CA1073992A - Engine idle control - Google Patents

Engine idle control

Info

Publication number
CA1073992A
CA1073992A CA295,339A CA295339A CA1073992A CA 1073992 A CA1073992 A CA 1073992A CA 295339 A CA295339 A CA 295339A CA 1073992 A CA1073992 A CA 1073992A
Authority
CA
Canada
Prior art keywords
engine
manual control
electronic
control switch
switch
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
CA295,339A
Other languages
French (fr)
Inventor
Paul D. Sperline
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
SPS Instrument Co
Original Assignee
SPS Instrument Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by SPS Instrument Co filed Critical SPS Instrument Co
Priority to CA295,339A priority Critical patent/CA1073992A/en
Application granted granted Critical
Publication of CA1073992A publication Critical patent/CA1073992A/en
Expired legal-status Critical Current

Links

Landscapes

  • Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
  • Control Of Throttle Valves Provided In The Intake System Or In The Exhaust System (AREA)

Abstract

Abstract of the Disclosure An automatic control for continuing idle operation of an internal combustion engine, particularly a diesel motor, to pro-vide proper engine conditioning before the engine is shut down.
Automatic control circuitry is added by connection to the contacts of a conventional manual control switch for the engine. Normally open contacts of a relay are pre-set during engine use to bypass the manual control switch for a predetermined time following sub-sequent opening of the switch. A first electronic detector moni-tors the closing of the switch, while a second electronic detector monitors its opening. The two detectors operate both the relay and an electronic timing mechanism. The timing mechanism opens the relay contacts following a predetermined period after the opening of the manual control switch. In this way shutdown of the engine is accomplished electronically as an automatic function following manual opening of the usual key switch.

Description

This disclosure relates to a time delay control for an internal combustion engine, particularly a diesel engine. It is designed as an accessory which can be added to a vehicle or other engine installation without modification of the normal engine wiring.
None of the accessory circuits is interposed in the conventional ignition wiring, and any possible malfunction in the accessory will not affect normal engine operation. The cooling idle period for the engine is timed automatically without any effort on the part of the operator.
A prior control of this type which has seen successful utilization with respect to diesel engines, requires manual setting prior to opening the ignition switch. While this operates very successfully, many owners of diesel engines would prefer a fully automatic control that does not require any activation by the engine operator.
To accomplish this, a complete new electronic circuit is provided according to the present disclosure. The electronic cir-cuit utilizes solid state devices that consume very little power and which have extreme reliability adaptable to the environment in which the control circuitry is utilized.
The invention broadly includes an accessory or attach-ment for an internal combustion engine having an electrical power control circuit that controls operation of an electrical load device. The usual direct current battery is used as a source of electrical power. The normal key-operated switch is utilized as the conventional manual control switch. The contacts of the switch are closed during normal operation of the engine power circuit and are open when the power circuit is normally inoperative. The accessory circuit is designed to maintain the engine power circuit operative for a preselected time following the opening of the manual 1~'7~
control switch.
The accessory circuit includes a relay having a coil and a pair of normally nonconductive contacts or terminals controlled by the coil. A first relay terminal is connected to the first con-tact of the manual switch at its battery side. The second relay terminal is operatively wired in series with the coil to the remain- -ing side of the battery.
A normally conductive transistor switch circuit is opera-tively wired in series between the second relay terminal and the remaining side of the battery.
Electronic timing means is provided for producing an elec-tric signal at its output following a predetermined period after its activation.
First electronic sensing means in the form of a diode is connected between the engine side of the manual control switch and the second relay terminal for detecting the closing of the manual control switch. Upon detecting such closing, it completes a current path across the power source through the relay terminals.
Second electronic switching means in the form of a tran-sistor is operatively connected between the load contact of themanual control switch and the second relay terminal. It has normally nonconductive terminals wired in series between the second relay terminal and the electronic timing means. It detects the opening of the manual control switch and then activates the electronic timing means.
The output of the electronic timing means is operatively connected to the electronic switching means for causing the nor-mally conductive terminals thereof to become nonconductive upon receipt of the electrical signal produced by the electronic timing means. This opens the power circuit to the relay and shuts down the engine through the operation of the electrical load device.

1~7 ~ 2 The drawing figure represents a schematic diagram of the automatic engine controls.
The apparatus described below is designed specifically to facilitate idling of diesel engines or other types of internal com-bustion engines where it is desirable to allow a few minutes of idle operation just before shutdown after normal engine operation under load. Such idle operation is normally required by diesel engine manufacturers to permit the internal temperature of the engine to stabilize before shutdown. Proper engine cooling increases engine efficiency and increases its normal life. Automatic control of the idling sequence also reduces air pollution by minimizing the length of required engine operation prior to shutdown and by assisting in the improvement of engine maintenance and efficiency. The apparatus permits the operator of the engine to manually initiate the idle operation, remove the engine key or other control element, and leave the engine running at idle. The device will then shut down the engine after a preselected period of time.
The drawing illustrates a schematic diagram of a control circuit for idling an internal combustion engine, particularly a diesel engine, after removal of the usual key from the controlling key switch in the engine's electrical system. In the case of a diesel engine, the controlling switch is either connected to the - solenoid operated fuel control valve on the fuel pump or the sole-noid engine cutoff on the injector control rack. In the case of a gasoline engine, the key operated switch is interposed in the igni-tion system. The controlling switch may or may not be key operated, but is manually opened and closed in some fashion. It might also be interlocked with other devices that operate the switch in con-junction with other manual control functions, such as a brake lever, transmission control, or throttle. The control circuit described Z
herein is applicable to the control of other devices, motors and engines, and is generally useful in sequentially operating a device by control of an electrical circuit.
The drawing schematically illustrates the application of the control circuit to a typical electrical system for an internal combustion engine, whether used in a vehicle or at a stationary location. The purpose of the circuit is to idle the engine for a short period of time before shutdown. This idling operation is attained automatically without manual effort on the part of the operator, and without requiring that the operator continue monitor-ing the engine after his use of it has been completed.
In the normal electrical control circuitry for such an ; engine, indicated generally by the numeral 10 in the drawings, there is a battery or source of direct current electrical energy, a switch 12, which is typically key operated and serves as the manual control switch for the engine, and an electrical load device, illustrated as solenoid valve 11. The valve 11 might be a conventional solenoid operated fuel control valve mounted on the fuel pump of a diesel engine or a solenoid engine cutoff valve mounted on the injector control rack.
The first and second contacts 13, 14 of the switch 12 are selectively closed to complete a power circuit across the terminals of battery 15 during normal operation of the engine.
This power circuit is typically opened when the engine is shut down by opening switch 12. In some engine applications, the opening of switch 12 must be combined with other manual or automatic functions to properly shut down the engine. The present control circuitry can be applied to any of these conventional arrangements.
In the illustrated embodiment, the negative terminal of battery 15 is grounded and its positive terminal is connected in 1(~7~9g~
the power circuit to the first contact 13 of the manual control switch 12. The second contact 14 of switch 12 is wired to the grounded electrical equipment or load, illustrated as solenoid valve 11.
The present control circuitry is connected in parallel with the existing circuitry and does not require any modification or revision of the wiring as designed and installed by the manufacturer of the engine. The control circuitry can be housed within a single sealed enclosure (not shown) and can be mounted on an engine dash-board or on any available control panel.
The control circuitry includes a relay including a coil 16and first and second normally open terminals 17, 18. The coil serves as energizing means to control opening and closing of the terminals 17, 18. While an electro-mechanical relay is illustrated, equivalent electronic components can be incorporated into the circuit when desired.
The first terminal 17 for the relay is operatively wired to the first contact 13 of the manual control switch 12. The second terminal 18 of the relay is operatively wired, in series with coil 16, to the grounded terminal of battery 15 through electronic switch-ing means comprising transistors 20, 21.
During normal use of the engine, the relay is operated by means of a diode 24 wired between the second contact 14 of switch 12 and the second terminal 18 of the relay. Diode 24 is capable of completing a direct current circuit from the second contact 14 of switch 12 through the relay coil 16 and transistor 20 to ground.
The diode 24 serves as a first electronic sensing means to detect closing of the manual control switch 12. This detection function is accomplished by completing a circuit through coil 16 to thereby close the circuit through the relay terminals 17, 18. Transistor 1~:1'7;~5~9'~
20 is wired in series with coil 16 so as to be normally conductive during the usual operation of the internal combustion engine 10.
A second electronic sensing means (shown in the form of a transistor 25) is interposed between the second contact 14 of switch 12 and the second terminal 18 of the relay. The base of transistor 25 is connected to the second contact 14, and its collector is wired to the second terminal 18 of the relay. These connections permit the transistor 25 to function as a diode between the relay and switch.
A conventional timer 22 and counter 23 is utilized to pro-vide electronic timing for operation of solenoid valve 11. Both are preferably integrated circuits, the timer being a 555 circuit and the counter being a 14040 counter circuit. The electronic spikes from the timer 22 are fed to the counter 23. A conventional reset circuit is used as an input to counter 23. When the requisite number of spikes has been counted, the counter 23 produces an out-put signal at its output terminal shown at 26. The output terminal 26 is connected to the base of transistor 21 in the electronic switching means interposed between the relay coil 16 and ground.
To understand operation of the apparatus, it is necessary to study the various components during the usual steps taken to con-trol the engine 10.
First, with the engine at rest, the switch 12 is open and no current is drawn by any of the components illustrated in the drawing.
When the switch 12 is closed to start or operate the engine 10, the solenoid valve 11 is operated and there is a momentary cur-rent path established through diode 24, coil 16 and the conducting terminals of transistor 20 to ground. The completion of a circuit through the coil 16 closes the relay terminals 17, 18 to maintain . . .

the circuit. Transistor 25 remains nonconducting and the electronic timing means is inoperative during the usual functioning of the engine 10. No current is passed by transistor 25 to the electronic timing means as there is no bias on the base to the collector of the transistor 25. Until the relay terminals 17, 18 close, transistor 25 is reverse biased. When the terminals 17, 18 of the relay are closed, the diode 24 will no longer conduct current and transistor 25 will be forward biased.
When the switch 12 is opened, a current path will be established through the relay terminals 17, 18 to maintain the cir-cuit of transistor 20 and the forward bias of transistor 25. The base current through transistor 25 operates the solenoid valve 11.
The emitter of transistor 25, which is now conductive, furnishes electrical power to initiate operation of the timer 22. A signal lamp 27 is shown wired across the timer to provide a visual indica-tion to the user to verify that the circuit is operative after open-ing of switch 12. The timer 22 and counter 23 then electronically measure a predetermined period of time (such as four minutes), while the components remain in a steady state continuing operation of the solenoid valve 11.
At the completion of the predetermined time period, an electrical pulse is produced at the output 25 in counter 23, which is applied to the base of transistor 21. This causes transistor 21 to become conductive and pull the base of transistor 20 to ground, thereby turning off transistor 20. Transistor 20 thereby serves as an electronic switch to open the circuit to the relay coil 16, which in turn opens the relay terminals 17, 18 and shuts down the entire apparatus. This returns the apparatus to its original state with the solenoid valve 11 inoperative and switch 12 open in preparation for subsequent use of the engine 10. The above automatic sequence ~ ~.~

1~)'7;~9 ~2 assures cooling of engine 10 after its use. Idle operation is - always timed automatically for a predetermined period following opening of the operator's key switch 12.
The electrical components illustrated are only examples of those which can be designed and chosen for this purpose. Equiva-lent electronic or electro-mechanical devices can be substituted when desired, so long as the functional relationship remains basically as described above.
For reasons of emergency, a system to manually override the automatic apparatus might be interposed. This can be done by interposing a normally closed manual switch (not shown) in the line leading directly to the solenoid valve 11 or in series with the term-inals 17, 18 of the relay. A normally open manual switch (not shown) might also be interposed between the base of transistor 20 and ground.
The control circuitry described above does not require alteration of the existing wiring in the vehicle. The usual relia-bility of the engine is not jeopardized in any manner should the timing mechanism fail to operate. In any respect, idling and cooling of the engine can be assured by the usual key operation of the switch 12 under the control of an operator.

, :

Claims

The embodiment of the invention, in which an exclusive property or privilege is claimed is defined as follows:
1. In an apparatus for maintaining operation of the elec-trical power control circuit of an internal combustion engine for a preselected period of time, the combination with an internal com-bustion engine, a direct current electrical power source, an elec-trical load device operable to shut down the engine, and a power circuit connecting said power source to said electrical load device;
said power circuit including a manual control switch having a first contact operatively connected to one side of the power source and a second contact operatively connected in series with the electrical load device to the remaining side of the power source; the manual control switch contacts being closed during normal operation of the power circuit and being open when the power circuit is normally in-operative;
the improvement comprising:
relay means including energizing means and a pair of nor-mally nonconductive terminals controlled thereby and adapted to be rendered conductive upon activation of said energizing means, a first terminal of the relay means being operatively wired to the first contact of the manual control switch, the second terminal of the relay means being operatively wired in series with said ener-gizing means to the remaining side of the power source;
electronic switching means having normally conductive terminals operatively wired in series between said second terminal of the relay means and the remaining side of the power source;
electronic timing means having an output terminal for pro-ducing an electrical signal at said output terminal following a predetermined period of time after activation of the electronic timing means;
first electronic sensing means operatively connected be-tween the second contact of the manual control switch and said second terminal of the relay means for detection of the closing of the manual control switch, said first electronic sensing means being operable, upon detecting the closing of the manual control switch, to complete a current path across the power source through the manual control switch, the energizing means and the normally conductive terminal of said electronic switch means to thereby cause the first and second terminals of the relay means to be con-ductive;
second electronic sensing means operatively connected between the second contact of the manual control switch and the second terminal of the relay means and having normally nonconduc-tive terminals wired in series between said second terminal of the relay means and said electronic timing means for detection of the opening of the manual control switch, said second electronic switch-ing means being operable to activate said electronic timing means upon detecting an opening of the manual control switch;
the output terminal of said electronic timing means being operatively connected to said electronic switching means for caus-ing said normally conductive terminals thereof to become noncon-ductive upon production of an electrical signal by said electronic timing means, thereby opening the power circuit to said energizing means.
CA295,339A 1978-01-19 1978-01-19 Engine idle control Expired CA1073992A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CA295,339A CA1073992A (en) 1978-01-19 1978-01-19 Engine idle control

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CA295,339A CA1073992A (en) 1978-01-19 1978-01-19 Engine idle control

Publications (1)

Publication Number Publication Date
CA1073992A true CA1073992A (en) 1980-03-18

Family

ID=4110583

Family Applications (1)

Application Number Title Priority Date Filing Date
CA295,339A Expired CA1073992A (en) 1978-01-19 1978-01-19 Engine idle control

Country Status (1)

Country Link
CA (1) CA1073992A (en)

Similar Documents

Publication Publication Date Title
US4088110A (en) Engine idle control
US4682044A (en) Engine idling load control means
CA1108274A (en) Engine stop-start electrical circuit
US5822978A (en) Method of controlling the electric heating of a catalytic converter
US5222469A (en) Apparatus for monitoring an internal combustion engine of a vehicle
US4924827A (en) Diesel engine shut-down device
US3680539A (en) Time delay control
US4466392A (en) Automatic engine stop-restart system
US4534326A (en) Stop/start engine control for a road vehicle
US4485772A (en) Automatic engine stop-restart system
US4371822A (en) Control device for pulse motors, having a fail safe function
US4083337A (en) Air-fuel ratio adjusting system
JPH0555695B2 (en)
US4037578A (en) Ignition safety control system
CA1073992A (en) Engine idle control
US5353762A (en) Modular automatic speed changing system
US3414734A (en) Automatic engine starting system
US2989644A (en) Safety systems for electric fuel pumps
US4231345A (en) Apparatus for controlling an electrical switching element in internal combustion engines
KR910010049A (en) Control method and device for idle control valve of internal combustion engine
US3790806A (en) Remote engine starting system
US5062400A (en) Diesel engine shut-down device
CA1245323A (en) Operational condition control device for an internal combustion engine
US4522164A (en) Cold-start assisting device for combustion engines
US4122355A (en) Vehicle engine automatic restart circuit

Legal Events

Date Code Title Description
MKEX Expiry