Contact arc extinguishing structure of switch

Abstract

A contact arc extinguishing structure of a switch belongs to the technical field of low-voltage apparatuses. Comprising an arc extinguish chamber and a contact system, the arc extinguish chamber comprises a pair of side walls, a plurality of grid sheets and a pair of gas generating parts, the grid sheets are arrayed between the pair of side walls, the gas generating parts are spaced to form an arc channel, the contact system comprises a moving contact, the moving contact comprises a long contact sheet and a short contact sheet, the long contact sheet extends into the arc channel, and the short contact sheet extends into the arc channel. The short contact piece is located on the outer side of the opening of the arc channel, the arc extinguish chamber further comprises a pair of matching surface bosses corresponding to the short contact piece, the matching surface bosses are matched with the swinging track of the short contact piece, a distance is kept between the pair of matching surface bosses and the head of the short contact piece, and the distance is smaller than 2 mm. As the matching surface boss which enables the end, facing the short contact piece, of the arc extinguish chamber is additionally arranged in the structure system of the arc extinguish chamber, a gap between the head of the short contact piece and the arc extinguish chamber can be greatly reduced through the matching surface boss, the amount of arc gas flowing into the head of the short contact piece is remarkably reduced, and breakdown at the short contact piece is effectively prevented.

Description

TECHNICAL FIELD

[0001] The utility model belongs to low voltage electrical apparatus technical field, concretely relates to a contact arc extinguishing structure of switch. BACKGROUND

[0002] Switch, especially disconnecting switch as important low voltage electrical apparatus, its realization carries current's on-off control, to satisfy to power supply network's on-off management.

[0003] Based on carrying current and arc's specific function, disconnecting switch's movable contact structure in prior art usually adopts long, short movable contact piece's form, when disconnecting switch's closing state, because short contact piece's length and contact area are larger than long contact piece, can provide better current conducting path, ensure current's uniform stable distribution transmission between contacts, avoid local overheating and ablation problem, short contact piece can also bear larger mechanical stress and thermal stress, ensure switch's stability and reliability in long-term operation process.Long contact piece can lengthen arc's path in the process of contact separation, utilize arc's natural extinguishing principle in lengthening process, drive arc to extinguish quickly, prevent arc's ablation to contact, guarantee disconnecting switch's service life.

[0004] Above all, movable contact's aforementioned long, short contact piece design can make carrying current and arc's two functions be completed by different contact pieces, and be favorable for shortening arc's position and arc extinguishing chamber's distance and accelerate arc's extinguishing.But, because ionized gas containing metal vapor diffuses downward to contact cavity under the action of air flow field or magnetic field factor when arc generates, at this time, because the insulation medium's intensity reduces here, is extremely easy to take place breakdown.Meanwhile, under long, short contact piece's structure, once short movable contact piece takes place breakdown, will result in arc's backtracking, cause breaking failure.This has been plagued in the field for a long time and the technical problem that expects to solve. UTILITY MODEL CONTENTS

[0005] The utility model's task is to provide a kind of contact arc extinguishing structure of switch that helps significantly reduce the arc gas amount of the short contact piece head of movable contact and effectively prevent arc breakdown at short contact piece.

[0006] The utility model discloses a switch contact arc extinguishing structure which is characterized by the following technical scheme, a switch contact arc extinguishing structure, including arc extinguishing chamber and contact system, the arc extinguishing chamber includes a pair of side walls, louver and gas generating element, the louver has a plurality of and array setting between a pair of side walls, the gas generating element has a pair and interval constitutes electric arc channel, the contact system includes movable contact, and the movable contact includes long contact sheet and short contact sheet, the long contact sheet dips into electric arc channel, and the short contact sheet is located electric arc channel opening's outside, the arc extinguishing chamber still includes a pair with the short contact piece corresponding cooperation face boss, cooperation face boss with short contact piece swing when the locus is matched, and the pair cooperation face boss and the head between short contact piece keep spacing, and this spacing is less than 2mm.

[0007] In the utility model, a pair of cooperation face bosses are arcuate, and the center of the arc of the cooperation face boss is concentric with the center of rotation of the short contact piece when swinging.

[0008] In the utility model, the spacing is 0.5-1mm.

[0009] In the utility model, the switch further includes a shell, a contact cavity for accommodating the contact system is formed in the shell, and the arc extinguishing chamber is located at the gas outlet side of the contact system.

[0010] In the utility model, a plugging boss is formed on the left and right outer sides of the arc extinguishing chamber, the plugging boss is in clearance fit with the inner side of the shell, and a gap of less than 1mm is kept between the plugging boss and the inner wall of the shell.

[0011] In the utility model, the gap is 0.5mm.

[0012] In the utility model, the plugging boss is located at the lower part of the outer side of the side wall.

[0013] In the utility model, the cooperation face boss is located on the surface of one end of the gas generating element facing the movable contact.

[0014] In the utility model, the gas generating element is made of a gas generating material.

[0015] The technical effect of the technical scheme provided by the utility model is that, because the cooperation face boss facing the short contact piece of the arc extinguishing chamber is added to the structural system of the arc extinguishing chamber, the gap between the head of the short contact piece and the arc extinguishing chamber can be greatly reduced by the cooperation face boss, the amount of arc gas flowing into the head of the short contact piece is significantly reduced, and thus the breakdown at the short contact piece can be effectively prevented. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is a schematic view that the arc extinguishing chamber and the contact system of the utility model are arranged in the shell.

[0017] Figure 2 for Figure 1 a partial schematic view of the arc extinguishing chamber;

[0018] Figure 3 for Figure 1 and Figure 2 a cross-sectional view of the internal structure of the arc extinguishing chamber;

[0019] Figure 4 for Figure 1 a detailed structural view of the contact system;

[0020] Figure 5 for Figure 1 , Figure 3 and Figure 4 a schematic view of the long contact blade cooperating with the cooperating face boss of the mating surface;

[0021] Figure 6 a schematic view of the long contact blade cooperating with the end cover located at the free end thereof;

[0022] Figure 7 for Figure 1 , Figure 3 and Figure 4 and Figure 6 a detailed structural view of the long contact blade;

[0023] Figure 8 for Figure 6 a detailed structural view of the end cover;

[0024] Figure 9 for Figure 8 a schematic view of the end cover after being turned through an angle; DETAILED DESCRIPTION

[0025] In order to enable persons skilled in the art to more clearly understand the technical essence and beneficial effects of the present application, the applicant will make a detailed description in the following manner by way of examples, but the description of the examples is not intended to limit the technical scheme of the present application, and any equivalent transformation which is only formal but not substantial and which is made according to the concept of the present application should be regarded as falling within the technical scheme of the present application.

[0026] In the following description, the directional or positional concepts of up, down, left, right, front and back which are possibly involved are based on the current position state of the Figure 1 , thus should not be understood as a special limitation on the technical scheme provided by the present application.

[0027] Please refer to Figure 1, shows the arc extinguishing chamber 1, the contact system and the housing 3, the housing 3 is formed with a contact cavity, the contact system is contained in the contact cavity, the arc extinguishing chamber 1 is installed inside the housing 1 and is located at the air outlet side of the aforementioned contact system, that is, the aforementioned arc extinguishing chamber 1 is located above the aforementioned contact system.

[0028] The aforementioned contact system includes a moving contact 2 and a stationary contact (not shown). The aforementioned moving contact 2 is usually rotatably arranged, and after rotation, it realizes contact or separation with the aforementioned stationary contact. When the aforementioned moving contact 2 is separated from the aforementioned stationary contact with electricity, an arc is generated therebetween, which moves upward into the aforementioned arc extinguishing chamber 1 and is extinguished in the arc extinguishing chamber 1.

[0029] Please refer to Figure 2 and Figure 3 , the aforementioned arc extinguishing chamber 1 includes a pair of side walls 11, a plurality of grid plates 12, a moving arc guiding plate 13 and a pair of gas generating members 14, the plurality of grid plates 12 are arranged in an array between the pair of side walls 11, the moving arc guiding plate 13 is installed inside the arc extinguishing chamber 1 and is used to guide the arc into the array of grid plates 12, and the pair of gas generating members 14 are spaced apart from each other to form an arc passage. Specifically, the aforementioned pair of gas generating members 14 are connected with one of the side walls 11 and the grid plates 12, respectively.

[0030] Please refer to Figure 4 , the moving contact 2 of the structure system of the aforementioned contact system includes a long contact plate 21 and a short contact plate 22. In this embodiment, the aforementioned long contact plate 21 is arranged in the center, and the short contact plate 22 is located on both sides of the aforementioned long contact plate 21. Since the long contact plate 21 has a longer extension length than the short contact plate 22, the long contact plate 21 extends into the aforementioned arc extinguishing chamber 1. Specifically, the aforementioned long contact plate 21 extends into the arc passage between the aforementioned pair of gas generating members 14, and the short contact plate 22 is located outside the aforementioned arc extinguishing chamber 1. More specifically, the aforementioned short contact plate 22 is located on both sides of the opening of the aforementioned arc passage.

[0031] Please refer to Figure 5 , the aforementioned arc extinguishing chamber 1 further includes a pair of matching surface bosses 100, which are located on both sides of the opening of the aforementioned arc passage and correspond to the aforementioned short contact plate 22 located in the area on both sides of the long contact plate 21, that is, there is a corresponding relationship between the aforementioned short contact plate 22 and the matching surface boss 100, specifically, a small gap is maintained therebetween.

[0032] Preferably, the pair of matching surface bosses 100 are adapted to the trajectory of the short contact plate 22 of the moving contact 2 when it swings, that is, they match the trajectory of the short contact plate 22 when it swings. And each maintains a distance D (0.5-1.5mm) from the head of the aforementioned short contact plate 22. Figure 5The spacing D between the cooperating face boss 100 and the head of the short contact 22 is less than 2 mm, preferably, the spacing D is 0.5-1 mm, and in the embodiment, the spacing D is 0.5-1 mm. Preferably, the pair of cooperating bosses 100 are circular arcs, and the centers of the circular arcs are concentric with the center of rotation of the short contact 22.

[0033] To improve the sealing effect between the two sides of the arc extinguishing chamber 1 and the inner side of the shell 3, the arc extinguishing chamber 1 has a blocking boss 200 on each of the left and right sides, which forms a gap fit with the inner side wall of the shell 3 to prevent arc gas from leaking. Preferably, the gap between the blocking boss 200 and the inner side wall of the shell 3 is controlled to be within 1 mm, and preferably 0.5 mm (0.5 mm is selected in the embodiment).

[0034] In the embodiment, the cooperating face boss 100 is located on the gas generating member 14, and preferably, the cooperating face boss 100 is located on the end surface of the gas generating member 14 close to the moving contact 2, and the blocking boss 200 is located on the side wall 11 and preferably on the lower part of the outer surface of the side wall 11. The gas generating member 14 is made of a gas generating material such as polyvinyl alcohol or triethanolamine oleate or other equivalent materials.

[0035] Since the cooperating face boss 100 and the head of the short contact 22 have a small gap fit, it is beneficial to reduce the amount of arc gas flowing to the head of the short contact 22, thereby preventing the situation of arc breakdown on the short contact 22.

[0036] Please refer to Figures 6 to 9 , the head of the long contact 21 is provided with an end cover 4, and the long contact 21 and the end cover 4 are fixed by rivets 300. The moving arc contact 211 is welded to the long contact 21.

[0037] As Figure 6The long contact piece 21 comprises a moving arc contact 211, a spring abutting cavity 212, a pin joint hole 213, a rivet mounting hole 214, a back boss 215, an extrusion groove 216, a positioning protrusion 217 and a head recess 218. The moving arc contact 211 is located on the side of the long contact piece 21 close to the static contact, and cooperates with the static arc contact on the static contact. The spring abutting cavity 212 is used for abutting one end of the contact spring 17. The pin joint hole 213 is used for the articulation of the long contact piece 21 and the contact support of the moving contact 2. That is, a pin shaft passes through the pin joint hole 213, and the two ends of the pin shaft are rotatably arranged on the contact side plate of the moving contact 2, so as to realize the articulation of the long contact piece 21 and the contact support. The rivet mounting hole 214 is used for the passage of the rivet 300, so as to realize the fixation between the long contact piece 21 and the end cover 4. The back boss 215 is located on the side of the long contact piece 21 away from the static contact, that is, the back boss 215 is located on the back of the long contact piece 21. The head recess 218 is arranged above the back boss 215, and is used for the mounting cooperation with the end cover 4. The extrusion groove 216 is located behind the moving arc contact 211, which can improve the strength of the head of the long contact piece 21, and prevent the head of the long contact piece 21 from being deformed after being impacted. The extrusion groove 216 is formed by an extrusion process, so as to improve the strength of the head of the long contact piece 21. Preferably, the extrusion groove 216 is arranged along the extension direction of the long contact piece 21. More preferably, the extrusion groove 216 is a pair of extrusion grooves, which are respectively arranged on the two sides of the long contact piece 21. In this embodiment, the length of the extrusion groove 216 is greater than the length of the moving arc contact 211. The positioning protrusion 217 protrudes outward from the side of the long contact piece 21, so as to abut and cooperate with the end cover 4, realize the fixed cooperation between the long contact piece 21 and the end cover 4, and strengthen the fixed mounting effect of the two, so as to prevent the two from being separated during the swinging of the long contact piece 21.

[0038] Preferably, the positioning protrusion 217 is crescent-shaped, so as to satisfy the fitting with the end cover 4. Preferably, the positioning protrusion 217 is a pair of positioning protrusions, which are respectively arranged on the two sides of the long contact piece 21. The pair of positioning protrusions 217 constitute positioning ears, and the pair of positioning protrusions 217 are symmetrically arranged.

[0039] As Figure 8 , 9 is a perspective view of the end cover 4. The end cover 4 is usually made of thermoplastic material, and is mounted on the head of the long contact piece 21, so as to control the time of entering the arc into the arc extinguishing chamber 4.

[0040] The aforementioned end cover 4 comprises a pair of cover side walls 41, which are arranged in a spaced manner and are attached to the side of the long contact piece 21.

[0041] The aforementioned end cover 4 further comprises a communication part 43, which is located on the side of the pair of cover side walls 41 close to the static contact. Preferably, the communication part 43 is located on the side of the end cover 4 away from the moving arc contact 211, and an extension part 44 is further arranged on the communication part 43. The extension part 44 extends away from the moving arc contact 211. A pair of corresponding mounting holes 45 are further arranged on the pair of cover side walls 41, which are used to cooperate with the rivets 300. Preferably, the extension part 44 is curved towards the static contact.

[0042] In the utility model, the fixing and mounting effect of the positioning protrusion 217 and the end cover 4 is improved, and the cooperation structure is more stable.

[0043] Meanwhile, the extrusion groove 216 is arranged, the strength of the head of the long contact piece 21 is improved, and the head of the long contact piece 21 is prevented from being deformed after being impacted.

[0044] In conclusion, the technical scheme provided by the utility model is that the cooperation face boss 100 is arranged on the end of the short contact piece close to the arc extinguishing chamber, so that the gap between the head of the short contact piece 22 and the arc extinguishing chamber 1 is greatly reduced, the amount of arc gas flowing into the head of the short contact piece 22 is greatly reduced, and the possibility of breakdown at the short contact piece 22 is reduced.

Claims

1. A contact arc extinguishing structure of a switch, comprising an arc chamber (1) and a contact system, said arc chamber (1) comprising a pair of side walls (11), a plurality of grid plates (12) and a pair of gas generating members (14), said grid plates (12) being arranged in an array between said pair of side walls (11), said gas generating members (14) being spaced to form an arc passage, said contact system comprising a moving contact (2) comprising a long contact plate (21) and a short contact plate (22), said long contact plate (21) being inserted into said arc passage, and said short contact plate (22) being located outside the opening of said arc passage, characterized in that: The arc extinguishing chamber (1) further comprises a pair of matching surface bosses (100) corresponding to the short contact pieces (22), the matching surface bosses (100) match the trajectory of the short contact pieces (22) when swinging, and the pair of matching surface bosses (100) and the head of the short contact pieces (22) keep a distance (D) of less than 2mm. ​ 2. An arc quenching contact structure for a switch as defined in claim 1, characterized in that: The pair of matching surface bosses (100) are circular arc-shaped, and the center of the matching surface bosses (100) is concentrically arranged with the rotation center of the short contact pieces (22) when swinging.

3. An arc quenching contact structure for a switch as defined in claim 1, characterized in that: The distance (D) is 0.5-1mm.

4. An arc quenching contact structure for a switch as defined in claim 1, characterized in that: The switch further comprises a shell (3) in which a contact cavity for accommodating the contact system is formed, and the arc extinguishing chamber (1) is located at the air outlet side of the contact system.

5. An arc quenching contact structure for a switch as claimed in claim 4, characterized in that: A blocking boss (200) is formed on the left and right outer sides of the arc extinguishing chamber (1), the blocking boss (200) is gap-fitted with the inner side of the shell (3), and the gap between the blocking boss (200) and the inner wall of the shell (3) is less than 1mm.

6. An arc quenching contact structure for a switch as claimed in claim 5, characterized in that: The gap is 0.5mm.

7. An arc quenching contact structure for a switch as defined in claim 5, characterized in that: The blocking boss (200) is located at the lower part of the outer side of the side wall (11).

8. An arc quenching contact structure for a switch as defined in claim 1, characterized in that: The matching surface boss (100) is located on the surface of the end of the gas generating element (14) towards the movable contact (2).

9. An arc quenching contact structure for a switch as claimed in claim 1 or 8, characterized in that: The gas generating element (14) is made of a gas generating material.

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