JP2019041025A - Electronic control device - Google Patents

Abstract

To provide an electronic control device capable of preventing erroneous detection of a fan abnormality.SOLUTION: An electronic control device comprises: a circuit board mounted with a control circuit unit; a housing for housing the circuit board inside; a blower unit including a fan whose driving is controlled by the control circuit unit and for air-cooling the housing; a temperature detection unit which detects a physical quantity correlating with a temperature of the circuit board; and an outside air temperature estimation unit which estimates a temperature outside the housing. In diagnostic mode, fan rotation is started when the temperature of the circuit board becomes a prescribed diagnostic threshold value or higher. In normal mode, fan rotation is started when the temperature of the circuit board becomes a prescribed first air-cooling threshold value or higher, and stopped when the temperature of the circuit board falls below a prescribed second cooling-air threshold value. When the estimated outside air temperature of the housing is higher than a diagnostic threshold value, the control circuit unit turns on a temporary abnormality flag for reserving the determination of the fan abnormality in diagnostic mode.SELECTED DRAWING: Figure 5

Description

  The disclosure of this specification relates to a fan-cooled electronic control device.

  In a vehicle, for example, an electronic control device that controls driving of an engine has been reduced in size. With the downsizing of the electronic control device, the installation area of the heat dissipating fins is narrowed, and it has become difficult to ensure heat dissipation. Therefore, as disclosed in Patent Document 1, a cooling system for cooling the vehicle control device main body is known.

JP 2000-234518 A

  By the way, in the cooling system disclosed in Patent Document 1, the housing can be cooled by the rotation of the fan, but the rotation of the fan is accompanied by the consumption of electric power. For this reason, it is preferable from the viewpoint of power saving to rotate the fan in a timely manner without cooling the housing more than necessary. However, if the blower unit is always turned on due to a failure or the like and the fan continues to rotate, excessive power consumption may be caused. On the other hand, in the state where the rotation of the fan is always off and does not rotate, the original purpose of cooling cannot be achieved. For this reason, there is a request to detect the always-on or always-off state that the fan does not intend. That is, there is a demand for a diagnostic function related to the fan.

  As a method of diagnosing fan rotation, for example, a command for forcibly rotating the fan may be issued, and then a fan failure may be detected based on the degree of cooling thereafter. .

  However, when there is a temperature increase outside the housing that exceeds the cooling capacity of the fan, it is not possible to distinguish between a fan abnormality and a temperature increase due to an external factor. That is, it is impossible to determine whether the temperature rises due to an abnormal stop of the fan or an abnormal temperature rise outside the housing, and there is a possibility that a fan abnormality is erroneously detected.

  Therefore, an object of the disclosure of this specification is to provide an electronic control device that can prevent erroneous detection of fan abnormality.

  The disclosure of this specification employs the following technical means to achieve the above object. Note that the reference numerals in parentheses described in the claims and in this section indicate a corresponding relationship with specific means described in the embodiments described later as one aspect, and limit the technical scope of the invention. Not what you want.

  In order to achieve the above object, an electronic control device disclosed in this specification includes a circuit board (30) on which a control circuit unit (34) is mounted, and a housing (20) in which the circuit board is accommodated. And a fan unit (41) whose drive is controlled by the control circuit unit, air blowing unit (40) for cooling the casing, and a temperature detection unit (35) for detecting a physical quantity correlated with the temperature (T) of the circuit board. ) And an outside air temperature estimating unit (36) for estimating a physical quantity correlated with the temperature (Tout) outside the housing, and the control circuit unit controls the fan based on the physical quantity detected by the temperature detecting unit as a control mode. A diagnosis mode for determining an abnormality and a normal mode for controlling a normal fan for air cooling. The diagnosis mode is started when the temperature of the circuit board exceeds a predetermined diagnosis threshold (T1). In mode, the temperature of the circuit board The rotation of the fan is started when the first air cooling threshold (Ton1) is exceeded, and the rotation of the fan is stopped when the temperature of the circuit board exceeds the predetermined second air cooling threshold (Toff). When the estimated outside temperature of the housing is higher than the diagnosis threshold, the temporary abnormality flag for holding the determination of the abnormality of the fan in the diagnosis mode is turned on.

  In the diagnosis mode, the presence or absence of an abnormality of the fan is detected based on a physical quantity correlated with the temperature detected by the temperature detection unit. That is, the fan abnormality is detected based on the temperature of the circuit board. If the temperature outside the housing is excessively high, the temperature of the circuit board does not drop sufficiently even if the fan is rotating correctly, and there is a risk that the abnormality of the fan is erroneously determined in the diagnosis mode. On the other hand, when the estimated temperature outside the housing is higher than the diagnosis threshold, the disclosed electronic control device suspends the determination of the fan abnormality in the diagnosis mode. For this reason, even if it is determined that the fan is abnormal in the diagnosis mode, it is not immediately determined that the abnormality is caused by the fan. Therefore, erroneous detection of fan abnormality can be prevented.

1 is a perspective view of an electronic control device according to a first embodiment. It is sectional drawing which follows the II-II line of FIG. It is a figure which shows an example of the circuit comprised by the fan board | substrate. It is a figure which shows the temperature change of the circuit board in diagnostic mode and normal mode. It is a flowchart which shows the control flow of an electronic control apparatus. It is a flowchart which shows the control flow of a temporary abnormality process.

  Hereinafter, a plurality of modes for carrying out the present disclosure will be described with reference to the drawings. In each embodiment, parts corresponding to the matters described in the preceding embodiment may be denoted by the same reference numerals, and redundant description may be omitted. When only a part of the configuration is described in each mode, the other modes described above can be applied to the other parts of the configuration. Not only combinations of parts that clearly indicate that combinations are possible in each form, but also forms may be partially combined even if they are not clearly specified, as long as there is no problem with the combination. Is possible.

  In the following, the thickness direction of the circuit board is indicated as the Z direction. Moreover, it is one direction orthogonal to the Z direction, and the longitudinal direction of the connector is indicated as the Y direction, and the direction orthogonal to both the Z direction and the Y direction is indicated as the X direction. Unless otherwise specified, the shape along the XY plane is a planar shape.

(First embodiment)
Initially, with reference to FIGS. 1-3, schematic structure of the electronic controller which concerns on this embodiment is demonstrated. In FIG. 2, the air flow accompanying the rotation of the fan is indicated by a one-dot chain line arrow.

  As shown in FIGS. 1 and 2, the electronic control device 10 includes a waterproof housing 20, a circuit board 30, and a blower unit 40. The electronic control device 10 is configured as an electronic control device (ECU) that controls an internal combustion engine of a vehicle.

  The waterproof housing 20 provides a waterproof space as an internal space 20 s that houses the circuit board 30. The waterproof housing 20 is divided into two members in the Z direction, which is the thickness direction of the circuit board 30, and one is a case 21 and the other is a cover 22. The waterproof housing 20 is configured by assembling a case 21 and a cover 22 with a seal member (not shown).

  The case 21 has a box shape with one side opened. In the present embodiment, the case 21 is formed using a metal material for heat dissipation. Specifically, the case 21 is formed by aluminum die casting.

  The bottom wall 210 of the case 21 has a substantially rectangular shape in plan view. One surface facing the outside of the bottom wall 210 of the case 21 is the outer surface 21a of the case, and in this embodiment, is a mounting surface on which the air blower unit 40 described later is mounted in the waterproof housing 20. One of the four side walls connected to the bottom wall 210 is provided with a notch (not shown). This notch is connected to the opening on one surface of the case 21.

  A plurality of through holes 211 are formed in the bottom wall 210. The through hole 211 is formed so as to penetrate from the outer surface 21a of the case 21 to the inner surface 21b. In the present embodiment, the case 21 includes a first housing portion 212 and a second housing portion 213 provided as a part of the bottom wall 210 so as to be recessed with respect to other portions of the bottom wall 210.

  The first accommodating portion 212 is provided on one end side in the X direction so as to accommodate the connector 33. The second accommodating portion 213 is provided to accommodate a high-profile component such as an aluminum electrolytic capacitor among the electronic components 32 constituting the circuit board 30. The second housing part 213 extends in the X direction, and one end is connected to the first housing part 212. The through hole 211 is formed in a portion of the bottom wall 210 excluding the first housing portion 212 and the second housing portion 213. The through hole 211 is formed in a substantially flat portion of the bottom wall 210.

  In addition, the code | symbol 214 shown in FIG. 1 is an attachment part for attaching the electronic control apparatus 10 to a vehicle, and the code | symbol 215 is a fixing hole for fixing the case 21 and the cover 22. As shown in FIG. A screw (not shown) is inserted into the fixing hole 215. The mounting portion 214 and the fixing hole 215 are provided integrally with the case 21.

  The cover 22 forms an internal space 20 s of the waterproof housing 20 together with the case 21. By assembling the case 21 and the cover 22, the opening on the one surface of the case 21 is closed by the cover 22. Moreover, the opening of one surface of the case 21 is closed by the cover 22, so that a notch formed in the side wall is partitioned and becomes an opening (not shown). Through this opening, a part of the connector 33 is exposed to the outside.

  In the present embodiment, the cover 22 is also formed using a metal material in order to improve heat dissipation. The cover 22 is also formed by aluminum die casting. The cover 22 has a box shape with a shallow bottom that opens on one side. The cover 22 has a plurality of heat radiation fins 220 on the outer surface side.

  The sealing member of the waterproof housing 20 has an internal space 20 s outside the waterproof housing 20 between the case 21 and the cover 22, between the case 21 and the connector 33, and between the cover 22 and the connector 33. It is provided to block communication with the space. The seal member is disposed on the peripheral edge of the case 21 and the cover 22 so as to surround the internal space 20s. The peripheral portions of the case 21 and the cover 22 are sealed in a watertight manner by the sealing member. As the seal member, for example, a liquid adhesive can be employed before curing.

  The circuit board 30 is fixed to the case 21. The circuit board 30 includes a printed board 31 and an electronic component 32 mounted on the printed board 31. The printed circuit board 31 has wirings arranged on a base material formed using an electrically insulating material such as a resin. A circuit is formed by the wiring and the electronic component 32. The printed circuit board 31 has a substantially rectangular plane shape. The electronic component 32 is mounted on at least one of the one surface 31 a that is the surface on the case 21 side and the back surface 31 b that is the surface on the cover 22 side in the printed circuit board 31. In the present embodiment, of the electronic component 32, a heating element such as a power MOSFET or a microcomputer is disposed on one surface 31a of the printed board 31 around the blower unit 40 in the XY plane as shown in FIG. Yes. The electronic component 32 includes a control circuit unit 34 that controls the driving of the blower unit described later. The control circuit unit 34 is mounted on the printed circuit board 31.

  The electronic component 32 includes a temperature detection unit 35 such as a temperature sensor using a PN junction diode. The temperature detector 35 is an element that detects the temperature T of the circuit board 30 directly or indirectly. The physical quantity detected by the temperature detector 35 is a physical quantity that correlates with the temperature of the circuit board 30. The physical quantity correlated with the temperature of the circuit board 30 is, for example, the direct temperature of the circuit board 30, the atmospheric temperature of the internal space 20s that conducts heat from the circuit board 30, and the temperature of the waterproof casing 20, and correspond to them. The voltage value and current value output from the temperature detection unit 35 are also included.

  Furthermore, the electronic component 32 includes an outside air temperature estimation unit 36 that estimates the temperature Tout outside the waterproof housing 20. When it is assumed that the electronic control unit 10 is a device that controls the internal combustion engine and is mounted in the engine room, the outside air temperature estimation unit 36 receives, for example, information on the water temperature and the intake air temperature of the internal combustion engine, Based on this information, the temperature in the engine room is estimated. When viewed from the circuit board 30 placed inside the waterproof casing 20, the temperature in the engine room is the temperature Tout outside the waterproof casing 20. If a thermometer or the like that directly detects the temperature in the engine room is installed in the engine room, the outside air temperature estimation unit 36 directly receives information on the temperature Tout of the outside air from the thermometer. You may get it.

  A connector 33 is mounted on the circuit board 30. The connector 33 is mounted on one end side in the X direction on the circuit board 30. A part of the connector 33 is exposed to the outside through the opening of the waterproof casing 20, and the remaining part is accommodated in the internal space 20s. Although not shown, the connector 33 includes a housing formed using a resin material and a plurality of terminals formed using a conductive material and held in the housing.

  The blower unit 40 is attached to the bottom wall 210 of the case 21. Specifically, it is mounted on the outer surface 21 a of the bottom wall 210 facing the outside of the waterproof housing 20. The blower unit 40 is attached so as to cover the plurality of through holes 211 of the case 21. The blower unit 40 forms a flow of air by rotation, and thereby cools the case 21 and thus the circuit board 30. The blower unit 40 includes a fan 41, a housing 42, and terminals 43. The structure of the fan 41 is the same as the well-known structure in the axial fan. For this reason, in FIG. 2, the fan 41 is illustrated in a simplified manner.

  The fan 41 has a shaft portion 410 and a plurality of blades 411. The shaft portion 410 includes a rotating shaft 410a. The blade 411 rotates integrally with the rotation shaft 410a. Therefore, the rotation shaft 410 a becomes the rotation axis of the fan 41. The blower unit 40 is attached to the case 21 so that the axial direction of the rotation shaft 410a, that is, the direction of the rotation axis of the fan 41 coincides with the Z direction. That is, the blade 411 rotates in an XY plane parallel to the outer surface 21a. The flow of air generated along with the rotation of the fan 41 is mainly in the Z direction. When the blade 411 rotates in the forward direction in the present embodiment, the air flows in a direction to blow from the outside to the outer surface 21a.

  The shaft portion 410 has a boss 410b in addition to the rotating shaft 410a. The boss 410b has a bottomed cylindrical shape that opens to the circuit board 30 side in the Z direction and is closed to the other end side. A plurality of blades 411 are provided at equal intervals on the outer peripheral surface of the boss. The blade 411 is located above the outer surface 21a of the peripheral portion of the through hole 211 in the Z direction. The boss 410b and the blade 411 are integrally formed as a so-called impeller. The rotating shaft 410a is provided inside the boss 410b, and one end is fixed to the approximate center of the boss 410b. The metal rotating shaft 410a is insert-molded into a resin impeller and integrated with the impeller. A magnet 410c is attached to the inner peripheral surface of the boss 410b. As described above, the rotor includes the boss 410b, the blade 411, the rotating shaft 410a, and the magnet 410c.

  In addition to the above, the shaft portion 410 includes a bearing (not shown), a coil 410d, a bearing holder 410e, and the like. The bearing supports the rotating shaft 410a in a rotatable manner. The bearing holder 410e holds a bearing. The bearing holder 410 e protrudes from the bottom wall 420 of the housing 42 in the Z direction. In the present embodiment, the bearing holder 410 e is integrally provided using the same material as the housing 42. The bearing is disposed on the inner peripheral surface of the bearing holder 410e. The coil 410d is disposed on the outer peripheral surface of the bearing holder 410e. As described above, the stator includes the coil 410d, the bearing, and the bearing holder 410e. That is, the fan 41 has a motor.

  The housing 42 accommodates the fan 41 rotatably. The housing 42 is disposed so as to cover the through hole 211 while facing the peripheral portion of the through hole 211 on the outer surface 21a. A plurality of ventilation holes are formed in the housing 42. The plurality of vent holes are formed at different positions in the Z direction so that the air flow along the outer surface 21a of the bottom wall 210 is formed with the rotation of the fan 41 (blade 411).

  The housing 42 has a bottom wall 420 and a side wall 421. The housing 42 is formed using a resin material. The side wall 421 has a cylindrical shape with both ends opened in the Z direction. One opening of the cylinder is a first vent 423 described later. The bottom wall 420 closes the other opening, and the housing 42 has a bottomed cylindrical shape as a whole. Corners of adjacent side walls 421, that is, connecting portions have rounded round shapes.

  The housing 42 has a first vent 423 and a second vent 424. When the fan 41 rotates forward, the first vent 423 functions as an air inlet and the second vent 424 functions as an exhaust. The first vent 423 opens in the XY plane, and is formed at a position farther in the Z direction than the fan 41 when viewed from the case 21. That is, the blade 411 of the fan 41 can be visually recognized by looking into the first vent from the Z direction. The second vent 424 is a vent that opens in the side wall 421 of the housing 42. The side wall 421 has a substantially rectangular shape with rounded corners when viewed from the front in the Z direction, and the second vent 424 includes two openings that open in the X direction and two openings that open in the Y direction. Become. The second vent hole 424 opens between the blade 411 and the outer surface 21a in the Z direction. That is, all the vent holes 423 and 424 are located above the outer surface 21a around the opening of the through hole 211 in the Z direction.

  In the present embodiment, if the air flow accompanying the forward rotation of the fan 41 is a flow that uses the first vent 423 as a suction port as described above, the air flows from the first vent 423 in the Z direction. The air flow is changed in the direction along the XY plane after being sucked into the air, discharged from the second vent 424, and escapes outward along the outer surface 21a of the case 21. By the way, since the air tends to be warmed in the vicinity of the waterproof casing 20 that easily stores heat, air that is farther from the waterproof casing 20 due to the forward rotation is removed from the waterproof casing than the air circulation due to the reverse rotation. The cooling effect becomes higher as it flows into the 20 side.

  The bottom wall 420 is fixed to the outer surface 21a of the case 21 through a seal member (not shown). The bottom wall 420 is fixed in contact with the outer surface 21 a around the through hole 211 so as to cover the through hole 211. The seal member is interposed between the bottom wall 420 and the outer surface 21a so as to surround the through hole 211, and prevents water and dust from entering the through hole 211 from the outside.

  The terminal 43 protrudes from the housing 42 toward the internal space 20 s and is electrically connected to the circuit board 30. The terminal 43 passes through the bottom wall 420 of the housing 42. The terminal 43 protrudes into the internal space 20 s while being inserted through the through hole 211 in the case 21. One end of the terminal 43 is electrically connected to the fan board 44 disposed in the housing 42, and the other end is connected to the circuit board 30. Thus, the fan substrate 44, that is, the blower unit 40 and the circuit board 30 are electrically connected via the terminal 43. The metal terminal 43 is integrated with the resin housing 42 by insert molding.

  A drive circuit for rotating the fan 41 is formed on the fan substrate 44. The fan substrate 44 is electrically connected to a coil 410 d that constitutes the shaft portion 410. When the coil 410d is energized through the circuit board 30, the terminal 43, and the fan board 44, the rotor described above rotates. Then, an air pressure difference is generated in the housing 42 due to the predetermined shape of the blade 411, and the air sucked from the first vent 423 is discharged from the second vent 424 as shown in FIG. 2. When the rotor is rotated in the direction opposite to the forward direction, the air sucked from the second vent 424 is discharged from the first vent 423.

  The fan substrate 44 is disposed below the blades 411 in the housing 42. The fan substrate 44 is fixed to the housing 42. In the present embodiment, the fan substrate 44 is sealed by the potting body 45. The fan substrate 44 is fixed to the housing 42 by terminals 43 and a potting body 45. The potting body 45 is provided in the housing 42 at a depth that does not block the second vent hole 424 and does not hinder the movement of the rotor such as the boss and the blade 411. Note that the sealing of the fan substrate 44 is not limited to the potting body 45. For example, a configuration in which the fan substrate 44 on which the terminals 43 are mounted is insert-molded in the housing 42 and the fan substrate 44 is sealed by the bottom wall 420 may be employed.

  As described above, the circuit board 30 and the fan board 44 are electrically connected by the terminals 43, and the rotation of the fan 41 is controlled by the control circuit unit 34 mounted on the circuit board 30. Specifically, as shown in FIG. 3, the control circuit unit 34 controls energization to the coil 410 d via a switch SW formed on the circuit board 30. That is, the control circuit unit 34 transmits a control signal for opening and closing the switch SW. In FIG. 3, for simplicity of explanation, the coil 410 d is illustrated as being connected in series between the power source VB and the switch SW. However, in actuality, an inverter circuit in which the fan substrate 44 forms a three-phase alternating current is illustrated. Have. As described above, the circuit board 33 and the fan board 44 are connected to each other through the power supply line and the signal line. The power supply line may be separately wired from the outside.

  The circuit board 30 in the present embodiment includes the control circuit unit 34, the temperature detection unit 35, and the outside air temperature estimation unit 36 as described above.

  As described above, the control circuit unit 34 controls the opening / closing of the switch SW by outputting a control signal to the switch SW. When the switch SW is closed, the circuit is configured such that the coil 410d is interposed between the power source VB and the reference potential GND, and the fan 41 rotates. At this time, the control signal output from the control circuit 34 to the switch SW is referred to as an ON signal. On the other hand, when the switch SW is opened, no current flows through the coil 410d between the power source VB and the reference potential GND, and the fan 41 does not rotate or stops rotating. At this time, the control signal output from the control circuit 34 to the switch SW is referred to as an off signal. In other words, the control circuit unit 34 controls the rotation of the fan 41 by outputting an on signal or an off signal to the switch SW of the fan substrate 44.

  The temperature detection unit 35 is a temperature sensor that uses, for example, a PN junction diode, and is an element that detects the temperature T of the circuit board 30 directly or indirectly. The physical quantity detected by the temperature detection unit 35 is a physical quantity that correlates with the temperature T of the circuit board 30. The physical quantity correlated with the temperature T of the circuit board 30 is, for example, the direct temperature of the circuit board 30, the atmospheric temperature of the internal space 20s that conducts heat from the circuit board 30, and the temperature of the waterproof housing 20. Since the temperature detection unit 35 converts the temperature into a corresponding voltage value or current value and outputs the converted voltage value or current value to the control circuit unit 34, the physical quantity includes the voltage value and the current value. Hereinafter, the physical quantity detected by the temperature detection unit 35 is simply referred to as a temperature T.

  The outside air temperature estimation unit 36 estimates the temperature in the engine room, that is, the temperature Tout outside the waterproof housing 20 based on, for example, information on the water temperature and intake air temperature of the internal combustion engine. Since the outside air temperature estimation unit 36 converts the temperature information into a corresponding voltage value or current value and outputs it to the control circuit unit 34, the physical quantity correlated with the temperature output by the outside air temperature estimation unit 36 includes a voltage value. And current values. Hereinafter, the physical quantity output by the outside air temperature estimation unit 36 is simply referred to as temperature Tout.

  Next, with reference to FIGS. 4 to 6, an example of the diagnosis control of the electronic control device 10 described above will be described, and the operation and effect by adopting the electronic control device 10 will be described.

  As shown in FIG. 4, the control circuit unit 34 has a diagnostic mode and a normal mode as control modes.

  The diagnosis mode is a mode for diagnosing an abnormality of the blower unit 40, and specifically, a mode for diagnosing whether or not the fan 41 is rotating properly. In the present embodiment, for example, when the temperature T detected by the temperature detection unit 35 is equal to or higher than a predetermined diagnostic threshold T1, the control circuit unit 34 issues an ON signal. If the fan 41 rotates correctly, the temperature T decreases. The control circuit unit 34 detects the presence or absence of an abnormality in the blower unit 40 based on a decrease in the temperature T due to the rotation of the fan 41 or a change in physical quantity corresponding to this temperature change. As an example of detecting whether there is an abnormality in the blower unit 40, in FIG. 4, after the temperature of the circuit board 30 reaches the diagnosis threshold value T1 and the fan 41 starts rotating at time t1, the temperature drop amount ΔT of the circuit board 30 is predetermined. If this amount is not reached, the control circuit unit 34 determines that the blower unit 40 is abnormal.

  The normal mode is a mode in which the waterproof casing 20 and the circuit board 30 are air-cooled by the rotation of the fan 41. When the temperature T detected by the temperature detection unit 35 is equal to or higher than a predetermined first air cooling threshold Ton1, the control circuit unit 34 issues an ON signal to rotate the fan 41. When the temperature T falls below the second air cooling threshold value Toff, the control circuit unit 34 issues an off signal to stop the rotation of the fan 41. The control circuit unit 34 generates an ON signal and an OFF signal based on the temperature T detected by the temperature detection unit 35, thereby preventing the circuit board 30 from overheating and excessive power consumption due to the rotation of the fan 41. Is suppressed.

  In addition, the control circuit unit 34 in the present embodiment can prevent erroneous detection of an abnormality of the fan 41 in the diagnosis mode based on the outside air temperature Tout estimated by the outside air temperature estimating unit 36. This will be described in detail below with reference to the flowcharts shown in FIGS.

  As shown in FIG. 5, step S101 is first executed. Step S <b> 101 is a step in which the control circuit unit 34 acquires the outside air temperature Tout estimated by the outside air temperature estimating unit 36.

  Next, step S102 is executed. Step S102 is a step in which the control circuit unit 34 compares the temperature Tout with a predetermined threshold temperature Tth. In step S102, which is executed first after the ignition switch is turned on, the threshold temperature Tth is set to the diagnostic threshold T1. That is, step S102 is a step in which the control circuit unit 34 compares the temperature Tout with the predetermined diagnostic threshold T1.

  If the condition of Tout ≧ T1 is satisfied, step S102 is YES and the process proceeds to step S103. Step S103 is a step in which the control circuit unit 34 turns on the temporary abnormality flag. The temporary abnormality flag is a flag for verifying the authenticity of the abnormality determination of the blower unit 40 determined in the diagnosis mode, and details will be described later. On the other hand, when the condition of Tout <T1 is satisfied, step S102 is NO, the process proceeds to step S110, and after the temporary abnormality flag is turned off, the process proceeds to step S104.

  Step S104 is a step in which the control circuit unit 34 determines whether the blower unit 40 is normal or abnormal in the diagnosis mode. In the electronic control device 10 according to the present embodiment, the control circuit unit 34 determines ΔT shown in FIG. 4 and compares it with a predetermined threshold value to determine whether or not the blower unit 40 is abnormal. If ΔT is not sufficiently large, it is determined that an abnormality has occurred in the blower unit 40. In addition, the method of abnormality diagnosis of the blower unit 40 in the diagnosis mode is not limited to the method based on ΔT. The abnormality diagnosis of the blower unit 40 can be performed by various methods based on the temperature T of the circuit board 30.

  Next, step S105 is executed. Step S105 is a step in which the control circuit unit 34 determines whether or not an abnormality is determined for the blower unit 40 in step S104. If no abnormality is found in the blower unit 40 in step S104 and step S105 is NO, the process proceeds to step S106, and the normality of the blower unit 40 is determined regardless of whether the temporary abnormality flag is on or off.

  On the other hand, if an abnormality determination is made for the blower unit 40, the determination in step S105 is YES and the process proceeds to step S107. Step S107 is a step in which the control circuit unit 34 determines whether or not the temporary abnormality flag is turned on. If the temporary abnormality flag is off, step S107 is NO, and the process proceeds to step S108 where the abnormality of the blower unit 40 is determined. If the temporary abnormality flag is turned on in step S103, the determination in step S107 is YES, and the process proceeds to step S109.

  Step S109 is a temporary abnormality process executed by the control circuit unit 34 when the temporary abnormality flag is on. This will be described in detail with reference to FIG.

  In the temporary abnormality process, step S201 is first executed. In step S201, the control circuit unit 34 changes the air cooling threshold at which the rotation of the fan 41 in the normal mode should start from the normal first air cooling threshold Ton1 to the third air cooling threshold Ton2 that is lower than the first air cooling threshold Ton1. It is a step.

  Next, step S202 is executed. Step S202 is a step in which the control mode of the blower unit 40 is shifted from the diagnosis mode to the normal mode.

  Next, step S203 is executed. Step S203 is a step of comparing the temperature T with the third air cooling threshold Ton2. If T <Ton2 is satisfied in step S203, the process proceeds to step S204, and the time from the transition to the normal mode is confirmed in step S202. If the predetermined time has not elapsed since the transition to the normal mode, the process returns to step S203, and the temperature T and the third air cooling threshold Ton2 are compared again. If it is determined in step S203 that T <Ton2 is satisfied and a predetermined time has elapsed since the transition to the normal mode in step S204, it is assumed that the outside air temperature Tout is relatively high (Tout ≧ T1). Since the temperature T of the substrate 30 has not reached the third air cooling threshold value Ton2, which is the threshold value for starting the rotation of the fan 41, it indicates that the fan 41 has rotated normally in the diagnosis mode. Therefore, it progresses to step S205 and the normality of the ventilation unit 40 is decided.

  On the other hand, if T ≧ Ton2 is satisfied in step S203, the process proceeds to step S206, and the rotation of the fan 41 is started. Next, step S207 is executed. Step S207 is a step of maintaining the rotation of the fan 41 for a predetermined time from the start of the rotation of the fan 41. The predetermined time in step S207 is referred to as wait time 1.

  Next, step S208 is executed. Step S208 is a step in which the control circuit unit 34 compares the temperature T of the circuit board 30 with the second cooling threshold Toff. Here, if T <Toff is satisfied, it means that the temperature T has fallen below the second cooling Toff after the wait time 1 has elapsed since the start of rotation of the fan 41, and indicates that the fan 41 is rotating properly. . Therefore, if T <Toff is satisfied, step S208 is NO and the process proceeds to step S205 to determine the normality of the blower unit 40.

  On the other hand, if T ≧ Toff is satisfied, the determination in step S208 is YES, and the process proceeds to step S209. Step S209 is a step in which the control circuit unit 34 compares the temperature T of the circuit board 30 with the first cooling threshold value Ton1.

  If T ≧ Ton1 is satisfied in step S209, a YES determination is made. Satisfying T ≧ Ton1 means that the temperature T of the circuit board 30 exceeds the third cooling threshold value Ton2 and reaches the first cooling threshold value Ton1 even though the ON signal related to the rotation of the fan 41 is issued. It means that In this case, the process proceeds to step S210, and the rotation of the fan 41 is maintained for a predetermined time. The predetermined time in step S210 is referred to as wait time 2. Then, it progresses to step S211. Step S211 is a step of comparing again the temperature T of the circuit board 30 and the first cooling threshold Ton1. At the time of execution of step S211, time has elapsed from the start of rotation of the fan 41 by wait time 1 + wait time 2. If T <Ton1 is satisfied at this point, step S211 is NO. This means that the fan 41 rotates correctly and cools the circuit board 30, so that the process proceeds to step S 205 and the normality of the blower unit 40 is determined. On the other hand, if T ≧ Ton1 is maintained, step S211 is YES. This suggests that the outside air temperature Tout exceeds the cooling capacity of the blower unit 40 even if the fan 41 is rotating. Therefore, it progresses to step S212 and the abnormality of the ventilation unit 40 is decided.

  If T <Ton1 is satisfied in step S209, a NO determination is made. Satisfying T <Ton1 means that the temperature T of the circuit board 30 varies between the first cooling threshold value Ton1 and the third cooling threshold value Ton2 even though the ON signal related to the rotation of the fan 41 is issued. It means that In this case, the process proceeds to step S213, and the rotation of the fan 41 is maintained for a predetermined time. The predetermined time in step S213 is referred to as wait time 3. Thereafter, the process proceeds to step S214. Step S214 is a step of comparing the temperature T of the circuit board 30 with the second cooling threshold value Toff. At the time of execution of step S214, time has elapsed from the start of rotation of the fan 41 by wait time 1 + wait time 3. If T <Toff is satisfied at this point, step S214 is NO. This means that the fan 41 rotates correctly and cools the circuit board 30, so that the process proceeds to step S 205 and the normality of the blower unit 40 is determined. On the other hand, if T ≧ Toff is maintained, step S214 is YES. This is because the heating amount of the circuit board 30 due to heat transfer from the outside air is small, that is, although the temperature T is assumed not to exceed the first cooling threshold Ton1, the temperature of the circuit board 30 is increased by the rotation of the fan 41. This suggests that the temperature does not fall to the second cooling threshold Toff that is the stop instruction temperature. Therefore, it progresses to step S212 and the abnormality of the ventilation unit 40 is decided.

As described above, even when the electronic control device 10 according to the present embodiment detects an abnormality of the blower unit 40 in the diagnosis mode, if the outside air temperature Tout is relatively high (Tout ≧ T1), the abnormality of the blower unit 40 is immediately detected. Is reconfirmed in the normal mode. And the normality or abnormality of the ventilation unit 40 is determined according to the change of the temperature of the circuit board 30 by rotation of the fan 41 in normal mode. Thus, erroneous detection of abnormality of the fan 41 can be suppressed.
(Other embodiments)
The preferred embodiment has been described above, but the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist disclosed in this specification.

  In the above-described embodiment, the operation after the normality of the blower unit 40 is confirmed and the operation after the abnormality of the blower unit 40 is confirmed are not mentioned. For example, when the abnormality of the blower unit 40 is confirmed It is preferable to execute a fail-safe operation such as lowering the engine speed or reducing the processing load on the circuit control unit 34.

  Further, when the normality of the blower unit 40 is determined, the threshold temperature for starting the rotation of the fan 41 in the normal mode may be returned from the third cooling threshold Ton2 to the original first cooling threshold Ton1.

  In addition, in step S102 in the control flow of the electronic control device 10 illustrated in FIG. 5, an example in which a predetermined diagnosis threshold T1 is used as a comparison target with the estimated outside air temperature Tout has been described. The comparison target may be variable. For example, immediately after the ignition switch is turned on, the outside air temperature Tout is compared with the diagnosis threshold value T1 in step S102, and in the diagnosis in a state in which a time has passed since the ignition switch was turned on, in step S102 The outside air temperature Tout and the first cooling threshold value Ton1 may be compared. This is because both the outside air temperature Tout and the circuit board 30 are heated to some extent after a while has passed since the ignition switch was turned on.

  Moreover, although the electronic control apparatus 10 showed the example comprised as a control apparatus which controls a vehicle engine, it is not limited to this.

DESCRIPTION OF SYMBOLS 10 ... Electronic control unit, 20 ... Waterproof housing, 20s ... Internal space, 21 ... Case, 21a ... Outer surface, 21b ... Inner surface, 210 ... Bottom wall, 211 ... Through-hole, 212 ... 1st accommodating part, 213 ... 2nd Accommodating portion, 214 ... mounting portion, 215 ... fixing hole, 22 ... cover, 220 ... heat radiation fin, 30 ... circuit board, 31 ... printed circuit board, 31a ... one side, 31b ... back side, 32 ... electronic component, 33 ... connector, 34 ... Control circuit part 35 ... Temperature detection part 36 ... Outside air temperature estimation part 40 ... Blower unit 41 ... Fan 410 ... Shaft part 410a ... Rotating shaft 411 ... Vane, 42 ... Housing, 420 ... Bottom wall, 421 ... Side wall, 422 ... Flange, 423 ... first vent, 424 ... second vent, 43 ... terminal, 44 ... fan substrate, 45 ... potting body, 50 ... second housing, 523 ... third Exhaust ports, 524 ... 4th vents

Claims (6)

A circuit board (30) on which a control circuit unit (34) is mounted;
A housing (20) in which the circuit board is housed;
A fan unit (41) whose driving is controlled by the control circuit unit, and a fan unit (40) for air-cooling the housing;
A temperature detector (35) for detecting a physical quantity correlated with the temperature (T) of the circuit board;
An outside air temperature estimating unit (36) for estimating a physical quantity correlated with the temperature outside the housing (Tout),
The control circuit unit, as a control mode,
A diagnostic mode for determining an abnormality of the fan based on a physical quantity detected by the temperature detection unit;
A normal mode for controlling the normal fan for air cooling, and
The diagnostic mode is started when the temperature of the circuit board becomes equal to or higher than a predetermined diagnostic threshold (T1),
In the normal mode, the fan starts rotating when the temperature of the circuit board becomes equal to or higher than a predetermined first air cooling threshold (Ton1), and when the temperature of the circuit board falls below a predetermined second air cooling threshold (Toff). The fan will stop spinning,
The electronic control device, wherein the control circuit unit turns on a temporary abnormality flag for suspending determination of abnormality of the fan in the diagnosis mode when the estimated temperature outside the casing is higher than the diagnosis threshold value.   The threshold value for starting the rotation of the fan is changed to a third air cooling threshold value (Ton2) lower than the first air cooling threshold value when the temporary abnormality flag is on in the normal mode. Electronic control device.   In the normal mode in which the temporary abnormality flag is on, after the temperature of the circuit board becomes equal to or higher than the third air cooling threshold and the fan starts to rotate, the temperature of the circuit board becomes the first air cooling threshold. 3. The abnormality of the fan is determined when the temperature becomes equal to or higher than a predetermined time after the start of rotation of the fan because the temperature of the circuit board does not fall below the first air cooling threshold. Electronic control unit.   In the normal mode in which the temporary abnormality flag is on, the temperature of the circuit board is set to the first temperature after a predetermined time after the temperature of the circuit board becomes equal to or higher than the third air cooling threshold and the fan starts to rotate. The electronic control device according to claim 2 or 3, wherein the abnormality of the fan is determined by not falling below a two-air cooling threshold.   In the normal mode in which the temporary abnormality flag is on, the temperature of the circuit board is set to the first temperature after a predetermined time after the temperature of the circuit board becomes equal to or higher than the third air cooling threshold and the fan starts to rotate. 5. The electronic control device according to claim 2, wherein normality of the fan is determined by falling below a threshold of 2 air cooling.   The electronic control unit according to claim 5, wherein when normality of the fan is determined, a threshold value for starting rotation of the fan in the normal mode is changed to the first air cooling threshold value.

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