Extrusion nozzle device of food 3D printer

Abstract

The application discloses an extrusion nozzle device of a food 3D printer, which comprises a shell, a central conveying pipe, a spiral conveying rod, an a motor, a holder and a variable extrusion nozzle assembly; the central conveying pipe is in the shell, one side of the upper part of the central conveying pipe is communicated with a feeding pipe, the spiral conveying rod rotates coaxially in the central conveying pipe, and the a motor is drivingly connected with the spiral conveying rod; the holder is below the central conveying pipe; the variable extrusion nozzle assembly is installed on the holder, and the discharge end of the lower part of the central conveying pipe is communicated and connected with the feeding end of the variable extrusion nozzle assembly through a hose; fine and efficient modes can be provided, and the modes can be switched at will.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of food 3D printing. BACKGROUND

[0002] Food 3D printing technology is developed on the basis of 3D printing technology. Its main working mode is to extrude edible slurry through air pressure or screw, and print according to the set program under the control of software, and the printed object can be immediately eaten or further processed.

[0003] The outer layer of food has more detailed patterns, shapes and other requirements. The printing process of the outer layer of food needs to be more detailed, which can form more detailed patterns on the surface of the food. In the mode of fine printing, there is a problem of low efficiency. When printing the inner layer of food, the complexity of the shape and pattern requirements is reduced, and the requirement of the fine degree is reduced, and the requirement of the efficiency is improved. Therefore, the print head needs to have two printing modes. The core content of the present case is that the print head can provide at least two printing modes required by the print head, and can be switched at will. SUMMARY

[0004] The purpose of the present application is to overcome the deficiencies in the prior art, and to provide an extrusion nozzle device of a food 3D printer, which can provide fine and high-efficiency modes at the same time.

[0005] Technical scheme: In order to achieve the above-mentioned purpose, an extrusion nozzle device of a food 3D printer of the present application comprises a shell, a central conveying pipe, a spiral conveying rod, an a motor, a gimbal and a variable extrusion nozzle assembly.

[0006] The central conveying pipe is in the shell, the upper side of the central conveying pipe is communicated with a feeding pipe, the spiral conveying rod rotates coaxially in the central conveying pipe, and the a motor is drivingly connected with the spiral conveying rod; the gimbal is below the central conveying pipe; the variable extrusion nozzle assembly is installed on the gimbal, and the discharge end of the lower part of the central conveying pipe is connected with the feeding end of the variable extrusion nozzle assembly through a hose.

[0007] Further, the gimbal has a through hole penetrating upward and downward at the axis, a hose joint is communicated and fixedly connected to the upper end of the through hole, and the lower end of the hose is communicated with the hose joint.

[0008] Further, a b motor is installed on the gimbal; the variable extrusion nozzle assembly comprises an adjusting gear fixed on the output shaft of the b motor, an outer threaded nozzle body and an inner threaded floating cylinder shell.

[0009] The internal thread of the inner floating cylinder shell is threadedly connected with the external thread of the external thread nozzle body, and the outer gear ring is fixedly arranged on the outer floating cylinder shell in a coaxial manner, and the outer gear ring is engaged with the adjusting gear, and the outer gear ring and the adjusting gear can slide relative to each other along the axial direction; the upper end of the external thread nozzle body is integrally connected with the nozzle fixed connector in a coaxial manner, and the internal structure of the integrated structure formed by the external thread nozzle body and the nozzle fixed connector is a material guiding channel which is vertically through, and the upper end of the nozzle fixed connector is fixedly connected with the communication hole in a communication manner.

[0010] Further, the lower end of the external thread nozzle body is integrally and communicatively provided with a discharging cone ring head which is thick at the upper end and thin at the lower end, the lower end of the discharging cone ring head is fixedly connected with the conical elastic material head in a coaxial manner, and the conical elastic material head is a conical shell body made of elastic material; the lower end of the conical elastic material head is provided with a material spraying port, and the lower part of the conical elastic material head is circumferentially arranged with a plurality of segmentation joints which extend along the generatrix direction of the conical elastic material head; the plurality of segmentation joints divide the lower part of the conical elastic material head into a plurality of petals, and when the pressure in the conical elastic material head increases without external constraint, the plurality of petals of the lower part of the conical elastic material head will expand in a "flowering" manner, so as to expand the material spraying port.

[0011] Further, the lower end of the inner floating cylinder shell is integrally and fixedly connected with the conical hard shell, and the lower end of the conical hard shell is coaxially provided with the constraint port whose inner diameter is larger than that of the material spraying port.

[0012] Further, in the initial state, the conical outer wall formed by the conical elastic material head and the discharging cone ring head is coaxially attached to the inner wall of the conical hard shell, and the lower end of the conical elastic material head protrudes downward out of the constraint port, so that the constraint port is sleeved on the outer wall of the lower end of the conical elastic material head, and the constraint port sleeved on the outer wall of the lower end of the conical elastic material head inhibits the "flowering" action of the plurality of petals of the lower part of the conical elastic material head.

[0013] Further, on the basis of the initial state, after the conical hard shell moves downward relatively, the constraint on the plurality of petals of the lower part of the conical elastic material head is released, and the conical outer wall formed by the conical elastic material head and the discharging cone ring head and the inner wall of the conical hard shell form a ring-shaped cavity.

[0014] Further, the conical elastic material spraying head comprises an elastic material spraying head lower section and an elastic material spraying head upper section, each of the split seams is on the elastic material spraying head lower section; further comprising a conical ring wall which is coaxially and integrally connected to the lower end of the material discharging conical ring head; the inner ring of the upper end of the elastic material spraying head upper section is fixedly and sealingly connected to the outer wall surface of the conical ring wall through a first ring of sealing adhesive joints; the inner ring of the lower end of the elastic material spraying head upper section is fixedly and sealingly connected to the outer wall surface of the conical ring wall through a second ring of sealing adhesive joints, so that a conical ring gap is formed between the inner wall surface of the elastic material spraying head upper section and the outer wall surface of the conical ring wall; the wall body of the integrated structure formed by the material discharging conical ring head and the conical ring wall is internally provided with a gas conveying channel, the upper gas inlet end of the gas conveying channel is connected to the gas outlet end of the gas pump, and the lower end of the gas conveying channel is communicated with the conical ring gap formed between the inner wall surface of the elastic material spraying head upper section and the outer wall surface of the conical ring wall.

[0015] Beneficial effects: in the fine printing mode, the restraining port sleeved on the outer wall of the lower end of the conical elastic material spraying head restrains the petals of the lower part of the conical elastic material spraying head from performing the "flowering" action; so that the restrained and expanded material spraying port sprays relatively small columnar paste food to the target printing position, the restrained and expanded material spraying port has the characteristics of printing food more finely and higher printing precision, is suitable for outer layer printing of food, and can form a more fine pattern on the surface of the food;

[0016] In the high-efficiency printing mode, the restraining port releases the restraint on the petals of the lower part of the conical elastic material spraying head, at this time, the petals of the lower part of the conical elastic material spraying head expand in the "flowering" shape under the internal food pressure, so that the material spraying port expands, and the expanded material spraying port sprays relatively thick columnar paste food to the target printing position, the expanded material spraying port has the characteristics of printing food more efficiently and higher printing efficiency, and is suitable for inner layer printing of food. BRIEF DESCRIPTION OF DRAWINGS

[0017] ATTACHMENT Figure 1 It is a schematic diagram of the whole printing head;

[0018] ATTACHMENT Figure 2 It is a schematic diagram of the central conveying pipe structure;

[0019] ATTACHMENT Figure 3 It is a schematic diagram of the assembly of the variable extrusion nozzle assembly;

[0020] ATTACHMENT Figure 4 It is a schematic diagram of the cooperation of the outer threaded nozzle body and the inner threaded floating cylinder shell;

[0021] ATTACHMENT Figure 5 It is an exploded view of the outer threaded nozzle body and the inner threaded floating cylinder shell;

[0022] ATTACHMENT Figure 6 It is a schematic diagram of the variable extrusion nozzle assembly;

[0023] ATTACHMENT Figure 7Improved front cross-sectional view of the external threaded nozzle body;

[0024] Attachment Figure 8 This is a cross-sectional view of the improved external threaded nozzle body;

[0025] Attachment Figure 9 Schematic diagram of various postures during the printing process. DETAILED DESCRIPTION

[0026] The present invention will be further described below with reference to the accompanying drawings.

[0027] As attached Figures 1 to 9 The extrusion nozzle device of a food 3D printer shown in the figure includes a shell 3, a central conveying pipe 8, a spiral conveying rod 9, a motor 1, a motor support 2, a pan-tilt table 5 and a variable extrusion nozzle assembly 40; the XYZ displacement device of the 3D printing device can drive the shell 3 to perform XYZ displacement.

[0028] The a motor support 2 is fixed to the upper end of the shell 3, the central conveying pipe 8 is coaxially arranged in the shell 3, and the upper end of the central conveying pipe 8 is fixedly connected to the lower part of the a motor support 2. One side of the upper part of the central conveying pipe 8 is obliquely connected to the feed pipe 7, and the spiral conveying rod 9 rotates coaxially in the central conveying pipe 8. The a motor 1 is on the a motor support 2, and the a motor 1 drives the spiral conveying rod 9.

[0029] A pan-tilt posture adjustment device 4 is provided at the lower part of the shell 3. The pan-tilt 5 is below the central conveying pipe 8 and is installed on the pan-tilt posture adjustment device 4 (the pan-tilt 5 can also be directly fixedly connected to the shell 3 through a structural arm, and the printing effect deviates a little). The variable extrusion nozzle assembly 40 is installed on the pan-tilt 5. The discharge end 10 at the lower part of the central conveying pipe 8 is connected to the feed end of the variable extrusion nozzle assembly 40 through a hose 19. The shape of the hose 19 itself can adaptably change; the pan-tilt posture adjustment device 4 can adjust the posture of the pan-tilt 5; the pan-tilt posture adjustment device 4 adopts the existing mature multi-axis pan-tilt posture adjustment device, which will not be described in detail in this case. It can change the posture of the pan-tilt 5 in real time, thereby changing the printing angle of the variable extrusion nozzle assembly 40.

[0030] like Figure 1 、 2 As shown in Figure 3, a connecting hole 20 is provided at the axis of the pan-tilt head 5, and the upper end of the connecting hole 20 is connected to and fixedly connected with a hose connector 17, and the lower end of the hose 19 is fixed and connected to the hose connector 17; a b motor 18 is installed on the pan-tilt head 5 through the b motor support 6; the variable extrusion nozzle assembly 40 includes an adjusting gear 12 fixed on the output shaft 11 of the b motor 18, an externally threaded nozzle body 28 and an internally threaded floating cylinder shell 14; the internal thread of the internally threaded floating cylinder shell 14 is matched with the external thread of the externally threaded nozzle body 28, and an external gear ring 130 is fixedly provided on the outer coaxial center of the internally threaded floating cylinder shell 14, and the external gear ring 130 is meshed with the adjusting gear 12, as shown in Figure 3.Figure 5 The outer tooth ring 130 and the adjusting gear 12 can slide relative to each other along the axial direction. The upper end of the outer threaded nozzle body 28 is integrally connected with a nozzle fixing connector 13 coaxially. The integral structure formed by the outer threaded nozzle body 28 and the nozzle fixing connector 13 has a material guiding channel 43 penetrating from top to bottom. The upper end of the nozzle fixing connector 13 is fixedly connected with the lower end of the communication hole 20.

[0031] As Figure 4 , 5 , 6; the lower end of the outer threaded nozzle body 28 is integrally connected with an upper-thick-and-lower-thin discharging cone ring head 27. The lower end of the discharging cone ring head 27 is fixedly connected with a conical elastic material spraying head 16 coaxially. The conical elastic material spraying head 16 is made of elastic silica gel material. The conical elastic material spraying head 16 is a conical shell made of elastic material. The lower end of the conical elastic material spraying head 16 is provided with a material spraying port 32. The lower part of the conical elastic material spraying head 16 is circumferentially arranged with a plurality of segmentation joints 29 extending along the generatrix direction of the conical elastic material spraying head 16. The plurality of segmentation joints 29 divide the lower part of the conical elastic material spraying head 16 into a plurality of petals. When the pressure in the conical elastic material spraying head 16 increases without external constraints, the plurality of petals of the lower part of the conical elastic material spraying head 16 will expand like a flower, so as to expand the material spraying port 32. The lower end of the inner threaded floating cylinder shell 14 is integrally fixedly connected with a conical hard shell 15. The lower end of the conical hard shell 15 is coaxially provided with a constraint port 31 with a larger inner diameter than the material spraying port 32.

[0032] In the initial state, the conical outer wall formed by the conical elastic material spraying head 16 and the discharging cone ring head 27 is coaxially attached to the inner wall of the conical hard shell 15, and the lower end of the conical elastic material spraying head 16 protrudes downward from the constraint port 31, so that the constraint port 31 is sleeved on the outer wall of the lower end of the conical elastic material spraying head 16. The constraint port 31 sleeved on the outer wall of the lower end of the conical elastic material spraying head 16 inhibits the plurality of petals of the lower part of the conical elastic material spraying head 16 from expanding like a flower.

[0033] On the basis of the initial state, after the conical hard shell 15 moves downward relative to the lower end, the conical outer wall formed by the conical elastic material spraying head 16 and the discharging cone ring head 27 and the inner wall of the conical hard shell 15 form a ring-shaped cavity 30.

[0034] Working principle:

[0035] The food material is continuously fed into the central conveying pipe 8 through the feeding pipe 7, and the spiral conveying rod 9 conveys the food material in the central conveying pipe 8 downward, and then the food material is extruded into the guide channel 43 through the hose 19 and the hose joint 17, and then the paste food material in the guide channel 43 is continuously extruded into the conical elastic nozzle 16 under pressure, so that the pressure in the conical elastic nozzle 16 increases, and because the restraint port 31 sleeved on the outer wall of the lower end of the conical elastic nozzle 16 inhibits the petals of the lower part of the conical elastic nozzle 16 from “blooming” in the initial state, so that the restrained and expanded nozzle 32 sprays relatively small columnar paste food at the target printing position, and the restrained and expanded nozzle 32 has the characteristics of printing food more delicate and higher printing precision, and is suitable for outer layer printing of food, and can form more delicate patterns on the surface of the food, but this mode has the problem of low efficiency.

[0036] The inner layer of the food is printed, and the requirement for delicacy is reduced, and the requirement for efficiency is increased. When the inner layer of the food is prepared to be printed, the motor b 18 is controlled to drive the adjusting gear 12 to rotate the outer gear ring 130, and then the conical hard shell 15 is relatively lowered under the thread transmission, at this time, the restraint port 31 sleeved on the outer wall of the lower end of the conical elastic nozzle 16 is separated from the outer wall of the conical elastic nozzle 16, so that the restraint port 31 releases the restraint on the petals of the lower part of the conical elastic nozzle 16, at this time, the petals of the lower part of the conical elastic nozzle 16 are expanded in the form of “blooming” under the internal food pressure, so that the nozzle 32 is expanded, and the expanded nozzle 32 sprays relatively thick columnar paste food at the target printing position, and the expanded nozzle 32 has the characteristics of printing food more efficiently and higher printing efficiency, and is suitable for inner layer printing of food.

[0037] In the process of the “high-efficiency inner layer printing mode”, after the conical hard shell 15 is relatively lowered under the thread transmission, the conical outer wall formed by the conical elastic nozzle 16 and the discharge cone ring head 27 and the inner wall of the conical hard shell 15 forms a ring-shaped cavity 30, because the petals of the lower part of the conical elastic nozzle 16 are expanded in the form of “blooming”, the original several split seams 29 are widened and are easy to overflow paste food into the ring-shaped cavity 30, and then the upper part of the ring-shaped cavity 30 is also easy to be filled with food, once the upper part of the ring-shaped cavity 30 is blocked by food, and the time is long, it will harden, and then not only causes the risk of mildew and deterioration, but also hinders the relative displacement of the conical hard shell 15, and then affects the switching of the two modes.

[0038] In the improved embodiment, an optimization scheme is provided, and the following improvements are made on the basis of the above structure:

[0039] AsFigure 8 The conical elastic material spraying head 16 comprises an elastic material spraying head lower section 16.1 and an elastic material spraying head upper section 16.2, each of the split seams 29 is on the elastic material spraying head lower section 16.1; further comprising a conical ring wall 25 coaxially and integrally connected to the lower end of the material discharging conical ring head 27; the inner ring of the upper end of the elastic material spraying head upper section 16.2 is fixedly and sealingly connected to the outer wall surface of the conical ring wall 25 through a first ring sealing glue joint 16a; the inner ring of the lower end of the elastic material spraying head upper section 16.2 is fixedly and sealingly connected to the outer wall surface of the conical ring wall 25 through a second ring sealing glue joint 16b, so that a conical ring gap is formed between the inner wall surface of the elastic material spraying head upper section 16.2 and the outer wall surface of the conical ring wall 25; the first ring sealing glue joint 16a and the second ring sealing glue joint 16b are both epoxy resin glue joint modes; the wall body of the integrated structure formed by the material discharging conical ring head 27 and the conical ring wall 25 is internally provided with a gas conveying channel 26, the upper gas inlet end of the gas conveying channel 26 is connected to the gas outlet end of a gas pump, and the lower end of the gas conveying channel 26 is communicated with the conical ring gap formed between the inner wall surface of the elastic material spraying head upper section 16.2 and the outer wall surface of the conical ring wall 25;

[0040] On the basis of the improvement, the process of changing from the fine printing mode to the inner layer mode of high-efficiency food printing is as follows:

[0041] When printing the inner layer of food, the requirement for fineness is reduced, and the requirement for efficiency is increased. When preparing to print the inner layer of food, first, the motor 1 is paused to pause the supply process of the food raw material, then the b motor 18 is controlled to rotate forward, so that the outer gear ring 130 is driven to rotate by the adjusting gear 12, and then the conical hard shell 15 is relatively lowered under the threaded transmission. At this time, the restraint port 31 originally sleeved on the outer wall of the lower end of the conical elastic material spraying head 16 is separated from the outer wall of the conical elastic material spraying head 16, so that the restraint port 31 releases the restraint on the lower part of the petals of the conical elastic material spraying head 16. At this time, the conical outer wall formed by the conical elastic material spraying head 16 and the material outlet conical ring head 27 together and the inner wall of the conical hard shell 15 form an annular cavity 30. At this time, the air pump is used to press air into the air supply channel 26, so that the pressure in the conical annular gap between the inner wall surface of the upper segment 16.2 of the elastic material spraying head and the outer wall surface of the conical ring wall 25 is increased, and then the upper segment 16.2 of the elastic material spraying head is inflated outward. The outer wall surface of the inflated elastic material spraying head upper segment 16.2 contacts the inner wall surface of the conical hard shell 15, thereby cutting off or filling the annular cavity 30. At this time, if the a motor 1 is restarted to restore the supply of food raw materials, the pressure in the conical elastic material spraying head 16 increases, and the lower part of the petals of the conical elastic material spraying head 16 will expand in a “flower” shape, thereby expanding the material spraying port 32, and the expanded material spraying port 32 sprays relatively coarse columnar paste-shaped food at the target printing position. The expanded material spraying port 32 has the characteristics of printing food more efficiently and higher printing efficiency, and is suitable for printing the inner layer of food. However, since the annular cavity 30 has been cut off and filled by the outwardly inflated elastic material spraying head upper segment 16.2, the problem of the annular cavity 30 being filled with food in the upper part by the overflow of paste-shaped food from the widened several segmentation seams 29 is avoided.

[0042] When it is necessary to return to the fine mode, the pressure in the air supply channel 26 is first released, and then the b motor 18 is controlled to reverse.

[0043] The above is only a preferred embodiment of the present application. It should be noted that those skilled in the art can make some improvements and refinements without departing from the principles of the present application, and these improvements and refinements should also be considered within the scope of protection of the present application.

Claims

1. An extrusion nozzle device for a food 3D printer, characterized by: The shell (3), the central conveying pipe (8), the spiral conveying rod (9), the a motor (1), the holder (5) and the variable extrusion nozzle assembly (40) are included. The b motor (18) is installed on the holder (5); the variable extrusion nozzle assembly (40) includes the adjusting gear (12) fixed on the output shaft (11) of the b motor (18), the outer thread nozzle body (28) and the inner thread floating cylinder shell (14); the inner thread of the inner thread floating cylinder shell (14) is threadedly matched with the outer thread of the outer thread nozzle body (28). The outer thread nozzle body (28) is integrally and communicatively provided with the discharging cone ring head (27) with the upper thick and the lower thin at the lower end; the discharging cone ring head (27) is coaxially and fixedly connected with the conical elastic material head (16) at the lower end; the conical elastic material head (16) is a conical shell body made of elastic material; the lower end of the conical elastic material head (16) is provided with the discharging port (32); the lower part of the conical elastic material head (16) is circumferentially and arrayed with a plurality of segmentation joints (29); each segmentation joint (29) extends along the conical generatrix of the conical elastic material head (16); the lower part of the conical elastic material head (16) is divided into a plurality of petal bodies by the segmentation joints (29); when the pressure in the conical elastic material head (16) increases without external constraints, the plurality of petal bodies of the lower part of the conical elastic material head (16) will expand like a flower, so as to expand the discharging port (32). The lower end of the inner thread floating cylinder shell (14) is integrally and fixedly connected with the conical hard shell (15); the lower end of the conical hard shell (15) is coaxially provided with the constraint port (31) with the inner diameter larger than the discharging port (32). In the initial state, the conical outer wall formed by the conical elastic material head (16) and the discharging cone ring head (27) is coaxially and attached to the inner wall of the conical hard shell (15); the lower end of the conical elastic material head (16) protrudes downward out of the constraint port (31), so that the constraint port (31) is sleeved on the outer wall of the lower end of the conical elastic material head (16); the constraint port (31) sleeved on the outer wall of the lower end of the conical elastic material head (16) restrains the plurality of petal bodies of the lower part of the conical elastic material head (16) from expanding like a flower. The conical elastic material head (16) includes the elastic material head lower segment (16.1) and the elastic material head upper segment (16.2); each segmentation joint (29) is on the elastic material head lower segment (16.1); the conical ring wall (25) integrally connected with the lower end of the discharging cone ring head (27); the inner circle of the upper end of the elastic material head upper segment (16.2) is fixedly and sealingly connected with the outer wall surface of the conical ring wall (25) through the first circle of sealing joint parts (16a); the inner circle of the lower end of the elastic material head upper segment (16.2) is fixedly and sealingly connected with the outer wall surface of the conical ring wall (25) through the second circle of sealing joint parts (16b), so that the inner wall surface of the elastic material head upper segment (16.2) and the outer wall surface of the conical ring wall (25) form the conical ring gap; the wall body of the integrated structure formed by the discharging cone ring head (27) and the conical ring wall (25) is provided with the gas conveying channel (26); the upper gas inlet end of the gas conveying channel (26) is connected with the gas outlet end of the gas pump; the lower end of the gas conveying channel (26) is communicated with the conical ring gap.

2. The extrusion nozzle device of a food 3D printer according to claim 1, characterized in that: On the basis of the initial state, the conical hard shell (15) is relatively moved downward, the constraint port (31) releases the constraint on the petals of the lower part of the conical elastic material spraying head (16), and the conical body formed by the conical elastic material spraying head (16) and the material outlet conical ring head (27) forms an annular cavity (30) between the inner wall of the conical hard shell (15).

3. The extrusion nozzle device of a food 3D printer according to claim 1, characterized in that: The central conveying pipe (8) is located in the shell (3), one side of the upper part of the central conveying pipe (8) is communicated with the feeding pipe (7), the spiral conveying rod (9) rotates coaxially in the central conveying pipe (8), and the motor (1) is drivingly connected with the spiral conveying rod (9); the holder (5) is located below the central conveying pipe (8); the variable extrusion nozzle assembly (40) is installed on the holder (5), and the outlet end (10) of the lower part of the central conveying pipe (8) is communicated and connected with the feeding end of the variable extrusion nozzle assembly (40) through the hose (19); The holder (5) is provided with a through communication hole (20) penetrating through the upper and lower parts, the upper end of the communication hole (20) is communicated and fixedly connected with the hose joint (17), and the lower end of the hose (19) is communicated with the hose joint (17).

4. The extrusion nozzle device of a food 3D printer according to claim 1, characterized in that: The outer spline (130) is fixedly arranged coaxially outside the inner thread floating cylinder shell (14), the outer spline (130) is engaged with the adjusting gear (12), and the outer spline (130) and the adjusting gear (12) can relatively slide in the axial direction; the nozzle fixed joint (13) is integrally connected coaxially at the upper end of the outer thread nozzle body (28), the inside of the integrated structure formed by the outer thread nozzle body (28) and the nozzle fixed joint (13) is a material guiding channel (43) penetrating through the upper and lower parts, and the upper end of the nozzle fixed joint (13) is fixedly and communicatedly connected with the lower end of the communication hole (20).

Images