Control valve for a camshaft adjuster

• US 9,879,793 B2
• Filed: 03/08/2013
• Issued: 01/30/2018
• Est. Priority Date: 05/25/2012
• Status: Active Grant

• Current Assignee: Schaeffler Technologies AG & Co.KG (INA-Holding Schaeffler GmbH & Co. KG)
• Original Assignee: Schaeffler Technologies AG & Co.KG (INA-Holding Schaeffler GmbH & Co. KG)
• Inventors: Bayrakdar, Ali
• Primary Examiner(s): PRICE, CRAIG JAMES
• Application Number:
  US14/402,521
• Publication Number:
  US 20150129066A1
• Time in Patent Office: 1,789 Days
• Field of Search: 13759618, 13762525, 13762549, 13762566, 13762567, 13762868, 123 9012, 123 9013, 123 9015, 123 9017, 123 9018, 123 9027, 123 9031
• CPC Class Codes: F01L 1/344 changing the angular relationship between crankshaft and camshaft, e.g. using helicoidal gear
• CPC Class Codes: F01L 1/3442 using hydraulic chambers with variable volume to transmit the rotating force
• CPC Class Codes: F01L 2001/34426 Oil control valves
• CPC Class Codes: F16K 15/1823 for ball check valves
• CPC Class Codes: Y10T 137/88054 Direct response normally closed valve limits direction of flow

Abstract

A control valve (4) for controlling pressure medium flows of a camshaft adjuster which includes a substantially hollow cylindrical valve housing (6), a control piston (12), which is guided axially displaceably inside the valve housing (6), and a non-return valve (22) which can be hydraulically released. In a region of a pressure medium inlet, the valve housing (6) includes a housing shaft (28) with an axial inflow bore (30) which widens in funnel-like manner towards the inlet side.

Claims

1. A control valve for controlling flows of pressurized medium of a camshaft adjuster, said control valve comprising:

an essentially hollow cylindrical valve housing,

a guided control piston movable in an axial direction inside the valve housing,

a non-return valve that is releasable hydraulically; and

a filter,

the valve housing including, in an area of a pressurized medium supply, a housing shaft with an axial supply hole that includes a funnel portion formed by a sidewall that gradually widens in a funnel shape toward an inlet of the axial supply hole,

wherein the filter is disposed entirely in the axial supply hole,

wherein a base of the filter is positioned adjacent to the non-return valve,

wherein the funnel portion abuts the base of the filter and extends past an outermost end of the filter, and

wherein the filter extends coaxially with the axial supply hole and is spaced from the sidewall in a radial direction such that a gap is formed between the filter and the sidewall, and

wherein the gap extends along an entire distance of the filter such that the filter does not contact the sidewall.

2. The control valve according to claim 1, further including a thread on an axial end of the housing shaft, and

wherein a wall thickness of the housing shaft is decreased in an axial region between the non-return valve and the thread by a reduction of an outer diameter.

3. The control valve according to claim 1, further comprising a hollow pressurized medium guide insert positioned in a hollow space of the valve housing.

4. The control valve according to claim 3, wherein an outer diameter of the pressurized medium guide insert is adapted to an inner diameter of the valve housing hollow space.

5. The control valve according to claim 3, further comprising a hollow cylindrical control sleeve arranged inside the pressurized medium guide insert.

6. The control valve according to claim 5, wherein the guided control piston is positioned inside the hollow cylindrical control sleeve.

7. The control valve according to claim 6, further comprising a securing ring arranged in a groove of the valve housing, the securing ring preventing an axial sliding of the control piston the control sleeve, or the pressurized medium guide insert.

8. The control valve according to claim 1, wherein the guided control piston is shifted against the force of a spring element that is supported on a spring bearing.

9. The control valve according to claim 1, further comprising first and second work connections and a discharge connection formed in the valve housing.

10. The control valve according to claim 9, wherein a supply connection is connected to the first or second work connection and the other of the first and second work connections is connected to the discharge connection as a function of the position of the guided control piston.