Wiping device

Abstract

Provided is a wiping device capable of performing wiping suitable for heavy rain without increasing power consumption.　The wiping device wipes rainwater from a surface to be wiped by using a prescribed power source to cause a wiper blade to engage in reciprocating motion, in which the wiping device comprises a power source driving unit that sets the wiping range in a heavy rain mode narrower than the wiping range in a normal mode, and sets the wiping range in the heavy rain mode to the minimum wiping area stipulated by law.

Description

[Technical field]

[0001] The present invention relates to a wiping device. [Background technology]

[0002] Patent Document 1 below discloses a wiper system control device. This wiper system control device controls the operation of a vehicle wiper system that includes a wiper blade that performs a reciprocating wiping action on a surface to be wiped and a raindrop sensor that detects the current amount of rainfall based on water droplets adhering to the surface to be wiped, in which the wiper blades include a driver's side wiper blade disposed on the driver's side of the vehicle and a passenger's side wiper blade disposed on the passenger's side of the vehicle, the driver's side wiper blade is driven by a first electric motor, and the passenger's side wiper blade is driven by a second electric motor provided separately from the first electric motor, and the control device drives and controls the first electric motor. A first wiper control device; The wiper control device has a second wiper control device connected to the first wiper control device by a communication line and controlling the drive of a second electric motor, the first electric motor and the second electric motor being synchronously controlled by the first and second control devices based on position information of both the driver's side wiper blade and the passenger's side wiper blade, and a heavy rain wiping area narrower than the normal wiping range of the driver's side wiper blade is set on the wiping surface near the driver's forward field of view, and the first and second control devices have a rainfall condition determination unit that determines the current rainfall condition based on an output signal from a raindrop sensor, and an operation mode change unit that, when the rainfall condition determination unit determines that the amount of rainfall is equal to or greater than a predetermined value and is a heavy rain condition, changes the operation mode of the wiper blade to a heavy rain mode in which the wiping range of the driver's side wiper blade is narrower than the normal wiping operation and the driver's side wiper blade is operated at high speed only within the heavy rain wiping area. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6349120 Summary of the Invention [Problem to be solved by the invention]

[0004] The wiping speed of a wiping device in Hi operation for heavy rain, etc., differs depending on the vehicle manufacturer and model, but one of the factors is that it is due to restrictions on load conditions such as differences in the length of the wiper arm and wiper blade, the maximum voltage of the drive motor, etc. In wiping devices with high loads such as four-section arms and long blades, it is necessary to use a drive motor with a high rating and to pass a large current in order to increase the rotation speed in Hi operation.

[0005] On the other hand, as vehicles become more electrified, reducing the power consumption of the wiper device has become an important issue, and ensuring visibility during heavy rain, which has become more common due to recent weather abnormalities, has become an issue that vehicle manufacturers must address. In other words, the requirements for the wiper device to handle heavy rain are contradictory in terms of power consumption. In order to meet these requirements, it is necessary to achieve wiping that is suitable for heavy rain without increasing the power consumption of the wiper device.

[0006] The present invention has been made in consideration of the above-mentioned circumstances, and aims to provide a wiping device that can achieve wiping during heavy rain without increasing power consumption. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, the present invention adopts, as a first solution relating to a wiping device, a wiping device that wipes rainwater from a surface to be wiped by causing a wiper blade to move back and forth using a predetermined power source, and is equipped with a power source drive unit that sets the wiping range in heavy rain mode to be narrower than the wiping range in normal mode, and sets the wiping range in heavy rain mode to the minimum wiping area specified by regulations.

[0008] In the present invention, as a second solution related to the wiping device, a means is adopted in which, in the above-mentioned first solution, the power source driving unit switches the operating mode from the normal mode to the heavy rain mode based on a switch signal of a mist switch provided in the vehicle.

[0009] The present invention employs a third solution relating to the wiping device, which is the second solution described above, in which the power source driving unit switches the operating mode from the normal mode to the heavy rain mode based on the length of time the mist switch is ON.

[0010] The present invention provides a fourth solution related to the wiping device, which is the third solution described above, in which the power source driving unit switches from the normal mode to the heavy rain mode when the ON time is greater than or equal to a predetermined threshold value.

[0011] The present invention adopts a fifth solution relating to the wiping device, in which, in any of the first to third solutions above, one or two power sources are provided, one of which reciprocates one or a pair of the wiper blades, and two of which reciprocate a pair of the wiper blades individually. Effect of the Invention

[0012] According to the present invention, it is possible to provide a wiping device that can achieve wiping that is suitable for heavy rain without increasing power consumption. [Brief description of the drawings]

[0013] [Figure 1] 1 is a block diagram showing a functional configuration of a wiping device A according to a first embodiment of the present invention. [Diagram 2] 4 is a flowchart showing the operation of the wiping device A according to the first embodiment of the present invention. [Diagram 3] 4 is a timing chart showing the operation of the wiping device A according to the first embodiment of the present invention. [Figure 4]FIG. 2 is a schematic diagram showing a wiping range (minimum wiping area) in the first embodiment of the present invention. [Diagram 5] 5 is a flowchart showing an operation mode switching process in the first embodiment of the present invention. [Figure 6] FIG. 11 is a block diagram showing a functional configuration of a wiping device AB according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] [First embodiment] First, a first embodiment of the present invention will be described with reference to Fig. 1 to Fig. 5. A wiping device A according to the first embodiment is a device mounted on various vehicles and wipes rainwater off the surface (wiped surface) of a windshield or a rear windshield.

[0015] As shown in FIG. 1, the wiping device A employs a dual motor drive system in which a pair of wiper blades 1a, 1b are driven individually by a pair of motors 7a, 7b as power sources. That is, the wiping device A according to the first embodiment is provided with two power sources, and the pair of wiper blades 1a, 1b are reciprocated individually by the two power sources. In the wiping device A according to the first embodiment, it is preferable to use brushless wiper motors for both of the pair of motors 7a, 7b. When the brushless wiper motor is rotated forward and backward at high speed repeatedly by the operation in the heavy rain mode, the brush wear powder caused by the sliding between the brush and the commutator, as in the wiper motor with a brush, is not generated, and the life of the wiper motor can be extended. In addition, by using a brushless wiper motor, forward and reverse rotation can be smoothly repeated, so that the wiper motor can be precisely reversed at the upper and lower reversal positions set for the heavy rain mode.

[0016] As shown in the figure, the wiping device A includes a pair of wiper blades 1a, 1b and a single drive device 10. In addition, in each reference character in Fig. 1, "a" indicates a member or part related to the driver's seat side of the vehicle, and "b" indicates a member or part related to the passenger's seat side of the vehicle.

[0017] As shown in the figure, the pair of wiper blades 1a, 1b are rod-shaped members arranged on the windshield W. The pair of wiper blades 1a, 1b abut against the surface (surface to be wiped) of the windshield W and wipe away rainwater present on the surface by performing a reciprocating motion (oscillating motion) over the surface to be wiped.

[0018] 1, the symbol Ra indicates the wiping range of the wiper blade 1a on the driver's side when the operating mode of the drive unit 10 is set to the normal mode, and the symbol Rb indicates the wiping range of the wiper blade 1b on the passenger's side when the operating mode of the drive unit 10 is set to the normal mode.

[0019] The pair of wiper blades 1a, 1b are mechanically connected to a drive unit 10 via a pair of wiper arms 2a, 2b. That is, the wiper blade 1a on the driver's seat side is connected to the drive unit 10 via the wiper arm 2a provided on the driver's seat side. The wiper blade 1b on the passenger's seat side is connected to the drive unit 10 via the wiper arm 2b provided on the passenger's seat side.

[0020] As shown in the figure, the pair of wiper arms 2a, 2b are rod-shaped members, one end of which is connected to the middle of the pair of wiper blades 1a, 1b, and the other end of which is connected to the pair of wiper shafts 3a, 3b. That is, the wiper arm 2a on the driver's seat side has one end connected to the middle of the wiper blade 1a on the driver's seat side, and the other end connected to the wiper shaft 3a on the driver's seat side.

[0021] On the other hand, one end of the passenger side wiper arm 2b is connected to a middle portion of the passenger side wiper blade 1b, and the other end is connected to the passenger side wiper shaft 3b. Note that such a pair of wiper arms 2a, 2b are members included in the components of the pair of wiper blades 1a, 1b.

[0022] The pair of wiper arms 2a, 2b function as power transmission parts that mechanically transmit the rotational power of the drive unit 10 to the pair of wiper blades 1a, 1b. The pair of wiper arms 2a, 2b also function as biasing members that press the pair of wiper blades 1a, 1b against the surface (wiped surface) of the windshield W with a predetermined pressing force.

[0023] The drive device 10 is a power generating device that reciprocates the pair of wiper blades 1a, 1b via the pair of wiper arms 2a, 2b. The drive device 10 rotates the pair of wiper shafts 3a, 3b within a predetermined angle range, thereby reciprocating the pair of wiper blades 1a, 1b placed on the surface of the windshield W (the surface to be wiped).

[0024] The drive device 10 includes a pair of motors 7a, 7b as power sources corresponding to the pair of wiper shafts 3a, 3b. Each of the pair of motors 7a, 7b includes a motor body 8 and a speed reduction mechanism 9. The drive device 10 also includes a pair of wiper control units 10a, 10b corresponding to the pair of motors 7a, 7b.

[0025] The pair of wiper control units 10a, 10b are power source drive units that drive the pair of motors 7a, 7b, which are power sources. The motor 7a on the driver's seat side is driven and controlled by the wiper control unit 10a to cause the wiper blade 1a on the driver's seat side to perform a reciprocating motion (oscillating motion) on the surface to be wiped. The motor 7b on the passenger's seat side is driven and controlled by the wiper control unit 10b to cause the wiper blade 1b on the passenger's seat side to perform a reciprocating motion (oscillating motion) on the surface to be wiped.

[0026] The wiper control unit 10a corresponding to the driver's seat side is composed of a control board including electronic circuits such as a CPU (Central Processing Unit) 21a, a communication circuit 22a, a ROM (Read Only Memory) 23a, a RAM (Random Access Memory) 24a, an angle detection circuit 31a, a drive circuit 32a, and a lock detection timer 33a, and is built into the speed reduction mechanism 9 of the motor 7a. The wiper control unit 10b corresponding to the passenger's seat side is composed of a control board including electronic circuits such as a CPU 21b, a communication circuit 22a, a ROM 23b, a RAM 24b, an angle detection circuit 31b, a drive circuit 32b, and a lock detection timer 33b, and is built into the speed reduction mechanism 9 of the motor 7b.

[0027] The wiper control unit 10a corresponding to the driver's seat side and the wiper control unit 10b corresponding to the passenger's seat side are connected to each other via a pair of communication circuits 22a, 22b. The wiper control unit 10a, which controls the driving of the motor 7a on the driver's seat side, is connected to the ECU, which is a higher-level control device of the vehicle, via a communication line. The wiper control unit 10a receives switch signals such as ON / OFF of the wiper switch, designation of heavy rain mode, ON / OFF of the mist switch, intermittent operation (Lo wipe, Hi wipe, INT wipe), etc. from the ECU.

[0028] In the drive device 10, the pair of motors 7a, 7b are feedback-controlled based on the elapsed time from an absolute position serving as a control reference, and the positions of the pair of wiper blades 1a, 1b are controlled. In this position control, the lower reversal positions LPa, LPb are used as the absolute positions, and the target rotation speeds TR of the pair of motors 7a, 7b at that time point are set in advance by an operation map in accordance with the elapsed time t from the lower reversal positions LPa, LPb.

[0029] Here, the driving device 10 has a normal mode and a heavy rain mode as operation modes. In the normal mode, the wiper control unit 10a controls the wiper to perform low-speed wiping (Lo wiping) at a predetermined speed, high-speed wiping (Hi wiping) faster than the low-speed wiping, and intermittent wiping (INT wiping) in which wiping control for performing low-speed wiping after a predetermined time has elapsed is repeated. In the heavy rain mode, the wiper control unit 10a controls the wiper motor 7a to repeatedly rotate forward and backward at a speed faster than the high-speed wiping, and to perform wiping control by reciprocating in a narrow wiping range NRa described later. That is, the above-mentioned operation maps include a heavy rain mode operation map that is applied when the operation mode is the heavy rain mode, and a normal mode operation map that is applied when the operation mode is other than the heavy rain mode. Such operation maps are stored in a pair of ROMs 23a and 23b. A target rotation speed TR different from the target rotation speed TR of the normal mode operation map is set in the heavy rain mode operation map. In the present invention, the concept of heavy rain includes localized heavy rainfall in a short period of time (guerilla downpour).

[0030] The pair of wiper control units 10a, 10b measure the elapsed time t from the lower reversal positions LPa, LPb in the pair of CPUs 21a, 21b, grasp the current rotation speeds of the pair of motors 7a, 7b, and compare the current rotation speeds at the elapsed time t with the target rotation speed TR. The pair of CPUs 21a, 21b directly control the pair of drive circuits 32a, 32b according to the difference between the current rotation speeds and the target rotation speed TR, thereby indirectly controlling the pair of motors 7a, 7b.

[0031] Between the pair of motors 7a, 7b and the pair of CPUs 21a, 21b, a pair of angle detection circuits 31a, 31b for detecting the positions of the pair of wiper blades 1a, 1b are provided. The pair of angle detection circuits 31a, 31b detect the positions of the pair of wiper blades 1a, 1b in proportion to the motor rotation angles of the pair of motors 7a, 7b. 1b The pair of angle detection circuits 31a, 31b outputs a relative position signal indicating the amount of movement of the wiper blade 1a, 1b. The pair of angle detection circuits 31a, 31b also output an absolute position signal indicating the position of a specific wiper blade of the pair of wiper blades 1a, 1b.

[0032] That is, the angle detection circuit 31a corresponding to the driver's seat side is provided between the motor 7a on the driver's seat side and the CPU 21a corresponding to the driver's seat side. This angle detection circuit 31a outputs a relative position signal that is proportional to the motor rotation angle of the motor 7a on the driver's seat side and indicates the amount of movement of the wiper blade 1a on the driver's seat side and an absolute position signal that indicates the position of a specific wiper blade.

[0033] The angle detection circuit 31b corresponding to the passenger side is provided between the motor 7b on the passenger side and the CPU 21b on the passenger side. This angle detection circuit 31b outputs a relative position signal that is proportional to the motor rotation angle of the motor 7b on the passenger side and indicates the amount of movement of the wiper blade 1b on the passenger side and an absolute position signal that indicates the position of a specific wiper blade.

[0034] The relative position signal is a pulse signal (motor pulse) generated with the rotation of the pair of motors 7a, 7b. The relative position signal is a pulse signal with a number of pulses proportional to the rotation angle of the pair of motors 7a, 7b. The absolute position signal is a single signal generated when the pair of wiper blades 1a, 1b reach a control reference position (e.g., the lower reversal positions LPa, LPb).

[0035] The rotation speed of the pair of motors 7a, 7b and the rotation speed of the pair of wiper shafts 3a, 3b have a fixed relationship based on the reduction ratio of the reduction mechanism 9. The rotation angle of the pair of wiper shafts 3a, 3b can be obtained by calculation based on the number of pulses of the relative position signal. In addition, there is a fixed relationship between the rotation angle of the pair of wiper shafts 3a, 3b and the movement angle of the pair of wiper blades 1a, 1b.

[0036] That is, by accumulating the number of pulses of the relative position signal, it is possible to detect the movement angle of the pair of wiper blades 1a, 1b. The pair of CPUs 21a, 21b detect the current positions of the pair of wiper blades 1a, 1b based on a combination of the result of accumulating the number of pulses of the relative position signal and the absolute position signal. 21bdetects the current motor rotation speeds of the pair of motors 7a, 7b by counting the relative position signals (motor pulses).

[0037] The pair of CPUs 21a, 21b measure the elapsed time t from the acquisition time of the absolute position signal using a built-in timer. In addition, the pair of CPUs 21a, 21b acquire the target positions of the pair of wiper blades 1a, 1b and the target rotation speeds TR of the pair of motors 7a, 7b at the current elapsed time from the ROMs 23a, 23b.

[0038] The pair of CPUs 21a, 21b compare the current positions of the pair of wiper blades 1a, 1b with the target positions, and grasp the current status of the pair of wiper blades 1a, 1b (delay or advance from the target position). The pair of CPUs 21a, 21b also calculate the rotation speeds of the pair of motors 7a, 7b based on the status of the rotation speeds of the pair of motors 7a, 7b (high or low from the target rotation speed TR), and control the rotation of the pair of motors 7a, 7b based on the calculated rotation speeds.

[0039] That is, the pair of ROMs 23a, 23b prestores the positions of the pair of wiper blades 1a, 1b and the target values ​​of the motor revolutions of the pair of motors 7a, 7b as an operation map, with the elapsed time t from the acquisition time of the absolute position signal as a parameter. The pair of CPUs 21a, 21b feedback-control the pair of motors 7a, 7b by comparing the target value of the motor revolutions in such an operation map with the current value.

[0040] In addition, in each operation map, the precedence relationship of the pair of wiper blades 1a, 1b is set in advance. Furthermore, in each operation map, the target rotation speed TR is determined according to the position of the other wiper blade based on the elapsed time t from the acquisition time of the absolute position signal and the current positions of the pair of wiper blades 1a, 1b. For example, even if the elapsed time t and the current positions of the pair of wiper blades 1a, 1b are the same, the target rotation speed TR is set to be large when the current position of the other wiper blade is closer to the wiper blade itself, and the target rotation speed TR is set to be small when the current position of the other wiper blade is farther away from the wiper blade itself.

[0041] The current positions of the pair of wiper blades 1a, 1b are exchanged between the pair of CPUs 21a, 21b via the pair of communication circuits 22a, 22b and written to the pair of RAMs 24a, 24b. The pair of CPUs 21a, 21b synchronously control the pair of motors 7a, 7b based on the positional relationship of the pair of wiper blades 1a, 1b written to the pair of RAMs 24a, 24b.

[0042] Next, a characteristic operation of the wiping device A according to the first embodiment will be described with reference to the flowchart shown in FIG.

[0043] The CPU 21a of the wiper control unit 10a acquires a switch signal at a predetermined timing by communicating with the ECU, which is a higher-level control device (step S1). The CPU 21a judges whether the switch signal specifies the heavy rain mode as the operation mode (step S2). If the judgment in step S2 is "No," that is, if the switch signal does not specify the heavy rain mode, the CPU 21a maintains the operation mode in the normal mode (step S3).

[0044] That is, the pair of CPUs 21a, 21b feedback-control the pair of motors 7a, 7b based on the normal mode operation map in the same manner as before receiving the switch signal. The stored positions are set closer to the engine compartment than the lower reversing positions LPa, LPb, and the pair of motors 7a, 7b are set in positions where they are difficult to see from inside the vehicle when they are not being used.

[0045] On the other hand, if the determination in step S2 is "Yes," that is, if the switch signal specifies the heavy rain mode, the CPU 21a switches the operation mode from the normal mode to the heavy rain mode (step S4). Then, the pair of CPUs 21a and 21b feedback-control the pair of motors 7a and 7b based on the heavy rain mode operation map instead of the normal mode operation map. When switching from a state where wiping in the normal mode is performed to the heavy rain mode, the pair of wiper blades 1a and 1b are moved to the upper reversal positions UPa and UPb or the lower reversal positions LPa and LPb, and then only one of the motors 7a is driven to reverse the wiper blade 1a toward the lower reversal position NLP or the upper reversal position NUP in the narrow wiping range NRa, and reciprocating oscillating wiping is performed in the narrow wiping range NRa. The other motor 7b can not only stop the wiper blade 1b at a position where it does not interfere with the wiper blade 1a, such as the lower reversal position LPb, the stored position, or the upper reversal position UPb, but can also perform reciprocating wiping of the wiper blade 1b in a range between the narrow wiping range NRa and the upper reversal position UPb, which does not interfere with the wiper blade 1a.

[0046] The feedback control of one of the motors 7a using this heavy rain mode operation map is such that, as shown in FIG. 3, the lower reversal position NLP of one of the wiper blades 1a is set higher than the lower reversal position LPa in the normal mode, and the upper reversal position NUP of one of the wiper blades 1a is set lower than the upper reversal position UPa in the normal mode.

[0047] That is, the wiping range (movement range) NRa of one wiper blade 1a in the heavy rain mode is set narrower than the wiping ranges Ra, Rb (movement ranges) of the pair of wiper blades 1a, 1b in the normal mode. Also, the wiping range (movement range) NRa in the heavy rain mode is set to include at least the legally stipulated "minimum wiping area" of forward visibility, as shown in FIG.

[0048] Here, the "minimum wiping area" refers to the "Area A" in the wiping area regulations on the wiped surface in Japanese and European Economic Community (EEC) regulations, and the "Area B" in the US regulations (FMVSS: Federal Motor Vehicle Safety Standards). of This shows a virtual range with four set positions defined by regulations, which corresponds to the "C area" in the wiping area regulations.

[0049] According to the first embodiment, it is possible to satisfy the legally stipulated "minimum wiping area" of forward visibility during heavy rain. As shown in Fig. 4, the minimum wiping area NA for wiping in the heavy rain mode is set as a first lower set position NPA, a second lower set position NPB of the minimum wiping area NA, which is adjacent to the first lower set position NPA in the vertical direction and set closer to the normal lower reversal position LPa, and a first upper set position NPC, which is adjacent to the first upper set position NPC in the vertical direction and set closer to the normal upper reversal position UPa, and a second upper set position NPD, which is adjacent to the first upper set position NPC in the vertical direction and set closer to the normal upper reversal position UPa, for the minimum wiping area NA when one wiper blade 1a moves from the normal upper reversal position UPa to the minimum wiping area NA. The area between the first lower set position NPA and the first upper set position NPC is set as the narrow wiping range NRa, and in the heavy rain mode, the narrow wiping range NRa is rotated at high speed and in the forward and reverse directions by using the brushless wiper motor, thereby wiping the driver's forward field of view "minimum wiping area." Furthermore, according to the first embodiment, the range over which the narrow wiping range NRa moves in the heavy rain mode is narrower than the ranges over which the wiping ranges Ra and Rb move in the normal mode, so that power saving of the wiping device A can be realized.

[0050] That is, in the first embodiment, the narrow wiping range NRa of one wiper blade 1a during heavy rain is limited to a "minimum wiping area" that is narrower than the range of movement of the wiping ranges Ra, Rb in the normal mode. Therefore, according to the first embodiment, it is possible to provide a wiping device A that can realize wiping suitable for heavy rain without increasing power consumption.

[0051] In the first embodiment, the processes in steps S1 and S2 are carried out according to the determination algorithm shown in the flowchart of FIG. Do That is, the CPU 21a of the wiper control unit 10a determines whether the switch signal acquired from the upper control device specifies the heavy rain mode. That is, the CPU 21a of the wiper control unit 10a performs a process of determining whether the heavy rain mode is specified based on a specific operation manner of the mist switch provided in the vehicle.

[0052] In this designation judgment process, the CPU 21a first acquires a switch signal (step S10). Then, the CPU 21a judges whether the switch signal acquired from the upper control device is an ON operation of the mist switch (step S11). If the judgment in step S11 is "No", that is, if the switch signal does not indicate an ON operation of the mist switch, the CPU 21a judges whether the current operation mode is a heavy rain mode (step S12).

[0053] If the determination in step S12 is "No," that is, if the current operation mode is not the heavy rain mode, the CPU 21a performs a control operation according to the switch signal acquired in step S10 (step S13). On the other hand, if the determination in step S12 is "Yes," that is, if the current operation mode is the heavy rain mode, the CPU 21a determines whether the switch signal acquired in step S10 is an instruction to turn off the wiper switch (step S14).

[0054] If the determination in step S14 is "No," that is, if the switch signal does not command the wiper switch to be turned off, the CPU 21a performs a control operation according to the switch signal acquired in step S10 (step S15). On the other hand, if the determination in step S14 is "Yes," that is, if the switch signal commands the wiper switch to be turned off, the CPU 21a continues the control operation based on the heavy rain mode (step S16).

[0055] On the other hand, if the determination in step S11 is "Yes," that is, if the switch signal indicates that the mist switch is turned ON, the CPU 21a counts (times) the ON time of the mist switch (step S17). Then, the CPU 21a determines whether the ON time of the mist switch exceeds a threshold value, for example, 3 seconds (step S18).

[0056] If the determination in step S18 is "No," that is, if the ON time of the mist switch does not exceed the threshold value, the CPU 21a performs a mist control operation (step S19). On the other hand, if the determination in step S18 is "Yes," that is, if the ON time of the mist switch is equal to or greater than the threshold value, the CPU 21a performs a control operation based on the heavy rain mode (step S20).

[0057] According to this heavy rain mode designation and determination process, a mist switch that is generally provided in vehicles is used to designate the heavy rain mode, so a dedicated switch for designating the heavy rain mode is not required. If a dedicated switch were added to the vehicle, the number of vehicle switches would increase, and there is a high possibility that the driver would not be able to operate it in an emergency, but by switching between normal mist operation and heavy rain mode depending on the length of time the existing mist switch is ON, it is possible to execute a control operation based on the heavy rain mode without the need for a new switch.

[0058] Second Embodiment Next, a second embodiment of the present invention will be described with reference to Fig. 6. In this second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals.

[0059] 6, the wiping device B according to the second embodiment includes a pair of wiper blades 1a and 1b, a pair of wiper arms 2a and 2b, a link mechanism 4, a motor 7, an angle detection circuit 31, a drive circuit 32, and a control unit 10A. The control unit 10A also includes a CPU 50, a ROM 51, and a RAM 52.

[0060] This wiping device B employs a single motor drive system in which a pair of wiper blades 1a, 1b are driven by a single motor 7 (power source) by mechanically connecting a pair of wiper arms 2a, 2b with a link mechanism 4. In other words, the wiping device B is provided with one power source, which reciprocates the pair of wiper blades 1a, 1b. This wiping device B wipes rainwater off the surface (wiped surface) of the vehicle's front windshield or rear windshield, like the wiping device A according to the first embodiment.

[0061] The link mechanism 4 is a mechanical component that is mechanically connected to the other ends of the pair of wiper arms 2a, 2b and also connected to the output shaft of the motor 7. The link mechanism 4 has a support shaft fixed to the vehicle and is rotatable around the support shaft. The output shaft of the motor 7 is connected to the link mechanism 4, and by manipulating the rotation angle of the link mechanism 4, the pair of wiper blades 1a, 1b are swung over the surface to be wiped.

[0062] The angle detection circuit 31 has the same functions as the pair of angle detection circuits 31a, 31b in the first embodiment, and outputs a relative position signal that indicates the amount of movement of the driver's side wiper blade 1a or the passenger side wiper blade 1b, which is proportional to the motor rotation angle of the motor 7. In addition, this angle detection circuit 31 outputs an absolute position signal that indicates the position of a specific wiper blade of the pair of wiper blades 1a, 1b.

[0063] The drive circuit 32 has the same functions as the drive circuits 32a and 32b in the first embodiment. CPU50 The drive circuit 32 drives the motor 7 based on a drive command input from the drive control unit 51. That is, the drive circuit 32 drives the motor 7 in accordance with the difference between the current rotation speed of the motor 7 and the target rotation speed TR.

[0064] The control unit 10A has the same functions as the wiper control unit 10a in the first embodiment, and has a normal mode and a heavy rain mode as operation modes. In addition, the control unit 10A directly controls the drive circuit 32 by referring to a switch signal input from a higher-level control device, thereby indirectly feedback-controlling the motor 7.

[0065] In this control unit 10A, the CPU 50 has the same functions as the CPU 21a in the first embodiment, and 51 The actuator 23 controls the drive circuit 32 based on the operation map stored in the actuator 23a, the relative position signal and absolute position signal input from the angle detection circuit 31, and the switch signal input from the higher-level control system.

[0066] ROM 51 The RAM 52 has the same function as the ROM 23a in the first embodiment, and stores an operation map for the normal mode and an operation map for the heavy rain mode. 52 A reference numeral 53 temporarily holds intermediate data generated by the CPU 50 .

[0067] In this wiping device B, the normal mode and the heavy rain mode are switched based on the length of time that the mist switch is ON in the switch signal. The wiping range (movement range) of the pair of wiper blades 1a, 1b in the heavy rain mode is set to be narrower than the wiping ranges Ra, Rb (movement range) of the pair of wiper blades 1a, 1b in the normal mode. Furthermore, in this wiping device B, the wiping range (movement range) in the heavy rain mode is set to the "minimum wiping area" of forward visibility stipulated by regulations, as shown in FIG. 4.

[0068] According to the second embodiment, it is possible to provide a wiping device B that can satisfy the "minimum wiping area" of forward visibility stipulated by regulations during heavy rain. Also, according to the second embodiment, the wiping range (movement range) in the heavy rain mode is narrower than the wiping ranges Ra, Rb (movement range) in the normal mode, so that the power saving of the wiping device B can be realized. In the case of the second embodiment of FIG. 6, the rotational force of one motor 7 is converted into the reciprocating swing of two wiper arms 2a, 2b by the link mechanism 4. In the heavy rain mode, the motor 7 is driven so as to wipe the minimum wiping area NA shown in FIG. 4 for the narrow wiping range on the driver's side, and the narrow wiping range NRb on the passenger's side is driven via the link mechanism 4 for the narrow wiping range on the passenger's side. This ensures the wiping range for the driver. The upper inversion positions NUPa, NUPb and the lower inversion positions NLPa, NLPb are set as the upper inversion position NUP and the lower inversion position NLP, as in the first embodiment. The narrow wiping range NRa relative to the minimum wiping area NA is set as the first lower set position NPA, the second lower set position NPB, the second lower set position NPB, the Above 1 The first set position NPC and the second upper set position NPD are set as follows.

[0069] Furthermore, according to the second embodiment, as in the first embodiment, a mist switch that is generally provided in a vehicle is used to specify the heavy rain mode, so a dedicated switch for specifying the heavy rain mode is not required. Therefore, according to the second embodiment, it is possible to execute a control operation based on the heavy rain mode without the need to provide a new switch.

[0070] The present invention is not limited to the above embodiment, and various modifications are possible. For example, the block diagrams in Fig. 1 and Fig. 6 are merely examples of control configurations, and various modifications are possible without departing from the spirit of the present invention. [Explanation of symbols]

[0071] Reference Signs List 1a, 1b... Wiper blade, 2a, 2b... Wiper arm, 3a, 3b... Wiper shaft, 7a, 7b... Motor (power source), 10a, 10b... Wiper control unit (power source drive unit), 21a, 21b... CPU, 22a, 22b... Communication circuit, 23a, 23b... ROM, 24a, 24b... RAM, 31a, 31b... Angle detection circuit, 32a, 32b... Drive circuit

Claims

1. A wiping device that wipes rainwater off a surface to be wiped by reciprocating wiper blades using a specified power source, the wiping device being characterized by having a power source drive unit that sets the wiping range in heavy rain mode to be narrower than the wiping range in normal mode, and that sets the wiping range in heavy rain mode to the minimum wiping area specified by regulations.

2. The wiping device according to claim 1, characterized in that the power source drive unit switches its operating mode from the normal mode to the heavy rain mode based on a switch signal from a mist switch provided in the vehicle.

3. The wiping device according to claim 2, characterized in that the power source drive unit switches the operating mode from the normal mode to the heavy rain mode based on the length of time that the mist switch is turned on.

4. The wiping device according to claim 3, characterized in that the power source drive unit switches from the normal mode to the heavy rain mode when the ON time is equal to or greater than a predetermined threshold value.

5. The wiping device according to claim 1, characterized in that one or two power sources are provided, one of which reciprocates one or a pair of the wiper blades, and two of which reciprocate a pair of the wiper blades individually.

6. The wiping device described in claim 1, characterized in that the power source is composed of a first brushless wiper motor and a second brushless wiper motor, the wiper blade is composed of a first wiper blade reciprocated by the first brushless wiper motor and a second wiper blade reciprocated by the second brushless wiper motor, and when the heavy rain mode is detected, the second brushless wiper motor is stopped and only the first brushless wiper motor is driven to wipe the minimum wiping area with the first wiper blade.

Images