JP3246173B2 - Condensing unit for vending machine refrigerator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a condensing unit for a refrigerator mounted on a vending machine for selling cold goods such as canned beverages, and more particularly to a noise reduction structure thereof.

[0002]

2. Description of the Related Art First, the structure of a vending machine to which the present invention is applied is shown in FIGS. In the figure, 1 is a main body case of a vending machine, 2 is an outer door, 3 is an inner door, 4 is a product outlet, 5 is a product rack, 6 is a product delivery shooter, and 7 is a cooler (evaporator of a refrigerator). , 8 is a fan in the refrigerator, 9 is a machine room defined in the lower part of the main body case 1, 10 is a condensing unit of a refrigerator installed in the machine room 9, the condensing unit 10 is a compressor 11, It comprises a combination of a container 12 and an external fan 13 and is mounted and arranged on a base 15 of the main body case 1 via a plate-shaped unit mount 15 made of sheet metal. At the front and rear ends of the base 14, a base plate is bent toward the back side to form a channel-shaped leg seat 14a, and an installation leg 16 is attached thereto. Also,
The unit mount 15 is a plate-shaped pallet formed by bending four sides of a thin steel plate having a plate thickness of about 1.2 mm and performing sheet metal processing, and a compressor 11, a condenser 12, and a fan 13 are fixed to the upper surface thereof with screws. I have.

[0003]

By the way, the condensing unit 10 of the refrigerator having the above-mentioned structure generates vibration and noise using the compressor, the fan 13 and the like as a sound source during operation. This vibration noise is not so much a problem when vending machines are used outdoors, but recently vending machines are often used indoors, and in such installation places, Since the noise generated from the condensing unit is annoying, measures to reduce the noise have become an important issue.

Here, the noise generated from the refrigerator condensing unit is such that the vibration accompanying the rotation of the compressor 11 propagates to the unit mounting base 14 and the base 15 and vibrates these to radiate to the surroundings. , The noise of the fan 13 and the like, but at present, almost no countermeasures against noise are taken in conventional vending machines. The present invention has been made in view of the above points, and an object of the present invention is to improve an installation portion equipped with a condensing unit so that noise generated from the condensing unit can be effectively reduced. An object of the present invention is to provide a noise reduction structure of a refrigerator condensing unit for a refrigerator.

[0005]

In order to achieve the above object, a condensing unit for a refrigerator according to the present invention comprises a condensing unit, an upper surface and a lower surface of a base of a vending machine equipped with a unit mounting base. A closed space is formed therebetween, and holes for absorbing and attenuating noise by a resonance effect are dispersedly formed on the upper surface thereof.

[0006]

[Operation] A closed space is formed between the upper surface and the bottom surface of the base, and holes are dispersedly opened on the upper surface side.
By setting the aperture ratio as described below, the unit mounting base and the base function as a sound resonance box, and noise is absorbed and attenuated by the resonance effect. In this case, since the resonance frequency f0 in the sound propagation system is given by the following equation (2), the discrete frequency at which the noise level of the condensing unit is high is represented by (2)
As the resonance frequency f0 in the expression, the hole diameter, the opening ratio, and the like of the holes opened on the upper surface of the unit mounting base and the base are determined.

[0007]

(Equation 2)

Here, C is the sound speed [m / s], S is the hole area [m ² ], t is the plate thickness [m], d is the hole diameter [m], and V is the volume of the closed space [m ³ ]. It is.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. In the drawings of the respective embodiments, the same components corresponding to those in FIG. 5 are denoted by the same reference numerals. Embodiment 1 FIGS. 1 (a) and 1 (b) show a principle diagram corresponding to claim 1 of the present invention. In this principle diagram, a closed space is formed by combining a unit mounting base 15 with a bottom plate 15c. 15d, and holes 15e whose hole diameter and aperture ratio are determined as described below are dispersedly opened on the upper surface of the unit mounting base.

With this configuration, the unit mounting base 15 acts as a resonance box, and the noise generated by the condensing unit is absorbed and attenuated by the unit mounting base 15. That is, a hole (round hole) 1 opened on the upper surface of the unit mounting base 15
Assuming that the hole diameter of 5e is d and the pitch between the holes is D, the above-mentioned equation (2) is expressed as the following equation (3).

[0011]

(Equation 3)

[0012] However, L is the thickness of the air layer of the closed space 15d [m], P is the numerical aperture of the hole 15e, P ≒ πd ^2/4
Expressed as D ^2. Here, the thickness t of the steel plate of the unit mount 15 is 3.2 mm, the hole pitch D is 100 mm, and the hole diameter d is 5 mm.
mm, the height of the closed space L = 10 mm, the resonance frequency f0
Is about 280 Hz and the resonance frequency f0 when the hole diameter d is 10 mm.
Is about 450 Hz. Therefore, holes 1 having different hole diameters d
By opening the opening 5e, a plurality of resonance frequencies can be set on the unit mounting base 15, whereby the noise reduction effect due to resonance in a wide frequency band is further improved.

FIG. 2 shows an embodiment corresponding to claim 1 of the present invention. In this embodiment, a channel-shaped leg seat 14a formed at the front and rear ends of a base 14 is used. The space remaining inside the leg seat 14a is defined as a closed space 14b, and a hole 14 is formed on the upper surface of the leg seat 14a in the same manner as the principle diagram of FIG.
c is a distributed aperture, and a noise attenuating function is provided by its resonance effect.

Embodiment 2 FIG. 3 shows an application embodiment in which Embodiment 1 is further developed. In this embodiment, the leg 1 of the base 14 is used.
4a, a bottom plate 14d is provided at the center of the base, and a closed space 1 is provided between the bottom plate 14d and the upper plate of the base 14.
4b, and holes 14c are dispersedly opened on the upper plate side.

As described in the first embodiment, the base 14
A channel-shaped leg 14a formed at the front and rear ends of the base 14 is used to form a gap remaining inside the leg 14a. As described in the second embodiment, the base 14 extends between the legs 14a of the base 14. A bottom plate 14d is provided at the center, and the bottom plate 14d and the base 1
It has been confirmed from the actual machine test that the noise level of the condensing unit is reduced by about 5 dB as compared with the configuration of FIG. 6 by forming a hole with the space between the upper plate 4 and the upper plate as a closed space 14b. .

[0016]

As described above, according to the present invention, the mounting of the base or the unit can be performed without making significant changes such as adding vibration and soundproof parts to the conventional condensing unit. The noise can be effectively reduced by applying only a small amount of processing to the table, and is particularly effective as a noise reduction measure when a vending machine is installed and used indoors.

[Brief description of the drawings]

FIGS. 1A and 1B are principle diagrams of a unit mount corresponding to a first embodiment of the present invention, wherein FIG. 1A is a plan view and FIG.

FIG. 2 is a configuration sectional view of a unit mounting base corresponding to the first embodiment of the present invention.

FIG. 3 is a configuration sectional view of a unit mount corresponding to a second embodiment of the present invention;

FIG. 4 is a configuration diagram of a vending machine to which the present invention is applied;

FIG. 5 is a diagram showing a conventional arrangement of a refrigerator condensing unit in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Condensing unit of a refrigerator 11 Compressor 12 Condenser 13 Fan 14 Base 14a Leg 14b Closed space 14c Hole 14d Bottom plate 15 Unit mounting base

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G07F 5/00-9/10 F25D 19/00 G10K 11/16

Claims (1)

(57) [Claims] 1. A refrigerator condensing unit having a compressor, a condenser and a fan mounted on a base of a vending machine via a plate-shaped unit mounting unit made of sheet metal. A condensing unit for a vending machine refrigerator, wherein a closed space is formed therebetween, and holes for absorbing and attenuating noise by a resonance effect are dispersedly formed on the upper surface thereof.