Method for operating vehicle seat comfort system

Abstract

The invention relates to a method for operating a vehicle seat comfort system, in which a pneumatic assembly is supplied with fluid by opening and closing at least one solenoid valve. This is accomplished in that the solenoid valve is opened and closed by applying a supply voltage (V) to move a movable part, preferably a piston, of the solenoid valve between an open position and a closed position. In the closing phase of the solenoid valve, the supply voltage (V) of the solenoid valve decreases in the form of a voltage ramp, preferably linearly, or the solenoid valve goes through at least one cycle or a plurality of cycles. Each cycle comprises at least one first phase (P1) and a second phase (P2) temporally following the first phase (P1). The supply voltage (V) of the solenoid valve is adjusted such that, in a first phase (P1), the movable part of the solenoid valve accelerates towards the closed position of the solenoid valve, and, in a second phase (P2), the supply voltage (V) of the solenoid valve is adjusted such that the acceleration of the movable part in the first phase (P1) is decelerated.

Description

Technical Field

[0001] The invention relates to a method for operating a vehicle seat comfort system. Background Art

[0002] Vehicle seat comfort systems are usually controlled by pneumatic systems, in which solenoid valves are used, which have to be opened and closed in order to perform seat comfort functions, such as massage or seat adjustment. In this case, the solenoid valve is loaded with a supply voltage, with the help of which it can be opened and closed. Usually, during opening and closing, two components that interact magnetically with each other (for example, a piston and an electromagnet that interacts with it) often move relative to each other against the preload of a spring, so that the piston or more generally the locking part returns to the closed state when the voltage supply stops. If such a valve is switched, a trigger voltage is required in order to move the piston or the movable locking part from the closed position to the open position. In order to close, the supply voltage V of the solenoid valve must be reduced to such an extent that the movable part of the solenoid valve, or the piston, moves towards the valve seat, i.e. towards its closed position, according to the time t (such as Figure 1 , the supply voltage V of the solenoid valve as a function of time t). The reduction of the voltage level V from the initial value V1 must be below the holding voltage V2, which is understood to be the supply voltage required to generate a sufficiently strong magnetic field in order to hold the solenoid valve in the open position. Depending on how abruptly the supply voltage V is reduced, noises often occur during the switching process, since the piston or the closure element is greatly accelerated and moved toward the valve seat. Summary of the invention

[0003] The object of the present invention is to provide a method for operating a vehicle seat comfort system in which the noise generated when closing the solenoid valves used can be reduced.

[0004] This object is achieved by a method having the features of claim 1 and a vehicle seat comfort system having the features of claim 7. Advantageous embodiments can be found in the dependent claims.

[0005] In the method according to the invention for operating a vehicle seat comfort system, the pneumatic component is supplied with fluid by opening and closing at least one solenoid valve. This is done by opening and closing the solenoid valve by applying a supply voltage. The supply voltage is reduced when the solenoid valve is closed. According to the invention, the supply voltage is varied in a defined manner during the closing phase of the solenoid valve.

[0006] According to a first variant of the invention, the supply voltage is reduced in the form of a voltage ramp. In this case, the voltage level of the supply voltage of the solenoid valve is preferably reduced, in particular to below the holding voltage, which is the minimum voltage required to keep the solenoid valve open. The reduction is carried out in the form of a gradual reduction, that is, not a sudden reduction to zero, but a slow reduction within a predetermined time period. The reduction is preferably carried out linearly. In this way, the movable part of the solenoid valve, such as a piston or a tappet, slowly approaches the valve seat. Noise generation is thereby prevented. The variant is preferably carried out until the solenoid valve is closed, that is, the movable part has reached the closed position. The described voltage ramp can also be realized in that the supply voltage is slightly reduced periodically, that is, in a plurality of cycles, and then slightly increased again, so that the movable part of the solenoid valve is accelerated in a rhythmic manner and at the same time immediately decelerated again by increasing the supply voltage by a small amount, wherein the reduction and increase are both carried out below the above-mentioned holding voltage.

[0007] According to another embodiment of the present invention, the change of the supply voltage is achieved in the following manner, that is, the supply voltage undergoes at least one cycle or multiple cycles. Preferably, this occurs until the electromagnetic valve is closed, that is, the movable part of the electromagnetic valve has reached the closed position. According to the present invention, each cycle includes at least one first phase and a second phase after the first phase in time. After in time does not mean that the second phase must be close to the end of the first phase in time. It is possible that there are one or more other phases of the cycle between the first phase and the second phase. Therefore, after in time only means that the second phase is carried out later than the first phase within a cycle. According to the present invention, the supply voltage of the electromagnetic valve is adjusted so that the acceleration of the movable part of the electromagnetic valve in the first phase is carried out towards the closed position of the electromagnetic valve. It can preferably be provided that in the first phase, the supply voltage is reduced to a level below the holding voltage until the holding voltage, the electromagnetic valve is still maintained in the open position.

[0008] All changes to the supply voltage are preferably carried out by a correspondingly designed control or regulating device.

[0009] The reduction and increase of the voltage variation curve of the supply voltage can generally be controlled or regulated so that the reduction and increase are performed linearly at least in sections. However, in principle, at least sectionally nonlinear supply voltage variation curves are also possible. Accordingly, nonlinear voltage ramps can also be performed.

[0010] In the second phase, the supply voltage of the solenoid valve is adjusted so that the acceleration of the movable part in the first phase is decelerated. It is preferably provided that in the second phase, the supply voltage is adjusted so that the supply voltage is above the maximum voltage value of the supply voltage applied in the first phase, preferably above the holding voltage, at least for a limited duration; or above the minimum voltage value of the supply voltage applied in the first phase, preferably below the holding voltage, at least for a limited duration; or above or below the minimum voltage value of the supply voltage applied in the first phase for a limited duration.

[0011] Finally, in a second variant of the invention, the corresponding movable part of the solenoid valve can also be decelerated or braked and moved toward the closed position or toward the valve seat in a discontinuous manner by purposefully changing the supply voltage, for example by oscillating the supply voltage, for example about the level of the holding voltage. The change can of course also be carried out in such a way that the oscillation is only below the holding voltage. It is also conceivable that the voltage value drops lower in the second phase than in the first phase, which explicitly includes the possibility that the voltage value remains constant at least at times in the second phase.

[0012] The invention reduces the noise generation, which is generated in particular when the movable part hits the valve seat. In this way, at least in theory, the corresponding voltage curve can be designed so that the movable part of the solenoid valve stops exactly when it reaches the valve seat and thus reduces the noise generation to a minimum.

[0013] In principle, any method is conceivable for realizing the reduction of the supply voltage according to the invention. Preferably, however, the supply voltage is controlled by means of a PWM signal. The duration of the first and second phases, i.e. the duration from the start of the voltage drop to the lowest point of the supply voltage and the subsequent rise, must be selected such that the voltage changes within one cycle neither too fast nor too slowly.

[0014] The length of a cycle, ie the temporal extension of phases P1 and P2, depends on the specific design of the solenoid valve used. Preferably, the duration of a cycle is in the range of 1 ms to 50 ms, preferably between 5 and 25 ms.

[0015] Another preferred variant of the method according to the invention provides that the movable part of the solenoid valve, preferably a piston, moves away from its valve seat when opening and moves towards the valve seat when closing. In a first phase, the movable part of the solenoid valve, preferably a piston, moves away from the open position of the solenoid valve. In principle, the solenoid valve can be preloaded towards the closed position, for example by a spring or the like. The same naturally also applies in the opposite direction, i.e. towards the open position.

[0016] Finally, the invention relates to a vehicle seat comfort system for carrying out the above-described method according to claim 7. The vehicle seat comfort system comprises a pneumatic system, a vehicle seat and at least one pneumatic component, preferably a fluid actuator, which is operated by the pneumatic system and integrated in the vehicle seat. The pneumatic system comprises at least one solenoid valve operated with a supply voltage. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The following is with the help of Figure 2 and Figure 3 The present invention is described in more detail.

[0018] Figure 1 shows an exemplary voltage / time curve when a solenoid valve is actuated according to the prior art,

[0019] Figure 2 shows an exemplary voltage / time curve for the actuation of a solenoid valve according to a first variant of the method according to the invention,

[0020] Figure 3 Show Figure 2 Detail A in FIG. 1 shows an alternative voltage profile.

[0021] Figure 4 shows an exemplary voltage / time curve for the actuation of a solenoid valve according to a second variant of the method according to the invention,

[0022] Figure 5 Show Figure 4 Detail A in FIG. 1 shows a possible first voltage profile,

[0023] Figure 6 Show Figure 4 Detail A in FIG. 1 has a view of a possible second voltage profile. DETAILED DESCRIPTION

[0024] exist Figure 2 In a first variant of the method according to the invention shown in , the solenoid valve is opened by increasing the supply voltage to a level V1. This voltage is reduced to a holding level V2 and the solenoid valve remains in the open position. In principle, by reducing the supply voltage, the movable part of the solenoid valve is accelerated towards the sealing seat. To close the valve, in the variant shown here, the supply voltage V is cyclically reduced (first phase P1) and increased (second phase P2). This corresponds mechanically to the alternation of acceleration and braking of the movable part of the solenoid valve. As in Figure 2As can be seen in the example, in the first phase P1, the supply voltage V drops to a level V3 below the holding voltage V2 and in the second phase P2 it rises again to a voltage level V4 above the holding voltage V2. This cycle, which includes the phases P1 and P2, is preferably repeated. In the example shown, it can be seen how the voltage profile of the supply voltage V(t) oscillates around the level of the holding voltage V2. From Figure 3 It can be seen from the alternative embodiment that in phase P2 the supply voltage V(t) no longer reaches the value V2 of the holding voltage. It is therefore entirely possible that, although oscillations occur, they do not occur around the level of the holding voltage V2, but below it, for example completely below it. In this case, the average voltage level can decrease over a plurality of periods in the time profile. Preferably, the supply voltage V is subjected to a plurality of periods P1, P2 until the acceleration of the movable part of the solenoid valve is at least so low that the noise generation when the movable part strikes the valve seat is at least reduced below an acceptable threshold.

[0025] exist Figure 4 In the variant of the method according to the invention shown in FIG. 1 , the ramp proceeds from the level of the holding voltage V2 to a voltage level V5 which is lower than this. This can be done by appropriately adjusting the control based on the control. It is possible here, as in Figure 6 ( Figure 4 As shown in the enlargement of detail A in FIG. 1 , a linear voltage ramp runs between level V2 and level V5, in which the voltage V(t) decreases linearly and strictly monotonically. The voltage curve V(t) can also decrease nonlinearly in principle (not shown).

[0026] This can also be controlled by the cycle described above. In the first phase P1, the supply voltage V is reduced from the holding voltage V2, and in the following phase P2, it is either further reduced, such as Figure 5 As shown in (the case Figure 4 (Detail A in the expansion), or the supply voltage V(t) remains constant in phase P2. Here, the cycle P1 / P2 can also be repeated until the voltage level V5 is reached, so that the movable part of the solenoid valve is braked long enough to avoid or at least significantly reduce the disturbing noise when the movable part hits the valve seat.

Claims

1. A method for operating a vehicle seat comfort system, in which a pneumatic element is supplied with fluid by opening and closing at least one solenoid valve, wherein: The solenoid valve is opened and closed by applying a supply voltage (V) to move a movable part of the solenoid valve, preferably a piston, between an open position and a closed position, It is characterized in that The supply voltage of the solenoid valve during the closing phase of the solenoid valve (V) i) decrease in the form of a voltage ramp, preferably linearly, or ii) undergoes at least one cycle or a plurality of cycles, wherein each cycle comprises at least one first phase (P1) and a second phase (P2) temporally following the first phase (P1), wherein the supply voltage (V) of the solenoid valve is adjusted so that in the first phase (P1) a movable part of the solenoid valve is accelerated toward a closed position of the solenoid valve, and in the second phase (P2) the supply voltage (V) of the solenoid valve is adjusted so that the acceleration of the movable part in the first phase (P1) is decelerated.

2. The method according to claim 1, It is characterized in that - perform step i), or - go through multiple cycles in step ii) Until the solenoid valve closes.

3. The method according to claim 1 or 2, It is characterized in that In a first phase ( P1 ), the supply voltage (V) is reduced to a level below the holding voltage ( V2 ) at which the solenoid valve remains in the open position.

4. The method according to any one of the preceding claims, It is characterized in that The supply voltage (V) is adjusted to a) at least for a limited duration, lies above the maximum voltage value of the supply voltage (V) applied in the first phase (P1), preferably above the holding voltage (V2), or b) at least for a limited duration, lies above the minimum voltage value of the supply voltage (V) applied in the first phase (P1), preferably below the holding voltage (V2), or c) is at or below a minimum voltage value of the supply voltage (V) applied in the first phase (P1) for a limited duration.

5. The method according to any one of the preceding claims, It is characterized in that The supply voltage (V) is controlled by a PWM signal.

6. The method according to any one of the preceding claims, It is characterized in that In a first phase ( P1 ), a movable part of the solenoid valve, preferably a piston, is moved out of the open position of the solenoid valve.

7. A vehicle seat comfort system for carrying out the method according to one of the preceding claims, the vehicle seat comfort system comprising a pneumatic system, a vehicle seat and at least one pneumatic component, preferably a fluid actuator, which is integrated in the vehicle seat and is operated by the pneumatic system, wherein: The pneumatic system comprises at least one solenoid valve which is operated with a supply voltage (V).

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