JP4776222B2 - Cooling storage - Google Patents

Description

  The present invention relates to a cooling storage in which a compressor of a refrigeration cycle is driven by an inverter circuit.

  This type of cooling storage has advantages such as power saving because it can control the speed of the motor for driving the compressor, and its development has been promoted in recent years. However, since the inverter circuit includes a semiconductor switching element that generates a large amount of heat, it is difficult to cool the inverter circuit. In addition, since the semiconductor switching element repeatedly turns on and off the current at a high frequency, there is a problem that a large amount of harmonics is included in the output line and it is easy to become a noise generation source. Also, the conventional type of cooling storage that drives the compressor at a constant speed is complicated by the overall circuit configuration and the circuit layout in the machine room is different because the inverter circuit and its control circuit are extra. For this reason, there is a problem that it must be designed and manufactured as a completely different model.

  Note that a refrigerator shown in FIG. 3 of Patent Document 1 is publicly known as a prior art considering heat dissipation of a semiconductor switching element. In this case, the semiconductor switching element of the inverter device is attached to a radiator having a large number of fins and air-cooled.

However, in such an air cooling method using a radiator, in the case of a commercial refrigerator used in a kitchen where a large amount of oil-containing air is generated, whether it is a refrigerator for home use, the radiator is oiled. There is a problem that the cooling efficiency is lowered at an early stage due to the adhesion of dust. Further, as shown in FIG. 1 of the same document 1, when the heat exchanger is omitted and the semiconductor switching element is attached to the metal plate constituting the box of the refrigerator, the distance between the semiconductor switching element and the compressor this time. In addition, the noise radiation through the box of the refrigerator appears and it becomes difficult to take measures against noise.
JP-A-9-324983

  The present invention has been completed based on the above-described circumstances, and is simple in structure despite being an inverter drive type, and can also suppress generation of noise while sufficiently cooling the inverter device. It aims to provide a cooling storage.

The invention according to claim 1 is a cooling storage in which a storage chamber is cooled by a refrigeration cycle including a compressor, a condenser, and a cooler, wherein the compressor driving motor is provided with a semiconductor switching element. The inverter circuit is housed in a closed metal casing having a heat sink plate formed on a part of the outer surface , and the semiconductor switching element can transfer heat to the heat sink plate. is the inverter unit by being mounted configuration Rutotomoni, said removably thermal insulation units stand mounted closing the opening formed in the ceiling portion of the insulating box constituting the storage compartment is provided, the lower surface of the unit base the one which cooler is provided in part, on the upper surface of the unit base, sequentially from the front side Serial condenser, the condenser cooling fan device causing the cooling air flowing through from the front to the rear of, and together with the compressor is al provided, in the vicinity of the side of the compressor, the inverter unit, wherein are installed a heat sink plate side is in a posture facing the cooling air path side cooling air passes from the cooling fan unit, and the heat sink plate has a rising wall portion facing the cooling air passage, said unit base The mounting board portion of the heat sink plate is attached to the unit base so that heat can be transferred .

The invention of claim 2 is the one described in claim 1, the outer surface of the front SL rising wall portion of the heat sink plate where the heat radiation fins extending along the flow path of the cooling air is projected Has characteristics.

<Invention of Claim 1>
According to the first aspect of the present invention, the inverter unit is mounted by heat-transferring the semiconductor switching element to the heat sink plate constituting a part of the outer surface of the metal casing while accommodating the inverter circuit in the closed metal casing. Since it comprised, the heat which generate | occur | produced from the semiconductor switching element is transmitted to a heat sink plate, and is cooled together with the cooling air which cools a compressor etc. In this case, since the inverter unit is arranged in the vicinity of the compressor with a cooling air passage through which the cooling air for cooling the compressor or the like passes, the cooling air flows between the compressor and the metal casing, particularly the heat sink plate. It flows smoothly, and excellent cooling efficiency is obtained.

  Moreover, compared with the structure which attaches an inverter unit to a compressor, it is hard to receive the heat from a compressor and is excellent in the coolability of a semiconductor switching element. Furthermore, since the casing of the inverter unit is a closed metal casing, a shielding effect is exhibited and noise radiation is suppressed. Moreover, since it is arranged in the vicinity of the compressor, the output line length of the inverter circuit is shortened, and this aspect is also effective in suppressing noise radiation.

Furthermore, since the compressor, the condenser, the cooling fan device, and the inverter unit are integrated on the unit base, manufacturing and maintenance become extremely easy.
The unit base becomes a ceiling heat insulating wall, and the compressor, condenser, cooling fan device and inverter unit are installed on the top surface. Can suppress the temperature rise.
The mounting substrate of the heat sink plate is mounted so as to be heat transfer unit carriage, while the lower surface of the unit base and the cooler is also provided with either small quantity leaked through cold heat unit carriage, in other words It is also possible to dissipate heat through the unit base, thereby cooling the inverter unit more efficiently.

<Invention of Claim 2 >
Since the outer surface of the rising wall portion of the heat over preparative sink plate radiating fins extending along the flow path of the cooling air are projected, it is possible to maintain high heat dissipation even when the heat sink plates in a small, heat radiation And miniaturization can be achieved.

<Embodiment>
Hereinafter, an embodiment of the present invention will be described with reference to FIGS. In this embodiment, the case where the present invention is applied to a commercial refrigerator-freezer is illustrated.

  The refrigerator-freezer is, for example, a four-door type, and includes a main body 10 formed of a heat insulating box having a front surface opened as shown in FIGS. 1 and 2, and the front opening is partitioned by a cross-shaped partition frame 11. As a result, four entrances 12 are formed, and a substantially 1/4 internal space corresponding to the entrance 12 at the upper right portion when viewed from the front is partitioned by a heat insulating partition wall 13 to form a freezer compartment 16. The remaining approximately 3/4 of the area is the refrigerator compartment 15. Each doorway 12 is fitted with a heat insulating door 17 so as to be swingable.

  On the ceiling surface of the main body 10, a machine room 20 is configured such that a curtain plate 19 (see FIG. 1) is set up around it. A rectangular opening 21 having the same size is formed on the upper surface of the main body 10 serving as the bottom surface of the machine room 20 so as to correspond to the ceiling wall of the refrigerator compartment 15 and the ceiling part of the freezer compartment 16. . A cooling unit 30 is individually attached to each opening 21. An operation electrical box 18 having a temperature control unit and a display unit is disposed at the right end of the front edge of the ceiling of the main body 10.

  As shown in FIGS. 3 and 4, the cooling unit 30 includes a compressor 32 having a motor (not shown), a condenser 33, a cooling fan device 34, and a cooler 35 connected by circulation through a refrigerant pipe 36. A cycle is configured, and these are collectively mounted on a unit table 38 on which the opening 21 described above is blocked. The unit base 38 is configured by filling a heat insulating material 38C between a metal upper outer shell 38A and a plastic inner shell 38B, and functions as a ceiling heat insulating wall. Of the constituent members of the refrigeration cycle, the cooler 35 is attached to the upper surface portion of the unit base 38, and the other constituent members are attached to the upper surface portion. In addition, a part of the refrigerant pipe 36 is formed with an annular portion 36A of, for example, about two turns covered with a heat insulating pipe above the compressor 32, and this is moved toward the cooling fan device 34 side. The top of the compressor 32 is covered in a shape.

On the other hand, as shown in FIG. 4, a drain pan 22 that also serves as a cooling duct is stretched downward on the ceiling of the refrigerating room 15 and the freezing room 16, and is cooled between the unit base 38. A chamber 23 is formed. A suction port 24 is provided on the upper side of the drain pan 22, a cooling fan 25 is provided, and a discharge port 26 is formed on the lower side.
Basically, when the cooling unit 30 and the cooling fan 25 are driven, the air in the refrigerator compartment 15 (freezer compartment 16) flows from the suction port 24 into the cooler compartment 23 as indicated by the arrow in FIG. The chilled room 15 is circulated in such a manner that the cold air generated by heat exchange while being sucked in and passed through the cooler 35 is blown out from the discharge port 26 to the refrigerated room 15 (freezer room 16). The inside of the (freezer compartment 16) is cooled.
The motor for driving the compressor 32 is driven by an inverter circuit that includes a semiconductor switching element and outputs alternating current of variable frequency. The inverter circuit is configured as an inverter unit 40 by housing a control circuit together with the semiconductor switching element in a metal casing, which will be described in detail below.

  As shown in FIGS. 5 and 6, the inverter unit 40 roughly accommodates a circuit board 41 on which an inverter circuit and a DC power supply circuit are formed in a metal casing 42 having a vertically long box shape. Is. Six MOS type FETs 43 (corresponding to the semiconductor switching elements of the present application, hereinafter simply referred to as FETs 43) serving as heat generating components in the inverter circuit are arranged along the lower edge side of the circuit board 41, for example, three each. Are attached to the two heat transfer plates 45 so as to be able to transfer heat. As shown in FIG. 6, the DC power supply circuit is formed in the left region of the circuit board 41, and the diode 46, which is a heat generating component in the DC power supply circuit, is arranged in a horizontal row with another FET 45. Is attached.

  As shown in FIG. 4, the casing 42 has a rectangular shape in plan view, and as shown in FIG. 3, has a vertically long box shape that is slightly lower than the condenser 33, and the compressor 32 on the unit table 38. In the vicinity of the right side, a cooling air passage 47 with a predetermined interval is opened, and the long side of the planar rectangle is attached in the depth direction (front-rear direction). As shown in FIG. 5, the casing 42 includes a heat sink plate 48 formed of a metal having excellent heat conductivity such as aluminum, and a cover 49 formed of a metal plate such as a zinc steel plate. The heat sink plate 48 is formed in an L-shaped plate shape including an attachment substrate portion 48A that constitutes the bottom surface of the casing 42 and a rising wall portion 48B that constitutes a plane of the casing 42 that extends substantially perpendicular thereto. The cover 49 has a shape that covers four surfaces of the casing 42 excluding the bottom surface and the back surface that are constituted by the heat sink plate 48, and the cover 49 is covered with the heat sink plate 48, so that the entry and exit of air is substantially suppressed. A casing 42 is configured.

  In the casing 42, the heat transfer block 50 is fixed to the upper surface of the heat sink plate 48 by screws 51, and the above-described heat transfer plate 45 is screwed to the upper surface of the heat transfer block 50 in an insulated state via an insulating sleeve 53. It is fixed by 54. The heat transfer plate 52 and the casing 42 are insulated between the heat transfer block 50 and the heat transfer plate 45 with a heat transfer sheet 55 excellent in thermal conductivity interposed therebetween. Note that a smoothing reactor 56 of a DC power supply circuit is attached to an upper position on the inner surface of the heat sink plate 48 at a substantially central portion in the width direction.

  Further, on the back surface (outer surface) side of the heat sink plate 48, for example, heat radiation fins 57 are formed over six stages. These heat radiating fins 57 are made of metal having excellent heat conductivity such as aluminum, and the upper five stages are channel-shaped and the lowermost stage is angle-shaped, and are fixed to the heat sink plate 40 by spot welding. These radiating fins 57 are fixed so as to extend in the lateral direction, and are arranged along the direction of the cooling air passing through the cooling air passage 47. In the channel-shaped radiating fins 57, the width of each groove is formed so as to be large enough to insert a human finger, for example, and the distance between the upper and lower radiating fins 57 is also as wide as possible. ing.

  The casing 42 is fixed to the unit base 38 with the lowermost radiating fins 57 and the mounting substrate portion 48A of the heat sink plate 48 in close contact with the upper outer shell 38A of the unit base 38, and the heat sink plate The heat from 48 can also be transmitted to the upper outer shell 38 </ b> A of the unit base 38.

  According to the above configuration, the heat generated in the FET 43 and the diode 46 of the inverter circuit is transmitted to the mounting board portion 48 </ b> A of the heat sink plate 48 through the heat transfer plate 45 and the heat transfer block 50. Since the heat sink plate 48 is made of aluminum having excellent thermal conductivity, the heat is quickly transmitted to the rising wall portion 48B and further to the heat radiating fins 50 group.

  On the other hand, when the inverter circuit is driven and the compressor 32 is operated, the cooling fan device 34 is also operated at the same time. As a result, as shown by an arrow in FIG. The air passes through the condenser 33 through the air filter 33 </ b> A detachably attached thereto, and further flows so as to hit the outer surface of the compressor 32 while cooling the condenser 33. Since the outer surface of the compressor 32 has a cylindrical shape, the cooling air flows along the arc surface so as to be distributed to both sides of the compressor 32.

  Here, the inverter unit 40 is disposed in the vicinity of the compressor 32, and is provided so that the heat sink plate 48 constituting the casing 42 faces the cooling air passage 47 through which the cooling air from the cooling fan device 34 passes. Therefore, heat radiation from the surface of the heat sink plate 48 is promoted by the cooling air passing through the cooling air passage 47, and the temperature rise is effectively suppressed. As a result, the temperature rise of electronic components such as the FET 43 in the casing 42 is suppressed, and stable operation can be expected. Of course, during the operation of the compressor 32, a large amount of heat is generated also in the compressor 32. This is cooled by the cooling air flowing on the outer surface of the compressor 32, the temperature rise is suppressed, and the cooling air passage 47 is separated. Since the inverter unit 40 is arranged, the heat of the compressor 32 does not reach the inverter unit 40 side and cause a temperature rise.

  In addition, while the FET 43 and the like can be efficiently cooled in this way, the casing 42 of the inverter unit 40 is configured as a closed type, so that cooling air does not enter the inside and heat is dissipated from the outer surface of the casing 42. The Therefore, even if oil in the kitchen is included in the air in the kitchen where the cooling storage is installed, it enters the casing 42 and adheres to the surface of the circuit board 41 with dust, resulting in insulation deterioration. Can be used even in harsh environments such as business use. Furthermore, dust and oil are removed from the air drawn into the condenser 33 by the cooling fan device 34 by the air filter 33A, and the surface of the casing 42 is kept clean, so that the cooling performance can be maintained high for a long period.

  Further, since the FET 43 in the inverter unit 40 performs a switching operation at a high speed, there is a circumstance that harmonic noise is likely to be radiated. In the present invention, the circuit board 41 including the electronic parts such as the FET 43 is made of the metal casing 42. Therefore, noise radiation from those electronic components can be reliably shielded. In addition, since the inverter unit 40 is disposed in the vicinity of the compressor 32, the total length of the output line from the inverter unit 40 to the compressor 32 is shortened, so that noise radiation from the output line can be suppressed. It can be expected not only to improve cooling but also to suppress noise. Moreover, since each inverter unit 40 is mounted on the unit base 38 close to the same right side as the operation electrical box 18, the wiring with the operation electrical box 18 can be shortened, and the harmonics. There is an effect that noise radiation can be further suppressed.

  In particular, in this embodiment, the heat sink plate 40 of the casing 42 is directed to the compressor 32 side, and a large number of heat dissipating fins 50 are arranged along the flow of cooling air. It becomes higher and the whole size can be reduced. In particular, in the present embodiment, the unit base 38 is configured as a ceiling heat insulating wall that is detachably attached so as to close the opening 21 formed in the ceiling portion of the heat insulating box body 10 constituting the refrigerator compartment, and is provided on the lower surface portion thereof. Since the cooler 23 is provided, the heat generated on the upper surface side of the unit base 38 is dissipated upward and the heat does not accumulate in the machine room. Further, since the casing 42 of the inverter unit 40 is fixed in contact with the upper outer shell 38A of the unit base 38, the heat from the unit base 38 is transmitted to the upper outer shell 38A, and the heat insulating material 38C on the lower surface and thus cooling is performed. The inverter unit 40 can be more efficiently cooled by the cold heat from the vessel 23.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention, and further, within the scope not departing from the gist of the invention other than the following. Various modifications can be made.

  (1) In the above embodiment, the two cooling units 30 are arranged on the upper surface of the heat insulation box body 10, and the refrigeration cycle and the inverter unit 40 are provided on each unit base 38. As shown in FIG. Of course, only one unit base 38 may be provided. Also, for example, even when two (or three or more) cooling units for a refrigerator compartment and a freezer compartment are arranged, an inverter unit is provided only on one side, the compressor is driven by an inverter, and an inverter unit is provided on the other side. Alternatively, the compressor may be driven at a fixed rotational speed.

  (2) In the above embodiment, the semiconductor switching element is fixed to the mounting substrate portion 48A of the heat sink plate 40. However, the structure is not limited to this, and the semiconductor switching element may be attached to the rising wall portion 48B and cooled.

The perspective view of the cooling storehouse which shows one Embodiment of this invention Disassembled perspective view of cooling storage Vertical section of cooling unit Top view of cooling unit Side view showing part of the inverter unit Side view of inverter unit The top view of the cooling storehouse which shows different embodiment of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Thermal insulation box main body 21 ... Opening part 23 ... Cooler 30 ... Cooling unit 32 ... Compressor 33 ... Condenser 34 ... Cooling fan apparatus 38 ... Unit base 40 ... Inverter unit 42 ... Casing 43 ... FET (semiconductor switching element)
48 ... Heat sink plate

Claims (2)

A cooling storage that cools the storage chamber by a refrigeration cycle including a compressor, a condenser, and a cooler, wherein the compressor driving motor is driven by an inverter circuit having a semiconductor switching element. In
The inverter circuit is housed in a part on a heat sink plate constituting the closed-in in a metal casing of the outer surface, and the semiconductor switching element in the inverter unit by being mounted for heat transfer to the heat sink plate is formed And
A heat-insulating unit base that is detachably attached by closing an opening formed in a ceiling portion of a heat-insulating box constituting the storage room is provided ,
While the cooler is provided on the lower surface of the unit base,
On the upper surface of the unit base, the condenser sequentially from the front side, with the condenser cooling fan device causing the cooling air flowing through from the front to the rear of, and the compressor is al provided,
In the vicinity of a side of the compressor, the inverter unit, is installed in a posture in which the heat sink plate side facing the cooling air path side cooling air passes from the cooling fan unit,
The heat sink plate is formed in an L shape including a rising wall portion facing the cooling air passage and an attachment substrate portion along the unit base, and the attachment substrate portion of the heat sink plate is formed on the unit base. A cooling storage, which is mounted so that heat can be transferred . Cold storage of claim 1, wherein the heat radiation fins extending along the flow path of the cooling air is projected from the outer surface of the front SL rising wall portion of the heat sink plate.

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