CN221176083U - Sealing structure and relay - Google Patents

Abstract

The application provides a sealing structure and a relay, and relates to the technical field of electrical equipment. The sealing structure is applied to the relay and comprises a ceramic cover and a frame piece. The ceramic hood includes an open side. The inside cavity of frame piece, the frame piece includes body and first turn-ups, and first turn-ups are connected in the body one side towards the ceramic cover, and first turn-ups are buckled towards the inside of frame piece relative body, and first turn-ups are the arc roughly, and first turn-ups are towards one side and the open side welding of ceramic cover. The application can stagger the blanking surface of the first flanging and the welding part of the first flanging for the ceramic cover, and avoid the influence of the blanking surface on the welding quality of the first flanging and the ceramic cover due to burrs and poor flatness. In addition, the application can reduce the contact area between the first flanging and the open side, improve the welding tightness and reliability between the ceramic cover and the frame piece, and ensure the insulation between the output loop and the outside in the space surrounded by the ceramic cover and the frame piece, thereby improving the electrical safety of the output loop.

Description

Sealing structure and relay

Technical Field

The application relates to the technical field of electrical equipment, in particular to a sealing structure and a relay.

Background

The relay is an electronic control device, and can control larger current by smaller current, thereby playing roles of automatic regulation, safety protection, circuit switching and the like in the circuit. Relays include a control system (also known as an input loop) and a controlled system (also known as an output loop), commonly used in automatic control circuits. The input loop is a low-voltage loop in the relay, and the output loop is a high-voltage loop in the relay.

The relay comprises a ceramic cover, a frame piece, a movable reed, a fixed contact and the like, wherein the movable reed and the fixed contact are both positioned in a space surrounded by the ceramic cover and the frame piece, and are both connected to a high-voltage loop. In general, the ceramic cover and the frame sheet are welded together to ensure insulation between the output circuit and the outside in the space surrounded by the ceramic cover and the frame sheet, thereby improving electrical safety of the output circuit.

However, in the prior art, the welding quality of the ceramic cover and the frame piece is poor, so that the sealing performance between the ceramic cover and the frame piece is low, good insulation between the output circuit and the outside cannot be ensured, and the electrical safety of the output circuit is not high.

Disclosure of utility model

In view of the above problems, embodiments of the present application provide a sealing structure and a relay, which can improve the welding tightness and reliability between a ceramic cover and a frame sheet, and ensure the insulation between an output circuit and the outside in a space surrounded by the ceramic cover and the frame sheet, thereby improving the electrical safety of the output circuit.

In a first aspect, the present application provides a sealing structure for a relay, the sealing structure comprising a ceramic cover and a frame piece. The ceramic hood includes an open side. The inside cavity of frame piece, the frame piece includes body and first turn-ups, and first turn-ups are connected in the body one side towards the ceramic cover, and first turn-ups are buckled towards the inside of frame piece relative body, and first turn-ups are the arc roughly, and first turn-ups are towards one side and the open side welding of ceramic cover.

The first flanging is connected to one side of the body, facing the ceramic cover, and is bent towards the inside of the frame sheet relative to the body, and the first flanging is approximately arc-shaped instead of planar. The generally arcuate first flange has a smaller contact area when in contact with the open side than when the planar first flange is in contact with the open side. Thus, high-density contact is easy to generate, and the welding strength and the welding quality reliability of the ceramic cover and the frame piece are convenient to improve. Further, the possibility of occurrence of a problem of uneven solder accumulation between the open side and the first flange can be reduced, and the possibility of occurrence of a problem of low solder tightness between the ceramic cover and the frame piece due to the occurrence of a solder stress can be reduced.

In addition, the first turn-ups are bent towards the inside of the frame piece, the first turn-ups are approximately arc-shaped, one side of the first turn-ups, which faces the ceramic cover, is welded with the open side, blanking faces of the first turn-ups can be bent towards the inside of the frame piece, and blanking faces of the first turn-ups are conveniently transferred to a position, which is used for being welded with the ceramic cover, of the first turn-ups. That is, the punched surface of the first flange is not used as a portion of the first flange to be welded to the ceramic cap. Under this condition, even if the blanking surface is poor in flatness due to burrs, the welding quality of the first flanging and the ceramic cover is not affected, and the welding tightness and reliability between the ceramic cover and the frame piece are improved conveniently.

In one possible embodiment, the side of the first flange facing the ceramic hood is in contact with the open side line.

Through above-mentioned scheme, with first turn-ups towards one side and the open side line contact of ceramic cover, rather than the face contact, the area of contact between one side and the open side of the first turn-ups towards the ceramic cover of being convenient for reduce like this to be convenient for improve the reliability of the welding strength and the welding quality of ceramic cover and frame piece.

In one possible embodiment, the side of the first flange facing the ceramic envelope comprises a planar section, which is welded to the open side. The dimensions of the planar segments are less than or equal to 0.5 mm in the direction of the wall thickness of the ceramic cap.

Through above-mentioned scheme, when being used for the blanking face of first turn-ups and first turn-ups with ceramic cover welded position stagger, can reduce the area of contact when first turn-ups and open side contact to improve the reliability of the welding strength and the welding quality of ceramic cover and frame piece, and improve the welding tightness between ceramic cover and the frame piece.

In one possible embodiment, the first flange is U-shaped or C-shaped, with the U-shaped or C-shaped opening facing away from the ceramic envelope.

In one possible solution, the first flange forms a weld after welding with the ceramic cover, and the first flange is symmetrically bent along the weld, so that the shape of the first flange on both sides of the weld is identical.

The first flanges are identical in shape on two sides of the welding seam, so that welding flux is uniformly distributed on two sides of the welding seam, the occurrence possibility of uneven welding flux accumulation between the open side and the first flanges can be reduced, and the occurrence possibility of lower welding tightness between the ceramic cover and the frame piece due to welding stress can be reduced.

In one possible embodiment, the frame piece is arranged at a position connected with the open side opposite to the middle position of the inner wall and the outer wall of the ceramic cover.

Through the scheme, the distance between the part, connected with the open side, of the frame piece to the inner wall of the ceramic cover is equal to the distance between the part, connected with the open side, of the frame piece to the outer wall of the ceramic cover. In this way, when the amount of solder deposited on both sides of the portion of the frame piece to be connected to the open side is uniform and the deposited shape is the same, large welding stress is not easily generated on both sides, and the welding tightness between the ceramic cover and the frame piece is reduced.

In one possible solution, a chamfer is provided between the outer wall and the open side of the ceramic hood.

Through the scheme, heat and welding pressure generated during the welding of the open side of the ceramic cover and the first flanging of the frame piece can be dispersed to the chamfer, so that the possibility of stress concentration of the ceramic cover around the welding seam is reduced, and the risk of edge breakage of the ceramic cover is reduced. And, the welding strength and the reliability of the welding quality of the welding part can be improved.

In a second aspect, the present application provides a relay comprising a first stationary contact lead-out terminal, a second stationary contact lead-out terminal, and a sealing structure of the first aspect, a ceramic housing of the sealing structure being provided with a first through-hole through which an end portion of the first stationary contact lead-out terminal is located in a cavity of the ceramic housing, and a second through-hole through which an end portion of the second stationary contact lead-out terminal is located in the cavity. The first stationary contact leading-out end and the second stationary contact leading-out end are both welded with the ceramic cover in a sealing way.

By the scheme, the sealing performance of the ceramic cover can be improved, so that the sealing performance of the sealing structure in the embodiment is improved. Therefore, the insulation between the output circuit in the sealing structure and the outside is convenient to ensure, and the electrical safety of the output circuit is improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for the description of the embodiments will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present application, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural diagram of a relay according to an embodiment of the present application at a first view angle.

Fig. 2 is a schematic structural diagram of a relay according to an embodiment of the present application at a second view angle.

Fig. 3 is an exploded view of a relay according to an embodiment of the present application.

Fig. 4 is a schematic structural diagram of a frame sheet according to an embodiment of the present application.

Fig. 5 is a cross-sectional view taken along section A-A of fig. 4.

Fig. 6 is a cross-sectional view taken along section B-B of fig. 1.

Fig. 7 is an enlarged view of the portion F in fig. 6.

Reference numerals illustrate:

100. A ceramic cover; 110. an open side; 120. an inner wall; 130. an outer wall; 140. chamfering; 150. a first through hole; 160. a second through hole;

200. A frame piece; 210. a body; 220. a first flanging;

300. A first stationary contact lead-out end;

400. And a second stationary contact leading-out end.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present application more apparent, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments of the present application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used in the description of the applications herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "comprising" and "having" and any variations thereof in the description and claims of the application and in the description of the drawings are intended to cover a non-exclusive inclusion.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearances of the phrase "an embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those of skill in the art will explicitly and implicitly appreciate that the embodiments described herein may be combined with other embodiments.

The term "and/or" is herein merely an association relationship describing an associated object, meaning that there may be three relationships, e.g., a and/or B, may represent: there are three cases, a, B, a and B simultaneously. In addition, the character "/" herein generally indicates that the front and rear associated objects are an "or" relationship.

The directional terms appearing in the following description are all directions shown in the drawings and are not limiting to the specific structure of the current limiting module of the present application. For example, in the description of the present application, the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are merely for convenience in describing the present application and simplifying the description, and do not indicate or imply that the device or element in question must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present application.

Furthermore, the terms first, second and the like in the description and in the claims or in the above-described figures, are used for distinguishing between different objects and not for describing a particular sequential order, and may be used to improve one or more of these features either explicitly or implicitly.

In the description of the present application, unless otherwise indicated, the meaning of "plurality" means two or more (including two), and similarly, "plural sets" means two or more (including two).

In the description of the present application, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., the terms "connected" or "connected" of a mechanical structure may refer to a physical connection, e.g., the physical connection may be a fixed connection, e.g., by a spacer, such as by a screw, bolt, or other spacer; the physical connection may also be a detachable connection, such as a snap-fit or snap-fit connection; the physical connection may also be an integral connection, such as a welded, glued or integrally formed connection. The specific meaning of the above terms in the present application will be understood in specific cases by those of ordinary skill in the art.

In order to make the person skilled in the art better understand the solution of the present application, the technical solution of the embodiment of the present application will be clearly and completely described below with reference to the accompanying drawings.

Fig. 1 is a schematic structural view of a relay provided in an embodiment of the present application at a first viewing angle, fig. 2 is a schematic structural view of a relay provided in an embodiment of the present application at a second viewing angle, fig. 3 is an exploded view of a relay provided in an embodiment of the present application, fig. 4 is a schematic structural view of a frame provided in an embodiment of the present application, fig. 5 is a cross-sectional view along A-A of fig. 4, and as shown in fig. 1 to 5, a sealing structure of the relay includes a ceramic cover 100 and a frame 200. The ceramic hood 100 includes an open side 110. The frame piece 200 is hollow, the frame piece 200 comprises a body 210 and a first flanging 220, the first flanging 220 is connected to one side of the body 210 facing the ceramic cover 100, the first flanging 220 is bent towards the inside of the frame piece 200 relative to the body 210, the first flanging 220 is approximately arc-shaped, and one side of the first flanging 220 facing the ceramic cover 100 is welded with the open side 110.

The ceramic cover 100 is substantially rectangular, and the ceramic cover 100 includes four side walls connected end to end and a bottom wall connected to the same side of the four side walls. The interior of the ceramic hood 100 is hollow, or the ceramic hood 100 has a hollow cavity. The ceramic hood 100 is open to one side of the frame piece 200, which is the open side 110 of the ceramic hood 100, and which is used for welding with the frame piece 200.

The frame piece 200 is generally in the shape of a Chinese character 'kou'. The perimeter dimension of the side of the frame piece 200 facing the open side 110 may be comparable to the perimeter dimension of the open side 110 to facilitate welding of the side of the frame piece 200 facing the open side 110 to the open side 110. In the case where the side of the frame piece 200 facing the ceramic cover 100 is welded to the open side 110 of the ceramic cover 100 and the side of the frame piece 200 facing away from the ceramic cover 100 is connected to the yoke plate, a receiving chamber for receiving structural members such as a movable reed, a stationary contact, and an arc extinguishing chamber of the relay may be formed between the ceramic cover 100, the frame piece 200, and the yoke plate.

Referring to fig. 1-5, the body 210 of the frame piece 200 is substantially parallel to the side wall of the ceramic cover 100, and the first flange 220 is not coplanar with the side wall of the ceramic cover 100 nor with the body 210.

The first flange 220 may be integrally formed on the side of the body 210 facing the ceramic cover 100, or the first flange 220 may be connected with the body 210 by plugging or clamping after being separately formed, which is not limited in the embodiment of the present application. In the case where the first flange 220 is integrally formed at the side of the body 210 facing the ceramic cover 100, since the frame piece 200 has a thin structure, the frame piece 200 may be formed by a stamping process so as to improve the forming efficiency of the frame piece 200.

The first flange 220 is generally arcuate, which means that the first flange 220 may be a strictly arcuate surface, or may include an arcuate surface section and a relatively short planar section. The arcuate surface may extend from the body 210 toward the interior of the frame piece 200 and away from the open side 110.

The first flange 220 may be generally U-shaped or C-shaped with the U-shaped or C-shaped opening facing away from the ceramic hood 100. In fact, the first flange 220 may have other shapes, as long as the first flange 220 is substantially arc-shaped, so that the blanking surface of the first flange 220 and the portion for welding with the ceramic cover 100 are staggered, and the contact area between the side of the arc-shaped first flange 220 facing the ceramic cover 100 and the open side 110 is smaller, which is not limited by the embodiment of the present application.

The side of the first flange 220 facing the ceramic envelope 100 and the open side 110 may be welded by means of brazing.

In the embodiment of the application, the first flange 220 is connected to the side of the body 210 facing the ceramic cover 100, the first flange 220 is bent towards the inside of the frame piece 200 relative to the body 210, and the first flange 220 is generally configured as an arc shape, rather than a plane shape. The generally arcuate first flange 220 has a smaller contact area with the open side 110 than the planar first flange 220. In this way, high-density contact is easily generated, so that the welding strength and the reliability of the welding quality of the ceramic cover 100 and the frame piece 200 can be improved. Also, the possibility of occurrence of a problem of uneven solder accumulation between the open side 110 and the first flange 220 can be reduced, so that the possibility of occurrence of a problem of low solder sealability between the ceramic cover 100 and the frame piece 200 due to the release of the generated solder stress can be reduced.

In addition, the first flange 220 is bent toward the inside of the frame piece 200, the first flange 220 is substantially arc-shaped, and the first flange 220 is welded to the open side 110 toward one side of the ceramic cover 100, so that the punched surface of the first flange 220 can be bent toward the inside of the frame piece 200, and the punched surface of the first flange 220 can be easily transferred to a position for welding with the ceramic cover 100, which is offset from the position of the first flange 220. That is, the punched surface of the first flange 220 is not used as a portion of the first flange 220 to be welded to the ceramic cover 100. In this case, even if the punched surface is not smooth due to burrs, the welding quality between the first flange 220 and the ceramic cap 100 is not affected, so that the welding tightness and reliability between the ceramic cap 100 and the frame piece 200 can be improved.

In some embodiments, the side of the first flange 220 facing the ceramic hood 100 is in line contact with the open side 110.

When the first flange 220 is bent to form an arc shape toward the inside of the frame piece 200, the greater the degree of bending, the more likely the first flange 220 is a line structure toward the side of the ceramic cover 100. The degree of bending of the first flange 220 may be adjusted according to the molding die.

In this embodiment, the side of the first flange 220 facing the ceramic cover 100 is in line contact with the open side 110, instead of in surface contact, so that the contact area between the side of the first flange 220 facing the ceramic cover 100 and the open side 110 is conveniently reduced, and the welding strength and the reliability of the welding quality of the ceramic cover 100 and the frame sheet 200 are conveniently improved.

In other embodiments, the side of the first flange 220 facing the ceramic hood 100 may include a planar section that is welded to the open side 110. And, in the wall thickness direction of the ceramic cap 100, the size of the planar segment is less than or equal to 0.5 mm.

The degree of bending of the first flange 220 described in the foregoing embodiment may be adjusted according to the forming mold, and due to errors or processing difficulty of the forming mold, a small straight line section may be reserved in the forming mold in some cases, so that a planar section may also exist in the formed first flange 220.

The molding die may reduce the size of the straight line segment as much as possible so that the size of the flat segment in the thickness direction of the ceramic cap 100 is less than or equal to 0.5mm.

Through the above scheme, when the blanking surface of the first flange 220 and the part of the first flange 220 used for welding with the ceramic cover 100 are staggered, the contact area of the first flange 220 when contacting with the open side 110 can be reduced, so that the welding strength and the welding quality reliability of the ceramic cover 100 and the frame piece 200 are improved, and the welding tightness between the ceramic cover 100 and the frame piece 200 is improved.

In some embodiments, the first flange 220 forms a weld after welding with the ceramic cover 100, and the first flange 220 is symmetrically bent along the weld such that the shape of the first flange 220 is the same on both sides of the weld.

The first flange 220 may be symmetrically bent when bent, whether it is U-shaped or C-shaped, or any other shape. The location of the bend line is the location for subsequent welding with the open side 110.

The first flange 220 is symmetrically bent along the welding seam, so that the shapes of the first flange 220 at two sides of the welding seam are identical, the welding flux is uniformly distributed at two sides of the welding seam, the possibility of uneven welding flux accumulation between the open side 110 and the first flange 220 can be reduced, and the possibility of low welding tightness between the ceramic cover 100 and the frame piece 200 caused by welding stress can be reduced.

Further, fig. 6 is a sectional view taken along the section B-B of fig. 1, and as shown in fig. 6, the frame piece 200 is used to connect the open side 110 at a position facing the middle of the inner wall 120 and the outer wall 130 of the ceramic cover 100.

Assuming that the portion corresponding to the inner wall 120 of the ceramic cover 100 in the B-B section is denoted as C, the portion corresponding to the outer wall 130 of the ceramic cover 100 in the B-B section is denoted as D, and the portion of the frame piece 200 used for connection with the open side 110 is denoted as E, E is between C and D, and E is a midpoint of a connection line between C and D, the midpoint being opposite to the intermediate portion of the inner wall 120 and the outer wall 130 of the ceramic cover 100.

The arrangement is such that the distance between the location of the frame piece 200 for connection with the open side 110 to the inner wall 120 of the ceramic hood 100 is equal to the distance between the location of the frame piece 200 for connection with the open side 110 to the outer wall 130 of the ceramic hood 100. In this way, when the amount of solder deposited on both sides of the portion of the frame piece 200 to be connected to the open side 110 is uniform and the deposited shape is the same, a large welding stress is not easily generated on both sides, and the welding tightness between the ceramic cover 100 and the frame piece 200 is reduced.

Fig. 7 is an enlarged view of portion F of fig. 6. In some embodiments, in combination with fig. 6 and 7, a chamfer 140 may be provided between the outer wall 130 and the open side 110 of the ceramic hood 100.

The chamfer 140 may be a straight chamfer or a round chamfer. The shape of the chamfer 140, and the size of the chamfer 140 are not limited in the embodiment of the present application.

The chamfer 140 is arranged between the outer wall 130 of the ceramic cover 100 and the open side 110, and heat and welding pressure generated when the open side 110 of the ceramic cover 100 is welded with the first flanging 220 of the frame piece 200 can be dispersed to the chamfer 140, so that the possibility of stress concentration of the ceramic cover 100 around welding seams is reduced, and the risk of edge breakage of the ceramic cover 100 is reduced. And, the welding strength and the reliability of the welding quality of the welding part can be improved. Here, the edge chipping refers to a phenomenon in which a part of the edge of the open side 110 is squeezed out or broken due to high temperature or welding pressure at the time of welding.

The embodiment of the present application also provides a circuit breaker, as shown in fig. 1 to 3, the relay includes a first stationary contact lead-out terminal 300, a second stationary contact lead-out terminal 400, and the aforementioned sealing structure.

The ceramic cap 100 of the sealing structure is provided with a first through hole 150 and a second through hole 160, the end of the first stationary contact terminal 300 is located in the cavity of the ceramic cap 100 through the first through hole 150, and the end of the second stationary contact terminal 400 is located in the cavity through the second through hole 160. The first stationary contact leading-out terminal 300 and the second stationary contact leading-out terminal 400 are both hermetically welded to the ceramic cap 100.

Since the structure and the beneficial effects of the frame sheet 200 in the sealing structure are described in detail in the previous embodiments, the disclosure is not repeated here.

The end of the first stationary contact lead-out end 300 facing the frame piece 200 is provided with a first stationary contact, and the end of the first stationary contact lead-out end 300 passing through the first through hole 150 and located in the cavity of the ceramic cover 100 is the end of the first stationary contact lead-out end 300 provided with the first stationary contact. Similarly, a second stationary contact is disposed at an end of the second stationary contact lead-out end 400 facing the frame sheet 200, and the end of the second stationary contact lead-out end 400 passing through the second through hole 160 and located in the cavity of the ceramic cover 100 is the end of the second stationary contact lead-out end 400 provided with the second stationary contact.

The first stationary contact lead-out terminal 300 and the second stationary contact lead-out terminal 400 are both hermetically welded to the ceramic cap 100, so that the sealability of the ceramic cap 100 can be improved, thereby improving the sealability of the sealing structure in the foregoing embodiments. Therefore, the insulation between the output circuit in the sealing structure and the outside is convenient to ensure, and the electrical safety of the output circuit is improved.

The above embodiments are only for illustrating the technical solution of the present application, and are not limiting; although the application has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims (8)

1. A sealing structure applied to a relay, comprising:

A ceramic cover including an open side;

The frame piece, the inside cavity of frame piece, the frame piece includes body and first turn-ups, first turn-ups connect in the body orientation one side of ceramic cover, first turn-ups are relative the body orientation the inside of frame piece is buckled, first turn-ups are the arc roughly, first turn-ups orientation one side of ceramic cover with open side welding.

2. The sealing structure according to claim 1, wherein a side of the first flange facing the ceramic cover is in contact with the open side line.

3. The sealing structure according to claim 1, wherein a side of the first flange facing the ceramic cover includes a planar section welded to the open side;

The dimension of the planar segment in the direction of the wall thickness of the ceramic cap is less than or equal to 0.5 mm.

4. A sealing arrangement according to any one of claims 1 to 3, wherein the first flange is U-shaped or C-shaped with the opening facing away from the ceramic envelope.

5. A sealing arrangement according to any one of claims 1 to 3, wherein the first flange forms a weld after welding with the ceramic cover, the first flange being symmetrically folded along the weld such that the first flange is of the same shape on both sides of the weld.

6. The sealing structure according to claim 5, wherein the portion of the frame piece to be connected to the open side is opposite to a middle portion of the inner wall and the outer wall of the ceramic cover.

7. The sealing structure according to claim 5, wherein a chamfer is provided between an outer wall of the ceramic cover and the open side.

8. A relay comprising a first stationary contact lead-out end, a second stationary contact lead-out end and a sealing structure according to any one of claims 1 to 7, wherein a ceramic cover of the sealing structure is provided with a first through hole and a second through hole, the end part of the first stationary contact lead-out end penetrates through the first through hole to be positioned in a cavity of the ceramic cover, and the end part of the second stationary contact lead-out end penetrates through the second through hole to be positioned in the cavity;

And the first static contact leading-out end and the second static contact leading-out end are both welded with the ceramic cover in a sealing way.