RU2233992C2 - Fuel injection control electronic-mechanical clutch - Google Patents

Abstract

FIELD: mechanical engineering; diesel engines.

SUBSTANCE: invention relates to devices for automatically changing moment of beginning of fuel injection into cylinders of vehicle diesel engine. Proposed electronic-mechanical clutch has housing, driving clutch member mechanically connected with diesel engine crankshaft and provided with straight splines, driven clutch member with helical splines rigidly coupled with camshaft of hinge-pressure fuel-injection pump, and spring-loaded sleeve installed for axial displacement and connected with driving and driven clutch members through straight and helical splines, and dc motor mechanically connected with step-down reduction gear and electrically coupled with electronic control unit. Clutch is furnished additionally with diesel engine crankshaft position pickup installed in housing over wheel-marker rigidly coupled with driving clutch member, high-pressure fuel-injection pump position pickup installed in housing over second wheel-marker rigidly fitted on camshaft of high-pressure fuel-injection pump. Step-down reduction gear is made in form of worn train whose worm wheel is installed coaxially with camshaft of high-pressure fuel-injection pump and rigidly coupled with two end face hourglass cams which are in constant contact with two rollers hinge secured in forked lever installed for turning in housing and spring-loaded through bushing and thrust bearings.

EFFECT: provision of reliable clutch of compact design.

2 cl, 4 dwg

Description

The invention relates to internal combustion engines, in particular to devices for automatically changing the moment of the beginning of fuel injection into the cylinders of a transport diesel engine.

Known electronically controlled couplings for automatically changing the start of fuel injection depending on the operating parameters of the diesel engine and environmental parameters [1-3], used in conjunction with monoblock high pressure fuel pumps (TNVD) on transport diesels. The simplest of the known designs of such couplings is [1], equipped as a drive with a linear positional electromagnet. The actuator of this design and several others, for example, with a hydraulic actuator [2], is based on a leading coupling with direct splines, kinematically connected to the crankshaft of the diesel engine, driven coupling with slanting splines, rigidly connected to the cam shaft of the high-pressure fuel pump and movable in axial direction, a sleeve with straight and oblique slots, connected to the leading coupling half through straight lines, and to the driven one through oblique slots.

However, the control clutches of the moment of the beginning of fuel injection, in which the hydraulic device is used as the drive mechanism, do not have simple and reliable ways of transferring the working fluid under pressure to the rotating shaft system.

The electronic-mechanical couplings for controlling the moment of injection start with a linear positional electromagnet do not have the mentioned drawbacks, however, their design is not possible, because To ensure the necessary working efforts, so large overall dimensions of the electromagnet are required that installing it near the shaft shaft is practically impossible.

In addition, there are known electronic-mechanical couplings for controlling the instant of fuel injection with the aforementioned splined actuator, where a DC motor is used as a drive [3] (prototype).

The disadvantages of this design are the poor arrangement in which the electric motor and the reduction gear are located separately from the actuator, and the insufficient accuracy of setting the angular position of the camshaft of the injection pump relative to the diesel crankshaft due to the very long kinematic chain from the electric motor to the actuator.

Thus, the electronic-mechanical coupling for regulating the moment of the beginning of fuel injection, taken as a prototype, has a housing kinematically connected to the diesel crankshaft with a direct coupling half, rigidly connected to the camshaft of the high-pressure fuel pump with a driven coupling half with oblique slots and mounted with axial movement a spring-loaded sleeve connected to the leading and driven half-couplings, respectively, through straight and oblique splines, a DC motor, mechanically connected with a reduction gear and electrically connected to the electronic control unit.

However, an excessively long kinematic chain connecting a DC motor with an actuating splined mechanism reduces the accuracy of positioning one coupling half relative to the other under conditions of quick-varying and shock loading of the shaft line and increases the overall dimensions of the layout of the electronic-mechanical coupling.

The proposed electronic-mechanical coupling is additionally equipped with a diesel crankshaft position sensor mounted in the housing above the marker wheel, rigidly connected to the drive coupling half, a camshaft position sensor of the high pressure fuel pump, mounted in the housing above the second marker wheel, rigidly mounted on the cam shaft a high pressure fuel pump, wherein the reduction gear is made in the form of a worm gear, the worm wheel of which is mounted coaxially with the camshaft vnogo high pressure pump and rigidly connected with two end caps globoid cams are in constant contact with the two rollers pivotally secured to the forked lever, pivotally mounted in the housing, spring-loaded through the sleeve and thrust bearing.

In addition, a valve motor may be used as a direct current electric motor.

This is a significant difference between the invention and the prototype.

The kinematic diagram of the electronic-mechanical coupling for controlling the moment of fuel injection start is shown in FIG. 1, the connection diagram of the electric motor with the worm and the electronic control unit is shown in FIG. 2, the sensors are installed in FIGS. 3 and 4.

The electronic-mechanical coupling consists of the following main elements: housing 1 (Fig. 1), in which a leading coupling half 3 with straight splines 4 is mounted on the bearing 2, kinematically connected to the crankshaft, a driven coupling half 5 with oblique splines 6, rigidly mounted on the cam the shaft 7 of the injection pump 8 and connected through the slots 4 and 6 of the sleeve 9, mounted with the possibility of axial movement, with the leading coupling 3, and the sleeve 9 is pressed by the spring 10 through the thrust bearing 11 and the rollers 12 to the end globoidal cams 13, made for one whole e with the worm wheel 14 mounted on the radial bearings 15 on the cam shaft 7 and resting through the thrust bearing 16 on the housing 1, the worm 17 (FIG. 2) of the worm gearbox is rigidly connected to a DC motor 18, electrically connected to the electronic control unit 19. The rollers 12 are pivotally mounted in the fork arm 20, pivotally mounted in the housing 1. The sensor 21 (Fig.3) of the position of the crankshaft of the diesel engine, electrically connected to the electronic control unit 19, is installed in the housing 1 above the wheel-marker 22, made m integrally with the driving coupling half 3, while sensor 23 (Figure 4) position of the cam shaft 7 is also mounted in the housing 1 above the wheel-timer 24 fixedly mounted on the cam shaft 7 pump 8.

The coupling operates as follows. The electronic control unit 19 as a result of the analysis of signals from sensors 21 and 23 about the relative angular position of the crankshaft and camshafts and from the sensors of the operating parameters of the diesel engine and the environment, generates a control signal for driving the electric motor 18, which begins to rotate together with the worm 17 and rotates the worm wheel 14 The cams 13 act on the rollers 12, which rotate together with the lever 20 clockwise or against it and, through the thrust bearing 11, move the sleeve 9 to the right or left, compressing or releasing May spring 10 and rotating the driven clutch half 5, and with it the cam shaft 7 as long as the latter does not take an angular position corresponding to the theoretically necessary, determined according to the electronic control unit algorithms.

The economic effect of the implementation of the present invention should be sought by reducing harmful emissions into the environment, since more precise control of the moment the fuel starts, especially depending on the load of the diesel engine, will allow more accurate fuel injection and more complete combustion, which positively affects and to reduce fuel consumption.

SOURCES OF INFORMATION

1. A.c. No. 808678 of the USSR. Clutch for automatic change of the fuel injection advance angle / A.S. Lyshevsky, Yu.G. Vatlin, V.A. Braginets // Bulletin of inventions. - 1981. - No. 8.

2. RU No. 2160375 C2, M. cl. F 02 D 1/12, F 02 M 59/20. Hydromechanical coupling for changing the injection advance angle / Gusev B.P., Gusev P.B. // - 2000.

3. A.S. No. 1379487 of the USSR. Coupling for automatic change of the fuel injection advance angle / V.V. Kurmanov, V.R. Laptev, S. B. Uskov, G. A. Azatyan, V. V. Eremeev // Bulletin of inventions. - 1988. - No. 9 (prototype).

Claims (2)

1. An electronic-mechanical coupling for controlling the moment of the start of fuel injection, comprising a housing kinematically connected to the diesel engine crankshaft with a straight spline, rigidly connected to the camshaft of the high pressure fuel pump, a driven half-clutch with oblique splines and a spring-loaded sleeve mounted axially movable connected to the leading and driven half-couplings, respectively, through direct and oblique splines, a DC motor, mechanically connected to a reduction gear ohm and electrically connected to the electronic control unit, characterized in that the clutch is additionally equipped with a diesel crankshaft position sensor mounted in the housing above the wheel-marker, rigidly connected to the driving coupling half, the camshaft position sensor of the high pressure fuel pump mounted in the housing above the second a marker wheel firmly mounted on the camshaft of the high-pressure fuel pump, the reduction gear being made in the form of a worm gear, the worm gear of which Credited coaxially with the cam shaft of the high pressure fuel pump and rigidly connected with two end caps globoid cams are in constant contact with the two rollers pivotally secured to the forked lever, pivotally mounted in the housing, spring-loaded through the sleeve and thrust bearing. 2. The electronic-mechanical coupling according to claim 1, characterized in that a valve electric motor is used as a direct current electric motor.

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