Arc extinguishing device and molded case circuit breaker

Abstract

The utility model discloses an arc extinguishing device and a molded case circuit breaker, the arc extinguishing device comprises an arc extinguishing chamber, a static contact and a gas production cover, the arc extinguishing chamber comprises a positioning frame and an arc extinguishing grid sheet, an opening is formed in the front middle part of the arc extinguishing chamber, and the static contact is provided with a static contact at the bottom in the opening; the gas production cover is arranged at the front part of the arc extinguish chamber, and a channel is formed in the opening; seen from top to bottom, in the front-back direction, one part of the static contact is located in the channel, the other part of the static contact backwards extends out of the channel and is set to be in the front-back direction, the length size of the part, located in the channel, of the static contact is A, the total length size of the static contact is B, and the relation that A = 0.6 B-0. 8B is met. According to the utility model, the structure is optimally designed, the arc extinguishing performance can be ensured, and the shell explosion probability can be reduced, so that the use performance and the service life of the circuit breaker can be ensured, and the circuit breaker has good practicability and generalizability.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of circuit breaker, more specifically, it relates to an arc extinguishing device and a molded case circuit breaker. BACKGROUND

[0002] During the breaking process of the circuit breaker, arc will be generated between the moving contact and the static contact, which will cause the internal gas of the circuit breaker to be highly ionized, and a large number of free metal ions will be generated, under the action of high pressure inside, if these free metal particles fly out of the circuit breaker, it may cause short circuit and burning of the surrounding line, thus causing an accident.

[0003] Therefore, the existing molded case circuit breaker is equipped with an arc extinguishing chamber, which achieves the effect of rapid arc extinguishing to improve the breaking capacity of the molded case circuit breaker. In order to further improve the arc extinguishing effect, a gas generating cover is arranged in front of the arc extinguishing chamber, the static contact point on the static contact is below the gas generating cover, and the arc generated when the moving contact and the static contact separate will heat the gas generating cover to generate a large amount of gas, thus promoting the arc to quickly enter the arc extinguishing chamber to achieve the purpose of gas blowing arc extinguishing.

[0004] However, the main problem of the existing arc extinguishing scheme is that in order to make the gas generating cover generate a large amount of gas instantaneously to push the arc to move quickly into the arc extinguishing chamber, the entire static contact is usually arranged inside the gas generating cover, so that a large amount of arc is concentrated inside the gas generating cover when the moving contact and the static contact separate, which causes the local pressure to increase suddenly and cannot be released quickly, thus easily causing the problem of circuit breaker shell explosion, especially the A\C side wall is easily exploded, thus affecting the service life of the circuit breaker and causing new safety hazards. TECHNICAL SOLUTION

[0005] The utility model provides a kind of arc extinguishing device and the molded case circuit breaker using it, by optimizing the structure of arc extinguishing device, it can effectively reduce the probability of shell explosion caused by local high pressure due to arc while ensuring arc extinguishing performance.

[0006] To achieve the above object, the utility model provides the following technical scheme:

[0007] Firstly, the utility model provides a kind of arc extinguishing device, including arc extinguishing chamber, static contact and gas generating cover, the arc extinguishing chamber includes positioning frame and multiple arc extinguishing fins arranged on positioning frame in up-down direction, the arc extinguishing chamber is formed with opening in front middle part, the static contact is arranged below arc extinguishing chamber and is provided with static contact point in the bottom of opening on static contact;The gas generating cover is arranged in front part of arc extinguishing chamber, and is formed with passage for the moving contact to extend into in opening;From top to bottom, part of the static contact point is in the passage, another part extends out of the passage rearward in front-rear direction, and is arranged in front-rear direction, the length of the part of static contact point in the passage is A, the total length of static contact point is B, and A=0.6B~0.8B is satisfied.

[0008] In some embodiments, two arc separation plates are oppositely arranged on the gas production cover and extend into the opening, the passage is formed between the two arc separation plates, the bottom of the two arc separation plates is connected by a connecting part, the connecting part covers the upper part of the static contact and avoids the static contact point.

[0009] In some embodiments, an arc-shaped surface is arranged on the upper part of the connecting part.

[0010] In some embodiments, a limiting baffle is arranged on the lower part of the gas production cover.

[0011] In some embodiments, a sleeve part is arranged on the gas production cover on the side of the arc separation plate opposite to the passage, the sleeve part is arranged in the up-down direction, a plug cavity is arranged on the rear side of the sleeve part, and the front end side of the arc extinguishing chamber extends into the plug cavity.

[0012] In some embodiments, a resisting surface is arranged on the bottom of the plug cavity on the gas production cover, and the arc extinguishing grid at the lower end abuts on the resisting surface.

[0013] In some embodiments, the static contact point is rectangular.

[0014] In the second aspect, the utility model provides a moulded case circuit breaker, including circuit breaker base and any above-mentioned arc extinguishing device, the installation cavity is formed on the circuit breaker base, and the arc extinguishing device is arranged in the installation cavity.

[0015] In some embodiments, two baffle plates are oppositely arranged on the front part of the arc extinguishing device on the circuit breaker base, a limiting plate is arranged in the installation cavity, a limiting slot arranged in the up-down direction is formed between the limiting plate and the baffle plate, and the sleeve part on the gas production cover is inserted into the limiting slot.

[0016] Compared with the prior art, the utility model discloses the beneficial effects are: the utility model discloses the structure optimization of arc extinguishing device, increases the gas production cover on the basis of traditional arc extinguishing chamber, and a large amount of gas is produced to arc can be more fully, fast into arc extinguishing chamber, guarantee arc extinguishing effect, further through setting in along the front -back direction, the length size of static contact point is A in the inside part of passage, and the total length size of static contact point is B, satisfy relation formula: A = 0.6B ~ 0.8B, by the static contact point mostly being arranged in the passage, a small part is arranged in the rear of passage and is close to arc extinguishing chamber middle part, so when the arc of the separation of moving contact and static contact can directly enter arc extinguishing chamber, another part then enters arc extinguishing chamber through the gas release of arc separation plate under the hot action, because the arc amount in the passage is reduced, therefore the gas production amount can be controlled, so good arc extinguishing effect can be reached while, by reducing the gas production of arc separation plate and reaching the purpose of reducing local pressure, so the probability of appearing shell explosion (that is, circuit breaker shell burst) can be effectively reduced, guarantee the service life of product. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 It is the explosion drawing of arc extinguishing device in the utility model;

[0018] Figure 2 It is the explosion drawing of arc extinguishing device in the utility model;

[0019] Figure 3 It is the stereogram of gas production cover in the utility model;

[0020] Figure 4 It is the plan view of arc extinguishing device in the utility model;

[0021] Figure 5 It is the stereogram of circuit breaker base and arc extinguishing device cooperation in the utility model;

[0022] Figure 6 It is Figure 5 the close -up view of C part in the utility model;

[0023] Figure 7 It is the stereogram of circuit breaker base in the utility model.

[0024] The reference signs shown in the drawing are: 1, arc extinguishing chamber;11, positioning frame;12, arc extinguishing fin;13, opening;2, static contact;21, static contact point;3, gas production cover;32, arc separation plate;33, passage;34, connecting portion;35, limit stop edge;36, sleeve part;37, insert cavity;38, resistance face;41, circuit breaker base;42, installation cavity;43, baffle;44, limit plate;45, limit slot. DETAILED DESCRIPTION

[0025] The technical solutions of the utility model will be described clearly and completely below in combination with the drawings. Obviously, the described embodiments are some of the embodiments of the utility model, rather than all the embodiments.

[0026] In the first aspect, the arc extinguishing device structure in the embodiments of the utility model is shown in the drawing, which comprises an arc extinguishing chamber 1 and a static contact 2. Figures 1 to 4 The arc extinguishing chamber 1 comprises a positioning frame 11 and a plurality of arc extinguishing fins 12 arranged on the positioning frame 11 in the up-down direction, and the positioning frame 11 is mainly used for fixing the arc extinguishing fins 12. The arc extinguishing fin 12 is a U-shaped fin structure. An opening 13 is formed in the front middle part of the arc extinguishing chamber 1. The static contact 2 is arranged below the arc extinguishing chamber 1 and is provided with a static contact point 21 on the static contact 2, which is located at the bottom of the opening 13. The static contact point 21 is preferably rectangular. When the moving contact is moved downward and the moving contact point on the moving contact is in contact with the static contact point 21, the moving contact and the static contact 2 are conducted. When the moving contact is moved upward and the moving contact point on the moving contact is separated from the static contact point 21, the moving contact and the static contact 2 are disconnected. The arc generated when the moving contact and the static contact 2 are separated can enter the arc extinguishing chamber 1, be cut into short arcs by the arc extinguishing fins 12 and be cooled sufficiently, thereby achieving the arc extinguishing effect.

[0027] In order to improve the arc extinguishing effect of the molded case circuit breaker, a gas generating cover 3 is arranged in the front part of the arc extinguishing chamber 1. The gas generating cover 3 is arranged in the front part of the arc extinguishing chamber 1 and forms a passage 33 for the moving contact to extend into the opening 13. In this way, the gas generating cover 3 releases a large amount of gas under the high heat generated by the arc when the moving contact and the static contact 2 are separated, which can promote the arc to enter the arc extinguishing chamber 1 more quickly, thereby improving the arc extinguishing effect. However, this may cause the problem that a large amount of gas is generated during breaking, which causes the local air pressure in the circuit breaker shell to increase suddenly, thereby causing the circuit breaker shell to burst.

[0028] In order to avoid the above-mentioned problems, the inventors further optimize the structure of the arc extinguishing device, and specifically set the relative position of the static contact point 21 and the passage 33. Referring to Figure 4As shown, from top to bottom in the front-rear direction, part of the static contact 21 is in the channel 33, and the other part extends backward beyond the channel 33 and is arranged along the front-rear direction, the length dimension of the part of the static contact 21 in the channel 33 is A, the total length dimension of the static contact 21 is B, and the relationship A=0.6B~0.8B is satisfied, for example, A=0.6B, or A=0.7B, or A=0.8B; the inventor has found through research that such arrangement can effectively reduce the probability of explosion of the circuit breaker shell caused by sudden increase of local air pressure in the circuit breaker shell while ensuring arc extinguishing performance, because by arranging most of the static contact 21 in the channel 33 and a small part of the static contact 21 behind the channel 33 and close to the middle of the arc extinguishing chamber 1, part of the arc generated when the moving contact and the static contact 2 separate can directly enter the arc extinguishing chamber 1, and the other part enters the arc extinguishing chamber 1 by the pushing action of the gas released by the heat of the arc separation plate 32, because the amount of arc in the channel 33 is reduced, the amount of gas generated can be controlled, which can achieve good arc extinguishing effect while reducing the amount of gas generated by the arc separation plate 32 to reduce the local pressure, thereby effectively reducing the probability of shell explosion (i.e. explosion of the circuit breaker shell) and ensuring the service life of the product.

[0029] Further, referring to Figures 1 to 4 As shown, two arc separation plates 32 extending into the opening 13 are arranged opposite to each other on the gas generating cover 3, the channel 33 is formed between the two arc separation plates 32, and the bottom of the two arc separation plates 32 is connected by a connecting part 34, the connecting part 34 covers the static contact 2 above and avoids the static contact 21, the arc separation plates 32 are connected by the connecting part 34 to form a whole, the connecting part 34 can be integrated with the arc separation plates 32 by injection molding to facilitate assembly and enhance the overall structure; moreover, the connecting part 34 covers the static contact 2 above to prevent the arc from directly contacting the surface of the static contact 2 and further prevent the arc from burning and damaging the surface of the static contact 2; further, the upper part of the connecting part 34 is arranged as an arc surface, which can play a flow guiding role to shorten the stagnation time of the arc at this position.

[0030] As Figure 3 As shown, the limit stop 35 extending downward is further arranged at the lower part of the two sides of the gas generating cover 3, by arranging the limit stop 35, when the gas generating cover 3 is installed into the molded case circuit breaker, the limit stop 35 abuts against the step in the circuit breaker base 41 to play a supporting and limiting role.

[0031] Referring to Figure 1 and Figure 2In order to enhance the wrapping of the gas production cover 3 to the arc extinguishing chamber 1, the gas production cover 3 is provided with a sleeve part 36 on the side of the arc separation plate 32 opposite to the channel 33, the sleeve part 36 is arranged along the up-down direction, the rear side of the sleeve part 36 is provided with an insertion cavity 37, the front end side of the arc extinguishing chamber 1 extends into the insertion cavity 37, the front side of the arc extinguishing chamber 1 can be closed by the sleeve part 36, and the sleeve part 36 can block the electric arc, thereby ensuring the arc extinguishing effect.

[0032] In order to quickly and reliably position the gas production cover 3 in the circuit breaker base 41, a resisting surface 38 is arranged on the bottom of the insertion cavity 37 of the gas production cover 3 (see Figure 3 ), and the arc extinguishing grid 12 at the lower end abuts on the resisting surface 38 downward, thereby limiting the gas production cover 3 to prevent the upward movement of the gas production cover 3.

[0033] In the second aspect, the structure of the molded case circuit breaker in the embodiment of the utility model is shown in Figures 5 to 7 , which comprises a circuit breaker base 41 and the arc extinguishing device in any of the above embodiments, the circuit breaker base 41 is provided with a mounting cavity 42, and the arc extinguishing device is arranged in the mounting cavity 42; since the molded case circuit breaker adopts the arc extinguishing device in the above embodiments, the molded case circuit breaker has all the advantages of the arc extinguishing device, and the embodiment will not be described here.

[0034] Further, referring to Figure 6 , the circuit breaker base 41 is provided with two opposite baffles 43 in front of the arc extinguishing device, the mounting cavity 42 is provided with a limiting plate 44, the limiting plate 44 and the baffles 43 form a limiting groove 45 arranged along the up-down direction, the sleeve part 36 of the gas production cover 3 is inserted into the limiting groove 45, the sleeve part 36 and the limiting groove 45 can limit the gas production cover 3 in the front-rear direction, and the limiting plate 44 can also block the electric arc to prevent the electric arc from wandering.

[0035] The specific embodiment is only an explanation of the utility model, and is not a limitation of the utility model, and those skilled in the art can make modifications to the embodiment without creative contribution according to the needs after reading the specification, but as long as the modifications are within the scope of the claims of the utility model, the modifications are protected by the patent law.

Claims

1. An arc extinguishing device comprising an arc extinguishing chamber, a stationary contact and a gas generating cover, the arc extinguishing chamber comprising a positioning frame and a plurality of arc extinguishing fins arranged on the positioning frame in a vertical direction, a middle portion of the arc extinguishing chamber being formed with an opening, the stationary contact being arranged below the arc extinguishing chamber and being provided with a stationary contact point at a bottom portion in the opening, the gas generating cover being arranged at a front portion of the arc extinguishing chamber and being formed with a passage in the opening for a movable contact to extend into, characterized in that, Two arc separation plates are oppositely arranged on the gas production cover and extend into the opening, and the channel is formed between the two arc separation plates. The two arc separation plates form a part of the static contact point in the channel and another part of the static contact point extends out of the channel in the front and back directions. The length of the part of the static contact point in the channel is A, the total length of the static contact point is B, and the relationship A=0.6B~0.8B is satisfied.

2. The device of claim 1, wherein, The bottom of the two arc separation plates is connected by a connecting part, and the connecting part covers the static contact head and avoids the static contact point.

3. The device of claim 2, wherein, An arc surface is arranged on the upper part of the connecting part.

4. The device of claim 2, wherein, A limiting baffle extending downward is arranged on the lower part of the two sides of the gas production cover.

5. The device of claim 2, wherein, A sleeve part is arranged on the side of the arc separation plate of the gas production cover, away from the channel, and the sleeve part is arranged in the up and down direction. An insertion cavity is arranged on the rear side of the sleeve part, and the front end side of the arc extinguishing chamber extends into the insertion cavity.

6. The device of claim 5, wherein, A resisting surface is arranged on the bottom of the insertion cavity of the gas production cover, and one arc extinguishing grid at the lower end abuts on the resisting surface.

7. The device of claim 1, wherein, The static contact point is in a rectangular shape.

8. A molded case circuit breaker characterized by, The circuit breaker base and the arc extinguishing device of any one of claims 1 to 7 are included, and the mounting cavity is formed on the circuit breaker base, and the arc extinguishing device is arranged in the mounting cavity.

9. The molded case circuit breaker of claim 8, wherein, Two baffle plates are arranged on the front part of the arc extinguishing device on the circuit breaker base, and the limiting plate is arranged in the mounting cavity. The limiting slot arranged in the up and down direction is formed between the limiting plate and the baffle plate, and the sleeve part of the gas production cover is inserted into the limiting slot.

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