Fuel control system for a gas-operated engine

• US 6,131,552 A
• Filed: 05/10/1999
• Issued: 10/17/2000
• Est. Priority Date: 08/14/1998
• Status: Expired due to Term

• Current Assignee: Woodward Governor Company
• Original Assignee: Dana Corporation (Dana, Inc.)
• Inventors: Pennala, Dean A., Paielli, Perry M.
• Primary Examiner(s): Yuen, Henry C.
• Assistant Examiner(s): HUYNH, HAI H
• Application Number:
  US09/309,056
• Time in Patent Office: 526 Days
• Field of Search: 123/525, 123/527, 123/526, 123/27 GE, 137/82, 251/129.17, 251/331
• US Class Current: 123/527
• CPC Class Codes: F02D 19/023 to adjust the fuel mass or volume flow
• CPC Class Codes: F02M 21/0212 comprising at least 3 C-Atoms, e.g. liquefied petroleum gas [LPG], propane or butane
• CPC Class Codes: F02M 21/0233 Details of actuators therefor
• CPC Class Codes: F02M 21/0239 Pressure or flow regulators therefor
• CPC Class Codes: F02M 21/04 Gas-air mixing apparatus
• CPC Class Codes: Y02T 10/30 Use of alternative fuels, e.g. biofuels

Abstract

A fuel control system for delivering gaseous fuel from a source through an air/fuel mixture to a gas-operated engine that includes at least one sensor for operative coupling to the engine to provide at least one electronic sensor signal responsive to engine operating conditions. An electronic control unit is responsive to the sensor signal(s) for providing a fuel control signal indicative of a desired quantity of fuel to be delivered to the engine. A pressure regulator, for disposition between the fuel source and the fuel/air mixture, is responsive to the fuel control signal for controlling delivery of gaseous fuel to the mixer. The pressure regulator includes a housing having an inlet for connection to the fuel source and an outlet for connection to the mixer. A valve is disposed within the housing and biased toward closure by a primary pressure regulating spring for controlling flow of fuel from the inlet to the outlet. A solenoid force motor is mounted on the housing and has a force coil for receiving and translating the fuel control signal. A rigid actuating member is driven by and extends from the coil into the housing directly to the valve-actuating lever for modulating control of the operative position of the valve in bypass mechanical force transmission relationship to the regulating spring, and thereby modulating control flow of gaseous fuel through the housing, as a function of the fuel control signal to the pressure regulator.

Claims

1. A fuel control system for delivering gaseous fuel from a source through an air/fuel mixer to a gas-operated engine, which comprises:

at least one sensor for operative coupling to the engine to provide at least one electronic sensor signal responsive to engine operating conditions,

an electronic control unit responsive to said at least one sensor signal for providing a fuel control signal indicative of a desired quantity of fuel to be delivered to the engine, and

a pressure regulator for disposition between the source and mixer, and responsive to said fuel control signal for controlling delivery of fuel from the source to the mixer,

said pressure regulator comprising a housing having an inlet for connection to the fuel source and an outlet for connection to the mixer, valve means disposed within said housing for controlling flow of fuel from said inlet to said outlet and wherein said valve means includes a valve member and a main pressure regulating spring that biases said valve member to a closed position relative to a housing-interior flow orifice communicating said inlet with said outlet, and a solenoid force motor having a solenoid coil and a rigid actuating member that extends from said coil within said housing and is mechanically operable coupled to said valve member independently of said spring for modulating the force applied by said spring to said valve member and thereby modulating the control of the operative position of said valve member, and therefore flow of fuel through said housing, as a function of said fuel control signal to said pressure regulator.

2. The system set forth in claim 1 wherein said valve means comprises a diaphragm disposed within said housing and lever means coupled to said diaphragm and said valve member and operably biased by said spring for opposing fuel flow through said housing so as to regulate pressure of fuel fed to the mixer.

3. The system set forth in claim 2 wherein said actuating member operably abuttingly engages but is not pull-connected to said lever, such that said actuating member can push against said lever but cannot pull on said lever.

4. The system set forth in claim 3 wherein said solenoid force motor is mounted on an external wall of said housing, with said actuating member extending through said wall of said housing to operatively engage said lever.

5. The system of claim 4 wherein said pressure regulator comprises a housing of the universal ported type with duel inlet bosses and dual outlet bosses with each of the inlet bosses communicating within the high pressure inlet chamber separated by a mid-plane wall of said housing from a low pressure outlet chamber that in turn communicates with both of said outlet bosses, and wherein one of said inlet bosses and one of said outlet bosses is normally plugged in use and the other of said inlet bosses is coupled to said gaseous fuel source and the other of said outlet bosses is coupled via a conduit to said mixer, and wherein said solenoid force motor is enclosed in a casing configured at one end for threading into said other of said outlet bosses in place of the plug normally closing the same to function as both a sealing plug for said other outlet boss and as the mounting structure for said solenoid force motor such that the associated said actuating member extends through said other boss into the interior of said low pressure chamber for operative disposition relative to said valve actuating lever.

6. The system of claim 5 wherein said actuating member comprises a rigid rod having a straight portion co-axially extending with the axis of the armature of said solenoid, said solenoid being a rotary type solenoid and operable for rotating said straight portion of said rod about its axis in response to the energizing signal actuating said solenoid force coil, said actuating member having a finger portion extending perpendicularly from said straight portion and terminating at a free end tip disposed between a valve-remote arm of said lever and said diaphragm for abuttingly engaging said valve-remote lever arm portion of said valve actuating lever in response to rotation of said armature coil rotating said actuating member finger tip into abutment with said lever.

7. The system as set forth in claim 4 wherein said solenoid force motor is of the rotary type and has an armature direct coupled and co-axially aligned with said rigid actuating member, said rigid actuating member having a portion extending into said housing and journalled supported for rotation therein, and wherein said valve actuating lever is mounted for pivotal motion on said actuating member and rigidly coupled thereto for co-rotation therewith in push-pull torque transmission cooperative engagement.

8. The system as set forth in claim 4 wherein said solenoid force motor is mounted on an exterior wall of said housing, said exterior wall being disposed on the side of said diaphragm remote from said valve actuating lever and defining with said diaphragm an atmospheric chamber vented to atmosphere via said wall, said solenoid force motor being mounted on said wall and having a linear actuator solenoid coil and associated linearly actuated piston type pintle and being operative to electromagnetically reciprocate said pintle along a line of action coincident with the normal operative motion of the center of said diaphragm that in turn is operatively mechanically coupled to one end of said valve actuating lever.

9. The system as set forth in claim 8 wherein said solenoid piston pintle has a free end abutting said diaphragm central portion to operatively engage said valve actuating lever in a push-only mode through the mechanical coupling connection of said diaphragm to said valve actuating lever.

10. The system as set forth in claim 9 wherein said solenoid piston pintle is coupled to said diaphragm and hence to said valve actuating lever via push-pull coupling means.

11. The system of claim 2 wherein said lever is pivotally supported within said housing on a fulcrum pivot disposed between said valve member and said spring and said valve member and lever are both disposed on the same side of said diaphragm, and wherein said actuating member operatively engages said lever on the side thereof opposite the side of said lever facing said spring.

12. The system of claim 11 wherein said actuating member engages said lever by acting on the side of said diaphragm opposite to that acted on by said spring and directly opposite a mechanical coupling engagement location between said lever and diaphragm.

13. The system of claim 11 wherein said actuating member directly operatively engages said lever in a zone located between said lever and said diaphragm.

14. The system set forth in claim 1 wherein said solenoid force motor is mounted on external wall of said housing, with said actuating member extending through a wall of said housing to engage said valve means without acting through said main pressure regulating spring.

15. The system set forth in claim 1 wherein said at least one sensor is responsive to at least one engine operating condition selected from the group consisting of engine speed, engine temperature, engine exhaust, air temperature and engine intake manifold air pressure.