JP2012020082A - Lumbar support member, seat structure for transportation equipment, and cushion for seat - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lumbar support member enabling a user to take a stable posture against longitudinal, vertical and lateral acceleration while providing the sufficient function of feeling a stroke within a limited space.SOLUTION: The lumbar support member 1 includes a laminated structure of a flexible plate-like body 10 with its rear face protrusively provided with a plurality of lateral projections arranged along a width direction at optional spaces in a height direction, and a soft cushion material 20 arranged on the rear side of the flexible plate-like body 10 and smaller in spring constant than the flexible plate-like body 10 when pressed in a thickness direction by a pressure plate with a diameter of 30 mm. Since the flexible plate-like body 10 has the lateral projections 10c, when a human load is applied, the lateral projections 10c press the soft cushion material 20. The soft cushion material 20 is not pressed on the whole surface but pressed in part. A predetermined feeling of a stroke is induced by being pressed by the lateral projections 10c.

Description

  The present invention relates to a seat structure for a transport device such as an automobile, an aircraft, and a train, a lumbar support member used for a seat cushion mounted on the seat structure, and a transport device including the lumbar support member. The present invention relates to a seat structure and a seat cushion.

  For example, in Patent Document 1, a torsion bar formed in a substantially U-shape is used, the upper arm part of the torsion bar is supported by a seat frame, and the intermediate arm part and the lower arm part are supported by a support plate. An automotive lumbar support is disclosed. Patent Document 2 discloses a lumbar support having two cushion members provided vertically along the lateral direction and a flexible plate covering the front side (side on which the human body is located), It is also disclosed that the lumbar support is accommodated in a pocket provided on the back side of the seat cushion.

JP-A-8-205956 JP 2006-204884 A

  The lumbar support device of Patent Document 1 uses a special shape as a torsion bar and connects the intermediate arm portion and the lower arm portion to the support plate to prevent the support plate from rolling and the seating fee. The ring is improved. The lumbar support device of Patent Document 1 tries to earn a stroke in a limited space using a specially shaped torsion bar, but it is necessary to produce a specially shaped torsion bar, There are problems in terms of cost and cost due to the complicated structure, such as the arrangement of multiple brackets for connecting the torsion bar to the seat frame and the support plate. Also, the elasticity of the torsion bar supports the person's lumbar spine while the support plate moves back and forth, and it can follow the person's back and forth movement, but the person when centrifugal acceleration on a curve or the like is applied Does not contribute much to the stability of the attitude.

  The lumbar support of Patent Document 2 avoids compression of the nervous system between the third lumbar vertebra and the fourth lumbar vertebra by arranging a flexible plate on the front side of the two cushion members, and follows the curve of the spine. It does not make you feel uncomfortable or uncomfortable due to its shape. However, the lumbar support of this Patent Document 2 is mainly intended to follow the curve of the spinal column by disposing a flexible plate, and has the effect of reducing the vibration transmissibility in the waist against vertical and longitudinal vibrations. Although it is high, there is no particular mention of improving the stability of the posture of a person when centrifugal acceleration is applied on a curve or the like.

  The present invention has been made in view of the above, and while being a simple, lightweight, and low-cost structure that can be manufactured, in a limited small space, it can sufficiently function a sense of stroke over the space, It is possible to change to a more stable posture while changing the position and angle with respect to the acceleration in the front and rear, up and down, left and right, rotation direction, and the seat structure provided in the transport equipment Another object of the present invention is to provide a lumbar support member that can also be used in a seat cushion that is used by being placed on the seat structure. Moreover, this invention makes it a subject to provide the seat structure for transport apparatuses which has this lumbar support member, and the cushion for seats.

  In order to solve the above problems, a lumbar support member of the present invention is a lumbar support member disposed in a seat back portion, and has a predetermined dimension along a width direction and a height direction of the seat back portion, and a back surface. In addition, a plurality of lateral ridges extending in the width direction projecting at an arbitrary interval in the height direction, and a flexible plate-like body disposed on the back side of the flexible plate-like body, It has a laminated structure with a soft cushion material having a low spring constant when pressed in the thickness direction by a pressure plate having a diameter of 30 mm rather than a flexible plate-like body.

  It is preferable that the dimension along the height direction of the said seat back part in the horizontal convex part of the said flexible plate-shaped body is the range of 10-40 mm. It is preferable that an elastic coating material is adhered to the back surface of the flexible plate-like body. It is preferable that the flexible plate is formed of a bead foam. It is preferable that the lateral ridges of the flexible plate-like body have a shape that increases in thickness toward the respective end portions in the width direction. It is preferable that the vertical ridge part along the height direction of the said seat back part is further laminated | stacked on the width direction both ends of the horizontal ridge part of the said flexible plate-shaped body. It is preferable that the soft cushion material is provided with a three-dimensional solid knitted fabric, and the spring constant when pressed in the thickness direction by a pressure plate having a diameter of 30 mm is equal to or less than the spring constant of the human buttocks muscle. The soft cushion material comprises urethane foam formed so that the spring constants are partially different, and the spring constant when pressed in the thickness direction by a pressure plate with a diameter of 30 mm is the spring constant of the human buttocks muscle It is preferable that it is equivalent or less. In the soft cushion material, it is preferable that two cylindrical parts above and below are formed substantially parallel to each other along the height direction of the seat back part. It is preferable that the flexible plate-like body and the soft cushion material are stored in a stacked state in a bag member and are unitized.

  Moreover, the seat structure for a transport device according to the present invention is a seat structure for a transport device including a seat cushion portion and a seat back portion, wherein the lumbar support member is a cushion material positioned at a waist portion of the seat back portion. It is provided on the back side. It is preferable that the lumbar support member is accommodated in a pocket portion formed on the back side of the cushion material located on the waist portion in the seat back portion.

  Further, the seat cushion of the present invention is a seat cushion used on a seat structure for transport equipment, wherein the lumbar support member is located at a waist portion of a seat back portion of the seat cushion. It is provided on the back side of the material. It is preferable that the lumbar support member is accommodated in a pocket portion formed on the back side of the cushion material located on the waist portion in the seat back portion.

  According to the present invention, the lumbar support member has a flexible plate-like body in which a plurality of lateral ridges along the width direction project from the back surface at arbitrary intervals in the height direction. Located on the back side of the flexible plate-like body, the spring constant when pressed in the thickness direction by a pressure plate with a diameter of 30 mm is lower than that of the flexible plate-like body, preferably equal to or less than the spring constant of the human buttocks muscle It consists of a laminated structure with soft cushion material. Since the flexible plate-like body has the lateral ridges, when a human load is applied, each lateral ridge partially presses the soft cushion material according to the magnitude of the load. That is, the entire surface of the soft cushion material is not pressed, but is partially pressed. Therefore, since the flexible plate-like body is deformed corresponding to the shape of the back of the person and has a spring characteristic, this spring characteristic is also useful for absorbing vibration. A soft cushion material, particularly a three-dimensional solid knitted fabric, exhibits high rigidity when pressed over a predetermined area, but exhibits soft spring characteristics when pressed partially. For this reason, it is partially pressed by the lateral ridge, and not only linear displacement but also rotation is born, and a predetermined stroke feeling is given while giving a subtle change in the direction of support. Moreover, since the spring characteristic of these soft cushion materials and the spring characteristic of a flexible plate-shaped body are arranged in series, the spring constant which combined both falls.

  In other words, when a person is seated, the flexible plate-like body is curved, but by having the lateral protrusions, the flexible protrusions bend while exhibiting a predetermined supporting pressure, and the lateral protrusions having a large pressure and displacement. Because it presses the soft cushion material and gives the above-mentioned feeling of stroke, it comes along the body side near both sides of the lumbar support member from the waist to the vicinity of the upper pelvis and the vicinity of the center, providing stable support so that it can be wrapped in all parts. You will get a feeling. In addition, not only when the acceleration in the front-rear direction and the vertical direction is input, but also when the acceleration in the left-right direction is input, the lateral convex strip portion with high pressure presses the soft cushion material, In the state, the flexible plate-like body is sensitively deformed in response to the acceleration fluctuation, and in addition, the soft cushion material is also sensitively deformed. These sensitive deformations follow the movement from the waist to the vicinity of the upper part of the pelvis, so that stable support is achieved. Further, although the stroke feeling is relative, according to the present invention, it is possible to give the person a larger stroke feeling than the stroke feeling normally assumed by the space allowed in the layout. Further, the seat back portion is configured by providing a pocket portion on the back side of the cushion material constituting the seat back portion in the seat structure for a transport device or the seat cushion, and accommodating the lumbar support member in the pocket portion. Since it is not fixed to the skeleton such as the back frame, it has high follow-up ability to the trunk, so that it can exhibit stable absorption for any of acceleration in the front / rear, up / down, left / right, and rotational directions. It is possible to follow the posture change and to exhibit a stable posture maintenance function.

  Further, the lumbar support member of the present invention has a very simple configuration of a laminate of a flexible plate-like body having a lateral ridge and a soft cushion material, and can be manufactured at a lighter weight and at a lower cost than the conventional one.

FIG. 1 is a perspective view of a lumbar support member according to one embodiment of the present invention and a seat cushion provided with the lumbar support member, as viewed from the back side. FIG. 2 is a perspective view of the seat cushion of FIG. 1 as seen from the front side. FIG. 3 is a plan view of the seat cushion of FIG. 1. 4 is a cross-sectional view taken along line AA in FIG. 5 is a cross-sectional view taken along line BB in FIG. FIG. 6 is an enlarged view of a portion C in FIG. 7A and 7B are diagrams showing a flexible plate-like body, in which FIG. 7A is a perspective view seen from the front side, and FIG. 7B is a perspective view seen from the back side. FIG. 8 is a diagram showing a flexible plate-like body, (a) is a plan view, (b) is a front view, (c) is a side view, (d) is a rear view, and (e) is ( It is AA sectional view taken on the line of b). FIG. 9 is a view for explaining a method of arranging a lumbar support member in the seat structure for a transport device. FIG. 10 is a view showing another example of a flexible plate-like body. FIG. 11 is a view showing still another example of the flexible plate-like body, in which (a) is a perspective view seen from the front side, (b) is a perspective view seen from the back side, and (c) is a front view. (D) is a side view, (e) is a rear view, (f) is a sectional view taken along line BB of (e), and (g) is a sectional view taken along line AA of (e). FIG. 12 is a diagram showing the frequency analysis result of the head acceleration in the test example, where (a) shows the frequency analysis result of the head longitudinal acceleration and (b) shows the frequency analysis result of the head lateral acceleration. (C) shows the frequency analysis results of the vertical acceleration of the head. FIG. 13 is a diagram showing the frequency analysis result of acceleration on the 6-axis shaker that is the acceleration of the input vibration in the test example, where (a) shows the frequency analysis result of longitudinal acceleration and (b) shows the lateral acceleration. (C) shows the frequency analysis result of vertical acceleration, respectively. FIG. 14 is a diagram showing the analysis result of the fatigue degree in the test example. FIG. 15 is a diagram in which the number of occurrences of the subharmonic in which the high-frequency vibration of 2.5 to 5 Hz is added to the 1 Hz waveform in the lateral acceleration of the test example is picked up in time series. FIG. 16 is a diagram showing, in time series, the number of occurrences of subharmonic in all frequency bands in the lateral acceleration of the test example. FIG. 17 shows a head acceleration waveform in a predetermined frequency band and a waveform of a crest factor of a threshold value 2 or more. (A) shows the case of “with twin lumbar”, and (b) shows “twin lumbar”. The cases of “none” are shown. FIG. 18 is a diagram showing the number of times that the crest factor threshold value 2 or more is exceeded in time series. FIG. 19 is a diagram showing a body pressure distribution at the start of measurement in the slalom running test using the drive simulation device. FIG. 20 is a diagram showing the body pressure distribution at the 36-second point in the slalom running test using the drive simulation device. FIG. 21 is a diagram showing a body pressure distribution at a 37-second point in a slalom running test using a drive simulation device. FIG. 22 is a view showing a body pressure distribution at a point of 37.8 seconds in the slalom running test using the drive simulation device. FIG. 23 is a diagram showing the body pressure distribution of FIG. 22 with the pressure scale changed.

  Hereinafter, the present invention will be described in more detail based on the embodiments shown in the drawings. 1 to 8 are views showing a lumbar support member 1 according to an embodiment of the present invention and a seat cushion 100 on which the lumbar support member 1 is disposed. As shown in these drawings, the lumbar support member 1 according to the present embodiment includes a flexible plate-like body 10 and a soft cushion material 20.

  The flexible plate-like body 10 is formed with a predetermined dimension along the width direction and the height direction of the seat back portion. “Having predetermined dimensions along the width direction and the height direction of the seat back portion” is not limited to being formed in a substantially rectangular shape in plan view as shown in FIGS. It is meant to include those formed in a square shape, a substantially elliptical shape, or the like. The surface portions of the upper edge portion 10a and the lower edge portion 10b of the flexible plate-like body 10 are curved so as to have a shape along the rear side when viewed from the side surface, whereby the upper edge portion 10a. And the shape which reduces the foreign material feeling by the edge part at the time of the lower edge part 10b contact | abutting the upper part of the pelvis from the waist | hip | lumbar part is contacted.

  The flexible plate-like body 10 is provided with a lateral protrusion 10c on the back surface thereof. The lateral ridge 10c protrudes in a band shape along the width direction of the flexible plate-like body 10, and extends along the height direction of the seat back portion 110, that is, along the vertical direction of the flexible plate-like body 10. A plurality of protrusions are provided at arbitrary intervals. In the present embodiment, four lateral protrusions 10c are formed at equal intervals. It is preferable that the dimension along the height direction (vertical direction of the flexible plate-shaped body 10) of the seat back part 110 is 50 mm or less, and the horizontal protruding part 10c is the range of 10-40 mm. Is preferred. More preferably, it is the range of 10-30 mm. In the case of a three-dimensional solid knitted fabric constituting the soft cushion material 20 described later, when a pressure is applied with a pressure plate having a large area of 200 mm in diameter, the spring constant increases. On the other hand, when pressure is applied with a pressure plate having a diameter of 30 mm, the spring constant is small and a soft spring action functions. For this reason, if the flexible plate-like body 10 does not have the lateral protrusions 10c, the soft cushion material 20 is pressed in a large area, so that the rigidity is high, the bottom is generated, and the feeling of stroke is generated. Although it is insufficient, when it has the lateral protrusion 10c as in this embodiment, a predetermined stroke feeling can be exhibited by a soft spring action, and high body pressure dispersibility is obtained at the stroke end. From the above, the vertical dimension of the lateral ridge 10c is more preferably 30 mm or less, corresponding to a pressure plate having a diameter of 30 mm, but the thickness of the pile adopted in the three-dimensional solid knitted fabric, etc. Therefore, even when the thickness is 40 mm or less or 50 mm or less, a soft spring characteristic with a small spring constant can be applied. Of course, the number of protrusions of the lateral ridges 10c is not limited to four as shown in the drawing, and the vertical dimension of the lateral ridges 10c and the flexible plate-like body 10 are not limited. The number is appropriately set according to the overall size and the like. Moreover, as shown in FIG. 11, the thickness of each lateral ridge portion 10c gradually increases toward the respective width direction end portion 10e (the protruding height of the lateral ridge portion 10c increases). It can also be. According to this aspect, the spring constant can be arbitrarily set by adjusting the protrusion height, and any of a non-linear spring characteristic and a linear spring characteristic can be arbitrarily selected.

  The flexible plate 10 is preferably a bead foam. By using the bead foam, the lumbar support member 1 can be reduced in weight. As the bead foam, for example, a foam molded body by a bead method of a resin containing at least one of polystyrene, polypropylene, and polyethylene can be used.

  The flexible plate-like body 10 is arranged so that the back surface side on which the lateral ridges 10c are formed is opposite to the human body. For this reason, when a person's load is applied, it curves so that the center part of the back surface side where the horizontal protruding item | line part 10c is located may bulge back. This bending generates a reaction force, the reaction force generates a spring constant, and the spring constant becomes a spring force that reduces external vibration input. In addition, the spring characteristic due to this curvature largely depends on the shape thereof, and it can be arbitrarily selected from a linear spring characteristic to a non-linear spring characteristic depending on the shape of the lateral ridge portion 10c, in particular, the protruding height and how to change the protruding height. Can be set. Further, in order to prevent cracking of the flexible plate-like body 10 or to give a softer spring constant, the back surface of the flexible plate-like body 10, that is, the outer surface and adjacent to the lateral protrusion 10 c. It is preferable that the elastic covering material is stuck on the surface between the lateral ridge portions 10c. This elastic covering material becomes the dominant element of the spring constant due to the bending stiffness (EI) caused by the bending. As the elastic covering material, for example, an elastic fiber nonwoven fabric having an elongation of 200% or more and a recovery rate at 100% elongation of 80% or more can be used. As such an elastic fiber nonwoven fabric, for example, a nonwoven fabric in which thermoplastic elastomer elastic fibers disclosed in Japanese Patent Application Laid-Open No. 2007-92217 are melt-bonded to each other can be used.

  As the soft cushion material 20, a material having a lower spring constant when pressed in the thickness direction by a pressure plate having a diameter of 30 mm than the flexible plate-like body 10 is used. Thus, as described above, a predetermined stroke feeling is exhibited by the soft spring action. In addition, the anchoring effect is generated by the horizontal protruding portion 10c of the flexible plate-like body 10 being bitten, the position of the flexible plate-like body 10c is determined, and a predetermined posture supporting pressure is also produced. As the soft cushion material 20, it is preferable to use a three-dimensional solid knitted fabric because a soft spring action can be remarkably functioned by a pressure plate having a diameter of 30 mm. The three-dimensional solid knitted fabric includes, for example, a pair of ground knitted fabrics spaced apart from each other and the pair of grounds as disclosed in JP 2002-331603 A, JP 2003-182427 A, and the like. The knitted fabric has a three-dimensional three-dimensional structure having a large number of connecting yarns that reciprocate between the knitted fabrics to couple them together. In addition, the spring constant obtained from the load-deflection characteristic when pressed with a pressure plate with a diameter of 30 mm is the spring constant of the human buttocks muscle obtained from the load-deflection characteristic when pressed with a pressure plate with a diameter of 30 mm. It is more preferable that it is equal to or less than (equal or smaller).

  The soft cushion material 20 has a low spring constant when pressed in the thickness direction by a pressure plate having a diameter of 30 mm, and preferably has a spring constant when pressed in the thickness direction by a pressure plate having a diameter of 30 mm. It is not limited to a three-dimensional solid knitted fabric as long as it is equal to or less than the muscle spring constant (equal or smaller). For example, it may be provided with urethane foam formed so that the spring constants are partially different.

  Note that the flexible plate-like body 10 also has a low spring constant when pressed in the thickness direction by a pressure plate having a diameter of 30 mm, preferably the same as the spring constant of the buttocks muscle of the human body, like the soft cushion material 20. Or lower than equivalent. As a result, the flexible plate-like body 10 and the soft cushion material 20 are balanced in a state where the spring constant is low. Therefore, when acceleration fluctuation occurs in the sitting state, the flexible plate-like body 10 and the soft cushion material 20 Both 20 are sensitively deformed. When such a sensitive deformation occurs, it is sensitive to the movement of the seated person and gives a stable feeling of support while being arranged in a limited small space.

  Further, the soft cushion material 20 is not used in one layer in order to give freedom in the front-rear direction stroke, left-right, up-down, and rotational directions, but as shown in FIG. It is preferable to form it so as to have a shape including two cylindrical portions 20a and 20b in the vertical direction along the direction, that is, an approximately 8-character cross section.

  Further, the lateral ridge portion 10 c of the flexible plate-like body 10 bites into the soft cushion material 20 in a linear manner when a human load is applied. The action becomes an anchor effect, and receives the force (shift force) that tries to shift to the left and right while relaxing the force in the left and right direction. In addition, rotation is also generated in the front-rear, up-down, left-right directions, and the support surface also rotates subtly. That is, it is elastically supported by the soft cushion material 20 and is not completely fixed, but the lumbar support member 1 of the present embodiment has a function of receiving such a displacement force. As it is affixed to the human body, it supports the trunk in a so-called “semi-floating state”.

  The flexible plate-like body 10 and the soft cushion material 20 are laminated so that the lateral ridge portion 10 c of the flexible plate-like body 10 is on the side in contact with the soft cushion material 20. For this reason, the clearance gap 11 is ensured between the soft cushion material 20 by the horizontal convex strip part 10c (refer FIG. 4). Since the air permeability is ensured by the gap 11, there is also an effect of suppressing stuffiness in the back of the person.

  The flexible plate-like body 10 and the soft cushion material 20 are provided on the back side of the cushion material located in the waist portion in the seat back portion of the seat structure for a transport device such as an automobile in the order of lamination as described above. As described above, the seat cushion 100 can of course be directly incorporated into a seat structure mounted on a transport device such as an automobile. However, as in the present embodiment, the seat cushion 100 used by being disposed on a seat structure for a transport device. It can also be provided on the back side of the cushion material located at the waist of the seat back portion 110.

  In consideration of the ease of incorporation into the seat structure and the seat cushion 100, the flexible plate-like body 10 and the soft cushion material 20 are placed in the bag member 30 as shown in FIGS. It is preferable to arrange them in a stacked state and unitize them. The material of the bag member 30 is not limited, and in addition to a two-dimensional cloth material, a three-dimensional solid knitted fabric or the like can be used for the purpose of giving a stroke.

  Here, in the seat cushion 100 of the present embodiment, the seat back portion 110 and the seat cushion portion 120 are integrally formed so as to abut on the surfaces of the seat back portion and the seat cushion portion of the seat structure for transport equipment. And is fixed to the seat structure for a transport device using belt members 130 provided at the upper and side portions of the seat back portion 110 and at the boundary portion between the seat back portion 110 and the seat cushion portion 120, respectively. The lumbar support member 1 in which the movable plate-like body 10 and the soft cushion material 20 are accommodated in the bag member 30 has a hook-and-loop fastener 30a provided on the bag member 30 as shown in FIGS. It is attached by joining to a surface fastener 110a provided on the back surface of the seat back portion 110. It is also possible to fix by sewing instead of using a hook-and-loop fastener.

  On the other hand, FIG. 9 is a view schematically showing a center cross section of the transport equipment seat structure 200. As described above, in the case of the transport equipment seat structure 200, the pocket portion 211 is formed on the back surface of the seat back portion 210, and the above-described lumbar support member 1 is inserted inside the pocket portion 211. preferable. Since the lumbar support member 1 is not directly connected to the skeleton such as the back frame constituting the seat back portion 210 by being accommodated and arranged in the pocket portion 211 in this way, the followability to the trunk is provided. Becomes higher. In addition, such a pocket part can also be provided in the back side of the seat back part 110 of the cushion 100 for seats shown in FIG.1 and FIG.2.

  Further, as shown in FIG. 10, the flexible plate-like body 10 has longitudinal ridges 10d along the height direction of the seat back portions 110 and 210 at both ends in the width direction of the lateral ridges 10c. Furthermore, it can also be set as the structure laminated | stacked. Thereby, when a human load is applied, the longitudinal ridges 10d and 10d at both ends serve as fulcrums, the lateral ridges 10c are more easily bent, and the stroke amount is also increased. Moreover, as shown in FIG. 12, each horizontal convex part 10c becomes thick gradually as it goes to each width direction edge part 10e (the protrusion height of the horizontal convex part 10c increases). It can also be. According to this aspect, the stroke amount can be increased without providing the vertical ridges.

Test Example 1:
(Test conditions)
A seat cushion 100 provided with a lumbar support member 1 at a position corresponding to the waist of the seat back portion 110 shown in FIGS. 1 to 7 on a commercially available car seat structure fixed on a six-axis vibrator. Placed. In the test, when the subject sits on the seat cushion 100, the seat cushion 100 is removed together with the lumbar support member 1, and the subject directly sits on the seat back portion and the seat cushion portion of the seat structure for an automobile. I went there when I sat down. The 6-axis shaker reproduces the vibrations obtained by driving in a city. All test times are 30 minutes.

(Head acceleration frequency analysis)
The longitudinal acceleration, lateral acceleration, and vertical acceleration of the head were measured with an accelerometer attached to the subject's head. The results are shown in FIGS. In FIG. 12, “With twin lumbar” is when the seat cushion 100 is used, and “Without twin lumbar” is when the seat cushion 100 is removed. FIGS. 13A to 13C are frequency analysis results of an accelerometer installed on the shaker table, and show input vibration. It can be seen that the input vibration is almost the same in both cases of “with twin lumbar” and “without twin lumbar” (in FIG. 13, the thin line in the case of “without twin lumbar” indicates “with twin lumbar”. Is not clearly visible because it overlaps the thick line.

  From FIG. 12 (a), with regard to the longitudinal acceleration, although “with twin lumbars” has a smaller power spectrum in the vicinity of 1.6 Hz to 2 Hz, no significant difference is observed in other frequency bands. On the other hand, for the lateral acceleration in FIG. 12B, the power spectrum of “with twin lumbar” is significantly smaller than the power spectrum of “without twin lumbar” in the vicinity of 2.5 Hz to 4.5 Hz. I understand. Similarly, in the vertical acceleration of FIG. 12C, the power spectrum of “with twin lumbar” is significantly smaller than the power spectrum of “without twin lumbar” in the vicinity of 2.5 Hz to 5 Hz. This is because the lumbar support member 1 disposed in the seat cushion 100 of the present invention has the above-described “anchor effect having a stroke” and “the stroke in a semi-floating state”, which are caused by the lateral displacement generated by the input of the left-right vibration. By "supporting", it is even by changing the direction to rotate the trunk. By converting the motion in the left-right direction into a rotational motion, the lateral acceleration is reduced. However, if such a rotational motion is likely to occur, the vertical motion is also suppressed, resulting in a decrease in the vertical acceleration.

(Fatigue comparison analysis)
FIG. 14 is a graph in which the degree of fatigue of the subject in each state of “with twin lumbar” and “without twin lumbar” is examined. The sensory evaluation of the subject was also shown along with the degree of fatigue. The degree of fatigue was determined by a method proposed by the present applicant in WO2005 / 039415A1. That is, during measurement, the fingertip plethysmograph is attached to the subject's finger, the power value is obtained from the time series data of the obtained fingertip plethysmogram, and the time series signal of the slope of the power value is subjected to absolute value processing. In this method, the integral value is calculated and the integral value is obtained as the fatigue level. FIG. 14 shows that the degree of progress of fatigue in the case of “with twin lumbar” is lower than that in the case of “without twin lumbar”. This is consistent with the sensory evaluation.

  Further, the number of occurrences of the subharmonic in each state of “with twin lumbar” and “without twin lumbar” is shown as a graph in FIGS. 15 and 16. FIG. 15 shows, in time series, the number of occurrences of the subharmonic in which high frequency vibration of 2.5 to 5 Hz is added to the 1 Hz waveform that is the characteristic change point and frequency band shown in FIG. FIG. 16 shows the number of occurrences of subharmonic in the entire frequency band. Looking at the total number of occurrences of the subharmonic in FIGS. 15 and 16, the total number of occurrences of “with twin lumbar” is less than that in the case of “without twin lumbar”. This shows the same tendency as the curve of the fatigue degree shown in FIG. 14, and it was found that there is a correlation between the number of occurrences of the subharmonic and the fatigue degree.

  Further, in each state of “with twin lumbar” and “without twin lumbar”, the head acceleration waveform of 2.5 to 5 Hz, which is the characteristic frequency band shown in FIG. 12, and the crest factor threshold value are 2 or more. The waveforms are also shown in FIG. In the case of “with twin lumbar” in FIG. 17A, both the head acceleration waveform and the crest factor waveform have substantially equal amplitudes in the vertical direction with reference to the zero point. This is due to the fact that a uniform motion occurs due to vibration, that is, a rotational motion centered on the trunk. On the other hand, in the case of “no twin lumbar” in FIG. 17B, the crest factor waveform is unevenly distributed above the zero point with respect to the head acceleration waveform. This means that when a vibration is input, the human body is not displaced evenly from side to side, but an impact of a predetermined level or more is biased to only one of them.

  Further, when the number of times that the threshold value of the crest factor is equal to or greater than 2 is accumulated, as shown in FIG. 18, the number of times that the “twin lumbar exists” threshold is exceeded is smaller than that in the case of “no twin lumbar”. This shows the same tendency as the curve of the fatigue level shown in FIG. 14, and it has been found that there is a correlation between the number of times the crest factor exceeds a predetermined threshold and the fatigue level.

Test example 2:
(Body pressure distribution)
Slalom (pylon slalom) traveling was performed using a drive simulation device. When the twin lumbar of the present invention is set on the seat of the drive simulation device (with twin lumbar), when sitting on the seat of the drive simulation device as it is (without twin lumbar), a commercially available seat cushion with built-in urethane foam is used. Slalom running was performed under each condition when set on the seat of the drive simulation device. In the case of “with twin lumbar”, the measurement was performed twice. The results are shown in FIGS.

  With “twin lumbar”, the support pressure in the vicinity of the waist is high at both timings from the start of measurement in both the first time and the second time. The support pressure near the lumbar region and the support pressure near the shoulder ribs are changed to the left and right until the point where the point is changed from left to right at 37.8 seconds after the point where the point is changed from left to right at 36 seconds. It does not spread out and is concentrated in almost the same position. This indicates that in the state of “with twin lumbar”, the trunk performs a rotational motion about the spinal column with respect to the input of lateral acceleration, and it can be seen that the lateral displacement force is suppressed. .

  In the case of “without twin lumbar” and the case of using “commercial seat cushion”, it can be seen that the pressure application range is expanded to the left and right due to the lateral acceleration compared to the time when the measurement was started. FIG. 23 shows the body pressure distribution of FIG. 22 with a different pressure scale. The body pressure distribution of “no twin lumbar” and “commercial seat cushion” is indicated by a circle. The pressure value appears at the position, and it can be seen that the range where the pressure is applied is clearly expanded to the left and right than at the start of measurement.

DESCRIPTION OF SYMBOLS 1 Lumber support member 10 Flexible plate-like body 10c Horizontal convex part 10d Vertical convex part 20 Soft cushion material 20a, 20b Cylindrical part 30 Bag member 100 Cushion for seat 110 Seat back part 200 Seat structure for transportation equipment 210 Seat Back part 211 Pocket part

Claims (14)

A lumbar support member disposed in the seat back portion,
The seat back portion has a predetermined dimension along the width direction and the height direction, and a plurality of lateral ridges along the width direction protrude on the back surface at arbitrary intervals in the height direction. A flexible plate,
It is arranged on the back side of the flexible plate-like body and has a laminated structure with a soft cushion material having a lower spring constant when pressed in the thickness direction by a pressure plate having a diameter of 30 mm than the flexible plate-like body. A lumbar support member.   2. The lumbar support member according to claim 1, wherein a dimension along a height direction of the seat back portion in the lateral ridge portion of the flexible plate-like body is in a range of 10 to 40 mm.   The lumbar support member according to claim 1, wherein an elastic covering material is attached to the back surface of the flexible plate-like body.   The lumbar support member according to any one of claims 1 to 3, wherein the flexible plate-like body is formed of a bead foam.   The lumbar support member according to any one of claims 1 to 4, wherein the lateral protrusions of the flexible plate-like body have a shape in which the thickness increases toward each end in the width direction.   The longitudinal convex part along the height direction of the said seat back part is further laminated | stacked on the width direction both ends of the horizontal convex part of the said flexible plate-shaped object, The any one of Claims 1-5. Lumber support member.   The soft cushion material comprises a three-dimensional solid knitted fabric, and a spring constant when pressed in a thickness direction by a pressure plate having a diameter of 30 mm is equal to or less than a spring constant of a human buttocks muscle. The lumbar support member according to any one of the above.   The soft cushion material comprises urethane foam formed so that the spring constants are partially different, and the spring constant when pressed in the thickness direction by a pressure plate with a diameter of 30 mm is the spring constant of the human buttocks muscle The lumbar support member according to any one of claims 1 to 6, wherein the lumbar support member is equal to or less than the same.   9. The lumbar support member according to claim 7, wherein the soft cushion material has two cylindrical portions formed vertically in parallel with each other along a height direction of the seat back portion.   The lumbar support member according to any one of claims 1 to 9, wherein the flexible plate-like body and the soft cushion material are accommodated in a state of being laminated in a bag member and unitized. A seat structure for a transport device having a seat cushion portion and a seat back portion,
The lumbar support member according to any one of claims 1 to 10, wherein the lumbar support member is provided on a back side of a cushion material located on a waist portion of the seat back portion.   12. The seat structure for a transport device according to claim 11, wherein the lumbar support member is accommodated in a pocket portion formed on a back side of a cushion material located at a waist portion in the seat back portion. A cushion for a seat used on a seat structure for a transport device,
The lumbar support member according to any one of claims 1 to 10, wherein the lumbar support member is provided on a back side of a cushion material located on a waist portion of a seat back portion of the seat cushion.   The seat cushion according to claim 13, wherein the lumbar support member is accommodated in a pocket portion formed on a back side of a cushion material located at a waist portion in the seat back portion.