Vehicle-mounted snow melting device

Abstract

To solve stuck that is caused by contact between snow piled on a road surface and an undersurface of a vehicle in a snowy road with a simple configuration for an on-board snow melting device.SOLUTION: An on-board snow melting device includes: an electrical heating wire 7 laid at an undersurface of a vehicle 10 so as to face a road surface on which the vehicle 10 travels; detection means 11-14 for detecting stuck of the vehicle 10 in a snowy road; and control means 20 for performing control of energizing the electrical heating wire 7 when detecting that the vehicle 10 is stuck in a snowy road.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an in-vehicle snow melting device mounted on a vehicle.

Background Art

[0002] Conventionally, as a device for assisting the driving operation of a vehicle in a cold region, there is known a device that melts snow accumulated on a glass by energizing a heating wire attached to the front glass. This type of heating wire is disposed, for example, outside the wiping area of the front glass by a wiper blade in the vehicle width direction. The wiper blade acts to move the snow accumulated on the glass toward the area where the heating wire is laid. Thereby, the snow accumulated on the glass is efficiently melted, and it becomes easier to secure the driver's field of view (see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] On the other hand, when the vehicle travels on a road surface where snow has not been removed or a road surface with deep grooves (furrows) formed by snow accumulation, the vehicle may stack up when the wheels are separated from the road surface while the lower surface of the vehicle is in contact with the snow on the road surface. In this case, even if the accelerator pedal is depressed, the wheels spin, and there is a problem that it is necessary to move the vehicle with other vehicles or a large number of people to ground the wheels. Such a problem becomes prominent in a vehicle with a low vehicle height (that is, a vehicle that is likely to be in a state where the lower surface of the vehicle rides on the snow on the road surface).

[0005] One of the objectives of this invention is to provide an on-board snow-melting device that can resolve vehicle-related issues such as getting stuck due to contact between the snow on the road surface and the underside of the vehicle, with a simple configuration, in light of the problems described above. However, other objectives of this invention include achieving effects and benefits that cannot be obtained with conventional technology, derived from the various configurations shown in the "Modes for Carrying Out the Invention" section below. [Means for solving the problem]

[0006] The disclosed vehicle-mounted snow melting device can be realized in the following embodiments (application examples) and solves at least some of the above-mentioned problems. Each of the embodiments from Embodiment 2 onward is an additional embodiment that can be appropriately selected and each of them is an embodiment that can be omitted. None of the embodiments from Embodiment 2 onward disclose any embodiments or configurations that are indispensable to this case.

[0007] Embodiment 1. The on-board snow melting device disclosed comprises a heating wire routed on the underside of the vehicle so as to face the road surface on which the vehicle travels, a detection means for detecting the vehicle getting stuck on a snowy road, and a control means for performing control to energize the heating wire when the vehicle getting stuck on a snowy road is detected. Embodiment 2. In Embodiment 1 described above, it is preferable that the vehicle is an electric vehicle equipped with a drive motor and a traction battery, and that the control means performs control to supply power from the traction battery to the heating element.

[0008] Embodiment 3. In Embodiment 2 described above, it is preferable that the vehicle is a hybrid vehicle equipped with a drive engine, and the control means performs control to start the drive engine. Embodiment 4. In Embodiment 3 described above, it is preferable that the hybrid vehicle is equipped with a generator that generates electricity using the power of the drive engine, and that the control means performs control to supply the power generated by the generator to the traction battery and the heating element.

[0009] Embodiment 5. In Embodiment 3 or 4 above, it is preferable that the exhaust pipe of the drive engine is routed on the underside of the vehicle, and the heating element is routed in a meandering manner so as to avoid the exhaust pipe and cover a planar area when viewed from the underside of the vehicle. Embodiment 6. In an embodiment including Embodiment 1 described above, it is preferable that the detection means determines that the distance of the wheels from the vehicle body is greater than or equal to a predetermined distance when detecting the stack.

[0010] Embodiment 7. In an embodiment including Embodiment 1 described above, it is preferable that the detection means determines an increase in the rotational speed of the drive wheels when detecting the stack. Embodiment 8. In an embodiment including Embodiment 1 described above, it is preferable that the detection means determines whether the vehicle has stopped when detecting the stack. Embodiment 9. In an embodiment including Embodiment 1 described above, it is preferable that the detection means determines that the temperature on the underside of the vehicle is below a predetermined temperature when detecting the stack. [Effects of the Invention]

[0011] According to the disclosed on-board snow melting device, when a vehicle is detected to be stuck on a snowy road, a control is implemented to energize heating wires routed on the underside of the vehicle so as to face the road surface, thereby efficiently melting the snow accumulated on the underside of the vehicle. This reduces the distance between the underside of the vehicle and the road surface (bottom of the rut) beneath the wheels, allowing the wheels to make contact with the road surface. Therefore, a simple configuration can be used to resolve the issue of the vehicle getting stuck on snowy roads. [Brief explanation of the drawing]

[0012] [Figure 1] This is a block diagram showing the configuration of a vehicle to which the on-board snow melting device of the present invention is applied. [Figure 2] Figure 1 is a schematic diagram illustrating the underside structure of the vehicle shown. [Figure 3] This block diagram shows the configuration of the control device as shown in Figure 1. [Figure 4]This is a flowchart illustrating the control flow by the control device. [Figure 5] This is a flowchart illustrating the control flow by the control device. [Modes for carrying out the invention]

[0013] The disclosed on-board snow melting device is applied to a vehicle 10 as shown in the following embodiment. This vehicle 10 is provided with heating wires 7 routed on its underside so as to face at least the road surface on which the vehicle 10 travels. The power supplied to the heating wires 7 is provided from a power storage device mounted on the vehicle 10. Specific examples of the power storage device include an auxiliary battery (12V battery), the vehicle 10's traction battery, a general-purpose storage battery, a fuel cell, and the like.

[0014] Suitable vehicles 10 to which the disclosed on-board snow melting device is applied include, for example, electric vehicles equipped with a drive motor and a traction battery. In this case, the traction battery, which stores the power to drive the drive motor, can be used as the power source for the heating element 7. Another suitable vehicle 10 is a hybrid vehicle equipped with a drive engine and a generator that generates electricity using engine power. In this case, it is possible to power the heating element 7 using the electricity generated by the generator.

[0015] The vehicle 10 described in the following embodiment is a plug-in hybrid electric vehicle (PHEV) equipped with a drive motor, a drive engine, a generator, and a traction battery. A plug-in hybrid vehicle refers to a hybrid vehicle that can be externally charged for its traction battery, or can supply power to various electrical appliances from its traction battery. The plug-in hybrid vehicle described here is provided with a charging port (inlet) for inserting a charging cable into which power is supplied from an external charging facility, and an outlet for external power supply. [Examples]

[0016] [1. Configuration] FIG. 1 is a block diagram showing the configuration of a vehicle 10 to which an in-vehicle snow melting device as an embodiment is applied. This vehicle 10 is a hybrid vehicle (electric vehicle) including a motor 1 (driving motor) and an engine 2 (driving engine) as driving sources, a generator 3 connected to the drive shaft of the engine 2, and an inverter 4 and a battery 5 (travel battery) connected to the motor 1 and the generator 3.

[0017] The motor 1 is, for example, a three-phase AC synchronous motor / generator. The motor 1 has a function of driving the vehicle 10 using the power of the battery 5 or the generated power of the generator 3, and a function of charging the battery 5 by regenerative power generation. The drive shaft of the motor 1 is connected to the drive wheels of the vehicle 10. A transmission mechanism or a differential mechanism (not shown) may be interposed on the power transmission path connecting the motor 1 and the drive wheels. The number of motors 1 is not limited. For example, a single motor 1 may drive the front wheels and / or the rear wheels, or a device configuration may be adopted in which a plurality of motors 1 are used to individually drive the front wheels and the rear wheels.

[0018] The engine 2 is, for example, an internal combustion engine such as a gasoline engine or a diesel engine. The exhaust pipe 6 of the engine 2 is routed along the lower surface of the vehicle 10 in the longitudinal direction of the vehicle. The generator 3 is, for example, a three-phase AC synchronous motor / generator. The generator 3 has a function as a motor for cranking when starting the engine 2 and a function as a generator for generating power when driven by the engine 2 after starting. The generated power of the generator 3 is used for driving the motor 1 or charging the battery 5. A transmission mechanism (not shown) may be interposed on the power transmission path connecting the engine 2 and the generator 3.

[0019] The battery 5 is a secondary battery that can supply a high-voltage direct current of several hundred volts, such as a lithium-ion secondary battery, a nickel-metal hydride battery, etc. The battery 5 is connected to the motor 1 and the generator 3 via an inverter 4. The inverter 4 is a power conversion device for converting the direct current power on the battery 5 side and the alternating current power on the motor 1 and generator 3 sides. The inverter 4 incorporates an inverter circuit including switching elements such as IGBTs (Insulated Gate Bipolar Transistors) and MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors).

[0020] By controlling the operating state (the on / off timing and driving frequency of the switching elements) of the inverter 4, the outputs (torques) of the motor 1 and the generator 3 are controlled. The operating state of the inverter 4 is controlled by the control device 20. The control device 20 is an electronic control device (computer, ECU, Electronic Control Unit) having at least the function of controlling the outputs (torques) of the motor 1 and the generator 3. Inside the control device 20, for example, a processor (central processing unit), a memory (main memory), a storage device (storage), an interface device, etc. are incorporated. The content of the control (control program) implemented by the control device 20 is stored in the memory, and the content is executed by being appropriately read into the processor.

[0021] As a driving mode (control mode regarding the driving force transmission path and the combination of driving forces used), the vehicle 10 has an EV mode in which the motor 1 is used for driving while the engine 2 is stopped, and a hybrid mode in which the motor 1 and the engine 2 are used together (in some cases, the engine 2 alone is used) for driving. The EV mode is a driving mode automatically selected in a relatively low-speed driving state, and the hybrid mode is a driving mode automatically selected in a relatively high-speed driving state. For the specific switching conditions of these driving modes, various known conditions can be applied.

[0022] A heating element 7 is provided on the underside of the vehicle 10 to melt snow on the underside of the vehicle 10 if the vehicle 10 gets stuck on a snowy road. The heating element 7 is routed on the underside of the vehicle 10 so as to face the road surface on which the vehicle 10 travels. As shown in Figure 1, the heating element 7 is provided in parallel with the inverter 4, branching off from the DC circuit connecting the battery 5 and the inverter 4. A switch 8 is also interposed along the routing path of the heating element 7 to control the energization state of the heating element 7. The operation state of the switch 8 is controlled by the control device 20.

[0023] Figure 2 illustrates the routing layout of the heating element 7. In a view from below the vehicle 10, the heating element 7 is routed to avoid the exhaust pipe 6 of the engine 2 and is routed in a meandering manner to cover a planar area. The exhaust pipe 6 of the engine 2 shown in Figure 2 is positioned, for example, near the center of the vehicle 10 in the width direction, and extends in the longitudinal direction of the vehicle. The rear end of the exhaust pipe 6 is connected to a muffler 16 located at the rear of the underside of the vehicle 10. The underside of the vehicle 10 is covered by a flat underside plate 17, and a slit-shaped cutout is formed in this underside plate 17 to expose the exhaust pipe 6 to the underside of the vehicle 10. The exhaust pipe 6 is routed in a layout corresponding to this slit-shaped cutout.

[0024] The heating element 7 is routed along the surface of the lower plate 17 on its underside. Preferably, the lower plate 17 is made of a material with high thermal conductivity. Furthermore, to enhance the protection of the exhaust pipe 6, the lower plate 17 is preferably routed almost horizontally below the lower end of the exhaust pipe 6. In this case, the heating element 7 is routed below the exhaust pipe 6 (i.e., closer to the road surface than the exhaust pipe 6), making it easier to efficiently melt snow on the underside of the vehicle 10 with the heating element 7.

[0025] In this embodiment, the control device 20 functions as a control means for performing snow-melting control to resolve a stuck state when the vehicle 10 becomes stuck on a snowy road. In performing this snow-melting control, the control device 20 controls the operating states of the engine 2, generator 3, inverter 4, switch 8, etc., based on information obtained from various devices. In addition, the control device 20 is connected to a tire position sensor 11, an underbody temperature sensor 12, an accelerator opening sensor 13, and a wheel speed sensor 14 via an in-vehicle communication network (not shown). The control device 20 performs snow-melting control based on the information obtained from these various sensors 11 to 14. These various sensors 11 to 14 also function as detection means for detecting when the vehicle 10 is stuck on a snowy road, in cooperation with the control device 20.

[0026] The tire position sensor 11 is a sensor for detecting the degree to which the wheel 15 is lifted off the road surface, and it detects the distance from the vehicle body to the axle of the wheel 15. For example, the tire position sensor 11 detects the distance from the vehicle body to the axle of the wheel 15 based on the amount of extension and contraction of the suspension connecting the wheel 15 and the side member. This distance becomes extremely large, for example, when the underside of the vehicle 10 is in contact with snow on the road surface and the wheel 15 is lifted off the road surface. Therefore, if this distance is greater than or equal to a predetermined distance, it can be determined that the wheel 15 is lifted off the road surface. The tire position sensor 11 is provided on at least the drive wheels.

[0027] The underside temperature sensor 12 is a sensor that detects the temperature of the underside of the vehicle 10. When the vehicle 10 is driving on a snowy road, the temperature detected here will be close to the freezing point. Therefore, based on the temperature detected here, it is possible to determine whether or not the vehicle 10 is driving on a snowy road. The underside temperature sensor 12 is installed at multiple locations on the underside of the vehicle 10, for example, as shown in Figure 2. The accelerator pedal position sensor 13 is a sensor that detects the amount the accelerator pedal is pressed. The wheel speed sensor 14 is a sensor that detects the angular velocity of the wheels 15. Based on the angular velocity detected here, the vehicle speed (movement speed) and odometer value (odometer reading, cumulative distance traveled) of the vehicle 10 are calculated. The wheel speed sensor 14 is installed on each of the four wheels, for example.

[0028] Figure 3 is a block diagram illustrating the specific configuration of the control device 20. This control device 20 includes a PHEV-ECU 21 (vehicle control device), an engine ECU 22 (engine control device), a motor ECU 23 (motor control device), and a BMU 24 (Battery Management Unit). These ECUs 21 to 24 are connected to each other via an in-vehicle communication network (not shown).

[0029] The PHEV-ECU21 is an electronic control unit that comprehensively manages all other electronic control units installed in the vehicle 10. Here, the operating status of various devices included in the powertrain and the driving status of the vehicle 10 are monitored, and the operating status of various devices by the various electronic control units is centrally managed. The driving mode of the vehicle 10 is selected and set by the PHEV-ECU21 based on the driving status of the vehicle 10 and the driver's input. In addition, the operating status of switch 8 in this embodiment is controlled by the PHEV-ECU21 or BMU24.

[0030] The engine ECU22 is an electronic control unit that specializes in controlling the operating state of engine 2. The motor ECU23 is an electronic control unit that specializes in controlling the operating state of motor 1, generator 3, and inverter 4. The output of motor 1 and generator 3 is controlled by the motor ECU23. The BMU24 is an electronic control unit that controls the operating state of battery 5. Here, the voltage, current, temperature, etc. of battery 5 are measured, and the charge level (SOC, State of Charge), degradation level (SOH, State of Health), maximum output, etc. are calculated.

[0031] [2. Control] The snow melting control performed by the control device 20 will be described in detail. The snow melting control in this embodiment is a control that melts the snow accumulated on the underside of the vehicle 10, and is started at least when the vehicle 10 gets stuck on a snowy road. Various conditions for determining whether or not the vehicle is stuck on a snowy road are exemplified below. In this embodiment, the snow melting control is started when both start conditions 1 and 2 are met, and either start condition 3 or 4 is met.

[0032] Starting condition 1. The driving mode of vehicle 10 is EV mode. Starting condition 2. The temperature on the underside of the vehicle 10 is below a predetermined temperature. Starting condition 3. The wheels 15 (drive wheels) are lifted off the road surface. Starting condition 4. Vehicle 10 is unable to move in response to accelerator operation. Starting condition 5. Vehicle 10's current location is within a snowy area. Starting condition 6. It is snowing at vehicle 10's current location. Starting condition 7. The charge level of battery 5 is above the specified charge level.

[0033] Starting condition 1 can be determined based on the driving mode set in the PHEV-ECU21. Determining starting condition 1 can promote snow melting on the underside of the vehicle 10 in situations where exhaust heat from the engine 2 cannot be expected. Starting conditions 2 to 4 can be determined based on information detected by the various sensors 11 to 14 described above. The predetermined temperature included in starting condition 2 is set to a temperature close to the freezing point, where the presence of snow on the road surface is estimated. Starting condition 3 can be determined, for example, by calculating the distance from the vehicle body to the axle of the wheel 15 based on the detected value of the tire position sensor 11, and confirming that this distance is greater than or equal to a predetermined distance. Alternatively, it can be determined if the state in which the distance is greater than or equal to a predetermined distance continues for a predetermined time or longer.

[0034] Starting conditions 5 and 6 can be determined based on, for example, the location information of the vehicle 10 measured by a car navigation system (not shown) or weather information obtained via the internet. Starting condition 7 can be determined based on the charge rate calculated by the BMU 24. In addition to the above, other starting conditions may be checked, such as whether there is a malfunction in the engine 2 or generator 3, the degree of deterioration of the battery 5, and the amount of fuel that can be supplied to the engine 2.

[0035] Furthermore, the snow melting control terminates when the vehicle 10 is freed from being stuck. However, if the snow melting control takes an excessively long time, the control may be stopped, taking into consideration possibilities such as over-discharge of the battery 5 or the presence of ice and snow that is difficult to melt. Examples of conditions for terminating the snow melting control are given below. In this embodiment, the snow melting control terminates when any of termination conditions 1 to 3 are met.

[0036] Termination condition 1. The snow melting control operation time exceeds the specified time. Termination condition 2. Wheel 15 (drive wheel) is in contact with the road surface. Termination condition 3. Vehicle 10 becomes capable of moving in response to accelerator operation. Termination condition 4. The charge level of battery 5 falls below the predetermined second charge level.

[0037] Termination condition 1 can be determined based on the duration of snow melting control, which is measured by a timer (not shown). The predetermined time included in termination condition 1 is set, for example, within a range of several minutes to several tens of minutes. Termination conditions 2 and 3 can be determined based on the information detected by the various sensors 11, 13, and 14 described above, and termination condition 4 can be determined based on the charge rate calculated by the BMU 24. The predetermined second charge rate for termination condition 4 may be the same value as the predetermined charge rate for start condition 7, or it may be a lower value than the predetermined charge rate. In addition to the above, termination conditions may also be checked for the presence or absence of engine 2 or generator 3 malfunctions, the degree of battery 5 deterioration, the amount of fuel that can be supplied to engine 2, etc.

[0038] Snow melting control includes a control that melts snow on the underside of the vehicle 10 by energizing the heating element 7 with at least the power from the battery 5. Preferably, in addition to this, it also includes a control that operates the engine 2 (a control that melts snow on the underside of the vehicle 10 using exhaust heat) and a control that energizes the heating element 7 with the power generated by the generator 3 (a control that melts snow on the underside of the vehicle 10 using the power generated by the generator 3). The operating state of the engine 2 is controlled by the engine ECU 22, and the operating state of the generator 3 is controlled by the motor ECU 23. In addition, the operating state of the switch 8 of the heating element 7 is controlled by the PHEV-ECU 21 and BMU 24.

[0039] [3. Flowchart] Figures 4 and 5 are flowcharts illustrating the procedure for snow melting control. The flowchart shown in Figure 4 relates to the determination of the start conditions for snow melting control and is executed repeatedly at predetermined intervals when the main switch (main power supply) of vehicle 10 is ON. The flowchart shown in Figure 5 relates to the determination of the end conditions for snow melting control and is executed repeatedly at predetermined intervals after snow melting control has started, instead of the flowchart shown in Figure 4.

[0040] In step A1 of Figure 4, it is determined whether the vehicle 10 is in EV mode. If the driving mode is EV mode, the process proceeds to step A2; otherwise, the control cycle ends. In step A2, it is determined whether or not the accelerator has been operated based on the detection information from the accelerator opening sensor 13. If the accelerator has been operated, the process proceeds to step A3; if there has been no accelerator operation, the process proceeds to step A5.

[0041] In step A3, it is determined whether the current value (latest value) of the tire rotation speed for the drive wheels is greater than the previous value (value calculated in a previous calculation cycle). Here, it is determined whether the drive wheels are rotating due to accelerator operation. If the drive wheels are rotating, the process proceeds to step A4; if they are not rotating (for example, if the drive wheels are constrained for some reason), the control for this control cycle ends.

[0042] In step A4, it is determined whether or not vehicle 10 is stuck. For example, it is determined whether the current odometer value, calculated based on the detection value of the wheel speed sensor 14, is equal to the previous value (whether or not the odometer value is constant). Alternatively, it is determined whether or not the vehicle speed is approximately zero. If it is determined that vehicle 10 is stuck, the process proceeds to step A6; if it is determined that vehicle 10 is not stuck, the control for this control cycle ends.

[0043] In step A5, which is performed when there is no accelerator operation, it is determined whether or not lift of the drive wheels has been detected. For example, it is determined whether or not the distance from the vehicle body to the axle of the wheel 15, calculated based on the value detected by the tire position sensor 11, is greater than or equal to a predetermined distance. Alternatively, it is determined whether or not the state in which that distance is greater than or equal to the predetermined distance has continued for a predetermined time or longer. If lift of the drive wheels is detected, the process proceeds to step A6; otherwise, the control for this control cycle ends.

[0044] In step A6, it is determined whether the temperature of the underside of the vehicle 10 is below a predetermined temperature. While steps A2 to A5 are for detecting when the vehicle 10 is stuck, step A6 is for determining whether the stuck vehicle is stuck on a snowy road. If the temperature of the underside is below the predetermined temperature, the process proceeds to step A7. On the other hand, if the temperature is above the predetermined temperature, it is determined that the vehicle is stuck on a road other than a snowy road, and the control for this control cycle ends.

[0045] In step A7, a control signal for connecting switch 8 is output from PHEV-ECU21 or BMU24, energizing the heating element 7 and initiating snow melting control. At this time, timing is started by a timer (not shown), and the duration of snow melting control is counted. In the following step A8, a control signal for starting engine 2 is output from engine ECU22, and engine 2 is driven. The operating states of generator 3 and inverter 4 are controlled by motor ECU23, and the power generated by generator 3 is introduced into the DC circuit connecting inverter 4 and battery 5. As a result, the power generated by generator 3 is supplied to battery 5 and heating element 7.

[0046] When snow melting control is initiated, the flow shown in Figure 5 begins. In step B1 of Figure 5, it is determined whether the duration of snow melting control is less than a predetermined time. If the duration is less than the predetermined time, the process proceeds to step B2. If the duration is equal to or greater than the predetermined time, it is determined that the conditions for ending snow melting control are met, and the process proceeds to step B6. In step B6, a control signal to disconnect switch 8 is output from PHEV-ECU21 or BMU24, stopping the power supply to the heating element 7. In the following step B7, a control signal to stop engine 2 is output from engine ECU22, rendering engine 2 inoperable and stopping power generation by generator 3. This completes the snow melting control.

[0047] In step B2, the presence or absence of accelerator operation is determined based on the detection information from the accelerator position sensor 13. If accelerator operation is detected, the process proceeds to step B3; otherwise, the process proceeds to step B5. In step B3, similar to step A3, it is determined whether or not the drive wheels are rotating due to accelerator operation. If the drive wheels are rotating, the process proceeds to step B4; otherwise, it proceeds to step B8 and snow melting control continues.

[0048] In step B4, it is determined whether or not the vehicle 10 has been freed from being stuck. For example, it is determined whether the current odometer value, calculated based on the detection value of the wheel speed sensor 14, is greater than the previous value. Alternatively, it is determined whether or not the vehicle speed is greater than or equal to a positive predetermined speed. If it is determined that the vehicle 10 has been freed from being stuck, the process proceeds to step B6 to terminate the snow melting control. On the other hand, if it is determined that the vehicle 10 has not been freed from being stuck, the process proceeds to step B8, and the snow melting control continues.

[0049] In step B5, it is determined whether or not contact with the ground has been detected by the drive wheels. For example, it is determined whether the distance from the vehicle body to the axle of the wheel 15, calculated based on the value detected by the tire position sensor 11, is less than a predetermined distance (normal value). Alternatively, it is determined whether the state in which the distance is less than the predetermined distance (normal value) has continued for a predetermined time or longer. If contact with the ground of the drive wheels is detected, the process proceeds to step B6 to terminate the snow melting control. On the other hand, if contact with the ground of the drive wheels is not detected, the process proceeds to step B8, and the snow melting control continues.

[0050] [4. Effects] (1) The vehicle-mounted snow melting device according to the above embodiment comprises a heating element 7, detection means (various sensors 11 to 14 and a control device 20), and control means (control device 20). The heating element 7 is routed on the underside of the vehicle 10 so as to face the road surface on which the vehicle 10 travels. The detection means detects when the vehicle 10 is stuck on a snowy road. The control means performs control to energize the heating element 7 when it is detected that the vehicle 10 is stuck on a snowy road.

[0051] In the above embodiment, when vehicle 10 is detected to be stuck on a snowy road, a control is implemented to energize the heating wires 7 routed on the underside of vehicle 10 so as to face the road surface, thereby efficiently melting the snow accumulated on the underside of vehicle 10. This shortens the distance between the underside of vehicle 10 and the road surface (bottom of the rut) beneath the wheels 15, allowing the wheels 15 to make contact with the road surface (ground contact). Therefore, vehicle 10 can be resolved from being stuck on snowy roads with a simple configuration, improving the usability of vehicle 10.

[0052] (2) The above-described on-board snow melting device can be applied to an electric vehicle (vehicle 10) equipped with a drive motor (motor 1) and a traction battery (battery 5), as shown in Figure 1. The control means can also implement control to supply power from the traction battery to the heating element 7. With this configuration, snow melting can be promoted by utilizing the power of the traction battery, which is not consumed when the vehicle 10 is stuck. In addition, since the traction battery can output a large current compared to, for example, an auxiliary battery, it can efficiently resolve snow-stuck conditions in a short time, further improving the convenience of the vehicle 10.

[0053] (3) The above-described on-board snow melting device can be applied to a hybrid vehicle (vehicle 10) equipped with a drive engine (engine 2), as shown in Figure 1. The control means can perform control to energize the heating element 7 and control to start the drive engine. With this configuration, snow melting can be efficiently promoted by utilizing the heat from the exhaust pipe 6 of the drive engine. Therefore, snow-stuck situations can be resolved quickly and efficiently, further improving the convenience of the vehicle 10.

[0054] (4) The above-described on-board snow melting device can be applied to a hybrid vehicle (vehicle 10) equipped with a generator 3 that generates electricity using the power of the drive engine, as shown in Figure 1. The control means can also control the supply of power generated by the generator 3 to the traction battery and the heating element 7. With this configuration, the power generated by the generator 3 can be used to quickly and efficiently resolve snow-stuck conditions. In addition, the power of the traction battery can be conserved, so for example, a reduction in the driving range after resolving snow-stuck conditions can be prevented, and the driving performance of the vehicle 10 can be ensured. Therefore, the convenience of the vehicle 10 can be further improved.

[0055] (5) In the above embodiment, the exhaust pipe 6 of the drive engine is routed on the underside of the vehicle 10. Also, as shown in Figure 2, the heating wire 7 is routed in a meandering manner to cover a planar area while avoiding the exhaust pipe 6 when viewed from below the vehicle 10. With this configuration, the area on the underside of the vehicle 10 other than the exhaust pipe 6 can be efficiently heated by the heating wire 7. In addition, by not providing the heating wire 7 directly below the exhaust pipe 6, exhaust heat can be efficiently transferred to the snow surface. Furthermore, compared to the case in which the heating wire 7 is routed over the entire underside of the vehicle 10, the length of the heating wire 7 (total length) can be shortened, and the energy saving effect can be enhanced.

[0056] (6) The above detection means can determine if the distance of the wheel 15 from the vehicle body is greater than or equal to a predetermined distance when detecting a vehicle stuck. This determination is made, for example, by comparing the distance from the vehicle body to the axle of the wheel 15 detected by the tire position sensor 11 with a predetermined distance set in advance. With this configuration, the state in which the wheel 15 is lifted off the road surface can be accurately grasped, and the accuracy of detecting a vehicle stuck on a snowy road can be improved.

[0057] (7) The above detection means can determine an increase in the rotation speed of the drive wheels when detecting a stuck state. This determination is made by comparing the current value with the previous value of the tire rotation speed of the drive wheels, for example, as shown in step A3 of Figure 4. With this configuration, the slip state of the drive wheels due to accelerator operation when stuck (i.e., the state in which the vehicle 10 does not move forward even when the accelerator pedal is pressed) can be accurately grasped, and the accuracy of detecting a stuck state on a snowy road can be improved.

[0058] (8) The above detection means can determine if the vehicle 10 is stopped when detecting a stuck vehicle. This determination is made by comparing the current odometer value with the previous odometer value, for example, as shown in step A4 of Figure 4. With this configuration, it is possible to accurately determine if the vehicle 10 is stuck (stopped), and the accuracy of detecting a stuck vehicle on a snowy road can be improved.

[0059] (9) The above detection means can determine that the temperature of the underside of the vehicle 10 is below a predetermined temperature when detecting a vehicle getting stuck. With this configuration, it is possible to accurately determine when the vehicle 10 is stuck due to snow (i.e., not stuck on a muddy or gravel road), and the accuracy of detecting snow road stuckness can be improved.

[0060] [5. Others] The above embodiments are merely illustrative examples, and there is no intention to exclude various modifications or applications of techniques not explicitly stated in these embodiments. Each configuration of these embodiments can be modified in various ways without departing from their intended purpose. Furthermore, each configuration of these embodiments can be selected or combined as needed.

[0061] In the above embodiment, snow melting control performed when the vehicle 10 is in EV mode has been described in detail, but the control may also be performed in other driving modes. The start and end conditions for snow melting control can be changed as appropriate. In the above embodiment, four sensors 11 to 14 were used as examples to describe how they function as detection means in cooperation with the control device 20, but some of the sensors 11 to 14 may also function as detection means. At a minimum, by performing snow melting control when it is detected that the vehicle 10 is stuck on a snowy road, the snow accumulated on the underside of the vehicle 10 can be efficiently melted, and the vehicle 10 can be freed from being stuck.

[0062] Furthermore, in the snow melting control according to the above embodiment, in addition to energizing the heating element 7, the engine 2 is started to generate electricity in the generator 3, and the generated electricity is used to efficiently melt the snow. However, starting the engine 2 and generating electricity in the generator 3 may be omitted. Also, the power used to energize the heating element 7 may be from the battery 5 (driving battery), or from an auxiliary battery (12V battery) or fuel cell, etc., which are not shown. The power source for energizing the heating element 7 can be changed as appropriate. [Industrial applicability]

[0063] This technology is applicable to the manufacturing industry of on-board snow melting devices installed in vehicles, and also to the manufacturing industry of vehicles equipped with on-board snow melting devices. [Explanation of symbols]

[0064] 1. Motor (Drive motor) 2. Engine (Drive engine) 3 Generators 4 Inverters 5. Battery (driving battery) 6 Exhaust pipes 7 Heating wire 8 switches 10 vehicles (electric vehicles, hybrid vehicles) 11. Tire position sensor (detection means) 12. Bottom surface temperature sensor (detection means) 13. Accelerator opening sensor (detection means) 14. Wheel speed sensor (detection means) 15 wheels 16 muffler 17 Bottom plate 20 Control device (control means, detection means) 21 PHEV-ECU 22 Engine ECU 23 Motor ECU 24 BMU

Claims

1. A heating element is routed on the underside of the vehicle so as to face the road surface on which the vehicle travels, A detection means for detecting when the vehicle gets stuck on a snowy road, A control means that implements a control to energize the heating element when the vehicle is detected to be stuck on a snowy road, A vehicle-mounted snow melting device characterized by being equipped with the following features.

2. The aforementioned vehicle is an electric vehicle equipped with a drive motor and a traction battery, The control means performs control to supply power from the traction battery to the heating element. The vehicle-mounted snow melting device according to claim 1, characterized in that...

3. The aforementioned vehicle is a hybrid vehicle equipped with a drive engine, The control means performs control to start the drive engine. The vehicle-mounted snow melting device according to claim 2, characterized in that...

4. The aforementioned hybrid vehicle is equipped with a generator that generates electricity using the power of the drive engine, The control means performs control to supply the power generated by the generator to the traction battery and the heating element. The vehicle-mounted snow melting device according to claim 3, characterized in that...

5. The exhaust pipe of the aforementioned drive engine is routed on the underside of the vehicle, The heating element is routed in a meandering manner so as to avoid the exhaust pipe and cover a planar area when viewed from below the vehicle. An on-board snow melting device according to claim 3 or 4, characterized in that it is a vehicle-mounted snow melting device.

6. When detecting the stack, the detection means determines that the distance of the wheels from the vehicle body is greater than or equal to a predetermined distance. The vehicle-mounted snow melting device according to claim 1, characterized in that...

7. The detection means determines an increase in the rotation speed of the drive wheels when detecting the stack. The vehicle-mounted snow melting device according to claim 1, characterized in that...

8. The detection means determines that the vehicle has stopped upon detecting the stack. The vehicle-mounted snow melting device according to claim 1, characterized in that...

9. The detection means determines that the temperature on the underside of the vehicle is below a predetermined temperature when detecting the stack. The vehicle-mounted snow melting device according to claim 1, characterized in that...

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