JP4675621B2 - Headrest control device - Google Patents

Description

  The present invention relates to a headrest control device capable of controlling a distance between a head of a seat occupant and a headrest by moving a headrest of a vehicle seat in the front-rear direction.

A technique related to this type of headrest control is disclosed in Patent Document 1, for example. In this technique, a headrest drive unit capable of moving the headrest forward is provided. In addition, a collision prediction sensor for predicting a rear collision of the vehicle before a predetermined time (for example, 1.0 second before the collision) is provided. When a prediction signal is input from the sensor to the control unit, the control signal is transmitted from the control unit to the headrest driving unit. This enables the headrest to approach the seat occupant's head when a rear collision is predicted, and reduces the burden on the neck when the upper body of the seat occupant falls back due to a reaction during a rear collision. Fulfill. Note that the distance in the front-rear direction between the headrest and the head of the seat occupant in a state where the vehicle is normally driven is ensured to be relatively large.
JP 2004-9891 A

  In the technique disclosed in Patent Document 1, after receiving a detection signal from the collision prediction sensor, it is necessary to move the headrest at a position far away from the head of the seated person toward the head. In this case, it takes time until the headrest is moved to a position capable of coping with the collision after the backward collision is predicted. For this reason, it is necessary to take measures such as setting the detection timing of the collision prediction early, or increasing the moving speed of the headrest by increasing the capacity of a motor that is a drive source of the headrest drive unit.

  The present invention is intended to solve such problems, and its purpose is to enable the headrest to be moved in a short time to a position capable of handling a rear collision of the vehicle when a collision is predicted or a collision is detected. It is to be.

The present invention is for achieving the above object, and is configured as follows.
A headrest driving mechanism capable of moving the headrest of the vehicle seat in the front-rear direction, a distance detection means capable of detecting a distance between the head of the seat occupant and the headrest in the moving direction of the headrest, and a collision Alternatively, it is a headrest control device comprising a collision detection means capable of detecting a collision prediction and a control means for operating the headrest drive mechanism to control the distance between the head of the seated occupant and the headrest, The control means includes a first control means for performing control for operating the headrest drive mechanism based on a detection signal from the distance detection means, and the headrest drive mechanism based on a detection signal from the collision detection means. And second control means for performing control for operating the . In normal times, moving always the headrest by operating the headrest driving mechanism at a predetermined position which can cope with the rear impact of the vehicle by the first control means. Wherein when the prediction signal from the collision detection means is detected, the proximity position where the headrest by operating the headrest driving mechanism by said second control means closer to the head of the seat occupant from the predetermined position of the Move to.
More preferably, the control by the first control means is performed a plurality of times as to whether or not the distance between the head of the seat occupant and the headrest is within a predetermined value range, and the distance is within a predetermined value range. It is to move the headrest only when it is measured to be outside a predetermined number of times continuously.

According to this configuration, the headrest at a predetermined position that can deal with a rearward collision of the vehicle can be moved to a close position close to the seated person's head when a collision prediction or a collision is detected. . That is, the headrest can be moved to a position that can cope with a rear collision of the vehicle in a short time. As a result, for example, the detection timing of the collision prediction can be set immediately before the collision, or conversely, if the detection timing is set as before, the moving speed of the headrest can be low, and the motor of the headrest driving mechanism can be reduced in capacity. .
Further, the first control means moves the headrest only when the distance between the head of the seat occupant and the headrest is continuously measured more than a predetermined number of times as being out of the predetermined value range. In this case, if the head of the seat occupant moves only momentarily, the headrest can be prevented from moving in response to the movement.

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 driving mechanism 30 is incorporated in the headrest 20. By actuating this drive 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. In other words, the headrest element 21 moves between a retracted position (the phantom line in FIG. 2) where the dividing lines of the headrest elements 21 and 22 are joined to each other and the forwardly advanced position (the solid line in FIG. 2). be able to. By moving the headrest element 21, it is possible to control the distance L between the head of the seat occupant H shown in FIG.

  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 the divided lines of the headrest elements 21 and 22 even when the headrest element 21 is moved to the forward position shown by the solid line in FIG. In addition, on the upper surface side of the headrest 20, a shielding sheet (not shown) that covers between the shielding members 24 is provided. As this shielding sheet, a resin film that can be flexibly deformed by the movement of the headrest element 21 is used. Thereby, even when the headrest element 21 is moved from the retracted position to the advanced position, or is moving, the inside of the headrest 20 is hidden so that it cannot be seen, and foreign matter is prevented from entering the inside.

FIG. 3 is an external perspective view showing the structure of the headrest 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 path between the retracted position and the advanced position.

  FIG. 4 is a block diagram of the headrest control device. A headrest sensor 40 shown in this drawing is a flexible thin plate-like capacitance sensor provided on the inner surface of the headrest element 21 on the front side (FIG. 2), and the head of the seat occupant H Relative position (distance L) can be detected in a non-contact state. Therefore, the headrest sensor 40 corresponds to the “distance detection means” in the present invention. The seat belt switch 42 is a switch that detects that the seat occupant H has worn a seat belt (not shown). In addition, the collision prediction unit 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, and transmits a detection signal to that effect to the control unit 44. The concept including the collision prediction means 43 and a collision sensor (not shown) for detecting a rear collision of the vehicle corresponds to the “collision detection means” of the present invention.

  The control means 44 is a first control means 44A that performs control for operating the headrest drive mechanism 30 based on a detection signal from the headrest sensor 40, and a headrest drive based on a detection signal from the collision prediction means 43. And second control means 44B for performing control for operating the mechanism 30. That is, based on the control signal from the control means 44, the motor 38a of the electric unit 38 rotates forward and backward. The headrest sensor 40 (capacitance sensor), the seat belt switch 42, and the collision prediction unit 43 are well-known techniques, and thus detailed description of these configurations is omitted.

  FIG. 5 is an explanatory diagram showing a distance L (mm) between the headrest 20 and the head of the seat occupant H. The “normal position” in this figure is a position where the headrest 20 is sufficiently away from the head, and the “appropriate position” is a position where the headrest 20 is close to the head of the seat occupant H so as to cope with a rearward collision of the vehicle. It corresponds to a predetermined position of the present invention. The “optimal position” is a position where the headrest 20 is further closer to the head of the seated person H than the predetermined position, and corresponds to the close position of the present invention. Note that the arrows F and R shown in FIG. 5 correspond to the arrows F and R in FIG.

  6 and 7 are flowcharts showing a control process for moving and adjusting the headrest 20 (headrest element 21) to an appropriate position (predetermined position) by the first control means 44A. The control processing shown in these flowcharts is started when, for example, an ignition switch (not shown) is turned on, and thereafter executed at regular time intervals. N1, N2, and N3 shown in these flowcharts are predetermined values for the distance L between the headrest 20 and the head of the seat occupant H, and the respective sizes are (N1 <N3 <N2). ) Is set. Note that C1 and C2 shown in the flowchart of FIG. 7 are counter variables, and the default value is “0”.

  First, the control flow shown in FIG. 6 will be described. In step S1 of FIG. 6, it is determined whether or not an ON signal is input from the seat belt switch. If the seatbelt switch 42 is off based on the determination result, it is assumed that the vehicle is not scheduled to travel, and the processing is finished (returns) as it is. On the other hand, if the seat belt switch 42 is on, the process proceeds to step S4, the detection signal from the headrest sensor 40 is read, and the distance L between the headrest 20 (headrest element 21) and the head of the seated person H is determined. Detect. Since the seat belt switch 42 detects whether or not the vehicle is scheduled to travel, it can be replaced with a seating sensor or the like provided on the seat cushion 12.

  Subsequently, in step S5, it is determined whether or not the distance L is a predetermined value N1 or less. If the distance L is equal to or smaller than the predetermined value N1 as a result of this determination, an actuation signal is transmitted to the drive mechanism 30 in step S6, and the headrest element 21 is moved in the direction of arrow R (rearward) until the distance L reaches the predetermined value N3. Direction).

  If the result of determination in step S5 is that the distance L exceeds the predetermined value N1, it is determined in step S7 whether or not the distance L is greater than or equal to the predetermined value N2. If the distance L is greater than or equal to the predetermined value N2 as a result of this determination, the process proceeds to step S8 and the headrest element 21 is moved in the direction of arrow F (forward) in FIG. 2 until the distance L reaches the predetermined value N3. If the distance L is less than the predetermined value N2 in the determination result in step S7, the process is finished (returns) as it is. As a result of the processing after step S5, the headrest element 21 is not moved when the distance L is in the region exceeding the predetermined value N1 and less than the predetermined value N2. Therefore, even if the head of the seat occupant H moves within the region, the troublesomeness that the headrest element 21 moves each time is eliminated.

  Next, the control flow shown in FIG. 7 will be described. The flowchart of FIG. 7 is obtained by adding a process of determining whether or not the counter of the control process has reached a predetermined reference value during steps S5 and S6 and between steps S7 and S8 in the flowchart of FIG. is there. Therefore, with respect to the same processing as that in the flowchart of FIG.

  If it is determined in step S5 of FIG. 7 that the distance L is equal to or less than the predetermined value N1, the process proceeds to step S5-1. In step S5-1, the counter variable C1 is set to “0”, and “1” is added to the counter variable C2. Thereafter, in step S5-2, a determination is made regarding the counter variable C2. As a result, when the counter variable C2 is equal to or greater than “5” (predetermined reference value), the process proceeds to step S6, and the headrest element 21 is moved to the arrow R until the distance L reaches the predetermined value N3 as described above. Move in the direction. If the counter variable C2 is less than “5”, the process is finished (returns) as it is.

  If it is determined in step S7 of FIG. 7 that the distance L is greater than or equal to the predetermined value N2, the process proceeds to step S7-1. Here, after “1” is added to the counter variable C1 and the counter variable C2 is set to “0”, the determination on the counter variable C1 is performed in step S7-2. As a result, when the counter variable C1 is “5” or more, the process proceeds to step S8, and the headrest element 21 is moved in the arrow F direction until the distance L reaches the predetermined value N3 as described above. Also in the determination result of step S7-2, when the counter variable C1 is less than “5”, the processing is finished as it is (returned).

  Therefore, according to the control flow shown in FIG. 7, the headrest element 21 is not moved in any direction of the arrows R and F unless the process is continuously counted five times or more. That is, control is performed so that the drive mechanism 30 is operated only when information for operating the headrest drive mechanism 30 is obtained a predetermined number of times within a predetermined time. As a result, the headrest element 21 does not move in response to the instantaneous movement of the head of the seat occupant H.

  When the vehicle is traveling backward, it is preferable that the headrest 20 is positioned rearward because it does not hinder driving in a turning posture. 6 and 7, when a reverse shift signal is detected, the headrest element 21 is moved in the direction of arrow R in FIG. 2 and held in the retracted position. Also, if the process of step S8 in FIGS. 6 and 7 is being performed, after the movement of the headrest element 21 is stopped, the headrest element 21 is quickly moved in the arrow R direction and held in the retracted position.

  FIG. 8 is a flowchart showing a control process for moving and adjusting the headrest 20 (headrest element 21) to the optimum position (position close to the head) with respect to the rear collision by the second control means 44B. In this drawing, N4 is a predetermined value L which is a predetermined distance L between the headrest 20 and the head of the seat occupant H, similarly to N1 to N3 in FIGS. 6 and 7, and is set to (N4 <N1). Yes. Further, the control process shown in FIG. 8 is executed alternately at predetermined time intervals with respect to the control process shown in FIG. 6 or FIG.

  In step ST1 shown in FIG. 8, it is determined whether or not a prediction signal is input from the collision prediction means 43. If there is no prediction signal based on this determination result, the processing is terminated as it is (returned). On the other hand, when the prediction signal is input, the process proceeds to step ST2, and a signal for moving the headrest 20 (headrest element 21) in the direction of arrow F (forward direction) in FIG. To do.

  Subsequently, in step ST3, it is determined whether or not the distance L is a predetermined value N4 or less. If the distance L is equal to or less than the predetermined value N4 as a result of the determination, the process proceeds to step ST4, a signal for stopping the operation of the drive mechanism 30 is transmitted, the movement of the headrest 20 (headrest element 21) is stopped, and the process is finished. (Return) If it is determined in step ST3 that the distance L exceeds the predetermined value N4, the process is finished (returns) as it is.

  According to the headrest control device in the present embodiment, the headrest element 21 is moved by the first control means 44A in the normal state so that the distance L between the headrest 20 and the head of the seat occupant H is about N3. It is controlled and the headrest 20 is held at an appropriate position. When the prediction signal from the collision predicting means 43 is detected, the second control means 44B moves the headrest element 21 from the front and rear position where the distance L is N3 toward the head of the seated person H. For this reason, the headrest 20 (headrest element 21) can be moved to the optimum position where the distance L is N4 in a short time. As a result, when a rearward collision is predicted, a countermeasure for reducing the burden on the neck of the seated person at the time of the collision is quickly performed.

  As described above, since the headrest 20 can be moved to the optimum position in a short time, the detection timing by the collision predicting means 43 can be set immediately before the collision from 1.0 seconds before the collision to 0.5 seconds before the collision. It becomes possible. Furthermore, as described above, the collision prediction means 43 can be replaced with a collision sensor (not shown). In that case, in step ST1 of FIG. 8, instead of the prediction signal from the collision prediction means 43, the determination is based on the signal from the collision sensor. On the other hand, when the detection timing by the collision predicting means 43 is set to about 1.0 seconds before the previous collision, the moving speed of the headrest element 21, that is, the operating speed of the drive mechanism 30 can be low, and the motor of the electric unit 38 38a can be reduced in capacity.

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, in the above description, the headrest element 21 that is a part of the headrest 20 is moved. However, depending on the type of the headrest 20 or the drive mechanism 30, the headrest 20 itself can be moved and controlled.
Further, the control shown in the flowchart of FIG. 8 can be executed by interrupt processing for the control shown in the flowchart of FIG. 6 or FIG.

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 Explanatory drawing which shows the distance of a headrest and a seat seated person's head One flowchart showing a control process for moving and adjusting the headrest to an appropriate position Another flowchart showing a control process for moving and adjusting the headrest to an appropriate position Flow chart showing control processing for moving and adjusting headrest to optimum position

Explanation of symbols

10 seat 20 headrest 30 headrest drive mechanism 40 headrest sensor (distance detection means)
43 Collision prediction means (collision detection means)
44 control means 44A first control means 44B second control means H seat occupant L distance

Claims (2)

A headrest driving mechanism capable of moving the headrest of the vehicle seat in the front-rear direction, distance detection means capable of detecting the distance between the head of the seat occupant and the headrest in the moving direction of the headrest, and a collision or collision A headrest control device comprising: a collision detection unit capable of detecting a prediction; and a control unit that operates the headrest drive mechanism to control the distance between the head of the seated occupant and the headrest,
The control means includes a first control means for performing control for operating the headrest drive mechanism based on a detection signal from the distance detection means, and the headrest drive mechanism based on a detection signal from the collision detection means. and a second control means for performing control for actuating the, in normal times, always possible deal with the headrest to the rear collision of the vehicle by operating the headrest driving mechanism by said first control means is set to move to a predetermined position, the sheet from the prediction when a signal is detected, the predetermined position the headrest by operating the headrest driving mechanism by said second control means from said collision detecting means A headrest control device set to move to a close position close to the head of the seated person. The headrest control device according to claim 1,
The control for moving the headrest to a predetermined position capable of coping with a rear collision of the vehicle by the first control means is whether the distance between the head of the seat occupant and the headrest is within a predetermined value range. The headrest control device is set to move the headrest only when the distance is measured a plurality of times and it is continuously measured that the distance is outside the range of the predetermined value for a predetermined number of times or more.

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