GB2376045A

GB2376045A - Using second-generation common rail fuel injection systems to provide hydraulic power to other devices

Info

Publication number: GB2376045A
Application number: GB0110375A
Authority: GB
Inventors: Martin Leonard Stanley Flint
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-04-27
Filing date: 2001-04-27
Publication date: 2002-12-04
Also published as: GB0110375D0

Abstract

A second-generation common rail fuel injection system, ie in which piezoelectric devices control and time hydraulic servo valves, provides hydraulic power for Automatic Variable Compression Devices (AVCD) and provides both hydraulic power and piezoelectric controls for a Piezo-Electric-Hydraulic Rotary Actuator (PEHRA) eg for the exhaust port of a two-cycle double acting barrel engine. For the AVCD, common rail pressure of 1500 to 2000 bar is reduced by a reducing valve to 10 to 15 bar, sufficient for a rapid response over the engine speed and load. Common rail pressure is reduced by about half by a pressure-reducing valve for the PEHRA which is required to operate the open top sleeve valve just prior to the inlet valve opening. The Rotary Actuator (RA) part of PEHRA converts the linear motion of the short stroke cylinder into rotary motion via an inclined cam track providing the sleeve valve with a combined reciprocating and twisting movement over its complete stroke. The sleeve valve may be closed by a stack of Belleville washer springs.

Description

ADDITIONS TO 2nd GENERATION COMMON RAIL FUEL INJECTION SYSTEMS TO PROVIDE HYDRAULIC POWER TO AUTOMATIC VARIABLE COMPRESSION DEVICES AND OPEN TOP SLEEVE VALVE FAST ACTUATION DEVICES The invention relates to additions and changes to 2nd Common Rail Fuel Injection systems that provide hydraulic power for Automatic Variable Compression Devices (AVCD) and to provide both hydraulic power and piezo-electric controls for Piezo-Electric-Hydraulic Rotary Actuator's (PEHRA).

To provide an understanding of how the above mentioned invention can be used in a Two Cycle Double Acting Barrel Cam Engine of the Hermann type using a Uniflow Sleeve Valve arrangement, is shown in Figures 1 and 2.

In addition to this invention, the engine design shown in Fig. 1 incorporates many other ideas and mechanisms already tried and tested on more conventional engine types, but not in a Two Cycle Double Acting Barrel Cam Engine of the Hermann type using a Uniflow Sleeve Valve arrangement.

2nd generation Common Rail Fuel Injection uses PiezoElectric devices to control and time Hydraulic Servo Valves. This technology is known to consistently and reliably open and close servo valves and subsequently Direct Fuel Injector nozzles in less than 100 microseconds. i. e. 1/10000 of a second. This enables injectors to respond in a more precise manner and many times faster than solenoid controlled injectors currently employed on 1st generation Common Rail Fuel Injection systems. "generation Common Rail Fuel Injection systems are conducted at a pressure of 1500 bar and eventually to 2000 bar and beyond.

The Two Cycle Double Acting Barrel Cam Engine shown in Fig. 1 has two additional requirements of the Common Rail Fuel Injection system, namely the Piezo-ElectricHydraulic Rotary Actuator (PEHRA) and the Automatic Variable Compression Device (AVCD).

The PEHRA especially requires the fast responces of the Piezo-Electric-Hydraulic servo valves, in order to meet the requirements that create the"Kadenacy Effect". The PEHRA operates the Open Top Sleeve Valve extremely fast and is required to be opened and closed in a duration less than 1/300th of a second. When the Two

Cycle Barrel Cam Engine shown in Fig. l is operating at an output shaft speed of 2000 rpm, the 1/3 ooth second to open and close the Exhaust Port represents 40 degrees of output shaft rotation. Kadenacy considered that 1/300th of a second was the maximum time for his "Effect" to be created. It seems the faster the better and that a bandwidth between 1/300 and 1/600 a second was ideal. This is extremely fast and beyond the capabilities of the current solenoid or conventional cam control technology, however, it is well within the capabilities of Piezo-Electric-Hydraulic servo valves.

The PEHRA is required to operate the Open Top Sleeve Valve consistently and at the exact moment in the expansion stroke, just prior to the Inlet Port opening.

The PEHRA achieves this by converting hydraulic pressure in a short stroke cylinder into rotary motion via an inclined cam profile track and ball bearings.

This rotary motion is transmitted to the Sleeve Valve with a combined reciprocating and twisting movement over it's complete stroke via a spherical bearing, to the point when the Exhaust Port is fully open. The Sleeve Valve is returned to the Exhaust Port closed position by stored energy in a stack of bellville washer springs concentric to the short stroke cylinder.

This return action is triggered by the Piezo-ElectricHydraulic servo valve releasing pressure from the short stroke cylinder and returning the hydraulic fluid to tank.

The timing of the PEHRA uses the same type of sensors as the PEHFI to trigger the Electronic Control Unit (ECU). The sensors are positioned relative to the Sleeve Valve and the Barrel Cam's angular disposition.

The AVCD, however, does not need PEHFI technology. Only hydraulic pressure from the Common Rail is required. Fuel supplied from the Common Rail serves as the hydraulic fluid at 1500 to 2000 bar pressure. It is reduced to 10 to 15 bar by the Pressure Reducing Valve (PRV), which is sufficient hydraulic pressure to create a rapid response of the AVCD over the engine speed and load range.

Conveniently, the Diesel fuel used in the Common Rail system is perfectly satisfactory as a hydraulic fluid for AVCD purposes and also serves as a coolant function.

Normally for conventional engines, the PEHFI system specifies a custom built Rotary High Pressure Pump to supply the Common Rail. However, conveniently and for much lower installed cost, the available reciprocating motion provided by the Barrel Engine's double action motion, supplies reciprocating motion via a linkage mechanism internally. This linkage operates two High Pressure reciprocating pump modules (See Fig. 2). The same type of linkage is also used to internally drive both Coolant and Lube Oil Pumps.

It is believed that the above mentioned PEHRA and AVCD system additions and changes to the PEHFI system plus the linkage mechanism to drive the HP Pump Modules are unique in 2nd generation PEHFI systems and form the basis of this patent.

For an understanding of the above additions and changes refer to the system diagram in Fig. 3 for the following description.

Lever 2 oscillates about its pivot and is driven by the reciprocating movement of the double acting piston/cam follower of the Barrel Cam engine via spherical bearing 4. The rod 3 is connected to the lever 2 by a spherical bearing and to both of the HP Pump modules 7. The HP Pump modules are of a similar design to conventional Diesel engine Jerk Pump units.

High pressure fuel is pumped via HP pipe 5 through Flow Control Valve (FCV) 11, HP pipe 12 and Pressure Control Valve (PCV) 13 to Common Rail 14.

Fuel is supplied to HP pump module 7 from Tank 10 via Filter 9, Low Pressure Pump 10 and Low Pressure Supply Pipe 6. Each of the Fuel Injectors 16 are fed by HP Pipes 15 from Common Rails 14. Fuel is released into the engines combustion chambers at the precise moments and periods of time by the Piezo-Electric-Hydraulic Servo Valve (PEHSV) 18. PEHSV 18 is controlled by timed pulsed signals down wires 34,35, 36 from the engine ECU 33.

The above described is basically standard 2nd generation Common Rail practice with the exception of the HP Pump modules instead of a rotary driven HP pump. The HP pump

module will need to have a bigger flow rate to accommodate the additional flow requirements for both PEHRA and AVCD needs at full load and speed.

Returning to Fig. 3 the PEHRA 19 is supplied by hydraulic pressure from the Common Rail by HP pipe 21 via Pressure Reducing Valve (PRV) 22 and HP pipe 23. In the same way as the Fuel Injectors are controlled and timed, PEHSV 24 is pulsed by engine ECU 33 via wires 37,38 and 39. The PEHRA opens and closes Sleeve Valve 1 via Fixed Pin 20 and a spherical bearing. In Fig. 3 there are shown six Sleeve Valves for a six combustion chamber Two Cycle Double Acting Barrel Engine. Figs. 1 and 2 shows sections through such an engine.

Continuing with Fig. 3 the AVCD 26 is supplied with hydraulic power by HP pipe 26a via PRV 27 through LP pipe and gallary 28. Return to tank 10 is via gallary and pipe 24.

Fig. l Two Cycle Double Acting Barrel Engine- Longitudinal Section.

Fig. 2 Two Cycle Double Acting Barrel Engine-End View direction A.

Fig. 3 Diagramm of the Common Rail Fuel injection system integrating the additions and changes to provide hydraulic power and Piezo-Electric-Hydraulic controlles for the PEHRA and AVCD.

Claims

CLAIM 1 Relates to additions and changes made to 2nd generation Common Rail Fuel Injection systems employed on modern diesel engines. These additions provide for extra hydraulic power and Piezo-Electric-Hydraulic control and timing functions to :- . energie and control PEHRA device to open and close an Exhaust Port by an Open Top Sleeve Valve at a precise moment in the expansion phase of a Two Cycle Double Acting Barrel Engine. The duration of the opening and closing of the Exhaust Port is to be less than 1/300tu of a second in order to create the Kadenacy Effect.

'Provide hydraulic power at a lower pressure to AVCD.

The changes relate to increasing the flow of both FCV and PCV, volume of the Common Rail to accommodate the additional hydraulic requirements. Other changes relate to the different and lower cost method of providing the Common Rail with HP hydraulic fluid (engine fuel).

Detail descriptions and claims for both the PEHRA, AVCD and Kadenacy Effect are covered by other patent applications.

CLAIM 2 Resulting from Claim 1 above, improvements in the Brake Thermal Efficiency (BTE) and Brake Mean Effective Pressure (BMEP), whilst achieving higher and smoother torque characteristics. Also lower exhaust temperatures and lower levels of emissions of a naturally aspirated (NA) and pressure charged and intercooled internal combustion engines of the Two or Four Cycle Double Acting Barrel Engine type.

CLAIM 3 Any internal combustion engine of the Two or Four Cycle Double Acting Barrel Engine type being fueled either by Diesel, DME, Syntrolium (Gas to Liquid Fuel), Gasoline, HC Gas or Hydrogen having a plurality of the inventions set forth in anyone of the preceding claims 1 and
2.