JP2008157170A - Motor-driven compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor-driven compressor with a built-in inverter, operable without impairing reliability and performance even at a high temperature and at strong vibration caused by its mounting to an engine surface, by efficiently cooling the inverter without enlarging a machine body vessel. <P>SOLUTION: This motor-driven compressor has a casing body 3 incorporated with a compression mechanism 5 and an electric motor 4 driving the compression mechanism 5, and an inverter case 7 incorporated with the inverter 8 driving the electric motor 4, and uses a suction refrigerant as a main cooling means for cooling a heating part 19 of the inverter 8. Performance and reliability are improved by restraining the promotion of deterioration by the heat of a part and a circuit for constituting the inverter 8 by thermally insulating and cooling a space in the inverter case 7 by a thermo-module 20. <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 113 is incorporated in a body container 112 that houses the electric motor 111, and the electric motor 111 is sandwiched between the compression mechanism 113. The inverter case 115 which accommodated the inverter control apparatus 114 located in the other side is shown and the structure provided with the said airframe container 112 and the airtight state was shown. The airframe container 112 and the inverter case 115 are arranged on the same axis 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 suction 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 inverter control device 114. After the heat exchange with the heat generating part, the air is sucked into the compression mechanism 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, when the compressor is operating at low speed, that is, when the refrigerant circulation amount is small, Alternatively, when the intake refrigerant temperature becomes high due to load fluctuation or the like, sufficient heat exchange cannot be performed, and the heat generating parts 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 the engine, the temperature inside the compressor rises abnormally due to heat from 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 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 quite severe. In the cooling technique disclosed in Patent Document 1, particularly in the case of a compressor mounted on a vehicle, the compressor parts are cooled due to the cooling of the inverter parts. In many cases, the mounting position, directionality, and the like are restricted, and improvement measures such as increasing the degree of freedom in design are required. 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), paying attention to the conventional problems described above.

  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. In the electric compressor, as the cooling means for cooling the inverter control device, the thermo module for transferring the heat of the suction refrigerant to the heat generating portion of the inverter control device and further cooling the internal space of the case cover is provided in the case. It is arranged in the cover. Further, in addition to the above configuration, the case cover is provided with heat insulating means for suppressing the movement of heat inside and outside the case cover.

  As a result, the heat generating part and its peripheral circuit in the inverter control device can be cooled by a combination of cooling using the suction refrigerant temperature and cooling using the heat absorption action by the thermo module. Further, the inside of the case cover is made less susceptible to external heat by the heat insulating 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. Thus, the inverter control device can be cooled, so that the efficiency of the inverter control device during operation of the compressor can be increased, and the acceleration of deterioration of the inverter components due to heat can be suppressed.

  Furthermore, by providing the case cover with heat insulating means, heat transfer inside and outside the case cover can be suppressed, and as a result, the heat absorption action of the thermo module is suppressed from being affected by external heat. The heat absorption and heat dissipation action of the thermo module can be effectively performed. In particular, when the electric compressor is directly mounted on an engine such as a hybrid vehicle, the electric compressor is exposed to a severe environment such as heating and vibration from the engine. Thus, the electric compressor can be operated without impairing the performance and reliability.

The invention according to claim 1 is made of a casing provided with a compression mechanism part for sucking, compressing and discharging refrigerant and an electric motor for driving the compression mechanism part, and made of a heat conductive material, and closes the opening of the casing. An inverter case, an inverter control device that is provided inside the inverter case and drives the electric motor, and a case cover that closes the inverter case, and sucks refrigerant and heat as cooling means for a heat generating part of the inverter control device. In the electric compressor to be replaced, a thermo module having a heat radiating surface and a heat absorbing surface and cooling a space formed by the inverter case and the case cover is provided, and further, the inverter case is interposed between the inner and outer sides of the inverter case. Is provided with heat insulating means for suppressing heat transfer.

  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. In order to cool the inside, even when the circulation amount of the refrigerant is small or when the electric compressor is in a high temperature state after the operation of the electric compressor is stopped, the temperature rise in the case cover is suppressed and the temperature of the inverter control device is suppressed. The rise can be suppressed, and as a result, acceleration of deterioration due to heat of the inverter component can be suppressed.

  Furthermore, the case cover can prevent adverse effects on electrical components due to rainwater, dust, etc., and can ensure long-term reliability. Also, the heat insulation inside and outside the case cover can be suppressed by the heat insulating means provided in the inverter case, and as a result, the heat absorption effect of the thermo module is increased due to the intrusion of external heat. Is suppressed, and the heat absorption and heat dissipation action of the thermo module can be effectively performed.

  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. Therefore, since the heat generating part of the inverter control device exchanges heat with the sucked refrigerant through the wall surface of the inverter case, the inverter control device can be cooled by the heat exchange (cooling action), and the heat of the inverter components Deterioration acceleration 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 radiating surface of the thermo module is in close contact with the inner surface of the case cover so as to allow heat conduction or heat transfer. By adopting such a configuration, the heat absorption action of the thermo module is performed in the space formed by the case cover and the inverter case, and the heat dissipation action can be performed as the heat transfer promoting means of the heat dissipation part. By promoting the heat radiation action by the heat transfer promoting means, the temperature difference between the heat absorbing surface and the heat radiating surface of the thermo module can be reduced, and the cooling efficiency of the thermo module can be increased.

  Furthermore, since the space can be cooled by the endothermic action of the thermo module and the temperature rise in the space can be suppressed, the inverter controller can also be cooled from its surroundings to suppress the temperature rise. In addition, acceleration of deterioration due to heat of the inverter component can be suppressed.

  According to a fourth aspect of the present invention, a portion other than the thermo module on the inner surface of the case cover is covered with a heat insulating material. With this configuration, the inner surface of the case cover is insulated except for the heat absorption part of the thermo module, and as a result, heat exchange with the outside air through the case cover is performed in the space in the case cover. Can be suppressed. As a result, heat exchange loss caused by heat outside the case cover entering through the case cover can be suppressed, and the inside of the case cover can be effectively cooled.

  The invention according to claim 5 is provided with an uneven portion that increases the outer surface area of the case cover on the outer surface of the case cover, and can further increase the heat dissipation capability of the heat dissipation portion in the thermo module, The cooling efficiency of the thermo module can be increased.

  In the invention according to claim 6, the case cover is provided with an elastic body for urging the thermo module in the close contact direction, and the thermo module can be fixed by the urging force of the elastic body. As a result, even if vibrations due to operation of the compressor or the like act on the case cover or the thermo module itself, the vibrations can be absorbed by the elastic force of the elastic body, thereby preventing the thermo module from being broken or damaged. It is something that can be done. 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 a seventh aspect of the present invention, the case cover is provided with a fixture for fixing the thermo module to the inner surface of the case cover via an elastic body provided on the heat absorption surface side of the thermo module, and the fixture And a heat insulating layer is provided at least at a part between the thermo module side portions. With this configuration, the thermo module can be fixed by the fixture and the elastic body and the above-described stress protection can be performed, and the heat insulating layer suppresses leakage of heat from the heat radiating portion of the thermo module from the case cover side to the heat absorbing portion. can do. 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 an eighth aspect of the present invention, a recess is provided on the inner surface of the case cover, the thermo module is disposed in the recess, and heat insulation is provided between at least a part of the peripheral wall of the recess and the side of the thermo module. A layer is formed. By adopting such a configuration, the arrangement in the concave portion can be used for positioning work when the thermo module is mounted, and the distance between the thermo module and the inverter control device can be shortened by making the case cover compact. Thus, the cooling heat of the endothermic surface accompanying the endothermic action of the thermo module can be made to act on the suppression of the temperature rise of the inverter control device.

  Furthermore, the heat insulation layer can prevent heat leakage from the heat radiating part side to the heat absorbing part side in the thermo module. As a result, the heat absorbing action and the heat radiating action in the thermo module are in a normal (rated) state or a state close thereto. It is possible to reduce the inhibition of cooling efficiency maintenance.

  According to a ninth aspect of the present invention, the heat absorption surface of the thermo module is made of a heat conductive material, and heat transfer acceleration means for promoting the heat absorption action of the heat absorption surface is provided in close contact with the heat absorption surface. An elastic body is brought into contact with the means, and the thermo module is attached to the case cover via the elastic body and heat transfer promoting means. By setting it as this structure, the cooling effect | action (endothermic effect | action) in the heat absorption surface of the said thermomodule is stabilized, and the cooling efficiency in the said thermomodule can be improved.

  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 air is promoted, the inverter control device can be efficiently cooled.

  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 the 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. A flow can be formed 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, a case of a horizontal electric compressor installed sideways by a mounting leg 2 around a body portion of the electric compressor 1 is shown as an example. FIG. 2 shows a cross-sectional perspective view of a mounting portion of the inverter control device 8 and the thermo module 20 in the electric compressor 1.

  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 having a plurality of mounting legs 2 at appropriate locations on the outer periphery, and the casing main 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 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 compressed in the compression space 9 as described above, and then from the discharge hole 12 located at the approximate center of the compression space 9. It discharges in the casing main body 3 through the discharge chamber 12a and the channel | path 12b mentioned later, and it discharges to the external cycle (not shown) which connected the heat exchanger etc. from the discharge port 13 provided in the casing main body 3. FIG. 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. In addition, 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 formed on the end wall 7b of the inverter case 7 on the opposite surface of the suction passage 16 (
The printed wiring board (hereinafter referred to as a circuit board) 18 and electronic components such as an electrolytic capacitor (not shown) are arranged on the outside. 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 integrally provided in 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 contact surface of the heat transfer surface member 19 with the end wall 7b is brought into close contact with 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.

  The end wall 7b of the inverter case 7 is in contact with the heat transfer surface member 19 of the inverter 8, and the end wall 7b also serves as heat transfer promoting means (for example, a heat sink) of the inverter 8. Further, the heat transfer promoting means is formed with the thickness of the end wall 7b, and is referred to in order to define the close contact position with the heat transfer surface member 19 in the inverter 8, particularly for increasing the heat capacity. Although the processing such as increasing the thickness is not performed, 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.

  Further, the inverter case 7 and the case cover 22 are joined via a heat insulating material 22a having heat resistance. With this configuration, heat transfer between the inverter case 7 and the case cover 22 is suppressed, and heat on the casing body 3 side is prevented from affecting the case cover 22. As the heat insulating material 22a, a sealing material having any of acrylic resin, fluorine rubber, fluorine resin, etc. as a component, or a material having a sealing function in addition to heat insulating properties such as plastic rubber is preferable. Specific materials can be selected within a well-known range.

  A thermo module 20 is attached to the inner surface of the case cover 22 to cool the internal space 24 formed together with the inverter case 7 by an endothermic effect. 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 of an electric insulator substrate such as a ceramic material (including a substrate mixed with a heat conductive material). A plurality of thermoelectric elements are arranged on the electrodes so that a current flows in series on the electrodes, and heat is generated on one surface and heat is absorbed on the other surface due to the Peltier effect by energization. Is what you do. 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 thermo module 20 is disposed in a recess 34 formed so as to protrude outward from the case cover 22, and its heat dissipation surface is in close contact with the flat surface of the recess 34 (in this embodiment, the bottom surface of the recess 34). It is attached and the endothermic surface faces the internal space 24. A heat sink 25 constituting the heat transfer promoting means of the present invention is provided in close contact with the heat absorbing surface. The heat sink 25 is made of aluminum metal or the like, and fins 25a that increase the surface area are provided on the surface thereof. The thermo module 20 and the heat sink 25 are fixed via an elastic body 27 by a fixture 26 attached to the inner 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 inner 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 to hold the periphery of the heat sink 25. Further, it mainly has a rubber component that has heat resistance and presses the outer periphery of the thermo module 20. An elastic material or the like 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 failure due to vibration impact of an electrode and thermoelectric element 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 for forming a heat insulating layer is provided between the side surfaces of the thermo module 20 and the heat sink 25 and the side walls of the recesses 34 facing these side surfaces. Therefore, the heat insulation space 28 restricts so-called heat conduction short circuit in which heat from the heat radiation surface of the thermo module 20 leaks to the heat absorption surface through the side wall of the recess 34 so that the thermo module 20 is as rated or close to it. Can drive to. The heat insulating layer is not limited to the heat insulating space 28, and may be any material or configuration that regulates direct heat transfer. By providing a heat resistant heat insulating material in the heat insulating space 28, a higher heat leak can be achieved. The regulatory effect can be expected.

  Further, the thermo module 20 is arranged at a higher position than the inverter 8 so that the cooling heat (cooling air) from the thermo module 20 (heat sink 25) is lowered to cool the inverter 8 efficiently. Further, as shown in FIG. 1, the thermomodule 20 and the inverter 8 are partly superposed in the projection direction (the axial direction of the compressor), so that the inverter is generated by the thermal radiation from the thermomodule 20 (heat sink 25). 8 can be cooled.

  In particular, by installing the thermo module 20 in the recess 34, the distance S between the inverter case 7 and the heat sink 25 in the case cover 22 is shortened. As a result, the volume of the internal space 24 is reduced to reduce the cooling load in the thermo module 20, and the heat absorption action (cooling action) of the thermo module 20 is more specialized in the cooling action of the internal space 24 and the inverter 8. Therefore, efficient operation of the electric compressor 1 can be expected. In addition, since the heat absorption surface (heat sink 25) is partially facing the inverter 8, the above-described radiation cooling works efficiently, and the components of the circuit board 18 or the inverter 8 can be efficiently cooled. it can.

  In addition, a large number of radiating fins 29 project from the outer surface of the case cover 22 to increase its surface area. Accordingly, the case cover 22 can function as heat transfer promoting means on the heat radiation surface side of the thermo module 20, which leads to a reduction in the number of parts for forming the heat transfer promoting means, that is, an increase in surface area, and the thermo module 20. The heat dissipating capability on the heat dissipating surface side is ensured, the temperature difference between the heat absorbing surface and the heat dissipating surface of the thermo module 20 is reduced, and the thermo module 20 can be operated with high efficiency.

  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, 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.

  Furthermore, a heat insulating and heat insulating inner cover 35 having heat resistance and heat insulating properties is provided on the inner surface of the case cover 22, and heat radiation from the thermo module 20 and heat from the outside affect the internal space 24 through the case cover 22. It is configured not to. The heat insulating inner surface cover 35 corresponds to the heat insulating means of the present invention, whereby the internal space 24 is cooled by the heat absorbing action of the thermo module 20 in a state where it is less affected by heat from the outside.

More specifically, the heat insulating inner surface cover 35 is formed in an annular shape so as to cover the inner surface of the case cover 22 excluding the thermo module 20, and is attached to the heat absorbing surface of the thermo module 20 through the central through hole so as to be able to conduct heat. The heat sink 25 is exposed. The heat insulating inner surface cover 35 may be any material that has heat resistance and can be processed along the inner surface shape of the inverter case 34, such as a heat insulating material mainly composed of glass fiber.
Further, the heat insulating inner surface cover 35 is provided with a vent hole 36 corresponding to the air inlet 30 and the air outlet 31 provided to prevent heat accumulation in the inner space 24 so that the inside space 24 can be ventilated. is doing.

  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, and the circuit board 18 is provided with a female connection portion 33 a connected to the inverter 8. The inverter 8 and the electric motor 4 are electrically connected via connection portions 33 and 33a. 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. The compression mechanism unit 5 sucks the sucked refrigerant 10 returned from a refrigeration cycle (not shown) having a known configuration through a suction port 11 provided in the inverter case 7. The low-temperature intake refrigerant 10 that has flowed into the casing body 3 cools the end wall 7b in the space of the intake refrigerant passage 16, and further exchanges heat with the heat transfer surface member 19 of the inverter 8 that is in close contact with the end wall 7b. 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 unit 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 12b provided in the outer peripheral part of the compression mechanism part 5 from the discharge chamber 12a, is discharged from the discharge outlet 13 of the casing main body 3 while cooling the electric motor 4, and flows into a refrigerating cycle. .

  As the refrigerant circulates, the end wall 7b of the inverter case 7 is cooled by the suction refrigerant. On the other hand, the inverter 8 generates heat from the heat generating part with continuous rotation control of the electric motor 4, but the temperature of the end wall 7b cooled by the suction refrigerant 10 as described above is transmitted to the heat transfer surface member 19 by heat conduction action. Therefore, the temperature rise is suppressed by cooling the heat transfer surface member 19.

  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 above, so that when the temperature is higher than the temperature outside the case cover 22, the natural air as shown by the arrow in FIG. The air is exhausted from the exhaust port 31 by convection, and then external air flows into the internal space 24 from the intake port 30, and the accumulation of hot air in the internal space 24 is suppressed by these flows.

  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 cooling effect cannot be expected only by the heat exchange action at the end wall 7b, and the inverter 8 is hotter than necessary. It may become. 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 of the case cover 22 is absorbed from the heat absorbing surface via the heat sink 25, and the heat dissipation surface is electrically driven via the case cover 22. An operation of radiating heat to the outside of the compressor 1 is performed. The movement of heat accompanying these operations is performed by heat conduction, and the temperature increase of the internal space 24 of the case cover 22 can be suppressed by the heat absorption action of the thermo module 20.

That is, as is well known, the thermo module 20 can control the heat absorption amount and the heat generation amount by controlling the energization amount (current amount). By controlling the energization amount to the optimum value, the temperature rise of the inverter 8 can be controlled. This can be suppressed by cooling due to the refrigerant temperature sucked through the end wall 7b and the effect of suppressing the temperature rise of the internal space 24 by the thermo module 20. In other words, the cooling by the thermo module 20 of the first embodiment controls the temperature of the environment (internal space 24) where the inverter 8 is installed, and the outside of the electric compressor 1 by the heat insulating inner surface cover 35. The temperature of the internal space 24 can be accurately controlled by suppressing the heat intrusion action from the inside.

  In this cooling, the circuit component of the circuit board 18 constituting the control circuit of the inverter 8 is compared with the configuration in which the heat transfer surface member 19 of the inverter 8 is brought into close contact with the heat absorption surface of the thermo module 20 and directly cooled by heat conduction. It is possible to suppress the acceleration of deterioration of the inverter parts by cooling mainly.

  Further, the case cover 22 protects the thermo module 20, the inverter 8, the circuit board 18, and the like from dust, rainwater, and the like, and the heat radiation surface of the thermo module 20 is attached in close contact with the recess 34 of the case cover 22. As a result, the case cover 22 can be made to function as a means for expanding the heat transfer surface and promoting heat transfer, such as a heat sink on the heat dissipation surface. Thereby, the thermal radiation effect | action of the thermomodule 20 can be accelerated | stimulated, As a result, the temperature difference of the thermal absorption surface of the thermomodule 20 and a thermal radiation surface can be made small, and the thermomodule 20 can be drive | operated with high efficiency. In addition, since the heat insulation inner surface cover 35 makes the inner space 24 less susceptible to external heat, the intrusion of external heat from the case cover 22 can be suppressed, and cooling due to the endothermic action of the thermo module 20 by the intrusion heat. The increase in temperature of the internal space 24 can be efficiently suppressed without hindering the action. As a result, the inverter 8 can be efficiently cooled, and acceleration of deterioration due to heat of the inverter components can be suppressed.

  In particular, the case cover 22 is provided with a plurality of heat dissipating fins 29 on the outer surface thereof to improve the heat dissipating ability, so that the heat conversion efficiency operation of the thermo module 20 can be enhanced and stabilized. Furthermore, it is possible to reduce the number of parts that form an enlarged heat transfer surface such as a heat sink on the heat radiating surface, and even if a separate component is provided, the size can be reduced. Further, since the thermo module 20 is superposed on the projection surface with the inverter 8, radiation cooling from the heat sink 25 also acts on the inverter 8 and can effectively cool the inverter 8.

  In particular, by mounting in the recess 34 formed in the case cover 22, the distance S between the thermo module 20 and the inverter 8 can be shortened, and the volume of the internal space 24 can be reduced, which is cooled by the endothermic action of the thermo module 20. In addition to reducing the load, the above-described radiation cooling is more strongly applied to the inverter 8, and the cooling effect (suppression of temperature rise) 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. An improvement in ventilation efficiency can be expected, and the cool air from the thermo module 20 or the heat sink 25 descends and cools so as to wrap around the inverter 8, so that a further cooling effect can be expected. Furthermore, the escape of the cold air can be expected to be suppressed by providing the intake port 30 at the intermediate position instead of the lowermost part.

  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 kept in close contact with the case cover 22 following the subtle thermal expansion and contraction. The module 20 can continuously perform heat dissipation and heat absorption, and can stably cool the internal space 24 of the case cover 22. In particular, the fixing of the thermo module 20 by the urging force of the elastic body 27 is effective not only for impacts such as thermal stress but also for vibrations caused by operation of the compressor, etc. Therefore, the electric compressor 1 is mounted on the vehicle. Even in such a case, the present invention can be applied, and it is possible to prevent a failure or breakage in which the thermomodule 20 falls off due to vibration or the electrode and the thermoelectric element are separated.

  In addition, a heat insulating space 28 is provided between the periphery of the side surface of the thermo module 20 and the recess 34 so that heat from the heat radiating surface of the thermo module 20 does not leak directly to the heat absorbing surface. The thermo module 20 can be operated in a normal (as rated) or near operating state, and the inhibition of cooling efficiency can be reduced. In this case, if the elastic body 27 is also formed of a known material having heat resistance and heat insulation properties such as heat resistant rubber, heat leakage can be further restricted, and the operation efficiency (cooling efficiency) of the thermo module 20 can be further increased. It can be expected.

  The heat insulating space 28 can be used as a positioning jig insertion space when the thermo module 20 is disposed in the recess 34. Furthermore, the heat insulating layer is not limited to the heat insulating space 28, and may be any material or configuration that regulates direct heat transfer. By providing a heat resistant heat insulating material in the heat insulating space 28, a higher heat insulating effect can be achieved. Can be expected. In this case, the side surface of the thermo module 20 is surrounded by a heat insulating material, and a space for a jig for sandwiching the thermo module 20 through the heat insulating material is provided in a part of the thermo module 20 so that the heat insulating material also serves as a spacer. The module 20 can also be positioned in the recess 34.

  Thus, formation of the heat insulation space 28 can be used for the positioning operation of the thermo module 20, and improvement in workability can be expected. The module control board 20b, which is a 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 of the electric motor 4 necessary for the control and the energizing signal are supplied. A power source or the like is shared with the circuit board 18. Therefore, the circuit configuration can be simplified.

  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 used for a vehicle, the mounting position and directionality of the compressor are restricted due to the cooling of the inverter components. Therefore, the degree of freedom of design is increased and 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 having a configuration in which the inverter 8 is cooled using the temperature of the suction refrigerant 10, or The present invention can be similarly applied to a vertically installed compressor that does not have a cooling configuration using the suction refrigerant temperature. In these cases, the thermo module 20 is attached (for example, the depth of the recess 34 or the recess). Various modifications can be made in details such as the shape and structure of the case cover 22, etc., but such a 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 for storing the inverter control device as compared with the conventional electric compressor with a built-in inverter control device. Assembling workability of the cooling means is easy, and it can be applied not only to a refrigeration and air conditioning system for a living room, but also to an environmental vehicle such as a hybrid vehicle, and further to a general vehicle. It can be applied to a wide range.

The front view which notched some electric compressors in Embodiment 1 of this invention Sectional perspective view of the inverter control device of the electric compressor and the mounting portion of the thermo module in the first 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 Inverter case 7b End part wall 8 Inverter (inverter control apparatus)
16 Suction passage 18 Circuit board 19 Heat transfer surface member 20 Thermo module 22 Case cover 24 Internal space 25 Heat sink (heat transfer promoting means)
25a Radiating fin 26 Fixing tool 27 Elastic body 28 Heat insulation space (heat insulation layer)
29 Radiation fins 30 Intake port 31 Exhaust port 34 Recessed part 35 Heat insulation inner surface cover

Claims (13)

A casing provided with a compression mechanism section for sucking, compressing and discharging refrigerant, and an electric motor for driving the compression mechanism section; an inverter case made of a heat conductive material and closing an opening of the casing; and an interior of the inverter case An electric compressor provided with an inverter control device for driving the electric motor, and a case cover for closing the inverter case, wherein heat is exchanged with the suction refrigerant as a cooling means for a heat generating portion of the inverter control device. A heat-dissipating surface and a heat-absorbing surface, provided with a thermo module for cooling a space formed by the inverter case and the case cover, and further provided with heat insulating means for suppressing heat transfer inside and outside the inverter case. Electric compressor provided. 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. 3. The electric compressor according to claim 1, wherein the case cover is formed of a heat conductive material, and a heat radiating surface of the thermo module is in close contact with the inner surface of the case cover so as to be capable of heat conduction or heat transfer. The electric compressor according to claim 3, wherein a portion other than the thermo module on the inner surface of the case cover is covered with a heat insulating material. The electric compressor according to any one of claims 1 to 4, wherein an uneven portion that increases an outer surface area of the case cover is provided on an outer surface of the case cover. The electric compressor according to any one of claims 3 to 5, wherein the case cover is provided with an elastic body that urges the thermo module in a close contact direction. The case cover is provided with a fixing member for fixing the thermo module to the inner surface of the case cover via an elastic body provided on the heat absorption surface side of the thermo module, and between the fixing device and the thermo module side portion. The electric compressor of Claim 6 which provided the heat insulation layer in at least one part. A recess is provided on an inner surface of the case cover, 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 as described in any one of. The heat absorption surface of the thermo module is formed of a heat conductive material, and is provided in close contact with heat transfer promotion means for promoting the heat absorption action of the heat absorption surface, and an elastic body is in contact with the heat transfer promotion means, The electric compressor according to any one of claims 6 to 8, wherein the thermo module is attached to the case cover via an elastic body and heat transfer promoting means. 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.