Short-circuit protection tripping mechanism for oil-immersed circuit breaker

Abstract

The utility model discloses an oil-immersed circuit breaker short circuit protection tripping mechanism which comprises an excitation conductor, an instantaneous armature, a limiting plate and a reset elastic piece, the instantaneous armature is rotatably arranged on a circuit breaker shell and located on the lower side of the excitation conductor, and the limiting plate is rotatably arranged on one side of the instantaneous armature and is in limiting fit with a contact mechanism of a circuit breaker. A push rod piece used for pushing the limiting plate to rotate is formed on the instantaneous armature, and the reset elastic piece is connected with the instantaneous armature. When a short-circuit fault occurs in the circuit breaker, the instantaneous armature is attracted by electromagnetic force to rotate towards one side of the excitation conductor, and the limiting plate is pushed to rotate through the push rod piece, so that the contact mechanism is triggered to execute tripping and opening actions, and after the short-circuit fault of the circuit breaker is relieved, the instantaneous armature is driven to rotate. And the instantaneous armature can rotate towards one side far away from the excitation conductor under the action of the elastic force of the reset elastic piece, so that the quick reset function of the instantaneous armature is realized, and the use safety and reliability of the product are improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to low voltage electrical apparatus technical field, concretely relates to a short circuit protection tripping mechanism of oil immersed circuit breaker. BACKGROUND

[0002] Oil immersed circuit breaker is a kind of power switch equipment using high insulation oil as medium, and oil is widely used in power system and industrial field.In power system, oil immersed circuit breaker is mainly used for the protection and control of power transmission and distribution network, can cut off and isolate fault current in circuit, protect power equipment and personal safety.When circuit works normally, circuit breaker can cut off or connect the circuit of power supply to achieve power-off, power supply and circuit conversion function.When overload, voltage loss, under voltage or short circuit fault occurs in circuit, circuit breaker can also automatically cut off the circuit to avoid endangering the safety of staff and normal operation of equipment.

[0003] An existing oil immersed circuit breaker on the market includes passive contact electrification mechanism, active contact electrification mechanism and short circuit electromagnetic protection assembly, and the short circuit electromagnetic protection assembly includes mounting plate and silicon steel sheet.The mounting plate is arranged on the insulating support, and the silicon steel sheet is installed on the mounting plate and below the bimetallic strip.When short circuit fault occurs on the load side of the circuit breaker, short circuit current reaches a certain value, and due to electromagnetic effect, the electromagnetic protection assembly is attracted to push the lock catch of the active contact electrification mechanism to unlock, and under the action of spring tension, the contact of the active contact electrification mechanism and the passive contact electrification mechanism is separated to realize short circuit protection function.From the structure of the existing short circuit electromagnetic protection assembly, it can be seen that the following problems still exist: when the electromagnetic protection assembly is attracted by electromagnetic force, it will rotate to one side of the bimetallic strip, and when the short circuit fault is removed, the electromagnetic protection assembly is reset by its own gravity rotation, which is easy to be stuck and cannot be reset in time or the reset is not in place, the structural stability is poor, and the short circuit protection function of the product is affected. SUMMARY

[0004] Therefore, the technical problem to be solved by the utility model is to overcome the problem that the electromagnetic protection assembly in the prior art resets by its own gravity rotation, is easy to be stuck and cannot be reset in time or the reset is not in place, and affects the short circuit protection function of the product.

[0005] To solve the above technical problems, the utility model provides a short circuit protection tripping mechanism of oil immersed circuit breaker, which comprises:

[0006] Excitation conductor connected to the main circuit of the circuit breaker;

[0007] Instantaneous operating armature rotatably arranged on the lower side of the excitation conductor in the circuit breaker housing, and a magnetically conductive core opposite to the instantaneous operating armature is arranged on the instantaneous operating armature;

[0008] The limiting plate is arranged on one side of the instantaneous armature in a rotating manner and is in limiting cooperation with a contact mechanism of the circuit breaker, and the contact mechanism performs a tripping action when the limiting cooperation with the limiting plate is released; a push rod member is formed on the instantaneous armature for pushing the limiting plate to rotate;

[0009] The reset elastic member is connected with the instantaneous armature and applies an elastic force to the instantaneous armature to rotate away from the side of the excitation conductor.

[0010] As a preferred solution, the instantaneous armature and the limiting plate are coaxially arranged on the circuit breaker housing through a rotating shaft.

[0011] As a preferred solution, the instantaneous armature includes a connecting plate part arranged on one side of the limiting plate, and an armature main body arranged on the other side of the limiting plate by bending extension of the connecting plate part, and the push rod member is integrally formed on one end side of the armature main body away from the connecting plate part.

[0012] As a preferred solution, the push rod member extends on the bottom side of the limiting plate in an L-shaped structure.

[0013] As a preferred solution, the reset elastic member is a torsion spring structure sleeved on the rotating shaft, and the torsion spring structure is limited between the limiting plate and the instantaneous armature, and two elastic end feet of the torsion spring structure are respectively extended to connect the instantaneous armature and the circuit breaker housing.

[0014] As a preferred solution, the circuit breaker housing is provided with a positioning block, and the connecting plate part of the instantaneous armature is provided with a positioning groove, so that one elastic end foot of the torsion spring structure abuts against the positioning block, and the other elastic end foot abuts against the positioning groove.

[0015] As a preferred solution, the magnetically conductive core includes a plurality of magnetically conductive sheets arranged in a laminated manner on the side surface of the armature main body.

[0016] As a preferred solution, the contact mechanism includes a movable support arranged on the circuit breaker housing in a rotating manner, a movable contact arranged on the movable support, and an operating assembly for driving the movable support to perform opening and closing operations, the movable contact is electrically connected with the excitation conductor through a flexible connection, and a tripping spring is arranged between the movable support and the circuit breaker housing.

[0017] As a preferred solution, the limiting plate is provided with a limiting clamping groove on the bottom side facing the movable support, and the upper end of the movable support away from the movable contact is connected in the limiting clamping groove to form limiting cooperation.

[0018] Compared with the prior art, the technical scheme of the utility model has the following advantages:

[0019] 1. The oil-immersed circuit breaker short-circuit protection tripping mechanism provided by the utility model, when a short-circuit fault occurs in the main circuit of the circuit breaker, a large short-circuit current passing through the excitation conductor generates an electromagnetic force attracting the instantaneous armature, the instantaneous armature is magnetized under the electromagnetic action, and the magnetization effect of the instantaneous armature can be enhanced through the magnetically conductive core, so as to improve the action sensitivity of the instantaneous tripping mechanism, make the instantaneous armature rotate to the side of the excitation conductor under the attraction of the electromagnetic force, and push the limiting plate to rotate through the push rod to release the limiting cooperation between the limiting plate and the contact mechanism, so as to trigger the contact mechanism to perform a tripping and opening action, thereby realizing the short-circuit opening protection of the circuit breaker, and when the short-circuit fault of the circuit breaker is eliminated, the instantaneous armature rotates to the side away from the excitation conductor under the elastic force of the reset elastic element, the fast reset function of the instantaneous armature can be realized, the situation that the instantaneous armature is stuck or not reset to the right position is avoided, the structural stability is good, and the normal use of the instantaneous tripping mechanism of the circuit breaker is ensured, thereby improving the safety and reliability of the product in use.

[0020] 2. In the oil-immersed circuit breaker short-circuit protection tripping mechanism provided by the utility model, the instantaneous armature is composed of a connecting plate part, an armature main body and a push rod assembly, the push rod is integrally formed on one end of the armature main body and extends to the bottom side of the limiting plate in an L-shaped structure, the integrated structure has good stability, is easy to form and manufacture, simplifies the installation structure, improves the installation efficiency, is conducive to the integrated installation of the instantaneous armature, and the limiting plate is located on the movement path of the push rod, so that the limiting plate is driven to rotate through the push rod when the instantaneous armature rotates under the electromagnetic force, thereby realizing the transmission cooperation between the instantaneous armature and the limiting plate.

[0021] 3. In the oil-immersed circuit breaker short-circuit protection tripping mechanism provided by the utility model, the instantaneous armature and the limiting plate are coaxially arranged in the circuit breaker shell through a rotating shaft, and the reset elastic element is a torsion spring structure sleeved on the rotating shaft and limited between the limiting plate and the instantaneous armature, so that the torsion spring structure can be prevented from being separated from the rotating shaft, the structure is compact, and the installation stability is good, then one elastic end foot of the torsion spring structure is abutted against the positioning block of the shell, and the other elastic end foot is abutted in the positioning groove of the instantaneous armature, so that the elastic reset function of the instantaneous armature is realized, and the reset action sensitivity and reliability of the instantaneous armature are improved. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the specific embodiments of the utility model or the technical solutions in the prior art, the drawings needed in the following specific embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the utility model, and other drawings can be obtained by those skilled in the art without creative labor.

[0023] Figure 1 It is a plane structure schematic view of the short-circuit protection tripping mechanism of the oil-immersed circuit breaker of the utility model.

[0024] Figure 2 It is a three-dimensional structure schematic view of the short-circuit protection tripping mechanism of the oil-immersed circuit breaker of the utility model.

[0025] Figure 3 It is an installation structure schematic view of the instantaneous armature of the utility model.

[0026] Figure 4 It is Figure 3 It is a three-dimensional structure schematic view of the instantaneous armature.

[0027] Mark 1, limit plate; 11, limit card slot; 2, excitation conductor; 3, reset elastic element; 4, instantaneous armature; 41, push rod; 42, armature main body; 43, coupling plate part; 44, positioning groove; 5, magnetic core; 6, rotating shaft; 7, contact mechanism; 71, dynamic support; 72, moving contact; 73, static contact; 74, opening spring; 75, operation assembly; 8, positioning block; 9, circuit breaker shell. DETAILED DESCRIPTION

[0028] The technical scheme of the utility model will be described clearly and completely in combination with the drawings, obviously, the described embodiments are a part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by the ordinary skilled in the art without making creative labor belong to the scope of protection of the utility model.

[0029] In the description of the utility model, it needs to be explained that the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0030] In the description of the utility model, it needs to be explained that, unless otherwise explicitly specified and limited, the terms "installation", "connection", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, or the communication inside two elements. For the ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0031] EMBODIMENT

[0032] The embodiment provides an oil-immersed circuit breaker short-circuit protection tripping mechanism, as shown in Figures 1-4 The oil-immersed circuit breaker short-circuit protection tripping mechanism comprises:

[0033] The excitation conductor 2 is connected to the main circuit of the circuit breaker;

[0034] The instantaneous armature 4 is rotatably arranged below the excitation conductor 2 in the circuit breaker housing 9, and the instantaneous armature 4 is provided with a magnetically conductive core 5 opposite to the instantaneous armature 4;

[0035] The limiting plate 1 is rotatably arranged on one side of the instantaneous armature and forms a limiting cooperation with the contact mechanism 7 of the circuit breaker, and the contact mechanism 7 performs a tripping action when the limiting cooperation with the limiting plate 1 is released; the instantaneous armature 4 is formed with a push rod 41 for pushing the limiting plate 1 to rotate;

[0036] The reset elastic member 3 is connected to the instantaneous armature 4 and applies an elastic force to the instantaneous armature 4 to rotate away from the excitation conductor 2.

[0037] In the above embodiment, when a short-circuit fault occurs in the main circuit of the circuit breaker, the electromagnetic force generated by the short-circuit large current passing through the excitation conductor 2 attracts the instantaneous armature 4, the instantaneous armature 4 is magnetized under the electromagnetic action, and the magnetization effect of the instantaneous armature 4 can be enhanced through the magnetically conductive core 5 to improve the action sensitivity of the instantaneous tripping mechanism, so that the instantaneous armature 4 is attracted to the side of the excitation conductor 2 and rotates, and the limiting plate 1 is pushed to rotate by the push rod 41 to release the limiting cooperation between the limiting plate 1 and the contact mechanism 7, thereby triggering the contact mechanism 7 to perform a tripping action, so as to realize the short-circuit tripping protection of the circuit breaker, and when the short-circuit fault of the circuit breaker is eliminated, the instantaneous armature 4 will rotate away from the excitation conductor 2 under the elastic force of the reset elastic member 3, which can quickly realize the automatic reset function of the instantaneous armature 4, avoid the instantaneous armature 4 from being stuck and not reset to the position, and has stable structure, which ensures the normal use of the instantaneous tripping mechanism of the circuit breaker and improves the safety and reliability of the product in use.

[0038] The specific arrangement of the instantaneous armature will be described in detail as follows: Figures 1-4

[0039] ​The instantaneous armature 4 and the limiting plate 1 are coaxially arranged in the circuit breaker shell 9 through the rotating shaft 6, the instantaneous armature 4 includes the connecting plate part 43 rotating on one side of the limiting plate 1, and the armature main body 42 extending on the other side of the limiting plate 1 by bending the connecting plate part 43, since the limiting plate 1 and the excitation conductor 2 are arranged in the circuit breaker shell 9 in a staggered manner, the design makes the instantaneous armature 4 just opposite to the excitation conductor 2 after passing the limiting plate 1, the push rod part 41 is integrally formed on the end side of the armature main body 42 away from the connecting plate part 43, according to the instantaneous armature 4 composed of the connecting plate part 43, the armature main body 42 and the push rod part 41, the push rod part 41 is integrally formed on the end of the armature main body 42 and extends on the bottom side of the limiting plate 1 in an L-shaped structure, the spacing between the L-shaped push rod part 41 and the limiting plate 1 is adjustable, the spacing between the push rod part 41 and the limiting plate 1 is adjusted according to different current specifications, and the short-circuit protection characteristic precision requirement is met. The integral structure has good stability, is convenient to form and manufacture, simplifies the installation structure, improves the installation efficiency, is conducive to realizing the integrated installation of the instantaneous armature 4, and the design makes the limiting plate 1 just located on the movement path of the push rod part 41, the limiting plate 1 is driven to rotate by the push rod part 41 when the instantaneous armature 4 is rotated under the action of the electromagnetic force, so that the transmission cooperation between the instantaneous armature 4 and the limiting plate 1 is realized.

[0040] As Figure 3 shown, the magnetic conducting core 5 includes a plurality of magnetic conducting sheets stacked on the side surface of the armature main body 42, the number of the magnetic conducting sheets can be increased or reduced according to the load current and the overcurrent protection value requirement to meet the protection action characteristic precision requirement, the magnetic conducting sheets are made of magnetic conducting material, the stacked magnetic conducting sheets have strong magnetic conducting capacity, improve the magnetization effect of the instantaneous armature 4, and can reduce the eddy current and hysteresis loss generated by the alternating magnetic field in the instantaneous armature 4, and effectively reduce the energy loss.

[0041] The specific setting mode of the reset elastic member will be described below. Figures 2-4

[0042] ​The reset elastic member 3 is a torsion spring structure sleeved on the rotating shaft 6, which is limited between the limiting plate 1 and the instantaneous operating armature 4, and two elastic end feet thereof are respectively extended to connect the instantaneous operating armature 4 and the circuit breaker shell 9, so that the torsion spring structure can be prevented from being separated from the rotating shaft 6, and the structure is compact and has good installation stability. As a preferred embodiment, the circuit breaker shell 9 is provided with a positioning block 8, and the coupling plate part 43 of the instantaneous operating armature 4 is provided with a positioning groove 44, so that one elastic end foot of the torsion spring structure abuts against the positioning block 8, and the other elastic end foot abuts against the positioning groove 44, so that the installation design realizes the elastic reset function of the instantaneous operating armature 4 and improves the reset action sensitivity and reliability of the instantaneous operating armature 4.

[0043] In the embodiment, the contact mechanism 7 includes a movable support 71 rotatably arranged on the circuit breaker shell 9, a movable contact 72 arranged on the movable support 71, an operating assembly 75 driving the movable support 71 to perform opening and closing operations, a static contact 73 arranged on the circuit breaker shell 9 and matched with the movable contact 72, the movable contact 72 is electrically connected with the excitation conductor 2 through a soft connection, the excitation conductor 2 is a bimetallic strip, a closing spring 74 is arranged between the movable support 71 and the circuit breaker shell 9, the bottom side of the limiting plate 1 facing the movable support 71 is provided with a limiting clamping groove 11, and the upper end of the movable support 71 away from the movable contact 72 is connected in the limiting clamping groove 11 to form a limiting match. According to the structure, when the contact mechanism 7 drives the movable contact 72 to contact the static contact 73 to be in a closed state, the closing spring 74 is stretched and stored. Therefore, when the limiting plate 1 is driven by the instantaneous operating armature 4 to rotate to the side away from the movable support 71, the limiting plate 1 is separated from the movable support 71. At this time, the contact mechanism 7 performs a tripping and opening operation under the spring force released by the closing spring 74, so as to realize the separation of the movable contact 72 and the static contact 73, thereby realizing the short-circuit opening protection function of the circuit breaker.

[0044] Obviously, the above embodiment is only an example for clearly illustrating, and is not a limitation to the embodiments. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. Here, all the embodiments need not and cannot be exhausted. The obvious changes or variations derived therefrom are still within the protection scope of the utility model.

Claims

1. An oil immersed circuit breaker short circuit protection trip mechanism characterized by, The application relates to a circuit breaker. An excitation conductor (2) is connected to the main circuit of the circuit breaker; A quick-acting armature (4) is arranged on the lower side of the excitation conductor (2) in the circuit breaker shell (9), and a magnetically conductive core (5) is arranged on the quick-acting armature (4) opposite to the quick-acting armature (4); A limiting plate (1) is arranged on one side of the quick-acting armature and is in limiting cooperation with a contact mechanism (7) of the circuit breaker, and the contact mechanism (7) performs a tripping action when the limiting cooperation with the limiting plate (1) is released; a push rod (41) is formed on the quick-acting armature (4) and is used for pushing the limiting plate (1) to rotate; A reset elastic element (3) is connected to the quick-acting armature (4) and applies an elastic force to the quick-acting armature (4) to rotate away from the excitation conductor (2).

2. The oil immersed circuit breaker short circuit protection trip unit of claim 1, wherein: The quick-acting armature (4) and the limiting plate (1) are coaxially arranged on the circuit breaker shell (9) through a rotating shaft (6).

3. The oil immersed circuit breaker short circuit protection trip unit of claim 2, wherein: The quick-acting armature (4) comprises a coupling plate portion (43) arranged on one side of the limiting plate (1) and an armature main body (42) arranged on the other side of the limiting plate (1) through bending extension of the coupling plate portion (43), and the push rod (41) is integrally formed on one end side of the armature main body (42) away from the coupling plate portion (43).

4. The oil immersed circuit breaker short circuit protection trip unit of claim 3, wherein: The push rod (41) extends on the bottom side of the limiting plate (1) in an L-shaped structure.

5. The oil immersed circuit breaker short circuit protection trip unit according to any one of claims 2-4, characterized in that: The reset elastic element (3) is a torsion spring structure sleeved on the rotating shaft (6), and the torsion spring structure is limited between the limiting plate (1) and the quick-acting armature (4), and two elastic end feet of the torsion spring structure are respectively connected to the quick-acting armature (4) and the circuit breaker shell (9).

6. The oil immersed circuit breaker short circuit protection trip unit of claim 5, wherein: The circuit breaker shell (9) is provided with a positioning block (8), and the coupling plate portion (43) of the quick-acting armature (4) is provided with a positioning groove (44), so that one elastic end foot of the torsion spring structure abuts against the positioning block (8), and one elastic end foot abuts against the positioning groove (44).

7. The oil immersed circuit breaker short circuit protection trip unit of claim 3, wherein: The magnetically conductive core (5) comprises a plurality of magnetically conductive sheets arranged in a laminated mode on one side surface of the armature main body (42).

8. The oil immersed circuit breaker short circuit protection trip unit of claim 1, wherein: The contact mechanism (7) comprises a movable support (71) arranged on the circuit breaker shell (9), a movable contact (72) arranged on the movable support (71), and an operating assembly (75) for driving the movable support (71) to perform opening and closing operations, the movable contact (72) is electrically connected to the excitation conductor (2) through a soft connection, and a tripping spring (74) is arranged between the movable support (71) and the circuit breaker shell (9).

9. The oil immersed circuit breaker short circuit protection trip unit of claim 8, wherein: The limiting plate (1) is provided with a limiting clamping groove (11) on the bottom side facing the movable support (71), and the upper end of the movable support (71) away from the movable contact (72) is connected in the limiting clamping groove (11) to form limiting cooperation.

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