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US-12624710-B2 - Pneumohydraulic pressure intensifier

US12624710B2US 12624710 B2US12624710 B2US 12624710B2US-12624710-B2

Abstract

A pneumohydraulic pressure intensifier includes at least one pneumatic piston that is coupled to a hydraulic pump. The pressure intensifier includes a regulator which allows to set the hydraulic output pressure. The regulator is coupled to a hydraulic pilot control valve which is adapted to interrupt the air supply to the pneumatic piston when a set maximum pressure is reached.

Inventors

  • Klaus Reitzig

Assignees

  • WS Wieländer + Schill Engineering GmbH & Co. KG

Dates

Publication Date
20260512
Application Date
20230908
Priority Date
20220912

Claims (12)

  1. 1 . A pneumohydraulic pressure intensifier ( 1 ), comprising: a hydraulic pump ( 300 ), including a hydraulic piston ( 301 ), a pressure valve ( 302 ) configured to open when the hydraulic piston ( 301 ) is advanced and hydraulic fluid is pushed out of the hydraulic pump ( 300 ) through the pressure valve ( 302 ), and a suction valve ( 303 ) configured to open when the hydraulic piston ( 301 ) is retracted and hydraulic fluid flows into the hydraulic pump ( 300 ) through the suction valve ( 303 ) while the pressure valve ( 302 ) is closed; a pneumatic piston ( 42 a , 42 b ) coupled to the hydraulic pump ( 300 ); a hydraulic pilot control valve ( 200 ) adapted to interrupt an air supply to the pneumatic piston ( 42 a , 42 b ); and a regulator configured to set a hydraulic output pressure; wherein the regulator is coupled to the hydraulic pilot control valve ( 200 ) and adapted to interrupt the air supply to the pneumatic piston ( 42 a , 42 b ) when a set maximum hydraulic output pressure is reached.
  2. 2 . The pneumohydraulic pressure intensifier ( 1 ) as in claim 1 , wherein the hydraulic pilot control valve ( 200 ) is coupled to a pneumatic valve ( 203 ), and wherein the pneumatic valve ( 203 ) opens or closes a pneumatic control line ( 107 ) leading to a main valve ( 100 ).
  3. 3 . The pneumohydraulic pressure intensifier ( 1 ) as in claim 2 , wherein the main valve ( 100 ) is a 5/2-way valve or a 5/3-way valve.
  4. 4 . The pneumohydraulic pressure intensifier ( 1 ) as in claim 1 , wherein the hydraulic pump ( 300 ) feeds hydraulic fluid when the pneumatic piston ( 42 a , 42 b ) is advanced, and wherein the pneumatic piston ( 42 a , 42 b ) can be reset by pneumatic pressure via a control valve ( 504 ).
  5. 5 . The pneumohydraulic pressure intensifier ( 1 ) as in claim 4 , wherein the pneumatic piston ( 42 a , 42 b ) is a tandem piston ( 40 ) including a first piston ( 42 a ) and a second piston ( 42 b ) coaxially arranged with the first piston ( 42 a ), and wherein in a working cycle the first and second pistons ( 42 a , 42 b ) are advanced by introduction of compressed air.
  6. 6 . The pneumohydraulic pressure intensifier ( 1 ) as in claim 5 , wherein the compressed air is fed into a working chamber ( 41 b ) of the second piston ( 42 b ) and through a passage ( 43 ) which connects the first piston ( 42 a ) to the second piston ( 42 b ).
  7. 7 . The pneumohydraulic pressure intensifier ( 1 ) as in claim 5 , wherein the tandem piston ( 40 ) can be reset by introducing the compressed air into a working chamber ( 41 a ) of the first piston ( 42 a ).
  8. 8 . The pneumohydraulic pressure intensifier ( 1 ) as in claim 5 , wherein a pneumatic control module is arranged between a first working chamber ( 41 a ) of the first piston ( 42 b ) and a second working chamber ( 41 b ) of the second piston ( 42 b ).
  9. 9 . The pneumohydraulic pressure intensifier ( 1 ) as in claim 8 , wherein the pneumatic control module comprises a first control valve ( 50 a ) leading into the first working chamber ( 41 a ), and a second control valve ( 50 b ) leading into the second working chamber ( 41 b ).
  10. 10 . The pneumohydraulic pressure intensifier ( 1 ) as in claim 9 , wherein the first control valve ( 50 a ) and the second control valve ( 50 b ) are adapted to actuate a directional control valve, and wherein the directional control valve directs the compressed air either into the first working chamber ( 41 a ) of the first piston ( 42 a ) or into the second working chamber ( 41 b ) of the second piston ( 42 b ).
  11. 11 . The pneumohydraulic pressure intensifier ( 1 ) as in claim 1 , wherein the pneumohydraulic pressure intensifier ( 1 ) is a portable hand-held device.
  12. 12 . A pressing or pulling tool selected from the group consisting of a riveting tool, a punching tool, a crimping tool, a spreading tool, and a cutting tool, the pressing or pulling tool comprising the pneumohydraulic pressure intensifier ( 1 ) as in claim 1 .

Description

CROSS-REFERENCE TO RELATED APPLICATION This application is a national stage application, filed under 35 U.S.C. § 371, of International Patent Application PCT/EP2023/074749, filed on Sep. 8, 2023, which claims the benefit of German Patent Application DE 10 2022 123 098.8, filed on Sep. 12, 2022. TECHNICAL FIELD The disclosure relates to a pneumohydraulic pressure intensifier. More particularly, the disclosure relates to a pneumohydraulic pressure intensifier which comes in the form of a hand-held device and drives a pressing or pulling device, in particular a riveting, punching or crimping device. BACKGROUND Pneumohydraulic pressure intensifiers have been known for generating high pressing and pulling forces. In particular, pressure intensifiers are known which oscillate and drive a hydraulic pump using a suction valve and a pressure valve and thus drive a hydraulic tool. Such a device can be compact and yet generate very high forces. Patent EP 3 360 648 B1 (inventor Klaus Reitzig) discloses such a pneumohydraulic pressure intensifier. In order to increase performance, this pressure intensifier comprises a tandem piston. A pneumohydraulic pressure intensifier is also known from published patent application DD 70 011 A1. In particular if such a pressure intensifier is used for a modular system encompassing various tool attachments, it is necessary to set the maximum pressure of the pressure intensifier. The set maximum pressure is proportional to the pressing or pulling force of the tool. For example, in the case of a riveting tool, the pulling or pressing force has to be set to a specific value depending on the rivet used and the sheet metal pairing provided. In the case of the pressure intensifier described in the above-mentioned patent, this is done using a pneumatic pressure control. The applied pneumatic pressure is set on the pneumatic side of the pressure intensifier. The pneumatic pressure is proportional to the hydraulic pressure. The hydraulic pressure therefore corresponds to the pneumatic pressure multiplied by the transmission ratio of the pressure intensifier. The transmission ratio is the effective piston area of the pneumatic piston(s) to the effective piston area of the hydraulic piston. Therefore, the hydraulic pressure and thus the maximum pressing or pulling force can be adjusted proportionally by reducing the pneumatic pressure. A pneumatic pressure reducer is designed in particular as an upstream pressure limiter. However, with such a pressure limiter, the volume flow of compressed air decreases when the pressure on the outlet side approaches the set maximum pressure. It has been found that this reduces the performance of the pneumohydraulic pressure intensifier. More particularly, the tool works more slowly towards the end of the working operation. In particular the oscillation frequency of the hydraulic pump may also reduce. SUMMARY The present disclosure is based on the object of further enhancing the performance of a pressure intensifier which is used in particular as a drive for hydraulically operated tools. The object is achieved by a pneumohydraulic pressure intensifier as disclosed and claimed. The invention relates to a pneumohydraulic pressure intensifier. This pressure intensifier in particular forms part of a pulling or pressing tool, in particular a riveting tool, punching tool, crimping or cutting tool. For being connected to a tool application, the pressure intensifier may comprise a quick release coupling. The pressure intensifier can come in the form of a hand-held device, but also as a stationary device. The pressure intensifier comprises at least one pneumatic piston which is coupled to a hydraulic pump. The pressure intensifier works in particular in an oscillating manner. For this purpose, the hydraulic pump may comprise a suction valve and a pressure valve. With each working stroke of the pneumatic piston, a hydraulic piston coupled to the pneumatic piston pumps hydraulic fluid. When the piston is reset, a suction valve draws hydraulic fluid into the working chamber of the hydraulic piston, which hydraulic fluid will be pumped towards the tool application during the next working stroke. The hydraulic output pressure of the pressure intensifier can be limited. This may be implemented, for example, using a control member, e.g. a setting wheel. Via a regulator, this allows to set the pressure force or pulling force of the tool application connected to the pressure intensifier, as described above. The regulator is coupled to a hydraulic pilot control valve, which is adapted to interrupt the air supply to the pneumatic piston when a set maximum pressure is reached. Thus, the applied pneumatic pressure is not only set on the pneumatic side. Rather, it is contemplated that the regulator allows to set the trigger pressure of a hydraulic valve. The hydraulic valve in turn is coupled to a pneumatic control valve which interrupts the air supply to the pneumatic piston when the