hopper

Abstract

Suppresses the accumulation of powdered resin material on the magnetic screen. [Solution] Hopper 30 is a hopper that supplies powdered resin material to continuous mixer 10 below, and includes hopper body 31 and a magnetic screen 42 that is disposed inside hopper body 31 and captures metallic foreign matter. Magnetic screen 42 is disposed in the internal space of hopper body 31 so as to cross the conveyance direction of the powdered resin material and has a magnetized attraction portion, and an opening that allows powdered resin material dropping from above magnetic screen 42 to pass downward. The attraction portion has a drop guide surface on its upper surface that slopes down toward the opening.

Description

[Technical Field]

[0001] The present invention relates to a hopper. [Background technology]

[0002] Patent Document 1 discloses a feeding device for feeding bulk material to the screw portion of a screw machine. As shown in FIG. 14, the feeding device 90 disclosed in Patent Document 1 includes a hopper 91 that receives bulk material from a supply pipe located above. The hopper 91 is equipped with a screen element 92 for removing metal particles contained in the bulk material, a drive device 93 for moving the screen element 92 back and forth, an opening 94 for removing metal particles remaining on the screen element 92 after it has been pulled out, and a cover element 95 for closing the opening 94. An induction coil is installed above the hopper 91 to detect metal particles contained in the bulk material fed to the hopper 91. When the induction coil detects metal particles, the screen element 92 below moves from a rest position to an operating position to capture the metal particles. The screen element 92 is magnetized and has a lattice-like shape with a minimum cross-sectional dimension larger than the maximum particle size of the bulk material. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-109871 Summary of the Invention [Problem to be solved by the invention]

[0004] The screen element 92 is manufactured in the form of a perforated plate by punching out a panel-shaped metal plate. As a result, part of the powder material to be supplied downstream remains and accumulates on the flat portion of the screen element 92, excluding the openings. This reduces the permeation efficiency of the powder resin material.

[0005] Therefore, the present invention has been made in consideration of the above-mentioned conventional technology, and its purpose is to suppress the accumulation of powdered resin material on a magnetic screen that captures metallic foreign matter. [Means for solving the problem]

[0006] To achieve the above object, the present invention provides a hopper for supplying powdered resin material to a kneader below, comprising a hopper body and a magnetic screen disposed within the hopper body for capturing metallic foreign objects. The magnetic screen has a magnetized attraction portion disposed in the interior space of the hopper body so as to cross the direction of transport of the powdered resin material, and an opening for allowing the powdered resin material falling from above the magnetic screen to pass downward. The attraction portion has a fall guide surface on its upper surface that slopes downward toward the opening.

[0007] In the hopper, the magnetic screen's suction portion has a drop guide surface in the area adjacent to the opening, reducing the area of ​​the flat portion where the powdered resin material is likely to accumulate compared to conventional magnetic screen structures. Furthermore, the powdered resin material that falls onto the drop guide surface easily slides down along the drop guide surface from the magnetic screen. These effects suppress the accumulation of the powdered resin material on the magnetic screen and improve the permeability of the powdered resin material compared to conventional magnetic screens that are flat except for the opening.

[0008] The magnetic screen may have a plurality of the openings, in which case the suction portion may have a plurality of the drop guide surfaces corresponding to the plurality of openings, and the drop guide surfaces adjacent to each other may intersect at an upper end of the suction portion.

[0009] In this embodiment, the drop guide surfaces of the suction parts intersect at the upper end of the suction part, so that a flat area is not formed at the upper end of the suction part, which prevents the powdered resin material from accumulating on the suction part, thereby more effectively improving the penetration efficiency of the powdered resin material.

[0010] The hopper may further include a mesh screen disposed in the internal space of the hopper body so as to cross the conveying direction of the powdered resin material. In this case, the mesh screen may be disposed below the magnetic screen and have finer meshes than the openings of the magnetic screen.

[0011] In this embodiment, the mesh screen can capture small non-magnetic foreign matter that cannot be captured by the magnetic screen, thereby more effectively preventing damage to the downstream kneader.

[0012] The hopper body may include a discharge port for discharging the powdered resin material from a lower end side of the hopper body. In this case, the hopper may further include a temporary mesh screen covering the discharge port. The temporary mesh screen has finer meshes than the mesh screen and may be attached during a test run of the kneading machine and removed from the hopper body during normal operation.

[0013] In this embodiment, because there is a high risk of small foreign objects, whether metallic or non-metallic, falling through during the test run, a temporary mesh screen with a finer mesh than the mesh screen used during normal operation is temporarily used. This prevents damage to the downstream kneader. However, the temporary mesh screen has a fine mesh that prevents powder from entering during normal operation. Therefore, by removing the temporary mesh screen during normal operation, it is possible to prevent a deterioration in the permeation efficiency of the powder resin material during normal operation.

[0014] The hopper body may further include an installation port for installing the magnetic screen in the hopper body or removing the magnetic screen from the hopper body. In this case, the magnetic screen may be installed in the hopper body in an inclined state such that its position decreases from the installation port toward the opposite side from the installation port.

[0015] In this embodiment, it is possible to reliably prevent the magnetic screen from coming out by itself under its own weight when the installation opening is opened. [Effects of the Invention]

[0016] As described above, according to the present invention, the accumulation of powdered resin material on the magnetic screen can be suppressed, thereby suppressing a deterioration in the penetration efficiency of the powdered resin material. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a view showing a continuous mixer to which a hopper according to an embodiment is attached. [Figure 2] FIG. 2 is a side view of the hopper. [Figure 3] FIG. 2 is a diagram showing the hopper as viewed from the material extrusion direction side of the continuous kneader. [Figure 4] FIG. 1 is a top view of a temporary mesh screen. [Figure 5] FIG. 10 shows a magnetic screen and a support. [Figure 6] 10A and 10B are diagrams for explaining the cross-sectional shape of a magnet bar included in the magnetic screen. [Figure 7] 10A and 10B are diagrams for explaining the cross-sectional shape of a magnet bar included in a magnetic screen according to a modified example. [Figure 8] 10A and 10B are diagrams for explaining the cross-sectional shape of a magnet bar included in a magnetic screen according to a modified example. [Figure 9] 10A and 10B are diagrams for explaining the cross-sectional shape of a magnet bar included in a magnetic screen according to a modified example. [Figure 10] 10A and 10B are diagrams for explaining the cross-sectional shape of a magnet bar included in a magnetic screen according to a modified example. [Figure 11] 10A and 10B are diagrams for explaining the cross-sectional shape of a magnet bar included in a magnetic screen according to a modified example. [Figure 12] FIG. 10 is a top view of a magnetic screen according to a modified example. [Figure 13] FIG. 10 is a top view of a magnetic screen according to a modified example. [Figure 14] FIG. 1 is a diagram showing a conventional hopper. DETAILED DESCRIPTION OF THE INVENTION

[0018] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0019] As shown in FIG. 1, a hopper 30 according to this embodiment is assembled to a continuous mixer 10 for use. The continuous mixer 10 includes a hopper section 11 having a conveying space 11a, and the hopper 30 is connected to this hopper section 11 via a bellows-shaped connecting member 12. The hopper 30 may be supported in a suspended state by a hanging jig (not shown). A powdered resin material is charged into the hopper 30, and this powdered resin material is introduced from the hopper 30 into the hopper section 11 of the continuous mixer 10. An example of the powdered resin material is polyolefin powder.

[0020] A pair of screw shafts 14, which are located within the conveying space 11a and are configured to be able to deliver the powdered resin material, are housed in the hopper section 11. Each screw shaft 14 has a rotor 17 for kneading the powdered resin material, and the pair of screw shafts 14 with the rotors 17 are driven by a motor (driver) 18.

[0021] A barrel 19 accommodating a pair of rotors 17 is adjacent to one side of the hopper section 11, and a drive end section 22 supporting a pair of rotary shafts 21 connected to the pair of screw shafts 14 is adjacent to the other side of the hopper section 11. The pair of rotary shafts 21 are connected to a drive shaft 18a of a motor 18. Therefore, the driving force generated by the motor 18 is transmitted to the pair of screw shafts 14 and the pair of rotors 17 via the pair of rotary shafts 21, causing the pair of screw shafts 14 and the pair of rotors 17 to rotate. As a result, the powdered resin material in the hopper section 11 is sent into the barrel 19, where it is kneaded.

[0022] 2 and 3, the hopper 30 includes a hollow hopper body 31, a magnetic screen 42 disposed inside the hopper body 31, and a mesh screen 43 disposed below the magnetic screen 42 inside the hopper body 31. The magnetic screen 42 and the mesh screen 43 can be installed through an installation opening 45 provided in the hopper body 31, and can also be removed from the hopper body 31 through the installation opening 45.

[0023] The hopper body 31 has a lower section 32 that narrows toward the bottom, and an upper section 33 located above the lower section 32. The upper section 33 is formed in a cylindrical shape with the same width at the top and bottom. The upper section 33 may be a cylindrical shape with a circular cross section or a cylindrical shape with a polygonal cross section.

[0024] An inlet (not shown) for the powdered resin material is provided on the top surface of the upper portion 33. That is, a nozzle or a silo (not shown) for supplying the powdered resin material is inserted into the inlet of the upper portion 33, and the powdered resin material is supplied into the hopper body 31 from the nozzle or the silo.

[0025] The upper portion 33 functions as a portion for attaching accessories. For example, a nozzle for supplying powdered resin material may be attached to the side of the upper portion 33 so that the nozzle is inserted into the side of the upper portion 33. In this case, the inlet on the top surface of the upper portion 33 is omitted. The upper portion 33 also functions as a portion for arranging the magnetic screen 42 and mesh screen 43 inserted through the installation opening 45.

[0026] The installation opening 45 is formed in one side wall 33a constituting the upper side portion 33, and a lid member 46 that opens and closes the installation opening 45 is provided at the installation opening 45. The lid member 46 is detachably attached to the one side wall 33a with fasteners including bolts and nuts so as to close the installation opening 45. The lid member 46 is removed when installing and removing the magnetic screen 42 and the mesh screen 43.

[0027] The magnetic screen 42 is a member for capturing metallic foreign matter contained in the powdered resin material supplied into the hopper body 31. The mesh screen 43 is a member for removing foreign matter that cannot be removed by the magnetic screen 42. The magnetic screen 42 and the mesh screen 43 are installed so as to cross the conveying direction of the powdered resin material.

[0028] The magnetic screen 42 and the mesh screen 43 are installed in a tilted manner, descending from the installation opening 45 toward the other side wall 33b opposite the one side wall 33a where the installation opening 45 is formed. Specifically, an upper rail 47 for guiding the magnetic screen 42 and a lower rail 48 for guiding the mesh screen 43 are provided within the upper portion 33, and the upper rail 47 and the lower rail 48 are fixed to the upper portion 33 in an extending position, descending from the one side wall 33a toward the other side wall 33b. Therefore, when the magnetic screen 42 is inserted into the upper portion 33 along the upper rail 47, the magnetic screen 42 is in a tilted position. When the mesh screen 43 is inserted into the upper portion 33 along the lower rail 48, the mesh screen 43 is also in a tilted position.

[0029] An inspection hatch 50 for collecting foreign matter is provided above the installation opening 45. By opening the inspection hatch 50, foreign matter captured by the magnetic screen 42 or mesh screen 43 can be collected.

[0030] The lower end of the hopper body 31 opens as a discharge port 35 that communicates with the kneading space of the hopper section 11 for the powdered resin material. A bellows-shaped connecting member 12 is provided between the lower end of the hopper body 31 and the hopper section 11. Therefore, the interior of the hopper body 31 communicates with the conveying space 11a through the internal space of the connecting member 12.

[0031] The hopper body 31 is disposed at a position separated from the hopper section 11 by a distance corresponding to the size of the connecting member 12. In addition, since the connecting member 12 is formed of a bellows, vibrations of the hopper section 11, i.e., the continuous mixer 10, are not transmitted to the hopper body 31.

[0032] The hopper body 31 is fastened to the connecting member 12 by fasteners 51. Therefore, by removing the fasteners 51, the hopper body 31 can be separated from the connecting member 12, i.e., the hopper section 11. Furthermore, because the hopper body 31 is positioned away from the hopper section 11, during maintenance of the rotor 17, space can be secured to remove the rotor 17 upward by shifting the hopper section 11 in the axial direction.

[0033] A temporary mesh screen 52 is disposed between the hopper body 31 and the connecting member 12 so as to cover the discharge outlet 35. The temporary mesh screen 52 has a mesh with finer openings than the mesh screen 43.

[0034] 4, the temporary mesh screen 52 is formed in an oval shape overall, similar to the cross-sectional shape of the connecting member 12. The temporary mesh screen 52 has a frame portion 52a to which fasteners 51 that are fastened to the connecting member 12 and the hopper body 31 can be fixed, and a mesh 52b fixed to the frame portion 52a.

[0035] The bellows connecting member 12 is compressed to form a gap between the hopper body 31 and the connecting member 12, and the temporary mesh screen 52 is inserted into the gap, thereby disposing the temporary mesh screen 52 between the connecting member 12 and the hopper body 31. In this state, the temporary mesh screen 52 can be fixed to the hopper body 31 and the connecting member 12 by the fasteners 51.

[0036] The temporary mesh screen 52 has finer mesh than the mesh screen 43. For this reason, the temporary mesh screen 52 is used only during test operation and is removed during normal operation.

[0037] As shown in Figures 2 and 3, an air knocker 37 is attached to the hopper body 31 to remove powder adhering to the wall surface of the hopper 30 from the wall surface. The air knocker 37 is attached to the outer wall surface of the hopper body 31. The air knocker 37 is configured to drive a cylinder piston with air, causing the piston to collide with the wall surface (inclined surface) of the hopper body 31, thereby impacting the hopper body 31. Powder accumulated on the inner wall surface of the hopper body 31 is dropped by the vibration of the hopper body 31. Note that the inner surface of the hopper body 31 is smooth and has steeply sloping portions, but depending on the type of material, powder is likely to adhere to the wall surface. For this reason, the air knocker 37 is designed to vibrate the inclined surface.

[0038] The air knocker 37 is connected to an air regulator 38 that controls the amount of air supplied to the air knocker 37. The air regulator 38 has an air filter built in that captures foreign matter contained in the air.

[0039] A sight window 40 is provided in the lower portion 32 of the hopper body 31. Therefore, the state inside the hopper body 31 can be confirmed through the sight window 40. This makes it possible to check whether powder has accumulated inside the hopper body 31, whether powder is passing through the hopper body 31, etc. Furthermore, to prevent powder from adhering to the sight window 40 and obscuring the inside of the hopper body 31, nitrogen gas may be blown onto the sight window 40 from the inside to keep powder from adhering to the sight window 40 at all times.

[0040] The sight glass 40 is attached to a surface 32a facing one side (for example, a direction perpendicular to the axial direction of the screw shaft 14) of the inclined surfaces that make up the lower portion 32. A glass window (not shown) may be provided on the other surface of the lower portion 32 (the side opposite to the sight glass 40). The glass window allows light to reach the inside of the hopper body 31, making it easier to see inside the hopper body 31.

[0041] As shown in FIG. 5, the magnetic screen 42 has an adsorption section 54 and multiple openings 55. The adsorption section 54 is magnetized and arranged in the internal space of the hopper body 31 so as to cross the conveying direction of the powdered resin material. In the example shown in FIG. 5, the adsorption section 54 includes multiple spaced apart, rod-shaped magnet bars 54a. The magnet bars 54a are composed of strong, round magnets. Therefore, they can capture magnetic bodies contained in the powdered resin material that falls with the powder from upstream equipment. The multiple magnet bars 54a are supported from below by supports 56 formed in a grid pattern so as to cross the multiple magnet bars 54a.

[0042] The openings 55 are defined by gaps between adjacent magnet bars 54a, and therefore allow the powder in the powdered resin material dropping from above the magnetic screen 42 to pass downward through the openings 55.

[0043] 6, the cross section of each magnet bar 54a is circular. Therefore, the upper surface of the magnet bar 54a is arc-shaped. As a result, the arc-shaped upper surface forms a pair of drop guide surfaces 58 that slope downward toward the adjacent opening 55. Therefore, the powder can easily slide downward along the drop guide surfaces 58, which can prevent the powder from accumulating on the magnet bar 54a (attraction portion 54).

[0044] The mesh screen 43 has a finer mesh than the magnetic screen 42. That is, the mesh of the mesh screen 43 has finer sieve openings than the openings 55 of the magnetic screen 42. Therefore, the mesh screen 43 can capture non-magnetic foreign matter that is too large for the magnetic screen 42 to capture.

[0045] As described above, in the hopper according to this embodiment, the suction portion 54 of the magnetic screen 42 has the drop guide surface 58 in the area adjacent to the opening 55, so the area of ​​the flat portion where the powdered resin material is likely to accumulate is reduced compared to conventional magnetic screen structures. In addition, the powdered resin material that falls onto the drop guide surface 58 easily slides down from the magnetic screen 42 along the drop guide surface 58. These effects make it possible to suppress the accumulation of the powdered resin material on the magnetic screen 42 and improve the permeability of the powdered resin material compared to magnetic screens with conventional structures that are flat except for the opening 55.

[0046] In this embodiment, the drop guide surfaces 58 of the magnet bars 54a intersect at the upper ends of the magnet bars 54a. This prevents a flat area from being formed at the upper ends of the magnet bars 54a. This prevents the powdered resin material from accumulating in the attraction section 54, thereby more effectively improving the penetration efficiency of the powdered resin material.

[0047] Furthermore, in this embodiment, the mesh screen 43 is installed below the magnetic screen 42, so that small non-magnetic foreign matter that cannot be captured by the magnetic screen 42 can be captured by the mesh screen 43. Therefore, damage to the continuous mixer 10 downstream can be more effectively prevented.

[0048] In this embodiment, a temporary mesh screen 52 is also provided. That is, during the test run, there is a high risk of small foreign objects, whether metallic or non-metallic, falling through, so the temporary mesh screen 52, which has a finer mesh than the mesh screen 43 used during normal operation, is temporarily used. This prevents damage to the downstream continuous mixer 10. However, the temporary mesh screen 52 has a fine mesh, which prevents powder from entering during normal operation. For this reason, by removing the temporary mesh screen 52 during normal operation, it is possible to prevent a deterioration in the permeation efficiency of the powder resin material during normal operation.

[0049] Furthermore, in this embodiment, the magnetic screen 42 is installed in an inclined state so that its position decreases as it moves from the installation opening 45 toward the opposite side of the installation opening 45, so that the magnetic screen 42 can be reliably prevented from coming out by its own weight when the installation opening 45 is opened.

[0050] The disclosed embodiments should be considered illustrative in all respects and not restrictive. The present invention is not limited to the above-described embodiments, and various modifications and improvements are possible without departing from the spirit and scope of the present invention. For example, in the above-described embodiments, the cross section of the magnet bar 54a is circular, but this is not limited thereto. As long as the upper surface of the attraction portion 54 has a drop guide surface 58 that slopes downward toward the opening 55, the cross section of the magnet bar 54a may be polygonal, as shown in Figures 7 and 8. If the shape is a polygon, such as a triangle or rhombus with a vertex at the top, the drop guide surface 58 will be included.

[0051] In these cases, an opening 55 is located on each side of each magnet bar 54a, and two (or more) drop guide surfaces 58 are provided to correspond to each opening 55. These two adjacent drop guide surfaces 58 intersect at the upper end of the magnet bar 54a (attraction portion 54). Therefore, the upper end of each magnet bar 54a is not a horizontal flat portion. This makes it possible to prevent the powder resin material from accumulating on the attraction portion 54.

[0052] 9, the magnet bars 54a may have a thin plate-like cross section with an inclined width. In this case, the surface facing diagonally upward becomes the drop guide surface 58. In this configuration, the adjacent magnet bars 54a may be arranged so as to partially overlap each other when viewed from above.

[0053] 10, the drop guide surface 58 may be curved. Although the upper end of the magnet bar 54a includes a horizontal, flat portion, the provision of the drop guide surface 58 reduces the area of ​​the flat portion on the upper surface. This reduces the amount of powder resin material that accumulates on the attraction unit 54.

[0054] 11, the attraction unit 54 may be configured with a plurality of magnet bars 54a arranged in parallel, each having an inclined surface at its upper corner. Even in this case, the provision of the drop guide surface 58 reduces the area of ​​the flat portion on the upper surface, thereby reducing the amount of powder resin material that accumulates on the attraction unit 54. The magnet bars 54a having the cross-sectional shape shown in FIG. 11 may be arranged in a lattice pattern. In this case, the openings 55 form the lattice.

[0055] 12 and 13, the suction portion 54 may be formed of a perforated flat plate having a plurality of openings 55 formed therein. In this case, an inclined drop guide surface 58 is formed at the upper end of each opening 55. The shape of the openings 55 may be rectangular as shown in FIG. 12, or may be circular as shown in FIG. 13.

[0056] In the above embodiment, an example has been described in which the hopper 30 is assembled to the continuous mixer 10, but the hopper 30 may also be assembled to a mixer of another type. That is, instead of being assembled to the continuous mixer 10, the hopper 30 may be assembled to a batch-type mixer, or may be assembled to a mixer other than a screw-type mixer. [Explanation of symbols]

[0057] 10: Continuous mixer 30: Hopper 31: Hopper body 35: Outlet 42: Magnetic screen 43: Mesh screen 45: Installation port 52: Temporary mesh screen 54: Adsorption part 54a: Magnet bar 55: Opening 58: Fall guide surface

Claims

1. A hopper that supplies powdered resin material to a kneader below, The hopper body, a magnetic screen disposed inside the hopper body and configured to capture metallic foreign objects; the magnetic screen has a magnetized attracting portion disposed in the internal space of the hopper body so as to cross the conveying direction of the powdered resin material, and an opening portion through which the powdered resin material dropping from above the magnetic screen passes downward, A hopper characterized in that the suction portion has a drop guide surface on its upper surface that descends toward the opening.

2. the magnetic screen has a plurality of the openings, the suction portion has a plurality of the drop guide surfaces corresponding to the plurality of openings, 2. The hopper according to claim 1, wherein the adjacent drop guide surfaces intersect at the upper end of the suction portion.

3. The hopper further includes a mesh screen disposed in the internal space of the hopper body so as to cross the direction of conveyance of the powder resin material, 2. The hopper according to claim 1, wherein the mesh screen is installed below the magnetic screen and has finer meshes than the openings of the magnetic screen.

4. the hopper body has a discharge port for discharging the powdered resin material from a lower end side of the hopper body, the hopper further comprises a temporary mesh screen covering the discharge outlet; 4. The hopper according to claim 3, wherein the temporary mesh screen has finer meshes than the mesh screen, is attached during a test run of the kneader, and is removed from the hopper body during normal operation.

5. The hopper body further includes an installation port for installing the magnetic screen in the hopper body or removing the magnetic screen from the hopper body, 2. The hopper according to claim 1, wherein the magnetic screen is installed in the hopper body in an inclined state so that the position of the magnetic screen decreases from the installation opening toward the opposite side of the installation opening.

Images