JP7733609B2 - Wiper control device - Google Patents

Description

The present invention relates to a wiper control device that includes a wiper motor and a controller that controls the wiper motor.

A wiper device is installed in the front of a vehicle such as an automobile. The wiper device includes a driver's side wiper member, a passenger side wiper member, and a wiper motor that drives these wiper members. Operating a wiper switch or similar device inside the vehicle activates the wiper motor, causing the wiper members to wipe across the windshield. This wipes away rainwater and other debris adhering to the windshield.

A wiper control device that controls such a wiper device is described, for example, in Patent Document 1. The wiper control device described in Patent Document 1 has a stop position retention function that operates to position the wiper blade (wiper member) in the lower reversal position (target position).

In the technology described in Patent Document 1, the controller stops the stop position holding function when chattering occurs, such as when the wiper blades do not reach the target position smoothly, while the stop position holding function is active. This prevents the wiper motor from being continuously energized due to an overload condition, etc.

JP 2013-052826 A

In the technology described in Patent Document 1, the controller stops the movement of the wiper members toward the target position if the wiper members do not reach the target position. Therefore, for example, when the wiper motor is driven intermittently, if the wiper members do not reach the target position due to external forces such as wind from traveling, the wiper control device stops, and then the wiper control device must be restarted.

The object of the present invention is to provide a wiper control device that makes it possible to change the intermittent stop position during intermittent driving, thereby enabling the intermittent function to operate continuously.

In one aspect of the present invention, a wiper control device includes a wiper motor that drives a wiper member to perform a wiping operation, and a controller that drives the wiper motor intermittently. The controller has a position retention control unit that drives the wiper motor to return the wiper member to the reference intermittent stop position when the wiper member is moved from the reference intermittent stop position by an external force while the wiper motor is intermittently stopped; a continuous drive determination unit that determines whether the wiper motor has been continuously driven by the position retention control unit; and an intermittent stop position change unit that changes the intermittent stop position of the wiper member to a corrected position different from the reference intermittent stop position when the continuous drive determination unit determines that the wiper motor has been continuously driven.

According to the present invention, when the continuous drive determination unit determines that the wiper motor has been continuously driven, the intermittent stop position change unit changes the intermittent stop position of the wiper member to a corrected position different from the reference intermittent stop position. This prevents the position retention control unit from repeatedly attempting to return the wiper member to the reference intermittent stop position, reducing the load on the wiper motor. Furthermore, it becomes possible to continue operating the intermittent function with the intermittent stop position changed, thereby improving comfort and convenience.

1 is a schematic diagram of a wiper control device mounted on a vehicle; FIG. 2 is a side view of the wiper motor. FIG. 4 is a view of the wiper motor as seen from the gear cover side. FIG. 2 is a block diagram of a wiper control device. 10A and 10B are diagrams illustrating the positions of the AS-side wiper blade and the hood. 10 is a flowchart showing the operation of the intermittent function. 10 is a timing chart showing the operation of the intermittent function. 10 is a flowchart corresponding to FIG. 6 of the second embodiment. 8 is a timing chart corresponding to FIG. 7 of the second embodiment; 10 is a part of a flowchart showing a third embodiment. 10 is a timing chart corresponding to FIG. 7 of the third embodiment.

[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings.

Figure 1 shows an overview of the wiper control device installed in a vehicle, Figure 2 shows a side view of the wiper motor, Figure 3 shows a view of the wiper motor from the gear cover side, Figure 4 shows a block diagram of the wiper control device, Figure 5 shows a diagram explaining the position of the AS side wiper blade and hood, Figure 6 shows a flowchart illustrating the operation of the intermittent function, and Figure 7 shows a timing chart illustrating the operation of the intermittent function.

[Wiper control device]
As shown in Fig. 1, a vehicle 10 such as an automobile is provided with a windshield 11 at the front side thereof. A wiper control device 20 is provided at the front side of the windshield 11 (at the bottom of Fig. 1) to wipe away rainwater, dust, and the like adhering to the windshield 11, thereby ensuring visibility for the driver and the like.

The wiper control device 20 includes a wiper drive mechanism 30, which is mounted inside a bulkhead (not shown) that forms the engine compartment of the vehicle 10. Furthermore, when the wiper control device 20 is in a stopped state, the wiper control device 20 is covered by the hood 12 of the vehicle 10 and is hidden behind the hood 12.

The wiper drive mechanism 30 includes a wiper motor 31 that is driven when the wiper switch 21 located inside the vehicle cabin is turned on; DR (driver's side) and AS (passenger's side) pivot shafts 32, 33 that are rotatably mounted on the vehicle 10; DR and AS wiper members (wiper members) 34, 35 whose base ends are fixed to the respective pivot shafts 32, 33 and whose tip ends wipe across the windshield 11; and a link mechanism 36 that transmits the output of the wiper motor 31 to the respective pivot shafts 32, 33.

The DR-side wiper member 34 includes a DR-side wiper arm 34a and a DR-side wiper blade 34b. The base end of the DR-side wiper arm 34a is fixed to the DR-side pivot shaft 32. The DR-side wiper blade 34b is attached to the tip end of the DR-side wiper arm 34a. The AS-side wiper member 35 includes an AS-side wiper arm 35a and an AS-side wiper blade 35b. The base end of the AS-side wiper arm 35a is fixed to the AS-side pivot shaft 33. The AS-side wiper blade 35b is attached to the tip end of the AS-side wiper arm 35a.

When the wiper motor 31 is driven, the pair of wiper blades 34b, 35b swing in sync via the link mechanism 36, wiping the windshield 11. This wipes away rainwater, dust, and other debris adhering to the DR-side and AS-side wiping areas 11a, 11b, enclosed by dashed lines in the figure. Note that the symbol LRP in the figure indicates the "lower reversal position" of the pair of wiper blades 34b, 35b, the symbol URP in the figure indicates the "upper reversal position" of the pair of wiper blades 34b, 35b, and the symbol HP in the figure indicates the "storage position" of the pair of wiper blades 34b, 35b.

In other words, while the wiper motor 31 is driven, the pair of wiper blades 34b, 35b reciprocate between the lower reversal position LRP and the upper reversal position URP. In contrast, when the wiper motor 31 is stopped (the wiper switch 21 is turned off), the pair of wiper blades 34b, 35b are stopped at the storage position HP.

Here, the lower reversal position LRP and storage position HP on the DR side and AS side are each located on the underside of the hood 12, near the edge portion 12a on the windshield 11 side of the hood 12. Specifically, the lower reversal position LRP is located closer to the edge portion 12a than the storage position HP. As a result, when the wiper motor 31 is stopped (stored), the pair of wiper blades 34b, 35b are hidden relatively deep inside the underside of the hood 12, improving the appearance of the vehicle 10 and the aerodynamic characteristics of the vehicle 10.

[Wiper motor]
2 to 4, the wiper motor 31 is a brushless motor. The wiper motor 31 includes a motor unit 40 and a speed reduction mechanism unit 50. The motor unit 40 has a motor case 41 that forms the outer shell of the motor unit 40. The motor case 41 is formed into a generally cylindrical shape with a bottom by pressing a steel plate or the like.

A stator 42 is fixed to the radially inner side of the motor case 41. The stator 42 is formed into a roughly cylindrical shape by laminating thin steel plates (magnetic material). A plurality of teeth (not shown) are formed on the radially inner side of the stator 42, and three-phase coils (not shown) for U, V, and W phases are wound around these teeth in a delta connection via insulating members. Note that the coils are not limited to a delta connection and can also be wound in a star connection.

The motor unit 40 also includes a rotor 43. The rotor 43 is rotatably mounted radially inside the stator 42 via a predetermined gap (air gap). The rotor 43 is formed into a roughly cylindrical shape by laminating multiple steel plates (magnetic material). Multiple permanent magnets (not shown) are integrally mounted on the rotor 43. The rotor 43 can be constructed as an IPM (Interior Permanent Magnet) structure, in which permanent magnets are embedded inside, or an SPM (Surface Permanent Magnet) structure, in which permanent magnets are attached to the outer peripheral surface.

The motor unit 40 includes a rotating shaft 44. The rotating shaft 44 is fixed to the center of rotation of the rotor 43, and the base end (upper side in Figure 3) of the rotating shaft 44 is rotatably housed inside the motor case 41. In contrast, the tip end (lower side in Figure 3) of the rotating shaft 44 is rotatably housed inside the gear case 51 that forms the reduction mechanism unit 50.

The rotating shaft 44 is rotatably supported by bearings (not shown) provided inside the motor case 41 and the gear case 51. Also, in Figure 3, the gear cover 52 (see Figure 2) that forms the reduction mechanism 50 is not shown.

A worm 44a that forms the reduction gear mechanism SD is integrally provided at the tip of the rotating shaft 44. Furthermore, a rotating shaft sensor magnet MG1 is fixed between the worm 44a of the rotating shaft 44 and the rotor 43. This rotating shaft sensor magnet MG1 is used to detect the rotation direction and rotation speed of the rotating shaft 44, as well as the rotational position of the rotor 43 relative to the stator 42. This makes it possible to precisely control the rotation state of the rotating shaft 44.

As shown in Figures 2 and 3, the reduction mechanism 50 includes a gear case 51 made of die-cast aluminum. The opening of the gear case 51 (the lower side in Figure 2 and the front side in Figure 3) is closed by a plastic gear cover 52.

The worm wheel 53 that forms the reduction gear mechanism SD is rotatably housed inside the gear case 51. The worm wheel 53 is formed in a roughly disk shape from a resin material such as polyacetal plastic, and has gear teeth 53a formed on its outer periphery. The gear teeth 53a of the worm wheel 53 mesh with the worm 44a.

The base end of the output shaft 53b is fixed to the center of rotation of the worm wheel 53, and the tip end of the output shaft 53b extends outside the gear case 51. The link mechanism 36 (see Figure 1) is fixed to the tip of the output shaft 53b. As a result, the rotation speed of the rotating shaft 44 is reduced by the worm 44a and worm wheel 53 (reduction mechanism SD), and this reduced, high-torque output is output from the output shaft 53b to the link mechanism 36.

In addition, as shown in FIG. 3, an output shaft sensor magnet MG2, formed in a roughly disk shape, is provided at the rotation center of the worm wheel 53, on the surface of the worm wheel 53 opposite the output shaft 53b. The output shaft sensor magnet MG2 is used to detect the rotational position of the output shaft 53b relative to the gear case 51. This makes it possible to accurately detect the positions of the pair of wiper blades 34b, 35b relative to the wiping ranges 11a, 11b, respectively.

[Control board]
As shown in Fig. 2, a control board 60 is mounted inside the gear cover 52. The control board 60 is electrically connected to an external connector (not shown) on the vehicle 10 via a connector connection portion (not shown) provided on the gear cover 52. This allows a drive current to be supplied to both the control board 60 and the motor unit 40. The control board 60 is also electrically connected to a wiper switch 21 that outputs a HI (high speed) signal, a LO (low speed) signal, and an INT (intermittent) signal. The control board 60 corresponds to the controller in the present invention.

[Inverter circuit]
As shown in FIG. 4, the control board 60 is provided with an inverter circuit 61. This inverter circuit 61 is electrically connected to an on-board battery and three-phase coils (not shown) of U, V, and W phases. The inverter circuit 61 has a plurality of switching elements such as field effect transistors (FETs), and these switching elements are switched at high speed using pulse width modulation (PWM) control to supply drive currents to the three-phase coils individually. As a result, the rotor 43 (see FIG. 3) rotates with a predetermined drive torque and rotational speed.

[Rotational axis sensor]
The control board 60 is also provided with rotational shaft sensors Su, Sv, and Sw. These rotational shaft sensors Su, Sv, and Sw are used to detect the rotational state of the rotating shaft 44, and three of them are provided corresponding to the three-phase coils of U, V, and W. The rotational shaft sensors Su, Sv, and Sw are made up of magnetic sensors such as Hall ICs. As shown in FIG. 3 , these rotational shaft sensors Su, Sv, and Sw are arranged on the control board 60 at portions facing the rotational shaft sensor magnet MG1 when viewed in the axial direction of the output shaft 53b.

[Output shaft sensor]
Furthermore, the control board 60 is provided with a single output shaft sensor So. This output shaft sensor So is used to detect the rotational state of the output shaft 53b (see FIGS. 2 and 3), i.e., the position of the pair of wiper blades 34b, 35b relative to the wiping areas 11a, 11b. The output shaft sensor So is made up of a magnetic sensor such as an MR sensor. As shown in FIG. 3, the output shaft sensor So is located on the control board 60 at a position facing the output shaft sensor magnet MG2 when viewed in the axial direction of the output shaft 53b.

[Vehicle speed information acquisition unit]
The control board 60 is also provided with a vehicle speed information acquisition unit Vs that acquires vehicle speed information of the vehicle 10. A vehicle speed signal from a vehicle speed sensor (not shown) provided in the vehicle 10 is input to this vehicle speed information acquisition unit Vs. Specifically, the control board 60 is electrically connected to an on-board controller (not shown) via CAN communication, LIN communication, or the like, and these exchange various types of information with each other. Therefore, the control board 60 can easily acquire the vehicle speed signal from the vehicle speed sensor.

[Position holding control unit]
Furthermore, the control board 60 is provided with a position holding control unit 62. This position holding control unit 62 is activated when the wiper switch 21 is intermittently operated (turned on) and receives an INT (intermittent) signal from the wiper switch 21. By operating the wiper switch 21 intermittently in this manner, the control board 60 intermittently drives the wiper motor 31, and the position holding control unit 62 starts operating.

When the wiper motor 31 is driven intermittently, the pair of wiper blades 34b, 35b are stopped for a predetermined time (e.g., a 30-second wait time) at a predetermined reference intermittent stop position INTP (see Figure 5). In other words, they are stopped for the predetermined time before starting the next wiping operation. This prevents the pair of wiper blades 34b, 35b from wiping back and forth too frequently during light rain, thereby reducing stress on the driver. The predetermined time (wait time for intermittent stop) can be determined as desired. In some wiper motors, the driver can adjust the wait time by operating a wait time adjustment dial (not shown) on the wiper switch 21.

The position holding control unit 62 has the function of stopping the pair of wiper blades 34b, 35b at the reference intermittent stop position INTP while the wiper motor 31 is intermittently stopped (during standby time). Specifically, for example, when the vehicle 10 is traveling at high speed (e.g., 100 km/h), the pair of wiper blades 34b, 35b may be affected by traveling wind (external force) and moved (shifted) from the reference intermittent stop position INTP. In such a case, the position holding control unit 62 drives the wiper motor 31 and controls the pair of wiper blades 34b, 35b, which have been moved by traveling wind, to return to the reference intermittent stop position INTP.

Here, the position holding control unit 62 determines whether the pair of wiper blades 34b, 35b have moved (shifted) relative to the reference intermittent stop position INTP based on the detection signal from the output shaft sensor So, which detects the rotational state of the output shaft 53b of the wiper motor 31.

[Continuous drive determination unit]
The control board 60 is also provided with a continuous drive determination unit 63. This continuous drive determination unit 63 determines whether the wiper motor 31 (motor unit 40) has been continuously driven by the position maintenance control unit 62. Specifically, in this embodiment, the position maintenance control unit 62 determines whether the wiper motor 31 has been continuously driven based on how many times it has returned the pair of wiper blades 34b, 35b to the reference intermittent stop position INTP (the number of return operations). In other words, whether the wiper motor 31 has been continuously driven is determined based on how well the "position maintenance function" of the position maintenance control unit 62 has worked.

[Return direction storage unit]
Furthermore, the control board 60 is provided with a return direction memory unit 64. This return direction memory unit 64 stores the direction (return direction) in which the position holding control unit 62 returns the pair of wiper blades 34b, 35b, which have been moved from the reference intermittent stop position INTP by wind while the vehicle 10 is traveling, toward the reference intermittent stop position INTP. For example, if the pair of wiper blades 34b, 35b are moved from the reference intermittent stop position INTP toward the storage position HP due to "wind blown in" near the edge portion 12a of the hood 12 while the vehicle 10 is traveling, the return direction at this time will be "toward the upper reversal position URP." The return direction memory unit 64 then stores this upper reversal position URP side.

[Intermittent stop position change unit]
The control board 60 is also provided with an intermittent stop position changing unit 65. The intermittent stop position changing unit 65 performs control to change the intermittent stop positions of the pair of wiper blades 34b, 35b to a corrected position CP different from the reference intermittent stop position INTP, based on the determination by the continuous drive determination unit 63 that the wiper motor 31 is being continuously driven. For example, if the pair of wiper blades 34b, 35b are moved toward the storage position HP by the entrained wind as described above, the intermittent stop positions of the pair of wiper blades 34b, 35b are set (corrected) to a position where the influence of the entrained wind is small, i.e., a position where the pair of wiper blades 34b, 35b will not be moved by the entrained wind.

Here, the intermittent stop position after correction will be referred to as the corrected position CP in the following explanation. In this embodiment, the corrected position CP is the predetermined upper adjustment position UAP (see Figure 5) (corrected position CP = upper adjustment position UAP). Note that the upper adjustment position UAP, which is the corrected position CP, is a position that is predetermined for the vehicle 10, for example, using FEM (Finite Element Method) analysis, taking into account the aerodynamic characteristics of the vehicle 10, specifically the angle between the hood 12 and the windshield 11, etc.

[Operation description]
Next, the operation of the control board 60 forming the wiper control device 20 configured as described above, particularly the operation of the intermittent stop position changing unit 65 that changes the intermittent stop positions of the pair of wiper blades 34b, 35b from the reference intermittent stop position INTP to the corrected position CP (upper adjustment position UAP), will be described in detail with reference to the drawings. For ease of explanation, only the AS-side wiper blade 35b is shown in FIG. Hereinafter, the description will be given assuming that it is the wiper blade 35b.

Before explaining the operation of the intermittent stop position change unit 65, we will now use Figure 5 to explain various positions of the wiper blade 35b relative to the windshield 11.

As shown in Figure 5, near the edge portion 12a of the hood 12, when the vehicle 10 is traveling at a speed of 100 km/h, for example, a strong entrained wind area AR1 (dark shaded area) is formed. Specifically, the entrained wind area AR1 is formed from the edge portion 12a toward the storage position HP. Note that entrained wind refers to wind flowing from the edge portion 12a toward the storage position HP, and when the vehicle speed is 100 km/h, the wiper blade 35b stopped in the entrained wind area AR1 is pressed toward the storage position HP by the entrained wind.

In contrast, an intermediate area AR2 (lightly shaded area) is also formed near the edge portion 12a, where the entrained wind and the "tailwind" compete with each other. Here, the tailwind refers to the wind that flows over the hood 12, passes through the edge portion 12a, and then flows over the windshield 11 toward the upper reversal position URP. When the wiper blade 35b is stopped in an area with a strong tailwind at a vehicle speed of 100 km/h, the tailwind presses the wiper blade 35b toward the upper reversal position URP.

As described above, the intermediate area AR2 is an area where the entrained wind and the tailwind compete with each other. In other words, it is an area where the wiper blade 35b is less likely to be pressed toward either the storage position HP or the upper reversal position URP. Therefore, in this embodiment, the correction position CP is set to the upper adjustment position UAP, which falls within the intermediate area AR2. Therefore, the wiper blade 35b stopped at the upper adjustment position UAP will not move toward the storage position HP or the upper reversal position URP, even if the vehicle speed is 100 km/h.

Note that Figure 5 illustrates an example where the vehicle speed is 100 km/h, but the position and size of the entangled wind area AR1 (dark shaded area) and intermediate area AR2 (light shaded area) will vary depending on the design of the vehicle 10 (sports type, sedan, etc.) and the vehicle speed. The position and size of the entangled wind area AR1 and intermediate area AR2 can be analyzed using, for example, FEM analysis.

Furthermore, when the vehicle 10 is traveling on a public road (maximum speed of approximately 50 km/h), the intermittent stop position of the wiper blade 35b is the reference intermittent stop position INTP, which is the same position as the lower reversal position LRP. Specifically, the reference intermittent stop position INTP (lower reversal position LRP) is located near the edge portion 12a, which is barely hidden by the hood 12. This makes it possible to improve the appearance of the vehicle 10 when viewed from the outside.

As shown in FIG. 5, a cowl top panel CT is provided near the storage position HP to conceal the wiper drive mechanism 30 mounted inside the bulkhead (not shown). In addition, in the wiping direction of the wiper blade 35b, a first lower adjustment position LAP1, a second lower adjustment position LAP2, and a lower adjustment lower limit position LLP are provided between the storage position HP and the reference intermittent stop position INTP (lower reversal position LRP).

The first and second lower adjustment positions LAP1, LAP2 and the lower adjustment lower limit position LLP are located in positions that are hidden by the hood 12 and are hardly affected by wind when the vehicle speed is 100 km/h. In other words, the first and second lower adjustment positions LAP1, LAP2 and the lower adjustment lower limit position LLP can also be used as the correction position CP (see embodiments 2 and 3).

Next, the specific operation of the intermittent stop position change unit 65 (see Figure 4) will be described in detail.

As shown in Figure 6, first, in step S1, the wiper switch 21 is intermittently operated (ON operation: INT SW ON) by the driver or other operator, which starts the intermittent operation of the wiper control device 20 (see Figure 1) and drives the wiper motor 31 intermittently.

In the following step S2, the vehicle speed information acquisition unit Vs (see Figure 4) determines whether the vehicle 10 is moving. Specifically, the vehicle speed information acquisition unit Vs determines whether a vehicle speed signal from the vehicle 10 has been received. If it is determined in step S2 that the vehicle 10 is stopped (no determination), the process proceeds to step S3. If it is determined in step S2 that the vehicle 10 is moving (yes determination), the process proceeds to step S4.

In step S3, the intermittent stop position change unit 65 leaves the intermittent stop position of the wiper blade 35b (see Figure 5) at the predetermined reference intermittent stop position INTP. In other words, the intermittent stop position change unit 65 does not change the intermittent stop position when the vehicle 10 is not moving (when the vehicle is stopped) (corrected position CP = reference intermittent stop position INTP). Then, proceed to step S5.

In step S5, it is determined whether the intermittent operation of the wiper switch 21 has been turned off. If it is determined that it has been turned off (yes: INT SW OFF), the process proceeds to step S6. Then, in step S6, the supply of drive current to the wiper control device 20 is stopped, and the intermittent operation of the wiper control device 20 is stopped (END). After the intermittent operation of the wiper switch 21 is turned off, the wiper blades 35b are automatically positioned in the storage position HP (see Figure 5). On the other hand, if it is determined in step S5 that the wiper switch 21 remains in intermittent operation (INT SW ON) (no), the process returns to step S2.

If the vehicle 10 is traveling (if step S3 returns a yes), the position retention control unit 62 determines in step S4 whether the position retention function was turned on while the wiper motor 31 was intermittently stopped. If step S4 determines that the position retention function is off (if step S4 returns a no), the process proceeds to step S3. That is, the intermittent stop position change unit 65 determines that the wiper blade 35b can be stopped at the reference intermittent stop position INTP, and does not change the intermittent stop position of the wiper blade 35b from the reference intermittent stop position INTP (corrected position CP = reference intermittent stop position INTP).

In contrast, if it is determined in step S4 that the position holding function has been turned on while the wiper motor 31 is intermittently stopped (yes determination), the process proceeds to step S7. In step S7, the continuous drive determination unit 63 determines whether the wiper motor 31 is being continuously driven by the position holding control unit 62. Specifically, in this embodiment, it determines whether the position holding function has been turned on a predetermined number of times (n times or more) in succession.

That is, as shown in FIG. 7, the position maintenance function is turned on three times in succession between time t1 and time t7, when the position maintenance function starts operating. In other words, in this embodiment, the predetermined number of times n is set to three. This number of three is pre-stored in the continuous drive determination unit 63 as a judgment threshold.

More specifically, when the wiper blade 35b is pushed from the reference intermittent stop position INTP toward the storage position HP by the entrained wind (external force) and moved to the movement position MP (time t1 → t2), the position holding control unit 62 then drives the wiper motor 31, returning the wiper blade 35b from the movement position MP to the reference intermittent stop position INTP (time t2 → t3). This drive of the wiper motor 31 (return operation) from the movement position MP to the reference intermittent stop position INTP is performed three times between time t1 and time t7. Here, the wiper motor 31 is driven by the position holding control unit 62 between time t2 → t3, time t4 → t5, and time t6 → t7.

Here, the return direction memory unit 64 provided on the control board 60 stores the direction in which the wiper blade 35b is returned from the movement position MP to the reference intermittent stop position INTP, i.e., the "return direction" of the wiper blade 35b. That is, in this embodiment, the return direction of the wiper blade 35b stored in the return direction memory unit 64 is toward the upper reversal position URP (between times t2 and t3, between times t4 and t5, and between times t6 and t7).

If step S7 returns no, meaning that the position maintenance function has not been turned on three or more times in succession, the process proceeds to step S3. That is, if the wiper blade 35b can be returned to the reference intermittent stop position INTP by turning on the position maintenance function less than three times (if the return operation is successful), the process proceeds to step S3, and the intermittent stop position of the wiper blade 35b remains at the reference intermittent stop position INTP (corrected position CP = reference intermittent stop position INTP).

In contrast, if step S7 returns yes, meaning that the position holding function has been turned on three or more times in succession, the process proceeds to step S8. In step S8, the intermittent stop position change unit 65 controls the intermittent stop position to move (shift) the intermittent stop position relative to the reference intermittent stop position INTP in the same direction as the return direction of the wiper blade 35b stored in the return direction memory unit 64, i.e., to the upper adjustment position UAP on the upper reversal position URP side (see the period from time t7 to time t8 in Figure 7).

In this way, when the wiper blade 35b cannot be returned to the reference intermittent stop position INTP due to the influence of entrained wind, the intermittent stop position change unit 65 moves (changes) the intermittent stop position to the upper adjustment position UAP, which is different from the reference intermittent stop position INTP. Specifically, in this embodiment, the correction position CP is the upper adjustment position UAP (correction position CP = upper adjustment position UAP).

Then, proceed to step S5, and as long as the wiper switch 21 remains in intermittent operation and the vehicle 10 is moving, taking into consideration that the position holding function was turned on in the previous control routine and that it was turned on a predetermined number of times or more in succession, i.e., based on the history of the previous control routine, the intermittent stop position change unit 65 continues to set the upper adjustment position UAP as the intermittent stop position of the wiper blade 35b (see time t8 onwards in Figure 7).

As described above in detail, with the wiper control device 20 according to this embodiment, when the continuous drive determination unit 63 determines that the wiper motor 31 is being continuously driven, the intermittent stop position change unit 65 changes the intermittent stop position of the wiper blade 35b to a corrected position CP (upper adjustment position UAP) different from the reference intermittent stop position INTP. This prevents the position retention control unit 62 from repeatedly attempting to return the wiper blade 35b to the reference intermittent stop position INTP, thereby reducing the load on the wiper motor 31. Furthermore, with the intermittent stop position changed (reference intermittent stop position INTP → upper adjustment position UAP), the intermittent function can be continuously operated, thereby improving comfort and convenience.

Furthermore, according to the wiper control device 20 of this embodiment, the control board 60 includes a return direction memory unit 64 that stores the return direction of the wiper blade 35b determined by the position holding control unit 62, and the corrected position CP is the upper adjustment position UAP, which is moved relative to the reference intermittent stop position INTP in the same direction as the return direction of the wiper blade 35b stored in the return direction memory unit 64. Therefore, as shown in FIG. 5, the changed intermittent stop position can be set as the upper adjustment position UAP near the edge portion 12a of the hood 12 and visible to the driver, etc. (a position not hidden by the hood 12). This allows the driver, etc. to easily check the operating status of the wiper control device 20 (such as whether the intermittent stop position has been changed).

Furthermore, with the wiper control device 20 according to this embodiment, repeated control by the position holding control unit 62 to return the wiper blade 35b to the reference intermittent stop position INTP is suppressed, and the load on the wiper motor 31 is reduced, thereby extending the life of the wiper control device 20 and improving the fuel efficiency of the vehicle 10. This makes it possible to contribute to the United Nations-led Sustainable Development Goals (SDGs), particularly to Goal 7 (Ensure access to affordable, reliable, sustainable and modern energy) and Goal 13 (Take urgent action to combat climate change and its impacts).

[Embodiment 2]
Next, a second embodiment of the present invention will be described in detail with reference to the drawings. Note that parts having the same functions as those in the first embodiment are given the same reference numerals, and detailed descriptions thereof will be omitted.

Figure 8 shows a flowchart corresponding to Figure 6 of embodiment 2, and Figure 9 shows a timing chart corresponding to Figure 7 of embodiment 2.

In embodiment 2, as shown in Figures 8 and 9, only the control content of the control board 60 (controller) differs from embodiment 1. Specifically, in embodiment 2, as shown in Figure 8, compared to embodiment 1 (see Figure 6), processing of step S21 (shaded portion) is added, processing of step S22 (shaded portion) is performed instead of processing of step S7 in Figure 6, and processing of step S23 (shaded portion) is performed instead of processing of step S8 in Figure 6.

As shown in FIG. 8, if the vehicle speed information acquisition unit Vs (see FIG. 4) determines in step S2 that the vehicle 10 is traveling (yes), then in the following step S21, the vehicle speed information acquisition unit Vs determines whether the current vehicle speed is equal to or greater than a predetermined vehicle speed threshold (threshold) Th. Here, the vehicle speed threshold Th is a constant pre-stored in the vehicle speed information acquisition unit Vs, and in this embodiment, the vehicle speed threshold Th is set to 100 km/h. That is, in embodiment 2, the position holding control unit 62 (see FIG. 4) starts control when the vehicle speed of the vehicle 10 is equal to or greater than the vehicle speed threshold Th. If the determination in step S21 is yes, the process proceeds to step S4; if the determination in step S21 is no, the process proceeds to step S3.

Furthermore, in step S4, if the position retention control unit 62 determines that the position retention function has been turned on (yes determination) while the wiper motor 31 is intermittently stopped, then in the following step S22, the continuous drive determination unit 63 (see FIG. 4) determines whether the wiper motor 31 (see FIG. 1) is being continuously driven by the position retention control unit 62. Specifically, unlike in embodiment 1, embodiment 2 determines whether the position retention function has been continuously turned on for a predetermined time Tm or more. In other words, while embodiment 1 looks at the "number of times the position retention function has been operated," embodiment 2 looks at the "operation time of the position retention function."

Specifically, as shown in Figure 9, the time t1 to t7 between the time t1 and the time t7 when the position holding function starts operating is the aforementioned "predetermined time Tm." Here, the predetermined time Tm (time t1 to t7), which is the operating time of the position holding function, is set to, for example, 10 seconds. This "10 seconds" is stored in advance in the continuous drive determination unit 63 as a judgment threshold.

As shown in Figure 9, from time t1 to t7, the wiper blade 35b (see Figure 5) is pushed from the reference intermittent stop position INTP toward the storage position HP by the entrained wind (external force) and moves to the movement position MP, and the position holding function operates from time t2 to t3, from time t4 to t5, and from time t6 to t7. In this way, the position holding control unit 62 controls the wiper blade 35b to return from the movement position MP to the reference intermittent stop position INTP.

In step S23, the intermittent stop position change unit 65 (see FIG. 4) controls the intermittent stop position to move (shift) from the reference intermittent stop position INTP to the first lower adjustment position LAP1 (see FIG. 5) (see the period from time t7 to time t8 in FIG. 9). Here, in embodiment 2, the correction position CP is the predetermined first lower adjustment position LAP1 (correction position CP = first lower adjustment position LAP1), and this first lower adjustment position LAP1 is the same position as the movement position MP (first lower adjustment position LAP1 = movement position MP).

In this way, in embodiment 2, the intermittent stop position change unit 65 moves the intermittent stop position relative to the reference intermittent stop position INTP in the direction opposite to the return direction of the wiper blade 35b stored in the return direction memory unit 64 (see Figure 4). In other words, the first lower adjustment position LAP1, which is located on the opposite side from the upper reversal position URP (the side toward the storage position HP), is set as the correction position CP.

When determining the first lower adjustment position LAP1 using FEM analysis or the like, it is desirable to ensure that it does not exceed the lower adjustment limit position LLP (see Figure 5). In other words, it is desirable to avoid setting the first lower adjustment position LAP1 in a position closer to the storage position HP than the lower adjustment limit position LLP. If the first lower adjustment position LAP1 were set to approximately the same position as the storage position HP, a relatively large area of the wiping range of the wiper blade 35b would be hidden by the hood 12. This could cause discomfort to the driver, etc.

Embodiment 2 configured as described above can also achieve the same effects as embodiment 1 described above. In addition, in embodiment 2, the correction position CP is the first lower adjustment position LAP1, which is moved relative to the reference intermittent stop position INTP in the direction opposite to the return direction of the wiper blade 35b stored in the return direction memory unit 64 (toward the storage position HP). Therefore, the wiper blade 35b can be covered by the hood 12 during an intermittent stop. This makes it possible to improve the appearance of the vehicle 10 during an intermittent stop.

In addition, in embodiment 2, the position holding control unit 62 begins control when the vehicle speed of the vehicle 10 reaches or exceeds the vehicle speed threshold Th. Therefore, when the vehicle speed is low (for example, about 30 km/h) and a sudden gust of wind or the like causes the wiper blade 35b to temporarily move, the position holding control unit 62 can be prevented from operating unnecessarily, thereby reducing the load on the wiper motor 31 and the control board 60.

[Third embodiment]
Next, a third embodiment of the present invention will be described in detail with reference to the drawings. Note that parts having the same functions as those in the first embodiment are given the same reference numerals, and detailed descriptions thereof will be omitted.

Figure 10 shows a portion of a flowchart illustrating embodiment 3, and Figure 11 shows a timing chart corresponding to Figure 7 of embodiment 3.

In embodiment 3, as shown in Figures 10 and 11, only the control content of the control board 60 (controller) differs from embodiment 1. Specifically, in embodiment 3, as shown in Figure 10, the processing of step S31 is performed instead of the processing of step S8 in embodiment 1 (see Figure 6).

Specifically, the intermittent stop position change unit 65 (see Figure 4) stores the movement amount AM of the wiper blade 35b from the reference intermittent stop position INTP to the movement position MP during the period from when the position holding function is turned on (yes judgment) in step S4 until the position holding function is turned on (yes judgment) a predetermined number of times n or more consecutively in step S7, that is, between time t1 and time t7 in Figure 11. Here, the movement amount AM is determined from the detection signal of the output shaft sensor So (see Figure 4) and is equal to the distance from the reference intermittent stop position INTP to the movement position MP.

In step S31, the intermittent stop position change unit 65 controls the intermittent stop position to move (shift) from the reference intermittent stop position INTP to the second lower adjustment position LAP2 (see FIG. 5). Specifically, the intermittent stop position change unit 65 moves (corrects) the intermittent stop position relative to the reference intermittent stop position INTP in the direction opposite to the return direction of the wiper blade 35b stored in the return direction memory unit 64 (see FIG. 4), i.e., to the second lower adjustment position LAP2 on the opposite side from the upper reversal position URP.

Here, the second lower adjustment position LAP2 is calculated by the intermittent stop position change unit 65 based on the stored movement amount AM. Specifically, the second lower adjustment position LAP2, which is the correction position CP, is set so that it is closer to the storage position HP than the movement position MP to which the wiper blade 35b is moved by entrained wind (external force). In other words, the intermittent stop position change unit 65 sets the movement amount from the reference intermittent stop position INTP to the correction position CP (second lower adjustment position LAP2) to be equal to or greater than the movement amount AM of the wiper blade 35b from the reference intermittent stop position INTP due to entrained wind.

Embodiment 3 configured as described above can also achieve the same effects as embodiment 2 described above. In addition, in embodiment 3, compared to embodiment 2, the correction position CP (second lower adjustment position LAP2) is located closer to the lower adjustment lower limit position LLP than the first lower adjustment position LAP1 (see Figures 5 and 9), making it less likely that strong wind will hit the wiper blade 35b.

The present invention is not limited to the above-described embodiments, and it goes without saying that various modifications are possible without departing from the spirit of the present invention. For example, in the above-described embodiments, the control board 60 serving as a controller is attached to the gear cover 52 of the wiper motor 31, but the present invention is not limited to this, and the control board 60 can also be mounted on an on-board controller installed in the vehicle 10.

In addition, in the above-described second and third embodiments, the vehicle speed threshold Th is set to 100 km/h and the predetermined time Tm is set to 10 seconds, but the present invention is not limited to this, and the wiper control device 20 can be tuned as desired depending on the design, driving performance, etc. of the vehicle 10 in which it is installed.

Furthermore, in each of the above-described embodiments, the wiper motor 31 is a brushless motor, but the present invention is not limited to this, and a motor with brushes can also be used.

Furthermore, in each of the above-described embodiments, the wiper control device 20 is used in a vehicle such as an automobile, but the present invention is not limited to this and can also be used in, for example, aircraft, railway vehicles, etc.

In addition, the materials, shapes, dimensions, numbers, installation locations, etc. of each component in each of the above-described embodiments are arbitrary as long as they achieve the present invention and are not limited to the above-described embodiments.

10: Vehicle, 11: Windshield, 11a: DR-side wiping range, 11b: AS-side wiping range, 12: Hood, 12a: Edge portion, 20: Wiper control device, 21: Wiper switch (intermittent switch), 30: Wiper drive mechanism, 31: Wiper motor, 32: DR-side pivot shaft, 33: AS-side pivot shaft, 34: DR-side wiper member (wiper member), 34a: DR-side wiper arm, 34b: D R-side wiper blade, 35: AS-side wiper member (wiper member), 35a: AS-side wiper arm, 35b: AS-side wiper blade (wiper blade), 36: link mechanism, 40: motor section, 41: motor case, 42: stator, 43: rotor, 44: rotating shaft, 44a: worm, 50: reduction mechanism section, 51: gear case, 52: gear cover, 53: worm wheel, 53a: gear teeth, 5 3b: output shaft, 60: control board (controller), 61: inverter circuit, 62: position holding control unit, 63: continuous drive determination unit, 64: return direction storage unit, 65: intermittent stop position change unit, AM: movement amount, AR1: entrained wind area, AR2: intermediate area, CP: correction position, CT: cowl top panel, HP: storage position, INTP: reference intermittent stop position, LAP1: first lower adjustment position, LAP2: second lower Side adjustment position, LLP: Lower adjustment lower limit position, LRP: Lower reversal position, MG1: Rotating shaft sensor magnet, MG2: Output shaft sensor magnet, MP: Moving position, SD: Speed reduction mechanism, So: Output shaft sensor, Su, Sv, Sw: Rotating shaft sensors, Th: Vehicle speed threshold (threshold), Tm: Predetermined time, UAP: Upper adjustment position, URP: Upper reversal position, Vs: Vehicle speed information acquisition unit, n: Predetermined number of times, t1 to t8: Time

Claims (5)

a wiper motor that drives the wiper member to perform a wiping operation;
a controller that intermittently drives the wiper motor;
A wiper control device comprising:
The controller
a position holding control unit that drives the wiper motor to return the wiper member to the reference intermittent stop position when the wiper member is moved from the reference intermittent stop position by an external force while the wiper motor is intermittently stopped;
a continuous drive determination unit that determines whether the wiper motor is continuously driven by the position holding control unit;
an intermittent stop position changing unit that changes an intermittent stop position of the wiper member to a correction position different from the reference intermittent stop position when the continuous drive determining unit determines that the wiper motor has been continuously driven;
having
Wiper control device. The wiper control device according to claim 1,
the controller includes a return direction storage unit that stores a return direction of the wiper member determined by the position holding control unit,
the corrected position is a position moved with respect to the reference intermittent stop position in the same direction as the return direction of the wiper member stored in the return direction storage unit,
Wiper control device. The wiper control device according to claim 1,
the controller includes a return direction storage unit that stores a return direction of the wiper member determined by the position holding control unit,
the corrected position is a position obtained by moving the wiper member in a direction opposite to the return direction of the wiper member stored in the return direction storage unit with respect to the reference intermittent stop position.
Wiper control device. a movement amount from the reference intermittent stop position to the correction position is equal to or greater than a movement amount of the wiper member from the reference intermittent stop position due to the external force;
The wiper control device according to claim 3 . The position holding control unit starts control when the vehicle speed reaches or exceeds a threshold value.
The wiper control device according to any one of claims 1 to 4.