Cam shaft phase setter comprising a control valve for hydraulically adjusting the phase position of a cam shaft

Patent metadata

Field	Value
Publication number	US-10072538-B2
Application number	US-201514970937-A
Country	US
Kind code	B2
Filing date	Dec 16, 2015
Priority date	Mar 9, 2010
Publication date	Sep 11, 2018
Grant date	Sep 11, 2018

Abstract

A cam shaft phase setter for adjusting the rotational angular position of a cam shaft relative to a crankshaft of an internal combustion engine by a hydraulic fluid, the cam shaft phase setter including: a stator connected to the crankshaft; a pressure chamber; a rotor connected to the cam shaft, the rotor being adjustable relative to the stator by introducing the fluid into the pressure chamber; a control valve including a valve housing and a valve piston; and an actuating unit for axially adjusting the valve piston; wherein the cam shaft phase setter is configured such that fluid flowing through the control valve flows back into an engine housing which rotatably mounts the cam shaft.

First claim

The invention claimed is:

1. A cam shaft phase setter comprising:
(a) a control valve for controlling feeding and draining of a hydraulic fluid into and out of pressure chambers which serve to adjust the rotational angular position of a cam shaft relative to a crankshaft of an internal combustion engine,
(b) the pressure chambers comprising a first chamber and a second chamber, one of the first chamber and second chamber for adjusting the cam shaft to lead relative to the crankshaft when the pressure is applied, and the other of the first chamber and the second chamber for adjusting the cam shaft to trail when the pressure is applied,
(c) the phase position of the cam shaft being set by introducing the pressurised fluid by the control valve into either the first chamber or the second chamber, and connecting the other type of pressure chambers in each case to a low-pressure side of the fluid,
(d) the control valve comprising:
(d1) a valve housing connectable, rotationally fixed, to the cam shaft or being formed by the cam shaft, such that when the cam shaft rotates, the control valve rotates together with the cam shaft, the valve housing comprising a first operating port for feeding said pressure fluid to the first chamber, a second operating port for feeding said pressure fluid to the second chamber, the second operating port being axially spaced from the first operating port, and a reservoir port for draining the fluid to a reservoir provided on the low-pressure side of the fluid,
(d2) a valve piston which can be axially adjusted back and forth in the valve housing between a first piston position and a second piston position and comprises an axial hollow space, a piston inlet for introducing fluid into the hollow space, and a piston outlet which leads out of the hollow space,
(d3) the piston outlet being connected to the first operating port in the first piston position and separated from the first operating port in the second piston position, the piston outlet being connected to the second operating port in the second piston position and separated from the second operating port in the first piston position, and

(e) the cam shaft phase setter further comprising an actuating unit, coupled to the valve piston, for axially adjusting the valve piston,
(f) wherein the valve piston comprises a recess which connects the first operation port of the valve housing to the reservoir port in the first position of the valve piston, and
(g) wherein behind the piston outlet, as viewed in the axial direction from the recess, a further axially extending recess is formed on the outer circumference of the valve piston, the further radial recess connected to the reservoir in the first position of the valve piston.

2. The cam shaft phase setter according to claim 1 , wherein the reservoir port extends outwards into a phase setter housing such that the fluid is drained through the reservoir port near the actuating unit into the phase setter housing and via the phase setter housing back into an engine housing or otherwise into a reservoir for the fluid.

3. The cam shaft phase setter according to claim 1 , wherein the first operating port extends radially through the circumference of the valve housing.

4. The cam shaft phase setter according to claim 1 , wherein the second operating port extends radially through the circumference of the valve housing.

5. The cam shaft phase setter according to claim 1 , wherein the piston outlet is a radial outlet on the circumference of the valve piston.

6. The cam shaft phase setter according to claim 1 , wherein the piston inlet leads axially into the hollow space on an axially facing side of the valve piston.

7. The cam shaft phase setter according to claim 1 , wherein the valve housing comprises a housing inlet for the fluid which flows to the control valve, and wherein the housing inlet is formed either on an axially facing side of the valve housing such that the fluid flows axially into the control valve, or as a radial inlet on the circumference of the valve housing.

8. The cam shaft phase setter according to claim 1 , wherein the valve piston comprises, on its circumference, a radial recess connecting the first operating port to the reservoir port in the second position of the valve piston.

9. The cam shaft phase setter according to claim 8 , wherein the recess is connected to the reservoir port in the first position of the valve piston and is fluidically separated from the first operating port in the first position of the valve piston by a sealing web of the valve piston.

10. The cam shaft phase setter according to claim 8 , wherein the recess connects the first operating port to the reservoir port in the second position of the valve piston such that the fluid can flow off from the first chamber and depressurise the first chamber.

11. The cam shaft phase setter according to claim 1 , wherein the valve piston comprises, on its circumference, a radial recess connecting the second operating port of the valve housing to the reservoir in the first position of the valve piston.

12. The cam shaft phase setter according to claim 1 , wherein the valve housing is inserted at an axial end of the cam shaft into a central accommodating space which is open towards the axially facing end of the cam shaft, from the axially facing end, or is placed at the axially facing end of the cam shaft.

13. The cam shaft phase setter according to claim 1 , wherein the valve housing is inserted into an accommodating space of the cam shaft and is screwed to the cam shaft or axially secured by a securing device.

14. The cam shaft phase setter according to claim 13 , wherein a tensioning screw which can be screwed to the cam shaft forms the valve housing.

15. The cam shaft phase setter according to claim 1 , comprising a stator which can be rotary-driven by the crankshaft, and a rotor which is connected, rotationally fixed, to the cam shaft and coupled to the stator such that torque is transmitted and which can be adjusted in its rotational angle relative to the stator by introducing the fluid into one of the first pressure chamber or the second pressure chamber.

16. The cam shaft phase setter according to claim 1 , further comprising a spring unit acting on the valve piston in the direction of the first position, wherein the actuating unit acts on the valve piston in the direction of the second position.

17. The cam shaft phase setter according to claim 1 , wherein the actuating unit comprises an electromagnetic coil which is connected, rotationally fixed, to an engine housing of the internal combustion engine, and an anchor which can be axially moved relative to the coil in order to transmit an axial actuating force of the actuating unit onto the valve piston.

18. The cam shaft phase setter according to claim 17 , wherein the valve piston can be rotated relative to the anchor.

19. The cam shaft phase setter according to claim 1 , wherein the actuating unit is arranged on the low-pressure side of the fluid.

20. The cam shaft phase setter according to claim 1 , wherein the actuating unit comprises an electromagnetic coil which is connected, rotationally fixed, to an engine housing of the internal combustion engine, the coil being connected, rotationally fixed, to a cover which is in turn fixedly connected to a phase setter housing which is mounted on the engine housing.

21. The cam shaft phase setter according to claim 1 , wherein the actuating unit comprises an electromagnetic coil which is connected, rotationall

Assignees

• Shw Automotive Gmbh
• Shw Automotive Gmbh

Inventors

• Welte Claus
• Meinig Uwe
• Bohner Juergen

Classifications

• F01L2001/3443

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• Y10T74/2102

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• F01L2001/34446

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• F01L2001/34433

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• F01L2001/34426

  Oil control valves · CPC title