A multi-gas flow passage air-cooled cutting device

Abstract

The application discloses a kind of multi-gas flow channel gas cooling cutting device, including sensor, sensor includes bottle body, upper end cap and connecting piece, connecting piece is connected with bottle body, bottle body is equipped with first gas hole, the outer side wall of connecting piece is equipped with a plurality of second gas hole, upper end cap is covered in bottle body;First connecting assembly, first connecting assembly is connected with connecting piece, and first connecting assembly is equipped with third gas hole;Second connecting assembly, second connecting assembly is connected with first connecting assembly, and second connecting assembly is equipped with a plurality of fourth gas hole.Cooling gas is formed by the cooperation between first gas hole, second gas hole, third gas hole and fourth gas hole Multiple gas flow channels, so that cooling gas cooling effect is applied to sensor, first connecting assembly and second connecting assembly, to improve the stability of sensor temperature, so that sensor controls the work stability of second connecting assembly.

Description

Technical Field

[0001] This invention relates to the field of cutting devices in laser cutting machines, and more particularly to a multi-airflow channel air-cooled cutting device. Background Technology

[0002] In the field of laser cutting technology, the cutting device uses sensors to control the height of the nozzle relative to the workpiece surface to ensure stable cutting and thus guarantee cutting quality. Because the nozzle and sensor are very close to the workpiece surface, the nozzle generates a large amount of heat during cutting, causing temperature instability in the sensor and consequently, instability in the sensor's control of the nozzle. This affects the cutting quality of the device, thus necessitating a cutting device with multi-channel cooling. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a multi-channel air-cooled cutting device.

[0004] According to a first aspect of the present invention, a multi-channel air-cooled cutting device includes a sensor, the sensor comprising a bottle body, an upper cap, and a connector, the connector being connected to the bottle body, the bottle body having a first gas hole, the outer wall of the connector having a plurality of second gas holes communicating with the first gas holes, the upper cap being closed to the bottle body, the upper cap being capable of sealing the bottle body and the connector; a first connecting assembly, the first connecting assembly being connected to the connector, the first connecting assembly having a third gas hole communicating with the second gas holes; a second connecting assembly, the second connecting assembly being connected to the first connecting assembly, the second connecting assembly having a plurality of fourth gas holes communicating with the third gas holes; and a sealing member, the sealing member being capable of sealing the connection between the first connecting assembly and the second connecting assembly; wherein, cooling gas is delivered through the first gas hole to the second gas hole, and then sprayed onto the workpiece through the third and fourth gas holes.

[0005] The multi-channel air-cooled cutting device according to embodiments of the present invention has at least the following technical effects: cooling gas enters the bottle body through the first gas hole, enters the connector through the second gas hole, and is then sprayed onto the workpiece through the third gas hole on the first connector and the fourth gas hole on the second connector respectively. The cooling gas passes through multiple airflow channels formed by the cooperation between the first gas hole, the second gas hole, the third gas hole and the fourth gas hole, so that the cooling gas cools the sensor, the first connector and the second connector, thereby improving the temperature stability of the sensor, thereby making the sensor control the operation of the second connector stable, and thus improving the service life of the sensor, the first connector and the second connector.

[0006] According to some embodiments of the present invention, the bottle body is provided with an annular groove in the middle, and a plurality of first gas cutting holes are provided extending downward around the annular groove. The first gas cutting holes communicate with the annular groove. The annular groove extends upward to form a second gas cutting hole, which communicates with the annular groove. The connector is provided with a third gas cutting hole in the middle that communicates with the second gas cutting hole. The first connecting component is provided with a fourth gas cutting hole in the middle that communicates with the third gas cutting hole. The second connecting component is provided with a fifth gas cutting hole in the middle that communicates with the fourth gas cutting hole.

[0007] According to some embodiments of the present invention, the second connecting component is a first nozzle, the second connecting component includes a first body and a second body, the first body is installed inside the second body, the fifth cutting gas hole is disposed in the middle of the first body, a plurality of fourth gas holes are disposed around the fifth cutting gas hole on the first body, the lower part of the second body is provided with an air outlet, a first gap is formed between the inner wall of the second body and the lower outer wall of the first body, and the first gap communicates with the fourth gas holes.

[0008] According to some embodiments of the present invention, the first body includes an upper cylindrical section and a lower conical section, the upper cylindrical section and the lower conical section are integrally formed, the lower part of the upper cylindrical section is installed in the air outlet, the lower conical section is installed in the air outlet, the upper cylindrical section and the inner wall of the second body form a second gap, and the cross-sectional area of ​​the second gap gradually decreases from top to bottom.

[0009] According to some embodiments of the present invention, the upper part of the upper half of the cylinder is provided with a first connecting part, the fourth gas hole is disposed on the first connecting part, the upper part of the second body is provided with a mounting groove, and the first connecting part is installed in the mounting groove.

[0010] According to some embodiments of the present invention, the second connecting component is a second nozzle, the second connecting component includes a third body and a high-temperature resistant structure, the fifth cutting gas hole is disposed in the middle of the third body, the high-temperature resistant structure is installed in the lower part of the fifth cutting gas hole, and the high-temperature resistant structure is provided with a sixth gas cutting hole communicating with the fifth cutting gas hole.

[0011] According to some embodiments of the present invention, the fifth cutting gas hole is a conical hole, which extends from the upper end face of the third body to the lower end face of the third body, and the cross-sectional area of ​​the fifth cutting gas hole gradually decreases from top to bottom.

[0012] According to some embodiments of the present invention, the second connecting assembly is a third nozzle, the second connecting assembly includes a fourth body, a second connecting portion and a blocking portion, the fifth cutting gas hole is disposed in the middle of the third body, the second connecting portion is connected to the lower part of the fourth body, the blocking portion is connected to the other end of the second connecting portion, and the fifth cutting gas hole is disposed through the second connecting portion and the blocking portion.

[0013] According to some embodiments of the present invention, a plurality of the fourth gas holes are arranged around the fourth body, and the central axis of the fourth gas holes is inclined relative to the central axis of the fifth cutting gas hole.

[0014] According to some embodiments of the present invention, the outer side of the blocking portion extends outward to form a protrusion, the outer diameter of the protrusion is larger than the outer diameter of the second connecting portion, the protrusion can block the cooling gas delivered by the fourth gas hole, and the cross-sectional area of ​​the protrusion gradually decreases from top to bottom.

[0015] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0016] Additional aspects and advantages of the invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0017] Figure 1 This is a schematic diagram of the structure of a multi-airflow channel air-cooled cutting device according to an embodiment of the present invention;

[0018] Figure 2 This is a cross-sectional view of a multi-airflow channel air-cooled cutting device in some embodiments;

[0019] Figure 3 This is a cross-sectional view of a multi-airflow channel air-cooled cutting device in some embodiments;

[0020] Figure 4 This is a cross-sectional view of a multi-airflow channel air-cooled cutting device in some embodiments;

[0021] Figure 5 This is a cross-sectional view of a multi-airflow channel air-cooled cutting device in some embodiments;

[0022] Figure 6 This is a cross-sectional view of the first connecting component;

[0023] Figure 7 This is a sectional view of the connector;

[0024] Figure 8 This is a cross-sectional view of the second connecting component in some embodiments;

[0025] Figure 9 This is a cross-sectional view of the sensor.

[0026] Figure label:

[0027] Sensor 100, bottle body 110, first gas hole 111, annular groove 112, first cutting gas hole 113, second cutting gas hole 114, third cutting gas hole 115, upper end cap 120, connector 130, second gas hole 131;

[0028] First connecting component 200, third gas hole 201, fourth cutting gas hole 202;

[0029] Second connecting component 300, fourth gas hole 301, fifth cutting gas hole 302, first main body 310, upper cylinder 311, lower cone 312, second gap 313, first connecting part 314, second main body 320, first gap 321, gas outlet 322, third main body 330, high temperature resistant structure 331, sixth gas cutting hole 332, fourth main body 340, second connecting part 341, blocking part 342, protrusion part 343;

[0030] Seal 400. Detailed Implementation

[0031] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0032] Reference Figures 1 to 9 As shown, a multi-channel air-cooled cutting device according to an embodiment of the present invention includes a sensor 100, a first connecting assembly 200, a sealing member 400, and a second connecting assembly 300. Figures 1 to 5 As shown, the sensor 100 includes a bottle body 110, an upper cap 120, and a connector 130, with the connector 130 mounted on the upper part of the bottle body 110. Figure 1 As shown, a first gas hole 111 for conveying cooling gas is provided on the outer wall of the bottle body 110. Several first gas outlets are provided at the upper part of the first gas hole 111, and these first gas outlets are respectively connected to the first gas hole 111. By providing several first gas outlets, the conveying efficiency of the cooling gas can be improved. Figure 1 and Figure 7As shown, the outer wall of the connector 130 is provided with a plurality of second gas holes 131, which communicate with the first gas hole 111 through the first gas outlet. The plurality of second gas holes 131 extend upwards and communicate to form a second gas outlet. By providing the second gas holes 131 and the second gas outlet in the connector 130, the cooling gas inside the bottle body 110 is transported through the connector 130 to the first connecting assembly 200. Figure 2 and Figure 5 As shown, the seal 400 can be a high-temperature resistant seal 400. The seal 400 can seal the connection between the first connecting component 200 and the second connecting component 300, thereby improving the airtightness between the first connecting component 200 and the second connecting component 300.

[0033] Specifically, a first airflow channel for cooling the sensor 100 is formed between the first gas hole 111 and the second gas hole 131. Figure 6 As shown, the first connecting assembly 200 is connected to the connector 130. The first connecting assembly 200 is provided with a third gas hole 201 communicating with the second gas hole 131. The third gas hole 201 is a second airflow channel for cooling the first connecting assembly 200. The lower part of the first connecting assembly 200 is provided with a plurality of air outlet holes 322 communicating with the third gas hole 201, thereby improving the delivery efficiency of cooling gas.

[0034] like Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 8 As shown, the second connecting component 300 is connected to the first connecting component 200. The second connecting component 300 is provided with a plurality of fourth gas holes 301, which are third airflow channels for cooling the second connecting component 300. The fourth gas holes 301 are connected to the third gas holes 201. Cooling gas enters the second connecting component 300 through the fourth cooling gas, thereby cooling the second connecting component 300 to prevent the second connecting component 300 from overheating and affecting its service life.

[0035] like Figures 2 to 5As shown, the upper cap 120 covers the bottle body 110, ensuring that the air passage for cooling gas between the first gas port 111 and the second gas port 131 is not disturbed by external factors. This allows the upper cap 120 to seal the installation connection between the bottle body 110 and the connector 130. The upper cap 120 has mounting holes, allowing the connector 130 to connect to the first connecting assembly 200 through the mounting holes, and enabling the second gas port 131 on the connector 130 to communicate with the third cooling port. Cooling gas enters the bottle body 110 through the first gas hole 111, then enters the connector 130 through the second gas hole 131, and is then sprayed onto the workpiece through the third gas hole 201 on the first connecting assembly 200 and the fourth gas hole 301 on the second connecting assembly 300. The cooling gas, through the multiple airflow channels formed by the cooperation of the first gas hole 111, the second gas hole 131, the third gas hole 201, and the fourth gas hole 301, cools the sensor 100, the first connecting assembly 200, and the second connecting assembly 300, thereby improving the temperature stability of the sensor 100 and ensuring stable operation of the sensor 100 in controlling the second connecting assembly 300. This, in turn, extends the service life of the sensor 100, the first connecting assembly 200, and the second connecting assembly 300. It should be noted that, in addition to supplying cooling gas, the first gas hole 111, the second gas hole 131, the third gas hole 201, and the fourth gas hole 301 can also supply combustion-supporting gases, such as methane, or protective gases, such as oxygen or nitrogen, depending on the specific circumstances.

[0036] In some embodiments of the present invention, such as Figure 1 , Figure 8 and Figure 9As shown, the bottle body 110 has an annular groove 112 in the middle for guiding the flow of cutting gas. Several first cutting gas holes 113 extend downwards around the annular groove 112, communicating with the annular groove 112. The annular groove 112 extends upwards to form second cutting gas holes 114, which also communicate with the annular groove 112. A third cutting gas hole 115 communicating with the second cutting gas hole 114 is located in the middle of the connector 130. A fourth cutting gas hole 202 communicating with the third cutting gas hole 115 is located in the middle of the first connecting assembly 200. A fifth cutting gas hole 302 communicating with the fourth cutting gas hole 202 is located in the middle of the second connecting assembly 300. The connection between the first and second cutting gas holes 113 and 114 forms a fourth airflow channel, and the connection between the third, fourth, and fifth cutting gas holes 115, 202, and 302 forms a fifth airflow channel. The fourth and fifth airflow channels are connected and used to transport cutting gas. By setting a first airflow channel, a second airflow channel, and a third airflow channel around the fourth airflow channel and the fifth airflow channel respectively, and by delivering cooling gas through the first airflow channel, the second airflow channel, and the third airflow channel respectively to cool the sensor 100, the first connecting component 200, and the second connecting component 300, the cutting gas is stably delivered in the fourth airflow channel and the fifth airflow channel respectively.

[0037] In a further embodiment of the present invention, such as Figure 2 and Figure 3 As shown, the second connecting assembly 300 is the first nozzle. The second connecting assembly 300 includes a first body 310 and a second body 320. The first body 310 is installed inside the second body 320. The fifth cutting gas hole 302 is located in the middle of the first body 310. Several fourth gas holes 301 are arranged around the fifth cutting gas hole 302 on the first body 310. The lower part of the second body 320 is provided with an exhaust hole 322. A first gap 321 is formed between the inner wall of the second body 320 and the lower outer wall of the first body 310. The first gap 321 and the fourth gas holes 301 are connected. Cooling gas is sprayed onto the workpiece through the several fourth gas holes 301 and the first gap 321. By setting the first gap 321 outside the fifth cutting gas hole 302, the cutting gas is surrounded by cooling gas and sprayed onto the workpiece together, thereby reducing the interference of outside air on the cutting gas. Specifically, the air outlet 322 is matched with the lower shape of the first body 310, so that after the first body 310 is installed on the second body 320, the air outlet 322 and the lower part of the first body 310 form a first gap 321.

[0038] In some embodiments of the present invention, such as Figure 2As shown, the first body 310 includes an upper cylindrical section 311 and a lower conical section 312, which are integrally formed. The lower part of the upper cylindrical section 311 is installed in the air outlet 322, and the lower conical section 312 is also installed in the air outlet 322. The upper cylindrical section 311 and the upper inner wall of the second body 320 form a second gap 313. The cross-sectional area of ​​the second gap 313 gradually decreases from top to bottom, thereby compressing the cooling gas in the gradually shrinking second gap 313. This allows the cooling gas to be ejected at a higher speed and / or pressure, thereby improving the delivery efficiency of the cooling gas.

[0039] In a further embodiment of the present invention, such as Figure 2 As shown, to facilitate the assembly of the first body 310 and the second body 320 into a single unit, the upper part of the cylindrical upper section 311 is provided with a first connecting part 314, and a fourth gas hole 301 is provided on the first connecting part 314. The upper part of the second body 320 is provided with a mounting groove, and the first connecting part 314 is installed in the mounting groove. It should be noted that the mounting groove is not marked on the accompanying drawings.

[0040] In some embodiments of the present invention, such as Figure 5 As shown, the second connecting assembly 300 is a second nozzle. The second connecting assembly 300 includes a third body 330 and a high-temperature resistant structure 331. A fifth cutting gas hole 302 is located in the middle of the third body 330, and the high-temperature resistant structure 331 is installed below the fifth cutting gas hole 302. The high-temperature resistant structure 331 has a sixth gas cutting hole 332 communicating with the fifth cutting gas hole 302. By installing the high-temperature resistant structure 331 in the lower part of the fifth cutting gas hole 302 and by providing the sixth gas cutting hole 332 on the high-temperature resistant structure 331, the high-temperature resistant structure 331 is less prone to deformation at high temperatures. Therefore, it can be ensured that the laser and / or cutting gas are better guided to the cutting position of the workpiece.

[0041] In a further embodiment of the present invention, such as Figure 5 As shown, the fifth cutting gas orifice 302 is a conical orifice, extending from the upper end face of the third body 330 to the lower end face of the third body 330. The cross-sectional area of ​​the fifth cutting gas orifice 302 gradually decreases from top to bottom; here, the cross-sectional area refers to the cross-section perpendicular to the fifth cutting gas orifice 302. The cutting gas is compressed within the gradually shrinking space of the fifth cutting gas orifice 302, thereby enabling the cutting gas to be ejected at a higher speed and / or pressure, thus improving the delivery efficiency of the cutting gas.

[0042] In some embodiments of the present invention, such as Figure 4 and Figure 5As shown, the second connecting assembly 300 is the third nozzle. The second connecting assembly 300 includes a fourth body 340, a second connecting portion 341, and a blocking portion 342. A fifth cutting gas hole 302 is disposed in the middle of the third body 330. The second connecting portion 341 is connected to the lower part of the fourth body 340, and the blocking portion 342 is connected to the other end of the second connecting portion 341. The fifth cutting gas hole 302 passes through both the second connecting portion 341 and the blocking portion 342. When the second connecting assembly 300 is configured as the third nozzle, the fifth cutting gas hole 302 and the fourth gas hole 301 deliver the same gas. By separating the fifth cutting gas hole 302 from the fourth gas hole 301 and by providing the blocking portion 342 at the bottom of the second connecting portion 341, the disturbance of the cutting gas by the cooling gas can be reduced, and the cooling gas can also cool the nozzle.

[0043] In a further embodiment of the present invention, such as Figure 4 , Figure 5 and Figure 8 As shown, a plurality of fourth gas holes 301 are arranged around the fourth main body 340, so that the cooling gas can uniformly cool the blocking part 342. Figure 8 As shown, by setting the central axis of the fourth gas hole 301 to be inclined relative to the central axis of the fifth cutting gas hole 302, the fourth gas hole 301 is not fully shown in the sectional view after cutting.

[0044] In some embodiments of the present invention, such as Figure 4 and Figure 5 As shown, the outer side of the blocking portion 342 extends outward to form a protrusion 343. The outer diameter of the protrusion 343 is larger than the outer diameter of the second connecting portion 341. The protrusion 343 can block the cooling gas delivered by the fourth gas hole 301. The cross-sectional area of ​​the protrusion 343 gradually decreases from top to bottom. Here, the cross-sectional area refers to the cross-section perpendicular to the central axis of the fifth cutting gas hole 302. Therefore, the cross-sectional area of ​​the protrusion 343 is the largest at the end near the fourth gas hole 301, thereby improving the blocking effect of the protrusion 343, making the cooling gas cool the blocking portion 342 for a longer time, and also saving materials.

[0045] In the description of this specification, references to terms such as "some embodiments" indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0046] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A multi-airflow channel air-cooled cutting device, characterized in that, include: The sensor (100) includes a bottle body (110), an upper cap (120), and a connector (130). The connector (130) is connected to the bottle body (110). The bottle body (110) is provided with a first gas hole (111). The outer wall of the connector (130) is provided with a plurality of second gas holes (131). The second gas holes (131) communicate with the first gas holes (111). The upper cap (120) is closed on the bottle body (110). The upper cap (120) can seal the bottle body (110) and the connector (130). A first connecting component (200) is connected to the connector (130). The first connecting component (200) is provided with a third gas hole (201), which communicates with the second gas hole (131). A second connecting component (300) is connected to the first connecting component (200). The second connecting component (300) is provided with a plurality of fourth gas holes (301), and the fourth gas holes (301) are connected to the third gas holes (201). A sealing element (400) is provided to seal the connection between the first connecting assembly (200) and the second connecting assembly (300); the sealing element (400) is a high-temperature resistant sealing element. The cooling gas is delivered to the second gas hole (131) through the first gas hole (111), and then sprayed onto the workpiece through the third gas hole (201) and the fourth gas hole (301). The bottle body (110) has an annular groove (112) in the middle, and a plurality of first gas cutting holes (113) are provided extending downward around the annular groove (112). The first gas cutting holes (113) are connected to the annular groove (112). The annular groove (112) extends upward to form a second gas cutting hole (114). The second gas cutting hole (114) is connected to the annular groove (112). The connector (130) has a third gas cutting hole (115) in the middle that is connected to the second gas cutting hole (114). The first connecting component (200) has a fourth gas cutting hole (202) in the middle that is connected to the third gas cutting hole (115). The second connecting component (300) has a fifth gas cutting hole (302) in the middle that is connected to the fourth gas cutting hole (202).

2. The multi-airflow channel air-cooled cutting device according to claim 1, characterized in that: The second connecting component (300) is a first nozzle. The second connecting component (300) includes a first body (310) and a second body (320). The first body (310) is installed inside the second body (320). The fifth cutting gas hole (302) is located in the middle of the first body (310). A plurality of fourth gas holes (301) are arranged around the fifth cutting gas hole (302) on the first body (310). The lower part of the second body (320) is provided with an air outlet (322). A first gap (321) is formed between the inner wall of the second body (320) and the lower outer wall of the first body (310). The first gap (321) and the fourth gas holes (301) are connected.

3. The multi-airflow channel air-cooled cutting device according to claim 2, characterized in that: The first main body (310) includes an upper cylindrical section (311) and a lower conical section (312). The upper cylindrical section (311) and the lower conical section (312) are integrally formed. The lower part of the upper cylindrical section (311) is installed in the air outlet (322), and the lower conical section (312) is installed in the air outlet (322). The upper cylindrical section (311) and the inner wall of the second main body (320) form a second gap (313). The cross-sectional area of ​​the second gap (313) gradually decreases from top to bottom.

4. The multi-airflow channel air-cooled cutting device according to claim 3, characterized in that: The upper half of the cylinder (311) is provided with a first connecting part (314), the fourth gas hole (301) is provided on the first connecting part (314), the upper part of the second body (320) is provided with an installation groove, and the first connecting part (314) is installed in the installation groove.

5. The multi-airflow channel air-cooled cutting device according to claim 1, characterized in that: The second connecting component (300) is a second nozzle. The second connecting component (300) includes a third body (330) and a high-temperature resistant structure (331). The fifth cutting gas hole (302) is disposed in the middle of the third body (330). The high-temperature resistant structure (331) is installed at the lower part of the fifth cutting gas hole (302). The high-temperature resistant structure (331) is provided with a sixth gas cutting hole (332) communicating with the fifth cutting gas hole (302).

6. The multi-airflow channel air-cooled cutting device according to claim 5, characterized in that: The fifth cutting gas hole (302) is a conical hole. The fifth cutting gas hole (302) extends from the upper end face of the third body (330) to the lower end face of the third body (330). The cross-sectional area of ​​the fifth cutting gas hole (302) gradually decreases from top to bottom.

7. The multi-airflow channel air-cooled cutting device according to claim 5, characterized in that: The second connecting assembly (300) is a third nozzle. The second connecting assembly (300) includes a fourth body (340), a second connecting part (341), and a blocking part (342). The fifth cutting gas hole (302) is disposed in the middle of the third body (330). The second connecting part (341) is connected to the lower part of the fourth body (340). The blocking part (342) is connected to the other end of the second connecting part (341). The fifth cutting gas hole (302) is disposed through the second connecting part (341) and the blocking part (342).

8. The multi-airflow channel air-cooled cutting device according to claim 7, characterized in that: A plurality of the fourth gas holes (301) are arranged around the fourth body (340), and the central axis of the fourth gas holes (301) is inclined relative to the central axis of the fifth cutting gas hole (302).

9. A multi-airflow channel air-cooled cutting device according to claim 8, characterized in that: The outer side of the blocking part (342) extends outward to form a protruding part (343). The outer diameter of the protruding part (343) is larger than the outer diameter of the second connecting part (341). The protruding part (343) can block the cooling gas delivered by the fourth gas hole (301). The cross-sectional area of ​​the protruding part (343) gradually decreases from top to bottom.

Images