WO2021104731A1

WO2021104731A1 - Motor vehicle seat having a recess and associated motor vehicle

Info

Publication number: WO2021104731A1
Application number: PCT/EP2020/078166
Authority: WO
Inventors: Christian Kuhley; Jürgen Maier; Eduard Wolf
Original assignee: Psa Automobiles Sa
Priority date: 2019-11-27
Filing date: 2020-10-07
Publication date: 2021-06-03
Also published as: EP4065415A1; DE102019218361A1

Abstract

The invention relates to a motor vehicle seat (7), comprising a seat base (2) and a backrest (5), the seat base (2) being delimited, from the point of a view of a sitting person, laterally to the left and to the right by respective side bolsters (8, 8'), and a recess (3) being provided in the seat base (2) as coccyx relief for the sitting person.

Description

MOTOR VEHICLE SEAT WITH A RECESS AND ASSOCIATED MOTOR VEHICLE Description

The invention relates to a motor vehicle seat, in the seat surface of which a Ausspa tion is provided as a pressure relief for a seated person, and to a motor vehicle with such a vehicle seat.

For use by an occupant, motor vehicle seats must have certain ergonomic properties in order to be able to accommodate this occupant in a sitting position for a long period of time. In addition, they should allow the driver to carry out his task, in the case of a vehicle the task of operating the vehicle, without putting too much strain on the human body. These include, for example, suitable seat surface lengths and widths, suitable lateral support in the seat cushion and the backrest, a suitable backrest height, suitable shoulder and lumbar support, etc. These properties can be summarized in the seat surface geometry that support the human body at predetermined points to allow an ergonomic sitting position. The aim is to take up the human body in the most natural possible posture, derived from the standing position.

When the occupant is specifically seated in a vehicle seat, it should be avoided that body regions are stressed that are not exposed to any stress during a natural posture. As described, the upright posture is the most natural for the human body. In this position, there is no weight on the tailbone.

The weight of the upper body is transferred through the lumbar vertebrae, the hips, the thigh joints and finally into the leg bones. If the occupant now sits in a vehicle seat, then a surface pressure is exerted on the buttocks. This pressure is also transmitted to the tailbone and ultimately to the lumbar vertebrae. This load path does not correspond to the naturally intended load of the Bone structure in the region of the coccyx, which can lead to long-term back pain caused by muscle tension in the lower lumbar vertebrae. This load is not taken into account in conventional vehicle seats, which is a problem.

US 2016/0200226 A1, DE 297 18 922 U1 and WO 96 / 11614A1 each disclose a vehicle seat with a recess for relieving pressure, among other things, of the coccyx. The recess extends all the way to the rear, i.e. to the very rear edge of the seat cushion, where the hinge area of the backrest is. The earlier priority DE 102019202295.2, which goes back to the applicant, describes a method with which the geometric data of a recess in the seat surface of a motor vehicle seat are determined in order to ensure relief of the coccyx.

It is an object of one embodiment of the invention to provide a motor vehicle seat with a recess in its seat surface and a motor vehicle equipped therewith which, through exact positioning, offers pressure relief where it is actually needed by the seated person and has the potential to be particularly small and / or to be designed to be elegant.

Another task can be seen in optimizing the pressure relief for the coccyx area.

These and other tasks are solved by the independent claims. Advantageous further developments result from the dependent claims.

According to one embodiment of the invention, a motor vehicle seat with a seat surface and a backrest is proposed in which the seat surface from the perspective of a seated person is bounded on the left and right by a side cheek and in which a recess is provided in the seat surface as a coccyx relief for a seated person is provided. With this choice of vehicle seat, because of the side bolsters, a seated person will move less to the side, i.e. in the transverse direction of the vehicle or in the direction of the hinge axis of the backrest, and during a journey their tailbone will be above the recess responsible for relieving the stony bone for longer. The pressure relief is improved by the lateral fixation of the seated person.

According to a second embodiment, the side cheeks are designed so that they can be spaced apart from one another. This adjustment option, which is provided in the transverse direction of the vehicle or in the direction of the hinge axis of the backrest, is adapted to the body dimensions of the seated person in the area of the seat surface or hip. This prevents a person who is narrow or petite in the hip area from sliding sideways on the seat surface through side cheeks that are too far apart, for example in a curve, and prevents the coccyx from being arranged above the recess.

It is also possible for the recess to have a ramp-shaped profile upwards, as seen in the direction of view of the seated person. As a result, dirt particles or crumbs that collect in the recess can be removed more easily and the production of the recess is easier.

Furthermore, a recess can be selected that is designed to be closed when viewed in the opposite direction to the direction in which the seated person is looking. In this embodiment, the hinge area of the backrest is spaced from the recess, which avoids unpleasant drafts in the area of the lower spine.

In a further embodiment, a cutout with straight edges is chosen, i. H. with straight edges in the plane of the seat. This makes it easier to line the recess with a seat cover on the inside.

In a further embodiment, 20 mm is selected as the minimum depth of the recess. The depth is measured in the geodetic direction. At a shallower depth, there is largely no more pressure relief. An aesthetically more appealing, because less prominent, recess is obtained if an elongated recess, which is aligned parallel to the two side cheeks, is provided, the length of which is between 50 mm and 150 mm.

It has proven useful if the recess has a transverse extension, that is, an extension in the transverse direction of the vehicle, between 10 mm and 140 mm, preferably between approx. 30 mm and approx. 75 mm and particularly preferably between approx. 45 mm and approx. 65 mm.

Another aspect of the invention relates to a motor vehicle, in particular a passenger car, with a motor vehicle seat according to one or more of the above-explained execution forms.

The invention is to be explained in more detail below with reference to figures that are not to scale. Here show:

1 shows extracts of a 3D CAD human model,

2 shows a vehicle seat.

The geometric data of the recess, in particular the length, depth and width, are determined using a method which is explained with the aid of FIG. 1.

Fig. 1 shows extracts of a 3D CAD human model 1 in a plane spanned by a torso line T 1 and a leg line B1, which together with the third axis projecting into the plane of the drawing, a coordinate system KS spans a coordinate system. Leg line B1 and torso line T 1, which can each be assigned to a virtual dummy or a seated virtual person, intersect at the origin U1. The arrow of the leg line B1 indicates the direction of view of the 3D CAD human model 1 when it is sitting on the seat surface 2.

In a first step, a torso line T1 and a leg line B1 intersecting it are defined, each of which can be assigned to the virtual dummy. Here define the torso line T1 and leg line B1 two axes of a three-dimensional coordinate system KS with an origin U1 at the point of intersection.

In a second step, the origin U1 of the coordinate system KS is arranged above the seat surface. In this respect, the assignable dummy is virtually placed on the seat.

In the third step, the position of the recess is selected in relation to the coordinate system KS with the proviso that the origin U1 comes to lie above the recess. Through this step, the body region to be relieved is placed in the area of the origin U1 above the recess in order to ensure relief.

The geometry data of the recess are then transformed from the coordinate system KS into the intrinsic coordinate system KS_i of the motor vehicle. KS_i is defined by a torso line T_i and a leg line B_i, which characterize a virtual person or dummy sitting on the real vehicle seat, in particular the driver or front passenger seat. The plane spanned by T_i and B_i is perpendicular to the third axis of KS_i, which runs in the transverse direction of the vehicle or in the direction of the hinge axis of the backrest of the motor vehicle seat. During the transformation, the origin U1 is shifted to the origin U_i of the intrinsic coordinate system KS_i and since then the leg line B1 is pivoted to B_i and the torso line T1 is pivoted to T_i. As a result of the coordinate transformation, the dummy is now virtually positioned on the vehicle seat and the position of the recess is determined in relation to the real vehicle. In the last-mentioned step, the geometry data specified in relation to the intrinsic coordinate system KS_i are selected for the recess in the seat surface.

With the above procedure, the pressure-loaded hip area in the area U1 or U_i and above that also the coccyx can be reliably relieved of pressure and, in particular, a locally limited pressure relief can be created. This avoids large and unsightly recesses in the seat, which brings greater freedom in the design of the seat in terms of size and / or shape of the recess, which promotes acceptance by the customer. The method is carried out with a computer program and thus virtually. There are various commercial products on the market for this, such as the RAMSIS 3D CAD human model from Human Solutions GmbH (DE), with which the ergonomically relevant body dimensions of women, men and children are very small and very large body length can be reproduced.

One can proceed in such a way that the origin U_i of the intrinsic coordinate system KS_i is placed on the H point (hip point) or the R point (seat reference point) of the motor vehicle. The H point and R point are known reference points that are determined by automobile manufacturers individually for each vehicle model. If, as suggested, the origin U_i is placed on the H-point, this choice causes the H-point to lie above the recess, so the ergonomically determined hip area is specifically relieved of pressure. The pressure relief is thus given precisely or locally where it is needed, so that it can be smaller.

The extension of the recess along leg line B1 for relieving pressure on the coccyx can be optimized with the aid of point S, which indicates the position of the coccyx in the coordinate system KS. The position of the coccyx or point S is provided by the calculation software used as part of the 3D CAD human model. The length of the recess, starting from point S, is approximately 30 mm to approximately 130 mm, measured in the direction of view along the leg line B1. The width of this interval results from the fact that in practice the seating positions of the riders vary due to their body size and they also slide a little forwards and backwards while driving. The width of the interval is chosen so that as many drivers as possible have an ergonomic advantage. This comes about because every person, regardless of the percentile, can first adjust the seat lengthways to suit their individual body size. As a result, the spread of the different sitting positions relative to the seat cushion is very small. This spread is covered by the interval.

An alternative procedure compared to that of the last paragraph consists in defining the extension of the recess along the leg line with the aid of second points E1 and E2 in the coordinate system KS. The points E1 and E2 are defined by the fact that they are the intersection points of a circle with a predeterminable radius r and the seat surface from the above point S, a connecting line L extending from point S being perpendicular to the seat surface and symmetrically dividing the arc with its end points E1 and E2. The point S therefore again reflects the position of the coccyx. Here you specify that E1 is further in the viewing direction than E2, so that in the case of a coordinate transformation in KS_i, point E1 in the vehicle comes to be further forward than E2. With this definition, the extension of the recess, starting from point E1 in the viewing direction along the leg line, is a maximum of 100 mm and opposite to this, i.e. opposite to the viewing direction, maximally up to point E2. This embodiment has the same advantages as the procedure in the last paragraph.

If point S is the tailbone tip of the dummy, then the pressure relief is calculated specifically for the tailbone tip.

In the example of Figures 1 and 2, the seat 2 has a recess 3. For positioning, the recess 3 is first arranged below the origin U1. For exact positioning, point S of the coccyx tip is determined and a circle with radius r is drawn around point S, which goes through U1. The radius r can be around 100 mm. A circle 4 intersects the seat 2 at two points E1 and E2. The circular sector defined by the three points E1, E2 and S is symmetrically divided by a connecting line L running perpendicular to the seat surface 2. To this extent, point E1 is also obtained by pivoting connecting line L by an angle a in L ‘; correspondingly, E2 is obtained by pivoting connecting line L by an angle -a in L”.

Starting from this, the recess 3 extends, starting from point E1 in the direction of the leg line B1, a maximum of 100 mm and in the opposite direction up to E2. The depth of the recess 3, determined in the direction of the vertical axis of the intrinsic coordinate system KS_i of the motor vehicle, is approximately 30 mm.

The extension of the recess perpendicular to the plane of the figure is 60 mm. This he makes possible that a seated person is supported with the two seat bumps but that The pressure in the coccyx is relieved through the recess 3. As indicated by the dashed line R, a ramp can be worked into the recess 3, which facilitates the removal of crumbs in the recess when the seat cover lines the recess from the inside.

After defining the geometry data of the recess 3 in the coordinate system KS, a transformation into the intrinsic coordinate system KS_i of the respective vehicle takes place. For this purpose, U1 is placed on U_i, B1 is pivoted to B_i and T 1 is pivoted to T_i.

In the intrinsic coordinate system KS_i, FIG. 2 shows the finished motor vehicle seat 7 with its seat surface 2, which from the perspective of a seated person has two side cheeks 8, 8 ′ and a backrest 5 on the left and right. The side cheeks 8, 8 'are designed to be movable in a direction that runs in the plane of the seat surface 2 and perpendicular to the dashed lines A, A ^' and can be moved by an electric motor. This mobility is indicated by the two arrows protruding from lines A and A '. By varying the distance between the side bolsters, the effectively usable seat surface width is adapted to the body dimensions of the seated person, so that the seated person slides less strongly in the transverse direction of the vehicle, especially when cornering. The coccyx is thus more reliably located above the recess 3, so that the pressure relief is greater.

The recess 3 is quite small, designed with straight edges K and towards the rear, ie to the area of the hinge 6 aligned in the transverse direction of the vehicle, executed ge closed to avoid drafts. The length of the recess in the direction of the leg line B_i is 100 mm, perpendicular to this in the transverse direction of the vehicle it is 45 mm wide.

Claims

1 . Motor vehicle seat (7) with a seat surface (2) and a backrest (5), the seat surface (2) from the perspective of a seated person being laterally bounded on the left and right by a side cheek (8, 8 ') and in which Seat (2) a recess (3) is provided as a coccyx relief for the seated person.

2. Motor vehicle seat according to claim 1, wherein the side cheeks (8, 8 ‘) are designed to be variable in distance from one another.

3. Motor vehicle seat according to claim 1 or 2, wherein the recess (3) seen in the direction of the seated person has a ramp-shaped course upwards.

4. Motor vehicle seat according to one of the preceding claims, in which the recess is designed to be closed when viewed opposite to the direction of view of the seated person.

5. Motor vehicle seat according to one of the preceding claims, in which a recess with straight edges K is selected.

6. Motor vehicle seat according to one of the preceding claims, in which the minimum depth of the recess is 20 mm.

7. Motor vehicle seat according to one of the preceding claims, in which an elongated, parallel to the two side walls (8, 8 ‘) aligned recess (3) is provided, the longitudinal extent of which is between 50 mm and 150 mm.

8. Motor vehicle with a motor vehicle seat (7) according to one of the preceding An

Claims.

9. Motor vehicle according to claim 8, wherein the tailbone or the tip of the stone bone S of a person sitting on the seat surface (2) is arranged above the recess (3).