System for dithering solenoids of hydraulically operated valves after engine ignition shut-off

• US 5,522,350 A
• Filed: 05/23/1995
• Issued: 06/04/1996
• Est. Priority Date: 05/23/1995
• Status: Expired due to Fees

• Current Assignee: Thomas J. Hollis
• Original Assignee: Thomas J. Hollis
• Inventors: Hollis, Thomas J.
• Primary Examiner(s): Kamen, Noah P.
• Application Number:
  US08/447,471
• Time in Patent Office: 378 Days
• Field of Search: 123/41.08, 123/41.1
• US Class Current: 123/41.1
• CPC Class Codes: F01M 5/001 Heating
• CPC Class Codes: F01M 5/002 Cooling
• CPC Class Codes: F01P 2007/146 using valves
• CPC Class Codes: F01P 2023/08 Microprocessor; Microcomputer
• CPC Class Codes: F01P 2025/04 Pressure
• CPC Class Codes: F01P 2025/08 Temperature
• CPC Class Codes: F01P 2025/13 Ambient temperature
• CPC Class Codes: F01P 2025/40 Oil temperature
• CPC Class Codes: F01P 2025/50 using two or more temperature sensors
• CPC Class Codes: F01P 2025/62 Load
• CPC Class Codes: F01P 2031/20 Warning devices
• CPC Class Codes: F01P 2031/22 using warning lamps
• CPC Class Codes: F01P 2037/02 starting
• CPC Class Codes: F01P 2060/00 Cooling circuits using auxiliaries
• CPC Class Codes: F01P 2060/04 Lubricant cooler
• CPC Class Codes: F01P 2060/08 Cabin heater
• CPC Class Codes: F01P 2060/10 Fuel manifold
• CPC Class Codes: F01P 2060/12 Turbo charger
• CPC Class Codes: F01P 2070/08 Using lubricant pressure as actuating fluid
• CPC Class Codes: F01P 7/167 by adjusting the pre-set temperature according to engine parameters, e.g. engine load, engine speed

Abstract

A system for controlling the flow of hydraulic fluid in lines leading to and from a solenoid injector which actuates a temperature control valve. The solenoid injector controls the actuation a temperature control valve between a first state for inhibiting flow of temperature control fluid and a second state for allowing flow of a temperature control fluid. The solenoid injector receives a flow of pressurized hydraulic fluid along the hydraulic line from a fluid reservoir. In order to drain the hydraulic fluid from the hydraulic line after engine shut-off, the hydraulic line is dithered in accordance with a predetermined schedule. An engine computer determines when the engine has been shut-off. After determining that the engine has been shut-off, the engine computer sends signals to the solenoid injector causing it to actuate between its open and closed positions in accordance with a predetermined schedule.

Claims

1. A method for dithering a hydraulic line in fluidic communication with a solenoid injector adapted for draining hydraulic fluid therefrom after engine shut-off, the solenoid injector having an open and a closed position, the solenoid injector being operative for actuating a temperature control valve between a first state for inhibiting flow of temperature control fluid and a second state for allowing flow of a temperature control fluid, wherein the method comprises the steps of:

(a) determining if the engine has been shut-off; and

(b) actuating the solenoid injector between the open position and the closed position in accordance with a predetermined schedule.

2. A system for dithering a hydraulic tube to drain hydraulic fluid therefrom after engine shut-off, the system comprising:

a temperature control valve adapted for controlling flow of a temperature control fluid between a first and second passageway, the temperature control valve having a first state for inhibiting flow the fluid flow and a second state for allowing the fluid flow;

at least one solenoid injector in fluidic communication with the temperature control valve, the solenoid having an open and a closed position, the solenoid injector being adapted for transmitting hydraulic fluid to the temperature control valve for actuating the valve between the first and second state;

a hydraulic fluid source;

at least one hydraulic fluid tube attached to the solenoid injector for transmitting hydraulic fluid from the hydraulic fluid source to the solenoid injector; and

an engine computer in communication with the solenoid injector for controlling the operation of the injector, the engine computer determining when the engine is shut-off, the engine computer providing signals to the solenoid injector in accordance with a predetermined schedule when the engine is shut-off, the signals causing the solenoid injector to open and close.

3. A method for dithering a hydraulic line in fluidic communication with a solenoid injector adapted for draining hydraulic fluid therefrom after engine shut-off, the solenoid injector having an open and a closed position, the solenoid injector being operative for actuating a temperature control valve between a first state for inhibiting flow of temperature control fluid and a second state for allowing flow of a temperature control fluid, wherein the method comprises the steps of:

(a) determining if the engine has been shut-off;

(b) determining the state of the temperature control valve;

(c) actuating the solenoid injector between the open position and the closed position in accordance with a predetermined schedule when the temperature control valve is in a desired state.

4. A method for dithering a hydraulic line according to claim 3 wherein the desired state of the temperature control valve is the first state.

5. A method for dithering a hydraulic line according to claim 3 wherein the desired state of the temperature control valve is the second state.

6. A system for dithering a hydraulic tube to drain hydraulic fluid therefrom after engine shut-off, the system comprising:

a temperature control valve adapted for controlling flow of a temperature control fluid between a first and second passageway, the temperature control valve having a first state for inhibiting flow the fluid flow and a second state for allowing the fluid flow;

at least one solenoid injector in fluidic communication with the temperature control valve, the solenoid having an open and a closed position, the solenoid injector being adapted for transmitting hydraulic fluid to the temperature control valve for actuating the valve between the first and second state;

a hydraulic fluid source;

at least one hydraulic fluid tube attached to the solenoid injector for transmitting hydraulic fluid from the hydraulic fluid source to the solenoid injector; and

an engine computer in communication with the solenoid injector for controlling the operation of the injector, the engine computer determining when the engine is shut-off and determining the state of the temperature control valve, the engine computer providing signals to the solenoid injector in accordance with a predetermined schedule when the engine is shut-off and the control valve is in a desired state, the signals causing the solenoid injector to open and close.

7. A system for dithering according to claim 6 wherein the desired state is the first state wherein flow of the temperature control fluid is inhibited between the first and second passageways.

8. A system for dithering according to claim 6 wherein the desired state is the second state wherein flow of the temperature control fluid is allowed between the first and second passageways.

9. A method for dithering a hydraulic line in fluidic communication with a solenoid injector adapted for draining hydraulic fluid therefrom after engine shut-off, the solenoid injector having an open and a closed position, the solenoid injector being operative for actuating a temperature control valve between a first state for inhibiting flow of temperature control fluid and a second state for allowing flow of a temperature control fluid, wherein the method comprises the steps of:

(a) determining if the engine has been shut-off;

(b) actuating the solenoid injector between the open position and the closed position in accordance with a predetermined schedule which oscillates the solenoid injector between the open position and the closed position.