JP5114350B2 - Inverter device - Google Patents

Description

  The present invention relates to an inverter device that converts AC power from a power source into AC power having an arbitrary frequency and voltage and supplies electricity to a motor or the like.

  FIG. 16 is a typical electric circuit configuration diagram of the inverter device. An AC voltage is applied to the electric circuit from a power source or the like via the terminal portion 16a of the terminal block 16. The applied AC voltage is rectified by the forward converter 51 and smoothed by the smoothing capacitor 12.

  Since the current that rushes into the smoothing capacitor 12 when the inverter device is started up is large, the rush current suppression circuit 14b including the current reducing resistor 14 and the relay 14a is provided, and the rush current is suppressed when the rush current is large. Suppressed by circuit 14b.

  The smoothed voltage across the smoothing capacitor 12 is converted into an AC voltage having a desired frequency by the inverse converter 52 and output through the terminal 16 b of the terminal block 16. The IGBT or the like constituting the inverse converter 52 is controlled to a desired operation state based on a command from the control circuit 53 and is driven by the driver circuit 54. A switching regulator circuit (DC / DC converter) is mounted in the driver circuit 54, and a DC voltage is generated and supplied to each component.

  The terminal block 16 is provided side by side with the current input terminal portion and the output terminal portion insulated from each other.

  FIGS. 17 and 18 are a typical conventional plan configuration diagram and a cross-sectional configuration schematic diagram of an inverter device, respectively. In FIG. 17 and FIG. 18, the main circuit board 11, the power circuit board 56, the control circuit board 57, and the power module 55 are accommodated in the housing case 20.

  On the component mounting surface (front surface) of the main circuit board 11, a lower smoothing capacitor 12A, an upper smoothing capacitor 12B, a step-up transformer 13, a current reducing resistor 14, a terminal block 16, and the like are arranged as shown in the figure.

  The housing case 20 is provided with an upper opening 22 on the upper surface, a lower opening 21 on the lower surface, and a side opening 23 on the side if necessary. Cooling air flows into the main circuit board 11 from the lower opening 21 and the side opening 23, and the air heated by the heat generated by the heat generating components on the main circuit board 11 is discharged from the upper opening 22.

  The main circuit board 11 is electrically connected to the power module 55 through a module connection portion 15 provided on the side of the main circuit board 11 and extending to the back surface side. The power module 55 is connected to the cooling fin 24. The heat generated from the power module 55 is transmitted to the cooling fins 24 by heat conduction, and is radiated by exchanging heat with the air around the cooling fins.

  In the structure described in Patent Document 1, even if the layout of a component is determined in consideration of electrical characteristics, the temperature rise of an electrical component sensitive to high temperature is actively managed to some extent by attaching a convection prevention plate. be able to.

JP 2008-92632 A

  In recent years, the miniaturization of components and the improvement of surface mounting technology have enabled the high-density mounting of components, and the miniaturization of inverter devices has progressed. On the other hand, in motors and industrial equipment to which the inverter device is applied, it is necessary to ensure its operation appropriately and to keep the output voltage of the inverter device high. For this reason, high power components such as the smoothing capacitor 12, the current reducing resistor 14, and the step-up transformer 13 used for smoothing the voltage flowing through the electric circuit of the inverter device have a required specification such as electric capacity and the like in order to ensure reliability. Since it is necessary to be satisfied, it cannot necessarily be downsized. Therefore, not only does the heat generation density increase due to the higher density of surface mount components, but the presence of large, high-power components used to maintain good electrical characteristics of the inverter hinders the flow of cooling air inside the housing. However, there is a problem that the reliability of the component is lowered due to an increase in the component temperature. In particular, the smoothing capacitor 12 generally has a lower component temperature upper limit that can ensure reliability than other components.

  Furthermore, since a higher voltage and a larger current flow through the components such as the smoothing capacitor 12, the current reducing resistor 14, and the step-up transformer 13 than the weak electric components used for control or the like, the wiring pattern on the board on which these components are arranged. Becomes thicker. Therefore, it is necessary to arrange them in consideration of electrical characteristics such as reduction of electrical loss of wiring patterns, reduction of unnecessary electromagnetic radiation, and securing of wiring patterns of other mounted components on the main circuit board 11.

  However, in the technique described in Patent Document 1, when the convection prevention plate is provided and the convection path is managed, the ventilation path is limited as a result, so that the amount of cooling air flowing inside decreases. Therefore, even if the temperature rise is partially suppressed, there is a problem that the overall cooling performance is not improved. Especially when heat is dissipated by air flow by natural convection without using a fan, the air flow pressure generated by buoyancy is very small, so the amount of cooling air is greatly reduced by managing the air flow path, There is a problem that heat dissipation becomes difficult.

  As mentioned above, in recent years, inverters have been downsized due to the increased density of surface-mounted components, not only increasing the heat generation density, but also due to the presence of large high-power components to keep the electrical characteristics of the inverter good, The flow of cooling air inside the housing is obstructed.

  In particular, an air-cooled inverter device using natural convection that does not use a fan has a problem in that the air volume of cooling air is small, and the reliability of the components decreases due to an increase in the component temperature.

  Further, high power components such as a smoothing capacitor and a current reducing resistor need to be arranged in consideration of electrical characteristics, and it is difficult to achieve both air flow and natural component cooling by natural convection.

  The objective of this invention is providing the inverter apparatus which solved the said problem.

  To achieve the above object, an inverter device of the present invention includes a circuit board on which electronic components are mounted, a terminal block electrically connected to the circuit board, the circuit board and the terminal block, and at least an upper surface. An inverter device having openings provided on a plurality of surfaces including a lower surface, wherein the circuit board is provided along a flow of air from the opening on the lower surface toward the opening on the upper surface, A plurality of smoothing capacitors adjacent to the step-up transformer and the current reducing resistor are mounted, and the upper side smoothing capacitor near the upper surface is closer to the side wall of the housing than the lower side smoothing capacitor near the lower surface. It is a feature.

  In addition to the above configuration, the plurality of smoothing capacitors may be provided on either one of the left and right sides of the circuit board for the step-up transformer and the current reducing resistor.

  Similarly, the interval between the lower-side smoothing capacitor and the adjacent step-up transformer or the current reducing resistor may be wider than the interval between the upper-side smoothing capacitor and the adjacent step-up transformer or the current reducing resistor. Good.

  Similarly, the circuit board has one or a plurality of module connection portions that are electronically connected to electronic components provided on another circuit board, and at least one of the module connection portions includes the lower smoothing capacitor. And the side wall of the housing.

  Similarly, the terminal block is provided on the lower surface side of the casing, and has a through-hole or a through-hole that opens toward a gap between the lower-side smoothing capacitor and the current reducing resistor or the step-up transformer. May be.

  Similarly, in the smoothing capacitor, step-up transformer, and current-reducing resistor, the height of the component mounted on the circuit board in the minimum height internal space that matches the electronic component having the minimum height from the circuit board. When the space occupancy rate of the electronic components mounted on the circuit board defined by the integral value integrated in the vertical direction of the casing is viewed from the distribution between the side walls of the casing, a recess is formed near the center. You may make it have the substantially two-prong shape which has.

  According to the present invention, even if a capacitor having a large electric capacity and a large size is used, the electric reliability is not impaired, and the reliability of the inverter device can be improved.

  An embodiment of the inverter device of the present invention will be described with reference to FIGS. FIG. 1 is a schematic view of an inverter device according to the present embodiment, and is an exploded perspective view of main components. 2 is a schematic plan view of the embodiment, FIG. 3 is a schematic cross-sectional view of the embodiment, and FIG. 4 is a view as seen from the lower surface side of the inverter device of the embodiment. In these drawings, the same members are denoted by the same reference numerals and description thereof is omitted.

  In FIG. 1, the housing case 20 has a lower opening 21 on the lower side so that the terminal block 16 provided on the main circuit board 11 can be faced. The lower opening is provided with a lid provided with a slit for separating the outside from the inside of the apparatus. If the operation panel 26 side is defined as the front surface and the cooling fin 24 side is defined as the back surface, the front side of the terminal block 16 will be described later. In addition, a housing case protrusion 20B is provided that separates the electronic component mounting portion from the outside with a gap.

  A side opening 23 is provided on the side of the housing case 20, and the side opening 23 serves as an inlet for cooling air to flow into the inside from the side of the housing case 20. The side opening 23 is also provided on the side of the housing case 20 on the opposite side. As will be described later, an upper opening 22 is provided in the upper part of the housing case 20.

  An operation panel 26 is provided on the front surface of the casing case 20. In the illustrated inverter device, one side is held by a hinge so that the inside of the casing case 20 is opened. Unlike the structure of FIG. 1, the operation panel 26 may be fixed to the housing case 20 by fitting.

  The housing case 20 has a plurality of circuit boards, and the main circuit board 11 is shown as a representative in FIG. The main circuit board 11 is provided with a terminal block 16 below the inverter device, and the air flow of natural convection enters from around the terminal block 16, that is, from the lower side of the inverter device, passes through the terminal block 16, and the housing case. 20 inside.

  In addition to the terminal block 16, the main circuit board 11 is provided with a smoothing capacitor 12 on one side as a main heat generating component and a current reducing resistor 14 and a step-up transformer 13 on the other side. In this embodiment, the current reducing resistor 14 is provided below the inverter device having the terminal block 16, and the step-up transformer 13 is provided above the inverter device above the housing case 20.

  The main circuit board 11 is attached to a base 40 having a plurality of cooling fins 24. Although the configuration is simply shown in this drawing, the detailed configuration between the main circuit board 11 and the base 40 having the cooling fins 24 will be described later.

  As shown in the plan view of FIG. 2, the inverter device of this embodiment is attached to a control panel or the like. The terminal block 16 is preferably arranged below the main circuit board 11 in order to improve workability such as wiring and screw tightening at the time of wiring.

  The current reducing resistor 14 is desirably arranged in the vicinity of the terminal block 16 in order to shorten the wiring length on the main circuit board 11 with the terminal block 16. The smoothing capacitor 12 is also preferably disposed in the vicinity of the terminal block 16 in order to shorten the wiring length with the terminal block 16. When a plurality of smoothing capacitors are installed to satisfy the required electric capacity, it is desirable to arrange them close to each other in order to shorten the wiring length between the smoothing capacitors 12.

  This is because a high voltage and a large current flow through the smoothing capacitor 12 and the current reducing resistor 14, but by reducing the wiring length of those components, it is possible to reduce the electrical loss of the wiring pattern and unnecessary electromagnetic radiation. Can do. Furthermore, since a large current flows through the smoothing capacitor 12 and the current reducing resistor 14, the wiring patterns for these components become thick. However, the wiring patterns are shortened by placing them close to each other, and other mountings on the board are possible. It is easy to secure the wiring pattern of the parts.

  That is, in order to improve such electrical characteristics, a layout in which the plurality of smoothing capacitors 12 and the current reducing resistors 14 are provided near the terminal block 16 is desirable. Although the current reducing resistor 14 is not shown in FIG. 2 and forms the inrush current suppression circuit 14b in combination with the relay 14a, the relay 14a is provided near the current reducing resistor 14 and the terminal block 16. It is desirable to have space.

  In FIG. 3, the cross section of the inverter apparatus in a present Example is shown. A casing fin 20 is attached, a cooling fin 24 that also serves as an attachment to a switchboard or the like is provided on the back side of the inverter device, and an operation panel 26 provided with a switch (not shown) for operating the inverter device is provided on the front side. Is provided.

  In the inverter device, a control circuit board 57, a main circuit board 11, and a power supply circuit board 56 including a back side control circuit board 57 a and a front side control circuit board 57 b are laminated in order from the front side. Although not shown, a plurality of electronic components are also mounted on the surfaces of the control circuit board 57 and the power supply circuit board 56.

  On the surface of the base 40 on which the cooling fins 24 are provided, a power module 55 having a large calorific value is bonded so as to be able to conduct heat with the cooling fins. The power module 55 is electrically connected to the main circuit board 11 through the module connecting portion 15, and the converted current is input / output via the module connecting portion 15. Note that the base 40 and the cooling fins 24 are integrally formed by die-casting, so that heat conduction and manufacturing are efficient.

  Relatively large components are mounted on the surface of the main circuit board 11, and these components are arranged on the surface of the main circuit board 11 as shown in FIGS. Further, as shown in FIGS. 3 and 4, a housing case is provided on the front side of the terminal block 16 in order to prevent foreign matter such as a driver from coming into contact with the main circuit board 11 or the back side control circuit board 57a and causing a failure. A protruding portion 20B is provided.

  2 and 3, the upper opening 22 and the lower opening 21 provided in the casing case 20 of the inverter device in this embodiment pass through the vicinity of the surface of the main circuit board 11 from the lower side of the inverter device. Convection of air flowing upwards of the device occurs. That is, in the inverter device according to the present embodiment, the lower surface side where the lower opening 21 is provided is attached in a substantially gravity direction. And by the natural convection of the air heated by the heat-generating component inside the housing case 20, air convection from the lower surface side to the upper surface side of the housing case 20 occurs. Then, the warmed air is discharged from the upper opening 22.

  In the inverter device in this embodiment, the heat generating components are cooled by this natural convection, and the temperature rise is suppressed. At this time, it is desirable that the upper opening 22 and the lower opening 21 be as large as possible.

  As shown in FIG. 4, a gap 21 </ b> A is provided at a lower portion of the housing case 20 between the terminal block 16 disposed below the inverter device and the housing case protrusion 20 </ b> B. Air flowing in from the lower opening 21 flows onto the main circuit board 11. At this time, it is desirable that a slit-like opening 21B is provided in the housing case protrusion 20B. Thereby, it is possible to allow air to flow into the main circuit board 11 through the opening 21B while preventing foreign matter from entering the housing case protrusion 20B. The lid that separates the inside and the outside of the housing case 20 may be removable.

  Next, returning to FIG. 2, the air flow and the temperature rise of the circuit elements in the inverter device of this embodiment will be described in detail. In this description, the general gravity direction in FIG. 2 is defined as the downward direction, the vertical direction is defined as the vertical direction, and the direction orthogonal to the vertical direction is defined as the horizontal direction.

  When the smoothing capacitors 12 are arranged in the vertical direction as in the inverter device of the present embodiment, the smoothing capacitor 12B arranged on the upper side close to the upper opening 22 is downstream of the convection in the housing case 20, The temperature of the air flowing around the smoothing capacitor 12B is higher than the temperature of the air flowing around the smoothing capacitor 12A arranged on the lower side near the lower opening 21. As a result, the temperature rise of the smoothing capacitor 12B tends to increase.

  Therefore, in this embodiment, as shown in FIG. 2, the smoothing capacitor 12B disposed on the upper side of the main circuit board 11 is provided at a position closer to the side wall side of the housing case 20 than the smoothing capacitor 12A disposed on the lower side. It was.

  As a result, a wider upper central gap 35 can be secured beside the smoothing capacitor 12B. Then, the air that flows into the main circuit board 11 from the lower opening 21 flows more effectively into the space beside the smoothing capacitor 12 </ b> B indicated by the upper central gap 35 and passes through the upper central gap 35. The air volume can be increased.

  Therefore, by providing the smoothing capacitor 12B closer to the side wall of the housing case 20 than the smoothing capacitor 12A, it was possible to effectively suppress the temperature rise of the smoothing capacitor 12B that tends to become high temperature.

  In FIG. 2, the air flowing in from the lower opening 21 flows on both sides of the smoothing capacitor 12B. If the upper center side gap 35 from the center of the smoothing capacitor 12B is increased, The space becomes relatively small, and the amount of air flowing through this portion decreases. However, the side wall side of the housing case 20 is the outer peripheral side of the main circuit board 11 and no other heat generating component having a large size is arranged, but the central side of the inverter device indicated by the upper central side gap 35 is In the example, it is adjacent to a heat generating component such as the step-up transformer 13. As described above, the upper central gap 35 surrounded by the plurality of heat generating components has a higher ambient temperature due to heat transfer from the surroundings.

  Therefore, by enlarging the upper center side gap 35, it is possible to increase the air volume of the air flowing in the higher temperature region, and it is possible to comprehensively suppress the temperature rise of the smoothing capacitor 12B.

  The operation of the upper central gap 35 will be described with reference to FIG. As described above, enlarging the smoothing capacitor 12B and the upper central gap 35 means reducing the distance between the smoothing capacitor 12B and the side wall of the housing case 20 (upper side wall gap 37). This upper side wall-side gap 37 was examined with reference to a lower side wall-side gap 38 that is a gap between the smoothing capacitor 12 </ b> A and the side wall of the housing case 20.

  FIG. 5 shows an example of the relationship between the size of the upper sidewall gap 37 relative to the lower sidewall gap 38 and the temperature rise of the smoothing capacitor 12B. Here, the temperature rise of the smoothing capacitor 12B is a ratio to the temperature rise value of the smoothing capacitor 12B when the sizes of the upper side wall gap 37 and the lower side wall gap 38 are the same.

  This is an analysis result when the simulation of the inverter device shown in FIG. 2 and FIG. 3 is performed, the size of the upper side wall gap 37 is changed, and the temperature rise of the smoothing capacitor 12B is calculated.

  In FIG. 5, the ratio of the size of the upper side wall gap 37 to the lower side wall gap 38 and the ratio of the temperature rise of the smoothing capacitor 12 </ b> B are approximately proportional to each other, and the size of the upper side wall gap 37 with respect to the size of the lower side wall gap 38. When the ratio is about 90% or more, the temperature increase suppression ratio is less than 1%.

  That is, if the difference between the position of the smoothing capacitor 12A and the smoothing capacitor 12B relative to the side wall of the housing case 20 is only an error, the effect of suppressing the temperature rise of the smoothing capacitor 12B is small, and the smoothing capacitor 12B is consciously used in the housing case. By disposing at a position close to the side wall of 20, it is possible to clearly suppress the temperature rise of the smoothing capacitor 12B.

  Returning to FIG. 2 again, the inverter device in this embodiment will be further described. In the inverter device of this embodiment, a plurality of smoothing capacitors 12 are arranged together on either the left or right side.

  When a plurality of smoothing capacitors 12 are provided on the main circuit board 11, it is necessary to connect the respective smoothing capacitors 12 with wiring. As described above, since a high voltage and a large current generally flow through the smoothing capacitor, the wiring pattern connected to the smoothing capacitor 12 also becomes thick. Therefore, by arranging the plurality of smoothing capacitors 12 on either the left or right side, the distance between the smoothing capacitors 12 is shortened, and the wiring patterns connecting them are shortened. It is possible to reduce electromagnetic radiation. Further, since the wiring pattern connected to the smoothing capacitor 12 is shortened, it is possible to secure the wiring pattern for other mounted components on the main circuit board 11.

  Further, as in the configuration of the present embodiment, the interval between the lower smoothing capacitor 12A and the adjacent step-up transformer 13 or the current reducing resistor 14 is set so that the step-up transformer 13 or the current reducing resistor 14 adjacent to the upper smoothing capacitor 12B. It is better to make it wider than the interval.

  In FIG. 2, the current reducing resistor 14 is disposed below the step-up transformer 13 adjacent to the smoothing capacitor 12. The space (lower center gap 36) between the current reducing resistor 14 and the smoothing capacitor 12A corresponding to the upstream path of the air convection flowing inside the inverter device corresponds to the downstream path of the air convection flowing inside the inverter device. By making it larger than the space (upper center side gap 35) between the step-up transformer 13 and the smoothing capacitor 12B, the resistance to the air flow on the upstream side of the air convection is reduced, and the lower center side gap 36 and the downstream gap are reduced. It becomes possible to increase the air volume of air at 35.

  If the lower central gap 36 is smaller than the upper central gap 35, the lower central gap 36 suppresses the flow of air that should originally go to the upper central gap 35.

  Therefore, by making the lower center side gap 36 larger than the upper center side gap 35, the flow toward the upper center side gap 35 is not obstructed, and as a result, the effect of increasing the upper center side gap 35 is maximized. You can save it. Thereby, it becomes possible to suppress the temperature rise of heat-generating electrical components sensitive to high temperatures such as the smoothing capacitor 12B.

  At this time, the current reducing resistor 14 is desirably arranged in a direction in which the lateral length W is shorter than the longitudinal length H. Thereby, the lower center side gap 36 can be made larger.

  Next, an embodiment of the present invention will be further described with reference to FIGS. At least one of the one or a plurality of module connection portions 15 included in the main circuit board 11 is disposed between the lower smoothing capacitor 12 </ b> A and the side wall of the housing case 20.

  As shown in FIG. 3, the power module 55 and the main circuit board 11 are electrically connected by the module connection portion 15. A current for power conversion is input / output to / from the terminal block 16, the power module 55, and the smoothing capacitor 12 via the module connection unit 15. Therefore, a high voltage and a large current flow through the module connecting portion 15, and the wiring to be connected becomes thick. Therefore, in order to improve electrical characteristics such as reduction of electric loss of the inverter device and reduction of electromagnetic radiation, the module connection portion 15 is provided in the vicinity of the terminal block 16 and the smoothing capacitor 12, and the wiring pattern is connected to the module connection portion 15. It is desirable to shorten the length.

  Further, as shown in FIG. 2, the module connection portion 15 is disposed between the smoothing capacitor 12 </ b> A provided below and the inner wall (side wall) of the housing case 20, so that the housing beside the smoothing capacitor 12 </ b> B provided above. It becomes easy to provide a space on the inner wall (side wall) side of the case 20. Thereby, the upper side smoothing capacitor 12B can be brought closer to the side wall side of the housing case 20, and the space beside the smoothing capacitor 12B disposed on the upper side in the upper center side gap 35 can be increased. As a result, the amount of air flowing from the lower opening 21 and passing through the upper center side gap 35 can be increased, the rise in the air temperature is suppressed, and the heat generating electrical components sensitive to high temperatures such as the smoothing capacitor 12B. Temperature rise can be suppressed.

  Further, the inverter device of this embodiment will be described with reference to FIGS. A side opening 23 is provided on the side surface of the housing case 20, and the size of the side opening 23 adjacent to the smoothing capacitor 12 is set to a size matching the plurality of smoothing capacitors 12.

  As shown in FIGS. 2 and 3, by providing the side opening 23 on the side surface of the housing case 20, in addition to the cooling air flowing through the upper center side gap 35, the cooling air from the side surface is allowed to flow and is smoothed. It is possible to suppress the temperature rise of the heat generating electrical components such as the capacitor 12.

  However, the approximate total amount of air flowing into the housing case 20 is determined by the size of the upper opening that is the outlet. When the side opening 23 is provided without considering anything, the amount of air flowing in from the lower opening 21 decreases as the inflow of air from the side opening increases.

  Therefore, by reducing the size of the side opening 23 in accordance with the size of the smoothing capacitor 12 for which the temperature rise is to be consciously suppressed, the side opening 23 is suppressed while suppressing the decrease in the amount of airflow flowing from the lower opening 21. Therefore, the cooling air can be rushed into the smoothing capacitor 12 intensively, and the temperature rise of the smoothing capacitor 12 can be suppressed.

  Further, the side opening 23 is also a path through which foreign matter such as dust that causes a failure of the inverter device enters the housing case.

  Regarding the side opening 23, it is desirable that the ratio As / At of the area As of the side opening 23 to the area At of the upper opening 22 is 0.25 or more. Here, it is assumed that the opening area is the sum of the area of the opening area obtained by dividing the aggregate area of the opening holes 23b with a square as shown in FIG.

  FIG. 7 is used to show the relationship between the ratio As / At between the side surface opening area As and the upper opening area At and the temperature rise of the smoothing capacitor 12B. Numerical simulation of the inverter device as shown in FIG. 2 was performed, and the temperature rise of the smoothing capacitor 12B with respect to the ratio As / At of the side opening area As and the upper opening area At was calculated and graphed, as shown in FIG. . Here, the ratio of the temperature rise value in each condition when the temperature rise value when there is no side opening 23 is 100 is shown as the temperature rise. In addition, a temperature rise when the side opening 23 is the entire opening is indicated by a dotted line.

  As shown in FIG. 7, the ratio As / At of the side surface opening area As and the top surface opening area At is set to 0.25 or more, so that the cooling air from both the central portion of the main circuit board 11 and the side surface The temperature rise of the heat-generating component can be suppressed as compared with the case where the side surface opening 23 is the entire surface opening.

  The side opening 23 may be provided on either the left or right side or both sides of the housing case 20 according to the amount of heat generated by the component, and the side opening 23 may be provided separately on one side. Needless to say.

  Furthermore, on the side surface of the housing case 20 opposite to the smoothing capacitor 12, it is needless to say that the size of the side opening 23 is preferably matched to the size of adjacent components such as the step-up transformer 13 and the current reducing resistor 14. Yes.

  An example of the effect in the present embodiment will be described with reference to FIGS. FIG. 9 shows one of the results of simulation analysis of the inverter device shown in FIGS. The temperature distribution on the horizontal line AA ′ passing through the center of the smoothing capacitor 12B shown in FIG. 8 was calculated from the simulation results for the cross section at the half height position of the step-up transformer 13 and shown in the graph of FIG.

  The air flow contributing to the cooling of the smoothing capacitor 12B is a flow in a space surrounded by the main circuit board 11, the smoothing capacitor 12B, and the step-up transformer 13 disposed on the side thereof, and represents an average flow in the space. Therefore, the cross section at the height position was selected.

  In FIG. 9, the graph named condition 1 is the result of simulation analysis of the inverter to which this embodiment is applied, and the graph named condition 2 is simulation analysis of the inverter device to which this embodiment is not applied. It is a result. The graph named condition 1 shows a small value near the center, and the present invention can confirm the effect that the temperature rise value in the housing case 20 is reduced.

  Other parts of the present embodiment that have not been described so far will be described with reference to FIGS. 2, 10, and 11. FIG. 10 is a perspective view of the terminal block 16. FIG. 11 is a plan view showing the flow of internal convection in FIG.

  As shown in FIG. 10, the terminal block penetrating portion 25 is provided in the terminal block 16 that fixes the electric wire with the screw 17. The terminal block penetrating portion 25 opens toward the gap between the lower smoothing capacitor 12A and the current reducing resistor 14 adjacent to the lower smoothing capacitor 12A.

  In FIG. 3, the air that cools the smoothing capacitor 12 and the like flows from the lower opening 21, but since the terminal block 16 is provided below the inverter device, the air from the lower opening 21 near the surface of the main circuit board 11. The air flow is blocked by the terminal block 16.

  Therefore, the terminal block 16 has a terminal block penetrating portion 25 at a position that opens toward the gap between the lower smoothing capacitor 12A and the current reducing resistor 14 adjacent to the lower smoothing capacitor 12A. As shown, a convection path penetrating the terminal block 16 is provided, and the air volume of the air flowing into the upper center side gap 35 is increased. As a result, an increase in the air temperature in the upper central gap 35 can be suppressed, and an increase in the temperature of heat generating electrical components sensitive to high temperatures such as the smoothing capacitor 12 in the surroundings can be suppressed.

  When the terminal block penetrating portion 25 is provided in the terminal block 16 at a position that opens toward the gap between the smoothing capacitor 12A and the current reducing resistor 14 adjacent thereto, the lateral length of the terminal block 16 increases. In some cases, the air volume on the side wall of the housing case 20 is reduced. However, since the cooling effect on the heat generating component by increasing the air volume of the upper central gap 35 where the heat generating components are dense is greater, it is possible to comprehensively suppress the temperature rise of the heat generating component such as the smoothing capacitor 12. It becomes.

  Further, as shown in FIG. 12, in order to increase the air volume of the air flowing into the upper center side gap 35, a spacer 41 for fixing and supporting the smoothing capacitor is provided on the contact surface between the smoothing capacitor 12 and the main circuit board 11, and the air You may provide the space which passes.

  As shown in FIG. 12, a space is provided between the smoothing capacitor 12 and the main circuit board 11 while the smoothing capacitor 12 is supported and fixed by the spacer 41, so that the upper center side in the vicinity of the surface of the main circuit board 11 is provided. A convection path for air penetrating toward the gap 35 is provided, and the air volume of the air flowing into the upper central gap 35 can be increased.

  That is, the smoothing capacitors 12A and 12B are usually mounted so that the bottom surfaces thereof are substantially in contact with the main circuit board 11, but a spacer 41 is provided so that a space is provided between the smoothing capacitors 12A and 12B and the main circuit board 11. By providing this, there is the same heat dissipation promoting effect as increasing the size of the lower central gap 36 and the upper central gap 35.

  Needless to say, the terminal block penetrating portion 25 is not limited to the shape or size of the terminal block penetrating portion 25 such as a rectangle or a circle as long as the terminal block penetrating portion 25 penetrates the terminal block 16 and serves as an air passage path.

  Next, an inverter device according to an embodiment of the present invention will be described with reference to FIGS. In a predetermined space on the main circuit board 11, a space occupancy ratio of components defined by an integrated value in the vertical direction of the component height mounted on the main circuit board 11 is defined as a space factor. As shown in FIG. 14, up to the minimum height of any one of the smoothing capacitor 12, the step-up transformer 13, and the current reducing resistor 14 on the mounting surface of the main circuit board 11 above the terminal block 16 The space defined as the thickness of the space was defined as the target. This is because the air flowing in contact with the heat generating component near the mounting surface of the main circuit board 11 greatly contributes to the suppression of the temperature rise of the heat generating component.

  FIG. 13 is a graph showing the distribution of the space factor between the side walls of the housing case 20, that is, in the left-right direction of the main circuit board 11. In the occupation rate calculation method, first, the examination space 43 is extracted from the target space as shown in FIG.

  Then, the volume occupied by the board component in the inspection space 43 is calculated, and the ratio of the component occupied volume to the volume of the inspection space 43 is calculated as the occupation ratio at the extraction position of the inspection space 43.

  In the graph shown in FIG. 13, the space factor increases at positions where heat generating components such as the smoothing capacitor 12 are dense, and the space factor decreases at positions where space is available. Therefore, the concave portion including the minimum point of the space factor in the vicinity of the center of the graph in FIG.

  As described above, since the cooling air flows in the area of the upper center side gap 35, the larger the area, the larger the air volume, and the temperature rise of the dense smoothing capacitor 12 and the like is suppressed. That is, the concave portion in the vicinity of the center of the space factor distribution shape as shown in FIG. 13 indicates the presence of a space through which cooling air flows in the vicinity of the upper central gap 35. That is, by arranging the smoothing capacitor 12, the step-up transformer 13, and the current reducing resistor 14 so that the left-right distribution shape of the space factor defined above becomes a roughly two-pronged shape having a recess near the center portion, The air volume flowing into the upper center side gap 35 can be increased, the smoothing capacitor 12 can be effectively cooled, and the temperature rise can be suppressed.

  Further, in FIG. 13, the area of the concave portion (A) near the center of the space factor distribution shape is a parameter representing the size of the space through which air flows in the upper central gap 35, whereas the left and right concave shapes (B) The size of the area (C) is a parameter representing the size of the region through which air flows on the side wall of the housing case 20 of the main circuit board 11.

  It is desirable that components such as the smoothing capacitor 12 are provided on the surface of the electric circuit 11 so that the area of the concave shape (A) is equal to or larger than the areas of the concave shapes (B) and (C). The amount of air flowing into the upper center side gap 35 can be further increased, and the smoothing capacitor 12 can be effectively cooled to suppress an increase in temperature.

  This is because, as described above, on the main circuit board 11, heat generating components such as the smoothing capacitor 12 are densely gathered, so that the temperature rise is larger in the central portion than on the side wall of the housing case 20. Therefore, it is more effective to suppress the temperature rise when the air is intensively flowed into the central portion of the main circuit board 11, and it is higher than the space on the main circuit board 11 on the side wall of the housing case 20 is increased. Increasing the space of the central gap 35 and concentrating the incoming air is more effective in suppressing the temperature rise.

  In order to achieve the above configuration, in the space factor distribution shape, the area of the concave shape (A) may be made larger than the areas of the concave shapes (B) and (C).

  The inverter apparatus in a present Example is demonstrated using FIG. A plurality of inverter devices 1 are attached by narrowing the space between the inverter devices 1 in the side surface direction.

  FIG. 15 shows a schematic diagram of an installation method in which the inverter device 1 is mounted in a substantially horizontal manner (side-by-side installation). In this side-by-side installation method, in order to reduce the total installation space of the plurality of inverter devices 1, the distance between the inverter devices 1 is set small, and a side opening adjacent to the narrow space is provided. Inflow of the cooling air from 23 becomes difficult.

  Normally, when the side-by-side installation method is adopted and the plurality of inverter devices 1 are installed in close contact with each other in the side surface direction, it becomes difficult for the cooling air to flow from the side opening 23.

  However, according to the present embodiment, it is possible to increase the air volume of the air flowing from the lower opening 21 toward the upper center side gap 35, so that the temperature rise of the heat-generating electrical component such as the smoothing capacitor 12 is efficiently suppressed. It becomes possible to do.

The disassembled perspective view of the inverter apparatus concerning one Example of this invention. The plane schematic diagram of the inverter apparatus in FIG. The cross-sectional schematic diagram of the inverter apparatus in FIG. The figure seen from the lower surface side of the inverter apparatus in FIG. The figure which showed the relationship between the distance of an upper side smoothing capacitor and a housing | casing case side wall, and the temperature rise of an upper side smoothing capacitor. The figure explaining the calculation area | region of the side surface opening part area of the inverter apparatus in FIG. The figure explaining the relationship between the ratio of a side opening part and an upper opening part, and the temperature rise of a smoothing capacitor. The figure which shows the part which simulated the flow of the air which cools the smoothing capacitor 12B. The figure explaining the temperature rise distribution which is a result of the simulation analysis in FIG. The perspective view explaining a terminal block. The figure explaining the path | route of the convection in an inverter apparatus. The figure explaining the spacer attached to the electronic component mounted in the circuit board. The figure explaining the distribution state of a space factor. The figure explaining the definition space of a space factor. The schematic diagram explaining the side-by-side installation state. The circuit block diagram of an inverter apparatus. The plane schematic diagram of the conventional inverter apparatus. The cross-sectional schematic diagram of the conventional inverter apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inverter apparatus 11 Main circuit board 12, 12A, 12B Smoothing capacitor 13 Step-up transformer 14 Current reducing resistor 14a Relay 14b Inrush current suppression circuit 15 Module connection part 16 Terminal block 17 Screw 20 Case 20B Case case protrusion 21 Lower part Opening 22 Upper opening 23 Side opening 24 Cooling fin 25 Terminal block penetration 26 Operation panel 31 Lower inflow air 32 Outflow air 33 Side inflow air 34 Convection path 35 Upper center side clearance 36 Lower center side clearance 37 Upper side wall clearance 38 Space 41 between smoothing capacitor 12A and housing case 20 side wall side Spacer 42 Component space 51 Forward converter 52 Reverse converter 53 Control circuit 54 Driver circuit 55 Power module 56 Power supply circuit board 57a Back side control circuit board 57b Surface Side control circuit board

Claims (6)

A circuit board on which electronic components are mounted, a terminal block electrically connected to the circuit board, the circuit board and the terminal block, and a housing having openings on a plurality of surfaces including at least an upper surface and a lower surface. An inverter device having a body,
The circuit board is provided along a flow of air from the opening on the lower surface to the opening on the upper surface, and includes a plurality of smoothing capacitors adjacent to the step-up transformer and the current reducing resistor, and is close to the upper surface upper side smoothing capacitor is in contact near the side wall of the housing than the lower side smoothing capacitor closer to the lower surface,
Inverter apparatus according to the step-up transformer or the distance between the down-flow resistor, wherein the Hirogeruko than the distance between the side wall of the housing and the upper side smoothing capacitor adjacent to the upper side smoothing capacitor.   The inverter device according to claim 1, wherein the plurality of smoothing capacitors are collectively provided on either the left or right side of the circuit board with respect to the step-up transformer and the current reducing resistor. apparatus. 2. The inverter device according to claim 1 , wherein the circuit board includes one or a plurality of module connection parts that are electronically connected to electronic components provided on another circuit board, and at least one of the module connection parts includes: An inverter device provided between the lower smoothing capacitor and a side wall of the casing . The inverter device according to claim 2, wherein the housing has a side opening on a side surface, and the side opening opens to face the plurality of smoothing capacitors . 2. The inverter device according to claim 1, wherein the terminal block is provided on a lower surface side of the housing and opens toward a gap between the lower smoothing capacitor and the step-down transformer adjacent to the lower-side smoothing capacitor. An inverter device comprising a part or a through hole . In the inverter apparatus請Motomeko 1 wherein, in said smoothing capacitor, the step-up transformer, the minimum combined electronic component height space is the height the minimum from the circuit board within the current decreasing resistor, said circuit When the space occupancy of the electronic component mounted on the circuit board defined by the integral value obtained by integrating the height of the component mounted on the board in the vertical direction of the casing is viewed as a distribution between the side walls of the casing. An inverter device having a substantially bifurcated shape having a recess in the vicinity of the center .

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