WO2010020538A1

WO2010020538A1 - Refrigerator generating less noise

Info

Publication number: WO2010020538A1
Application number: PCT/EP2009/060096
Authority: WO
Inventors: Rastislav Andrejco; Murat Darka; Adolf Feinauer; Jochen HÄRLEN; Robert Keidler
Original assignee: BSH Bosch und Siemens Hausgeräte GmbH
Priority date: 2008-08-22
Filing date: 2009-08-04
Publication date: 2010-02-25
Also published as: RU2011108700A; EP2326897B1; RU2499207C2; EP2326897A1; DE102008041478A1; CN102132116A; ES2396616T3; CN102132116B

Abstract

Disclosed is a refrigerator comprising a wall (6, 18) that surrounds a chilled interior (3) and has a heat-insulating layer (9), and a component (8, 16) which transmits structure-borne noise to the wall (6, 18). In said refrigerator, a vibration-damping layer (11) containing bitumen is mounted on an external face of the heat-insulating layer (9) of the wall (6, 18).

Description

Noise-reduced refrigeration unit

The present invention relates to a refrigerator with a component emitting operating noise and means for suppressing the radiation of these operating noise to the outside.

DE 198 18 993 A1 describes a refrigeration device with a wall surrounding a cooled interior, a heat-insulating layer and an evaporator, which is mounted on the side facing the interior of the heat-insulating layer and is excited by turbulence of the injected refrigerant to vibrate. In order to reduce the transmission of the vibrations of the evaporator into the heat-insulating layer and its radiation on the outside of the layer, a bituminous foil is attached to the evaporator. The bituminous film increases the mass of the evaporator and thereby shifts its natural vibration frequencies, so that the evaporator is largely resistant to vibration for operatively acting on him exciter frequencies.

Complete suppression of the evaporator vibrations is not achieved by the bitumen film. In addition, the applicability of this known solution is limited to structure-borne noise generated in the evaporator. Other noise sources that may be present in the refrigeration device, such as a fan, are not attenuated noticeably.

From US 56 69 232 a refrigeration device is known in which a steel plate is embedded in order to reduce the sound radiation between a heat-insulating layer and an outer skin of the housing wall. Due to its high rigidity, the steel plate causes a shift of the resonant frequencies of the wall to higher frequencies. Another proposal of the same document is to attach a vibration absorbing layer between the heat insulating layer and an inner container of the housing. Both proposals are not fully satisfactory, since the embedded steel plate brings a significant increase in weight and cost and the interior of the refrigerator completely lining noise-absorbing layer reduces the usable volume of the interior.

The object of the present invention is therefore to provide a refrigeration device which enables a simple reduction of the noise emission during operation with a simple housing construction.

The object is achieved by a vibration-damping bituminous layer is attached to an outside of the heat-insulating layer of the wall in a refrigeration device with a surrounding a cooled interior, a heat-insulating layer having wall and a structure-borne sound to the wall component. Although the bitumen-containing layer, in contrast to the teaching of DE 198 18 993 A1, is no longer attached directly to the noise-generating component, but rather to the outside of the housing wall, a direct coupling to the noise-generating component, by means of which its natural vibration frequencies could be shifted, is eliminated this turns out to be of little importance for the effectiveness, since the bitumen-containing layer instead influences the resonance behavior of the housing wall. But if the housing wall is successfully prevented from oscillating, it does not emit sound to the outside, even if a sound source inside the housing gives it. In addition, the bitumen-containing layer disposed outside the heat insulating layer proves to be more effective in vibration damping than a corresponding inner layer. The reason for this is that with decreasing temperature the bitumen strongly hardens and damping by dissipation in the bituminous layer practically does not take place when it is cooled.

A particularly simple structure can be realized if the bitumen-containing layer is exposed on an outer side of the wall and is therefore connected to the wall on one side only. But it can also be mounted between the heat-insulating layer and the heat-insulating layer covering outer skin. Preferably, the bitumen-containing layer is fixed by at least one viscoelastic compound layer. Such a layer, which can be formed for example by a double-sided adhesive tape, in turn can contribute to noise reduction by dissipation of vibration energy.

When the bitumen-containing layer is disposed between the heat insulating layer and the outer skin, it may be fixed to both by a viscoelastic layer, and the sound penetrating from the inside to the outside is attenuated by dissipation in both layers.

A good damping effect with low use of material can be achieved if the bituminous layer is limited to a central region of the substantially flat wall. When the wall is stimulated to vibrate by structure-borne noise, the points with the highest vibration amplitude are generally located in a central region, so that here the weight increase by the bituminous layer has the greatest effect.

The bituminous layer is most effective when it and the structure-borne sound transmitting component face each other on opposite sides of the wall.

For a good damping effect, a basis weight of the bitumen-containing layer between two and ten kilograms per square meter has proven to be expedient.

The layer may be substantially pure bitumen. In order to optimize properties such as specific gravity, thermal insulation value, elasticity and dissipation capacity, however, aggregate particles may also be bound in the bituminous layer. For increasing the density and for improving the thermal insulation value, mineral aggregate particles are particularly suitable. In order to improve the elasticity and the dissipation capacity of the layer, fibers or filaments can be bound in the bitumen, both in uncrosslinked form and in the form of a nonwoven or woven fabric. Further features and advantages of the invention will become apparent from the following description of embodiments with reference to the accompanying figures. Show it:

1 shows a schematic section through an inventive refrigeration device.

2 shows a detail section through the rear wall of the refrigeration device.

3 shows a section through the rear wall according to a modification;

Fig. 4 is a similar to Fig. 1 section through a refrigerator according to a second

Embodiment of the invention; and

Fig. 5 is an analogous to FIG. 1 section according to a third embodiment.

The housing of the refrigerator shown in Fig. 1 comprises in a conventional manner a body 1 and at least one hinged to the body 1 door 2, which defines a cooling space 3 together with this. At the back of the body 1, a machine room 4 is recessed, in which a compressor 5 is housed. The compressor is part of a refrigerant circuit, together with an outside attached to a rear wall 6 of the body 1 condenser 7 and an evaporator 8. The evaporator 8 is enclosed between an insulating material layer 9 and the refrigerator 3 delimiting plastic inner container.

Refrigerant from the condenser 7 reaches the evaporator 8 via a narrow capillary 10. When the refrigerant exits the capillary 10 into the evaporator 8, turbulences may occur which excite the oscillations of the evaporator 8. These vibrations are transmitted to the insulation material layer 9 and, if they are not effectively damped, can excite externally audible vibrations of the body 1. To suppress these vibrations, the evaporator 8 is mounted on the outside of the insulating material layer 9 opposite a plate 1 1 bitumenhaltigem material, due to the high density difference to the adjacent insulating material layer 9 of this is only slightly excitable to vibrations.

Since the plate 11 is located on the outside of the insulating material layer 9, it is hardly cooled by the evaporator 8, and their temperature may at best be slightly lower than that of the environment. At these temperatures, the bitumen of the plate 1 1 is relatively easy partly plastic, partly elastically deformable. Due to the plastic deformability are coupled externally into the plate 11 coupled vibrations in this strongly and their energy is converted into heat.

In the embodiment shown here, the condenser 7 is mounted in the immediate vicinity of the plate 1 1 behind the rear wall 6, so that when the compressor has been in operation for a while, the condenser 7, the plate 11 is heated. The temperature of the bitumen may therefore even be above the ambient temperature. The heating increases the plasticity of the bitumen and thus the damping effect of the plate 1 1.

Fig. 2 shows in an enlarged horizontal section a first example of the structure of the rear wall 6. A solid outer skin 12 made of plastic, solid cardboard or other fiber material in the form of a shallow shell surrounds the insulating material layer 9. edges 13 of the shell are not dense with here shown outer skin panels of side walls, floor or ceiling of the body 1 connected. The bituminous plate 1 1 is enclosed between the outer skin 12 and the insulation material layer 9 and connected to both in each case via a viscoelastic layer, here a double-sided adhesive tape 14. The elasticity of the adhesive tape 14 allows transverse displacements between the opposing surfaces of the plate 1 1 and the insulating material layer 9 and the outer skin 12, which occur at bending vibrations of the outer skin 12, but attenuates them by the viscosity of its adhesive and thus additionally contributes to the damping of Vibrations of the insulating material layer 9 and the outer skin 12 at.

The plate 1 1 does not cover the entire outer skin 12, but only a central portion of this, which makes up about 40 to 80 percent of the surface of the outer skin 12. Placement and expansion of the plate 1 1 are set so that the plate 11 on the antinodes of the main, low-frequency natural oscillations of Outer skin 12 extends so that it is effectively damped by the plate 1 1 and their vibration amplitude is reduced.

3 shows a horizontal section according to a modified embodiment, in which the bituminous plate 1 1 is arranged on the outside of the outer skin 12 and is fastened by a single layer of adhesive tape 14. In this embodiment, the attenuation of the second adhesive tape layer of the embodiment of Fig. 2, but the total attenuation effect can be quite equivalent to that of the structure of Fig. 2, since the outer bitumen 11 in operation is usually warmer than that between outer skin 12 and insulating material layer. 9 embedded plate.

FIG. 4 shows, in a section analogous to FIG. 1, a refrigeration device according to the invention in no-frost construction with an evaporator 8 accommodated in a chamber 15 separated from the refrigerator compartment 3 and a ventilator 16 for driving the air exchange between the compartment 15 and the refrigerator compartment 3 In such a refrigerator, the fan 16 may be a significant source of outwardly radiated operating noise. The fan 16 is arranged here so that its vibrations essentially stimulate the rear wall 6 of the body 1 to vibrate. In order to dampen the vibrations of the rear wall 6, a bitumen plate 1 1 is provided on the outside of the fan 16 opposite. This can, as shown in Fig. 2, embedded in the rear wall 6 or be mounted on the outside according to the Fig. 3 on the rear wall.

A condenser 7 could be mounted as shown in Figure 1 in front of the rear wall. in the case shown here, it is housed in the engine room 4 adjacent to the compressor 5, and a second fan 17 provides for the discharge of heated to condenser 7 and compressor 5 air from the engine room 4. When the exhaust air flow is guided along the rear wall 6, promotes the heat of the exhaust air turn the plasticity and thus the damping efficiency of the bitumen plate 1 1. The hot air can also be dissipated by other means, such as a hollow base 18 of the device.

If not the rear wall 6, but another wall of the body 1 is most excited by the fan 16 to vibrate, the bitumen plate 11 may of course also be attached to this wall. Fig. 5 shows the case where the bitumen plate 11, the ceiling 18 of the body 1 damped. The bituminous plate 1 1 is here at least partially received in a lower side hollow worktop 19, which is mounted on top of the body 1.

The composition of the bitumen plate 11 may be different. It can consist of essentially pure bitumen or be mixed with various surcharges. In order to increase the mass of the plate 1 1 at a constant plate thickness, mineral additives such as minerals are considered. Fibers and filaments, especially those of low tensile elongation, can improve damping by resisting deformation of the bituminous sheet 11 and thereby force the bitumen in its immediate vicinity to undergo increased plastic deformation. The fibers or filaments may be embedded unconnected to one another in the bitumen; but they can also be incorporated as a fleece or as a fabric.

Claims

claims

1. Refrigerating appliance with a cooled interior (3) surrounding, a heat-insulating layer (9) having wall (6, 18) and a structure-borne noise to the wall (6, 18) transmitting component (8, 16), characterized in that a vibration damping bituminous layer (11) is attached to an outside of the heat insulating layer (9) of the wall (6, 18).

2. Refrigerating appliance according to claim 1, characterized in that the bitumen-containing

Layer (1 1) on an outer side of the wall (6, 18) is exposed.

3. Refrigerating appliance according to claim 1, characterized in that the bitumen-containing layer (11) between the heat-insulating layer (9) and a heat-insulating layer covering outer skin (12) is mounted.

4. Refrigerating appliance according to one of the preceding claims, characterized in that the bitumen-containing layer (11) is fixed by at least one viscoelastic compound layer (14).

5. Refrigerating appliance according to one of the preceding claims, characterized in that the bitumen-containing layer (1 1) is limited to a central region of the substantially flat wall (6, 18).

6. Refrigerating appliance according to one of the preceding claims, characterized in that the bitumen-containing layer (11) and the structure-borne sound transmitting component (8, 16) on opposite sides of the wall (6, 18) opposite each other.

7. Refrigerating appliance according to one of the preceding claims, characterized in that the bitumen-containing layer (11) has a basis weight between 2 and 10 kg / m ² .

8. Refrigerating appliance according to one of the preceding claims, characterized in that the bitumen-containing layer (1 1) is substantially pure bitumen.

9. Refrigerating appliance according to one of the preceding claims, characterized in that the bitumen-containing layer (1 1) contains aggregate particles bound in bitumen.

10. Refrigerating appliance according to one of the preceding claims, characterized in that the bitumen-containing layer (1 1) bound in bitumen

Contains fibers or filaments.

1 1. Refrigerating appliance according to claim 10, characterized in that the fibers or filaments form a non-woven or a fabric.