Structure of the rotating blades in food mixers

Abstract

To provide a structure of a rotary blade for mixer, in a vertical type food material mixer, capable of solving shaft shake in mixing, by a simple structure, mixing a large amount of air with a food material to be agitated in the mixing for reducing a specific gravity of the food material to be agitated.SOLUTION: There is provided a structure of a rotary blade attached to a mixer for food material, in a same horizontal rotation plane, there is provided a plurality of blade parts which extends from a rotation center to a rotation radial direction, the plurality of blade parts has a plane shape which is a point symmetry with respect to the rotation center shaft, and a plane shape of the blade parts is formed of an outside curve part facing the rotation direction, and an inside curve part with its back facing the rotation direction, in which a curvature radius of the outside curve part is greater than a curvature radius of the inside curve part. In addition, an outer edge lower face of the outside curve part, and an outside edge upper face of the inside curve part have an inclination angle to a vertical lower direction.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a mixer for food ingredients, and more specifically, to the shape and structure of a rotary blade attached to a large commercial vertical mixer that crushes, mixes, and kneads food ingredients. [Background technology]

[0002] In the food manufacturing industry, large vertical mixers with rotating blades installed at approximately the center of the bottom of the mixing vessel are often used, as shown in the attached Figure 14. This type of mixer mainly consists of a mixing vessel a in which the ingredients are crushed, mixed, and kneaded, a rotating blade b installed at approximately the center of the bottom of the mixing vessel a, a drive unit c containing an electric motor and reduction gear mechanism that rotates the rotating blade b, and a control unit d containing various electronic circuits and an operation panel that control the mixing operation.

[0003] Incidentally, the reason why such a large commercial mixer is called a "vertical mixer" is because the rotating blades b are driven by a vertical rotating shaft at approximately the center of the bottom of the mixing vessel a of the mixer. In addition, stainless steel is mainly used as the material for each part of such an ingredient mixer from the viewpoint of its strength, corrosion resistance, and hygiene for food and ingredients.

[0004] In this mixer, the rotating blade b is used to crush, break, and shred the ingredients to be mixed, and to mix and knead them, and various shapes are used. That is, a rotating blade of an appropriate shape is selected according to the type of ingredients to be mixed and the food application, and is attached as an attachment to the rotating shaft a2 that protrudes from approximately the center of the bottom of the mixing vessel a into the inside of the mixing vessel a. One specific shape of the rotating blade b is shown in the attached Figure 15.

[0005] The rotary blade b in Fig. 15 has a structure in which multiple blades (blade) b1 having a planar shape as shown in the attached Fig. 16 are stacked vertically with a ring-shaped spacer b2 in between (two blades in the example of Fig. 15). As shown in Fig. 16, the planar shape of the blade b1 curves in the opposite direction to the rotation direction as it moves from the rotation center axis to the rotation centrifugal side, forming a so-called "magatama-shaped" shape. The rotation axis is located approximately at the center of the so-called "magatama-shaped through hole" of this magatama-shaped shape.

[0006] As mentioned above, the actual rotating blade b is used by stacking two blades b1 on top of each other in two tiers with a spacer b2 in between and attaching them to the central axis of rotation. In this case, in order to maintain a balance of the rotation moment of the rotating blade during mixing, the two blades b1 are fixed in positions that are axially symmetric (point symmetric) with respect to the central axis of rotation.

[0007] When using this mixer to mix various ingredients such as cream, cake batter, or fruit pulp, first, various ingredients are put into the mixing vessel a, and then the openable lid a1 on the top of the mixing vessel is closed, and a predetermined operation instruction is given from the control unit d. As a result, inside the mixing vessel a, the rotary blade b is rotated by the electric motor or reduction gear mechanism built into the drive unit c, and the ingredients are crushed, mixed, and kneaded for a predetermined period of time based on a predetermined process.

[0008] In addition, in the course of the series of treatments, as necessary, for example, the mixing vessel a is subjected to cooling / heating treatment using cold water or hot water, or a gas such as air is blown into the mixing vessel a. Note that illustrations and explanations of the equipment and members required for these treatments are omitted because they are not directly related to the gist of the present invention. By carrying out these treatments, it is possible to create a unique flavor and texture for each of the various mixed ingredients.

[0009] However, when mixing is performed with such a mixer, the horizontal positions of the two blades arranged symmetrically about the axis of the rotating blade b as described above differ above and below with respect to the vertical direction of the central axis of rotation. This causes a shift in the point of action of the rotational moment with respect to the central axis of each blade. This can cause the so-called "shaft wobble", which is an eccentric vibration (yaw movement) of the rotating shaft, when the rotation speed of the mixer is increased.

[0010] On the other hand, when mixing ingredients with a mixer, the specific gravity of the ingredients after mixing is often an issue. That is, the smaller the specific gravity, the more air is contained in the ingredients after mixing, and the more mellow the taste and texture of the ingredients, such as cake batter, become.

[0011] In order to increase the air content in the mixed ingredients, i.e., to reduce their specific gravity, it is effective to increase the number of times the blades cross the mixed ingredients during the mixing process, because this increases the number of times the blades tear apart the pile of mixed ingredients in the mixing vessel, increasing the opportunities for the air around the mixed ingredients to be mixed into the mixed ingredients.

[0012] In the above-mentioned conventional example, when the horizontal rotation surface of one blade b1 is focused on, when the blade b1 rotates once inside the mixing vessel, the blade crosses the pile of ingredients only once. Therefore, in order to increase the number of times that the blade b1 crosses the pile of ingredients, it was necessary to increase the rotation speed of the rotating blade. However, an increase in the mixer rotation speed not only increases the power consumption, but also has the disadvantage that the temperature of the ingredients increases due to friction during mixing, resulting in a deterioration in the flavor and texture of the ingredients.

[0013] To overcome these drawbacks, a technology such as that shown in Patent Document 1 has been disclosed. In this technology, a rotating blade is provided at the bottom of a container of an ingredient mixer (food processor), and the planar shape of each blade is curved in the opposite direction to the rotation direction from the central axis of rotation to the centrifugal side.

[0014] [Patent Document 1] JP 2018-64760 A Summary of the Invention [Problem to be solved by the invention]

[0015] However, the technology shown in Patent Document 1 does not aim to solve the various problems raised in this patent, but is mainly aimed at reducing the load on the rotating parts such as the motor of the food processor. In addition, the rotary blade in this patent document is always composed of two blades of the same shape, which are regarded as one rotary blade, and each blade is rotated in the opposite direction to obtain the desired effect. Therefore, it does not suggest a fundamental solution to the problems of the present invention mentioned above.

[0016] The present invention aims to solve the above-mentioned problems by providing a rotating blade structure for a large vertical food mixer that solves the yawing (axial wobble) of the rotation center shaft during mixing with a simple structure, and mixes a large amount of air into the mixed food during the mixing process, thereby reducing the specific gravity of the mixed food. [Means for solving the problem]

[0017] The structure of the rotary blade attached to the food mixer according to the first aspect of the present invention is as follows: A plurality of blades (blade portions) extending from a central axis of rotation along a radial direction of rotation within the horizontal rotation plane of the same rotary blade are provided, and the blades (blade portions) have a planar shape that is point symmetrical with respect to the central axis of rotation. And the blade portion isThe outer curved portion faces the rotation direction, and the inner curved portion faces away from the rotation direction. The radius of curvature of the outer curved portion is larger than the radius of curvature of the inner curved portion. A structure of a rotary blade, The outer edge lower surface of the outer curved portion has a predetermined inclination angle (taper) toward the vertical direction, the outer edge upper surface of the inner curved portion has a predetermined inclination angle (taper) toward the vertical direction, and the blade (blade) portion has a predetermined angle of attack facing the horizontal rotation plane of the blade (blade) portion in the direction of rotation, the predetermined inclination angle and the set angle of attack are both in the angle range of 22° to 32°, and the range in which the inclination angle (taper) is set is 1 / 4 to 1 / 3 of the blade width length in the rotation direction of the blade (blade) portion. Effect of the Invention

[0022] According to the present invention, which is equipped with the above-mentioned means for solving the problems, it is possible to prevent the shaft from shaking during the mixing process in a large vertical food mixer, and to reduce the specific gravity of the mixed food after mixing, thereby producing food with a mellow and good texture. In addition, it is not necessary to rotate the mixer at a relatively high speed, and it is also possible to omit the cooling process of the mixing vessel during mixing. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following describes the best mode for implementing the present invention with reference to the accompanying drawings.

[0024] (1) Structure of the rotating blade of the food mixer based on the present invention The structure of a rotary blade 1 of a food mixer based on the present invention (hereinafter simply referred to as "the rotary blade 1") is shown in the attached Fig. 1. As shown in the figure, the rotary blade 1 is mainly composed of a blade 11, a fixing bracket 12, and a rotary shaft base 13. It is preferable to use stainless steel materials for the materials used in each component of the rotary blade 1 from the viewpoints of strength, corrosion resistance, and hygiene with respect to the food to be mixed.

[0025] Next, a perspective view of the blade 11 alone is shown in the attached Fig. 2. The blade 11 is intended to crush, break, stir, and knead the ingredients to be stirred, and has two blade (blade) parts that extend in the radial direction centered on the rotation axis. Each blade (blade) part has a planar shape that is point symmetric (axially symmetric) with respect to the center of the rotation axis.

[0026] Furthermore, the planar shape of each blade portion consists of an outer curved portion facing the direction of rotation and an inner curved portion facing away from the direction of rotation, and the radius of curvature of the outer curved portion is greater than the radius of curvature of the inner curved portion (i.e., the radius of curvature of the outer curved portion is smaller than that of the inner curved portion).

[0027] Therefore, the planar shape of the blade (blade) portion is gradually curved back against the direction of rotation as it moves in the centrifugal direction from the central axis of rotation. Note that the blade 11 shown in Fig. 2 can be interpreted as having two blade (blade) portions extending axially symmetrically from the central axis, so for convenience, the rotating blade shown in Fig. 1 is referred to as a rotating blade with a "two-wing" structure, likening it to a general propeller.

[0028] The present invention is characterized in that the outer edge lower surface of the outer curved part of the blade (blade) is provided with a predetermined inclination angle (taper) θ directed vertically downward, as shown in the schematic cross-sectional view of the blade in Fig. 3(a). Since the outer curved part of the blade (blade) faces the direction of rotation of the rotary blade, the ingredients to be mixed are pressed against the outer curved part of the blade (blade) at high speed during the mixing process.

[0029] Therefore, by providing such an inclination angle θ on the outer edge underside of the outer curved portion, the ingredients to be stirred that are below the horizontal rotation plane of the blade 11 are guided by the inclination of the inclination angle θ and pushed down toward the bottom of the stirring vessel as shown by the arrow in Figure 3(a). In other words, the pile of ingredients to be stirred that is in the stirring vessel is effectively cut and separated by the contact of the blade (edge) portion.

[0030] By the way, the inclination angle θ is based on the results of actual experiments. 22 degrees < θ < 32 degrees By setting the mixing speed within this range, the cutting and piling-up separation effect on the ingredients being mixed is enhanced, which is considered to be suitable for mixing processing.

[0031] In addition, regarding the length α of the blade (blade) part, the longer the length, the stronger the pushing down and guiding effect on the mixed food material becomes, but the thickness of the blade (blade) part becomes thinner and its strength may decrease. Therefore, based on various experimental results, it is considered preferable that the value of α is about 1 / 4 to 1 / 3 of the width of the blade (blade) part in the rotation direction on average.

[0032] On the other hand, to obtain a similar effect, a downward inclination angle (taper) β may be provided on the upper outer edge surface of the inner curved part of the blade 11 facing away from the direction of rotation, as shown in Fig. 3(b). As a result, the flow of the food material passing over the upper surface of the blade (blade) part is guided in the direction of the arrow in Fig. 3(b) by the inclination angle β, and the food material to be stirred is directed toward the bottom of the mixing vessel.

[0033] Furthermore, in order to enhance the above-mentioned effects, the blade of the rotary cutter may be regarded as a wing body, and a mechanical analogy regarding a wing body moving in a fluid such as air or water may be applied. That is, as shown in the attached Fig. 4, an attack angle γ related to a wing body may be provided with respect to the horizontal plane of rotation of the blade (blade) part over the entire length of the blade (blade) part, facing the direction of rotation of the blade (blade).

[0034] As a result, the flow of the ingredients being cut by the blade (edge) and passing through the underside of the blade is guided toward the bottom of the mixing vessel by the attack angle γ as shown by the arrow in the figure. On the other hand, the flow of the ingredients being mixed passing through the upper surface of the blade, after leaving the rear outer edge of the blade, is also directed toward the bottom of the mixing vessel by the influence of the attack angle γ. It is considered preferable that the values ​​of β and γ are approximately the same as the aforementioned θ.

[0035] In the present invention, the planar shape of the blade 11 is not limited to the shape shown in Fig. 2. For example, as shown in the attached Fig. 5, it is possible to have a so-called four-sided blade (blade) structure that extends in four directions along the direction of the radius of rotation from the central axis of rotation. Incidentally, when a mixing process is performed using the blade 11 shown in Fig. 5, the number of times that the blade (blade) crosses the pile of ingredients to be mixed during one rotation of the blade 11 is twice as many as that of the blade in Fig. 2.

[0036] This promotes the cutting and piling up separation effect of the mixed ingredients during the mixing process, and even though the mixing is done in a short time and at a low speed, it is possible to obtain mixed ingredients that have been more thoroughly mixed and kneaded. Furthermore, the mixing of air into the piled up mixed ingredients is also promoted, making it possible to reduce the specific gravity of the mixed ingredients through the mixing process.

[0037] Furthermore, the present invention is not limited to the structure of the rotary blade 1 using only one blade 11. For example, as shown in the attached Fig. 6, a plurality of blades 11 may be stacked in a plurality of stages in the vertical direction of the central axis of rotation, sandwiching a ring-shaped spacer member 14. Incidentally, in the example shown in Fig. 6, three blades 11 of the so-called two-stage structure shown in Fig. 2 are stacked in the vertical direction of the central axis of rotation, shifted by 120 degrees each.

[0038] By adopting this type of blade structure, the number of times the blade tears through the pile of ingredients per rotation of the blade increases by three times compared to the case shown in Figure 1 (where only one blade with a two-wing structure is used). This increases the opportunities for the surrounding air to be taken into the ingredients, making it possible to reduce the specific gravity of the ingredients after mixing.

[0039] In addition, by using such a blade edge with an upper and lower multiple structure, the number of blade (blade) parts that come into contact with the material being mixed is increased, so that even in the case of food ingredients that contain a lot of hard solid materials, such as seed pulp, the mixing process can be carried out in a short period of time and at a relatively low rotation speed.

[0040] (2) Operational verification test of the rotating blade structure of the food mixer according to the present invention Next, the operation and effects of the rotating blade structure of the food mixer according to the present invention during mixing will be explained based on the following demonstration test examples.

[0041] (2-1) Demonstration Test Example 1 First, an example of a demonstration test in which mixing was performed using the two-pronged blade 11 shown in Figure 1 is shown. In this demonstration test, mixing was performed using food materials (specifically butter and cream) that were mainly made from oil and fat, and the mixer was rotated at 500 rpm from the start of mixing.

[0042] In this demonstration test, the specific gravity of the ingredients being mixed dropped to about 0.87 about 8 minutes after the start. Incidentally, the specific gravity of the ingredients being mixed (mainly oily and fatty materials) before mixing was about 1.2. The ingredients were also almost completely mixed by the mixing process. For reference, the attached Figure 7 shows a photo of the state of the ingredients just after they were put into the mixing vessel, and Figure 8 shows a photo of the inside of the mixing vessel after about 8 minutes of mixing had passed.

[0043] In addition, the temperature of the mixed ingredients (mainly oily materials) at the start of mixing was 5.7 degrees Celsius, but rose to 14.6 degrees Celsius after the mixing process. Generally, in order to reduce the specific gravity of the mixed ingredients during mixing, it is essential to cool the entire mixing vessel by circulating cooling water and keep its temperature low in order to increase the amount of air taken in by the mixed ingredients. However, in this demonstration test, we were able to obtain a good specific gravity value of the mixed ingredients as described above, even though we did not specifically cool the entire mixing vessel with cooling water.

[0044] (2-2) Demonstration Test Example 2 Next, we will show the results of a demonstration test using a rotating blade in which the blades 11 of the so-called two-pronged structure shown in Figure 6 are shifted by 120 degrees and three blades are stacked vertically to the central axis of rotation. Photographs of the actual rotating blades used in this test are shown in the attached Figure 9 (horizontal photograph) and Figure 10 (oblique photograph).

[0045] In this demonstration test, as in the above-mentioned Test Example 1, the ingredients to be mixed were butter and cream, which are mainly made from oil and fat materials, and the rotation speed of the mixer was 500 (rpm), the same as in the previous test. In this demonstration test, the specific gravity of the ingredients to be mixed dropped to 0.85 about 4 minutes after the mixing process started, and the ingredients to be mixed were almost completely mixed and kneaded. As in the previous test, the attached Figure 11 shows a photograph of the state immediately after the ingredients to be mixed were put into the mixing vessel, and Figure 12 shows a photograph of the inside of the mixing vessel after the mixing process.

[0046] In addition, the temperature of the ingredients (mainly oil and fat materials) when mixing started was 7.8 degrees Celsius, but after mixing, it rose to 14.3 degrees Celsius. As with the previous test, no special cooling process was performed on the entire mixing vessel in this demonstration test.

[0047] (2-3) Demonstration Test Example 3 Next, we will explain the additional test using the three-ply blade used in Test Example 2. In this demonstration test, after the mixing process started, the rotation speed of the mixer was changed in the following steps. [1st step] 500 (rpm): 4 minutes [2nd step] 750 (rpm): 1 minute [Third step] 300 (rpm): 5 minutes The main ingredients used for the food to be stirred (butter and cream) were the same as those used in the previous demonstration test.

[0048] As a result of this demonstration test, the specific gravity of the mixed ingredients after the mixing process (after the third step) dropped to 0.74. It is particularly noteworthy that in the latter half of the mixing process, a good specific gravity was obtained for the mixed ingredients despite the low rotation speed of 300 rpm. Figure 13 shows a photograph of the inside of the mixing vessel after the mixing process. Incidentally, with the conventional type of rotary blade shown in Figure 15 above, it was difficult to reduce the specific gravity after mixing to below 0.86, even when the mixing process was performed at high rotation speed while the mixing vessel was cooled.

[0049] In addition, in this test, the temperature of the food ingredients (mainly oily and fatty materials) at the start of mixing was 3.3 to 5.7 degrees Celsius, but after the mixing process, it rose to 15.8 degrees Celsius. As with the previous test, no special cooling process was performed on the entire mixing vessel in this demonstration test.

[0050] As explained above, by using the rotary blade structure according to the present invention, the food ingredients can be mixed and kneaded at low speed for a short time without high speed or long time mixing, and the flavor and texture of the food are not lost. In addition, since the mixing vessel does not need to be cooled during mixing, the advantages of reduced power consumption, simplified operation, and improved work efficiency can be expected.

[0051] It goes without saying that the embodiments of the present invention are not limited to the examples described above. For example, the shape, arrangement, or material of each part constituting each example can be appropriately changed in accordance with the actual embodiment without departing from the spirit of the present invention. [Industrial Applicability]

[0052] The configuration of the present invention can be used in various food manufacturing industries that require stirring and kneading of ingredients, including the dairy product industry and the confectionery industry. [Brief description of the drawings]

[0053] [Figure 1] FIG. 2 is a perspective view showing the structure of a rotary blade in the food mixer according to the present invention. [Diagram 2] FIG. 2 is a perspective view showing a structure of a blade in the rotary blade of FIG. [Diagram 3] 1A-1D are schematic vertical cross-sectional views of various blades according to the invention; [Figure 4] 1A-1D are schematic vertical cross-sectional views of various blades according to the invention; [Diagram 5] FIG. 11 is a perspective view showing a rotary blade having another structure according to the present invention. [Figure 6] FIG. 11 is a perspective view showing another structure of a rotary blade according to the present invention. [Figure 7] 1 is a photograph of the food material to be mixed before the start of the mixing process in Demonstration Test Example 1. [Figure 8] 1 is a photograph of the mixed food material after mixing processing in Demonstration Test Example 1. [Figure 9] 1 is a photograph (planar direction) showing the structure of the rotary blade used in Demonstration Test Examples 2 and 3. [Figure 10] 1 is a photograph (oblique view) showing the structure of the rotary blade used in Demonstration Test Examples 2 and 3. [Figure 11] 1 is a photograph of the food material to be mixed before the start of the mixing process in Demonstration Test Example 2. [Figure 12] 1 is a photograph of the mixed food material after mixing in Demonstration Test Example 2. [Figure 13] 1 is a photograph of the mixed food material after mixing processing in Demonstration Test Example 3. [Figure 14] FIG. 1 is an explanatory diagram showing an example of a typical commercial vertical food mixer. [Figure 15] FIG. 15 is a perspective view showing an example of a rotary blade used in the mixer of FIG. 14. [Figure 16] FIG. 16 is a perspective view showing the structure of a blade used in the rotary cutter of FIG. 15. [Explanation of symbols]

[0054] 1 ... Rotary blade structure based on the present invention 11 ... Blade 11 12 ... Fixing bracket 13 ... Rotating shaft base 14 ...Spacer member a …Mixing vessel a1 … Opening and closing lid of mixing vessel a2…Rotation axis b … Rotary blade b1 ... Blade b2 ... Spacer c … Rotation drive unit d …Rotation control section

Claims

[Claim 1] A rotary blade structure comprising a rotary blade attached to a food mixer, the rotary blade having a plurality of blades extending from a central axis of rotation along a radial direction of rotation within a horizontal rotational plane of the rotary blade, the blades having a planar shape that is point-symmetrical with respect to the central axis of rotation, and the blades each having an outer curved portion facing the direction of rotation and an inner curved portion facing away from the direction of rotation, the radius of curvature of the outer curved portion being greater than the radius of curvature of the inner curved portion, A rotating blade structure for an ingredient mixer, characterized in that a predetermined angle of inclination (taper) is provided in the vertical direction on the lower outer edge of the outer curved portion, a predetermined angle of inclination (taper) is provided in the vertical direction on the upper outer edge of the inner curved portion, and the blade (blade) portion has a predetermined angle of attack facing the horizontal rotation plane of the blade (blade) portion in the direction of rotation, the predetermined angle of inclination and the set angle of attack are both in the angle range of 22° to 32°, and the range in which the angle of inclination (taper) is provided is 1 / 4 to 1 / 3 of the blade width length in the rotation direction of the blade (blade) portion.

Images