JP2014139069A - Power seat device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power seat device capable of reducing accumulation of fatigue of a person seated for a long time by using a method different from massaging.SOLUTION: A power seat device includes: a power seat that includes attitude changing mechanisms 14 to 20 for changing an attitude of a seated person depending on an increase/decrease of a pressure applied to the seated person; and a control device 21 controlling the attitude changing mechanisms 14 to 20. The control device 21 switches an attitude constraint state in which the pressure applied from the attitude changing mechanisms 14 to 20 to the seated person is set to a pressure other than zero to/from an attitude relaxing state in which the pressure applied to the seated person is set to a pressure lower than the pressure applied in the attitude constraint state. Furthermore, each of the states is kept at least for one minute.

Description

  The present invention relates to a power seat device including a power seat, and the power seat has a posture change mechanism that changes the posture of the seated person by increasing or decreasing the pressure applied to the seated person.

  Examples of the seat posture changing mechanism include a reclining mechanism, a seating surface tilting mechanism, an ottoman tilting mechanism, a rear upper tilting mechanism, a lumbar support, a rear side support, and a seating side support. There is a power seat that drives these posture changing mechanisms using a driving device such as a motor. For example, Patent Documents 1 to 4 describe devices that drive a lumbar support. Patent Document 1 describes that the lumbar plate is moved back and forth periodically or aperiodically to reduce the fatigue of the seated person.

  Patent Documents 5 to 7 describe that the posture of a seated person, the degree of fatigue, the degree of arousal, and the like are detected based on the body pressure distribution on the seat seat surface or the seat back surface. Furthermore, Patent Document 7 describes that the sheet shape is changed so as to correspond to a fatigue site.

  Further, Patent Document 8 quantitatively calculates the degree of fatigue of a seated person using an arithmetic expression determined by a statistical method based on the amount of deflection at the lower part of the back of the seat and the downward load on the seat seat surface. It is described to do. Patent Document 9 describes a capacitive sensor formed of an elastomer. Further, Non-Patent Document 1 describes a fatigue evaluation method.

JP-A-5-168545 Japanese Patent Laid-Open No. 61-257333 JP 9-37891 A JP-A-64-44355 JP 11-326084 A JP 2002-8159 A Japanese Examined Patent Publication No. 6-55577 Japanese Patent No. 4216546 Japanese Patent No. 4565359

“Development of simple evaluation method for long-term differential fatigue using fingertip volume pulse wave information”, Ergonomics, Vol. 40, no. 5, pp. 254-263 (2004)

  By the way, the fatigue of the seated person can be reduced by performing massage on the seated person. Patent Document 1 corresponds to a so-called massage function because the lumbar support is moved back and forth at short intervals. However, for example, when applied to a driver's seat of a vehicle, there is a driver who does not want to change the seat shape in a short time during driving.

  Therefore, an object of the present invention is to provide a power seat device that can apply a technique different from massage and reduce accumulation of fatigue of a seated person for a long time.

  The power seat device according to this means includes a power seat having a posture changing mechanism that changes the posture of the seated person by increasing or decreasing the pressure applied to the seated person, and a control device that controls the posture changing mechanism. The control device switches between a posture constraint state in which the applied pressure to the seated person by the posture change mechanism is a pressure other than zero and a posture relaxation state in which the applied pressure is lower than the applied pressure in the posture constraint state, For at least 1 minute.

  In this way, the posture is changed with respect to the seated person by switching between the posture constraint state and the posture relaxation state. However, instead of switching the state in 10 seconds or less like a massage, each state is held for 1 minute or longer. By holding the applied pressure at a high level for 1 minute or longer, the seated person obtains a sense of restrained posture. This sensation approximates a sensation like posture correction and is completely different from a sensation like massage.

  Here, it is said that humans are less likely to get tired when the spine is in an inverted S shape like when standing. Therefore, the lumbar support presses the lumbar spine so that the seated person's spine has an inverted S-shape. That is, by holding the posture restrained state with a lumbar support or the like, the posture of the seated person can be made to be less fatigued. However, it has been found that fatigue increases when sitting in a posture-constrained state for a long time. Therefore, instead of continuing the posture restrained state, switching between the posture restrained state and the posture relaxed state can reliably reduce the accumulation of fatigue of the seated person for a long time.

<Embodiment>
Here, the suitable embodiment of the power seat apparatus which concerns on this means is demonstrated below. That is, the power seat device according to the present means is not limited to the following preferred modes.

  The control device may hold the posture constraint state and the posture relaxation state for 5 minutes or more and 24 minutes or less, respectively. Here, it was found that the effect of reducing the accumulation of fatigue can be obtained at the moment of changing from the posture restrained state to the posture relaxed state and the moment of changing from the posture relaxed state to the posture restrained state. Therefore, by setting each state to 5 minutes or more, the seated person can be surely affected by the change from the posture restrained state to the posture relaxed state and the change from the posture relaxed state to the posture restrained state. Can do. As a result, the effect of reducing the accumulation of fatigue can be reliably exhibited. In addition, by setting the posture restraint state within 24 minutes, it is possible to reduce the adverse effect of the posture restraint state continuing for a long time. Furthermore, by setting the posture constraint state and the posture relaxation state within 24 minutes, the number of changes between the posture constraint state and the posture relaxation state can be sufficiently obtained. As a result, the effect of reducing the accumulation of fatigue can be reliably exhibited.

  In addition, the control device may set the holding time of the posture restrained state and the holding time of the posture relaxed state to 5 minutes or more and within 24 minutes, and set the holding time of the posture restricted state to be longer than the holding time of the posture relaxed state. Thereby, the effect of reducing the accumulation of fatigue can be reliably exhibited.

  Moreover, the said control apparatus is good to switch the state of the said attitude | position change mechanism at the timing of the predetermined time. This facilitates the setting of the control device.

  The power seat device further includes a load sensor that detects a load distribution on at least one of a seating surface and a back surface of the power seat, and the control device is configured to perform the posture change mechanism based on the load distribution. The posture restraint state or the posture relaxation state may be made different. Thereby, according to a seated person, a posture restraint state or a posture relaxation state can be varied. As a result, it is possible to obtain an appropriate fatigue reduction effect corresponding to the seated person.

  Further, the load sensor detects a load distribution on the back surface of the power seat, the posture changing mechanism is any one of a lumbar support, a back side support, and a back upper tilt mechanism, and the control device Based on this, it is preferable that the posture restraint state is varied by adjusting the position where the posture change mechanism functions. As a result, any of the lumbar support, the rear side support, and the rear upper tilt mechanism can surely obtain the effect of reducing the accumulation of fatigue of the seated person.

Moreover, the said control apparatus is good to adjust the position which the said attitude | position change mechanism functions based on the seated person's physique information obtained by the said load distribution in the back surface of the said power seat. Thereby, the effect of reducing the accumulation of fatigue of the seated person can be obtained with certainty.
For example, the controller changes the posture changing mechanism based on the physique information, the length from the lumbar spine to the shoulder, the lumbar spine height, and the lateral width of the load range obtained from the load distribution on the back surface of the power seat. It is recommended to adjust the functioning position. Thereby, the effect of reducing the accumulation of fatigue of the seated person can be obtained with certainty.

  Further, the load sensor detects a load distribution on the seat surface of the power seat, the posture changing mechanism is a seat surface side support, and the control device functions as the seat surface side support based on the load distribution. It is preferable to change the posture restraint state by adjusting the position to be changed. Thereby, the seat surface side support can surely obtain the effect of reducing the accumulation of fatigue of the seated person.

Moreover, the said control apparatus is good to adjust the position which the said seat surface side support functions based on the seated person's physique information obtained by the said load distribution in the seat surface of the said power seat. Thereby, the effect of reducing the accumulation of fatigue of the seated person can be obtained with certainty.
For example, the control device, based on the physique information, the position of the center of gravity of the load obtained from the load distribution on the seat surface of the power seat, the size of the buttock, and the position of the buttock in the front-rear direction It is recommended to adjust the functioning position of the surface side support. Thereby, the effect of reducing the accumulation of fatigue of the seated person can be obtained with certainty.

  Further, the posture change mechanism is any one of a reclining mechanism, a seating surface tilt mechanism, and an ottoman tilt mechanism, and the control device applies an applied pressure between the posture constraint state and the posture relaxation state based on the load distribution. It is preferable to vary the posture relaxation state by varying the amount of change of. Thereby, the effect of reducing the accumulation of fatigue of the seated person can be obtained with certainty.

  Moreover, the said control apparatus is good to vary the variation | change_quantity of the applied pressure of the said attitude | position restraint state and the said attitude | position relaxation state based on the ratio of the load in the seat surface of the said power seat, and the load in a back surface. Thereby, the reduction effect of accumulation | storage of suitable fatigue according to a seated person's physique can be acquired.

  The control device may determine whether or not the posture change mechanism can be driven based on a sum of a load on the seating surface and a load on the back surface of the power seat. Accordingly, the posture changing mechanism can be driven for the seated person who can reduce the accumulation of fatigue by driving the posture changing mechanism according to the physique of the seated person.

  The power seat device further includes a load sensor that detects a load distribution on at least one of a seating surface and a back surface of the power seat, and the control device switches between a posture constraint state and a posture relaxation state based on the load distribution. You may do it. By grasping the change of the load distribution, the fatigue progress of the seated person can be predicted. Thereby, it is possible to optimally adjust the drive timing of the posture changing mechanism, and to more effectively reduce the accumulation of fatigue in a long-time seated person.

  The load sensor detects the load for each section when the installation surface is partitioned into a plurality of sections, and the control device switches between the posture restrained state and the posture relaxed state based on the time change of the load for each section. May be. It can be predicted that fatigue is progressing in the corresponding section of the seated person as the time change of the load for each section is larger. Accordingly, it is possible to optimally adjust the drive timing of the posture change mechanism and to reliably reduce the accumulation of fatigue in a long-time seated person.

  The load sensor detects the load distribution for each section when the installation surface is partitioned into a plurality of sections, and the control device calculates the load center of gravity for each section based on the load distribution for each section, and the load for each section. Based on the center of gravity, the posture constraint state and the posture relaxation state may be switched. A change in the center of gravity of the load in the section means that the posture of the seated person has changed. The degree of fatigue of the seated person or the progress of fatigue can be predicted from the change in posture. Therefore, it is possible to optimally adjust the drive timing of the posture change mechanism and reduce the accumulation of fatigue in a long-time seated person.

  The power seat may include a plurality of posture change mechanisms, and the control device may control the posture change mechanism set according to the load distribution detected by the load sensor. Based on the load distribution detected by the load sensor, it is possible to predict in which part of the seated person the fatigue is accumulated or is likely to be accumulated. Further, the power seat is provided with a plurality of posture change mechanisms. Therefore, by driving each posture changing mechanism in accordance with the fatigued part of the seated person, it is possible to effectively reduce the accumulation of fatigue on the fatigued part.

  Further, the load sensor should be formed into a planar shape with an elastomer, be able to measure the load distribution, and be stretchable and deformable in the surface tangential direction. The epidermis of the power seat is deformed according to the change in the posture of the seated person. Therefore, by forming the load sensor so as to be stretchable and deformable in the surface tangential direction with the elastomer, it is possible to follow the deformed shape of the skin of the power seat. That is, since the load sensor can be prevented from slipping in the surface direction of the seat, the detection position can be prevented from changing. At the same time, since the load sensor can follow the deformed shape of the skin of the power seat, a natural seating posture can be provided without giving the seated person an uncomfortable feeling based on the presence of the load sensor. As a result, information dependent on the position to be detected, for example, time variation of the load, the center of gravity of the load, etc. can be detected with high accuracy. Therefore, it is possible to predict the accumulation of fatigue of the seated person with high accuracy.

  If the load sensor is made of a thermoplastic resin or a thermosetting resin, it cannot follow the deformed shape of the skin of the power sheet because it does not have flexibility of expansion and contraction. As a result, the seated person feels uncomfortable (for example, a feeling of tension), which not only makes the seat uncomfortable, but also becomes a restraining factor for the deformation of the skin of the power seat and cannot provide a natural seating posture. Reduction is difficult to achieve.

  Further, the load sensor may be a capacitive sensor configured by a pair of electrodes formed of an elastomer and a dielectric layer formed of an elastomer interposed between the pair of electrodes. Thereby, a discomfort is not given to a seated person. In addition, even if the electrode formed with the elastomer expands and contracts, it is preferable that the change in conductivity of the electrode is small. Therefore, even when the seated person is seated and the power seat is deformed and the load sensor is stretched and deformed, the conductivity is good and the function as an electrode can be maintained. As a result, the capacitance can be measured with high accuracy, and as a result, the load distribution can be measured with high accuracy.

It is a figure which shows the power seat in 1st embodiment, and is a figure of the state which moved the lumbar support to the front side. It is a figure which shows the power seat in 1st embodiment, and is a figure of the state which moved the lumbar support to the back side. It is a control block diagram of a power seat device. It is a figure which shows the behavior at the time of changing the restraint degree of a lumbar support every 30 minutes. It is a figure which shows the behavior at the time of changing the restraint degree of a lumbar support every 5 minutes. It is a figure which shows the fatigue degree based on a fingertip volume pulse wave when the restraint degree of a lumbar support is made into the state shown to FIG. 1B. The result of having performed 3 times about the same subject is shown. It is a figure which shows the fatigue degree based on a finger tip volume pulse wave when operating a lumbar support as shown to FIG. 3A. The result of having performed 3 times about the same subject is shown. It is a figure which shows the fatigue degree based on a finger tip volume pulse wave when operating a lumbar support as shown to FIG. 3B. The result of having performed 3 times about the same subject is shown. It is a figure which shows each average value of FIG. 4A, FIG. 4B, and FIG. 4C. It is a figure shown about the other behavior of the restraint degree of a lumbar support. It is a figure which shows the fatigue degree based on a finger tip volume pulse wave when operating a lumbar support as shown to FIG. 6A. For another subject, when the degree of restraint of the lumbar support is zero, when it is changed every 5 minutes, when it is changed every 15 minutes, when it is changed every 30 minutes, the fingertip volume pulse It is a figure which shows the fatigue degree based on a wave. It is a figure which shows the fatigue degree based on the fingertip volume pulse wave at the time of changing the holding time of the restrained state of a lumbar support, and the holding time of a relaxation state with respect to another subject. It is a figure which shows the power seat in 2nd embodiment. It is a figure which shows the front view of the load sensor of FIG. It is sectional drawing of the load sensor of FIG. 10A. It is a control block diagram of a power seat device. It is a flowchart which shows the process of a control apparatus. It is a figure which shows load distribution of the load sensor of a back surface. It is a figure which shows the behavior of the X direction position of a load gravity center when the restraint degree of a lumbar support is made into the state shown to FIG. 1B. It is a figure which shows the behavior of the Y direction position of a load gravity center when the restraint degree of a lumbar support is made into the state shown to FIG. 1B. It is a figure which shows the behavior of the X direction position of a load gravity center when operating the restraint degree of a lumbar support as shown to FIG. 3A. It is a figure which shows the behavior of the Y direction position of a load gravity center when operating the restraint degree of a lumbar support as shown to FIG. 3A. It is a figure which shows the behavior of the X direction position of a load gravity center when operating the restraint degree of a lumbar support as shown in FIG. 3B. It is a figure which shows the behavior of the Y direction position of a load gravity center when operating the restraint degree of a lumbar support as shown in FIG. 3B. It is a figure which shows the power seat in 3rd embodiment. It is a control block diagram of a power seat device. It is a flowchart which shows the process of a control apparatus. It is a figure which shows the load distribution of the load sensor of a back surface immediately after an experiment start. It is a figure which shows the load distribution of the load sensor of a seat surface immediately after an experiment start. It is a figure which shows the load distribution of the load sensor of the back surface in the middle of experiment. It is a figure which shows the load distribution of the load sensor of the seat surface in the middle of experiment. It is a figure which shows the load distribution of the load sensor of a back surface just before completion | finish of experiment. It is a figure which shows the load distribution of the load sensor of the seat surface just before completion | finish of experiment. It is a flowchart which shows the process of the control apparatus in 4th embodiment. It is the figure which made the power seat and the lumbar support the first state. It is a figure which shows load distribution of the load sensor of a back surface. It is a figure which shows the load distribution of the load sensor of a seat surface. It is a figure which shows the behavior of the average pressure in division R11. It is a figure which shows the behavior of the average pressure in division R12. It is a figure which shows the behavior of the average pressure in division R13. It is a figure which shows the behavior of the average pressure in the division L11. It is a figure which shows the behavior of the average pressure in the division L12. It is a figure which shows the behavior of the average pressure in the division L13. It is the figure which made the power seat and the lumbar support the first state. It is a figure which shows load distribution of the load sensor of a back surface. It is a figure which shows the load distribution of the load sensor of a seat surface. It is a figure which shows the behavior of the average pressure in division R11. It is a figure which shows the behavior of the average pressure in division R12. It is a figure which shows the behavior of the average pressure in division R13. It is a figure which shows the behavior of the average pressure in the division L11. It is a figure which shows the behavior of the average pressure in the division L12. It is a figure which shows the behavior of the average pressure in the division L13. It is a figure which shows the power seat in 5th embodiment. It is a flowchart which shows the process of a control apparatus. It is a figure which shows load distribution of the load sensor of a back surface. It is a figure which shows the fatigue degree based on the finger plethysmogram when the provision pressure of a lumbar support is given to a comfortable height, and when it is given to an unpleasant height. It is a flowchart which shows the process of the control apparatus in 6th embodiment. It is a figure explaining the variation | change_quantity of a reclining angle.

<First embodiment>
(Description of power seat)
The power seat includes a posture change mechanism. The posture change mechanism changes the posture of the seated person by increasing or decreasing the pressure applied to the seated person. The posture changing mechanism includes a lumbar support, a reclining mechanism, a seating surface tilt mechanism, an ottoman tilt mechanism, a rear upper tilt mechanism, a rear side support, and a seating side support.

  The power seat according to the present embodiment will be described with reference to FIGS. 1A and 1B. The power seat is used for, for example, an automobile seat. Of course, it can also be applied to seats other than automobiles. Specifically, as shown in FIGS. 1A and 1B, the power seat includes a seat surface 11, a back surface 12, and a headrest 13. Furthermore, a lumbar support 14 as a posture changing mechanism is provided on the back surface 12. The lumbar support 14 can change the pressure applied to the seated person's waist according to the position in the front-rear direction. That is, as shown in FIG. 1A, when the lumbar support 14 is positioned on the front side, the seated person's lumbar spine is restrained. On the other hand, as shown in FIG. 1B, when the lumbar support 14 is positioned on the rear side, the restraint of the seated person's lumbar spine is relaxed.

  The power seat has a reclining mechanism, a seat tilt mechanism, an ottoman tilt mechanism, and a rear upper tilt mechanism as a posture change mechanism that changes the posture of the seat occupant by increasing or decreasing the pressure applied to the seat occupant. And a rear side support (a mechanism for tightening the side of the upper body of the seated person from the left and right), a side support for the seat (a mechanism for tightening the side of the lower body of the seated person from the left and right), and the like. However, in the present embodiment, the lumbar support 14 will be described as an example.

(Control block diagram of power seat device)
Next, a control block diagram of the power seat device will be described with reference to FIG. As shown in FIG. 2, the power seat device includes a control device 21 and a lumbar support 14 as a drive device 22. The control device 21 controls the drive device 22. Here, the control device 21 controls the position of the lumbar support 14 at a predetermined timing (sequential). Details will be described later.

(Experiment)
Next, in order to measure the fatigue level of the subject according to the position of the lumbar support 14, the following experiments 1 to 3 were performed. Here, the fatigue degree used the method of the nonpatent literature 1 mentioned above.

(Experiment 1)
In Experiment 1, the lumbar support 14 was positioned most rearward as shown in FIG. 1B, and the lumbar support 14 did not restrain the lumbar spine of the subject. In this state, the subject continues to sit on the power seat for 90 minutes, and using the driving simulator environment, the subject operates the steering wheel, accelerator, brake, etc. equivalent to the actual driving of the automobile, We performed an experimental run that simulated the running of In addition, the finger plethysmogram was measured. The degree of fatigue of the subject was calculated based on the measured fingertip volume pulse wave. Here, since the calculation of the fatigue level based on the fingertip volume pulse wave is well known, detailed description thereof is omitted. The above experiment was performed three times for the same subject.

(Experiment 2)
In Experiment 2, as shown in FIG. 3A, the lumbar support 14 is in a state of a restraint degree of 0.7 (the state shown in FIG. 1A) for the first 30 minutes and in an unconstrained state (shown in FIG. 1B) for the next 30 minutes. State (described as 0 state), and the last 30 minutes is a state with a constraint degree of 0.5 (a state similar to FIG. 1A). Here, the degree of restriction means the degree of restriction with respect to the maximum restriction state, and the degree of restriction 0.7 means a degree of restriction of 70% of the degree of restriction 1.0 which is the maximum restriction state. The first and last 30 minutes are in a posture restraint state where the pressure applied by the lumbar support 14 to the seated person is a pressure other than zero, and in the middle 30 minutes, the pressure applied by the lumbar support 14 is lower than the pressure applied in the posture restraint state. The posture is relaxed with pressure (zero here). The measurement is the same as in Experiment 1.

(Experiment 3)
In Experiment 3, as shown in FIG. 3B, the degree of restraint of the lumbar support 14 is switched between a state of 1.0 (state shown in FIG. 1A) and a state of 0 (state shown in FIG. 1B) every 5 minutes. . That is, the posture restraint state and the posture relaxation state by the lumbar support 14 are switched every 5 minutes. The measurement is the same as in Experiment 1.

(Experimental result)
As a result of Experiment 1, the degree of fatigue with respect to the elapsed time from the start of the experiment is as shown in FIG. 4A. As a result of Experiment 2, the degree of fatigue with respect to the elapsed time from the start of the experiment is as shown in FIG. 4B. As a result of Experiment 3, the degree of fatigue with respect to the elapsed time from the start of the experiment is as shown in FIG. 4C. In any result, the fatigue level gradually increases as time passes.

  These are compared as follows. In order to facilitate comparison, the average values Aave, Bave, and Cave of each experiment shown in FIG. 5 are referred to. In FIG. 5, Aave is an average value for three times in FIG. 4A, Bave is an average value for three times in FIG. 4B, and Cave is an average value for three times in FIG. 4C.

  According to FIG. 5, compared to a state where the degree of restraint of the lumbar support 14 is 0 (Aave), it is better to change the posture of the seated person by switching between the posture restrained state and the posture relaxed state like Bave and Cave. It can be seen that the accumulation of fatigue is small. However, Bave of Experiment 2 is in a state where the accumulation of fatigue is relatively smaller compared to Aave of Experiment 1 in the first stage from the start of the experiment, but the accumulation of fatigue is in Experiment 1 in the vicinity of 60 minutes. As high as Aave. When analyzed in more detail, according to Bave, the degree of restraint of the lumbar support 14 is large immediately after switching from 0 to 1.0 and immediately after switching from 1.0 to 0. Further, according to Cave in FIG. 5, by switching the degree of restraint every 5 minutes, the accumulation of the fatigue level can be reduced during the entire experiment compared to Bave.

  Perform these analyses. In Experiments 2 and 3, the change in applied pressure is not switched in 10 seconds or less as in massage, but the posture restrained state and posture relaxed state are maintained for 1 minute or longer. By holding each state for a certain time or more, the seated person can obtain a sense that the posture is restrained and a sense that is released from the state. The former sensation approximates that of posture correction. In other words, it is completely different from a massage-like sensation.

  Here, it is said that humans are less likely to get tired when the spine is in an inverted S shape like when standing. Therefore, the lumbar support 14 presses the lumbar spine so that the spine of the seated person has an inverted S shape. That is, by holding the posture restrained state by the lumbar support 14, it is possible to make the posture of the seated person less fatigued. However, comparing Bave and Cave, it was found that fatigue increases when sitting in a posture-constrained state for a long time. Therefore, instead of continuing the posture restraint state, it is possible to reduce the accumulation of fatigue of the seated person for a long time by switching between the posture restraint state and the posture relaxed state.

  In other words, like Bave, holding the posture restrained state and the posture relaxed state for 1 minute or more and less than 30 minutes respectively reduces the accumulation of fatigue. In particular, it is considered that each state should be maintained for 5 minutes or more and less than 30 minutes. From Bave, it was found that the effect of reducing the accumulation of fatigue can be obtained at the moment of changing from the posture restrained state to the posture relaxed state and the moment of changing from the posture relaxed state to the posture restrained state. Therefore, by setting each state to 5 minutes or more, the seated person can be surely affected by the change from the posture restrained state to the posture relaxed state and the change from the posture relaxed state to the posture restrained state. Can do. As a result, the effect of reducing the accumulation of fatigue can be reliably exhibited.

  In addition, by setting the posture restrained state for less than 30 minutes, it is possible to reduce the adverse effects caused by continuing the posture restrained state for a long time. Furthermore, by setting the posture constraint state and the posture relaxation state to less than 30 minutes, the number of changes between the posture constraint state and the posture relaxation state can be sufficiently obtained. As a result, the effect of reducing the accumulation of fatigue can be reliably exhibited.

<Deformation mode>
In the experiments 2 and 3, the degree of restraint of the lumbar support 14 was periodically changed. In addition, as shown in FIG. 6A, the degree of restraint of the lumbar support 14 is changed. The fatigue level in this case is as shown in FIG. 6B. Here, the degree of restraint of the lumbar support 14 is 0 → 0.6, 0.6 → 1.0, and the like means a change from the posture relaxation state to the posture restraint state, and 0.5 → 0, 0.6 → 0, 1.0 → 0.6, etc. means a change from the posture restrained state to the posture relaxed state. As can be seen from FIGS. 6A and 6B, it is considered that the accumulation rate of the fatigue level is reduced at the timing of switching between the posture constraint state and the posture relaxation state.

  A similar experiment was performed on subjects different from the above. In Case 1, the degree of restraint of the lumbar support 14 is zero. In case 2, the degree of restraint of the lumbar support 14 is changed from 0 → 0 → 0.7 → 1.0 → 0 → 0.7 → 0 → 0.5 → 0.5 → 0 → 0.4 → every 5 minutes. It was changed in the order of 0 → 0.5 → 0 → 0.5 → 0 → 0.8 → 0. In case 3, the degree of restraint of the lumbar support 14 was changed in order of 0 → 0.6 → 0 → 0.4 → 0 → 0.7 every 15 minutes. In Case 4, the lumbar support 14 was changed in order of 0.7 → 0 → 0.5 every 30 minutes.

  The fingertip volume pulse wave in this case is shown in FIG. In FIG. 7, case 1 is indicated by a thick solid line, case 2 is indicated by a thin solid line, case 3 is indicated by a two-dot chain line, and case 4 is indicated by a broken line. From this result, accumulation of fatigue is less when the degree of restraint of the lumbar support 14 is changed than when it is not changed. Further, less fatigue is accumulated when the degree of restraint of the lumbar support 14 is changed every 30 minutes than when the degree of restraint is changed every 5 minutes or 15 minutes. From this, it is considered that the degree of restraint of the lumbar support 14 should be changed with a holding time of 5 minutes or more and less than 30 minutes.

  Further, the same experiment was performed on subjects different from the above. In case 5, the degree of restraint of the lumbar support 14 is zero. In case 6, the degree of restraint of the lumbar support 14 is changed from 0 (15 minutes) → 0.6 (15 minutes) → 0 (15 minutes) → 0.6 (15 minutes) → 0 (15 minutes) → 0.6 ( 15 minutes). In case 7, the restraint degree of the lumbar support 14 is changed from 0 (6 minutes) → 0.6 (24 minutes) → 0 (6 minutes) → 0.6 (24 minutes) → 0 (6 minutes) → 0.6 ( 24 minutes). In case 8, the degree of restraint of the lumbar support 14 is 0 (24 minutes) → 0.6 (6 minutes) → 0 (24 minutes) → 0.6 (6 minutes) → 0 (24 minutes) → 0.6 ( 6 minutes).

  The fingertip volume pulse wave in this case is shown in FIG. In FIG. 8, case 5 is indicated by a thick solid line, case 6 is indicated by a thin solid line, case 7 is indicated by a broken line, and case 8 is indicated by a two-dot chain line. From this result, accumulation of fatigue is less when the degree of restraint of the lumbar support 14 is changed than when it is not changed. Furthermore, it is considered to be good to change with a holding time of 24 minutes or less.

  Furthermore, in the case 6 where the holding time in the restrained state and the holding time in the relaxed state are the same, or in the case 7 where the holding time in the restrained state is longer than the holding time in the relaxed state, the holding time in the restrained state is the holding time in the relaxed state. Compared to the shorter case 8, there is less fatigue accumulation. Therefore, when the degree of restraint of the lumbar support 14 is switched at a predetermined timing, it is considered that the restraint state holding time should be set to be equal to or more than the relaxed state holding time.

  Further, the degree of restraint of the lumbar support 14 may be operated in a range from zero to about 0.6. When the degree of restraint of the lumbar support 14 is 1.0, an excessive restraining force is applied to the seated person. Even if the restraining force feels comfortable if it is a massage operation, in the present embodiment, as described above, since it is held for a longer time than the massage fluctuation time, there is a risk of discomfort. Therefore, not operating the lumbar support 14 to the maximum degree of restraint within the range in which the normal lumbar support 14 can operate leads to a reduction in fatigue accumulation for the seated person.

<Second embodiment>
In the present embodiment, as shown in FIG. 9, a back load sensor 31 for detecting a load distribution is further provided on the back surface 12 as compared with the first embodiment. The back load sensor 31 detects the distribution of the load received from the back of the seated person. A sheet-like sensor made of elastomer is applied to the back load sensor 31. In particular, the rear load sensor 31 can be extended and deformed in the surface tangential direction. Thereby, even if the back surface 12 of the power seat is deformed by the load received from the back surface of the seated person, the back surface load sensor 31 can follow the deformation, and a highly accurate load distribution can be detected.

  Here, the detail of the back surface load sensor 31 is demonstrated with reference to FIG. 10A and 10B. As the back load sensor 31, a capacitive sensor formed of an elastomer is used. The capacitance type sensor 31 has a pair of electrodes arranged facing each other with a distance in the surface normal direction (vertical direction in FIG. 10B) arranged in a matrix, and can be elastically deformed between the pair of electrodes. A dielectric layer is disposed. In FIG. 10A, a capacitive sensor in which a pair of electrodes is arranged in a matrix of 9 rows in the horizontal direction (hereinafter referred to as “X direction”) and 9 rows in the vertical direction (hereinafter referred to as “Y direction”). 31 is shown. In FIG. 10A, a portion surrounded by A indicates one of a pair of electrodes.

  However, the capacitance type sensor 31 is configured as follows because the number of electrodes and the number of wirings increase when the electrodes are scattered in a matrix. That is, the capacitive sensor 31 includes a first electrode group 41, a second electrode group 42, a dielectric layer 43 provided between the electrodes, a surface on the second electrode group 42 side, and a surface on the first electrode group 41 side. Insulating layers 44 and 45 are provided so as to cover the back surface.

  In the first electrode group 41, a plurality (for example, 9 rows) of long plate-shaped first electrodes 41a to 41i extending in the X direction are arranged in parallel in the Y direction (direction orthogonal to the X axis direction). The second electrode group 42 includes a plurality (for example, nine rows) of long plate-shaped second electrodes 42 a to 42 i extending in the Y direction and arranged in parallel to the X direction. Are arranged opposite to each other at a distance. Here, the second electrode group 42 is disposed on the surface side of the capacitive sensor 31 with respect to the first electrode group 41. Here, each of the portions where the first electrode group 41 and the second electrode group 42 intersect constitute a pair of electrodes.

  The distance between the first electrodes 41a to 41i and the second electrodes 42a to 42i changes according to the external force F applied to the surface of the capacitive sensor 31, and the first electrodes 41a to 41a change along with this change. The electrostatic capacitance between 41i and the second electrodes 42a to 42i changes. Since it is well known that the capacitance is inversely proportional to the distance between the electrodes, detailed description is omitted.

  The first and second electrodes 41a to 41i and 42a to 42i are formed of the same material. Specifically, the materials of the first and second electrodes 41a to 41i and 42a to 42i are formed by blending a conductive filler in an elastomer. The first and second electrodes 41a to 41i and 42a to 42i have flexibility and expandable properties.

  Examples of the elastomer constituting the first and second electrodes 41a to 41i and 42a to 42i include silicone rubber, ethylene-propylene copolymer rubber, natural rubber, styrene-butadiene copolymer rubber, acrylonitrile-butadiene copolymer rubber, and acrylic rubber. Epichlorohydrin rubber, chlorosulfonated polyethylene, chlorinated polyethylene, urethane rubber and the like can be applied. Further, the conductive filler blended in the first and second electrodes 41a to 41i and 42a to 42i may be any particles having conductivity, such as conductive carbon black, carbon nanotubes, carbon nanotube derivatives, graphite. A conductive carbon fiber can be applied.

  The dielectric layer 43 is formed of an elastomer and has flexibility and a stretchable property, like the first and second electrodes 41a to 41i and 42a to 42i. Examples of the elastomer constituting the dielectric layer 43 include silicone rubber, acrylonitrile-butadiene copolymer rubber, acrylic rubber, epichlorohydrin rubber, chlorosulfonated polyethylene, chlorinated polyethylene, and urethane rubber.

  The dielectric layer 43 has a set thickness and is formed to be approximately the same as or larger than the outer shape of the first and second electrode groups 41 and 42. The insulating layers 44 and 45 are flexible and extendable and contractible in the same manner as the first and second electrodes 41a to 41i and 42a to 42i. As the elastomer constituting the insulating layers 44 and 45, for example, the material described as the elastomer constituting the dielectric layer 43 is applied.

  The capacitive sensor 31 has wiring (not shown). The wiring is formed by blending a conductive filler in an elastomer as in the case of the electrode.

  Here, even if the 1st, 2nd electrode 41a-41i, 42a-42i comprised as mentioned above expands-contracts, it is formed so that the change of the electroconductivity of an electrode may become small. Therefore, even when the seated person is seated, the power seat is deformed, and even if the capacitive sensor 31 is stretched and deformed, the electrical conductivity is good and the function as an electrode can be maintained. As a result, the capacitance can be measured with high accuracy, and as a result, the load distribution can be measured with high accuracy.

  In this case, as shown in FIG. 11, the control device 21 does not control the degree of restraint of the lumbar support 14 at a predetermined timing, but based on the load distribution detected by the rear load sensor 31. Switch between state and posture relaxed state.

  Control processing by the control device 21 will be described with reference to FIG. The control device 21 calculates the load center of gravity G based on the load distribution detected by the back surface load sensor 31 (step S1). Subsequently, it is determined whether or not the movement amount of the load gravity center G is equal to or greater than a threshold value (step S2). If not, the process returns to step S1 (S2: N). On the other hand, when the moving amount of the load gravity center G is equal to or greater than the threshold (S2: Y), the drive device 22 is driven according to the moving amount of the load gravity center G (step S3). Specifically, the degree of restraint of the lumbar support 14 is controlled according to the amount of movement of the load gravity center G.

(Explanation of load distribution)
The load distribution and the load gravity center G by the back load sensor 31 will be described with reference to FIG. In FIG. 13, the load distribution by the back surface load sensor 31 is shown. The magnitude of the load is expressed by shading. The darker the color, the larger the load, and the lighter the color, the smaller the load. That is, a high load is shown in the back surface 12 of the power seat near the seated person's waist and near the shoulder ribs. The center of gravity in the entire load distribution is a position indicated by G. The load distribution and the load center of gravity G change as the seating time elapses.

(Time change of load center of gravity)
Experiments similar to Experiments 1 to 3 described in the first embodiment were performed, and the load distribution was detected by the back surface load sensor 31. And the time change of the position of the load gravity center G was calculated. 14A and 14B show the results of Experiment 1, that is, the results when the lumbar support 14 is not used. Each of the drawings shows the movement amount of the load center of gravity G in the X coordinate and the movement amount in the Y coordinate. 15A and 15B show the results of Experiment 2, that is, the results when the degree of restraint of the lumbar support 14 is changed every 30 minutes. 16A and 16B show the results of Experiment 3, that is, the results when the degree of restraint of the lumbar support 14 is changed every 5 minutes.

  In a state where the lumbar support 14 is not used, the position of the load gravity center G changes without directionality (without regularity) as shown in FIGS. 14A and 14B. On the other hand, when switching between the restrained state and the relaxed state every 30 minutes, as shown in FIG. 15B, the Y coordinate of the load gravity center G changes in almost one direction. Further, when switching between the restrained state and the relaxed state every 5 minutes, as shown in FIGS. 16A and 16B, the X coordinate and the Y coordinate of the load gravity center G are changed substantially in one direction.

  Here, the position of the load gravity center G is considered to be related to the fatigued part of the seated person. That is, when the lumbar support 14 is not used, the seated person's fatigue site changes randomly. On the other hand, when the lumbar support 14 is changed, the fatigue portion of the seated person is gradually shifted. Therefore, grasping the position of the load gravity center G can predict which part of the seated person has accumulated fatigue or is likely to accumulate it.

  Thus, it can be seen that it is preferable to change the degree of restraint of the lumbar support 14 so that the coordinates of the load gravity center G move in one direction. In particular, it can be seen that it is preferable to move in one direction not only in one of the XY of the load gravity center G but in both directions of XY.

  Therefore, in step S3 of FIG. 12, the degree of restraint of the lumbar support 14 is controlled so that the moving direction of the load gravity center G becomes one direction according to the amount of movement of the load gravity center G from the initial stage. More specifically, the amount of movement of the load gravity center G from the initial stage is calculated for each of the X coordinate and the Y coordinate, and the degree of constraint of the lumbar support 14 is such that the movement direction of the load gravity center G at each coordinate is one direction. To control.

  That is, the degree of restraint of the lumbar support 14 is changed in accordance with the predicted accumulated portion of fatigue so that the fatigue of the seated person is less likely to accumulate. As a result, as shown by Cave in FIG. 5, accumulation of fatigue of the seated person can be reduced. That is, accumulation of fatigue in a long-time seated person can be reliably reduced. Furthermore, by applying the back load sensor 31 formed of an elastomer, the back load sensor 31 can follow the deformed shape of the skin of the power seat. Therefore, a natural seating posture can be provided without giving the seated person an uncomfortable feeling based on the presence of the back surface load sensor 31. As a result, information dependent on the position to be detected, for example, time variation of the load, the center of gravity of the load, etc. can be detected with high accuracy. Therefore, it is possible to predict the accumulation of fatigue of the seated person with high accuracy.

  If the back load sensor 31 is made of a thermoplastic resin or a thermosetting resin, it cannot follow the deformed shape of the skin of the power sheet because it does not have flexibility of expansion and contraction. As a result, the seated person feels uncomfortable (for example, a feeling of tension), which not only makes the seat uncomfortable, but also becomes a restraining factor for the deformation of the skin of the power seat and cannot provide a natural seating posture. Reduction is difficult to achieve.

<Third embodiment>
In the present embodiment, as shown in FIG. 17, a seating surface load sensor 32 for detecting a load distribution is further provided on the seating surface 11 as compared with the second embodiment. The seat load sensor 32 detects the distribution of the load received from the seat surface of the seated person. As the seat load sensor 32, as in the case of the back load sensor 31, a sheet-like sensor formed of elastomer is applied. Thereby, even if the seat surface 11 of the power seat is deformed by the load received from the seat surface of the seated person, the seat surface load sensor 32 can follow the deformation, and a highly accurate load distribution can be detected.

  In this case, as shown in FIG. 18, the control device 21 switches between the posture constraint state and the posture relaxation state based on the respective load distributions detected by the back surface load sensor 31 and the seating surface load sensor 32. Here, in the present embodiment, the control device 21 includes, as a driving device, in addition to the lumbar support 14, a reclining mechanism 15 (not shown), a seating surface tilt mechanism 16 (not shown), an ottoman tilt mechanism 17 (not shown), and an upper back portion (not shown). The tilt mechanism 18, the back side support 19 (not shown), and the seat side support 20 (not shown) are controlled. That is, the plurality of driving devices are appropriately driven to restrict the posture of the seated person or to relax the seated person.

  The reclining mechanism 15 enters a posture restrained state because the applied pressure increases as the reclining angle θ increases, and enters a posture relaxed state as the angle θ decreases. The seat tilt mechanism 16 is in a posture restrained state because the applied pressure increases as the seat tilt angle φ is increased, and is in a posture relaxed state as the angle φ is decreased. The ottoman tilt mechanism 17 and the back upper tilt mechanism 18 are in a posture restrained state as the applied pressure increases as the angle is increased, and are in a posture relaxed state as the angle is decreased. The rear upper tilt mechanism 18 is a mechanism for tilting the upper part of the rear surface 12. The rear side support 19 and the seat side support 20 are in a posture restrained state as the position in the direction of tightening the side part of the seated person's upper body or lower body from the left and right, and in the opposite direction, the posture is relaxed.

  Control processing by the control device 21 will be described with reference to FIG. The control device 21 calculates the load gravity centers GR1-GR4, GL1-GL4 of the sections R1-R4, L1-L4 based on the load distributions detected by the back load sensor 31 and the seat load sensor 32 (step S11). ). Each section R1-R4, L1-L4 and each load gravity center GR1-GR4, GL1-GL4 will be described later.

  Subsequently, it is determined whether or not the amount of movement of each load center of gravity G is equal to or greater than a threshold value (step S12). If not, the process returns to step S11 (S12: N). On the other hand, when the movement amount of each load gravity center G is equal to or greater than the threshold (S12: Y), the lumbar support 14, the reclining mechanism 15, the seat surface tilt mechanism 16, and the ottoman tilt mechanism according to the movement amount of each load gravity center G. 17, the rear upper tilt mechanism 18, the rear side support 19, and the seating surface side support 20 are driven (step S13).

(Explanation of the section and the center of gravity of each section)
20A, FIG. 20B, FIG. 21A, FIG. 21B, FIG. 22A about each division R1-R4, L1-L4 in the load distribution by each load sensor 31, 32, and the load gravity center GR1-GR4, GL1-GL4 in each division. This will be described with reference to FIG. 22B. 20A shows the load distribution of the back surface load sensor 31 immediately after the start of the experiment, FIG. 20B shows the load distribution of the seat surface load sensor 32 immediately after the start of the experiment, and FIG. 21A shows the load distribution of the back surface load sensor 31 during the experiment. 21B shows the load distribution of the seat load sensor 32 during the experiment, FIG. 22A shows the load distribution of the back load sensor 31 just before the end of the experiment, and FIG. 22B shows the load distribution of the seat load sensor 32 just before the end of the experiment. The load distribution is shown.

  In each figure, the darker the color, the larger the load, and the lighter the color, the smaller the load. That is, a high load is shown in the back surface 12 of the power seat near the seated person's waist and near the shoulder ribs. In addition, a high load is shown in the vicinity of the seated person's buttocks and the left and right thighs of the seat surface 11 of the power seat.

  Here, the load distribution of the back surface load sensor 31 is divided into four sections R1, R2, L1, and L2. The sections R1 and L1 include the vicinity of the shoulder ribs, and the sections R2 and L2 include the vicinity of the waist. Further, the load distribution of the seating surface load sensor 32 is divided into four sections R3, R4, L3, and L4. The sections R3 and L3 include the vicinity of the buttocks, and the sections R4 and L4 include the vicinity of the thigh.

  And each gravity center in load distribution of each division R1-R4, L1-L4 becomes a position shown by GR1-GR4, GL1-GL4. The load gravity centers GR1-GR4, GL1-GL4 of each section change as the seating time elapses. In particular, it can be seen that the load on the right foot side and the vicinity of the waist increases with time.

  Here, the fact that the load center of gravity in each section changes means that the posture of the seated person has changed. From the change in posture, the fatigue level or progress of fatigue of the seated person can be predicted. Therefore, it is possible to optimally adjust the drive timing of the posture change mechanism and reduce the accumulation of fatigue in a long-time seated person.

  In particular, the power seat includes a plurality of driving devices 14-20. Therefore, it is predicted which part of the seated person has fatigue accumulated or is likely to be accumulated depending on the amount of movement of the load gravity centers GR1-GR4, GL1-GL4 in each of the sections R1-R4, L1-L4. it can. Therefore, by driving each driving device in accordance with the fatigued portion of the seated person, it is possible to effectively reduce the accumulation of fatigue on the fatigued portion.

  For example, if the amount of movement of the positions of the center of gravity GR4, GL4 of the thigh sections R4, L4 is greater than or equal to a threshold value, fatigue may accumulate in the thigh or fatigue may accumulate in the thigh. Predictable. In this case, the control device 21 drives the seat surface tilt mechanism 16 to increase or decrease the seat surface tilt angle φ. Also in this case, each state is maintained within a period of 5 minutes to 24 minutes. However, when fatigue is predicted to accumulate in the thigh, not only the seat tilt mechanism 16 is driven, but the lumbar support 14, the reclining mechanism 15, the ottoman tilt mechanism 17, the rear upper tilt mechanism 18, and the rear side support. 19 and the seat side support 20 may be driven to change the posture of the seated person as a whole, thereby reducing the accumulation of fatigue.

  Further, the control device 21 drives, for example, the lumbar support 14 and the reclining mechanism 15 when the movement amount of the positions of the gravity centers GR2 and GL2 of the sections R2 and L2 near the waist exceeds a threshold value. Further, the seat surface tilt mechanism 16, the ottoman tilt mechanism 17, the rear upper tilt mechanism 18, the rear side support 19, and the seat surface side support 20 can be used simultaneously.

  In this way, the fatigue of the seated person can be increased by appropriately driving the predetermined drive device 14-20 according to the amount of movement of the load gravity centers GR1-GR4, GL1-GL4 in the sections R1-R4, L1-L4. The posture can be changed according to the part. As a result, the accumulation of fatigue of the seated person can be reliably reduced.

<Fourth embodiment>
This embodiment applies the same control block diagram as the third embodiment shown in FIG. However, the control processing of the control device 21 is different. Control processing of the control device 21 will be described with reference to FIG.

  Control processing by the control device 21 will be described with reference to FIG. Based on the load distribution detected by the back load sensor 31 and the seat load sensor 32, the control device 21 calculates the average pressure in each of the sections R11-R13, L11-L13 (step S21). Each section R11-R13, L11-L13 will be described later.

  Subsequently, it is determined whether or not the change amount per unit time of the average pressure in each of the sections R11-R13, L11-L13 is equal to or greater than a threshold value (step S12). N). On the other hand, when the change amount per unit time of each average pressure is equal to or greater than the threshold value (S22: Y), the lumbar support 14, the reclining mechanism 15, the seat surface tilt mechanism 16, and the ottoman tilt mechanism 17 according to each change amount. Then, the rear upper tilt mechanism 18, the rear side support 19, and the seat side support 20 are driven (step S23).

(Explanation of compartment and mean pressure in the compartment)
Next, the average pressure in the sections R11-R13, L11-L13 and each section will be described. First, the case where the state of the power seat is as shown in FIG. 24 will be described. In this state, the reclining angle θ is 75 deg and the lumbar support 14 has moved forward. That is, it is a state with a high restraint degree with respect to a seated person.

  At a certain moment at this time, the load distribution by the back surface load sensor 31 and the seating surface load sensor 32 is as shown in FIGS. 25A and 25B. Here, as shown in FIGS. 25A and 25B, the sections R11 and L11 correspond to the vicinity of the left and right hips, the sections R12 and L12 correspond to the vicinity of the left and right hips, and the sections R13 and L13 include the large left and right parts. Corresponds to the vicinity of the thigh. And in step S21 (shown in FIG. 23) by the control apparatus 21, the average pressure of each division R11-R13, L11-L13 shown to FIG. 25A and FIG. 25B is calculated.

  The behavior of the average pressure in each compartment was as shown in FIGS. 26A-26F. For example, in FIGS. 26A and 26D, it can be seen that the amount of change per unit time of the average pressure increases immediately after the start of the experiment. That is, the load on the waist is large. Moreover, in FIG. 26C, the amount of change per unit time of the average pressure increases over a long period from the start of the experiment. That is, the load on the right thigh is large. From this, it can be predicted that fatigue has accumulated or is likely to be accumulated in the left and right waist and right thigh.

  Moreover, the case where the state of a power seat is as shown in FIG. 27 is demonstrated. In this state, the reclining angle θ is 65 degrees, and the lumbar support 14 has moved most backward. That is, it is a state with a low restraint degree to a seated person.

  At a certain moment at this time, the load distribution by the back surface load sensor 31 and the seating surface load sensor 32 is as shown in FIGS. 28A and 28B. And in step S21 (shown in FIG. 23) by the control apparatus 21, the average pressure of each division R11-R13, L11-L13 shown to FIG. 28A and FIG. 28B is calculated. The behavior of the average pressure in each compartment was as shown in FIGS. 29A-29F. In FIG. 29C and FIG. 29F, the amount of change per unit time of the average pressure increases over a long period from the start of the experiment. That is, the load on the left and right thighs is large. From this, it can be predicted that fatigue has accumulated in the left and right thighs, or that there is a risk of accumulation.

  And from each figure, the variation | change_quantity per unit time of the average pressure of each division changes with the states and seating time of a power seat. Therefore, by deriving the association between the part where the amount of change is large and how to change the state of the power seat, the relationship between the two can be determined in advance.

  Therefore, in step S23 (shown in FIG. 23), the control device 21 determines the lumbar support 14, the reclining mechanism 15, the seat surface tilt mechanism 16, the ottoman tilt mechanism 17, the rear upper tilt mechanism 18, and the rear side support in accordance with each change amount. 19 and the seating surface side support 20 can be driven. That is, by optimally adjusting the drive timing of the posture change mechanism, it is possible to reliably reduce the accumulation of fatigue in a long-time seated person.

<Fifth embodiment>
In the present embodiment, as shown in FIG. 30, a height adjustment actuator 14a for the lumbar support 14 is further provided in the second embodiment. The height adjustment actuator 14a can adjust the height of the lumbar support 14, and can change the height of pressure applied to the main part of the seated person by the lumbar support 14.

  Here, the control device 21 can change the height of pressure applied to the main part of the seated person by the lumbar support 14 based on the physique information of the seated person obtained from the load distribution on the back surface 12. Here, the length ΔH from the lumbar spine to the shoulder, the lumbar spine height L, and the width of the load range are used as the physique information of the seated person.

  Control processing of the control device 21 at this time will be described with reference to FIGS. 31 and 32. FIG. As shown in FIG. 31, the control device 21 calculates the length ΔH from the seated person's lumbar spine to the shoulder, the lumbar spine height L, and the lateral width of the load range based on the load distribution detected by the back surface load sensor 31. (Step S31). The length ΔH from the lumbar spine to the shoulder is a length from the maximum height to the minimum height indicating a load exceeding the threshold value of the load distribution. The lumbar vertebra height L is a minimum height indicating a load exceeding the load distribution threshold. Further, the lateral width of the load range is a left-right range indicating a load exceeding the load distribution threshold.

Subsequently, the control device 21 calculates the comfortable height Ha of pressure application by the lumbar support 14 based on the length ΔH from the lumbar spine to the shoulder and the lumbar spine height L (step S32). The comfortable height is calculated according to equation (1). Furthermore, the control device 21 adjusts the calculated comfortable height Ha based on the lateral width of the load range.
[Equation 1]
Ha = L + ΔH / 3 (1)

  Subsequently, the control device 21 drives the height adjustment actuator 14a so that the pressure application height by the lumbar support 14 is the comfortable height Ha (step S33). Note that the comfort height Ha calculated by the above calculation is included in a range where most people feel comfortable. Therefore, the actual comfortable height can be sufficiently estimated by the comfortable height Ha calculated as described above. The height Gha of the load gravity center G after driving the height adjustment actuator 14a to the comfortable height Ha is smaller than the height Gh of the load gravity center G before adjustment, that is, Gh> Gha. The validity of the comfortable height Ha can also be verified by verifying.

  Here, about the case where the height of the lumbar support 14 was made into different height, the fatigue degree of the subject was measured. Specifically, when the seated person receives pressure from the lumbar support 14 at a comfortable height and when the seated person receives pressure from the lumbar support 14 at a height different from the comfortable height, The fatigue level of the person was measured.

  The comfortable height is not the above-described calculation formula, but the height at which the subject feels most comfortable. Note that this comfortable height approximates the comfortable height Ha obtained by the above-described calculation formula. Further, the unpleasant height was the lumbar vertebra position farthest from the pelvis (the lumbar vertebra position close to the shoulder).

  In any case, the restraint degree of the lumbar support 14 is 0 (15 minutes) → 0.6 (15 minutes) → 0 (15 minutes) → 0.6 (15 minutes) → 0 with respect to the subject. (15 minutes) → 0.6 (15 minutes). FIG. 33 shows the fingertip volume pulse group in these cases. In FIG. 33, the comfortable height is indicated by a thick solid line, and the uncomfortable height is indicated by a thin solid line. Thus, it can be seen that when pressure is applied by the lumbar support 14 at a comfortable height, the accumulation of fatigue is less than in the case of an uncomfortable height.

<Deformation mode>
Here, in the fifth embodiment, the height of the lumbar support 14 is adjusted. In addition, the present invention can be similarly applied to the rear side support 19 and the rear upper tilt mechanism 18. That is, the height to which pressure is applied by the back side support 19 is adjusted based on the load distribution on the back surface 12. Further, the tilt height is adjusted by the back upper tilt mechanism 18 based on the load distribution on the back surface 12. Thus, the position where the posture change mechanism functions can be adjusted based on the height of the load center of gravity obtained from the load distribution on the back surface 12. As a result, the fatigue of the seated person can be reduced.

  In the above embodiment, the center of gravity of the load distribution on the back surface 12 acquired using the back surface load sensor 31 is used. In addition to this, using the seat load sensor 32 (shown in FIG. 17), the functioning position of the seat side support 20 is adjusted based on the physique information of the seated person obtained from the load distribution of the seat surface 11. Can do. Here, the front-rear direction position of the load center of gravity of the seating surface 11, the size of the buttocks, and the front-rear direction position of the buttocks are used as the physique information of the seated person. That is, the control device 21 calculates a comfortable front-rear direction position based on the information as physique information. And it adjusts so that the front-back direction position to which the pressure by the seat surface side support 20 is applied becomes the calculated comfortable front-back direction position.

<Sixth embodiment>
In the present embodiment, as shown in FIG. 17, the power seat device includes a back load sensor 31 and a seat load sensor 32, and includes a reclining mechanism 15. Control processing of the control device 21 in the present embodiment will be described with reference to FIG.

  Based on the load distribution on the back surface 12 detected by the back surface load sensor 31, the control device 21 calculates the total back load Wb (step S41). Subsequently, the control device 21 calculates the total sum Ws of the seating load based on the load distribution on the seating surface detected by the seating load sensor 32 (step S42). Subsequently, the control device 21 determines whether or not the sum of the back load total Wb and the seat load total Ws is larger than a preset threshold Th (step S43).

  Here, the sum of the total back load Wb and the total seat load Ws corresponds to the physique of the seated person. That is, Wb + Ws increases when the seated person is large, and Wb + Ws decreases when the seated person is small. Therefore, the threshold value Th is a value corresponding to the case where the seated person is small.

  Subsequently, when the sum of Wb + Ws is larger than the threshold value Th (S43: Yes), a ratio Wb / Ws between the total back load Wb and the total seat load Ws is calculated. The fluctuation angle α of the reclining angle θ is calculated according to the ratio Wb / Ws (step S44). Then, the control device 21 drives the reclining mechanism 15 based on the fluctuation angle α (step S45).

  Here, the variation angle α is an angle that varies with respect to the initial angle θ1 of the reclining mechanism 15. That is, as shown in FIG. 35, the reclining angle θ is set to θ1 (15 minutes) → θ1-α (15 minutes) → θ1 (15 minutes) → θ1-α (15 minutes) → θ1 (15 minutes) → θ1- Change in the order of α (15 minutes). Here, the larger the ratio Wb / Ws, the larger the variation angle α. That is, as the ratio Wb / Ws increases, the difference between the reclining angle θ1 in the initial posture state and the reclining angle θ1-α in the posture change state increases.

  In the reclining mechanism 15, for the seated person, the greater the reclining angle θ, the greater the pressure applied to the posture change, and the smaller the reclining angle θ, the smaller the applied pressure to the posture change. That is, changing the reclining angle θ in the posture change state means that the applied pressure change amount (corresponding to α) differs between the posture restraint state (corresponding to θ1) and the posture relaxation state (corresponding to θ1-α). Means. Thus, the posture of the seated person is surely changed by changing the posture according to the physique of the seated person. As a result, the accumulation of fatigue of the seated person can be reduced.

  On the other hand, if the condition is not satisfied in step S43 (S43: No), that is, if the seated person is small, the process is terminated. When the seated person is small, the seated person does not lean against the back surface 12 or leans very lightly. For this reason, even if the reclining angle θ is changed, the posture of the seated person cannot be changed. Therefore, in such a case, the reclining mechanism 15 is not driven.

<Deformation mode>
Here, in the sixth embodiment, the fluctuation angle α of the reclining mechanism 15 is adjusted. In addition, the present invention can be similarly applied to the seat surface tilt mechanism 16 and the ottoman tilt mechanism 17. That is, based on the load distribution on the seat surface 11 and the back surface 12, the amount of change in applied pressure between the posture restrained state and the posture relaxed state is made different. In this way, when the initial state is set to the posture restrained state, the posture relaxed state is changed. Also in this case, accumulation of fatigue of the seated person can be reduced.

11: Seat surface, 12: Back surface, 13: Headrest, 14: Lumber support (driving device, posture changing mechanism), 15: Reclining mechanism (driving device, posture changing mechanism), 16: Seat tilt mechanism (driving device, posture) Change mechanism), 17: Ottoman tilt mechanism (drive device, posture change mechanism), 18: Back upper tilt mechanism (drive device, posture change mechanism), 19: Back side support (drive device, posture change mechanism), 20: Seat surface Side support (drive device, posture change mechanism), 21: control device, 31: back load sensor, 32: seat load sensor, R1-R4, L1-L4, R11-R13, L11-L13: section, 41, 42: A pair of electrodes, 43: dielectric layer

Claims (20)

A power seat having a posture change mechanism that changes the posture of the seated person by increasing or decreasing the pressure applied to the seated person;
A control device for controlling the posture change mechanism;
With
The control device includes:
Switching between a posture constraint state in which the applied pressure to the seated person by the posture change mechanism is a pressure other than zero and a posture relaxation state in which the applied pressure is lower than the applied pressure in the posture constraint state,
A power seat device that holds each state for at least 1 minute.   2. The power seat device according to claim 1, wherein the control device holds the posture constraint state and the posture relaxation state for 5 minutes to 24 minutes, respectively.   The control device sets the holding time of the posture restrained state and the holding time of the posture relaxed state to 5 minutes or more and 24 minutes or less, and sets the holding time of the posture restricted state to be longer than the holding time of the posture relaxed state. Item 3. The power seat device according to Item 2.   The power control device according to any one of claims 1 to 3, wherein the control device switches the state of the posture change mechanism at a predetermined timing. The power seat device further includes a load sensor that detects a load distribution on at least one of a seating surface and a back surface of the power seat,
5. The power seat device according to claim 4, wherein the control device varies the posture constraint state or the posture relaxation state by the posture change mechanism based on the load distribution. The load sensor detects a load distribution on the back surface of the power seat,
The posture change mechanism is any one of a lumbar support, a rear side support, and a rear upper tilt mechanism.
6. The power seat device according to claim 5, wherein the control device varies the posture constraint state by adjusting a position where the posture change mechanism functions based on the load distribution.   The power control device according to claim 6, wherein the control device adjusts a position where the posture changing mechanism functions based on the physique information of the seated person obtained from the load distribution on the back surface of the power seat.   The control device functions as the posture change mechanism based on the length from the lumbar spine to the shoulder, the lumbar spine height, and the lateral width of the load range obtained from the load distribution on the back surface of the power seat as the physique information. The power seat device according to claim 7, wherein a position to be adjusted is adjusted. The load sensor detects a load distribution on the seat surface of the power seat,
The posture change mechanism is a seat side support.
The power seat device according to claim 5, wherein the control device varies the posture restrained state by adjusting a position where the seating surface side support functions based on the load distribution.   The power seat device according to claim 9, wherein the control device adjusts a position where the posture changing mechanism functions based on the physique information of the seated person obtained from the load distribution on the seating surface of the power seat. .   The control device, based on the physique information, based on the front-rear position of the load center of gravity obtained from the load distribution on the seat surface of the power seat, the size of the buttock, and the front-rear direction position of the buttock, The power seat device according to claim 10, wherein the functioning position is adjusted. The posture change mechanism is one of a reclining mechanism, a seating surface tilt mechanism, and an ottoman tilt mechanism,
6. The power seat according to claim 5, wherein the control device makes the posture relaxation state different by changing a change amount of an applied pressure between the posture constraint state and the posture relaxation state based on the load distribution. apparatus.   The power according to claim 12, wherein the control device varies the amount of change in applied pressure between the posture restrained state and the posture relaxed state based on a ratio of a load on the seating surface and a load on the rear surface of the power seat. Sheet device.   The power control device according to claim 12 or 13, wherein the control device determines whether or not the posture change mechanism can be driven based on a sum of a load on a seating surface and a load on a rear surface of the power seat. The power seat device is
And a load sensor for detecting a load distribution on at least one of a seating surface and a back surface of the power seat,
The power control device according to any one of claims 1 to 3, wherein the control device switches between the posture constraint state and the posture relaxation state based on the load distribution. The load sensor detects a load for each section when the installation surface is partitioned into a plurality of sections,
The power seat device according to claim 15, wherein the control device switches between the posture constraint state and the posture relaxation state based on a time change of the load for each section. The load sensor detects a load distribution for each section when the installation surface is partitioned into a plurality of sections,
The control device calculates a load center of gravity for each section based on the load distribution for each section, and switches between the posture constraint state and the posture relaxation state based on the load center of gravity for each section. 15. The power seat device according to 15. The power seat includes a plurality of posture change mechanisms,
The power seat device according to any one of claims 15 to 17, wherein the control device controls the posture change mechanism set in accordance with a load distribution detected by the load sensor.   The power seat device according to any one of claims 15 to 18, wherein the load sensor is formed in a planar shape from an elastomer, can measure a load distribution, and can be extended and deformed in a surface tangential direction.   The load sensor is a capacitive sensor configured by a pair of electrodes formed of an elastomer and a dielectric layer formed of an elastomer interposed between the pair of electrodes. The power seat device according to any one of the descriptions.