Intake manifold pressure compensation for the closed-loop pressure regulation of a fuel pump

• US 5,133,323 A
• Filed: 06/25/1991
• Issued: 07/28/1992
• Est. Priority Date: 06/25/1991
• Status: Expired due to Fees

• Current Assignee: Siemens Automotive LP (Siemens AG)
• Original Assignee: Siemens Automotive LP (Siemens AG)
• Inventors: Treusch, Christopher J.
• Primary Examiner(s): MILLER, CARL STUART
• Application Number:
  US07/720,964
• Time in Patent Office: 399 Days
• Field of Search: 123/497, 123/499, 123/463, 123/494, 73/119 A
• US Class Current: 123/494
• CPC Class Codes: F02D 2200/0602 Fuel pressure
• CPC Class Codes: F02D 2250/31 Control of the fuel pressure
• CPC Class Codes: F02D 41/3082 Control of electrical fuel pumps
• CPC Class Codes: F02M 51/02 specially for low-pressure fuel-injection F02M51/005 takes precedence; pumpsper se F02M51/04; injectors per se F02M51/08
• CPC Class Codes: F02M 65/003 Measuring variation of fuel pressure in high pressure line
• CPC Class Codes: F02M 69/16 characterised by means for metering continuous fuel flow to injectors or means for varying fuel pressure upstream of continuously or intermittently operated injectors
• CPC Class Codes: F02M 69/54 Arrangement of fuel pressure regulators

Abstract

The fuel supply system of an internal combustion engine delivers liquid fuel to electrically operated fuel injectors by means of an electric pump whose output pressure is regulated by control electronics which receives as feedback from a pressure sensor connected into a fuel delivery passage serving the injectors a signal representing the pressure differential between manifold absolute pressure (MAP) and absolute pumped fuel pressure. The pressure sensor has a movable wall that divides its interior into an intake manifold pressure sensing chamber space communicated to the engine intake manifold and a fuel pressure sensing chamber space communicated to the fuel delivery line to the injectors. A magnet is mounted on a central region of the movable wall to transmit a signal to a Hall-effect sensor mounted within the intake manifold pressure sensing chamber space. The feedback pressure signal is derived from the Hall-effect sensor sensing the position of the magnet, and hence that of the movable wall.

Claims

1. In an internal combustion engine having a fuel supply system comprising a variable output pressure electric pump that pumps liquid fuel through a fuel discharge device into an air passage to form a combustible air-fuel mixture that is combusted in combustion chamber space of the engine to power the engine, and wherein the output pressure of the pump is controlled by a pressure sensor that is disposed to sense the pressure of the fuel being pumped by said pump and that acts via an electronic feedback control loop containing control electronics to cause the pump output pressure to be closed-loop regulated to a commanded pressure, the improvement which comprises said pressure sensor comprising a housing divided by a movable wall into a fuel pressure sensing chamber space and an intake manifold pressure sensing chamber space, means communicating said fuel pressure sensing chamber space to sense the pressure of the fuel being pumped by said pump, means communicating said intake manifold pressure sensing chamber space to an intake manifold of the engine to sense intake manifold pressure, means to cause said movable wall to be selectively positioned within said housing in accordance with the pressure differential between said fuel pressure sensing chamber space and said intake manifold pressure sensing chamber space, signal generating means for generating a signal indicative of the position to which said movable wall is selectively positioned, and means for relaying said signal to said control electronics, and wherein said control electronics comprises means acting upon said signal in furtherance of the closed-loop regulation of the commanded pump pressure, said signal generating means comprising transmitter means that is carried by said movable wall to transmit the selective position assumed by said movable wall in response to the pressure differential between said fuel pressure sensing chamber space and said intake manifold pressure sensing chamber space, and receiver means for generating said signal disposed within said intake manifold pressure sensing chamber space so as to be exposed to the pressure in said intake manifold pressure sensing chamber space for receiving from said transmitter means the selective position assumed by said movable wall, said receiver means generating said signal, and wherein said receiver means is mounted on an electronic circuit board assembly that is disposed within said intake manifold pressure sensing chamber space so as to be exposed to the pressure in said intake manifold pressure sensing chamber space, said receiving means comprising a receiver mounted on said electronic circuit board assembly and electronic circuitry mounted on said electronic circuit board assembly separate from, but in electrical association with, said receiver for co-action with said receiver to provide said signal, and electrical connector means extending from said electronic circuit board assembly in sealed relation through said housing to provide for the delivery for said signal to said control electronics.

2. The improvement set forth in claim 1 in which said transmitter means is disposed within said intake manifold pressure sensing chamber space in non-contacting relation to said receiver means.

3. The improvement set forth in claim 2 in which said transmitter means comprises a permanent magnet.

4. The improvement set forth in claim 3 in which said receiver comprises a Hall-effect sensor.

5. For use in an internal combustion engine having a fuel supply system comprising a variable output pressure electric pump that pumps liquid fuel through a fuel discharge device into an air passage to form a combustible air-fuel mixture that is combusted in combustion chamber space of the engine to power the engine, and wherein the output pressure of the pump is controlled by a pressure sensor that is disposed to sense the pressure of the fuel being pumped by the pump and that acts via an electronic feedback control loop containing control electronics to cause the pump output pressure to be closed-loop regulated to a commanded pressure, wherein said control electronics comprises means acting upon said signal in furtherance of the closed-loop regulation of the commanded pump pressure, an improved form of said pressure sensor which comprises a housing divided by a movable wall into a fuel pressure sensing chamber space and an intake manifold pressure sensing chamber space, means providing for the communicating of said fuel pressure sensing chamber space for sensing the pressure of the fuel being pumped by the pump, means providing for the communicating of said intake manifold pressure sensing chamber space for sensing intake manifold pressure, means to cause said movable wall to be selectively positioned within said housing in accordance with the pressure differential between said fuel pressure sensing chamber space and said intake manifold pressure sensing chamber space, signal generating means for generating a signal indicative of the position to which said movable wall is selectively positioned, and means providing for the relaying of said signal to the control electronics, said signal generating means comprising transmitter means that is carried by said movable wall to transmit the selective position assumed by said movable wall in response to the pressure differential between said fuel pressure sensing chamber space and said intake manifold pressure sensing chamber space, and receiver means for generating said signal disposed within said intake manifold pressure sensing chamber space for exposure to the pressure in said intake manifold pressure sensing chamber space and for receiving from said transmitter means the selective position assumed by said movable wall, said receiver means generating said signal, and wherein said receiver means is mounted on an electronic circuit board assembly that is disposed within said intake manifold pressure sensing chamber space for exposure to the pressure in said intake manifold pressure sensing chamber space, said receiving means comprising a receiver mounted on said electronic circuit board assembly and electronic circuitry mounted on said electronic circuit board assembly separate from, but in electrical association with, said receiver for co-action with said receiver to provide said signal, and electrical connector means extending from said electronic circuit board assembly in sealed relation through said housing to provide for the delivery for said signal to the control electronics.

6. The improved form of pressure sensor as set forth in claim 5 in which said transmitter means is disposed within said intake manifold pressure sensing chamber space in non-contacting relation to said receiver means.

7. The improved form of pressure sensor as set forth in claim 6 in which said transmitter means comprises a permanent magnet.

8. The improved form of pressure sensor as set forth in claim 7 in which said receiver comprises a Hall-effect sensor.