A negative pressure filling head

Abstract

The application relates to the technical field of food packaging, in particular to a negative pressure filling head which comprises a base structure, a filling head fixedly connected with the base structure, a gas flow channel and a powder flow channel arranged in the filling head, a through portion arranged between the gas flow channel and the powder flow channel, the through portion allowing the gas to pass through and blocking the powder material, a sliding sealing structure which is slidingly sleeved outside the filling head and sealingly attached to the filling head, a guide rod structure which is fixedly connected with the base structure at one end and fixedly connected with the sliding sealing structure at the other end, and the sliding sealing structure is sealingly attached to the open end of a tank body to form a sealed space in the tank body, and the guide rod structure provides stable extrusion force for the sliding sealing structure during the movement of the tank body relative to the base structure. The application provides the negative pressure filling head which can effectively improve the granularity of the finally filled material and the filling accuracy.

Description

Technical Field

[0001] This invention relates to the field of food packaging technology, and in particular to a negative pressure filling head. Background Technology

[0002] Negative pressure filling is one of the main filling methods for powder materials. It achieves contact sealing by moving the tank containing the powder to be filled relative to the sealing structure on the negative pressure filling head, thereby forming a sealed space inside the tank. By controlling the valve, the gas inside the tank is extracted to form a negative pressure, and the material in the hopper is guided into the container through the negative pressure filling head by the pressure difference.

[0003] Currently, by controlling the degree of negative pressure, filling time, and effective filling volume of the container, the filling weight can be controlled, and the container returns to normal pressure after filling. However, the filling effect of the aforementioned negative pressure filling head is often affected by the following problems during use:

[0004] On the one hand, existing negative pressure filling heads are equipped with a shut-off mechanism that completely shuts off the outlet of the powder flow channel after the filling process is completed to prevent material dripping and scattering. This method is compatible with materials of different flowability. However, the shut-off mechanism in this method needs to operate within the material, which can damage the particle size of the material during the operation.

[0005] On the other hand, during the filling process, the open end of the tank is sealed by the sealing structure set by the negative pressure filling head. However, the existing sealing method is only suitable for working conditions where the position of the tank relative to the negative pressure filling head is fixed during the filling process. Given the fluctuations in mechanical structure and raw material prices, existing intelligent production lines often require dynamic adjustment of the height of the negative pressure filling head relative to each tank. This allows for real-time adjustment of the filling volume based on actual fluctuations, ensuring filling accuracy through a feedback mechanism. Under this requirement, the existing sealing method, which seals the tank by applying gas pressure to the sealing structure through a gas buffer space, experiences pressure fluctuations within the gas buffer space during the position adjustment process between the negative pressure filling head and the tank. This can potentially lead to insufficient sealing pressure or excessive compression of the tank.

[0006] Given the aforementioned problems, it is difficult to further improve the current filling effect. Summary of the Invention

[0007] This invention provides a negative pressure filling head, which can effectively solve the problems in the background art.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0009] A negative pressure filling head, comprising:

[0010] Basic structure;

[0011] The filling head is fixedly connected to the foundation structure and has a gas flow channel and a powder flow channel inside. A through part is provided between the gas flow channel and the powder flow channel, and the through part allows gas to pass through while blocking the powder material.

[0012] A sliding sealing structure is slidably fitted onto the outside of the filling head and seals tightly against the filling head;

[0013] The guide rod structure has one end fixedly connected to the base structure and the other end fixedly connected to the sliding sealing structure;

[0014] When the sliding sealing structure is sealed and fitted with the open end of the tank, a sealed space is formed inside the tank. The guide rod structure provides a stable compressive force to the sliding sealing structure during the movement of the tank relative to the base structure.

[0015] Furthermore, the guide rod structure is a magnetic spring guide rod.

[0016] Furthermore, the through section includes a number of holes, the mesh size of which is determined according to the mesh size of the powder material.

[0017] Furthermore, the method for determining the mesh size specification of the holes includes:

[0018] Set a reference content;

[0019] For powder materials, the range of mesh sizes from large to small mesh is determined to be the range of content of the reference content.

[0020] Determine the lower limit of the mesh count specification range, and use the lower limit to determine the mesh count specification of the hole position.

[0021] Furthermore, the mesh size specification of the hole position is determined by the lower limit value, specifically by setting the mesh size specification of the hole position to 1.5 to 2.5 times the lower limit value.

[0022] Furthermore, the gas flow channel includes a material interception negative pressure channel and a filling negative pressure channel;

[0023] The negative pressure filling channel is open at its end toward the inside of the tank;

[0024] The through section is located between the material interception negative pressure channel and the powder flow channel, and the end of the material interception negative pressure channel facing the inside of the tank is sealed.

[0025] Furthermore, the filling head includes an inner tube, a middle tube, and an outer tube arranged sequentially from the inner ring to the outer ring, and the through portion is located at the end of the inner tube;

[0026] The inner tube is internally connected, forming the powder flow channel;

[0027] A material-cutting negative pressure channel is formed between the middle tube body, the inner tube body, and the through part, and the end of the material-cutting negative pressure channel facing the inside of the tank body is sealed.

[0028] A filling negative pressure channel is formed between the middle tube and the outer tube, and the filling negative pressure channel is open at the end facing the inside of the tank.

[0029] Furthermore, it also includes wire mesh;

[0030] The mesh is disposed at the outlet of the powder flow channel and includes several hollow areas for feeding, as well as connecting bridges that separate the hollow areas. The connecting bridges block the powder material after feeding is completed.

[0031] Furthermore, it also includes a filter screen;

[0032] The filter screen is located at the open end of the filling negative pressure channel and is used to filter the powder inside the tank.

[0033] Furthermore, it also includes ring structures;

[0034] The mesh is fitted and installed at the end of the through section, and the outer edge of the mesh seals the end of the material cutting negative pressure channel toward the inside of the tank.

[0035] The filter screen is at least in contact with the outer tube and the mesh, and the ring structure is fixedly connected to the outer tube and provides the required compressive force to the filter screen for contact.

[0036] The filter screen provides a squeezing force to the mesh sheet to conform to the end of the through section.

[0037] The technical solution of this invention can achieve the following technical effects:

[0038] This invention provides a negative pressure filling head that effectively improves both the particle size and filling accuracy of the final filled material. The negative pressure filling head eliminates the need for a shut-off mechanism, thus avoiding damage to the material particle size. Material shut-off is achieved through a through-hole. After feeding, when the gas flow channel obtains a negative pressure for material shut-off, it generates suction on the powder material in the powder flow channel through the through-hole. This suction adsorbs a layer of material at the location corresponding to the through-hole on the inner wall of the powder flow channel. The material at this location becomes compacted and difficult to fall, thereby achieving the purpose of material shut-off.

[0039] Furthermore, the guide rod structure connects the base structure and the sliding seal structure, and provides a stable extrusion force to the sliding seal structure during the movement of the tank relative to the base structure. During implementation, the guide rod structure ensures that the extrusion force reaches the required value. During the filling process, the stable extrusion force keeps the sealing environment established inside the tank stable. In intelligent production lines where the height of the negative pressure filling head relative to the tank needs to be dynamically adjusted, this stability will play a greater technical advantage. The dynamically stable sealing environment can adapt to the dynamic changes in the filling volume and ensure the accuracy of the filling volume. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 and Figure 2 These are schematic diagrams of the negative pressure filling head at different angles.

[0042] Figure 3 Top view of the negative pressure filling head;

[0043] Figure 4 For negative pressure filling head in Figure 3 Sectional view at point AA;

[0044] Figure 5 For negative pressure filling head in Figure 3 Sectional view at point BB;

[0045] Figure 6 A flowchart illustrating the method for determining the mesh size specification of the hole position;

[0046] Figure 7 An exploded view of a negative pressure filling head;

[0047] Figure 8 for Figure 4 A magnified view of a section at point C;

[0048] Figure 9 This is a schematic diagram of the mesh structure;

[0049] Figure 10 for Figure 5 A magnified view of a section at point D;

[0050] Figure 11 for Figure 7 A magnified view of a section at point E in the middle;

[0051] Figure descriptions: 1. Basic structure; 11. Raised edge structure; 2. Filling head; 21. Gas flow channel; 21a. Material interception negative pressure channel; 21b. Filling negative pressure channel; 22. Powder flow channel; 23. Through section; 24. Inner tube; 25. Middle tube; 26. Outer tube; 3. Sliding sealing structure; 31. First sealing surface; 32. Second sealing surface; 4. Guide rod structure; 5. Mesh; 51. Hollowed-out area; 52. Connecting bridge; 6. Filter screen; 61. Mesh body; 62. Frame; 7. Ring structure. Detailed Implementation

[0052] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0053] Example 1

[0054] like Figures 1-5 As shown, a negative pressure filling head includes:

[0055] The base structure 1 is connected to the hopper when the negative pressure filling head is installed, receiving powder material from the hopper. The filling head 2 is fixedly connected to the base structure 1 and has a gas flow channel 21 and a powder flow channel 22 inside. In this embodiment, the powder material flowing in the powder flow channel 22 flows through the base structure 1. A through part 23 is provided between the gas flow channel 21 and the powder flow channel 22, which allows gas to pass through while blocking the powder material. The sliding sealing structure 3 is slidably fitted outside the filling head 2 and is sealed and fitted with the filling head 2. The guide rod structure 4 is fixedly connected at one end to the base structure 1 and at the other end to the sliding sealing structure 3. When the sliding sealing structure 3 is sealed and fitted with the open end of the tank, a sealed space is formed inside the tank. During the movement of the tank relative to the base structure 1, the guide rod structure 4 provides a stable extrusion force to the sliding sealing structure 3.

[0056] In this embodiment, a negative pressure filling head is provided that can effectively improve both the particle size of the final filled material and the accuracy of the filling amount.

[0057] Specifically, in this embodiment, the negative pressure filling head omits the shut-off mechanism, thereby avoiding damage to the particle size of the material. The material shut-off is achieved through the through-hole 23, which is implemented as follows:

[0058] When the feeding is finished, when the gas flow channel 21 obtains the negative pressure for material interception based on the purpose of material interception, it will generate suction force on the powder material in the powder flow channel 22 through the through part 23. This suction force adsorbs a layer of material at the position corresponding to the through part 23 on the inner wall of the powder flow channel 22. The material at this position becomes compact and difficult to fall, thereby achieving the purpose of material interception.

[0059] In addition, in this embodiment, the base structure 1 and the sliding sealing structure 3 are connected by the guide rod structure 4, and a stable extrusion force is provided to the sliding sealing structure 3 during the movement of the tank relative to the base structure 1. During implementation, the guide rod structure 4 can make the extrusion force obtain the required value. During the filling process, the stable extrusion force ensures that the sealing environment established inside the tank remains stable. In intelligent production lines where the height of the negative pressure filling head relative to the tank needs to be dynamically adjusted, this stability will play a greater technical advantage. The dynamically stable sealing environment can adapt to the dynamic changes in the filling amount and ensure the accuracy of the filling amount.

[0060] In this preferred embodiment, the guide rod structure 4 is a magnetic spring guide rod. Two to four magnetic spring guide rods can be evenly distributed, thus ensuring a uniform distribution of the extrusion force application points. Taking the sliding sealing structure 3 sealing with the can body through the first sealing surface 31 as an example, the evenly distributed extrusion force application points ensure uniform force distribution across the first sealing surface 31. Taking the filling head 2 maintaining a fixed position during filling while the empty can moves vertically for position adjustment as an example, when the empty can rises to different heights relative to the filling head 2, the magnetic spring guide rods can ensure that the sealing force applied to the empty can remains consistent and does not change with height.

[0061] Example 2

[0062] Based on Embodiment 1, the through section 23 has been structurally optimized in this embodiment, as follows: The through section 23 includes several holes, and the mesh size of the holes is determined according to the mesh size of the powder material.

[0063] In this embodiment, by establishing the above-mentioned correlation, when filling different types of powder materials, the mesh size of the pores can be reasonably adjusted to effectively achieve the purpose of blocking the powder materials by allowing gas to pass through the through-hole 23.

[0064] During implementation, such as Figure 7 As shown, the location where the through section 23 is set can be processed and installed as an independent component, which facilitates adaptive replacement according to the specific filling requirements of the powder material, and also facilitates processing and cleaning during subsequent use.

[0065] As a preferred embodiment, such as Figure 6 As shown, the method for determining the mesh size specification of the hole position includes:

[0066] A1: Set a reference content; in this embodiment, a reference content of 0.1% is used as an example;

[0067] A2: For powder materials, determine the range of mesh sizes for which the content is a reference content in the direction from large mesh to small mesh; for example, in this embodiment, the range of mesh sizes for powder materials with a content of 0.1% in the direction from large mesh to small mesh is 400 mesh or larger.

[0068] A3: Determine the lower limit of the mesh count specification range, and then determine the mesh count specification for each hole position based on this lower limit. Corresponding to step A2, the lower limit value mentioned in this step is 400 mesh, so the mesh count specification for each hole position is determined based on this value.

[0069] As a further preferred embodiment, the mesh size specification of the hole position is determined by a lower limit value. Specifically, the mesh size specification of the hole position is set to 1.5 to 2.5 times the lower limit value. For example, if the lower limit value is 400 mesh and the mesh size specification of the hole position is set to twice the lower limit value, then the hole position data specification is 800 mesh, that is, the through part 23 is set to be an 800 mesh porous tube; as another example, if the lower limit value is 300 mesh and the mesh size specification of the hole position is set to 2.5 times the lower limit value, then the hole position data specification is 750 mesh, that is, the through part 23 is set to be a 750 mesh porous tube.

[0070] The optimization method adopted for the through-hole 23 in this embodiment is directly related to the particle size distribution of the powder material. It uses the critical lower limit value of specific small-sized particles in the material as a benchmark and achieves scientific selection of pore size through reasonable multiplication factor setting. This ensures that the pore size is small enough to effectively block most material particles, especially critical-sized particles, and reliably form a tight "material sealing layer" under negative pressure suction to intercept the material. On the other hand, it also ensures that the pore size is large enough relative to the critical value of the smallest particle to avoid excessive blockage of pores by small particles. This ensures that the negative pressure gas can pass smoothly through the through-hole 23 to generate the required adsorption force, thereby improving the reliability and consistency of negative pressure adsorption interception and avoiding material leakage due to excessively large pore size, or airflow obstruction, insufficient adsorption force, or easy blockage due to excessively small pore size.

[0071] In this embodiment, the orifice positions are scientifically set, and the negative pressure adsorption interception is optimized by precisely matching the material characteristics, which significantly improves the equipment's versatility, adaptability and switching efficiency for different materials.

[0072] Example 3

[0073] Based on Embodiment 1, this embodiment provides a dual-channel gas flow channel 21. Specifically, the gas flow channel 21 includes a material-cutting negative pressure channel 21a and a filling negative pressure channel 21b. The filling negative pressure channel 21b is open at its end facing the inside of the tank, allowing gas inside the tank to flow outward to form the required filling negative pressure, and allowing external gas to flow into the tank to achieve a state of communication with the atmosphere. A through-hole 23 is disposed between the material-cutting negative pressure channel 21a and the powder flow channel 22. The end of the material-cutting negative pressure channel 21a facing the inside of the tank is sealed. After the material is discharged and the material-cutting negative pressure is obtained, the material-cutting negative pressure channel 21a provides suction to the powder material in the powder flow channel 22 through the through-hole 23. The material-cutting negative pressure channel 21a also allows external gas to enter to achieve a state of communication with the atmosphere, thereby releasing the blockage of the powder material.

[0074] In this embodiment, the negative pressure function is controlled in stages by optimizing the dual channels of the gas flow channel 21:

[0075] The filling negative pressure channel 21b constructs the main filling negative pressure environment. The open end design directly connects to the internal space of the tank. By evacuating air, the overall filling negative pressure environment is quickly established in the tank. The gas in the tank can be quickly removed by the annular channel with an appropriately increased flow cross section, which significantly improves the filling efficiency. When the filling is finished, it is switched to the air inlet channel to introduce gas into the tank to achieve depressurization.

[0076] The material interception negative pressure channel 21a is specifically designed for precise material interception control. The end sealing and through-hole structure 23 are designed to generate an adsorption layer on the inner wall of the powder channel. The closed end structure concentrates the negative pressure energy in the through-hole area 23, which can generate a relatively concentrated adsorption force at a precise position on the inner wall of the powder channel. The concentrated local suction ensures that a dense material sealing layer is formed quickly and stably on the inner wall of the powder channel, ensuring the accuracy of the filling amount.

[0077] In this embodiment, the two negative pressure channels are physically isolated, which allows for optimization of the parameters of the filling negative pressure channel 21b and the material cutting negative pressure channel 21a, achieving the best balance between global efficiency and local accuracy.

[0078] As one specific structural implementation of this embodiment, such as Figure 7 , 8As shown in Figures 10 and 11, the filling head 2 includes an inner tube 24, a middle tube 25, and an outer tube 26 arranged sequentially from the inner ring to the outer ring. A through section 23 is provided at the end of the inner tube 24. The inner tube 24 is internally connected to form a powder flow channel 22. A material interception negative pressure channel 21a is formed between the middle tube 25, the inner tube 24, and the through section 23. The end of the material interception negative pressure channel 21a facing the inside of the tank is sealed. After the material is discharged and the material interception negative pressure is obtained, the through section 23 provides suction to the powder material in the powder flow channel 22. The material interception negative pressure channel 21a also allows external gas to enter to achieve a state of communication with the atmosphere. A filling negative pressure channel 21b is formed between the middle tube 25 and the outer tube 26. The end of the filling negative pressure channel 21b facing the inside of the tank is open to allow gas inside the tank to flow outward to form the required filling negative pressure, and to allow external gas to flow into the tank to achieve a state of communication with the atmosphere.

[0079] As a further preferred embodiment, the base structure 1 includes a pipe body connected to the hopper, the pipe body being connected to the powder flow channel, and a protruding edge structure 11 extending outward from the end. The inner pipe body 24, the middle pipe body 25, and the outer pipe body 26 are all fixedly connected to the base structure 1 through the protruding edge structure 11.

[0080] In this preferred embodiment, a specific structural form of the filling head 2 that achieves the aforementioned dual-channel configuration is provided. In this preferred embodiment, the raised edge structure 11 of the base structure 1 serves as the sole reference, simultaneously connecting the inner tube 24, the middle tube 25, and the outer tube 26. All components are installed with the raised edge structure 11 as the positioning reference, completely avoiding the accumulation of related deviations caused by multi-layered sleeve nesting. The annular gap accuracy of the material cutting negative pressure channel 21a and the filling negative pressure channel 21b is controllable, ensuring uniform airflow distribution and improving negative pressure stability. At the same time, the overall resistance of the filling head 2 to external loads is enhanced, such as tank off-center load collisions, reducing the risk of deformation.

[0081] During implementation, different tubes can be processed based on different special processing requirements, including but not limited to the sliding sealing requirements of the outer tube 26 and the second sealing surface 32 on the sliding sealing structure 3, and the processing requirements of the through portion 23 of the inner tube 24. In this embodiment, the through portion 23 is provided at the end of the inner tube 24. This includes processing the position of the through portion 23 as an independent component as described in Embodiment 2, and then fixing it to the inner tube 24. It also includes making the through portion 23 a part of the inner tube 24, and obtaining it directly by processing a hole of a set mesh size on the inner tube 24. All of the above methods are within the protection scope of this invention.

[0082] To further ensure the material cutting effect based on the through section 23, as a preferred embodiment of the above, such as Figures 7-10As shown, the negative pressure filling head also includes a mesh 5; the mesh 5 is set at the outlet of the powder flow channel 22, including several hollow areas 51 for feeding, and connecting bridges 52 that separate the hollow areas 51. The connecting bridges 52 block the powder material after feeding is finished.

[0083] In this preferred embodiment, the perforated area 51 in the mesh 5 allows the powder material to be fed through the perforated area 51 under the negative pressure inside the tank. During the material shut-off stage, the material becomes compacted due to adsorption by the through-hole 23, and the connecting bridge 52 further ensures a better material shut-off effect. In this preferred embodiment, the perforated area 51 can preferably be arranged in a single-ring or double-ring configuration, and the number can be selected based on the flow area of ​​the discharge port and the parameters of the powder material, with a possible structure of 3 to 10 holes.

[0084] As a preferred embodiment, the negative pressure filling head also includes a filter screen 6; the filter screen 6 is disposed at the open end of the filling negative pressure channel 21b and is used to filter the powder in the tank to prevent the powder material from flying outward from the filling negative pressure channel 21b during the filling process.

[0085] To improve the assembly efficiency and structural stability of the entire negative pressure filling head, in this embodiment, the negative pressure filling head preferably also includes a ring structure 7; the mesh 5 is fitted and installed at the end of the through part 23, and the end of the material cutting negative pressure channel 21a facing the inside of the tank is blocked by the outer edge; the filter screen 6 is fitted at least with the outer tube 26 and the mesh 5, the ring structure 7 is fixedly connected to the outer tube 26, and provides the required extrusion force to the filter screen 6 for fitting; the filter screen 6 provides the extrusion force to the mesh 5 for fitting at the end of the through part 23.

[0086] As a further preferred embodiment, the end of the through portion 23 can be recessed inward relative to the ends of the middle tube 25 and the outer tube 26, forming a flush surface with the ends of the middle tube 25 and the outer tube 26 after the mesh 5 is installed. This method can achieve the radial positioning of the mesh 5. The filter screen 6 is attached to the outer tube 26, the middle tube 25 and the mesh 5 respectively through the flush surface. The mesh 5 can be provided with a boss in the middle, and the inner ring of the filter screen 6 is positioned in the radial direction by attaching with the boss.

[0087] For the assembly of the negative pressure filling head with the above-mentioned structure, after the through part 23 is installed in place relative to the middle tube 25 and the outer tube 26, the mesh 5 is installed first. This process does not require fixing the mesh 5; it can simply be placed in place. Of course, if additional fixing methods are added to further ensure the fixing effect, this is also within the scope of protection of this invention. For example, the mesh 5 can be fixed relative to the through part 23 and / or the middle tube 25 by adhesive bonding. Then, the filter screen 6 is installed. When a flush surface is formed, the filter screen 6 can be a simple sheet structure. The positioning method during installation is simple. Similarly, this is the most efficient method, and there is no need to fix the filter screen 6; it can simply be placed in place. Finally, the ring structure 7 is installed relative to the outer tube 26. Adhesive bonding, threaded fixing, snap-fit ​​fixing, etc., are all within the scope of protection of this invention. After fixing, the mesh 5 and the filter screen 6 can be fixed simultaneously by the transmission of extrusion pressure, and the sealing of the material cutting negative pressure channel 21a is also achieved.

[0088] In this preferred embodiment, the filter screen 6 needs to have sufficient rigidity to achieve fixation under compression through shape stability, while simultaneously providing compressive force to the mesh 5. Therefore, it can be a one-piece structure, or a separate structure can be used when the rigidity of the filter part is insufficient; for example... Figure 7 As shown, the structure is divided into a mesh body 61 and a frame 62. The frame 62 is rigid by an inner ring that provides compressive force to the mesh 5, an outer ring that bears the compressive force of the ring structure 7, and the connecting part between the inner and outer rings, while the mesh body 61 performs the filtering function.

[0089] Those skilled in the art should understand that this invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to this invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A negative pressure filling head, characterized in that, include: Basic structure; The filling head is fixedly connected to the foundation structure and has a gas flow channel and a powder flow channel inside. A through part is provided between the gas flow channel and the powder flow channel, and the through part allows gas to pass through while blocking the powder material. A sliding sealing structure is slidably fitted onto the outside of the filling head and seals tightly against the filling head; The guide rod structure has one end fixedly connected to the base structure and the other end fixedly connected to the sliding sealing structure; When the sliding sealing structure is sealed and fitted with the open end of the tank, a sealed space is formed inside the tank. The guide rod structure provides a stable compressive force to the sliding sealing structure during the movement of the tank relative to the base structure. The gas flow channel includes a material interception negative pressure channel and a filling negative pressure channel; The negative pressure filling channel is open at its end toward the inside of the tank; The through section is located between the material interception negative pressure channel and the powder flow channel, and the end of the material interception negative pressure channel facing the inside of the tank is sealed.

2. The negative pressure filling head according to claim 1, characterized in that, The guide rod structure is a magnetic spring guide rod.

3. The negative pressure filling head according to claim 1, characterized in that, The through section includes several holes, the mesh size of which is determined according to the mesh size of the powder material.

4. The negative pressure filling head according to claim 3, characterized in that, The method for determining the mesh size specification of the hole position includes: Set a reference content; For powder materials, the range of mesh sizes from large to small mesh is determined to be the range of content of the reference content. Determine the lower limit of the mesh count specification range, and use the lower limit to determine the mesh count specification of the hole position.

5. The negative pressure filling head according to claim 4, characterized in that, The mesh size specification of the hole position is determined by the lower limit value, specifically by setting the mesh size specification of the hole position to 1.5 to 2.5 times the lower limit value.

6. The negative pressure filling head according to claim 1, characterized in that, The filling head includes an inner tube, a middle tube, and an outer tube arranged sequentially from the inner ring to the outer ring, and the through portion is located at the end of the inner tube. The inner tube is internally connected, forming the powder flow channel; A material-cutting negative pressure channel is formed between the middle tube body, the inner tube body, and the through part, and the end of the material-cutting negative pressure channel facing the inside of the tank body is sealed. A filling negative pressure channel is formed between the middle tube and the outer tube, and the filling negative pressure channel is open at the end facing the inside of the tank.

7. The negative pressure filling head according to claim 6, characterized in that, It also includes mesh panels; The mesh is disposed at the outlet of the powder flow channel and includes several hollow areas for feeding, as well as connecting bridges that separate the hollow areas. The connecting bridges block the powder material after feeding is completed.

8. The negative pressure filling head according to claim 7, characterized in that, It also includes a filter screen; The filter screen is located at the open end of the filling negative pressure channel and is used to filter the powder inside the tank.

9. The negative pressure filling head according to claim 8, characterized in that, It also includes ring structures; The mesh is fitted and installed at the end of the through section, and the outer edge of the mesh seals the end of the material cutting negative pressure channel toward the inside of the tank. The filter screen is at least in contact with the outer tube and the mesh, and the ring structure is fixedly connected to the outer tube and provides the required compressive force to the filter screen for contact. The filter screen provides a squeezing force to the mesh sheet to conform to the end of the through section.

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