WO2015067861A1

WO2015067861A1 - Method for regulating a shock absorbing gear shift actuator

Info

Publication number: WO2015067861A1
Application number: PCT/FR2014/052343
Authority: WO
Inventors: Sophie RIVET; Ludovic MERIENNE
Original assignee: Renault S.A.S
Priority date: 2013-11-05
Filing date: 2014-09-22
Publication date: 2015-05-14
Also published as: FR3012861B1; FR3012861A1

Abstract

A method for regulating a gear shift actuator with a motorised sliding gear comprising a control element (2) for controlling a mechanical assistance system having a spring (9) capable firstly of accumulating energy when the teeth (8) of the sliding gear (7) abut against those of the pinion to be dog coupled (13) in order to shift gears and secondly of restoring this energy by expansion, in order to assist the meshing of the teeth (8) of the sliding gear between those of the pinion (13), characterised in that the control voltage of the drive motor is controlled between the start of shifting and the abutting of the teeth (8) of the sliding gear in a basic regulation mode imposing a predefined voltage on the electric motor, and in that the control voltage is reduced during the abutment period, in order to limit the compression of the spring (9).

Description

METHOD OF CONTROLLING A PASSING ACTUATOR

SHOCKPROOF

The present invention relates to the control of shifts in a gearbox with parallel shafts provided with an electric actuator for controlling shifts.

It relates to a method for regulating a motorized passenger gearshift actuator comprising a control element of a spring-loaded mechanical assistance system, able to accumulate, in a first step, energy when the teeth of the motor walkman come into abutment against those of the pinion to work to shift a speed, and restore this energy by relaxation in a second time, to assist the engagement of the teeth of the walker between those of the pinion.

This invention finds a non-limiting application, on "robotized" type gearboxes, that is to say, whose operation is that of a manual gearbox, but whose gearshift is automated, without synchronization mechanisms the idle gear when engaging a gear.

In the internal shift control systems without synchronization mechanisms, generally used flat toothed players, or "clabots", which are in most cases in abutment against the teeth of the sprocket gear clutch, before turn slightly with respect to the pinion to be able to engage between his teeth.

This type of control is generally used for applications in "formula one" or rally, where the time of shifting is the paramount criterion. On less sporting vehicles, the problem to be solved is to obtain the shortest possible passage time, without generating shock at the engagement. To achieve the comfort levels required on passenger vehicles, passage assistance devices may be used, involving a resistance spring capable of accumulating energy by compressing itself during the synchronization phase. release the energy at the end of it, to facilitate the interconnection of the pinion.

By the publication FR 2 988 800, there is known a system for actuating a cliploaded walkman, comprising a rigid fork displacement bridge provided with two arms engaged around a fork control shaft, so as to allow its own axial displacement along this axis under the control of an external passage control member. The system further comprises a resistance spring surrounded around the fork axis between the two arms of the bridge and two stop rings supported between the ends of the spring and the arms of the bridge, so as to slide with a movement limited along the axis.

With such a device, the principle of assistance is to compress a spring which stores the energy supplied by the actuator when the teeth of the player and the pinion are in abutment, and to release this energy when the clutching is possible, by acceleration of the fork. The acceleration obtained depends on the compression of the spring, and therefore the torque transmitted by the electric motor during the phase when the teeth are in abutment.

As indicated in FIG. 1, such an actuation system can be electrically controlled in the following manner: a finger 1, which is moved in rotation by an electric motor (not represented), drives in translation the mechanical assembly constituted by the clutch 2 and the bridge 3, which pushes the fork shaft 4 and the fork 6 through the assistance system comprising the spring 7. The fork 6 is itself positioned in the 8a groove of the player 8, and moves to the clutch (or "décraboter") in the pinion 9, during a commitment (disengagement) report.

Control is by the voltage applied to the electric motor of one actuator. The variables measured and used in the regulation are the finger position and the current of the actuator. It is the position of the fork which determines the shifting, but this measurement is not accessible to regulation. The control regulation is effected on the position of the finger, which is upstream of the assistance means in the control kinematic chain.

During the stop phase of the teeth of the player on those of the pinion, the regulation of position of the finger tends to increase the engine torque to compensate for the resistance of the spring, at the risk of not being able to brake the system sufficiently, when the player is released. If the position of the fork / player is too high, there may be a shock between the player and the pinion, due to the stop at the bottom of the teeth. In addition, the duration of the stop phase is not constant, since it depends on the relative position of the gears during the decision of the passage of speed, which is random. It also depends on the relative speed of the pinion and the player, which depends on the regulation capacity of the system by the electric traction motor.

Finally, a strong reduction in the compression of the spring is not desirable because it would have the effect of slowing the movement of the player and unnecessarily lengthen the passage time, in cases where there is no problem of stop, since the teeth of the player pass directly between those of the pinion.

The present invention aims to achieve a rapid change of speed, without causing the desired position of the player to be exceeded, in order to avoid feeling and to hear the shock of his teeth between those of the pinion.

For this purpose, it plans to control the control voltage of the drive motor by imposing on the electric motor a determined voltage between the beginning of the passage and the abutment of the teeth of the player, and to reduce this voltage during the stop period to limit the compression of the spring.

The regulation thus has two distinct modes, between which it switches during the detection of the stop, and during the release of the teeth of the player.

These arrangements make it possible to control the overrunning position of the player, by regulating the position of the control finger of the clutch, by integrating in its control a detection of the thrust of the player against the teeth of the pinion, so as to limit the torque applied to the finger, during the stop phase.

Other features and advantages of the present invention will become apparent from the present invention, with reference to the accompanying drawings, in which:

FIG. 1 shows the mechanical principle of the actuator whose regulation must be ensured,

Figure 2 summarizes the proposed actuator control, and

Figure 3 details the basic regulation of Figure 1

The electric shift actuator illustrated in a nonlimiting manner in FIG. 1 is under the control of an electric motor, not shown, whose output shaft drives a rotating part 1, connected in rotation with a control element, such as a gearshift finger 2. The finger 2 is engaged in the groove 3 of a rigid bridge 3, as described in the publication FR 2 988 800, which is provided with two arms 3a engaged around the control shaft 4 of a fork 6 for controlling a player 7 with flat teeth, or "clabots" 8. Moving of the player is carried out under the control of the engine receiving the position information of a position sensor, for example the position of the finger 2, and a resistance spring 9 wound around the axis 4 between the two arms 3a of the trigger guard. Two rings 11 limit the maximum compression of the spring 9 and the deflection of the bridge on the axis, thanks to the presence of their oblong slots 11a in which moves a pin 12, fixed on the axis 4.

When engaging a gear, the assembly consisting of the trigger guard, spring, bushings, fork shaft, and fork, moves in a block until the fork encounters resistance. at the bearing of the teeth 8 of the player against the teeth 13a of the pinion 13. The spring 9 is compressed between the rings 11 by the further movement of the bridge 3 in a loading phase of the spring, between the support of the player against the pinion, and its interconnection on it, that is to say the engagement of its teeth between those of the pinion. The spring then relaxes by restoring the energy it has accumulated, to assist the engagement of the player on the pinion.

The method of regulating a gearshift actuator proposed relates to such a motorized player, comprising a control element of a spring-loaded mechanical assistance system capable of accumulating energy at a first time when the teeth of the player come into abutment against those of the pinion to clutch to pass the speed and to restore this energy by relaxation in a second time, to assist the engagement of the teeth of the walker between those of the pinion.

According to Figure 2, the principle of regulation is based on the alternation of two modes of regulation:

a basic regulation, from the order of passage, until the stop of the teeth of the player and pinion, in which the maximum power of the motor can be used to move the player, and

a waiting regulation, between the entry in abutment and the release of the player.

The regulation switches between these two modes of regulation, during the detection of the stop, and during the release of the teeth of the walkman by those of the pinion.

Between the start of the passage and the stop of the teeth of the player, the control voltage of the drive motor is controlled in a first control mode. This basic regulation, illustrated in a non-limiting manner in FIG. 3, is a control of the motor power supply voltage U at the maximum power of the motor. The voltage is slaved to a position setpoint of a control element of the actuator between the beginning of the passage and the stop of the player, such as the finger 2 in the non-limiting embodiment of the invention described. It then exploits as input, a position of the finger position, a measurement of its position, and a measurement of the current. A displacement speed instruction, resulting from the difference between the measurement and the position command multiplied by a gain K, is compared with the measured speed. Depending on the detected speed error, a first integral proportional corrector delivers a current setpoint. This setpoint is compared with the measurement of the current in the motor, in a second integral proportional corrector, for controlling the control voltage U of the motor, at its maximum power.

When all the parts (finger, trigger guard, spring, rings, axle, fork and clutch), moves in block, the torque delivered by the engine is equivalent to the friction, the product of the acceleration of the parts, by the mass of the block. When the applied torque exceeds this product, the difference corresponds to the compressive spring compressive force, which means that the teeth of the walkman have come into abutment against those of the pinion. The instantaneous engine torque is not known, but the system has a current measurement. The detection of the stop can thus be ensured by comparing the integral of the motor current, with the speed of movement of the finger, calculated from its position measurement.

The standby regulation is implemented during the stop period of the player. Its purpose is to limit the final overrun of the walkman position, while maintaining a sufficient compression of the spring to enjoy the benefits of this mechanical assistance. Under these conditions, the waiting regulation must at the same time:

• limit the applied torque (spring compression), and

· Limit the integral action of the regulators during the stop phase to reduce the inertia during unblocking.

For this, the position setpoint of the control element is changed during the stop period of the teeth of the player. In a variant, the voltage imposed on the electric motor can be reduced by modifying the current setpoint.

Thanks to the mechanical assistance, the fork is launched by the spring, as soon as the teeth of the pinion do not block anymore the walkman. The release of the teeth of the player can therefore be detected by a peak speed on the control element.

The advantages of the invention are considerable. In particular, it is possible to limit the exceeding of the position setpoint, and of the pinion during the stop, without affecting the basic regulation. This makes it possible to adjust this position control as well as possible, in particular to realize the position instruction in the shortest time, in cases where there is no problem of stop, that is to say when the teeth of the walkman engage directly between those of the pinion.

Claims

1. A method of regulating a motor-driven power shift actuator (7) comprising a control element (2) of a spring-loaded mechanical assistance system (9) able to accumulate in a first step of the energy when the teeth (8) of the player (7) abut against those of the pinion (13) to shift the speed and restore this energy by relaxation in a second time to assist the engagement of the teeth (8) of the sliding between those of the pinion (13), characterized in that the control voltage of the drive motor is controlled between the beginning of the passage and the abutment of the teeth (8) of the player in a basic regulation mode imposing the electric motor a determined voltage, and in that the control voltage is reduced during the stop period, to limit the compression of the spring (9).

2. Control method according to claim 1, characterized in that the regulation switches between two distinct control modes, during the detection of the stop and during the release of the teeth (8) of the player (7) by those of the pinion (13).

3. Control method according to claim 2, characterized in that the stop is detected by comparing the integral of the motor current, with the speed of movement of the control element (2), calculated from its measurement position.

4. Control method according to claim 1, 2 or 3, characterized in that the voltage is slaved to a position setpoint of a control element of the actuator between the beginning of the passage and the stop of the player.

5. Control method according to one of the preceding claims, characterized in that the position setpoint of the control element is modified during the stop period of the teeth of the player against those of the pinion.

6. Control method according to one of claims 1 to 4, characterized in that the voltage imposed on the electric motor is reduced by changing the current setpoint.

7. Control method according to one of claims 2 to 6, characterized in that the release of the teeth of the player is detected by a peak speed on the control element.

8. Control method according to one of the preceding claims, characterized in that the control element is a control finger of a range of player.