US 3895616 A
To adjust a breaker support plate of a distributorbreaker assembly, a link is coupled to the plate to rotate the plate with respect to the breaker camshaft, the link being controlled to move the breaker plate over a first excursion distance a under influence of a first force, and, to additionally retard the spark, to provide for additional excursion over a further distance b, the displacement forces being generated, for example, by vacuum chambers, electromagnetic means (separately or mixed) in such a manner that the displacement of the link controlling angular position of the breaker plate will be cumulative, as commanded by application of the separate forces. The forces themselves can be controlled, for example, in dependence on engine operating parameters, for example temperature of exhaust system reactors, speed of the engine, mode of operation (delivering power, idling, or in engine braking mode) or the like.
Description (OCR text may contain errors)
United States Patent Steinke IGNITION CONTACT BREAKER SYSTEM FOR INTERNAL COMBUSTION ENGINE Beard 123/117 A Primary Examiner-Wendell E. Burns Assistant ExaminerJames Winthrop Canson, Jr. Attorney, Agent, or Firm-Flynn & Frishauf  ABSTRACT To adjust a breaker support plate of a distributorbreaker assembly, a link is coupled to the plate to rotate the plate with respect to the breaker camshaft. the link being controlled to move the breaker plate over a first excursion distance a under influence of a first force, and, to additionally retard the spark, to provide for additional excursion over a further distance b, the displacement forces being generated. for example, by vacuum chambers, electromagnetic means (separately or mixed) in such a manner that the displacement of the link controlling angular position of the breaker plate will be cumulative, as commanded by application of the separate forces. The forces themselves can be controlled, for example, in dependence on engine operating parameters, for example temperature of exhaust system reactors, speed of the engine, mode of operation (delivering power, idling, or in engine braking mode) or the like.
31 Claims, 5 Drawing Figures PATENTEBJUL22|915 3895616 SHEET 2 IGNITION CONTACT BREAKER SYSTEM FOR INTERNAL COMBUSTION ENGINE The present invention relates to an ignition contact breaker system for internal combustion engines, and more particularly to such a system in which the timing of the ignition pulses. relative to angular position of the engine crankshaft can be adjusted in accordance with more than one engine operating parameter.
Various arrangements have previously been proposed to change the ignition timing. In order to improve ignition so that the exhaust gases emitted from the engine will be as free from noxious polluting components as possible, ignition timing of the engine can be adjusted, by delaying or advancing spark, to improve the combustion process. Exhaust sensors are used, which provide electrical output signals representative of the composition of the exhaust gases, the signals then being applied to suitable networks to provide control signals which adjust the timing of the spark, typically by delaying ignition, to improve combustion so that the exhaust gases from the engine will have less noxious components.
In accordance with a proposal (see, for example German published Patent Application OS 1601425) the ignition timing is delayed, by delaying the spark, by a predetermined angular extent, with respect to engine crankshaft or camshaft, when the engine is operated in idling, partial load, or under conditions of engine braking, that is, when power is fed from the wheels to the engine.
If the internal combustion engine utilizes reactors, particularly catalytic reactors in order to treat the exhaust gases from the engine, then it has been found that such reactors or other exhaust gas treating devices become fully effective when they have reached a certain operating temperature. It is desirable to reduce the emission of noxious components from the engine also during the warm-up of the engine. It is thus necessary that the exhaust treatment devices, typically the air reactors, reach the operating temperatures quickly. The hot exhaust gases from the engine can be used in order to heat the reactors. The retardation of ignition usually commanded for idling, partial loading or engine braking conditions is usually, however, now sufficient in order to heat the reactors with sufficient rapidity. It may be necessary to retard the spark more than normal, ordinary spark retardation devices can effect, for example by an additional crankshaft angle which may well reach about or even more.
Additional retardation of ignition can be utilized, advantageously, particularly when the engine operates under engine braking conditions, and when engine speed is relatively high. Without special precautions, the air-fuel mixture becomes quite rich when operating under engine braking, and excess fuel may reach the point where the spark can no longer ignite the air-fuel mixture. This is additionally enhanced by the presence of remanent or remaining portions of gases in the cylinder. Supply of additional, excess air could be utilized in order to provide for ignition. This, however, may then lead to the engine supplying power so that, instead of acting as a brake, the engine will provide energy to the wheels. This, however, is not desired by the driver. It has been found that by additionally retarding the spark, the fuel air mixture can be ignited nevertheless without delivering power to the engine, and engine braking operation is sufficiently ensured while also burning any excess fuel.
It is an object of the present invention to provide a device which will effect spark retardation, under control of signals representative of exhaust gas composition, which is simple, provides for sufficient spark retardation, and can be easily constructed and adapted to existing devices and technology.
The present invention thus relates to an ignition contact and breaker system to provide ignition pulses for internal combustion engines, which is enclosed in the usual housing and provided with a camshaft. passing through a support plate which is rotatably adjustably mounted in the housing, surrounding the camshaft. Breaker contacts are located on the support plate, and are engaged by the camshaft, opening and closing in synchronism with rotation of the engine, and hence the camshaft. The support plate itself is rotatably mounted about the camshaft, for rocking or swinging movement to adjust the relative angular position of the breaker contacts with respect to the lands of the cam of the camshaft.
Subject matter of the present invention:
Briefly, the plate is so arranged and rotatably so connected with respect to the camshaft that it can be adjusted under command of a plurality of control parameters. A link is connected to the plate and means are provided to move the link by a first excursion, for example'under command of a standard vacuum spark advance-retardation control system. An additional means is provided to superimpose an additional movement on the link, additionally to retard the spark, the additional means being operated under control of a sensor responding to engine operating parameters such as exhaust composition, operation under engine braking conditions or the like.
In accordance with an embodiment of the present invention, the first means is a diaphragm chamber, connected with a link to the rotatable plate. The link can bear against an abutment body, typically part of the housing, with an abutment element, such as an adjustment nut on the link. Upon change of diaphragm position of the diaphragm chamber, the link will be operated for a first distance, which is limited by engagement of the abutment element with the abutment body. The ignition timing can be further retarded by rotating the plate, by additional excursion of the link, by a second angular extent by moving the abutment body, and thus with it the link and the abutment element, for example by a second diaphragm chamber. Springs are provided in order to ensure movement of the link without lost motion.
The invention will be described by way of example with reference to the accompanying drawings, wherein:
FIG. 1 is a longitudinal sectional view, somewhat schematic, of the adjustment portion to adjust the operating plate of a breaker assembly for internal combustion engine;
FIG. 2 is a view similar to FIG. 1, illustrating another embodiment;
FIG. 3 is a view similar to FIG. 1 illustrating a third embodiment;
FIG. 4 is a view similar to FIG. 1 illustrating pressure and electromagnetic force responsive positioning of the breaker plate;
FIG. is a view similar to FIG. 4 and illustrating another embodiment.
The internal combustion engine itself is not illustrated, and nor is the ignition system or the breaker assembly. The entire system, and its cooperation with other parts of a distributor is illustrated in Automotive Vehicles, U.S. Government Publication TM9-8000 Principles of Automotive Vehicles, chapter on Buttery Ignition (I956).
Breaker contacts 1, are operated from a cam 2 driven by the camshaft 3 coupled to the engine. Camshaft 3 is connected to the crankshaft or camshaft of the engine and is rotated in direction of arrow A upon operation of the internal combustion engine.
Breaker 1 includes a fixed contact 5 located on a support plate 4 and a movable contact 7 located on a breaker arm 6 which is pressed under influence of a spring (not shown) against contact 5. The cam 2, which functions as a pulse or trigger device is formed as a square cam 8 (for a four-cylinder engine), the tips 10 of which engage an insulating tip or pin 9 secured to the movable arm 6. Upon rotation of the shaft 3, the contacts 5, 7 will open in timed sequence, and synchronism, with rotation of shaft 3. Upon breaking of the contact, an ignition pulse is provided, for example by interrupting current flowing through an ignition coil, by triggering an electronic ignition device, or the like, so that from the secondary of the ignition coil an appropriate spark impulse will be provided to ignite the fuelair mixture within the cylinder'of the internal combustion engine. In general, upon breaking of contacts 5, 7 the signal source 1 will provide a trigger signal.
The signal source 1 is secured to a base plate l1,
which is angularly rotatable about shaft 3. Shaft 3.
passes through a central opening 12 of plate 11. Plate 11 itself can be rotated over a limited angular extent within the housing of the assembly, typically the entire distributor assembly, shown in fragmentary and schematic cross section at 13. An adjustment link 15 is pivoted at 14 to plate 11, and coupled to a diaphragm chamber 16 secured to housing 13, in order to adjust the position of the link in accordance with pressure, or rather, vacuum, within the diaphragm/chamber l6 and angularly adjust the position of plate 11 and hence the relative angular position of the tip or pin 9 with respect to the shaft 3 and the lands of the cam 8.
The spark or ignition timing can be retarded over a first angular region by moving the link 15 over a first distance a. Moving the link over this distance will change the angular relationship of the signal or pulse source 1 with respect to an angular range, relative to instantaneous positions of shaft 3. Link 15 extends through an opening 18 formed in an abutment or stop member 17. An abutment element 20, typically a nut 41 with a counternut 45 to secure its position on link 15 which is threaded, acts as a counterabutment against abutment body 17. Movement of the link 15 is counter the force of a spring 19 within chamber 16.
The first adjustment step, or range a corresponds to an angularchange of spark retardation utilized in ordinary idling, or engine braking conditions of the internal combustion engine, and providing for burning of the fuel and hence decrease of emission of noxious'exhaust gases.
The angular change of the position of the pulse source or ignition breaker contacts with respect to the shaft can be additionally changed by adding a second excursion b to the first excursion a. The abutment body 17 can itself be moved counter the force of a second spring 21. Thus, movement of link 15 will be the sum of the excursions a b, the two movements or excursions adding smoothly to each other. By additionally retarding the spark by the second distance or excursion b, ignition of the fuel-air mixture is reliably ensured, and used particularly under engine braking conditions, when the engine operates at high speed. or for optimum rapid heating of the exhaust gas treatment devices, typically catalytic reactors, upon starting of the engine.
Spring 21 is a compression spring, and bears at one end against the abutment body 17; at its other end it bears against an inner wall of housing 22 of the diaphragm chamber 16. An adjustment screw 23 is provided, having a central opening 24 so that the link 15 can pass into the diaphragm chamber 16. The diaphragm chamber housing 22 is additionally formed at its lower end, adjacent housing 13 of the distributor.- breaker, with an opening 25 so that link 15 can pass from the breaker housing 13 into diaphragm chamber 16. Adjustment screw 23 has a bearing surface at its inner side, facing the lower (FIG. 1) opening 25 against which spring 21 can abut. It is screwed into a circular plate 26 which is held between a spacer sleeve 27 and a turned-over edge of the cup-shaped housing portion 28. The circular plate 26 facilitates assembly.
The first spring 19 is also a compression spring. The direction in which link 15 must be moved, upon compression of spring 19, is the same as that in which the abutment body 17 is moved upon compression of the second spring 21.
Housing 22 enclosing the first diaphragm 16 includes a disk membrane 29 secured at its central portion to the link 15. Its edge portion is crimped in a turned-over end of the diaphragm housing 22. The adjustment screw 23 is fixedly secured to a dished circular housing portion 30, for example by soldering, brazing, or the like; its edge portion includes the disk membrane 29 and a cup or pot-shaped housing portion 31 and is turned thereover and crimped together.
The second diaphragm chamber includes a ringshaped membrane 32, which closes off the open side of a trough 33, encircling the adjustment link 15. The inner edge of trough 33 is turned over'and crimped, with interposition of a sealing ring 34, to the membrane 32. The outer edge of the trough 33, as well as the outer edge of membrane 32 is secured, by means of a sealing ring 35, between the spacer sleeve 27 and an in-turned upset shoulder 36 formed in housing portion 28.
A support body 38 is secured by means of a rivet 36 and a seal washer 37 to the membrane 32. The support body 38 has a central aperture 39 through which the adjustment link 15 can pass. Support body 38 is cupshaped, with an extra central circular recess in order to support spring 21.
A chamber 40 is formed within the diaphragm unit 16, defined by the housing part 31 on the one hand, and
membrane 29 on the other. Vacuum arising in the chamber 40 and applied through stub 42 causes up ward deflection of the membrane, against the force of spring 19, so that link 15 is moved upwardly until stub 20, formed by screw 41, meets the abutment body 17, formed by the in-turned flange or shoulder of the lower housing portion 38. The strength of spring 21 is so matched to the structure that the vacuum in chamber 40 would be insufficient to compress spring 21. Vacuum within the chamber 40, which may be termed the ignition retardation chamber is supplied over stub 42 connected, for example, to the inlet manifold or inlet duct leading to the engine, from the carburetor, and connected downstream on the throttle. This vacuum can be controlled, for example, by means of a valve (not shown) which permits vacuum to be applied to chamber 42, in dependence on position of the throttle. that is, when the engine operates in idling mode. or in engine braking mode, that is, when power is transferred from the wheels to the engine rather than from the engine to the wheels.
The abutment body 17 can be moved counter the force of spring 21 when an additional force isapplied. This additional force is derived from vacuum applied to chamber 43, with respect to atmospheric pressure, to lift the abutment body 17. The additional chamber 43 is defined by membrane 32 and the trough-shaped element 33. Vacuum in chamber 43 is applied through a vacuum supply stub 44, extending into chamber 43, and likewise connected to a point in the inlet system of the engine where a vacuum arises, that is, to the carburetor vacuum system downstream of the throttle. Vacuum is permitted to be applied to chamber 43 by a controlled valve, for example by an electromagnetically controlled valve which opens the connection of vacuum to duct 44 below a certain temperature of the exhaust gas treatment devices, such as the reactors, or above a certain speed of the internal combustion engine, or, if desired, based on other operating parameters, or sensed parameters of the engine. The vacuum can also be controlled by logical conjunction or disjunction of signals representative of operating, or operation parameters of the engine. An electromagnetic valve, not shown, is then energized to permit vacuum from the inlet manifold or inlet system of the engine to be applied to chamber 43 so that the vacuum in the chamber can permit body 17 to rise. It is necessary that vacuum is present in the chamber 40 as well as that the link will follow the abutment body 17. This vacuum can reliably be ensured by controlling the valve connected to stub 42, that is to the upper chamber 40, also by electromagnetic means so that the valve will receive sufficient current below a certain operating temperature of the exhaust gas treatment devices, or when the engine operates in the braking mode, and dependent on throttle position. The temperature of the treatment devices, such as reactors can be derived by means of a temperature sensitive resistor; the throttle position can be measured by coupling the throttle to the slider of a monitoring potentiometer, and deriving output signals therefrom. Nut 41, forming the abutment element on link 15 is secured to the link 15 by a counternut 45 to prevent relative rotation and to hold the setting. The size of opening 25 is so selected that nut 41 can pass therethrough; the nut will, however, abut against the body portion 38 of the abutment body 17. The first distance of excursion a is defined by the distance between nut 41 and abutment body 17. Abutment body 17, itself, is defined by the housing portion 38, which has a punched-out cup-shaped extension to receive spring 21 and which bears against the edge formed by the opening 25 in the housing wall part 38, as well as housing part 13. The opening 39, centrally within the abutment body 17 is thus large enough to pass link 15, but is smaller than nut 41. Spring 21 is secured to the cupshaped depression formed by the part or portion 38. The housing part 30 connected to housing part 28 by means of screw 23 has an inwardly extending projection which bears against a washer or bearing disk 46 which is screwed on the inner end of link 15. A pin 47 extends from the wahser or disk 46, over which the membrane 29 is placed. A holding washer 49 is located at the other end of the membrane and secured to pin 47 by being riveted over, as seen at 48. Membrane 29 is thus securely held between the disk 46 and washer 49. Washer 49 has up-turned flanges at its circumferential end in order to form a cup-shaped housing for compression spring 19. The other end of spring 19 bears against housing 31. A sleeve 50 is secured to housing part or portion 31; the far end of the sleeve is threaded to receive an adjustment screw 51, against which spring 19 can bear. The center portion of screw 51 is bored out and capped, and an adjustment screw 52 is threaded into the bore of screw 51. Adjustment screw 52 functions as a limit for the excursion of link 15, that is, it limits the longitudinal travel of the link 15 by engagement of the rivet head 48 with the lower face of screw 52 upon upwardly travel of link 15. Setting of the adjustment screw 51, which is held in position by a resilient washer, changes the spring tension of spring 19, but requires readjustment of screw 52. The overall or entire excursion, that is, the sum of the excursion distances a and b is defined by the distance, at rest position, between the rivet head 48 and the lower face of screw 52, as seen in FIG. 1. Thus, the entire retardation of the ignition timing, that is, the angular movement of plate 11 is defined by the setting of screw 52, the initial spark retardation being defined by the setting of nut 41, locked in position by counternut 45.
Summarizing, deflection of membrane 29, due to vacuum in chamber 40 causes spark retardation by movement of link 15, the maximum movement being defined by distance a, as set by the setting of abutment element 20 (nut 41) on the link 15. Additional spark retardation can be obtained by providing vacuum in chamber 43 through duct 44, causing upward deflection of membrane 32, and permitting lifting of the abutment shoulder formed by the in-turned edge of the abutment body 17, against which screw 41 then will bear, for the maximum extent defined as distance b, that is, until the end of link 15 and its associated end disk and rivet 48 engages the lower face of adjustment screw 52. Application of vacuum to the respective chambers is controlled by valves, in accordance with engine operating, or operation parameters.
The arrangement of FIG. 1 is particularly simple, and the springs 19, 21 can easily be assembled; the relative strength of the springs can readily be matched to operating and design requirements of various types of internal combustion engines.
Embodiment of FIG. 2
The system of FIG. 2, in which similar parts have been given similar reference numerals additionally includes a spark advance chamber 53. The troughshaped element 33, which together with the ring membrane 32 defines the second or additional vacuum chamber 43 is here located at the side opposite the chamber 16. The second spring 2l, which again is a compression spring, bears against the outside of a depressed central portion of the housing part 38 forming the abutment body 17. The drawn-out, bulged central portion of the housing part 38 and the inner end of the housing part surrounding the inlet opening 25 defines the distance corresponding to the second or additional excursion b, that is, to the second angular range of adjustment of the ignition timing angle. The housing part 38, at the side opposite the entry opening 25. engages with a separating wall 54 which is secured at its edge in the cup-shaped housing part 28. The edge of separating wall 54, the sealing ring 35, the outer edge of the ring-shaped trough 33 and the outer edge of membrane 32 are compressed between the spacer ring 27 and an inset shoulder 36 formed on the outer housing wall 28 at its lower region (see FIG. 2). The separating wall 54 is formed with a central opening 55, and bent upwardly to form an upwardly extending flange 56 defining, at its inside, the opening 55. Link extends through opening 55 of the separating wall 54. A cylindrical element or sleeve 57 surrounds link 15. A first compression spring 19 surrounds cylinder 57. Cylinder 57 is formed with a section of reduced diameter at its lower end, as seen at 58, the shoulder 59 being formed by the reduced section forming the abutment 20. Cylinder 57, with its reduced section 58 can pass through bore 39. An abutment plate 60 is secured to the reduced section, press fitted thereon, so that cylinder 57 is supported on the abutment body 38 at the side facing opening 25. The abutment body 17, that is, the housing section or part 38 has the central bore 39 which forms the opening 18 in the abutment body 17, having the same function as in FIG. 1. The selected distance between the edge or abutment shoulder 59 and the opposite central part of housing portion 38, that is, the abutment body 17, defines the first excursion a, and hence the first angular deflection of plate 11 upon movement of link 15 by this distance :1. Cylinder 57 has a projecting flange 61 at the end opposite the opening 25. The side of flange 61 facing opening is an abutment side for spring 19, the other end of which surrounds sleeve 57 and is supported at the inner side of the housing part 38.'The upper side (FIG. 2) of spring 19 supports membrane 29. Membrane 29, which is a disk membrane, is supported indirectly. that is, over a support element 62 which is screwed on the end of link 15 extending into diaphragm chamber 16. The attachment element 62 is formed with a flange 63 at the side facing the entry opening 25. Flange 63 bears against cylinder 57. The attachment element 62 is formed with a projecting extension or pin 64 extending through the central opening of an auxiliary membrane 65 and over a support shell 66 supporting the auxiliary membrane 65, then through membrane 29 and then through the central opening of the dished washer 49. The end of pin 64 extending beyond washer 49 is deformed, so that the ele ments 65, 66, 29, 49 are securely connected togetherv The support shell 66, surrounding a major portion of auxiliary membrane 65 is soldered to collar 56 extending upwardly from the separating wall 54.
The spark, retardation chamber 40 is defined by the disk membrane 29, the auxiliary membrane 65, separating wall 54, and, at its outer side, spacer sleeve 27. Connecting stub 42 extends into chamber 40. The additional retardation chamber 43 is defined by the ring trough 33 and ring membrane 32. Connecting stub 44 connects to a vacuum source, and application of vacuum over stubs 42, 44, respectively will deflect the membrane, as described in connection with the operation of the device of FIG. 1.
A spark advance chamber 53 is defined by the disk membrane 29 and housing portion 67. Housing portion 67 is cup-shaped, inverted over housing part 28. The
cup-shaped housing portion 67 has a marginal edge.
where it is held, together with disk membrane 29 and a ring-disk 68, between the spacer sleeve 27 and the inturned flange or edge of housing part 28. Upon application of vacuum to the spark advance chamber 53, link 15 is pulled counter the force of spark advance spring 69, which is located between the washer 49 and the opposite, top wall of the cup-shaped housing 67. The spark advance excursion distance has been indicated as c in FIG. 2 (immediately above adjustment nut 70) and isdefined by the distance between nut 70 and the frame of housing 13 for the distributorbreaker contact assembly. Housing'l3 is bulged out, to provide a flat abutment surface for nut 70, which is secured against relative rotation by a counternut 72. The frame portion 71 of housing 13 has an opening in alignment with opening 29.
Vacuum is applied to the spark advance chamber 53 in known manner (and not further describedsee the aforementioned literature reference) by connecting vacuum to a supply stub 73. Vacuum can be applied, under control of a valve, for example, 7 upon partial loading of the internal combustion engine, by connecting stub 73v to a point downstream of the carburetor throttle, preferably just behind the throttle of the internal combustion engine with which the system is to be used.
Embodiment of FIG. 3
The major difference between the embodiment of FIG. 3 and that of FIG. 2 is that the ring membrane 32 is utilized to define or close off the retardation chamber 40, and that the disk membrane 29, then, is utilized to I close off the additional retardation chamber 43. All
parts which are similar have been given similar reference numerals and will not be described again.
The retardation chamber 40 is defined by the ringtrough element 33 and ring membrane 32. Ring membrane 32 is located at the side away from entry opening 25. The support body 38 secured to ring membrane 32 is so shaped that it can receive the first spring 19 in a cup-shaped projecting portion. The other end of spring 19 is secured to an outer groove in a holding disk 74, supported adjacent opening 25 of the cup-shaped housing part 28. Support body 38, at the side away from entry opening 25, bears against a separating wall 75 which corresponds to separating wall 54 both in shape and with respect to location in the entire diaphragm chamber assembly 16. A central opening 76 is formed in the separating wall 75 which has an up-turned flange 77 at its inner end. The adjustment link 15 extends through central opening 76. Link 15 is surrounded by a sleeve 78. Second spring 21 surrounds sleeve 78, and spring 19 surrounds spring 21. Sleeve 78 forms the abutment body 17. The sleeve 78 is formed with a longitudinal bore 79, through which link 15 passes, the bore forming the relief or recess 18 associated with the abutment body 17. Sleeve 78 is formed with a flange 80 at the side opposite entry opening 25. Second spring 21 rests against the flange 80. The other end of second spring 21 is supported at an inner depression formed in the dished washer 74 located adjacent entry opening 25. The selected distance between the side of flange 80 away from entry opening 25 and the opposite side of the element 62, forming a projecting abutment 20, defines the first excursion distance a, and thus the first angular excursion of plate 11 upon rocking of the plate by link 15 about its center. Flange 80 is selected to be somewhat smaller in diameter than the central portion of the bore 39 formed in the abutment body 38.
Sleeve 78 is formed of reduced diameter, at 81, at the terminal portion adjacent entry opening 25. The reduced section 81 extends through the dished washer 74, entry opening 25, as well as the frame portion 71 of housing 13. The end extending from the frame portion 71 has an abutment ring 82 secured therein in order to properly support and guide sleeve 78. The second excursion distance or step b, and thus the second angular excursion of plate 11 is defined by the distance of the edge 83, formed by the reduced section 81 and the central portion of the dished washer 74. A sealing membrane 84 is secured to auxiliary membrane 65 in a manner similar to FIG. 2, and connected in similar manner by element 62. The edge zone of sealing mem-' brane 84 is soldered to the upstanding flange 77 formed on the separating wall 75. The additional adjustment chamber 43 is thus defined by the disk membrane 29, sealing membrane 84, separating wall 75 and support ring 27. i
The spark advance adjustment is constructed somewhat differently from the embodiment of FIG. 2. The spark advance excursion c is limited by the facing side 85 of sleeve 78 which is remote from disk membrane 29; in other words, the limit of travel of the spark advance excursion c is defined by abutment of nut 70 against the facing side 85 of element 82.
Vacuum is introduced into the various chambers 40, 43, 53 as previously disclosed. The connecting stub 42. in this embodiment, terminates in chamber 40 defined by the ring membrane, whereas stub 44 terminates in chamber 43 defined by disk membrane 29.
Embodiment of FIG. 4
Same parts have been given the same reference numerals and will not be described again. The chamber 43 is omitted in this example, and additional deflection force to provide excursion oflink 15 is generated by an electromagnet assembly 86, including an armature 87 which forms the abutment body 17. Armature 87 has a longitudinal bore 88, forming opening 18 in the abutment body 17 (FIG. 1) and which permits movement of the adjustment link 15, which extends through longitudinal bore, with respect to the armature 87, by shifting position of the armature 87. Armature 87 is surrounded by the coil 89 of electromagnet 86. Coil 89 is held in a coil frame 90, formed with a longitudinal central opening 91 in which the armature 87 is slidably received. Magnet 86 is enclosed by a cup-shaped housing 92, which is secured to the bottom of cup-shaped housing part 93, for example by soldering, spot welding or the like. The bottom of housing part 93 is secured to frame 71 of housing 13, and formed with entry opening 25 to the membrane or diaphragm assembly 16. Opening 25 is smaller in diameter than the cross section of the longitudinal opening 91 within the magnet coil 89. Armature 87 is formed with a relieved portion 94 which seats in entry opening 25. The side of armature 87 extending from the housing of diaphragm chamber assembly 16 is located opposite nut 41, forming the abutment element 20. Nut 41 is fixed in position by a threaded sleeve 95 which simultaneously secures together two portions of the adjustment link 15. The first excursion distance a is defined by the distance between nut 41 and armature 87, so that the first spark retardation angle is likewise defined thereby.
The side of armature 87 which is remote from entry opening 25 faces a yoke 96, with an intervening air gap. Yoke 96 is fixed to the housing 92 of the electromagnet. The side of armature 87 remote from entry opening 25 has a central relief 97 formed therein in which the second spring 21 is supported. The other end of spring 21 is supported against a depression formed in housing 92 for the electromagnet. Housing 92. at that end. is formed with a passage 99 for link 15. Yoke 96 is cylindrical, and has a central bore 98 through which both link 15 and spring 21 can pass. The excursion or travel of armature 87, that is, the bridging of the air gap 91 definesthe second excursion distance b, and thus the second angular excursion of plate 11.
Link 15 extends beyond opening 99 in housing 92 to the central opening 100 in disk membrane 29. The terminal end of link 15, extending through membrane 29, is formed with a flat extension in form of a flange or disk 101. Flange or disk 101 abuts against the inside of a cup-shaped sleeve-like hollow member 102. The entry to the member 102 is of reduced cross section and permits free passage of link 15. The reduced cross section 103, dished washer 49, and the central opening through membrane 29 are all press fitted together, and held in position by a support plate 105.
The retardation chamber 40 is defined by the side of membrane 29 remote from entry opening 25 and the portion of a housing 105 extending thereover. Housing portion 105, at its edge, is formed with a flange and connected to membrane 29 by a bent-over end of housing part 93, so that both housing parts 93, 105 as well as membrane 29 are secured together. First spring 19 is located between the dished washer 49 and the opposite wall of housing part 105.
A compensation spring 106 is provided in order to reduce the forces necessary to be generated by magnet 86, that is, to limit the magnetic forces necessary to attract armature 87 to yoke 96. The compensation spring may be located in various positions,for example, between the extending flange 101 and the reduced section 103 of sleeve 102.
Chamber 40 has vacuum applied thereto, as previously described in connection with FIG. 1. Electromagnet 86, when energized, must provide sufficient force in order to attract armature 87 counter the force of the second spring 21, and being assisted by the bias of compensation spring 106. Supplying sufficient current through winding 89 lifts armature 87 upwardly. The current in coil 89 of the electromagnet may be derived, for example, from an amplifier or controller or relay or the like controlled by an electrical sensor responsive to temperature of exhaust gas treatment devices or the like, electrical sensors responsive to throttle position, speed of the engine, or other parameters of operation, or operating conditions of the engine.
Embodiment of FIG. 5:
Similar parts have been given similar reference numerals and will not be explained again. The additional force is electromagnetically generated and, in addition to the forces provided by FIG. 4, spark advance adjustment (downward movement of link 15) can also be commanded.
The retardation chamber 40 is constructed similar to the system disclosed in connection with FIG. 3. Chamber 40 is defined by the ring trough 33 and ring membrane 32, both surrounding the entry opening 25. The support body 38, forming the abutment body 17 is secured to ring membrane 32. It is bulged upwardly and is supported on the side facing the entry opening 25 by a first spring 19 as well as by the compensating spring 106. The first spring 19 is supported at its other end on the housing portion 28, in which the entry opening 25 is formed, whereas the compensating spring 106 extends to a limiting or stop member 107 screwed on link 15. To separate the springs, the housing part defining the entry opening is bent upwardly into a flange 108, which also secures the spring 19 in position. Stop element 109 is fixed in place, and held against accidental rotation by counternut 109. The side of the support body 38 opposite entry opening 25 is engaged by a support surface 110, fixed in the diaphragm chamber assembly 16, and immovable with respect to the housing 22. Support surface 110 is formed, for example, by a portion of the separating wall 75. Separating wall 75 has a free central opening 76 through which the link 15 extends. Likewise, first spring 19, compensating spring 106 and the central, outwardly bulged extension 38 can extend through the opening 76 in separating wall 75.
Link 15 is constructed in two parts. In the region of the cup-shaped bulge of support or abutment body 38 the link is separated, the two parts of link 15 being secured together by a junction sleeve 111. A support pro-. jection 112 abuts sleeve 111, and bears against the center portion of disk membrane 29. The other end of disk membrane 29 is clamped against the support 112 by the dished washer 49, held in position by flange 113 formed on the upper side of link 15 and screwed into the junction sleeve 112.
The spark advance chamber 53 is defined by the side of the disk membrane 29 remote from entry opening 25 and the inverted cup-shaped housing part 67. A separate spark advance spring is not necessary since, in this embodiment, the compensating spring 106 takes over this operating function.
The inverted cup-shaped housing portion is shaped to provide an additional transverse wall 114, formed with a central opening 115 for link 15. The upper side of separating wall 114 supports magnet 86 which is secured thereto, for example by soldering, spot welding or the like. Magnet 86 is enclosed by housing 92, formed with an entry opening 99. Link 15 extends through housing opening 99 into longitudinal bore 88 of armature 87 forming the abutment body 17. The end of link 17 which projects beyond armature 87 has an abutment screw 116 screwed thereon, surrounded by a flange l 17 formed on the armature 87. The facing side of flange 117 abuts against an adjustment screw 118. Adjustment screw 118 is screwed into sleeve 1 19 which is attached to the side of the magnet housing 92 remote from entry opening. Screw 118 has a further central opening through which a set screw 120 passes which is opposed to the far, upper end of link 15, that is, the end opposite the entry opening 25.
Second spring 21 is located in opening 97 of armature 87, and extends through the opening 99 in magnet housing 92, bearing against the separating wall 114 at its other end.
The first excursion distance a and thus the first partial angle of rotation of the breaker plate 11 is defined by the distance between screw 116 and armature 87, in the direction of link 15. The second excursion distance I), and thus the second angular portion of the ignition ,40 in order to provide for thesecond'excursion distance b.
Various changes and modifications may be made within the inventive concept and features described in:
connection with any embodiment may be applied to other embodiments as applicable and desired.
I claim: 7
1. In combination with an internal combustion engine, an ignition contactbreaker system to provide ignition pulses for the internal combustion engine having a housing ('13), a camshaft (3) in the housing, a support plate (11) rotatably located in the housing and surrounding the camshaft, and breaker contacts (4,
' 5, 6, 7) located on the plate adapted to be engaged by the camshaft and opening and closing in synchronism with rotation of the camshaft,
means to rotate the support plate to adjust the relative angular position of the breaker contacts with respect to the lands of the camof the camshaft comprising a coupling link (15) secured to the plate (11) to rotatably move the plate;
first motion transmitting means (29, 40) coupled to the link (15) to move the link by a first distance (a) and hence rotate the plate (11) by a first angular excursion;
and means (32, 43) superimposing additional movement on said link in the same direction as said first distance (a) to move said link by an additional second distance (b) and hence rotate the plate by an additional second angular excursion.
2. System according to claim 1 wherein at least one of said motion transmitting means comprises a diaphragm chamber and a membrane.
3. System according to claim 1 including stop means (20) coupled to the link (15) and abutment means (17) located in interfering relation to the stop means (20), the distance between the stop means and the abutment means defining said first excursion (a) over which the link may be moved;
and wherein the means superimposing additional ment means comprises an element which is at least, in
part, disk-shaped and is formed with an opening (18), the link extending through said opening;
a first spring (19) is provided holding the link in position counter the direction of motion to effect said excursion over the first distance (a);
and second spring means (21) are provided biasing the position of said abutment means, said means superimposing additional movement on said link providing a force counter the bias of said second spring means.
5. System according to claim 4 including a housing retaining said motion transmitting means (29, 40; 32, 43);
the second spring being a compression spring bearing, with one side, against said abutment means (17) and with the other against said housing (22).
6. System according to claim 5 wherein the first spring (19) comprises a compression spring having one end bearing against said link and providing a bias force counter the direction of said first motion transmitting means, the other end of said spring bearing against said housing.
7. System according to claim 1 wherein said first motion transmitting means comprises a diaphragm chamber having a diaphragm (29), a housing (22) surrounding said diaphragm and clamping said diaphragm in said chamber to separate said chamber into two differential pressure zones;
the link being coupled to the membrane (29).
8. System according to claim 1 wherein one of said motion transmitting means comprises a ring membrane (32), said movement transmitting means being included within a housing;
a trough-shaped ring element (33) within the housing and secured to the ring membrane, the ring membrane forming with the trough-shaped element a chamber adapted to contain differential pressure with respect to ambient pressure in the housing; and
a support body (38) secured to the ring membrane and movable upon excursion of the ring membrane upon differential pressure being applied thereto.
9. System according to claim 8 wherein the support body comprises a pot-shaped element (38) having a central bore (39) the link (15) passing through the central bore;
and spring means (21) entering into the concave portion of the pot-shaped support body.
10. System according to claim 1 wherein said first motion transmitting means comprises a vacuum chamber;
spring means (19) engaging said link and being compressible upon introduction of vacuum into said chamber;
second spring means (21) engageable by said link said additional movement generating means superimposing movement on said link having sufficient force to overcome the spring bias of said second spring means (21).
11. System according to claim 10 including stop means (20) coupled to the link and abutment means (17) located in interfering relation to said stop means (20) the abutment means being biased into a first position by said second spring means (21).
12. System according to claim 1 1 wherein said means superimposing additional movement on said link comprises a diaphragm chamber (43) subject to vacuum (44);
the force of vacuum in said diaphragm chamber (43) being sufficient to overcome the force of said second spring means (21) and permit excursion of said abutment (17) and hence superimposition of movement of said link by said second distance (b) over the first distance (a) counter the force of said first spring (19).
13. System according to claim 10 comprising a housing for said first diaphragm chamber (40) including a disk membrane, the disk membrane being secured in the housing (22) defining, in part, said chamber (40).
14. System according to claim 9 wherein said additional movement generating means is formed by the chamber defined between the ring membrane (32) and the trough-shaped element (33);
stop means (20) are coupled to a link l5) and abutme'nt means (17), located in interfering relation to the stop means (20) are formed on the support body. 15. System according to claim 14 wherein the housing is formed with an entry opening (25), the link (15) passing into the entry opening, said entry opening being of such size that said stop means (20) coupled to the link can pass therethrough and into the housing;
the ring membrane (32) facing said opening (25 the support body (38) extending towards the opening (25) in the housing and bearing against the housing, the aperture (39) through the support body 38) being of such size that said stop means (20) coupled to the link (15) cannot pass therethrough; the spring means are compression spring means (21) located intermediate the housing (23) and the portion of the support body (38) surrounding the aperture (39) therethrough and surrounding said link (15);
said first motion transmitting means (29, 40) comprising a diaphragm chamber having a diaphragm (29) coupled to the link (15) and located at the terminal end of the link remote from said support plate (11);
second spring means (19) biasing said link into a position counter the direction of movement of said diaphragm chamber under influence of differential pressure applied thereto;
means (46, 24) limiting the movement under influence of said spring means (19);
and means (52) facing the terminal end of the link remote from said plate, secured in the housing (22) and limiting total excursion of said link under influence of said movement transmitting means.
16. System according to claim 15 wherein said second spring (19) is located in alignment with said link 15), said housing being formed with an extension (50) at least in part receiving said second spring (19), and adjustable means (51) retaining the terminal end of said second spring 19) in position in said housing and permitting adjustment of the tension force of said second spring.
17. System according to claim 15 wherein the total movement limiting means comprises an adjustable element (52) axially aligned with said link (l5).
18. System according to claim 14 wherein (FIG. 2) said first and second motion transmitting means comprises diaphragm chambers;
a housing (22) surrounding said chambers and formed with an entry opening (25) through which said link (15) passes;
the trough-shaped element (33) being located within said housing and facing away from said entry opening the spring means (21) are compression spring means (21) bearing against said support body (38) at a position remote from said entry opening, the support body being spaced from the housing wall adjacent the entry opening (25),, said spacing corresponding to the second excursion distance (b);
a separating wall (54) located within said housing (22) and forming an abutment for said support body (38) under compressive force'of said compression spring (21 the separating wall (54) separating the housing into two chambers;
a ring-membrane (29) defining one of said chambers,
conjointly with the housing walls and said separating wall;
means (65) movably sealing said chamber to the separating wall;
a guide sleeve (57) surrounding said link and second spring means (19) surrounding said guide sleeve, said guide sleeve and link bearing against said disk membrane (29);
the terminal end of the cylinder remote from said disk membrane and facing the entry opening (25) being formed with a shoulder (58) and forming stop means engageable against the support body (38) to define said first excursion (a) whereby movement of the disk membrane (29) permits movement of the link (15) counter the force of the second spring (19) until the stop means (20) engaging the abutment (17) formed by the support body (38) during the first excursion of the link, and the support body (38) is additionally movable upon deflection of the ring membrane (32) counter the force of the first spring (21), thus moving the abutment means (17) and permitting said second excursion.
19. System according to claim 1 wherein said first and second motion transmitting means comprises a disk membrane and a ring membrane, respectively, and
housing means forming, with said disk membrane, a diaphragm chamber;
and a trough-shaped element secured to the ring membrane and forming with said ring membrane an additional diaphragm chamber.
20. System according to claim 18 wherein the first and second springs (21, 19) are concentric, one within the other, the sleeve (57, 78) being formed with a flange-like radial extension wide enough to extend over the inner one of said springs (21), the outer of said springs (19) bearing against the support element (38);
the support element being formed with a cylindrical extension (FIG. 3) adapted to receive the outer one (19) of said springs therein.
21. System according to claim 20 wherein the radial flange (80) of the sleeve is of lesser diameter than the opening (39) in the support body (38) to permit passage of the sleeve therethrough.
22. System according to claim 1 wherein the one of said motion transmitting means comprises electromagnetic means;
stop means (20) are coupled to the link and abutment means (17 are provided connected in interfering relation to the stop means (20) said abut ment means comprising an armature (87) associated with the electromagnetic means. i
23. System according to claim 22 (FIG. 4) including a housing retaining said motion transmitting means, the link (15) passing through the housing (22);
and the electromagnetic means includes an electromagnet (86), the armature having a path of movement corresponding to one of said excursion distances.
24. System according to claim 23 wherein the path of movement of the armature corresponds to said second additional excursion distance (b), and said first motion transmitting means comprises a vacuum diaphragm chamber.
25. System according to claim 24 further comprising compensating spring means (106) located within the housing and providing a bias force against said link (15) after the link has been moved by said first excursion distance (a), the force of said compensating spring means (106) becoming active after said first excursion and corresponding, in direction, to the force exerted by the electromagnet on the armature, to assist excursion of the link (15) over said second excursion distance (12) upon energization of the electromagnet (86).
26. System according to claim 25 wherein the electromagnet is retained within the housing (22), the housing being formed with an opening (25), the armature facing said opening;
the stop means (20) being secured to said link (15) and facing said armature (87);
compression spring means (21) separating said armature from said electromagnet, and in extended position, defining an air gap between said armature and said electromagnet, the distance of said air gap defining one of said excursion distances (b);
a vacuum diaphragm chamber having a disk membrane (29) within said housing (22) and second spring means (19) biasing said membrane counter the action of vacuum in the vacuum diaphragm chamber;
I and a retaining member surrounding said link and secured to said membrane, extending in the vacuum portion of thevacuum diaphragm chamber, the retaining member (102) having said compensation spring means located therein, the compensating spring means bearing against the link (15) and against the membrane.
27. System according to claim 26 wherein the vacuum chamber comprises a trough-shaped chamber element and a ring membrane (32) sealed against the trough-shaped element to provide a trough-shaped diaphragm chamber, the ring membrane forming the diaphragm for the chamber;
the trough-shaped element (33) being located within the housing (22) in a direction facing away from the entry opening of said link (15) into said housing (.22);
"a support body (38) having a central aperture (39) secured to the ring-membrane;
the compensating spring (106) surrounding said link (15) and providing spring force between said link and said support body (38), spring means (19) providing spring force between said support body and said housing, and acting in the same direction as said compensating spring;
and further spring means (21) bearing against the armature (87) and a portion (1 14) of the housing to bias the position of the armature with respect to the housing, and permit movement of the armature,
counter the force of said further spring (21) upon energization of the electromagnet.
28. System according to claim 1 wherein said coupling link comprises a rod (15) projecting from the plate;
and said first motion transmitting means and said additional motion transmitting means are aligned with respect to the axis of said rod and act colinearly.
29. System according to claim 1 including spark advance motion transmitting means (53) acting on said coupling link (15) in the direction counter said first and second motion transmitting means to move said coupling link in a direction which is subtractive with said spark advance excursion (c).