Device for controlling the pressure to be supplied to a hydrostatic steering unit
First Claim
1. A device for controlling the pressure to be supplied to a hydrostatic steering unit by means of a control signal, having a pressure control device and a rotary slide valve arrangement, having at least two slide valve elements, one of said slide valve elements being rotatable by means of a steering means, another of said slide valve elements including means for correction by means of a measuring motor through which the flow passes, said slide valve elements being rotatable relative to one another through a limited angle of rotation on either side of a neutral setting, and said slide valve elements have control openings which form at least one first throttle, said first throttle being closed in the neutral setting in an intake path to a steering motor, at least one second throttle, said second throttle being closed in the neutral setting in a return of the steering motor, and at least one control throttle, said control throttle being open in the neutral setting and being connected between a tap for the control signal and tank, the control throttle, together with a series throttle, forming a series circuit independent of the intake path of the steering motor, said circuit being supplied from a pressure source and having a closing characteristic that extends substantially across an entire working range of the angle of rotation of the slide valve elements.
4 Assignments
0 Petitions
Accused Products
Abstract
In a device for controlling the pressure to be supplied to a hydrostatic steering unit (1) by means of a control signal (s), there is a rotary slide valve arrangement, one slide valve element of which is rotatable by means of a steering means (5) and the other side valve element of which is corrected by means of a measuring motor (16). Together with a series throttle (AV), a control throttle (AS) forms a series circuit independent of the intake path of the steering motor (4), which circuit is connected between a pressure source (CF) and the tank (6). The control throttle (AS) has a closing characteristic that extends substantially across the entire working range of the angle of rotation of the slide valve elements. The control signal (s) is tapped between the series throttle (AV) and the control throttle (AS). This provides a pressure control that is independent of load.
11 Citations
11 Claims
- 1. A device for controlling the pressure to be supplied to a hydrostatic steering unit by means of a control signal, having a pressure control device and a rotary slide valve arrangement, having at least two slide valve elements, one of said slide valve elements being rotatable by means of a steering means, another of said slide valve elements including means for correction by means of a measuring motor through which the flow passes, said slide valve elements being rotatable relative to one another through a limited angle of rotation on either side of a neutral setting, and said slide valve elements have control openings which form at least one first throttle, said first throttle being closed in the neutral setting in an intake path to a steering motor, at least one second throttle, said second throttle being closed in the neutral setting in a return of the steering motor, and at least one control throttle, said control throttle being open in the neutral setting and being connected between a tap for the control signal and tank, the control throttle, together with a series throttle, forming a series circuit independent of the intake path of the steering motor, said circuit being supplied from a pressure source and having a closing characteristic that extends substantially across an entire working range of the angle of rotation of the slide valve elements.
Specification