Seat with variable pressure cavities, which have a flexible support wall

p0001The invention relates to a seat with variable pressure hollow chambers, with the features stated in the preamble of claim 1.

p0002Such a seat is known from DE 35 41 537 A1, which comprises a plurality of air chambers in the seat and back area, which may have different pressure values ​​for setting a specific body pressure distribution. In each air chamber opens a pneumatic line, which can be closed by a valve and is on the one hand with a pressure line and on the other hand connected to an outlet line in which a drain valve is located. In a branching off from the pressure line by-line, a single pressure sensor is disposed, the air chamber to the respective possible by successively connecting these by-line determination of the air pressure in the air chamber. With this arrangement it is not possible at the same time in an air chamber to increase the air pressure and decrease in any other chamber. The pressure line can not be burdened cost of an accumulator with a constant pressure, while opening the drain valve in the outlet of the pressure in the pressure line drops abruptly. With the single pressure sensor, the reciprocal pressure influencing the air compartments are themselves not to acquire or considered. In the seat a few air chambers are merely provided that allow for the locally different surface loads by the seat occupant no targeted relief for example in an area with very high surface pressure.

p0003A similar vehicle seat is disclosed in DE 40 22 433 C2, in which the air chambers are loaded with a rising and falling pressure in order to achieve a massaging effect.

p0004The invention is based is to provide a seat with the features specified in the preamble of claim 1 which allows the loaded of the seat occupant seat areas a local pressure change the task.

p0005This object is achieved by the features specified in patent claim 1. Through the arrangement of several, at least provided with an elastic retaining wall hollow chambers with pressure sensors in the longitudinal direction of the leg support areas as well as in the buttock support region of the pressure in the hollow chambers in question can be lowered to the heavily loaded seat surface areas, whereby the surface pressure is reduced according to the body surface of the seat occupant , In only lightly loaded areas of the pressure in the hollow chambers in question can be increased to achieve a more uniform surface load. The seating comfort is substantially improved. The circulation of the seat occupant can be excited with an alternating, for example wavy progressive change in pressure in the individual chambers, for example to avoid a fatigue of the seat occupant. Once in each hollow chamber has a closable via a valve pressure line and one of a valve closable outlet line opens, single or multiple hollow chambers can be simultaneously connected to the compressed air and other hollow chambers for lowering the pressure to an outlet, said about the pressure sensor in the hollow chambers, the interaction of different pressures are detected in the hollow chambers and correcting system behavior immediately.

p0006Advantageous embodiments of the invention are the subject of dependent claims.

p0007An embodiment of the invention is illustrated by a drawing with a single figure which shows an outline sketch.

p0008In the single figure, a seat of a motor vehicle is shown in simplified form in view of the surface of the seat part 1 and the lower part of the backrest. 2 The climate zone of the seat portion 1 and the backrest 2 is in each case a plurality of hollow chambers 3, 3 'and 3' ', 3' '' split down resilient mat. Each hollow chamber has at least one upper elastic support wall, via which the pressure in the seat supporting surface of the seat occupant is variable. To preserve clarity, only some of the hollow chambers 3, 3 ', 3' ', 3' '' with reference numerals are provided. As can be seen from the figure, five hollow chambers are arranged in succession in the two tavern bearing surfaces 4, 4 '. In tailbone area 5 of the seat occupant is another hollow chamber and in front of it in the buttock support region 6 further nine hollow chambers are arranged approximately like a grid. For lateral support 'the leg support surfaces 4, 4' each, three hollow chambers are laterally outward in a side region 7, 7 arranged in series. Approximately in the lumbar region of the backrest 2 side by side five hollow chambers are horizontally provided, wherein a further hollow chamber 3 '' 'is on the hollow chamber located in the spinal region of the seat occupant. In each hollow chamber 3, 3 ', 3' ', 3' '' is a pressure sensor 8, 8 ', 8' ', 8' '' is provided, for example, below, above or in the upper hollow chamber wall of the respective hollow chamber 3, 3 ', 3' ', 3' '' is arranged. For the sake of clarity only some of the pressure sensor 8, 8 ', 8' ', 8' '' with reference numerals are provided. With reference to the hollow chamber 3 is given hereinafter simplified as the pressure in each of the hollow chambers 3, 3 ', 3' ', 3' 'can be increased or decreased'. In each hollow chamber 3, 3 ', 3' ', 3' '' opens a valve 9 by a closable inlet pressure line 10, the constant pressure is preferably of a regulating device 11 resilient. For this purpose, an accumulator 12 is disposed in the pressure line 10, which is to be charged by a pump 13 or the like, which preferably sucks in air a gaseous or liquid medium from the environment or with formation of the control device as a closed system from a low pressure accumulator. Also opens into each of the hollow chambers 3, 3 ', 3' ', 3' '' a by a discharge valve 14 closable outlet conduit 15 which is connected to the relaxed medium or the ambient air or a low pressure accumulator. The arrows, the inflow and outflow direction is indicated. The pressure sensor 8, 8 ', 8' ', 8' '' are each connected via a pressure sensing line 16 to the control device eleventh In addition, all the intake valves 9 via a respective control line 17 and all the exhaust valves 14 each connected via a control line 18 to the regulating device 11 and controllable by this, to open the inlet in question 9 and exhaust valve 14 and to close. To the control device 11. Further, the pressure accumulator 12 via a line 19 and the pump 13 are connected via a line twentieth In the control device or a data memory which are desired pressure values ​​for all hollow chambers 3, 3 ', 3' ', 3' '' entered or entered manually via controls 21 of the seat occupant and to save. In the driving operation is carried out continuously or according to predetermined or adjustable time periods for all hollow chambers 3, 3 ', 3' ', 3' '' at the same time by detecting the respective pressures in the hollow chambers 3, 3 ', 3' ', 3' '' via the pressure sensor 8, 8 ', 8' ', 8' '' and comparison with the stored target pressure values, a readjustment of the respective pressure in the respective hollow chamber 3, 3 ', 3' ', 3' '' until the measured pressures coincide approximately with the respective desired pressure values. The target pressure values ​​or set by the control device 11 to such values ​​that a fatigue-free sitting without excessive local pressure loading is possible. In the control device 11 are maximum pressure loads for the respective hollow chambers 3, 3 ', 3' ', 3' '' is entered, which are not exceeded. The control device may also be a device, such as an electronic, have detected the constitution and / or seat movements of the seat occupant sensors and it automatically identifies new target pressure values ​​that are important for the control process, the. In the automatic determination of the target pressure values ​​by the regulating device stored pressure distributions and possibly from a particular seat occupant previously set pressure distributions for nominal pressure values ​​are considered. In the exemplary embodiment are all pressure sensors 8, 8 ', 8' ', 8' '' Hydro sensors embedded in liquid piezoresistive pressure sensors, which detect the pressure in the liquid independent of direction. The pressure sensors have for example a diameter of 20 mm and a thickness of about 2 to 3 mm, which are embedded in the hollow chambers having mat. With the variable pressure hollow chambers 3 '', 3 '' 'in the backrest 2, the pressure load can be changed low to the spine of a seat occupant. With the outer hollow chambers 8 '' a lateral back support is effected at lateral accelerations, for example when cornering. A lateral support of the legs of the seat occupant, for example, when cornering is effected via the in the side areas 7, 7 'arranged hollow chambers.

p0009The invention can also be performed by the embodiment notwithstanding. The hollow chambers may be provided only in the seat part of a seat user, or as in the embodiment also on the backrest. The distribution and size of the cavities is arbitrary per se. Preferably, each hollow chamber is provided with a pressure sensor. but it can also be provided other hollow chambers which are not pressure-variable, and therefore have no associated pressure transducer. The inlet and outlet valves can be any valves which are connected, for example to a common valve. Of each respective hollow chamber, air or another gaseous or liquid medium can be added. It is essential that the hollow chamber in the seat portion comprises at least one resilient support wall via the through-pressure change in the hollow chamber of the force acting in the seat supporting surface of seat occupant pressure is locally variable.