JP2612065B2 - Freezer refrigerator - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerator and, more particularly, to a refrigerator which is suitable for reducing noise and increasing air flow due to an axial fan.

2. Description of the Related Art A refrigerator having an axial fan for forcibly circulating cooling air in a wall at the back of a refrigerator is disclosed in, for example,
The technique described in -87580 is known.

According to the publication, the axial flow fan originally has an axial suction function. However, the axial flow fan has an obstructing wall at the back of the fan in the axial direction. A refrigerator having a so-called centripetal arrangement in which a suction direction is limited to upper, lower, left, and right radial directions, and a cooler is disposed below the refrigerator to use one-way suction is disclosed. .

In addition, the hub of the axial flow fan has a cylindrical or rectangular cross section with a flat tip on the suction side.

[Problems to be Solved by the Invention] In the above-described conventional technique, the axial flow fan has a wall surface at the back thereof and a cooler is positioned below the fan. 60 to 70% of the air volume is sucked in the lower part (cooler side) and 30 to 40% in the upper part (anti-cooler side). In the refrigerator, the fan shaft is shortened in order to secure a large volume in the refrigerator. Therefore, the air flow behind the hub of the axial fan is narrowed, so that the flow velocity becomes large. Further, the cooling air flowing into the blade from above the hub above the fan axis is directed upward along the edge of the hub and the periphery. There is a problem that the noise is increased without giving sufficient consideration to the occurrence of turbulence when passing through.
In other words, the cooling air sucked above the fan axis is accompanied by the turbulence and wake turbulence generated from the edge of the hub, so that the rotational sound of the axial flow fan (rotational frequency x frequency of blades) is generated. It becomes large and unpleasant sound. In addition, the pressure applied to the blade fluctuates due to the turbulence of the suction air, and the fluctuation of the pressure amplifies the motor vibration via the fan shaft and causes the vibration of the refrigerator to increase.

As described above, since the flow velocity behind the hub is large, the turbulence extends to the suction flow above the fan axis, and the motor vibration is accompanied, the overall noise level is increased and the air volume is reduced. There was a problem.

In addition, the flow of cooling air from below to above may be around the outside in addition to directly behind the fan, but the influence of the flow resistance behind the hub, which is a short distance, is large. The fluid noise can be somewhat improved by increasing the length of the fan shaft, but if the shaft is lengthened, the motor vibration increases, and in some cases, the motor life becomes a problem.

The present invention has been made in order to solve the above-mentioned problems of the prior art, and reduces the turbulence and the ventilation resistance of the air flow traversing the hub portion of the fan, reduces the rotating noise, has a good sound feeling, An object of the present invention is to provide a refrigerator having a low noise level and a large air volume.

[Means for Solving the Problems] In order to achieve the above object, a refrigerator according to the present invention has a configuration in which a fan motor whose axis is directed forward is arranged on a wall portion inside the refrigerator, and a tip of the shaft is provided. Axial fan is mounted on the side, and a cooler is arranged on one of the left, right, upper and lower sides in the radial direction of the axial fan, and the axial fan draws cooling air from the cooler side into the storage chamber. In a refrigerating refrigerator that is configured to discharge air, the space between the fan and the motor is used as a suction air passage, and the fan shaft is traversed by the fan shaft, the top of the hub that constitutes the fan on the air passage side is tapered. It is formed in.

In addition, the axial flow fan is such that its hub extends to the discharge side longer than the blade position, and the tip of the hub in the discharge direction is formed smaller than the outer diameter of the blade and larger in the radial direction than the diameter of the blade root. is there.

[Operation] The operation of the above technical means is as follows.

That is, since the top of the hub on the side of the air passage is tapered, even if the suction air flows from near the rear of the hub and crosses above the fan shaft, the occurrence of turbulence is reduced, and the noise of the blade can be reduced. As for the rotation noise, the blade passes through the flow portion with less disturbance, so that the noise can be reduced. Therefore, the overall noise level can be reduced, and the vibration noise can be reduced.

In addition, by increasing the area of the ventilation passage near the rear of the hub, the flow velocity can be reduced, and the above-described effect can be increased. In addition, since the airflow increases, the speed can be reduced by that much, and the noise reduction effect can be further improved.

By the way, in the prior art described in Japanese Patent Application Laid-Open No. 57-87580, by providing a rectifying guide plate which is close to the discharge side and slightly away from the fan, it can be called a shielding cone to prevent backflow and noise caused by turbulent flow of the hub. Was shielding. This rectifying guide plate provides serviceability such as installation and removal of fans,
There was a difficulty in centering with Juan.

In the present invention, the hub of the axial flow fan extends to the discharge side longer than the blade position and is formed in the same body as the blade, so that the wind guiding surface can be continuous, and the conventional flow guide plate (shielding cone) As described above, the noise reduction effect, performance stability, and serviceability can be improved.

Embodiments Embodiments of the present invention will be described below with reference to FIGS. 1 to 6.

FIG. 1 is a partial longitudinal sectional view of a refrigerator according to an embodiment of the present invention, FIG. 2 is a perspective view of an axial fan which is a main part of FIG. 1, and FIG. FIG. 4 is a noise spectrum diagram showing the effect of the axial fan, and FIG. 4 is a vibration spectrum diagram showing the effect of the axial fan in FIG.

In FIG. 1, reference numeral 1 denotes an outer box, 2 denotes an inner box, and a foamed heat insulating material or the like is filled between the boxes to constitute a refrigerator-freezer main body.

Reference numeral 3 denotes a motor for the axial flow fan, 4 denotes a motor case for housing and supporting the motor 3, and 5 denotes a vibration-proof rubber of a supporting portion thereof, which are embedded in the outer box 1 at the back of the refrigerator. It is attached to the shape. 6 is a mouth ring plate, 7
Is an axial fan whose periphery is protected by the mouth ring plate 6.

As shown in FIG. 2, the axial fan 7 includes a blade 7a, a hub 7b, and a boss 7c, and is fitted to a fan shaft 7d directly connected to the motor 3. Hub 7b has blade 7a
The diameter of the hub 7b at the root is smaller on the suction side than on the discharge side, and the top is tapered.

8 is a cooler arranged below the axial fan 7;
Is a return passage formed in the inner box 2, 10 is a freezing room, and 11 is a refrigerator room.

As shown in FIG. 1, the axial fan 7 is mounted on a wall at the back of the freezing compartment 1, and the axial fan 7 is located on one of the left, right, upper and lower sides of the wall, in this example, downward. The cooler 8 is arranged.

In such a configuration, when the motor 3 is driven to rotate the axial fan 7, the axial fan 7 draws cooling air from the cooler 8 side as shown by the solid line and the direction line A, and
The cooling air is discharged to the cooler 8 through the return passage 9 again.
Pass through.

The axial flow fan 7 has a suction action not only below the axis of the fan shaft 7d (cooler 8 side) but also above the fan axis. Describing the upper suction operation, the space between the fan blade 7a and the motor 3 is a suction air passage, and the fan shaft 7d crosses the air passage. The direction line A in FIG. 1 emphasizes this. Immediately behind the hub 7b, which is close to the cooler 8, the air flow produces a flow upward from the fan axis. Although the hub 7b is orthogonal to the suction air passage at the rear, the turbulence caused by the hub 7b is reduced because the top is tapered, and the hub 7b crosses upward with a smooth flow and faces upward. Since the diameter of the nozzle 7b is gradually increased toward the discharge side, the blade 7a passes through the flow portion with less turbulence. Further, since the flow velocity behind the hub 7b is also small, the rotation noise can be reduced and the noise can be reduced.

Therefore, pressure fluctuation applied to the blade 7a is reduced, and vibration applied to the motor 3 via the fan shaft 7d can be reduced. Further, since the ventilation resistance of the cooling air flowing upward from the fan axis becomes small, the air volume can be increased.

FIG. 3 shows a comparison between the conventional product and the noise spectrum in the above embodiment, wherein the horizontal axis represents the frequency (Hz),
The vertical axis indicates the sound pressure level (dB), the solid line indicates the conventional sound pressure level, and the broken line indicates the sound pressure level of the present embodiment.

The co-product was an axial fan with an outer diameter of 90 mm and four blades, installed in a refrigerator having an inner volume of 360, operated at 3000 min ^-1 , and measured noise at a position 1 m ahead.

It has been confirmed that the sound pressure level can be remarkably reduced to 3 dB at the rotating sound frequency (3000 × 4/60 = 200 Hz).

In this experiment, in order to eliminate the influence of the vibration of the motor, the motor was not supported by the anti-vibration rubber 5 as shown in FIG. 1 and the periphery of the motor 3 was supported by a sufficiently soft sponge rubber.

Although the overall value was reduced by 1 dB due to the reduction of the rotating sound, the peak value was reduced, which improved the sound sensation and increased the airflow by 4%. Also, if the air volume is reduced to the same level, the speed can be further reduced by 1 dB, and the overall value is 2 dB.
Could be reduced.

Vibration of the back surface of the outer box 1 on the motor shaft (fan shaft) of the refrigerator having the axial fan 7 mounted thereon using the vibration isolating rubber 5 as shown in FIGS. This is the result of comparing vibration spectra at the same rotation speed of 3000 min ^-1 . The horizontal axis represents frequency (Hz), and the vertical axis represents vibration acceleration (cm).
/ s ² ), and (a) shows the measurement results of this example,
(B) is a measurement result of the conventional technology.

In this embodiment, the vibration acceleration of the motor 3 mounting portion (the back of the outer case 1) due to the rotation noise of the axial flow fan 7 is reduced by about 35% around the rotation sound frequency of 200 Hz, as is apparent from FIG. In addition, 300Hz-500 generated at the natural frequency of the outer case 1
Hz vibration was reduced by 20%. Similarly, 50Hz (vibration due to the dynamic imbalance of the fan) and 120Hz (vibration due to the motor electromagnetic force) also decreased, confirming that the overall noise level of the refrigerator was reduced by 2dB at 1m in front and 3dB at 1m behind.

As described above, according to the present embodiment, the following effects can be obtained.

1) Since the top of the axial flow fan on the air passage side of the hub is formed to be tapered, it is possible to reduce the generation of turbulence of the circulation cooling air from the hub even if the hub is orthogonal to the suction air passage immediately after. Therefore, rotation noise can be reduced.

2) The vibration of the motor and the box is reduced, and the noise in the entire refrigerator-freezer can be reduced.

3) Since the effective air path area behind the hub is increased and the ventilation resistance is reduced, the air volume can be increased.

Next, FIG. 5 is a perspective view of an axial fan used in a refrigerator according to another embodiment of the present invention, and FIG. 6 is a longitudinal sectional view of the axial fan of FIG. In the figure, the same reference numerals as those in FIGS. 1 and 2 indicate the same parts.

The hub 12b of the axial fan 7A shown in FIGS. 5 and 6 has a tapered suction side, a hub 12b longer than the blade 7a position on the discharge side, and a tip diameter d in the discharge direction of the blade 7a. smaller than the outer diameter D _2, and larger than the diameter D ₁ of the blade root, and forming a guide surface 12c of the wind.

By attaching such an axial flow fan 7A to a refrigerator-freezer in the same manner as in FIG. 1, the same effects as those of the embodiment of FIG. 1 can be expected, and the following effects unique to this embodiment are provided. There is.

1) Since the wind guide surface 12c is formed integrally and continuously with the hub 12b, the flow of the cooling air is smoothed, and the backflow from the suction side is prevented by the hub 12b to further reduce the noise. did.

2) Since the wind guide surface 12c is integrally formed with the hub 12b, the centering work like the conventional rectifying guide plate is not required, the workability is good, and the variation in the performance of the product can be reduced.

In each of the above embodiments, the example in which the cooler is disposed below the axial fan is described. However, the present invention is not limited to this, and one of right, left, up, and down with respect to the axial fan is provided. May be arranged.

[Effects of the Invention] As described in detail above, according to the present invention, the turbulence of the air flow traversing the hub portion of the fan and the ventilation resistance are reduced, the rotational noise is reduced, the sound quality is improved, and the noise is reduced. A refrigerator having a low level and a large air volume can be provided.

[Brief description of the drawings]

FIG. 1 is a partial longitudinal sectional view of a refrigerator according to an embodiment of the present invention, and FIG. FIG. 3 is a perspective view of an axial fan as a main part of FIG. 1, FIG. 3 is a noise spectrum diagram showing an effect of the axial fan of FIG. 1, and FIG. 4 is an effect of the axial fan of FIG. FIG. 5 is a perspective view of an axial fan used in a refrigerator according to another embodiment of the present invention, and FIG. 6 is a longitudinal sectional view of the axial fan of FIG. . 1 ... Outer box, 3 ... Motor, 7,7A ... Axial flow fan, 7a
…… Blade, 7b, 12b …… Hub, 7c …… Boss, 7d …… Fan shaft, 8 …… Cooler, 10 …… Freezer compartment, 11… Refrigerator compartment,
12c …… The wind guiding surface.

Claims (3)

(57) [Claims] 1. A fan for a fan with a shaft directed forward is disposed on a wall portion inside the refrigerator, and an axial fan is mounted on a tip side of the shaft.
A cooler is disposed on one of the left, right, upper and lower sides in the radial direction of the axial fan, and the axial fan is configured to discharge cooling air from the cooler side into the suction chamber, In a refrigerating refrigerator in which a space between the motor and the motor is used as a suction air passage, and a fan shaft crosses the air passage, a top portion of a hub constituting the fan on the air passage side is tapered. Freezer refrigerator. 2. The refrigerator according to claim 1, wherein the axial flow fan has a hub at a blade root position where the diameter of the hub is smaller on the suction side than on the discharge side and the top is tapered. 3. The axial flow fan has a hub extending to the discharge side longer than the blade position, and the tip of the hub in the discharge direction is
3. The refrigerator according to claim 1, wherein the refrigerator is formed to be smaller than an outer diameter of the blade and larger in a radial direction than a diameter of a root portion of the blade.