MXPA99000212A

MXPA99000212A - Temporization system of combusti injection

Info

Publication number: MXPA99000212A
Application number: MXPA/A/1999/000212A
Authority: MX
Inventors: J Devine Michael; L Kiliz Robert
Original assignee: Timing Systems Inc
Priority date: 1996-06-19
Filing date: 1999-01-04
Publication date: 2000-06-05

Abstract

An electronic timing (or timing) system for controlling the injection angle of a fuel pump is described, comprising an inlet sleeve (12), an outlet drum (3o), an intermediate drive sleeve (30), an drive plate (60), a drive fork (76) and a stepper motor (90). The drive sleeve (30) includes a pair of bolts or needles (32) projecting radially inwardly and outwardly and the drum (36) and the inlet sleeve (12) include both helical grooves (38) and (16) ) respectively, through which the pins or needles (32) are projected. The vertical movement of the fork (76) causes the axial movement of the drive plate (60) and the drive sleeve (30), which causes a relative rotational adjustment of the angle between the input sleeve (12) and the drum output (36) to delay and advance the timing (or timing) of the fuel injection system

Description

FUEL INJECTION TIMING SYSTEM Technical Field The present invention is concerned with fuel injection systems and more particularly with an apparatus for controlling the timing or synchronization of fuel injection pumps in internal combustion engines.

BACKGROUND OF THE INVENTION U.S. Patent Nos. 3,934,430 of Fuso, 4,566,421 of Bauer et al., 3,603,112 of Sola, 5,417,187 of Meyer et al., 5,447,126 of Kondoh et al., Describe various timing systems (or timing) of the fuel injection pump that include intermediate couplings between an axle. of cams and a drive shaft. These intermediate couplings are axially adjustable by means of a drive source taken from the motor. For example, Fuso describes a source of hydraulic fluid pressure (16) energized by the engine oil pump, which applies dosed pressure to an inlet (22) of a hydraulic actuator of a timing control device (10) (or timing) of the injection. The present invention is an improvement over the design concepts described by these and other patents, wherein the power source or power source for controlling the REF. 29184 relative angular position of a cam shaft to a drive shaft is dependent on the crankshaft or other operating part of the engine. Another timing system currently used by fuel injection pumps includes a mechanical, centrifugally driven device, which varies a cam on an auxiliary drive to the fuel injection pump to adjust the relative cam angle by approximately seven degrees of rotation of the crankshaft. In such a system, the relative cam angle is directly proportional to the revolutions per minute of the engine. The present invention provides a more sophisticated method for controlling the angle of the fuel pump which is continuously variable over a greater range of degrees and without consideration of the revolutions per minute of the engine.

BRIEF DESCRIPTION OF THE INVENTION Briefly described, the present invention comprises a timing system for fuel injection to control the angular position of a fuel injection pump of a diesel engine. The timing system comprises an output drive element adapted to be rotationally coupled to a pump shaft of the injection pump to rotate the shaft of the injection pump about its axis. The timing system further includes an input drive element adapted to be rotationally coupled to a drive source. An intermediate drive sleeve is axially movable along an axis of the pump shaft between the input and output drive elements. An actuator is movable along an axis perpendicular to the axis of the pump shaft and coupled to the intermediate sleeve, to move the intermediate sleeve along the axis of the pump shaft. The intermediate sleeve is coupled to the output drive element in a manner wherein the movement of the intermediate sleeve along the axis of the pump shaft causes the rotational movement of the output drive member around the shaft of the pump shaft. The intermediate sleeve is also coupled to the input drive element in a manner wherein axial movement of the intermediate sleeve causes the intermediate sleeve to rotate about the axis of the pump shaft. In service, the actuator axially urges the intermediate sleeve along the axis of the pump shaft to adjust the angular position of the output drive member relative to the input drive element.

In accordance with one aspect of the invention, the intermediate drive sleeve includes a pair of radially projecting bolts or needles and the output drive member includes a pair of helical grooves or grooves. Each slot or helical groove is adapted to receive a pin or needle and cause rotation of the output drive member as the intermediate sleeve moves axially along the axis of the pump shaft. Preferably, the needles are positioned 180 ° apart on opposite sides of the intermediate sleeve and the helical grooves or grooves of the output drive member are positioned 180 degrees on opposite sides of the output drive member. This provides a pair of coupling forces to rotate the output drive element. According to another aspect of the invention, the input drive element also includes a pair of helical grooves or grooves, each slot or helical groove being adapted to receive a pin or needle. The helical grooves of the input drive element are curved in a direction opposite to that of the helical grooves of the output drive element, such that the linear movement of the intermediate sleeve causes rotation of the intermediate sleeve because the bolts The needles are coupled with the helical grooves of the input drive element. In this way, the axial movement of the intermediate sleeve causes it to rotate with respect to the input drive element and causes the output drive element to rotate with respect to the intermediate drive sleeve. Thus, the angular rotation for a given axial movement of the intermediate drive sleeve is obtained twice. In accordance with one aspect of the invention, the actuator includes a drive plate that is axially movable and includes a pair of radially projecting journals. The drive plate engages with the intermediate drive sleeve. The actuator also includes a fork drive having a pair of angular grooves, each groove receiving a die from the drive plate. The movement of the fork drive in a direction perpendicular to the axis of the pump shaft causes the drive plate to move axially along the axis of the pump shaft, thereby moving the intermediate drive sleeve along the shaft. of the pump tree. Preferably, the actuator includes a stepper motor for moving the fork drive. A stepper motor allows control of the timing system of the present invention at engine start. This provides control of the timing (or timing) of the fuel injection in a time of minimum fuel efficiency and maximum expulsion of the exhaust. According to another aspect of the invention, the output drive element includes an opening for receiving the pump shaft. An adapter is provided for positioning in the opening of the output drive element. The adapter includes an internal opening dimensioned to closely match the external diameter of the pump shaft. As such, the output drive element can be coupled to pump shafts of varying diameters by selecting an adapter with an internal opening about the size of the diameter of the pump shaft. This allows the timing system of the present invention to be updated to existing diesel engines, regardless of the design of its pump shaft. In addition, the input shaft of the timer is hollow to allow installation without dismantling the timer system. These and other features, objects and advantages will become apparent from the following detailed description of the best mode, when read in conjunction with the accompanying drawings and the claims, which are incorporated herein as part of the description of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings, similar reference numerals refer to like parts in all the various views, wherein: Figure 1 is a pictorial view of the exploded timing device of the present invention; Figure 2 is a vertical sectional view of the timing device of the present invention; Figure 3 is an end view of the timing device of Figure 2; and Figure 4 is a schematic diagram of the control system for the timing device of Figures 1-3.

BEST MODE FOR CARRYING OUT THE INVENTION With reference to Figures 1 and 2, the present invention comprises a fuel injection timing device 10 including an input sleeve 12 adapted to be rotatably coupled to an auxiliary drive source or maybe the gear train of a diesel engine. The inlet sleeve 12 includes a flange 14 for coupling the inlet sleeve to the drive source. The inlet sleeve 12 also includes a pair of helical grooves 16 (only one shown in Figure 1), which are 180 degrees opposite each other, around the inner end of the inlet sleeve 12. The helical grooves 16 are spirally distributed counterclockwise inwardly from the inner end of the sleeve 12. A sealed annular double row ball bearing or bearing 18 is mounted on the inlet sleeve 12 and retained thereon by means of a retaining ring 19, shown in Figure 2. The inlet sleeve 12 functions as an input drive element that engages a drive source and transfers a rotational drive force to the components of the invention, discussed herein. An end, rectangular, inlet plate 20 includes a central opening 22 for receiving the inlet sleeve 12 and the bearing 18. The inlet sleeve 12 is rotationally carried by the inlet end plate 20 and held against it by the flange 14. and a pair of retaining rings 23. The input end plate 20 forms part of the support housing for the timing device 10. An intermediate cylindrical drive sleeve 30 is rotationally coupled to the inlet sleeve 12. The diameter of the inlet sleeve 12 is smaller than the diameter of the drive sleeve 30. Thus, the input sleeve 12 is positioned within the drive sleeve 30, as best seen in FIG. 2. The drive sleeve 30 includes a pair of pins or pins drive 32 (only one shown in figure 1). The driving pins or pins 32 are 180 degrees apart from each other and extend radially inwardly and outwardly of the drive sleeve 30. Inward projecting portions of the drive pins or pins 32 travel in helical grooves 16 of the inlet sleeve 12 and provide the rotational engagement therebetween, that is, the rotation of the inlet sleeve 12 causes the sleeve 30 of the drive rotates due to the drive coupling between the bolts 32 and the grooves 16. A cylindrical outlet drum 36 includes a pair of helical grooves 38. The helical grooves 38 are coiled in the clockwise direction, opposite to each other. the spiral of the helical grooves 16 of the inlet sleeve 12. The outlet drum 36 also includes an internal cylindrical hub 40. The hub 40 and the drum 36 form between them an annular chamber 42. The outer diameter of the outlet drum 36 is slightly larger than the diameter of the inlet sleeve 12 and the diameter of the hub 40 is slightly larger than the diameter of the sleeve of the hub. inlet 12. The annular chamber 42 receives the inner end of the inlet sleeve 12 and also receives the actuating sleeve 30. The outwardly projecting bolts or needles 32 of the actuating sleeve 30 extend in helical grooves 38 of the output drum 36. This arrangement, as the bolt and slot coupling between the inlet sleeve 12 and the drive sleeve 30, provides a rotational engagement between the output drum 36 and the drive sleeve 30. The output drum functions as an output drive element. which couples the intermediate drive sleeve to the pump shaft and imparts a rotational force to the pump shaft of the intermediate drive sleeve. An outlet end plate 48 includes a central opening 50 for receiving the outlet drum 36. The exit drum 36 includes a widened flange 47 along its inner edge. The flange 47 fits against the outlet end plate 48 and together with a retaining ring 51 (FIG. 2) holds the output drum 36 in position relative to the outlet end plate 48. An annular bushing 49, shown in Fig. 2, is provided in the central opening 50 between the output end plate 48 and the output drum 36, to allow the output drum 36 to rotate freely within the output end plate 48 . The output end plate 48 forms part of the case of the timing device 10 and together with the input end plate 20 defines the front and rear sides of the timing device. The output end plate 48 also includes a set of four guide rods 54 of the drive plate for aligning the output end plate 48 with the input end plate 20. The inlet end plate 20 includes a set of four corresponding openings 56 for receiving the guide rods 54. The ends of the rods 54 are snapped into the openings 56. The inlet sleeve 12, the intermediate drive sleeve 30 and the output drum 36 are the three rotatably coupled, with the inlet sleeve 12 positioned inside the drive sleeve 30 and with the inlet sleeve 12 and the drive sleeve 30 positioned within the annular chamber 42 of the outlet drum 36 In service, the inlet sleeve 12, the drive sleeve 30 and the outlet drum 36 rotate together about an axis 59 of the pump shaft, as discussed hereinafter. The inner surface 56 of the hub 40 is tapered inwardly, as shown in Fig. 2. Preferably, the driving end of a fuel pump shaft 56 is also tapered to create a strong fit between the pump shaft 56 and the hub 40. A stud nut 57 is threadably coupled to a threaded end of the pump shaft 57 and provides a secure coupling of the pump shaft 57 to the output drum 36. One of the main advantages of the present invention is its adaptability to the updating market. The diameters of the diesel engine pump axles vary from one manufacturer to another. To allow the timing device of the present invention to be mounted to the pump shafts of various sizes, a plurality of pump shaft adapters can be provided, one of which is shown in Figure 1, denoted by the number 58. The adapter 58 is tapered in shape and is sized to fit inside the hub 40. The key grooves in the adapter 58 allow it to be adapted in a smaller diameter pump shaft. With this arrangement, the timing device can be upgraded to a variety of fuel injection pumps, regardless of the size of the pump shaft. The present invention will allow the above diesel engines to meet the emission requirements of the engine, especially as such emission requirements become stricter in the future. A rectangular drive plate 60 includes a central opening 62 through which the coupled, interengaging arrangement of the input sleeve 12, the drive sleeve 30 and the output drum 36 is positioned. An annular gap 66 is formed around the the central opening 62 on both sides of the drive plate 60. In conjunction with the annular recesses 66, the intermediate drive sleeve 30 includes a pair of spaced annular grooves 68. A pair of thrust bearing retainers 70 are received in the annular recesses or recesses 66 and retained therein by retaining rings 71. The retaining rings 71 the thrust bearings 70 and the drive plate 60 are retained around the intermediate drive sleeve 30. Each thrust bearing 70 is a needle roller bearing with hardened thrust plates. The drive plate 60 includes a set of four holes 75 of the corner. The guide rods 54 extend through the corner holes 75 and thereby limit the movement of the drive plate 60 to axial movement along the axis 59. In other words, the rods 54 retain the drive plate 60. and the drive sleeve 30 concentric with the inlet and outlet sleeves 12 and 36. A drive yoke 76, facing downwards, includes a pair of downwardly extending legs 78, each including an angular slot 80. Each Slot 80 is angular from the outlet end plate 48 down towards the input end plate 20. The drive plate 60 also includes a pair of stubs 74 projecting laterally. A slit 84 is provided which extends vertically on the outer side of each leg 78 of the fork 76. Each slit 84 receives the head of a trunnion 74. The fork 76 includes a threaded opening 88 along its upper bridge. An electric motor 90 includes a threaded gear bolt actuator 92, which is adapted to engage threadably with the opening 88 in the fork 76. The motor 90 is an electronically driven motor, controlled by a microprocessor controller, discussed later in the present. The rotation of the gear actuator 92 causes the fork 76 to move up and down, which in turn causes the slots 80 to drive the journals 74 and the drive plate 60 axially along the axis of rotation 59 of the pump tree. The axial movement of the drive plate 60 drives the intermediate drive sleeve 30 axially, as the drive sleeve 30 rotates. In turn, the drive sleeve 30 rotates the output drum 36 relative to the input sleeve. 12. This is obtained due to the coupling of the drive pins 32 with the helical grooves 38, 16. The rotation of the output drum 36 in relation to the input sleeve 12 is obtained as both components rotate and drive the shaft of the bomb. As a result, the rotation of the pump shaft is either accelerated or braked, which provides the means to control the cam angle of the fuel injection pump, to advance or retard the timing of the pump. At the start of the engine, the timing device of the present invention obtains significant advantages over the prior art systems. The timing device may delay the timing of a diesel engine at start-up, due to the electrical power source required by the engine 90. It is not necessary for the engine to be in operation for the device to operate. Such timing control of the engine at start-up may decrease and in some cases eliminate the cold-start problems experienced by most diesel engines. With the more stringent engine emission emission requirements to be determined in the future, the present invention provides a low cost and still effective system to meet these requirements. Additionally, as the revolutions per minute of the engine increase, the timing of the fuel injection pump may be advanced or delayed as determined by the revolutions per minute of the engine., the exhaust temperature, the manifold temperature, the coolant temperature, the engine load, the crankshaft speed, the fuel support position, the throat position, the altitude and other criteria, as it is well understood those experienced in the art. Diesel engines equipped with the present invention must also realize improved fuel efficiency and increased power and comply with changes in emission requirements without the need for other more complicated and expensive control systems designed to meet the requirements of more severe emission. With reference to Figure 1, a pair of side plates 100, 102 and a lower plate 104 fixedly secure the outlet end plate 48 and the input end plate 20, to fix the spacing between these two plates. The stepper motor 90 is secured to the end plates 20, 48 via brackets or brackets 94, which lift the motor 90 above the end plates 20, 48. This provides an internal travel chamber 95 which accommodates the movement of the motor. the fork 76. In figure 2, the fork 76 is shown in solid lines in a first lowered position. In this position, the fork 76 moves the intermediate drive sleeve 30 to the left towards the outlet end plate 48. The drive sleeve 30 is shown in continuous lines in this forward position. The fork 76 is shown in dashed lines in a second raised position. In this position, the fork 76 moves the drive sleeve 30 to the right toward the input end plate 20. The drive sleeve 30 is shown in dashed lines in this second position. The vertical movement of the fork 76 between its lowered and raised positions is indicated by the arrow 96. The axial movement of the drive sleeve 30 between its forward and backward positions is indicated by the arrow 97. Figure 3 illustrates the coupling between the dies 74 and the angular grooves 80. The vertical movement of the fork 76 is created by the travel of the trunnions 74 within the slots 80. The slits 84 provide a travel path for the trunnion heads 74 without interference with the side plates. 100, 102. The timing system of the present invention includes an electronic control system, shown schematically in Figure 4. A position detector is mechanically coupled to the gear motor drive of the stepper motor. The position detector creates a voltage representing the current position of the stepper motor, which corresponds to the injection angle of the fuel pump.

An input / output interface circuit 110 receives input signals from various inputs of the motor, as listed in FIG. 4 and conditions these signals for a controller 112 of the microprocessor. The input / output interface circuit 110 also receives a voltage signal from the position detector of the stepper motor. The circuits 110 also condition and send a control signal 114 from the actuator to the stepper motor. The microprocessor controller 112 calculates the appropriate injection angle when using the monitored parameters discussed above and a look-up table. The look-up table is stored in an EEPROM 116. The EEPROM 116 is pre-programmed with the information necessary for controlling the injection angle for the particular type of motor that is controlled. The look-up table for a particular engine is a multidimensional map of the ideal injection angle against the operating conditions. The microprocessor controller 112 sends a signal, via the input / output interface 110 to the motor, to move the drive sleeve to its proper position. The drive components of the present invention are preferably all made of steel, except the end plates 20, 48, the side plates 100 102, the bottom plate 104 and the bracket 94, which may be made of aluminum. The drive plate 60 is also made of aluminum or steel, except for the journals 74, which are made of steel and are threaded on the sides of the drive plate 60. The bearings are made of standard bearing steel 52100 or 440C. Other materials may be used if they become preferred without affecting the function of the invention. Also, other motors can be used, such as brushless motors, servomotors, gear motors, etc. As long as the motors can be controlled by the microprocessor, the purpose of the invention remains unchanged. Any change of materials or motors will be to increase the reliability, as long as the function remains the same. It is noted that, in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is the conventional one for the manufacture of the objects to which it refers. Having described the invention as above, property is claimed as contained in the following:

Claims

Claims 1. A fuel injection timing system for controlling the angular position of a diesel engine fuel injection pump, characterized in that it comprises: an output drive element adapted to be rotatably coupled to a fuel shaft. the pump of the injection pump, for rotating the shaft of the injection pump about its axis: an input drive element adapted to be rotatably coupled to a drive source; an intermediate drive sleeve, axially movable along an axis of the pump shaft between the input and output drive elements and an actuator movable along an axis perpendicular to the axis of the pump shaft and coupled to the intermediate sleeve, for moving the intermediate sleeve along the shaft of the pump shaft; the intermediate sleeve is coupled to the output drive element in a manner wherein the movement of the intermediate sleeve along the axis of the pump shaft causes the rotational movement of the output drive member about the axis of the pump shaft; the intermediate sleeve is also coupled to the input drive element, in a manner where the axial movement of the intermediate sleeve causes the intermediate sleeve to rotate about the axis of the pump shaft, whereby the actuator axially drives the intermediate sleeve to along the shaft of the pump shaft to adjust the angular position of the output drive member relative to the input drive element.
2. The system in accordance with the claim 1, characterized in that the intermediate drive sleeve includes a pair of radially projecting bolts or needles and the output drive element includes a pair of helical grooves or grooves, each helical groove being adapted to receive a bolt or needle and cause the rotation of the output drive element as the intermediate sleeve moves axially along the axis of the pump shaft.
3. The system in accordance with the claim 2, characterized in that the pins or needles are positioned 180 degrees apart on opposite sides of the intermediate sleeve and the helical grooves of the output drive member are positioned 180 degrees on opposite sides of the output drive element.
4. The system according to claim 2, characterized in that the input drive element also includes a pair of helical grooves, each helical groove is adapted to receive a pin or needle, the helical grooves of the input drive element are curved in a opposite direction to that of the helical grooves of the output drive element, such that linear movement of the intermediate sleeve causes rotation of the intermediate sleeve due to the bolts or needles engaging the helical grooves of the input drive element .
The system according to claim 1, characterized in that the actuator includes a drive plate that is axially movable and includes a pair of trunnions projecting radially, the actuating plate engages the intermediate coupling sleeve, the actuator it also includes a fork drive having a pair of angular grooves, each groove receiving a die from the drive plate, such that the movement of the fork drive in a direction perpendicular to the axis of the pump shaft causes the plate to move of drive axially along the shaft of the pump shaft, to thereby move the intermediate drive sleeve along the axis of the pump shaft.
6. The system according to claim 1, characterized in that the actuator includes a stepper motor for moving the fork drive.
7. The system in accordance with the claim 1, characterized in that the output drive element includes an opening for receiving the pump shaft and further comprises an adapter for positioning in the opening of the output drive element, the adapter includes an inlet opening dimensioned to fit closely to the diameter outside of the pump shaft, whereby the output drive element can be coupled to pump shafts of varying diameters by selecting an adapter with an internal opening about the size of the diameter of the pump shaft.