JP2019162982A - Noise suppression control system of door mirror - Google Patents

Abstract

To suppress noise of a door mirror which occurs when a vehicle receives cross wind during travel.SOLUTION: A noise suppression control system 20 of a door mirror includes a door mirror having a housing which is rotatable around a rotation center axis which is provided on a fitting part fixed to a side door of a vehicle. Herein, an angle of a reference surface of the housing, which passes a rotation center, toward a vehicle rear side with respect to a face along a vehicle longitudinal direction of the side door is referred to as a housing angle. A side wind characteristic value concerning a wind speed of cross wind received by the vehicle and a wind direction angle with respect to a vehicle traveling direction, and a vehicle speed are acquired, and whether or not the vehicle speed exceeds a vehicle speed threshold and the side wind characteristic value exceeds a side wind characteristic threshold is determined. When such determination is affirmed, an absolute value of the housing angle is so made as to be large thereby rotating the housing toward a vehicle front side, and when such determination is affirmed, control for maintaining the housing angle is performed.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to a door mirror noise suppression control system, and more particularly to a door mirror noise suppression control system that suppresses noise generated in a door mirror when a vehicle receives a crosswind while traveling.

  Side mirrors for viewing the rear side of the vehicle are provided on the side of the passenger car. There are two types of side mirrors that are attached in front of the door hinge portion of the passenger car and those that are attached to the front pillar. The latter is called a door mirror. Since the door mirror protrudes from the front pillar to the outside of the vehicle, air resistance generated when the vehicle travels generates a vortex around the door mirror, generating wind noise and vibrating the side of the vehicle. In particular, when the wind noise fluctuates over time, it becomes a fuzzy sound. Since the door mirror is mounted at a position close to a seat such as a driver's seat in the passenger compartment, noise such as wind noise and rustle noise and vibrations on the side of the vehicle cause discomfort to users such as drivers.

  In Patent Document 1, as a door mirror control device, when a vehicle travels at a low speed, the door mirror main body stands up to approximately 90 degrees with respect to the door, and at a high speed travel, the door mirror actuator is automatically driven to set the angle of the door mirror main body to the door. Making it smaller is disclosed.

  Patent Document 2 discloses a configuration in which a housing that covers a mirror, which is a mirror body, is rotatably supported on a base provided on a side door of a vehicle.

JP-A-7-277077 JP 2008-238962 A

  The vehicle may receive crosswinds while driving. When the crosswind is received, the combined speed of the vehicle speed and the wind speed is inclined with respect to the traveling direction of the vehicle, and the wind is applied to the door mirror from the oblique direction. As a result, the flow around the door mirror is changed, noise is generated, and the vehicle side surface is vibrated. Regarding the generated noise and the excitation force on the side surface of the vehicle, it is known that the door mirror on the downstream side is larger than the door mirror on the upstream side with respect to the air flow in the oblique direction received by the vehicle. In addition, when the direction of the crosswind changes and the direction of the slanting air flow that the vehicle receives changes, the left and right door mirrors that are provided on both sides of the vehicle have the door mirror that generates more noise and vibration force on the side of the vehicle. It changes from side to side. Therefore, there is a demand for a door mirror noise suppression control system that can suppress door mirror noise that occurs when the vehicle receives a crosswind while traveling and the excitation force that is generated on the side of the vehicle.

  A door mirror noise suppression control system according to the present disclosure includes a vehicle speed acquisition unit that acquires a vehicle speed, a cross wind characteristic value acquisition unit that acquires a cross wind characteristic value related to a wind speed of a cross wind received by the vehicle, and a wind direction angle with respect to the vehicle traveling direction, A door mirror composed of a mounting portion fixed to a side door of a vehicle, a housing including a mirror body that is a mirror body and rotatable relative to the mounting portion, and a housing around a rotation center axis provided in the mounting portion The vehicle drive speed and the crosswind characteristic value are defined as the housing angle, which is the angle at which the reference plane of the housing passing through the central axis of rotation and the reference plane of the housing that passes through the rotation center axis faces the rear side of the vehicle. For each, the noise generated by the airflow around the door mirror is compared with a predetermined vehicle speed threshold value and a crosswind characteristic threshold value. If the crosswind characteristic value exceeds the crosswind characteristic threshold value and the determination is affirmative, the absolute value of the housing angle is increased and the housing is rotated toward the front side of the vehicle. A control unit that performs control to maintain the housing angle on the housing drive unit when the result is negative.

  According to the above configuration, when the vehicle receives a crosswind while traveling, the vehicle speed, and the crosswind characteristic value related to the wind speed and the wind direction of the crosswind, respectively, a vehicle speed threshold value determined in advance with respect to noise generated by the airflow around the door mirror, and Compare with the crosswind characteristic threshold. When the crosswind characteristic value exceeds the crosswind characteristic threshold value when the vehicle speed exceeds the vehicle speed threshold value, the door mirror housing is rotated toward the front side of the vehicle with respect to the surface of the side door along the vehicle front-rear direction. . As a result, the direction of the air flow received by the door mirror when there is a cross wind is close to the direction of the air flow received by the door mirror when there is no cross wind, and the noise generated around the door mirror is reduced to a level close to that when there is no cross wind. To do. In this way, it is possible to suppress the door mirror noise that occurs when the vehicle receives a crosswind while traveling.

  In the noise suppression control system for a door mirror according to the present disclosure, the cross wind characteristic value is an air flow that is an angle formed by a combined vector of a cross wind vector and a vehicle speed vector defined by the wind speed and the wind direction angle with respect to the traveling direction of the vehicle. It is a yaw angle, and the cross wind characteristic threshold is preferably an air flow yaw threshold angle at which noise generated by the air flow around the door mirror becomes a predetermined noise threshold.

  According to the above configuration, the airflow yaw angle is used as the side wind characteristic value, and the airflow yaw threshold angle is used as the side wind characteristic threshold. Since the air flow yaw angle indicates the direction of the air flow that the vehicle receives obliquely when the vehicle receives a crosswind while traveling, it is easy to identify the downstream door mirror for the air flow that is considered to be noisy. Further, since the air flow yawing threshold angle is an air flow yawing angle at which noise due to airflow around the door mirror becomes a noise threshold, the door mirror having a high noise is rotated forward by the air flow yawing threshold angle. Thus, it can be in the same state as the air flow without the air flow fluctuation angle. In this way, it is possible to suppress the door mirror noise that occurs when the vehicle receives a crosswind while traveling.

  In the door mirror noise suppression control system according to the present disclosure, when the determination is affirmative, the control unit determines whether the left and right door mirrors disposed on the left and right sides of the vehicle have airflow around the vehicle determined by the airflow yaw angle. Among them, only the door mirror disposed on the downstream side is rotated by the absolute value of the air flow fluctuation threshold angle in the direction of increasing the absolute value of the housing angle, and the control is performed to maintain the housing angle of the door mirror disposed on the upstream side. .

  According to the above configuration, the door mirror housing disposed on the downstream side of the louder side is rotated to the vehicle front side by the absolute value of the air flow yaw threshold angle, so that it is the same as the air flow without the air flow yaw angle. It can be in a state and the generation of noise can be suppressed. The door mirror disposed on the upstream side of the lower noise level does not exceed the cross wind characteristic threshold value, and the noise due to the airflow around the door mirror does not exceed the threshold value, so that it can be left as it is. In this way, it is possible to suppress door mirror noise that occurs when the vehicle receives a crosswind while traveling.

  In the noise suppression control system for a door mirror according to the present disclosure, the cross wind characteristic value is defined as an air flow bias that is an angle formed by a combined vector of a cross wind vector and a vehicle speed vector defined by the wind speed and the wind direction angle with respect to the vehicle traveling direction. The rocking angle is the absolute value of the fluctuation range of the airflow yaw angle during a predetermined elapsed time, and the side wind characteristic threshold is the airflow around the door mirror when there is no airflow yaw angle fluctuation during the predetermined elapse period. It is preferable that the absolute value of the air flow yaw threshold angle corresponding to a predetermined noise threshold for noise generated by the above is twice.

  When the air flow yaw angle fluctuates during a predetermined period of time, the loudest door mirror of the left and right door mirrors provided on both sides of the vehicle changes to the left and right. In this case, if the airflow yaw angle is used as the side wind characteristic value and the airflow yaw threshold angle is used as the side wind characteristic threshold value, the absolute value of the housing angle is rapidly changed for the left and right door mirrors.

  According to the above configuration, the absolute value of the fluctuation range of the air flow yaw angle during a predetermined elapsed time is used as the side wind characteristic value, and twice the absolute value of the air flow yaw threshold angle is used as the side wind characteristic threshold value. Thereby, even if the air flow yaw angle fluctuates within a predetermined time, the absolute value of the fluctuation range of the air flow yaw angle in the predetermined elapse period does not exceed twice the absolute value of the air flow yaw threshold angle. As long as any door mirror housing angle is maintained. In other words, if the fluctuation range of the air flow yaw angle is within ± (absolute value of the air flow yaw threshold angle), the housing angle of any door mirror is maintained. The absolute value of the angle is changed. Therefore, it is possible to prevent the absolute value of the housing angle from changing rapidly for the left and right door mirrors.

  In the door mirror noise suppression control system according to the present disclosure, when the determination is affirmative, the control unit determines whether the left and right door mirrors disposed on the left and right sides of the vehicle have airflow around the vehicle determined by the airflow yaw angle. In either case, control is performed to rotate the housing angle at a predetermined angle smaller than the absolute value of the air flow yawing threshold angle in the direction of increasing the absolute value of the housing angle.

  According to the above configuration, when the absolute value of the fluctuation value of the air flow yaw angle during the predetermined elapsed period exceeds the air flow yaw threshold angle, any door mirror is smaller than the absolute value of the air flow yaw threshold angle. The housing is rotated forward of the vehicle at a predetermined angle. As a result, noise is generated to some extent for any of the door mirrors, but noise fluctuations are averaged for the left and right door mirrors. Thereby, the discomfort with respect to the annoying noise of the vehicle user can be reduced.

  The door mirror noise suppression control system according to the present disclosure includes a mirror body drive unit that rotates the mirror body with respect to the housing, and the control unit increases the absolute value of the housing angle so that the mirror surface of the mirror body is a side door vehicle. It is preferable to perform control to maintain a constant angle formed by the mirror surface of the mirror body with respect to the surface along the vehicle front-rear direction of the side door by compensating for the inclination with respect to the surface along the front-rear direction.

  According to the above configuration, even if the absolute value of the housing angle of the door mirror is changed, the angle formed by the mirror surface of the mirror body with respect to the surface along the vehicle front-rear direction of the side door is kept constant. For example, the view of the mirror surface of the mirror body of the door mirror is secured.

  According to the noise suppression control system for a door mirror configured as described above, it is possible to suppress the noise of the door mirror that is generated when the vehicle receives a crosswind while traveling.

It is a block diagram of the noise suppression control system of the door mirror which concerns on embodiment. Fig.1 (a) is a top view of the vehicle by which the noise suppression control system of the door mirror which concerns on embodiment is mounted, (b) is a detailed block diagram of the B section of (a). It is a perspective view of the door mirror in the noise suppression control system of the door mirror which concerns on embodiment. It is a flowchart which shows the noise suppression control procedure in the noise suppression control system of the door mirror which concerns on embodiment. In FIG. 3, it is a figure which shows two examples about the door mirror of the upstream of the air flow of the diagonal direction which a vehicle receives, and the door mirror of a downstream. FIG. 4 is a content explanatory diagram of the procedure of FIG. 3. It is a flowchart which shows the noise suppression control procedure different from FIG. FIG. 7 is a content explanatory diagram of the procedure of FIG. 6.

  Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The shapes, materials, and the like described below are illustrative examples, and can be appropriately changed according to the specifications of the door mirror noise suppression control system. In the following description, the same elements are denoted by the same reference symbols in all the drawings, and redundant description is omitted.

  FIG. 1 is a configuration diagram of a door mirror noise suppression control system 20 according to the embodiment. Hereinafter, unless otherwise specified, the door mirror noise suppression control system 20 is referred to as a noise suppression control system 20. The noise includes wind noise and rustle sound that is a time change of wind noise. FIG. 1 is a top view of a vehicle 10 on which a noise suppression control system 20 is mounted, and FIG. 1B is a detailed configuration diagram of part B of FIG.

  In the following drawings, the vehicle front-rear direction, the vehicle width direction, and the vehicle vertical direction are shown as appropriate. Regarding the vehicle longitudinal direction, the direction indicated by FR is the vehicle front side, and the opposite direction is the vehicle rear side. Regarding the vehicle width direction, the right direction is the right side of the vehicle and the left direction is the left side of the vehicle when viewed from the vehicle rear side. Regarding the vehicle vertical direction, the direction toward the road surface is the vehicle lower side, and the opposite side is the vehicle upper side.

The vehicle 10 includes a door mirror 30 on the right side of the vehicle and a door mirror 32 on the left side of the vehicle. The door mirror 30 is attached to the surface of the right side door of the vehicle 10 along the vehicle front-rear direction, and the door mirror 32 is attached to the surface of the left side door of the vehicle 10 along the vehicle front-rear direction. Hereinafter, the direction along the vehicle front-rear direction of the right side door of the vehicle 10 is D _R -D _R, and the direction along the vehicle front-rear direction of the left side door of the vehicle 10 is D _L -D _L. Door mirror 30 is attached to a surface along the D _R -D _R lines, the door mirror 32 is attached to a surface along the D _L -D _L lines.

  The noise suppression control system 20 is a system that suppresses the noise generated around the door mirrors 30 and 32 and the excitation force on the side of the vehicle when the vehicle 10 receives a cross wind. The noise suppression control system 20 is accurately referred to as the suppression control system 20 for the excitation force against the noise and the vehicle side surface, but is simply referred to as the noise suppression control system 20 below. The same applies to the description of the scope of claims.

  That is, when the vehicle 10 receives a crosswind, the airflow around the door mirrors 30 and 32 changes, and noise is generated around the door mirrors 30 and 32 and an excitation force is generated on the side of the vehicle as compared with a case where the vehicle 10 receives a crosswind. To do. Therefore, the noise generated around the door mirrors 30 and 32 and the excitation force on the side of the vehicle when the vehicle 10 receives a crosswind are generated with the same change in aerodynamic force, and the evaluation is noise. The only difference is the excitation force applied to the side of the vehicle. Therefore, hereinafter, unless otherwise specified, when the vehicle 10 receives a crosswind, “noise and excitation force to the side of the vehicle” are referred to as “noise”. For example, “suppression of noise generation” means “suppression of generation of noise and vibration force on the vehicle side surface”, and “noise threshold” means “threshold value of vibration force on the noise and vehicle side surface”, “The magnitude of noise” indicates “the magnitude of noise and excitation force on the side of the vehicle”. The same applies to the description of the scope of claims.

  The noise suppression control system 20 includes a noise suppression control portion for the door mirror 20 and a noise suppression control portion for the door mirror 32. Since these two have the same configuration, a noise suppression portion for the door mirror 30 will be described below as the noise suppression control system 20. FIG. 1B is an internal configuration diagram of the noise suppression control system 20.

  The noise suppression control system 20 includes a door mirror 30, a vehicle speed acquisition unit 56, and a cross wind characteristic value acquisition unit 58. The door mirror 30 includes a mounting portion 40 and a housing 42, and the housing 42 includes a mirror main body 44 that is a mirror body. FIG. 2 shows a perspective view of the door mirror 30.

The mounting portion 40 is a member that is fixed to the side door of the vehicle 10, supports the housing 42 rotatably around the rotation center axis 46, and supports the mirror body 44 rotatably. The attachment portion 40 is fixedly attached to a surface along the line D _L -D _L.

  The housing 42 is a housing component that is disposed so as to cover the attachment portion 40 while holding the mirror surface of the mirror body 44 exposed to the vehicle rear side. In the housing inner space of the housing 42, a housing driving unit 50 that rotates the housing 42 about the rotation center axis 46 with respect to the mounting portion 40, and a mirror body 44 is rotated about the rotation center axis 48 with respect to the housing 42. A mirror main body drive unit 52 and a control unit 54 are arranged. As the housing driving unit 50 and the mirror main body driving unit 52, small motors are used.

  The rotation of the housing 42 with respect to the mounting portion 40 is performed around the rotation center axis 46. Here, an angle at which the reference surface of the housing 42 passing through the rotation center axis 46 faces the vehicle rear side with respect to the surface along the vehicle front-rear direction of the side door is defined as a housing angle α. FIG. 1B shows a reference axis HH of the housing 42 that passes through the rotation center axis 46. A reference plane of the housing 42 that passes through the rotation center axis 46 is a plane that includes the reference axis HH and is perpendicular to the upper surface of the mounting portion 40. The upper surface of the mounting portion 40 can be a plane parallel to the road surface. In this case, the reference plane of the housing 42 that passes through the rotation center axis 46 includes the reference axis H-H and is a plane parallel to the vehicle vertical direction. A line parallel to the direction. The housing 42 is rotationally driven around the C-C axis by the housing driving unit 50.

Housing angle α, since the reference plane of the housing 42 passing through the rotation center shaft 46 along the vehicle longitudinal direction of the side door surface is at an angle facing the vehicle rear side, as shown in FIG. 2, D _R -D _This is the angle formed by the HH line with respect to the _R line. The housing angle α of the door mirror 30 and the housing angle α of the door mirror 32 have the same absolute value but opposite signs. Accordingly, the sign of the angle increasing counterclockwise around the reference point for measuring the angle in a plane perpendicular to the vertical direction of the vehicle is positive, and the sign of the angle increasing clockwise is negative. As shown in FIG. 1A, the housing angle α of the door mirror 30 is a positive value, and the housing angle α of the door mirror 32 is a negative value.

  In the specification of the vehicle 10, the housing angle α is set so that the noise based on the airflow around the door mirrors 30 and 32 is minimized when the vehicle 10 receives a traveling wind based on the vehicle speed V without the vehicle 10 receiving a crosswind. Set to When the vehicle 10 receives a cross wind, the air flow around the door mirrors 30 and 32 changes compared to a case where the vehicle 10 does not receive a cross wind, so that the noise based on the air flow around the door mirrors 30 and 32 increases from the minimum value. If the absolute value of the housing angle α is changed when the vehicle 10 is subjected to cross wind, the air flow around the door mirrors 30 and 32 can be brought close to the air flow when the cross wind is not received. An increase in noise based on the flow can be suppressed. A housing drive 50 is used to change the absolute value of the housing angle α.

  The mirror main body 44 is rotated so that the normal direction of the mirror surface of the mirror main body 44 does not change when viewed from the driver's seat user even when the housing 42 rotates around the rotation center axis 46 with respect to the mounting portion 40. Is called. That is, by changing the absolute value of the housing angle, it is compensated that the mirror surface of the mirror body 44 is inclined with respect to the surface along the vehicle front-rear direction of the side door, and the mirror surface of the mirror body 44 is moved in the vehicle front-rear direction of the side door. Rotation is performed to maintain a constant angle relative to the along plane. Although the rotation center shaft 48 for rotating the mirror main body 44 is provided in the housing 42, it may be provided in the mounting portion 40 instead. In this case, the rotation angle is different from the rotation angle when the rotation center shaft 48 is provided in the housing 42.

  Based on the vehicle speed V acquired from the vehicle speed acquisition unit 56 and the crosswind characteristic value acquired from the crosswind characteristic value acquisition unit 58, the control unit 54 controls the mounting unit 40 to suppress the generation of noise around the door mirror 30. The housing 42 is rotated to change the absolute value of the housing angle α. Further, based on the change of the absolute value of the housing angle α, the mirror main body 44 is rotated with respect to the housing 42, and the angle formed by the mirror surface of the mirror main body 44 with respect to the surface along the vehicle front-rear direction of the side door is constant. To maintain the control. Details of the control for suppressing the generation of noise will be described later.

  The vehicle speed acquisition unit 56 acquires the vehicle speed V with respect to the road surface when traveling forward of the vehicle 10. As the vehicle speed acquisition unit 56, a sensor that detects the rotational speed of the drive shaft of the vehicle 10 can be used. Instead of the sensor, vehicle speed information may be acquired from a control device (not shown) of the vehicle 10. The acquired vehicle speed V data is transmitted to the control unit 54 of the door mirror 30 via an appropriate signal line. The vehicle speed acquisition unit 56 is provided not on the door mirror 30 side but on the main body of the vehicle 10.

  The crosswind characteristic value acquisition unit 58 acquires a characteristic value indicating that noise is generated around the door mirror 30 when the vehicle 10 receives a crosswind. As a characteristic value for the occurrence of noise, a noise meter is arranged in the vehicle interior of the vehicle 10 and the noise level detected by the noise meter is the most direct, but may include noise causes other than crosswinds. Alternatively, information on the wind speed and direction of the wind at the currently traveling point can be acquired from the navigation device provided in the vehicle 10 and used as the cross wind characteristic value. However, the wind speed and direction of the cross wind actually received by the vehicle 10 can be obtained. It can happen that it is different from the angle. Therefore, as the cross wind characteristic value, an air flow yaw angle β that is an angle formed by a combined vector of the cross wind vector and the vehicle speed vector defined by the wind speed and the wind direction angle with respect to the traveling direction of the vehicle 10 is used. The cross wind characteristic value acquisition unit 58 is provided with an anemometer, a pressure sensor, or the like on the front surface or both side surfaces of the vehicle 10 to determine the wind speed v and the wind direction angle, and based on this, calculates the air flow yaw angle β. Get. The acquired airflow fluctuation angle β as the crosswind characteristic value is transmitted to the control unit 54 using an appropriate signal line.

  In FIG. 1A, the cross wind vector is in the direction from the left side of the vehicle to the right side of the vehicle 10 with respect to the vehicle 10, the absolute value of the wind speed is v, and the vehicle speed vector is in a direction parallel to the longitudinal direction of the vehicle 10. The combined vector when the absolute value of the vehicle speed is V is indicated by a white arrow. The white arrow indicates the direction of the air flow 60 when the vehicle 10 receives a cross wind and the magnitude of the flow velocity. Since β is an angle, it has a sign. The sign of β is positive in the counterclockwise direction and negative in the clockwise direction with the tip of the airflow 60 as a reference point for measuring the angle. When the cross wind blows from the left side of the vehicle to the right side of the vehicle, β is a positive value as shown in FIG. On the other hand, when the cross wind blows from the right side of the vehicle to the left side of the vehicle, β is a negative value (see FIG. 4).

  Next, the contents of control performed by the control unit 54 on the housing drive unit 50 in order to suppress the generation of noise around the door mirrors 30 and 32 will be described. FIG. 3 is a flowchart showing a noise suppression control procedure in the noise suppression control system 20. Each procedure corresponds to each processing procedure of the noise suppression control program stored in the memory of the control unit 54. The control unit 54 performs noise suppression control by executing each processing procedure of the noise suppression control program.

  When the vehicle 10 is started and initialized, the control device of the vehicle 10 starts up, and when the control unit 54 starts up, the noise suppression control program also starts up.

As the noise suppression control, two determination procedures are performed. One is a determining vehicle speed V is whether exceeds a predetermined vehicle speed threshold value V ₀ (S10). The noise around the door mirror 30 is generated by the air flow 60 when the wind velocity v of the cross wind is high to some extent. However, when the wind speed v of the cross wind is higher than the vehicle speed V at which the vehicle 10 travels, the safety of travel of the vehicle 10 is affected. Therefore, it is necessary to suppress the generation of noise around the door mirror 30 when the vehicle speed V is high to some extent. For example, if the wind speed v is 10 m / s, this is 36 km / h, and the vehicle 10 refrains from traveling in terms of safety. The vehicle 10 travels at a maximum wind speed v of about 3 to 5 m / s. In this case, the vehicle speed V is approximately equal to the wind speed v, and the running stability cannot be maintained. Vehicle speed V is required. For these reasons, the vehicle speed V at which noise generation must be suppressed needs to be large to some extent, and a vehicle speed threshold value is used as the reference. An example of the vehicle speed threshold V ₀ is about 50 km / h. This is an exemplification, and is appropriately changed from other specifications of the vehicle 10 and the like.

Another determination is whether the crosswind characteristic value exceeds the crosswind characteristic threshold. Here, since the airflow yaw angle β is used as the crosswind characteristic value, the crosswind characteristic threshold is the airflow yaw threshold angle β ₀ at which the noise generated around the door mirror 30 by the airflow 60 becomes a predetermined noise threshold. As described with respect to the vehicle speed threshold V ₀ , when the noise generated around the door mirror 30 due to the air flow 60 is a problem, the vehicle speed V is several times the wind speed v, so (v / V) is set to (several minutes). As 1), the air flow fluctuation threshold angle β ₀ can be determined. As an example, the airflow oscillation threshold angle β ₀ = 10 degrees. In this case, since cot (10 degrees) = 6.968, the air flow oscillation angle β when (v / V) is about (1/7) is the air flow oscillation threshold angle β ₀ . This is an illustrative example, and an appropriate angle of about 10 degrees may be set as the air flow fluctuation threshold angle β ₀ .

In the vehicle 10, when the cross wind blows from the left side of the vehicle to the right side of the vehicle, the air flow yaw angle β is a positive value, so the air flow yaw threshold angle β ₀ is also a positive value, which is +10 in the above example. Degree. When the cross wind blows from the vehicle right side to the vehicle left side, the air flow yaw angle β is a negative value, so the air flow yaw threshold angle β ₀ is also a negative value, which is −10 degrees in the above example. . Taking into account the sign, determining whether more than a crosswind characteristic value crosswind characteristics threshold, the absolute value of the air flow yaw angle beta is, whether more than the absolute value of the air flow yaw threshold angle beta ₀ This is the determination of (S12).

  Either the determination of S10 or the determination of S12 may be performed first, but if the determination of S10 is affirmative and the determination of S12 is affirmative, the process proceeds to S14. In S14, a process of increasing the absolute value of the housing angle α and rotating the housing 42 toward the front side of the vehicle is performed. If at least one of the determination in S10 and the determination in S12 is negative, the process does not proceed to S14, the housing angle α is maintained as it is, and the process returns to S10 of the first procedure.

Whether the process proceeds to S14 or returns to S10 differs between the door mirror 30 and the door mirror 32. This is because it is known that the noise generated around the door mirror on the downstream side is larger than the noise generated around the door mirror on the upstream side with respect to the oblique air flow 60 received by the vehicle 10. It is. That is, the control unit 54 has only the door mirror disposed on the downstream side of the left and right door mirrors 30 and 32 disposed on the left and right sides of the vehicle 10 with respect to the air flow 60 around the vehicle 10 determined by the air flow fluctuation angle β. Is rotated in a direction to increase the absolute value of the housing angle α. The rotation angle is an absolute value of the air flow fluctuation threshold angle β ₀ . That is, from the state of the absolute value of the housing angles alpha, a state of the (absolute value of the housing angle alpha) + (the absolute value of airflow yaw threshold angle β _0)] (S14). In the above example, the absolute value of the housing angle α, which is an initial design setting value, is rotated 10 degrees in the forward direction of the vehicle. After the process of S14 is performed, the process returns to S10 of the first procedure.

  On the other hand, among the left and right door mirrors 30 and 32 disposed on the left and right sides of the vehicle 10, the door angle α is maintained for the door mirror disposed on the upstream side, and the process returns to the first procedure S10.

  FIG. 4 is a diagram for explaining two examples of the door mirror on the downstream side and the door mirror on the upstream side with respect to the air flow 60 in the oblique direction received by the vehicle 10. FIG. 4A shows a case where the vehicle 10 receives a cross wind blowing from the left side of the vehicle to the right side of the vehicle, and the air flow fluctuation angle β is a positive value. In this case, the direction of the oblique air flow 60 received by the vehicle 10 is from the left front of the vehicle 10 toward the vehicle 10. The air flow 60 is divided into a shunt component 62 that flows on the right side of the vehicle 10 and a shunt component 64 that flows on the left side of the vehicle 10, and merges at the rear of the vehicle 10. When the path length of the shunt component 62 is compared with the path length of the shunt component 64, (path length of the shunt component 62)> (path length of the shunt component 64). A shunt component 62 having a long path length flows around the door mirror 30 on the right side of the vehicle, and a shunt component 64 having a short path length flows around the door mirror 32 on the left side of the vehicle. When the air flow 60 is viewed from a branch point where the diversion component 62 and the diversion component 64 are separated, the door mirror 30 is on the downstream side and the door mirror 32 is on the upstream side.

  FIG. 4B shows a case where the vehicle 10 receives a cross wind blowing from the right side of the vehicle to the left side of the vehicle, and the air flow fluctuation angle β is a negative value. In this case, the direction of the airflow 60 in the oblique direction received by the vehicle 10 is from the right front side of the vehicle 10 toward the vehicle 10. The air flow 60 is divided into a shunt component 62 that flows on the right side of the vehicle 10 and a shunt component 64 that flows on the left side of the vehicle 10, and merges at the rear of the vehicle 10. When the path length of the shunt component 62 is compared with the path length of the shunt component 64, (path length of the shunt component 62) <(path length of the shunt component 64). A shunt component 64 having a long path length flows around the door mirror 32 on the left side of the vehicle, and a shunt component 62 having a short path length flows around the door mirror 30 on the right side of the vehicle. When the air flow 60 is viewed from a branch point where the diversion component 62 and the diversion component 64 are separated, the door mirror 32 is on the downstream side and the door mirror 30 is on the upstream side.

  In FIG. 4A, when the air flow 60 is divided into a diversion component 62 and a diversion component 64, the flow velocity of the diversion component 62 having a long path length is faster than the flow velocity of the diversion component 64 having a short path length. In terms of pressure, a flow with a higher flow velocity is on the low pressure side, so vortices are more likely to occur than on the high pressure side. For this reason, when the airflow around the door mirrors 30 and 32 is compared, the flow rate of airflow around the door mirror 30 on the downstream side is fast, the pressure is low, and vortices are likely to be generated, so the level of generated noise increases. . This is the reason why the noise generated around the door mirror on the downstream side is larger than the noise generated around the door mirror on the upstream side with respect to the air flow 60 in the oblique direction received by the vehicle 10.

  As shown in FIGS. 4A and 4B, the housing of the left and right door mirrors 30 and 32 disposed on the left and right sides of the vehicle 10 depending on whether the air flow fluctuation angle β is a positive value or a negative value. The door mirror arranged on the downstream side that rotates in the direction of increasing the absolute value of the angle α changes. When the air flow yaw angle β is a positive value, the door mirror 30 is on the downstream side, and when the air flow yaw angle β is a negative value, the door mirror 32 is on the downstream side.

  FIG. 5 is a diagram for explaining that noise can be suppressed by rotating the downstream door mirror in the direction of increasing the absolute value of the housing angle α. Each figure is a view showing the air flow 60 and the vortex 70 generated on the downstream side of the door mirror 30 by extracting the periphery of the door mirror 30 in FIG.

FIG. 5A shows a case where the vehicle 10 is not subjected to cross wind, the direction of the air flow 60 is parallel to the D _R -D _R direction, and the air flow fluctuation angle β = 0. The direction of the reference axis HH of the housing 42 of the door mirror 30 is inclined by θ ₀ with respect to the air flow 60. θ ₀ = (180 degrees−α). In the shape design specification of the vehicle 10, θ ₀ is set so as to minimize the noise around the door mirror 30 when it is not subjected to cross wind, and therefore the generation of the vortex 70 that causes the noise around the door mirror 30 is minimized. It is limited to the limit.

FIG. 5B shows a case where the vehicle 10 receives wind blowing from the left side of the vehicle to the right side of the vehicle. The direction of the air flow 60 is inclined at a positive air flow fluctuation angle β with respect to the D _R -D _R direction. For this reason, the direction of the reference axis HH of the housing 42 of the door mirror 30 is inclined (θ ₀ + β) with respect to the air flow 60. Since this state is shifted from θ ₀ that minimizes the noise around the door mirror 30, the vortex 72 generated on the downstream side of the door mirror 30 becomes larger than in the case of (a), and the noise around the door mirror 30 is increased. growing.

FIG. 5C shows a case where the vehicle 10 receives wind blowing from the left side of the vehicle to the right side of the vehicle, as in FIG. 5B, but the housing angle α of the door mirror 30 is rotated to the front side of the vehicle (α + β ). In this way, the direction of the reference axis HH of the housing 42 of the door mirror 30 is inclined at {(θ ₀ −β) + β} = θ ₀ with respect to the air flow 60 as shown in FIG. Thus, the state returns to the state of FIG. As a result, the vortex 70 generated on the downstream side of the door mirror 30 becomes smaller than the vortex 72 in the case of (b), and the noise around the door mirror 30 returns to the minimum design value. This is the state of S14 in FIG.

For reference, FIG. 5C shows the case where the vehicle 10 receives wind blowing from the right side of the vehicle to the left side of the vehicle, and the door mirror 30 is in the state of the door mirror upstream of the air flow 60. Therefore, the air flow direction 60 is inclined in the D _R -D to _R direction, the negative air flow yaw angle beta. The direction of the reference axis HH of the housing 42 of the door mirror 30 is inclined (θ ₀ −β) with respect to the air flow 60. This state deviates from θ ₀ that minimizes the noise around the door mirror 30, but, as described in FIG. 4, in the state of the door mirror upstream of the air flow 60, the flow rate of the air flow is low. Since the pressure is on the high pressure side, the generation of vortex 74 is small and noise generation is not a problem.

  In the above description, it is assumed that the vector of the cross wind received by the vehicle 10 does not change over time, or even if there is no time change enough to reverse the sign of the airflow yaw angle β. Actually, while the vehicle 10 is traveling, the direction of the cross wind may fluctuate, and the direction of the oblique air flow received by the vehicle 10 may change. For example, when the air condition is unstable and the wind direction is unstable, or when the direction of the road curve is repeatedly changed from side to side, the sign of the air flow fluctuation angle β may be reversed over time.

When the sign of the air flow yaw angle β is repeatedly reversed with the passage of time, the door mirror with the louder noise generated from the two door mirrors 30 and 32 provided on both sides of the vehicle 10 moves to the left and right with the passage of time. It will change. In this case, the air flow yaw angle beta used as crosswind characteristic value, the air flow yaw threshold angle beta ₀ used as crosswind characteristics threshold, and then executes the process described in FIG. 3, rapidly for the left and right side mirrors 30 and 32 The absolute value of the housing angle α will be changed. Thereby, there is a high possibility that the discomfort given to the user such as the driver is increased.

FIG. 6 is a flowchart showing the procedure of the noise suppression control used when the sign of the air flow fluctuation angle β is repeatedly reversed over time. As the noise suppression control, two determination procedures are performed as in FIG. One is a determining vehicle speed V is whether exceeds a predetermined vehicle speed threshold value V ₀ (S20). Since the contents of this procedure are the same as the contents of S10 in FIG. 3, detailed description thereof is omitted.

Another determination is whether or not the crosswind characteristic value exceeds the crosswind characteristic threshold. Here, unlike S12 in FIG. 3, the airflow fluctuation in a predetermined predetermined period is used as the crosswind characteristic value. The fluctuation range of the angle β is used. Then, as the cross wind characteristic threshold value, the air flow yaw threshold angle β ₀ corresponding to a predetermined noise threshold value for noise generated by the air flow around the door mirror when there is no change in the air flow yaw angle β in the predetermined elapsed period is 2 Use double. beta, considering the sign of the beta _0, it is determined whether more than {absolute value of the variation width of the air flow yaw angle beta} is {2 times the absolute value of the air flow yaw threshold angle beta _0} (S22).

FIG. 7 is a diagram showing a state in which {the absolute value of the fluctuation range of the airflow yaw angle β} exceeds {twice the absolute value of the airflow yaw threshold angle β ₀ }. The horizontal axis of each figure of FIG. 7 is time, the vertical axis | shaft of Fig.7 (a) is the airflow oscillation angle (beta), and the vertical axis | shaft of (b) is a noise magnitude. Since the magnitude of the noise is equivalent to the magnitude of the excitation force received by the vehicle side surface, the excitation force received by the vehicle side surface may be used as the noise level. As the magnitude of noise, sound pressure or a sensory evaluation value can be used.

In FIG. 7A, the air flow fluctuation angle β varies sinusoidally in positive and negative directions, the maximum value on the positive side is larger than + β ₀ , and the minimum value on the negative side is smaller than (−β ₀ ). . That is, {the absolute value of the fluctuation range of the airflow yaw angle β} exceeds {twice the absolute value of the airflow yaw threshold angle β ₀ }.

  When the magnitude of noise corresponding to FIG. 7A is viewed in the waveform on the left side of FIG. 7B, it greatly fluctuates in accordance with the fluctuation of the air flow fluctuation angle β. The waveform on the left side of FIG. 7B is a waveform of the magnitude of noise during a predetermined predetermined period. The predetermined elapsed period can be determined by the time when the fluctuation of the noise makes the user uncomfortable, the number of repetitions of the fluctuation, or the like.

  Returning to FIG. 6, either the determination of S20 or the determination of S22 may be performed first, but if the determination of S20 is affirmative and the determination of S22 is affirmative, the process proceeds to S24. If at least one of the determination in S20 and the determination in S22 is negative, the process does not proceed to S24, the housing angle α is maintained as it is, and the process returns to S20 in the first procedure.

In S24, with respect to the airflow around the vehicle determined by the airflow yaw angle β, the absolute value of the housing angle α is increased for both the left and right door mirrors 30 and 32 disposed on the left and right sides of the vehicle 10. And the air flow fluctuation threshold angle β ₀ is rotated at a predetermined angle smaller than the absolute value. Considering the signs of α, β, β ₀ , (the absolute value of the housing angle α) is {(the absolute value of the housing angle α) + (a predetermined angle smaller than the absolute value of the airflow yaw threshold angle β ₀ ) }. The predetermined angle, using {angle of (1/2) of the absolute value of the air flow yaw threshold angle beta _0}. This is an example for explanation, and an angle different from this may be used as long as it is less than {the absolute value of the air flow fluctuation threshold angle β ₀ }.

Referring to FIG. 7, the state where {the absolute value of the fluctuation range of the airflow yaw angle β} exceeds {twice the absolute value of the airflow yaw threshold angle β ₀ } continues even after a predetermined elapsed period. . When {absolute value of housing angle α} is changed to {(absolute value of housing angle α) + (predetermined angle smaller than the absolute value of air flow fluctuation threshold angle β ₀ )} after a predetermined lapse period, Corresponding to this, the fluctuation range of the noise does not become zero, but is suppressed to a considerably small level. Thereby, about the door mirrors 30 and 32, the fluctuation | variation of a noise is averaged about the door mirror on either side. Thereby, the discomfort of the user of the vehicle 10 can be reduced. Further, it is possible to prevent the absolute value of the housing angle α from being changed rapidly for the left and right door mirrors 30 and 32.

  According to the door mirror noise suppression control system 20 configured as described above, when the vehicle 10 receives a crosswind while traveling, the vehicle speed and the crosswind characteristic value are respectively determined in advance with respect to the noise generated by the airflow around the door mirrors 30 and 32. It compares with a vehicle speed threshold value and a crosswind characteristic threshold value. When the crosswind characteristic value exceeds the crosswind characteristic threshold value when the vehicle speed exceeds the vehicle speed threshold value, the housing 42 of the door mirrors 30 and 32 is placed on the vehicle front side with respect to the surface along the vehicle front-rear direction of the side door. Rotate toward. As a result, the direction of the air flow received by the door mirrors 30 and 32 when there is a cross wind is close to the direction of the air flow received by the door mirrors 30 and 32 when there is no cross wind, and the noise generated around the door mirrors 30 and 32 is It drops to a level close to that when there is no crosswind. In this way, it is possible to suppress the noise generated when the vehicle 10 receives a crosswind while traveling and the excitation force on the side surface of the vehicle.

  DESCRIPTION OF SYMBOLS 10 Vehicle, 20 Noise suppression control system (of door mirror), 30, 32 Door mirror, 40 Mounting part, 42 Housing, 44 Mirror main body, 46, 48 Rotation center axis, 50 Housing drive part, 52 Mirror main body drive part, 54 Control part , 56 Vehicle speed acquisition unit, 58 Cross wind characteristic value acquisition unit, 60 Air flow, 62, 64 Shunt component, 70, 72, 74 Vortex.

Claims (6)

A vehicle speed acquisition unit for acquiring the vehicle speed;
A crosswind characteristic value acquisition unit for acquiring a crosswind characteristic value related to a wind speed of the crosswind received by the vehicle and a wind direction angle with respect to the vehicle traveling direction;
An attachment part fixed to the side door of the vehicle, and a door mirror composed of a housing that includes a mirror body that is a mirror body and is rotatable with respect to the attachment part;
A housing drive unit that rotationally drives the housing around a rotation center axis provided in the attachment unit;
The angle at which the reference surface of the housing passing through the rotation center axis faces the vehicle rear side with respect to the surface along the vehicle front-rear direction of the side door is defined as a housing angle.
For each of the vehicle speed and the cross wind characteristic value, the vehicle speed exceeds the vehicle speed threshold value compared with a vehicle speed threshold value and a cross wind characteristic threshold value that are predetermined with respect to noise generated by the airflow around the door mirror, and It is determined whether or not the crosswind characteristic value exceeds the crosswind characteristic threshold value. If the determination is affirmative, the absolute value of the housing angle is increased and the housing is rotated toward the front side of the vehicle. A control unit that controls the housing drive unit to maintain the housing angle when
A door mirror noise suppression control system.   The cross wind characteristic value is an air flow yaw angle that is an angle formed by a combined vector of the cross wind vector and the vehicle speed vector defined by the wind speed and the wind direction angle with respect to the traveling direction of the vehicle, 2. The door mirror noise suppression control system according to claim 1, wherein the cross wind characteristic threshold is an air flow oscillation threshold angle at which the noise generated by the air flow around the door mirror becomes a predetermined noise threshold. The controller is
If the determination is affirmative,
Regarding the airflow around the vehicle determined by the airflow yaw angle, only the door mirror disposed on the downstream side of the left and right door mirrors disposed on the left and right sides of the vehicle is increased in the absolute value of the housing angle. 3. The door mirror noise suppression control system according to claim 2, wherein the control is performed by rotating only the absolute value of the air flow yaw threshold angle to maintain the housing angle of the door mirror disposed on the upstream side.   The cross wind characteristic value is determined in advance as an air flow yaw angle that is an angle formed by a combined vector of the cross wind vector and the vehicle speed vector defined by the wind speed and the wind direction angle with respect to the traveling direction of the vehicle. The cross wind characteristic threshold value is generated by the air flow around the door mirror when there is no change in the air flow yaw angle during the predetermined elapse period. The noise suppression control system for a door mirror according to claim 1, wherein the noise suppression control system for the door mirror is twice the absolute value of an air flow yaw threshold angle corresponding to a predetermined noise threshold for noise. The controller is
If the determination is affirmative,
With respect to the airflow around the vehicle determined by the airflow yaw angle, the airflow is increased in the direction in which the absolute value of the housing angle is increased with respect to any of the left and right door mirrors disposed on the left and right sides of the vehicle. The door mirror noise suppression control system according to claim 4, wherein the control is performed to rotate at a predetermined angle smaller than an absolute value of the yaw threshold angle. A mirror body drive unit for rotating the mirror body relative to the housing;
The controller is
The absolute value of the housing angle is increased to compensate that the mirror surface of the mirror main body is inclined with respect to the surface along the vehicle front-rear direction of the side door, and the mirror surface of the mirror main body is front-rear of the side door of the vehicle. The door mirror noise suppression control system according to claim 3 or 5, wherein control is performed to maintain a constant angle formed with respect to the surface along the direction.

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