JPH10187250A - Method for supporting vibration isolation of equipment for generating periodical vibration - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the vibration of an equipment itself to be a vibration generation source by reducing the transmission of vibration in a specific direction only by setting up the interval of supporting positions of the equipment on a base. SOLUTION: In the case of supporting the equipment 1 for generating periodical vibration on the base 2 by plural supporting tools 3a, 3b, the interval of the supporting tools 3a, 3b on the base side is set up in accordance with frequency for vibration proof and vibration transmitted from the equipment 1 to the base 2 through respective supporting tools 3a, 3b is allowed to interfere at a reverse phase in a required direction to reduce the transmission of vibration in the required direction. Consequently conventional vibration insulation can be rationally used together.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anti-vibration mechanism for a device that generates a periodic vibration, such as a pump, a fan, and an engine.

[0002]

2. Description of the Related Art When a device that generates vibration such as a pump, a fan, an engine or the like is installed on a wall of a building, conventionally, as shown in FIG. The vibration isolating rubber d and the like are interposed therebetween and supported, and the vibration insulating effect prevents or reduces the transmission of the vibration of the device a through the foundation c to the wall.

[0003]

[SUMMARY OF THE INVENTION However vibration isolation effect by the vibration-proof rubber or the like is not obtained unless high frequency than the natural frequency f ₀ as shown in FIG. The natural frequency is
If the support rigidity of the support tool b that supports the device a can be reduced if the support rigidity is reduced, a lower frequency, and vibration isolation in a wide frequency range can be performed.
Lowering the support stiffness increases the static deflection, which limits the support strength. Therefore, vibration isolation by vibration-proof rubber or the like is heavy and generates a low frequency (for example, 100 Hz vibration in a 50 Hz power system area). The body itself vibrates more. An object of the present invention is to solve such a problem.

[0004]

In order to solve the above-mentioned problems, according to the present invention, when a device that generates a periodic vibration is supported on a base by a plurality of supports, the base corresponding to the vibration-proof frequency is set. We propose an anti-vibration support method that reduces the transmission of vibration in the desired direction by setting the spacing between the supports on the side and causing the vibration transmitted from the device to the foundation through each support to interfere in opposite phases in the desired direction. .

According to the present invention, in the above configuration,
When the vibration of the frequency to be damped from the device is transmitted to each support in the same phase, the interval between each support is
It is proposed to reduce the transmission of vibration in the linear direction connecting the supports by setting the length to a half wavelength or an odd multiple of the target vibration transmitted through the foundation.

Further, according to the present invention, in the above-mentioned configuration, when the vibration of the frequency to be damped from the device is transmitted to each support in an opposite phase, the distance between the supports is set to the object transmitted through the base. It is proposed to reduce the transmission of vibration in the direction of the perpendicular bisector of the straight line connecting the supports by setting the vibration to a half wavelength or an odd multiple thereof.

According to the present invention, in the above-mentioned configuration, when the vibration of the frequency to be damped from the device is transmitted to each support in an opposite phase, the distance between the supports is determined by the object transmitted through the base. It is proposed to reduce the transmission of vibration in the linear direction connecting the supports by setting the wavelength of the vibration or its integral multiple.

According to the present invention, in the above configuration, when the vibration of the frequency to be damped from the device is transmitted to each support with a phase difference Δ, the direction of the hyperbola that satisfies the following equation is set to the vibration transmission. It is proposed to set the interval and position between each support as a direction for measuring the reduction of the distance. Note that {(PA−PB) / λ} = − (Δ / 2π) + n, where A and B: the center of the support position by the support, PA, PB: the length of the line segment, P: the position on the hyperbola, λ : Wavelength of target vibration transmitted through the foundation, Δ: (phase of target vibration transmitted to B) − (phase of target vibration transmitted to A), n: integer

Further, the present invention proposes that in the above structure, at least the portion between the supports is made of a material having a low sound speed.

In the present invention, it is proposed that vibration supporting means is added to each support in the above-mentioned structure.

According to the present invention, when a device that generates periodic vibration is supported on a foundation by a plurality of supports, the vibration transmitted to the foundation through each support is set by setting the spacing between the supports. It is possible to cause interference in the desired direction in opposite phase, and thus it is possible to reduce the transmission of vibration in the desired direction.

If the distance between the supports for reducing the vibration transmission becomes too long, at least the base material between the supports is made of a material having a low sound velocity, so that the distance is shortened. can do.

When the above-described vibration isolation by the interference and the vibration isolation are used in combination, the former can measure the vibration of the low-frequency fundamental wave, and the latter can measure the harmonic component.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the embodiments shown in the drawings. First, FIG. 1 schematically shows a first embodiment of the present invention, in which a schematic diagram in a side direction is shown on an upper side, and a schematic diagram in a plane direction is shown on a lower side. Reference numeral 1 denotes a device that generates a periodic vibration such as a pump, a fan, a motor, an engine, and the like, and reference numeral 2 denotes a foundation formed on a wall of a building. In this embodiment, the device 1 is supported on the foundation 2 by two supports 3a and 3b. Reference numerals 4a and 4b indicate support positions of the support on the base 2, and the distance between the centers of the positions is L.

Now, the wavelength of the vibration transmitted by the device 1 to the foundation is λ.
Vibrates at a certain frequency.
Or at least two supports 3a, 3
Assuming that the portion b vibrates in the same phase, the distance L between the centers of the support positions 4a and 4b on the foundation 2 is set to a half wavelength λ / 2 (or an odd multiple thereof). After the vibration transmitted to the support position 4a through 3a and transmitted from the device 1 to the support position 4b through the support 3b,
The vibration transmitted to the support position 4a through the foundation 2 has a phase difference of π.
Therefore, they interfere with each other and cancel each other. Similarly, of the positions on the straight line 5 passing through the centers of the support positions 4a and 4b,
Since the phase difference is also π at all positions except between the support positions 4a and 4b, they interfere with each other and cancel each other, so that the transmission of vibration in the direction of the straight line 5 is reduced. However, on the vertical bisector 6 of the line segments 4a and 4b on the straight line 5, interference occurs with a phase difference of 0, so that the vibration transmission becomes rather large in the direction of the vertical bisector 6. Therefore device 1
Is designed to be supported by the two supports 3a and 3b so that the direction of the straight line 5 coincides with the direction in which vibration is not to be transmitted in the building. The effect of reducing the transmission of vibration in the direction of the straight line 5 can be obtained by adding another support (not shown) outside the two supports 3a and 3b at an interval of half wavelength λ / 2 along the straight line 5. The same is done.

Next, similarly to the above, the device 1 vibrates at a frequency where the wavelength of the vibration transmitted through the foundation is λ, but the form of the vibration is different from the above, and the two supports 3a, 3b oscillates in the opposite phase, the supporting positions 4a, 4a,
When the distance L between the centers of 4b is set to half wavelength λ / 2 (or an odd multiple thereof), on the vertical bisector 6 of the line segments 4a and 4b on the straight line 5, contrary to the above case, Supporting tools 3a, 3
Since the vibration passing through b interferes with the phase difference π, they cancel each other, and the transmission of the vibration in the direction of the perpendicular bisector 6 is reduced. Conversely, on the straight line 5, interference occurs with a phase difference of 0, so that the vibration transmission is rather large in the direction of the perpendicular bisector 6.

Further, similarly to the above, the device 1 is vibrating at a frequency where the wavelength of the vibration transmitted through the foundation is λ, and the form of the vibration is such that the two support members 3a and 3b of the device 1 have opposite phases. When the distance L between the centers of the support positions 4a and 4b on the foundation 2 is set to the wavelength λ (or an integral multiple thereof), unlike the above case, Above, they interfere with each other with the phase difference π, so that they cancel each other, and the transmission of vibration in the direction of the straight line 5 is reduced. In addition, on the vertical bisector 6 of the line segments 4a and 4b on the straight line 5, interference occurs with a phase difference of 0, so that vibration transmission becomes larger in the direction of the vertical bisector 6.

Next, as a low-frequency vibration in each of the devices 1, there is, for example, a 100-Hz vibration in a 50-Hz power system area.
The above supporting positions 4a and 4b when vibration is attenuated by a and 3b
For example, when the base 2 is made of iron, the sound speed (transverse wave) is 3240 m / sec, the wavelength λ is 32.4 m, and therefore, the half wavelength λ / 2 is set. Tool 3
The distance L between a and 3b is L = 16.2 m, which is a very wide interval.

In such a case, if the foundation 2 is made of a substance having a low sound speed, for example, lead, the sound speed (transverse wave) of lead is
Since it is 690 m / sec, the wavelength λ is 6.9 m. Therefore, the distance L ′ between the supports 3 a and 3 b set to the half wavelength λ / 2 is 3.
The distance is 45 m, and the interval can be significantly reduced. In this case, the substance having a low sound speed may not be provided on the entire base 2, but may be provided only on at least the portion 7 between the supports 3 a and 3 b of the base 2. That is, FIG. 2 shows an example in which lead is provided only between the supports 3a and 3b as a substance having a low sound speed.
In this example, similarly to the above, the device 1 vibrates at a frequency in which the wavelength of the target vibration is λ (Fe) in iron and λ (Pb) in lead, and the form of the vibration is all parts of the device 1, Alternatively, it is assumed that at least two support members 3a and 3b vibrate in phase with each other. The half wavelength λ / 2 at the sound speed is set.
In this state, the phase difference Δ of the vibration transmitted from A and B at an arbitrary point P on the straight line 5 passing through the centers A and B of the support positions 4a and 4b is as follows. Δ = 2π [{PQ / λ (Fe)} + {QA / λ (Pb)}-{PQ / λ (Fe)}-{QB / λ (Pb)}] = 2π [{QA / λ (Pb) }-{QB / λ (Pb)}] = 2π {AB / λ (Pb)} = π As shown in the above equation, an arbitrary point P on a straight line 5 passing through the centers A and B of the support positions 4a and 4b. Since the phase difference Δ = π of the vibrations transmitted from A and B is equal to each other, on the straight line 5, the vibrations interfere with each other because of the phase difference π. I understand. As shown in FIG. 2, the method of constructing only the portion 7 between the supports 3a and 3b of the foundation 2 with a substance having a low sound velocity is a method of reducing the transmission of vibration in the direction of the straight line 5 in each of the above methods. Applicable to In FIG. 2, the same components as those in FIG. 1 are denoted by the same reference numerals, and redundant description will be omitted.

The mode of vibration of the device 1 in the method described above is such that the two supports 3a and 3b of the device 1 vibrate in the same phase and the opposite phase, but FIG. It is to explain. That is, two supports 3
a, 3b, when the device 1 is supported,
When the vibration from is transmitted to the supports 3a and 3b with an arbitrary phase difference Δ, as shown in FIG. 3, a hyperbola that satisfies the following equation (that is, if the difference between the distances from the two fixed points is constant, Of each support 3 is defined as a direction for reducing vibration transmission, that is, a direction in which vibration interferes with a phase difference π.
The distance and position between a and 3b can be set. {(PA−PB) / λ} = − (Δ / 2π) + n where A, B: center of the support position by the support, PA, PB: length of the line segment, P: position on the hyperbola, λ: Wavelength of target vibration transmitted through the foundation, Δ: (phase of target vibration transmitted to B) − (phase of target vibration transmitted to A), n: integer

In the embodiment described above, the device 1 is supported by the two supports 3a and 3b. However, three or more supports are arranged not on the same straight line but on a plane. However, by setting the positional relationship in the same manner as described above, vibration transmission in a desired direction can be reduced.

FIG. 4 shows an embodiment in which three or more supporting members are arranged and supported not on the same straight line but on a plane to reduce the transmission of vibration in a specific direction. In this embodiment, the device 1 oscillates at a frequency where the wavelength of the vibration transmitted through the foundation is λ, and as a form of the vibration, all parts of the device 1 oscillate in the same phase. Are supported on the foundation 2 by four supports 4a, 4b, 4c, 4d arranged on the vertices of a square having a half wavelength λ / 2. In such a support configuration, at a sufficiently distant position on the x-axis, the vibrations (synthetic waves) from the support positions 4a and 4c and the vibrations (synthetic waves) from the support positions 4b and 4d interfere with a phase difference π. Cancel each other out. Similarly, at a sufficiently distant position on the y-axis, the vibrations (synthetic waves) from the support positions 4a and 4b and the vibrations (synthetic waves) from the support positions 4c and 4d interfere with each other due to the phase difference π and cancel each other. Therefore, in the above-described support configuration, vibration transmission can be reduced in both the x-axis direction and the y-axis direction in the drawing.

The above-described vibration damping method using interference according to the present invention can be applied alone, but can also be used in combination with conventional vibration insulation. That is, although not shown, the support 3 (3a, 3b, 3) in the above description is used.
c, 3d) and an anti-vibration rubber can be interposed between the device 1 or the foundation 2. By adopting such a support structure of the device 1, in the case of vibration isolation by interference, it is possible to perform the vibration isolation of a low-frequency fundamental wave in a specific direction, and in the vibration isolation, the vibration isolation of the harmonic component of the vibration is effectively performed. be able to. As described above, since the vibration isolation at this time may be performed for vibration isolation of a harmonic component, it is not necessary to suppress the supporting rigidity to be low.

In the embodiment described above, the device 1 is hung on the ceiling wall by the support 3, but the present invention can be applied to a device in which the device 1 is supported on the floor by the support. Of course.

[0025]

As described above, the present invention has the following effects. a. The vibration isolation by the interference of the present invention is intended to reduce the transmission of the vibration in a specific direction only by setting the interval of the supporting portion of the device to the foundation. There is no problem in supporting strength such as static deflection, and vibration of the device itself, which is a vibration source, is not increased. b. On the premise of vibration isolation by interference, vibration isolation by vibration isolation rubber or the like can be used rationally in this case, and in this case, the former can perform vibration isolation in a specific direction of the low frequency fundamental wave of vibration. The latter makes it possible to effectively prevent vibration harmonic components.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram schematically showing a first embodiment of the present invention.

FIG. 2 is an explanatory diagram schematically showing a second embodiment of the present invention.

FIG. 3 is an explanatory view schematically showing a third embodiment of the present invention.

FIG. 4 is an explanatory diagram schematically showing a fourth embodiment of the present invention.

FIG. 5 is a schematic view illustrating a conventional method of supporting a device for measuring vibrations by vibration isolation.

FIG. 6 is an explanatory diagram showing a vibration damping effect by conventional vibration insulation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Device 2 Foundation 3 (3a, 3b, 3c, 3d) Supporting tool 4 (4a, 4b, 4c, 4d) Supporting position 5 Straight line 6 Vertical bisector 7 Part of material with slow sound speed

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI F04B 39/00 102 F04B 39/00 102V H02K 5/24 H02K 5/24 A

Claims (7)

[Claims] When a device that generates periodic vibration is supported on a foundation by a plurality of supports, an interval between the supports on the foundation side is set in accordance with a frequency to be damped, and each support is set from the device. A method for supporting a vibration-generating device, wherein the vibration transmitted in the desired direction is reduced by interfering the vibration transmitted to the foundation through the anti-phase in a desired direction. 2. In a case where vibration of a frequency to be damped from an apparatus is transmitted to each support in the same phase, the interval between each support is set to a half wavelength of the target vibration transmitted through the foundation or an odd multiple thereof. 2. The method according to claim 1, wherein the transmission of vibrations in the direction of a straight line connecting the supports is reduced by setting the length of the vibrations. 3. In the case where vibration of a frequency to be damped from an apparatus is transmitted to each support in an opposite phase, the interval between each support is set to a half wavelength of the target vibration transmitted through the foundation or an odd multiple thereof. 2. The method according to claim 1, wherein the vibration transmission in the direction of a perpendicular bisector of a straight line connecting the supports is reduced. 4. When the vibration of the frequency to be damped from the device is transmitted to each support in opposite phase, the interval between each support is set to the wavelength of the target vibration transmitted through the foundation or an integral multiple thereof. 2. The method according to claim 1, wherein the setting is to reduce the transmission of vibrations in a linear direction connecting the supports. 5. When the vibration of the frequency to be damped from the device is transmitted to each support with a phase difference Δ, the direction of the hyperbola that satisfies the following equation is defined as the direction for reducing the vibration transmission. 2. The vibration isolating support mechanism for a device that generates a periodic vibration according to claim 1, wherein an interval and a position between the components are set. {{(PA−PB) / λ} = − (Δ / 2π) + n Where A, B: center of the support position by the support, PA, PB: length of the line segment, P: position on the hyperbola, λ: wavelength of the target vibration transmitted through the foundation, Δ: (target vibration transmitted to B Phase) − (phase of target vibration transmitted to A), n: integer 6. The base according to claim 1, wherein at least a portion between the supports is made of a material having a low sound speed.
6. A method for supporting a device that generates periodic vibration according to any one of items 6 to 6. 7. A vibration isolating support mechanism for a device that generates a periodic vibration according to claim 1, wherein a vibration insulating means is added to each support.