JPH02186127A - Prevention of load change shock - Google Patents

Abstract

PURPOSE: To prevent a load fluctuation shock by automatically pressing a clutch between an internal combustion engine and a transmission from an inertial position corresponding engaging position to a connecting position accompanied with slipping when an acceleration pedal is operated from an inertial position to a load position. CONSTITUTION: When an acceleration pedal 12 is suddenly operated from an inertial position to a load position, based on the rotational speeds of a crankshaft 2 and a transmission input shaft 4 detected by rotation sensors 10 and 11, a controller 9 presses a clutch 3 from a slip running position to a connecting position by a control system 8 in order to transmit continuously increased torque. On the other hand, when the pedal 12 is operated in a reverse direction, the clutch 3 is temporarily turned OFF and, then, the clutch 3 is connected again until specified slipping is generated. Thus, a load fluctuation shock generated when a sudden change occurs in an acceleration pedal position is prevented.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention includes an internal combustion engine, a transmission device, and a clutch,
The present invention relates to a method for preventing load fluctuations caused by sudden changes in the accelerator pedal in a vehicle, particularly a passenger car, in which the clutch is disposed between an internal combustion engine and a transmission and is capable of controlling transmittable torque.

[Conventional technology and its problems]

During rapid load changes in motor vehicle drives, so-called load change shocks occur. This load fluctuation shock significantly impairs the ride comfort of an automobile. Such load change shocks occur particularly when accelerating the internal combustion engine from coasting to full throttle, and also to a small extent when releasing the accelerator pedal from a full throttle position or a position close to the full throttle position.

This load fluctuation is caused by a sudden zero crossing of the torque produced by the internal combustion engine. This torque excites the vibrating systems of the drive train with relatively large amplitudes. , the reaction moments acting on the drive train bearings result in a load change shock that is clearly felt by the passengers.

[Problem of invention]

The problem underlying the invention is, on the one hand, when operating the accelerator pedal from the inert position to the loaded position, in particular when operating the accelerator pedal from the zero position to the load position! ! It is an object of the present invention to provide a method for preventing load fluctuation shocks which occur when accelerating an I-engine at full throttle, on the other hand, when operating the accelerator pedal from a load position to a coasting position.

[Means for Solving the Problem] This problem is solved according to the features of claims 1 and 4, when operating the accelerator pedal from the inertial position to the load position position.
Because the clutch transmits a continuously increasing torque from an engaged position corresponding to the inertia position of the accelerator pedal, with a predeterminable slip between the rotational speed of the internal combustion engine and the rotational speed of the transmission input. or when operating the accelerator pedal from the load position to the coasting position, the clutch is temporarily activated before the conversion of the internal combustion engine from traction to coasting operation. This is achieved by automatically switching off completely and then operating again in the connecting direction until a predeterminable slip occurs between the internal combustion engine and the transmission input.

[Action of the invention]

Move the accelerator pedal from the inert position to the load position.

When operating the clutch violently, the clutch is operated as follows. That is, from the slip operating position it occupies in the coasting position, it is biased into the engaged position in order to transmit a continuously increasing torque. On the other hand, when the accelerator pedal is suddenly operated in the opposite direction, from the load position to the coast position,
The clutch is first fully disengaged before reaching the switching point from traction to coasting operation. Thereafter, the clutch is connected again until a predetermined slip occurs. In the present invention, in the coasting position of the accelerator pedal, the clutch is operated in a slipping state. That is, the clutch is connected in such a way that a predetermined difference, for example 100 rpm, is maintained between the rotational speed of the internal combustion engine and the rotational speed of the transmission manual part.

It is well known that a predetermined amount of slip is allowed in automobile clutches. Thereby, for example below a predetermined rotational speed of the internal combustion engine, the damping of non-uniform movements arising from the internal combustion engine is at least partially moved away from the driven part. However, the method according to the present invention is not aimed at steady or nearly steady operation, but rather at unsteady operation during sudden load changes. , provides a means to sufficiently avoid the load fluctuation shock that occurs there. When accelerating the internal combustion engine from a resting position of the accelerator pedal, the increase in the torque transmittable by the clutch is controlled as a function of the rotational speed and/or acceleration of the internal combustion engine. In this case, this increase is limited to the maximum allowed value.

If the load change is reversed, the clutch is completely disengaged before reaching the switching point from traction to freewheeling operation. The switching point is determined by detecting the actuation displacement of the accelerator pedal or the actuation speed of the accelerator pedal and by taking into account the so-called zero moment line of the internal combustion engine.

〔Example〕

The method according to the invention will be explained in detail below on the basis of the embodiment shown in the figures.

In FIG. 1, reference numeral 1 designates a motor vehicle drive engine consisting of an internal combustion engine, in particular a multi-cylinder reciprocating piston engine. The crankshaft 2 of the internal combustion engine is connected to an input shaft 4 of a transmission 5 via a latch 3 which can be controlled in relation to the transmittable I-lux. As is known, the transmission 5 is connected via a differential 6 to driven wheels 7 of the motor vehicle in order to transmit drive power.

Reference numeral 8 designates an adjusting device attached to the latch 3 so as to be controllable. This regulating device can be controlled by a control device 9 in order to operate the clutch 3 appropriately. To this end, the control bag W9 obtains information from various signal transmitters. For example, the rotation speed of the crankshaft 2 is obtained from the rotation speed transmitter 10, and the rotation speed of the transmission input shaft 4 is obtained from the rotation speed transmitter 11.

Furthermore, the control device 9 obtains information from the position transmitter 13 regarding the position of an accelerator pedal 12 attached to the vehicle.

This accelerator pedal can be actuated by the driver in order to consciously adjust an output regulating member attached to the internal combustion engine 1, for example a throttle valve 14 provided in the intake pipe 15 of the internal combustion engine.

In conventional motor vehicles, load fluctuations occur during very rapid changes in the accelerator pedal.

This load change shock is particularly noticeable when the internal combustion engine is accelerated from coasting to high torque traction operation, in particular to a full throttle position, or, on the contrary, when the internal combustion engine is accelerated into relatively high torque traction operation, e.g. Occurs when operating from full throttle operation to coasting operation. In order to prevent this load fluctuation shock, the present invention provides a certain clutch control method. First, a description will be given of a clutch control method in the case of sudden acceleration of the internal combustion engine from coasting, that is, in the case of operating the accelerator pedal from the zero throttle position to the full throttle position. Such an accelerator pedal operation is shown in the graph of FIG. In this case, the accelerator pedal is at rest.

is operated from zero to full throttle. During this actuation of the accelerator pedal, the torque and rotational speed change as shown in FIGS. 3 and 4. The torque and the rotational speed are respectively measured at the crankshaft 2 and the transmission input shaft 4, and with regard to the torque, the torque that can be transmitted by the clutch 3 is also detected. At that time, in the coasting position of the accelerator pedal,
That is, when the accelerator pedal is released, between the torque of the drive engine l and the torque of the transmission human power shaft 4,
This shows that there is a difference between the rotational speed of the crankshaft 2 and the rotational speed of the transmission input shaft 4, which is kept constant. This difference is caused by a deliberate slip in the clutch 3. In this case, the clutch is not fully engaged by the adjusting device 8, but a rotational speed difference of, for example, 100 rpm is maintained. This is the rotation speed transmitter 10
The actual rotational speed difference detected by the control device 9
This is done by comparing it with the planned target value. The deviation between setpoint value and actual value is calculated by control device 9 and used for appropriate control of regulating device 8. Third
The torque that can be transmitted from the clutch, indicated by MdK in the figure, is the vehicle torque MdA generated at the transmission input shaft 4 based on clutch slip during coasting operation,
t by a predetermined amount. Torque Md, transmitted to the crankshaft 2 of the internal combustion engine l. , corresponds quantitatively to the torque MdK that can be transmitted by the clutch. But here, unlike the positive traction moment of an internal combustion engine,
It is shown as a negative quantity.

At the moment t0 of the changeover of the accelerator pedal from the zero throttle position to the full throttle position, the torque of the internal combustion engine increases to the maximum traction moment with a practically negligible delay. However, the torque which can be transmitted by the clutch does not change rapidly when load fluctuation shocks are avoided. Starting from the value that occurs in the free-wheeling state, the torque that can be transmitted by the clutch increases continuously up to the final state value by appropriate actuation of the clutch in the direction of engagement. This increase in the transmittable torque can then be controlled as a function of the rotational speed of the internal combustion engine or as a function of the acceleration of the internal combustion engine. In this case, a predetermined maximum increase value must not be exceeded. This maximum increase value is
It is determined from the viewpoint of ride comfort and depends on various criteria, such as the maximum power of the internal combustion engine provided, the engine bearings, etc. If allowed to increase too quickly, load shock can occur.

On the other hand, if the increase value is too small, the rotational speed of the internal combustion engine will increase excessively. This is because only a portion of the drive moment generated by the internal combustion engine is transmitted to the driven part via the clutch, and the remaining torque increases the rotational speed of the internal combustion engine.

The I-lux applied from the engine to the driven part naturally corresponds to the torque that can be transmitted from the clutch. Therefore, the driven moment Md□ starts from the value during coasting, and
Continuously increases up to the maximum driven moment. At the end of this process, this maximum The driven moment Mdabt is less than or equal to the maximum driving moment Md, , of the internal combustion engine.

As mentioned above, in general, the clutch slips during traction operation only at a predetermined rotation speed of, for example, 3000 revolutions per minute or less. On the other hand, above this limit speed, the clutch is fully engaged.

That is, there is no difference in rotational speed between the crankshaft and the transmission input shaft. In Figures 3 and 4, the break line indicates the torque MdA when there is no clutch slip at the end of the process.
bL or Md, and rotation speed. . , is shown.

The graphs of FIGS. 5 to 7, like the graphs of FIGS. 2 to 4, describe the method according to the invention for abruptly operating the accelerator pedal from its load position to its coasting position. . In the embodiment shown here, for example, the accelerator pedal is actuated from a maximum actuating position to a zero position between times t0 and t2. That is, the accelerator pedal is released (takes foot off). Corresponding to this progression of the accelerator pedal,
The course of the drive torque Mdmo of the internal combustion engine from the maximum torque to zero torque changes. The torque Md that can be transmitted by the clutch remains constant for the time being. This torque is, at the beginning of the process, initially smaller by the torque difference or the drive torque Md of the internal combustion engine, depending on whether the clutch is operated in slip. , is the same size as .

However, in order to avoid load shocks during the transition from traction to freewheeling, the clutch is disengaged before the internal combustion engine reaches the point of transition from traction to freewheeling. The transition point between traction and inertia, indicated by tl in Figures 5 to 7, is determined by monitoring the rotational speed of the internal combustion engine and the amount of operation of the accelerator pedal, taking into account the so-called zero moment line shown in Figure 8. is required. This zero moment line marks the limit line between overrun and traction operation of the internal combustion engine and, for the respective rotational speed of the internal combustion engine, specifies the accelerator pedal position at which the limit is reached. Since the zero moment line can be stored in control bag W9, the accelerator pedal position can be determined for the respective rotational speed of the internal combustion engine. In this accelerator pedal position, the internal combustion engine transitions from traction operation to coasting operation. In order to ensure that the clutch is disengaged during the transition from traction to coasting operation, the disengagement operation of the clutch should be carried out in advance.

The control of the clutch disengagement process is therefore dependent on the position of the accelerator pedal, so that when the accelerator pedal position falls below a predetermined distance from the zero motor line, disengagement of the clutch is automatically initiated by the control device. be done. Furthermore, the operating speed of the accelerator pedal can also be involved as a controlled variable. That is, the differential value of the operation displacement of the accelerator pedal with respect to time can also be involved. This is a reliable sign that the internal combustion engine has transitioned from traction operation to coasting operation when a predetermined operating speed is exceeded and additionally a predetermined distance from the zero moment line is reached.

After the clutch has been disengaged, a period of time has elapsed before the clutch is re-engaged. This connection is made in such a way that during overrun operation, a slip is again maintained between the rotational speed of the internal combustion engine and the rotational speed of the transmission input shaft. The engagement movement of the clutch can then be controlled as a function of the speed difference between the crankshaft and the transmission input shaft and possibly as a function of the first derivative of the speed of the crankshaft with respect to time. be.

〔Effect of the invention〕

An important advantage of the method proposed by the present invention is that, by implementing a suitable method of clutch slip control, load fluctuation shocks that conventionally occur during sudden changes in the accelerator pedal position can be largely avoided. It is in. That is, the ride comfort of a car equipped with such a device is significantly improved.

[Brief explanation of the drawing]

1 is a schematic diagram of a drive device for a motor vehicle operated according to the method according to the invention; FIG. 2 is a graph showing the accelerator pedal displacement versus time for full throttle acceleration from the coasting position of the accelerator pedal; Figure 3 is a graph showing the progression of torque over time corresponding to the accelerator pedal operation in Figure 2, and Figure 4 is a graph of the rotational speed of the internal combustion engine and transmission drive shaft for the accelerator pedal position shown in Figure 2. Figure 5 is a graph of time vs. rotational speed showing the progression of the sudden adjustment from full throttle position to zero throttle position; Figure 6 is a graph of accelerator pedal displacement vs. time showing the progression of the sudden adjustment from full throttle position to zero throttle position; Figure 6 is the graph of Figure 5. A corresponding time-torque graph showing the course of the torque of the internal combustion engine, driven shaft and clutch; FIG. 7 is a time-speed graph showing the course of the rotational speed of the internal combustion engine and the transmission input shaft; FIG. 8 is a graph of accelerator pedal displacement versus rotational speed, which shows the course of the so-called zero moment line, ie the switching point between traction operation and coasting operation of the internal combustion engine. ■... Internal combustion engine, 2... Crankshaft, 3... Clutch, 4... Transmission input shaft, 5... Transmission (transmission device), 12... Accelerator pedal procedure amendment document Heisei August 4, 1 year

Claims (6)

[Claims] 1. In vehicles, especially passenger cars, which are equipped with an internal combustion engine, a transmission, and a clutch, and where the clutch is located between the internal combustion engine and the transmission and is capable of controlling the transmittable torque, load fluctuation shock due to sudden changes in the accelerator pedal In this method, when operating the accelerator pedal (12) from the inertial position to the load position, the clutch (3)
is the rotational speed of the internal combustion engine (1, 2) and the transmission input part (4).
), with a predeterminable slip between the rotational speeds of A method for preventing load fluctuation shock characterized by: 2. 2. The method for preventing load fluctuation shocks according to claim 1, characterized in that the increase in the torque transmittable by the clutch (3) is controlled as a function of the rotational speed and/or acceleration of the internal combustion engine (1). 3. 3. A method for preventing load fluctuation shocks according to claim 1 or claim 2, characterized in that the increase in the torque that can be transmitted by the clutch (3) is limited to a maximum permissible increase value. 4. In vehicles, especially passenger cars, which are equipped with an internal combustion engine, a transmission, and a clutch, and where the clutch is located between the internal combustion engine and the transmission and is capable of controlling the transmittable torque, load fluctuation shock due to sudden changes in the accelerator pedal In this method, when operating the accelerator pedal (12) from the load position to the inertia position, the clutch (3)
are automatically completely switched off for the time being before the conversion of the internal combustion engine (1) from traction-coupled operation to overrun operation, and then the internal combustion engine (1, 2) and the transmission input (4) are switched off again. ) A method for preventing load fluctuation shocks, characterized in that the device is operated in the connection direction until a predeterminable slip occurs between 5. 5. The method for preventing load fluctuation shocks according to claim 4, characterized in that the clutch (3) is disengaged depending on the actuating displacement of the accelerator pedal (12). 6. 6. Method for preventing load fluctuation shocks according to claim 4 or claim 5, characterized in that the clutch (3) is disengaged depending on the operating speed of the accelerator pedal (12).