the top of the relay and the top of the transformer. Furthermore, this improves the manufacturability and performance of the components, and allows for a wider range of component selection.

[0060] In this embodiment, the upper surface of the folded section 32 refers to the surface of the folded section 32 at the highest point in the height direction, and the upper surface of the mutual inductor 2 refers to the surface of the mutual inductor 2 at the highest point in the height direction.

[0061] In this embodiment, the first lead-out end 11 faces the bottom of the meter case 6 and is used to be connected to the live wire input end of the electric meter, and the second lead-out end 12 faces the mutual inductor 2 .

[0062] In one embodiment, see Figure 6As shown, the second lead-out end 12 is plate-shaped and has a width direction (indicated by the arrow direction Y), which is perpendicular to the height direction of the case 6 and the axis of the magnetic core; an avoidance space 121 is provided on one side of the width direction of the second lead-out end 12, so that at least part of the projection of the folded section 32 in the set plane is located in the side wall 13 of the relay 1 close to the transformer 2, and an extension portion 122 is provided on the other side of the width direction of the second lead-out end 12, wherein the set plane is the plane where the side wall 13 of the relay 1 close to the transformer 2 is located.

[0063] By providing an avoidance space 121 on one side of the width direction of the second lead-out end 12, the folded section 32 can be tilted and moved closer to the second lead-out end 12 when bending, so that at least part of the projection of the folded section 32 in the set plane is located inside the side wall 13 of the relay 1 close to the mutual inductor 2, see Figure 3 As shown, only a small portion of the folded-back section 32 protrudes from the outside of the side wall 13 , thereby facilitating reduction in the width dimension of the residual current detection device.

[0064] At the same time, by providing an extension portion 122 on one side of the second lead-out end 12 corresponding to the avoidance space 121, it can be ensured that the current-carrying area of the second lead-out end 12 does not change significantly, thereby ensuring that the temperature of the second lead-out end 12 is within a reasonable range without obvious heating.

[0065] In one embodiment, see Figure 6 As shown, in the width direction of the second lead-out terminal 12 , the dimension W2 of the extension portion 122 is not less than the dimension W1 of the avoidance space 121 .

[0066] It should be understood that after the relay 1 and the transformer 2 are inserted into the circuit board 7 in the electric meter, the end face of the extension portion 122 faces the circuit board 7. On the premise that the extension portion 122 does not interfere with the circuit board 7, the size W2 of the extension portion 122 can be as large as possible.

[0067] In one embodiment, the extension portion 122 and the second lead end 12 are integrally formed, which not only facilitates processing but also improves the overall structural strength of the second lead end 12 and the stability of the connection between the second lead end 12 and the passing section 31 .

[0068] In one embodiment, see Figure 9As shown, the folded-back section 32 includes a first sub-segment 321, a second sub-segment 322 and a third sub-segment 323. One end of the first sub-segment 321 is connected to the passing section 31, and the other end of the first sub-segment 321 is connected to one end of the second sub-segment 322. The second sub-segment 322 extends toward the direction close to the relay 1, and the other end of the second sub-segment 322 is connected to one end of the third sub-segment 323. The other end of the third sub-segment 323 is used to be connected to the live wire output terminal of the electric meter.

[0069] For example, see Figure 1 and Figure 2 As shown, the first sub-segment 321 is bent in an oblique direction to a position on the upper front side of the transformer 2, the second sub-segment 322 extends in a direction substantially parallel to the axis of the magnetic core toward the relay 1, and the third sub-segment 323 extends toward the bottom of the relay 1. At the same time, since the second lead-out end 12 is provided with an avoidance space 121, the third sub-segment 323 can be inclined toward the second lead-out end 12, so that a portion of the third sub-segment 323 is located within the avoidance space 121, thereby reducing the size of the portion of the third sub-segment 323 protruding from the side wall 13 of the relay 1.

[0070] It should be understood that the position of the free end of the third sub-segment 323 can be adjusted according to the position of the live wire output end of the electric meter. For example, the position of the free end of the third sub-segment 323 can be changed by bending the third sub-segment 323 to facilitate alignment and welding with the live wire output end of the electric meter.

[0071] In this embodiment, the first sub-segment 321 , the second sub-segment 322 and the third sub-segment 323 are integrally formed.

[0072] In one embodiment, see Figure 2 As shown, the projections of the first sub-segment 321 and the third sub-segment 323 in the set plane are both located within the side wall 13 of the relay 1 close to the transformer 2 , and at least part of the projection of the second sub-segment 322 in the set plane is located within the side wall 13 of the relay 1 close to the transformer 2 .

[0073] For example, Figure 2 The dotted line in FIG represents the side edge of the side wall 13 of the relay 1 close to the transformer 2. The projection of most of the second sub-segment 322 in the set plane is located inside the side wall 13 of the relay 1 close to the transformer 2 (i.e. Figure 2 Only a small portion of the relay 1 away from the transformer 2 has its projection in the set plane located outside the side wall 13 of the relay 1 close to the transformer 2 (i.e. Figure 2 above the dotted line).

[0074] In one embodiment, the end of the through section 31 has a connecting piece 311, the connecting piece 311 is provided with a limiting portion, and the second lead-out end 12 is provided with a limiting matching portion. The limiting matching portion cooperates with the limiting portion to align the connecting piece 311 with the second lead-out end 12, and the connecting piece 311 and the second lead-out end 12 are welded.

[0075] By cooperating with the limiting matching portion, the position of the connecting piece 311 can be limited, so that the position of the connecting piece 311 and the second lead end 12 can be aligned, which facilitates welding and fixing the connecting piece 311 and the second lead end 12.

[0076] In some embodiments, see Figure 8 and Figure 9 As shown, the limiting portion is a limiting notch 3111, and the limiting mating portion is a limiting protrusion 123. For example, there are two limiting notches 3111, which are positioned opposite each other on either side of the connecting piece 311. Accordingly, there are also two limiting protrusions 123, which are respectively retained within the two limiting notches 3111.

[0077] For example, see Figure 6 As shown, one of the limiting protrusions 123 is located on the surface of the second lead-out end 12 , and the other limiting protrusion 123 is located on the surface of the extending portion 122 .

[0078] In other embodiments, the limiting portion may also be a limiting protrusion 123 , and the limiting matching portion may be a limiting notch 3111 .

[0079] In one embodiment, see Figure 1 As shown, the mutual inductor 2 further includes a housing 21 , the magnetic core is installed in the housing 21 , and the housing 21 is provided with a positioning structure, which is used to position the first sub-segment 321 .

[0080] Since the first subsection 321 is bent in an inclined direction, in order to improve assembly efficiency, a positioning structure is provided on the housing 21 , which can position the first subsection 321 during assembly, thereby ensuring that the live wire connector 3 is quickly installed in place.

[0081] In some embodiments, see Figure 1 and Figure 2 As shown, the positioning structure includes two positioning protrusions 211 , which are spaced apart to form a positioning groove, and a portion of the first sub-segment 321 close to the second sub-segment 322 is limited to the positioning groove.

[0082] Exemplarily, the two positioning protrusions 211 are both arranged on the end face of the housing 21 away from the relay 1, and the extension direction of the two positioning protrusions 211 is substantially parallel to the axis of the magnetic core. During assembly, it is ensured that the part of the first sub-segment 321 close to the second sub-segment 322 can enter the positioning groove from the notch of the positioning groove.

[0083] It should be noted that the positioning structure is not limited to the above form. Other forms of positioning structures can be selected according to production and processing requirements, product appearance, etc., as long as the positioning function of the first sub-segment 321 can be achieved.

[0084] In one embodiment, see Figure 4 As shown, the housing 21 of the transformer 2 is provided with a guide structure 212 , the guide structure 212 has a guide surface, and the extension direction of the second sub-segment 322 is parallel to the guide surface.

[0085] Exemplarily, the guide structure 212 may include a rectangular block structure, and the guide surface is the surface of the rectangular block structure close to the second sub-segment 322. The shape of the surface is a rectangle, and the length direction of the rectangle is consistent with the extension direction of the second sub-segment 322. In this way, the guiding distance of the guide surface to the second sub-segment 322 can be increased, thereby enhancing the guiding effect.

[0086] In one embodiment, see Figure 11 As shown, the isolation portion 5 includes an isolation plate 51 , which is detachably connected to the mutual inductor 2 . The isolation plate 51 is located between the through section 31 and the neutral line connector 4 to provide insulation between the through section 31 and the neutral line connector 4 .

[0087] In order to prevent the isolation plate 51 from loosening, in this embodiment, support parts 52 are provided on both long sides of the isolation plate 51. Exemplarily, the support parts 52 can be support rods, which abut against the inner ring wall of the outer shell 21, thereby improving the stability of the isolation plate 51 and ensuring the insulation isolation effect between the through section 31 and the second connecting section 42.

[0088] In one embodiment, see Figure 3 and Figure 11 As shown, a first positioning groove 511 is provided on the surface of the isolation plate 51 close to the passing section 31, and the passing section 31 is limited to the first positioning groove 511; a second positioning groove 512 is provided on the surface of the isolation plate 51 close to the neutral line connector 4, and the neutral line connector 4 is limited to the second positioning groove 512.

[0089] Exemplarily, the first positioning groove 511 and the second positioning groove 512 may both be arc-shaped grooves to match the circumferential surface of the cylindrical copper rod.

[0090] In one embodiment, see Figure 1As shown, the residual current detection device further includes a neutral line detection pin 22 and a live line detection pin 16 . The neutral line detection pin 22 is connected to the neutral line connector 4 , and the live line detection pin 16 is connected to the first lead-out terminal 11 .

[0091] Exemplarily, the neutral line detection pin 22 may be welded to the first connection section 41 of the neutral line connector 4 , and the live line detection pin 16 may be integrally formed with the first lead-out end 11 .

[0092] See also Figure 3 As shown, the relay further includes a coil lead-out pin 14 and an auxiliary lead-out pin 15 , which are used to connect to a circuit board of an electric meter.

[0093] Figure 12 The arrow direction Z in the figure indicates the height direction of the case, the arrow direction Y indicates the width direction of the case, and the arrow direction X indicates the length direction of the case. Figure 12 As shown, this embodiment also provides an electric meter, including a meter case 6, a terminal block 8 and a residual current detection device provided in this embodiment, the meter case 6 includes a back plate, and the back plate is installed with a circuit board 7; the terminal block 8 is installed on the meter case 6, and the terminal block 8 is provided with a first terminal 81, a second terminal 82, a third terminal 83 and a fourth terminal 84; the first lead-out end 11 is connected to the first terminal 81, the free end of the folded-back section 32 is connected to the second terminal 82, the end of the neutral wire connector 4 close to the relay 1 is connected to the third terminal 83, and the end of the neutral wire connector 4 away from the relay 1 is connected to the fourth terminal 84.

[0094] The electric meter provided in this embodiment uses the residual current detection device provided in this embodiment. Since the top of the relay 1 is higher than the top of the transformer 2, and at the same time, in the height direction, the upper surface of the folded section 32 is lower than the upper surface of the transformer 2, that is, the projection of the upper surface of the folded section 32 in the plane where the back plate is located is located below the projection of the upper surface of the transformer 2 in the plane where the back plate is located; it is ensured that the part between the top of the relay 1 and the top of the transformer 2 will not be blocked by the folded section 32, so that more components can be arranged in the area of the circuit board 7 corresponding to the space between the top of the relay 1 and the top of the transformer 2.

[0095] In this embodiment, the upper surface of the folded section 32 refers to the surface of the folded section 32 that is at the highest point in the height direction, that is, the surface of the folded section 32 that is farthest from the top of the terminal block 8. The upper surface of the transformer 2 refers to the surface of the transformer 2 that is at the highest point in the height direction, that is, the surface of the transformer 2 that is farthest from the top of the terminal block 8.

[0096] The current flows from the outdoor live wire through the first terminal 81 (i.e., the live wire input terminal of the meter), from the relay 1 to the second terminal 82 (i.e., the live wire output terminal of the meter), and then into the indoor live wire. After passing through the electrical load, the current flows from the indoor neutral wire through the fourth terminal 84 (i.e., the neutral wire input terminal of the meter), through the transformer 2, and then flows from the third terminal 83 (i.e., the neutral wire output terminal of the meter) into the outdoor neutral wire.

[0097] When detecting residual current, the live current flows through live connector 3, and the neutral current flows through neutral connector 4. Both the live and neutral currents pass through the magnetic core through-hole of transformer 2 simultaneously, with equal magnitude and opposite directions. That is, the direction of the current in through-section 31 is opposite to the direction of the current in the portion of neutral connector 4 located within the through-hole. Neutral connector 4 is insulated from through-section 31 by isolation 5. If an imbalance in the live and neutral currents occurs, a corresponding secondary current will be sensed on the secondary side of transformer 2. This secondary current, flowing through the metering chip circuit in the electric meter, can be used to analyze whether there is an electrical safety issue, such as a broken wire leak or power theft.

[0098] Exemplarily, the neutral line detection pin 22 is used to collect the neutral line signal, and the live line detection pin 16 is used to collect the live line signal. The circuit board 7 is provided with a chip for comparing the neutral line current and the live line current and calculating the leakage current to realize leakage current detection.

[0099] Finally, it should be noted that: it is understandable that the various embodiments / implementations provided by the present invention can be combined with each other without causing any contradiction, and will not be illustrated one by one here.

[0100] In the embodiments of the utility model, the terms "first," "second," and "third" are used for descriptive purposes only and should not be understood to indicate or imply relative importance; the term "plurality" refers to two or more, unless otherwise expressly defined. Terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, "connected" can mean a fixed connection, a detachable connection, or an integral connection; "connected" can mean a direct connection or an indirect connection through an intermediary. For those skilled in the art, the specific meanings of the above terms in the embodiments of the utility model can be understood according to the specific circumstances.

[0101] In the description of the utility model embodiments, it should be understood that the terms "up", "down", "left", "right", "front", "back", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the utility model embodiments and simplifying the description, rather than indicating or implying that the device or unit referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, it cannot be understood as a limitation on the utility model embodiments.

[0102] Throughout this specification, terms such as "one embodiment," "some embodiments," and "specific embodiments" mean that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the utility model. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0103] The above are merely preferred embodiments of the utility model and are not intended to limit the utility model. Those skilled in the art will readily appreciate that various modifications and variations of the utility model embodiments are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the utility model embodiments shall be included within the scope of protection of the utility model embodiments.

Claims

1. A residual current detection device, characterized in that: The residual current detection device is used to be installed in a case of an electric meter, the case having a height direction, the residual current detection device comprising a relay, a mutual inductor, a live wire connector, and a neutral wire connector, the relay and the mutual inductor being arranged in a direction perpendicular to the height direction, the relay comprising a first lead-out terminal and a second lead-out terminal; the mutual inductor comprising a magnetic core, the magnetic core having a through hole, the axis of the through hole being perpendicular to the height direction, the through hole corresponding to an end of the second lead-out terminal; The live wire connector includes a passing section and a folded-back section, one end of the passing section is fixedly connected to the second lead-out end, the passing section passes through the magnetic core, and the folded-back section is located outside the mutual inductor; The neutral line connector is passed through the through hole, and an isolation portion is provided between the neutral line connector and the passing section; Wherein, the live wire connector and the neutral wire connector are both metal rods that can be bent and shaped arbitrarily.

2. The residual current detection device according to claim 1, characterized in that: In the height direction, an upper surface of the folded section is lower than an upper surface of the mutual inductor.

3. The residual current detection device according to claim 1, characterized in that: The second lead-out end is plate-shaped and has a width direction, which is perpendicular to the height direction of the case and the axis of the magnetic core; an avoidance space is provided on one side of the width direction of the second lead-out end so that at least part of the projection of the folded section in the set plane is located within the side wall of the relay close to the transformer, and an extension portion is provided on the other side of the width direction of the second lead-out end, wherein the set plane is the plane where the side wall of the relay close to the transformer is located.

4. The residual current detection device according to claim 3, characterized in that: In the width direction of the second lead-out end, the size of the extension portion is not less than the size of the avoidance space.

5. The residual current detection device according to claim 3, characterized in that: The folding section includes a first sub-segment, a second sub-segment and a third sub-segment, one end of the first sub-segment is connected to the passing section, the other end of the first sub-segment is connected to one end of the second sub-segment, the second sub-segment extends toward the direction close to the relay, the other end of the second sub-segment is connected to one end of the third sub-segment, and the other end of the third sub-segment is used to be connected to the live wire output end of the electric meter.

6. The residual current detection device according to claim 5, characterized in that: Projections of the first subsegment and the third subsegment on the set plane are both located within the side wall of the relay close to the transformer, and at least part of the projection of the second subsegment on the set plane is located within the side wall of the relay close to the transformer.

7. The residual current detection device according to claim 5, characterized in that: The mutual inductor further includes a shell, the magnetic core is installed in the shell, and the shell is provided with a positioning structure, and the positioning structure is used to position the first sub-segment.

8. The residual current detection device according to claim 7, characterized in that: The positioning structure includes two positioning protrusions, which are spaced apart to form a positioning groove, and a portion of the first sub-segment close to the second sub-segment is limited to the positioning groove.

9. The residual current detection device according to claim 5, characterized in that: The mutual inductor further includes a shell, the magnetic core is installed in the shell, the shell is provided with a guide structure, the guide structure has a guide surface, and the extension direction of the second sub-segment is parallel to the guide surface.

10. The residual current detection device according to any one of claims 1 to 9, characterized in that: The neutral wire connector is U-shaped and includes a first connecting section, a second connecting section and a third connecting section connected in sequence. The second connecting section is passed through the through hole. The first connecting section is located on the side of the mutual inductor close to the relay, and the third connecting section is located on the side of the mutual inductor away from the relay. The first connecting section is used to connect to the neutral wire output terminal of the electric meter, and the third connecting section is used to connect to the neutral wire input terminal of the electric meter.

11. The residual current detection device according to any one of claims 1 to 9, characterized in that: The isolation portion includes an isolation plate, which is detachably connected to the mutual inductor and is located between the passing section and the neutral line connector.

12. The residual current detection device according to claim 11, characterized in that: A first positioning groove is provided on the surface of the isolation plate close to the passing section, and the passing section is located in the first positioning groove; a second positioning groove is provided on the surface of the isolation plate close to the neutral line connector, and the neutral line connector is located in the second positioning groove.

13. The residual current detection device according to any one of claims 1 to 9, characterized in that: The end of the passing section has a connecting piece, the connecting piece is provided with a limiting portion, the second lead-out end is provided with a limiting matching portion, the limiting matching portion cooperates with the limiting portion to align the connecting piece with the second lead-out end, and the connecting piece is welded to the second lead-out end.

14. The residual current detection device according to claim 13, characterized in that: One of the limiting portion and the limiting matching portion is a limiting notch, and the other is a limiting protrusion.

15. The residual current detection device according to any one of claims 1 to 9, characterized in that: It also includes a neutral line detection pin and a live line detection pin, wherein the neutral line detection pin is connected to the neutral line connector, and the live line detection pin is connected to the first lead-out end.

16. An electric meter, characterized in that: The residual current detection device comprises a meter case, a terminal block, and any one of claims 1 to 15, wherein the meter case comprises a back plate, and a circuit board is mounted on the back plate; the terminal block is mounted on the meter case, and the terminal block is provided with a first terminal, a second terminal, a third terminal, and a fourth terminal; The first lead-out end is connected to the first terminal, the free end of the folded-back section is connected to the second terminal, the end of the neutral wire connector close to the relay is connected to the third terminal, and the end of the neutral wire connector away from the relay is connected to the fourth terminal.

Images