Engine valve actuation

Patent metadata

Field	Value
Publication number	US-11788442-B2
Application number	US-202217886699-A
Country	US
Kind code	B2
Filing date	Aug 12, 2022
Priority date	Dec 19, 2018
Publication date	Oct 17, 2023
Grant date	Oct 17, 2023

Abstract

An electromagnetic valve actuator and method of control thereof. The electromagnetic valve actuator is for at least one valve of an internal combustion engine, the electromagnetic valve actuator comprising: a rotor; a stator for rotating the rotor; output means for actuating the valve in dependence on rotation of the rotor; mechanical energy storage means arranged to store energy in dependence on rotation of the rotor and release the energy to assist rotation of the rotor and phase varying means for varying a phase between the mechanical energy storage means and the output means.

First claim

We claim:

1. An electromagnetic valve actuator for at least one valve of an internal combustion engine, the electromagnetic valve actuator comprising:
a rotor;
a stator configured to rotate the rotor;
an output means arranged on the rotor, the output means configured to actuate the at least one valve based on rotation of the rotor; and
a mechanical energy storage means arranged to alternately store and release energy based on the rotation of the rotor so as to assist the stator in rotating the rotor when the energy is released,
wherein the mechanical energy storage means includes a cam with an asymmetric profile.

2. The electromagnetic valve actuator of claim 1 , wherein the asymmetric profile includes an energy storage flank with a first profile, and an energy release flank with a second profile different from the first profile, and
wherein the mechanical energy storage means alternately stores and releases the energy via the energy storage flank and the energy release flank, respectively.

3. The electromagnetic valve actuator of claim 2 , wherein an average steepness of the energy storage flank is less than an average steepness of the energy release flank.

4. The electromagnetic valve actuator of claim 3 , wherein the energy storage flank and the energy release flank are arranged on a single lobe of the cam.

5. The electromagnetic valve actuator of claim 1 , wherein the output means is desmodromic.

6. The electromagnetic valve actuator of claim 1 , wherein, when assisting in the rotating of the rotor, a ratio of a torque supplied via the mechanical energy storage means to a torque supplied via the stator is at least 0.40 and at most 0.95.

7. The electromagnetic valve actuator of claim 6 , wherein the torque supplied via the stator is less than a torque required to fully open the at least one valve at an engine speed above 5000 rpm.

8. The electromagnetic valve actuator of claim 1 , wherein the mechanical energy storage means further includes a resilient member.

9. The electromagnetic valve actuator of claim 8 , wherein the resilient member is a cantilever spring.

10. The electromagnetic valve actuator of claim 9 , wherein the output means comprises an output cam.

11. The electromagnetic valve actuator of claim 1 , wherein a peak lift of the cam occurs between a closing of the at least one valve and a next opening of the at least one valve.

12. An engine control unit (ECU) for the electromagnetic valve actuator of claim 1 , the ECU configured to control the stator so as to rotate the rotor past an energy storage flank of the cam.

13. The ECU of claim 12 , wherein the ECU is further configured to control the stator so as to desmodromically close the at least one valve.

14. A valve actuation system comprising the ECU of claim 12 .

15. An internal combustion engine comprising the valve actuation system of claim 14 .

16. A vehicle comprising the internal combustion engine of claim 15 .

17. An internal combustion engine comprising the ECU of claim 12 .

18. An internal combustion engine comprising the electromagnetic valve actuator of claim 1 .

19. A vehicle comprising the internal combustion engine of claim 18 .

20. A method for controlling the electromagnetic valve actuator of claim 1 , the method comprising:
controlling the stator so as to rotate the rotor past an energy storage flank of the cam.

Assignees

• Jaguar Land Rover Ltd

Inventors

• Stone Roger
• Tyrrell Richard
• Kelly David

Classifications

• F01L9/40 Primary

  Methods of operation thereof; Control of valve actuation, e.g. duration or lift · CPC title

• F01L9/22

  actuated by rotary motors · CPC title

• F01L1/30

  characterised by the provision of positively opened and closed valves, i.e. desmodromic valves · CPC title

• F02D2013/0296

  Changing the valve lift only · CPC title

• F01L1/08 Primary

  Shape of cams · CPC title