JP6911592B2 - Vibration damping structure and its manufacturing method - Google Patents

Description

The present invention relates to a vibration damping structure or the like capable of reducing vibration.

The smaller the vibration generated during the operation of an electric motor (motor, generator, etc.) is preferable in order to ensure the reliability, accuracy, low noise, etc. of the equipment. Therefore, in addition to suppressing the generation of vibration itself, many proposals have been made regarding a vibration damping structure that effectively reduces the generated vibration. A description related to such a vibration damping structure is described in, for example, Patent Document 1 below.

Japanese Unexamined Patent Publication No. 2012-82880

Patent Document 1 proposes a vibration damping structure in which a motion promoting member having a convex curved surface is arranged in a hollow body and the hollow body is filled with powder or granular material. This vibration damping structure integrally vibrates the hollow body and the motion promoting member in the same direction as the vibration direction of the vibration damping target ([0035]), and absorbs vibration energy by friction or collision between them and the powder or granular material. Has been done.

The vibration damping structure of Patent Document 1 is a closed space with a motion promoting member that simply increases the contact area with the powder or granular material, as opposed to the conventional vibration damping member in which the powder or granular material is filled in the hollow closed space. It's just a placement. After all, such a vibration damping structure can hardly absorb vibration energy such as a small vibration having a vibration acceleration of less than 1 G, and cannot secure sufficient vibration damping property, as in the conventional one.

The vibration damping structure of Patent Document 1 is attached to the end face of the motor stator (housing, case, housing), which is the vibration damping target (vibration source), as a separate member ([0042]).

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a vibration damping structure having a new structure capable of reducing vibration.

As a result of diligent research to solve this problem, the present inventor has come up with the idea of providing an exciting portion that easily receives vibration from a vibration source and easily vibrates in the internal space that accommodates a fluid material such as powder. .. It was also confirmed that a high damping effect can be obtained by using such a damping structure. By developing this result, the present invention described below has been completed.

《Vibration damping structure》
(1) The vibration damping structure of the present invention includes a skeleton portion forming an internal space partitioned by columns and / or walls, and a conduction portion having one end connected to the skeleton portion and extending into the internal space. It is provided with an exciting portion that is in the internal space, is connected to the conductive portion, and extends to the conductive portion, and at least a fluid material that is in contact with the exciting portion.

(2) According to the vibration damping structure of the present invention, it is possible to effectively absorb the vibration energy of vibrations in a wider band than before and secure excellent vibration damping properties. The reason for this can be considered as follows.

In the case of the vibration damping structure of the present invention, the excitation portion is not released in the internal space, and the vibration of the skeleton portion is directly transmitted to the excitation portion via the conduction portion. Here, the exciting portion is expanded more than the conductive portion, and is supported by a thin conductive portion at at least one place. Therefore, even if the vibration (for example, amplitude, vibration acceleration) in the skeleton portion or the conduction portion is slight, the exciting portion can vibrate (amplitude) more than them. Then, the fluid material in the internal space not only comes into contact / collision with the skeleton part and the conduction part, but also comes into contact / collision with the exciting part more. As a result, the vibration energy introduced into the skeleton portion is effectively dissipated, and the vibration damping structure of the present invention exhibits high vibration damping properties.

<< Manufacturing method of damping structure >>
The present invention can also be grasped as a method for manufacturing a vibration damping structure. For example, in the case of a vibration damping structure using powder as a fluid material, it is preferable to manufacture the vibration damping structure by the powder lamination method. According to the powder lamination method, when the skeleton portion, the conduction portion and the excitation portion are formed, the internal space can also be filled with the powder, so that the vibration damping structure can be efficiently manufactured.

The powder lamination method is a kind of lamination modeling method (so-called three-dimensional modeling method or 3D printer method), and may be a powder sintering lamination modeling method or a powder fixation lamination modeling method. According to the powder sintering layered manufacturing method, the raw material powder of each layer is sequentially irradiated with laser light or the like as a heating source, and the raw material powder is sequentially sintered (including melting) to have a vibration damping structure. Can manufacture the body. According to the powder-fixed laminated molding method, a vibration-damping structure can be manufactured by sequentially spraying an adhesive (ink) on the raw material powder of each layer and sequentially binding the raw material powder. In either case, the skeleton, conduction, and excitation are formed by sintering or binding of the raw material powder (simply referred to as "sintering, etc."), and the raw material powder remains in the internal space without being sintered. Becomes a fluid material.

"others"
Unless otherwise specified, "x to y" in the present specification includes a lower limit value x and an upper limit value y. A range such as "ab" may be newly established with any numerical value included in the various numerical values or numerical ranges described in the present specification as a new lower limit value or upper limit value.

It is a schematic diagram which shows the appearance, the inside (perspective) and (unit) cell of the vibration damping member which is one Example. It is a schematic diagram which shows the cross section of the cell of the vibration damping member which is another Example. It is a schematic diagram which shows the state of the sound pressure measurement used for evaluating the vibration damping property. It is a graph which shows the sound pressure measurement result which concerns on each sample. It is a schematic diagram which shows the cross section of the cell of another vibration damping member.

One or more components arbitrarily selected from the present specification may be added to the components of the present invention. The contents described in the present specification are appropriately applicable not only to the vibration damping structure of the present invention but also to the manufacturing method thereof. Even a methodical component can be a component of an object.

《Skeletal part》
The skeleton is composed of columns or walls and forms an internal space. The internal space may be an open space or a closed space. When an open space is formed by a skeleton portion composed of columns, it is preferable that at least the outermost surface of the vibration damping structure is a partition wall in order to prevent leakage of the fluid material. For example, it is preferable that at least the outermost surface of the skeleton portion arranged on the outermost side is made of a wall.

However, it is more preferable that a closed space (internal space) is formed by a skeleton portion composed of a wall (partition wall), and each closed space is filled with a fluid material. As a result, the fluid material can surely come into contact with not only the exciting portion but also the wall surface of the skeleton portion, and more vibration energy can be absorbed.

《Conduction part / Excitation part》
The conducting portion and the exciting portion are located in an internal space formed by the skeleton portion, one end of the conducting portion is connected to the skeleton portion, and the other end of the conducting portion is connected to the exciting portion. Therefore, the exciting portion vibrates (or swings) in the internal space via the conductive portion.

It is preferable that the exciting portion and the conducting portion differ in at least one or more in shape (including surface shape), size (volume), specific surface area, mass, density (including material) and the like. When the excitation part is expanded from the conduction part, the excitation part is in a state of being supported by the conduction part (for example, cantilever support), and it becomes easy to vibrate (large amplitude), and the contact area with the fluid material also increases. preferable. In particular, it is preferable that the exciting portion has a larger volume, mass, and surface area than one conducting portion.

It is sufficient that there is one or more excitation units in one internal space. It is more preferable to increase the number of excited parts arranged per internal space or devise the shape of the excited parts to increase the surface area of the excited parts that can come into contact with the fluid material. The number of conduction portions connected to one excitation portion may be singular or plural.

Further, the outer surface of the excitation portion or the conduction portion or the inner outer surface of the skeleton portion may be made uneven or roughened to increase the surface area thereof. As a result, the surface area of each part in contact with the fluid material increases, and the amount of vibration energy absorbed also increases.

《Fluid material》
The fluid material may be any material that can come into contact with the surface of the excitation part or the like and absorb vibration energy, and may be a solid (for example, powder (including coarse particles), gel, etc.) or a liquid (for example, oil, gel, etc.). It may be. The materials thereof are, for example, metal, resin, rubber, ceramics and the like. It is preferable to use a non-magnetic material as a fluid material for vibration damping of a device (motor, etc.) that utilizes magnetic force.

《Vibration damping member》
The vibration damping structure may be composed of only a set of a skeleton part, a conduction part, an excitation part and a fluidizing material, or may be a vibration damping member in which a plurality of unit cells are connected in succession with the set as a unit cell. In the present invention, the size of the damping structure and the unit cell does not matter. Therefore, a large number of fine or small unit cells may be assembled to form one vibration damping structure (vibration damping member), or large unit cells may be assembled at the level of one or several to several tens. Therefore, one vibration damping structure (vibration damping member) may be configured. If a vibration damping member in which a large number of small unit cells are assembled is used, it is possible to efficiently suppress vibrations such as minute vibrations having a small amplitude but a large frequency. Further, the vibration damping member may be a combination of a plurality of unit cells having different forms (size, shape, etc.). As a result, it is possible to efficiently suppress vibrations including various frequencies and amplitudes.

The vibration damping member of the present invention may be a general-purpose product or a dedicated product. The general-purpose product is, for example, a plate-shaped, block-shaped, columnar, tubular, annular, or other general-purpose shaped member. The dedicated product is, for example, an essential member having a shape that conforms to the device or device to be vibration-damped. For example, the damping member is not retrofitted to existing equipment or devices, but constitutes, for example, at least a portion of the housing (eg, motor housing or casing) that surrounds the vibration source. It is preferable that the casing is used.

Incidentally, the materials of the skeleton portion, the conduction portion, the excitation portion and the fluid material according to the present invention may be different, all may be the same, or may be a combination of a plurality of materials. Further, the skeleton portion, the conduction portion and the excitation portion may be integrally molded (including laminated molding), or may be connected by using a fastener such as a screw or a joining means such as welding. The former is preferable when the unit cell is fine (for example, one side is 10 mm or less) or small (for example, one side is 500 mm or less). The latter is preferable when the unit cell is large (for example, one side is more than 500 mm).

Multiple samples were prepared and their damping effect was evaluated. The present invention will be described in more detail below with reference to such specific examples.

《Manufacturing of sample》
(1) Sample 1
The vibration damping member 10 shown in FIG. 1 was manufactured by the powder sintering laminated molding method. The vibration damping member 10 (vibration damping structure) has a rectangular parallelepiped shape (101 mm × 51 mm × 16 mm) in appearance, and a large number (20 × 10) cells 1 (unit cells) having a cubic shape (side 5 mm) inside are regularly arranged. × 3) Arranged.

The cell 1 includes a skeleton portion 11, a conduction portion 12, an excitation portion 13, and a powder 14 (fluid material) that is fluidly filled in the internal space. The skeleton portion 11 has six square-shaped partition walls, and constitutes a cubic-shaped internal space (closed space).

The conducting portion 12 is a thin and short columnar (φ0.5 mm) strut, and extends diagonally from four corners (corners) inside one partition wall of the skeleton portion 11. The excitation portion 13 is composed of a sphere (φ3 mm) arranged at a substantially central portion of the internal space, and is supported by the other end of the conduction portion 12. The internal space is filled with powder 14. The vibration damping member 10 thus obtained is referred to as sample 1.

The powder sintering layered manufacturing method was carried out using a so-called 3D printer (manufactured by SLM280HL SLM Solutions). As the raw material powder, a commercially available AlSi10Mg powder (component composition: Al-10 wt% Si-0.35 wt% Mg, particle size: 20 to 63 μm) was used. The raw material powder remaining in the internal space is the powder 14 described above. Incidentally, since the above-mentioned raw material powder has excellent fluidity, it is also preferable as a fluid material.

(2) Sample 2
A vibration damping member (sample 2) composed of the cell 2 having the shape of the cell 1 changed was also prepared. As shown in FIG. 2, the cell 2 includes a skeleton portion 21, a conduction portion 22, an excitation portion 23, and a powder 24 (fluid material) that is fluidly filled in the internal space. The skeleton portion 21 is also composed of six square-shaped partition walls, and constitutes a cubic-shaped internal space (closed space).

The conducting portion 22 is a short columnar (φ0.5 mm) strut, and one of the conductive portions 22 projects in a normal shape from the center of one partition wall of the skeleton portion 21. The exciting portion 23 includes a solid sphere 231 (φ1.5 mm) arranged at a substantially central portion of the internal space and a hollow sphere 232 (φ3.5 mm × φ2.5 mm) containing the solid sphere 231. The solid sphere 231 is supported at the other end of the conduction portion 22, and the hollow sphere 232 is supported in the middle of the conduction portion 22. The internal space is filled with the powder 24 made of the above-mentioned raw material powder. In addition, sample 2 is produced in the same manner as sample 1.

(3) Samples C1 and C2
As comparative samples, sample C1 excluding the powder 14 to be filled in the internal space of the damping member 10 and sample C2 made of a solid rolled material (JIS A2017) having the same size as the damping member 10 were also prepared.

"measurement"
As shown in FIG. 3, each sample suspended by a wire is lightly hit with a hammer. At this time, the sound pressure generated from each sample is measured over time with a sound level meter arranged below the sound pressure. In this way, as shown in FIG. 4, the time change of the sound pressure related to each sample was obtained.

"evaluation"
As is clear from FIG. 4, it can be seen that the sound pressure of Sample 1 and Sample 2 decreased sharply at an early stage, and the sample 1 and Sample 2 exhibited high vibration damping properties. In particular, it can be seen that the sample 2 having a large contact area with the powder has a higher sound pressure attenuation property.

On the other hand, even if the sample C1 has the same structure as the sample 1 (skeleton part, conduction part and excitation part), since it does not contain powder (fluid material), the sound pressure is not attenuated so much and the vibration damping property is improved. It turns out to be inferior. Further, in the sample C2 which is a solid Al alloy plate, the sound pressure was hardly attenuated, and the initial sound pressure continued for a long time.

<< Modification example >>
The cell 1 shown in FIG. 1 may be deformed as, for example, the cell 3 shown in FIG. 5 (1) and the cell 4 shown in FIG. 5 (2). Like the cell 1, the cell 3 also includes a skeleton portion 31, a conduction portion 32, an excitation portion 33, and a powder 34 (fluid material) that is fluidly filled in the internal space. However, the conduction portion 32 is formed by extending four thin and short cylinders diagonally from the inner corners of the facing partition walls of the skeleton portion 11. The central other end of these eight conductive portions 32 is connected to the spherical exciting portion 33 in the center of the internal space. Since the cell 1 and the cell 3 have different vibration characteristics, the frequency band in which the vibration energy can be efficiently absorbed can be adjusted by properly using them.

Like the cell 1, the cell 4 also includes a skeleton portion 41, a conduction portion 42, an excitation portion 43, and a powder 44 (fluid material) that is fluidly filled in the internal space. However, the inner surface of the partition wall of the skeleton portion 41 and the outer surface of the exciting portion 43 have an uneven pattern, and the contact area with the powder 44 is increased. As a result, more vibration energy can be absorbed, so that the vibration damping member made of the cell 4 has a high vibration damping effect.

1 cell (unit cell)
10 Vibration damping member (vibration damping structure)
11 Skeleton part 12 Conduction part 13 Excitation part 14 Powder (fluid material)

Claims (8)

A skeleton that forms an internal space partitioned by columns and / or walls,
A columnar conductive portion whose one end is connected to the skeleton portion and extends into the internal space,
An exciting part that is in the internal space, is connected to the conducting part, and extends to the conducting part.
It is provided with at least a fluid material that comes into contact with the excitation unit .
Backbone unit, said transmission guide portion and該励Fubu is integrated with Na Ru damping mass. The skeleton is composed of partition walls
The internal space is a closed space
The vibration damping structure according to claim 1, wherein the fluidized material is filled in the closed space. The vibration damping structure according to claim 1 or 2, which is a vibration damping member in which a plurality of unit cells including the skeleton portion, the conduction portion, the excitation portion, and the fluidizing material are connected in succession. The vibration damping structure according to claim 3, wherein the vibration damping member constitutes at least a part of a housing surrounding the vibration source or a housing connected to the vibration source. The vibration damping structure according to any one of claims 1 to 4, wherein the fluidizing material is a powder. The vibration damping structure according to any one of claims 1 to 5, wherein the excitation unit is substantially spherical. The vibration damping structure according to any one of claims 1 to 6, wherein the excitation unit has a solid sphere and a hollow sphere containing the solid sphere. A method for producing a vibration damping structure according to any one of claims 1 to 7, wherein the vibration damping structure is manufactured by a powder lamination method.

Images