Vehicle electronic control device and electric power steering device

Abstract

This electronic control device for a vehicle is provided with: a control device (6) that controls an electric motor (4); a connector (7) connecting the control device to the outside; and a moisture detection unit (15) that is provided inside the control device or inside the connector and detects water stored inside the control device or inside the connector on the lower side in the vertical direction (VD).

Description

Technical Field

[0001] The present disclosure relates to an electronic control device and an electric power steering device for a vehicle. Background Art

[0002] The electric power steering device includes an electric motor that generates a steering assist torque for the steering gear, and a steering control device (vehicle electronic control device) that controls the electric motor, and applies a steering assist force to the steering mechanism of a vehicle such as an automobile. This power steering device includes a power transmission mechanism that converts the rotational force of the output shaft of the electric motor into an axial force of a rack rod and transmits it to the rack rod.

[0003] The rack bar and part of the power transmission mechanism are housed in a waterproof housing, but when water intrudes into the housing, the water enters the motor from the output side of the motor through the power transmission mechanism. The following patent document 1 discloses a technology for detecting water intrusion into a motor based on a change in resistance between a motor wire and a motor housing. Prior art literature Patent Literature

[0004] Patent Document 1: Japanese Patent No. 6459492 Summary of the invention Technical problem to be solved by the invention

[0005] In addition, when an electrical short circuit occurs between the motor wire and the motor housing, the steering assist function of the power steering device is lost. Therefore, in order to avoid an electrical short circuit between the motor wire and the motor housing due to dimensional and assembly deviations during manufacturing, a sufficient gap is set between the motor wire and the motor housing.

[0006] When the space between the motor wire and the motor housing is large, the resistance value of the resistor used to detect water intrusion into the motor is large, and the change in resistance when water intrudes is easily affected by the degree of immersion, so the detection deviation is large and the accuracy is reduced. In addition, in the motor drive, due to PWM (Pulse Width Modulation) drive, etc., there is always voltage fluctuation in the motor wire, so it is difficult to monitor the resistance change between the motor wire and the motor housing due to water intrusion with high accuracy only by the terminal voltage of the winding.

[0007] The present disclosure has been made in view of the above circumstances, and an object of the present disclosure is to provide a vehicle electronic control device and an electric power steering device capable of detecting water intrusion with high accuracy regardless of whether the electric motor is being driven or not. Technical means for solving technical problems

[0008] In order to solve the above-mentioned problems, an electronic control device for a vehicle in one aspect of the present disclosure includes: a control device, which controls a motor; a connector, which connects the control device to the outside; and a moisture detection unit, which is arranged in the control device or in the connector, and detects water stored in the control device or in the connector on the vertical lower side.

[0009] Furthermore, an electric power steering apparatus according to one aspect of the present disclosure includes: an electric motor that generates a steering assist torque for a steering gear; and the above-described vehicle electronic control device that controls driving of the electric motor. Effects of the Invention

[0010] According to the present disclosure, there is an effect that water intrusion can be detected with high accuracy regardless of whether the motor is being driven or not. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is a block diagram showing a main part configuration of the electric power steering device according to the first embodiment of the present disclosure. Figure 2 This is a diagram showing a schematic configuration of a vehicle electronic control device according to Embodiment 1 of the present disclosure. Figure 3 : is a block diagram showing the circuit configuration of the control device in Embodiment 1 of the present disclosure. Figure 4 It is a diagram showing a configuration example of a moisture detection pad in Embodiment 1 of the present disclosure. Figure 5 This is a block diagram showing a modified example of the control device in Embodiment 1 of the present disclosure. Figure 6 This is a diagram showing a schematic configuration of a vehicle electronic control device according to a second embodiment of the present disclosure. Figure 7 This is a block diagram showing a circuit configuration of a vehicle electronic control device according to a second embodiment of the present disclosure. Figure 8 It is a diagram showing a configuration example of a moisture detection terminal in Embodiment 2 of the present disclosure. DETAILED DESCRIPTION

[0012] Hereinafter, the electronic control device for a vehicle and the electric power steering device according to the embodiments of the present disclosure will be described in detail with reference to the drawings. In addition, in each embodiment, the same or corresponding parts are marked with the same reference numerals, and the description of the repeated parts is omitted.

[0013] (Implementation Method 1) <Electric Power Steering> Figure 11 is a block diagram showing the main structure of the electric power steering device according to the first embodiment of the present disclosure. Figure 1 As shown, the electric power steering device PS of this embodiment includes a steering wheel 1, a steering shaft 2, a rack bar 3, a motor 4, a power transmission mechanism 5, a control device 6 (vehicle electronic control device), a connector 7 (vehicle electronic control device) and a housing 8.

[0014] The steering wheel 1 is a so-called steering wheel, and is operated by the driver of the vehicle to provide a steering angle to a steering wheel (not shown) of the vehicle. The steering shaft 2 is connected to the steering wheel 1, and rotates according to the rotation of the steering wheel 1. The rack bar 3 is coupled to the steering shaft 2, and moves in the axial direction according to the rotation of the steering shaft 2. In addition, a mechanism for steering a steering wheel (not shown) including the steering wheel 1, the steering shaft 2, and the rack bar 3 is referred to as a "steering gear".

[0015] The motor 4 provides a steering assist torque to the steering gear under the control of the control device 6. The motor 4 is a three-phase brushless motor having a three-phase winding composed of, for example, a U-phase winding, a V-phase winding, and a W-phase winding. In addition, the motor 4 may be a motor having a brush or a multi-phase motor having a multi-phase winding of three or more phases. The power transmission mechanism 5 converts the rotational force of the output shaft of the motor 4 into an axial force of the rack bar 3 and transmits it to the rack bar 3.

[0016] The control device 6 controls the driving of the motor 4 based on the detection results of various sensors (not shown) for detecting the steering torque, steering angle, etc. of the steering wheel 1, thereby generating a steering assist torque for the steering gear. The connector 7 connects the control device 6 to the outside (for example, another ECU (Electronic Control Unit) provided in the vehicle). The housing 8 accommodates the rack bar 3 and the power transmission mechanism 5. In addition, the rack bar 3 and a part of the power transmission mechanism 5 are housed in the housing 8 having a waterproof structure.

[0017] <Electronic control device for vehicle> Figure 2 1 is a diagram showing a schematic structure of a vehicle electronic control device according to Embodiment 1 of the present disclosure. Figure 2 As shown, the control device 6 as a part of the electronic control device for a vehicle includes a substrate SB on which a circuit pattern is formed and various electronic components are mounted. Figure 3 The circuit shown in FIG. 1 realizes the function of the control device 6 .

[0018] The substrate SB includes a substrate SB whose surface is erected along the vertical direction VD. The substrate SB is connected to the winding 4a housed in the motor housing (not shown) of the motor 4, and is connected to the terminals T1 and T2 provided on the connector 7. In addition, the connector 7 can be arranged on the lateral side of the control device 6, or on the upper side or the lower side of the control device 6, but preferably, the terminals T1 and T2 are arranged above the moisture detection pad 15 (described in detail later).

[0019] Figure 3 is a block diagram showing the circuit structure of the control device in Embodiment 1 of the present disclosure. Figure 3 As shown, the control device 6 includes a CPU (Central Processing Unit) 11, a drive circuit 12, a motor driver 13, a motor terminal voltage monitor 14 and a moisture detection pad 15 (moisture detection unit).

[0020] The CPU 11 outputs a control signal for controlling the drive circuit 12 based on the detection results of the above-mentioned various sensors (sensors for detecting the steering torque, steering angle, etc. of the steering wheel 1). The drive circuit 12 generates a drive signal for driving the motor driver 13 under the control of the CPU 11. In addition, a sensor for detecting the current flowing through the motor driver 13 is provided in the drive circuit 12. The detection result of the sensor is output to the CPU 11.

[0021] The motor driver 13 drives the motor 4 based on the drive signal output from the drive circuit 12. The motor driver 13 includes an inverter that converts direct current supplied from an external power source into alternating current, for example, and supplies the converted alternating current (U-phase power, V-phase power, or W-phase power) to the motor 4. The motor terminal voltage monitor 14 monitors the terminal voltage of each phase (U-phase, V-phase, W-phase) of the motor 4. The terminal voltage monitored by the motor terminal voltage monitor 14 is output to the CPU 11 and monitored.

[0022] The moisture detection pad 15 is formed on the substrate SB and is a pad for detecting water stored in the control device 6 at the lower side in the vertical direction VD. The moisture detection pad 15 is formed as a part of the circuit pattern of the substrate SB, for example. Figure 2 As shown, the moisture detection pad 15 is arranged at the bottom of the vertical direction VD on the substrate SB. Specifically, the moisture detection pad 15 is preferably arranged at a lower position than other electronic components and energized through holes on the substrate SB. This is to detect water before other electronic components or energized through holes are affected by water and cause abnormalities in the energized current of the motor 4.

[0023] Figure 41 is a diagram showing a structural example of a moisture detection pad in Embodiment 1 of the present disclosure. Figure 4 As shown, the moisture detection pad 15 comprises pads 15a, 15b of a rectangular shape formed at regular intervals. The interval between pads 15a, 15b can be freely set according to required detection sensitivity. Pad 15a is grounded, and pad 15b is connected to motor terminal voltage monitor 14. When the moisture detection pad 15 is immersed in water, the resistance between pads 15a, 15b changes. By this resistance change, the water stored in the vertical direction VD lower side in the control device 6 can be detected.

[0024] like Figure 3 As shown, the moisture detection pad 15 is connected to the motor terminal voltage monitor 14. The motor terminal voltage monitor 14 is set to change the output voltage according to the change of the resistance of the moisture detection pad 15. The CPU 11 determines whether there is an abnormality based on the output voltage of the motor terminal voltage monitor 14.

[0025] In the above structure, when water enters the control device 6, the entered water is stored on the lower side of the vertical direction VD of the control device 6. When the amount of water stored on the lower side of the vertical direction VD of the control device 6 increases, and both the pads 15a and 15b provided on the moisture detection pad 15 are immersed in water, the resistance of the moisture detection pad 15 changes. When the resistance of the moisture detection pad 15 changes, the output voltage of the motor terminal voltage monitor 14 changes, and thus the CPU 11 determines that an abnormality has occurred.

[0026] As mentioned above, in the present embodiment, water detection pad 15 is arranged on the bottom of the vertical direction VD of the substrate SB possessed by control device 6, and the water on the lower side of the vertical direction VD stored in control device 6 is detected according to the change of the resistance of water detection pad 15.Here, in the present embodiment, owing to water detection pad 15 is formed as a part of the circuit pattern of substrate SB, therefore the interval between pad 15a, 15b can be freely set according to required detection sensitivity, and the deviation of the interval between pad 15a, 15b can be reduced.Therefore, compared with prior art (technology of detecting water intruding motor based on the resistance change between motor line and motor housing), detection sensitivity is easily improved.

[0027] Furthermore, in this embodiment, unlike the prior art, the water is not detected by the change in resistance between the motor wire and the motor housing, but the water stored on the lower side in the vertical direction VD in the control device 6 is detected by using a dedicated moisture detection pad 15 formed on the substrate SB. Therefore, even if the motor 4 is being driven, it is not affected by the change in the motor terminal voltage, so the intrusion of water can be detected with high accuracy regardless of whether the motor 4 is being driven.

[0028] In addition, in this embodiment, the moisture detection pad 15 is connected to the motor terminal voltage monitor 14, and when the resistance of the moisture detection pad 15 changes, the output voltage of the motor terminal voltage monitor 14 changes. Then, the PCU 11 determines whether there is an abnormality based on the output voltage of the motor terminal voltage monitor 14. As a result, an additional detection circuit is not required, and the increase in component area and cost can be suppressed.

[0029] In addition, in the above-mentioned embodiment, the example of forming a moisture detection pad 15 at the bottom of the substrate SB that is erected is described. However, the moisture detection pad 15 can be formed with a plurality of moisture detection pads 15 at the bottom of the substrate SB. By forming a plurality of moisture detection pads 15, for example, even if the installation angle of the control device 6 with respect to the vehicle changes, at least one of the plurality of moisture detection pads 15 can be configured at the bottom.

[0030] <Modification of the control device> Figure 5 is a block diagram showing a modified example of the control device in the first embodiment of the present disclosure. Figure 5 In, with Figure 3 The same modules are marked with the same reference numerals. Figure 5 The control device 6A of this modified example is shown in Figure 3 The control device 6 shown in the figure is provided with a moisture detection circuit 16 (moisture detection unit) and Figure 3 The control device 6 shown has a structure in which the CPU 11 is replaced with a CPU 11A.

[0031] Moisture detection circuit 16 is arranged between moisture detection pad 15 and CPU11A, detects moisture based on the resistance change of moisture detection pad 15, and outputs the result to CPU11A. Moisture detection circuit 16 is a structure including a conversion circuit that for example converts the resistance of moisture detection pad 15 into voltage and a comparison circuit that the voltage after being converted by the conversion circuit is compared with the determination threshold voltage for judging whether there is moisture. Moisture detection circuit 16 with this structure can only adjust the detection sensitivity by changing the determination threshold voltage, without changing moisture detection pad 15. Therefore, when changing the detection sensitivity, it is not necessary to change the man-hour and the expense of substrate SB.

[0032] CPU11A has Figure 3 However, the CPU 11A determines the presence or absence of abnormality based on the moisture detection result output from the moisture detection circuit 16 instead of the output voltage of the motor terminal voltage monitor 14 .

[0033] For example, moisture detection circuit 16 can be for example only the structure that comprises the conversion circuit that is used for converting the resistance of moisture detection pad 15 into voltage.Under the situation of this structure, the voltage after being converted by the conversion circuit can be output to CPU11A, and be judged by CPU11A whether there is moisture.By changing the program used in CPU11A, can easily change the determination threshold value that is used for judging whether there is moisture.Therefore, when changing the detection sensitivity, do not need to change the man-hour and the expense of substrate SB.

[0034] (Implementation Method 2) <Electric Power Steering> The electric power steering device of this embodiment has Figure 1 That is, it includes a steering wheel 1, a steering shaft 2, a rack bar 3, a motor 4, a power transmission mechanism 5, a control device 6, a connector 7, and a housing 8. Therefore, a detailed description of the electric power steering device of this embodiment will be omitted.

[0035] <Electronic control device for vehicle> Figure 6 2 is a diagram showing a schematic structure of a vehicle electronic control device according to a second embodiment of the present disclosure. Figure 6 In, with Figure 2 The same structures are marked with the same reference numerals. Figure 6 As shown, in this embodiment, a moisture detection terminal 17 (moisture detection unit) is provided on the connector 7 constituting a part of the vehicle electronic control device, and the moisture detection pad 15 (refer to FIG. 1 ) of the control device 6 constituting a part of the vehicle electronic control device is omitted. Figure 2 That is, in the present embodiment, the moisture detection terminal 17 is provided in the connector 7 instead of the moisture detection pad 15 of the control device 6 .

[0036] The moisture detection terminal 17 is arranged at the lowest part in the vertical direction VD in the connector 7. Specifically, the moisture detection terminal 17 is preferably arranged at a lower position than the substrate SB provided on the control device 6. This is to detect water before the electronic components or the power through holes provided on the substrate SB are affected by water and cause abnormalities in the power current of the motor 4, etc., in the event of water infiltration. Such a connector 7 is connected to the substrate SB of the control device 6.

[0037] In addition, in Embodiment 1, the connector 7 may be provided on any of the lateral side, the upper side, and the lower side of the control device 6. However, in this embodiment, in order to prevent the electronic components or the power-carrying through holes provided on the substrate SB of the control device 6 from being affected by water, the connector 7 is arranged on the lateral side or the lower side of the control device 6.

[0038] Figure 7 : is a block diagram showing a circuit structure of a vehicle electronic control device according to a second embodiment of the present disclosure. Figure 7 As shown in FIG. 1 , the electronic control device for a vehicle of the present embodiment includes a control device 6B and a connector 7. The control device 6B has a connector 7a and a connector 7b. Figure 5 The structure of the moisture detection pad 15 included in the control device 6A shown in the figure. The moisture detection terminal 17 provided on the connector 7 is connected to the moisture detection circuit 16 of the control device 6B.

[0039] Figure 8 2 is a diagram showing a structural example of a moisture detection terminal in Embodiment 2 of the present disclosure. Figure 8 As shown, the water detection terminal 17 comprises terminals 17a, 17b of a rectangular shape formed at a predetermined interval. Since the water detection terminal 17 is formed by, for example, inserting resin molding or external embedding, the interval between the terminals 17a, 17b can be freely set according to the required detection sensitivity. Terminals 17a, 17b are all connected to the water detection circuit 16 of the control device 6B. When the water detection terminal 17 is immersed in water, the resistance between the terminals 17a, 17b changes. The water detection circuit 16 detects water based on the resistance change of the water detection terminal 17, and outputs its result to CPU11A. CPU11A judges whether there is anomaly based on the water detection result output from the water detection circuit 16. In this way, the water stored in the vertical direction VD lower side in the connector 7 can be detected.

[0040] In the above structure, when water enters the connector 7, the entered water is stored on the lower side of the vertical direction VD of the connector 7. When the amount of water stored on the lower side of the vertical direction VD of the connector 7 increases, and both the terminals 17a and 17b provided at the water detection terminal 17 are immersed in water, the resistance of the water detection terminal 17 changes. As a result, the voltage converted by the water detection circuit 16 changes, thereby causing the comparison result of the determination threshold voltage to change. As a result, the detection result indicating that water is detected is output from the water detection circuit 16, and the CPU 11A determines that an abnormality has occurred based on the detection result of the water detection circuit 16.

[0041] As described above, in the present embodiment, the water detection terminal 17 is disposed at the lowest portion of the vertical direction VD of the connector 7, and water stored in the lower side of the vertical direction VD in the connector 7 is detected based on the change in the resistance of the water detection terminal 17. Here, in the present embodiment, since it is formed by insert resin molding or external embedding, the interval between the terminals 17a and 17b can be freely set according to the required detection sensitivity, and the deviation of the interval between the terminals 17a and 17b can be reduced. Therefore, it is easy to improve the detection sensitivity compared with the related art (a technique for detecting water intrusion into the motor based on a change in resistance between the motor wire and the motor housing).

[0042] Furthermore, in this embodiment, unlike the prior art, water is not detected by the change in resistance between the motor wire and the motor housing, but water stored on the lower side of the vertical direction VD in the connector 7 is detected by using the dedicated water detection terminal 17 provided in the connector 7. Therefore, even if the motor 4 is being driven, it is not affected by the change in the voltage at the motor terminal, so the intrusion of water can be detected with high accuracy regardless of whether the motor 4 is being driven.

[0043] In addition, in the present embodiment, the moisture detection terminal 17 is connected to the moisture detection circuit 16 of the control device 6B, the resistance of the moisture detection terminal 17 is converted into a voltage, and the moisture is detected according to the comparison result between the converted voltage and the judgment threshold voltage. Therefore, in the present embodiment, the detection sensitivity can be adjusted only by changing the judgment threshold voltage without changing the moisture detection terminal 17. Therefore, when the detection sensitivity is changed, the man-hours and expenses of the connector 7 do not need to be changed.

[0044] In addition, as in the modified example of embodiment 1, the moisture detection circuit 16 can be a structure that only includes a conversion circuit for converting the resistance of the moisture detection terminal 17 into a voltage. In the case of this structure, the voltage converted by the conversion circuit can be output to the CPU 11A, and the CPU 11A determines whether there is moisture. By changing the program used in the CPU 11A, the determination threshold for determining whether there is moisture can be easily changed. Therefore, when the detection sensitivity is changed, it is not necessary to change the man-hours and expenses of the connector 7.

[0045] In addition, in the above-mentioned embodiment, an example in which one moisture detection terminal 17 is provided at the lowest portion of the connector 7 is described. However, a plurality of moisture detection terminals 17 may be provided at the lowest portion of the connector 7. By providing a plurality of moisture detection terminals 17, for example, even if the installation angle of the control device 6B relative to the vehicle is changed, at least one of the plurality of moisture detection terminals 17 may be configured at the lowest portion.

[0046] The embodiments of the present disclosure have been described above, but the present disclosure is not limited to the above-described embodiments and may be freely changed without departing from the spirit of the present disclosure. Description of symbols

[0047] 4…motor, 6, 6A, 6B…control device, 7…connector, CPU…11, 11A, 14…motor terminal voltage monitor, 15…moisture detection pad, 15a, 15b…gasket, 16…moisture detection circuit, 17…moisture detection terminal, 17a, 17b…terminal, PS…electric power steering device, SB…substrate, VD…vertical direction.

Claims

1. An electronic control device for a vehicle, It is characterized in that include: a control device, the control device controlling the electric motor; a connector for connecting the control device to the outside; as well as A moisture detection unit is provided in the control device or in the connector and detects water stored in the control device or in the connector at a vertically lower side.

2. The electronic control device for a vehicle according to claim 1, It is characterized in that The moisture detection unit includes a moisture detection pad formed on a substrate in the control device.

3. The vehicle electronic control device according to claim 2, It is characterized in that The moisture detection pad is located at a lower position than other electronic components and power-on vias on the substrate.

4. The vehicle electronic control device according to claim 2 or 3, It is characterized in that The control device includes: a motor terminal voltage monitor that monitors the terminal voltage of the motor; and A CPU monitors the monitoring result of the motor terminal voltage monitor, The moisture detection pad is connected to the motor terminal voltage monitor, The motor terminal voltage monitor is configured to change the output voltage according to the change of the resistance of the moisture detection pad. The CPU determines whether or not there is an abnormality based on an output voltage of the motor terminal voltage monitor.

5. The vehicle electronic control device according to claim 2 or 3, It is characterized in that The moisture detection unit includes a moisture detection circuit, which detects water stored in the control device according to a change in the resistance of the moisture detection pad. The control device includes a CPU, and the CPU determines whether there is an abnormality based on the detection result of the moisture detection circuit.

6. The vehicle electronic control device according to claim 1, It is characterized in that The moisture detection unit includes a moisture detection terminal disposed in the connector.

7. The vehicle electronic control device according to claim 6, It is characterized in that The moisture detection terminal is located at a lower position than the substrate in the control device.

8. The vehicle electronic control device according to claim 6 or 7, It is characterized in that The moisture detection unit includes a moisture detection circuit, which detects water stored in the control device according to a change in resistance of the moisture detection terminal. The control device includes a CPU, and the CPU determines whether there is an abnormality based on the detection result of the moisture detection circuit.

9. An electric power steering device, It is characterized in that include: an electric motor that generates a steering assist torque for the steering gear; as well as The vehicle electronic control device according to any one of claims 1 to 8, wherein the vehicle electronic control device controls the driving of the electric motor.

Images