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DE-102013226655-B4 - Directional control valve

DE102013226655B4DE 102013226655 B4DE102013226655 B4DE 102013226655B4DE-102013226655-B4

Abstract

Hydrostatic directional control valve (1) with a valve housing (6) in which a valve bore (4) is formed in which a valve spool (2) is guided, with which a fluid connection to at least two consumer ports (A, B) can be controlled, characterized in that the valve spool (2) is designed as a sleeve, wherein a fluidic separation between the two consumer ports (A, B) is effected by a separating piece (8) arranged within the valve spool (2) and supported in a fixed position on the valve housing (6).

Inventors

  • Johannes Wolf

Assignees

  • ROBERT BOSCH GMBH

Dates

Publication Date
20260513
Application Date
20131219

Claims (15)

  1. Hydrostatic directional control valve (1) with a valve housing (6) in which a valve bore (4) is formed in which a valve spool (2) is guided, with which a fluid connection to at least two consumer ports (A, B) can be controlled, characterized in that the valve spool (2) is designed as a sleeve, wherein a fluidic separation between the two consumer ports (A, B) is effected by a separating piece (8) arranged within the valve spool (2) and supported in a fixed position on the valve housing (6).
  2. Directional control valve (1) to Claim 1 , wherein a housing-fixed retaining element (10) for stationary support of the separating piece (8) is inserted into a recess (20) of the separating piece (8).
  3. Directional control valve (1) to Claim 2 , wherein the retaining element (10) extends from the valve housing (6) through an opening (12, 14) formed in the valve slide (2) to the recess (20) of the separating piece (8), wherein the opening (12, 14) is designed such that the valve slide (2) is displaceable in the longitudinal direction relative to the retaining element (10) and is substantially secured against rotation.
  4. Directional control valve (1) to Claim 3 , wherein the separating piece (8) is designed such that it covers the opening (12, 14).
  5. Directional control valve (1) according to one of the preceding claims, wherein at least one window (22, 24) is formed on each side of the separating piece (8) in the valve slide (2) for the fluid connection to a respective consumer connection (A, B) via the valve slide (2).
  6. Directional control valve (1) to Claim 5 , wherein the valve slide (2) is largely open in the circumferential direction in the area of at least one window (22, 24).
  7. Directional control valve (1) to Claim 5 or 6 , wherein a plurality of windows (22, 24) for the respective fluid connection to a respective consumer connection (A, B) via the valve slide (2) The webs (26, 28) extending approximately axially are separated from each other in the circumferential direction.
  8. Directional control valve (1) to a Claims 5 until 7 , wherein the separating piece (8) in the valve slide (2) separates two cavities (64, 66) from each other, wherein the windows (22, 24) serve for the fluid connection of a respective consumer port (A, B) with a respective cavity (64, 66), and wherein a control window (74, 76) is provided for controlling a fluid connection between a pressure port P and the respective cavity (64, 66).
  9. Directional control valve (1) to Claim 8 , wherein at least one further control window (78, 80) is provided for controlling a fluidic connection between the respective cavity (64, 66) and a respective tank connection (T).
  10. Directional control valve (1) to Claim 8 or 9 , wherein at least one control window (74, 76, 78, 80) has a fine control notch (82).
  11. Directional control valve (1) according to one of the preceding claims, wherein a pin (38) is fixed at the end of the valve slide (2), which extends away from the valve slide (2) and can be connected to an actuator for actuating the valve slide (2).
  12. Directional control valve (1) to Claim 11 , wherein at least one bridge (42, 40) for fixing the pin (38) is provided at the end of the valve slide (2), extending inwards from an inner surface of the valve slide (2).
  13. Directional control valve (1) to Claim 12 , wherein a pin (38, 52) is provided at each of the end sections of the valve slide (2), each of which is held by at least one web (40, 42).
  14. Directional control valve (1) to Claim 13 , wherein an end face (60, 62) of a respective pin (52, 38) corresponds to a respective end face (70, 48) of the valve slide (2).
  15. Directional control valve (1) to one of the Claims 5 until 14 , wherein the windows (22, 24) and/or the control windows (74 - 80) of the valve slide (2) are milled or wire eroded.

Description

The invention relates to a hydrostatic directional control valve according to the preamble of claim 1. In the EP 0 894 299 B1 A directional control valve of this type is disclosed. It has a valve housing in which a pressure port, a tank port, and a consumer port are formed. A fluid connection between these ports can be controlled via a valve spool. This spool is slidably guided in a valve bore of the valve housing. The valve spool has a sleeve section, each end of which is closed by a sealing element. Four elongated holes, arranged one behind the other in the circumferential direction, are provided in the sleeve section; these serve as control edges. A disadvantage of this solution is that the valve spool is subjected to comparatively high pressure and flow forces. This results in high actuation forces required by the actuator and a comparatively low adjustment dynamic of the valve spool. Furthermore, this 3-way pressure valve with a single consumer connection has a limited range of applications. DE 10 2006 040 052 A1 reveals a multi-way valve with centering device. In contrast, the invention is based on the objective of creating a directional control valve that eliminates the aforementioned disadvantages. This problem is solved with a hydrostatic directional control valve according to the features of claim 1. Other advantageous embodiments of the invention are the subject of further dependent claims. According to the invention, a hydrostatic directional control valve with a valve housing is provided. A valve bore is formed in the housing, in which a valve spool is slidably guided. A fluid connection to at least two consumer ports, which are fluidically separated within the valve, can be controlled via the valve spool. According to the invention, the valve spool is designed as a sleeve or sleeve spool. Advantageously, a separating element is provided within the valve spool for fluidically separating the consumer ports. This separating element can be fixedly supported on the valve housing. This solution has the advantage that, due to the fixed support of the separating piece, no pressure and/or flow forces are transmitted from the separating piece to the valve spool. Furthermore, the valve spool has only a few (annular) surfaces where pressure and/or flow forces can act. Thus, due to the separating piece and the sleeve-shaped design of the valve spool, extremely low pressure and/or flow forces act upon it, yet it can still be used to control multiple consumer connections. In conventional directional control valves with continuously adjustable valve spools, the pressure and/or flow forces acting on the spool can increase significantly with increasing stroke. Due to the design of the directional control valve according to the invention, low pressure and/or flow forces act on the valve spool, which is why a large stroke for the valve spool is possible with comparatively low actuation forces. The larger stroke, in turn, leads to a higher fluid flow rate through the directional control valve. If a conventional actuator is used to operate the valve spool, it will require less power. Due to the lower pressure and flow forces, it is conceivable to use a comparatively small actuator, thus saving installation space and costs. However, if a conventional actuator is used, it will have a higher power limit. Due to its sleeve-like design, the valve slide has a comparatively low mass. Furthermore, such a valve slide exhibits relatively high natural frequencies. For this reason, it can be operated with high dynamics without reaching its natural frequencies. It is conceivable that the valve slide is guided with slight play between the valve bore and the separating piece. In a further embodiment of the invention, a housing-mounted retaining element can be provided to fix the separating piece, which engages in a recess of the separating piece. Advantageously, the retaining element extends from the valve housing through an opening formed in the valve spool and engages in the recess of the separating piece. The opening interacts with the retaining element in such a way that it acts as an anti-rotation device for the valve spool. Additionally, it is designed to allow the valve spool to slide longitudinally relative to the retaining element. The recess in the separating piece can extend diagonally or radially through it completely. The retaining element, in turn, can then completely penetrate the recess via two openings, particularly those diametrically positioned in the valve slide, and be fixed or supported at its two end sections on the valve housing. The opening, or the respective opening, is advantageously designed as a simple elongated slot extending longitudinally along the valve spool. The retaining element can be pin-shaped. The width of the elongated slot is chosen such that the retaining element can slide relative to the slot, and the valve spool is also essentially secured against rotation. The length of the elongated