Pneumatic unit for a hydropneumatic pressure booster

Abstract

A pneumatic unit for a hydropneumatic pressure booster has a system line that leads from a compressed air inlet to a compressed air outlet. A bypass line runs parallel to the system line and it is connected to the system line via first and second compressed air switches. A compressed air reservoir is connected in the bypass line, and a pressure intensifier is connected in the region between the first compressed air switch and the compressed air reservoir. The pneumatic unit makes available to the pressure booster a sufficiently high pneumatic pressure for carrying out at least one operational step of a connected hydraulic tool, even in the case of a pressure decrease or pressure failure in the supplying pneumatic line. For that purpose, the second compressed air switch is configured for switching the compressed air flow between the system line and the bypass line.

Claims

1. A pneumatic unit for a hydropneumatic pressure booster, the pneumatic unit comprising: a compressed air inlet, a compressed air outlet, and a system line leading from said compressed air inlet to said compressed air outlet; a bypass line connected in parallel with said system line between said compressed air inlet and said compressed air outlet; a first compressed air switch and a second compressed air switch connecting said bypass line to said system line; a compressed air reservoir connected in said bypass line; a pressure intensifier connected between said first compressed air switch and said compressed air reservoir; and wherein said second compressed air switch is configured to switch a compressed air flow between said system line and said bypass line.

2. The pneumatic unit according to claim 1, wherein said second compressed air switch is a pneumatic shuttle valve being an OR valve, and a pressure control valve is connected between said compressed air reservoir and said pneumatic shuttle valve.

3. The pneumatic unit according to claim 1, which comprises an adjustable pressure-dependent blocking valve disposed between said compressed air outlet and said second compressed air switch.

4. The pneumatic unit according to claim 3, which comprises a pressure switch configured to actuate said blocking valve, said pressure switch being connected to said system line between said second compressed air switch and said blocking valve.

5. The pneumatic unit according to claim 4, wherein said blocking valve is a 5/2-way valve and said pressure switch is connected to a 3/2-way valve which, for controlling said blocking valve, is connected to said blocking valve.

6. The pneumatic unit according to claim 1, which comprises a compressed air generator connected between said compressed air reservoir and said second compressed air switch.

7. The pneumatic unit according to claim 6, wherein said compressed air generator is connected to an optically functioning and/or acoustically functioning indicator unit.

8. The pneumatic unit according to claim 6, wherein said compressed air generator is connected to a connecting element for connection to an indicator unit.

9. The pneumatic unit according to claim 1, which comprises a support frame with receiving elements for mounting the hydropneumatic pressure booster on the pneumatic unit.

10. The pneumatic unit according to claim 9, wherein said receiving elements are tubular elements configured for accommodating support feet.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

(1) FIG. 1 is a representation of the functioning of a pneumatic unit with a connected pressure booster, in normal operation;

(2) FIG. 2 is a representation of the functioning of the pneumatic unit with a connected pressure booster according to FIG. 1, with compressed air being supplied by an air reservoir of the pneumatic unit;

(3) FIG. 3 is a first perspective view of the pneumatic unit according to FIG. 1;

(4) FIG. 4 is a second perspective view of the pneumatic unit according to FIG. 1; and

(5) FIG. 5 is a perspective view of the pneumatic unit and pressure booster according to FIG. 1 (disposed adjoining one another), along with an associated hydraulic tool.

DETAILED DESCRIPTION OF THE INVENTION

(6) Referring now to the figures of the drawing in detail and first, particularly, to FIGS. 1 and 2 thereof, there is shown a schematic representation of an exemplary embodiment of a pneumatic unit 1. The pneumatic unit 1 is connected via a compressed air inlet 2 to an external compressed air supply 20, which in motor vehicle workshops is usually at a level of 6 bar. The compressed air flowing into the pneumatic unit 1 via the compressed air inlet 2 is conducted, via a compressed air switch 5, into the system line 4 and a bypass line 7. Via the bypass line 7, the compressed air flow passes into a pressure intensifier 9, which doubles the inlet pressure of the compressed air. A compressed air reservoir 8 connects to the pressure intensifier 9; the compressed air supplied by the pressure intensifier 9 is stored in this reservoir. A pressure control valve 10 connects to the compressed air reservoir 8; this valve reduces the compressed air supplied by the compressed air reservoir 8 to a value slightly below the pressure applied at the compressed air inlet 2, which in the present example is 6 bar. As a result, a pressure applied to the second compressed air switch, which is configured as a pneumatic shuttle valve (OR valve) 6, and is connected to the pressure control valve 10, is slightly below the line pressure of the system line 4, which is also connected to the pneumatic shuttle valve (OR valve) 6.

(7) In normal operation as illustrated in FIG. 1, i.e. at a constant line pressure in the system line 4, the pneumatic shuttle valve 6 is in the position illustrated in FIG. 1, in which the compressed air flows via the compressed air inlet 2 and the first compressed air switch 5 via the system line 4 and through the pneumatic shuttle valve 6, in the direction toward a compressed air outlet 3. The compressed air made available from the compressed air reservoir 8 is blocked by the pneumatic shuttle valve 6.

(8) Additionally, a pressure switch 12 is disposed in the region between the pneumatic shuttle valve 6 and the compressed air outlet 3; this switch 12 is configured such that, at a prescribed line pressure, in the present instance 6 bar, it switches a blocking valve 11, which is configured as a 5/2-way valve, via a 3/2-way valve 13, so that the system line 4 makes available the compressed air flow to the compressed air outlet 3.

(9) In the present exemplary embodiment, a pressure booster 18 is disposed at the compressed air outlet 3, which pressure booster converts the pneumatic pressure to a hydraulic pressure which can be used to actuate a hydraulic tool 19 connected to the pressure booster 18, wherein an indicator unit in the form of an LED 21 is disposed on the hydraulic tool 19.

(10) If a pressure decrease or a pressure failure occurs, whereby the pressure in the system line 4 falls below the prescribed value, in the present example 6 bar, then the pneumatic shuttle valve 6 switches into the status illustrated in FIG. 2, in which the compressed air flow from the compressed air reservoir 8 is made available. Accordingly, once the required system pressure is further on applied by the compressed air reservoir 8 in the region of the system line 4 adjoining the pneumatic shuttle valve 6, the pressure switch 12 behaves as in normal operation and makes the compressed air flow available to the compressed air outlet 3 via the 3/2-way valve 13 and the 5/2-way valve 11.

(11) A compressed air generator 14 is disposed in the bypass line 7, in the region between the pressure control valve 10 and the pneumatic shuttle valve 6; the generator 14 generates electricity in the manner of a turbine. When compressed air is supplied to the compressed air outlet 3 via the compressed air reservoir 8, the compressed air driven generator 14 is continuously supplied with compressed air which flows through it, and it generates electrical energy which is conducted via a line to the LED 21 disposed on the hydraulic tool 19, which then starts to emit light. Thereby the LED 21 signals to the tool operator that the pressure available in the system line 4 is insufficient, and that now the pneumatic unit 1 is providing compressed air via the compressed air reservoir 8.

(12) By appropriate dimensioning of the compressed air reservoir 8, the tool operator can, however, at least finish the operation that has been begun (driving out a piston on the hydraulic tool, developing the maximum pressure, and retracting the working piston).

(13) FIGS. 3 and 4 are perspective views of the pneumatic unit 1. On a support frame 15 of the pneumatic unit 1, there are, inter alia, four receiving elements configured as tubular elements 16, disposed at a spacing distance from each other. The tubular elements 16 are configured to accommodate support feet 17 of the pressure booster 18. The pneumatic unit 1 and the pressure booster 18 thus form a compact assembly. The pressure booster 18 serves to supply a hydraulic tool 19, via a hydraulic line not illustrated here (see FIG. 5).

(14) The following is a summary list of reference numerals and the corresponding structure used in the above description of the invention: 1 Pneumatic unit 2 Compressed air inlet 3 Compressed air outlet 4 System line 5 First compressed air switch 6 Second compressed air switch/OR valve 7 Bypass line 8 Compressed air reservoir 9 Pressure intensifier 10 Pressure control valve 11 Blocking valve/5/2-way valve 12 Pressure switch 13 3/2-way valve 14 Compressed air generator 15 Support frame 16 Receiving elements/tubular elements 17 Support feet 18 Pressure booster 19 Hydraulic tool 20 Compressed air supply 21 Indicator unit/LED