JP2008163765A - Electric compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric compressor with a built-in inverter capable of efficiently cooling the inverter without enlarging a machine body vessel and operating without deteriorating reliability and performance even under a high temperature and sever vibration environment such as engine direct mounting. <P>SOLUTION: In the electric compressor, provided with a compression mechanism part 5, a casing main body 3 having a motor 4 driving the compression mechanism part 5 built therein, and an inverter case 7 having an inverter 8 driving the motor 4 built therein and using suction refrigerant as a main cooling means for cooling a heat transmission surface member 19 of the inverter 8, a space in the inverter case 7 is insulated and cooled by a thermo module 20, and performance and reliability are improved by prohibiting deterioration acceleration by heat of components and a circuit constructing the inverter 8. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention incorporates a compression mechanism section and an electric motor for driving the compression mechanism section in an airframe container (casing), and further includes an inverter control device for controlling the driving (rotation) of the electric motor provided in the airframe container. It relates to a compressor.

  As this type of electric compressor, a compressor unit including a compression mechanism unit and an electric motor, and a storage unit of an inverter control device that controls driving of the electric motor are partitioned in an airtight state and integrated as a single body container. It is known (see, for example, Patent Document 1).

  FIG. 3 is a longitudinal sectional view of the electric compressor shown in Patent Document 1, in which a compression mechanism portion 113 is incorporated in a body container 112 containing the electric motor 111, and further opposite to the electric motor 111 so as to sandwich the compression mechanism portion 113 therebetween. The inverter case 115 which accommodated the inverter control apparatus 114 located in the side has shown the structure provided by being partitioned off with the body container 112 in the airtight state.

  Airframe container 112 and inverter case 115 are arranged coaxially and fastened with bolts or the like. Further, the inverter control device 114 is arranged such that the heat generating portion faces the compression mechanism portion 113.

  Therefore, the refrigerant sucked from the suction port 116 provided in the compression mechanism unit 113 is once led to the passage 117 formed between the inverter case 115 and the compression mechanism unit 113, and the heat generation unit of the inverter control device 114 After heat exchange, the air is sucked into the compression mechanism unit 113.

Further, the refrigerant gas compressed by the compression mechanism unit 113 cools the electric motor 111 and is then discharged from the discharge port 118 provided in the body container 112.
JP 2004-183631 A

  However, since the structure described in Patent Document 1 is a structure that cools the high heat-generating parts of the inverter control device 114 only by the temperature of the suction refrigerant, the compressor is operated at low speed, that is, when the refrigerant circulation amount is small, or When the intake refrigerant temperature becomes high due to load fluctuation or the like, sufficient heat exchange cannot be performed, and the heat generating components of the inverter control device 114 may be insufficiently cooled, which may greatly affect performance and reliability.

  In addition, when the compressor is used as an air conditioner for an automobile and is directly attached to an engine, the temperature inside the compressor is abnormally increased due to the heat of the engine, and even when the compressor is stopped, The inverter component is heated to a high temperature by the heat of the engine and includes a factor that accelerates the deterioration of the inverter component by the heating.

  As described above, the environment in which the compressor is mounted on the engine may exceed 100 ° C., and it is in a state where it is exposed to a considerably high temperature even in a parking state under hot weather.

  Further, even in an air conditioner for a living room such as an electric vehicle or a room air conditioner, the inverter control device 114 is exposed to the same environment and similarly includes a factor that accelerates deterioration of components due to heat.

  Therefore, the reliability conditions required for the inverter parts are considerably severe, and the cooling technique disclosed in Patent Document 1 has a limit in suppressing the deterioration of the inverter parts, and particularly in the case of a compressor mounted on a vehicle. However, due to the cooling of the inverter components, the mounting position and direction of the compressor are often restricted, and improvement measures such as increasing the degree of freedom in design have been demanded.

  Furthermore, since the inverter control device 114 has a characteristic of generating heat during operation, a configuration for cooling the inverter control device 114 is required regardless of whether or not the engine is mounted.

  An object of the present invention is to provide an electric compressor that can efficiently cool an inverter control device without increasing the size of a fuselage container (casing), focusing on the above-described conventional problems.

  In order to solve the above-described conventional problems, the present invention utilizes an endothermic action of a thermo module (also referred to as a Peltier element or a Peltier module) in addition to cooling the inverter control device using the suction refrigerant temperature. In addition, the heat absorbing action of the thermo module is provided so that the heat absorbing action of the thermo module is less susceptible to the influence of heat from the outside of the compressor.

  More specifically, an inverter case with a built-in inverter control device for driving and controlling the motor is incorporated in a casing containing a compression mechanism for sucking, compressing and discharging refrigerant and an electric motor for driving the compression mechanism. The electric compressor includes a case cover that closes the inverter case, and serves as a cooling means for cooling the inverter control device so as to transfer heat of the suction refrigerant to the heat generating portion of the inverter control device. Is provided with a thermo module for cooling.

  Further, in addition to the above configuration, the case cover that closes the inverter case is provided with heat insulating means that suppresses heat transfer inside and outside the case cover.

  As a result, the heat generating part and its peripheral circuits in the inverter control device are cooled by a combination of cooling using the temperature of the suction refrigerant (return refrigerant) and cooling by the endothermic action of the thermo module, or the temperature rise is suppressed. can do.

  Moreover, it can suppress that the temperature in an inverter case receives the influence of external heat by the said heat insulation means.

  The electric compressor of the present invention cools the inverter control device that controls the rotation and driving of the motor by the temperature of the suction refrigerant (return refrigerant) and the cooling action of the internal space of the case cover by the thermo module (including suppression of temperature rise). )can do.

  Therefore, not only during the operation of the compressor and immediately after the shutdown, but also to control the energization of the thermo module when necessary, such as when the inverter controller is exposed to a high temperature state when the compressor is stopped. Can cool the inverter control device (including suppression of temperature rise), so that it is possible to suppress a decrease in the efficiency of the inverter control device during operation of the compressor, and deterioration of inverter components due to heat. (Acceleration of deterioration) can be suppressed.

  In addition, by providing the inverter case with heat insulation means, heat transfer inside and outside the inverter case can be suppressed, and as a result, the heat absorption action of the thermo module is suppressed from being influenced by external heat. Thus, the heat absorption and heat dissipation action of the thermo module can be effectively performed.

  In addition, when the electric compressor is directly mounted on an engine such as a hybrid vehicle, it is exposed to a severe environment such as heating and vibration from the engine. The electric compressor can be operated without impairing the performance and reliability as the electric compressor. Furthermore, since the cooling effect of the inverter device can be expected, the degree of freedom in design can be improved in the mounting position or directionality in the electric compressor.

  The invention according to claim 1 is formed of a compression mechanism portion for sucking, compressing and discharging refrigerant, a casing having a built-in electric motor for driving the compression mechanism portion, and a thermally conductive material, and closing the opening of the casing. An inverter case, an inverter control device that is built in the inverter case and drives the electric motor, and a case cover that closes the inverter case, and exchanges heat with the intake refrigerant as a cooling means of the heat generating part of the inverter control device In the electric compressor constructed as described above, a heat dissipating surface and a heat absorbing surface are provided, a thermo module for cooling the case cover is provided, and heat insulating means for suppressing heat transfer inside and outside the case cover is provided on the case cover. It is provided.

  With this configuration, in addition to cooling the heat generating part in the inverter control device using the cold heat of the suction refrigerant (return refrigerant) of the compression mechanism part, the case cover is absorbed by the heat absorption action of the thermo module. Since the inside can be cooled, the inverter control is performed by suppressing the temperature rise in the case cover even in a state where the circulation amount of the suction refrigerant is small or in a high temperature state after the operation of the electric compressor is stopped. The temperature rise of the apparatus can be suppressed, and as a result, deterioration of the inverter component due to heat (acceleration of deterioration) can be suppressed.

  Further, since the heat insulation means suppresses heat transfer inside and outside the case cover, it is possible to efficiently cool the inside of the case cover by the thermo module by suppressing the heat exchange action between the case cover and the outside air. it can.

  In addition, the case cover can prevent adverse effects on electrical components due to rainwater, dust, etc., and can ensure long-term reliability.

  According to a second aspect of the present invention, as the casing is closed by the inverter case, a passage for the suction refrigerant in the compression mechanism is formed on the back surface of the inverter case, and the heat generating portion of the inverter control device is made of the suction refrigerant. It is attached to the surface of the inverter case to be cooled so that heat conduction or heat transfer is possible.

  With this configuration, the heat generating portion of the inverter control device exchanges heat with the suction refrigerant through the wall surface of the inverter case, so that the inverter control device is cooled by the heat exchange (cooling action) (suppression of temperature rise). Deterioration of the inverter component due to heat (acceleration of deterioration) can be suppressed.

  According to a third aspect of the present invention, the case cover is formed of a heat conductive material, and the heat absorption surface of the thermo module is closely attached to the outer surface of the case cover so as to be capable of heat conduction or heat transfer.

  By adopting such a configuration, the case cover can also serve as a heat transfer promoting member such as a heat sink in which the heat transfer surface of the heat absorption surface in the thermo module is enlarged, thereby promoting the heat transfer action of the thermo module. it can. As a result, the endothermic action of the thermo module can be stabilized and the cooling efficiency of the thermo module can be increased.

  Furthermore, the space formed by the case cover and the inverter case can be cooled by the endothermic action of the thermo module, and thus the cooling by the thermo module suppresses the increase in the ambient temperature of the entire inverter control device. Acting, it is possible to suppress acceleration of deterioration of the inverter component due to heat.

  According to a fourth aspect of the present invention, the case cover is attached to at least one of the casing body or the inverter case via a heat insulating material.

  With this configuration, the heat on the casing body side is hardly transmitted to the case cover side, and as a result, the cooling action of the thermo module is hardly hindered, and the cooling action in the case cover by the thermo module is reduced. Can be performed more effectively.

  According to a fifth aspect of the present invention, the heat insulating means comprises a heat insulating case that covers a portion of the case cover other than the heat radiating portion of the thermo module.

  By adopting such a configuration, the outer surface of the case cover is thermally insulated except for the heat radiating portion of the thermo module, and as a result, the heat exchange range between the case cover and the outside air can be suppressed, and the heat outside the case cover is It is possible to suppress adverse effects such as entering through the case cover and inhibiting the cooling action by the thermo module.

  In a sixth aspect of the present invention, heat transfer promoting means including heat radiating means is provided on the heat radiating surface of the thermo module.

  By adopting such a configuration, the heat dissipating capacity of the heat dissipating part in the thermo module can be increased. As a result, the difference between the heat dissipating surface temperature and the heat absorbing surface temperature of the thermo module can be reduced, and the cooling efficiency of the thermo module can be increased. it can.

  According to a seventh aspect of the present invention, the case cover is provided with an elastic body that urges the thermo module in a direction in close contact with the case cover.

  With this configuration, the thermo module can be pressed and fixed to the inverter case by the urging force of the elastic body. As a result, vibration or thermal stress accompanying operation of the compressor or the like is attached to the case cover or the thermo module itself. Even if this works, the vibration or stress is absorbed by the elastic force of the elastic body, so that the failure or breakage of the thermo module can be prevented.

  Further, even if the case cover is slightly distorted due to thermal expansion / contraction, etc., it is possible to maintain the contact state with the thermo module by elastic deformation (biasing force) of the elastic body, As a result, it is possible to stabilize the endothermic action and the heat release action of the thermo module.

  According to an eighth aspect of the present invention, the case cover is provided with a fixture for fixing the thermo module to the outer surface of the case cover via an elastic body provided on the heat radiating surface side of the thermo module. And a heat insulating layer is provided at least at a part between the thermo module side portions.

  By adopting such a configuration, the thermo module can be fixed by the fixture and the elastic body, and the above-described vibration and stress can be protected, and the heat insulating layer prevents heat leakage from the heat radiation surface to the heat absorption surface of the thermo module. Can be suppressed. As a result, the endothermic surface, the endothermic action from the heat radiating surface, and the endothermic action of the thermomodule can be performed in a normal (rated) state or in a state close thereto, and the inhibition of cooling efficiency maintenance can be reduced.

  According to a ninth aspect of the present invention, the case cover is provided with a concave portion projecting toward the inverter case, the thermo module is disposed in the concave portion, and at least a part of the peripheral wall of the concave portion and the thermo module side portion. A heat insulating layer is formed between them.

  By adopting such a configuration, the arrangement in the recess can be used for positioning work when the thermo module is mounted, and the degree of protrusion of the thermo module into the case cover is increased, so that the space volume in the case cover is increased. Can be reduced.

  As a result, the cooling load (space volume) of the thermo module can be reduced, and the distance between the thermo module and the inverter control device can be reduced. By reducing this cooling load and shortening the distance between the thermo module and the inverter control device, the cooling heat of the heat absorption surface accompanying the heat absorption action of the thermo module can be made to act on the suppression of the temperature rise of the inverter control device. It is.

  Furthermore, the heat insulation layer can regulate (suppress) heat leakage from the heat radiating portion side to the heat absorbing portion side in the thermo module, and as a result, the heat absorbing action and heat radiating action in the thermo module are regular (rated). Thus, it is possible to reduce the hindrance to maintaining the cooling efficiency.

  The invention according to claim 10 is the one in which the thermo module is positioned above the inverter device. By adopting such a configuration, the convection in which the air in the case cover cooled by the thermo module is lowered. When the conditions are such that heat transfer between the inverter control device and the air is promoted, temperature rise of the inverter control device can be suppressed.

  The invention according to claim 11 is provided with ventilation means for communicating the inside and outside of the case cover in the case cover. By adopting such a configuration, it is possible to prevent heat accumulation in the case cover, and to The control device can be efficiently cooled.

  According to a twelfth aspect of the present invention, the ventilation means includes at least an intake port and an exhaust port provided in the case cover and an inner space of the case cover.

  With such a configuration, an air flow can be formed in the case cover, and heat accumulation in the case cover can be suppressed.

  According to a thirteenth aspect of the present invention, at least one of the air supply port and the exhaust port is provided at a position higher than the thermo module. Therefore, the escape of high-temperature air in the case cover is smooth, and the relatively low-temperature cooling air easily convects downward, so that the cooling action in the case cover can be performed efficiently.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a front view in which a part of the electric compressor in Embodiment 1 of the present invention is cut away. In the first embodiment, the case of a horizontal electric compressor installed sideways by mounting legs 2 provided around the casing of the electric compressor 1 is shown as an example. FIG. 2 is a perspective view showing a cross section of an attachment portion of the inverter control device and the thermo module in the electric compressor of the embodiment.

  In the figure, an electric compressor 1 is formed in a bottomed cylindrical shape with one end opened, and is made of a metal casing body 3 provided with a plurality of mounting legs 2 at appropriate locations on the outer periphery, and incorporated in the casing body 3. An electric motor (DC brushless motor) 4 having a stator and a rotor, and a compression mechanism portion 5 fitted or press-fitted into the casing body 3 are main components. The rotating shaft 6 of the electric motor 4 is composed of the compression mechanism portion 5. A drive shaft is configured.

  And the opening edge part by the side of the compression mechanism part 5 in the casing main body 3 is obstruct | occluded by metal inverter cases 7, such as aluminum die-casting, and the casing main body 3 is made into the sealing state.

  The motor 4 is driven and its rotational speed is controlled by an inverter control device (hereinafter referred to as an inverter) 8 incorporated in the inverter case 7. In the electric compressor 1, the refrigerant to be handled is a gas refrigerant, and lubricating oil is employed as a liquid for lubrication of each sliding portion, sealing of the sliding portion in the compression mechanism portion 5, and lubrication.

  The compression mechanism unit 5 of the electric compressor 1 according to the first embodiment is of a scroll type and has a well-known configuration, and returns from an external cycle due to the volume change of the compression space 9 formed in the compression mechanism unit 5. The suction refrigerant (return refrigerant) 10 is sucked into the suction side of the compression mechanism portion 5 from the suction port 11 provided in the inverter case 7 and is compressed in the compression space 9 as described above, and then located at the approximate center of the compression space 9. Discharge from the discharge hole 12 into the casing body 3 through a discharge chamber 12a and a passage 12b, which will be described later, and discharge to an external cycle (not shown) connected to a heat exchanger or the like from a discharge port 13 provided in the casing body 3. .

  Since the above-described configuration of the compression mechanism 5 and the electric motor 4 in the casing body 3 may be a known configuration, a detailed description thereof will be omitted.

  On the other hand, the inverter case 7 fitted with good sealing performance on the opening side of the casing body 3 via a seal member 14 such as an O-ring is fixed to the casing body 3 by appropriate means (not shown) such as bolt tightening. ing.

  The inverter case 7 is airtightly combined with the compression mechanism 5 (fixed end plate of the fixed scroll) by a partition member 7a provided on the inner surface thereof and a seal member 15 such as an O-ring provided on the tip thereof, and the suction port 11 A suction space 16 is formed by forming a sealed space that leads from the suction mechanism to the suction side of the compression mechanism section 5.

  Further, a discharge chamber 12 a communicating with the discharge hole 12 of the compression mechanism unit 5 via the partition wall 17 is located in a part of the space of the suction passage 16.

  The inverter 8 is disposed on the opposite surface (outer side) of the suction passage 16 on the end wall 7b of the inverter case 7, and includes an electronic circuit such as a printed wiring board (hereinafter referred to as a circuit board) 18 and an electrolytic capacitor (not shown). Constructed with parts.

  More specifically, as shown in FIG. 2, the circuit board 18 includes a well-known IPM (intelligent power module) 18a including a switching element having a high heat generation, a control circuit unit 18b mainly composed of a microcomputer, and the like. A heat transfer surface member 19 constituting a heat transfer surface such as a heat sink is provided integrally with the heat generating portion of the IPM 18a. Further, by fixing the circuit board 18 to the boss portion 7c provided at an appropriate location of the inverter case 7 with the bolt 21, the heat transfer surface member 19 of the IPM 18a is in close contact with the end wall 7b so as to be able to conduct heat or transfer heat. is doing. If necessary, the heat transfer surface member 19 and the end wall 7b are brought into close contact with each other through a heat conductive grease or the like to reduce heat resistance and increase heat transfer efficiency. You can also.

  In addition to the control circuit of the electric motor 4, a module control board 20 b including a circuit unit 20 a that controls energization of a thermo module 20 described later is also provided in parallel on the circuit board 18. Similar to the circuit board 18, the module control board 20 b is bolted to a boss (not shown) formed at an appropriate location of the inverter case 7.

  The control circuit unit 18b and the module control board 20b mounted on the circuit board 18 may be heat resistant according to the environment where the electric compressor 1 is installed.

  A heat transfer surface member 19 of the inverter 8 is in contact with the end wall 7b of the inverter case 7, and the end wall 7b also serves as a heat transfer promoting member that functions as a heat sink in the inverter 8, for example. . Further, the portion of the end wall 7b where the heat transfer surface member 19 abuts is formed by the thickness of the end wall 7b, and is referred to in order to define the contact position with the heat transfer surface member 19 in the inverter 8. In particular, processing such as increasing the thickness is not performed in order to increase the heat capacity, but the thickness can be set as necessary.

  Further, a case cover 22 that closes the inverter 8 and the circuit board 18 is attached to the inverter case 7 with bolts 23. The case cover 22 is made of a metal such as an aluminum die cast, like the inverter case 7, and forms a dustproof / waterproof structure so that dust or rainwater does not affect the inverter 8 or the circuit board 18.

  The case cover 22 is provided with a heat insulating material 22a on the contact surface (opening periphery) with the inverter case 7 to suppress heat transfer between the case cover 22 and the inverter case 7 side. This heat insulating material 22a has a sealing function as well as heat resistance, such as a sealing material or plastic rubber made of any of acrylic resin, fluorine rubber, fluorine resin, etc., as well as heat resistance. preferable. Specific materials can be selected within a known range.

  A thermo module 20 that cools the internal space 24 formed together with the inverter case 7 is attached to the outer surface of the case cover 22. As is well known, the thermo module 20 is also referred to as a Peltier element or a Peltier module. For example, the thermo module 20 is formed on an electric insulator substrate formed of an electric insulator (including a material mixed with a heat conductive material) such as a ceramic material. A plurality of thermoelectric elements are arranged so that a current flows in series on the electrodes, and heat is generated on one side and heat is absorbed on the other side by the Peltier effect by energization. It is. Here, “cooling” will be described as meaning that, in addition to lowering the temperature of the internal space 24, it also means suppressing the temperature rise of the internal space 24.

  The case cover 22 is formed with a recess 34 projecting toward the inverter case 7, and the thermo module 20 is disposed in the recess 34, and its heat absorption surface is a flat portion of the recess 34 (in the present embodiment). The bottom surface of the recess 34 is attached in close contact, and the heat radiating surface faces the external space.

  The heat radiation surface of the thermo module 20 is provided with heat transfer promoting means for promoting the heat radiation action. In the first embodiment, a heat sink 25 made of aluminum metal or the like is used as the heat transfer promoting means on the heat radiating surface side, and the heat radiating action is promoted. The heat sink 25 is provided in close contact with the bottom surface of the recess 34. ing. The heat sink 25 is provided with fins 25a that increase the surface area. Thereby, the heat dissipation capability in the thermo module 20 is increased, the temperature difference between the heat dissipation surface temperature and the heat absorption surface temperature is reduced, and the heat absorption capability of the thermo module 20 is improved.

  The thermo module 20 and the heat sink 25 are fixed via an elastic body 27 by a fixture 26 attached to the outer surface of the case cover 22 by appropriate means such as screwing.

  Therefore, the thermo module 20 and the heat sink 25 are fixed in a state of being pressed against the bottom surface of the case cover 22 by the urging force of the elastic body 27. In such a configuration, the close contact surfaces of the thermo module 20, the case cover 22, and the heat sink 25 are brought into close contact with each other via a heat conductive grease or the like, thereby reducing the thermal resistance and further increasing the heat transfer efficiency. Can do.

  As described above, when the pressing and fixing of the thermo module 20 is taken into consideration, the elastic body 27 is not pressed by a point, but is pressed by a surface, for example, a shape along the peripheral shape of the heat sink 25 and the peripheral edge of the heat sink 25. A coil-shaped spring material that holds the heat sink, or an annular spring material that is formed in a corrugated plate shape so as to press the periphery of the heat sink 25. Further, the rubber component has heat resistance and presses the outer periphery of the thermo module 20. An elastic material as a main component is preferable.

  For example, in the case of an electric compressor mounted as a vehicle air conditioner, the pressing and fixing of the thermo module 20 by the elastic body 27 can absorb vibration from the vehicle, vibration from the engine, or the like by the elastic body 27. As a result, the thermo module 20 is a useful mounting structure as a measure for preventing the electrode and the thermoelectric element from being peeled off due to vibration shock or damage due to vibration shock of an electrical insulator substrate such as a ceramic material.

  Furthermore, a heat insulating space 28 that forms a heat insulating layer is provided between the side surface of the thermo module 20, the side wall of the recess 34, and between the fixture 26 and the side surface of the thermo module 20. Therefore, the heat insulation space 28 restricts (suppresses) the heat on the heat radiation surface side of the thermo module 20 from leaking directly to the heat absorption surface side through the side wall of the fixture 26 or the recess 34, and the thermo module 20 is rated. You can drive to or near the street.

  Furthermore, the heat insulation space 28 can also be used as a positioning jig insertion space when the thermo module 20 is disposed in the recess 34. Further, the heat insulating layer is not limited to the heat insulating space 28, and may be any material or configuration that restricts direct heat transfer. By providing a heat resistant heat insulating material in the heat insulating space 28, higher heat can be obtained. Leak regulation effect can be expected. In this case, the thermo module 20 is configured so as to surround the side surface of the thermo module 20, and a space for a jig for sandwiching the thermo module 20 through the heat insulator is provided in a part of the thermo module. 20 can also be positioned in the recess 34.

  As described above, the formation of the heat insulating space 28 can be used for the positioning operation of the thermo module 20, and improvement in workability can be expected.

  Further, since the heat absorption surface of the thermo module 20 is in close contact with the case cover 22, the case cover 22 forms so-called heat transfer promoting means that expands the area of the heat absorption surface in the thermo module 20 and promotes the heat absorption action. ing. As a result, the endothermic effect generated on the endothermic surface of the thermo module 20 spreads over the entire surface of the case cover 22, but the effect tends to decline as the distance from the thermo module 20 increases due to loss of heat transfer resistance or the like.

  However, since the thermo module 20 is positioned approximately at the center of the case cover 22 and higher than the inverter 8, the cooling heat (cooling air) from the heat absorption surface is lowered to cool the inverter 8. Can act on.

  Further, as shown in FIG. 1, the temperature of the inverter 8 is also affected by radiation cooling from the thermomodule 20 by arranging the thermomodule 20 and the inverter 8 so as to partially overlap in the projection direction (axial direction of the compressor). The rise can be suppressed.

  In particular, by installing the thermo module 20 in the recess 34 protruding into the internal space 24, the facing distance S with the inverter 8 is shortened, and the heat absorption surface is partially but facing the inverter 8, The above-mentioned radiation cooling acts, and the temperature rise of the components of the circuit board 18 or the inverter 8 can be suppressed.

  Here, the close contact between the heat transfer surface member 19 and the end wall 7b of the inverter 8 and the close contact between the heat radiation surface of the thermo module 20 and the case cover 22 can perform heat conduction to the extent that the effects described below can be expected. This also corresponds to the case of heat transfer action involving very small voids. In the following explanation, the heat transfer effect including the above-described extremely small voids is referred to as heat conduction. explain.

  Further, a heat insulating cover 29 corresponding to the heat insulating means of the present invention is provided on the outer surface of the case cover 22, and the heat absorbing action of the thermo module 20 is regulated so as not to easily exchange heat with external heat. Thereby, the case cover 22 can perform a cooling action by the thermo module 20 in the internal space 24 in a state where the heat transfer from the outside is small.

  The heat insulating cover 29 is formed in a bottomed cylindrical shape, and has a configuration in which a through hole is provided at a portion corresponding to the bottom surface so that the heat sink 25 on the heat radiating surface side of the thermo module 20 is exposed. The heat insulating cover 29 may be any material that can be processed or molded along the shape of the case cover 22 such as a heat insulating material mainly composed of glass fiber, but preferably has heat resistance.

  Further, the case cover 22 is provided with an intake port 30 and an exhaust port 31 that communicate with the internal space 24 and the outside at different positions to form a ventilation passage in the case cover 22 including the internal space 24. Here, the intake port 30 and the exhaust port 31 positioned higher than the intake port 30 are uniquely defined from the characteristics that cool air having a low temperature falls and hot air having a high temperature rises. For example, intake and exhaust may be performed in reverse depending on a change in the surrounding environment in the electric compressor 1 such as a strong wind blowing on the electric compressor 1 or a pressure difference inside and outside the case cover 22. In addition, a known film body that allows air permeation and rejects moisture permeation may be provided in the intake port 30 and the exhaust port 31 as necessary.

  In addition, the heat insulating cover 29 is also provided with ventilation holes 35 corresponding to the intake ports 30 and the exhaust ports 31 so that the above-described ventilation can be performed.

  Further, the inverter case 7 is provided with a connection chamber 32 that is positioned alongside the suction passage 16 with the partition wall 7a interposed therebetween. A male connection portion (compressor) connected to the electric motor 4 is provided in the connection chamber 32. Terminal) 33 is provided. The connection portion 33 is fixed to the circuit board 18 and connected to a female connection portion 33 a connected to the inverter 8. Therefore, the inverter 8 and the electric motor 4 are electrically connected via the connection portions 33 and 33a.

  Further, the connecting portions 33 and 33a are set so that their positions coincide with each other when the circuit board 18 is fixed to the inverter case 7. As a result, the connection portions 33 and 33a can be connected simultaneously with the fixing operation of the circuit board 18 to the inverter case 7, and the assembly workability can be improved. Such connection may be configured such that the connection portion 33a is connected to the circuit board 18 via a lead wire (not shown) as necessary.

  As is well known, the drive (rotation) control of the electric motor 4 by the inverter 8 is performed by monitoring loads such as the air-conditioning room temperature and the refrigerant temperature by a detection means (not shown), and by a load signal and a control signal based on the results, The rotation of the electric motor 4 is controlled at a frequency of. Since the specific control contents of the electric motor 4 are not directly related to the gist of the present invention, the description thereof is omitted here.

  Next, the operation of the electric compressor 1 having the above configuration and the cooling operation of the inverter 8 will be described.

  When the electric motor 4 is rotated by the start control of the inverter 8, the rotation shaft (drive shaft) 6 is also rotated along with this, and the compression mechanism unit 5 is driven via the rotation shaft 6.

  Therefore, the compression mechanism 5 sucks the suction refrigerant 10 that is a return refrigerant from a refrigeration cycle (not shown) having a known configuration through the suction port 11 provided in the inverter case 7.

  The low-temperature suction refrigerant 10 that has flowed into the casing body 3 from the suction port 11 cools the end wall 7b in the space of the suction refrigerant passage 16, and further, the heat transfer surface member of the inverter 8 that is in close contact with the end wall 7b ( Heat is exchanged with the heat generating portion 19, and the heat transfer surface member 19 is cooled and flows into the compression space 9 through a passage hole (not shown) of the compression mechanism portion 5.

  The refrigerant that has flowed into the compression space 9 is compressed by the volume reduction movement of the compression space 9 accompanying the circular orbit movement of the compression mechanism section 5, and is discharged from the discharge hole 12 communicating with the final compression space to the discharge chamber 12a. And it enters into the electric motor 4 side through the channel | path 12a provided in the outer peripheral part of the compression mechanism part 5 from the discharge chamber 12a, is discharged from the discharge port 13 of the casing main body 3 while cooling the electric motor 4, and goes to an external refrigerating cycle. And flow.

  By continuing the flow of the refrigerant, the inverter 8 generates heat from the heat generating portion with the continuous rotation control of the electric motor 4. As described above, the heat transfer surface member is exchanged by heat exchange at the end wall 7 b by the suction refrigerant 10. Since 19 is cooled, the temperature rise is suppressed.

  Further, the air in the internal space 24 of the case cover 22 due to the heat generated by the inverter 8 is provided with the exhaust port 31 upward, so that when the temperature is higher than the temperature outside the case cover 22, the natural convection causes the arrow in FIG. As shown in FIG. 5, the air is discharged from the exhaust port 31 and the vent hole 35, and then external air flows into the internal space 24 from the intake port 30, and the flow of hot air in the internal space 24 is suppressed by these flows. Is done.

  Although suppression of the temperature rise of the inverter 8 can be expected to have a certain effect in a predetermined range of rotation of the electric compressor 1, the intake refrigerant 10 is reduced when the refrigerant circulation amount decreases in the low rotation range or when the refrigeration cycle load varies. When the temperature of the electric compressor 1 rises, or immediately after the electric compressor 1 is stopped, the effect cannot be expected only by the cooling action at the end wall 7b, and the inverter 8 becomes higher than necessary. There is a case.

  In particular, if the electric compressor 1 is used for a vehicle, the compressor may be exposed to a temperature of 100 ° C. or higher due to high radiant heat from the engine immediately after the vehicle stops.

  Since the heating of the inverter 8 at such a high temperature accelerates the deterioration of related parts, in the first embodiment, it is necessary to quickly reduce the temperature of the internal space 24 in the case cover 22. It is also necessary to control so that the temperature does not reach such a high temperature.

  In the first embodiment, by controlling energization of the thermo module 20, the temperature of the internal space 24 is absorbed by the heat absorption surface and the case cover 22, and the heat generation surface passes through the heat sink 25 to the outside of the electric compressor 1. It dissipates heat and suppresses the temperature rise in the internal space 24 of the case cover 22.

  That is, as is well known, the thermo module 20 can control the heat absorption amount and the heat generation amount in proportion to the energization amount (current amount). By controlling the energization amount to an optimum value, the temperature rise of the inverter 8 can be controlled. In addition to the cooling by the return refrigerant temperature through the end wall 7b, it can be suppressed by the combination with the cooling action of the internal space 24 by the thermo module 20.

  In other words, the cooling of the inverter 8 according to the first embodiment controls the temperature of the environment (internal space 24) in which the inverter 8 is installed, and is insulated from the outside of the electric compressor 1 by the heat insulating cover 29. By suppressing the intrusion of heat, the temperature of the internal space 24 can be accurately controlled.

  Compared with the configuration in which the inverter 8 is directly cooled, such cooling cools the circuit components of the circuit board 18 constituting the control circuit of the inverter 8 and suppresses deterioration of the inverter components due to heat (acceleration of deterioration). It can be done.

  Further, the case cover 22 provides a dustproof / waterproof structure such as the thermo module 20, the inverter 8, and the circuit board 18, and the heat absorption surface of the thermo module 20 is attached in close contact with the recess 34 of the case cover 22. The case cover 22 can function as a heat transfer surface expansion means and a heat transfer promoting means such as a heat sink of the heat absorption surface, and the number of components and the amount of component materials can be reduced. This also makes it possible to operate the thermo module 20 with high efficiency by reducing the temperature difference between the heat absorbing surface and the heat radiating surface across the case cover 22. In addition, since it is made difficult to be affected by external heat by the heat insulating cover 29, intrusion of external heat from the case cover 22 can be suppressed, and the cooling action of the thermo module 20 is not hindered by the intrusion heat. The internal space 24 can be efficiently cooled or temperature rise can be suppressed.

  Moreover, since the heat insulating material 22a is provided also about the junction part of the case cover 22 and the inverter case 7, the heat transfer between the case cover 22 side and the inverter case 7 side can be suppressed. As a result, a change in heat load (environment) in the internal space 24 can be suppressed. This leads to the capability setting necessary for the capacity setting of the thermo module 20 and the cooling of the inverter 8 (including suppression of temperature rise), and the inverter 8 can be efficiently cooled. As a result, deterioration of the inverter component due to heat can be suppressed.

  In particular, since the heat sink 25 is provided with a plurality of heat radiation fins 25a on its outer surface to improve the heat radiation capacity, the heat conversion efficiency operation of the thermo module 20 can be enhanced and stabilized.

  Further, since the thermo module 20 is superposed on the projection surface with the inverter 8, radiation cooling via the case cover 22 also assists the cooling action (suppression of temperature rise) of the inverter 8.

  In particular, by mounting in the recess 34 formed in the case cover 22, the structure protrudes into the internal space 24, which reduces the distance S between the thermo module 20 and the inverter 8, and the radiation cooling action is stronger and the inverter 8. In addition, the volume of the internal space 24 can be reduced by the formation of the recess 34, which leads to a reduction in the load that the thermo module 20 cools, and the cooling effect can be further improved.

  Further, since the case cover 22 is provided with the intake port 30 and the exhaust port 31, particularly when the temperature of the internal space 24 is higher than the temperature outside the case cover 22, the case cover is utilized by utilizing natural convection of cold air and warm air. 22 and the exhaust port 31 is provided at a position higher than the intake port 30. Therefore, as shown by the arrows in FIG. 1, it is easy to supply and exhaust air by natural convection of cold air and warm air. Improvement in ventilation efficiency can be expected, and the intake port 30 is provided not at the bottom but at an intermediate position, so that the escape of cold air can be suppressed and a ventilation effect can be expected. Moreover, since the cool air from the heat absorption surface of the thermo module 20 descends so as to wrap the inverter 8 and performs a cooling action, the cooling action of the inverter 8 can be subsidized.

  Further, since the thermo module 20 is configured to be pressed and fixed to the case cover 22 by the urging force of the elastic body 27, the thermo module 20 is maintained in close contact with the case cover 22 by following the thermal expansion and contraction. The heat transfer action can be continued, and the internal space 24 of the case cover 22 can be cooled stably.

  In particular, the fixing of the thermo module 20 by the urging force of the elastic body 27 is effective not only for impact such as thermal stress but also for vibration and the like, and is therefore the case where the electric compressor 1 is mounted on a vehicle. However, it is possible to prevent the electrode and the thermoelectric element from being peeled off due to vibration shock or damage to the electric insulator substrate such as ceramic material due to vibration shock.

  Furthermore, a heat insulating space 28 is provided between the periphery of the side surface of the thermo module 20 and between the recess 34 and the fixture 26 so as not to cause a so-called heat conduction short circuit in which heat of the heat radiating portion in the thermo module 20 leaks directly to the heat absorbing portion side. Therefore, the thermo module 20 can be operated in a normal (as rated) or near operating condition, and the inhibition of cooling efficiency maintenance can be reduced.

  In this case, if the elastic body 27 is also formed of a well-known material having heat resistance and heat insulation properties such as heat resistant rubber, the heat transfer can be further restricted and the operation efficiency of the thermo module 20 can be expected to be further improved. is there.

  Here, instead of the heat insulating space 28, a heat insulating material may be arranged between the side surface of the thermo module 20 and the side surface of the recess 29. In such a configuration, the heat insulating material can be expected to suppress the movement of the thermo module 20 due to the vibration of the compressor.

  The module control board 20b, which is a control control unit of the thermo module 20, is arranged in parallel with the circuit board 18 for driving the electric motor 4 in the case cover 22, so that the rotation signal and energization of the electric motor 4 necessary for control are provided. The power source is shared with the circuit board 18. As a result, the circuit configuration can be simplified, and the electric circuit system can be assembled from the same direction all at once, and the assembly workability can be improved.

  As described above, according to the first embodiment, in the conventional electric compressor 1 with a built-in inverter, the size and weight of the electric compressor 1 are substantially maintained by the addition of the small and light component called the thermo module 20. Auxiliary cooling of the inverter 8 is possible, and even when the electric compressor 1 is mounted on a vehicle, the mounting property to the vehicle is not impaired.

  In the first embodiment, the case of a horizontally installed compressor has been described. However, a vertically installed compressor, or a compressor that does not have a configuration for cooling the inverter 8 with suction refrigerant is also used. In these cases, the thermo module 20 can be mounted in various ways (for example, the depth of the recessed portion 34 or mounted without using the recessed portion 34), the details of the shape and structure of the case cover 22, and the like. However, this structure does not depart from the present invention.

  The electric compressor according to the present invention can improve the reliability of the electronic component by providing a cooling means for the space in which the inverter device is accommodated, as compared with the conventional electric compressor with a built-in inverter device. Assembling workability is also easy, and it can be applied not only to refrigeration and air conditioning systems for living rooms, but also to environmental vehicles such as hybrid vehicles, and general vehicles, etc., and to other refrigeration systems for storing articles such as refrigerators. Is also widely applicable.

The front view which notched some electric compressors in Embodiment 1 of this invention Cross-sectional perspective view of an inverter control device for an electric compressor and a mounting portion of a thermo module in the same embodiment Vertical section of an electric compressor showing a conventional example

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electric compressor 3 Casing main body 4 Electric motor 5 Compression mechanism part 7 Cover body 7b End part wall 8 Inverter (inverter control apparatus)
16 Suction passage 18 Circuit board 19 Heat transfer surface member (heat generating part)
DESCRIPTION OF SYMBOLS 20 Thermo module 22 Inverter case 22a Thermal insulation material 24 Internal space 25 Heat sink 25a Radiation fin 26 Fixing tool 27 Elastic body 28 Thermal insulation space (thermal insulation layer)
29 Insulation cover (insulation means)
30 Inlet 31 Exhaust Out 34 Recess

Claims (13)

  A compressor mechanism that sucks, compresses and discharges the refrigerant; a casing that includes a motor that drives the compressor mechanism; an inverter case that is formed of a thermally conductive material and closes the opening of the casing; and the inverter case In the built-in inverter control device that drives the electric motor, and a case cover that closes the inverter case, the electric compressor that exchanges heat with the suction refrigerant as a cooling means of the heat generating portion of the inverter control device, An electric compressor having a heat radiating surface and a heat absorbing surface, provided with a thermo module for cooling the case cover, and further provided with heat insulating means for suppressing heat transfer inside and outside the case cover.   As the casing is closed by the inverter case, a suction refrigerant passage in the compression mechanism is formed on the back surface of the inverter case, and the heat generating part of the inverter control device is heated to the surface of the inverter case cooled by the suction refrigerant. The electric compressor according to claim 1, wherein the electric compressor is attached so as to be capable of conducting or transferring heat.   The electric compressor according to claim 1, wherein the case cover is made of a heat conductive material, and the heat absorption surface of the thermo module is in close contact with the outer surface of the case cover so that heat conduction or heat transfer is possible.   The electric compressor according to any one of claims 1 to 3, wherein the case cover is attached to at least one of the casing body or the inverter case via a heat insulating material.   The electric compressor according to any one of claims 1 to 4, wherein the heat insulating unit is configured of a heat insulating case that covers a portion of the case cover other than a heat radiating portion of the thermo module.   The electric compressor according to any one of claims 1 to 5, wherein a heat transfer accelerating unit including a heat radiating unit is provided on a heat radiating surface of the thermo module.   The electric compressor according to any one of claims 3 to 6, wherein the case cover is provided with an elastic body that urges the thermo module in a direction in close contact with the case cover.   The case cover is provided with a fixture for fixing the thermo module to the outer surface of the inverter case via an elastic body provided on the heat radiation surface side of the thermo module, and between the fixture and the side of the thermo module. The electric compressor of Claim 7 which provided the heat insulation layer in at least one part of.   The case cover is provided with a recess protruding toward the inverter case, the thermo module is disposed in the recess, and a heat insulating layer is formed between at least a part of the peripheral wall of the recess and the side of the thermo module. The electric compressor according to any one of claims 3 to 8.   The electric compressor according to any one of claims 1 to 9, wherein the thermo module is positioned above the inverter device.   The electric compressor according to any one of claims 1 to 10, wherein the case cover is provided with ventilation means for communicating the inside and outside of the case cover.   The electric compressor according to claim 11, wherein the ventilation means includes at least an air inlet and an air outlet provided in the case cover and an inner space of the case cover.   The electric compressor according to claim 12, wherein at least one of the air supply port and the exhaust port is provided at a position higher than the thermo module.