Blower and casing

Abstract

To provide a blower and casing capable of enhancing sound muffling effect.SOLUTION: There is provided a blower 10 equipped with a motor 11, a propeller 12 driven by the motor 11, and a casing 13 that contains the motor 11 and the propeller 12, secures the motor 11, and has openings at the front and rear, which comprises a female thread portion 14 having a female thread formed directly or indirectly on an inner portion of the casing 13, and an inscribed member 15 in which a first sound propagation path C1 is formed through an inner portion in the front and rear directions and is arranged to inscribe the female thread 14. And by allowing the inscribed member 15 to move in the front-back direction relative to the female thread 14, a path length of the sound propagation path C2 formed between the female thread 14 and the inscribed member 15 is variable.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a blower and a casing. [Background technology]

[0002] Regarding the problem of increased noise caused by increasing the airflow power of blowers such as hair dryers, there is a technology that controls some of the sound waves that make up the noise so that they are in opposite phase, causing the respective sound waves to interfere with each other and thus achieving noise reduction (see, for example, Patent Document 1).

[0003] There is also a technology in which a second transparent area, through which sound passes that is shifted by half a wavelength from the wavelength of the sound passing through the first transparent area, is placed around the first transparent area through which air and sound pass, and sound is silenced by the sounds that pass through both areas interfering with each other at the exit (for example, Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2-252404 [Patent Document 2] US Patent Application Publication No. 2020 / 0043456 Summary of the Invention [Problem to be solved by the invention]

[0005] However, there are individual differences in the manufacturing process of devices, and in some cases noise reduction cannot be achieved as designed. In addition, there are individual differences in the frequencies that users perceive as noise, which can result in insufficient noise reduction.

[0006] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide a blower and a casing that can enhance the noise reduction effect. [Means for solving the problem]

[0007] In order to achieve the above object, the blower (10) according to claim 1 of the present invention comprises: A motor (11); a propeller (12) driven by the motor (11); A blower (10) including a casing (13) that houses the motor (11) and the propeller (12), fixes the motor (11), and has openings at the front and rear, a female thread portion (14) in which a female thread is formed directly or indirectly on a part of the inside of the casing (13); an internal contact member (15) that is disposed so that at least a portion of the internal contact member (15) is inscribed in the female screw portion (14), the internal contact member (15) having an interior that penetrates in the front-rear direction to form a first sound propagation path (C1), The inscribed member (15) is arranged to be movable in the forward and backward directions relative to the female thread portion (14), thereby making it possible to vary the path length of a second sound propagation path (C2) formed between the female thread portion (14) and the inscribed member (15). The term "inscribed" here includes screw engagement.

[0008] The blower (10) according to claim 2 is The female screw portion (14) is characterized in that it is a multiple-start screw having multiple threads formed therein.

[0009] The blower (10) according to claim 3 is The internal contact member (15) is characterized by having a male threaded portion (15) on the outer periphery of which a male thread is formed to screw into the female threaded portion (14).

[0010] The blower (10) according to claim 4 is The inscribed member (15) is characterized in that it is cylindrical.

[0011] The blower (10) according to claim 5 further comprises: At least one of the threads has a length different from the other threads.

[0012] The casing (13) according to claim 6 is A casing (13) for propagating sound waves therein, a female thread portion (14) in which a female thread is formed directly or indirectly on a part of the inside of the casing (13); an internal contact member (15) that is disposed so as to be inscribed in the female screw portion (14) and that has an interior penetrating in the front-rear direction to form a first sound propagation path (C1) for the sound wave; The inscribed member (15) is made movable in the forward / backward direction relative to the female thread portion (14), thereby making it possible to vary the path length of a second sound propagation path (C2) formed between the female thread portion (14) and the inscribed member (15) for propagating the sound waves.

[0013] Here, the symbols in parentheses indicate corresponding elements or items in the drawings and in the detailed description to be described later. Effect of the Invention

[0014] According to the present invention, a casing is provided with a female thread portion having a female thread formed directly or indirectly on a portion of the inside of the casing, and an inscribed member that penetrates the interior in the front-to-rear direction to form a first sound propagation path and is arranged so as to inscribe the female thread portion.By making the inscribed member movable in the front-to-rear direction relative to the female thread portion, the path length of the second sound propagation path formed between the female thread portion and the inscribed member is made variable, and therefore sound can be silenced when the path length difference between the first sound propagation path and the second sound propagation path is half a wavelength. In addition, since the path difference can be fine-tuned, even if there are individual differences in the equipment, the path length difference between the first sound propagation path and the second sound propagation path can be adjusted to half a wavelength by fine-tuning, thereby improving the sound-reduction effect. In other words, even if there are individual differences in equipment and sound cannot be silenced as designed, the inscribed member can move relatively in the forward and backward directions, so that the path length difference between the first sound propagation path and the second sound propagation path for that individual device can be made half the wavelength, making it possible to silence the sound.

[0015] Furthermore, according to the present invention, since the female screw portion is a multiple-start screw having multiple threads, the second sound propagation path can have multiple path lengths, and therefore the flow rate of air passing through the second sound propagation path is increased, thereby improving the sound deadening effect.

[0016] Furthermore, according to the present invention, the inscribed member is a male threaded portion having a male thread formed on its outer periphery that can be screwed into the female threaded portion, so that the path length of the second sound propagation path can be changed by using the inscribed member as a screw. Therefore, since the path length of the second sound propagation path can be finely adjusted, the peak of the frequency to be silenced can be finely adjusted.

[0017] Furthermore, according to the present invention, since the inscribed member is cylindrical, the path length difference between the first sound propagation path and the second sound propagation path can be changed by linearly moving the inscribed member back and forth.

[0018] In addition, according to the present invention, since the length of at least one thread is different from the lengths of the other threads, a second sound propagation path having a different path length can be provided, thereby making it possible to mute sound at a plurality of frequencies. In this specification, muffling refers to reducing sound, not making sound completely inaudible.

[0019] Incidentally, there is no mention at all in Patent Documents 1 and 2 of the point of varying the path length to the second sound propagation path as in the present invention. [Brief description of the drawings]

[0020] [Figure 1] 1 is a perspective view showing a blower according to a first embodiment of the present invention. [Diagram 2] 1 is an exploded perspective view showing a blower according to a first embodiment of the present invention. [Diagram 3] 1 is a cross-sectional view showing a blower according to a first embodiment of the present invention. [Figure 4]1A shows the state of the female thread portion and the inscribed member in the blower according to the first embodiment of the present invention, where (a) shows the state where the female thread portion and the inscribed member are separated, (b) shows the state where the inscribed member starts to enter the female thread portion, (c) shows the state where the inscribed member has entered one revolution into the female thread portion, and (d) shows the state where the inscribed member has entered completely into the female thread portion. Also, (a'), (b'), (c'), and (d') show the state where the female thread portion in (a), (b), (c), and (d) is an oblique cross-sectional view. [Diagram 5] FIG. 4 is a perspective view showing a blower according to a second embodiment of the present invention. [Figure 6] FIG. 4 is an exploded perspective view showing a blower according to a second embodiment of the present invention. [Figure 7] FIG. 11 is a perspective view showing one thread of a female screw portion in a blower according to a second embodiment of the present invention. [Figure 8] 5A and 5B are cross-sectional views showing a blower according to a second embodiment of the present invention, in which (a) shows the inscribed member in its most advanced state, (b) shows the inscribed member in its retracted state by half its length, and (c) shows the inscribed member in its most retracted state. [Figure 9] 5A and 5B are perspective views showing a blower according to another embodiment of the present invention, in which FIG. 5A shows a state seen from the front and FIG. 5B shows a state seen from the rear. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] First embodiment A blower 10, particularly a hair dryer, according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 4. FIG. The blower 10 includes a motor 11, a propeller 12, a casing 13, a female screw portion 14, and an internal member 15.

[0022] The motor 11 is a power source for driving a propeller 12 (described later) using an external power source, and is disposed within a casing 13 .

[0023] The propeller 12 is connected to the rear of the motor 11 and is driven by the motor 11, and generates an air flow from the rear to the front by rotating on its axis.

[0024] The casing 13 is a substantially cylindrical housing that is open at the front and rear, and contains the motor 11 and the propeller 12 therein to fix the motor 11 in place. In addition, since the blower 10 according to this embodiment is a hair dryer, the casing 13 also contains and fixes a heater in front of the motor 11.

[0025] The front opening of the casing 13 is called the air outlet, and the rear opening is called the air inlet. The casing 13 has a scale on its outer periphery on the suction port side, so that the amount of rotation of the female screw portion 14, which will be described later, can be determined.

[0026] The female screw portion 14 is a cylindrical body whose interior is penetrated in the front-rear direction and whose outer diameter is approximately equal to the inner diameter of the casing 13, and can be attached to the inside rear part (suction port) of the casing 13 via an internal contact member 15 described later. Further, the female screw portion 14 is provided with a screw thread in the inward direction of the cylindrical body, thereby forming a female screw.

[0027] The inscribed member 15 can be attached to the fixing member 16 described later, and has an interior that penetrates in the front-to-rear direction to form a first sound propagation path C1, and is a male threaded portion 15 with a male thread formed on its outer periphery that can be screwed into the female threaded portion 14. When the female thread portion 14 and the male thread portion 15 are screwed together, a gap is formed between the root of the female thread portion 14 and the thread 15a of the male thread portion 15. This gap is referred to as a second sound propagation path C2 in this specification.

[0028] The fixing member 16 is a flat cylindrical body whose outer shape is approximately the same as that of the female threaded portion 14, and is attached to the inside rear of the casing 13. A hole is formed in the center of the flat cylindrical body into which the inscribed member 15 can be fitted and fixed.

[0029] Since the female thread portion 14 and the male thread portion 15 are screwed together, the inscribed member 15 (male thread portion 15) is movable in the front-rear direction relative to the female thread portion 14, as shown in FIG.

[0030] Since the female thread portion 14 and the male thread portion 15 are screwed together in this manner, the path length of the second sound propagation path C2 is variable. That is, as shown in Figures 4(d) and (d'), when the female thread portion 14 is screwed into the male thread portion 15 to the maximum extent, the overlap between the female thread portion 14 and the male thread portion 15 in the front-rear direction is the largest. At this time, the path length of the second sound propagation path C2 is the largest.

[0031] 4(b) and (b'), when the amount of screwing of the female thread portion 14 relative to the male thread portion 15 is small, the overlap in the front-rear direction between the female thread portion 14 and the male thread portion 15 is small. At this time, the path length of the second sound propagation path C2 is short.

[0032] In this embodiment, since the male screw portion 15 is fixed to the casing 13 via the fixing member 16, the female screw portion 14 advances and retreats relative to the casing 13 (is screwed).

[0033] (Sound deadening mechanism) Next, the noise reduction mechanism will be described. Since sound is a sound wave, noise is reduced by the mutual interference of sound waves in opposite phases. In other words, if a sound wave that is the source of noise is superimposed on a sound wave that is shifted by half a wavelength, they will interfere and the noise will be silenced.

[0034] In addition, since the generated sound waves have various wavelengths and are composed of a superposition of these, the term "muffling" used in this specification does not mean that sound is completely eliminated, but rather that the sound of the target sound wave is cancelled out by mutual interference with a sound wave of the opposite phase, making the overall sound heard quieter.

[0035] In this embodiment, if the path length difference between the first sound propagation path C1 and the second sound propagation path C2 is set to half the wavelength of the passing sound wave, the sound waves passing through this portion will interfere with each other and be muted. For example, if the passing sound wave (sound wave to be silenced) is 500 Hz (wavelength 680 mm), the sound wave can be silenced by setting the path length difference to 340 mm.

[0036] Here, the path length of the first sound propagation path C1 is fixed since it is equal to the length of the inscribed member 15 in the front-to-rear direction. However, if the path length of the first sound propagation path C1 is assumed to be 25 mm and the path length of the second sound propagation path C2 is assumed to be 365 mm, the path length difference is 340 mm. In this embodiment, the diameter of the substantially cylindrical casing 13 is 72.1 mm, the inner diameter of the first sound propagation path is 38.1 mm, and the length is 25 mm. When the inscribed member 15 is screwed into the female thread portion 14 by two revolutions, the path length of the second sound propagation path C2 is 365 mm, and the path length difference is 340 mm. This state is called the amount of rotation of the female thread portion 14 being two revolutions. This is the state shown in Figures 4(d) and (d'). As mentioned above, the frequency band of the noise to be silenced in this case is 500 Hz.

[0037] It is known that a hair dryer generates a wide range of noise from 500 to 2000 Hz when in operation. Therefore, if you want to eliminate noise of 500 Hz (wavelength 680 mm), the path length difference should be 340 mm; if you want to eliminate noise of 1000 Hz (wavelength 340 mm), the path length difference should be 170 mm; and if you want to eliminate noise of 2000 Hz (wavelength 170 mm), the path length difference should be 85 mm.

[0038] In this embodiment, for example, when the female screw portion 14 rotates one and a half times, the path length of the second sound propagation path C2 is 274 mm, and the path length difference is 249 mm. Therefore, the silencing noise band is 683 Hz. When the female screw portion 14 rotates one revolution (FIGS. 4(c) and 4(c')), the path length of the second sound propagation path C2 is 183 mm, and the path length difference is 158 mm. Therefore, the silencing noise band is 1076 Hz. When the female screw portion 14 is rotated half a turn, the path length of the second sound propagation path C2 is 91 mm, and the path length difference is 66 mm. Therefore, the silencing noise band is 2576 Hz.

[0039] The blower 10 configured as described above comprises a female thread portion 14 in which a female thread is indirectly formed on a part of the inside of the casing 13, and an inscribed member 15 whose interior penetrates in the front-to-rear direction to form a first sound propagation path C1 and is arranged so that a part of it is inscribed in the female thread portion 14. By arranging the inscribed member 15 so that it can move freely in the front-to-rear direction relative to the female thread portion 14, the path length of the second sound propagation path C2 formed between the female thread portion 14 and the inscribed member 15 is made variable, and therefore sound can be silenced when the path length difference between the first sound propagation path C1 and the second sound propagation path C2 is half a wavelength.

[0040] In addition, since the path difference can be fine-tuned, even if there are individual differences in the equipment, the path length difference between the first sound propagation path C1 and the second sound propagation path C2 can be adjusted to half a wavelength by fine-tuning, thereby improving the noise reduction effect. In other words, even if there are individual differences in equipment and sound cannot be silenced as designed, and there are individual differences in the frequencies that are perceived as noise depending on the user, since the inscribed member 15 can move relatively in the forward and backward directions, the path length difference between the first sound propagation path C1 and the second sound propagation path C2 can be made half the wavelength for that individual device, and sound can be silenced.

[0041] Second Embodiment Next, a blower 10 according to a second embodiment of the present invention will be described with reference to Figures 5 to 8. Note that the same parts as those in the first embodiment are denoted by the same reference numerals.

[0042] The difference between this embodiment and the first embodiment is the female screw portion 14 and the internal contact member 15, and the other components are the same as those of the first embodiment. Descriptions of the motor 11 and the propeller 12 are omitted.

[0043] The female screw portion 14 is formed by directly threading the casing 13 on the inner side of the air outlet port. The female screw portion 14 has six threads 14a, forming a six-start thread. That is, the threads 14a as shown in FIG. 7 are arranged such that the ends, which are the beginnings of the threads 14a, are positioned at positions shifted by 60°.

[0044] The inscribed member 15 is cylindrical and has a length of 90 mm in the front-rear direction. In other words, unlike the inscribed member 15 according to the first embodiment, the outer circumferential surface of the inscribed member 15 has no threads formed thereon and is smooth. The path length of the first sound propagation path C1 is 90 mm.

[0045] Furthermore, the outer diameter of the inscribed member 15 is configured so that, when the inscribed member 15 is inserted into the casing 13, the outer peripheral surface of the inscribed member 15 comes into inscribed contact with the thread 14a of the female screw portion 14. That is, in this embodiment, the gap surrounded by the outer circumferential surface of the inscribed member 15 and the adjacent threads 14a of the female screw portion 14 is the second sound propagation path C2.

[0046] Furthermore, a slider 15b is provided on the upper rear end of the inscribed member 15, and is guided by a guide groove 13a provided on the upper part of the casing 13. The slider 15b may be provided by integral molding with the inscribed member 15, or may be provided so as to be removable therefrom, and may be provided so as to allow the inscribed member to be attached to the guide groove 13a, for example, by configuring the casing 13 with an assembled structure that is divided at the boundary of the guide groove 13a.

[0047] Here, when the path length of the first sound propagation path C1 is 90 mm and the path length of the second sound propagation path C2 is 450 mm (when the inscribed member 15 is moved all the way forward as shown in Figure 8(a)), the path length difference between the first sound propagation path C1 and the second sound propagation path C2 is 360 mm. In this case, the frequency to be silenced is 472.2 Hz, calculated by dividing the sound speed by the wavelength, since the sound speed is 340 m / s and the path length difference is half a wavelength.

[0048] Next, as shown in FIG. 8(b), when the inscribed member 15 is slid backward by half its length, the path length of the first sound propagation path C1 becomes 45 mm, the path length of the second sound propagation path C2 becomes 225 mm, and the path length difference is 180 mm. The frequency to be silenced in this case is 944.4 Hz.

[0049] Here, the path length of the first sound propagation path C1 is described as 45 mm even though the length of the inscribed member 15 in the front-to-rear direction itself does not change, but this is because the path length is set to the overlapping portion in the front-to-rear direction with the female thread portion 14. The reason for this is that in the non-overlapping portion, there is no difference in the path length through which air passes inside and outside the inscribed member 15.

[0050] Also, when the inscribed member 15 is slid backward by 3 / 4 of its length (retracted all the way) as shown in Figure 8 (c), the path length of the first sound propagation path C1 is 22.5 mm, the path length of the second sound propagation path C2 is 112.5 mm, and the path length difference is 90 mm. The frequency to be silenced in this case is 1888.9 Hz.

[0051] According to the blower 10 configured as described above, in addition to the effects of the blower 10 according to the first embodiment, since the female screw portion 14 is a six-thread screw having six threads 14a, it is possible to provide a plurality of different path lengths for the second sound propagation path C2. Therefore, the amount of sound propagation of the air passing through the second sound propagation path C2 increases, and the sound deadening effect is improved.

[0052] In the first embodiment, the male thread portion 15 and the female thread portion 14 are provided on the suction port side, but the present invention is not limited to this, and the male thread portion and the female thread portion may be provided on the outlet side as shown in Fig. 9. Alternatively, the male thread portion and the female thread portion may be provided on both the suction port side and the outlet side. In addition, although the path difference of the sound propagation path is varied by rotating the female screw portion 14, the present invention is not limited to this. For example, the female screw portion 14 may be engaged with the fixing member 16 to attach and fix it, while the outer circumferential portion of the inscribed member 15, which is formed of an approximately cylindrical body, may be extended to the suction port side of the casing 13, or only the handle provided on the inscribed member 15 may be exposed to the outside of the casing 13, thereby allowing the inscribed member 15 to rotate on the suction port side, thereby varying the path difference of the sound propagation path. In this way, the path difference of the sound propagation path may be varied by rotating the male screw portion 15.

[0053] In the second embodiment, the female thread portion 14 is a six-start thread, but may be another multiple-start thread. Of course, in the second embodiment, the female thread portion 14 does not have to be a multiple start thread. In addition, a female thread is formed directly on the inside of the blowing section of the casing 13, and no threads are formed on the outer peripheral surface of the inscribed member 15. However, it is also possible to have the casing 13 have a smooth inner surface without a female thread, and form a male thread on the outer peripheral surface of the inscribed member 15, so that when the inscribed member 15 is inserted into the casing 13, the inner peripheral surface of the casing 13 is inscribed with the threads of the male thread of the inscribed member 15, thereby varying the path difference of the sound propagation path.

[0054] Furthermore, when the female thread portion 14 is a multiple thread, the length of the thread 14a may be made different from the length of the other threads 14a by positioning the rear end of the thread 14a constituting the female thread portion 14 forward. This allows the second sound propagation path C2 having a different path length to be provided, making it possible to simultaneously mute sounds of a plurality of frequencies.

[0055] In addition, in this embodiment, a dryer is used as an example of the blower 10, but the present invention is not limited to this. Furthermore, it is possible to provide a casing 13 for reducing noise from the independently existing blower 10 in order to muffle the noise.

[0056] Furthermore, the path lengths of the first sound propagation path C1 and the second sound propagation path C2 and the frequency of the sound to be silenced are not limited to those in this embodiment, and can be designed as appropriate. [Explanation of symbols]

[0057] 10 Blower 11 Motor 12 Propeller 13 Casing 13a Guide groove 14 Female thread 14a thread 15 Internal contact part (male thread) 15a thread 15b Slider 16 Fixing member C1 First sound propagation path C2 Second sound propagation path

Claims

1. A motor, A propeller driven by the motor; and A blower including a casing that houses the motor and the propeller and fixes the motor and has front and rear openings, A female thread portion in which a female thread is formed directly or indirectly on a part of the inside of the casing; an internal contact member having an interior penetrating in the front-rear direction to form a first sound propagation path and arranged so that at least a portion of the internal contact member is inscribed in the female screw portion; A blower characterized in that the inscribed member is freely movable in the forward and backward directions relative to the female thread portion, thereby making it possible to vary the path length of a second sound propagation path formed between the female thread portion and the inscribed member.

2. 2. The blower according to claim 1, wherein the female screw portion is a multiple start screw having a plurality of threads.

3. 3. The blower according to claim 1, wherein the internal contact member is a male threaded portion having a male thread formed on an outer periphery thereof, the male threaded portion being screwed into the female threaded portion.

4. The blower according to claim 1 or 2, wherein the inscribed member is cylindrical.

5. 3. The blower of claim 2, wherein the length of at least one of the threads is different from the length of the other of the threads.

6. A casing for propagating sound waves therein, A female thread portion in which a female thread is formed directly or indirectly on a part of the inside of the casing; An internal contact member having an interior penetrating in the front-rear direction to form a first sound propagation path for the sound wave and arranged to be inscribed in the female screw portion, A casing characterized in that by making it possible to continuously move the inscribed member in the forward / backward direction relative to the female thread portion, the path length of a second sound propagation path formed between the female thread portion and the inscribed member and used to propagate the sound waves can be continuously varied, thereby making it possible to fine-tune the path difference between the first sound propagation path and the second sound propagation path.

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