Contact arc extinguishing system

Abstract

A contact arc extinguishing system belongs to the technical field of low-voltage apparatuses. Comprising a contact system and an arc extinguish chamber located in the opening direction of the contact system, the contact system comprises a moving contact and a static contact, an arc striking piece is installed on the static contact, and the arc extinguish chamber further comprises a pair of insulation blocks located on the two sides of the arc striking piece. The matching surfaces, close to the arc striking sheet, of the insulating blocks are planes or cambered surfaces, and an upward narrowing channel is formed between the pair of matching surfaces. The utility model has the advantages that a pair of insulating blocks is formed and positioned on the two sides of the arc striking sheet on the static contact, the space at the static arc striking sheet can be effectively reduced, the electric arc rise is facilitated due to the reduction of the space, and meanwhile, the insulating gas generated by the insulating blocks is closer to the static contact and the arc striking sheet, so that the reignition at the contact is prevented.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of low-voltage electrical apparatus, and particularly relates to a contact arc extinguishing system. BACKGROUND

[0002] Switches are very important electrical apparatus in power supply and distribution lines, and can cut off the current to realize the disconnection of the circuit, thereby protecting the lines and electrical apparatus. The switch usually comprises a contact system, and the contact system comprises a moving contact and a static contact. The moving contact is in contact with or separated from the static contact after being actuated, thereby realizing the conduction or disconnection of the switch. As known in the art, when the switch is disconnected, an arc is generated between the moving contact and the static contact. Since the arc energy is relatively large, it brings great difficulty to the disconnection of the switch. Therefore, an arc extinguishing chamber is usually arranged in the switch to extinguish the arc generated when the moving contact is separated from the static contact. Only when the arc is extinguished, the circuit is disconnected.

[0003] A gas generating insulating member is usually arranged in the arc extinguishing chamber. When the arc enters the arc extinguishing chamber, the gas generating insulating member is heated to absorb the arc energy. Meanwhile, the insulating gas released from the gas generating insulating member can also accelerate the extinction of the arc. However, in the prior art, the gas generating insulating member is usually not considered to be matched with the arc striking piece on the static contact, thereby being not conducive to the arc entering the grid piece more quickly. SUMMARY

[0004] The utility model discloses a contact arc extinguishing system, which is characterized in that a pair of insulating blocks are arranged on both sides of the arc striking piece on the static contact, so as to reduce the space of the arc striking piece and facilitate the rising of the arc.

[0005] The utility model discloses a contact arc extinguishing system, which is characterized in that a pair of insulating blocks are arranged on both sides of the arc striking piece on the static contact, so as to reduce the space of the arc striking piece and facilitate the rising of the arc.

[0006] In one specific embodiment of the utility model, one side of the insulating block close to the inner wall of the shell is provided with a pair of clamping legs, and the head of the clamping leg is provided with a clamping hook. Correspondingly, a clamping hole is arranged on the inner wall of the shell, the clamping leg is inserted into the clamping hole, a clamping table is arranged in the clamping hole, and the clamping hook is buckled with the clamping table.

[0007] In another specific embodiment of the utility model, a positioning cavity is arranged on the inner wall of the shell, and the end face of the insulating block close to the inner wall of the shell is embedded into the positioning cavity.

[0008] In still another specific embodiment of the present application, a positioning protrusion is further arranged on the end face of the insulating block close to the inner wall of the shell; correspondingly, a positioning hole is arranged on the inner wall of the shell, and the positioning protrusion is embedded into the positioning hole.

[0009] In still another specific embodiment of the present application, the positioning hole and the positioning protrusion are both rectangular.

[0010] In still another specific embodiment of the present application, the arc striking piece comprises a mounting portion, a communication portion and a head portion, the stationary contact comprises a gasket, and the gasket surrounds the arc striking piece; the mounting portion is used for riveting with the conductive block of the stationary contact, the head portion is located at the extension end of the arc striking piece and is attached to the gasket, and the communication portion connects the mounting portion and the head portion.

[0011] In still another specific embodiment of the present application, the communication portion has a narrowing section, the width of the narrowing section gradually decreases during the extension of the arc striking piece towards the arc extinguishing chamber, and the communication portion has a structure of bulging away from the stationary contact.

[0012] In still another specific embodiment of the present application, a pair of the insulating blocks are located on both sides of the narrowing section.

[0013] In still another specific embodiment of the present application, an array of grid fins is installed in the shell, the length of the insulating block in the array direction of the grid fins is D1, and the length of the shell installed into the arc extinguishing cavity accommodating the arc extinguishing chamber in the array direction of the grid fins is D2; the ratio of D1 to D2 is 1 / 5 to 1 / 8.

[0014] In still another specific embodiment of the present application, the shell comprises a first side wall and a second side wall, the first side wall and the second side wall are spliced to form the shell; one of the pair of insulating blocks is flush with the interface of the first side wall close to the stationary contact and is located inside the first side wall, and the other insulating block is flush with the interface of the second side wall close to the stationary contact and is located inside the second side wall.

[0015] The present application has the beneficial effects of forming a pair of insulating blocks and locating the insulating blocks on both sides of the arc striking piece on the stationary contact, effectively reducing the space of the arc striking piece, preventing arc transverse migration, and facilitating the rising of arc due to the reduction of space; meanwhile, the insulating gas generated by the insulating blocks is closer to the stationary contact and the arc striking piece, preventing reignition at the contact. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 A three-dimensional structure schematic view of the insulating block after installation according to the utility model;

[0017] Figure 2 A plane structure schematic view of the insulating block installed on the side wall of the arc extinguishing chamber according to the utility model;

[0018] Figure 3 A structure schematic view of the static contact according to the utility model;

[0019] Figure 4 A structure schematic view of the first embodiment of the insulating block according to the utility model;

[0020] Figure 5 A partial schematic view of the insulating block installed on the inner wall of the side wall of the arc extinguishing chamber in the first embodiment according to the utility model;

[0021] Figure 6 A partial schematic view of the insulating block installed on the outer wall of the side wall of the arc extinguishing chamber in the first embodiment according to the utility model;

[0022] Figure 7 A structure schematic view of the second embodiment of the insulating block according to the utility model;

[0023] Figure 8 A partial schematic view of the insulating block installed on the inner wall of the side wall of the arc extinguishing chamber in the second embodiment according to the utility model.

[0024] In the figure: 1. arc extinguishing chamber, 11. shell, 111. first side wall, 112. clamping hole, 1121. clamping table, 113. positioning cavity, 114. positioning hole, 115. second side wall, 12. grid sheet; 2. static contact, 21. arc contact part, 22. static contact point, 23. gasket; 3. arc starting sheet, 31. mounting part, 32. communication part, 33. head; 4. insulating block, 41. end face, 411. matching surface, 412. cavity, 413. partition wall, 42. clamping leg, 421. clamping hook, 43. positioning protrusion. DETAILED DESCRIPTION

[0025] The specific embodiments of the utility model will be described in detail below in combination with the drawings, but the description of the embodiments is not a limitation on the technical solutions, and any formal but not substantial changes according to the concept of the utility model should be regarded as the protection scope of the utility model.

[0026] In the following description, the directional or positional concepts of up, down, left, right, front and back are based on the positions shown in the corresponding drawings, which are only provided for the technical solutions of the utility model and simplify the description, and thus cannot be understood as a special limitation on the technical solutions provided by the utility model. Example 1

[0027] like Figure 1 As shown, the switch includes a contact system and an operating mechanism (not shown) that drives the contact system to move. An arc extinguishing chamber 1 is provided in the opening direction of the contact system. The contact system includes a moving contact (not shown) and a stationary contact 2. The operating mechanism drives the moving contact to swing and then come into contact with or separate from the stationary contact, thereby closing or opening the switch.

[0028] The static contact 2 comprises a conductive block, on which is mounted an arc-striking piece 3. Typically, the arc-striking piece 3 is welded to the conductive block. The conductive block is provided with an arc contact portion 21 and a static contact 22. The static contact 22 is located below the arc contact portion 21, while the arc-striking piece 3 is located above the arc contact portion 21.

[0029] The static contact 22 is used to contact and cooperate with the moving contact on the moving contact to carry current, while the arc contact portion 21 is used to contact and cooperate with the head of the moving contact piece of the moving contact to start the arc. The arc starting piece 3 is used to guide the arc into the arc extinguishing chamber 1 above.

[0030] A gasket 23 is positioned above the conductive block. This gasket 23 surrounds the arc-striking piece 3 and is secured to the switch housing along with the arc-striking piece 3. Specifically, the gasket 23 has a recessed cavity for the head of the arc-striking piece 3 to fit into. This cavity is a countersunk cavity that aligns with the head of the arc-striking piece 3. This allows the arc-striking piece 3 to press against the gasket 23 from above.

[0031] The arc extinguishing chamber 1 includes a housing 11, in which an array of grid plates 12 is installed. The housing 11 includes a first side wall 111 and a second side wall 115, which are spliced ​​together to form the housing 11. The grid plates 12 are installed between the first side wall 111 and the second side wall 115.

[0032] The arc-starting piece 3 extends upward from the static contact 2 and is placed at one end of the array grid 12 in the array direction.

[0033] Combine Figure 2 Insulating blocks 4 are mounted on the inner sidewalls of the housing 11, i.e., one insulating block 4 is mounted on each of the first sidewall 111 and the second sidewall 115. Therefore, the insulating blocks 4 form a pair and are located at one end facing the static contact 2.

[0034] like Figure 3 , a pair of the insulating blocks 4 are located on both sides of the arc striking piece 3. Specifically, a pair of the insulating blocks 4 are located on both outer sides of the arc striking piece 3.

[0035] The arc striking piece 3 comprises a mounting portion 31, a communicating portion 32 and a head portion 33, one end of the communicating portion 32 is connected with the mounting portion 31, and the other end is connected with the head portion 33. A slot is arranged in the middle of the arc striking piece 3, and the slot is a closed slot, that is, both ends of the slot are closed.

[0036] The mounting portion 31 refers to a portion riveted in the conductive block of the static contact 2, which is used for riveting with the conductive block of the static contact 2; the head portion 33 refers to a portion located at the extension end of the arc striking piece 3 and abutting with the gasket 23, and the communicating portion 32 refers to a portion located between the mounting portion 31 and the head portion 33. The communicating portion 32 has a narrowing section, and the width of the narrowing section gradually decreases along the extension of the arc striking piece 3 to the arc extinguishing chamber 1. Preferably, the narrowing edges on both sides of the narrowing section are symmetrically arranged with the center line of the arc striking piece 3. More specifically, the communicating portion 32 has a structure that bulges away from the static contact 2.

[0037] An installation hole is arranged on the arc striking piece 3 and above the slot, and the installation hole cooperates with a screw to achieve the fixed installation of the arc striking piece 3 and the gasket 23.

[0038] Specifically, see Figure 3 Preferably, a pair of the insulating blocks 4 are located in the range of the communicating portion 32 on both sides of the extension direction of the arc striking piece 3, that is, a pair of the insulating blocks 4 are located on both sides of the narrowing edges.

[0039] In combination with Figure 2 , Figure 4 , Figure 5 and Figure 6 , the insulating block 4 is installed in the inner wall of the first side wall 111 by clamping, and more specifically, the insulating block 4 is flush with the interface of the first side wall 111 close to the static contact 2 and is located inside the first side wall 111. The clamping refers to the clamping by using a clamping leg or a clamping strip.

[0040] In this embodiment, specifically, a pair of clamping legs 42 are arranged on the side of the insulating block 4 close to the inner wall of the first side wall 111, the clamping legs 42 have elasticity, and the head portion of the clamping leg 42 has a clamping hook 421; correspondingly, a clamping hole 112 is arranged on the first side wall 111, and the clamping leg 42 extends into the clamping hole 112. A clamping table 1121 is arranged in the clamping hole 112, and the clamping hook 421 is buckled with the clamping table 1121. This clamping manner makes the installation of the insulating block 4 and the first side wall 111 stable, and the insulating block 4 will not fall off due to vibration.

[0041] In order to improve the installation positioning between the insulation block 4 and the first side wall 111, a positioning cavity 113 is arranged on the first side wall 111, and the end surface 41 of the insulation block 4 close to the first side wall 111 is embedded into the positioning cavity 113, so as to ensure the positioning effect of the two.

[0042] The installation relationship between the insulation block 4 and the first side wall 111 is described above, and the other insulation block 4 is flush with the interface of the second side wall 115 close to the static contact 2 and is located inside the second side wall 115. The installation relationship is the same, and will not be described here.

[0043] Since the insulation block 4 is usually made of a gas generating material, in order to meet the requirements of the injection molding process, the insulation block 4 has a partition wall 413 inside, and the partition wall 413 is arranged to form a cavity 412 inside the insulation block 4. The matching surface 411 of the insulation block 4 close to the arc striking piece 3 is a plane, preferably a plane with an inclined angle. The matching surface 411 corresponds to and matches the narrowed edge on the arc striking piece 3. Embodiment 2

[0044] As Figure 7 , Figure 8 is a second embodiment of the insulation block 4. The difference between it and the first embodiment is that the end surface of the insulation block 4 close to the first side wall 111 is also provided with a positioning protrusion 43, and correspondingly, the inner wall surface of the first side wall 111 is provided with a positioning hole 114, and the positioning protrusion 43 is embedded into the positioning hole 114, so as to realize the installation positioning between the insulation block 4 and the first side wall 111. Preferably, the positioning hole 114 and the positioning protrusion 43 are both rectangular. Similarly, the other insulation block 4 also has the same difference on the second side wall 115.

[0045] The matching surface 411 of the insulation block 4 close to the arc striking piece 3 is an arc surface, which is not a conical surface.

[0046] In the above two embodiments, since a pair of insulation blocks 4 are arranged on both sides of the arc striking piece 3 and are installed on the inner side wall of the housing 11 of the arc extinguishing chamber 1, when the arc is generated, the space on both sides of the arc striking piece 3 is occupied by the insulation block 4 when the arc moves on the arc striking piece 3. Therefore, the arc has no space to move horizontally, and at the same time, the reduced space makes the arc have greater upward moving aerodynamic force.

[0047] Preferably, the insulating block 4 is a gas generating element. After being ignited, it releases insulating gas. Due to the location of the insulating block 4, the insulating gas is densely present at the static contact 2, which effectively prevents the reignition of arc at the contact.

[0048] Due to the fact that the pair of end portions 411 are inclined planes or circular arc surfaces, the pair of insulating blocks 4 form upwardly narrowing gas channels, which can increase the flow rate and facilitate the pushing of arc into the grid 12 of the arc extinguishing chamber 1.

[0049] See Figure 2 The length of the insulating block 4 in the array direction of the grid 12 is D1, and the length of the housing 11 in the array direction of the grid 12 when installed in the arc extinguishing chamber of the switch is D2. In order to produce the size of the insulating block 4 that can match the size of the arc extinguishing chamber 1 or the size of the static contact 2, for large or small switches, when the size of the arc extinguishing chamber 1 and the static contact 2 is enlarged or reduced, the size of the insulating block 4 can be changed accordingly to adapt to the needs of switches of various sizes, and the ratio of D1 to D2 is 1 / 5 to 1 / 8, and in the preferred embodiment, it is 1 / 7.

[0050] As Figure 3 In the extension direction of the arc generating sheet 3, the height D3 of the insulating block 4 should match the shape of the arc generating sheet 3, and preferably, the height D3 is within the height range of the communication portion 32 of the arc generating sheet 3.

Claims

1. A contact arc extinguishing system, comprising a contact system and an arc extinguishing chamber (1) located in the opening direction of the contact system, the contact system comprising a moving contact and a stationary contact (2), an arc striking piece (3) being mounted on the stationary contact (2), and further comprising a pair of insulating blocks (4) located on both sides of the arc striking piece (3), characterized in that: The insulating block (4) is clamped on the inner wall of the shell (11) of the arc extinguishing chamber (1); the mating surface (411) of the insulating block (4) close to the arc striking piece (3) is a plane or an arc surface, and an upwardly narrowing channel is formed between the pair of mating surfaces (411).

2. A contact arc extinguishing system according to claim 1, characterized in that: The insulating block (4) is provided with a pair of clamping feet (42) on one side close to the inner wall of the shell (11), and the heads of the clamping feet (42) have clamping hooks (421); correspondingly, a clamping hole (112) is provided on the inner wall of the shell (11), and the clamping foot (42) extends into the clamping hole (112), and a clamping platform (1121) is provided in the clamping hole (112), and the clamping hook (421) is snap-fitted with the clamping platform (1121).

3. A contact arc extinguishing system according to claim 2, characterized in that: A positioning cavity (113) is provided on the inner wall of the shell (11), and the end surface (41) of the insulating block (4) close to the inner wall of the shell (11) is embedded in the positioning cavity (113).

4. A contact arc extinguishing system according to claim 2, characterized in that: A positioning protrusion (43) is also provided on the end surface (41) of the insulating block (4) close to the inner wall of the shell (11); correspondingly, a positioning hole (114) is provided on the inner wall of the shell (11), and the positioning protrusion (43) is embedded in the positioning hole (114).

5. A contact arc extinguishing system according to claim 4, characterized in that: The positioning hole (114) and the positioning protrusion (43) are both rectangular.

6. A contact arc extinguishing system according to claim 1, characterized in that: The arc-striking piece (3) includes a mounting portion (31), a connecting portion (32) and a head portion (33); the static contact (2) includes a gasket (23); the gasket (23) surrounds the arc-striking piece (3); the mounting portion (31) is used for riveting with the conductive block of the static contact (2); the head portion (33) is located at the extended end of the arc-striking piece (3) and is in contact with the gasket (23); the connecting portion (32) connects the mounting portion (31) and the head portion (33).

7. A contact arc extinguishing system according to claim 6, characterized in that: The connecting portion (32) has a narrowing section, the width of which gradually decreases as it extends along the arc striking piece (3) toward the arc extinguishing chamber (1), and the connecting portion (32) has a structure that bulges away from the static contact (2).

8. A contact arc extinguishing system according to claim 7, characterized in that: A pair of insulating blocks (4) are located on both sides of the narrowed section.

9. The contact arc extinguishing system according to claim 1, characterized in that: An array of grid plates (12) is installed in the housing (11), and the length of the insulating block (4) in the array direction of the grid plates (12) is D1; ​​accordingly, the length of the housing (11) installed in the arc extinguishing cavity accommodating the arc extinguishing chamber (1) in the array direction of the grid plates (12) is D2, and the ratio of D1 to D2 is 1 / 5 to 1 / 8.

10. The contact arc extinguishing system according to claim 1, characterized in that: The shell (11) includes a first side wall (111) and a second side wall (115), and the first side wall (111) and the second side wall (115) are spliced ​​together to form the shell (11); one of the pair of insulating blocks (4) is flush with the interface of the first side wall (111) close to the static contact (2) and is located inside the first side wall (111), while the other insulating block is flush with the interface of the second side wall (115) close to the static contact (2) and is located inside the second side wall (115).

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