CN211980547U

CN211980547U - Contact mechanism and switching device

Info

Publication number: CN211980547U
Application number: CN201922487344.0U
Authority: CN
Inventors: 胡建国
Original assignee: Zhejiang Chint Electrics Co Ltd
Current assignee: Zhejiang Chint Electrics Co Ltd
Priority date: 2019-12-30
Filing date: 2019-12-30
Publication date: 2020-11-20
Anticipated expiration: 2029-12-30

Abstract

The utility model provides a contact mechanism, its includes electrically conductive piece, electrically conductive piece includes movable contact bridge and magnetism support piece, and movable contact bridge and magnetism support piece are range upon range of setting, and electrically conductive piece passes through the spring mounting in the base, one side of movable contact bridge is equipped with the movable contact, and magnetism support piece sets up the opposite side at movable contact bridge, and one side that magnetism support piece kept away from movable contact bridge and spring coupling, the spring can promote magnetism support piece through the spring self-restoring force and drive electrically conductive piece and move to the static contact, and it is spacing on the base to make one side that movable contact bridge is close to the static contact support, keeps away from the base when movable contact bridge and static contact, and the spring promotes magnetism support piece and drives movable contact bridge and support on the static contact, and magnetism support piece not only. The utility model also provides a switching device, including the run-on plate with contact mechanism, when short-circuit current appears, magnetic support piece's both ends constitute the magnetic circuit with the run-on plate respectively, drive electric arc removes to the explosion chamber at both ends.

Description

Contact mechanism and switching device

Technical Field

The utility model relates to a low-voltage apparatus field especially relates to a contact mechanism and switching device.

Background

The switch electric appliance controls the on-off of the circuit through the contact mechanism, the moving contact of the contact mechanism is in contact with the fixed contact, the circuit is switched on, the moving contact is separated from the fixed contact, and the circuit is switched off, for example, the switch electric appliance with a protection function such as a starter or a breaker can automatically separate the moving contact from the fixed contact when the circuit has a fault such as short circuit and the like, so that the circuit is switched off, and the protection of the load on the circuit and the access circuit is realized. However, as the contact mechanism needs to flow the same current as the load, when the line generates short-circuit current, the arc generated by the contact mechanism in the large-current breaking process is ignited into arc extinguishing chambers at two ends of the bracket base by the moving contact and the static contact so as to extinguish the arc, and whether the arc can be quickly and effectively introduced into the arc extinguishing chambers is determined, so that the speed of arc extinguishing is determined, and the breaking capacity of the switching device is determined.

In addition, when the circuit produces short-circuit current, because the electric current is very big, can produce great electronic repulsion in the twinkling of an eye between the moving contact, if the moving contact adopts the movable contact bridge of bridge type structure, electronic repulsion can be used in movable contact bridge both ends, simultaneously the middle part of movable contact bridge receives the spring and breaks the effect of withstanding behind a certain position, high temperature that short-circuit current produced leads to touching bridge intensity to reduce in addition, can make movable contact bridge both ends take place to warp the bending, lead to the short circuit to break the back, the overtravel is not enough when moving contact and static contact recontact, switching apparatus probably can't switch on the circuit.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to overcome prior art's defect, provide a contact mechanism that intensity is high, convenient assembly, good heat dissipation.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

the utility model provides a contact mechanism, its includes electrically conductive piece, electrically conductive piece includes movable contact bridge and magnetism support piece, and movable contact bridge and magnetism support piece are range upon range of setting, and electrically conductive piece passes through the spring mounting in the base, one side of movable contact bridge is equipped with the movable contact, and magnetism support piece sets up the opposite side at the movable contact bridge, and one side that magnetism support piece kept away from the movable contact bridge is connected with the spring, and the spring can promote magnetism support piece through the spring self-restoring force and drive electrically conductive piece and move to the static contact, and it is spacing on the base to make one side that the movable contact bridge is close to the static contact support, keeps away from the base when the movable contact bridge contacts with the static contact, and the.

Preferably, still support including the contact, the base includes the installation department, and the middle part of installation department is equipped with vertical installation cavity, and contact support, electrically conductive piece and spring are installed in the installation cavity from top to bottom in proper order, and the side of installation department is equipped with the mounting hole that supplies electrically conductive piece to cross, and the one end and the magnetism support piece of spring are connected, and the other end and the pedestal connection of spring, spring promotion magnetism support piece make the movable contact bridge support spacing on the top side lateral wall of mounting hole, and the contact support is used for driving electrically conductive compression spring to remove to the direction of keeping away from the static contact.

Preferably, two isolation plates arranged at intervals are further arranged on two sides of the mounting portion respectively, and a space for the conductive piece to move at two ends and for isolating the electric arc is formed between the two isolation plates on each side respectively.

Preferably, the movable contact bridge is a copper movable contact bridge, and the magnetic support member is an iron magnetic support member.

Preferably, the magnetic support member is provided with a limiting hole, and the movable contact bridge is provided with a limiting convex hull in limiting fit with the limiting hole.

Preferably, the contact support comprises a support seat matched with the side surface of the movable contact bridge far away from the magnetic support piece, and two support plates oppositely arranged on two sides of the conductive piece in the width direction, one ends of the two support plates are respectively connected with the support seat, and the inner sides of the two support plates are respectively matched with the movable contact bridge and two sides of the magnetic support piece in the width direction.

Preferably, the side edges of the two sides of the movable contact bridge are respectively provided with two limiting blocks, the two limiting blocks on the two sides are oppositely arranged on the two sides of the corresponding supporting plate, and the two limiting blocks are respectively in limiting fit with the side edges of the two sides of the supporting plate along the length direction of the conductive piece.

Preferably, the side edges of the two sides of the middle part of the magnetic support member are respectively provided with limiting plates protruding outwards, the inner sides of the two supporting plates are respectively provided with limiting grooves, and the limiting plates on the two sides of the magnetic support member respectively extend into the limiting grooves of the corresponding supporting plates to be in sliding fit along the moving direction of the conductive member; the convex surface of the limiting plate is arc-shaped, the shape of the inner wall of the limiting groove is matched with that of the limiting plate, and two sides of the spring are limited between the inner walls of the two limiting grooves.

Preferably, the movable contact bridge comprises a first conductive part in a straight plate structure and two second conductive parts respectively connected with two ends of the first conductive part, the two second conductive parts respectively incline to one side far away from the static contact, and a movable contact is arranged on the side surface, close to the static contact, of the first conductive part; the magnetic support comprises a first support part in a straight plate structure and two second support parts respectively connected with two ends of the first support part, the two second support parts are respectively inclined towards one side far away from the static contact, the side surface of one side of the first support part is connected with the spring, and the side surface of the other side of the first support part is attached to the side surface of the first conductive part far away from the static contact; the inclination angles of the second supporting parts at the two ends of the first supporting part are larger than the inclination angles of the second conducting parts at the two ends of the first conducting part.

The utility model provides a switching device, its includes contact mechanism to and two respectively with movable contact bridge both ends complex explosion chambers, keep away from the one side of movable contact bridge at two static contacts and be equipped with the run-on plate respectively, two run-on plates are magnetic material, and two run-on plates cooperate with magnetic support piece's both ends respectively, make magnetic support piece's both ends constitute the magnetic circuit with the run-on plate respectively when electric current passes through movable contact bridge.

The utility model also provides a switching device, it includes contact mechanism to and two respectively with movable contact bridge both ends complex explosion chamber, one side of keeping away from movable contact bridge at two static contacts is equipped with the run-on plate respectively, and two run-on plates are magnetic material, and two run-on plates respectively with magnetic support piece's both ends cooperation, make magnetic support piece's both ends constitute the magnetic circuit with the run-on plate respectively when the electric current passes through movable contact bridge.

The utility model discloses a switching apparatus, when short-circuit current appeared, magnetic support piece's both ends respectively with the magnetic circuit that the striking plate constitutes, can drive electric arc and remove to the explosion chamber at both ends, extinguish electric arc sooner, improve the disconnected heavy current's of switching apparatus ability.

Drawings

FIG. 1 is a cross-sectional view of a switching device according to an embodiment of the present invention;

fig. 2 is another cross-sectional view of a switching device according to an embodiment of the present invention;

fig. 3 is a cross-sectional view of a contact mechanism according to an embodiment of the invention;

fig. 4 is a top view of a contact mechanism according to an embodiment of the present invention;

fig. 5 is an exploded view of a contact mechanism according to an embodiment of the invention;

FIG. 6 is a schematic diagram of the support member and contact support of an embodiment of the present invention;

fig. 7 is a schematic bottom structure diagram of a contact mechanism according to an embodiment of the present invention;

FIG. 8 is a top view of a support member according to an embodiment of the present invention;

fig. 9 is a schematic structural diagram of a moving contact bridge according to an embodiment of the present invention;

fig. 10 is a schematic structural diagram of a base according to an embodiment of the present invention.

Detailed Description

The following description will further describe a specific embodiment of the contact mechanism of the present invention with reference to the embodiments shown in fig. 1 to 10. The contact mechanism of the present invention is not limited to the description of the following embodiments.

As shown in fig. 1-2, the contact mechanism of the present invention includes a conductive component 1 installed on a base 5 and two static contacts 2 respectively engaged with two ends of the conductive component 1 and respectively connected to a line, and when two ends of the conductive component 1 are respectively contacted with two static contacts 2, a path is formed between the two static contacts 2 to conduct the line.

As shown in fig. 3-5, the conductive device 1 includes a movable contact bridge 11 and a magnetic support 12, the movable contact bridge 11 and the magnetic support 12 are stacked, the conductive device 1 is installed in the base 5 through a spring 4, a movable contact 115 is disposed on one side of the movable contact bridge 11, the magnetic support 12 is disposed on the other side of the movable contact bridge 11, one side of the magnetic support 12 away from the movable contact bridge 11 is connected to the spring 4, the spring 4 can push the magnetic support 12 through a spring self-restoring force to drive the conductive device 1 to move towards the stationary contact 2, one side of the movable contact bridge 11 close to the stationary contact 2 abuts against the base 5 for limiting, the movable contact bridge 11 is away from the base 5 when contacting with the stationary contact 2, and the spring 4 pushes the magnetic support 12 to drive the movable contact bridge 11 to abut.

The utility model discloses a contact mechanism, through the magnetic support piece 12 with 11 range upon range of settings of movable contact bridge, not only can hold movable contact bridge 11 and form into a whole with movable contact bridge 11, the bulk strength of movable contact bridge 11 has been increased, and magnetic support piece 12 still has the cooling effect of temperature conduction, can improve movable contact bridge 11's temperature resistance, can effectively reduce or prevent that movable contact bridge 11 from producing under the effect of electronic repulsion and warping, and the overtravel is not enough when preventing moving contact and static contact to lead to the circuit can't switch on. In addition, the magnetic support piece 12 stacked with the movable contact bridge 11 can be improved on the basis of not changing the movable contact bridge 11 in the prior art, and has the advantages of simple structure, low cost, easy realization, convenient assembly and convenient popularization.

As shown in fig. 1-2, the utility model also provides a switching device, include the utility model contact mechanism to and two respectively with 11 both ends complex explosion chambers 6 of movable contact bridge, one side of keeping away from movable contact bridge 11 at two static contacts 2 is equipped with run-on plate 7 respectively, two run-on plates 7 are magnetic material, and two run-on plates 7 respectively with the both ends cooperation of magnetic support piece 12, make the both ends of magnetic support piece 12 constitute the magnetic circuit with run-on plate 7 respectively when electric current passes through movable contact bridge 11. When short-circuit current occurs, the two ends of the magnetic support 12 and the arc striking plate 7 form a magnetic circuit respectively, so that electric arcs can be driven to move towards the arc extinguishing chambers 6 at the two ends, the electric arcs can be extinguished more quickly, and the capacity of breaking large current of the switching device is improved.

Fig. 3-10 show the specific embodiment of the contact mechanism of the utility model, electrically conductive piece 1 is including the movable contact bridge 11 and the magnetic support piece 12 of range upon range of setting, and electrically conductive piece 1 is installed in base 5 through spring 4, one side of movable contact bridge 11 is equipped with movable contact 115, and magnetic support piece 12 sets up the opposite side at movable contact bridge 11, and one side that magnetic support piece 12 kept away from movable contact bridge 11 is connected with spring 4, and spring 4 can promote magnetic support piece 12 to drive electrically conductive piece 1 and remove to static contact 2, and it is spacing to support on base 5 to make one side that movable contact bridge 11 is close to static contact 2, keeps away from base 5 when movable contact bridge 11 contacts with static contact 2, and spring 4 promotes magnetic support piece 12 and drives movable contact bridge 11 and support on static contact 2.

Further, the device comprises a contact support 3, the base 5 comprises a mounting portion 52, a vertical mounting cavity is arranged in the middle of the mounting portion 52, the contact support 3, the conductive member 1 and the spring 4 are sequentially mounted in the mounting cavity from top to bottom, the contact support 3, the conductive member 1 and the spring 4 can move up and down in the mounting cavity, a mounting hole for the conductive member 1 to pass through is formed in the side surface of the mounting portion 52 of the contact support 3, one end of the spring 4 is connected with the magnetic support member 12, the other end of the spring 4 is connected with the base 5, the contact support 3 is connected with an operating mechanism and an electromagnetic system, the operating mechanism can be manually driven to drive the contact support 3 to move up and down, so as to drive a moving contact of the conductive member to contact or separate from the static contact, in addition, in an initial state, the spring 4 pushes the magnetic support member 12 to enable the moving contact bridge 11 to abut, when a circuit is in a short circuit or the like, the electromagnetic system can timely and automatically drive the contact support 3 to move downwards so that the moving contact is separated from the fixed contact, namely, the electromagnetic system can drive the contact support 3 to drive the conductive piece 1 and the compression spring 4 to move towards the direction far away from the fixed contact 2 after automatic action, so that the circuit protection effect is achieved. The contact support 3, the movable contact bridge 11 and the magnetic support 12 can be directly assembled with the base 5 into a whole without additional parts or processes for fixing the magnetic support 12, and the device has the characteristics of simple structure, small volume and convenient assembly.

Further, two sides of the mounting portion 52 are respectively provided with two isolation plates 53 arranged at intervals, and a space for moving two ends of the conductive member 1 and isolating the arc is formed between the two isolation plates 53 on each side.

Further, the movable contact bridge 11 is a copper movable contact bridge, and the magnetic support 12 is a ferromagnetic support 12 which generates a magnetic field for driving the arc to move towards the arc extinguishing chamber 6 when the current passes through the movable contact bridge 11. When short-circuit current occurs, the magnetic support 12 can not only ensure the strength of the movable contact bridge 11, but also generate a magnetic field through the magnetic support 12 to drive the electric arc to move towards the arc extinguish chamber 6, so that the electric arc can be extinguished more quickly, the damage of the electric arc to the movable contact bridge 11 is reduced, and the reliability of the movable contact bridge 11 is further improved. Preferably, the movable contact bridge 11 and the magnetic support 12 are integrally formed. Of course, other materials may be used for the movable contact bridge 11 and the magnetic support 12. In addition, the movable contact bridge 11 and the magnetic support 12 may also be an integrated copper-iron composite board, all belonging to the protection scope of the present invention.

Furthermore, a limiting hole 122 is formed in the magnetic support 12, and a limiting convex hull 112 which is in limiting fit with the limiting hole 122 is formed in the movable contact bridge 11. The movable contact bridge 11 is inserted into the limit hole 122 of the magnetic support member 12 through the limit convex hull 112 for limit matching, so that the relative movement between the magnetic support member 12 and the movable contact bridge 11 can be prevented, the fitting contact is ensured, the difficulty of assembly can be reduced, and the movable contact bridge 11 and the magnetic support member 12 can be conveniently positioned. Of course, a plurality of limiting convex hulls 112 and limiting holes 122 can be arranged, and the plurality of limiting convex hulls 112 and the limiting holes 122 can be matched to play a role in circumferential limiting. Preferably, when only one set of the limiting convex hull 112 and the limiting hole 122 are provided, the limiting convex hull 112 and the limiting hole 122 are correspondingly provided at the central positions of the magnetic support 12 and the movable contact bridge 11, respectively.

As shown in fig. 5-8, the contact holder 3 includes a holder 31 engaged with a side of the movable contact bridge 11 away from the magnetic support 12, and two support plates 32 oppositely disposed at two sides of the conductive member 1 in the width direction, one ends of the two support plates 32 are respectively connected to the holder 31, and inner sides of the two support plates 32 are respectively engaged with the movable contact bridge 11 and two sides of the magnetic support 12 in the width direction. The contact support 3 is matched with the movable contact bridge 11 through the support seat 31, and meanwhile, the width directions of the movable contact bridge 11 and the magnetic support piece 12 can be limited through the support plate 32, so that the movable contact bridge 11 and the magnetic support piece 12 are prevented from moving and rotating along the horizontal direction, and when the movable contact bridge 11 and the magnetic support piece 12 move up and down along the height direction of the support plate 32, the movable contact bridge 11 and the magnetic support piece 12 are ensured to be tightly attached.

Further, the side edges of the two sides of the movable contact bridge 11 are respectively provided with two limiting blocks 111, the two limiting blocks 111 on the two sides are oppositely arranged on the two sides of the corresponding supporting plate 32, and the two limiting blocks 111 are respectively in limit fit with the side edges of the two sides of the supporting plate 32 along the length direction of the conductive piece 1. The two supporting plates 32 are respectively limited between the two limiting blocks 111 on the corresponding side edges, so that the movable contact bridge 11 is ensured not to move along the length direction, and the movable contact bridge 11 and the magnetic support 12 are further ensured to be tightly attached.

Further, the side edges of the two sides of the middle of the magnetic support 12 are respectively provided with a limiting plate 121 protruding outwards, the inner sides of the two supporting plates 32 are respectively provided with a limiting groove 33, and the limiting plates 121 on the two sides of the magnetic support 12 respectively extend into the limiting grooves 33 of the corresponding supporting plates 32 and are in sliding fit with each other along the moving direction of the conductive piece 1. The magnetic support member 12 is ensured not to move along the length direction, and the movable contact bridge 11 and the magnetic support member 12 are further ensured to be tightly attached.

Further, the convex surface of the limiting plate 121 forms an arc shape, the shape of the inner wall of the limiting groove 33 is matched with the shape of the limiting plate 121, and two sides of the spring 4 are limited between the inner walls of the two limiting grooves 33. The contact surface of limiting plate 121 and spacing groove 33 is the cambered surface, not only can play limiting displacement and the effect of direction to magnetic support 12, but also can play the effect spacing spring 4, guarantees spring 4's angle.

As shown in fig. 3, 8, and 9, the movable contact bridge 11 includes a first conductive portion 113 in a straight plate structure, and two second conductive portions 114 respectively connected to two ends of the first conductive portion 113, where the two second conductive portions 114 are respectively inclined to a side away from the stationary contact 2, and a movable contact 115 is disposed on a side of the first conductive portion 113 close to the stationary contact 2; the magnetic support 12 includes a first support portion 123 in a straight plate structure, and two second support portions 124 connected to two ends of the first support portion 123, the two second support portions 124 are respectively inclined toward a side away from the fixed contact 2, a side surface of one side of the first support portion 123 is connected to the spring 4, and a side surface of the other side of the first support portion 123 is attached to a side surface of the first conductive portion 113 away from the fixed contact 2. Preferably, the inclination angle of the second supporting portion 124 at both ends of the first supporting portion 123 is larger than the inclination angle of the second conductive portion 114 at both ends of the first conductive portion 113.

As the preferred embodiment of the contact mechanism of the present invention, the magnetic support 12 is made of iron (with magnetic performance), a limiting hole 122 is provided in the middle of the support 1, and the limiting hole 122 is matched with the limiting convex hull 112 formed below the movable contact bridge 11 for limiting. The middle of the magnetic support 12 is provided with a circular arc-shaped limiting plate 121, and the limiting plate 121 is matched with a circular arc-shaped limiting groove 33 on the inner side of a supporting plate 32 of the contact support 3 for limiting. At the same time, the circular arc-shaped limiting groove 33 can also play the role of limiting the spring 4 (the spring 4 moves inside the supporting plate 32). Two limiting ribs 51 arranged on the base 5 play a role of limiting the upward limit position of the movable contact bridge 11 under the action of the spring 4. The state of the whole contact mechanism after being installed is that the lower surface of the movable contact bridge 11 is tightly attached and contacted with the magnetic support 12, one end of the spring 4 is contacted with the bottom of the base 5, the other end of the spring 4 is contacted with the lower surface of the magnetic support 12, the upper surface of the movable contact bridge 11 is pressed by the contact support 3, and the contact support 3 can flexibly move up and down in the base 5.

After the switch electric appliance is completely assembled, the magnetic support 12 is positioned below the movable contact bridge 11, and the two arc striking plates 7 are respectively positioned above the two static contacts 2. When the short-circuit current is cut off, the strong short-circuit current can generate a magnetic field near the contact mechanism, the two arc striking plates 7 positioned above and the magnetic support 12 positioned below form a magnetic circuit, so that the magnetic field effect near the contact is greatly enhanced, the moving speed of the electric arc is accelerated, the electric arc is quickly led away by the arc extinguishing chamber 6, and the cutting-off capacity of the product is effectively improved. Meanwhile, the magnetic support 12 is in close contact with the moving contact bridge 11, so that deformation of the moving contact bridge 11 under the action of an electric repulsion force of a short circuit large current can be effectively prevented, and the situation that the moving contact is not in overtravel enough when in re-contact with the fixed contact and the circuit of the switching device can not be conducted can be effectively avoided.

The foregoing is a more detailed description of the present invention, taken in conjunction with the specific preferred embodiments thereof, and it is not intended that the invention be limited to the specific embodiments shown and described. To the utility model belongs to the technical field of ordinary technical personnel, do not deviate from the utility model discloses under the prerequisite of design, can also make a plurality of simple deductions or replacement, all should regard as belonging to the utility model discloses a protection scope.

Claims

1. A contact mechanism, characterized by: comprises a conductive piece, the conductive piece comprises a movable contact bridge (11) and a magnetic support piece (12), the movable contact bridge (11) and the magnetic support piece (12) are arranged in a stacking way, the conductive piece (1) is arranged in a base (5) through a spring (4), one side of the movable contact bridge (11) is provided with a movable contact (115), the magnetic support piece (12) is arranged on the other side of the movable contact bridge (11), one side, far away from the movable contact bridge (11), of the magnetic support piece (12) is connected with the spring (4), the spring (4) can push the magnetic support piece (12) to drive the conductive piece (1) to move towards the static contact (2) through the self-restoring force of the spring, one side, close to the static contact (2), of the movable contact bridge (11) is abutted to the base (5) for limiting, the movable contact bridge (11) is far away from the base (5) when in contact with the static contact (2), and the spring (4) pushes the magnetic support piece (12) to drive the movable contact bridge (11) to be abutted to the.

2. The contact mechanism of claim 1, wherein: still include contact support (3), base (5) are including installation department (52), the middle part of installation department (52) is equipped with vertical installation cavity, contact support (3), electrically conductive piece (1) and spring (4) are installed in the installation cavity from top to bottom in proper order, the side of installation department (52) is equipped with the mounting hole that supplies electrically conductive piece (1) to cross, the one end and the magnetism support piece (12) of spring (4) are connected, the other end and the base (5) of spring (4) are connected, spring (4) promote magnetism support piece (12) make to make touch bridge (11) support spacing on the top side wall of mounting hole, contact support (3) are used for driving electrically conductive piece (1) compression spring (4) to the direction removal of keeping away from static contact (2).

3. The contact mechanism of claim 2, wherein: two sides of the mounting part (52) are respectively provided with two isolation plates (53) which are arranged at intervals, and a space which can be used for moving two ends of the conductive piece (1) and isolating electric arcs is formed between the two isolation plates (53) on each side.

4. The contact mechanism of claim 1, wherein: the movable contact bridge (11) is a copper movable contact bridge, and the magnetic support piece (12) is an iron magnetic support piece.

5. The contact mechanism of claim 1, wherein: the magnetic support piece (12) is provided with a limiting hole (122), and the movable contact bridge (11) is provided with a limiting convex hull (112) in limiting fit with the limiting hole (122).

6. The contact mechanism of claim 2, wherein: the contact support (3) comprises a support seat (31) matched with the side face, far away from the magnetic support piece (12), of the movable contact bridge (11) and two support plates (32) oppositely arranged on two sides of the conductive piece (1) in the width direction, one ends of the two support plates (32) are respectively connected with the support seat (31), and the inner sides of the two support plates (32) are respectively matched with two sides of the movable contact bridge (11) and the magnetic support piece (12) in the width direction.

7. The contact mechanism of claim 6, wherein: the side edges of two sides of the movable contact bridge (11) are respectively provided with two limiting blocks (111), the two limiting blocks (111) of the two sides are oppositely arranged on two sides of the corresponding supporting plate (32), and the two limiting blocks (111) are respectively in limiting fit with the side edges of the two sides of the supporting plate (32) along the length direction of the conductive piece (1).

8. The contact mechanism of claim 6, wherein: limiting plates (121) protruding outwards are arranged on the side edges of the two sides of the middle of the magnetic support piece (12), limiting grooves (33) are arranged on the inner sides of the two supporting plates (32), and the limiting plates (121) on the two sides of the magnetic support piece (12) extend into the limiting grooves (33) of the corresponding supporting plates (32) respectively and are in sliding fit along the moving direction of the conductive piece (1); the convex surface of the limiting plate (121) is arc-shaped, the shape of the inner wall of the limiting groove (33) is matched with that of the limiting plate (121), and two sides of the spring (4) are limited between the inner walls of the two limiting grooves (33).

9. The contact mechanism of claim 1, wherein: the movable contact bridge (11) comprises a first conductive part (113) in a straight plate structure and two second conductive parts (114) respectively connected with two ends of the first conductive part (113), the two second conductive parts (114) respectively incline to one side far away from the static contact (2), and a movable contact (115) is arranged on the side surface, close to the static contact (2), of the first conductive part (113); the magnetic support (12) comprises a first support part (123) in a straight plate structure and two second support parts (124) respectively connected with two ends of the first support part (123), the two second support parts (124) are respectively inclined towards one side far away from the static contact (2), the side surface of one side of the first support part (123) is connected with the spring (4), and the side surface of the other side of the first support part (123) is attached to the side surface of the first conductive part (113) far away from the static contact (2); the inclination angle of the second supporting part (124) at the two ends of the first supporting part (123) is larger than that of the second conducting part (114) at the two ends of the first conducting part (113).

10. A switching apparatus, characterized in that: the contact mechanism comprises a contact mechanism according to any one of claims 1 to 9, and two arc extinguishing chambers (6) respectively matched with two ends of a movable contact bridge (11), wherein an arc striking plate (7) is respectively arranged on one side of two fixed contacts (2) far away from the movable contact bridge (11), the two arc striking plates (7) are made of magnetic materials, the two arc striking plates (7) are respectively matched with two ends of a magnetic support piece (12), and when current passes through the movable contact bridge (11), two ends of the magnetic support piece (12) respectively form magnetic circuits with the arc striking plates (7).