Apparatus for adjustably controlling valve movement and fuel injection

Abstract

An apparatus adjustably controls intake and exhaust valve movement and fuel injection of an engine. valve movement and injection is adjustably controlled in response to electrical signals delivered to a piezoelectric motor which in turn delivers hydraulic signals through a single spool valve.

Description

TECHNICAL FIELD

This invention relates generally to an apparatus for adjustably controlling valve movement and fuel injection of an engine. More specifically, this invention relates to means for adjustably controlling valve movement and fuel injection of an engine in response to electrical signals.

BACKGROUND ART

A conventional internal combustion engine uses either a cam and push rod system or a direct acting overhead cam operating on a rocker-arm to actuate the engine poppet valves. The camshaft typically runs the length of the engine and is driven by a gear train off of the crankshaft. The engine valve timing events are fixed with respect to the crankshaft position and the lift rate of the valve is proportional to engine speed. These restrictions upon the engine valves induce compromises in engine performance regarding fuel consumption, emissions, torque, and idle quality. To minimize these compromises, numerous methods have been introduced to vary the phasing of the intake and exhaust valve cams relative to crankshaft position. The variable valve actuation mechanisms are inherently costly and complex.

The diesel engine camshaft with direct fuel injection typically has a cam to drive the injector plunger. The fuel injector cam ,4'1a to position 2a through a 20:1 amplification or area ratio between the piezo disks and the spool 24. At this position, the exhaust valve low pressure line 28 is ready to close and the high pressure line 26 is ready to open.

By increasing the voltage to 600 v. for example, the spool moves to 1 mm position. The exhaust low pressure is fully closed and the high pressure is open. That actuates the exhaust valve 6 and the exhaust plunger 38 for as long as the timing event is required.

By switching from high pressure to low pressure, reducing voltage from 600 v back to 300 v, and allowing the valve momentum to complete the valve opening cycle, hydraulic power consumption is reduced. This is an effective method of power recuperation.

By increasing the voltage to 900 v, the spool location 1b moves to position 2b and closes the HP line 21 26 and at the same time opens low pressure line 28' 28. The exhaust valve spring (not shown) shuts the exhaust valve 6 and completes the exhaust valve actuation. The same recuperation power reduction scheme applies here during the valve closing. The reduction in power consumption is even more effective in closing than in opening. Further, the closing recuperation power reduction will assist in reducing valve seating velocity.

By increasing the voltage to 1200 v, the spool location 1g moves to a position 2g. The whereby the intake valve low pressure line 28" 28 is ready to close and the high pressure 26" line 26 is ready to open.

Further, increasing the voltage to 1500 v fully closes the intake valve low pressure line and the high pressure line is wide open and communicates with the passages 42 and 47, thereby actuating the intake valve 4 through the intake plunger 46. The same recuperation power reduction technique employed for the exhaust valve can be applied for the intake valve 4.

When the voltage increases to 1800 v the spool moves from to a position 1i to 2i. The whereby the passage 42 will be shut off and the high pressure line 26" 26 will be closed. The low pressure line 28" 28 will be open. The intake valve spring will shut the intake valve 4 and complete the intake valve actuation.

Other aspects, objects and advantages of this invention can be obtained from a study of the drawings, the disclosure and the appended claims.

Claims

1. Apparatus for adjustably controlling valve movement and fuel injection of an engine having at least one fuel injection system, one exhaust valve system, one intake valve system, a microprocessor controller for receiving input signals and delivering engine controlling electrical signals, and a liquid pressure system, comprising:

a single piezoelectric motor electric motor means connectable to the microprocessor controller and the liquid pressure system and being adapted to receive engine controlling electrical signals from the microprocessor and controllably delivering pressurized liquid signals to the liquid pressure system in response to said received signal; and

a spool valve having a single spool, said spool valve having a plurality of inlets and outlets and being connectable to the liquid pressure system for receiving said pressurized liquid signals therefrom and controllably moving the single spool of the spool valve , and said spool valve delivering exhaust and intake valve system and fuel injection system controlling signals to the exhaust and intake valve systems and injector the fuel injection system, and said spool valve controlling both valve movement of the exhaust and intake valve systems and fuel injection system responsive to engine controlling electrical signals received by said piezoelectric motor electric motor means.

2. An apparatus, as set forth in claim 1, wherein the piezoelectric motor electric motor means includes an amplifier piston adapted to increase, to a preselected magnitude, the pressure of the pressurized liquid signals delivered from the piezoelectric electric motor means.

3. An apparatus, as set forth in claim 2, wherein the amplifier piston increases the liquid pressure signals to a ratio magnitude in the range of about 5:1 to about 9:1.

4. An apparatus, as set forth in claim 3, wherein the ratio magnitude is about 7:1.

5. An apparatus, as set forth in claim 1, wherein the spool of the spool valve is spring biased to a first position and movable in response to receiving the pressurized liquid signal.

6. An apparatus, as set forth in claim 5, including a Bellville spring and wherein the spool of the spool valve is biased by said Bellville spring.

7. An apparatus, as set forth in claim 1, wherein the liquid of the liquid pressure system and liquid controlling systems signals is diesel fuel.

8. An apparatus, as set forth in claim 1, wherein the injection system and the valve systems are powered by pressurized liquid from the spool valve.

9. An apparatus, as set forth in claim 1, wherein the engine has a plurality of cylinders each having at least one fuel injection system, at least one exhaust valve system and, at least one intake valve system connected to, a respective piezoelectric motor electric motor means and a respective spool valve, each of said piezoelectric motors electric motor means and spool valves being connectable to a common liquid pressure system.

10. An apparatus, as set forth in claim 9, wherein the plurality of piezoelectric motors electric motor means are connected to and receive controlling electrical signals from a single microprocessor.

11. An apparatus, as set forth in claim 1, wherein the liquid pressure system is a rail system.

12. An apparatus, as set forth in claim 11, wherein the liquid pressure rail system has a high pressure rail and a low pressure rail.

13. an apparatus, as set forth in claim 12, wherein the high pressure rail is maintained at a pressure in the range of about 2000 to about 4000 psia/psig.

14. An apparatus, as set forth in claim 13, wherein the high pressure rail is maintained at a pressure of about 3000 psia/psig.

15. An apparatus, as set forth in claim 12, wherein the low pressure rail is maintained at a pressure in the range of about 100 to about 300 psia/psig.

16. An apparatus, as set forth in claim 15, wherein the low pressure rail is maintained at a pressure of about 200 psia/psig.