WO2006097210A1

WO2006097210A1 - Electrohydraulic gear control device

Info

Publication number: WO2006097210A1
Application number: PCT/EP2006/001994
Authority: WO
Inventors: Georg Gierer; Thilo Schmidt
Original assignee: Zf Friedrichshafen Ag
Priority date: 2005-03-18
Filing date: 2006-03-04
Publication date: 2006-09-21
Also published as: DE102005012586B4; DE102005012586A1

Abstract

The invention relates to an electrohydraulic gear control device (1) comprising an electric gear control unit, several pressure control valves (5, A1 bis E1) which are electrically controllable thereby and several pressure regulating valves (A3 to E3) and switching valves which are exposed to a pilot hydraulic pressure supplied by the control valves (5, A1 to E1) and make it possible to control gear switching elements (A to E) by a control pressure (p_A to p_E), respectively, necessary for representing a required operating state. The inventive device also comprises an emergency gear shifting valve (SV_2) which, is placed in the first control position thereof when the gear control unit is activated, wherein the switching elements (A to E) connectable to a force stream for representing, the required operating state of the automatic gear, respectively, are connected in a corresponding manner, and is placed, when the gear control unit is deactivated, in the second switching position thereof, wherein the switching elements (A, B, D, E) connectable for representing an emergency transmission ( 3' to 5' to R') associated with a transmission area, respectively, are controllable by means of a control pressure (p_A, p_B, p_D, p_E) required therefor and a selective switching valve (SV_1) interacts with the emergency gear shifting valve (SV_2) in such a way that the emergency transmission ( 3' to 5' to R') associated with a transmission area is engaged.

Description

Electrohydraulic transmission control device

The invention relates to an electro-hydraulic transmission control device with an electric transmission control device and with a plurality of controllable by the transmission control pressure control valves and a plurality depending on the control of the pressure control valves each acted upon with a hydrauliscfien pilot pressure pressure control valves and switching valves, by means of which switching elements of a transmission with each to represent a requested operating condition the transmission required control pressure can be controlled.

From DE 198 58 541 A1 and DE 198 58 543 A1 electro-hydraulic transmission control devices for six-speed automatic transmission with five switching elements are known, by means of which a multi-stage emergency concept is feasible. The emergency operation concept is started when an error is detected in an electric transmission control device and the transmission control device active during operation is deactivated such that pressure control valves which are electrically controllable by the electric transmission control device can no longer be activated by the inactive and then de-energized transmission control device. The multi-stage emergency concept is provided in case of failure of the electric transmission control device to insert at high vehicle speeds in the automatic transmission as high as possible emergency gear or the current vehicle speed adapted emergency gear ratio, which has little effect on a drive train of a vehicle.

Since with such a high emergency gear ratio at the output of a vehicle only low tensile forces can be displayed, a start of the vehicle from standstill is difficult or impossible to carry out. For this Reason, it is provided that a further emergency transmission ratio, which corresponds to a smaller ratio of the automatic transmission, in emergency mode in the transmission can be inserted, to change the emergency transmission ratio basically a restart of the vehicle is performed.

However, the known from the prior art electro-hydraulic transmission control devices have the disadvantage that two of the switching elements are controlled alternately via a single pressure control valve, whereby the connection between the pressure control valve and the thus controllable switching elements is temporarily interrupted during the alternating control. Due to the changing controls there is the possibility that accumulates air in the connecting lines between the pressure control valve and the thus controllable switching elements, which applicatively can be eliminated only with great effort or over corresponding and high cost causing hydraulic measures can be prevented. In addition, both approaches can be implemented only by an extremely complex control of the correspondingly redesigned electro-hydraulic transmission control device.

The present invention is therefore based on the object to provide an electro-hydraulic transmission control device, by means of which a multi-stage emergency switching concept with a low control and regulatory effort is feasible.

According to the invention this object is achieved with an electro-hydraulic transmission control device according to the features of claim 1.

The electrohydraulic transmission control device according to the invention is provided with an electric transmission control device and with a plurality of pressure control valves which are electrically controllable by the transmission control device and also formed in response to the control of the pressure control valves each acted upon by a hydraulic pilot pressure pressure control valves and shunt valves. By means of the pressure control valves, the pressure control valves and the switching valves switching elements of a transmission with each required to represent a requested operating condition of the transmission control pressure can be controlled. The pressure control venti Ie and the switching valves are at inactive transmission control device via the then de-energized pressure control valves acted upon with hydraulic pressure such that in the transmission of a transmission range of the transmission associated translation over at least two simultaneously in the power flow in the presence of an operating condition of a transmission the gearbox switched switching elements is inserted, a predefined and at least one translation of the transmission comprehensive translation associated emergency transmission is represented by at least two simultaneously switched into the power flow switching elements.

To implement an emergency running concept known from the prior art, the electrohydraulic transmission control device is designed with an emergency gearshift valve, which is in a first shift position with the gearbox control device activated, in which the respective switching elements to be engaged in the power flow to represent a requested operating state of the automatic transmission can be engaged and which is in a second switching position when the transmission control device is deactivated or inactive, in which the switching elements to be connected for displaying the emergency transmission associated with the transmission range can be actuated with the control pressure required for this purpose without triggering the pressure control valves on the transmission control device. In addition, a selector switch valve is provided, which cooperates with the emergency gearshift valve in such a way that the emergency transmission ratio associated with the transmission range is engaged in the transmission.

Thus, in the electro-hydraulic transmission control device with the transmission control device active, i. H. when current pressure control valves, a normal driving operation of a vehicle, in which the various ratios of a transmission depending on various ih the transmission control device stored switching strategies are placed taking into account a current operating state of a drive train of a vehicle, performed in a conventional manner. At the same time with the electro-hydraulic transmission control device according to the invention, a multi-stage emergency switching concept with structurally little effort, a simple control concept and a small number of components can be realized.

In addition, by the design of the electro-hydraulic transmission control device in a simple manner prevents air accumulation in the area between the pressure control valves and the switching elements, since each switching element is assigned a separate pressure control valve, whereby a mutual control of two or more switching elements is bypassed by a single pressure control valve.

That is, with the electrohydraulic transmission control device according to the present invention, both a normal running operation of a vehicle and an emergency running operation in which there is a fault in the electric transmission control device that disconnects a connection between the electronics and the hydraulics of the electro-hydraulic transmission control device and the hydraulics from the electronics do not is more controllable, is feasible, the hydraulic in emergency operation depending on the present at the time of failure of the electronic operating state of the transmission or the car matgetriebes selects a predefined and useful strategy for inserting a required for the further driving of the vehicle translation. This procedure can advantageously be realized with a small amount of control and control effort, since pressure signals from elements of the electrohydraulic transmission control device are used both to control the emergency gearshift valve and to actuate the selector selector valve, which can only be made available with little design effort.

Further advantages and advantageous embodiments of the invention will become apparent from the claims and the embodiments described in principle with reference to the drawings, wherein in the description of the various embodiments for clarity, the same reference numerals are used for construction and functionally identical components.

It shows:

Fig. 1a is a simplified illustrated hydraulic control scheme of the invention electrohydraulic transmission control device with manual selector slide;

FIG. 1b shows a switching logic of the electrohydraulic transmission control device according to the invention according to FIG. 1 a; FIG.

Fig. 2a is a simplified illustrated hydraulic control diagram of a second embodiment of the electrohydraulic transmission control device according to the invention with electric selector lever; 2b shows a switching logic of the electro-hydraulic transmission control device according to the invention according to FIG. 2a; and

Fig. 3 is a comparison of curves of the driving pressures of the switching elements for displaying the emergency gear ratios during the connection of these switching elements in emergency operation of the transmission control device according to the invention according to Fig. 1a and Fig. 2a.

In Fig. 1a, a hydraulic control diagram of an electro-hydraulic transmission control device 1 is shown schematically, which is provided for driving a non-illustrated and designed as an automatic transmission. In the automatic transmission, according to the shift logic shown in FIG. 1b, six translations "1", "2", "3", "4", "5", "6" for forward travel and a "R" gear ratio for reverse travel are respectively closed - And switching off five switching elements A, B, C, D and E representable, wherein the respective translation to be inserted both as a function of a generated via a selector slide 2 driver command specification and depending on various stored in a likewise not shown electrical transmission control switching strategies.

The selector slide 2 is in various selector lever positions "Pos D", "Pos P", "Pos N", "Pos R" adjustable, wherein in a selector lever position "Pos D" the translations "1" to "6" for forward drive in the automatic transmission In a second selector lever position "Pos N", a force flow of a drive train of a vehicle in the area of the automatic transmission is interrupted in such a way that essentially no torque can be transmitted from the output in the direction of the prime mover or in the opposite direction via the automatic transmission. In a third selector lever position "Pos R" in the automatic transmission, the translation "R" is engaged for reversing, while in a fourth selector lever position not shown "Pos P" a mechanical parking brake is engaged, bringing the output of a vehicle in a conventional manner is held against rotation.

In addition, a hydraulic pump 3 is provided, by means of which, in a manner known per se, in connection with a system pressure valve 4 arranged downstream of the hydraulic pump, which is designed as a pressure limiting valve, a system pressure p_sys required for controlling the switching elements A to E can be made available.

Furthermore, the electro-hydraulic transmission control device 1 comprises a plurality of pressure control valves 5, A1, B1, C1, D1 and E1, which are electrically controlled via the electric transmission control device, are opened or closed according to their execution in the energized state, and one each a switching element A, B, C. , D, E is assigned. In this case, the pressure control valve 5, by means of which the system pressure p_sys can be modulated with the transmission control device active, is fully opened in the de-energized state, so that the system pressure p_sys becomes maximum. In the energized state of the pressure control valve 5, the system pressure p_sys is set as a function of the electrical activation by the pressure control valve 5 as a function of a control specification of the electrical transmission control device. In addition, several switching valves A2, D2A, D2 B ₁ E2, SV_1, SV_2 and SV_3 and several pressure control venti Ie A3, B3, C3, D3A, D3B and E3 are provided.

Downstream of the system pressure valve 4, a reducing valve 6 designed as a pressure reducing valve is provided, via which a reducing pressure p_red which can be fed to the pressure control valves 5, A1, B1, C1, D1, E1 is regulated. The respectively applied to the pressure control valves 5, AI ₁ BI ₁ CI ₁ D1 and E1 control pressure p_red is converted with active transmission control device in response to the energization of the pressure control valves 5, AI ₁ BI ₁ CI ₁ DI ₁ E1 corresponding to the system pressure valve 4, the switching valves and the Pressure control valves of the electro-hydraulic transmission control device 1 as so-called pilot pressure p_VS out, wherein each provided for a switching element A to E pilot pressure p_VS is in each case extended by the designation of the corresponding switching element A to E. For example, the control pressure p_VS_A is the pilot pressure for the switching element A.

In addition, the electro-hydraulic transmission control device 1 comprises so-called OR valves 7 and 8, each having two outgoing and one outgoing line, wherein each of the incoming line is connected to the outgoing line via the OR valve 7 and 8, respectively, in which the higher hydraulic pressure is present , In addition, downstream of the reducing valve 6 between the Reduzierventil 6 and a pressure medium reservoir or an oil sump 10 of the automatic transmission designed as a plate valve pressure relief valve 9 is arranged by means of which in the hydraulic system of the electro-hydraulic transmission control device 1, a so-called Vorbefülldruck, preferably in the range of 0, 25 bar, is maintained in order to prevent the entry of air into the hydraulic line system of the electro-hydraulic transmission control device 1.

Depending on a selector lever position of the selector slide 2 engaged by the driver, the pressure control valves 5, AI ₁ BI ₁ CI, D1 and E1 as well as the switching elements A to E are activated in the switching logic shown in tabular form in FIG. 1b, the number 0 each indicating an inactive state of the relevant component and the number 1 each represents an active state of the relevant component in the switching logic. Thus, for example, when requested first gear ratio "1", the pressure control valve A1, which is in the energized state, ie with active transmission control device, open and in response to the energization of the voltage applied by the reducing 6 control pressure p_red in a correspondingly changed form to the only two switching positions having switching valve A2 and the pressure control valve A3 of the switching element A forwards.

In this case, the pressure control valve A1 is energized such that the switching valve A2 and the pressure control valve A3 are each acted upon by a pilot pressure p_VS__A and at the pressure control venti I A3 via the selector slide 2 pending system pressure p_sys in the required manner to the switching element A as control pressure p_A is performed.

At the same time, the pressure control valve D1, which is likewise open in the energized state, is electrically actuated by the transmission control device in the extent required for the connection of the switching element D, so that the control pressure p_red is adapted to the required pilot pressure p_VS_D and the switching valves D2A, D2B and the pressure control valves D3A, D3B are controlled with the pilot pressure p_VS_D. This activation, in turn, causes the system pressure p_sys, which is applied to the pressure regulating valve D2A via the switching valve SV_3, to act as the control pressure p_D of the switching element D at the height required for the switching element D to be connected.

Furthermore, in the switching logic fields labeled with the sign "+/-", this sign each represents a control phase of the so marked component of the electro-hydraulic transmission control device 1 with active transmission control device, which is why such marked components not like the other elements exactly a specific switching logic can be assigned are. The various ratios "1" to "6" for forward drive and the translation "R" for reverse drive are each inserted by two simultaneously switched into the Kraftfiuss the transmission switching elements in the automatic transmission, the translations "1" to "3" a first gear range and the translation "R" for reversing is presently assigned as a single translation to a third translation area.

In addition, it is apparent from the switching logic that the representation of the translations "1" to "3" of the first gear ratio in each case the switching element A is switched in conjunction with the switching element D _1, the switching element C or the switching element B in the Kraftfiuss of the transmission while the switching element E for displaying the translations "4" to "6" of the second transmission range in conjunction with a respective other switching element A, B or C is switched into the Kraftfiuss. The translation "R" is presently inserted by the simultaneously switched switching elements B and D in the transmission.

It also follows that the switching element B is used both for the representation of the third translation "3" of the first gear ratio and the fifth gear ratio "5" of the second gear range and in addition to the representation of the translation "R" for reverse drive.

In the event of an error in the transmission control device, the transmission control-side energization of the pressure control valves 5 and A1 to E1 is interrupted so that the pressure control valves A1, C1, D1 and E1 are closed while the pressure control valves 5 and B1 are fully opened. As a result, the system pressure valve 4 is supplied with the maximum pilot pressure p_VS_5 of the pressure control valve 5 and the system pressure p_sys assumes a maximum value. At the same time, that too Switching element B associated pressure control venti I B3 with the full pilot pressure ρ_VS_B of the pressure control valve B1 is applied, so that the pressure control valve B3 is switched and the switching element B with its full switching pressure p_A, which corresponds to the system pressure p_sys in this operating state of the electro-hydraulic transmission control device 1, is applied, and is switched in accordance with the prevailing at the time of failure of the transmission control device operating state of the electro-hydraulic transmission control device in the force foot of the automatic transmission or remains switched on in this.

This emergency operating strategy is based on the fact that, due to the above-described shift strategy, the shift element B is predefined as a so-called emergency shift element, which is in each case switched into the power flow of the automatic transmission in order to display various emergency ratios "3", "5", "R" Each of the three translation areas is associated with an emergency gear ratio, wherein the first gear ratio associated emergency gear ratio of the third forward gear or the third translation "3", the switching element B and the switching element A are switched simultaneously in the power flow of the automatic transmission corresponds to the representation.

Furthermore, the fifth transmission ratio is assigned the fifth transmission ratio "5" as the emergency transmission ratio, to the representation of which the emergency gear shift element B and the shifting element E are to be engaged simultaneously in the power flow of the automatic transmission.

If the electric transmission control device fails when the reverse gear is engaged, the automatic transmission is left in the operating state of the automatic transmission prevailing at the time of the failure of the electric transmission control device, with the transmission ratio "R" for Reverse drive at the same time in the power flow zuzuschaltende switching elements B and D are acted upon directly from the system pressure valve 4 or via the selector slide 2 with the system pressure p_sys.

When the transmission control device is active, the shifting elements A to E are actuated via the pressure control valves A1 to E1 that can be actuated electrically by the transmission control device. Since the pressure control valves A1 to E1 with deactivated or inactive transmission control device are no longer electrically controllable, and the switching elements A, C, D and E via their associated pressure control valves A1, C1, D1, E1 no longer with the p_sys for applying the applied system pressure required pilot pressure p_VS_A, p_VS_C, p_VS_D or p_VS_E in the extent necessary for the connection are provided with inactive transmission control other controls depending on the control pressure p_B of the switching element or the emergency switching element B and present at the time of failure of the transmission control operating state of the automatic transmission ,

To implement a hydraulic emergency concept, the shift valves SV_1 and SV_2 which are not actively involved in the control of the automatic transmission when the transmission control device is active are provided, wherein the shift valve SV_1 is referred to below as the selector switch valve and the shift valve SV_2 as the emergency shift valve.

The emergency gearshift valve SV_2 is acted upon with active transmission control device in the region of an end face of its valve spool 11 in such a way with the pilot pressures p_VS_A, p_VS_D and p_VS_E that the emergency gearshift valve SV_2 is held over all operating ranges of the automatic transmission against a spring device 12 in the position shown in Fig. 1a, the corresponds to a first switching position and in which a connection tion 13 between a control line 14 of the emergency gear shift element B and the selection switching valve SV_1 is blocked in the area of the emergency gearshift valve SV_2.

Of course, it is at the discretion of the skilled person the emergency gear valve SV_2 during normal driving in response to another pressure signal, such as the pilot pressure p_VS_5 of the pressure control valve 5, by means of which the system pressure p_sys is modulated to hold in the switching position shown in Fig. 1a.

Inactive electrical transmission control device, the end face of the valve spool 11 of the emergency gearshift valve SV_2 is not supplied with the pilot pressures p_VS_A, p_VS_D or ρ_VS_E, so that the valve spool 11 is shifted from the spring means 12 from the position shown in Fig. 1 a in its second switching position and the Connecting line 13 is unlocked in the area of Notgangschaltventils SV_2. So that the control pressure p_B, which essentially corresponds to the system p_sys when the transmission control device is inactive, is forwarded in the direction of the selector switch valve SV_1. In the area of the selection switching valve SV_1, the further switching element A, E, D to be connected in addition to the emergency switching element B, in each case to represent a particular emergency transmission ratio "3", "5", "R", is selected as a function of a current operating state of the automatic transmission.

The selector switch valve SV_1 is located in the position shown in Fig. 1a in its by the applied control pressure p_E of the switching element E against a spring device 15 switched second switching position, in which the inactive transmission control device via the connecting line 13 applied control pressure p_B the emergency switching element B on an additional piston 16 of the pressure control valve E3 is performed. This causes the Zusatzschaltkolbeπ 16 of the pressure control valve E3 on the valve spool 17 of Druckregelventifs E3 comes to rest and the pressure control valve E3 is switched such that the voltage applied via a line 18 system pressure ρ_sys is guided as the control pressure pJΞ in the direction of Schaltelermentes E.

Characterized in that the end face of a valve spool 19 of the selector switch valve SV_1 with the control pressure pJΞ of the switching element E is acted upon is the Auswahlschaltventii SVJ at all translations "4", "5", "6" of the second translation range in the in Fig. 1 a In the event of a failure of the transmission control device, the control pressure p_J3 of the emergency transmission element B applied to the selection control valve SV_1 is then directed via the emergency transmission valve SV_2 to the pressure control valve E3 of the switching element E. This results in the system pressure p_sys applied to the pressure control valve E3 via the line 18 the switching element E is supplied as a control pressure p_E and the switching element E in addition to the emergency switching element B for displaying the second gear ratio associated emergency gear ratio "5" is switched into the power flow of the automatic transmission.

In this case, the control circuit of the switching element E is a so-called hydraulic Merkspeicher, since the control circuit of the switching element E is formed with respect to the driving pressure p_E with such inertia that the driving pressure p_E of the switching element E in case of failure of the transmission control device in an operating state of the automatic transmission in which one of the ratios "4" to "6" associated with the second gear range is engaged in the transmission, as long as it is above a pressure value holding the selector switch valve SV_1 ύef shown in Fig. 1a and in the transmission in the event of a failure of the transmission control unit Direction of the second gear ratio associated emergency gear ratio "5" is inserted.

If the electric transmission control device fails in an operating state of the automatic transmission in which one of the ratios "1" to "3" of the first transmission range in the automatic transmission is engaged, the selector switch valve SV_1 is in its first switching position, in which the valve spool 19 of the selector switch valve SV_1 ^~ mlt his acted upon by the control pressure p_E face completely abuts the housing of the selector switch valve SVJ. Then, when the transmission control device is inactive, the control pressure p_J3 of the emergency transmission switching element B, which is switched through via the connecting line 13 and the emergency transmission switching valve SV_2, is directed to the pressure control valve A3 of the switching element A. In this case, an auxiliary switching piston 20 of the pressure control valve A3 is acted upon on a valve spool 21 facing away from the control pressure p_B the emergency switching element B and switched such that the switching element A is applied via line 18 to the system pressure p_sys as control pressure p_A and together with the switching element B. for displaying the emergency transmission ratio "3" assigned to the first transmission range, is switched into the power flow of the automatic transmission.

The design of the pressure control valves A3 and E3 with the additional switching piston 16 or 20 makes it possible for the interactions on the operation of the pressure control valve to be as low as possible during normal operation of the electrohydraulic transmission control device 1, in which the transmission control device is active are. The additional switching piston 16 and 20 of the pressure control valves E3 and A3 take over only when the transmission control device inactive, the control function of the pressure control valves A1 and E1, since failing inactive transmission control device whose control signals. The valve spool 21 and the auxiliary switching piston 20 of the pressure control valve A3 and the auxiliary switching piston 16 and the valve spool 17 of the pressure control valve E3 each delimit a control chamber 22 and 23, which are each acted upon by the pilot pressure p_VS_A or p_VS_E of the corresponding switching element A or E, wherein in each case on the control chamber 22 and 23 facing away from the associated auxiliary switching piston 20 and 16, a further control chamber 24 or 25 is provided, the inactive transmission control device with the control pressure p_B the emergency switching element B in the manner described above for the emergency control of the switching element A and E are acted upon.

Of course, it is at the discretion of the skilled person to pressurize the pressure control valve A3 and / or the pressure control valve E3 in Notschaltbetrieb instead of the control pressure p_B the emergency switching element B with the pilot pressure p_VS_B the emergency transmission element B and turn on in the manner described above in the power flow of the transmission ,

In Fig. 2a is a hydraulic control diagram of a second embodiment of an electro-hydraulic transmission control device according to the invention is shown, which is coupled to an electric selector lever and which is operated with active transmission control device according to the switching logic shown in Fig. 2b. The control scheme differs from the control scheme shown in Fig. 1 a only in partial areas, which is why in the following description is essentially discussed in more detail the differences.

The control diagram of the electro-hydraulic transmission control device 1 shown in FIG. 2a is provided with a so-called parking brake valve 26 and a parking lock actuator 27 designed as an electromagnetic valve executed, which are provided in a conventional manner for driving a mechanical parking brake device.

In addition, the electro-hydraulic transmission control device 1 according to FIG. 2a is designed with a position valve 28 which can be acted upon by a pilot control pressure p_VS_29 of a solenoid valve 29 that can be controlled by the transmission control device. The positional valve 28 is arranged downstream of the system pressure valve 4, wherein the system pressure p_sys in the switching position of the positional valve 28 shown in FIG. 2a can be guided via the positional valve 28 in the direction of the pressure control valves A3, B3 and E3. The pressure control valves C3 and D3A or D3B are connected directly to the system pressure valve 4 and thus acted upon independently of the switching position of the position valve 28 to the system pressure p_sys.

In the normal operating state of the electric transmission control device in which the pressure control valves 5 and A1 to E1 and the solenoid valve 29 are electrically controlled by the transmission control device, the solenoid valve 29 is on all operating states of the automatic transmission to the operating state of the automatic transmission, in which the electric selector lever in position "Pos P" is adjusted, energized, so that at least one main switching piston 30 of the positional valve 28, which is spring-loaded by a spring means 31 in the direction of a Zusatzschaltkolbens 32 of the positional valve 28, by the pilot pressure p_VS_29 of the solenoid valve 29 in the switching position shown in Fig. 2a held.

At the same time the emergency gearshift valve SV_2 is held against the spring device 12 in its first switching position by the pilot pressure p_VS_29 of the solenoid valve 29 when the transmission control device is active, whereby the connecting line 13 between the control line 14 of the emergency gang switching element B and the selector switch valve SV_1 in the region of Emergency switching valve SV2 is locked. Thus, the pressure signal or the pilot pressure p_VS_29 of the solenoid valve 29 in normal operation of the electro-hydraulic transmission control device 1 according to FIG. 2a replaces the pressure signals of the pressure control valves A1, D1 and E1 of the electrohydraulic transmission control device 1 according to FIG. 1a for the emergency gearshift valve SV_2 over almost all operating states of the automatic transmission.

In case of failure of the transmission control device, the solenoid valve 29 is de-energized and closed, so that the pilot pressure p_VS_29 of the solenoid valve 29 drops substantially to zero and that the notgangschaltelementseitigen blocking the connecting line 13 required pressure signal is eliminated. In this operating state of the solenoid valve 29, the emergency gearshift valve SV_2 is switched in the manner described above by the spring device 12 in its second switching position and the voltage applied via the connecting line 13 control pressure p_B is guided via the connecting line 13 and the emergency gearshift valve SV_2 to the selector switch valve SVJ.

The selector switch valve SV_1 is in dependence on a present at the time of failure of the transmission control device operating state of the automatic transmission either in the second switching position shown in Fig. 2a or in its first switching position. In the second switching position of the selector switch valve SV_1 the switched through the Notgangschaltventil SV_2 control pressure p_B of the switching element B or the emergency switching element B is forwarded in the direction of the pressure control valve E3 of the switching element E, which in turn leads to such a switching of the pressure control valve E3 of the switching element E that the Switching element E with the system pressure p_sys, which is maximum due to the normally open pressure control valve 5, is acted upon. In the first switching position of the selector switch valve SV_1, the pressure control valve A3 of the switching element A in the manner described in more detail with reference to FIG. 1 a is applied to the control pressure p_B of the emergency switching element B.

The system pressure p_sys is also carried out in the direction of the switching elements A, B and E when the solenoid valve 29 is de-energized because the auxiliary switching piston 32 of the positional valve 28 is remote from the main switching piston 30 as a function of the operating state of the automatic transmission present at the time of failure of the transmission control device End face either with the control pressure p_A of the switching element A or the control pressure p_E of the switching element E via the designed as a ball valve valve 33 and also executed as a ball valve Orventil 34 is acted upon so that the main switching piston 30 in the switching position shown in Fig. 2a against Spring device 31 is held.

In the electro-hydraulic transmission control device 1 according to FIG. 1a, in contrast to the transmission control device according to FIG. 2a, a third transmission range with a further emergency transmission ratio is included in the emergency transmission concept, wherein the third transmission range comprises the ratio "R" for reversing and the third transmission ratio third gear ratio associated emergency gear ratio "R" corresponds to the reverse gear, in which the gear shift element B and the switching element D are simultaneously switched into the power flow of the automatic transmission, while the other switching elements A, C and E are turned off so that there is essentially no Torque is feasible.

The translation "R" for reversing is thus represented by simultaneous connection of the emergency gear shift element B and the switching element D referred to below as the reverse drive shift element, the emergency gear shift element B and the reverse gear shift element D being active Transmission control device via the respectively corresponding pressure control valves B1 and D1 or via these set pilot pressures p_VS_B or p_VS_E are switchable.

When the transmission control device is inactive, the pressure control valve D1 assigned to the reverse drive shift element D is closed, with which the pilot control pressure p_VS_D, which can be set via the pressure control valve D1, is at least approximately zero. For this reason, when the transmission ratio is inactive, the reverse gear shift element D is actuated to display the emergency transmission ratio "R" associated with the third transmission range via a pressure signal in the range of the shift valves D2A, D2B and the pressure control valves D3A, D3B switched by the selector slide 2 in the region of the emergency shift element SV_2, if the Selector slide 2 in a reverse position equivalent "Pos P" is folded. Then the system pressure p_sys applied by the system pressure valve 4 via the switching valve SV_3 to the pressure control valves D3A, D3B system pressure in the direction of the switching element D is forwarded.

The emergency switching element B is controlled in the manner described above via the normally open pressure control valve B1 and via the pressure control valve B3 with the required for the connection control pressure p_B, which essentially corresponds to the system pressure p_sys driven. Although the switching elements A and E are controlled in the manner described above in response to the switching position of the selector switch valve SV_1, but the system pressure p_sys at the selector lever position "Pos P" is not applied to these switching elements, which is why a switching of the switching elements A and E is omitted.

The emergency gearshift valve SV_2 is at active transmission control device and with engaged translation "R" for reverse drive in response to the pilot pressure p_VS_D of the reverse gear shift element D or al- ternatively thereto in response to a signal from the selector lever 2 outgoing pressure signal in its first switching position in which the connecting line 13 is locked in the area of the Notgangschaltventils SV_2 held.

The above-described and feasible with the electro-hydraulic transmission control device 1 according to Fig. 1a emergency switching concept for the range of translation for forward drive and the gear range for reversing has the advantage that the switching elements A and ETwelche to display the emergency transmissions "3" and "5" of the two translation areas for forward drive be switched in each case in combination with the emergency switching element B in the power flow, inactive transmission control device only at a forward travel equivalent position of the selector lever 2 with the required for the connection control pressure p_A or p_E be applied and the reverse drive D ₁ which for displaying the third Translation ratio associated emergency gear ratio "R" in combination with the emergency gear shift element B is switched into the power flow, only in a reverse drive equivalent position of the selector slide 2 m it is applied to the required for the connection control pressure p_D. In order for a faulty control of the switching elements A, B, D and E in the emergency switching operation of the electro-hydraulic transmission control device 1 according to FIG. 1a is effectively and easily and inexpensively avoided.

Basically, in both illustrated in the drawings embodiments of the transmission control devices is a change from the emergency gear ratio "5" of the second transmission range, which includes the translations "4" to "6", which are provided to implement higher vehicle speeds, in the first gear ratio associated emergency transmission "3", which in turn includes the translations "1" to "3" loaded at lower vehicle speeds, only by one Switching the selection switching valve SV_1 of its second switching position in its first switching position possible.

Switching the selection scarf valve SV__1 is both in the transmission control device according to Fig. 1a and in the transmission control device according to Fig. 2a in principle possible if the signal present at select switching valve SV_1 pressure signal of the switching element E is lowered such das§ ^~ switches the Auswahischaltventil SV_1 and Actuation pressure p_B of the switching element B of Auswahischaltventil SV_1 instead of the pressure control valve E3 of the switching element E in the direction of the pressure control valve A3 of the switching element A is performed, which ultimately leads to a loading of the switching element A with the required for the connection of the switching element A control pressure p_A.

The interruption of the pressure signal applied to the selection switching valve SV_1 can be accomplished, for example, by switching off the engine of the vehicle or by briefly switching the selector slide to the neutral position "Pos N", the selector switching valve SV_1 being switched over by its spring device 15 if the pressure signal is absent.

In addition, however, there is also the possibility that the Auswahischaltventil SV_1 is formed in a non-illustrated further advantageous embodiment with a hydraulic or mechanical latching, which is actively reset via the selector slide 2 by moving the selector slide in the position "Pos R" for reverse and after shifting the selector switch valve SV_1 into its initial position, the lower emergency transmission ratio "3" in the automatic transmission is established. The additional switching piston 16 and 20 of the pressure control venti Ie E3 and A3 are stepped executable to the variation of the diameter of the auxiliary switching piston 16 and 20 to the respectively switched switching elements A or E respectively applied control pressure to the corresponding emergency transmission "initial" or ""5" to adapt. This is necessary in order to keep the component loads of the shift elements A and E in emergency operation of the electrohydraulic transmission control device 1 as low as possible and the connection of the emergency gear ratios "3" and "5" by ejrf§ corresponding slip phase of the switching elements A and E to soften during the connection phase. This procedure results from the knowledge that due to the forces acting during the emergency shift dynamic forces caused, for example, by the change in the ratio in the transmission speed changes, components of the automatic transmission can be charged in an inadmissible manner.

FIG. 3 shows the course of the triggering pressure p_B of the emergency shift shift element B in comparison to the courses of the triggering pressures p_A and p_E of the shift elements A and E when the transmission control device is inactive. On the basis of the graphical comparison of the switching pressures p_A, p_B, p_E of the switching elements A, B and E it can be seen that the emergency switching element B is acted upon at the end of its connection with the full system pressure p_sys. The switching elements A and E are acted upon switched state each with a relation to the system pressure p_sys reduced switching pressure, which results from the set on the auxiliary switching piston 16 and 20 area ratio. This simple structural measure has the advantage that the switching elements A and E initially transition to the time T_1 shown in FIG. 3 in a slip mode which ends at a time T_2. This compared to normal driving long slipping Operation of the switching elements A and E leads to a harmonious and low-load connection of the switching elements A and E ₁ whereby damage to components of the automatic transmission can be avoided in a simple manner.

Bezuαszeichen

1 electrohydraulic transmission control device 1

2 selector slide

3 hydraulic pump

4 system pressure valve

5 pressure control valve

6 reducing valve

7 Oder valve

8 Oder valve

9 pressure relief valve

10 oil sump

11 Valve spool of the emergency gearshift valve

12 Spring device of the emergency gearshift valve

13 connection line

14 control line

15 spring device of the selector valve

16 additional switching piston of the pressure control valve E3

17 Valve slide of the pressure control valve E3

18 line

19 Valve spool of the selector valve

20 additional switching piston of the pressure control valve A3

21 Valve slide of the pressure control valve A3

22 Control chamber of the pressure control valve A3

23 Control chamber of the pressure control valve E3

24 further control chamber of the pressure control valve A3

25 further control chamber of the pressure control valve E3

26 parking lock valve

27 Parking lock actuator 28 position valve

29 solenoid valve

30 main switching piston of the position valve

31 Spring device of the position valve

32 additional switching piston of the position valve

33 Oder valve

34 Oder valve

A1, B1, C1, D1, E1 pressure control valve

A2, D2A, D2B, E2 switching valve

A3, B3, C3, D3A, D3B, E3 pressure control valve

SV_1 selector switch valve

SV_2 Emergency switching valve

SV_3 Control valve p_red Control pressure p_VS_A to p_VS_E Pilot pressure p_VS_5 Pilot pressure p_A to p_E Control pressure p_sys System pressure

A to E switching element

"1" to "6" translation for forward drive

"R" translation for reverse

"Pos D", "Pos N", selector lever position

"Pos R", "Pos P" selector lever position

Claims

Patent claims

1. Electrohydraulic transmission control device (1) with an electrical transmission control device and with a plurality of electrically controllable by the transmission control pressure control valves (5, A1, B1, C1, D1, E1) and more in response to the control of the pressure control valves (5, A1 to E1) each with a hydraulic pilot pressure (p_VS_A, p_VS ^' _B, p_VS_C, p_VS_D, p_VS__E) acted upon pressure control valves (A3, B3, C3, D3A, D3B, E3) and switching valves (A2, D2A, D2B, E2), by means of which switching elements (A, B ₁ C ₁ D, E) of a transmission with the respectively required for displaying a requested operating state of the transmission control pressure (p_A, p_B, p_C, p_D, p_E) can be controlled, the pressure control valves (A3 to E3) and the switching valves (A2 to E2 ) with inactive transmission control device via the then normally switched pressure control valves (5, A1 to E1), each of which is associated with a switching element (A to E), so with hydraulic m pressure can be acted upon, that in the presence of an operating condition of the transmission, to which in the transmission a transmission range of the transmission associated translation ("1";"2";"3";"4";"5";"6","R") is engaged via at least two switching elements (A, D; A, C; A, B; A, E; B, E; C, E; B, D) simultaneously connected in the power flow of the transmission an emergency transmission ratio ("3";"5.") predefined and associated with at least one translation ("1";"2";"3";"4";"5";"6";"R") of the transmission; ";" R ") is represented by at least two simultaneously connected in the power flow switching elements (A, B; B ₁ E; B, D), wherein an emergency gearshift valve (SV__2) is provided, which is in activated gearbox control device in its first switching position in which the respective switching elements (A to E) to be switched into the power flow in order to represent a requested operating state of the automatic transmission can be correspondingly engaged, and which in a transmission control device is deactivated second switching position is located in which the switching means (A, B, B, E, B, D) to be switched to represent the respective emergency ratio ("3", "5", "R") associated with the transmission range with the required control pressure (p_A , p_B, p_D, p_E), and wherein a selection switching valve (SV_1) is provided, which interacts with the emergency gearshift valve (SV_2) such that the emergency transmission ratio ("3", "5", "R") assigned to the transmission range is engaged becomes.

2. Electrohydraulic transmission control device according .Anspruch 1, characterized in that the different translations ("1" to "6") of the transmission for forward travel are divided into at least two translation ranges, wherein one of the switching elements (B) is provided as an emergency gang switching element, which is provided both for the representation of at least one translation ("3") of the first translation region and for the representation of at least one translation ("5") of the second translation region and which can be represented by the emergency switching element (B) translations ("3" or " 5 ") are each the translation areas associated emergency translations.

3. Electrohydraulic transmission control device according to claim 2, characterized in that at the pressure control valve (B1), which is the emergency gear shift element (B) associated, applied hydraulic control pressure (p_red) with inactive transmission control device in function of the functional design of the pressure control valve (B1) accordingly adapted height as pilot pressure (p_VS_B) in the direction of the emergency gear shift element (B) associated pressure control valve (B3) is feasible.

4. Electrohydraulic transmission control device according to claim 3, characterized in that the other switching elements (A ₁ C to E) associated pressure control valves (A1, C1 to E1) at inactive Transmission control device are closed and the respective these other pressure control valves (A1, C1 to E1) associated switching valves (A2 to E2) of each of the pressure control valves (A1, C1 to E1) adjacent the control pressure (p_red) are separated.

5. Electrohydraulic transmission control device according to one of claims 1 to 4, characterized in that the emergency gearshift valve (SV_2) with active transmission control each of the pilot pressure (p_VS_A, p_VS_D, p_VS_E) of a pressure control valve (A1, D1, E1), which a Representation of a requested operating state of the transmission in the power flow switched switching element (A ₁ D, E) is assigned, against a on the valve spool (11) acting spring device (12) in its first switching position is durable.

6. Electrohydraulic transmission control device according to one of claims 1 to 5, characterized in that the emergency gearshift valve (SV_2) with active transmission control device via a permanently energized solenoid valve (29) against a on the valve spool (11) acting spring means (12) with a pressure signal ( p_VS_29) of the solenoid valve (29) acted upon and is durable in its first switching position.

7. Electrohydraulic transmission control device according to one of claims 1 to 6, characterized in that the emergency gearshift valve (SV_2) with active transmission control device via repeatedly used and inactive transmission control device closed pressure control valves (D1, E1) against a on the valve spool (11) acting spring device ( 12) is acted upon by a pressure signal and is durable in its first switching position, wherein the pressure control valves (D1, E1) via at least one OR valve (8) can be brought into operative connection with the emergency gearshift valve (SV_2).

8. Electrohydraulic transmission control device according to one of claims 1 to 7, characterized in that the emergency gearshift valve is acted upon by an inactive transmission control valve closed pressure control valve against a spring valve acting on the spring device with a pressure signal and durable in its first switching position, wherein a System pressure in response to the pilot pressure of the pressure control valve is modulated.

9. Electro-hydraulic transmission control device according to one of claims 6 to 8, characterized in that the emergency gearshift valve (SV_2) with inactive transmission control device of the spring means (12) is switchable to its second switching position.

10. Electrohydraulic transmission control device according to one of claims 5 to 9, characterized in that a connecting line (13) between the selector switch valve (SV_1) and one between the pressure control valve (B3) of the emergency gear shift element (B) and the emergency gear shift element (B) in the first shift position of the emergency gearshift valve (SV_2) is disabled.

11. Electrohydraulic transmission control device according to claim 10, characterized in that the connecting line (13) is unlocked in the second switching position of the emergency gearshift valve (SV_2) and the control pressure (p_B) of the emergency gearshift element (B) in response to a switching position of the selector valve (SV_1) respectively Direction of at least one pressure control valve (A3, E3) of one of the other switching elements (A; E) is feasible, so that the required for the representation of the selected depending on the current operating state of the transmission emergency transmission ("3", "5") switching elements (A, B ; A, E) are connected in the power flow of the transmission.

12. Electrohydraulic transmission control device according to one of claims 2 to 12, characterized in that all the translations ("1", "2", "3") of the first gear ratio via the same switching element (A) are shown, the pressure control valve (A3) at inactive Transmission control device via the selection switching valve (SV_1) with the control pressure (p_B) or the pilot pressure of the emergency gear shift element (B) can be acted upon, wherein the switching element (A) for displaying the translations ("1", "2", "3") of the first gear ratio to display the emergency transmission ratio ("3") associated with the ^" first transmission range" together with the emergency transmission element (B) in the power flow of the transmission.

13. Electro-hydraulic transmission control device according to one of claims 2 to 12, characterized in that all the translations ("4", "5", "6") of the second transmission range over the same switching element (E) are shown, the pressure control valve (E3) at inactive transmission control device via the selection switching valve (SV_1) in such a way with the control pressure (p_B) or the pilot pressure of the emergency gear shift element (B) can be acted upon, wherein the switching element (E) for displaying the translations ("4", "5", "6") of second translation range for displaying the second transmission range associated emergency gear ratio ("5") is switched together with the emergency switching element (B) in the power flow.

14. Electrohydraulic transmission control device according to claim 13, characterized in that the selector switch valve (SV_1) of the control pressure (p_E) opposite to the representation of the translations ("4", "5", "6") provided for the second gear shift element switching element (E) one on the valve spool (19) of the selector switch valve (SV_1) acting spring means (15) is acted upon and in response to a the resultant total force component acting on the valve slide (19) is switched into a first or a second switch position, wherein the control pressure (p_B) or the pilot pressure (p_VS_B) of the emergency shift element (B) in the first shift position of the selector switch valve (SVJ) on the pressure control valve ( A3) of the gearshifting element (A) provided for displaying the translations ("1", "2", "3") of the first gear ratio range and in the second switching position of the selector valve (SV_1) on the pressure regulating valve (E3) of the deTranslations (" 4 "," 5 "," 6 ") of the second transmission range provided switching element (E) is applied.

15. Electrohydraulic transmission control device according to claim 13 or 14, characterized in that the pressure regulating valve (A3) of the switching element (A) for displaying the translations ("1", "2", "3") of the first transmission range and / or the pressure control valve ( E3) of the switching element (E) for displaying the translations ("4", "5", "6") of the second transmission range with a valve spool (21, 17) and an auxiliary switching piston (16, 20) is executed, wherein the valve spool ( 21, 17) and the auxiliary switching piston (16, 20) are mutually displaceable and limit a common control chamber (22, 23), which is acted upon by the pilot pressure (p_VS_A, ρ_VS_E) of the switching element (A, E), and wherein on the the control chamber (22, 23) facing away from the auxiliary switching piston (16, 20), a further control chamber (24, 25) is provided, the inactive transmission control device with the control pressure (p_B) of the emergency gear shift element (B) can be acted upon.

16. An electro-hydraulic transmission control device according to claim 15, characterized in that the auxiliary switching piston (20) of the pressure control valve (A3) of the switching element (A) for displaying the translations ("1", "2", "3") of the first translation range and / or the additional piston (16) of the pressure regulating valve (E3) of the switching element (E) for displaying the Translations ("4", "5", "6") of the second translation area is stepped such that the height of the drive pressure (p_A, p_E) of the switching element (A) for displaying the translations ("1", "2", "3") of the first transmission range and / or the switching element (E) for displaying the translations ("4", "5", "6") of the second transmission range and / or a connection phase of one of the switching elements (A or E) at inactive Transmission control device of the height of the control pressure (p_A to p_E) and / or the connection phase of the switching elements (A or E) deviates with active transmission control device.

17. An electro-hydraulic transmission control device according to one of claims 1 to 16, characterized in that a third transmission range is provided for reversing, comprising at least one translation ("R).

18. Electrohydraulic transmission control device according to claim 17, characterized in that the translation ("R") for reversing also by switching the emergency gear shift element (B) and a reverse drive shift element (D) can be displayed, which corresponds to the third gear ratio associated emergency gear ratio.

19. Electrohydraulic transmission control device according to claim 18, characterized in that the emergency gear shift element (B) and the reverse drive shift element (D) with active transmission control means via the respectively corresponding pressure control valves (B1, D1) are switchable, wherein the reverse drive switching element (D) associated pressure control valve ( D1) is closed when the transmission control device is inactive and the pilot control pressure (p_VS_D) which can be set via the pressure control valve (D1) is at least approximately zero.

20. Electrohydraulic transmission control device according to claim 18 or 19, characterized in that the reverse drive shift element (D) is activated with an inactive transmission control device for displaying the third transmission range associated emergency transmission ("R") via a manual selector slide (2) through-connected pressure signal, if the selector slide (2) is in a position equivalent to reverse ("Pos R") is folded.

21. Electrohydraulic transmission control device according to claim 20, characterized in that the emergency gearshift valve (SV_2) with gear ratio ("R") for reverse drive and with active transmission control device in dependence on the pilot pressure (p_VS_D) of the reverse gear shift element (D) or one of the selector lever (2). outgoing pressure signal is held in its first switching position.

22. Electrohydraulic transmission control device according to one of claims 18 to 21, characterized in that the switching elements (A to E) ₁ which for representing the emergency gear ratios ("3", "5") of the two translation ranges for forward travel respectively in combination with the emergency gear shift element ( B) are switched into the power flow, at inactive transmission control device only at a forward travel equivalent position of the selector lever (2) with the required for the connection control pressure (p_A to p_E) are applied and the reverse drive switching element (D), which for displaying the third Transmission ratio associated emergency gear ratio ("R") in combination with the emergency gear shift element (B) is switched into the power flow, only at a reverse position equivalent position ("Pos R") of the selector lever (WS) with the required for the connection control pressure (p_D) is charged.

23. Electro-hydraulic transmission control device according to one of claims 2 to 22, characterized in that a change of the emergency gear ratio ("5") of the second transmission range, the translations ("4", "5", "6") includes, for the implementation higher vehicle speeds are provided, in the emergency gear ratio ("3") of the first gear ratio of the translations ("1", "2", "3"), which are engaged at lower vehicle speeds, by switching the selector valve (SV_1) of his second switching position takes place in its first switching position.