A dry ice deburring device for circuit boards

Abstract

A dry ice deburring device for circuit boards belongs to the technical field of circuit board processing through the spraying of particulate materials. It includes a base with a lower spray section and a lower pressing mechanism. The lower pressing mechanism has a lifting and movable lower pressing frame, and the lower pressing frame has an upper drawing section located directly above the lower spray section. A vertical mounting plate is fixed to the base, and the vertical mounting plate has multiple mixing sections. The mixing sections are connected to the lower spray section via a fourth pipe. Multiple containers are connected to the upper drawing section, and each container is connected to an air pump via a first pipe. The mixing sections are connected to an air supply pump via a second pipe and also to a dry ice particle supply pump via a third pipe. The application of this device can improve the effect and efficiency of deburring the inner walls of circuit board holes.

Description

Technical Field

[0001] This invention relates to the field of circuit board processing technology through the spraying of particulate materials, and more particularly to a circuit board dry ice deburring device. Background Technology

[0002] To facilitate connections between layers and the insertion of electronic components, circuit boards are often machined with multiple through-holes and blind vias of varying sizes using a router. During machining, wear and retraction of the router tool can create burrs of different shapes, such as needle-like, whisker-like, spherical, and rod-like, on the inner walls of these through-holes and blind vias. These burrs mostly appear at the hole openings or inside the holes. These burrs are easily ground into the holes during circuit board grinding, forming difficult-to-remove internal burrs that affect the diameter of through-holes and blind vias. During the dry film lamination process, excessively large burrs can puncture the dry film, resulting in a "no copper in the hole" defect, causing metallization failure, electrical connection interruption, and uneven copper deposition thickness on the inner walls of the holes during copper plating, further affecting the electrical connection performance of the circuit board.

[0003] Common deburring methods include: 1) controlling processing parameters to fundamentally reduce burr generation; 2) evaluating and promptly replacing drill bits to avoid burr formation due to dulling; 3) post-processing deburring using lasers; 4) plasma deburring through holes; and 5) manual deburring. The first and second methods are the main means of reducing burrs and play an important role in production, but neither can completely eliminate burrs. The third method, laser deburring, has significant advantages for large-diameter through-holes; however, it cannot deburr blind holes, and when processing small-diameter through-holes, it often results in large burn-off areas, thus limiting its applicability. Furthermore, because deburring is done hole-by-hole, it suffers from low processing efficiency. The fourth method has significant advantages in PCB surface cleaning, but its effectiveness in deburring is limited. The fifth method is inefficient and its processing effect is difficult to control. Summary of the Invention

[0004] This invention provides a dry ice deburring device for circuit boards to overcome the shortcomings of the prior art and solve the problems of poor deburring effect and low efficiency of circuit board hole wall.

[0005] In order to achieve the objectives of this invention, the following technologies are proposed:

[0006] A dry ice deburring device for circuit boards includes a base, a lower spray section on the base, a lower pressing mechanism on the base, a lifting and movable lower pressing frame on the lower pressing mechanism, an upper drawing section on the lower pressing frame, the upper drawing section being located directly above the lower spray section, a vertical mounting plate fixed on the base, a plurality of mixing sections on the vertical mounting plate, the mixing sections being connected to the lower spray section via a fourth pipe, a plurality of containers being connected to the upper drawing section, the containers being connected to an air pump via a first pipe, the mixing sections being connected to an air supply pump via a second pipe, and the mixing sections being connected to a dry ice pellet supply pump via a third pipe.

[0007] In application, the circuit board is located between the upper suction section and the lower spray section. The lower spray section sprays a mixture of dry ice particles and air onto the lower side of the circuit board, while the upper suction section draws in the gas above the circuit board. The mixture of dry ice particles and air passes through the through-holes of the circuit board, causing the burrs on the inner wall of the through-holes to detach and be drawn into the container.

[0008] Furthermore, the mixing section includes an end plate fixed to a vertical mounting plate. Multiple first pipe heads are connected to the outer side of the end plate. The first pipe heads are connected to a fourth pipeline. A first threaded ring is welded to the inner side of the end plate. A pointed cone shell with a pointed cone-shaped structure is formed on the inner end of the first threaded ring. Multiple first through holes are opened on the conical surface of the pointed cone shell. A first sleeve is connected to the outer periphery of the first threaded ring. A second threaded ring is connected to the inner periphery of the other end of the first sleeve. A second sleeve is formed on the other end of the second threaded ring. A third threaded ring is connected to the inner periphery of the second threaded ring. A first conical nozzle with a conical structure is formed on the third threaded ring. The diameter of the first conical nozzle facing the pointed cone shell is smaller than the diameter of the other end.

[0009] A ring of peripheral holes is opened on the periphery of the second sleeve. An outer ring with a concave cross-section is welded to the outer periphery of the second sleeve. The peripheral holes are located inside the outer ring. A second pipe head is connected to the periphery of the outer ring and is connected to the third pipe.

[0010] The second sleeve has an end ring formed at its end. The outer end of the end ring is connected to a first end cap. A third tube head is inserted through the first end cap and connected to the second pipe. A first inner ring is welded to the inner end of the third tube head. The inner end of the first end cap abuts against the outer end face of the first inner ring. A fourth threaded ring is provided on the inner end of the first end cap. The fourth threaded ring is connected to the inner circumference of the end ring. A second conical nozzle is formed on the inner end of the fourth threaded ring. The second conical nozzle is located in the contraction chamber. The diameter of the second conical nozzle facing the mixing chamber is smaller than the diameter of its other end.

[0011] Furthermore, a sealing protrusion is formed on the inner side of the end plate, and the sealing protrusion is embedded in the end of the first sleeve.

[0012] Furthermore, a mixing cavity is formed inside the second sleeve, and conical cavities are formed at both ends of the mixing cavity. A contraction cavity is formed at the other end of the conical cavity. The inner diameter of the contraction cavity is smaller than the inner diameter of the mixing cavity, and the outer ring is located at the mixing cavity.

[0013] Furthermore, the lower spray section includes a base plate, the upper wall of which is formed with a rectangular convex ring, and a distribution plate is fixed on the base plate. The upper wall of the distribution plate is formed with multiple flow channels, which are rectangular ring structures with their geometric centers coinciding. Each flow channel has multiple air inlets on its inner circumference, and the other end of each air inlet is connected to a fourth pipe head. The lower end of the fourth pipe head passes through the base plate and is connected to the other end of the fourth pipe. The upper end of the distribution plate is fixed with a top cover, which has multiple rings of lower spray holes. Each ring of lower spray holes is arranged in a rectangular ring, and each ring of lower spray holes corresponds to each flow channel. Each ring of lower spray holes is connected to its corresponding flow channel.

[0014] Furthermore, the lower wall of the upper cover is formed with multiple rectangular rings, which correspond one-to-one with the flow channels. The rectangular rings extend into the flow channels corresponding to them, and the outer periphery of the rectangular rings abuts against the outer periphery of the flow channels.

[0015] Furthermore, multiple stepped holes are provided on each side of the rectangular convex ring, and a movable rod is movably installed in the stepped hole. The lower end of the movable rod is provided with an end cap, which is located below the base plate. A first spring is sleeved on the upper end of the movable rod. An L-shaped pad is provided above each corner of the rectangular convex ring. The pad is connected to the upper end of multiple movable rods. The upper end of the first spring abuts against the lower wall of the pad and the lower end of the first spring abuts against the bottom of the stepped hole. An L-shaped limiting member is formed at the corner of the pad. An L-shaped limiting groove is provided on the inner side of the limiting member. The bottom surface of the limiting groove is flush with the upper surface of the pad.

[0016] Furthermore, an upper protrusion is formed on each side of the rectangular convex ring, and there is a notch between two adjacent pads. When the lower wall of the pad abuts against the upper wall of the rectangular convex ring, the upper protrusion is located between the notches.

[0017] Furthermore, the upper suction part includes a lower pressure cover fixed to the lower pressure frame. The upper wall of the lower pressure cover has multiple rows of suction holes arranged in a circular array around its geometric center. The suction holes in each row are arranged at equal intervals. Multiple filling and suction protrusions are fixed on the lower pressure cover. The upper end of the filling and suction protrusions is fixed to a filling and suction top cover by screws. Each filling and suction top cover is connected to a fifth tube head. The interior of each filling and suction protrusion, the lower wall of the filling and suction top cover, and the upper wall of the lower pressure cover form a suction cavity. Each row of suction holes is connected to the suction cavity. A suction plate is fixed on the lower wall of the lower pressure cover. Multiple annular grooves are formed with an opening on the upper wall of the suction plate. The annular grooves are rectangular annular structures and the geometric centers of each annular groove coincide. The size of each annular groove is arranged on the suction plate in a manner that gradually increases from the geometric center outward. The annular grooves are connected to the suction cavity through multiple suction holes.

[0018] The lower wall of the suction plate is formed with a lower ring plate, and each edge of the lower ring plate is formed with a lower pressure strip. When the suction plate moves downward, the lower wall of the lower ring plate abuts against the upper wall of the limiting member, and the lower wall of the lower pressure strip abuts against the upper wall of the pad.

[0019] Furthermore, the container includes a relay tube connected to the fifth tube head, the upper end of the relay tube is connected to a fifth threaded tube, the upper end of the fifth threaded tube is formed with a suction can, the upper end of the suction can is formed with a sixth threaded tube, the outer periphery of the sixth threaded tube is connected to an upper end cap, the upper end cap is connected to a sixth tube head, the sixth tube head is connected to the first pipeline, the lower end of the suction can is formed with an upper convex cone, the outer periphery of the upper convex cone has a conical structure, the upper convex cone has a conical hole, the diameter of the upper end of the conical hole is smaller than the diameter of its lower end, the conical hole is connected to the relay tube, the bottom of the upper end cap is connected to a seventh threaded ring, the seventh threaded ring is connected to the sixth tube head, the lower end of the seventh threaded ring is formed with a concave shell with a concave longitudinal section, the lower end of the concave shell is formed with a conical shell, the diameter of the lower end of the conical shell is smaller than the diameter of its upper end, the conical shell has multiple second through holes on the conical wall, and a filter membrane is fixed on the outer periphery of the conical shell.

[0020] The advantages of the above technical solution are:

[0021] This invention employs a mixture of dry ice particles and air to remove burrs from circuit board holes or slots. Firstly, it utilizes the principle that dry ice absorbs heat during sublimation, thus embrittles the burrs. Secondly, it leverages the pressure difference between the upper and lower sides of the circuit board, allowing airflow to scour the inner walls of the holes, thereby achieving the purpose of deburring the inner walls of the holes. Furthermore, because this deburring method uses airflow scouring, it is comprehensive and thorough. Moreover, this treatment method is not affected by the size of the circuit board holes. It can also be used to embrittle burrs in blind holes or some rectangular slots using dry ice, followed by air scouring to remove the burrs.

[0022] In the process of deburring, this invention controls the impact intensity on different areas of the underside of the circuit board to prevent warping due to temperature differences in different areas of the circuit board.

[0023] This invention facilitates the collection of burrs, thus preventing them from affecting the smooth flow of pipelines.

[0024] This invention facilitates the cutting of circuit boards. Attached Figure Description

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will now be described in further detail with reference to the accompanying drawings.

[0026] Figure 1 A three-dimensional structural diagram of a dry ice deburring device for circuit boards is shown.

[0027] Figure 2 A three-dimensional structural diagram of the pressing mechanism is shown.

[0028] Figure 3 A three-dimensional structural diagram of the base and the mixing section after connection is shown.

[0029] Figure 4 A cross-sectional structural diagram of the mixing section is shown.

[0030] Figure 5 A three-dimensional structural diagram of the base, lower spray section, and upper drawer section after connection is shown.

[0031] Figure 6 A cross-sectional structural diagram of the lower spray section and the upper extraction section is shown.

[0032] Figure 7 An exploded view of the lower spray section and the upper extraction section along the vertical direction is shown.

[0033] Figure 8 The diagram shows the connection structure between the container and the upper part of the upper drawer.

[0034] Figure 9 A cross-sectional structural diagram of the mixing section is shown.

[0035] Figure 10 A cross-sectional view of the suction tank is shown.

[0036] Figure 11 A cross-sectional structural diagram of the mixing section housing component is shown.

[0037] Figure label:

[0038] Base 1, Vertical mounting plate 10, Lower spray section 2, Column 200, Upper ring plate 201, Base plate 202, Rectangular protruding ring 203, Upper protrusion 204, Stepped hole 205, Distribution plate 206, Flow channel 207, Air inlet 208, Fourth pipe head 209, Upper cover 210, Rectangular ring 211, Lower spray hole 212, Movable rod 213, End cap 214, Pad 215, Limiting component 216, Limiting groove 217, First spring 218, Lower pressing mechanism 3, Vertical back plate 30, guide rail; 31, sliding sleeve; 32, lower pressure frame; 33, lower pressure cylinder; 34, upper suction part; 4, lower pressure cover; 400, filling and suction cover; 401, fifth pipe head; 402, filling and suction convex shell; 403, suction hole; 404, suction plate; 405, annular groove; 406, suction eye; 407, rectangular sealing ring; 408, lower ring plate; 409, lower pressure strip; 410, debris container; 5, first pipeline; 500, relay pipe; 501, fifth threaded pipe; 502, suction tank; 503, upper convex cone; 504. Tapered hole 505, eighth threaded ring 506, tapered ring 507, lower extension ring 508, sealing cap 509, upturned flange 510, fourth through hole 511, connecting plate 512, filter plate 513, filter membrane 514, third through hole 515, second spring 516, middle rod 517, limiting ring 518, fifth through hole 519, cup 520, sixth threaded tube 521, upper end cap 522, sixth tube head 523, seventh threaded ring 524, concave shell 525 526, conical shell, 527, second through hole, 528, outer connecting ring, 529, sixth through hole, 530, connecting pipe, 531, outer convex ring, 532, inner top ring, 533, mixing tank, 534, vent hole, 535, fifth threaded ring, 536, end sealing plate, 537, filter cover, 538, inner connecting ring, 539, ring cone, 540, waist-shaped hole, 542, sealing cone cover, 543, sealing insert ring, 544, connecting rod, inner top head, 545, third spring, 547. 548, 549, 550, 6, 6, 600, 601, 602, 603, 604, 605, 606, 607, 608, 609, 610, 611, 612, 613, 614, 615, 616, 617, 618, 619, 620, 621, 622, 623, 624, 625, 625, 7. Circuit board. Detailed Implementation

[0039] like Figure 1As shown, a dry ice deburring device for circuit boards includes a base 1, a lower spray section 2, a lower pressing mechanism 3, an upper extraction section 4, a container 5, and a mixing section 6. The lower spray section 2 and the lower pressing mechanism 3 are mounted on the base 1, and the upper extraction section 4 is mounted on the lower pressing mechanism 3 and located directly above the lower spray section 2. A vertical mounting plate 10 is fixed to the base 1 by screws. Multiple mixing sections 6 are mounted on the vertical mounting plate 10. The mixing sections 6 are connected to the lower spray section 2 through a fourth pipe 602. Multiple containers 5 are connected to the upper extraction section 4. The containers 5 are respectively connected to an air pump through a first pipe 500. The mixing sections 6 are connected to an air supply pump through a second pipe 600. The mixing sections 6 are also connected to a dry ice granule supply pump through a third pipe 601.

[0040] In application, circuit board 7 is located between upper suction section 4 and lower spray section 2. Lower spray section 2 sprays a mixture of dry ice particles and air onto the lower side of circuit board 7, while upper suction section 4 draws in the gas above circuit board 7 to allow the mixture of dry ice particles and air to pass through the through-hole of circuit board 7. Firstly, the sublimation of dry ice lowers the temperature of circuit board 7 and its surrounding environment, causing the burrs on the inner wall of the holes in circuit board 7 to become brittle. When the mixture of dry ice particles and air passes through the through-hole of circuit board 7, firstly, some of the unsublimated dry ice particles strike the burrs, causing them to detach from the inner wall of the hole; secondly, some of the sublimated dry ice particles within the through-hole create a shock effect on the burrs, facilitating their detachment; and thirdly, when air (which contains carbon dioxide, and sublimated dry ice is also gaseous, referred to as air below for ease of description) passes through the through-hole, it washes over the burrs, also facilitating their detachment. Ultimately, the burrs are drawn into container 5, while air is extracted by an air pump to prevent excessive carbon dioxide concentration in the processing area from causing personal injury to the operator.

[0041] like Figure 2 As shown, the pressing mechanism 3 includes a vertical back plate 30 fixed to the base 1 by screws. A pair of vertically arranged guide rails 31 are fixed to the front side of the vertical back plate 30 by screws. A sliding sleeve 32 is slidably provided on the vertical back plate 30. A pressing frame 33 is fixed to the sliding sleeve 32 by screws. A pressing cylinder 34 is fixed to the vertical back plate 30 by screws. The movable end of the pressing cylinder 34 is fixed to the pressing frame 33.

[0042] like Figure 3 and Figure 4As shown, the mixing unit 6 includes an end plate 603 fixed to the vertical mounting plate 10 by screws. Multiple first pipe heads 604 are connected to the outer side of the end plate 603. A fourth pipe 602 is fitted onto each first pipe head 604. A first threaded ring 606 is welded to the inner side of the end plate 603. A pointed conical shell 607 with a pointed conical structure is formed on the inner end of the first threaded ring 606. Multiple first through holes 608 are formed on the conical surface of the pointed conical shell 607. A first sleeve 609 is threadedly connected to the outer periphery of the first threaded ring 606. A sealing convex ring 60 is formed on the inner side of the end plate 603. 5. A sealing ring 605 is embedded in the end of the first sleeve 609 to improve the sealing effect. The inner circumference of the other end of the first sleeve 609 is connected to a second threaded ring 610 by a thread. The other end of the second threaded ring 610 is formed with a second sleeve 613. The inner circumference of the second threaded ring 610 is connected to a third threaded ring 611 by a thread. The third threaded ring 611 is formed with a first conical nozzle 612 with a conical structure. The diameter of the first conical nozzle 612 facing the pointed cone shell 607 is smaller than the diameter of the other end. The nozzle of the first conical nozzle 612 is directly opposite the pointed cone end of the pointed cone shell 607.

[0043] The second sleeve 613 has a cylindrical mixing cavity 614 inside. The two ends of the mixing cavity 614 are respectively formed with conical cavities 615. The other end of the conical cavity 615 is formed with a contraction cavity 616. The inner diameter of the contraction cavity 616 is smaller than the inner diameter of the mixing cavity 614. The inner diameter of the conical cavity 615 facing the contraction cavity 616 is smaller than the inner diameter of the other end. A circumferential hole 617 is opened on the periphery of the mixing cavity 614. The outer ring 618 with a concave cross-section is welded to the outer periphery of the second sleeve 613. The outer ring 618 is located at the mixing cavity 614, and the circumferential hole 617 is located inside the outer ring 618. The periphery of the outer ring 618 is connected to a second pipe head 619, which is connected to the third pipe 601.

[0044] The end of the second sleeve 613 is formed with an end ring 620. The outer end of the end ring 620 is connected to a first end cap 621 by a thread. A third tube head 623 is passed through the first end cap 621. The third tube head 623 is connected to the second pipeline 600. A first inner ring 622 is welded to the inner end of the third tube head 623. The inner end of the first end cap 621 abuts against the outer end face of the first inner ring 622. A fourth threaded ring 624 is provided on the inner end of the first end cap 621. The fourth threaded ring 624 is connected to the inner circumference of the end ring 620 by a thread. A second conical nozzle 625 is formed on the inner end of the fourth threaded ring 624. The second conical nozzle 625 is located in the contraction chamber 616. The nozzle of the second conical nozzle 625 faces the mixing chamber 614. The diameter of the end of the second conical nozzle 625 facing the mixing chamber 614 is smaller than the diameter of its other end.

[0045] During mixing, the dried air enters the second conical nozzle 625 through the third nozzle 623, and after the passage space is narrowed through the nozzle 625, it is sprayed at high speed into the mixing chamber 614. Meanwhile, dry ice particles enter the outer ring 618 through the second nozzle 619, and then converge at the center of the mixing chamber 614 through the peripheral hole 617. When the high-speed air encounters the dry ice particles, it impacts the dry ice, causing it to break up again. Furthermore, the air entering the chamber causes some of the dry ice to absorb heat, further accelerating its breakup. The dry ice and air mixture is then sprayed onto the outer conical surface of the pointed cone shell 607 through the nozzle 612. Increasing the flow rate of the dry ice and air mixture increases the impact force of the dry ice striking the outer conical surface of the pointed cone shell 607, thereby achieving… The purpose is to further break up the dry ice. Then, the dry ice and air mixture will be transported through the first through hole 608 and along the fourth pipe 602 to the lower spray section 2. In this way, the breaking effect of the dry ice can be improved, thereby increasing the density of dry ice particles per unit space. When the dry ice comes into contact with the burrs on the inner wall of the hole, the heat absorption effect of the dry ice causes the burrs to become brittle. The micro-vibration formed after the dry ice absorbs heat and sublimates achieves the effect of removing burrs. Since the mixture of uniformly mixed air and dry ice is introduced, the air flow can also make it easier for the dry ice to pass through the holes on the circuit board 7, thereby improving the burr removal effect. The flowing air can also blow the burrs upwards for easy collection, so as to prevent the burrs from clogging the pipes.

[0046] like Figures 5 to 7As shown, the lower spray section 2 includes multiple columns 200 fixed to the base 1 by screws. An upper ring plate 201 is fixed to the upper end of each column 200 by screws. A base plate 202 is formed on the inner circumference of the upper ring plate 201. A rectangular protruding ring 203 is formed on the upper wall of the base plate 202. An upper protrusion 204 is formed on each side of the rectangular protruding ring 203. A distribution plate 206 is fixed to the base plate 202 by screws. The distribution plate 206 is located inside the rectangular protruding ring 203 and distributes... The upper wall of the disk 206 has multiple flow channels 207 formed by an opening. The flow channels 207 have a rectangular annular structure and the geometric centers of each flow channel 207 coincide. The flow channels 207 are arranged on the base plate 202 with their dimensions gradually increasing from the geometric center outwards. The inner circumference of each flow channel 207 has multiple L-shaped air inlets 208. The vertical section of the air inlet 208 penetrates the lower wall of the distribution disk 206, and the lower end of the vertical section of the air inlet 208 is connected by a screw. A fourth pipe head 209 is connected to the bottom plate 202. The lower end of the fourth pipe head 209 is connected to the other end of the fourth pipe 602. Multiple fourth pipe heads 209, which are used to connect a flow channel 207, are respectively connected to the first pipe head 604 on one of the mixing parts 6 through the fourth pipe 602. The upper end of the distribution plate 206 is fixed with a top cover 210 by screws. Multiple rings of lower spray holes 212 are opened on the top cover 210. The lower spray holes 212 are arranged in a rectangular ring, and there is a one-to-one correspondence between each ring of lower spray holes 212 and each flow channel 207. Each ring of lower spray holes 212 is connected to the corresponding flow channel 207. The lower wall of the upper cover 210 is formed with multiple rings of rectangular rings 211. The rectangular rings 211 are in a one-to-one correspondence with the flow channels 207. The rectangular rings 211 extend into the corresponding flow channels 207, and the outer periphery of the rectangular rings 211 abuts against the outer periphery of the flow channels 207.

[0047] The rectangular arrangement of the lower spray holes 212, with each ring of holes 212 connected to the flow channel 207, serves several purposes. First, since each mixing section 6 controls one ring of lower spray holes 212, the supply of the air and dry ice mixture ensures that the amount of dry ice-air mixture ejected from different locations is equal. This guarantees that during deburring of the circuit board 7, the upward-sprayed air and dry ice mixture is approximately uniform across the board. Furthermore, controlling the spray flow rate ensures that the cooling rate on the lower side of the circuit board 7 is approximately uniform, preventing warping due to uneven cooling rates. Second, the number of lower spray holes 212 varies within each ring, with density increasing from the inside out, further maximizing the uniformity of the dry ice-air mixture ejected from each area. Third, since the ejected substance is not traditional dry ice particles but an ice-air mixture, the cooling rate during deburring can be controlled by adjusting the ratio of the two, thus meeting the deburring requirements of circuit boards 7 made of different materials.

[0048] Multiple stepped holes 205 are formed along each side of the rectangular convex ring 203 from top to bottom. A movable rod 213 is movably installed within each stepped hole 205. An end cap 214 is provided at the lower end of the movable rod 213, located below the base plate 202. A first spring 218 is fitted onto the upper end of the movable rod 213. L-shaped pads 215 are respectively provided above the corners of the rectangular convex ring 203. There is a notch between adjacent pads 215. When the lower wall of the pad 215 abuts against the upper wall of the rectangular convex ring 203, the upper protrusion 204 is positioned between the notches. 215 is threaded to the upper end of multiple movable rods 213. The upper end of the first spring 218 abuts against the lower wall of the pad 215, and the lower end of the first spring 218 abuts against the bottom of the stepped hole 205. An L-shaped limiting member 216 is formed at the corner of the pad 215. An L-shaped limiting groove 217 is opened on the inner side of the limiting member 216. The bottom surface of the limiting groove 217 is flush with the upper surface of the pad 215. After the circuit board 7 is placed, the inner wall of the limiting groove 217 constrains the periphery of the circuit board 7, and the lower wall of the circuit board 7 abuts against the pad 215.

[0049] like Figures 5 to 7 As shown, the upper suction part 4 includes a lower pressure cover 400 fixed to the lower pressure frame 33 by screws. The lower wall of the lower pressure cover 400 has a rectangular annular groove. The upper wall of the lower pressure cover 400 has multiple rows of suction holes 404 arranged in a circular array around its geometric center. The suction holes 404 in each row of suction holes 404 are arranged at equal intervals, so that the suction holes 404 are distributed in a polygonal annular shape on the lower pressure cover 400. Multiple filling protrusions 403 are fixed to the lower pressure cover 400 by screws. The upper end of the filling protrusion 403 is fixed to the filling upper cover 401 by screws. Each filling upper cover 401 is connected to a fifth tube head 402. The interior of each filling protrusion 403, the lower wall of the filling upper cover 401, and the lower pressure cover 400 are all connected to the lower pressure frame 33. The upper wall of the 0 forms a suction cavity, and each row of suction holes 404 is connected to the suction cavity. The lower wall of the lower pressure cover 400 is fixed with a suction plate 405 by screws. The upper wall of the suction plate 405 is formed with a rectangular sealing ring 408, which is embedded in a rectangular annular groove. The upper wall of the suction plate 405 is formed with multiple annular grooves 406. The annular grooves 406 are rectangular annular structures and the geometric centers of each annular groove 406 coincide. The size of each annular groove 406 is arranged on the suction plate 405 in a step-by-step manner from the geometric center outward. The annular grooves 406 are connected to the suction holes 404, and one annular groove 406 is connected to multiple suction holes 404. Multiple suction holes 407 are opened at the bottom of the annular grooves 406.

[0050] The lower wall of the suction plate 405 is formed with a lower ring plate 409, and each edge of the lower ring plate 409 is formed with a lower pressure strip 410. When the suction plate 405 moves downward, the lower wall of the lower ring plate 409 abuts against the upper wall of the limiting member 216, and the lower wall of the lower pressure strip 410 abuts against the upper wall of the pad 215. In order to ensure the sealing effect, rubber pads are fixed to the lower wall of the lower pressure strip 410, the upper and lower walls of the pad 215, the lower wall of the lower ring plate 409, the upper wall of the limiting member 216, the upper wall of the rectangular protrusion 203, and the upper wall of the upper protrusion 204.

[0051] During the deburring process, the pressure on the upper side of the circuit board 7 is lower than that on the lower side due to the extraction of gas into the cavity formed between the lower wall of the suction plate 405 and the upper wall of the circuit board 7. This pressure difference is caused by suction. Therefore, during the process, the sublimated dry ice and air can flow upward through the through holes of the circuit board 7. During the flow, the frozen and embrittled burrs are moved upward together and finally sucked into the container 5 by the suction. In summary, the flow of gas can scrape away the embrittled burrs or burrs that are attached to the inner wall of the circuit board hole, and also facilitate the collection of burrs.

[0052] like Figures 8 to 11As shown, in one embodiment, the container 5 includes a relay pipe 501 threadedly connected to a fifth pipe head 402. The upper end of the relay pipe 501 is threadedly connected to the fifth threaded pipe 502. The upper end of the fifth threaded pipe 502 is formed with a suction can 503. The upper end of the suction can 503 is formed with a sixth threaded pipe 521. The outer periphery of the sixth threaded pipe 521 is threadedly connected to an upper end cap 522. A sixth pipe head 523 is connected to the upper end cap 522. The sixth pipe head 523 is connected to the first pipe 5. On the upper part, the lower end of the suction can 503 is coaxially formed with an upper convex cone 504. The outer periphery of the upper convex cone 504 has a conical structure. The diameter of the upper end of the outer periphery of the upper convex cone 504 is smaller than the diameter of its lower end. A conical hole 505 is formed inside the upper convex cone 504. The diameter of the upper end of the conical hole 505 is smaller than the diameter of its lower end. The conical hole 505 is connected to the relay pipe 501. The conical hole 505 is designed to increase the flow rate of the gas, thereby facilitating the suction of burrs into the suction can 503 and avoiding backflow problems caused by burrs. The bottom of the upper cover 522 is connected to a seventh threaded ring 524 via threads. The seventh threaded ring 524 communicates with the sixth tube head 523. The lower end of the seventh threaded ring 524 is formed with a concave shell 525 with a concave longitudinal section. The lower end of the concave shell 525 is formed with a conical shell 526. The diameter of the lower end of the conical shell 526 is smaller than the diameter of its upper end. Multiple second through holes 527 are opened on the conical wall of the conical shell 526. A filter membrane is fixed on the outer periphery of the conical shell 526 to prevent burrs from entering the pipeline with the airflow during the extraction process and affecting the operation of the air pump. The inner wall of the suction tank 503 is connected to a filter disc 513 via threads. Multiple third through holes 515 are opened on the filter disc 513. A filter membrane 514 is fixed on the upper end of the filter disc 513. The filter membrane 514 can further improve the blocking effect of burrs, etc.

[0053] like Figures 8 to 11As shown, in another embodiment, the burrs collected by the above method need to be removed from the upper cover 522 and the filter plate 513 before they can be poured out, which is inconvenient to operate. Furthermore, as the number of uses increases, the burrs adhere to the filter membrane 514, causing poor gas suction. Therefore, the following method can also be used to collect the burrs. A central rod 517 is coaxially and movably mounted on the filter disc 513. The upper end of the central rod 517 is threadedly connected to a conical cup 520. The cup 520 has an open upper end, and its upper diameter is larger than its lower diameter. The cup 520 is located directly below the conical shell 526. A limiting ring 518 is fixed to the central rod 517, located below the filter disc 513. The lower end of the central rod 517 is threadedly connected to a connecting disc 512. A second spring 516 is fitted onto the lower end of the central rod 517. The lower end of the second spring 516 abuts against the upper wall of the connecting disc 512, and the upper end of the second spring 516 abuts against the lower wall of the filter disc 513. The lower end of the connecting disc 512 has a conical, densely packed... The sealing cover 509 has an upper diameter smaller than its lower diameter. The lower outer periphery of the sealing cover 509 is formed with an upward-curving flange 510. Below the filter disc 513, there is an eighth threaded ring 506. The eighth threaded ring 506 is threadedly connected to the inner periphery of the suction can 503. The lower end of the eighth threaded ring 506 is formed with a conical ring 507. The lower diameter of the conical ring 507 is smaller than its upper diameter. Multiple fourth through holes 511 are opened on the conical wall of the conical ring 507. The lower end of the conical ring 507 is open. The lower end of the conical ring 507 is formed with a lower extension ring 508. The lower end of the lower extension ring 508 is open and formed with an embedded ring groove. During suction, the upward-curving flange 510 is engaged in the embedded ring groove.

[0054] The lower outer periphery of the suction can 503 is formed with an outer connecting ring 528. The inner end of the outer connecting ring 528 is connected to a fifth through hole 519. The inner diameter of the fifth through hole 519 is the same as the inner diameter of the outer connecting ring 528. The inner end of the fifth through hole 519 is connected to a sixth through hole 530. The inner diameter of the fifth through hole 519 is larger than the inner diameter of the sixth through hole 530. The connection between the fifth through hole 519 and the sixth through hole 530 is transitioned through a hole with a tapered structure. The inner end of the sixth through hole 530 is formed with a tapered hole 529. The diameter of the inner end of the tapered hole 529 is smaller than the diameter of its outer end. The inner end of the tapered hole 529 is connected to a seventh through hole 548. The seventh through hole 548 is connected to the interior of the suction can 503.

[0055] A connecting pipe 531 is provided inside the fifth through hole 519 and the sixth through hole 530. An outer convex ring 532 is formed on the outer periphery of the connecting pipe 531. The inner end of the outer convex ring 532 has a tapered structure, and the outer periphery of the inner end of the outer convex ring 532 abuts against the inner wall of the transition hole between the fifth through hole 519 and the sixth through hole 530. An inner top ring 533 is threadedly connected to an outer connecting ring 528. The inner end of the inner top ring 533 abuts against the outer end of the outer convex ring 532. A miscellaneous container 534 is threadedly connected to the outer end of the connecting pipe 531. Multiple openings are formed on the outer periphery of the miscellaneous container 534. A vent 535; a fifth threaded ring 536 is threadedly connected to the inner side of the outer end of the mixing tank 534; an end sealing plate 537 is provided at the outer end of the fifth threaded ring 536; a cylindrical filter cover 538 is fixed to the inner circumference of the fifth threaded ring 536; an inner connecting ring 539 is threadedly connected to the inner end of the mixing tank 534; a truncated cone 540 is formed on the inner connecting ring 539 facing the end sealing plate 537; the diameter of one end of the truncated cone 540 facing the end sealing plate 537 is smaller than the diameter of the other end; multiple waists are formed on the truncated cone 540. A sealing ring groove is formed on the conical surface of the annular cone 540, which has a hole 541. A connecting rod 544 is movably mounted on the annular cone 540 and the inner connecting ring 539. A sealing cone cover 542 is threadedly connected to the outer end of the connecting rod 544. The diameter of the end of the sealing cone cover 542 facing the end sealing plate 537 is smaller than the diameter of the other end. A sealing insert ring 543 is formed at the open end of the sealing cone cover 542. During suction, the sealing insert ring 543 is inserted into the sealing ring groove, and the inner conical wall of the sealing cone cover 542 abuts against the outer wall of the annular cone 540. The inner end of the connecting rod 544... An inner head 545 is threadedly connected to a connecting rod 544, and a third spring 547 is fitted on the connecting rod 544. One end of the third spring 547 abuts against the end of the inner head 545, and the other end of the third spring 547 abuts against the inner wall of the inner connecting ring 539. An insert post 549 is provided on the inner end of the inner head 545, and a sealing cone surface 550 is formed on the inner end of the inner head 545. The diameter of the inner end of the sealing cone surface 550 is smaller than the diameter of its outer end. During suction, the insert post 549 is inserted into the seventh through hole 548, and the sealing cone surface 550 abuts against the conical hole 529.

[0056] The deburring method for through holes and blind holes on the circuit board described in the above embodiment is as follows:

[0057] Step 01: The operator places the circuit board 7 on the pad 215, and the four corners of the circuit board 7 are constrained by the limiting member 216.

[0058] Step 02: Activate the lowering cylinder 34 to move the lowering frame 33 and the upper drawing part 4 downward along the guide rail 31.

[0059] During the downward movement, the lower wall of the pressure bar 410 abuts against the upper wall of the pad 215, and the lower wall of the lower ring plate 409 abuts against the upper wall of the limiting member 216. During the downward pressing process, the first spring 218 is compressed, and finally the lower wall of the pad 215 abuts against the upper wall of the rectangular convex ring 203, and the lower wall of the pressure bar 410 also abuts against the upper protrusion 204. At this time, an upper cavity is formed between the upper side of the circuit board 7 and the lower side of the suction plate 405, and a lower cavity is formed between the lower side of the circuit board 7 and the upper wall of the upper cover 210. This sealing method avoids the increase of carbon dioxide concentration in the space where the equipment is located during dry ice processing, which may endanger the personal safety of the operators.

[0060] Step 03: The air supply pump supplies air to the mixing section 6 through the second pipe 600, while the dry ice particle supply pump supplies broken dry ice particles to the mixing section 6 through the third pipe 601. Air is sprayed into the mixing chamber 614 through the second conical nozzle 625, and dry ice particles are also sprayed into the mixing chamber 614 through the peripheral hole 617. When the dry ice is sprayed into the mixing chamber 614 from the peripheral hole 617, it breaks again due to impact. The incoming air then drives the dry ice particles to gather at the first conical nozzle 612. During this process, the impact between the dry ice particles and the inner wall of the first conical nozzle 612 further breaks them apart. Then, the dry ice and air are sprayed at high speed through the nozzle of the first conical nozzle 612. The dry ice particles exit onto the outer wall of the conical shell 607, where they are broken up and thoroughly mixed. They are then conveyed into the conical shell 607 through the first through-hole 608. Subsequently, the dry ice particles and air are conveyed to the same flow channel 207 through various fourth pipes 602. Finally, they are sprayed upwards into the lower cavity and onto the lower side of the circuit board 7 through a ring of downward spray holes 212 corresponding to the flow channel 207. This causes the dry ice particles to be sprayed onto the lower surface of the circuit board 7, the through-holes of the circuit board 7, and the slots of the circuit board 7. When the dry ice comes into contact with the various structures of the circuit board 7, the temperature of the circuit board 7 is higher than that of the dry ice, causing the dry ice to absorb heat. This leads to embrittlement of burrs and dirt on the lower surface and holes of the circuit board 7. The above describes only one mixing method for dry ice and air in mixing section 6. The other mixing sections 6 operate in the same way, differing only in the amount of air input in each mixing section 6.

[0061] Step 04, which follows step 03, involves starting the air pump. When the air pump starts, its suction function draws air from the upper cavity through the first pipe 500. During the suction process, the air injected in step 03 and some incompletely sublimated particles flow into the upper cavity through the through holes. As they move, the dry ice particles strike the burrs, causing them to fall off. In addition, as the air flows, some of the detached burrs move upward through the through holes. During this movement, the air scouring the inner wall of the holes and the detached burrs further dislodge the burrs. They then move into the upper cavity and, under the suction force, enter the various containers 5 through the suction holes 407 and 404 to be collected. Air with a high carbon dioxide concentration is drawn out by the air pump and discharged into the air handling system.

[0062] One method of collecting burrs in the container 5 is that these burrs are sucked into each suction can 503. The burrs that enter the suction can 503 will be blocked by the filter membrane 514 or the filter screen. If cleaning is required, the upper cover 522 is opened and the burrs inside are collected.

[0063] Another method for collecting burrs in the container 5 is as follows: when the air pump is used for suction, the sealing cap 509 will move upward and the second spring 516 will be compressed. As the sealing cap 509 moves upward, the conical hole 505 will be opened, and the cup 520 will also move upward until the limiting ring 518 abuts against the lower wall of the filter disc 513. At this time, there is an air flow gap between the inner wall of the cup 520 and the conical shell 526. Due to the suction force, the cup 520 will have an upward pulling force, which can overcome the elasticity of the second spring 516 and the gravity of related components, and avoid the second spring 516 and gravity affecting the opening effect of the sealing cap 509. At this time, the upward protrusion 510 is locked in the embedded ring groove. At this time, the burrs will be collected into the suction tank 503. In addition, when the air pump is used for suction, the sealing cone surface 550 abuts against the inner wall of the cone hole 529 under the action of the elastic force of the third spring 547 and the suction force, thereby achieving the purpose of sealing the seventh through hole 548.

[0064] After the burrs on the circuit board 7 are removed, the inflation pump inflates the suction tank 503 through the first pipe 500. As the suction force generated by the inflation pump disappears, the sealing cap 509, under the elastic force of the second spring 516 and the gravity of related components, will be fastened onto the upper convex cone 504 to prevent air from entering the upper suction part 4 through the cone hole 505. During the inflation process, the impact force of the air on the outside of the sealing cap 509 will ensure the stability of its cover. Furthermore, as air is introduced, the burrs adhering to the filter membrane 514, the filter screen, and entering the conical ring 507 are blown downwards to the bottom of the suction tank 503. At the same time, as air is introduced, the inner top head 545 moves outwards. During the movement, the sealing cone cover 542 releases the blockage of the waist-shaped hole 541, and then enters the impurity tank 534 through the waist-shaped hole 541 and is blocked by the filter cover 538. The air is discharged through the exhaust hole 535. In this way, the burrs are finally collected in the impurity tank 534. During cleaning, the end sealing plate 537 is removed, and the burrs in the filter cover 538 are cleaned away.

[0065] Step 05: Activate the downward pressing cylinder 34, move the upward drawing part 4 upward, and the circuit board 7 will be lifted by the action of the first spring 218. Then, the circuit board is flipped over to perform burr removal on the other side of the circuit board 7 through the above steps 01 to 04. After completion, the circuit board 7 is taken out.

[0066] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Obviously, those skilled in the art can make various modifications and variations to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention also intends to include these modifications and variations.

Claims

1. A dry ice deburring device for circuit boards, characterized in that, Includes a base (1), on which a lower spray section (2) and a lower pressing mechanism (3) are provided. The lower pressing mechanism (3) has a lifting and movable lower pressing frame (33). The lower pressing frame (33) has an upper drawing section (4). The upper drawing section (4) is located directly above the lower spray section (2). A vertical mounting plate (10) is fixed on the base (1). A plurality of mixing sections (6) are provided on the vertical mounting plate (10). The mixing section (6) is connected to the lower spray section (2) through a fourth pipe (602). A plurality of containers (5) are connected to the upper drawing section (4). The containers (5) are respectively connected to an air pump through a first pipe (500). The mixing section (6) is connected to an air supply pump through a second pipe (600). The mixing section (6) is also connected to a dry ice pellet supply pump through a third pipe (601). In application, the circuit board (7) is located between the upper suction part (4) and the lower spray part (2). The lower spray part (2) sprays a mixture of dry ice particles and air onto the lower side of the circuit board (7). The upper suction part (4) draws in the gas above the circuit board (7). The mixture of dry ice particles and air passes through the through hole of the circuit board (7) so that the burrs on the inner wall of the through hole of the circuit board (7) are removed and sucked into the container (5).

2. The circuit board dry ice deburring device according to claim 1, characterized in that, The mixing section (6) includes an end plate (603) fixed to a vertical mounting plate (10). Multiple first pipe heads (604) are connected to the outer side of the end plate (603). The first pipe heads (604) are connected to a fourth pipe (602). A first threaded ring (606) is welded to the inner side of the end plate (603). The inner end of the first threaded ring (606) is formed with a pointed conical shell (607) whose inner end has a pointed conical structure. Multiple first through holes (608) are opened on the conical surface of the pointed conical shell (607). (606) has a first sleeve (609) connected to its outer periphery, a second threaded ring (610) connected to the inner periphery of the other end of the first sleeve (609), a second sleeve (613) formed at the other end of the second threaded ring (610), a third threaded ring (611) connected to the inner periphery of the second threaded ring (610), and a first conical nozzle (612) with a conical structure formed on the third threaded ring (611). The diameter of the first conical nozzle (612) facing the pointed conical shell (607) is smaller than the diameter of the other end. A circumferential hole (617) is provided on the periphery of the second sleeve (613). An outer ring (618) with a concave cross-section is welded to the outer periphery of the second sleeve (613). The circumferential hole (617) is located inside the outer ring (618). A second pipe head (619) is connected to the periphery of the outer ring (618). The second pipe head (619) is connected to the third pipe (601). The end of the second sleeve (613) is formed with an end ring (620). The outer end of the end ring (620) is connected to a first end cap (621). A third tube head (623) is passed through the first end cap (621). The third tube head (623) is connected to the second pipeline (600). A first inner ring (622) is welded to the inner end of the third tube head (623). The inner end of the first end cap (621) abuts against the outer end face of the first inner ring (622). A fourth threaded ring (624) is provided on the inner end of the first end cap (621). The fourth threaded ring (624) is connected to the inner circumference of the end ring (620). A second conical nozzle (625) is formed on the inner end of the fourth threaded ring (624). The second conical nozzle (625) is located in the contraction chamber (616). The diameter of the second conical nozzle (625) facing the mixing chamber (614) is smaller than the diameter of its other end.

3. The circuit board dry ice deburring device according to claim 2, characterized in that, The inner side of the end plate (603) is formed with a sealing protrusion (605), which is embedded in the end of the first sleeve (609).

4. The circuit board dry ice deburring device according to claim 2, characterized in that, The second sleeve (613) has a mixing cavity (614) inside. The two ends of the mixing cavity (614) are respectively formed with conical cavities (615). The other end of the conical cavity (615) is formed with a contraction cavity (616). The inner diameter of the contraction cavity (616) is smaller than the inner diameter of the mixing cavity (614). The outer ring (618) is located at the mixing cavity (614).

5. The circuit board dry ice deburring device according to claim 1, characterized in that, The lower spray section (2) includes a base plate (202), the upper wall of which is formed with a rectangular convex ring (203). A distribution plate (206) is fixed on the base plate (202). The upper wall of the distribution plate (206) is formed with multiple flow channels (207). The flow channels (207) are rectangular ring structures and the geometric centers of each flow channel (207) coincide. Multiple air inlets (208) are opened on the inner circumference of each flow channel (207). The other end of the air inlet (208) is connected to a fourth pipe head (209). The fourth pipe head ( The lower end of the fourth pipe head (209) is inserted into the base plate (202). The lower end of the fourth pipe head (209) is connected to the other end of the fourth pipe (602). The upper end of the distribution plate (206) is fixed with a top cover (210). Multiple rings of lower spray holes (212) are opened on the top cover (210). Each ring of lower spray holes (212) is arranged in a rectangular ring. Each ring of lower spray holes (212) corresponds to each flow channel (207). Each ring of lower spray holes (212) is connected to the corresponding flow channel (207).

6. The circuit board dry ice deburring device according to claim 5, characterized in that, The lower wall of the cover (210) is formed with multiple rectangular rings (211). The rectangular rings (211) and the flow channels (207) are in a one-to-one correspondence. The rectangular rings (211) extend into the flow channels (207) corresponding to them, and the outer periphery of the rectangular rings (211) abuts against the outer periphery of the flow channels (207).

7. The circuit board dry ice deburring device according to claim 5, characterized in that, Multiple stepped holes (205) are provided on each side of the rectangular convex ring (203). A movable rod (213) is movably installed in the stepped hole (205). An end cap (214) is provided at the lower end of the movable rod (213). The end cap (214) is located below the base plate (202). A first spring (218) is sleeved on the upper end of the movable rod (213). An L-shaped pad (215) is provided above each corner of the rectangular convex ring (203). 5) Connected to the upper end of multiple movable rods (213), the upper end of the first spring (218) abuts against the lower wall of the pad (215), and the lower end of the first spring (218) abuts against the bottom of the stepped hole (205). A limiting member (216) with an L-shaped structure is formed at the corner of the pad (215). A limiting groove (217) with an L-shaped structure is opened on the inner side of the limiting member (216). The bottom surface of the limiting groove (217) is flush with the upper surface of the pad (215).

8. The circuit board dry ice deburring device according to claim 7, characterized in that, A top protrusion (204) is formed on each side of the rectangular protruding ring (203), and there is a gap between two adjacent pads (215). When the lower wall of the pad (215) abuts against the upper wall of the rectangular protruding ring (203), the top protrusion (204) is located between the gaps.

9. The circuit board dry ice deburring device according to claim 8, characterized in that, The upper suction section (4) includes a lower pressure cover (400) fixed to the lower pressure frame (33). The upper wall of the lower pressure cover (400) is provided with multiple rows of suction holes (404) arranged in a circular array around its geometric center. The suction holes (404) in each row of suction holes (404) are arranged in an equally spaced array. Multiple filling protrusions (403) are fixed on the lower pressure cover (400). The upper end of the filling protrusion (403) is fixed with a filling top cover (401) by screws. A fifth tube head (402) is connected to each filling top cover (401). The interior of each filling protrusion (403) and the lower part of the filling top cover (401) are connected to the fifth tube head (402). The upper wall of the wall and the lower pressure cover (400) forms a suction cavity. Each row of suction holes (404) is connected to the suction cavity. The lower wall of the lower pressure cover (400) is fixed with a suction plate (405). The upper wall of the suction plate (405) is formed with multiple annular grooves (406). The annular grooves (406) are rectangular annular structures and the geometric centers of each annular groove (406) coincide. The size of each annular groove (406) increases gradually from the geometric center outward. The annular grooves (406) are connected to the suction cavity through multiple suction holes (404). Multiple suction holes (407) are opened at the bottom of the annular grooves (406). The lower wall of the suction plate (405) is formed with a lower ring plate (409), and each side of the lower ring plate (409) is formed with a lower pressure strip (410). When the suction plate (405) moves downward, the lower wall of the lower ring plate (409) abuts against the upper wall of the limiting member (216), and the lower wall of the lower pressure strip (410) abuts against the upper wall of the pad (215).

10. The circuit board dry ice deburring device according to claim 9, characterized in that, The container (5) includes a relay pipe (501) connected to the fifth pipe head (402), the upper end of which is connected to a fifth threaded pipe (502). The upper end of the fifth threaded pipe (502) is formed with a suction can (503), the upper end of the suction can (503) is formed with a sixth threaded pipe (521), the outer periphery of the sixth threaded pipe (521) is connected with an upper end cap (522), the upper end cap (522) is connected to a sixth pipe head (523), the sixth pipe head (523) is connected to the first pipeline (500), the lower end of the suction can (503) is formed with an upper convex cone (504), the outer periphery of the upper convex cone (504) is conical, and the upper convex cone (504) is formed with a conical structure. A conical hole (505) has a diameter at its upper end smaller than that at its lower end. The conical hole (505) is connected to the relay pipe (501). The bottom of the upper end cap (522) is connected to a seventh threaded ring (524). The seventh threaded ring (524) is connected to the sixth pipe head (523). The lower end of the seventh threaded ring (524) is formed with a concave shell (525) with a concave longitudinal section. The lower end of the concave shell (525) is formed with a conical shell (526). The diameter at the lower end of the conical shell (526) is smaller than that at its upper end. Multiple second through holes (527) are opened on the conical wall of the conical shell (526). A filter membrane is fixed on the outer periphery of the conical shell (526).

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