Pressure reducer

Abstract

A pressure reducer, comprising an outer cylinder with a first air supply connector on a first end side of the outer cylinder and a second air supply connector on a second end side of the outer cylinder is provided. A piston can be guided movably in the outer cylinder. A first air chamber is arranged between the first air supply connector of the outer cylinder and the first front surface of the piston, and a second air chamber is arranged between the second air supply connector of the outer cylinder and a second front surface of the piston. The surface areas of the two front surfaces of the piston are of different size. The pressure reducer is suitable for reducing a second air pressure which prevails in the second air chamber in a pulsed manner proportionally to a first air pressure which prevails in the first air chamber, by a first air connection.

Claims

1. A pressure reducer, comprising: an outer cylinder with a first air supply connector on a first end side of the outer cylinder and a second air supply connector on a second end side of the outer cylinder; a piston guided movably in the outer cylinder with a first end-side front surface and a second end-side front surface; a first air chamber arranged between the first air supply connector of the outer cylinder and the first front surface of the piston, and a second air chamber arranged between the second air supply connector of the outer cylinder and the second end-side front surface of the piston; and a channel having two interconnected lines and extending inside the piston, the channel forming a first part of a first air connection in a first position of the piston and forming a first part of a second air connection in a second position of the piston, wherein the surface areas of the two front surfaces of the piston are of different size, and wherein the pressure reducer is configured to reduce a second air pressure which prevails in the second air chamber in a pulsed manner proportionally to a first air pressure which prevails in the first air chamber by the first air connection which comprises the channel and a second part of the first air connection that are configured between the first air chamber and the second air chamber temporarily in the first position of the piston with respect to the outer cylinder.

2. The pressure reducer according to claim 1, wherein the piston is in the second position relative to the outer cylinder, the second air connection comprising the channel and a second part of the second air connection is formed temporarily, by means of which the air is removed from the second air chamber to the surroundings.

3. The pressure reducer according to claim 1, wherein the second part of the first air connection is formed by a bypass line.

4. The pressure reducer according to claim 2, wherein the second part of the second air connection is formed by a vent line which leads out of the outer cylinder.

5. The pressure reducer according to claim 1, wherein a first mechanical compression spring having a first spring preloading force is arranged between the first air supply connector of the outer cylinder and the first front surface of the piston and a second mechanical compression spring having a second spring preloading force is arranged between the second air supply connector of the outer cylinder and the second front surface of the piston.

6. The pressure reducer according to claim 1, wherein the ratio of the surface area of the second front surface of the piston to the surface area of the first front surface of the piston is between 1.2 to 20.

7. The pressure reducer according to claim 1, wherein the pressure reducer is arranged between a first component associated with the first air supply connector and a second component associated with the second air supply connector.

8. The pressure reducer according to claim 7, wherein the first component is a device in a vehicle seat, and the second component is one of a horizontal suspension, a damper, a hydraulic accumulator, a seat cushion contour adaptation, and a lumbar massage system of the vehicle seat.

9. The pressure reducer according to claim 1, wherein the lines of the channel are cylindrical, the centre axis of a first line of the channel being arranged so as to align with the centre axis of the piston and the centre axis of a second line of the channel being arranged so as to extend perpendicularly to the centre axis of the first line of the channel, the second line of the channel being arranged so as to pass continuously through the piston.

10. The pressure reducer according to claim 6, wherein the ratio of the surface area of the second front surface of the piston to the surface area of the first front surface of the piston is 2.

11. The pressure reducer according to claim 8, wherein the device in the vehicle seat is one of a level control and a vertical spring.

12. A pressure reducer, comprising: an outer cylinder with a first air supply connector on a first end side of the outer cylinder and a second air supply connector on a second end side of the outer cylinder; a piston guided movably in the outer cylinder with a first end-side front surface and a second end-side front surface, wherein the surface areas of the two front surfaces of the piston are of different size; a first air chamber arranged between the first air supply connector of the outer cylinder and the first front surface of the piston, and a second air chamber arranged between the second air supply connector of the outer cylinder and the second end-side front surface of the piston; and a first mechanical compression spring having a first spring preloading force arranged between the first air supply connector of the outer cylinder and the first front surface of the piston, and a second mechanical compression spring having a second spring preloading force arranged between the second air supply connector of the outer cylinder and the second front surface of the piston; wherein the pressure reducer is configured to reduce a second air pressure that prevails in the second air chamber in a pulsed manner proportionally to a first air pressure that prevails in the first air chamber by a first air connection that comprises two parts that are configured between the first air chamber and the second air chamber temporarily in a first position of the piston with respect to the outer cylinder.

13. A pressure reducer, comprising: an outer cylinder with a first air supply connector on a first end side of the outer cylinder and a second air supply connector on a second end side of the outer cylinder; a piston guided movably in the outer cylinder with a first end-side front surface and a second end-side front surface, wherein the surface areas of the two front surfaces of the piston are of different size; a first air chamber arranged between the first air supply connector of the outer cylinder and the first front surface of the piston, and a second air chamber arranged between the second air supply connector of the outer cylinder and the second end-side front surface of the piston; and a channel having two interconnected lines and extending inside the piston, wherein the lines of the channel are cylindrical, wherein the centre axis of a first line of the channel is arranged so as to align with the centre axis of the piston, wherein the centre axis of a second line of the channel is arranged to extend perpendicularly to the centre axis of the first line of the channel, wherein the second line of the channel is arranged so as to pass continuously through the piston; wherein the pressure reducer is configured to reduce a second air pressure that prevails in the second air chamber in a pulsed manner proportionally to a first air pressure that prevails in the first air chamber by a first air connection that comprises the channel and a second part of the first air connection is configured between the first air chamber and the second air chamber temporarily in a first position of the piston with respect to the outer cylinder.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic cross-sectional view of a proportional pulse pressure reducer in the neutral position;

(2) FIG. 2 is a schematic cross-sectional view of the proportional pulse pressure reducer from FIG. 1 in the position in which air is introduced;

(3) FIG. 3 is a schematic cross-sectional view of the proportional pulse pressure reducer from FIG. 1 in the venting position;

(4) FIG. 4 shows fields of use of the pressure reducer according to the invention.

DETAILED DESCRIPTION

(5) FIG. 1 shows the pressure reducer 1 according to the invention in an equilibrium position or neutral position N respectively. In this example, the pressure reducer is constructed from an outer cylinder 2 and a piston 3 which can be guided movably therein. An air supply connector A1, A2 is arranged in each case at the two end sides C1, C2 of the outer cylinder 2. An air chamber K1, K2 is formed in each case between these air supply connections A1, A2 and the front surfaces S1, S2 of the piston. In this example, the piston 3 is stabilised in the outer cylinder 2 by two compression springs f1 and f2 having the spring preloading forces F1 and F2. Pressure P1 prevails in the first air chamber K1 and pressure P2 prevails in the second air chamber. In this respect, the outer cylinder 2 has a cavity 12 in which the piston 3 can be movably guided.

(6) In this example, this cavity is divided into a first part 12a, a second part 12b and a third part 12c, the third part 12c being arranged at the second air supply connector A2, the second part 12b being arranged so as to directly follow the third part 12c, and the first part 12a being arranged so as to directly follow the second part. A fourth part, which could be arranged, for example, to directly follow the first part 12a next to the first air supply connector A1, is not provided in this example, i.e. the first part 12a extends as far as the first air supply connector A1. A first annular transition surface 2a is formed between the third part 12c and the second part 12b and a second annular transition surface 2b is formed between the second part 12b and the first part 12a.

(7) The piston 3 consists of a first part 3a and of a second part 3b which are both cylindrical. In this example, the diameter and thus the front surface S2 of the second part 3b of the piston is greater than the diameter and thus the front surface S1 of the first part 3a of the piston 3. An annular transition surface 3c is formed at the transition between the first part 3a and the second part 3b of the piston.

(8) A channel 6 which is divided into a first part 6a and a second part 6b extends in the piston 3. In this case, the first part 6a of the channel 6 is cylindrical, its centre axis being arranged so as to align with the centre axis of the piston 3. The second, also cylindrical part 6b of the channel 6 is directly connected thereto. The centre axis of the second part 6b is arranged so as to extend perpendicularly to the centre axis of the first part 6a, the second part 6b being arranged so as to extend continuously through the piston 3. In this example, the second part 6b is arranged such that its centre axis intersects the centre axis of the piston 3.

(9) At an outlet opening 8a, a bypass line 8, which extends in the connection outside the outer cylinder 2 and leads back into the outer cylinder 2 at an inlet opening 8b, extends out of the first air chamber K1. In the neutral position N, a first air connection 4 does not exist between the first air chamber K1 and the second air chamber K2, since the piston position is arranged such that the bypass line 8 does not form a connection to the channel 6 in the piston 3 at the inlet opening 8b.

(10) At the same time, arranged at a further outlet opening 9a is a vent line 9 which leads to the surroundings U. In the neutral position N, a second air connection 5 does not exist between the second air chamber K2 and the surroundings U, since the piston position is arranged such that the vent line 9 does not form a connection to the channel 6 in the piston 3 at the outlet opening 9a.

(11) A cylindrical cavity is formed between the transition surface 2b between the second part 12b and the first part 12a of the cavity 12 in the outer cylinder 2 and the transition surface 3c between the first part 3a and the second part 3b of the piston. The front surfaces S1, S2 of the piston 2 are positioned at a distance from the air supply connectors A1, A2 by the preloading forces F1, F2 of the compression springs f1, f2. FIG. 1 here shows a neutral position N in which the compression springs f1, f2 are equal and are also arranged equally, i.e. in particular the spring preloading forces F1 and F2 thereof are also equal.

(12) The equilibrium position or neutral position N of the system respectively, shown in FIG. 1, is characterised in that a proportionality factor n, where n is greater than 1 for example, describes the ratio between the surface areas S2 and S1 and also the ratio between the pressures P1 and P2.

(13) Thus, the following applies according to equation 1:

(14) $\begin{array}{cc}\frac{S2}{S1}=n=\frac{P1}{P2}& \left[\mathrm{Equation}1\right]\end{array}$

(15) In the neutral position, both spring preloading forces F1 and F2 are equal. In the neutral position N, the following applies according to equation 2:
F1=F2[Equation 2]:

(16) The equilibrium position or neutral position N of the system is therefore described by equation 3:
S1.Math.P1+F1=S2.Math.P2+F2[Equation 3]:

(17) When the system pressure, i.e. pressure P1, increases in the first air chamber K1, and the system is no longer balanced because the ratio between the two pressures P1, P2 no longer corresponds to the predeterminable proportionality factor n, the piston 3 moves to the left towards the second air chamber K2 as far as the stop face 2a. In this illustrated example, the end position of the piston 3 is determined by the stop face 2a.

(18) Thus, the following applies according to equation 4:

(19) $\begin{array}{cc}n<\frac{P1}{P2}& \left[\mathrm{Equation}4\right]\end{array}$

(20) This produces equation 5 which describes the state in the system in position G1:
S1.Math.P1+F1=S2.Math.P2+F2[Equation 5]:

(21) At the same time, the piston 3 is in the first position G1 such that a first air connection 4 is formed between the bypass line 8 and the channel 6 in the piston 3. The first air connection 4 ensures that when air is consumed at the second air supply connector A2, i.e. when the second pressure P2 prevailing in the second chamber K2 falls and the piston 3 moves out of the neutral position N towards the second chamber K2, i.e. when it is in the first position G1 described above, a certain amount of air can be removed from the first chamber K1 into the second chamber K2 (arrow 10) and so the piston 3 again moves towards the neutral position N and the second pressure P2 is thus increased until the ratio between the two pressures P1, P2 again corresponds to the proportionality factor n according to the neutral position N. During permanent air consumption, this procedure is repeated time and again and the first chamber K1 is supplied in a pulsed manner with air from the second chamber K2 via the first air connection 4. In this respect, the first air chamber K1 is always connected to an inexhaustible air supply.

(22) FIG. 3 describes the formation of the second air connection 5. The second air connection 5 is required when there is a change of driver and the system pressure in the seat, i.e. the pressure P1 in the first chamber K1, falls because a light driver, instead of a heavy driver, sits down immediately thereafter. The ratio between the first pressure P1 in the first air chamber K1 and the second pressure P2 in the second air chamber K2 now again no longer corresponds to the proportionality factor n, but the second pressure P2 has to be reduced. In this example, the piston 3 is positioned such that the transition surface 3c between the two parts 3a and 3b of the piston 3 is in contact with the transition surface 2b between the second part 12b and the first part 12a of the cavity 12 in the outer cylinder 2.

(23) Thus, the following applies according to equation 6:

(24) $\begin{array}{cc}n>\frac{P1}{P2}& \left[\mathrm{Equation}6\right]\end{array}$

(25) This produces equation 7 which describes the state in the system in position G2:
S1.Math.P1+F1<S2.Math.P2+F2[Equation 7]:

(26) At the same time, the piston 3 is in the second position G2 such that a second air connection 5 is formed between the vent line 9 and the channel 6 in the piston 3. Here, the second air connection 5 ensures that in the described situation when the piston 3 moves out of the neutral position N towards the first air chamber K1, i.e. when it is in the above-described second position G2, a certain amount of air can be removed from the second chamber K2 to the ambient air or to the surroundings U (arrow 11) and so the piston 3 again moves towards the neutral position N until the second pressure P2 in the second chamber K2 is reduced to such an extent that the ratio between the two pressures P1, P2 again corresponds to the proportionality factor n according to the neutral position N.

(27) FIG. 4 shows different air-assisted systems which can, for example, be associated with a vehicle seat. Thus, the first component (B1) corresponds to a device in a vehicle seat, in particular a vertical spring, and the second component (B2) corresponds, for example, to a horizontal suspension, a damper, a hydraulic accumulator, a seat cushion contour adaptation or a lumbar massage system of the vehicle seat.

(28) All the features disclosed in the application documents are claimed as being essential to the invention provided that, individually or in combination, they are novel over the prior art.

LIST OF REFERENCE SIGNS

(29) 1 pressure reducer

(30) 2 outer cylinder

(31) 2a transition surface (stop face)

(32) 2b transition surface (stop face)

(33) 3 piston

(34) 3a part of the piston

(35) 3b part of the piston

(36) 3c transition surface (stop face)

(37) 4 first air connection

(38) 4a first part of the first air connection (channel 6 in the piston)

(39) 4b second part of the first air connection (bypass line)

(40) 4c second air connection

(41) 5a first part of the second air connection (channel 6 in the piston)

(42) 5b second part of the second air connection (vent channel)

(43) 6 channel

(44) 6a channel portion

(45) 6b channel portion

(46) 7 third air connection, extending in the channel

(47) 8 bypass line

(48) 8a outlet opening

(49) 8b inlet opening

(50) 9 vent line

(51) 9a outlet opening

(52) 10 supplied air (arrow)

(53) 11 vent (arrow)

(54) 12 cavity in the outer cylinder

(55) 12a part of the cavity in the outer cylinder

(56) 12b part of the cavity in the outer cylinder

(57) 12c part of the cavity in the outer cylinder

(58) 12d part of the cavity in the outer cylinder

(59) A1 air supply connector

(60) A2 air supply connector

(61) B1 component charged with air pressure

(62) B2 component charged with air pressure

(63) C1 end side of the outer cylinder

(64) C2 end side of the outer cylinder

(65) D1 diameter of the piston

(66) D2 diameter of the piston

(67) E1 end of the piston

(68) E2 end of the piston

(69) f1 compression spring

(70) f2 compression spring

(71) F1 preloading force

(72) F2 preloading force

(73) G1 position of the piston

(74) G2 position of the piston

(75) I1 inner front surface of outer cylinder

(76) I2 inner front surface of outer cylinder

(77) K1 chamber

(78) K2 chamber

(79) N neutral position

(80) n proportionality factor

(81) P1 air pressure

(82) P2 air pressure