DE3607329C2 - - Google Patents

Description

The invention relates to a control device for a Manual transmission, in particular a switchable under load, multi-stage gear transmission for motor vehicles, the for switching the individual gear shifters on or off fen pressure-operated switching elements in the form of Friction clutch and / or friction brake elements has, the pressure medium supply to each switch element is influenced by a control valve and a control circuit is provided which depends on ability of various operating parameters, such as. B. the Drive and / or output speed of the manual transmission and / or the position of the fuel rail, an order switching of the gearbox triggers.

With such gearboxes, it depends on of the switching operation taking place under load, which both in traction as well as in overrun can, interruptions in the power transmission largely to avoid. The gearbox is particularly important as smoothly as possible between the individual Switching switching levels.  

DE-OS 27 08 621 describes such a tax direction for a manual transmission, in which over ent speaking clutch and brake elements different Speed ratios between the input and output shaft about a planetary gear set can. The switching process is done either manually a shift sequence lever or automatically from a shift point calculator initiated, the actual time from control process through a logical control scarf tion takes place. Switch signals serve the ver different switching intervals according to individual compo nents and components of a control loop for printing of the pressure actuating the clutch and brake elements unlock or lock by means of.

The control loop consists of a with the output shaft in Connected converter, its output signal Measure of the transmitted torque is. This signal controls an electrohy via a pulse width modulator draulic control valve for the pressure medium, with which the Control loop is closed.

In this control device, the controlled variable is the turning point moment detected by the torque transducer and after appropriate processing to the pulse width modulator to be led. The controlled system consists of the control nerve til as well as the transmission, on which also the torque the drive shaft has an influence. This results in a extraordinarily "long" control loop (from the transmission via the torque sensor to the valve), which are not fast re allows gel operations. Add to that the provided by control valves caused inertia, which u. a. through a "Memory effect" of the required choke becomes.  

From DE-AS 25 41 600 is also a control device the above Kind known in which the control valves are designed as hydraulic valves whose Piston slide on the one hand from an actuating piston and on the other hand act counter to it the damping piston is actuated. The supply of the Pressure medium to the actuating piston takes place because of separate pilot valves that are electric be operated. For individual pressure control to enable during the switching process this control device additionally one or more Vent shut-off valves through which the relief the clutch or brake elements delayed can be. A disadvantage of this known tax However, the high cost of valves is one of the features and pressure medium lines because of the purely hydraulic actuated control valves, which are also electro magnetic pilot valves as well as the ventilation Make the shut-off valve necessary. Next is by night part that the timing of the regulated pressure construction in particular through the use of chokes is defined in the control lines, so not can be adjusted to the operating parameters.

Even at a pressure known from DE-AS 18 17 467 middle-actuated switching device is the component Considerable effort, as here also for each the gear shift element is initially a pressure medium actuated control valve and additionally in turn  electrically operated control valve is provided.

DE-PS 22 09 447 describes a hydraulic shift device with switching pressure control, for each Ge Gear shift element and a pressure medium switching valve a common pressure for all gear shift elements has control valve. The pressure control valve controlled by means of electrical signals that the fluid pressure before each switching operation is gradually lowered, with the beginning and the end the pressure reduction by means of an individual timer which is freely adjustable for each switching process. However the amount of pressure drop can only be dependent on the position of the fuel rail and only unit Lich in the entire hydraulic system, so not indi viduell adjust in each pressure medium line. Out of it the following results: If during a gear change sels (relieving a previously activated switch elements and loading another switching element a third gear shift element tet should remain, then there is a risk that this third switching element temporarily slips (Risk of premature wear).

The invention has for its object a tax to design the device of the type mentioned at the beginning, that for each new gear shift to be switched on a short-term individual pressure control at the same time low component costs and consequently increased functional reliability is possible. In doing so  the regulation of pressure or pressure build-up especially in Dependence on the new gearbox to be switched on Switching element, also from the switching direction (upshift or downshift) and the operating states, such as driving speed, the engine load, the position of the fuel rail etc. can be done. Possibly the duration of the pressure control should also be dependent of one or more of the aforementioned sizes can be controlled.

This object is achieved according to the invention in that the control valve is designed as a combined electromagnetic switching and pressure control valve, in which the force of the armature of the electromagnet acting on and adjusting the armature of the electromagnet can be adjusted by changing the magnetic field strength, the electromagnet for determining a the measured value forming the actual value (x) for the instantaneous magnetic induction and thus the magnetic force generated, a device is provided for generating a measurement voltage proportional to the temporal change in induction, to which at least one integration element is connected, which converts the measurement voltage into the measurement variable proportional to the induction That a control element is also provided, which generates a manipulated variable (y) for the excitation current of the electromagnet by comparing the actual value (x) emitted by the integration element and a setpoint value (w) specified by the control circuit, so that the magnetic force and Above that, the pressure of the pressure medium actuating the switching element is adjusted to a value corresponding to the setpoint value, and that finally a timing element is provided, which time-limits the control process of the control element that begins each time a shifting of the gearbox is triggered, so that the actual value and / or the setpoint assumes a minimum or maximum value.

The progress achieved by the invention exists first in that with a little effort hydraulic components, namely only one at a time Control valve for each switching element to be actuated the gearbox still has individual control of the Pressure medium and in particular its actual temporal ver runs depending on different, for switching significant operating parameters is possible.

A suitable control valve is for example known from DE-AS 20 19 345. The one described there Pressure control valve is out with an electromagnet equips its magnetic force to control the pressure is adjustable with the help of a controller. This is the pressure control valve continues with a magnetic Provide the field strength sensing encoder element, its signal size is used for regulation.

As such, this encoder element can be described there level of a magnetic field dependent resistor or also be formed by a Hall generator.  

Because of the mechanical and thermal sensitivity as well as the temperature dependence of the off it is recommended to use the output signals of these elements against when using such control valves in vehicles driven that to determine the current magnetic induction in the form of an auxiliary winding an induction loop is provided. Likewise can but also the Er inducing the magnetic field control coil itself can be used as both from DE-AS 20 19 345 itself already emerges, which is already accelerating with the rule dealt with. Not even before published patent application P 35 36 671.0-14 describes a geeig nice pressure control valve, as well as DE-PS 27 20 877.

The latter two possibilities of the magnetic field measurement are particularly useful in the context of the invention, since here a single pressure control process is only about extends a few seconds. This leaves signal errors the inevitable in the integration links At least offset voltages and voltage drifts occur disruptively with longer integration times small enough that they remain meaningless and can be neglected.

In a first embodiment of the invention, for each control valve has its own integration and / or time and / or control element can be provided. This makes an extremely universal tax possibility.

When switching from one gear to another it suffices to switch the switching element directly, d. H. without switching off pressure control and only the pressure  of the newly actuated switching element for a short time regulate. In a preferred embodiment of the Er The invention is therefore common to all control valves complete integration, timing and control element provided, wherein the connection of the integrator with the Auxiliary winding of the respectively active control valve, as well the transfer of the manipulated variable of the control element to Electromagnets of the respectively active control valve a switch operated by the control circuit direction. This is another significant one Reduction of the otherwise required electrical or electronic components possible. The switch direction can in a particularly simple manner from be formed a multiplex module.

The timer is advantageously between the Integration element and the actual value input of the rule arranged and occupied at the end of the time the control process limited the actual value to its Mini malwert, so that the manipulated variable its maximum value assumes. This ensures that at the end of the rule determined by the timer time interval the currently switched on switching element is under full pressure. The However, the control device can also do this forms be that the timer to terminate the integration process Zero resets, which increases the integration already in its initial state for the next switching operation.  

Finally, there is also the possibility that the Timer between the control circuit and the Re member is arranged and to end the rule process sets the target value to a maximum value, see above that the manipulated variable takes its maximum value.

The control circuit can be used for every switching operation generate an individual setpoint. Besides, can an individual timer for each switching operation be seen.

The following are based on the drawing Exemplary embodiments explained in more detail; it shows

Fig. 1, the control device in a schematic representation;

Fig. 2 shows another embodiment of the article of FIG. 1, only partially illustrated

Fig. 3 is an axial section through one of the tile Steuerven,

Fig. 4 is a fragmentary representation of the subject matter of FIG. 1 in another embodiment.

The Steuerein direction shown in the drawing in Fig. 1 is provided for a manual transmission, esp. For a switchable under load, multi-stage gear wheel transmission for motor vehicles. To switch on or around the individual gear shift stages, the manual transmission in Fig. 1, not shown, pressure-operated switching element in the form of clutch and / or brake elements, which are actuated via pressure medium lines 15, 25, 35 . For example, it can be assumed that the switching element connected to line 15 is actuated to insert the 1st gan, the other lines 25 and 35 being depressurized at the same time. In a corresponding manner, the line 25 is pressurized in 2nd gear with pressure, the lines 15 and 35 being depressurized. The invention is explained below using this simple example, in which only one of the pressure medium lines 15 , 25 , or 35 is struck with pressure in each gear. However, the invention can also be used in gearboxes in which several (preferably two) switching elements have to be actuated simultaneously by pressurization in each gear.

The pressure medium supply to each switching element is influenced by a control valve 10 , 20 , 30 , the individual control valves 10 , 20 , 30 being connected via a common supply line 5 to a pump 6 , which generates the required switching pressure. A pressure control valve 6 a keeps the pressure in line 5 at a constant value. Finally, a control circuit 9 is provided which, depending on various operating parameters of the transmission or of the vehicle, triggers a changeover of the manual transmission. These operating parameters, the detection of which is not shown in the drawing, are, for example, the input and / or output speeds n of the gearbox and the position of the fuel meter M , which represents a measure of the engine load. The control circuit forms 9 commands for switching the transmission from these operating parameters:

from idle to gear 1 (line 01 ),
from gear 1 to gear 2 (line 12 ),
from gear 2 to gear 3 (line 23 ),
from course 3 to course 2 (line 32 ),
from gear 2 to gear 1 (line 21 ).

As a result, the control circuit 9 determines which of the switching stages is to be switched on again.

Each of the control valves 10 , 20 , 30 is designed as a combined electromagnetic switching and pressure regulating valve, preferably according to FIG. 3. I.e. on the example of the control valve 10 : it connects as a switching valve the pressure medium line 15 either with the supply line 5 or with the relief line 18th In addition, it can regulate the pressure in the pressure medium line 15 briefly to a certain value as a control valve. During such a pressure control process, the force of the armature 22 acting on the valve body 11 and displacing it can be adjusted by changing the magnetic field strength of the electromagnet 16 . In detail, the valve body 11 is cup-shaped and axially displaceable via an actuating bolt 22 connected to the armature 22 ' . The valve body 11 is in a Ven valve housing 11 ' by two axially arranged one behind the other, the valve body 11 leading ring flanges 11 a , 11 b divided into three interiors 24 , 26 , 28 . The central interior 26 is connected to the pressure medium source 6 via the supply line 5 , while the interior 24 in the region of the open end of the valve body 11 via the pressure medium line 15 is connected to a switching element 8 indicated here as a circle. A relief line 18 leads from the interior 28 , which is adjacent to the electric magnet 16 , to the outside, for example into a sump 14 .

In the area of its bottom, the valve body 11 is provided with radially extending bores 13 , the diameter of which is at most equal to the width of the annular flange 11 b , so that the bores 13 are covered completely or almost completely with the corresponding position of the valve body by the annular flange 11 b . In this "pressure control position", in which the holes 13 are symmetrical to the ring flange 11 b , can - for the duration of a control process, which will be described below - adjust a balance between the attacking on the valve body 11 shifting forces. I.e. the magnetic force transmitted by the bolt 22 ' in this state is equal to the pressure force acting on the valve body 11 from the pressure in the line 15 . If the magnetic force is less than the stated compressive force, in particular when the electromagnet is switched off, then the valve body 11 is moved from the “pressure control position” to the electromagnet 16 . This ent ent a free (unthrottled) connection between the switching element 8 and the sump 14 on the Boh stanchions 13 , whereby the switching element is relieved. When the valve body 11 is shifted in the opposite direction, triggered by the adjustment of the magnetic force to its unregulated maximum value, on the other hand the interiors 24 and 26 are connected with one another and thus the pump 6 is connected to the switching element 8 .

During the pressure control process, which always takes place at the start of the pressure medium supply to a switch element 8 to be switched on and is limited in time, the excitation current of the electromagnet 16 can be regulated, as is indicated schematically in FIG. 1. For detecting the magnetic force, the electromagnet 16 a is in the range of the excitation coil 16 'arranged auxiliary winding 17th At the connecting lines of the auxiliary winding 17 are designated in Fig. 3 with 17 a and 17 b , the connecting lines of the excitation coil 16 ' with 16 a and 16 b . The voltage induced in the auxiliary winding 17 is proportional to the temporal change in the magnetic induction. It is fed via lines 17 a , 17 c to an integration element 51 , which integrates a voltage directly proportional to the magnetic induction by temporal integration (as known from DE-AS 20 19 345). This is also a measure of the instantaneous field strength and thus the magnetic force generated and serves as a measured variable forming the actual value. Furthermore, a control element 50 is provided, which generates a manipulated variable y for the excitation current of the electromagnet 16 by comparing the actual value x output by the integration element 51 via the line 53 , 53 ' with a desired value w , so that the magnetic force and above that the pressure of the the switching element actuating the pressure medium (line 15 ) is adjusted to a value corresponding to the setpoint. This manipulated variable y is a line 52 , 52 ' an electrically controllable switching element, for. B. a Schalttransis gate 19 which supplies the solenoid current (line 16 a ) according to the manipulated variable y of the control element 50 . All switching transistors are connected via a supply line 160 to a current source 161 . Finally, a timer is seen 49 provided that the respective in eliciting an Umschal of the transmission processing starting control operation of the control member 50 limited, so that on closing of the actual and / or setpoint mal- a mini or assumes the maximum value.

It is important that the control circuit 9 forms an individual setpoint for each switching operation, which (simultaneously with the issue of the relevant switching command) by means of one of the lines 01 ' , 12 ', 23 ' , 32' or 21 ' to a digital-analog Converter 39 and from there as an analog signal via line 48 to the control element 50 is supplied.

Basically, it is possible that for each control valve 10 , 20 , 30 a separate integration, time, or control element 51 , 49 , 50 is provided, whereby universal control and regulation options are available, which, however, require a greater amount of electrical or . entail electronic assemblies. Depending on the application, however, it will be sufficient to provide only a few of these elements more times. In Fig. 2 it is partially indicated that, for example, for each of the switching operations, a separate timer 490 to 494 can be provided. Each time the control circuit 9 issues a switchover command, one of the timers is activated via the relevant signal line 01 , 12 , 23 , 32 or 21 . Thus, an individual time period of the pressure control can be given for each switching process.

However, within the scope of the invention there is also the particularly advantageous possibility of providing a common integration, timing and control element 51 , 49 , 50 for each control valve, the connection of the integration element 51 with the respectively active auxiliary winding 17 ( Line 17 a , 17 c ) and the transmission of the manipulated variable y of the control element 50 to the respectively active electromagnet 16 via a switching device 40 actuated by the control circuit 9 by means of the signal lines 01 , 12 , 23 , 32 , 21 . This switching device 40 can be formed in a particularly simple manner by a multiplex module in example integrated circuit technology. In Fig. 1 it is indicated schematically that the switching device 40 has four switching positions N (idle) and I, II, III for gears 1 to 3.

In the embodiment examples shown in the drawing, the timing element 49 (or the timing elements 490 to 494 ) is arranged between the integration element 51 and the actual value input of the control element 50 . This timer 49 is at the end of the time-limited control operation the actual value to its Mini malwert, whereby the output from the control member 50 is manipulated variable y takes its maximum value. The respectively actuated control valve 10 , 20 , 30 thereby acts on the assigned switching element with maximum pressure. However, the timing element 49 can also reset the integration element 51 to zero at the end of the control process, so that the actual value again assumes its minimum value, as a result of which the integration element 51 is already in its initial state for the next switching operation.

Alternatively, as shown in Fig. 1 dash-dotted lines, the timing element 49 'can also be arranged between the control circuit 9 and the control element 50 . The timer 49 ' then sets the target value to the maximum value at the same time, whereby the manipulated variable also assumes its maximum value.

Fig. 4 finally shows an embodiment with a control valve 10 , in which the excitation coil of the electromagnet 16 itself is used to determine the instantaneous magnetic induction. For this purpose, the voltage source 161 in the circuit via the switching transistor 19 and the excitation coil of the electromagnet another measuring resistor R _{M placed} in series, which causes a voltage drop from which the measurement proportional to the induction can be formed.

Since the voltage drop across the measuring resistor contains a constant DC component, this must first be suppressed by a differentiating circuit 67 and the output signal thereof must then be integrated in a first integration element 71 to recover the original signal. Since this voltage is proportional to the flux change in the magnet 16 , a second integration by the integrating member 72 is required, which then supplies a voltage proportional to the magnetic field present in the electromagnet 12 , the further processing of which is evident from FIG. 1.

Claims (11)

1.Control device for a manual transmission, in particular a switchable multi-stage gear transmission for motor vehicles, which has pressure-operated switching elements in the form of clutch and / or braking elements for switching on or switching over the individual gear shift stages, the pressure medium supply to each Switching element is influenced by a control valve and a control circuit is provided which, depending on various operating parameters such as. B. the drive speed and / or output speed of the Schaltge gearbox and the position of the fuel distributor triggers a switching of the gearbox, characterized in that the control valve ( 10 , 20 , 30 ) is designed as a combined electromagnetic switching and pressure control valve, in which the force of the valve body ( 11 ) attack the and this adjusting armature ( 22 ) of the electromagnet ( 16 ) can be adjusted by changing the magnetic field strength, the electromagnet for determining an actual value (x) forming the measurement variable for the instantaneous magnetic induction and thus the magnetic force generated a device ( 17 or R _M ) is provided for generating a measurement voltage proportional to the temporal induction change, to which at least one integration element ( 51 or 71 and 72 ) is connected, which the measurement voltage into the Induction propor tional measured variable converts that a control element ( 50 ) is also provided, which is by V Comparison of the actual value (x ) given by the integration element ( 51 ) and a setpoint value (w ) predetermined by the control circuit ( 9 ) generates a manipulated variable (y) for the excitation current of the electromagnet ( 16 ), so that the magnetic force and above that the pressure of the the switching element actuating pressure is adjusted by means of a value corresponding to the target value (w) , and that finally a time element ( 49 ) is provided, which starts the control process of the control element ( 50 ) each time when a changeover from the manual transmission starts , so that the actual value (x) and / or the target value (w) then assumes a minimum or maximum value. 2. Control device according to claim 1, characterized in that the device ( 17 ) is formed by an auxiliary winding. 3. Control device according to claim 1, characterized in that the device ( 66 ) is formed by the magnetic field inducing excitation coil. 4. Control device according to claims 1 to 3, characterized in that for each control valve ( 10 , 20 , 30 ) a separate integration and / or time and / or control element ( 51 , 49 , 50 ) is provided. 5. Control device according to claims 1 to 3, characterized in that a common integration, time and control element ( 51, 49, 50 ) is provided for all control valves ( 10, 20, 30 ) and the connection of the integration element ( 51st ) with the measuring voltage generator (e.g. auxiliary winding 17 ) of the respective active control valve (e.g. 10 ) and the transmission of the manipulated variable (y) of the control element ( 50 ) to the electromagnet ( 16 ) of the respectively active control valve (e.g. B. 10 ) via a control circuit ( 9 ) actuated switching device ( 40 ). 6. Control device according to claim 5, characterized in that the switching device ( 40 ) is formed by a multiplex module. 7. Control device according to claims 1 to 6, characterized in that the timing element ( 49 ) between the integration element ( 51 ) and the actual value input of the control element ( 50 ) is arranged and at the end of the time-limited control process the actual value (x ) sets to its minimum value so that the manipulated variable (line 52 ) assumes its maximum value. 8. A control device according to claim 7, characterized in that the timer (49) for Beendi the control action supply the integration element (51) to zero resetting, is whereby the integration member (51) is already in its initial state for the next shift. 9. Control device according to claims 1 to 6, characterized in that the timing element ( 49 ' ) between the control circuit ( 9 ) and the control element ( 50 ) is arranged and to complete the control process, the target value (w) to its maximum value sets so that the manipulated variable (y) takes its maximum value. 10. Control device according to one of claims 1 to 9, characterized in that the control circuit ( 9 ) for each switching operation ( 01, 12, 23, 32, 21 ) an individual setpoint (line 01 ', 12', 23 ', 32' , 21 ' ) generated. 11. Control device according to one of claims 1 to 10, characterized in that for each switching operation ( 01, 12, 23, 32, 21 ) an individual timer ( 490 to 494 ) is provided ( Fig. 2).