Mill body and milling device

Abstract

This is a mill mortar made of ceramics with a glassy cutting edge whose surface is glazed to improve sharpness. [Solution] The milling machine includes an annular outer blade 7 having a spiral multi-thread inner peripheral blade 7a formed on its inner peripheral surface, and an approximately conical inner blade 8 having a spiral multi-thread outer peripheral blade 8a formed on its outer peripheral surface, which is inserted into an inner peripheral hole of the outer blade 7 and driven to rotate. The base material of the outer blade 7 and the inner blade 8 is made of ceramics, and the surface of the base material has a glassy skin that is glazed and fired to become a crushing blade. The cutting edge has an uneven surface where the ceramic and glassy material are ground.

Description

[Technical field]

[0001] The present invention relates to a mill mortar and a milling device using the same, and more particularly to a mill mortar and a milling device using the same, for use in manual or electric mills for grinding food materials such as coffee beans, sesame seeds, tea leaves, and spices. [Background technology]

[0002] For a long time, manual and electrically driven tools have been known for grinding food materials such as coffee beans, sesame seeds, tea leaves, and spices, and various methods and mechanisms have been proposed and widely used. Among them, the applicant proposed a manual mill device. In this mill device, the mortar for grinding the material to be ground has a mortar composed of an annular outer blade with a blade shape formed on the inner circumference and an approximately conical inner blade with a blade shape formed on the outer circumference, which is inserted into the outer blade and driven to rotate (for example, Patent Document 1). This mortar has also been proposed to be made of ceramics. Furthermore, the applicant proposed a blade shape for the mortar composed of the outer blade and the inner blade, which has less uneven grinding and can produce a large amount of powder with a desired particle size, thereby achieving particle size stability (Patent Document 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] WO2017 / 109836 [Patent Document 2] WO2020 / 217500 Summary of the Invention [Problem to be solved by the invention]

[0004] On the other hand, when grinding objects such as coffee beans, the blade shape formed on the outer blade and inner blade of the mortar wears with continued use and becomes dull. When the sharpness becomes dull, fine powder increases, and in the case of coffee beans, this can cause unpleasant tastes such as astringency. In addition, for example, when coffee beans, spices, etc. are ground with a metal mortar, people who are sensitive to taste will feel a metallic odor, so a metal mortar is not suitable. Therefore, the applicant has proposed, manufactured, and sold a ceramic mortar, but since the ceramic mortar is hard, there is a problem that the tip of the blade is easily chipped, even if slightly, when grinding objects such as coffee beans and spices. Furthermore, when grinding objects to be ground, it is preferable to discharge the objects as quickly as possible after grinding. In general, ceramics are known to have characteristics such as being hard and brittle, being resistant to wear, being heat resistant, and being resistant to corrosion. However, ceramic mortars are not surface-treated, such as polished, after firing. This creates a rough surface, which can cause the material to get caught on it, making it difficult for the material crushed by the outer and inner blades to be discharged from the crushing position. If the material is not discharged smoothly when crushing, it will be compressed and easily become a powder with smaller particle size.

[0005] The present invention aims to achieve the following objects against the background of the above problems. An object of the present invention is to provide a mill body made of ceramics which provides good cutting ability for materials to be ground, and a mill device using the same. Another object of the present invention is to provide a mill die body made of ceramics which has high dischargeability of ground material, and a mill apparatus using the same. Yet another object of the present invention is to provide a ceramic die. Regrinding The present invention aims to provide a mill body and a mill device thereof, which can achieve the above object. [Means for solving the problem]

[0006] In order to solve the above problems, the present invention takes the following measures. In other words, the mill mortar of the present invention 1 is a mill device having a mortar consisting of an annular outer blade with a spiral, multi-strand inner blade formed on its inner surface, and an approximately conical inner blade which is inserted into the inner hole of the outer blade and driven to rotate, and which has a spiral, multi-strand outer blade formed on its outer surface, characterized in that the base materials of the outer blade and the inner blade are made of ceramics, and the surface of the base material has a glassy skin which is glazed and fired.

[0007] The mill mortar of the present invention 2 is characterized in that, in the present invention 1, the cutting edges of the inner blade and the outer blade are grinding surfaces having uneven surfaces formed by grinding the ceramics and / or the vitreous material. The mill dies of the third invention are characterized in that, in the second invention, the grinding surface has a wavy uneven surface in which the glassy substance is chipped.

[0008] The mill mortar of Invention 4 is characterized in that, in Invention 1 or 2, the grinding surface of the lower part of the inner blade is formed into a spherical or conical surface, and the lower part of the outer blade is a spherical or conical surface. The mill device of Invention 5 according to Inventions 1 to 3 is characterized in that the inner blade is rotated by a manual handle.

[0009] [Ceramics] The ceramics referred to in this invention are the materials that compose the outer and inner blades of the mill mortar, and are not special, but are generally called pottery, porcelain, etc., and are made of inorganic materials. Compared to metals and plastics, they are hard and brittle, resistant to wear, heat-resistant, and resistant to corrosion.

[0010] [glaze] The glaze referred to in the present invention is applied to the surface of the ceramics constituting the outer blade and the inner blade, and is fired to form a glassy skin, which is a common type used for pottery, porcelain, etc. Therefore, the glaze contains glass powder with a typical particle size of, for example, about 7 μm or less, and also contains, for example, feldspar, clay, limestone, silica, talc, etc. The content of the glass powder in the glaze is not particularly limited, but the content of the glass powder is preferably, for example, 50% by weight or more and less than 100% by weight, and more preferably 70% by weight or more and less than 100% by weight, based on the total weight of the solids contained in the glaze. [Glassy skin] The vitreous skin in the present invention is a layer formed on the surface of the ceramic outer and inner blades that constitute the mill mortar, and serves as the cutting edge for crushing objects such as coffee grains. The vitreous skin is hard and has sharp edges when ground, so when used for shearing, crushing, etc. objects such as coffee beans, it provides good cutting performance and high crushing efficiency. [Grinding surface] The ground surface in the present invention refers to the portion of the inner and outer cutting edges that has an uneven surface formed by grinding or polishing the ceramic and / or glass material. The grinding surface may be processed by grinding with a fixed grindstone or by polishing the inner and outer cutting edges together with free abrasive grains. Effect of the Invention

[0011] The mortar of the present invention has a ceramic body and a glassy skin formed on its surface by sintering, making it hard and sharp for cutting materials to be crushed, allowing smooth removal of crushed materials after crushing, and enabling it to be reground and polished after wearing down. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a perspective view showing the appearance of a coffee mill device. [Diagram 2] FIG. 2 is a cross-sectional view taken along line AA of FIG. [Diagram 3] FIG. 3 is an exploded view of the coffee grinder device. [Figure 4] FIG. 4 is an enlarged vertical cross-sectional view showing the outer cutter and the inner cutter. [Diagram 5] FIG. 5 is an enlarged perspective view showing the outer cutter and the inner cutter as viewed from below. [Figure 6] FIG. 6 is an enlarged perspective view showing the outer cutter and the inner cutter as viewed from above. [Figure 7] FIG. 7 is an external view showing a method of grinding the outer cutter blade with a conical grindstone and the grinding wheel. [Figure 8] FIG. 8 is an external view showing a method of grinding the outer cutter blade with a hemispherical grindstone and the grinding wheel. [Figure 9] FIG. 9 is an external view showing a method of grinding the outer cutter blade with a spherical grindstone and the grinding wheel. [Figure 10] FIG. 10 is a cross-sectional view showing a method of grinding the inner cutting edge with a cylindrical conical grindstone and the grinding wheel. [Figure 11] Figure 11 is a surface photograph of the ground cutting edge of the outer blade taken with a scanning electron microscope (SEM). [Figure 12] Figure 12 is a surface photograph of the unpolished cutting edge of the outer blade taken with a scanning electron microscope (SEM). [Figure 13] Figure 13 is a surface photograph of the ground cutting edge of the inner blade taken with a scanning electron microscope (SEM). [Figure 14] Figure 14 is a surface photograph of the unpolished cutting edge of the inner blade taken with a scanning electron microscope (SEM). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is an external view showing the appearance of a coffee mill device, Fig. 2 is a cross-sectional view taken along line AA in Fig. 1, and Fig. 3 is an exploded view of the coffee mill device. As shown in Figs. 1 to 3, the mill device 1 includes a grinding unit 2 that grinds coffee beans 5 to produce coffee powder 5a, a drive shaft 3 whose lower end is connected to an inner blade 8 that rotates within the grinding unit 2, and an operating handle 4 whose one end is connected to the drive shaft 3. A grip 16 is provided at the other end of the operating handle 4 to be held and operated. The crushing unit 2 includes a cylindrical container body 6 that is open at the top and bottom, an annular outer blade 7 that is fixed non-rotatably to the lower part of the container body 6 and has a helical, multi-thread inner peripheral blade 7a formed in a spherical shape on its inner peripheral surface, an approximately conical inner blade 8 that is non-rotatably inserted into the lower part of the drive shaft 3 while facing inside the outer blade 7 and has a helical, multi-thread outer peripheral blade 8a formed on its outer peripheral surface, and an adjustment nut 9 that is screwed into the threaded part 3a at the lower end of the drive shaft 3. The inner blade 8 is non-rotatably fitted to the outside of the drive shaft 3 via a rotation-stopping member 10.

[0014] The crushing unit 2 includes a disk-shaped lid 11 that is detachably fitted to the upper end opening 6a of the container body 6, and a bottomed cylindrical storage container 12 that is detachably fitted to the lower end opening 6b of the container body 6. In such a crushing unit 2, the lid 11, the container body 6, and the storage container 12 are made of, for example, synthetic resin, metal, or ceramics, and an axial hole 11a is opened in the approximate center of the lid 11 in a plan view. A cylindrical shaft support portion 13a is disposed on the axis inside the container body 6, and this shaft support portion 13a is fixed to the inner wall 6c of the container body 6 via a fixing portion 13b. The shaft support portion 13a and the fixing portion 13b form a bearing 13. Positioning washers 14 and 15 are fitted into the upper and lower ends of the shaft support portion 13a. As a result, the upper end of the drive shaft 3 is inserted through the shaft hole 11a and protrudes upward, and the middle portion can be rotatably supported by the bearing 13 via washers 14 and 15.

[0015] FIG. 4 is an enlarged vertical cross-sectional view showing the outer blade 7 and the inner blade 8, FIG. 5 is an enlarged perspective view showing the outer blade 7 and the inner blade 8 as viewed from below, and FIG. 6 is an enlarged perspective view showing the outer blade 7 and the inner blade 8 as viewed from above. As shown in FIG. 4 to FIG. 6, the outer blade 7 is made of ceramics, and as the inner peripheral blade 7a, a coarse feed blade 7a1 is formed on the upper inner peripheral surface. In addition, the lower end opening edge of the outer blade 7 is formed to expand in diameter toward the outside, and a fine crushing blade 7a2 is formed on this inclined surface in a spherical shape. The inner blade 8 is also made of ceramics, and as the outer peripheral blade 8a, a coarse spiral feed blade 8a1 is formed on the upper outer peripheral surface, while a fine crushing blade 8a2 is formed on the lower outer peripheral surface in a conical shape. Furthermore, the inner blade 8 is formed with a through hole 8b penetrating vertically. The rotation stop member 10 is made of, for example, synthetic resin, and has a shaft hole 10a penetrating vertically, through which the above-mentioned drive shaft 3 is inserted. The protrusions 3b, 3b protruding from the lower side surface of the drive shaft 3 are engaged with the slit portion 10b1 of the shaft portion 10b of the anti-rotation member 10, so that the anti-rotation member 10 can be inserted onto the drive shaft 3 so as to be unable to rotate.

[0016] The shaft 10b is inserted into the through hole 8b of the inner blade 8 from below, and the flange portion 10b2 at the tip of the shaft 10b of the rotation-stopping member 10 is engaged with the opening edge of the through hole 8b of the inner blade 8. The rotation-stopping member 10 can be attached to the inner blade 8 so as not to rotate by fitting and engaging a plurality of locking protrusions (not shown) formed on the outer periphery of the shaft 10b facing upward into a plurality of locking recesses 8c on the underside of the inner blade 8. In addition, the above-mentioned adjusting nut 9 is made of, for example, synthetic resin, and has a screw hole 9a penetrating vertically, into which the screw portion 3a of the above-mentioned drive shaft 3 is screwed. A rotatable annular portion 9b is formed on the underside of the rotation-stopping member 10 at the top of the adjusting nut 9. As a result, the shaft 10b of the rotation-stopping member 10 is inserted into the through hole 8b of the inner blade 8, and the inner blade 8 and the rotation-stopping member 10 are attached and integrated so as not to rotate. Furthermore, by inserting the lower end of the drive shaft 3 into the axial hole 10a of the anti-rotation member 10 and engaging the protrusions 3b, 3b of the drive shaft 3 with the slit portion 10b1 of the shaft portion 10b, the inner blade 8 can be inserted into the drive shaft 3 via the anti-rotation member 10 so as to be unable to rotate.

[0017] Furthermore, by screwing the threaded portion 3a at the lower end of the drive shaft 3 into the screw hole 9a of the adjustment nut 9, the crushing blades 7a2, 8a2 of the outer blade 7 fixed to the container body 6 so as not to rotate and the inner blade 8 through which the drive shaft 3 is inserted so as not to rotate can be arranged in a state where they face each other. In addition, a biasing spring 33 is wound on the drive shaft 3 between the washer 15 for positioning the drive shaft 3 and the flange portion 10b2 of the rotation prevention member 10. By rotating the adjustment nut 9 screwed into the threaded portion 3a, the inner blade 8 integrated with the rotation prevention member 10 can be pushed toward the outer blade 7 against the elastic force of the biasing spring 33. This allows the interval between the crushing blades 7a2, 8a2 to be precisely changed, and the grain size of the coffee powder 5a to be finely adjusted.

[0018] In the above-described configuration, when the mill device 1 is used for grinding, the operating handle 4 is first removed from the upper end of the drive shaft 3, and then the lid 11 of the grinding unit 2 is removed upward from the container body 6 to open the upper end opening 6a, and coffee beans 5 are thrown into the container body 6 through the upper end opening 6a. The thrown coffee beans 5 then flow down inside the container body 6 and enter the gap 19 between the cylindrical outer blade 7 and the approximately conical inner blade 8 inserted into the outer blade 7 from below. Thereafter, the upper end opening 6a of the container body 6 is closed again with the lid 11, and one end of the operating handle 4 is connected to the upper end of the drive shaft 3 protruding from the shaft hole 11a of the lid 11. Then, the container body 6 is held with one hand and the grip 16 of the operating handle 4 is gripped with the other hand and rotated, whereby the inner blade 8 rotates and the coffee beans 5 are ground between the outer blade 7 and the inner blade 8. The resulting coffee powder 5a flows down and accumulates in the internal space of the lower storage container 12. Then, this storage container 12 can be detached downward from the container body 6, and the coffee powder 5a in the storage container 12 can be taken out and used.

[0019] At this time, the coffee beans 5 are crushed and forcibly sent downward in a gap 19 between a feed blade 7a1 on the upper inner peripheral surface of the outer blade 7 fixed inside the container body 6 and a feed blade 8a1 on the upper outer peripheral surface of the inner blade 8 which is manually rotated in one direction relative to the outer blade 7. The coffee beans 5 are then efficiently discharged in a state where they are further crushed between the crushing blades 7a2, 8a2 formed on the outer blade 7 and the inner blade 8. Furthermore, as described above, the inner blade 8 is advanced and retreated in the axial direction along the drive shaft 3 using an adjustment nut 9 screwed onto the lower end of the drive shaft 3, thereby precisely changing the interval between the crushing blades 7a2, 8a2, and adjusting the grain size of the coffee powder 5a according to the type of coffee beans 5 and preferences.

[0020] The outer blade 7 and the inner blade 8 of the embodiment of the present invention are made of ceramics, and are glazed and fired. The material of the outer blade 7 and the inner blade 8 is reinforced porcelain clay (manufactured by Yamaka Toryo Co., Ltd. (headquarters: Gifu Prefecture, Japan), product name IMP-1 (containing alumina), with deflocculating agent A2 added as an additive), which is formed into a predetermined shape and then dried. The glaze used is product name SAG-8 (manufactured by Yamaka Toryo Co., Ltd., with bittern added as an additive). After this glaze is applied to the dried outer blade 7 and inner blade 8, they are oxidized and fired in an electric furnace at a firing temperature of 1280°C for about 10 hours. The outer blade 7 and the inner blade 8 may be formed by a conventional method, dried, bisque fired, and then fired. In the embodiment of the present invention, the outer blade 7 and the inner blade 8 that have been glazed and fired are ground with a grinding wheel, and the glassy surface is polished before use. FIG. 7 is an external view showing a method of grinding the edge (crushing edge 7a2) of the outer cutter 7 with a conical grindstone 74 and the grinding wheel.

[0021] FIG. 8 is an external view showing a method of grinding the blade (crushing blade 7a2) of the outer blade 7 with a hemispherical grindstone 75 and the grinding wheel. FIG. 9 is an external view showing a method of grinding the blade (crushing blade 7a2) of the outer blade 7 with a spherical grindstone 76 and the grinding wheel. FIG. 10 is a cross-sectional view showing a method of grinding the blade (crushing blade 8a2) of the inner blade 8 with a cylindrical conical grindstone 83 and the grinding wheel. In addition to the grinding method using the grinding wheel shown in FIG. 7 to FIG. 10, there is also a method of grinding the outer blade 7 and the inner blade 8 by rubbing them together (co-rubbing). This grinding is performed with an abrasive that is a free abrasive such as cerium oxide abrasive. FIG. 11(a) to FIG. 11(f) are surface photographs of the ground cutting edge of the outer blade 7 viewed with a scanning electron microscope (SEM). Figure 11(a) is at a magnification of 50x, Figure 11(b) is at a magnification of 100x, Figure 11(c) is at a magnification of 200x, Figure 11(d) is at a magnification of 300x, Figure 11(e) is at a magnification of 500x, and Figure 11(f) is at a magnification of 1000x. Figures 12(a) to 12(e) are surface photographs of the unpolished cutting edge of outer blade 7 taken with a scanning electron microscope (SEM).

[0022] Fig. 12(a) is a 50x magnification, Fig. 12(b) is a 100x magnification, Fig. 12(c) is a 200x magnification, Fig. 12(d) is a 300x magnification, and Fig. 12(e) is a 500x magnification. Figs. 13(a) to 13(f) are surface photographs of the ground cutting edge of the inner blade 8 taken with a scanning electron microscope (SEM). Fig. 13(a) is a 50x magnification, Fig. 13(b) is a 100x magnification, Fig. 13(c) is a 500x magnification, Fig. 13(d) is a 1000x magnification, Fig. 13(e) is a 2000x magnification, and Fig. 13(f) is a 3000x magnification. Figs. 14(a) to 14(e) are surface photographs of the unground cutting edge of the inner blade 8 taken with a scanning electron microscope (SEM). FIG. 14(a) is at a magnification of 50x, FIG. 14(b) is at a magnification of 100x, FIG. 14(c) is at a magnification of 200x, FIG. 14(d) is at a magnification of 500x, and FIG. 14(e) is at a magnification of 1000x.

[0023] As shown in the scanning electron microscope photographs of Figures 11 to 14, the outer blade 7 and inner blade 8, which have been glazed and ground, have a wavy, finely uneven surface where the glassy part of the glaze has been ground away. This finely uneven surface has few surface irregularities and is not rough, so the material to be crushed does not get caught, and the material crushed by the outer blade 7 and inner blade 8 is easily discharged from the crushing position, so the material is sharply cut. In addition, because the surfaces of the outer blade 7 and inner blade 8 are covered with a glass skin, if they wear down and become dull, they can be re-ground to improve their sharpness.

[0024] [Other embodiments] The outer blade 7 and the inner blade 8 described above have a wavy, finely uneven surface formed by grinding the glassy glaze. However, grinding is not essential to form this finely uneven surface. When the mill device 1 is used, the outer blade 7 and the inner blade 8 as fired wear down their cutting edges by crushing objects to be crushed, such as coffee beans. In particular, the glassy glaze part on the cutting edge surface wears down gradually from the beginning of use, and this wear results in a finely uneven surface. That is, the cutting edges of the glazed outer blade 7 and the inner blade 8 are naturally formed by use. However, when uneven wear occurs, it is recommended to reshape them by regrinding or repolishing them. In addition, a conical grindstone 74, a hemispherical grindstone 75, and a spherical grindstone 76 are used to grind the outer blade 7, and a conical grindstone 83 is used to grind the inner blade 8. However, the shape of these grindstones is not limited to this, and for example, the inner blade 8 may be ground with a grindstone having a convex spherical surface, a concave spherical surface, or the like. [Explanation of symbols]

[0025] 1...Mill equipment 11…Lid 11a...Shaft hole 12...Storage container 13...Bearing 13a…Axis branch 13b…Fixed part 14, 15…Washer 16…Grip 19…Gap 2...Crushing unit 3...Drive shaft 3b…Protrusion 3a…Threaded part 33... Spring 4…Operation handle 5. Coffee beans 5a…Coffee powder 6…Container body 6a...Top opening 6b…Bottom opening 6c…Inner wall 7...Outer blade 74...Conical grindstone 75...Semi-spherical grinding wheel 76...Spherical grinding wheel 7a…Inner peripheral blade 7a1…Feed blade 7a2…Crushing blade 8…Inner blade 83...Conical grindstone 8a…Peripheral blade 8a1…Feed blade 8a2...Crushing blade 8b...Through hole 8c…Latching recess 9…Adjustment nut 9a…Screw hole 9b...Annular section 10...Anti-rotation member 10a…Shaft hole 10b...Shaft part 10b1…Slit part 10b2...Flange part

Claims

1. an annular outer blade having a spiral multi-thread inner peripheral blade formed on an inner peripheral surface; A mill die having an inner blade having a generally conical shape, the inner blade being inserted into an inner peripheral hole of the outer blade and being driven to rotate, and the outer peripheral surface of the inner blade being formed with a spiral multi-thread outer peripheral blade, The base material of the outer blade and the inner blade is made of ceramics, and the surface of the base material has a glassy skin that is glazed and fired; The inner blade has a plurality of protrusions on its upper outer circumferential surface, and a coarse spiral feed blade is formed on the outer circumferential surface of the protrusions. The outer blade has a substantially triangular upper end opening, which is an opening on the opposite side to a lower end opening on which the inner blade is inserted, The distance between the edge of the upper end opening and the feed blade is long at some points and short at other points. A mill die body characterized in that

2. The mill die according to claim 1, The cutting edges of the inner peripheral blade and the outer peripheral blade are grinding surfaces having uneven surfaces formed by grinding the vitreous material, The ground surface has a wavy uneven surface where the glass material is chipped. A mill die body characterized in that

3. The mill die according to claim 2, The grinding surface of the lower part of the inner peripheral blade is formed into a spherical or conical surface, and the lower part of the outer peripheral blade is formed into a spherical or conical surface. A mill die body characterized in that

4. A milling device using the mill die according to claim 1 or 2, The inner blade is rotated by a manual handle. A mill apparatus comprising:

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