Hydraulic load-sensing control arrangement

Patent metadata

Field	Value
Publication number	US-9695843-B2
Application number	US-201314382252-A
Country	US
Kind code	B2
Filing date	Feb 27, 2013
Priority date	Mar 1, 2012
Publication date	Jul 4, 2017
Grant date	Jul 4, 2017

Abstract

A hydraulic load-sensing control arrangement for a first and second hydraulic consumer has a variable displacement pump having load-sensing regulation, to which the highest respective load-sensing pressure of consumers is reported. The first consumer has the highest load pressure in normal operation and therefore the highest load-sensing pressure dependent on the load pressure. A pressure reducing valve is arranged in the pressure medium flow path between the variable displacement pump and the first consumer. A spring force from a regulating spring and a regulating pressure dependent on the load pressure of the first consumer are applied in the opening direction of a valve gate in this pressure reducing valve and pressure is applied directly downstream from the pressure reducing valve in the closing direction thereof. A pressure equivalent of the spring force of the regulating spring and the regulating pressure are greater than a pressure of the variable displacement pump.

First claim

The invention claimed is:

1. A hydraulic load sensing control arrangement for a first and second hydraulic consumer, comprising:
a hydraulic pump configured to supply the first and second consumers and including a load sensing regulating system to which a respectively highest load sensing pressure of the consumers, which is dependent on a load pressure, is indicated, the first consumer being configured to have the highest load pressure in normal operation of the control arrangement;
a pressure reducing valve located in a pressure medium flow path between the hydraulic pump and the first consumer, said pressure reducing valve having a valve spool configured to be subjected (i) in a closing direction to a pressure downstream of the pressure reducing valve and (ii) in an opening direction to a regulating pressure dependent on the load pressure of the first consumer and to a spring force of a regulating spring; and
a control line having a first nozzle, wherein:
in normal operation, a pressure equivalent of the spring force together with the regulating pressure is greater than a pump pressure;
the regulating pressure is tapped from the pressure medium flow path between the pressure reducing valve and the first consumer via the control line;
the control line includes a second nozzle located downstream of the first nozzle;
the first and second nozzles form a pressure divider;
the regulating pressure for the pressure reducing valve is tapped in the pressure medium flow path between the first and second nozzles; and
a pressure downstream of the second nozzle is the load sensing pressure of the first consumer.

2. The control arrangement as claimed in claim 1 , wherein the pressure divider is designed in such a way that, in a regulating mode of the pressure reducing valve, a pressure drop across the first and second nozzles between a pressure tap of a load sensing indicator line and an inlet of the pressure limiting valve, together with a pressure equivalent of the spring force of the regulating spring, is greater than a pressure difference between the pump pressure and the highest load sensing pressure of the consumers.

3. The control arrangement as claimed in claim 1 , wherein the load sensing pressure of the first consumer is limited by a pressure limiting valve.

4. The control arrangement as claimed in claim 1 , wherein the pressure reducing valve is a pressure compensator.

5. The control arrangement as claimed in claim 1 , wherein:
said control arrangement is configured to control a hydraulic drilling unit; and
the first consumer is a hydraulic hammering device and the second consumer is a hydraulic feed device.

6. The control arrangement as claimed in claim 1 , further comprising:
a control valve located in the pressure medium flow path between the pressure reducing valve and the first consumer and configured to open and close a pressure medium connection between the pressure reducing valve and the first consumer.

Assignees

• Bosch Gmbh Robert

Inventors

• Buettner Peter
• Rueppel Robert
• Ikonen Timo

Classifications

• F15B11/163 Primary

  for sharing the pump output equally amongst users or groups of users, e.g. using anti-saturation, pressure compensation · CPC title

• F15B2211/6054

  using shuttle valves · CPC title

• F15B2211/40507

  with constant throttles or orifices · CPC title

• F15B2211/20546

  variable capacity · CPC title

• F15B2211/6051

  having valve means between output member and the load sensing circuit · CPC title