US2939964A - Starting systems - Google Patents

Description

June 1960 P. L. SCHNEIDER ETAL 2,939,964

STARTING SYSTEMS Filed March 6, 1957 INVENTORS P401. L. SCHNEIDER B RTHUR Wham/mm ATTORNEY STARTING SYSTEMS Paul L. Schneider and Arthur W. Alexander, Anderson,

Ind., assignors to General Motors Corporation, Detroit, Mich., a corporation of Delaware Filed Mar. 6, 1957, Ser. No. 644,350

1 Claim. (Cl. 290-38) This invention relates to starting systems for internal combustion engines and is more particularly concerned with starting systems wherein the control of the actuation of the starter is accomplished without human assistance.

Internal combustion engines which are used as emergency sources of power frequently are equipped with automatic starting systems. That is, the energization of the starting system for the engine is initiated automatically in response to an outside event without human assistance or attention. Further, these engines frequently are installed at some remote location. Therefore, if these engines are to fulfill their expected function, the starting systems for these engines must be virtually fool-proof. While the starting systems which will be herein described may be used to supply cranking torque to other than stationary emergency power equipment, it is particularly suited to installations wherein the engine is started and operated without human attention.

On a typical starting system for an internal combustion engine, such as shown in US. Patent 2,716,895, the starting motor is provided with a starter drive. This starter drive includes a pinion gear which is moved into meshing engagement with the ring gear on the engine to be started. The starting motor when energized supplies the cranking torque to cause the engine to become selfoperative. The movement of the starter drive pinion gear into meshing engagement with the ring gear is accomplished by a solenoid which not only moves the pinion gear into engagement but also closes the circuit to the starting motor. On occasion, it has been found that tooth abutment will occur between the pinion and the ring gear of the engine when the pinion gear is moved into engaging position. When this tooth end abutment occurs, the teeth of the pinion gear abut the end of the teeth of the ring gear and are prevented from passing into the spaces between the teeth of the ring gear. When this occurs, the solenoid of the starting system will continue to be energized to urge the pinion gear toward the meshing engagement. The current flow through the solenoid windings during these periods will be abnormally high and may ultimately cause the solenoid coil Winding to become overheated. This overheatingof the solenoid will ultimately result in a short which may result in failure of the entire starting system.

It is an object, therefore, of the present invention to prevent the overheating and resulting shorting of the solenoid in an automatic starting system for internal combustion engines.

In carrying out the above object, it is another object of the present invention to prevent overheating of the solenoid in an automatic starting motor apparatus for an internal combustion engine and to cause a recycling of the starting motor circuit in event tooth end abutment occurs between the pinion gear of the starting motor drive and the ring gear of the engine to be cranked.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein pre- United States Patent ferred embodiments of the present invention are clearly shown.

In the drawings:

The single figure illustrates an automatic starting motor system incorporating the features of the present invention.

In the drawing, the starting motor for the internal combustion engine, not shown, includes; a starting motor 20, a starter drive 22, a starter motor solenoid 24, a storage battery 26 and a means for controlling the energization of the starting motor solenoid 22 and the starting motor 20.

The starting motor 20 is of the conventional type and the starter drive may also be of the conventional type and may include a sprag or roller type clutch 27 as, for example, as disclosed in application, Serial No. 558,468, filed January 11, 1956, and assigned to the assignee of the present invention.

The solenoid 24 is provided with an outer casing 28 which, in practice, is usually attached to the frame of the starting motor. The casing 28 encloses a pair of solenoid windings 30 and 32, a solenoid plunger 34, a magnetic pole piece 36 and a movable contact 38 which is arranged to engage the stationary contacts 40 and 41. The solenoid plunger 34 is suitably connected through a link 42 and a lever 44 with the starter drive 22. The contact 40 is connected directly to the battery 26. The contact 41 is connected through a lead 46, to the field 48 of the starting motor 20, and the armature of the starting motor, not shown, to ground 50, from whence the circuit is complete to the ground 50 of the battery. Winding 30 of the solenoid is formed of relatively fine wire which has one of its ends connected directly to ground 50 and the other end connected through a lead 52 to a circuit which will be later described. Winding 32, which is formed of heavier wire, has one of its ends connected to lead 52 and its other end connected to the terminal for contact 41. From the above, it is apparent that when current is supplied from the battery through a means which will be later described, to lead 52, current will flow through both windings 30 and 32. The current through winding 30 will be directly connected to ground 50 and the current flow through winding 32 will pass from the lower terminal 41 through lead 46, field 48 and the armature of starting motor to ground 50. When current flows through these windings, the magnetic attraction set up in pole piece 36 will cause the solenoid plunger to move to the right, thereby moving the starter drive 22 so that the pinion 54 is moved toward the ring gear 56 which is con nected to the engine to be started. If there is no abutment between the pinion gear 54 and ring gear 56, the teeth of the pinion gear will pass into engagement with the ring gear. When this occurs, the plunger 34 will have moved sufficiently to the right to cause the contacts 38 to engage contacts 40 and 41 and complete the circuit between the battery and the starting motor so that the motor will become energized. Also, when the contact 38 closes the circuit through contacts 40 and 41, the winding 32 will be shorted out of the circuit so that the winding 30 will act as a hold-in winding to maintain the plunger in the attracted position. When the starting motor is energized, it will rotate the shaft 58 which will cause the pinion gear to be rotated to supply the cranking torque to the ring gear 56 of the engine.

The generating system which is used to charge the battery 26 forms a part of the control means for the starting system according to the present invention. In the embodiment shown, the generator 60 has one output lead 61 connected to ground 50. The other output lead 62 is connected through a junction 63 with the generator terminal 64 of a conventional current and voltage switch and regulator as used in present day automotive vehicles; The regulator 65 has an internal circuit that is prefer "non/"described.

The s'olenoid rcla'y 78'has ahactuating coil 34 mass "on a magnetic core '86 "which will attract thefiirni'a 88 andcauseehgagcmentbetween the contacts 9 Whenever the coil 84 'is energized. The contact z carried on the armature 88 and is connected in th the circuit breaker 76 with lead 52. The contact 'cfinnectcdth'roughalead 94 and lead 74 with the/battery 26 One endof the'actuating coil"84 of the'relay 781s connected thr'ou gha lead 96 with the junction63. The other end ofthe coil 8-1 is connectcdthrough the 'va'cuiiin switch 80 and the control switch 82 to lead '74'to battery Theswitch 82 is the main control switch and maybe arranged to be either manually closed or closed automasonry by some suitablemeans was to be responsive to "an 'outsidc'event as for an'example a failure in power which would require that'the stationary engine be started to supply emergency :electric'c'urrent to a system. The switch Sil'is preferably a pressure type switch which are *well known which 'rnay be either connected to the oil -rircssure 'systein of the engine which is to be started or to the'engine'vacinirn. In either case the switch 80 is arranged so the contacts are normally closed when the engine is inoperative and will open after the 'oil "pressure of the engine or the engine vacuum reaches a "predetermined value at which time the engine is selfoperative. This type of switch is also well known and in the particular embodiment shown the switch comprises a fluid motor 80:: containing the usual flexible diaphragm which is moved leftwardly when a predetermined vacuum pressure exists within chamber 8%. The diaphragm operates switch contacts 80c which are normally held closed by 'a spring 8 nd until the spring is overcome by vacuum in chamber 89b.

From tl1 ea b ve 'it is apparentthat when switch 82 and switch 80 are closed, current will flow from the battery 26 through lead 74 to the actuating coil 84, lead 96, junction 63, lead 62 where it will be grounded through the gener'ator-60 at ground 50. The current flow'thr'ough coil 84 will eausethe armature to move and close con- 'ta'cts '90 and 92. When, however, the engine becomes self operative to cause the generator to produce a current and voltage, the "voltage of the generator 60 will oppose 'the'volt'a'ge of the battery and cause the voltage and current flow to the actuating coil 84 to become practically "zero. W henthis occurs, the actuating can will an be energized sufii'e'iently to "attract armature 8'8 and continue the closure of contacts 99 and 92. This ar rangeinent provides -'a 's'afety feature to' cause thcopeni'n'g or contacts Q and 92 when the prime mover is selfoperative. I g

e "ch 76 may be of any suitable. type which is current responsive and may be of the type disclosed in US. Patent 2,699,161. This switch is of the hot Wife 9 and will cause openin of the contacts 7611 after a predetermined amount "or current has passed through hot wire 76b for a predetermined time. This switch is "also adapted to cause reclo'sure of the contacts 76a of.

circuit breaker 76 after the current flow therethrough has 'ee ed for a predet rmined time. The hot wire 76b of t e circuit breaker 76 is preferably designed so that a prolonged 'c'trnestnow through both windings 30 and '32 of the solenoid 24 \villfc'iuse the circuit breaker 76 t6 u't neither the st state valuecf current i c ,r .,,l.-A. 7, through winding 30 nor the instantaneous surge of curl r 4 rent through windings 30 and 32 will cause opening of the circuit breaker 76. The switch 76 includes a conducting frame 760 which is pivoted at 76d. A spring 76:: constantly biases the frame 760 in a clockwise direction and toward an insulated stop. One of the contacts 76:: is connected with one side of armature 88 while the other contact is electrically connected to one side of hot Wire 76b and through a spring arm 76 to frame 76c. The frame 76c 'is electrically connected with lead 52. The hot'wire 76b is formed of any suitable wire that clongates upon'heating due to the passage of a current therethrough and which contracts upon "cooling. Thus, when contacts 76a are closed, current flows through hot wire 76b and through frame 760, the hot wire being heated during this time' The resistance of the hot wire and circuit through the frame 760 are so proportioned that upon prolonged current fiow through windings 3t) and 32 the hot wire elongates sufficiently so that spring 76c moves the frame to a position to open contacts 76a. When the wire 76b cools, it contracts and'once more closes contacts 76a. 7

With theabove circuit arrangement in mind, the oper ation thereof will now be described. When switch 82. is closed, the coil winding 84 will be energized to setup a magnetic attraction in core 86 to cause the movement of armature 88 to close the contacts 90'and 9 2. The

closure of contacts 90 and 92 will cause the circuit from the battery to the armature 88 and circuit breaker 76 to be complete so that current will flow through lead 52 through both windings 30and 32 of the solenoid 28. When current flows through windings 30 and 32, the plunger 34 will be attracted to move'the pinion gear 54 toward the ring gear. If there is no tooth abutment between the gear teeth on the pinion 54 and ring gear 56, the solenoid plunger will travel a suflicient'distance to the right to cause contact 38 to close the circuit between contacts 40 and 41 so as to complete the circuit from the battery to the starting motor. This in mm will causethe winding 32 to be deenergized so that the circuit breaker does not open the circuit to winding 30. When tooth end abutment occurs, the contact 38 is not moved sufliciently to engage the contacts 40 and 41 and current will continue to how through both windings 30 and 32. This current flow will cause the hot wire of the circuit breaker 76 to cause an opening of the contacts of circuit breaker 76. When thejcontactls of circuit breaker 76.open the circuit to both windings 30 and 32 will be broken and the solenoid 24 will be deenergized in spite of the fact that the switch 82 is closed. After a predetermined period of time, the circuit breaker 76 will operate and reclose the circuit to windings 30 and 32 so the starter drive 22 is again moved toward the ring gear. Should abutment again occur, then the circuit breaker 76 will again open to repeat the cycle of deenergizing and energizing the coil windings 30 and 3:2 Arepetition of theabove cycles will cause starting motor and starter drive parts to finally move sufliciently so that the pinion gear is positioned to pass into meshing engagement with the ring gear. This will permit the starting motor to be energized Jtocr an-k the'engine. After the engine is self operative, the circuit to the actuating coil 84 will be opened or deenergized byfthe action or the switch or the output of generator 60 to cause dee'nerg iza'tion of the starting motor and th starting motor solenoid as heretofore described.

What is claimed is as follows:

In a "starting system for an internal combustion engine having a ring gear that is adapted to mesh with a pinion; the combination comprising; a starting motor, a source of current for energizing said starting 'motor', a starter drive including a pinion bodily movable into crank ing engagement with the ring gear of said engine for transmitting torque between said motor and engine, a first electric switch connected between said starting motor and said source of current for completing a circuit there 5 between, a solenoid actuator including a first holding winding, :1 second winding and a movable plunger, means connecting said plunger with said starter drive for moving said pinion into engagement with said ring gear when said first and second solenoid windings are energized, means connecting said plunger and switch for operating said switch to a closed position only after said pinion has meshed with the ring gear, a second electric switch connected between said current source and said first and second solenoid windings for completing a circuit therebetween, means responsive to current flow of greater than a predetermined magnitude through said first and second solenoid windings for opening said second switch and for maintaining said second switch in an open position for a predetermined time interval, said second switch remaining closed at a value of current flow through said 3 windings that is less than said predetermined magnitude,

means for automatically reclosing said second switch after said predetermined time interval to automatically References Cited in the file of this patent UNITED STATES PATENTS 1,901,285 Christian Mar. 14, 1935 2,197,726 Johnson Apr. 6, 1940 2,302,687 Dyer Nov. 24, 1942 2,602,144 B01168 July 1, 1952 2,654,035 Rowell Sept. 29, 1953 2,699,161 Pees Jan. 11, 1955 15 2,716,895 Antonidis Sept. 6. 1955 FOREIGN PATENTS 379,805 Great Britain Sept. 8, 1932

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