TWI518731B - Residual current protection trip mechanism and release - Google Patents

Description

Residual current protection tripping mechanism and trip unit

The present invention relates to a molded case circuit breaker, and more particularly to a thermal electromagnetic release for the molded case circuit breaker, the thermal electromagnetic release can be combined with a residual current protector to achieve overload protection and short circuit protection Also achieves residual current protection.

Molded case circuit breakers are widely used in medium and low voltage circuits to distribute electrical energy and protect circuits, power supplies and electrical equipment.

The molded case circuit breaker is usually equipped with a trip unit, which performs protection functions, namely: overload protection, short circuit protection, time delay protection and leakage protection. As a traditional mechanical structure, the circuit breaker is generally based on thermal overload protection and short circuit protection. The thermal overload protection device is usually realized by a bimetal and a current loop. When the temperature exceeds a certain threshold, the bimetal deforms to push the trip mechanism, so that the trip unit is tripped. The short circuit protection is usually composed of a coil and an electromagnet. When the short circuit current exceeds a certain threshold, the electromagnet acts to push the trip mechanism, and the buckle is tripped.

In addition, in addition to the above protection function, a residual current protection device is usually disposed in the molded case circuit breaker, and the residual current protection device realizes a residual current protection function, and the residual current protection device can identify a fault leakage current in the circuit, thereby ensuring personnel and System security.

In view of the trend of miniaturization and cost reduction of molded case circuit breakers, the residual current protection device is usually matched with the thermal magnetic release device to cut off the fault leakage current in the circuit. And after the fault is discharged, the mechanism of the thermal magnetic trip unit should realize the reset of the trip unit and the circuit breaker body only after the residual current protection device is reset.

In the prior art circuit breaker, although the cooperation of the residual current protection device and the thermal magnetic release mechanism can be realized, the residual current protection device is required to provide a large tripping force, and the design margin is small, and therefore, a short circuit occurs. After the fault or the mechanism is contaminated, the trip unit cannot be tripped or mis-tripped, and the reliability is lowered.

Thus, there has been a need for improvements in existing thermal electromagnetic trips and residual current protection mechanisms.

In view of the above circumstances, the present invention provides a novel residual current trip mechanism including a drawbar and a jumper, the jumper interacting with the drawbar such that the jumper is in a normal working position and a trip position Inter-action, the drawbar has a first engaging portion and a second engaging portion, and a residual current protection rod of the residual current protection device interacts with the first engaging portion to cause the drawbar to act, thereby actuating the jump The buckle is unlocked, and at least one of the overload protection device and the short circuit protection device interacts with the second engagement portion to cause the drawbar to act, thereby actuating the trip buckle to be released.

The second engaging portion is a rotating arm to cooperate with the short circuit protection device, and the drawbar further includes a third engaging portion that cooperates with the overload protection device to cause the overload protection to occur The drawbar moves.

With the above configuration, the residual current protection device, the overload protection device, the short circuit protection device, and the like share a trip protection mechanism, thereby simplifying the structure and saving cost. Moreover, since the mechanism of the residual circuit protection of the trip unit is the same as the short circuit protection and the overload protection, that is, the tripping pushes the circuit breaker mechanism to trip, thereby simplifying the trip design between the trip unit and the circuit breaker body. It also simplifies the fault current indication design.

Preferably, the action of the jumper between the normal working position and the trip position is a translational action. In addition, the residual current protection rod acts on the residual current protection rod engaging portion such that the traction rod rotates in a first direction, and at least one of the overload protection device and the short circuit protection device acts on the first The two engaging portions rotate the drawbar in the first direction. Preferably, the drawbar has a buckle portion, and the jumper has a lap end, and the drawbar is biased such that a buckle portion thereof overlaps with the lap joint of the jumper to The jumper is maintained in the normal working position.

Through such a structure, the jump buckle realizes the tripping by the translational sliding, ensuring reliable driving of the circuit breaker mechanism to be released, the tripping process is simple, and the action is ensured to be reliable and stable. The residual current protection rod can cooperate with the residual current protector to push the trip mechanism to trip when a leakage current fault occurs, thereby cutting off the fault current. In order to realize the jump buckle, the tripping force required by the residual current protector can be significantly reduced, thereby significantly increasing the design margin and improving the reliability of the product, especially after the short-circuit fault occurs (the mechanism is seriously polluted) Reliability of the remaining circuit protection functions.

Preferably, when the residual current protection device is triggered, the residual current protection rod is translated along its length to push the traction rod.

With this structure, compared with the structure in which the residual current protection rod rotates to push the traction rod in the prior art, the space required for the movement of the residual current protection rod can be saved, the motion reliability of the residual current protection rod can be improved, and the residual current can be reduced. The triggering force of the protection device.

Preferably, the residual current protection rod is provided with a guiding limiter portion that interacts with a corresponding portion disposed on the trip mechanism base or the circuit breaker housing to The residual current protection rod guides the residual current protection rod during movement and limits the movement stroke of the residual current protection rod. Preferably, the guiding stop portion is a guiding groove formed on one side of the residual current protection rod, and the corresponding portion is a base or a circuit breaker housing disposed on the trip mechanism The upper guiding boss is inserted into the guiding groove.

With this configuration, the movement stability of the residual current protection rod can be ensured with a simple structure. Preferably, the residual current protection rod engaging portion is a platform portion disposed on one side of the drawbar, and the platform portion is inserted into a recessed portion formed on the residual current protection rod such that the residual current During the translation of the protection rod, the recessed portion abuts and pushes the platform portion of the tow bar.

With this configuration, when the residual current protection device is not reset, since the platform portion of the drawbar is inserted into the recessed portion of the residual current protection lever, the rotation of the drawbar in the reset direction is prevented. That is to say, the trip mechanism and the trip unit body can be reset only after the residual current protection device is reset, thereby improving the safety of the device.

The residual current protection trip mechanism may further include a bracket having a guiding chute, the jumper being slidably mounted in the guiding chute, and being guided by the guiding chute .

By setting the bracket, the jumper can be positioned more accurately and the action of the jumper is guided by the bracket, which improves the reliability of the jump buckle.

Preferably, the residual current protection trip mechanism is mounted on the housing of the trip unit to form an element.

With this structure, the entire trip unit is assembled as a whole with the circuit breaker, and is interchangeable (between the circuit breaker and the trip unit; between the trip unit and the residual current protector), which is convenient for industrial production and satisfaction. The needs of different customers. The structure of the tripping mechanism is also effective in shortening the production and assembly time of the circuit breaker, and is more convenient for production, storage and management.

According to another aspect of the present invention, there is also provided a trip unit including the above-described trip mechanism.

Other aspects, features, and advantages will be readily apparent as they become readily apparent by reference to the appended claims.

In describing the embodiments shown in the figures, specific terminology is employed for the sake of clarity. However, the disclosure of this patent specification is not intended to be limited to the specific terms so selected, and it is understood that each specific element includes all technical equivalents that operate in a similar manner and achieve similar effects. In the following description, the terms "including", "comprising", and the like, are to be understood as open-ended, and it is intended that other elements or components that are not specified may be present in addition to the elements or components specified. These unspecified elements or components are readily conceivable by those skilled in the art in light of the teachings of the present invention.

The exemplary embodiments are described with reference to the accompanying drawings, which are not intended to limit the scope of the invention, and all the components or elements described in the exemplary embodiments of the disclosure are not necessarily Less.

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. 1 and 2 illustrate a trip unit 100 in accordance with a preferred embodiment of the present invention. As known in the prior art, the trip unit 100 mainly includes a main housing 101, an assembly portion (not shown) that assembles the trip unit 100 with the circuit breaker, and a protection device housed in the main housing 101 ( Not shown), and a trip mechanism 102 or the like that is substantially mounted on the upper portion of the main casing 101. The protection device comprises an overload protection device, a short circuit protection device and a residual current protection device. In the event of an overload, a short circuit, a fault leakage current, etc., the protection device is triggered, so that the trip mechanism is tripped. Since these protection devices can be used in the same protection device as in the prior art, it is not the key to the present invention. Therefore, those skilled in the art can implement the structure in the prior art, and will not be described in detail herein.

Referring now to the drawings, and in particular to Figures 3 through 10, a trip mechanism 102 in accordance with a preferred embodiment of the present invention will be described in detail. The trip mechanism 102 is designed in the form of an element that is detachably mountable to the top of the main housing 101 of the trip unit 100 and that can be versatile between a plurality of different types of trip units. The installed trip unit 100 can then be assembled to the circuit breaker as a whole.

As shown in FIGS. 1 and 2, the trip mechanism 102 basically includes a bracket 10, a drawbar 20, a jumper 30, and a residual current protection bar 40. The bracket 10 is mounted on the main housing 101 of the trip unit 100 to accommodate the drawbar 20 of the trip mechanism 102, the jumper 30, and the residual current protection lever 40. The drawbar 20 is pivotable with a shaft passing therethrough, the opposite ends of which are mounted on the side panels 50, respectively. Of course, the shaft can also be integral with the drawbar 20, and the ends of the shaft (i.e., the ends of the drawbar 20) can be pivotally mounted on the side panel 50.

In addition, the drawbar 20 is biased in a predetermined direction by means of a return spring (not shown). The return spring may be a torsion spring having one end of the twisted arm caught on the drawbar 20 and the other end being caught in a corresponding slot (not shown) of the main casing 101 so as to be in a predetermined direction (clockwise in the present invention) The bias rod 20 is biased. Of course, other forms of springs or spring elements can be used to achieve the same function, which are all within the scope of the invention.

As shown in Fig. 3, the drawbar 20 is substantially long rod-shaped, and a buckle portion 21 is provided on one side of its outer circumference (the level side in Fig. 3) so as to overlap the jumper 30 which will be described later. Further, on the other side of the outer circumference of the drawbar 20 (the lower side in FIG. 3), a plurality of rotary arms 22A-22C are provided, and after being mounted on the trip unit 100, the rotary arms 22A-22C are respectively and three The triggering elements of the phase short circuit protection device are engaged. On the upper side of the drawbar 20 in Fig. 3, three projections 24A-24C are provided corresponding to the three phases, and the projections 24A-24C are provided with holes 25A-25C into which the heat adjustment screws (not shown) are screwed. Go to these holes. After assembly, these thermal adjustment screws cooperate with the triggering elements of the overload protection device, respectively. The length of the thermal adjustment screw extending from the apertures 25A-25C can be adjusted to adjust the stroke length of the entire overload protection mechanism and the amount of clearance between the overturning screw and the triggering element of the overload protection device. Further, a residual current protection lever engagement portion 23 is provided on the drawbar 20 at a position different from substantially the same side of the rotary arms 22A-22C, the residual current protection lever engagement portion 23 and the residual current protection lever 40 which will be described below. They are joined and formed into a substantially platform shape.

Referring now to Figures 4 and 8, the jumper 30 is generally elongate, having a generally hook-shaped overlapping end 31 at one end and a generally disc-shaped actuator portion 33 at the other end that urges the circuit breaker mechanism latching device Then cut off the fault current. In addition, ribs 32 are provided on the body of the jumper to increase the strength of the entire jumper 30. As shown in FIG. 8, after assembly, the jumper 30 is located above the drawbar 20, and the overlapping end 31 of the jumper 30 overlaps the buckle portion 21 of the drawbar 20. As shown, in the preferred embodiment of the present invention, the overlapping end 31 of the jumper 30 is hook-shaped, and the overlapping portion 21 of the drawbar 20 is substantially stepped, but those skilled in the art can understand that Any suitable shape may be employed without departing from the scope of the invention, as long as the two can achieve a releasable overlap.

Referring now to Figures 6 and 7, the jumper 30 is mounted in the guide chute 11 of the bracket 10. The bracket 10 is mounted on the base of the trip mechanism 102. And a guiding slot (not shown) is provided in the guiding slot 11 of the bracket 10 to cooperate with the rib 32 of the jumper 30, and it is determined that the jumper 30 is correctly installed and guides the jump during the movement of the jumper 30. The movement of the buckle 30. Of course, the present invention is not limited to such a guiding structure, but any guiding structure can be used to achieve the guiding effect on the jumper 30. A biasing spring (not shown) is disposed between the jumper 30 and the bracket 10 to bias the jumper 30 in the direction shown by A in Figs. 10A and 10B.

Referring now to Figures 5 and 9, the residual current protection bar 40 is elongate, and the residual current protection bar 40 slides in a predetermined direction when the residual current protection device is triggered. The residual current protection lever 40 is guided to move by means of a corresponding guiding portion (not shown) on the housing 101 of the trip unit 100. Specifically, a convex portion is formed on one side of the protective rod 40, and a guiding groove 411 is formed in the convex portion 41. After assembly, a guide boss (not shown) as a guide portion on the trip unit housing 101 is inserted into the guide groove 411 so that the protection lever 40 can only be in the longitudinal direction of the guide groove 411. (the direction along the length of the guard bar 40 in Fig. 5) moves back and forth, and the length of the stroke of the movement is defined by the length of the guide groove 411 in the length direction. Of course, other forms of guiding and limiting structure can also be used. For example, the guiding boss is formed on the protection rod 40, and the guiding groove is formed on the main casing 101 of the trip unit, which are all included in the present. Within the scope of protection of the invention.

In addition, the residual current protection rod 40 is formed at a corresponding position in the longitudinal direction thereof with a recessed portion 42 sized to be engageable with the residual current protection rod engagement portion 23 of the drawbar 20, specifically, After assembly, the residual current protection lever engagement portion 23 of the drawbar 20 is inserted into the recessed portion 42 so as to push the drawbar 20 by the engagement of the residual current protection lever engagement portion 23 and the recessed portion 42 as the protection lever 40 moves. Turn. However, the engagement between the drawbar 20 and the residual current protection bar 40 may also adopt other structures, for example, forming a boss on the protection bar, the boss may abut the remaining current of the drawbar to protect the lever engagement portion to push the traction bar to rotate. Alternatively, other joining methods such as pins and cymbals may be employed, and therefore, all structures that can achieve the above functions are within the scope of the present invention.

Next, the operation of the trip mechanism of the present invention will be described with reference to Figs. 10A and 10B.

Fig. 10A shows the state before the trip mechanism is triggered. As shown in FIG. 10A, in this state, under the action of the return spring of the drawbar 20, the overlapping end 31 of the jumper 30 and the snap portion 21 of the drawbar 20 are overlapped to each other, and the jumper 30 is held in place. . And the residual current protection lever engagement portion 23 is inserted into the recessed portion 42 of the residual current protection lever 40. The trip unit 100 is in normal working condition.

In the event of a fault leakage current, a residual current protection device (not shown) is triggered such that the residual current protection bar 40 moves in the direction indicated by arrow A in FIG. 10A, whereby the recessed portion 42 of the protection bar 40 pushes the drawbar 20 The residual current protection lever engages the portion 23 such that the drawbar 20 rotates counterclockwise about the shaft in FIG. As the drawbar 20 rotates, the buckle portion 21 of the drawbar 20 is disengaged from the overlapping end 31 of the jumper 30, whereby the retaining action of the drawbar 20 on the jumper 30 is lost, and the jumper 30 is biased spring. Under the action of (not shown) and under the guidance of the guiding mechanism of the bracket 10, it is translated in the direction indicated by the arrow A in Fig. 10A, and the trip button 30 pushes the circuit breaker mechanism locking device, thereby cutting off the fault current. Fig. 10B shows the state at this time.

If the failure is not eliminated, although the jumper 30 is pushed in the opposite direction to the direction indicated by the arrow A, since the drawbar 20 is pushed by the recessed portion 42 of the residual current protection lever 40 to the position shown in Fig. 10B at this time and is in failure Before the leakage current is eliminated, the residual current protection rod 40 cannot be reset to hinder the traction rod 20 from rotating in the clockwise direction. Therefore, the overlapping portion 21 of the drawbar 20 and the overlapping end 31 of the jumper 30 cannot overlap each other, and therefore, the jump Buckle 30 cannot be reset. After the fault is eliminated, the jumper 30 is pushed in a direction opposite to the direction indicated by the arrow A in Fig. 10A, at which time, since the residual current protection lever 40 no longer hinders the rotation of the drawbar 20, the drawbar 20 is at the return spring Under the action of the clockwise rotation in FIG. 10, the buckle portion 21 of the drawbar 20 and the overlapping end 31 of the jumper 30 overlap each other, and the entire trip mechanism is reset.

The trip mechanism according to a preferred embodiment of the present invention has been described above with reference to a residual current protection device, and as already mentioned above, the drawbar 20 is also provided with a plurality of arms 22A-22C, which can be associated with The short circuit protection device cooperates, and the heat adjustment screw provided on the drawbar 20 cooperates with the overload protection device. Therefore, when one of the protection devices such as the overload protection device and the short circuit protection device is triggered by an overload current, a short circuit current, or the like, the trigger portion of the protection device pushes the arm 22 or the heat adjustment screw of the drawbar 20, thereby As a result, the drawbar 20 is rotated, and the entire trip mechanism is tripped, and the whole working mode is similar to that described above with reference to the residual current protection device, and details are not described herein again.

It will be apparent to some embodiments of the invention that have been described that they can be varied in many ways. The elements and/or features of the different exemplary embodiments may be combined with each other and/or substituted for each other within the scope of the disclosure and claims. For example, in a specific embodiment, the drawbar 20 is provided with three arms 22A-22C and three heat-setting screws 25A-25C to correspond to the three-phase power. However, the number of them is not limited, and one or more arms or heat-adjusting screws may be used depending on the conditions of use. The lap portion of the drawbar may be in the form of a protrusion that overlaps the lapped portion of the recessed form on the jumper and vice versa. The jumper 30 is provided with a rib 32 to increase the strength of the jumper 30 while the rib 32 also serves as a guided portion of the jumper 30 to engage with a corresponding portion of the bracket to achieve a sliding guide to the jumper 30. It is of course also possible to form the strength-increasing ribs and guiding portions into two different portions, and also to adopt various other guiding structures commonly used in the art. The specific positions of the lap portion and the arm of the drawbar 10 can be changed depending on the overall design of the trip unit, and are not limited to those shown in the drawings. Such variations are not to be interpreted as a departure from the scope of the invention, but all such modifications are intended to be included within the scope of the invention.

100‧‧‧Retractor

101‧‧‧Main housing

102‧‧‧ Tripping mechanism

10‧‧‧ bracket

20‧‧‧ drawbar

21‧‧‧ buckle part

22A-22C‧‧‧Rotary arm

24A-24C‧‧‧Protruding

25A-25C‧‧‧ hole

30‧‧‧Bounce

31‧‧‧ lap end

32‧‧‧ rib

33‧‧‧Execution

40‧‧‧Residual current protection rod

41‧‧‧ protruding parts

411‧‧‧ guiding slot

42‧‧‧ recessed part

50‧‧‧ side panels

1 is a perspective view showing a trip unit according to an embodiment of the present invention;

Figure 2 is a perspective view showing the trip unit shown in Figure 1 from another perspective;

Figure 3 is a perspective view showing the drawbar in the trip protection mechanism for the trip unit shown in Figure 1;

Figure 4 is a perspective view showing a jumper in the trip protection mechanism for the trip unit shown in Figure 1;

Figure 5 is a perspective view showing a residual current protection rod in the trip protection mechanism for the trip unit shown in Figure 1;

Figure 6 is a perspective view showing a bracket used in the trip protection mechanism of the trip unit shown in Figure 1;

Figure 7 is a schematic view showing the jumper shown in Figure 4 assembled with the bracket shown in Figure 6;

Figure 8 is a schematic view showing the drawbar shown in Figure 3 assembled with the jumper shown in Figure 4;

Figure 9 is a schematic view showing the drawbar shown in Figure 3 assembled with the residual current protection bar shown in Figure 5;

10 is a schematic diagram for explaining residual current protection, wherein FIG. 10A is a state before the residual current protection mechanism is triggered, that is, a state before the trip mechanism is tripped, and FIG. 10B is a state after the tripping mechanism is tripped after the remaining power protection mechanism is triggered. status.

The drawings are intended to describe exemplary embodiments of the present disclosure and are not to be construed as limiting. The drawings are not to be considered as drawn to scale unless otherwise indicated.

100. . . Trip unit

101. . . Main housing

10. . . support

20. . . Tow bar

40. . . Residual current protection rod

50. . . Side panel

Claims (12)

A residual current protection tripping mechanism includes a main housing, a drawbar and a jumper, wherein the jumper and the drawbar overlap each other to cause the jumper to translate between a normal working position and a tripping position a return spring is interposed between the main housing and the drawbar to bias the drawbar; the drawbar has a first engagement portion and a second engagement portion, and the residual current protection device cooperates with the first engagement portion Actuating the drawbar to actuate the trip buckle, and at least one of the overload protection device and the short circuit protection device interacts with the second engagement portion to cause the drawbar to act, thereby actuating the Jump button release. The residual current protection tripping mechanism of claim 1, wherein the drawbar has a buckle portion, and the jumper has a lap end, the buckle portion of the drawbar and the jumper The lap ends overlap each other to maintain the jumper in a normal working position. The residual current protection tripping mechanism according to claim 1, wherein the second engaging portion is a rotating arm, and the rotating arm and the short-circuit protecting device cooperate with each other. The residual current protection tripping mechanism of claim 3, further comprising a third engaging portion that cooperates with the overload protection device to achieve tripping of the trip mechanism. The residual current protection tripping mechanism of claim 4, wherein the third engaging portion is a heat setting screw provided in a protrusion formed on the drawbar. The residual current protection tripping mechanism according to any one of claims 1 to 5, characterized in that, when the residual current protection device is triggered, the residual current protection rod of the residual current protection device and the first The engagement portion interacts to translate the residual current protection bar to push the drawbar to rotate. The residual current protection tripping mechanism of claim 6, wherein the residual current protection rod has a recessed portion, and the first engaging portion of the drawbar is configured to be inserted into a shape of the platform in the recessed portion . The residual current protection tripping mechanism of claim 6, wherein the residual current protection rod has a guiding limit portion, and the guiding limiting portion cooperates with the corresponding guiding portion. The guiding movement of the residual current protection rod is guided and the stroke length of the translational movement of the residual current protection rod is defined. The residual current protection tripping mechanism of claim 8, wherein the guiding limiting component is a guiding groove formed on the residual current protection rod, and the corresponding guiding portion is A boss formed on the trip unit housing, the boss being inserted into the guide slot. The residual current protection tripping mechanism of claim 6, further comprising a bracket having a guiding chute, the trip buckle being slidably mounted in the guiding chute, and The guiding chute guides the sliding. A trip unit includes at least one of an overload protection device and a short circuit protection device, and a residual current protection device, wherein the release device further includes the remaining one of any one of claims 1-10 Current protection tripping mechanism, the At least one of the overload protection device and the short circuit protection device cooperates with a second engagement portion of the drawbar of the trip mechanism, and the residual current protection device cooperates with the first engagement portion of the drawbar to cause the trip Unbuttoned. The trip unit of claim 11, wherein the trip unit is interchangeably assembled as a component to the circuit breaker.