JP2015115984A - Dew condensation preventing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dew condensation preventing device preventing the generation of dew condensation without a cost increase and also without requiring application of additional waterproofing measures.SOLUTION: A dew condensation preventing device 1 includes: a temperature measurement part 10 measuring outside temperature before the start of operation of a three-phase motor 50; a control board 20 controlling an operation of the three-phase motor 50 and including an electronic component mounted thereon, the electronic component being self-heated through energization; an energization condition setting part 30 setting the energization condition of the control board 20 on the basis of the outside temperature; and an energization control part 40 to energize the control board 20 on the basis of the energization condition so that the electronic component is self-heated.

Description

  The present invention relates to a dew condensation prevention device that prevents dew condensation on a control board on which an electronic component that self-heats when energized is mounted.

  Conventionally, in a substrate on which an electronic component that self-heats when energized is mounted, a technique for preventing the substrate from condensing has been studied in order to prevent migration and short-circuiting of terminals of the electronic component (for example, Patent Document 1). -3).

  The dew condensation preventing structure for a substrate described in Patent Document 1 has an opening through which outside air can flow in, a heat conductive member is provided inside a housing in which the substrate is accommodated, and the heat conductive member is disposed inside the housing. In contact with a heat source provided in the substrate and a region near the opening in the substrate. Thereby, the part which does not want to dew condensation is warmed by a heat source, and dew condensation is not generated.

  In the LED lamp described in Patent Document 2, a module substrate on which an LED chip is mounted is fixed to one end of a heat radiating body, and a through hole is formed to communicate the inside and outside of a globe attached so as to cover the module substrate. Yes. This through hole reduces the temperature difference between the inside and outside of the glove and prevents condensation.

  The dew condensation prevention heater described in Patent Document 3 includes a heat generation circuit having a current setting unit and a temperature detection circuit having a temperature setting unit and a temperature detection unit in an enclosure, and an output detected by the temperature detection unit. When the output exceeds the output set by the temperature setting means, the output of the current setting means is prohibited, and when the output detected by the temperature detection means falls below the output set by the temperature setting means, the output of the current setting means is permitted. As a result, the inside of the housing is warmed to prevent the occurrence of condensation.

JP 2012-99557 A JP 2013-69599 A JP2013-164901A

  In the technique described in Patent Document 1, since it is necessary to draw the heat conductive member within the casing, it is necessary to increase the size of the casing accordingly. Moreover, since it is necessary to provide a heat conductive member, it becomes a factor of a cost increase. Moreover, in the technique described in Patent Document 2, since a through hole penetrating the glove is formed, the waterproofness of the glove becomes a concern. Therefore, when it is used for a part that requires waterproofing, it is necessary to take a waterproofing treatment. Furthermore, the technique described in Patent Document 3 requires a heat generating circuit, and accordingly, the size of the housing needs to be increased. In addition, it is necessary to provide a heat generating circuit separately, which causes an increase in cost.

  SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a dew condensation prevention device that prevents the occurrence of dew condensation that does not require additional measures against waterproofing without increasing costs.

  In order to achieve the above object, the dew condensation prevention control device according to the present invention has a characteristic configuration in which a temperature measuring unit that measures the outside air temperature before starting operation of the control target device, and control of the operation of the control target device, A control board on which an electronic component that self-heats is mounted, an energization condition setting unit that sets energization conditions of the control board based on the outside air temperature, and energizing the control board based on the energization conditions And an energization control unit that self-heats the component.

  With such a characteristic configuration, it is possible to warm the surface of the control board by causing the electronic components mounted on the control board to self-heat according to the outside air temperature before energizing the control board. Therefore, even when the outside air temperature is low, it is possible to prevent condensation on the control board, so that it is not necessary to take a waterproof measure such as coating. Moreover, since the electronic component mounted on the control board can be conventionally used for controlling the operation of the control target device, it is not necessary to provide a new electronic component. Therefore, the cost is not increased.

  The energization condition is preferably set according to the current outside air temperature.

  With such a configuration, it is possible to directly determine whether or not condensation is likely to occur using the outside air temperature, and thus it is possible to reliably prevent the occurrence of condensation.

  Further, it is preferable that the energization condition setting unit sets an energization start time for energizing the control board according to the outside air temperature.

  With such a configuration, for example, when the possibility of dew condensation is low, it is possible to perform control to delay energization of the control board. Therefore, since the control board is not energized more than necessary, the power consumption related to the dew condensation prevention process can be reduced.

  In addition, it is preferable that the device to be controlled is a three-phase motor included in a vehicle, and the control board is equipped with an inverter that controls driving of the three-phase motor.

  For example, when a vehicle that travels using electric energy such as an electric vehicle or a hybrid vehicle starts traveling from a parked state, a motor is used as a power source in the early stage of traveling. For this reason, with the above-described configuration, it is possible to prevent condensation on the control board even when the vehicle that has been parked and stopped at a low temperature is traveled, so that it is possible to prevent malfunction of the inverter. It becomes.

It is a block diagram which shows typically the structure of the dew condensation prevention apparatus which concerns on this embodiment. It is a figure which shows typically the temperature rise of the control board according to external temperature. It is a figure which shows typically the temperature rise of the control board according to external temperature. It is a figure which shows typically the temperature rise of the control board according to external temperature. It is a flowchart which shows the process of a dew condensation prevention apparatus.

  The dew condensation prevention apparatus according to the present invention is configured to have a function of preventing the occurrence of dew condensation even under the dew condensation occurrence condition. Hereinafter, the dew condensation prevention apparatus 1 of this embodiment is demonstrated.

  FIG. 1 is a block diagram schematically showing the configuration of the dew condensation prevention device 1 of the present embodiment. As shown in FIG. 1, the dew condensation prevention apparatus 1 is configured to include each function unit of a temperature measurement unit 10, a control board 20, an energization condition setting unit 30, and an energization control unit 40. Each functional unit has a CPU as a core member, and the above-described functional units for performing various processes for preventing the occurrence of condensation are constructed by hardware and / or software. In the present embodiment, the dew condensation prevention device 1 is provided in a hybrid vehicle that uses an engine and an electric motor as a power source, and an electric vehicle that uses an electric motor as a power source. Hereinafter, an example in the case of being provided in a hybrid vehicle will be described.

  The temperature measuring unit 10 measures the outside air temperature before the operation of the control target device is started. The control target device is a device whose operation is controlled by the control board 20 energized by an energization control unit 40 described later. When the control board 20 controls the operation, the control board 20 itself does not control the operation, but the control board 20 is operated based on the control signal from the energization control unit 40, and as a result, the control target device is controlled. It means to do. Therefore, in other words, it corresponds to the energization control unit 40 controlling the operation via the control board 20. In this embodiment, the control target device corresponds to the three-phase motor 50 included in the vehicle (hybrid vehicle). Hereinafter, the control target device will be described as the three-phase motor 50. The outside air temperature is the temperature outside the vehicle. Therefore, the temperature measurement unit 10 measures the temperature outside the vehicle before starting the operation of the three-phase motor 50. The measurement result is transmitted to an energization condition setting unit 30 described later.

  The control board 20 is mounted with electronic components that control the operation of the three-phase motor 50 and self-heat when energized. In the present embodiment, the control board 20 is mounted with an inverter that controls driving of the three-phase motor 50. Therefore, an electronic component that self-heats when energized corresponds to a switching element (for example, FET or IGBT) that constitutes an inverter.

  Here, the control board 20 is provided at a position communicating with the outside air in the hybrid vehicle. The position communicating with the outside air is a position exposed to the outside air, and corresponds to, for example, a boundary portion between the engine room and the vehicle compartment. Of course, a sealed space that is indirectly exposed to the outside air is also included. Therefore, the position communicating with the outside air corresponds to a position where the temperature reaches the same level as the outside air temperature when the vehicle is parked for a long time after the engine is stopped. For this reason, the surface of the control board 20 reaches the same temperature as the outside air temperature when the vehicle is parked for a long time after the engine of the vehicle is stopped.

  Therefore, for example, when the outside air temperature is 0 ° C. or less, the surface of the control board 20 may be condensed when a long time has passed after the vehicle stops and the inverter is energized. In such a case, the terminals of components mounted on the control board 20 are short-circuited and cause a failure, or migration occurs in a soldered portion, and the reliability and life of the product are shortened. Therefore, the energization condition setting unit 30 sets the energization condition of the control board 20 based on the outside air temperature. The outside air temperature is a temperature outside the vehicle measured by the temperature measurement unit 10 before starting the operation of the three-phase motor 50. The control board 20 is a board on which an inverter that controls energization of the three-phase motor 50 is mounted. For this reason, in this embodiment, the energization condition is set according to the current outside air temperature.

  Here, when the outside air temperature is 0 ° C. or lower, it is an environment in which condensation is very likely to occur. For this reason, in such a case, as shown in FIG. 2, an energization condition is set so that the control board 20 quickly warms up. That is, the energization condition setting unit 30 sets the current flowing through the switching element of the inverter to be increased in accordance with the ignition switch being pressed (IG-ON). Thereby, it becomes possible to warm up faster than the control board 20 in the case where no dew condensation countermeasures shown in FIG. 2 are taken.

  On the other hand, when the outside air temperature is 10 ° C. or higher, it is an environment in which condensation does not easily occur. For this reason, in such a case, it is not necessary to set an energization condition that causes the control board 20 to warm, so the energization condition setting unit 30 does not set an energization condition for preventing condensation. Therefore, the energization control unit 40 energizes according to the required torque of the three-phase motor 50 required from the host system, and warms up based on the current according to the required torque as shown in FIG.

  Further, in the case where the outside air temperature is greater than 0 ° C. and less than 10 ° C., the possibility of dew condensation is reduced if the control board 20 is heated to some extent. Therefore, as shown in FIG. 4, the energization condition setting unit 30 delays the start timing of energizing the control board 20 with respect to the IG-ON timing. In this case, as shown in FIG. 4, the gradient of the temperature rise is changed by changing the magnitude of the current to be supplied according to the outside air temperature (the temperature of the surface of the control board 20) before the start of current supply. Is possible. That is, when the outside air temperature is greater than 0 ° C. and less than 10 ° C., the higher the temperature, the smaller the current to be energized, and the lower the temperature, the greater the current to be energized. In this way, the energization condition setting unit 30 sets the energization start timing for energizing the control board 20 according to the outside air temperature. The energization condition set by the energization condition setting unit 30 is transmitted to the energization control unit 40 described later. As a result, it is possible to warm up faster than the control board 20 in the case where no dew condensation countermeasures are taken as indicated by the broken lines in FIG.

  The energization control unit 40 energizes the control board 20 based on energization conditions to cause the electronic component to self-heat. In the present embodiment, the control board 20 is a board on which an inverter that drives the three-phase motor 50 is mounted, and the electronic component is a switching element that constitutes the inverter. For this reason, the energization control unit 40 corresponds to a PWM control unit. Therefore, the energization control unit 40 adjusts DUTY based on the energization condition set by the energization condition setting unit 30, and performs PWM control of the switching element. That is, in the energization condition that warms up the electronic component earlier, the DUTY is adjusted so that the current flowing through the switching element becomes large, and in the energization condition that warms up the electronic component slowly, the current that flows through the switching element DUTY is adjusted so that becomes smaller. As a result, a current flows from the power supply 60 to the control board 20, the switching element generates heat according to the current, and the control board 20 is warmed to prevent the occurrence of condensation.

  Next, processing related to condensation prevention performed by the condensation prevention apparatus 1 will be described with reference to the flowchart of FIG. First, the outside temperature is measured by the temperature measuring unit 10 (step # 1). If the outside air temperature is 0 ° C. or lower (step # 2: Yes), the energization condition setting unit 30 sets an energization condition to perform immediate energization in order to quickly increase the temperature of the control board 20 (step # 3). ).

  The energization control unit 40 energizes the control board 20 based on the set energization conditions (step # 4). As a result, when the control board 20 warms up and then there is no possibility of condensation, the energization control for preventing condensation is terminated.

  On the other hand, in step # 2, if the outside air temperature is higher than 0 ° C. (step # 2: No) and the outside air temperature is 10 ° C. or more (step # 5: No), there is little possibility of condensation. The dew condensation prevention apparatus 1 ends the process without performing energization control related to dew condensation prevention.

  In step # 5, if the outside air temperature is not 10 ° C. or higher (step # 5: Yes), the process is suspended until a preset time has elapsed (step # 6: No), and thereafter (step # 6). : Yes), the energization condition setting unit 30 sets the energization condition based on the outside air temperature (step # 7).

  Then, the energization control unit 40 energizes the control board 20 based on the energization conditions set (step # 4). Thereafter, when there is no possibility that the control board 20 warms up and condensation occurs, the energization control for preventing condensation is terminated. It should be noted that the above-described step # 6 and step # 7 are defined to hold the process until a predetermined time elapses in the energization condition, and either of them may be performed first.

[Other Embodiments]
In the above embodiment, the energization condition is described as being set according to the current outside air temperature, but may be set according to the surface temperature of the control board 20, for example. Even with such a configuration, it is possible to prevent condensation on the control board 20.

  In the above embodiment, the energization condition setting unit 30 has been described as setting the energization start time for energizing the control board 20 according to the outside air temperature. That is, when the outside air temperature is a predetermined temperature, the energization condition setting unit 30 has been described as delaying the start timing of energizing the control board 20 with respect to the IG-ON timing. .

  In the embodiment described above, the control target device is the three-phase motor 50 and the control board 20 is provided with an inverter. However, the present invention can be applied to other uses. Therefore, the control board 20 may be a board that is not mounted on the vehicle, and the control target device may be a device other than the motor.

  INDUSTRIAL APPLICABILITY The present invention can be used in a dew condensation prevention device that prevents dew condensation on a control board on which a component that generates heat when energized is mounted, in particular, a control board that controls driving of a control target device provided in a vehicle.

1: Condensation prevention device 10: Temperature measurement unit 20: Control board 30: Energization condition setting unit 40: PWM control unit (energization control unit)
50: Three-phase motor (device to be controlled)

Claims (4)

Before starting the operation of the controlled device, a temperature measurement unit that measures the outside air temperature,
A control board on which electronic components that control operation of the control target device and self-heat when energized are mounted;
An energization condition setting unit configured to set an energization condition of the control board based on the outside air temperature;
An energization control unit configured to energize the control board based on the energization condition to self-heat the electronic component;
Condensation prevention device.   The dew condensation prevention device according to claim 1, wherein the energization condition is set according to the current outside air temperature.   The dew condensation prevention device according to claim 1 or 2, wherein the energization condition setting unit sets an energization start timing for energizing the control board according to the outside air temperature.   The dew condensation prevention device according to any one of claims 1 to 3, wherein the control target device is a three-phase motor included in a vehicle, and the control board includes an inverter that controls driving of the three-phase motor.

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