CN210984663U

CN210984663U - Operating mechanism of low-voltage molded case circuit breaker

Info

Publication number: CN210984663U
Application number: CN202020055232.8U
Authority: CN
Inventors: 顾建青; 唐维春; 管瑞良
Original assignee: Changshu Switchgear Manufacturing Co Ltd
Current assignee: Changshu Switchgear Manufacturing Co Ltd
Priority date: 2020-01-10
Filing date: 2020-01-10
Publication date: 2020-07-10
Anticipated expiration: 2030-01-10

Abstract

An operating mechanism of a low-voltage molded case circuit breaker comprises a handle lever component, a support, a jump buckle lever, a first locking piece, a main spring, an elbow connecting rod mechanism, a rotating shaft and a contact component, wherein the elbow connecting rod mechanism comprises an upper connecting rod and a lower connecting rod, the axis of a hinge shaft of the upper connecting rod and the lower connecting rod is marked as A, and the main spring is arranged between the hinge shaft of the upper connecting rod and the hinge shaft of the lower connecting rod and the handle lever component; the handle lever assembly is supported on the pair of side plates, and the jump buckle lever is supported between the pair of side plates; the first locking piece is matched with the jump buckle lever; the rotating shaft is connected with the lower connecting rod, and the rotating center is marked as B; the contact assembly comprises a moving contact and a fixed contact, a contact spring is arranged between the moving contact and the rotating shaft, a cavity is arranged on one side plate, a first stop surface is arranged on the cavity wall of the cavity, and the first stop surface is parallel to a connecting line from A to B or forms an included angle of-15 degrees to 15 degrees with the connecting line from A to B. The quick tripping can be realized without increasing the action energy.

Description

Operating mechanism of low-voltage molded case circuit breaker

Technical Field

The utility model belongs to the technical field of low-voltage apparatus, concretely relates to operating device of low-voltage moulded case circuit breaker.

Background

As is known in the art, the closing or opening operation of a low voltage molded case circuit breaker can complete a circuit or break a circuit, and the broken circuit referred to herein generally means a broken fault circuit, which is also referred to as an abnormal circuit, and a typical example of the fault circuit is a short circuit. The operating mechanism is an actuating mechanism for switching on or switching off the circuit of the low-voltage molded case circuit breaker, and when the circuit is overloaded or short-circuited, the molded case circuit breaker protection release detects the abnormity and actuates the operating mechanism to release, so that the circuit is quickly switched off. When a fault large current such as a short-circuit current is broken, an electric arc is often generated when a fracture is opened, namely, a moving contact of a contact system of the circuit breaker is opened relative to a fixed contact, and the tripping action speed of an operating mechanism has direct influence on the size of electric arc energy generated in the fault large current breaking process.

When short-circuit heavy current is encountered, electric repulsion force is generated between the moving contact and the static contact to promote the moving contact to be repelled in advance before tripping action of the mechanism, arcing (electric arc generation) is generated between the moving contact of the moving contact and the static contact of the static contact, so that the operating mechanism is required to act before the moving contact falls back to be contacted with the static contact again to intercept the moving contact falling back, if the tripping action of the operating mechanism is slow, the moving contact and the static contact cannot be intercepted or prevented from falling back in time, secondary contact can be generated between the moving contact and the static contact, and electric arc energy in the breaking process can be increased rapidly to cause breaking failure.

For a general fault current, which is not yet sufficient to repel the moving contacts, the movable contact opens by the tripping action of the mechanism and the opening speed of the movable contact depends on the tripping speed of the operating mechanism, in particular: the faster the tripping speed is, the more beneficial the electric arc between the movable contact and the fixed contact to be quickly generated and elongated, thereby quickly extinguishing the electric arc, reducing the electric arc energy in the breaking process, reducing the ablation influence degree of the electric arc on the contacts and avoiding the excessive loss of the contacts.

The improvement of the tripping operation speed of the operating mechanism of the low-voltage molded case circuit breaker is always the direction pursued in the industry, and the tripping speed is generally improved by a technical means of increasing the operation energy of the operating mechanism at present, but the larger the operation energy of the operating mechanism is, the more severe the requirement on the strength of the structural member, i.e. the structural strength is, because the operation energy of the operating mechanism is in direct proportion to the strength of the structural member of the operating mechanism. In addition, the greater the operating energy of the operating mechanism, the more likely it is that excessive wear will occur during operation.

Disclosure of Invention

The utility model aims to provide an operating device that helps showing the low pressure moulded case circuit breaker who improves dropout functioning speed under the prerequisite that does not increase the functioning energy.

The utility model aims to provide an operating mechanism of a low-voltage molded case circuit breaker, which comprises a handle lever component, a bracket, a jump buckle lever, a first locking piece, a main spring, an elbow connecting rod mechanism, a rotating shaft and a contact component, wherein the elbow connecting rod mechanism comprises an upper connecting rod and a lower connecting rod which are hinged and connected by an upper connecting rod hinged shaft and a lower connecting rod hinged shaft, the axle center of the upper connecting rod hinged shaft and the lower connecting rod hinged shaft is marked as A, and the main spring is connected and arranged between the upper connecting rod hinged shaft and the lower connecting rod hinged shaft and the handle lever component; the bracket is composed of a pair of side plates which are arranged oppositely and fixedly connected with each other, and the upper and lower connecting rod hinge shafts are movably supported between the pair of side plates; the handle lever component is pivotally supported on a pair of side plates of the bracket, and the jump buckle lever is pivotally supported between the pair of side plates of the bracket through the jump buckle lever and is pivotally connected with the upper connecting rod; the first locking piece is matched with the jump buckle lever and used for locking or unlocking the jump buckle lever; the rotating shaft is rotationally connected with the lower connecting rod, the rotating center is marked as B, and the rotation is realized through the action of the elbow connecting rod mechanism; the contact assembly comprises a moving contact and a fixed contact which are matched with each other, the moving contact is pivoted on the rotating shaft, a contact spring used for providing pretightening force to provide contact pressure when switching on is arranged between the moving contact and the rotating shaft, one side plate of the pair of side plates is provided with a containing cavity, the end parts of the articulated shafts of the upper connecting rod and the lower connecting rod are inserted into the containing cavity, a first stop surface is formed on the cavity wall of the cavity, the first stop surface is positioned between the hinge shaft of the upper and lower connecting rods and the pivot shaft of the jump buckle lever, and the first stop surface is parallel to a connecting line from A to B or forms an included angle of-15 degrees to 15 degrees with the connecting line from A to B, during the overtravel process of the initial tripping action stage of the operating mechanism, the articulated shaft of the upper connecting rod and the lower connecting rod moves along the track limited by the first stop surface, so that the moving contact is driven to be quickly separated from the static contact.

In a specific embodiment of the present invention, when the circuit breaker is switched on, the connection line between the first and second contact pins and the rotation center O of the rotation shaft are connected to the connection line between the first and second contact pins₂The connecting line between the two forms an included angle of 85-95 degrees.

In another specific embodiment of the present invention, the chamber wall of the chamber further comprises a second stop surface and a third stop surface, the first stop surface and the second stop surface form a face-to-face relationship, and the third stop surface is located between the first and second stop surfaces.

In another specific embodiment of the present invention, the other side plate of the pair of side plates is also provided with a cavity, and the cavity corresponds to the cavity of the one side plate.

The technical scheme provided by the utility model the technical effect lie in: because the side plates forming the bracket are respectively provided with a containing cavity at the corresponding positions, and the end parts of the upper connecting rod articulated shaft and the lower connecting rod articulated shaft for the upper connecting rod and the lower connecting rod of the elbow connecting rod mechanism are inserted into the containing cavities, and the cavity wall of the containing cavity is provided with a first stopping surface, a second stopping surface and a third stopping surface, further, because the first stopping surface corresponds to the position between the upper connecting rod articulated shaft and the lower connecting rod articulated shaft and the trip lever pivot, the upper connecting rod articulated shaft and the lower connecting rod articulated shaft are enabled to move along the track limited by the first stopping surface in the initial tripping action stage of the operating mechanism, compared with the tripping action that the upper connecting rod articulated shaft and the lower connecting rod articulated shaft lean against the trip lever pivot together along with the upper connecting rod in the prior art, the speed of pulling the rotating shaft can be obviously improved, the tripping action can be carried out at a higher speed in the overtravel stage of, the purpose of quick action can be achieved before the tripping lever is not contacted with the stop shaft. The purpose of realizing quick tripping without increasing the action energy is achieved.

Drawings

Fig. 1 is a schematic view of the handle lever assembly, the jump buckle lever, the first and second locking members, the traction rod, the upper connecting rod and the lower connecting rod of the elbow connecting rod mechanism of the present invention assembled on the bracket.

Fig. 2 is a schematic view of a pair of side plates of the bracket shown in fig. 1.

Fig. 3 is the schematic diagram of the operating mechanism of the low-voltage molded case circuit breaker of the present invention in the open state.

Fig. 4 is the schematic diagram of the operating mechanism of the low-voltage molded case circuit breaker of the present invention in the re-buckling state. .

Fig. 5 is the schematic diagram of the operating mechanism of the low-voltage molded case circuit breaker in the closing state.

Fig. 6 is a state diagram of the contact between the upper connecting rod clamping end of the upper connecting rod hinge shaft area and the tripping lever pivot when the operating mechanism of the low-voltage molded case circuit breaker is in the closing state.

Fig. 7 is a state diagram of the moving contact of the contact assembly just contacting with the rotating shaft.

Fig. 8 is a state diagram of the moving contact and the fixed contact of the contact assembly being separated when the trip lever is stopped by the stop shaft.

Fig. 9 is a schematic diagram of a tripping state of the low-voltage molded case circuit breaker when the hinge shaft of the upper and lower connecting rods drives the upper connecting rod, the lower connecting rod and the rotating shaft provided with the moving contact to move to the third stopping surface and stop moving due to the limitation of the third stopping surface.

Fig. 10 is a schematic view of the movable contact of the contact assembly just contacting the rotating shaft according to the present invention.

Detailed Description

Referring to fig. 1 to 10, the operating mechanism of the present invention is a planar linkage mechanism, which includes a lever assembly 1,Bracket 5, jump buckle lever 2, first latch 4, second latch 3, traction rod 8, main spring 9, elbow linkage, rotating shaft 40 and contact assembly 20. The elbow connecting rod mechanism comprises an upper connecting rod 6 and a lower connecting rod 7, the upper connecting rod 6 and the lower connecting rod 7 are hinged through an upper connecting rod hinging shaft 10 and a lower connecting rod hinging shaft 10, and the axle center of the upper connecting rod hinging shaft 10 and the axle center of the lower connecting rod hinging shaft are marked as A. A main spring 9 is connected between the upper and lower connecting rod articulated shafts 10 and the handle lever component 1; the bracket 5 is composed of a pair of side plates 51 which are arranged opposite to each other and fixedly connected with each other, and the handle lever assembly 1 is pivotally supported on the pair of side plates 51 of the bracket 5; the trip lever 2 is pivotally supported between the pair of side plates 51 of the bracket 5 by a trip lever pivot shaft 21 having a rotation center O of the trip lever pivot shaft 21 and pivotally connected to the upper link 6₁(ii) a The first locking piece 4 is matched with the jump buckle lever 2, and the second locking piece 3 is matched with the first locking piece 4; the traction rod 8 is connected with the second locking fastener 3 and rotates along with the rotation of the second locking fastener 3; the pivot shaft 40 is pivoted by the action of the toggle linkage and the pivot shaft 40 is pivotally connected to the lower link 7 as previously described, this centre of rotation being denoted B. The contact assembly 20 includes a movable contact 201 and a stationary contact 202 cooperating with each other, the movable contact 201 is pivotally mounted on the rotating shaft 40, and the rotating center of the rotating shaft 40 is O₂(ii) a A contact spring 50 for providing a biasing force to provide a contact pressure at the time of closing is provided between the movable contact 201 and the rotating shaft 40, and the upper and lower link hinge shafts 10 are movably supported between the pair of side plates 51.

As the technical scheme provided by the utility model: a cavity 511 is opened on one of the pair of side plates 51, preferably, a cavity 511 is opened on each of the pair of side plates 51 and at the corresponding position, the end of the upper and lower link hinge shaft 10 extends into the cavity 511, a first stop face 5111 is formed on the cavity wall of the cavity 511, the first stop face 5111 is located between the upper and lower link hinge shaft 10 and the trip lever pivot shaft 21, and the first stop face 5111 is parallel to the connection line from a to B or forms an included angle of-15 ° to 15 ° with the connection line from a to B, and the operating mechanism goes beyond the initial stage of the trip action of the operating mechanismIn the process, the upper and lower link hinge shafts 10 move along the track defined by the first stop face 5111, so as to drive the moving contact 201 to be quickly separated from the stationary contact 202. Specifically, when the circuit breaker is switched on, a connecting line from the A to the B and a rotation center O from the B to the rotating shaft 40₂The connecting line between the two forms an included angle of 85-95 degrees. Preferably, a connecting line from the A to the B and a rotating center O from the B to the rotating shaft 40₂The included angle formed by the connecting lines is 90 degrees. When the operating mechanism is tripped, the lap joint of the trip lever 2, the first locking piece 4 and the second locking piece 3 in the operating mechanism is broken, the trip lever 2 drives the upper connecting rod 6 to rotate around the trip lever pivot 21 under the action of the main spring force of the main spring 9, the upper connecting rod 6 drives the lower connecting rod 7, the lower connecting rod 7 drives the rotating shaft 40, and after the rotating shaft 40 rotates by a small angle to abut against the movable contact 201, the movable contact 201 is driven to rotate together by overcoming the contact pressure of the contact spring 50 until the movable contact 201 is completely separated from the fixed contact 202. Therefore, the overtravel process is a process before the lower link 7 drives the rotating shaft 40 to start to move until the rotating shaft 40 rotates a smaller angle to collide with the movable contact 201, and the movable contact 201 and the fixed contact 202 are not completely separated.

Since the pair of side plates 51 of the bracket 5 are connected by a connecting cross plate, the entire bracket 5 is a U-shaped member (shown in fig. 1), four mounting fulcrums 514 are symmetrically disposed on the pair of side plates 51, a mounting fulcrum fixing screw 5141 is disposed on each mounting fulcrum 514, and the entire bracket 5 is fixed to a base (not shown) of the circuit breaker by the mounting fulcrum fixing screws 5141. The aforementioned first latch member 4 is rotatably supported between the pair of side plates 51 by the first latch pivot 41, and the aforementioned second latch member 3 is rotatably supported between the pair of side plates 51 by the second latch pivot 31. Also shown in fig. 1 is a stop shaft 515 supported between a pair of side plates 51. A handle lever pivoting portion 516 for pivoting the handle lever assembly 1 on the bracket 5, i.e., pivoting on the pair of side plates 51, a closing limit stopper 512 for a closing operation of the handle lever, and an opening limit stopper 513 for an opening operation are provided on the pair of side plates 51 and at positions corresponding to each other.

Fig. 1 clearly shows a state in which both ends of the upper and lower link hinge shafts 10 are respectively inserted into the receiving cavities 511 of the pair of side plates 51. As shown in fig. 2, a second stop surface 5112 and a third stop surface 5113 are further formed on the cavity wall of the cavity 511, the first stop surface 5111 and the second stop surface 5112 form a face-to-face relationship, and the third stop surface 5113 is located between the first and

second stop surfaces

5111 and 5112.

When the operating mechanism is in a brake-off state, the trip lever 2 is lapped and stably kept with the first locking piece 4 and the second locking piece 3 of the structural system of the locking system, and the two end parts of the upper connecting rod hinging shaft 10 and the lower connecting rod hinging shaft 10 are limited through the second stop faces 5112 of the accommodating cavities 511 on the pair of side plates 51 of the bracket 5, so that the brake-off state of the upper connecting rod 6, the lower connecting rod 7 and the rotating shaft 40 is determined.

When the operating mechanism is in a tripping state, the position of the trip lever 2 is limited by the stop shaft 515 on the bracket 5, and the two end parts of the upper and lower link hinge shafts 10 are limited by the third stop faces 5113 of the cavities 511 on the pair of side plates 51 of the bracket 5, so that the tripping state of the upper link 6, the lower link 7 and the rotating shaft 40 is determined.

When the operating mechanism is in a closed state, the trip lever 2 is stably overlapped with the first locking part 4 and the second locking part 3 of the structural system of the locking system, and the closed state of the upper link 6, the lower link 7 and the rotating shaft 40 is determined by the contact of the upper link stopping end 61 (shown in fig. 6) of the upper link 6 in the area close to the upper link hinge shaft 10 and the trip lever pivot 21.

Referring to fig. 5, fig. 7, fig. 8, fig. 9 and fig. 10 in detail, first to fig. 5, in a closing state of the circuit breaker, the operating mechanism is tripped, the trip lever 2 is detached from the lap joint of the first locking piece 4 and the second locking piece 3, the trip lever 2 rotates counterclockwise under the action of the main spring force of the main spring 9, at this time, the upper link stopping end 61 of the upper link 6 abuts against the trip lever pivot 21, and the trip lever 2 drives the upper link 6 to rotate counterclockwise around the trip lever pivot 21 together.

With continued reference to FIGS. 5, 7, 8, 9 and 10Referring to fig. 7 and 10, since the first stop surface 5111 is located between the upper and lower link hinge shafts 10 and the trip lever pivot 21, and the first stop surface 5111 is parallel to the connection line from a to B or forms an included angle in the range of-15 degrees to 15 degrees, the included angle between the first stop surface 5111 and the connection line from a to B is an included angle formed between the projection of the first stop surface 5111 on the plane of the planar link mechanism and the projection of the connection line AB on the plane of the planar link mechanism, so that the upper link 6 is caused to rotate counterclockwise around the trip lever pivot 21 in the drawing along with the trip lever 2, and simultaneously, the upper and lower link hinge shafts 10 move upward along the track defined by the first stop surface 5111, since the connection line AB and the connection line AO₂In a right angle relationship or a relationship close to the right angle relationship, the moment arm of the lower link 7 to the rotating shaft 40 is maximized, that is, the torque of the pulling force on the lower link 7 to the rotating shaft 40 is maximized (when the moving contact 201 shown in fig. 10 is just in contact with the rotating shaft 40, the lower link 7 drives the rotating shaft 40), which accelerates the upper link 6 to drive the lower link 7, and thus the rotating shaft 40 to move. Therefore, during the overtravel process, that is, during the process before the lower link 7 drives the rotating shaft 40 to rotate by a small angle and the rotating shaft 40 collides with the movable contact 201 and the fixed contact 202 are not completely separated, the movement of the rotating shaft 40 at the overtravel stage is accelerated due to the existence of the first stop face 5111. Further, after the rotating shaft 40 contacts the moving contact 201 (the moving contact 201 contacts the rotating shaft 40 shown in fig. 7), the two are driven by the upper and lower link hinge shafts 10 of the upper link 6 and the lower link 7 to move together (after the rotating shaft 40 contacts the moving contact 201, the assistant component of the contact spring 50 is finished, and then the main spring 9 providing the brake separating force), specifically, the main spring force of the main spring 9 pulls the upper and lower link hinge shafts 10 to move upwards along the track defined by the first stop surface 5111, and at this time, the trip lever 2 and the stop shaft 515 are not yet contacted.

Referring to fig. 8, when the trip lever 2 is stopped by the stop shaft 515, the movable contact 201 is separated from the fixed contact 202, and then the upper link 6 rotates counterclockwise around the trip lever pivot 21 of the trip lever 2 under the action of the main spring force of the main spring 9, so that the upper link hinge shaft 10 is separated from the first stop face 5111 and pivots with the upper link 6.

Referring to fig. 9, when the upper and lower link hinge shafts 10 drive the upper link 6, the lower link 7 and the rotating shaft 40 provided with the movable contact 201 to move to the third stopping surface 5113, the third stopping surface is stopped by the limit of the third stopping surface, and the position is the tripping state of the circuit breaker.

Referring to fig. 1, the handle lever assembly 1 is disposed outside the pair of side plates 51 of the bracket 5 and pivots about the pivot portion 516 on the pair of side plates 51 of the bracket 5, and the two side clamping plates 11 of the handle lever assembly 1 are kept in the closing position by the closing limit stoppers 512 on the pair of side plates 51 of the bracket 5 during the closing and opening operation, and are limited in the opening limit position by the opening limit stoppers 513 on the pair of side plates 51 of the bracket 5. The both side plates 11 of the handle lever assembly 1 substantially cover the cavities 511 of the pair of both side plates 51 of the bracket 5 in the above-mentioned movable section, and restrict the upper and lower link hinge shafts 10, specifically, the axial displacement of the upper and lower link hinge shafts 10.

The utility model discloses except that the applicant in the above technical effect column the technical effect, still can know through the reading to this embodiment: by adjusting the track of the first stop face 5111, the tripping speed of the mechanism can be optimized in the design stage, and the optimal technical effect can be achieved. The accelerated tripping action is comprehensively verified without increasing the operating energy.

Claims

1. An operating mechanism of a low-voltage molded case circuit breaker comprises a handle lever component (1), a support (5), a jump buckle lever (2), a first locking piece (4), a main spring (9), an elbow connecting rod mechanism, a rotating shaft (40) and a contact component (20), wherein the elbow connecting rod mechanism comprises an upper connecting rod (6) and a lower connecting rod (7), the upper connecting rod (6) and the lower connecting rod (7) are hinged and connected through an upper connecting rod hinged shaft and a lower connecting rod hinged shaft (10), the axis of the upper connecting rod hinged shaft and the lower connecting rod hinged shaft (10) is marked as A, and the main spring (9) is connected between the upper connecting rod hinged shaft and the lower connecting rod hinged shaft (10) and the handle; the bracket (5) is composed of a pair of side plates (51) which are arranged oppositely and fixedly connected with each other, and the upper and lower connecting rod articulated shafts (10) are movably supported between the pair of side plates (51); the handle lever component (1) is pivotally supported on a pair of side plates (51) of the bracket (5), and the jump buckle lever (2) is pivotally supported between the pair of side plates (51) of the bracket (5) through a jump buckle lever pivot shaft (21) and is pivotally connected with the upper connecting rod (6); the first locking piece (4) is matched with the jump buckle lever (2) and used for locking or unlocking the jump buckle lever (2); the rotating shaft (40) is rotationally connected with the lower connecting rod (7), the rotating center is marked as B, and the rotation is realized through the action of the elbow connecting rod mechanism; the contact assembly (20) comprises a movable contact (201) and a fixed contact (202) which are mutually matched, the movable contact (201) is pivoted on a rotating shaft (40), a contact spring (50) used for providing pretightening force to provide contact pressure when the switch is switched on is arranged between the movable contact (201) and the rotating shaft (40), one side plate of a pair of side plates (51) is provided with a cavity (511), the end parts of upper and lower connecting rod hinged shafts (10) extend into the cavity (511), and a first stop surface (5111) is formed on the cavity wall of the cavity (511), and the contact assembly is characterized in that the first stop surface (5111) is positioned between the upper and lower connecting rod hinged shafts (10) and a trip lever pivot shaft (21), and the first stop surface (5111) is parallel to a connecting line from A to B or forms an included angle of-15 degrees to 15 degrees with the connecting line from A to B, in the overtravel process of the initial stage of the tripping action of the operating mechanism, the articulated shaft (10) of the upper connecting rod and the lower connecting rod moves along the track limited by the first stop surface (5111), so that the moving contact (201) and the static contact (202) are driven to be quickly separated.

2. The operating mechanism of low voltage molded case circuit breaker according to claim 1, wherein when the circuit breaker is closed, a connecting line from the A to the B and a rotation center O from the B to the rotation shaft (40) are connected₂The connecting line between the two forms an included angle of 85-95 degrees.

3. The operating mechanism of the low voltage molded case circuit breaker according to claim 1, wherein the cavity wall of the cavity (511) further comprises a second stop surface (5112) and a third stop surface (5113), the first stop surface (5111) and the second stop surface (5112) form a face-to-face relationship, and the third stop surface (5113) is located between the first and second stop surfaces (5111, 5112).

4. The operating mechanism of the low voltage molded case circuit breaker according to claim 1, wherein the other side plate of the pair of side plates (51) is also formed with a cavity (511), and the cavity (511) of the one side plate corresponds to each other.