EP2629315A1 - Actuation mechanisms for circuit breakers - Google Patents

Abstract

The operating mechanism (1) has cam slot (23) that is provided with shift shaft (3). A toggle lever spring (25) is connected with operating element (15). The torque-proof toggle lever shaft (21) is connected with toggle lever (19). A control profile is equipped with primary switching on control cam and primary switch off control cam. The primary switching on control cam is connected with secondary switching on control cam. The primary switching off control cam is connected with secondary switching off control cam.

Description

The invention relates to an actuating mechanism for power switching devices according to the preamble of claim 1. The invention described below finds application for electric power switching devices for switching and protecting low-voltage switchgear or motors, for example for circuit breakers and switch-disconnectors.

The publication EP 0584503 A1 describes a generic actuating mechanism. This actuating mechanism for a circuit breaker consists of a transverse switching shaft, are mounted on the according to the number of poles of the circuit breaker of contact force springs acted upon contact arms pivotally, and a switching mechanism for manual or automatic transfer of the shift shaft in the ON, OFF or TRIPPED position serves. In the ON position, fixed contacts attached to the contact arms communicate with stationary contacts attached to contact carriers defined in the mold housing. On the other hand, in the OFF and TRIPPED positions, the movable contacts are separated from the stationary contacts. The switching mechanism is inserted between two side plates supported in the molded housing in which a shift gate connected to an actuating element is pivotally mounted. Two toggle levers are connected via a spaced engaging in cam slots of the shift shaft toggle shaft. A toggle spring attacks on train between shift gate and toggle shaft. One of the shift gate entnehmbarer support lever is supported in the side plates and the toggle lever are frictionally supported in the support lever under the action of the toggle spring. A Verklinkungsmechanismus consists of a lockable with the support lever lever, a pawl and arranged between a support lever and pawl pawl spring. The pawl lever and holding this in locking position pawl are non-positively by means of the pawl spring Recesses of the side plates pivotally mounted. The latch is acted upon by release members of the circuit breaker, whereby at abnormal current conditions in the circuit controlled by the circuit breaker of the latch lever is released from its locking position with the support lever, as a result, the switching mechanism triggers and transferred the shift shaft to the TRIPPED position.

For use of the above-described actuating mechanism for certain switch-disconnector support lever and Verklinkungsmechanismus can be omitted. This eliminates the function of triggering.

In the above-described actuating mechanism is disadvantageous that the separation distance between the contact arms or the movable contacts and the associated contact carriers or the stationary contacts in the OFF state for certain applications, especially when using the power switching device in DC circuits, is not sufficient.

pamphlet DE 3105774 A1 describes an actuating mechanism for a circuit breaker with a greater separation distance between the movable and stationary contacts for the TRIPPED position, whereas the separation distance is limited in the OFF position. pamphlet EP 2161732 A2 describes a provided for a motor protection switch actuating mechanism which is equipped to reduce the actuating forces with a connection pressure member having a cam curve frontally. This actuating mechanism is not suitable for power switching devices of the type mentioned.

The invention is therefore based on the task of increasing the separation distance in the OFF position with improved starting torque.

Based on an actuating mechanism of the type mentioned, the object is achieved by the features of the independent claim, while the dependent claims advantageous or expedient developments of the invention can be found.

According to the invention, the at least one cam slot having a Einschaltsteuerkurve and a similar Ausschaltsteuerkurve and rotatably connected to the at least one toggle lever with a Einschaltsteuernocken and a Ausschaltsteuernocken provided, wherein the Einschaltsteuernocken the transition of the actuating mechanism from the OFF to the ON position with the Turn-on control curve and the Ausschaltsteuernocken cooperates in the transition of the actuating mechanism from the ON to the OFF position with the Ausschaltsteuerkurve.

Due to the inventive arrangement of the control cam and formation of the cams with respect to different curved, i. On the one hand, the transition from the OFF to the ON position, the shift shaft is first high rotational speed over a much larger closing angle in the direction of Turned ON position to slow it but with high torque to increase the contact pressure of the movable contact on the stationary contact. On the other hand, in the transition from the ON to the OFF position, the shift shaft is first relieved of its torque and then pivoted at high rotational speed over an enlarged, corresponding to the closing angle opening angle in the direction of the OFF position.

The rapid pivoting of the shift shaft over the enlarged opening angle in the direction of the ON position is achieved in that the toggle shaft acted upon with its Einschaltsteuernocken the shift shaft in the range of their seen from the pivot point of the shift shaft concave first Einschaltsteuerabschnittes at high incidence. The structure of the increased contact pressure is achieved by the toggle shaft applied to the end of the transition of the toggle lever from the OFF position to the ON position with the ON control cam, the switching shaft in the region of its substantially rectilinear third ON control at a small angle of attack. An optimal one Passing the shift shaft from the phase with a large angle of rotation with rapid rotation in the phase with increasing torque at slow rotational movement is achieved in that in the course of the transition from the OFF in the ON position, the toggle shaft with its Einschaltsteuernocken the shift shaft in the area of their from the fulcrum of the Actuated switching shaft seen convexly curved second power-on control section.

At the beginning of the transition of the toggle lever from the ON position to the OFF position, the reduction of the contact pressure by releasing the Einschaltsteuernockens from the third power-on control section takes place. An optimal transition of the switching shaft from the phase with decreasing torque at slow rotational movement in the phase with a large angle of rotation with rapid rotation and the subsequent rapid pivoting of the switching shaft on the increased opening angle towards the OFF position is achieved in that in the course of the transition from the ON- in the OFF position, the toggle shaft with its Ausschaltsteuernocken the shift shaft on the turn-on control curve substantially conforming turn-off control curve leads.

The means according to the invention improves the path-torque curve of the contact arms, resulting firstly in the increased separation distance in the OFF position between the at least one movable and stationary contact and secondly in ensuring a high contact pressure between these contacts. This leads to significantly improved switching characteristics of the associated power switching device, which predestines this power switching device for use in DC systems. To achieve the stated advantages, the actuating mechanism requires no additional components.

An advantageous embodiment of the invention is that connect to a round profile part of the toggle lever shaft on both sides of the control cam. In particular, the round profile part is followed by an edge-rounded, rectangular-shaped cam profile part. This easy-to-produce control profile interacts with good torque transmission and little friction with the cams.

An extension of the control profile over the entire length is both advantageous in the production of the toggle lever shaft and for a reliable connection with the at least one toggle lever.

A pair of spaced knee lever favors the torque transfer to the shift shaft.

An expedient embodiment consists in the transition of Ausschaltsteuerkurve in the turn-on control curve at a closed end of the cam slot.

Furthermore, two identical cam slots are advantageous for the torque transmission and the assembly of the actuating mechanism, if these are formed in a pair of mutually axially spaced fork-like projections of the switching shaft.

Furthermore, it is expedient to store the switching mechanism between two side plates.

To use the actuating mechanism according to the invention for power switching devices with tripping function of at least one toggle lever is mounted in a stationary support, entrained by the shift gate and lockable by means of a Verklinkungsmechanismus support lever.

To use the actuating mechanism according to the invention for power switching devices without tripping function of at least one toggle lever is mounted stationary.

Fig. 1 und 2:

räumliche Darstellungen des erfindungsgemäßen Betätigungsmechanismus aus unterschiedlichen Blickwinkeln;

Fig. 3:

eine Seitenansicht des Betätigungsmechanismus in EIN-Stellung;

Fig. 4:

Einzelheiten aus Fig. 3 in AUS-Stellung des Betätigungsmechanismus;

Fig. 5 bis 10:

Einzelheiten aus Fig. 4 in unterschiedlichen Stellungen des Betätigungsmechanismus;

Fig. 11:

als Einzelheit die Kniehebelwelle in vergrößerter axialer Ansicht.

Further details and advantages of the invention will become apparent from the following, explained with reference to figures embodiment. Show it

1 and 2:

spatial representations of the actuating mechanism according to the invention from different angles;

3:

a side view of the actuating mechanism in the ON position;

4:

Details from Fig. 3 in the OFF position of the operating mechanism;

5 to 10:

Details from Fig. 4 in different positions of the actuating mechanism;

Fig. 11:

as a detail, the toggle shaft in an enlarged axial view.

The FIGS. 1 to 3 show an embodiment of the actuating mechanism 1 according to the invention for a power switching device. As a power switching device, a single-pole circuit breaker is provided in the example. The actuating mechanism 1 and other components of the circuit breaker are mounted in a mold housing, not shown. The actuating mechanism 1 consists of a transverse switching shaft 3 and a switching mechanism 5. On the switching shaft 3, one of a contact force spring (not visible) acted upon contact arm 7 is pivotally mounted. The switching mechanism 5 is used for manual or automatic transfer of the switching shaft 3 in the ON, OFF or TRIPPED position. In the ON position shown here, a movable contact 9 attached to the contact arm 7 contacts a stationary contact 11 which is fixed to a contact carrier (not shown) fixed in the molded housing. On the other hand, in the OFF and in the TRIPPED position, the movable contact 9 is separated from the stationary contact 11. The switching mechanism 5 is inserted between two side plates 13 held in the mold housing, of which only one is shown. In the side plates 13 connected to an actuator 15 U-shaped shift gate 17 is pivotally mounted. A pair of toggle levers 19 are connected via a toggle shaft 21 at a distance. The toggle shaft 21 engages in two mutually spaced cam slots 23 of the switching shaft 3 a. A helical toggle spring 25 acts on train between shift gate 17 and toggle shaft 21 at. One of the shift gate 17 entnehmbarer U-shaped support lever 27 is in the side plates 13 and the knee lever 19 are pivotally supported in the support lever 27 under the action of the toggle spring 25, wherein the toggle lever 19 are connected via the toggle lever shaft 21 in the region of their free ends. A Verklinkungsmechanismus 30 consists of a lockable with the support lever 27 pawl lever 29, a pawl 31 and arranged between the support lever 27 and pawl 31 pawl spring (not visible). The latch lever 29 and the pawl 31 holding it in the locking position are pivotally mounted by means of the pawl spring in recesses of the side plates 13. The pawl 31 is acted upon by tripping members of the circuit breaker, whereby at abnormal current conditions in the circuit controlled by the circuit breaker the latch lever 29 is released from its locking position with the support lever 27, as a result, the switching mechanism 5 triggers and the shift shaft 3 in the TRIPPED position passes.

The shift gate 17 and the toggle 19 together with the toggle spring 25 form a tilting system. When moving the shift gate 17 from the OFF to the ON position or vice versa tilt after overcoming the dead center of the tilting system, the toggle lever 19 and thus the shift shaft 3 and the contact arm 7 abruptly in the ON or OFF position. Further details and functional details of the actuating mechanism 1 described so far, the document EP 0584503 A1 be removed. Distinctive features and effects are described below on the basis of FIGS. 4 to 11 described.

Fig. 4 In detail, the switching shaft 3, the contact arm 7, one of the toggle lever 19 and the toggle shaft 21. The switching shaft 3 pivots upon actuation of the switching mechanism 5 about its axis of rotation 32. Between two projecting from the switching shaft 3 fork-shaped projections 33, 35 is the cam slot 23 trained. This is limited in its responsible for the transfer of the switching shaft 3 in the ON or OFF position section by a complex formed Einschaltsteuerkurve 37 and a relation to this substantially geometrically similar Ausschaltsteuerkurve 39. The Ausschaltsteuerkurve 39 is offset from the Einschaltsteuerkurve 37 in the Ausschalttrichtung 41 of the shift shaft 3 or located in the example further away from the movable contact 9. At the inner closed end 43 of the cam slot 23, which in the example compared to other parts of the cam slot 23 next to the rotational axis 32, the turn-on control curve 37 and the turn-off control curve 39 converge.

Starting from the end 43 of the cam slot 23 and with increasing distance from the rotation axis 32, the turn-on control curve 37 is subsequently composed of a first, second and third turn-on control section 45, 47 and 49, respectively. When viewed from the rotation axis 32, the first turn-on control section 45 runs concavely or curving toward the rotation axis 32. Also, viewed from the rotation axis 32, the second turn-on control portion 47 that is shorter in comparison with the first turn-on control portion 45 convexly curves away from the rotation axis 32. The third power-on control section 49 is substantially rectilinear.

The non-rotatably connected to the two knee levers 19 toggle shaft 21 is equipped with a control profile, as closer Fig. 11 can be seen. This control profile consists of a circular section-like round profile part 51, a Einschaltsteuernocken 53 and a Ausschaltsteuernocken 55. The Einschaltsteuernocken 53 closes on one side, ie in the direction of the on movement of the toggle shaft 21 and the knee lever 19 (see Fig. 4 to Fig. 7 ), to the round profile part 51. The Ausschaltsteuernocken 55 closes to the other side, ie in the direction of the turn-off movement of the toggle shaft 21 and the knee lever 19 (see FIGS. 7 to 10 ), to the round profile part 51. In this case, the round profile part 51 is in an edge-rounded, the turn-on control cam 53 and the Ausschaltsteuernocken 55 forming rectangular cam profile part 57 via. How out Fig. 2 It can be seen, the control profile extends over the entire length of the toggle shaft 21. The Einschaltsteuernocken 53 acts with the turn-on control cam 37 and the Ausschaltsteuernocken 55 cooperates with the Ausschaltsteuerkurve 41, as described below with reference to Fig. 4 to Fig. 10 is described.

Fig. 4 shows the OFF position of toggle lever 19, shift shaft 3 and contact arm 7. Compared to the generic state of the art, the contact arm 7 has a significantly increased opening angle to the ON position on the Einschaltsteuernocken 53 touched without noticeable force that portion of the first Einschaltsteuerabschnittes 45, the inner end 43 of the cam slot 23 goes out. Furthermore, a first connecting line 59 between the tilting axis 63 of the rocker arm 19 and the toggle lever shaft 21 and a second connecting line 61 between the rotational axis 32 of the switching shaft 3 and the pivot axis 65 of the contact arm 7 on the shift shaft 3 located.

Fig. 5 shows a first phase during the switch-on process. The knee lever 19 are opposite to the OFF position in Fig. 4 pivoted about an angle of about 17 ° clockwise (see first connecting line 59). The toggle shaft 21 slides with its Einschaltsteuernocken 53 along the first Einschaltsteuerabschnitt 45 along. Due to the concave design of the first switch-on control section 45, the switching shaft 3 was pivoted at a high rotational speed with respect to the OFF position by a relatively large angle of rotation of approximately 29 ° in the counterclockwise direction (compare second connecting line 61). This rapid pivoting of the switching shaft 3 and thus of the contact arm 7 mounted thereon takes place as a result of the relatively large angle of attack of the contacting surfaces of the switch-on control cam 53 and the first switch-on control section 45 with a relatively low torque.

Fig. 6 shows a second phase at power-up. The knee lever 19 are opposite to the position in Fig. 5 further pivoted clockwise at an angle of about 5 ° (compare first connecting line 59). In this phase, the movable contact 9 is hit on the stationary contact 11, but it is still not exercised sufficient contact pressure. The toggle shaft 21 slides with its turn-on control cam 53 along the second turn-on control section 47. So far, the shift shaft 3 has been compared to the position in Fig. 5 pivoted by a further angle of about 13 ° in the counterclockwise direction (see second connecting line 61). Due to the convex design of the second power-on control section 47 and the thus decreasing angle of attack of touching surfaces of Einschaltsteuernocken 53 and second Einschaltsteuerabschnitt 47 increases with increasing pivot angle of the rocker arm 19, the torque transmission from the toggle shaft 21 to the shift shaft 3 and the angular transmission.

Fig. 7 shows the ON position at the end of the switch-on process. The toggle shaft 21 slides with its Einschaltsteuernocken 53 on the rectilinear third Einschaltsteuerabschnitt 49. The knee lever 19 are opposite to the position in Fig. 6 about a further angle of about 8 ° clockwise pivoted (compare first connecting line 59). The switching shaft 3, however, is pivoted only by a further angle of about 2.5 ° in the counterclockwise direction (see second connecting line 61). This results from the small intersecting angle 67 between a radiating outgoing from the axis of rotation 32 of the shift shaft 3 and the level 69 of the third Einschaltsteuerabschnittes 49. The resulting relatively small angle of the Einschaltsteuernocken 53 to the third Einschaltsteuerabschnitt 49 leads to a large torque transfer from the toggle levers 19 on the shift shaft 3 at low angular transmission. By this large torque of the required high contact pressure between the movable contact 9 and stationary contact 11 is generated. Here, the shift shaft 3 had to move only to the so-called stroke against the force of the contact force spring.

Fig. 8 shows a first phase when switching off. The knee lever 19 are opposite to the ON position in Fig. 7 pivoted by an angle of about 8 ° in the counterclockwise direction (compare first connecting line 59). The toggle shaft 21 slides with its Ausschaltsteuernocken 55 on a second Einschaltsteuerabschnitt 47 opposite first Ausschaltsteuerabschnitt 73 of the Ausschaltsteuerkurve 39 along. The first switch-off control section 73 is analogous to the opposite second switch-on control section 47 viewed from the rotational axis 32 of the switching shaft 3 from convex. The shift shaft 3 was opposite to the position in Fig. 7 pivoted by an angle of about 6 ° clockwise (see second connecting line 61). In this phase, the movable contact 9 has lifted slightly with progressive degradation of the contact pressure of the stationary contact 11.

Fig. 9 shows a second phase when switching off. The knee lever 19 are opposite to their position in Fig. 8 pivoted by a further angle of about 5 ° in the counterclockwise direction (compare first connecting line 59). The

Toggle shaft 21 begins to slide with its Ausschaltsteuernocken 55 on a first Einschaltsteuerabschnitt 45 opposite second Ausschaltsteuerabschnitt 75 of the Ausschaltsteuerkurve 39 along. The second turn-off control section 75 is analogous to the opposite first turn-on control section 45 viewed from the rotational axis 32 of the switching shaft 3 from concave. The shift shaft 3 was opposite to the position in Fig. 8 pivoted by a further angle of about 13 ° clockwise (see second connecting line 61). In this phase begins, due to the concave configuration of the second Ausschaltsteuerabschnittes 75 and due to the steep angle of attack of the touching surfaces of Ausschaltsteuernocken 55 and second Ausschaltsteuerabschnitt 75, the angular transmission of the toggle lever 19 on the shift shaft 3 and thus increase the rotational speed of the contact 7.

Fig. 10 finally shows a third phase of the switch-off, just before taking the OFF position according to Fig. 4 , The knee lever 19 are opposite to their position in Fig. 9 pivoted by a further angle of about 5 ° in the counterclockwise direction (compare first connecting line 59). The toggle shaft 21 comes with its Ausschaltsteuernocken 55 on the second Ausschaltsteuerabschnitt 75 along sliding at the inner end 43 of the cam slot 23 and the Ausschaltsteuerkurve 39. The shift shaft 3 is opposite to its position in Fig. 9 about a relatively large angle of about 14 ° clockwise pivoted (see second connecting line 61).

By the actuating mechanism 1 according to the invention on the one hand a large separation distance between the movable contact 9 and stationary contact 11 is achieved in the OFF position and on the other hand ensures a high contact pressure between the contacts 9 and 11. In the transition from the ON position according to Fig. 7 in the OFF position according to Fig. 4 or vice versa is transmitted from the toggle levers 19 a rotational movement about an angle of about 37 ° on the shift shaft 3 (see second connecting line 61). The knee lever 19 tilt at an angle of about 30 ° (see first connecting line 59).

The present invention is not limited to the embodiment described above, but also includes all the same in the context of the invention embodiments. For example, the invention also includes actuating mechanisms on the switching shaft a plurality of contact arms are mounted. The invention also includes actuating mechanisms, the switching mechanism is executed without support lever and Verklinkungsmechanismus, wherein the toggle or the stationary, for example in the side plates, are stored. Such actuating mechanisms are used in power switching devices that are designed as a circuit breaker and do not require a tripping function.

LIST OF REFERENCE NUMBERS

1

actuating mechanism

3

shift shaft

5

switching mechanism

7

contact

9; 11

contacts

13

side plates

15

actuator

17

shift gate

19

toggle

21

Toggle wave

23

cam slot

25

Toggle spring

27

support lever

29

ratchet lever

30

latching mechanism

31

pawl

32

axis of rotation

33; 35

projections

37

Einschaltsteuerkurve

39

Ausschaltsteuerkurve

41

the disconnection

43

The End

45; 47; 49

Einschaltsteuerabschnitte

51

Round profile part

53

Einschaltsteuernocken

55

Ausschaltsteuernocken

57

Cam profile part

59; 61

connecting lines

63

tilt axis

65

swivel axis

67

cutting angle

69

radius

71

gradient layer

73; 75

Ausschaltsteuerabschnitt

Claims (10)

Actuation mechanism for power switching devices, consisting of a transverse, stationary bearing and with at least one cam slot (23) provided switching shaft (3) for the storage and operation of at least one spring-loaded contact arm (7), - A switching mechanism (5) for transferring the switching shaft (3) in the ON and the OFF position, in turn containing a with an actuating element (15) connected and fixedly mounted pivoting shift gate (17), at least one pivotally mounted toggle lever (19) , a toggle lever shaft (21) connected to the toggle lever (19) at the free end thereof and engaging in the cam slot (23), and a toggle lever spring (25) engaging between the shift gate (17) and toggle shaft (21), characterized - That the at least one cam slot (23) by a complex formed Einschaltsteuerkurve (37) and a relation to this substantially geometrically similar and in Ausschaltrichtung (41) of the switching shaft (3) offset Ausschaltsteuerkurve (39) is formed, - That with progressive distance from the axis of rotation (32) of the switching shaft (3), the turn-on control curve (37) from a to the rotation axis (32) out towards the first turn-on control (45), an adjoining and away from the axis of rotation (32) there is a third turn-on control section (47) which curves, and a third straight-line control section (49) extending therealong, which runs essentially rectilinearly and runs at a small intersection angle (67) with respect to a radius (69) originating from the rotary axis (32). - That the non-rotatably connected to the at least one toggle lever (19) connected to the toggle shaft (21) with a Einschaltsteuernocken (53) and a Ausschaltsteuernocken (55) exhibiting control profile and - That the Einschaltsteuernocken (53) with the Einschaltsteuerkurve (37) and the Ausschaltsteuernocken (55) with the Ausschaltsteuerkurve (39) is operatively connected. Actuating mechanism according to the preceding claim, characterized in that the control profile has a circular segment-like round profile part (51) and that the Einschaltsteuernocken (53) in the switch-on direction of the toggle lever (19) to one side and the Ausschaltsteuernocken (55) in Ausschaltetrichtung (41) of the toggle lever (19) connects to the other side of the round profile part (51). Actuating mechanism according to the preceding claim, characterized in that the round profile part (51) of the toggle shaft (21) merges into an edge-rounded, the Einschaltsteuernocken (53) and the Ausschaltsteuernocken (55) forming rectangular cam profile part (57). Actuating mechanism according to one of the preceding claims, characterized in that the control profile extends over the entire length of the toggle lever shaft (21). Actuating mechanism according to one of the preceding claims,
characterized by a pair of spaced-apart toggle lever (19). Actuating mechanism according to one of the preceding claims, characterized in that the switch-on control curve (37) and the switch-off control curve (39) at a closed end (43) of the cam slot (23) are connected. Actuating mechanism according to one of the preceding claims,
are formed of the switching shaft (3), characterized by two axially spaced uniform cam slots (23) each fork-like in a pair of projections (35 33). Actuating mechanism according to one of the preceding claims, characterized in that the switching mechanism (5) between two side plates (13) is mounted. Actuating mechanism according to one of claims 1 to 8, characterized in that the at least one toggle lever (19) is supported in a stationary supporting, by the shift gate (17) mitnehmbaren and by means of a Verklinkungsmechanismus (30) lockable support lever (27). Actuating mechanism according to one of claims 1 to 8, characterized in that the at least one toggle lever (19) is mounted stationary.

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