FR2746164A1 - DEVICE FOR CONTROLLING A CONTINUOUSLY OPERATED GEARBOX - Google Patents

Abstract

Adjustment system for a belt gearbox (4) whose ratio is infinitely adjustable, whose engine side (610) cooperates with the engine (1) of the vehicle and whose outlet side (611) cooperates with the vehicle wheels, the motor side and the output side comprising at least one element (6) sliding axially under the effect of a control signal (Psec), characterized by means (17) for detecting the sound and the signal (Psec) is formed at least based on the detected sound.

Description

STATE OF THE ART The invention relates to a device for controlling a

  continuously operating gearbox, also known as a variator, with a belt gearbox adjustment system, the ratio of which is infinitely adjustable,

  tor cooperates with the engine of the vehicle and the output side of which

  tie cooperates with the vehicle wheels, the engine side and the

  outlet side comprising at least one sliding element axially

  under the effect of a control signal.

  The invention supplements or replaces the current regulation

  belt tension of the gearbox belt at

  bearing, continuous (CVT) with electro-hydraulic actuator.

  CVT gearbox with regulation of the

  belt tension is for example described in the docu-

  DE-OS 44 11 628 or EP-0 451 887. Figure 1 shows in

  cuts such a gearbox. The internal combustion engine

  dull 1 can be controlled by a throttle flap 2 which defines the motor torque Mm. The throttle flap 2 is for example mechanically or electrically coupled to the pedal

  accelerator (not shown). The internal combustion engine

  dull 1 is usually coupled via an em-

  clutch and / or converter 3 on the engine side (primary side)

  CVT 4 gearbox. The output side or secondary side

  The CVT 4 gearbox is connected by a transmission-

  downstream (not shown) to the wheels of the vehicle. The CVT gearbox has on the primary side and on the secondary side,

  each time a conical pulley 5 and 6 sliding axially.

  To set the speed ratio, a primary pressure is created

  mayor Pprim or a corresponding secondary pressure Psec in

  oil chambers 7 and 8. By an appropriate choice, large

  primary pressure regulator Pprim and secondary pressure adjustment date, it is necessary to ensure that) the transmission ratio i corresponds to the desired ratio between the primary rotational speed Nprim and the secondary rotational speed Nsec, and

  2) the force transmission belt 9 (chain or belt-

  goose) is pressed hard enough against the pulleys

  to avoid slipping of the belt 9.

  The point 1 mentioned above is satisfied by a transmission or primary electrohydraulic speed control. For point 2, a

  belt tension regulation 11.

  For regulating the ratio or the tension of

  belt, engine 1 and CVT gearbox 4 are equal

  of rotational speed sensors 12, 13, 14 which detect the rotational speed Mm of the motor, the rotational speed

  primary Nprim and secondary rotation speed Nsec.

  In the case of the master / slave principle used the

  more frequently and shown in FIG. 1, the pressure se-

  condaire Psec is used to adjust the belt tension and the

  primary pressure Pprim is used to set the transmission ratio

  primary rotation speed or speed. In the case of the partner principle, which is possible as a variant, the regulation of the belt tension influences both the primary pressure and the

secondary pressure.

  In general, we can say that for the regu-

  belt tension, a feedback signal is used

  setting in the form of a pressure PB. According to the documentation, there are several methods of regulating the belt tension; however, these processes all work in a way

  similar. In the following we will use the DE-OS- documents

  44 11 628 and EP-0 451 887 for the description.

  Figure 2 shows the regulation of the belt tension described in these documents. From the angle

  of the throttle valve and the rotation speed Nm of the

  tor, the supplied motor torque Tm is defined according to the characteristic field 34. The blocks 38 and 35 make it possible to calculate the primary torque Tpr supplied by the converter. Block 45 calculates the transmission ratio of the CVT gearbox. Block 46 makes it possible to evaluate the secondary torque Tsec from the report

  transmission and primary torque Tpr.

  Block 49 calculates the secondary radius Rsec from

  transmission report transmission. According to block 52, the minimum secondary pressure Psec required is defined from the secondary radius and the secondary torque Tsec. After the increase of a reserve pressure in block 64, the signal is smoothed by a low-pass filter 68. Then, the average pressure Psec

  (CENTR) generated by the centrifugal force on the second pulley

  daire, is subtracted by block 60 from the pressure indicated above. In addition, the result of the pressure 63 is influenced by a sensor signal to measure the unevenness of the ground 94 and then one limits to a range selected by a limiter 168. The result of the calculations thus carried out Psec (TV) is used by the pressure control circuit 70, 72. The pressure control circuit finally ensures that the pressure Psec (MV) on the secondary disk is set to the value Psec (DV).

  In the publication "Status der cvt-Entwicklung-

  Vorteile und Grenzen des Systems ", 2nd colloquium Fahrzeug- und Motortechnik'89, (Aachen) it is indicated that an optimal CVT gearbox must not only have an optimal regulation strategy, but also a performance as good as possible and a low noise level. This document shows that both when using a belt or chain for the transmission of forces, this results in noise

operation.

  The present invention aims to optimize my-

  niere simple a continuously adjustable gearbox, known,

  as for its performance and its noise.

  To this end, the invention relates to a control device of the type defined above, characterized by means for detecting sound, and the control signal is formed at

less depending on the sound detected.

  Advantages of the invention The invention has as its starting point a system for adjusting a belt gearbox whose speed ratio is continuously adjustable, and whose drive side

  cooperates with the engine of the vehicle, and the output side coo-

  father with vehicle wheels. The drive side and the output side have at least one sliding element axially in

  function of a control signal and which have main-

  the shape of a conical pulley. The heart of the invention is

  to create means to detect noise and to train if-

  general control at least as a function of the noise detected.

  It is in particular provided that the noise detection means are provided in the vicinity of the gearbox for

  detect noises from the gearbox. It is also possible to detect variations in air pressure and / or detect the noise of the body. Taking into account the noises from the gearbox

  braids we arrive in a simple way to a quiet operation and an optimum efficiency for the gearbox because so

  general, the noise is generated by excessive friction

  both between a belt or a chain transmitting the torque

engine.

  According to an advantageous development of the invention,

  the control signal is formed so that a value which represents

  feels the base pressure is combined with a dependent component

  of the noise detected. The reason is that we define everything

  first a certain basic pressure by a character field

  motor characteristics, corresponding (depending on power

  motor detected or motor torque detected).

  As indicated above, when determining the base pressure, the desired transmission ratio is taken into account and the minimum belt tension is achieved. By a simple control or action according to the invention using the

  noise detected, in general, taking into account the

  gearbox output rotation size, it is

  then possible to work with minimum friction. The-

  tection of the driving power or the engine torque can be done according to the detected load of the engine and according to the

  detected motor speed.

  The control signal is formed by reducing to half

minimum noise detected.

  It is particularly advantageous to form the

  control signal, to use only selected components

  the noise detected. The reason is that the components

  of noise created by the friction to be optimized can be com-

  if necessary, linked to noise components not related to friction (for example a pump noise). These components can be separated by filtering the total signal so that to influence the control signal, only the noise components directly related to the friction of the

  gearbox. We can foresee for this that the noise

  tecté is subjected to a frequency analysis and that only the frequencies selected are used to form the

control signal.

  According to other advantageous features of the invention: - the axially sliding element is essentially under the

shape of a conical pulley.

  - the means for detecting the sound are mounted near the

  gearbox to detect noises from the gearbox

  braids. - the system forms the control signal to combine with a

  value representing the base pressure, a component

during detected sound.

  - the value representing the base pressure is dependent on

  the motive power detected or the engine torque detected.

  - the detection of engine power or engine torque is

  done according to the detected load of the motor and in function

  tion of the detected engine speed.

  - the control signal is formed to minimize the

its detected.

  - the control signal is formed only with components

your choices of the detected sound.

  - the detected sound is subjected to a frequency analysis and only

  the selected frequencies are used to form

the control signal.

Drawings

  The present invention will be described below in detail.

  more detailed with the help of exemplary embodiments

  shown schematically in the accompanying drawings in which: - Figure 1 is a schematic sectional view of a gearbox structure according to the prior art, - Figure 2 is a block diagram corresponding to Figure 1, - Figure 3 shows the arrangement of the sound sensor in space, - Figure 4 is a block diagram explaining the method of the invention, - Figure 5 shows a frequency spectrum of the detected sound, - Figure 6 is an overall block diagram of the invention. Example of embodiment FIG. 3 shows under the reference 9, means for transmitting the forces between the primary pulley 15 and the secondary pulley 16. As already indicated, the motive force of the motor vehicle is transmitted by a belt or chain 9 between the primary side shown in Figure 1 and the secondary side also shown in this figure and belonging

  to the belt transmission. It may be a court-

  compression link wheel, known according to the state of the art

  or a link chain also known according to the state of the art. As an example, see

  example to the publication mentioned above "Status der cvt-

  Entwicklung-Vorteile und Grenzen des Systems ", 2nd colloquium Fahrzeugund Motortechnik'89, (Aachen), pages 553 et seq. The essential for the invention in this embodiment, is the mounting of the noise sensor 17 near the gearbox. This noise sensor 17 measures the operating noise of the belt or of the chain 9;

  noises are notably caused by friction on lice

  the conics on the drive side or on the outlet side. The noise sensor 17 can detect sound or noise by detecting changes in air pressure. As a variant or in addition,

  we can also detect the noise of the gearbox body

  braids. FIG. 5 shows by way of example a distribution of the frequencies of the noise detected for a rotation speed

  motor constant of the order of 3000 revolutions per minute.

  As shown in FIG. 4, the block 52 forms a minimum base pressure Psec. This preset a minimum pressure

  for the adjustment pulleys corresponds to the predefined engine torque

  terminated by the engine characteristics field. This has been described above using Figure 2 and blocks 34, 35,

  46 shown in this figure. In this example of realization

  tion, block 52 of Figure 4 corresponds to the block with the same reference in Figure 2. It is important for this example

  of realization, that the basic pressure in block 102 con-

  have a sound-dependent component in combination. For this-

  the sound G is determined using the sound sensor 17 already de-

  crit. This sound G can either be supplied directly to block 102 or, as it appears in FIG. 4, first a frequency analyzer 101. In this case, block 102 receives only certain selected components G '. Block 102 supplies the secondary pressure Psec to the pressure regulator 70, controlled (see FIG. 2). The formation of the pressure Psec is such that the sound G, detected or that the components of its sound G ', detected min are reduced to the minimum. At this basic pressure Psec we thus modulate a pressure component to minimize the sound

  detected or the sound components, retained.

  Figure 6 shows an overall block diagram of the invention. The power supplied by engine 1 is adjusted by ignition or injection 601. The output shaft 610 is

  connected to the engine side of a continuous short-range gearbox

  line 4 (neglecting the clutch or converter). We are

  refer to figure 1 for the description of the vi- box

  tesses continuously. The spokes on the primary side and on the se-

  condaire of the chain belt 9 are defined by

  primary and secondary pressures. This is expected to be a

  pressure regulator 604 and a hydraulic pressure tank

  as 605. The pressure can be detected if necessary by the pressure sensor 606. In addition, to minimize or increase the pressure on the primary side, there is a valve 603. The

  regulation of belt tension or speed ratio

  tesse is controlled or regulated by the ECU control unit.

  For this, this control unit receives the rotation speed.

  tion Nn of the engine, the output speed of the gearbox Nsec, the output signal G of the noise sensor 17, the engine torque Tm and the temperature T of the gearbox

of speeds.

Claims (3)

R E V E N D I C A TIONS   1) Adjustment system of a belt gearbox (4), whose ratio is infinitely adjustable, including the motor side (610)   cooperates with the engine (1) of the vehicle and the output side of which   tie (611) cooperates with the wheels of the vehicle, the motor side and the output side comprising at least one element (6) sliding axially under the effect of a control signal (Psec), characterized by means (17) to detect the sound, and the control signal   (Psec) is formed at least based on the detected sound.   ) System according to claim 1, characterized in that the axially sliding element (6) is essentially under the shape of a conical pulley.   ) System according to claim 1, characterized in that the means (17) for detecting sound are mounted near the gearbox to detect noises from the gearbox. 4) System according to claim 1, characterized in that   it forms the control signal (Psec) to combine with a va-   min their (Psec) representing the base pressure, a component depending on the sound (G) detected.    ) System according to claim 4, characterized in that min   the value (Psec) representing the base pressure is dependent   of the motive power detected or the engine torque (Tm) detected. 60) System according to claim 5, characterized in that the detection of the driving power or of the engine torque (Tm)   is done according to the detected load of the motor and in function   tion of the detected rotational speed of the motor (Nm) 70) System according to claim 1, characterized in that the control signal (Psec) is formed to minimize the detected sound.   8) System according to claim 1, characterized in that   the control signal (Psec) is formed only with com- selected poses of the detected sound.   9) System according to claim 1, characterized in that the detected sound is subjected to a frequency analysis and only   selected frequencies are used to form the if- General order (Psec)