Washer nozzle defrosting device

Abstract

The washer nozzles are defrosted using a simple configuration. [Solution] The washer nozzle defrosting device comprises an inverter connected to a battery that supplies power to a motor generator, a washer nozzle that sprays washer fluid, a vibration element provided in contact with the washer nozzle and that generates ultrasonic vibrations, wiring connecting the inverter and the vibration element, and a control circuit that controls the inverter.

Description

Technical Field

[0001] The present invention relates to the technical field of washer nozzle thawing devices.

Background Art

[0002] Conventionally, a washer nozzle has been proposed in which an ultrasonic vibrator is provided inside a nozzle body, and when a washer injection port is frozen, ultrasonic vibration is generated from the ultrasonic vibrator to thaw the washer injection port by the ultrasonic vibration (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the technology of Patent Document 1, it is necessary to provide a device for generating ultrasonic vibration from the ultrasonic vibrator, and there is a possibility that the configuration may become complicated.

[0005] The present invention has been made in view of the above circumstances, and an object thereof is to thaw a washer nozzle with a simple configuration.

Means for Solving the Problems

[0006] A washer nozzle thawing device according to an embodiment of the present invention includes an inverter connected to a battery that supplies power to a motor - generator, a washer nozzle that injects washer liquid, a vibration element that is provided in contact with the washer nozzle and generates ultrasonic vibration, a wiring that connects the inverter and the vibration element, and a control circuit that controls the inverter.

Effects of the Invention

[0007] According to the present invention, the washer nozzle can be defrosted with a simple configuration. [Brief explanation of the drawing]

[0008] [Figure 1] This is a diagram showing the vehicle's configuration. [Figure 2] This is a perspective view showing the front structure of the vehicle. [Figure 3] This diagram shows the configuration of a washer nozzle. [Figure 4] This is a flowchart illustrating the process of defrosting the washer nozzle. [Figure 5] This figure shows an estimated map of freezing levels based on the history of ambient temperatures. [Figure 6] This figure shows the frequency and gain for each freezing level. [Figure 7] This flowchart shows the flow of the washer nozzle defrosting process in a modified example. [Modes for carrying out the invention]

[0009] <1. Vehicle Configuration> Figure 1 is a diagram showing the configuration overview of Vehicle 1. As shown in Figure 1, Vehicle 1 is an electric vehicle or hybrid vehicle equipped with a motor generator 2 (indicated as "M / G" in the figure) as a power source. Vehicle 1 comprises the motor generator 2, a high-voltage battery 3, an inverter 4, a power transmission cable 5, and a washer nozzle defrosting device 10.

[0010] The motor-generator 2 is the power source that drives the vehicle 1, and is, for example, a three-phase AC motor. The motor-generator 2 generates driving force using electricity supplied from the high-voltage battery 3 via the inverter 4 and power transmission cable 5, and transmits this driving force to the drive wheels to drive the vehicle 1. If the vehicle 1 is a hybrid vehicle, it will also be equipped with an engine as a power source.

[0011] The motor generator 2 can generate power by performing regenerative operation. The power generated by the regenerative operation of the motor generator 2 is supplied to the high-voltage battery 3 via the inverter 4 and the power transmission cable 5.

[0012] The inverter 4 converts the DC current supplied from the high-voltage battery 3 into a three-phase AC current and supplies it to the motor generator 2 via the power transmission cable 5. Furthermore, when the motor generator 2 performs regenerative operation, the inverter 4 converts the AC current supplied from the motor generator 2 into a DC current and supplies it to the high-voltage battery 3 via the power transmission cable 5.

[0013] Inverter 4 is, for example, a VVVF (Variable Voltage Variable Frequency) inverter equipped with six switching elements. The switching elements are, for example, IGBTs (Insulated Gate Bipolar Transistors), with diodes connected in antiparallel. The switching elements are connected in pairs in series to form the U-phase, V-phase, and W-phase legs, respectively. One pair of switching elements in each leg are connected in parallel to the positive terminal of the high-voltage battery 3, and the other pair of switching elements are connected in parallel to the negative terminal of the high-voltage battery 3. In addition, the U-phase terminal, V-phase terminal, and W-phase terminal of the motor generator 2 are connected to the connection points of the switching elements that make up each leg, respectively.

[0014] The switching element operates based on the PWM (Pulse Width Modulation) control of the control circuit 12, which will be described in more detail later. Specifically, the switching element operates when a control signal from the control circuit 12 is input to its gate, and outputs an AC current of a predetermined frequency and voltage to each terminal of the motor generator 2.

[0015] The high-voltage battery 3 is a secondary battery such as a lithium-ion battery, and outputs and stores electric power at a high voltage of, for example, 100V or 200V. The high-voltage battery 3 can be charged by the regenerative operation of the motor generator 2. Further, the high-voltage battery 3 may be capable of being charged by power supply from an external device (not shown).

[0016] The washer nozzle thawing device 10 includes a washer device 11, a control circuit 12, a vibration element 13, wiring 14, a switch element 15, a thawing switch 16, and an outside air temperature sensor 17. Further, the high-voltage battery 3 and the inverter 4 also function as part of the washer nozzle thawing device 10. The washer nozzle thawing device 10 is a device for thawing the washer nozzle 24 (FIG. 3) of the washer device 11 when the washer nozzle 24 freezes.

[0017] The washer device 11 is a device for injecting washer liquid onto the windshield 22, and includes the washer nozzle 24 shown in FIG. 2 and a pump or the like for injecting the washer liquid from the washer nozzle 24.

[0018] FIG. 2 is a perspective view showing the front structure of the vehicle. As shown in FIG. 2, a bonnet 21 and a windshield 22 are provided at the front of the vehicle 1. A washer nozzle 24 and a wiper mechanism 25 are attached to a cowl louver 23 that is adjacent to the front edge of the windshield 22 and provided at the boundary with the bonnet 21.

[0019] The washer nozzle 24 injects washer liquid toward the windshield 22. The wiper mechanism 25 is arranged such that a rubber attached to the blade contacts the windshield 22, and wipes off raindrops and dirt on the windshield 22 when it operates.

[0020] Returning to Figure 1, the washer device 11 (more precisely, the washer nozzle 24) is equipped with a vibrating element 13. The vibrating element 13 is, for example, a capacitor or a reactor, and is capable of generating ultrasonic vibrations.

[0021] Figure 3 shows the configuration of the washer nozzle 24. As shown in Figure 3, the washer nozzle 24 is provided with a nozzle cover 31. The nozzle cover 31 is made of, for example, resin, and a nozzle spray opening 32 is formed on its upper side surface.

[0022] A washer pipe 33 is connected to the nozzle nozzle 32. Washer fluid stored in a washer fluid tank (not shown) is guided through the washer pipe 33 to the nozzle nozzle 32 and sprayed from the nozzle nozzle 32 toward the windshield 22.

[0023] Furthermore, in the washer nozzle 24, a vibrating element 13 is attached near the nozzle spray opening 32 and the washer piping 33. The vibrating element 13 is housed inside the nozzle cover 31, but it may also be provided outside the nozzle cover 31. In other words, the vibrating element 13 can be located inside or outside the washer nozzle 24, as long as it is in contact with the washer nozzle 24.

[0024] One end of the wiring 14 is connected to the vibration element 13. The other end of the wiring 14 is connected to the inverter 4. Specifically, the other end of the wiring 14 is connected to the connection point of the switching element that constitutes one of the three legs of the inverter 4 (for example, the U-phase leg). Therefore, the wiring 14 connects the vibration element 13 and the inverter 4, and it is possible to transmit the electrical vibrations generated by the inverter 4 to the vibration element 13.

[0025] The vibration element 13 converts the electrical vibrations transmitted from the inverter 4 into mechanical vibrations. Specifically, the vibration element 13 has a mechanical resonance point at the carrier frequency when the inverter 4 is operating, and generates ultrasonic vibrations at a frequency corresponding to the carrier frequency of the inverter 4. Furthermore, the vibration element 13 vibrates ultrasonically with a gain (amplitude) proportional to the amplitude (voltage) of the electrical vibrations generated by the inverter 4.

[0026] Therefore, in the washer nozzle defrosting device 10, the frequency and gain (amplitude) of the ultrasonic vibration generated by the vibration element 13 can be changed by changing the carrier frequency and voltage of the inverter 4.

[0027] A switch element 15 is provided in the middle of the wiring 14. Based on the control of the control circuit 12, the switch element 15 switches between connecting and disconnecting the vibration element 13 and the inverter 4.

[0028] The control circuit 12 is an ECU (Electronic Control Unit) and controls the operation of the inverter 4, the operation of the washer device 11, and the on / off control of the switch element 15. However, the control circuit 12 may be composed of multiple ECUs, and the operation control of the inverter 4, the operation control of the washer device 11, and the on / off control of the switch element 15 may be performed by different ECUs.

[0029] The defrost switch 16 is a switch operated by the driver to cause the control circuit 12 to execute a process to defrost the washer nozzle 24 when the washer nozzle 24 has frozen. When the defrost switch 16 is operated, the control circuit 12 executes various processes to defrost the washer nozzle 24 based on the operation.

[0030] <2. Washer nozzle defrosting process> Next, we will explain the washer nozzle thawing process, which thaws the washer nozzle 24 when it freezes.

[0031] Here, freezing of the washer nozzle 24 includes both the freezing of moisture adhering to the area around the nozzle outlet 32 ​​and the freezing of the washer fluid in the washer piping 33. When the washer nozzle 24 freezes, even if the washer switch (not shown) is operated and the washer system 11 is activated, washer fluid will not be sprayed from the washer nozzle 24. As a result, it becomes impossible to wipe away water droplets and dirt from the surface of the windshield 22.

[0032] Therefore, in vehicle 1, a washer nozzle thawing process is performed to thaw the washer nozzle 24 when it freezes.

[0033] Figure 4 is a flowchart showing the flow of the washer nozzle defrosting process. The washer nozzle 24 is started when the start switch is operated and vehicle 1 is READY-ON.

[0034] As shown in Figure 4, when the washer nozzle defrosting process is started, in step S1 the control circuit 12 determines whether the vehicle 1 is stationary. Since the washer nozzle defrosting process changes the carrier frequency and voltage of the inverter 4, it is preferable to perform this process when the motor generator 2 is not operating. Therefore, in step S1, it is determined whether the vehicle 1 is stationary. Whether or not the vehicle 1 is stationary can be determined, for example, based on the measurement result of a vehicle speed sensor (not shown).

[0035] If vehicle 1 is not stationary (No in step S1), the washer nozzle defrosting process is terminated. If vehicle 1 is stationary (Yes in step S2), in step S2, the control circuit 12 determines whether the defrosting switch 16 has been operated.

[0036] If the defrost switch 16 is not operated (No in step S2), that is, if the driver has determined that it is not necessary to defrost the washer nozzles 24, the process returns to step S1. If the defrost switch 16 is operated (Yes in step S2), in step S3 the control circuit 12 acquires the outside temperature history, which shows the measurement result of the outside temperature sensor 17, and the washer usage history, which shows the usage history of the washer device 11.

[0037] The outside temperature history includes information on outside temperatures at predetermined intervals in the past. The washer usage history includes information on the date and time when the washer device 11 was used.

[0038] In step S4, the control circuit 12 determines the frequency and gain of the ultrasonic vibrations to be generated by the vibrating element 13 based on the outside temperature history and the washer usage history.

[0039] Figure 5 shows an estimated map of freezing levels based on ambient temperature history. Figure 6 shows the frequency and gain for each freezing level.

[0040] In step S4, the control circuit 12 first determines the freezing level based on the ambient temperature history. The freezing level is set to, for example, three levels. Freezing level "1" is the level at which the washer nozzle 24 is considered to be surface-frozen, and is the lowest freezing level. Freezing level "2" is the level at which the washer nozzle 24 is considered to be moderately frozen, and is the middle freezing level. Freezing level "3" is the level at which the washer nozzle 24 is considered to be deeply frozen, and is the highest freezing level.

[0041] When the control circuit 12 acquires the outside temperature history, it determines the freezing level by referring to the estimation map shown in Figure 5, based on the time the vehicle 1 was stopped and the outside temperature at that time. For example, if the outside temperature is -5°C and the vehicle 1 was stopped for 5 hours (5h), the control circuit 12 determines the freezing level to be "2".

[0042] However, since the outside temperature may change when vehicle 1 is stopped, it may be possible to accumulate the outside temperature every hour, for example, and determine the freezing level based on the accumulated outside temperature. In this case, it is conceivable to use an estimation map that shows the freezing level for the accumulated outside temperature.

[0043] Furthermore, the control circuit 12 corrects the freezing level based on the washer usage history. For example, if the washer system 11 was used immediately before vehicle 1 was stopped, washer fluid remains around the nozzle nozzle 32, making the washer nozzle 24 prone to freezing, so the control circuit 1 is increased by 1. However, the control circuit 12 may choose not to modify the freezing level based on the washer usage history.

[0044] Once the freezing level is determined in this way, the control circuit 12 determines the frequency and gain of the ultrasonic vibration according to the freezing level, as shown in Figure 6. As shown in Figure 6, at freezing level "1", the frequency is set to 10 kHz and the gain to 1. The gain represents the amplification factor relative to the amplitude of the ultrasonic vibration, which is predetermined.

[0045] In step S5, the control circuit 12 operates the inverter 4 to generate ultrasonic vibrations of the determined frequency and gain from the vibrating element 13. Here, the inverter 4 is controlled to operate at a carrier frequency and voltage corresponding to the determined frequency and gain. The control circuit 12 also turns on the switch element 15 to connect the inverter 4 and the vibrating element 13. As a result, the electrical signal generated by the inverter 4 is transmitted to the vibrating element 13, and the vibrating element 13 generates ultrasonic vibrations of the determined frequency and gain.

[0046] The vibrating element 13 transmits the generated ultrasonic vibrations to the frozen portion (ice molecules) of the washer nozzle 24, thereby generating heat and melting the ice molecules. In this case, the higher the frequency of the ultrasonic vibration, the longer the distance (deeper the depth) the ultrasonic vibration is transmitted. Therefore, by increasing the frequency as the freezing level increases, the ultrasonic vibration can be transmitted deeper into the frozen area, making it possible to thaw the washer nozzle 24 more quickly.

[0047] Furthermore, the vibration energy of ultrasonic vibrations increases as the gain is increased. Therefore, the higher the freezing level, the greater the vibration energy can be increased by increasing the gain, making it possible to defrost the washer nozzle 24 more quickly.

[0048] In step S6, the control circuit 12 determines whether the washer nozzle 24 has thawed. If the washer nozzle 24 has not thawed even after the defrost switch 16 has been operated to release the washer nozzle 24 from freezing, the driver will operate the defrost switch 16 again. Therefore, the control circuit 12 determines that the washer nozzle 24 has thawed if the driver has not operated the defrost switch 16 again within a predetermined time, or if the vehicle 1 has started moving.

[0049] If the washer nozzle 24 is not thawed (No in step S6), the control circuit 12 increases the freezing level by one step in step S7 and returns to step S5. This facilitates the thawing of the washer nozzle 24.

[0050] On the other hand, if the washer nozzle 24 is defrosted (Yes in step S6), the washer nozzle defrosting process is terminated.

[0051] <3. Variant> Although embodiments of the present invention have been described above, the present invention is not limited to the above-described examples and can take on a variety of configurations. For example, in the above embodiment, the control circuit 12 determines the frequency and gain of ultrasonic vibration based on the ambient temperature history and the washer usage history. However, the control circuit 12 may also determine the frequency and gain of ultrasonic vibration based on at least one of the ambient temperature history and the washer usage history.

[0052] Furthermore, in the above embodiment, the washer nozzle defrosting process is performed while the vehicle 1 is stopped. However, the washer nozzle defrosting process may also be performed while the vehicle 1 is in motion.

[0053] Furthermore, although three freezing levels are provided in the above embodiment, any number of freezing levels may be used.

[0054] Furthermore, in the above embodiment, a washer nozzle defrosting device 10 for defrosting washer nozzles 24 that spray washer fluid onto the windshield 22 was described. However, the washer nozzle defrosting device 10 may also be used to defrost washer nozzles that spray washer fluid onto the rear window, washer nozzles that spray washer fluid onto the headlights, and so on.

[0055] Furthermore, the above embodiment described a technique for defrosting the washer nozzle 24. However, the technique for defrosting the washer nozzle 24 described above may also be applied when defrosting door handles, fuel flaps, charging flaps, hoods, rear hatches, etc. In this case, for example, the vehicle 1 may be accessed from an external terminal such as a smartphone, and the technology to defrost the washer nozzle 24 may be executed remotely.

[0056] Furthermore, in the above embodiment, the defrost switch 16 is not operated again by the driver within a predetermined time, or the vehicle 1 starts moving, which determines whether the washer nozzle 24 has defrosted. However, the control circuit 12 may determine that the washer nozzle 24 has defrosted if, for example, the outside temperature rises above 0°C.

[0057] Furthermore, in the above embodiment, the control circuit 12 determines the frequency and gain of the inverter 4 based on the ambient temperature history and the washer usage history. However, the control circuit 12 may determine the frequency of the inverter 4 based on at least one of the ambient temperature history and the washer usage history, and determine the gain based on whether or not the washer nozzle 24 has been defrosted.

[0058] Figure 7 is a flowchart showing the flow of the washer nozzle defrosting process in a modified example. Processes identical to those in Figure 4 are denoted by the same reference numerals and their descriptions are omitted.

[0059] As shown in Figure 7, after acquiring the ambient temperature history and washer usage history in step S3, the control circuit 12 determines the freezing level in step S14. The method for determining the freezing level is the same as in step S4. Subsequently, the control circuit 12 determines only the frequency of ultrasonic vibration based on the freezing level. That is, it determines the frequency by referring only to the relationship between the freezing level and frequency in Figure 6. The control circuit 12 also determines the gain to "1".

[0060] Subsequently, in step S15, the control circuit 12 operates the inverter 4 based on the determined frequency and gain. In the following step S16, the control circuit 12 determines whether the washer nozzle 24 has been defrosted. If the washer nozzle 24 has not been defrosted (No in step S16), in step S17, the control circuit 12 increases the gain by one step and proceeds to step S15. On the other hand, if the washer nozzle 24 has been defrosted (Yes in step S16), the washer nozzle defrosting process is terminated. Thus, it is also possible to determine the frequency of ultrasonic vibration based on at least one of the outside temperature history and the washer usage history, and to determine the gain based on whether or not the washer nozzle 24 has been defrosted.

[0061] <6. Summary of Embodiments> As described above, the washer nozzle defrosting device 10 of the embodiment comprises an inverter 4 connected to a battery (high-voltage battery 3) that supplies power to the motor generator 2, a washer nozzle 24 that sprays washer fluid, a vibration element 13 provided in contact with the washer nozzle 24 and that generates ultrasonic vibrations, wiring 14 connecting the inverter 4 and the vibration element 13, and a control circuit 12 that controls the inverter 4. As a result, the washer nozzle defrosting device 10 can generate ultrasonic vibrations from the vibration element 13 by transmitting the electrical vibrations generated by the inverter 4 to the vibration element 13. Therefore, the washer nozzle defrosting device 10 does not require the installation of a new device for generating ultrasonic vibrations from the vibrating element 13. Thus, the washer nozzle defrosting device 10 can defrost the washer nozzle 24 with a simple configuration.

[0062] The control circuit 12 determines the frequency and gain of the ultrasonic vibration generated by the vibrating element 13 based on the ambient temperature, and controls the inverter 4 to generate ultrasonic vibration from the vibrating element 13 at the determined frequency and gain. This allows the vibration element 13 to generate ultrasonic vibrations at the optimal frequency and gain according to the freezing state (freezing level) of the washer nozzle 24. Therefore, the washer nozzle thawing device 10 can reduce the time it takes for the washer nozzle 24 to thaw. In addition, the washer nozzle thawing device 10 can minimize the energy required to generate ultrasonic vibrations from the vibration element 13.

[0063] The control circuit 12 determines the freezing state (freezing level) of the washer nozzle 24 based on the usage history of the washer device 11. This makes it possible to determine that when the washer nozzle defrosting device 10 was used immediately before, there is still washer fluid remaining around the nozzle nozzle 32, creating a situation where it is prone to freezing. Thus, the washer nozzle defrosting device 10 can accurately determine the frozen state (freezing level) of the washer nozzle 24.

[0064] The control circuit 12 controls the inverter 4 to change at least one of the frequency and gain of the ultrasonic vibration generated by the vibrating element 13 if the washer nozzle 24 is not defrosted. This allows the washer nozzle 24 to defrost more quickly.

[0065] The control circuit 12 controls the inverter 4 to increase the gain of the ultrasonic vibration generated by the vibrating element 13 if the washer nozzle 24 is not defrosted. This increases the vibration energy of the ultrasonic vibrations generated from the vibrating element 13, allowing the washer nozzle 24 to defrost more quickly. [Explanation of Symbols]

[0066] 1 vehicle 3 High-voltage battery 4 Inverters 10 Washer nozzle defrosting device 12 Control circuits 13. Vibration element 14 Wiring 24 Washer Nozzles

Claims

1. An inverter connected to a battery that supplies power to the motor generator, The washer nozzle that sprays washer fluid, A vibrating element is provided in contact with the washer nozzle and generates ultrasonic vibrations, Wiring connecting the inverter and the vibration element, A control circuit for controlling the inverter, A washer nozzle defrosting device equipped with the following features.

2. The control circuit determines the frequency and gain of the ultrasonic vibration generated by the vibrating element based on the ambient temperature, and controls the inverter to generate ultrasonic vibration from the vibrating element at the determined frequency and gain. The washer nozzle defrosting device according to claim 1.

3. The control circuit determines the freezing state of the washer nozzle based on the usage history of the washer system. A washer nozzle defrosting device according to claim 1 or claim 2.

4. The control circuit controls the inverter to change at least one of the frequency and gain of the ultrasonic vibration generated by the vibrating element when the washer nozzle is not defrosted. The washer nozzle defrosting device according to claim 2.

5. The control circuit controls the inverter to increase the gain of the ultrasonic vibration generated by the vibrating element when the washer nozzle is not defrosted. The washer nozzle defrosting device according to claim 2.

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