JP2005253867A - Vehicle seat - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle seat which reduces movement of a occupant to the right and left by increasing friction between the occupant and the seat back when acceleration in a lateral direction is generated. <P>SOLUTION: The seat is provided with a seat cushion mounted on the vehicle and the upper part and lower part of the seat back fitted so as to be reclined with respect to the seat cushion. The relative angles of the upper part and lower part of the seat back are variable. Then, the seat is provided with: a seat drive judging part 102 for controlling an angle formed by the seat cushion and the seat back and an angle formed by the lower part and the upper part of the seat back; and a lateral direction acceleration detection means 115 for detecting acceleration in a lateral direction acting on the vehicle. According to the acceleration in the lateral direction obtained by the detection means 115, the angle formed by the seat cushion and the seat back and the angle formed by the lower part and the upper part of the seat back are adjusted to increase the friction between the occupant and the seat back. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a vehicle seat, and more particularly to a technique for reducing occupant fatigue when lateral acceleration occurs.

As a conventional vehicle seat, for example, as described in JP-A-5-229372 (Patent Document 1), the side support can be made variable according to the acceleration in the lateral direction of the vehicle, or JP-A-3-32943. As described in (Patent Document 2), a method of tilting the entire sheet is known. Furthermore, as described in JP-A-6-277126 (Patent Document 3), a folded sheet in which a seat back is divided into two is known.
Japanese Patent Laid-Open No. 5-229372 JP-A-3-32943 JP-A-6-277126

  However, in such a conventional vehicle seat, by adding a support mechanism corresponding to the lateral acceleration in addition to the seat original adjustment mechanism, the seat weight increases or the mechanism becomes complicated. There is a problem.

  In addition, in a folding seat that does not perform control according to acceleration, when lateral acceleration acts on the vehicle, the occupant tilts to the left and right, causing a sense of incongruity in driving operation and at the same time the body resists acceleration. In order to maintain the posture, there is a problem that fatigue of the trunk increases.

  In order to achieve the above object, the present invention includes a seat cushion mounted on a vehicle, and a seat back that is tiltably attached to the seat cushion, and the seat back has a variable relative angle. In a vehicle seat divided into a lower back portion and an upper seat back portion, a control means for controlling an angle formed by the seat cushion and the seat back and an angle formed by the lower seat back portion and the upper seat back, and acting on the vehicle Lateral acceleration acquisition means for acquiring lateral acceleration, and an angle formed by the seat cushion and the seat back according to the magnitude of the lateral acceleration obtained from the lateral acceleration acquisition means, and The angle formed between the lower part of the seat back and the upper part of the seat back is adjusted, and the friction between the occupant and the seat back is adjusted. And wherein the increasing force.

  In the vehicle seat according to the present invention, when the lateral acceleration detecting means detects the occurrence of the lateral acceleration exceeding a predetermined level, the seat back is driven by driving the seat back, the seat cushion, or the seat belt. Since the dynamic friction force between the passenger and the occupant can be increased, the movement of the occupant in the left-right direction can be suppressed, the posture can be easily maintained, and fatigue of the trunk of the occupant can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a vehicle seat according to the first embodiment of the present invention. The vehicle seat 100 controls a seat belt, an upper seat back, a lower seat back, and a seat cushion of a seat mounted on the vehicle in accordance with lateral acceleration acting on the vehicle from the lateral direction. As shown in FIG. 1, a seat belt drive control unit 112 that controls driving of the seat belt, a seat back upper drive control unit 109 that controls driving of the upper portion of the seat back, and a seat that controls driving of the lower portion of the seat back. A lower back drive control unit 106 and a seat cushion drive control unit 103 that controls the drive of the seat cushion are provided.

  Further, the seat belt state detecting means 113 for detecting the state of the seat belt and outputting the detection data to the seat belt drive control unit 112, and detecting the state of the upper portion of the seat back and detecting the detected data as the seat back upper drive control unit. 109, a seat back upper state detecting means 110 for outputting to 109, a seat back lower state detecting means 107 for detecting the state of the lower seat back and outputting this detection data to the lower seat back drive control unit 106, and the state of the seat cushion. Seat cushion state detection means 104 that detects and outputs the detection data to the seat cushion drive control unit 103 is provided.

  Further, a seat belt driving unit 114 that drives the seat belt under the control of the seat belt driving control unit 112, a seat back upper driving unit 111 that drives the upper portion of the seat back under the control of the seat back upper driving control unit 109, and a seat A lower seat back driving means 108 for driving the lower seat back under the control of the lower back drive control section 106 and a seat cushion driving means 105 for driving the seat cushion under the control of the seat cushion drive control section 103 are provided.

  Further, a lateral acceleration detection means (lateral acceleration acquisition means) 115 for detecting a lateral acceleration generated in the vehicle, and a current seat state, that is, a seat belt, a seat back upper part, a seat back lower part, and a seat cushion state A sheet state storage means 116 for storing the sheet and a sheet drive calculation unit 101 for calculating the driving amount of the sheet. Further, the sheet drive calculation unit 101 determines the sheet drive based on the lateral acceleration and the sheet state. Is provided with a sheet drive determination unit (control means) 102 that outputs a command signal regarding the drive amount of the sheet obtained in step S1 to each drive control unit 112, 109, 106, 103.

  Next, the operation of the vehicle seat according to the present embodiment as described above will be described with reference to the flowchart shown in FIG. 2 and the mechanism operation conceptual diagram shown in FIG.

  First, at the time of normal boarding, in step S20, the driver creates a driving posture based on the sense of the individual so as to be optimized in driving on a general road. At this time, as shown in FIG. 3A, the normal driver is in the driving posture without making the relative relationship between the seat back upper portion 12 and the seat back lower portion 11 bend. The sheet setting at this time is stored in the sheet state storage unit 116.

  Next, the vehicle enters the running state, and the lateral acceleration detected by the lateral acceleration detection means 115 installed in the vehicle in the process of step S21 is predetermined by the seat drive determination unit 102. If it is determined that the value exceeds the value, the process proceeds to steps S22, S25, and S28.

  That is, in the process of step S22, the seat back lower state detection unit 107 and the seat back upper state detection unit 110 detect the upper and lower states of the seat back. Further, in step S24, an instruction signal corresponding to the drive amount is output to the seat back upper drive means 111 and the seat back lower drive means 108 by each drive control unit 109, 106, and the seat back upper part And drive the lower part.

  In step S25, the seat cushion state detection means 104 detects the state of the seat cushion, and in step S26, the seat drive calculation unit 101 determines the driving amount of the seat cushion. In step S27, Then, an instruction signal corresponding to the driving amount is output to the seat cushion driving means 105 by the seat cushion driving control unit 103 to drive the seat cushion.

  On the other hand, in the process of step S28, the upper and lower states of the seat belt are detected by the seat belt state detecting means 113, and the driving amount of the seat belt is determined by the seat drive calculation unit 101 by the process of step S29. In step S30, the seat belt drive controller 112 outputs an instruction signal corresponding to the drive amount to the seat belt drive means 114 to drive the seat belt.

  Hereinafter, specific operations of the processes in steps S22 to S24, steps S25 to S27, and steps S28 to S30 described above will be described as examples.

[First embodiment]
In the processes of steps S22 to S24, the seat back lower portion 11 is tilted rearward with respect to the seat back upper portion 12, thereby making the seat back in a folded state and increasing the frictional force of the occupant against the seat back, thereby increasing the lateral acceleration. Suppresses left and right movement of occupants during occurrence

[Second Embodiment]
In the processes of steps S22 to S24, the seat back upper portion 12 is tilted forward with respect to the seat back lower portion 11, thereby making the seat back in a folded state and increasing the frictional force of the occupant against the seat back, thereby increasing the lateral acceleration. Suppresses left and right movement of occupants during occurrence

[Third embodiment]
In the processes of steps S22 to S24, the entire seat back is tilted backward while maintaining the relative angle between the seat back lower portion 11 and the seat back lower portion 12 that is set to a reclining angle set in advance. As a result, the occupant is inclined backward, and the weighted share of the seat back is greater than that during normal driving (when the vehicle is not tilted backward). As a result, the reaction force of the seat back increases and the seat back increases. The dynamic friction force between the passenger and the passenger increases. In addition, by taking a leaning posture, the center of gravity position of the occupant's upper body is relatively closer to the seatbone, the moment arm of the inertial force generated by the lateral acceleration is reduced, and the occupant is affected by the inertial force. It becomes difficult to receive. Therefore, the lateral movement of the occupant when the lateral acceleration occurs can be suppressed.

[Fourth embodiment]
In the processing of steps S25 to S27, the support provided at the lower portion of the seat cushion 13 is driven by the seat cushion driving means 105, and tilted so that the front side of the seat cushion 13 moves upward. Thereby, the seat bone position of the occupant is fixed with respect to the front-rear direction of the seat, and the lateral movement of the occupant's buttocks with respect to the seat can be suppressed when lateral acceleration occurs.

  FIG. 3B shows a state in which the seat back is tilted backward and the seat cushion 13 is tilted by performing the processing of the third embodiment and the processing of the fourth embodiment.

[Fifth embodiment]
In the processes of steps S28 to S30, the seat belt is driven in the retracting direction by a predetermined amount. As a result, the seat and the occupant are more improved in adhesion than in normal traveling, and the seat reaction force is increased. For this reason, the dynamic friction force is further increased, and it can be made difficult to be affected by the inertial force in the lateral direction.

  Thereafter, if it is determined in step S31 in FIG. 2 that the lateral acceleration obtained by the lateral acceleration detecting means 115 has decreased to the predetermined value or less, the seat belt is stored in advance in step S32. The seat cushion is returned to the original state in step S33, and the upper and lower portions of the seat back are returned to the original state in step S34.

  Next, in the control flow described above, the drive control units 103, 106, 109, and 112 of the seat cushion, the upper and lower portions of the seat back, and the seat belt drive the respective driving means 105, 108, 111, and 114. The processing flow when performing the drive control upon receiving the signal of each state detection means 104, 107, 110, 113 will be described with reference to the flowchart shown in FIG.

  First, in step S40, target values for the state after driving when driving the sheet to the state of the sheet at the time of occurrence of lateral acceleration are set in the driving control units 103, 106, 109, 112, and the driving means 105, Drive signals are output to 108, 111 and 114. At this time, the driving means 105, 108, 111, and 114 are operated in the process of step S41, and the state detection values are constantly monitored by the state detection means 104, 107, 110, and 113 in step S42. Drive until the target value is reached. This process is common to all the drive control units 103, 106, 109, and 112 in this embodiment.

  Next, the relationship between the reclining angle of the seat back and the frictional force will be described. Here, for the purpose of conceptualization, a case where there is no folded state will be described as an example.

  As shown in FIG. 6, when sitting in a normal posture on a seat back inclined at a reclining angle θ, the weight of the upper body Mg is the vertical reaction force Fc from the seat cushion and the vertical reaction force of the seat back. Supported by Fb. That is, Mg = Fc + Fb.

  At this time, the normal component of the seat back reaction force is Fb · cos θ, and the maximum static frictional force of the upper body is μ × Fb · cos θ, where μ is the coefficient of friction between the seat and the occupant.

  If the reclining angle is reclined to θ−Ψ, the weight distribution of the seat back and the seat cushion is closer to the seat back, and the weight of the upper body W is closer to the seat back. The dead weight W is a vertical reaction force (Fc + FΨ) · cos (θ−Ψ) from the seat cushion, and when deformed, the following expression (1) is established.

(Fc + FΨ) .cos (θ−Ψ) = (Fc + FΨ) × (cosθcosΨ + sinθsinΨ)
... (1)
At this time, since both θ and Ψ are obviously π / 2 (= 90 °) or less, all the trigonometric function components are positive, so the perpendicular component of the seat back reaction force increases. Therefore, the maximum static frictional force of the upper body is μ × (Fb + FΨ) × (cosθcosΨ + sinθsinΨ), and increases with a trigonometric function as a component, and thus increases nonlinearly. As a result, a characteristic curve as shown in FIG. 7 is obtained, and it is understood that the frictional force increases as the reclining angle increases.

  Next, the relationship between the acceleration generated in the lateral direction and the required reclining angle will be described. Now, it is assumed that the lateral acceleration α acts on the occupant due to turning or the like. At this time, as shown in FIG. 8, an inertial force Mα proportional to the weight M of the occupant's upper body acts. On the other hand, the state where the occupant does not move on the seat back is when the relationship expressed by the following equation (2) is established between the occupant and the static friction force.

Mα <μ × Fb · cosθ (2)
Therefore, the required friction coefficient varies depending on the strength of the lateral acceleration, and the necessary friction force increases nonlinearly with respect to the reclining angle. Therefore, the relationship between the lateral acceleration and the required reclining angle is also nonlinear. A characteristic curve as shown in FIG. 9 is obtained. From this result, it is understood that the reclining angle required to maintain the state increases as the lateral acceleration increases. In the above-described third example of the present embodiment, the seat back is tilted backward using this relational expression so as to reduce the driver's left-right movement with respect to the occurrence of lateral acceleration.

  As described above, in the vehicle seat according to the present embodiment, the influence of the lateral inertia force received by the occupant is minimized, so that the occupant appropriately performs the driving operation even when the lateral acceleration acts on the vehicle. This eliminates the need to use muscular strength that resists inertial force, thus enabling driving with less fatigue.

  In addition, by driving the seat cushion, upper and lower seat backs, and the seat belt against the inertia force generated by the lateral acceleration acting on the vehicle, the friction force between the passenger and the seat is increased and the inertia force is increased. By making the moment arm smaller, it is possible to provide a proper driving operation and a driving posture with less fatigue by minimizing the relative lateral movement of the passenger with respect to the seat.

  That is, in the vehicle seat according to the present invention, when the occurrence of lateral acceleration exceeding a predetermined level is detected by the lateral acceleration detection means, by driving the seat back, the seat cushion, or the seat belt, Since the dynamic friction force between the seat back and the occupant can be increased, the movement of the occupant in the left-right direction can be suppressed, the posture can be easily maintained, and fatigue of the trunk of the occupant can be reduced. it can.

  Furthermore, in the first embodiment described above, the lower part of the seat back is tilted backward with respect to the upper part of the seat back, so that the frictional force between the occupant and the seat back can be increased, and the lateral movement of the occupant with respect to the seat is suppressed. Therefore, fatigue of the trunk of the occupant can be reduced.

  In the second embodiment, since the upper part of the seat back is tilted forward with respect to the lower part of the seat back, the frictional force between the occupant and the seat back can be increased, and the lateral movement of the occupant with respect to the seat is suppressed. Therefore, fatigue of the trunk of the occupant can be reduced.

  Furthermore, in the third embodiment, the entire seat back is tilted backward while maintaining the reclining angle between the seat back lower portion and the seat back upper portion, so that the frictional force between the occupant and the seat back can be increased. Since the lateral movement of the occupant relative to the seat can be suppressed, fatigue of the trunk of the occupant can be reduced. In the third embodiment, the length of the moment arm with respect to the buttocks at the center of gravity of the occupant's upper body can be shortened, so that the lateral movement of the occupant relative to the seat can be further suppressed.

  Further, in the fourth embodiment, the seat cushion is tilted by driving the support provided at the lower portion of the seat cushion, and the seat bone position of the occupant is fixed in the front-rear direction of the seat. It can be suppressed and fatigue of the trunk of the occupant can be reduced.

  Furthermore, in the fifth embodiment, since the tension of the seat belt is increased when the lateral acceleration occurs, the adhesion between the occupant and the seat back becomes stronger, and accordingly, the frictional force between the occupant and the seat back is increased. Since it can be increased and the lateral movement of the occupant relative to the seat can be suppressed, fatigue of the trunk of the occupant can be reduced.

  In the fifth embodiment described above, a method of increasing the dynamic friction force generated between the seat and the occupant by increasing the reaction force generated between the seat and the occupant by tightening the seat belt more strongly when the lateral acceleration occurs. It was adopted. Here, since the friction force changes in proportion to the reaction force and the friction coefficient, the same effect can be obtained also by changing the friction coefficient of the sheet skin. Specifically, it is possible to increase the coefficient of friction in the left-right direction by causing the raising direction of the skin material to flow in the left-right direction from the center of the seat. It is possible to obtain the effect of suppressing the fatigue of the trunk of the occupant.

  In the present embodiment, the lateral acceleration acting on the vehicle is detected by the lateral acceleration detecting means 115 installed in the vehicle in advance. However, the lateral acceleration generated by driving is determined by the vehicle speed and the steering of the steering wheel. It depends on the speed and vehicle characteristics specific to each car.

  Therefore, as shown in FIG. 5, if the relationship between the vehicle speed and the steering speed is obtained in advance, the control start limit curve of the lateral acceleration is predetermined based on the mutual relationship, and the control effective area is set, the lateral acceleration is obtained. The same process as described above can be performed without using the detection means 115, and the same effect can be obtained.

  Even when lateral acceleration occurs in the vehicle, it is extremely useful because it can be fixed to the seat without imposing a burden on the passenger.

It is a block diagram which shows the structure of the vehicle seat which concerns on one Embodiment of this invention. It is a flowchart which shows operation | movement of the vehicle seat which concerns on one Embodiment of this invention. It is explanatory drawing which shows the state of a sheet | seat, (a) shows a normal state, (b) shows the state at the time of lateral acceleration generation | occurrence | production. It is a flowchart which shows the processing operation in each drive control part. It is a characteristic view used when estimating the magnitude | size of a lateral acceleration from the relationship between a vehicle speed and a steering speed. It is explanatory drawing which shows the relationship between a reclining angle and frictional force when a passenger | crew seated on the seat. It is a characteristic view which shows the relationship between a reclining angle and a frictional force. It is explanatory drawing which shows the relationship between a passenger | crew's own weight and the inertial force which acts on a horizontal direction. It is a characteristic view which shows the relationship between the lateral direction acceleration which acts on a passenger | crew, and a required reclining angle.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Seat back lower part 12 Seat back upper part 13 Seat cushion 101 Seat drive calculating part 102 Seat drive judgment part (control means)
DESCRIPTION OF SYMBOLS 103 Seat cushion drive control part 104 Seat cushion state detection means 105 Seat cushion drive means 106 Seat back lower part drive control part 107 Seat back lower part state detection means 108 Seat back lower part drive means 109 Seat back upper part drive control part 110 Seat back upper part state detection Means 111 Seat lower upper drive means 112 Seat belt drive control unit 113 Seat belt state detection means 114 Seat belt drive means 115 Lateral acceleration detection means (lateral acceleration acquisition means)
116 Sheet state storage means

Claims (9)

A seat cushion mounted on a vehicle, and a seat back that is attached to the seat cushion so as to be tiltable. The seat back is divided into a seat back lower portion and a seat back upper portion having a variable relative angle. In vehicle seats,
Control means for controlling an angle formed by the seat cushion and the seat back and an angle formed by the lower seat back and the upper seat back;
Lateral acceleration acquisition means for acquiring lateral acceleration acting on the vehicle,
Adjusting the angle between the seat cushion and the seat back and the angle between the lower seat back and the upper seat back according to the magnitude of the lateral acceleration obtained from the lateral acceleration acquisition means, A vehicle seat characterized by increasing a frictional force with the seat back.   The vehicle according to claim 1, wherein the control unit increases a frictional force between an occupant and the upper portion of the seat back by tilting the lower portion of the seat back with respect to the upper portion of the seat back. Sheet.   The vehicle according to claim 1, wherein the control unit increases a frictional force between an occupant and the upper part of the seat back by tilting the upper part of the seat back forward with respect to the lower part of the seat back. Sheet.   The control means increases the frictional force between the occupant and the seat back by tilting the reclining angle of the entire seat back backward while maintaining the relative angle between the upper portion of the seat back and the lower portion of the seat back. The vehicle seat according to claim 1.   The vehicular seat according to any one of claims 1 to 4, wherein a frictional force increasing means for improving a frictional force between the seat back and an occupant is provided.   6. The vehicle seat according to claim 5, wherein the frictional force increasing means is a seat skin that is provided on the surface of the seatback and has a friction coefficient in the left-right direction larger than a friction coefficient in the vertical direction by raising.   The frictional force increasing means is a seat belt, and when the lateral acceleration occurs, the occupant and the occupant are tightened to the seat back side with a predetermined tension set in advance. 6. The vehicle seat according to claim 5, wherein a frictional force between the seat back and the seat back is increased.   The control means changes the relative position of the occupant trunk to the buttocks by changing the posture of the occupant by driving the seat back, and adjusts the length of the moment arm with respect to the heel of the occupant's upper body center of gravity. The vehicle seat according to claim 1. The control means drives a support body provided at a lower portion of the seat cushion to generate a lateral acceleration, and fixes the seat bone position of the occupant in the front-rear direction of the seat. The vehicle seat described in 1.

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