Wiping device

Abstract

The invention provides a wiping device which can realize wiping corresponding to rainstorm without increasing power consumption. A wiper device that wipes rainwater on a surface to be wiped by reciprocating a wiper blade using a predetermined power source includes a power source driving unit that sets a wiping range in a rainstorm mode to be narrower than a wiping range in a normal mode, and that drives the wiper blade to move back and forth in the normal mode. The wiping range of the rainstorm mode is set to be the minimum wiping area specified by the regulations.

Description

Technical Field

[0001] The invention relates to a scraping device. Background Art

[0002] In the following patent document 1, a wiper system control device is disclosed. The wiper system control device is a control device that performs motion control of a vehicle wiper system, wherein the vehicle wiper system includes a wiper blade that performs a reciprocating wiping motion on a wiping surface, and a raindrop sensor that senses the current rainfall based on water droplets attached to the wiping surface, wherein the wiper blade includes a driver's seat side wiper blade disposed on the driver's seat side of the vehicle and a passenger seat side wiper blade disposed on the passenger seat side of the vehicle, the driver's seat side wiper blade is driven by a first electric motor, and the passenger seat side wiper blade is driven by a second electric motor that is independently provided from the first electric motor, and the control device includes a second wiper control device that is connected to the first wiper control device that drives and controls the first electric motor through a communication line and drives and controls the second electric motor, and the first electric motor and The second electric motor is synchronously controlled by the first control device and the second control device based on the position information of the driver's side wiper blade and the front passenger side wiper blade. On the wiping surface, a heavy rain wiping area that is narrower than the normal wiping range of the driver's side wiper blade is set near the driver's front field of view. The first control device and the second control device have a rainfall state determination unit and an action mode change unit. The rainfall state determination unit determines the current rainfall state based on the output signal of the raindrop sensor. When the rainfall state determination unit determines that the rainfall amount is above a specified value and the heavy rain state is present, the action mode change unit changes the action form of the wiper blade to a heavy rain mode in which the wiping range of the driver's side wiper blade is narrowed compared to the normal wiping action, and the driver's side wiper blade is operated at high speed only in the heavy rain wiping area.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent No. 6349120 Summary of the invention

[0006] Problems to be solved by the invention

[0007] The wiping speed of the high-speed (Hi) operation of the wiper device corresponding to heavy rain varies depending on the vehicle manufacturer or model, but as one of the factors, it is sometimes restricted by load conditions such as the length of the wiper arm and the wiper blade or the maximum voltage of the drive motor. In a wiper device with a high load such as a four-section arm or a long wiper blade, in order to increase the speed of the Hi operation, a drive motor with a large rating is required to flow a large current.

[0008] On the other hand, as the electrification of vehicles progresses, reducing the power consumption of the wiper device has become an important topic, and ensuring visibility during heavy rains that have increased due to recent abnormal weather has also become a topic that vehicle manufacturers should strive to address. In other words, the requirements for the wiper device as a countermeasure for heavy rains are contradictory from the perspective of power consumption. In order to achieve the requirements, it is necessary to achieve wiping corresponding to heavy rains without increasing the power consumption of the wiper device.

[0009] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a wiping device capable of achieving wiping corresponding to heavy rain without increasing power consumption.

[0010] Technical means of solving problems

[0011] In order to achieve the above-mentioned purpose, in the present invention, the following means are adopted as the first solution involved in the wiping device: a wiping device that wipes rainwater on the wiped surface by utilizing a specified power source to make a wiper blade reciprocate, and the wiping device includes a power source driving unit, which sets the wiping range of the heavy rain mode to be narrower than the wiping range of the normal mode, and sets the wiping range of the heavy rain mode to the minimum wiping area specified by regulations.

[0012] In the present invention, as a second solution for the wiper device, the following means is adopted: in the first solution, the operation mode of the power source drive unit is switched from the normal mode to the heavy rain mode based on a switch signal of a light mist switch provided on the vehicle.

[0013] In the present invention, as a third solution means related to the wiper device, the following means is adopted: in the second solution means, the operation mode of the power source drive unit is switched from the normal mode to the heavy rain mode based on the length of the on-time of the light mist switch.

[0014] In the present invention, as a fourth solution of the wiper device, in the third solution, when the on time is equal to or longer than a predetermined threshold, the power source drive unit switches from the normal mode to the heavy rain mode.

[0015] In the present invention, the following means is adopted as the fifth solution involved in the wiping device: in any one of the first solution to the third solution, the power source is provided with one or two, and one power source is utilized to make one or a pair of the wiper blades reciprocate, and two power sources are utilized to make a pair of the wiper blades reciprocate independently.

[0016] Effects of the Invention

[0017] According to the present invention, a wiping device capable of achieving wiping corresponding to heavy rain without increasing power consumption can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] [ Figure 1 ] is a block diagram showing the functional structure of the wiping device A according to the first embodiment of the present invention.

[0019] [ Figure 2 ] is a flow chart showing the operation of the wiping device A according to the first embodiment of the present invention.

[0020] [ Figure 3 ] is a timing diagram showing the operation of the wiping device A according to the first embodiment of the present invention.

[0021] [ Figure 4 ] is a schematic diagram showing the wiping range (minimum wiping area) in the first embodiment of the present invention.

[0022] [ Figure 5 ] is a flowchart showing the switching process of the action mode in the first embodiment of the present invention.

[0023] [ Figure 6 ] is a block diagram showing the functional structure of the wiping device A according to the second embodiment of the present invention. DETAILED DESCRIPTION

[0024] [First embodiment]

[0025] First, refer to Figure 1 to Figure 5 A first embodiment of the present invention will be described. A wiper device A according to the first embodiment is mounted on various vehicles and wipes rainwater on the surface (wiped surface) of a front glass or a rear glass.

[0026] like Figure 1As shown, the wiper device A adopts a dual motor drive method in which a pair of wiper blades 1a and 1b are independently driven by a pair of motors 7a and 7b as power sources. That is, the wiper device A of the first embodiment is provided with two power sources, and the pair of wiper blades 1a and 1b are independently reciprocated by the two power sources. In the wiper device A of the first embodiment, it is preferred that both of the pair of motors 7a and 7b use brushless wiper motors. When the brushless wiper motor is repeatedly rotated forward and reverse at high speed by the action in the heavy rain mode, the wear powder of the brush generated by the sliding of the brush and the commutator (commutator) as in the wiper motor with a brush is not generated, so the life of the wiper motor can be extended and the life can be extended. In addition, by using a brushless wiper motor, the forward rotation and reverse rotation can be smoothly repeated, so it can be reversed with good accuracy at the upper reversal position and the lower reversal position set for the use of the heavy rain mode.

[0027] As shown in the figure, the wiping device A includes a pair of wiper blades 1a, 1b and a single driving device 10. Figure 1 In each symbol of , "a" indicates a member or part related to the driver's seat side of the vehicle. In addition, "b" indicates a member or part related to the passenger seat side of the vehicle.

[0028] As shown in the figure, a pair of wiper blades 1a, 1b are rod-shaped members arranged on the front glass W. The pair of wiper blades 1a, 1b abut against the surface (wiped surface) of the front glass W and reciprocate (swing) on ​​the wiped surface to wipe rainwater on the wiped surface.

[0029] In addition, Figure 1 In FIG. 1 , symbol Ra represents the wiping range of the wiper blade 1a on the driver's seat side when the operation mode of the drive device 10 is set to the normal mode. Symbol Rb represents the wiping range of the wiper blade 1b on the passenger's seat side when the operation mode of the drive device 10 is set to the normal mode.

[0030] A pair of wiper blades 1a and 1b are mechanically connected to a drive device 10 via a pair of wiper arms 2a and 2b. That is, the wiper blade 1a on the driver's seat side is connected to the drive device 10 via the wiper arm 2a provided on the driver's seat side. The wiper blade 1b on the passenger seat side is connected to the drive device 10 via the wiper arm 2b provided on the passenger seat side.

[0031] As shown in the figure, a pair of wiper arms 2a, 2b are rod-shaped members, and one end is connected to the middle part of a pair of wiper blades 1a, 1b, and the other end is connected to a pair of wiper shafts 3a, 3b. That is, one end of the wiper arm 2a on the driver's seat side is connected to the middle part of the wiper blade 1a on the driver's seat side, and the other end is connected to the wiper shaft 3a on the driver's seat side.

[0032] On the other hand, one end of the wiper arm 2b on the passenger seat side is connected to the middle part of the wiper blade 1b on the passenger seat side, and the other end is connected to the wiper shaft 3b on the passenger seat side. In addition, such a pair of wiper arms 2a, 2b are components included in the components of the pair of wiper blades 1a, 1b.

[0033] The pair of wiper arms 2a, 2b function as power transmission parts that mechanically transmit the rotational power of the drive device 10 to the pair of wiper blades 1a, 1b. In addition, the pair of wiper arms 2a, 2b function as biasing members that press the pair of wiper blades 1a, 1b against the surface (wiped surface) of the front glass W with a predetermined pressing force.

[0034] The driving device 10 is a power generating device for reciprocating a pair of wiper blades 1a and 1b via a pair of wiper arms 2a and 2b. The driving device 10 reciprocates a pair of wiper blades 1a and 1b placed on the surface (wiped surface) of the front glass W by rotating a pair of wiper shafts 3a and 3b within a predetermined angle range.

[0035] The drive device 10 includes a pair of motors 7a and 7b as power sources corresponding to the pair of wiper shafts 3a and 3b. The pair of motors 7a and 7b each include a motor body 8 and a speed reduction mechanism 9. In addition, the drive device 10 includes a pair of wiper control units 10a and 10b corresponding to the pair of motors 7a and 7b.

[0036] The pair of wiper control units 10a and 10b are power source driving units that drive the pair of motors 7a and 7b as power sources. The motor 7a on the driver's seat side is driven and controlled by the wiper control unit 10a, thereby causing the wiper blade 1a on the driver's seat side to reciprocate (swing) on ​​the wiped surface. The motor 7b on the passenger seat side is driven and controlled by the wiper control unit 10b, thereby causing the wiper blade 1b on the passenger seat side to reciprocate (swing) on ​​the wiped surface.

[0037] The wiper control unit 10a corresponding to the driver's seat side is composed of a control substrate, which includes an electronic circuit including a central processing unit (CPU) 21a, a communication circuit 22a, a read only memory (ROM) 23a, a random access memory (RAM) 24a, an angle detection circuit 31a, a drive circuit 32a, and a lock detection timer 33a, and the wiper control unit 10a is built in the speed reduction mechanism 9 of the motor 7a. In addition, the wiper control unit 10b corresponding to the passenger seat side is composed of a control substrate, which includes an electronic circuit including 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 the wiper control unit 10b is built in the speed reduction mechanism 9 of the motor 7b.

[0038] The wiper control unit 10a corresponding to the driver's seat side and the wiper control unit 10b corresponding to the passenger seat side are connected to each other in a communication manner through a pair of communication circuits 22a and 22b. In addition, the wiper control unit 10a that drives and controls the motor 7a on the driver's seat side is connected to the electronic control unit (ECU) of the vehicle as a higher-level control device via a communication line. Switch signals such as the on / off of the wiper switch, the designation of the heavy rain mode, the on / off of the light mist switch, and intermittent operation (low-speed (Lo) wiping, high-speed (Hi) wiping, and intermittent (INT) wiping) are input from the ECU to the wiper control unit 10a.

[0039] In the driving device 10, the position of the pair of wiper blades 1a and 1b is controlled by feedback control of the pair of motors 7a and 7b based on the elapsed time from the absolute position that serves as a reference for control. In the position control, the lower reversal position LPa and the lower reversal position LPb are used as absolute positions, and the target rotation speed TR of the pair of motors 7a and 7b at this time point is set in advance by a work map according to the elapsed time t from the lower reversal position LPa and the lower reversal position LPb.

[0040] Here, in the drive device 10, there are a normal mode and a heavy rain mode as the action mode. In the normal mode, the wiper control unit 10a performs wiping control for low-speed wiping (Lo wiping) at a prescribed speed, high-speed wiping (Hi wiping) faster than low-speed wiping, and intermittent wiping (INT wiping) in which wiping control is repeatedly performed after a prescribed time has passed. In the heavy rain mode, the wiper control unit 10a causes the wiper motor 7a to repeatedly rotate forward and reverse at a speed faster than high-speed wiping, thereby performing wiping control in a reciprocating swing in a narrow wiping range NRa described later. That is, in the working map, there is a working map for the heavy rain mode applied when the action mode is the heavy rain mode and a working map for the normal mode applied when the action mode is other than the heavy rain mode. Such working maps are stored in a pair of ROMs 23a and 23b, respectively. In the working map for the heavy rain mode, a target speed TR different from the target speed TR of the working map for the normal mode is set. In addition, the heavy rain in the present invention is a concept that also includes a violent heavy rain that falls locally in a short period of time (guerrilla heavy rain).

[0041] The pair of wiper control units 10a, 10b count the elapsed time t from the lower reversal position LPa, the lower reversal position LPb in the pair of CPUs 21a, 21b, grasp the current rotation speed of the pair of motors 7a, 7b, and compare the current rotation speed 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 speed and the target rotation speed TR, thereby indirectly controlling the pair of motors 7a, 7b.

[0042] A pair of angle detection circuits 31a and 31b are provided between the pair of motors 7a and 7b and the pair of CPUs 21a and 21b to detect the positions of the pair of wiper blades 1a and 1b. The pair of angle detection circuits 31a and 31b output relative position signals that are proportional to the motor rotation angles of the pair of motors 7a and 7b and represent the movement amounts of the pair of wiper blades 1a and 1b. In addition, the pair of angle detection circuits 31a and 31b output absolute position signals that represent the position of a specific wiper blade in the pair of wiper blades 1a and 1b.

[0043] 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 on the driver's seat side. The angle detection circuit 31a outputs a relative position signal which is proportional to the motor rotation angle of the motor 7a on the driver's seat side and indicates the movement amount of the wiper blade 1a on the driver's seat side, and an absolute position signal indicating the position of a specific wiper blade.

[0044] The angle detection circuit 31b corresponding to the passenger seat side is provided between the motor 7b on the passenger seat side and the CPU 21b on the passenger seat side. The angle detection circuit 31b outputs a relative position signal which is proportional to the motor rotation angle of the motor 7b on the passenger seat side and indicates the movement amount of the wiper blade 1b on the passenger seat side, and an absolute position signal indicating the position of a specific wiper blade.

[0045] 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 pulse number proportional to the rotation angle of the pair of motors 7a, 7b. The absolute position signal is a single signal issued when the pair of wiper blades 1a, 1b arrive at the control reference position (for example, the lower reverse position LPa, the lower reverse position LPb).

[0046] The rotation speed of the pair of motors 7a, 7b and the rotation speed of the pair of wiper shafts 3a, 3b are in a certain 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 calculating the number of pulses based on the relative position signal. In addition, the rotation angle of the pair of wiper shafts 3a, 3b and the moving angle of the pair of wiper blades 1a, 1b are in a certain relationship.

[0047] That is, by accumulating the number of pulses of the relative position signal, the moving angle of the pair of wiper blades 1a and 1b can be detected. The pair of CPUs 21a and 21b detect the current position of the pair of wiper blades 1a and 1b based on the combination of the accumulated result of the number of pulses of the relative position signal and the absolute position signal. In addition, the pair of CPUs 21a and 21b detect the current motor speed of the pair of motors 7a and 7b by counting the relative position signal (motor pulses).

[0048] The CPUs 21a and 21b use built-in timers to measure the elapsed time t from the time of acquiring the absolute position signal. The CPUs 21a and 21b acquire the target positions of the wiper blades 1a and 1b and the target rotation speeds TR of the motors 7a and 7b at the current elapsed time from the ROMs 23a and 23b.

[0049] The pair of CPUs 21a and 21b compare the current positions of the pair of wiper blades 1a and 1b with the target positions to grasp the current status of the pair of wiper blades 1a and 1b (whether they are behind or ahead of the target positions). In addition, the pair of CPUs 21a and 21b calculate the rotation speeds of the pair of motors 7a and 7b based on the status of the rotation speeds of the pair of motors 7a and 7b (how high or low they are relative to the target rotation speed TR), and control the rotation of the pair of motors 7a and 7b based on the rotation speeds.

[0050] That is, the positions of the pair of wiper blades 1a and 1b and the target values ​​of the motor speeds of the pair of motors 7a and 7b are stored in advance in the form of an operation map in the pair of ROMs 23a and 23b using the elapsed time t from the time when the absolute position signal is obtained as a parameter. The pair of CPUs 21a and 21b perform feedback control on the pair of motors 7a and 7b by comparing the target values ​​of the motor speeds in the operation map with the current values.

[0051] In addition, in each operation map, the precedence relationship between the pair of wiper blades 1a and 1b is preset. Furthermore, in each operation map, the target speed TR is determined based on the elapsed time t from the acquisition time of the absolute position signal and the current position of the pair of wiper blades 1a and 1b, and according to the position of the other party. For example, even if the elapsed time t and the current position of the pair of wiper blades 1a and 1b are the same, when the current position of the other party is close to the self, the target speed TR is set in a manner that becomes larger, and when the current position of the other party is far from the self, the target speed TR is set in a manner that becomes smaller.

[0052] The current positions of the pair of wiper blades 1a and 1b are exchanged between the pair of CPUs 21a and 21b via the pair of communication circuits 22a and 22b and written into the pair of RAMs 24a and 24b. The pair of CPUs 21a and 21b synchronously control the pair of motors 7a and 7b based on the positional relationship of the pair of wiper blades 1a and 1b written into the pair of RAMs 24a and 24b.

[0053] Next, follow Figure 2 The flowchart shown explains the characteristic operation of the wiping device A according to the first embodiment.

[0054] The CPU 21a of the wiper control unit 10a communicates with the ECU as a higher-level control device to obtain a switch signal at a predetermined timing (step S1). The CPU 21a determines whether the switch signal is a signal that specifies the heavy rain mode as the operation mode (step S2). Then, if the CPU 21a determines in step S2 that the switch signal is "No", that is, if the switch signal is not a signal that specifies the heavy rain mode, the operation mode is maintained at the normal mode (step S3).

[0055] That is, the pair of CPUs 21a and 21b perform feedback control on the pair of motors 7a and 7b based on the normal mode operation map as before receiving the switch signal. In addition, the storage position is set to be closer to the engine room side than the lower reversal position LPa and the lower reversal position LPb, and each wiper blade is set to a position that is not easily visible from the inside of the vehicle when the pair of motors 7a and 7b are not used.

[0056] On the other hand, when the judgment of CPU 21a in step S2 is "Yes", that is, when the switch signal is a signal specifying the heavy rain mode, the operation mode is switched from the normal mode to the heavy rain mode (step S4). Then, a pair of CPUs 21a and 21b perform feedback control on a pair of motors 7a and 7b based on the heavy rain mode operation map instead of the normal mode operation map. When the state of wiping in the normal mode is switched to the heavy rain mode, after the pair of wiper blades 1a and 1b are moved to the upper reversal position UPa, the upper reversal position UPb or the lower reversal position LPa, the lower reversal position LPb, 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 of the narrow wiping range NRa, and reciprocating wiping is performed within the narrow wiping range NRa. The other motor 7b can not only stop the wiper blade 1b at a position such as the lower reversal position LPb, the storage position or the upper reversal position UPb which does not interfere with the wiper blade 1a, but also make the wiper blade 1b reciprocate and wipe within the range between the narrow wiping range NRa and the upper reversal position UPb which does not interfere with the wiper blade 1a.

[0057] like Figure 3 As shown, in the feedback control of one of the motors 7a using the working map for the heavy rain mode, the lower reversal position NLP of one of the wiper blades 1a is set to be higher than the lower reversal position LPa of the normal mode, and the upper reversal position NUP of one of the wiper blades 1a is set to be lower than the upper reversal position UPa of the normal mode.

[0058] That is, the wiping range (moving range) NRa of one wiper blade 1a in the heavy rain mode is set to be narrower than the wiping range Ra and the wiping range Rb (moving range) of the pair of wiper blades 1a and 1b in the normal mode. Figure 4 As shown, the wiping range (movement range) NRa in the heavy rain mode is set to include at least the “minimum wiping area” of the forward field of vision prescribed by laws and regulations.

[0059] Here, the so-called "minimum wiping area" refers to a hypothetical range with four setting positions defined by regulations, which is equivalent to "Area A" in the wiping area regulations on the wiped surface of Japanese and European Economic Community (EEC) regulations and "Area C" in the wiping area regulations of U.S. regulations (Federal Motor Vehicle Safety Standards (FMVSS)).

[0060] Through this first embodiment, the "minimum wiping area" of the forward field of vision stipulated by the law can be met during heavy rain. Figure 4 As shown, in the minimum wiping area NA for wiping in the heavy rain mode, the position at which one of the wiper blades 1a initially overlaps with the minimum wiping area NA when moving from the normal lower reversal position LPa toward the minimum wiping area NA is set as the first lower setting position NPA, and the second lower setting position NPB of the minimum wiping area NA is set adjacent to the first lower setting position NPA in the up-down direction and biased towards the normal lower reversal position LPa, the position at which one of the wiper blades 1a initially overlaps with the minimum wiping area NA when moving from the normal upper reversal position UPa toward the minimum wiping area NA is set as the first upper setting position NPC, and the second upper setting position NPD is set adjacent to the first upper setting position NPC in the up-down direction and biased towards the normal upper reversal position UPa. The narrow wiping range NRa is set between the first lower setting position NPA and the first upper setting position NPC, and the brushless wiper motor is used to rotate at high speed and perform forward and reverse rotation control in the narrow wiping range NRa in the heavy rain mode, thereby wiping the "minimum wiping area" in the driver's front field of vision. In addition, according to the first embodiment, since the range of movement in the narrow wiping range NRa in the heavy rain mode is narrower than the range of movement in the wiping range Ra and the wiping range Rb in the normal mode, the power saving of the wiping device A can be achieved.

[0061] That is, in the first embodiment, the narrow wiping range NRa of one of the wiper blades 1a during heavy rain is limited to a forward visual field "minimum wiping area" that is narrower than the range moved in the wiping range Ra and the wiping range Rb in the normal mode. Therefore, the first embodiment can provide a wiping device A that can achieve wiping corresponding to heavy rain without increasing power consumption.

[0062] In addition, in the first embodiment, according to Figure 5 The judgment algorithm shown in the flowchart shown in the figure judges the processing of step S1 and step S2, that is, judges whether the switch signal obtained from the upper control device is a signal for designating the heavy rain mode. That is, the CPU 21a of the wiper control unit 10a performs the designation judgment processing of the heavy rain mode based on the special operation form of the light mist switch provided on the vehicle.

[0063] In the designation determination process, the CPU 21a first obtains a switch signal (step S10). Then, the CPU 21a determines whether the switch signal obtained from the upper control device is an on operation of the mist switch (step S11). When the CPU 21a determines "no" in step S11, that is, when the switch signal is not a signal indicating an on operation of the mist switch, it determines whether the current operation mode is the heavy rain mode (step S12).

[0064] Then, when the CPU 21a determines "No" in step S12, that is, when the current operation mode is not the heavy rain mode, the CPU 21a performs a control operation based on the switch signal obtained in step S10 (step S13). On the other hand, when the CPU 21a determines "Yes" in step S12, that is, when the current operation mode is the heavy rain mode, the CPU 21a determines whether the switch signal obtained in step S10 is a signal indicating that the wiper switch is turned off (step S14).

[0065] Then, when the judgment of step S14 is “No”, that is, when the switch signal is not a signal indicating the wiper switch is turned off, the CPU 21a performs a control operation based on the switch signal acquired in step S10 (step S15). On the other hand, when the judgment of step S14 is “Yes”, that is, when the switch signal is a signal indicating the wiper switch is turned off, the CPU 21a continues to perform a control operation based on the heavy rain mode (step S16).

[0066] On the other hand, when the judgment of step S11 is "yes", that is, when the switch signal is a signal indicating the on operation of the mist switch, 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).

[0067] Then, when the CPU 21a determines "No" in step S18, that is, when the on-time of the light mist switch does not exceed the threshold value, the light mist control operation is performed (step S19). On the other hand, when the CPU 21a determines "Yes" in step S18, that is, when the on-time of the light mist switch is greater than the threshold value, the control operation based on the heavy rain mode is performed (step S20).

[0068] By this designation judgment process of the heavy rain mode, since the light mist switch generally provided in the vehicle is used for designation of the heavy rain mode, a dedicated switch for designating the heavy rain mode is not required. In the case where a dedicated switch is additionally provided to the vehicle, the structure of the vehicle switch increases, and there is a high possibility that the driver cannot perform instantaneous operation, but by switching between the normal light mist action and the heavy rain mode according to the length of the on-time of the light mist switch already provided, the control action based on the heavy rain mode can be performed without providing a new switch.

[0069] [Second embodiment]

[0070] Next, refer to Figure 6 A second embodiment of the present invention will be described. In the second embodiment, the same components as those of the first embodiment are denoted by the same reference numerals.

[0071] like Figure 6 As shown, the wiper device B of the second embodiment includes a pair of wiper blades 1a, 1b, a pair of wiper arms 2a, 2b, a link mechanism 4, a motor 7, an angle detection circuit 31, a drive circuit 32, and a control unit 10A. In addition, the control unit 10A includes a CPU 50, a ROM 51, and a RAM 52.

[0072] The wiper device B adopts a single motor drive method, and the single motor drive method mechanically connects a pair of wiper arms 2a and 2b using a link mechanism 4, thereby driving a pair of wiper blades 1a and 1b using a single motor 7 (power source). That is, the wiper device B is provided with one power source, and the pair of wiper blades 1a and 1b are reciprocated by the one power source. This wiper device B wipes rainwater on the surface (wiped surface) of the front glass or rear glass of the vehicle in the same manner as the wiper device A of the first embodiment.

[0073] The link mechanism 4 is a mechanical part that is mechanically connected to the other ends of the pair of wiper arms 2a, 2b and is also connected to the output shaft of the motor 7. In addition, the link mechanism 4 includes 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 the pair of wiper blades 1a, 1b are swung on the wiped surface by operating the rotation angle of the link mechanism 4.

[0074] The angle detection circuit 31 has the same function as the pair of angle detection circuits 31a and 31b in the first embodiment, and outputs a relative position signal which is proportional to the motor rotation angle of the motor 7 and indicates the movement amount of the wiper blade 1a on the driver's seat side or the wiper blade 1b on the passenger seat side. In addition, the angle detection circuit 31 outputs an absolute position signal indicating the position of a specific wiper blade of the pair of wiper blades 1a and 1b.

[0075] The drive circuit 32 has the same functions as the drive circuits 32a and 32b in the first embodiment, and drives the motor 7 based on the drive command input from the drive control unit 51. That is, the drive circuit 32 drives the motor 7 according to the difference between the current rotation speed of the motor 7 and the target rotation speed TR.

[0076] The control unit 10A has the same functions as the wiper control unit 10a in the first embodiment, and includes 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 the switch signal input from the host control device, thereby indirectly performing feedback control on the motor 7.

[0077] In the control unit 10A, the CPU 50 has the same functions as the CPU 21a in the first embodiment, and controls the drive circuit 32 based on the work map stored in the ROM 23a, the relative position signal and the absolute position signal input from the angle detection circuit 31, and the switch signal input from the upper control system.

[0078] The ROM 52 has the same function as the ROM 23 a in the first embodiment, and stores the normal mode operation map and the heavy rain mode operation map. The RAM 53 temporarily holds the intermediate generation data of the CPU 50 .

[0079] In this wiping device B, the normal mode and the heavy rain mode are switched based on the length of the on-time of the light mist switch in the switch signal. In addition, the wiping range (movement range) of the pair of wiper blades 1a and 1b in the heavy rain mode is set to be narrower than the wiping range Ra and the wiping range Rb (movement range) of the pair of wiper blades 1a and 1b in the normal mode. Figure 4 As shown, the wiping range (moving range) in the heavy rain mode is set to the "minimum wiping area" of the forward field of vision specified by laws and regulations.

[0080] This second embodiment can provide a wiping device B that can meet the "minimum wiping area" of the forward field of vision required by the law during heavy rain. In addition, the second embodiment makes the wiping range (moving range) in the heavy rain mode narrower than the wiping range Ra and wiping range Rb (moving range) in the normal mode, so that the wiping device B can save power. Figure 6 In the second embodiment, the rotational force of the motor 7 is converted into the reciprocating swing of the two wiper arms 2a and 2b by the link mechanism 4. In the narrow wiping range on the driver's seat side in the heavy rain mode, the motor 7 is driven to Figure 4In the narrow wiping range on the passenger seat side, the wiping is performed in the minimum wiping area NA shown in the figure, and in the narrow wiping range on the passenger seat side, the wiping is driven in the narrow wiping range NRb on the passenger seat side via the link mechanism 4. In this way, the wiping range of the driver can be ensured. In addition, regarding the setting of the upper reversal position NUPa, the upper reversal position NUPb, the lower reversal position NLPa, and the lower reversal position NLPb, they are set to the upper reversal position NUP and the lower reversal position NLP in the same manner as in the first embodiment, and regarding the setting of the narrow wiping range NRa relative to the minimum wiping area NA, it is set to the first lower side setting position NPA, the second lower side setting position NPB, the second lower side setting position NPC, and the second upper side setting position NPD in the same manner as in the first embodiment.

[0081] Furthermore, in the second embodiment, similarly to the first embodiment, since the light mist switch generally provided in the vehicle is used for designating the heavy rain mode, a dedicated switch for designating the heavy rain mode is not required. Therefore, in the second embodiment, the control operation based on the heavy rain mode can be executed without providing a new switch.

[0082] In addition, the present invention is not limited to the above-mentioned embodiment, but can be modified in various ways. For example, Figure 1 and Figure 6 The block diagram is merely an example of a control structure and various modifications can be made without departing from the gist of the present invention.

[0083] Explanation of symbols

[0084] 1a, 1b: Wiper blades

[0085] 2a, 2b: Wiper arms

[0086] 3a, 3b: Wiper shaft

[0087] 7a, 7b: Motor (power source)

[0088] 10a, 10b: Wiper control unit (power source drive unit)

[0089] 21a, 21b: CPU

[0090] 22a, 22b: Communication circuit

[0091] 23a, 23b: ROM

[0092] 24a, 24b: RAM

[0093] 31a, 31b: Angle detection circuit

[0094] 32a, 32b: driving circuit

Claims

1. A wiping device, which wipes rainwater on a wiped surface by reciprocating a wiper blade using a predetermined power source, wherein: The invention comprises a power source driving unit which sets a wiping range in a heavy rain mode to be narrower than a wiping range in a normal mode and sets the wiping range in the heavy rain mode to a minimum wiping area prescribed by laws and regulations.

2. The wiper device according to claim 1, characterized in that: The operation mode of the power source driving unit is switched from the normal mode to the heavy rain mode based on a switch signal of a light mist switch provided on the vehicle.

3. The wiper device according to claim 2, characterized in that: The operation mode of the power source driving unit is switched from the normal mode to the heavy rain mode based on the length of the ON time of the mist switch.

4. The wiper device according to claim 3, characterized in that: When the on time is equal to or longer than a predetermined threshold, the power source driving unit switches from the normal mode to the heavy rain mode.

5. The wiper device according to claim 1, characterized in that: One or two power sources are provided. One power source is used to make one or a pair of wiper blades reciprocate. Two power sources are used to make a pair of wiper blades reciprocate independently.

6. The wiper device according to claim 1, characterized in that: The power source includes a first brushless wiper motor and a second brushless wiper motor, and the wiper blade includes a first wiper blade that reciprocates through the first brushless wiper motor and a second wiper blade that is reciprocally driven through the second brushless wiper motor. When the heavy rain mode is detected, the second brushless wiper motor is stopped and only the first brushless wiper motor is driven, and the minimum wiping area is wiped by the first wiper blade.

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