MXPA97006115A - Method for starting an inte combustion engine - Google Patents

Abstract

The present invention relates to a method for reducing visible exhaust generated by an electronically controlled internal combustion engine that burns diesel fuel and having a plurality of electronic unit injectors one of each injector is coupled with one of each of a plurality of cylinders and at least one injection valve, in the method comprises the steps of: starting the internal combustion engine to burn the diesel fuel, accelerating the internal combustion engine to reach a speed of vacuum, maintain speed of vacuum operation, preventing the diesel fuel from being burned by a first predetermined number of the plurality of cylinders, by electronically controlling a solenoid valve in each of the associated electronic fuel injectors to prevent fuel flow through them , measure a fixed amount of the diesel fuel that has to be injected a in the second predetermined number of the plurality of cylinders, inject a preliminary portion of the fixed amount of diesel fuel determined when the injection valve is in a first position and injecting the remaining portion of the fixed amount diesel fuel in the second predetermined number of the plurality of cylinders when the injection valve is in a second predetermined position that differs from the first predetermined position

Description

METHOD TO START AN INTERNAL COMBUSTION ENGINE.

DE S C R I P C I O N 1. - Field of the invention.

The present invention relates to internal combustion engines for motor vehicles. More specifically, the present invention relates to a method for reducing white smoke and idling time of internal combustion engines for motor vehicles. 2. - Description of the related art.

The efficiency of fuels and contaminants are two very important concerns for consumers interested in life and in the environment. Therefore, there is an almost continuous effort to increase efficiencies and reduce pollutants in the Automotive Industry. Internal combustion engines that burn diesel fuel take a long time to reach a vacuum speed (at (RPM) from a cold start compared to spark-ignited engines.) This factor increases the consumption of diesel fuel by those diesel-powered engines US Patent No. 5 '465, 101, issued to Hunt on November 14, 1995, is directed to the cold start of internal combustion engines in general.This reference describes a control system of fuel in which a cold-start fuel injector is mounted in the air intake passage downstream of a throat for the internal combustion engine.A three-way air valve has an air inlet fluidically connected to the intake of air upstream of the throat, A motor control unit controls the actuation of the air valve and fluidically connects an inlet to a first outlet , a second exit or both exits. In addition, the air valve can close the fluid communication between the inlet and the outlets. This device is undesirable because it introduces new "hardware" that must be coordinated with thecooperation of other necessary components of the internal combustion engine. More specifically, the fuel injector and the air valve must be coordinated in such a way that the fuel injector and the Air valve work to reduce the amount of time it takes the engine to achieve a vacuum speed. The patent of the U.S.A. no. 5 '492, 100, issued to Ishii et al. on February 20, 1996, describes a fuel control device that prevents an internal combustion engine from using all of its cylinders except when the operating mode of all cylinders can be changed convincingly from the partial operation mode of the cylinders . The valves are changed using a control mechanism that selectively operates the valve change. The valve change is activated in a target operation mode selected by the operating mode selector. However, this patent does not disclose the use of fuel ratios to minimize the pollutants expelled by an internal combustion engine that works with diesel fuel that will reduce the amount of pollutants expelled by the engine.

THE INVENTION.

A method is described for reducing a period of time between starting and running under vacuum of an internal combustion engine having a plurality of cylinders and a cam shaft. The method includes the steps of measuring a fixed amount of the fuel to be injected into each of the various cylinders. Then the rotational position of the camshaft is measured. A preliminary portion of the fixed amount of fuel is injected into the cylinders when the camshaft is in a predetermined first rotational position. The remaining portion of the fixed amount of fuel is then injected into the cylinders when the camshaft is in a second predetermined rotational position, which differs from the first predetermined rotational position. An advantage of the invention is the ability to effectively reduce the time it takes an internal combustion engine that works with diesel fuel to achieve a speed of idling from a cold start. Another advantage associated with the invention is the ability to reduce the period of time in which an internal combustion engine can reach a vacuum speed without modifying the engine hardware. Still another advantage of the invention, includes the reduction of pollutants expelled by the internal combustion engine, while the internal combustion engine, is trying to reach a speed of running under vacuum.

BRIEF DESCRIPTION OF THE DRAWINGS.

Other advantages of the invention will be readily appreciated when it is better understood with reference to the following detailed description, when considered in connection with the accompanying drawings, in which: Figure 1 is a perspective view partially in Cutting of an internal combustion engine that burns diesel fuel. Figure 2 is a block diagram of a first section of a method of the present invention. Figure 3 is a block diagram of a second portion of a method of the present invention. Figure 4 is a graphic representation of the output, when the method of Figure 2 is performed.

Figure 5 is a graphic representation of the white smoke exhaust output using the method shown in Figure 2; and Figure 6 is a graphic representation of the white smoke emission using the method of Figure 2, in combination with the method of Figure 3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS.

With reference to Figure 1, an internal combustion engine is indicated in general with numeral 10. The internal combustion engine 10 is of the type that burns diesel fuel. The diesel fuel is injected or forced into several cylinders 12 (3 of the 6 cylinders 12 are shown in section view). Although there are six cylinders in this embodiment, any number of cylinders can be used. A cam shaft housed under the head 14 of the motor rotates in relation to the various cylinders 12 and is used as the mechanism for opening and closing the plurality of cylinders 12 towards the intake and exhaust manifolds. The camshaft moves the valves that open and close gates or inlet and outlet holes that lead to and exit these distributors. For purposes of discussion, the various cylinders 12 are divided into a first half 16 and a second half (not shown). When the internal combustion engine 10 (hereinafter referred to as the diesel engine 10) is put to work in a normal manner, the diesel fuel is injected into each of the several cylinders 12 to generate power and to rotate an axle of cams (not illustrated). When the diesel engine 10 is being started, it takes time for the diesel engine to reach a vacuum speed of about 900 rpm in one embodiment. During the initial start-up period to the point at which the diesel engine 10 has reached a vacuum speed, the diesel engine 10 sprays white smoke. This white smoke is caused by the inefficient combustion at low temperature of the fuel by the engine 10 during the period of operation discussed above. Returning to Figure 2, a method is described which substantially reduces the amount of white smoke expelled by the diesel engine 10 after starting and the point to which the diesel engine 10 reaches its idle speed. The method starts at 20 where the engine control module (MCM) is started at 22. The engine specifications are put together at 24. The type of engine specifications that meet at 24 is the oil temperature. oil, coolant temperature, revolutions per minute, distributor pressures and the like. Once the data is collected, it is determined if the diesel engine 10 requires the operation of the half of the engine, in 26. If the operation of the half of the engine is required, the idle speed is maintained at 28. Then it is prevented that the diesel fuel be burned by the first half 16 of the various cylinders 12 by 30. The operating cylinders, ie the second half of the various cylinders 12 receive the majority of the fuel by 32. In one embodiment, the amount of fuel is approximately 80% to 90% of the amount - total fuel that will be injected into the cylinder during the operation of the complete engine. An injection method with electronic pilot is enabled for the operation of the cylinders in 34, The method of injection with electronic pilot - will be discussed7 in great detail subsequently. Then, it is determined at 26, if the motor requires normal operation, ie the operation of the complete motor. If so, the diesel engine 10 is returned to normal operation at 38. Normal operation also occurs when the diesel engine 10 is accelerated beyond its speed of travel to the v. However, if this is not the case, more data is gathered in relation to the diesel engine in 24. The method is terminated at 40 after the diesel engine 10 has returned to normal operation. With reference to figure 3, the injection method with electronic pilot is shown in detail. The electronic piloting method is used in two different ways in two separate and different times between starting and running under vacuum of the diesel engine 10. First, the method of injection with electronic pilot, is used in combination with the method of operation with half the cylinders to reduce the noise and vibrations of the diesel engine 10 while operating in the operation mode with half the cylinders, as shown in general in 34 in figure 12. In this way In operation, the electronic pilot injection method is used pri- maily after the diesel engine 10 has reached a vacuum speed when used in combination with the half-cylinder operation method. Alternatively, the method of injection with pilot -electronic is used independently of the method of operation -with half of the cylinders. In this way, the method of ijjection with electronic pilot is used before reaching a vacuum speed, that is, immediately after a cold start. This method is used in this way to reduce the time it takes the engine to reach a speed of idling or after a cold start. Therefore, the method of injection with electronic pilot can be used initially at the start to reduce the amount of time required to reach a speed of operation under vacuum. However, it will be noted that only after the diesel engine 10 has reached a speed of idling is when the injection with electronic pilot is used in combination with the operation method of half the cylinders, as described before, and shown in Figure 2, so that noise and vibrations can be reduced. With reference to Figure 3, the method of injection with electronic pilot starts at 42. The engine control module (MCM) starts at 44. The engine specifications, similar to those that meet at 24 in the figure 2, meet at 46, Then it is determined if the engine started at 48, If the engine did not start, that is, it started up, meet at 46 more engine specifications. If the engine is started, the rotational position of the camshaft 14 is measured at 50. At a first predetermined rotational position, a preliminary portion of a fixed amount of diesel fuel is injected into a cylinder corresponding to the first predetermined rotational position. This first percent injection of the total fuel is preformed at 52. It will be appreciated by those skilled in the art that the first predetermined rotational position is actually a set of rotational positions for a given set of cylinders and wherein a single rotational position is associated with each sensitive cylinder. Therefore, there are as many predetermined first rotational positions as cylinders in the diesel engine 10. In one embodiment, the first predetermined rotational position is between 10 ° and 20 ° before the upper dead center (ACMS), the -preliminary portion of the fixed amount of diesel fuel injected in this first predetermined rotational position is between 5 and 15% approximately of the fixed amount of diesel fuel. The position The rotational axis of the camshaft is measured again at 54. A remaining portion of the fixed amount of diesel fuel is injected into a cylinder when the cam shaft is at a second predetermined rotational position that differs from the first predetermined rotational position. This injection of the remaining amount of diesel fuel is done at 56. The remaining portion of diesel fuel may be the total amount of fuel remaining that will have been used on that particular cylinder at the time when it is not being used in the method. of injection with electronic pilot. Alternatively, the fixed amount of diesel fuel - injected, can be reduced to 80-90% of the total amount - of fuel designated to be consumed or burned in that cylinder at that moment. Once the remaining amount of fuel has been burned by that piston stroke, it is determined if the start has been completed at 58. If it has not been completed, the first -measurement of the rotational position is taken again at 50, if start-up has been completed, the method instructs the motor control module to enter a start-up mode at 60, a mode capable of starting at high RPM, accelerating or starting up under vacuum after it is finished -the method at 62. With respect to the method of injection with pilot -electronic and with reference to figure 4, it is shown that a control valve (discussed subsequently) takes a portion of the arm of the rocker of injection that is used to open the intake valve that allows the diesel fuel to enter the cylinder so that it is burnt. The control valve closes at 64. As pressure is formed along the line segment 66, pressure is also formed on the arm of the injection rocker arm. When there is sufficient pressure in the control valve, the pressure of the arm of the injector arm is forced to exceed 5000 psi, the pilot or preliminary portion of the diesel fuel is injected into the cylinder. The control valve opens at 68 releasing the pressure on the arm of the injection rocker arm at 70. After the pressures on the arm of the injection rocker fall below 5000 psi, the pilot is terminated. In this embodiment, the control valve closes between 12 ° ACMS and 5 ° ACMS, whereby a difference of 7 ° is created to define a real separation space in the pressure 72 of the arm of the injection rocker arm. The control valve closes again at 74, which allows to increase the pressure on the arm of the injection rocker arm. The main injection or the remaining portion of the fixed amount of diesel fuel is injected into the cylinder starting at 76 and continuing to be injected until the control valve is opened at 78 where the main injection stops at 79. With reference to Figure 5 shows specifications in graphic representation where the speed of the engine in the related technique reaches 900 rpm in approximately 60 sec. for a cold start, while, its vacuum running is approximately 480 sec. The opacity percentage of the white juice is shown to reach 90% almost immediately. After this, the percentage opacity of white smoke decreases slowly until it reaches 30% opacity after 600 sec. These data were collected in diesel engine operation using all the cylinders and with the injection method with electronic pilot. On the other hand, using the operation method with half the motor, together with the method of injection with electronic lotion, the output of the white smoke is presented graphically in figure 6. As illustrated in this figure, the opacity percentage of the white smoke never reaches a value equal to the maximum percentage of capacity obtained when the diesel engine 10 is started without the operation of half the engine. Furthermore, the opacity percentage falls drastically and continues to decrease to almost 0% until, at 78, the entire motor is used where the opacity in% jumps up to 30%. The present invention has been described and illustrated in way. It will be understood that the terminology that has been used is intended to be of the nature of the -words of the description rather than as a limitation. Many modifications and variations of the present invention are possible in light of the above teachings. Therefore, within the scope of the attached clauses, the present invention can be practiced in other ways than what specifically described.

Claims (2)

1. R E I V I N D I C A C I O N S Method to reduce a period of time between starting and running under vacuum of an internal combustion engine having several cylinders, the method comprising the steps of: measuring a fixed amount of fuel to be injected into each one of several cylinders; - measure the rotational position of the camshaft; - injecting a preliminary portion of the fixed amount of fuel when the camshaft is in a predetermined first rotational position; and - injecting a remaining portion of the fixed amount of fuel when the camshaft is in a second predetermined rotational position that differs from the first predetermined rotational position.
2. 2. Method according to claim 1, including the step of detecting the internal combustion engine to determine when the internal combustion engine is started, 3. Method according to claim 1, which includes the step of detecting when the internal combustion engine is under vacuum. 4 - A method to reduce the exhaust -visible generated by an internal combustion engine that has several cylinders and burns diesel fuel, the method comprises the steps to start the internal combustion engine to burn the diesel fuel; - accelerate the internal combustion engine so that it reaches a speed of running under vacuum; - maintain the running speed at vacuum; and - preventing diesel fuel from being burned by a first predetermined number of the various indros cylinders. 5-r Method according to claim 4, which includes the step of burning a majority of the diesel fuel in a second predetermined number of the various indile = cil. 6. Method according to the representation 5, wherein the first predetermined number of the several cylinders is equal to a first half of the several cylinders 7. * > The method according to claim 6, which includes the step of providing the diesel fuel to the first half of the plurality of cylinders, when the internal combustion engine accelerates beyond the idle speed. 8, - Method according to claim 7, which includes the stage of collecting specifications that define the operation of the internal combustion engine. 9. A method to reduce the exhaust vj. sible generated by an internal combustion engine that burns diesel fuel and has several cylinders and a cam shaft, the method comprises the steps of: - starting the internal combustion engine to burn the diesel fuel; - accelerating the internal combustion engine so that it reaches a speed of idling; - Maintain idle speed; < - preventing the diesel fuel from being burned by a first predetermined number of the various ci 1 indros; measuring a fixed amount of the diesel fuel to be injected into the first predetermined number of the various cylinders; «- inject a preliminary portion of the fixed amount of diesel fuel when the axis of -levas is in a first rotational position? and - injecting the remaining portion of the fixed amount of the diesel fuel when the camshaft is in a second predetermined rotational position that differs from the first predetermined rotational position. 10, < The method according to claim 9, which includes the step of burning a majority of the diesel fuel; in a second predetermined number of the various -cil indros, 11.- Method according to claim 10 wherein the first predetermined number of the various cylinders, is equal to a first half of the several cylinders. The method according to claim 11, which includes the step of providing the diesel fuel to the first half of the various cylinders when the internal combustion engine accelerates beyond the idle speed. 13. Method according to claim 12, which includes the step of collecting specifications that define the operation of the internal combustion engine. EXTRACT A method to start an engine, reducing the white smoke and the starting time runs idle. The method includes the combination of producing two sub-fuel injections in the cylinders of the internal combustion engine at different points in the rotational position of at least one cam shaft of the engine and reducing the number of combustion cylinders by half. The two sub-fuel injections reduce the idle start time. Once the engine is idling, the operation of half the cylinders reduces the white smoke emitted by them. The two sub-injections of fuel are also used, when operating half of the cylinders, to reduce the noise.