Mill body for milling and milling apparatus

Abstract

The mortar body for the mill is made of ceramics and has a vitreous cutting blade having a surface made of glaze for improving sharpness.SOLUTION: A mortar of a mill device is composed of an annular outer blade 7 in which a spiral multi-thread inner peripheral blade 7a is formed on an inner peripheral surface, and a substantially conical inner blade 8 which is inserted into an inner peripheral hole of the outer blade 7 and rotationally driven and in which a spiral multi-thread outer peripheral blade 8a is formed on an outer peripheral surface. The base material of the outer blade 7 and the inner blade 8 is a ceramic material, and the surface of the base material has a glazed and baked vitreous skin that serves as a crushing blade. The cutting edge has an uneven surface formed by grinding ceramics and vitreous material.SELECTED DRAWING: Figure 5

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] Tools for grinding food materials such as coffee beans, sesame seeds, tea leaves, and spices have long been known, including manual and electrically driven types, and various methods and mechanisms have been proposed and widely used. Among these, the present applicant has proposed a manual milling device. In this milling device, the mortar for grinding the material to be ground comprises an annular outer blade with a blade shape formed on the inner circumference and a roughly conical inner blade with a blade shape formed on the outer circumference, inserted into the outer blade and driven to rotate (e.g., Patent Document 1). A ceramic mortar has also been proposed. Furthermore, the present applicant has proposed a blade shape for the mortar, consisting of the outer and inner blades, that minimizes grinding unevenness, produces a large amount of powder with the desired particle size, and achieves stable particle size (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 materials such as coffee beans, the blade shapes formed on the outer and inner blades of the mortar wear over time, causing them to lose their sharpness. This dullness results in an increase in fine powder, which, in the case of coffee beans, can cause unpleasant flavors such as astringency. Furthermore, for example, grinding coffee beans or spices with a metal mortar can cause people with sensitive tastes to notice a metallic odor, making metal mortars unsuitable. The present applicant has therefore proposed, manufactured, and sold ceramic mortars. However, because ceramic mortars are hard, there is a problem in that the blade tips are prone to slight chipping when grinding materials such as coffee beans or spices. Furthermore, when grinding materials, it is preferable to discharge the material as quickly as possible after grinding. Generally, ceramics are known for their hardness, wear resistance, heat resistance, and corrosion resistance. However, ceramic mortars are not subjected to surface treatment such as polishing after firing. This creates a rough surface, which can catch the material to be crushed, 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 the material, it will be compressed even after being crushed, and will likely turn into powder with smaller particle sizes.

[0005] The present invention aims to achieve the following objects against the backdrop of the above problems. An object of the present invention is to provide a mill die made of ceramics that cuts materials to be ground with good sharpness, 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 pulverized material, and a mill apparatus using the same. A further object of the present invention is to provide a mill die made of ceramics that can be ground by a re-inspection machine, and a mill apparatus using the die. [Means for solving the problem]

[0006] In order to solve the above problems, the present invention employs the following means. That is, 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-thread inner peripheral blade formed on its inner peripheral surface, and an approximately conical inner blade that is inserted into the inner peripheral hole of the outer blade and driven to rotate, and has a spiral, multi-thread outer peripheral blade formed on its outer peripheral 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 that is glazed and fired.

[0007] The mill mortar of Invention 2 is characterized in that, in Invention 1, the cutting edges of the inner cutting edge and the outer cutting edge are grinding surfaces having uneven surfaces where the ceramic and / or the glassy material has been ground. The mill die of Invention 3 is Invention 2, wherein the grinding surface has a wavy uneven surface where 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 cutting edge is formed into a spherical or conical surface, and the lower part of the outer cutting edge is formed into a spherical or conical surface. The mill device of Invention 5 is characterized in that, in Inventions 1 to 3, the inner cutter is rotated by a manual handle.

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

[0010] [glaze] The glaze referred to in the present invention is a glaze applied to the surface of the ceramics that make up the outer and inner blades, and is fired to form a glassy surface, a type commonly used in 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 amount of glass powder contained in the glaze is not particularly limited, but the amount of glass powder is preferably, for example, 50% by weight or more but less than 100% by weight, and more preferably 70% by weight or more but less than 100% by weight, based on the total weight of the solids contained in the glaze. [Glassy skin] The glassy skin referred to in the present invention is a layer formed on the surface of the ceramic outer and inner blades that make up the mill mortar, and serves as the cutting edge for crushing objects such as coffee beans. The glassy skin is hard and, when ground, forms a sharp cutting edge at the corners, resulting in good cutting performance and efficient crushing when used to shear, crush, etc. objects such as coffee beans. [Grinding surface] The ground surface in this 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 ground surface may be processed by grinding with a fixed grindstone or by polishing the inner and outer cutting edges together with free abrasive grains. [Effects of the Invention]

[0011] The mortar of the present invention has a ceramic body and a glassy surface formed by firing, making it hard and sharp for grinding materials, allowing for smooth removal of the ground material after grinding, and allowing for re-grinding and polishing after wear. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a perspective view showing the appearance of a coffee mill device. [Figure 2] FIG. 2 is a cross-sectional view taken along line AA in FIG. [Figure 3] FIG. 3 is an exploded view of the coffee grinder. [Figure 4] FIG. 4 is an enlarged vertical cross-sectional view showing the outer cutter and the inner cutter. [Figure 5] FIG. 5 is an enlarged perspective view showing the outer cutter and 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 grindstone. [Figure 10] FIG. 10 is a cross-sectional view showing a method for grinding the inner cutting edge with a cylindrical conical grindstone and the grindstone. [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 cutting edge taken with a scanning electron microscope (SEM). [Figure 14] Figure 14 is a surface photograph of the unpolished cutting edge of the inner cutting edge taken with a scanning electron microscope (SEM). DETAILED DESCRIPTION OF THE INVENTION

[0013] An embodiment of the present invention will now be described with reference to the drawings. Fig. 1 is an external view showing the exterior of a coffee mill, 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. As shown in Figs. 1 to 3, the mill 1 comprises a grinding unit 2 that grinds coffee beans 5 into 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 allow the user to hold and operate it. The crushing unit 2 comprises a cylindrical container body 6 that is open at the top and bottom, an annular outer cutter 7 that is fixed non-rotatably to the lower part of the container body 6 and has a spiral, multi-thread inner peripheral blade 7a formed on its inner peripheral surface in a spherical shape, an approximately conical inner cutter 8 that is non-rotatably inserted into the lower part of the drive shaft 3 while facing the inside of the outer cutter 7 and has a spiral, multi-thread outer peripheral blade 8a formed on its outer peripheral surface, and an adjustment nut 9 that is threaded onto the threaded portion 3a at the lower end of the drive shaft 3. The inner cutter 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 removably fitted to the upper opening 6a of the container body 6, and a bottomed, cylindrical storage container 12 that is open upward and removably fitted to the lower opening 6b of the container body 6. In this crushing unit 2, the lid 11, container body 6, and storage container 12 are made of, for example, synthetic resin, metal, or ceramic, and an axial hole 11a is opened at approximately the center of the lid 11 in a plan view. A cylindrical bearing 13a is disposed on the axis of the interior of the container body 6, and this bearing 13a is fixed to the inner wall 6c of the container body 6 via a fixing portion 13b. The bearing 13 is formed by the bearing 13a and the fixing portion 13b. Positioning washers 14 and 15 are fitted into the upper and lower ends of the bearing 13a. As a result, the upper end of the drive shaft 3 is inserted into the shaft hole 11a and protrudes upward, and the middle portion can be rotatably supported by the bearing 13 with the washers 14 and 15.

[0015] FIG. 4 is an enlarged longitudinal cross-sectional view of the outer cutter 7 and the inner cutter 8, FIG. 5 is an enlarged perspective view of the outer cutter 7 and the inner cutter 8 as viewed from below, and FIG. 6 is an enlarged perspective view of the outer cutter 7 and the inner cutter 8 as viewed from above. As shown in FIGS. 4 to 6, the outer cutter 7 is made of ceramic, and the inner cutter 7a has a coarse feed blade 7a1 formed on its upper inner surface as the inner cutter 7a. The lower end opening edge of the outer cutter 7 is formed to expand in diameter outward, and this inclined surface has a fine crushing blade 7a2 formed in a spherical shape. The inner cutter 8 is also made of ceramic, and the outer cutter 8a has a coarse spiral feed blade 8a1 formed on its upper outer surface as the outer cutter 7a, and a fine crushing blade 8a2 formed in a conical shape on its lower outer surface. Furthermore, the inner cutter 8 has a through-hole 8b penetrating vertically. The anti-rotation member 10 is made of, for example, synthetic resin, and has a shaft hole 10a penetrating vertically, through which the 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 not to be able to rotate.

[0016] The shaft 10b is inserted into the through-hole 8b of the inner cutter 8 from below, thereby engaging the flange 10b2 at the tip of the shaft 10b of the anti-rotation member 10 with the opening edge of the through-hole 8b of the inner cutter 8. Furthermore, by engaging and engaging multiple locking protrusions (not shown) formed upward on the outer periphery of the shaft 10b with multiple locking recesses 8c on the underside of the inner cutter 8, the anti-rotation member 10 can be fixed to the inner cutter 8. Additionally, the adjusting nut 9 is made of, for example, synthetic resin, and has a threaded hole 9a that penetrates vertically. The threaded portion 3a of the drive shaft 3 is threaded into this threaded hole 9a. A rotatable annular portion 9b is formed on the upper part of the adjusting nut 9 and on the underside of the anti-rotation member 10. Thus, the shaft 10b of the anti-rotation member 10 is inserted into the through-hole 8b of the inner cutter 8, and the inner cutter 8 and the anti-rotation member 10 are fixed and integrated together in a non-rotatable manner. Furthermore, by inserting the lower end of the drive shaft 3 into the shaft hole 10a of the anti-rotation member 10 and engaging the ribs 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 not to be able to rotate.

[0017] Furthermore, by threading the threaded portion 3a at the lower end of the drive shaft 3 into the threaded hole 9a of the adjusting nut 9, the crushing blades 7a2, 8a2 of the outer cutter 7, which is fixed non-rotatably to the container body 6, and the inner cutter 8, through which the drive shaft 3 is non-rotatably inserted, can be arranged facing each other. In addition, a biasing spring 33 is wound around the drive shaft 3 between the washer 15 for positioning the drive shaft 3 and the flange portion 10b2 of the anti-rotation member 10. By rotating the adjusting nut 9 threaded onto the threaded portion 3a, the inner cutter 8, which is integrated with the anti-rotation member 10, can be pushed toward the outer cutter 7 against the elastic force of the biasing spring 33. This allows the spacing between the crushing blades 7a2, 8a2 to be precisely adjusted, enabling fine adjustment of the grind size of the coffee powder 5a.

[0018] When using the mill device 1 configured as described above for grinding, first, the operating handle 4 is removed from the upper end of the drive shaft 3, and then the lid 11 of the grinding unit 2 is removed and attached upward from the container body 6 to open the upper opening 6a. Coffee beans 5 are then poured into the container body 6 through the upper opening 6a. The poured coffee beans 5 then flow down inside the container body 6 and enter the gap 19 between the cylindrical outer blade 7 and the generally conical inner blade 8 inserted into the outer blade 7 from below. The upper opening 6a of the container body 6 is then 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 axial hole 11a of the lid 11. Then, the container body 6 is held in one hand and the grip 16 of the operating handle 4 is gripped and rotated with the other hand, causing the inner blade 8 to rotate and grind the coffee beans 5 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 inside the storage container 12 can be taken out and used.

[0019] During this process, 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 cutter 7 fixed inside the container body 6 and a feed blade 8a1 on the upper outer peripheral surface of the inner cutter 8, which is manually rotated in one direction relative to the outer cutter 7. The coffee beans 5 are then crushed even finer between the crushing blades 7a2, 8a2 formed on the outer cutter 7 and the inner cutter 8, and are efficiently discharged. Furthermore, as described above, the inner cutter 8 is advanced and retreated axially along the drive shaft 3 using an adjustment nut 9 threaded onto the lower end of the drive shaft 3, thereby precisely changing the spacing between the crushing blades 7a2, 8a2 and adjusting the particle size of the coffee powder 5a according to the type of coffee beans 5 and the user's preference.

[0020] In the embodiment of the present invention, the outer blade 7 and inner blade 8 are made of ceramics and are glazed and fired. The outer blade 7 and inner blade 8 are made of 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). They are 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). The dried outer blade 7 and inner blade 8 are then coated with the glaze and oxidized and fired in an electric furnace at 1280°C for approximately 10 hours. The outer blade 7 and inner blade 8 may also be formed, dried, bisque fired, and then fired using conventional methods. In the embodiment of the present invention, the glazed and fired outer blade 7 and inner blade 8 are ground with a grinding wheel to polish the glassy surface before use. FIG. 7 is an external view showing a method of grinding the blade (crushing blade 7a2) of the outer cutter 7 with a conical grindstone 74 and the grinding wheel.

[0021] Figure 8 is an external view of the grinding wheel and a method for grinding the outer blade 7 (crushing blade 7a2) with a hemispherical grinding wheel 75. Figure 9 is an external view of the grinding wheel and a method for grinding the outer blade 7 (crushing blade 7a2) with a spherical grinding wheel 76. Figure 10 is a cross-sectional view of the grinding wheel and a method for grinding the inner blade 8 (crushing blade 8a2) with a cylindrical conical grinding wheel 83. In addition to the grinding methods using grinding wheels shown in Figures 7 to 10, there is also a method of grinding the outer blade 7 and inner blade 8 by rubbing them together (co-grinding). This method involves grinding with a loose abrasive, such as cerium oxide abrasive. Figures 11(a) to 11(f) are surface photographs of the ground cutting edge of the outer blade 7 taken 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 unground cutting edge of the outer blade 7 taken with a scanning electron microscope (SEM).

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

[0023] As shown in the scanning electron microscope photographs of Figures 11 to 14, the glazed and polished outer blades 7 and inner blades 8 have a wavy, finely textured surface where the glassy glaze has been ground away. This finely textured surface has few irregularities and is not rough, so the material to be crushed does not get caught, and the material crushed by the outer blades 7 and inner blades 8 is easily discharged from the crushing position, resulting in excellent cutting performance for the material. Furthermore, because the surfaces of the outer blades 7 and inner blades 8 are coated with a glass skin, if they wear out and become dull, they can be re-sharpened to improve their sharpness.

[0024] [Other embodiments] The outer blade 7 and inner blade 8 described above have a wavy, finely textured surface formed by grinding the glassy glaze. However, grinding is not required to form this finely textured surface. When using the mill device 1, the edges of the fired outer blade 7 and inner blade 8 wear down as they crush materials such as coffee beans. In particular, the glassy glaze portion of the cutting edge gradually wears away from the initial use, resulting in a finely textured surface. In other words, the glazed outer blade 7 and inner blade 8 naturally develop their cutting edges with use. However, if uneven wear occurs, it is recommended to reshape them by regrinding or repolishing. Furthermore, a conical grinding wheel 74, a hemispherical grinding wheel 75, and a spherical grinding wheel 76 were used to grind the outer blade 7, and a conical grinding wheel 83 was used to grind the inner blade 8. However, the shape of these grindstones is not limited to this, and for example, grinding of the inner cutting edge 8 may be performed using 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...biasing spring 4...Operating handle 5...Coffee beans 5a...Coffee powder 6...Container body 6a...Top opening 6b…Bottom opening 6c…Inner wall 7...Outer blade 74...Conical grinding stone 75...Semi-spherical grinding stone 76...Spherical grinding stone 7a…Inner peripheral blade 7a1...feed blade 7a2…Crushing blade 8...Inner blade 83...Conical grinding stone 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 its inner peripheral surface; an inner cutter having a generally conical shape, which is inserted into the inner peripheral hole of the outer cutter and rotated, and which has a spiral multi-thread outer cutter formed on its outer peripheral surface; A milling device having a mortar comprising: The base material of the outer cutter and the inner cutter is made of ceramic, and the surface of the base material has a glassy skin that is glazed and fired. A mill die body characterized in that it is

2. The mill die body according to claim 1, The cutting edges of the inner cutting edge and the outer cutting edge are grinding surfaces having uneven surfaces formed by grinding the ceramic and / or the vitreous material. A mill die body characterized by:

3. The mill die body according to claim 2, The ground surface has a wavy uneven surface where the glassy substance is chipped. A mill die body characterized by:

4. The mill die body according to claim 1 or 2, The grinding surface of the lower part of the inner peripheral cutting edge is formed into a spherical or conical surface, and the lower part of the outer peripheral cutting edge is formed into a spherical or conical surface. A mill die body characterized by:

5. A mill device using the mill die body according to any one of claims 1 to 3, The inner blade is rotated by a manual handle. A mill apparatus characterized by:

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