JP4159267B2 - Elevator silencer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a silencer for a rope hoisting elevator, and more particularly to a silencer for a sound leaking from a through hole in a machine room floor to a hoistway side.
[0002]
[Prior art]
Generally, a rope hoisting elevator (including a lift) is provided with a machine room equipped with a hoisting machine on the upper floor of the hoistway, and the main rope that is wound around the hoisting machine and penetrates the hoistway through the through hole of the machine room floor, Suspend the car and fishing weight to carry the load up and down. The dimension of the through hole is determined so as not to contact even when the rope is swaying during operation, and is 30 cm × 38 cm, for example, when the main rope has seven ropes.
[0003]
The hoisting machine is equipped with a motor, sheave, brake, etc., and the sound generated during driving propagates into the hoistway through the through hole in the floor of the machine room and leaks into the car and the halls of each floor, resulting in noise.
[0004]
In order to prevent such sound leakage from the through hole, a method of attaching a silencer duct to the through hole has been proposed (Japanese Utility Model Publication No. 57-106670). As shown in FIG. 21 (a), the muffler duct 100 surrounds the main rope 101, and is provided with a sound absorbing material 102 attached at a necessary minimum interval to allow the swing width of the rope 101 to swing. This prevents noise from leaking into the car and elevator hall.
[0005]
Furthermore, a method of attaching a resonance type resonator utilizing Helmholtz resonance to this duct has been proposed. As shown in FIG. 21 (b), a cavity 103 and a hole 104 leading to the duct are provided in the middle of the duct 100 to prevent noise due to the carrier frequency of the 4 kHz inverter generated from the hoisting machine.
[0006]
[Problems to be solved by the invention]
The silencer duct 100 is used to reduce the noise of about 500 Hz or higher and high frequencies as shown in FIG. 22 (a) in order to rely on the effect of absorbing sound by attaching a porous sound absorbing material such as glass wool or rock wool to the inner wall. Although effective, it has little effect on low frequency noise. The attenuation amount TL (dB) of the silencer duct and the silence attenuation frequency f (Hz) of the maximum attenuation amount are shown in Equation (1) and Equation (2).
[0007]
TL≈ (α−0.1) Pl / S (1)
f = c / D (2)
Here, α: sound absorption coefficient of the sound absorbing material, P: perimeter of the silencer duct, S: sectional area of the silencer duct, l: length of the silencer duct, C: speed of sound, D: sectional dimension of the silencer duct (diameter or short side) Length)) in meters (m).
[0008]
In equation (1), the attenuation increases in proportion to the sound absorption coefficient α, but the actual attenuation characteristic of the duct is as small as 1 dB below 500 Hz as shown in FIG. Further, when the length D of one side of the duct is equal to the wavelength λ / 2 of the sound wave and λ from the equation (2), the vibration of the sound wave is large at the portion where the sound absorbing material 102 is pasted as shown in FIG. Therefore, as shown in FIG. 22A, only the sound reduction per 1800 Hz is effective. Further, as can be seen from the equation (1), since the attenuation depends on the length of the silencer duct, even if the length l of the silencer duct is 1 m, the reduction can be only 2.5 dB. Actually, the length of the muffler duct is limited to about 50 cm because there is a stand on which the hoist is installed on the floor of the machine room, and the attenuation is about 1.2 dB. For this reason, the duct is less effective for low frequency sound reduction.
[0009]
Further, in the structure in which the resonator is attached to the above-described duct, noise due to a carrier frequency of 4 kHz is used for prevention. The volume of the cavity 103 of the resonator as shown in FIG. 22B is V, the cross-sectional area of the hole 104 is S, and the length of the hole 104 is L.₄, The resonance frequency is f₄The speed of sound is c, and the correction value δ of the opening end of the hole is shown in equation (3).
[0010]
f₄= C / 2π (S / V (1 + δ))^1/2... (3)
Resonance frequency f in the above relational expression (3)₄If the dimensions of each part are appropriately set with respect to (carrier frequency 4 kHz), the air in the hole 104 part vibrates violently with respect to the sound in the duct 100 and the hole 104, and the sound having the carrier frequency 4 kHz due to friction. Resonates with and absorbs sound.
[0011]
However, in the machine room where the duct 100 is installed, the temperature t may differ by 40 ° C. or more in the daytime when the motor is operated and in the morning when the motor does not operate so much. Since it changes by 10%, the resonance frequency is off by 10%.
[0012]
c = 331.5 + 0.6t (4)
Therefore, at a certain set temperature, it is effective for noise reduction, but at other temperatures, the resonance-type silencing frequency characteristic changes significantly as shown in FIG.₄However, at frequencies that deviate by 10%, there is a drawback that noise reduction is rapidly inferior. Moreover, the reduction effect other than this frequency is low.
[0013]
Even with the above configuration, it is difficult to completely prevent noise leaking from the through hole. Therefore, the sound absorbing material is wound around the motor casing in the hoisting machine, the sound absorbing material is attached to the motor support, and the main sheave of the hoisting machine is The whole is surrounded by a soundproof case. If the hoist itself is provided with soundproofing means such as a soundproof cover, the equipment will be unnecessarily large, and a cooling device will be installed as a heat countermeasure in the soundproof cover, thereby reducing the effective space in the machine room. In addition to making it narrower, it will lead to an increase in elevator manufacturing costs.
[0014]
The present invention solves the above-described disadvantages, and provides an silencer for an elevator that effectively blocks noise generated in a machine room and propagating to a hoistway side through a through hole at the through hole.
[0015]
[Means for Solving the Problems]
  A first aspect of the present invention is the noise reduction device disposed in the through hole portion provided with a through hole through which a rope for suspending the car and the counterweight is provided on the floor of the machine room equipped with the hoisting machine.
  The silencer surrounds the rope, and is connected to the inlet pipe from the winding device side, an expansion pipe connected to the inlet pipe and having a larger cross-sectional area than the inlet pipe, and a tail connected to the expansion pipe and having a smaller cross-sectional area than the expansion pipe. The cross section of the expansion pipe, inlet pipe and tail pipe is S₁, S₂, S₃Then, S₁/ S₂≧ 2.0 and S₁/ S₃≧ 2.0, and the length of the expansion pipe in the direction of the slope has an odd multiple of 1/4 wavelength of the sound wave of the frequency to be silenced among the sound waves propagating through the through hole. There is a silencer for the elevator. Here, the cross-sectional area of each pipe refers to the cross-sectional area surrounded by the inner wall of each pipe in a plane (cross section) perpendicular to the rope.Furthermore, two expansion tubes that cut sound waves having two different main frequencies propagating through the through hole are connected in combination, and the expansion tube has a long side and a short side, and the rope penetrates in the height direction. It is a rectangular parallelepiped and is arranged so that the long sides of the two-stage expansion pipes are orthogonal to each other.
[0016]
  As a result, an expansion tube can be formed in a part of the tube portion, and the sound can be reduced by causing rapid expansion and contraction to interfere with the sound. Since the frequency of this sound reduction frequency can be adjusted by the length of the expansion tube, it can be adjusted to the frequency at which noise is generated, noise can be effectively reduced, and sound leakage from the machine room is reduced.Furthermore, two specific frequencies to be reduced can be adjusted, and sound leakage from the machine room can be further reduced. Furthermore, by making the expansion tube a rectangular parallelepiped and intersecting the long side with a cross, the interference of the sound wave when the sound wave passes through the pipe line can be improved rather than matching the long side, and a predetermined frequency is desired. To reduce.
[0017]
  The second of the present invention isIn the silencer provided in the through hole through which the rope for suspending the car and the counterweight passes through the floor of the machine room equipped with the hoisting machine,
The silencer surrounds the rope, and is connected to the inlet pipe from the winding device side, an expansion pipe connected to the inlet pipe and having a larger cross-sectional area than the inlet pipe, and a tail connected to the expansion pipe and having a smaller cross-sectional area than the expansion pipe. A cross-sectional area of the expansion pipe, the inlet pipe, and the tail pipe. S ₁ , S ₂ , S ₃ Then, S ₁ / S ₂ ≧ 2.0 and S ₁ / S ₃ ≧ 2.0, and the length of the expansion tube in the direction of the slope has an odd multiple of 1/4 wavelength of the sound wave of the frequency to be silenced among the sound waves propagating through the through hole. There is a silencer for the elevator. Here, the cross-sectional area of each pipe refers to the cross-sectional area surrounded by the inner wall of each pipe in a plane (cross section) perpendicular to the rope. Furthermore, two expansion tubes that cut sound waves of two different main predetermined frequencies propagating through the inside of the through hole are connected in combination, and the two expansion tubes have the same vertical and horizontal dimensions and a rope in the height direction. It is a cube that penetrates and is arranged so that the corners of each expansion tube do not overlap each other in the height direction.
[0018]
  As a result, an expansion tube can be formed in a part of the tube portion, and the sound can be reduced by causing rapid expansion and contraction to interfere with the sound. Since the frequency of this sound reduction frequency can be adjusted by the length of the expansion tube, it can be adjusted to the frequency at which noise is generated, noise can be effectively reduced, and sound leakage from the machine room is reduced. Furthermore, two specific frequencies to be reduced can be adjusted, and sound leakage from the machine room can be further reduced. Further, by shifting the corners of the two-stage expansion tubes so that the corners are, for example, 45 degrees with each other, the asymmetry can be relaxed to increase the interference of sound waves passing therethrough and to increase the volume level. .
[0019]
  First of the present inventionNo. 3 is characterized in that at least the length of the tail tube of the entrance tube and the tail tube has an odd multiple of 1/2 wavelength of the sound wave having a frequency to be silenced. The length of the tail tube affects the frequency characteristics of the sound reduction effect. As the length increases, the cut frequency shifts to the low frequency side and the low frequency range is reduced. When the length is ½ wavelength of the sound wave, the maximum sound reduction is shown.
[0029]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0030]
A first embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 2 (a), a hoisting machine 11, a main sheave 12, a control device 13 having a speed reducer, a speed governor, an electromagnetic device and the like installed in a machine room 10 on the top floor of the building, a damper device 14, a building A car 17 and a counterweight 18, which are located in the hoistway 15 provided vertically long through each floor of the main sheave 12 and run up and down attached to both ends of the main rope 16 wound around the main sheave 12. In addition, it is constituted by a guide rail (not shown) for a car and a counterweight. Reference numerals 21 and 22 denote halls on each floor. The floor 19 of the machine room 10 is provided with a through hole 20 through which at least two main ropes penetrate, and the main rope 16 wound around the main sheave 12 passes through the through hole 20 and the car 17 and the counterweight 18. These are fixed to and suspended. When the main rope 16 moves through the through-hole 20 in both the upper and lower directions, some shaking occurs in the through-hole. As shown in FIG. 2B, the dimension of the through-hole 20 is such that the rope 16 passes when the rope 16 passes through a parallel arrangement of 6 to 12 ropes that are generally used. The dimensions of the vertical a and the horizontal b are determined so that the rope does not come into contact with the horizontal shaking of the through hole. For example, the number of seven is often 30 cm × 38 cm.
[0031]
As shown in FIG. 1, the silencer 30 includes an expansion tube 31 that cuts a sound wave having a predetermined frequency that propagates through the through hole 20 so that sound in the machine chamber 10 does not leak from the through hole 20 to the outside. It has a structure in which an inlet pipe 32 and a tail pipe 33 into which sound from the machine room enters are connected in this order, and a cross-sectional area perpendicular to the rope of the expansion pipe 31 is S.₁, S is the cross-sectional area perpendicular to the rope of the inlet pipe 32₂, S is the cross-sectional area perpendicular to the rope of the tail tube 33₃Then, m = S₁/ S₂≧ 2.0 and m = S₁/ S₃It is an expansion type silencer which is ≧ 2.0. Here, m is an expansion ratio. (S₁, S₂, S₃Are cross sections with respect to the direction of the main rope in the pipe space.
[0032]
This sound reduction principle is to reduce sound by causing sound to interfere by abrupt expansion or contraction of a part of a rope pipeline. The main rope of the expansion tube 31 has a length L in the direction 16a, that is, in the axial direction of the through hole.₁Is a length that is an odd multiple of a quarter wavelength of a wavelength that cuts a sound wave having a predetermined frequency propagating through the through hole 20.
[0033]
The sound reduction TL (dB) can be obtained by the following equation (5).
[0034]
TL = log10 (1+ (1/4) (m-1 / m)²sin²(KL₁)) ... (5)
Here, m: expansion ratio, k = 2πf / c, f: frequency, and c: speed of sound.
[0035]
The length L of the expansion tube 31₁Is set based on the following grounds. For example, when the noise of the hoisting machine is 270 Hz, the wavelength λ of this frequency is obtained by the following equation (6) when the sound speed c is 340 m / sec.
[0036]
λ = c / f (6)
From equation (6), the wavelength is 126 cm at 270 Hz. Therefore, in order to set the attenuation amount to the maximum value, it may be set to be an odd multiple of ¼ of the wavelength λ, and can be obtained by the following equation (7).
[0037]
L₁= (C / 4f) (2n + 1) = (1/4) × λ (2n + 1) (7)
Here (n = 0, 1, 2, ...)
From the above, when n = 0, L₁Is 31.5 cm.
[0038]
From Equation (7), the frequency with the sound reduction effect is an odd-numbered periodic frequency. The carrier frequency of the inverter power supply for driving the motor of the hoisting machine is 4 kHz, but since this is an odd multiple of this frequency, noise can be reduced.
[0039]
FIG. 3 and FIG. 4 show the sound reduction characteristics for various values using the expansion ratio m as a parameter. In FIG. 3, the horizontal axis represents frequency, the vertical axis represents volume reduction (dB), and FIG. 4 represents the expansion ratio on the horizontal axis and volume reduction (dB) on the vertical axis. From this result, when m = 1.5, the sound reduction is as small as about 1.5 dB, and when m = 2.0, the reduction of 2.2 dB at the periodic frequency peaks of 270 Hz, 810 Hz, 1350 Hz,. The effect is recognized. It is recognized that the noise reduction from the elevator's machine room is improved if there is a volume reduction of 2.0 dB or more, and therefore the expansion ratio m needs to be 2.0 or more. m is practically up to about 12 times.
[0040]
Further, FIG. 5 shows the result of an experiment conducted at an expansion ratio m = 3 as confirmation of the reduction in the machine room installation. In the figure, the noise level dB of the hoisting machine 11 in the machine room is measured in the machine room as a change in time. A curve a indicates that the noise level at the time of descent and ascending, which is the operation of the elevator, is 82 dB to 52 dB when the silencer is not installed. FIG. 5B shows a frequency analysis of the noise during the above operation. The maximum value of the frequency in the time history is peak-held during operation, and according to this result, the maximum peaks are seen at 270 Hz and 4 kHz. 270 Hz is generated from the hoisting machine, and is caused by the resonance of the natural frequency of the hoisting machine and the operating frequency of the inverter power supply, which is 45 Hz and six times that of 270 Hz. 4 kHz is a carrier frequency of the inverter power supply, which is a time high frequency component generated when the power is turned on, and is generated from the motor of the hoisting machine.
[0041]
This noise data is for models with a large capacity of the hoist, but the frequency of noise generated from the motor of the small and medium capacity hoist also shows the same tendency as the large capacity, A significant peak of the spectrum is seen in the high frequency range of 4 kHz and 8 KHz.
[0042]
As shown by the curve b in FIG. 5A, the noise peak was 82 dB in the conventional characteristic a, but in this embodiment, it was recognized that the noise peak was reduced to 75 dB as in the characteristic b. Also in the frequency analysis result shown in FIG. 5 (b), it was confirmed that the characteristic was a characteristic b with respect to the conventional characteristic a, and the remarkable frequencies of 270 Hz and 4 kHz were reduced by 5 dB or more. Next, as shown in FIG. 6A, the shape of the expansion tube 31 is a hollow cylinder, and the inlet tube 32 and the tail tube 33 are hollow rectangular tubes having a rectangular cross section along the through hole 20. In this case, as shown in FIG. 6B, the expansion tube 31 may be a hollow rectangular parallelepiped, and the shape can be variously modified. However, the expansion ratio m = S₁/ S₂≧ 2.0 and m = S₁/ S₃≧ 2.0.
[0043]
If the expansion tube is cylindrical, the equivalent diameter d of the inlet tube₂Can be obtained by the equation (8).
[0044]
d₂= (4 × a₂Xb₂)^1/2(8)
For example, the dimension of the through hole₂= 30 cm, b₂= 38cm
d₂= (4 × 30 × 38 / π) 1 / 2≈38.1
If m = 2, the diameter of the expansion tube may be 53.8 cm or more. The characteristic change due to temperature is different from the sound reduction characteristic of the conventional apparatus as shown in FIG. 23, and the influence of the frequency range of the sound reduction range has a margin since the sound is reduced to a sine wave shape as shown in FIG.
[0045]
In the present embodiment, the material constituting the silencer is a 2.3 mm thick steel mild steel material. The material is not limited to this, and other metals such as aluminum, or synthetic resins can be used.
[0046]
According to the present embodiment, the pipe part through which the rope passes is composed of an inlet pipe, an expansion pipe, and a tail pipe, and an expansion and contraction space is formed in the pipe part, so that sound efficiently interferes with each other for a specific frequency. Can be attenuated. This sound reduction frequency can be adjusted by the length of the expansion tube, can be adjusted to the frequency of the sound generated from the machine room, and the sound leaking from the machine room to the hoistway is reduced.
[0047]
In this embodiment, the length of the inlet pipe and the tail pipe are set to have the same length in the direction of the direction. However, the inlet pipe 32 causes the sound wave interference of the expansion pipe and is made shorter than the tail pipe. You can also
[0048]
A second embodiment of the present invention will be described based on the characteristics shown in FIGS. Length L of tail tube 33₃However, it is set as the structure which has the odd multiple length of 1/2 wavelength of the wavelength which cuts the predetermined | prescribed frequency which propagates the inside of the through-hole 20. FIG.
[0049]
FIG. 7 shows a comparison of 0.3 wavelength (a), 0.5 wavelength (1/2 wavelength) (b), and 0.8 wavelength (c). Tail tube length L₃Affects the frequency characteristics of the sound reduction effect, and the cut frequency shifts to the lower frequency side as the length increases. If the tail tube is attached, the overall silencing effect does not increase, but the reduction effect shifts toward the lower frequency. This also shows the maximum sound reduction when the wavelength of the sound wave is ½ wavelength, the noise is effectively reduced, and then the tail tube length L₃To maximize the attenuation value in this embodiment, L₃To 63 cm. This length is the wavelength ½ of 270 Hz, which is the center of sound reduction, and can be obtained from equation (5).
[0050]
A third embodiment of the present invention will be described with reference to FIGS. In the following embodiment, the same reference numerals as those in FIG. 1 denote the same parts. The expansion pipes 34 and 35 having the same wavelength as the length of the noise frequency generated in the two different machine chambers propagating in the through hole 20 are connected by a two-stage combination intermediate tail pipe 33a. A silencer 40 is provided. For example, it can be applied when two specific frequencies of 270 Hz and 1000 Hz have to be cut, and the length L of one expansion tube 34 as shown in FIG.₁Is 31.5 cm for 270 Hz, and the length L of the other expansion tube 35₁'Is set to 8.5 cm for 1000 Hz. As shown in FIG. 9, two specific frequencies to be reduced can be adjusted to obtain a comprehensive characteristic, and can be adjusted to main noise frequencies generated from the machine room, thereby reducing noise from the machine room.
[0051]
A fourth embodiment of the present invention will be described with reference to FIG. In the two-stage combination elevator silencer 40, one expansion pipe 34 is installed on the floor 19 of the machine room 10, and the other expansion pipe 35 is installed below the floor 19 of the machine room, that is, on the ceiling below the machine room. 19 is connected and installed by an intermediate tail pipe (of the expansion pipe 34) 33a. The ceiling of the hoistway 15 and the inside of the machine room 10 are limited in places where the silencer is installed in the height direction. With this configuration, a space in the height direction in which the silencer is installed can be reduced.
[0052]
A fifth embodiment of the present invention will be described with reference to FIG. When the shape of the expansion tube is a rectangular parallelepiped, the long sides 34l and 35l of the rectangular parallelepiped of the two-stage connected expansion tubes 34 and 35 shown in FIG. The configuration. According to this, since the sound wave is caused to interfere by the expansion ratio m, when the sound wave passes through the pipe line, the long side of the rectangular parallelepiped of the two-stage expansion pipe is used as a sound wave propagation path. Non-objectivity can be alleviated, noise is effectively reduced, and leakage from the machine room is reduced.
[0053]
A sixth embodiment of the present invention will be described with reference to FIG. When the shape of the expansion tube of FIG. 8 is a cube, the corners 34c and 35c of the two connected expansion tubes 34a and 35a are installed so that the corners do not coincide with each other so that the corners 34c and 35c are 45 degrees. And According to this, since the sound wave is caused to interfere by the expansion ratio m as in the fifth embodiment, when the sound wave passes through the pipe line, the sound wave of the two-stage expansion pipe passes through the pipe line. Since the cube corners of the two-stage expansion pipes coincide with each other, non-objectivity can be reduced, noise is effectively reduced, and leakage sound from the machine room is reduced.
[0054]
A seventh embodiment of the present invention will be described. Although not shown in the drawings, the shape of the expansion tube is a regular cube, and the lengths of the three sides are the same. According to this, the maximum sound reduction is shown when the wavelength of the sound wave is ¼ wavelength, and the three sides of the expansion tube cube are made to coincide with each other, so that the three sides have the same wavelength, so noise is effective. And leakage sound from the machine room is reduced.
[0055]
An eighth embodiment of the present invention will be described with reference to FIG. 0.7 L is set as the length between the connecting portions 36 where the inlet pipe tail pipe 33 is connected to the expansion pipe 31 with respect to the length L of the expansion pipe that cuts the frequency of noise generated in the machine room. 3L is the length of the expansion pipe outer peripheral portion 37, and a gradient is gradually provided in the radial direction of the expansion pipe. According to this, since the maximum sound reduction is shown when the wavelength of the sound wave is ¼ wavelength, by reducing the L dimension of the expansion tube, it is reduced in a frequency range within the range of 270 Hz. It is effective when sounding. For example, noise is effectively reduced with respect to noise having a frequency band of about 190 Hz to 350 Hz, and leakage sound from the machine room is reduced.
[0056]
In the present embodiment, L is increased as it goes to the outer diameter side of the expansion pipe, but conversely, L may be reduced as the outer diameter is increased.
[0057]
A ninth embodiment of the present invention will be described with reference to FIG. As shown in FIG. 14A, the inlet pipe 32 is inserted into the expansion pipe 31 up to ½ of the length L in the hole penetration direction of the expansion pipe. According to this, as shown by a curve a in FIG. 14 (b), there is a sound reduction effect of a characteristic that the sound is reduced at an even multiple of 2f, 6f, 10f, 14f, 18f,. The leakage noise from the machine room is reduced.
[0058]
A tenth embodiment of the present invention will be described with reference to FIG. As shown in FIG. 15A, the tail tube 33 is inserted into the expansion tube 31 up to ½ of the expansion tube length L. According to this, as shown by the curve a in FIG. 15 (b), the characteristic that the sound is reduced at an odd multiple frequency has a sound reduction effect even at an even multiple frequency of 4f, 12f,... The even number of times of noise is effectively reduced, and the leakage sound from the machine room is reduced.
[0059]
An eleventh embodiment of the present invention will be described with reference to FIG. As shown in FIG. 16A, the end of the inlet pipe 32 is inserted into the expansion pipe 31 to ¼ of the expansion pipe length L, and the end of the tail pipe 33 is inserted into the expansion pipe 31 to ¼ of the expansion pipe length L. It is assumed that it has been inserted. According to this, there is a sound reduction effect of the characteristic that the sound is reduced at the entire frequency as shown by the curve a in FIG. 16B, and the even number of noises is effectively reduced as compared with the ninth and tenth embodiments. In addition, the leakage sound from the machine room is reduced.
[0060]
A twelfth embodiment of the present invention will be described with reference to FIG. The sound absorbing material 25 is attached to the inner walls of the expansion pipe 31, the inlet pipe 32 and the tail pipe 33, and the length L of the expansion pipe 31 is₁Is configured to be 1.2 times the length L required for the frequency. According to this, the sound absorbing characteristic of the sound absorbing material is increased, and there is a sound reducing effect of the characteristic that the sound is reduced in the high sound range, the noise is effectively reduced, and the leakage sound from the machine room is reduced. From the measurement result shown in the curve a in FIG. 18, the correction coefficient τ can be expressed by Equation (5).
[0061]
L₁= (Τ / 4) × λ (2n + 1)
When the main component of the hoisting machine noise is 270 Hz, the length L of the expansion pipe 31₁Is matched to (1/4 wavelength) × 1.2 and 1/2 wavelength, so that the phase of the sound wave is shifted to the opposite phase, and the sound wave cancels each other due to the interference action, and is greatly attenuated. As a result, the noise at 270 Hz is greatly reduced.
[0062]
In this way, the leakage sound from the machine room is reduced. In other words, if the correction coefficient τ = 1.2 is added, in this embodiment, L₁= 37.8 cm. In addition, it is needless to say that the noise reduction effect is increased by increasing the ratio of the cross-sectional areas of the expansion pipe 31, the inlet pipe 32 and the tail pipe 33 as much as possible to show the noise reduction effect. Absent.
[0063]
In the above embodiment, the lengths of the expansion tube and the tail tube are set to 270 Hz. However, the length is not limited to this, and may be appropriately selected according to noise.
[0064]
Further, a sound absorbing material 25 made of, for example, porous plastic, glass wool, felt rock wool, aluminum sintered material, or the like is attached to the inner surfaces of the expansion pipe, the inlet pipe, and the tail pipe. In this embodiment, 30 cm thick rock wool is attached with an adhesive.
[0065]
A thirteenth embodiment of the present invention will be described with reference to FIG. As shown in the figure, the sound absorbing material 25 of the above embodiment is attached to a position separated from the inner wall 31d of the expansion pipe 31 from 5 cm to 10 cm. As shown in FIG. 19B, the effect of the sound absorbing material is increased by setting a distance from the wall surface 31d. According to this, a low frequency sound absorption coefficient is improved by providing an air layer behind the sound absorbing material. The reason for this is that a long wavelength (low frequency) sound is effectively reduced because it is separated from the wall surface 31d so that the loss due to resistance coincides with the maximum particle velocity. This is the position where the characteristic of the sound absorbing material acts to the maximum, and has the effect of reducing the sound that is reduced in the high frequency range, effectively reducing the noise and reducing the leakage sound from the machine room.
[0066]
A fourteenth embodiment of the present invention will be described with reference to FIG. A floor hole 29 for passing the through hole, and a tail pipe 33 inserted into the floor hole and buried in the cinder concrete 19a, and the tail pipe 33 and the expansion pipe 31 can be connected and assembled with bolts 28 and the like. It is set as the structure which divided | segmented. This simplifies on-site assembly and improves workability. In this example, the expansion pipe 31 is provided on the floor. However, the inlet pipe 32 may be fixed to the floor hole 29 and the expansion pipe 31 may be disposed on the lower floor side.
[0067]
【The invention's effect】
According to the present invention, the noise generated from a hoisting machine or the like is propagated to a hoistway, a car, an elevator hall, etc. Can be prevented.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a main part showing a first embodiment of the present invention.
2A is a cross-sectional view of a first embodiment of the present invention, and FIG. 2B is a schematic plan view of a through hole.
3A, 3B, 3C, and 3D are curve diagrams showing the relationship between an expansion ratio m, frequency, and volume reduction.
FIG. 4 is a curve diagram of the relationship between the expansion ratio m and the volume reduction.
FIG. 5A is a curve diagram showing the noise level reduction effect associated with the hoist driving showing the characteristics of the first embodiment, and FIG. 5B shows the noise level and the reduction effect with respect to the frequency of the first embodiment. Curve diagram.
6A is a perspective view of the silencer of the first embodiment, and FIG. 6B is a perspective view of a modification.
FIGS. 7A, 7B, and 7C are curve diagrams for explaining sound reduction in the second embodiment.
FIG. 8 is a cross-sectional view of a third embodiment.
FIG. 9 is a curve diagram for explaining sound reduction according to the third embodiment.
FIG. 10 is a sectional view showing a fourth embodiment.
FIG. 11 is a perspective view showing a fifth embodiment.
FIG. 12 is a perspective view showing a sixth embodiment.
FIG. 13 is a cross-sectional view showing an eighth embodiment.
14A is a sectional view of a ninth embodiment, and FIG. 14B is a characteristic diagram thereof.
15A is a sectional view of a tenth embodiment, and FIG. 15B is a characteristic diagram thereof.
16A is a sectional view of an eleventh embodiment, and FIG. 16B is a characteristic diagram thereof.
FIG. 17 is a sectional view of a twelfth embodiment.
FIG. 18 is a sound reduction characteristic diagram of the twelfth embodiment.
FIG. 19A is a cross-sectional view showing a thirteenth embodiment, and FIG. 19B is a view for explaining the sound reducing action.
FIG. 20 is a sectional view showing a fourteenth embodiment.
FIGS. 21A and 21B are cross-sectional views showing the prior art.
FIGS. 22A and 22B are diagrams for explaining the characteristics and operation of the prior art, respectively.
FIG. 23 is a diagram illustrating characteristics of a conventional technique.
[Explanation of symbols]
10: Machine room
11: Winding machine
12: Main sheave
13: Control device
14: Damper device
15: hoistway
16: Main rope
17: Car
18: counterweight
19: Floor
20: Through hole
21 and 22: Elevator hall
25: Sound absorbing material
28: Bolt
31: Expansion tube
32: Entrance pipe
33: Tail tube
S₁: Cross section of expansion tube
S₂: Cross section of entrance pipe
S₃: Cross section of tail pipe
L₁: Length of expansion tube

Claims (3)

In the silencer provided in the through hole through which the rope for suspending the car and the counterweight passes through the floor of the machine room equipped with the hoisting machine,
The silencer surrounds the rope, and is connected to the inlet pipe from the hoisting device side, an expansion pipe connected to the inlet pipe and having a larger cross-sectional area perpendicular to the rope than the inlet pipe and the expansion pipe. It consists of a tail pipe having a smaller cross-sectional area perpendicular to the rope than the expansion pipe, and the cross-sectional areas of the expansion pipe, the inlet pipe and the tail pipe are S ₁ , S ₂ and S ₃ ,
S ₁ / S ₂ ≧ 2.0 and S ₁ / S ₃ ≧ 2.0
, And the have a odd double length of a quarter wavelength of the sound wave frequency to be mute of sound waves length of So direction to the rope of the expansion pipe is propagated through the through hole,
Two expansion tubes that cut sound waves of two different main predetermined frequencies propagating through the inside of the through hole are connected in combination in two stages,
The expansion tube is a rectangular parallelepiped having a long side and a short side and the rope penetrates in the height direction, and the long sides of the two-stage expansion tubes are arranged so as to be orthogonal to each other;
An elevator silencer characterized by the following. In the silencer provided in the through hole through which the rope for suspending the car and the counterweight passes through the floor of the machine room equipped with the hoisting machine,
The silencer surrounds the rope, and is connected to the inlet pipe from the hoisting device side, an expansion pipe connected to the inlet pipe and having a larger cross-sectional area perpendicular to the rope than the inlet pipe and the expansion pipe. It consists of a tail pipe having a smaller cross-sectional area perpendicular to the rope than the expansion pipe, and the cross-sectional areas of the expansion pipe, the inlet pipe and the tail pipe are S ₁ , S ₂ and S ₃ ,
S ₁ / S ₂ ≧ 2.0 and S ₁ / S ₃ ≧ 2.0
The length of the direction of the rope of the expansion tube has an odd multiple of a quarter wavelength of the sound wave of the frequency to be silenced among the sound waves propagating through the through hole,
Two expansion tubes that cut sound waves of two different main predetermined frequencies propagating through the inside of the through hole are connected in combination in two stages,
The two-stage expansion pipes are made of a cube in which the rope penetrates in the height direction with the same vertical and horizontal dimensions, and are arranged so that the corners of the respective expansion pipes do not overlap each other in the height direction,
An elevator silencer characterized by the following . The elevator silencer according to claim 1 or 2, wherein at least the length of the tail pipe of the entrance pipe and the tail pipe is an odd multiple of a half wavelength of a sound wave having a frequency to be silenced.

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