JP2020097012A - Stirring blade and stirring device - Google Patents

Abstract

To make it possible to manufacture a stirring blade at a low cost, and to provide a stirring blade or the like having stirring performance equal to that of a stirring blade of which the whole is manufactured by cutting, casting, a three-dimensional printer and so on.SOLUTION: A stirring blade comprises plural blade parts 2, 4 which rotate around an axis, are provided on stems 1, 3 and are arranged around the axis. Each of the plural blade parts 2, 4 has an inward end 21 in a radial direction r perpendicular to the axis, and a forward bent part which is connected to the inner end and is convexed forward in a rotation direction θ. The blade parts 2, 4 are configured from plural face parts having different inclined angles in the rotation direction. Adjacent face parts are connected via bent parts 23, 43.SELECTED DRAWING: Figure 1

Description

The present invention relates to a stirring blade and a stirring device.

BACKGROUND ART A stirring device having stirring blades is used as a device for performing stirring such as dispersion and mixing of a stirring target such as a liquid or a mixture of powder and liquid. Patent Document 1 discloses an example of a conventional stirring blade and a stirring device. In the configuration disclosed in this document, the rotary blade is attached to the tip of the rotary shaft that is rotationally driven. The rotary blades are rotated in a container accommodating an object to be stirred, thereby performing stirring such as dispersion and mixing of the object to be stirred.

Here, stirring is a concept including dispersion and mixing. Dispersing an object to be stirred is an operation of dispersing other substances (for example, liquid or powder) in a micro state in a substance (for example, liquid) that is chemically one phase. Further, mixing the stirring target is an operation of stirring the stirring target in the container so that the stirring target housed in the container has a more uniform property. In order to further enhance the dispersion in the stirring device, it is important to concentrate the force of the stirring blade on a small part of the stirring target, and it often works in the region existing in the immediate vicinity of the stirring blade. On the other hand, in order to further enhance the mixing in the stirrer, it is important to cause the force of the stirring blades to act on the whole stirring target housed in the container to cause the stirring target to flow. As described above, in order to enhance the dispersion and the mixing with one stirring blade, it is required to achieve the opposite behaviors at the same time. In particular, the higher the viscosity of the object to be stirred, the more difficult it is to enhance the dispersion and mixing.

The stirring blade disclosed in Patent Document 1 is formed as having a base portion and a plurality of blade portions connected to the base portion by appropriately cutting and bending a plate material made of a single metal material. .. In order to achieve a higher degree of agitation, it is necessary to set the shape, size, angle, etc. of the blades in various ways. However, the blade portion obtained by cutting and bending a plate material made of a single metal material is naturally limited in shape, size, angle and the like. Further, if the blade portion is made larger or more upright, there is a concern that the base portion may lack support for the blade portion.

As an effective means for solving this problem, the inventor of the present application has proposed a stirring blade and a stirring device disclosed in Patent Document 2. The stirring blade is a stirring blade that is rotated around the axial direction, and includes a base portion and a blade group including a plurality of blade portions that are located on one axial side with respect to the base portion and that are arranged in the rotation direction. The blade portion has a front curved portion that is connected to the inner end in the radial direction and that is convex forward in the rotation direction when viewed in the axial direction.

One of the factors that enhance mixing with the stirring blade of Patent Document 2 is the contribution of the front curved portion of the blade. As a result of verification by the inventors, by making the front curved portion convex forward in the rotational direction, the object to be treated is strongly sucked at the inner end, and further provided with a rear curved portion convex backward in the rotational direction. As a result, the suctioned object to be processed moves more smoothly outward in the radial direction, whereby the degree of dispersion and mixing can be enhanced.

However, since the stirring blade of the cited document 2 has a complicated shape, it is necessary to manufacture the whole by a cutting process, casting, a 3D printer, or the like, which causes a problem in manufacturing cost. As a method of solving this problem, a method of manufacturing the base portion and the blade portion separately and joining the blade portion to the base portion by welding or the like can be considered, but this method can solve the problem of manufacturing cost. However, there is a problem that the stirring performance equivalent to that of the stirring blade manufactured by cutting or the like cannot be obtained.

JP, 10-180073, A International Publication No. 2017/212935

The present invention is to solve the above problems, stirring blades can be manufactured at low cost, and stirring is performed by a method in which the base portion and the blade portion are separately manufactured and the blade portion is joined to the base portion by welding or the like. An object of the present invention is to provide a stirring blade having a stirring performance equivalent to that of a stirring blade manufactured by cutting, casting, a 3D printer, or the like even when manufacturing the blade, and a stirring device using the blade.

Specifically, the stirring blade of the present invention is provided with a plurality of blade portions that rotate around an axis and that are provided on a base portion and are arranged around the axis, and each of the plurality of blade portions includes An agitation blade having an inner end in a radial direction perpendicular to the axis and a forward curved portion connected to the inner end and convex toward the front in the rotation direction, wherein the blade portion has an inclination angle in the rotation direction. Is composed of a plurality of different surface portions, and adjacent surface portions of the surface portions are connected to each other via a bent portion (claim 1). Preferably, each of the blade portions has a rear curved portion that is connected to the front curved portion outward in the radial direction and is convex rearward in the rotation direction (claim 2 ). More preferably, the blade portion is joined to the base portion (claim 3).

A stirring blade according to another aspect of the present invention includes a plurality of first blade portions and second blade portions that rotate around an axis and that are provided in a base portion and are arranged around the axis, the first blade portion And the second blade portion each has an inner end in the radial direction perpendicular to the axis and a front curved portion connected to the inner end and protruding forward in the rotation direction, and the base portion is It has a first side and a second side in a direction parallel to the axis, the first blade portion is provided on the first side and arranged around the axis, and the second blade portion has the first side. A stirring blade provided on the second side and arranged around the axis, wherein the first blade portion and the second blade portion are configured by a plurality of planes having different inclination angles in the rotation direction, In the surface portions, the adjacent surface portions are connected to each other via the bent portion (claim 4).

Preferably, each of the first blade portion and the second blade portion has a rear curved portion that is connected to the front curved portion outward in the radial direction and is convex rearward in the rotation direction (claim 5). ). More preferably, the positions of the plurality of first blade portions in the rotation direction are different from the positions of the plurality of second blade portions (claim 6 ). More preferably, the base portion has a first inclined surface and a second inclined surface that are tapered in directions opposite to each other, and the plurality of first blade portions are provided on the first inclined surface. The plurality of second blade portions are provided on the second inclined surface (claim 7). More preferably, the first blade portion and the second blade portion are joined to the base portion (claim 8).

Further, the stirring device of the present invention includes the stirring blade, a container for accommodating a stirring target, and a rotary shaft that is inserted into the container and to which the stirring blade is attached (claim 9).

According to the present invention, the stirring blade can be manufactured at low cost, and even if the stirring blade is manufactured by a method of separately manufacturing the base portion and the blade portion and connecting the blade portion to the base portion by welding or the like, It is possible to provide a stirring blade having the same stirring performance as a stirring blade manufactured by cutting, casting, or a 3D printer, and a stirring device using the blade.

Other features and advantages of the present invention will become more apparent from the detailed description given below with reference to the accompanying drawings.

It is a perspective view which shows the stirring blade which concerns on this invention. It is a front view which shows the stirring blade which concerns on this invention. It is a top view which shows the stirring blade which concerns on this invention. It is a perspective view which shows the stirring blade which concerns on another embodiment of this invention.

Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the drawings. 1-3 show one embodiment of the stirring blade according to the present invention, and FIG. 4 shows another embodiment of the stirring blade according to the present invention.

FIG. 1 is a perspective view showing the stirring blade A1. FIG. 2 is a front view showing the stirring blade A1. FIG. 3 is a plan view showing the stirring blade A1 viewed from the upper side in the z direction in FIGS. 1 and 2. The rotation direction θ is a direction in which the stirring blade A1 rotates, and is a direction generally referred to as a circumferential direction with respect to the axial direction z and the radial direction r.

The stirring blade A1 is attached to the stirring device shown in Patent Document 2 (see FIGS. 13 and 24 of the same document), and constitutes the stirring device B1. The stirrer B1 includes a container, a rotary shaft, and a drive unit. The container contains an object to be stirred, which is to be dispersed and mixed. A stirring blade A1 is attached to the end of the rotary shaft and is inserted into the stirring target of the container. The drive unit rotates the rotary shaft around the axial direction, and includes, for example, a motor.

As a structure for attaching the stirring blade A1 to the rotating shaft of the stirring device B1, various mounting mechanisms such as an engaging mechanism and a fastening mechanism may be adopted, and the rotating shaft and at least a part of the stirring blade A1 are integrated. It may be a structure formed in.

As shown in FIGS. 1 to 3, the base portion 1 has a taper shape in the axial direction z, and the base portion 3 has a taper shape in the direction opposite to the axial direction z. It is a truncated cone (a truncated cone). The plurality of blades 2 and 4 are supported on the inclined surfaces 11 and 31 of the bases 1 and 3 in a state of being arranged at equal intervals. The base portion 1 and the base portion 3 are connected by a connecting portion 5 arranged concentrically with the rotating shaft in a state of being separated from each other in the axial direction z.

The blade portion 2 and the blade portion 4 are provided at positions displaced in the rotation direction θ. In the illustrated example, the blade portion 2 and the blade portion 4 are arranged at positions shifted by 45 degrees (90 degrees/2) in the rotation direction θ.

The plurality of blades 2 and 4 have the same shape, and are bent by the bent portions 23 and 43. In the illustrated example, the plurality of blade portions 2 and 4 have three bent portions 23 and 43 per blade and four flat areas (face portions 24 and 44) defined by the bent portions 23 and 43. Owns Further, as the surface portion 24 is located in the axial direction z and the surface portion 44 is located in the direction opposite to the axial direction z, the surface portion 24 is inclined so as to be located in the front in the rotation direction θ. The surface portions 24 and 44 are not limited to those having flat plate portions, and may have curved plate shapes. 2 to 3, the bent portions 23 and 43 are omitted for convenience sake.

The blade portions 2 and 4 have inner ends 21 and 41. The inner end 21 is the innermost end of the blade portions 2 and 4 in the radial direction r. In the illustrated example, the inner ends 21 and 41 coincide with the joining portions of the inclined surfaces 11 and 31 of the blade portions 2 and 4 and the base portions 1 and 3.

The number of blades 2 and 4 arranged on the bases 1 and 3 is not particularly limited. In the stirring blade A1, the number of the blade portions 2 and the number of the blade portions 4 are each four. Further, the blade portions 2 and 4 are arranged at an equal pitch, and in the illustrated example, the pitch is 90 degrees.

The blade portions 2 and 4 have a front curved portion and a rear curved portion which are not shown. The front curved portion and the rear curved portion can be defined in the same manner as the definition method described in Patent Document 2. The front curved portion is a portion that is connected to the inner ends 21 and 41 and is convex forward in the rotation direction θ when viewed in the axial direction z. More specifically, the front curved portion is both ends of the front curved portion in the radial direction r. The shape is convex forward in the rotation direction θ with respect to the virtual straight line connecting the two. In the present embodiment, the front curved portion is composed of two regions of the surface portion 24 located on the axial direction z side and two regions of the surface portion 44 located on the opposite side to the axial direction z.

The rear curved portion is a portion that is connected outward in the radial direction r with respect to the front curved portion and that is convex rearward in the rotation direction θ when viewed in the axial direction z. More specifically, the rear curved portion has a shape that is convex rearward in the rotation direction θ with respect to an imaginary straight line connecting both ends in the radial direction r of the rear curved portion. In the present embodiment, the backward curved portion is composed of two regions of the surface portion 24 located on the side opposite to the axial direction z, and two regions of the surface portion 44 located on the axial direction z side.

Materials forming the bases 1 and 3 and the blades 2 and 4 are not particularly limited, and preferable examples include metal materials such as stainless steel.

The stirring blade A1 is manufactured by a method in which the bases 1 and 3 and the blades 2 and 4 are separately manufactured and then joined. As a joining method, mechanical joining (shrink fitting, caulking, etc.), chemical joining (adhesion, etc.), and metallurgical joining (fusion welding, pressure welding, brazing, etc.) can be used. In the present embodiment, they are joined by welding (fusion welding). The base portion 1 and the base portion 3 to which the blade portions 2 and 4 are welded as described above are connected to each other in the state of being separated from each other in the axial direction z by the connecting portion 5 arranged concentrically with the rotating shaft. The connecting method is not particularly limited, and joining, screwing or the like can be used.

The bases 1 and 3 can be manufactured by machining (cutting, forging, etc.), casting, or a 3D printer. In this embodiment, it is manufactured by cutting.

The blades 2 and 4 can be manufactured by machining or the like. In this embodiment, it is manufactured by punching and bending.

Next, the operation of the stirring blade A1 will be described.

As a factor of the sophistication of the mixing by the stirring blade A1, first, the contribution of the forward curved portion of the blade portions 2 and 4 can be mentioned. According to the research conducted by the inventors, by making the front bent portion convex forward in the rotational direction θ, the suction target is sucked more strongly at the inner ends 21 and 41, while the suctioned stirring target is outside the radial direction r. It was found that it was possible to move it more smoothly. This strong suction and smooth movement are considered to be one of the factors that cause the mixing of the whole stirring target.

In addition, according to the research conducted by the inventors, by providing a backward curved portion that is convex rearward in the rotation direction θ, it is possible to obtain a stronger effect of discharging the suctioned stirring target from the stirring blade A1 outward in the radial direction r. It turned out to be. By the synergistic effect of the enhancement of suction by the front curved portion and the enhancement of discharge by the rear curved portion, the mixing of the whole stirring target can be promoted.

Further, by tilting the blades 2 and 4 forward in the rotation direction θ, it is possible to prevent the bubbles mixed in the stirring object from staying behind the rotation direction θ of the blades 2 and 4. The retention of air bubbles can be a factor that hinders the mixing of the stirring target by the stirring blade A1. According to the stirring blade A1, it is possible to suppress the bubbles from remaining, which is preferable for enhancing the mixing of the stirring target.

FIG. 4 is a perspective view showing the stirring blade A2. The rotation direction θ is a direction in which the stirring blade A2 rotates, and is a direction generally referred to as a circumferential direction with respect to the axial direction z and the radial direction r. Further, the arrows in these figures indicate the direction in which the stirring blade A2 rotates.

As shown in FIG. 4, the stirring blade A2 is the same as the stirring blade A1 except that the stirring blade A2 is composed only of the base portion 1 and the blade portion 2 of the stirring blade A1. The stirring blade A2 is attached to the stirring device shown in Patent Document 2 (see FIG. 4 of the same document) to form a stirring device B2.

The stirring device B2 includes a container, a rotary shaft, and a drive unit. The container contains an object to be stirred, which is to be dispersed and mixed. A stirring blade A2 is attached to the end of the rotary shaft and is inserted into the stirring target of the container. The drive unit rotates the rotary shaft around the axial direction, and includes, for example, a motor. As a structure for attaching the stirring blade A2 to the rotary shaft of the stirring device B2, various engaging mechanisms or fastening mechanisms such as a fastening mechanism may be adopted, and the rotary shaft and at least a part of the stirring blade A2 are integrated. It may be a structure formed in.

The stirrer according to the present invention is not limited to the above embodiment. The specific configuration of each part of the stirring device according to the present invention can be modified in various ways.

A1, A2: Stirring blades B1, B2: Stirring device 1: Base part 2: Blade part 3: Base part 4: Blade part 5: Connection part 11: Inclined part 21: Inner end 22: Face part 23: Bent part 31: Inclined part 41: inner end 42: surface portion 43: bent portion r: radial direction z: axial direction θ: rotational direction

Claims (9)

Rotate around the axis,
A plurality of blades provided on the base and arranged around the axis,
The plurality of blade portions are stirring blades each having an inner end in a radial direction perpendicular to the axis and a front curved portion connected to the inner end and being convex forward in the rotation direction,
The blade portion is composed of a plurality of surface portions having different inclination angles in the rotation direction,
In the surface portion, adjacent surface portions are connected to each other via a bent portion.
A stirring blade characterized by that. The stirring blade according to claim 1, wherein each of the blade portions has a rear curved portion that is connected to the front curved portion outward in the radial direction and is convex rearward in the rotation direction. The stirring blade according to claim 1, wherein the blade portion is joined to a base portion. Rotate around the axis,
A plurality of first blade portions and second blade portions provided on the base portion and arranged around the axis,
The first blade portion and the second blade portion each have an inner end in the radial direction perpendicular to the axis and a front curved portion that is connected to the inner end and is convex forward in the rotational direction,
The base has a first side and a second side in a direction parallel to the axis,
The first blade portion is a stirring blade provided on the first side and arranged around the axis, and the second blade portion is a stirring blade provided on the second side and arranged around the axis,
The first blade portion and the second blade portion are composed of a plurality of planes having different inclination angles in the rotation direction,
In the surface portion, adjacent surface portions are connected to each other via a bent portion.
A stirring blade characterized by that. The said each 1st each blade part and the 2nd blade part have the back curved part connected to the said radial direction outer side with respect to the said front curved part, respectively, and is convex in the said rotation direction back. Stirring blade. The stirring blade according to claim 4, wherein the plurality of first blade portions are different in position in the rotation direction from the plurality of second blade portions. The base portion has a first inclined surface and a second inclined surface which are tapered in directions opposite to each other, and the plurality of first blade portions are provided on the first inclined surface, and The stirring blade according to claim 5, wherein the plurality of second blade portions are provided on the second inclined surface. The stirring blade according to claim 4, wherein the first blade portion and the second blade portion are joined to a base portion. A stirring blade according to any one of claims 1 to 8,
A container for accommodating the stirring target,
A rotary shaft inserted into the container and having the stirring blade attached thereto;
A stirrer.