JP4480596B2 - Headrest control device for vehicle - Google Patents

Description

  The present invention moves a part of the headrest toward the seated person's head based on a detection signal from a collision prediction detection means capable of detecting in advance that there is a possibility of a collision. The present invention relates to a headrest control device in a vehicle that can be operated.

  A technique related to this type of headrest control is disclosed in Patent Document 1, for example. This technology includes a collision prediction detection unit that predicts a rear collision of a vehicle in advance (for example, 1.0 second before the collision). Based on the signal from the collision prediction detection means, the headrest is moved forward to approach the head of the seated person. Thereby, the performance of reducing the burden placed on the neck of the seat occupant at the time of a rear collision is achieved.

As described above, in the control for moving the headrest forward based on the collision prediction signal, for example, when the collision is avoided, it is necessary to return the headrest to the original normal position. Further, in order to move the entire headrest, the load applied to the drive mechanism is large and a large capacity motor or the like is required. Thus, a configuration is adopted in which the headrest is divided into both front and back elements, and both elements are coupled so that the front elements can be moved in the front-rear direction.
JP 2004-9891 A

  In the configuration in which the headrest element on the front side is moved forward based on the collision prediction signal, when the headrest element is subsequently returned to the normal position, foreign matter may be sandwiched between the divided portions of both headrest elements.

  The present invention is intended to solve such problems, and its purpose is to prevent foreign matter from being caught between the divided portions of both headrest elements when the headrest element moved forward is returned to the normal position. It is to be.

The present invention is for achieving the above object, and is configured as follows.
In a vehicle capable of receiving a detection signal from a collision prediction detection means capable of predicting a collision in advance, the headrest includes a front-side headrest element capable of supporting the seated person's head, and a rear-side headrest element. It is divided into a headrest element, and these both headrest elements are connected so that the headrest element on the front side can be moved in the front-rear direction, and by the operation of the drive mechanism based on the detection signal from the collision prediction detection means, A headrest control device in a vehicle for moving a headrest element on a front side from a normal position where split parts of both headrest elements are joined toward a head of a seat occupant, and the front side is controlled by the operation of a motor in the drive mechanism . Between the headrest elements when the headrest elements are moved to return to their normal positions. A laser sensor for detecting that there is a foreign object, the basis of the detection of the foreign object by the laser sensor, the deceleration or stopping the rotation of the motor in the drive mechanism in order to prevent the foreign matter is sandwiched between the divided portions of both the headrest element And a control unit . And the laser sensor is arrange | positioned only at the left-right part of the headrest, and the upper part along the outer peripheral part between the division parts of both headrest elements.
Thereby, when returning the headrest element on the front side to the normal position from the state where the headrest element is moved toward the head of the seat occupant, it is possible to prevent foreign matter from being sandwiched between the divided portions of both headrest elements. By using a laser sensor as means for detecting the presence of foreign matter between the divided portions of both headrest elements, the presence of foreign matter can be detected relatively quickly.

The best mode for carrying out the present invention will be described below with reference to the drawings.
FIG. 1 is a side view showing a vehicle seat. As shown in this drawing, the seat 10 includes a seat cushion 12 and a seat back 14. The headrest 20 is mounted near the center of the upper surface of the seat back 14. That is, the headrest 20 includes a pair of legs 26 that protrude downward from the lower surface thereof, and these legs 38 are connected to a frame (not shown) in the seat back 14.

  FIG. 2 is an enlarged side view of the headrest 20. The headrest 20 is divided into a headrest element 21 on the front side and a headrest element 22 on the back side. A headrest drive mechanism 30 is incorporated in the headrest 20, and both headrest elements 21 and 22 are connected through the drive mechanism 30. Then, by actuating the driving mechanism 30, the front-side headrest element 21 can be reciprocated in the vehicle front-rear direction with respect to the rear-side headrest element 22. That is, the headrest element 21 moves between a normal position (the phantom line in FIG. 2) where the divided portions 23 of the headrest elements 21 and 22 are joined to each other and a position diagonally above and forward (a solid line in FIG. 2). be able to. By moving the headrest element 21, the distance between the head of the seat occupant H shown in FIG. 1 and the headrest 20 changes.

  As shown in FIG. 2, the front-side headrest element 21 includes a shielding member 24 that protrudes from both sides thereof toward the back-side headrest element 22. These shielding members 24 enter the inside of the headrest element 22 and are polymerized. This superposition allowance is set so as to cover between the divided portions 23 of the headrest elements 21 and 22 even when the headrest element 21 is moved to the position indicated by the solid line in FIG. Note that a shielding sheet (not shown) is provided on the upper surface side of the headrest 20 so as to cover between the divided portions 23 of the headrest elements 21 and 22 and between the shielding members 24. As this shielding sheet, a resin film that can be flexibly deformed by the movement of the headrest element 21 is used. Thereby, even if the headrest element 21 moves forward from the normal position or is moving, the inside of the headrest 20 is hidden so that it cannot be seen.

FIG. 3 is an external perspective view showing the structure of the drive mechanism 30. The configuration of the drive mechanism 30 will be briefly described with reference to this drawing.
First, the drive mechanism 30 has a configuration in which a pair of front and rear bases 31 and 32 are connected by a pair of left and right X-shaped links 34. One base 31 is coupled in the front-side headrest element 21, and the other base 32 is coupled in the back-side headrest element 22. The pair of links 34 includes two link members 35 and 36, respectively, and intermediate portions of the link members 35 and 36 are rotatably connected. Both end portions of these link members 35 and 36 are connected to side portions 31a and 32a provided integrally on both sides of both bases 31 and 32, respectively.

  Specifically, with respect to one link member 35 in the pair of links 34, each front end portion (lower end portion) is rotatably connected to the side portion 31a of the base 31 by a pin 35a, and each rear end portion ( The upper end portion) is rotatably connected to the side portion 32a of the base 32 by a pin 35b. About the other link member 36 in a pair of link 34, each front end part (upper end part) and rear end part (lower end part) are mutually couple | bonded by the shafts 36a and 36b. Both ends of one shaft 36 a are slidably connected to a vertically long guide hole 31 b formed in the side portion 31 a of the base 31, and both ends of the other shaft 36 b are formed in the side portion 32 a of the base 32. It is slidably connected to the vertically long guide hole 32b.

  The base 32 on the back side includes an electric unit 38 that is a drive source of the drive mechanism 30. The motor 38 a of the electric unit 38 is attached to the inside of the base 32. The drive shaft of the motor 38a is connected to the shaft 36b of the link 34 through the ball screw portion 38b. By the function of the ball screw portion 38b, the forward / reverse rotation of the motor 38a (drive shaft) is converted into the lifting / lowering operation of the shaft 36b. Therefore, based on the drive control of the electric unit 38, both X-shaped links 34 move like a pantograph, and the base 31 approaches or separates from the base 32. As a result, the headrest element 21 moves in an arcuate locus between the virtual line position (normal position) and the solid line position in FIG.

  FIG. 4 is a block diagram of the headrest control device. The headrest sensor 40 shown in this drawing is a combination of a capacitance sensor 40a and a touch sensor 40b. The electrostatic capacity sensor 40a and the touch sensor 40b are provided on a thin sheet surface having flexibility and provided on the inner surface of the headrest element 21 on the front side (FIG. 2). The electrostatic capacity sensor 40a detects the relative position (distance) with the head of the seat occupant H by a change in electrostatic capacity, and the touch sensor 40b applies a load to the surface of the headrest element 21. This is detected by electrode contact. These detection signals are transmitted to the control unit 44.

  The collision prediction detection means 43 predicts a rear collision based on the inter-vehicle distance and relative speed between the host vehicle and the rear vehicle in the pre-crash safety system mounted on the vehicle, and sends a detection signal to that effect to the control unit 44. To call. The control unit 44 performs control for operating the drive mechanism 30 mainly based on detection signals from the headrest sensor 40 and the collision prediction detection unit 43. That is, the drive of the motor 38a of the electric unit 38 is controlled based on the control signal from the control unit 44. In addition, as the collision prediction detection means 43, it is also possible to utilize information communication systems other than the system mounted in the vehicle. For example, it is possible to receive information from ITS (Intelligent Transport Systems) and perform control by the control unit 44 based on the detection signal.

  FIG. 5 is an external perspective view of the headrest 20 as viewed obliquely from the rear. In the headrest 20 shown in this drawing, a laser sensor 42 (light emitting side sensor 42a and light receiving side sensor 42b) is provided in a split portion 23 of both headrest elements 21 and 22. This laser sensor 42 functions as a “foreign matter detection means” in the control flow process of FIG. 8 described later. That is, the laser sensor 42 is a sensor for detecting that a foreign object is located in the divided portion 23 of both headrest elements 21 and 22. Therefore, for example, the light emission side sensor 42 a is provided in the division part 23 of the headrest element 21, and the light reception side sensor 42 b is provided in the division part 23 of the headrest element 22.

  The light-emitting side sensor 42a and the light-receiving side sensor 42b are provided in the left and right, upper and lower regions constituting the divided portion 23 of both headrest elements 21 and 22. However, the laser sensor 42 may be omitted because the division part 23 at the lower part of the headrest 20 is less likely to pinch foreign matter. Further, the laser sensors 42 (the light emitting side sensor 42a and the light receiving side sensor 42b) are arranged at a constant interval along the dividing portion 23, and the interval is set to 10 to 20 mm in consideration of detection of an occupant's finger or the like. Is set. The laser sensor 42 may be of a type in which the light emitting side sensor 42a and the light receiving side sensor 42b are integrated to serve as a mutual function. In that case, it is only necessary to provide the laser sensor 42 in one of the divided portions 23 of the headrest elements 21 and 22.

  6 to 8 are flowcharts for explaining the movement process of the headrest 20 (headrest element 21) by the control unit 44. The control processing in these flowcharts is started when, for example, an ignition switch (not shown) is turned on, and thereafter executed at regular time intervals. In each flowchart, F1 is a flag indicating that there is a prediction signal from the collision prediction detection means 43, and F2 is a long press of the touch sensor 40b (FIG. 6) or a lapse of a predetermined time by a timer (FIG. 7). ). 6 and 7, F3 is a flag indicating that the rotational speed of the motor 38a in the electric unit 38 is within a normal range, and F4 is a flag indicating that the rotational speed of the motor 38a has been abnormally reduced. . Further, F5 in the flowchart of FIG. 8 is a flag indicating that foreign matter has been detected from the laser sensor. The default values of these flags F1 to F5 are all “0”.

  First, the flowchart shown in FIG. 6 will be described. In step S1 of this control process, the flag F1 is determined. If the flag F1 is not "1" based on the determination result, the process proceeds to step S2 and whether or not the prediction signal from the collision prediction detection means 43 is received. Judging. Based on the determination result, if no prediction signal is input, the processing ends as it is (returns). On the other hand, if a collision prediction signal is input, the flag F1 is set to “1” in step S3, and the process proceeds to step S4. In step S4, the headrest element 21 is moved forward from the normal position. Thus, the headrest element 21 is brought close to the head of the seat occupant H to prepare for a rear collision of the vehicle, and then the process proceeds to step S5. Also, when the flag F1 is “1” in the determination result of step S1, the process proceeds to step S5.

  In step S5, the flag F2 is determined. If the flag F2 is not "1" as a result of this determination, the process proceeds to step S6 to determine whether or not the touch sensor 40b has been pressed for a long time. If the touch sensor 40b has not been pressed for a long time based on the determination result, the process ends (returns) as it is. On the other hand, if the touch sensor 40b is being pressed for a long time, the flag F2 is set to “1” in step S7, and then the process proceeds to step S8 to move the headrest element 21 backward.

  That is, the long press operation of the touch sensor 40b returns the headrest element 21 located near the head of the seat occupant H to the normal position by the operation of the drive mechanism 30 when the collision of the vehicle is avoided. This is an artificial start-up operation. After starting the return operation of the headrest element 21 in this way, the process proceeds to step S9. Also, when the flag F2 is “1” in the determination result of step S5, the process proceeds to step S9.

  In step S9, the flag F3 is determined. As a result, if the flag F3 is not “1”, the process proceeds to step S10 to determine whether or not the rotational speed of the motor 38a in the drive mechanism 30 is equal to or greater than a predetermined value N1. If the number of rotations of the motor 38a is less than the predetermined value N1 based on this determination result, the process is finished (returns) as it is. On the other hand, when the rotational speed of the motor 38a is equal to or greater than the predetermined value N1, the flag F3 is set to “1” in step S11, and the process proceeds to step S12. Also, when the flag F3 is “1” in the determination result of step S9, the process proceeds to step S12. The predetermined value N1 is a reference value when the rotational speed of the motor 38a is within a normal range, and it is detected that the rotational speed of the motor 38a has increased to the normal value based on the determination in step S10. Can do.

  In step S12, the flag F4 is determined. If the flag F4 is “1” as a result of this determination, the processing ends as it is (returns). If the flag F4 is not "1", the process proceeds to step S13 to determine whether or not the rotational speed of the motor 38a is equal to or less than a predetermined value N2. If the number of revolutions of the motor 38a exceeds the predetermined value N2 as a result of this determination, the processing is terminated as it is (returned). On the other hand, if the rotational speed of the motor 38a is equal to or less than the predetermined value N2, the process proceeds to step S14, the flag F4 is set to "1", and then the backward movement of the headrest element 21 is stopped in step S15. In step S16, the headrest element 21 is moved forward. Subsequently, in step S17, the flags F2, F3, and F4 are set to “0”, respectively, and then the process ends (returns).

  The predetermined value N2 is an allowable lower limit value for the rotation speed of the motor 38a, and it can be detected that the rotation speed of the motor 38a is abnormally decreased by the determination in step S13. In this manner, foreign matter is caught between the divided portions 23 of both headrest elements 21 and 22 by detecting an abnormal decrease in the rotational speed of the motor 38a during the returning operation of the headrest element 21, that is, an increase in the load on the motor 38a. Can be detected. And when the foreign material is detected in the dividing portion 23, the returning operation of the headrest element 21 is stopped, and the headrest element 21 is moved forward to eliminate the foreign object.

  The means for detecting the rotational speed fluctuation (load fluctuation) in the motor 38a is specifically an ammeter or a voltmeter for measuring the drive current or voltage of the motor 38a. These are the “foreign matter detecting means” in the present invention. It corresponds to. In addition, the control function of the control unit 44 that stops the rotation of the motor 38a and stops the return operation of the headrest element 21 when foreign matter is detected corresponds to “avoidance means” in the present invention. The magnitude relationship between the rotational speeds N1 and N2 needs to be (N1> N2) in order to maintain control stability.

  Next, the flowchart shown in FIG. 7 will be described. Also in this control process, the flag F1 is determined in step S20, and the processes in steps S21 to S23 based on the determination result are the same as the processes in steps S2 to S4 in the flowchart shown in FIG. In the control flow of FIG. 7, after the headrest element 21 is moved forward from the normal position in step S23, the timer is started in step S24, and the process proceeds to the next step S25. In step S25, the flag F2 is determined.

  If the flag F2 is not “1” as a result of the determination in step S25, the process proceeds to step S26 to determine whether or not the time from the start of the timer operation is a predetermined time or more. When the time of this timer is less than the predetermined time, the processing is finished as it is (returned). On the other hand, if the time of the timer has exceeded a predetermined time, the flag F2 is set to “1” in step S27, and then the process proceeds to step S28 to move the headrest element 21 backward. Next, the process proceeds to step S29, and the processes from step S29 to step S37 are continued. However, the processing in steps S29 to S37 is the same as the processing in steps S9 to S17 in the flowchart shown in FIG.

  In the control of FIG. 7, when a predetermined time elapses after the headrest element 21 moves forward, the return operation of the headrest element 21 is automatically started. Thereafter, similarly to the control of FIG. 6, the control using the functions of “foreign matter detection means” and “avoidance means” during the return operation of the headrest element 21 is performed. That is, by detecting the load fluctuation of the motor 38a when the headrest element 21 is returning, it is detected that a foreign object has been sandwiched between the divided portions 23 of the headrest elements 21 and 22, and the headrest element is detected when the foreign object is detected. The return operation of 21 is stopped to prevent foreign matter from being caught.

  Next, the flowchart shown in FIG. 8 will be described. Also in this control process, the flag F1 is determined in step S40, and the processes in steps S41 to S47 based on the determination result are the same as the processes in steps S2 to S8 in the flowchart shown in FIG. In the control flow of FIG. 8, in order to return the headrest element 21 to the normal position in step S47, the backward movement is started, and the laser sensor 42 is turned on in step S48. Thereafter, the process proceeds to step S49, and the flag F5 is determined.

  As a result of the determination in step S49, if the flag F5 is “1”, the processing is finished as it is (returned). On the other hand, if the flag F5 is not "1", the process proceeds to step S50, and it is determined whether or not the laser sensor 42 has detected that there is a foreign object between the divided portions 23 of both headrest elements 21 and 22. As a result, if there is no foreign matter detection signal from the laser sensor 42, the processing is finished (return). On the other hand, if a foreign matter detection signal is input, the process proceeds to step S51 where the flag F5 is set to "1", and then the backward movement of the headrest element 21 is stopped in step S52, and the headrest in step S53. Move element 21 forward. Subsequently, in step S54, the flags F2 and F5 are set to “0”, respectively, and the processing is ended (returned).

  In the control process of FIG. 8, the laser sensor 42 corresponds to the “foreign matter detecting means” in the present invention. The detection of the foreign matter by the laser sensor 42 can detect the presence of the foreign matter before the foreign matter is sandwiched between the divided portions 23 of the headrest elements 21 and 22 as compared to the case where the load fluctuation of the motor 38a is used. . In this control as well, the “avoidance means” is a function of the control unit 44 that stops the returning operation of the headrest element 21 when a foreign object is detected.

Although the best mode for carrying out the present invention has been described above with reference to the drawings, this embodiment can be easily changed or modified without departing from the spirit of the present invention.
For example, when movement for returning the headrest element 21 to the normal position after moving forward is started, it is possible to control to issue an alarm by a sound from a buzzer or the like or by blinking a lamp. In addition, a switch different from the touch sensor 40b can be used as an activation switch for returning the headrest element 21 to the normal position. In this case, by providing the switch in a portion away from the divided portion 23 of both headrest elements 21 and 22, the foreign object is prevented from being caught in the divided portion 23.
Further, the “avoidance means” may be a control for reducing the rotation speed of the motor 38a instead of the control for stopping the rotation of the motor 38a. That is, by reducing the return speed of the headrest element 21, foreign matters can be removed from the dividing portion 23 during that time.

Side view showing a vehicle seat Side view with enlarged headrest External perspective view showing the structure of the headrest drive mechanism Headrest control device block diagram External perspective view of headrest viewed from diagonally behind Flow chart for explaining headrest movement processing Another flowchart for explaining the headrest moving process Yet another flowchart for explaining the headrest moving process

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Seat 20 Headrest 21, 22 Headrest element 23 Dividing part 30 Headrest drive mechanism 38a Motor 42 Laser sensor 43 Collision prediction detection means 44 Control part H Seat occupant

Claims (1)

In a vehicle capable of receiving a detection signal from a collision prediction detection means capable of predicting a collision in advance, the headrest includes a front-side headrest element capable of supporting the seated person's head, and a rear-side headrest element. It is divided into a headrest element, and these both headrest elements are connected so that the headrest element on the front side can be moved in the front-rear direction, and by the operation of the drive mechanism based on the detection signal from the collision prediction detection means, A headrest control device in a vehicle for moving a headrest element on the front side from a normal position where divided parts of both headrest elements are joined toward a head of a seat occupant,
A laser sensor for detecting the presence of foreign matter between the divided portions of the headrest elements when the headrest element on the front side is moved to return to the normal position by the operation of the motor in the drive mechanism, and the laser sensor And a controller that decelerates or stops the rotation of the motor in the drive mechanism in order to avoid foreign matter being caught between the divided parts of both headrest elements based on the detection of foreign substances by the laser sensor, and the laser sensor divides both headrest elements The headrest control apparatus in the vehicle arrange | positioned only in the left-right part of the headrest, and the upper part along the outer peripheral part between parts .

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