Patent Description:
Automotive comfort systems with air bladders for shaping the seat cushion or the backrest of an automotive seat are known. Presently such comfort systems comprise motor actuated air pumps that supply compressed air to fill air bladders with the desired amount of air. Further, the filling and release of air of such air bladders is usually controlled by solenoid air valves.

Further, the document <CIT> discloses generally a pump on a piezoelectric basis that is used for filling an air bladder within a headrest of a vehicle seat.

The documents <CIT> and <CIT> disclose miniature integrated fluid systems produced by an integrated method. The miniature fluid systems are applicable for example in micro pumps, micro atomizers, print heads or industrial printers.

The document <CIT> discloses a piezoelectric pump in which the common passive one-way inlet and outlet valves are replaced by an actively inlet valve and active outlet valve. The active valves can be electrically actuated and controlled.

The document <CIT> discloses a multi-valve module having a ceramic piezoelectric actuator for a seat having a pneumatically controlled air cell.

However, there is still a need to further improve automotive comfort systems comprising air bladders.

The above-mentioned problem is solved by a pump valve arrangement according to claim <NUM> and by a comfort system for a vehicle seat according to claim <NUM>.

Particularly, the above mentioned problem is solved by a pump valve arrangement for providing compressed air to air bladders of an automotive comfort system within a vehicle seat, the pump valve arrangement comprising a piezoelectrically actuated air pump for providing compressed air, the air pump comprising at least one piezoelectric element for actuating the air pump; a plurality of electrically actuated air valves for selectively filling, holding the pressure and releasing air from the air bladders, wherein the air valves are in fluid connection with the air pump; a housing; and a printed circuit board that is arranged within the housing, and the air valves are electrically connected to the printed circuit board; wherein the air valves are arranged within the housing; and the air pump and the air valves are mounted adjacent to each other without relative movement.

The pump valve arrangement provides an integration of all mechanical components for filling, holding the pressure and releasing a plurality of air bladders of an automotive comfort system within one integrated unit. This integration into a structural unit saves additional parts and mounting effort. Further, the pump valve arrangement unit due to the integration requires less space than conventional solutions. Since the air pump is piezoelectrically actuated by its piezoelectric element, large and costly mechanical parts, like electric pump motors or mechanical pumps can be saved. This particularly decreases the overall weight compared to standard pumps and valve arrangements and further decreases costs and space consumption. Further, the air pump and the air valves can be actuated by a common control electronics since they are mounted adjacent to each other and without relative movement. This reduces effort for the actuation electronics as well as mounting and wiring effort.

Preferably, the air pump are electrically connected to the printed circuit board. The printed circuit board provides electrical control signals to the air pump and the air valves.

Preferably, at least one of the air pump and the air valves are additionally mechanically connected to the printed circuit board. In addition to electrically controlling the air pump and/or the air valves the printed circuit board can also mechanically support these elements. Thus, the printed circuit board can be the only element mechanically holding the air pump and/or the air valves and replace other mechanical holding elements. This is particularly useful as a piezoelectrically actuated air pump is very lightweight. The pump may be fixed on the printed circuit board with its soldered contacts for ease of construction. This may further provide an overall smaller pump valve arrangement.

Preferably, the air pump and/or the air valves are mechanically connected to the housing. The air pump and the air valves can also be connected to the housing for additional mechanical stability.

Preferably, the air pump is mechanically connected to the printed circuit board and/or to the housing by at least one screw and/or welded plastic pin and/or soldered electrical pin and/or rivet and/or glue. These mounting elements provide a stable mechanical connection for the air pump and are easy to produce, particularly since the air pump is very lightweight such that only small dimensions of the mounting elements are required.

Preferably, the fluid connection length between the air pump and the air valves is <NUM> or less, preferably <NUM> or less, or preferably <NUM> or less, or preferably <NUM> or less, or preferably <NUM> or less. Since the piezoelectrically actuated air pump is small compared to ordinary air pumps it can be easily arranged close to the arrangement of the air valves. Thus, the fluid connection between the air pump and the air valves can be very short.

Preferably, the air pump is mounted within the housing. Thus, a pump valves unit is provided that can be integrated as one piece into the vehicle seat, preferably directly into the backrest.

Preferably, the air pump is arranged outside the housing. If the air pump is arranged outside the housing a smaller housing and more design flexibility can be obtained.

Preferably, the air pump is fluidly connected to the air valves via a tube. The connection between the air pump and the air valves can be established by a tube, preferably by an elastic tube. This again increases the design flexibility.

Preferably, the air pump is mounted on an outer side of the housing.

Preferably, the air pump and the housing are both connected to a common protection plate. The connection plate can be mounted within the vehicle seat, preferably within the backrest of the vehicle seat, at an appropriate position and carry the air pump and the housing with the valves inside.

Preferably, the air pump is a double action piezoelectric air pump comprising a piezoelectric membrane that separates two air chambers within the air pump. A piezoelectric membrane integrates the function of the membrane with the piezoelectric actuation in one single element. The piezoelectric membrane is arranged to compress air if a corresponding electrical voltage is applied. Thus, no additional air membrane or air piston or the like are necessary in the air pump, what makes the pump valve arrangement very reliable and robust. In a double action piezoelectric air pump the piezoelectric membrane commonly actuates two pump air chambers and pumps air in both movement directions. This minimizes the components of the pump portion and doubles the pumping power of the pump piezoelectric element.

Preferably, the air pump comprises two air outlets which are connected to the air valves via an air connector having two air inlets and one air outlet. The air connector preferably connects the two air chambers of the double action piezoelectric air pump and provides for a single air outlet. Preferably, the pump valve arrangement further comprises a control electronics for controlling the air pump and/or the air valves, wherein the control electronics is arranged within the housing and/or is mounted to the printed circuit board. Thus, the pump valve arrangement is a unit that provides all functions for controlling the air volume or air pressure within a plurality of air bladders within a vehicle seat.

In the following, preferred embodiments of the invention are disclosed by reference to the accompanying figures, in which shows:.

In the following preferred embodiments of the invention are described with respect to the figures.

As shown in <FIG> a pump valve arrangement <NUM> is part of a comfort system <NUM> arranged within the backrest <NUM> or a seat cushion <NUM> of an automotive seat <NUM>. Preferably, the pump valve arrangement <NUM> is connected to a plurality of air bladders <NUM> of the comfort system <NUM> via air conduits <NUM> and provides for a controlled inflation and deflation of the air bladders <NUM>. The pump valve arrangement <NUM> has the following functionality: An air pump <NUM> takes in air from the ambient, compresses it to some extend and provides this compressed air to the filling air valves <NUM>. A selected one of the filling air valves <NUM> opens electrically and provides the compressed air to a respective air bladder <NUM> via a respective air conduit <NUM>. If the respective filling air valve <NUM> closes the air pressure is maintained within the respective air bladder <NUM>. Further, the pump valve arrangement <NUM> is able to release the air in a controlled manner from the air bladder <NUM> to the ambient by opening a selected one of electrically actuated release air valves <NUM>.

The filling air valves <NUM> and the release air valves <NUM> could be of the same type or be the same valves. Preferably, the filling air valves <NUM> and the release air valves <NUM> are <NUM>/<NUM>-way valves, <NUM>/<NUM>-way valves or <NUM>/<NUM>-way valves. In other embodiments the filling air valves <NUM> may be of a different type than the release air valves <NUM>. In a preferred embodiment the filling air valves <NUM> and the release air valves <NUM> are preferably <NUM>/<NUM>-way solenoid valves.

In a further embodiment shown in <FIG> the pump valve arrangement <NUM> comprises three <NUM>/<NUM>-way valves <NUM>, preferably three <NUM>/<NUM>-way solenoid valves <NUM>. In this embodiment one <NUM>/<NUM>-way filling air valve <NUM> and one <NUM>/<NUM>-way release air valve <NUM> of the embodiment of <FIG> are functionally combined into one <NUM>/<NUM>-way air valve <NUM>. Thus, for the filling and release of one air bladder <NUM> only one <NUM>/<NUM>-way air valve <NUM> is necessary. This may reduce the size and complexity of the pump valve arrangement <NUM> compared to the embodiment of <FIG>. Such <NUM>/<NUM>-way air valves <NUM> can be used in any of the embodiments instead of the <NUM>/<NUM>-way filling air valves <NUM> and the <NUM>/<NUM>-way release air valves <NUM>.

<FIG> shows a three-dimensional view of a pump valve arrangement <NUM> for supplying three air bladders <NUM> with compressed air. The pump valve arrangement <NUM> comprises a piezoelectrically actuated air pump <NUM> and three electrically actuated filling air valves <NUM> that are fluidly connected to the air pump <NUM>. Further, the pump valve arrangement <NUM> comprises three electrically actuated release air valves <NUM> that are also fluidly connected to the air pump <NUM> and to a respective one of the conduits <NUM> to the air bladders <NUM>. The conduits <NUM> are connected to respective air sockets <NUM> (see <FIG> and <FIG>) of the filling air valves <NUM>.

In the embodiment of <FIG> and <FIG> the air valves <NUM>, <NUM> and the air pump <NUM> are electrically and mechanically connected to a common printed circuit board (PCB) <NUM>. The printed circuit board <NUM> further comprises electric control electronics (not shown) and an electrical connector <NUM> for connecting the PCB <NUM> with an electric or electronic bus of the vehicle.

The pump valve arrangement <NUM> comprises a housing <NUM>. The housing <NUM> can be opened and preferably comprises two housing halves <NUM>, <NUM> (see <FIG>), wherein in <FIG> only the lower housing half <NUM> is shown. In the embodiment of <FIG> the air pump <NUM> and the plurality of air valves <NUM>, <NUM> are arranged within the housing <NUM>. The housing <NUM> further comprises mounting eyes <NUM> that can be used to mount the pump valve arrangement <NUM> with the vehicle seat <NUM>. The mounting eyes <NUM> can be used in combination with plastic fastener bolts <NUM> as shown in <FIG> or any other suitable mounting means.

The air pump <NUM> is piezoelectrically actuated. Thus, it comprises a piezoelectric element (not shown) that moves a piston or a membrane within the air pump <NUM>. In a preferred embodiment the air pump <NUM> comprises a piezoelectric element in the form of a pump piezoelectric membrane that directly compresses air within the air pump.

Preferably, the air pump <NUM> is a double action piezoelectric air pump, wherein piezoelectric membrane that separates two air chambers within the air pump <NUM>. In this embodiment the piezoelectric membrane separates the interior of the air pump into a first pump air chamber on one side of the pump piezoelectric membrane and a second pump air chamber on the other side of the pump piezoelectric membrane. The pump piezoelectric membrane is preferably a thin circular disc that is able to reciprocally deform or swing in two directions if a corresponding actuation voltage is applied to it. By this movement reciprocally an overpressure and an underpressure is generated in each of the two pump air chambers. The pump piezoelectric membrane is mounted by its periphery to side walls of the air chambers.

The double action piezoelectric air pump <NUM> comprises two air outlets <NUM>, one for each of the two air chambers (see <FIG>). An air connector <NUM> is provided for connecting the two air outlets <NUM> with the plurality of air valves <NUM>, <NUM>. The air connector <NUM> comprises two air inlets <NUM> that are fluidly connected to the air outlets <NUM> and one air outlet <NUM> that is fluidly connected to a distribution conduit <NUM> of the air valves <NUM>, <NUM>.

As shown in <FIG> the air connector <NUM> comprises a plastic housing <NUM> that forms a cavity and provides the air outlet <NUM>. The air connector <NUM> further comprises an elastomeric insert <NUM> placed within the housing cavity, wherein the insert <NUM> forms the two air inlets <NUM>. Due to the elastomeric insert <NUM> an air-tight connection of the air connector <NUM> to the air pump <NUM> is provided.

<FIG> show three different possibilities to mechanically mount the air pump <NUM> to the printed circuit board <NUM>. In the embodiment of <FIG> the air pump <NUM> is mounted to the printed circuit board <NUM> via plastic pins <NUM> of the air pump <NUM>. The plastic pins <NUM> extent through holes within the printed circuit board <NUM> and are heat welded at the underside of the printed circuit board <NUM> to form an expanded head. The plastic pins <NUM> only provide a mechanical connection of the air pump <NUM> with the printed circuit board <NUM>. The electrical connection of the air pump <NUM> with the printed circuit board <NUM> is established separately, i. e with wires or electrical pins, like pins <NUM> (see <FIG>).

In the embodiment of <FIG> the air pump <NUM> is mounted to the printed circuit board <NUM> via electrical pins <NUM> of the air pump <NUM>. The electrical pins <NUM> are metallic and extend through holes in the printed circuit board <NUM> and are then welded from the underside of the printed circuit board to electric traces thereof. Thus, the soldered electrical pins <NUM> provide both an electric and a mechanical connection of the air pump <NUM> with the printed circuit board <NUM>.

In the embodiment of <FIG> the air pump <NUM> is mounted to the printed circuit board <NUM> by screws <NUM>. The screws <NUM> extend through holes of the printed circuit board <NUM> and are screwed from the underside of the printed circuit board <NUM> into receptacles <NUM> of the air pump <NUM>. The screws <NUM> provides a mechanical connection of the air pump <NUM> with the printed circuit board <NUM>. The electrical connection of the air pump <NUM> with the printed circuit board <NUM> is established separately, i.e. with wires or electrical pins, like pins <NUM> (see <FIG>).

<FIG> and <FIG> show further embodiments of a pump valve arrangement <NUM> in which the air pump <NUM> is mounted outside a housing <NUM>. Unlike the housing <NUM> of <FIG> the housing <NUM> does not house the air pump <NUM> and can thus be smaller in size. The housing <NUM> comprises an upper <NUM> and a lower housing half <NUM> which are connected to each other. The housing <NUM> houses the printed circuit board <NUM> and the plurality of air valves <NUM>, <NUM>. The housing <NUM> comprises mounting eyes <NUM> for mounting the pump valve arrangement within the vehicle seat <NUM>.

In the embodiment of <FIG> the air pump <NUM> is mounted on the outer side of the housing <NUM>, preferably on the free side of the upper housing halve <NUM>. Preferably the air pump <NUM> is mounted by screws that are screwed from the interior of the upper housing half <NUM> into receptacles <NUM> of the air pump <NUM>. The receptacles <NUM> are part of the housing of the air pump <NUM> and are extending to the outside of the of the housing such that the air chambers withing the air pump <NUM> can have a preferably circular section which is optimal for a circular disc shaped piezoelectric membrane (not shown) of the air pump <NUM>.

In the embodiment of <FIG> the outlet of the air connector <NUM> is connected to the air valves <NUM>, <NUM> within the housing <NUM> via a tube <NUM>. In the embodiment of <FIG> preferably a U-shaped tube <NUM> is used.

The fluid connection between the air pump <NUM> and the air valves <NUM>, <NUM> is <NUM> or less, preferably <NUM> or less, or preferably <NUM> or less, or preferably <NUM> or less, or preferably <NUM> or less. In the embodiment of <FIG> the tube <NUM>, which provides the fluid connection in this embodiment, has a length of ca.

In the embodiment of <FIG> the air pump <NUM> and the housing <NUM> are both connected to a common protection plate <NUM>. The air pump <NUM> is preferably mounted to the protection plate <NUM> via plastic rivets or plastic fastener bolts <NUM> that are inserted into holes of the protection plate <NUM> and which extend into corresponding receptacles <NUM> of the air pump housing. Similarly, the housing <NUM> is mounted to the protection plate by plastic rivets or plastic fastener bolts <NUM>. The protection plate <NUM> is mounted within the vehicle seat <NUM> at an appropriate position.

Claim 1:
Pump valve arrangement (<NUM>) for providing compressed air to air bladders (<NUM>) of an automotive comfort system (<NUM>) within a vehicle seat (<NUM>), the pump valve arrangement (<NUM>) comprising:
a. a piezoelectrically actuated air pump (<NUM>) for providing the compressed air, the air pump (<NUM>) comprising at least one piezoelectric element for actuating the air pump (<NUM>);
b. a plurality of electrically actuated air valves (<NUM>, <NUM>, <NUM>) for selectively filling, holding the pressure and releasing air from the air bladders (<NUM>), wherein the air valves (<NUM>, <NUM>, <NUM>) are in fluid connection with the air pump (<NUM>);
c. a housing (<NUM>, <NUM>); and
d. a printed circuit board (<NUM>) that is arranged within the housing (<NUM>, <NUM>), and the air valves (<NUM>, <NUM>, <NUM>) are electrically connected to the printed circuit board (<NUM>); wherein
e. the air valves (<NUM>, <NUM>, <NUM>) are arranged within the housing (<NUM>, <NUM>); and
f. the air pump (<NUM>) and the air valves (<NUM>, <NUM>, <NUM>) are mounted adjacent to each other without relative movement.