Patent Description:
Electronic cigarette in existing technologies generally includes an atomization assembly and a battery assembly. One end of the atomization assembly is provided with a first electrode for electrical connection with the battery assembly. Inside the first electrode are sleeved an insulating ring and a second electrode in sequence. The atomization assembly is internally provided with an electric heating wire, a first end of which electric heating wire is electrically connected to the second electrode, and a second end of which electric heating wire is connected to the first electrode. The second electrode defines a through hole. The first end of the electric heating wire is welded to the end surface of the second electrode. In such a structure, since the through hole on the second electrode extends along the axial direction, the through hole is easy to be plugged by solder tin when the lead of the electric heating wire is welded.

In order to solve the above technical problem, those skilled in the art design an electronic cigarette, which includes an atomization assembly, a first electrode and a second electrode that are inserted into an end part of the atomization assembly. The atomization assembly accommodates an electric heating wire for atomizing an e-liquid, a first lead and a second lead in electrical connection with the electric heating wire. The second electrode includes an extension portion stretching into the atomization assembly, the second lead is electrically connected to the extension portion, and the first lead is electrically connected to the first electrode. The extension portion defines on a side surface thereof at least one first through hole for air to flow, so that the likeliness of hole plugging can be reduced when the second lead is electrically connected to the second electrode through welding. However, in order to avoid hole plugging, the used solder is less when welding, which is not convenient for welding, and the welding is not firm, so the service life is short. <CIT> relates to an electronic cigarette and an atomisation assembly and a power source assembly thereof. <CIT> relates to an electronic cigarette comprising an atomizing assembly and a battery rod assembly. <CIT> relates to an electronic cigarette and an atomization assembly and a power supply assembly thereof. <CIT> relates to a printing heating body atomizer which comprises a hollow atomizing sleeve.

In order to solve the problem in the existing technologies, the present disclosure provides an atomization member and an electronic cigarette which are firm in welding and convenient to produce.

In a first aspect, the present disclosure provides an atomization member, including: an e-liquid storage body, an atomizing core, a connecting seat and an electrode, wherein the e-liquid storage body is internally provided with an e-liquid storage cavity for accommodating an e-liquid, the atomizing core includes an electric heating element having a connecting pin, and the electric heating element is used for atomizing at least part of the e-liquid supplied to the electric heating element from the e-liquid storage cavity, the connecting seat is connected to the e-liquid storage body, the electrode is fixed on the connecting seat, and the electrode defines thereon a connecting hole passing through the electrode and an accommodating recess, a hole opening at one end of the connecting hole is located in the accommodating recess to communicate with the accommodating recess, and at least part of the connecting pin is inserted into the connecting hole and extends into the accommodating recess, thereby forming a connection with the electrode.

Optional, the electrode presents a sheet shape and is arranged extending along an end face of the connecting seat.

Optional, the accommodating recess is located on a surface of the electrode away from the connecting seat and extends towards another surface close to the connecting seat.

Optional, the accommodating recess is configured for filling a solder, at least part of the connecting pin extends into the accommodating recess and forms soldering connection with the electrode.

Optional, a recess opening of the accommodating recess is hole shaped and has a bigger diameter than the hole opening of the connecting hole.

Optional, the connecting seat defines a through hole, the electrode is provided with a locating protrusion at the hole opening of the connecting hole, the locating protrusion is inserted into the through hole, and the connecting pin passes through the through hole to connect to the electrode.

Optional, the connecting seat defines a first fixing recess, and the electrode is inserted into the first fixing recess.

Optional, the electrode includes a main body made of a magnetic material and a protection layer located on a surface of the main body, and the electrode is further configured for magnetic connection with the battery assembly.

Optional, the e-liquid storage body defines therein an air channel and an e-liquid storage cavity surrounding the air channel, the connecting seat defines a first air inlet communicated with the air channel, and the first air inlet is arranged spaced from the electrode.

Optional, the atomization assembly further includes a first filter screen, wherein the first filter screen is located between the atomizing core and the connecting seat, for filtering the e-liquid leaking towards the first air inlet.

Optional, a surface of the connecting seat facing the e-liquid storage body defines a second fixing recess, the first filter screen is inserted into the second fixing recess, and an air exit of the first air inlet is located on a bottom wall of the second fixing recess.

Optional, the atomization assembly further includes a sealing plug, wherein the sealing plug includes a cover body and a column body, the column body is located on one side of the cover body away from the connecting seat and is connected to the cover body, the e-liquid storage body defines an e-liquid filling hole, the e-liquid filling hole is communicated with the e-liquid storage cavity, the sealing plug is located between the e-liquid storage body and the connecting seat, and the column body is inserted into the e-liquid filling hole.

Optional, the sealing plug defines a connecting groove passing through the cover body and extending into the column body, the connecting seat is provided with a connecting column, and the connecting column is inserted into the connecting groove.

Optional, the e-liquid storage body includes an e-liquid storage sleeve and a separation sleeve, the separation sleeve includes an air tube and a fixing seat, the air tube includes a first end and a second end which are arranged opposite to each other, the air tube is located inside the e-liquid storage sleeve, the first end of the air tube is connected to the e-liquid storage sleeve, the second end of the air tube is connected to the fixing seat, and the atomizing core is accommodated inside the air tube; the fixing seat is connected to the e-liquid storage sleeve, wherein the air tube and the fixing seat are a one-piece structure shaped by injection in a mold.

Optional, the air tube is a part made of a metallic material, and the fixing seat is a part made of a non-metallic material.

Optional, the air tube includes a first vent section, a second vent section and a connecting section; the connecting section is located between the first vent section and the second vent section and is connected to the first vent section and the second vent section, the second vent section has a section area bigger than that of the first vent section, and the atomizing core is accommodated inside the second vent section.

In a second aspect, the present disclosure further provides an electronic cigarette, including the atomization assembly according to any item described above in the first aspect.

The present disclosure has the following benefits. As the electrode is fixed on the end face of the connecting seat, the electrode defines a connecting hole and a solder accommodating recess, a hole opening at one end of the connecting hole is located in the solder accommodating recess, and at least part of the connecting pin is inserted into the connecting hole and welded to the electrode, during welding, the solder accommodating recess is used for containing solder, so that the solder is uneasy to flow out and easy to flow into the connecting hole, more solder can be applied to the surrounding of the connecting pin to reduce the likeliness of rosin joint; therefore, the welding is firm and the service life is long. In addition, since the solder will not arbitrarily flow easily, the production is convenient.

One or more embodiments are illustrated through the image(s) in corresponding drawing(s). These illustrations do not form restrictions to the embodiments. Elements in the drawings with a same reference number are expressed as similar elements, and the images in the drawings do not form restrictions unless otherwise stated.

For a better understanding of the present disclosure, a detailed description is provided to the present disclosure in conjunction with the drawings and specific embodiments. It is to be noted that when an element is described as "fixed on"/ "fixedly connected to" another element, it may be directly on the another element, or there might be one or more intermediate elements between them. When one element is described as "connected to" another element, it may be directly connected to the another element, or there might be one or more intermediate elements between them. Terms "vertical", "horizontal", "left", "right," "inner", "outer" and similar expressions used in this description are merely for illustration.

Unless otherwise defined, all technical and scientific terms used in the description have the same meaning as those normally understood by the skill in the technical field of the present disclosure. The terms used in the description of the present disclosure are just for describing specific implementations, not to limit the present disclosure. Terms "and/or" used in the description include any and all combinations of one or more listed items.

In addition, technical features involved in different embodiments of the present disclosure described below can be combined mutually if no conflict is incurred.

In the description, the installation includes fixing or limiting one element or device to a particular position or place by means of welding, screwing, clamping, bonding and the like, the element or device can remain stationary at a specific position or place or move within a limited range, and the element or device can be or not be detached after fixed or limited to the particular position or place, which are limited in the present disclosure.

Referring to <FIG>, the present disclosure provides an atomization assembly, which includes an e-liquid storage body <NUM>, an atomizing core <NUM>, a connecting seat <NUM> and an electrode <NUM>. The e-liquid storage body <NUM> defines therein an e-liquid storage cavity a and an air channel b. The e-liquid storage body <NUM> includes an e-liquid storage sleeve <NUM> and a separation sleeve <NUM>, wherein the e-liquid storage sleeve <NUM> is provided with a first end and a second end which are arranged opposite to each other, the first end of the e-liquid storage sleeve <NUM> defines an air outlet <NUM>, and a hole opening of the air outlet <NUM> facing the separation sleeve <NUM> is provided with an insertion slot <NUM>. During smoking, an aerosol formed by e-liquid atomization is discharged from the air outlet <NUM> for the user to inhale.

The separation sleeve <NUM> includes an air tube <NUM> and a fixing seat <NUM>, the air tube <NUM> includes a first end and a second end which are arranged opposite to each other, the air tube <NUM> is inserted into the e-liquid storage sleeve <NUM>, the first end of the air tube <NUM> is connected to the e-liquid storage sleeve <NUM>, and the second end of the air tube <NUM> is connected to the fixing seat <NUM>. The air tube <NUM> forms therein the air channel b, the air channel b is communicated with the air outlet <NUM>, between the air tube <NUM> and the e-liquid storage sleeve <NUM> is formed the e-liquid storage cavity a, that is, the e-liquid storage cavity a is arranged surrounding the air tube <NUM>, and the e-liquid storage cavity a is configured for storing the e-liquid. The air tube <NUM> defines an e-liquid outlet <NUM> at a position corresponding to the atomizing core <NUM>, to discharge the e-liquid inside the e-liquid storage cavity a to the atomizing core <NUM>.

The air tube <NUM> includes a first vent section <NUM>, a second vent section <NUM> and a connecting section <NUM>; the connecting section <NUM> is located between the first vent section <NUM> and the second vent section <NUM> and is connected to the first vent section <NUM> and the second vent section <NUM>, and the second vent section <NUM> has a section area bigger than that of the first vent section <NUM>. It is understandable that in some embodiments the air tube <NUM> is formed by a first vent section <NUM> and a second vent section <NUM> that are directly connected, wherein the first vent section <NUM> and the second vent section <NUM> have a same section area.

The fixing seat <NUM> is arranged covering a cavity opening of the e-liquid storage cavity a and is connected to the e-liquid storage sleeve <NUM>. The air tube <NUM> and the fixing seat <NUM> are a one-piece structure shaped by injection in a mold, wherein the air tube <NUM> is a part made of a metallic material, and the fixing seat <NUM> is a part made of a non-metallic material. That is to say, during preparation, place the metallic air tube <NUM> in an injection mold, and shape the fixing seat <NUM> through injection into the mold, so that the air tube <NUM> and the fixing seat <NUM> become a one-piece structure. Preferably, the air tube <NUM> is a stainless steel part, and the fixing seat <NUM> is a plastic part; therefore, not only good tightness is achieved, but the air tube <NUM> is not easy to be impacted by the e-liquid. It is understandable that the air tube <NUM> may be a part made of other metallic materials, and the fixing seat <NUM> may be a part made of other non-metallic materials.

The fixing seat <NUM> defines an installing recess <NUM> and an e-liquid filling hole <NUM>, wherein the installing recess <NUM> is located at a surface of the fixing seat <NUM> away from the e-liquid storage cavity a, and the installing recess <NUM> has a side wall defining a buckling groove <NUM>. The e-liquid filling hole <NUM> is communicated with the e-liquid storage cavity a and the installing recess <NUM>. It is understandable that the position of the e-liquid filling hole <NUM> is not specifically limited here as long as the e-liquid storage body <NUM> defines the e-liquid filling hole <NUM>. For example, the e-liquid filling hole <NUM> may be defined on the outside of the installing recess <NUM>. The installing recess <NUM> is communicated with the air channel b.

The e-liquid storage body <NUM> further includes a sealing ring <NUM>, and the first end of the air tube <NUM> is connected to the sealing ring <NUM>, so as to connect to the e-liquid storage sleeve <NUM> via the sealing ring <NUM>. The second end of the air tube <NUM> is inserted into the fixing seat <NUM>. Specifically, the sealing ring <NUM> defines an abutting groove <NUM> on an end face of one end thereof; the sealing ring <NUM> is inserted at least in part into the insertion slot <NUM>, so that the sealing ring <NUM> is fixed through the insertion slot <NUM>, which can better avoid e-liquid leakage. In the present embodiment, one end of the sealing ring <NUM> is inserted into the insertion slot <NUM>, and the other end of the sealing ring <NUM> is located outside the insertion slot <NUM>.

It is understandable that in some embodiments the sealing ring <NUM> may be completely located inside the insertion slot <NUM>. The first end of the air tube <NUM> is inserted into the abutting groove <NUM>, and the second end of the air tube <NUM> is inserted into the fixing seat <NUM>, which can better prevent leakage of e-liquid. It is understandable that the sealing ring <NUM> may be made of elastic materials such as silicone or polyurethane. In some embodiments, the abutting groove <NUM> may not be required, and the first end of the air tube <NUM> elastically presses against the end face of the sealing ring <NUM>. Of course, the sealing ring <NUM> may not be required too, and the air tube <NUM> is directly connected to the e-liquid storage sleeve <NUM>. In some embodiments, the e-liquid storage sleeve <NUM> includes a tubular sleeve body and an annular cover body, wherein the cover body is located at one end of the sleeve body and is detachably connected to the sleeve body, the air tube <NUM> passes through the cover body, and a user can inhale aerosol directly through the air tube when smoking. Thus, the structure of the e-liquid storage sleeve <NUM> is not specifically limited here, as long as it can be used for storing the e-liquid.

The e-liquid storage body <NUM> further includes a second filter screen <NUM>, the second filter screen <NUM> is inserted into the insertion slot <NUM> and is clamped between the sealing ring <NUM> and the e-liquid storage sleeve <NUM>. The second filter screen <NUM> is configured to filter the large-particle aerosol discharged from the air tube <NUM>, thereby preventing a user inhaling the large-particle aerosol and enabling a good user experience. The second filter screen <NUM> may be formed by weaving, or may be formed by stamping from a plate, which is not specifically limited here.

The atomizing core <NUM> is inserted into the air tube <NUM> and is located inside the second vent section <NUM>. Through the blocking of the connecting section <NUM>, the atomizing core <NUM> can be prevented from being excessively inserted into the air tube <NUM>, which facilitates assembling. The atomizing core <NUM> includes an e-liquid absorption element <NUM> and an electric heating element <NUM>, wherein the e-liquid absorption element <NUM> is inserted into the air channel b, to absorb the e-liquid inside the e-liquid storage cavity a. The electric heating element <NUM> is in contact with the e-liquid absorption element <NUM>, to atomize the e-liquid on the e-liquid absorption element <NUM>. The electric heating element <NUM> is provided with a connecting pin <NUM>. It is understandable that the e-liquid absorption element <NUM> may be a glass fiber string extending into the e-liquid storage cavity a, and the electric heating element <NUM> may be an electric heating wire wound on the glass fiber string. The e-liquid absorption element <NUM> may also be a fiber cotton wound into a tubular shape, the electric heating element <NUM> is an electric heating wire wound into a columnar shape, and the electric heating element <NUM> is inserted into the e-liquid absorption element <NUM>. Therefore, the atomizing core <NUM> only needs to include the electric heating element <NUM> having the connecting pin <NUM>, and the electric heating element <NUM> is used for atomizing at least part of the e-liquid supplied to the electric heating element <NUM> from the e-liquid storage cavity a. The structure of the atomizing core <NUM> is not specifically limited here. It is understandable that the position of the atomizing core <NUM> may be arranged as needed and the position is not specifically limited here.

In the present embodiment, the e-liquid absorption element <NUM> includes a porous ceramic tube <NUM> and a cotton cloth <NUM> wound on outside of the porous ceramic tube <NUM>. Through the cotton cloth <NUM>, the e-liquid inside the e-liquid storage cavity a is absorbed to the porous ceramic tube <NUM>. The electric heating element <NUM> includes an electric heating wire <NUM> and the connecting pin <NUM>, wherein the electric heating wire <NUM> is inserted into the porous ceramic tube <NUM> and contacts an inner wall of the porous ceramic tube <NUM>, thereby contacting the e-liquid absorption element <NUM>. One end of the connecting pin <NUM> is connected to the electric heating wire <NUM>, while the other end of the connecting pin <NUM> is laser welded to the electrode <NUM>.

The connecting seat <NUM> is provided with a buckling protrusion <NUM> on a peripheral surface thereof, the connecting seat <NUM> is inserted into the installing recess <NUM>, and the buckling protrusion <NUM> is in buckled connection with the buckling groove <NUM>, so that the connecting seat <NUM> is connected to the e-liquid storage body <NUM>. The connecting seat <NUM> further define a through hole <NUM>, a first air inlet <NUM>, a first fixing recess <NUM>, a second fixing recess <NUM> and a connecting column <NUM>, wherein the connecting pin <NUM> passes through the through hole <NUM> to be welded to the electrode <NUM>, the first air inlet <NUM> is communicated with the air channel b, thus, during smoking, air outside the atomization assembly can flow into the air channel b from the first air inlet <NUM> to bring the aerosol inside the air channel b out from the air outlet <NUM>. The first air inlet <NUM> is arranged spaced from the electrode <NUM>, which can better avoid the solder blocking the first air inlet <NUM>. The second fixing recess <NUM> is located on a surface of the connecting seat <NUM> facing the e-liquid storage body, and a bottom wall of the second fixing recess <NUM> is provided with a supporting protrusion <NUM>, wherein the supporting protrusion <NUM> may present a bar shape, a ring shape or a square shape, etc..

The electrode <NUM> is fixed on an end face of the connecting seat <NUM>, and through the electrode <NUM> the atomization assembly is connected to the battery assembly. During smoking, the battery assembly supplies power to the electric heating element <NUM> through the electrode <NUM>. The electrode <NUM> defines a connecting hole <NUM> and a solder accommodating recess <NUM>. A hole opening at one end of the connecting hole <NUM> is located in the solder accommodating recess <NUM>, and at least part of the connecting pin <NUM> is inserted into the connecting hole <NUM> and welded to the electrode <NUM>.

As the electrode <NUM> is fixed on the end face of the connecting seat <NUM>, the electrode <NUM> defines a connecting hole <NUM> and a solder accommodating recess <NUM>, a hole opening at one end of the connecting hole <NUM> is located in the solder accommodating recess <NUM>, and at least part of the connecting pin <NUM> is inserted into the connecting hole <NUM> and welded to the electrode <NUM>, during welding, the solder accommodating recess <NUM> is used for containing solder, so that the solder is uneasy to flow out and easy to flow into the connecting hole <NUM>, more solder can be applied to the surrounding of the connecting pin <NUM> to reduce the likeliness of rosin joint; therefore, the welding is firm and the service life is long. In addition, since the solder will not arbitrarily flow easily, the production is convenient.

In the present embodiment, the electrode <NUM> presents a sheet shape and is arranged extending along and in an end face of the connecting seat <NUM>, that is, the sheet shaped electrode <NUM> is arranged extending along a horizontal direction of the atomization assembly, which not only can increase the contact area when electrically connected to the battery assembly and avoid problems of unreliable electrical connection, but also can reduce the difficulty of manufacture. It is understandable that the electrode <NUM> may be plate shaped or bar shaped and the like. To well fix the electrode <NUM>, the electrode <NUM> is inserted into the first fixing recess <NUM>.

The solder accommodating recess <NUM> is located on a surface of the electrode <NUM> away from the connecting seat <NUM> and extends towards another surface close to the connecting seat <NUM>, and the connecting pin <NUM> passes through the connecting hole <NUM> and extends into the solder accommodating recess <NUM>; therefore, during welding, the connecting pin <NUM> may be welded after the electrode <NUM> is assembled, thus the connection is reliable, and this avoids problems of unreliable connection due to the installation of the electrode <NUM> after the welding of the connecting pin <NUM>. It is understandable that in some embodiments the solder accommodating recess <NUM> may be defined on the surface of the electrode <NUM> facing the connecting seat <NUM>.

A recess opening of the solder accommodating recess <NUM> is hole shaped and is bigger than the hole opening of the connecting hole <NUM>. The solder accommodating recess <NUM> is arranged coaxial to the connecting hole <NUM>; thus, during welding, the solder can be applied to the surrounding of the connecting pin <NUM>, thereby enabling a secure connection. The electrode <NUM> is provided with a locating protrusion <NUM> at the hole opening of the connecting hole <NUM>, and the locating protrusion <NUM> is inserted into the through hole <NUM>, which facilitates locating during welding. In the present embodiment, the electrode <NUM> includes a main body made of a magnetic material and a protection layer located on a surface of the main body, and the electrode <NUM> is further configured for magnetic connection with the battery assembly. That is to say, besides power transmission, the electrode <NUM> is further configured for connection with the battery assembly, which can avoid problems in the prior art that the battery assembly is in reliable connection with the atomization assembly while the power transmission is not necessarily reliable. The magnetic material may be iron, cobalt, nickel and other materials. The protection layer may be a metallic layer, a metallic oxide layer and the like. In the present embodiment, the protection layer employs the material of gold, which can improve the conductivity. It is understandable that the material of the electrode <NUM> is not specifically limited here.

The atomization assembly further includes a first filter screen <NUM> and a sealing plug <NUM>. The first filter screen <NUM> is located between the atomizing core <NUM> and the connecting seat <NUM> and is inserted into the second fixing recess <NUM>, for filtering the e-liquid leaking towards the first air inlet <NUM> and thus avoiding the e-liquid leaking to the battery assembly to cause a problem of short circuit of the battery assembly. An air exit of the first air inlet <NUM> is located on a bottom wall of the second fixing recess <NUM>. The supporting protrusion <NUM> abuts against the first filter screen <NUM>, which reduces the contact area between the first filter screen <NUM> and the connecting seat <NUM> and enables better filtering. Preferably, the supporting protrusion <NUM> is arranged surrounding the first air inlet <NUM>, thus it can better support the filter screen and the contact area is less.

The sealing plug <NUM> is located between the e-liquid storage body <NUM> and the connecting seat <NUM>, and includes a cover body <NUM> and a column body <NUM>; the cover body <NUM> is located in the installing recess <NUM> and defines a second air inlet <NUM>; the second air inlet <NUM> corresponds to the positions of the first air inlet <NUM> and the air channel b, to import the air flowing from the first air inlet <NUM> to the air channel b. Herein, the fixing seat <NUM> defines a third air inlet (not shown) communicated with the second air inlet <NUM> and the air channel b respectively, so that the air can pass through in sequence the first air inlet <NUM>, the second air inlet <NUM>, the third air inlet and the air channel to be discharged from the air outlet <NUM> for a user to inhale. The column body <NUM> is located on one side of the cover body <NUM> away from the connecting seat <NUM> and is connected to the cover body <NUM>. The column body <NUM> is inserted into the e-liquid filling hole <NUM>, to better seal the e-liquid. During production, after the e-liquid storage body <NUM> is assembled, an e-liquid is filled into the e-liquid storage cavity a through the e-liquid filling hole <NUM>. The production is convenient. The sealing plug <NUM> defines a connecting groove <NUM> passing through the cover body <NUM> and extending into the column body <NUM>, and the connecting column <NUM> is inserted into the connecting groove <NUM>, so that the sealing plug <NUM> achieves a better tightness and improves the sealing performance.

Referring to <FIG>, the present disclosure further provides an electronic cigarette, which includes an atomization assembly <NUM> and a battery assembly <NUM>. The atomization assembly <NUM> is the one as described above, and the battery assembly <NUM> is electrically connected to the atomization assembly <NUM>, to supply power to the atomization assembly <NUM>. Since the atomization assembly <NUM> of the electronic cigarette is of the same structure as the above atomization assembly <NUM>, it has the same technical effects.

To summarize, since the air tube <NUM> and the fixing seat <NUM> are a one-piece structure shaped by injection in a mold, there is no need to arrange a sealing ring between the air tube <NUM> and the fixing seat <NUM> to seal the e-liquid. The structure is simple, not only cost is saved but e-liquid leakage is better avoided, it is convenient for automated production and the production efficiency is increased. Since the air tube <NUM> is a part made of a metallic material, it can better avoid generating thermal deformation to cause leakage of e-liquid when the atomizing core <NUM> atomizes the e-liquid and thus better guarantees the tightness.

Claim 1:
An atomization assembly (<NUM>), configured to combine with a battery assembly (<NUM>) to form an electronic cigarette, comprising: an e-liquid storage body (<NUM>), an atomizing core (<NUM>) , a connecting seat (<NUM>) and an electrode (<NUM>), characterized in that the e-liquid storage body (<NUM>) is internally provided with an e-liquid storage cavity (a) for accommodating an e-liquid, the atomizing core (<NUM>) comprises an electric heating element (<NUM>) having a connecting pin (<NUM>), and the electric heating element (<NUM>) is used for atomizing at least part of the e-liquid supplied to the electric heating element (<NUM>) from the e-liquid storage cavity (a), the connecting seat (<NUM>) is connected to the e-liquid storage body (<NUM>), the electrode (<NUM>) is fixed on the connecting seat (<NUM>), and the electrode (<NUM>) defines thereon a connecting hole (<NUM>) passing through the electrode (<NUM>) and an accommodating recess (<NUM>), a hole opening at one end of the connecting hole (<NUM>) is located in the accommodating recess (<NUM>) to communicate with the accommodating recess (<NUM>), and at least part of the connecting pin (<NUM>) is inserted into the connecting hole (<NUM>) and extends into the accommodating recess (<NUM>), thereby forming a connection with the electrode (<NUM>).