The invention relates to a device for actuating switching elements of a
Transmission device according to the im
Preamble of claim 1 further defined type.
From the DE 103 47 203 A1
is a motor vehicle drive train with a pump arrangement for supplying a coupling device with pressure medium and / or operating medium and / or for supplying a transmission with pressure medium and a corresponding pump assembly and a corresponding actuator assembly for the transmission actuation known.
Hydraulic system becomes the shift rod operation of a dual-clutch transmission
controlled, with the for
required hydraulic actuating pressure
is generated by a hydraulic pump. Between those provided for the shift rod operation
double-acting hydraulic cylinders and the pump device are
Switch valves provided by means of which piston chambers of the
double-acting hydraulic cylinder depending on different requested translations
be subjected to working pressure. There are next to one like that
called four-edge valve three so-called multiplex valves or
Distributor switching valves provided to that of the pump assembly
generated hydraulic pressure in the for providing a translation
in the dual-clutch transmission required height the piston chamber or the
the double-acting hydraulic cylinder in the for the shift rod operation too
to be able to.
However, it is that the double-acting hydraulic cylinder of the
known hydraulic system only via a volume flow control
are controlled by means of the height of a piston chamber of a
Dop pelt acting hydraulic cylinder supplied working pressure due
Leakage-related pressure losses only to an insufficient extent
is adjustable. However, this is especially in the range of
Switching elements of a transmission problematic, since this to reduce
the component loads during
the compensation of differential speeds with advantageous for the synchronization forces
The present invention is therefore based on the object, a device
Switching elements of a transmission device available
provide, by means of the operating forces depending on the operating condition and
are gentle on the components.
According to the invention this
Task with a device according to the features of claim
of switching elements of a transmission device in which each too
Switching element is associated with a double-acting hydraulic cylinder,
their piston chambers
Operating state dependent means
Valves can be acted upon by hydraulic working pressure is
at least one four-edge valve for adjusting the hydraulic
Working pressure provided. The four-edge valve is with one over one
Pressure regulator adjustable pilot pressure against a spring force
a spring device acted upon.
This is according to the invention
Four-edge valve designed as a pressure-variable pressure reducing valve, in which
the hydraulic working pressure set by the four-edge valve
for pressure control on an effective surface of a valve spool of
Four-edge valve is applied. The valve spool locks at pressure values of the
Working pressure greater than
the working pressure to be currently set by the four-edge valve is
Connection between a supply pressure and the supply pressure
standing supply control tongue and one with the piston chamber, the
to be provided with working pressure, related work control tongue
and connects the work control tongue to a relief control tongue.
In order to
is the working pressure of a piston chamber of a double-acting
Hydraulic cylinder to operate
fed to a switching element
is controlled in a simple manner adjustable so that
the force acting on the switching element actuating force is adjustable.
This means that one in the hydraulic path between the four-edge valve
and a piston space to be acted upon by the working pressure
double-acting hydraulic cylinder leakage is not present
Undefined decrease in working pressure leads, as these hydraulic
Losses due to pressure or force control in the area of the four-edge valve
is and the piston chamber of the hydraulic cylinder with the actually requested
Working pressure is applied.
Advantages and advantageous developments of the invention result
from the claims
and the principle described with reference to the drawing
1 a hydraulic diagram of a first embodiment of a device according to the invention for actuating switching elements of a transmission device;
2 a 1 corresponding representation of a second embodiment of a device according to the invention with two four-edge valves;
3 a partial view of a hydraulic scheme of a third embodiment of an inventively designed device in which each double-acting hydraulic cylinder in each case a four-edge valve is connected upstream and
4 Characteristics of the working pressures for a first piston chamber and a second piston chamber of a double-acting hydraulic cylinder as a function of the pilot pressure of a four-edge valve.
In 1 is a hydraulic schematic of a device 1 for actuating switching elements of a presently designed as a dual-clutch transmission device shown. The switching elements are in the in 1 illustrated embodiment designed as conventional synchronizers, by means of which speed differences between rotating shafts and over the synchronizers to be connected to the shafts gear pairs are compensated in a conventional manner.
Each of the switching elements to be actuated is presently a double-acting hydraulic cylinder 2 . 3 . 4 . 5 and 6 assigned to their piston chambers 2A . 2 B . 3A . 3B . 4A . 4B . 5A . 5B . 6A and 6B operating state dependent can be acted upon by valves with hydraulic working pressure. In this case, a four-edge valve is provided for adjusting the hydraulic working pressure p_A, with a pressure control valve designed as a proportional valve 8th adjustable pilot pressure p_VS_7 against a spring force of a spring device 9 can be acted upon.
The four-edge valve 7 is designed as a pressure variable pressure reducing valve, in which the four-edge valve 7 set hydraulic pressure for pressure control in each case on an effective surface of a valve spool 7_S of the four-edged valve 7 is applied. The valve spool 7_S locks at pressures of working pressure greater than that of the four-edge valve 7 currently to be set working pressure, the connection between a related to a system pressure p_sys supply control tongue 11A respectively. 11B and one with the piston chamber 2A respectively. 2 B . 3A respectively. 3B . 4A respectively. 4B . 5A respectively. 5B or 6A respectively. 6B worker to work pressure related work control tongue 12A . 12B and connects the work control tongue 12A respectively. 12B with a relief control tongue 13 ,
Downstream of the four-edge valve 7 are four switching valves 14 . 15 . 16 and 17 provided by means of which of the four-edge valve 7 set working pressure operating state-dependent to the piston chambers 2A to 6B the double-acting hydraulic cylinder 2 to 6 are feasible. Furthermore, the device comprises 1 another designed as a proportional valve pressure control valve 18 as well as three solenoid valves 19 . 20 and 21 , which are electrically actuated via the electrical transmission control device, are opened or closed according to their execution in the energized state and in each case a switching valve 14 to 17 are assigned to control the switching valves with an operating state-dependent variable pilot pressure p_VS_14, p_VS_16, p_VS_15 or p_VS_17. Upstream of the four-edge valve 7 is another switching valve 22 provided, via which the system pressure p_sys in the presence of a corresponding pilot pressure p_VS_22 in the direction of the four-edge valve 7 is passed through.
In another embodiment, the further switching valve 22 also downstream of the four-edge valve 7 be arranged.
At the pressure control valves 8th and 18 as well as on the solenoid valves 19 to 21 is a control pressure p_red, the active with the transmission control device in response to the energization of the pressure control valves 8th and 18 as well as the solenoid valves 19 to 21 accordingly changed the switching valves 14 to 17 , the four-edge valve 7 and a transfer case 23 be supplied. The latter transfer case 23 is provided for connecting a further drive axle of a vehicle, so that the vehicle can be operated depending on the driver with more than one drive axle in a conventional manner.
In addition, two designed as a plate valves pressure relief valves 24 and 25 provided by means of which in the hydraulic system of the device 1 a so-called Vorbefülldruck, for example, is in the range of 0.25 bar, maintained to the entry of air into the hydraulic line system of the device 1 to avoid.
The double-acting hydraulic cylinders 2 to 6 are basically identical and each with a piston 2C . 3C . 4C . 5C or 6C and an associated shift rod 2D . 3D . 4D . 5D or 6D executed, so that in dependence of in the piston spaces 2A and 2 B . 3A and 3B . 4A and 4B . 5A and 5B or 6A and 6B set working pressures hydraulic energy in a translational actuation movement for the shift rails 2D to 6D is convertible to the associated with the shift rails in a manner not shown manner Actuate switching elements accordingly.
In this case, it is provided that via the hydraulic cylinder 2 depending on the position of the piston 2C who in 1 is shown in its preferred neutral center position to engage either a sixth forward gear or a fourth forward gear. This is the piston 2C starting from its neutral center position, in which neither the sixth forward gear stage nor the fourth forward gear stage is engaged in the transmission device, to move to its first end position or in its second end position.
About the hydraulic cylinder 3 is either a reverse gear or a second forward gear in the same manner as in the hydraulic cylinder 2 by appropriate pressurization of the two piston chambers 3A and 3B inserted.
The hydraulic cylinder 4 is provided for engaging a first forward speed or a third forward speed, while by means of the hydraulic cylinder 5 a fifth forward gear or a seventh forward gear in the transmission device can be inserted. The hydraulic cylinder 6 is present for switching between a "high-range" and a "low-range" in the transfer case 23 intended.
In addition, the device is 1 at the in 1 illustrated embodiment with a transfer case shift valve 26 executed, by means of which a friction clutch, not shown, of the transfer case 23 is controllable with the control pressure required for the connection of the further drive axle.
2 shows a hydraulic diagram of a second embodiment of a device according to the invention 1 in which the switching valve 15 through another four-edge valve 27 is replaced. The additional four-edge valve 27 In the present case, the pressure control valve is designed as a proportional valve 28 with the for the operation of the hydraulic cylinder 3 required pilot pressure p_VS_27 driven. This means that in the execution of the device 1 according to 2 instead of the solenoid valve 20 the pressure control valve 28 is provided.
In 3 is a hydraulic diagram of a third embodiment of a device according to the invention 1 shown in which each hydraulic cylinder 2 to 6 exactly a four-edge valve 7 . 27 . 29 and 30 is associated with the executed as a proportional valves pressure control valves 8th . 28 . 33 . 34 . 36 be controlled with the respective required pilot pressure p_VS_7, p_VS_27, p_VS_29, p_VS_30 and p_VS_31. The valve spool 7_S of the four-edge valve 7 is shown in a first end position, in which the supply control tongue 11A with the work control tongue 12A connected while the supply control tongue 11B from the work control tongue 12B is disconnected and both the work control tongue 12A as well as the work control tongue 12B from the relief control tongue 13 are separated.
A valve spool 27_S of the four-edge valve 27 is in 3 shown in its middle position, in which both the supply control tongue 11A as well as the supply control tongue 11B from the corresponding work control tongue 12A respectively. 12B and in addition also from the relief control tongue 13 are separated.
For the sake of simplicity, both the transfer case 23 as well as the pressure relief valves 24 and 25 the hydraulic schemes according to 1 and 2 in 3 not shown. Of course, it is up to the professional who disposes of the device 1 according to in 3 controllable transmission device in the in 1 and 2 Coupled with the manner illustrated with a transfer case to operate a vehicle as a four-wheel drive vehicle.
This in 3 illustrated third embodiment of an inventive device executed 1 has in contrast to the embodiment according to 2 and also the first embodiment according to 1 the advantage on that the piston chambers 2A to 6B by means of the directly associated four-edge valves 7 . 27 . 29 . 30 and 31 with in comparison to the statements according to 1 and 2 Considerably shorter hydraulic supply lines are controlled, whereby hydraulic losses, which to Be impairments of the control of the hydraulic cylinder 2 to 6 lead, be reduced in a simple manner.
Furthermore, with the device 1 according to 3 much shorter switching times feasible, since the switching valves 14 to 17 the device according to 1 or the switching valves 14 . 16 and 17 the device 1 according to 2 when reversing the valve slide from one end position to the other end position have a certain dead time, which adversely affect the switching time, especially in multiple circuits in the transmission.
4 shows the course of the working pressure p_A_2A and the course of the working pressure p_A_2B above the pilot pressure p_VS_7 of the four-edge valve 7 , based on which the operation of the four-edge valve 7 will be described in more detail below. At this point it should be noted that all shown in the drawing Four-edge valves essentially have an identical structure and that the four-edge valves in each case the same nachbeschriebene principle of action is based, so the principle of action only based on the hydraulic cylinder 2 and the corresponding in the drawing or cooperating four-edge valve 7 is described.
From the illustration according to 4 shows that the four-edge valve 7 has two control ranges R1 and R2, wherein the first control range R1 for adjusting the working pressure p_A_2A of the first piston chamber 2A of the double-acting hydraulic cylinder 2 and the second control region R2 for adjusting the working pressure p_A_2B of the second piston chamber 2 B of the double-acting hydraulic cylinder 2 is provided. Furthermore, a so-called base point region FP is provided between the two control regions R1 and R2, which has a pressure range of the pilot pressure p_VS_7 of the four-edge valve 7 represents, within the neither the first piston chamber 2A still the second piston chamber 2 B of the double-acting hydraulic cylinder 2 with working pressure p_A_2A, p_A_2B is applied.
The working pressure p_A_2A has its maximum value p_A_2A_max when the pilot pressure p_VS_7 assumes a value p_VS_7 (1), to which the valve spool 7_S of the four-edged valve 7 from the spring device 9 of the four-edged valve 7 completely in his in 3 shown first end position is shifted, so that the connection between the supply control edge 11A and the one with the piston chamber 2A connected working control edge 12A is completely open.
Starting from the pressure value p_VS_7 (1) of the pilot pressure p_VS_7, the working pressure p_A_2A of the piston chamber increases 2A of the hydraulic cylinder 2 with increasing pressure values over the first control range R1 proportional to the pilot pressure p_VS_7, and has a pressure value p_VS_7 (2) substantially a pressure of zero bar, wherein the working pressure p_A_2A of the piston chamber 2A remains at this level with further increasing pressure values of the pilot pressure p_VS_7.
The working pressure p_A_2B is set substantially to zero bar both during the first control range R1 and during the base point range FP up to the start of the second control range R2, which extends between pressure values p_VS_7 (3) and p_VS_7 (4). In the base area FP is the four-edge valve 7 or its valve slide 7_S in the neutral position, in which the four-edge valve 7 applied system pressure p_sys not in the direction of the hydraulic cylinder 2 is forwarded.
Upon reaching the pressure value p_VS_7 (3) of the pilot pressure p_VS_7 of the four-edge valve 7 becomes the valve spool 7_S increasingly in its second end position, in which the spring device 9 of the four-edge valve 7 fully pressurized, shifted, with increasing pressure values of the pilot pressure p_VS_7 the working pressure p_A_2B increases in the direction of a maximum pressure value p_A_2B_max, with the pressure value p_VS_7 (4), to which the connection between the supply control edge 11B and the working-control edge 12B from the valve spool 7_S is completely released, corresponds.
From the illustration according to 4 shows that the pressure value p_A_2B_max of the working pressure p_A_2B of the second piston chamber 2 B greater than the maximum working pressure p_A_2A_max of the first piston chamber 2A is. This results from the fact that the second piston chamber 2 B facing end face of the piston 2C opposite to the first piston chamber 2A facing end face to that of the piston rod 2D claimed active area is reduced, so that the piston 2C of the hydraulic cylinder 2 both starting from the first piston chamber 2A as well as from the second piston chamber 2 B each with the same force is controlled.
Of course, it is up to the expert, the piston 2C starting from the piston chamber 2A or from the piston chamber 2 B with different degrees of force to control, for example, when engaging a switching element or a synchronization or when disengaging the synchronization to provide different sized actuating forces available.
In addition to the precontrol of the working pressures p_A_2A, p_A_2B of the piston chambers 2A . 2 B via the pilot pressure p_VS_7 an automatic pressure control is provided, which on the feedback of the working pressure p_A_2A or p_A_2B on feedback control edges 32A . 32B is provided. In each case, a return line branches 33A respectively. 33B of connecting lines 34A respectively. 34B which is between the working control edges 12A respectively. 12B and the piston chambers 2A and 2 B run in the direction of the return control edges 32A . 32B of the four-edge valve 7 from.
This ensures that the working pressure p_A_2A or p_A_2B automatically adjusts itself to the pressure value set via the current pilot pressure value p_VS_7. That means that with the four-edge valve 7 in the area of the hydraulic cylinder 2 a so-called force control is feasible by means of the piston 2C or the piston rod 2D is exactly controllable with the currently required actuation force and sensible for driving comfort le synchronizing operations in the area of one via the shift rod 2D actuated synchronization can be operated in each case with the currently required for a harmonic synchronization operation actuation force.
That means the control of the piston 2C or the shift rod 2D regardless of any leaks in the hydraulic system between the four-edge valve 7 and the piston chambers 2A and 2 B is feasible, which is not possible with known from the prior art controlled valves.
The further switching valve 22 will be at the in 1 . 2 and 3 illustrated embodiments of the device 1 acted upon by a separate actuator, not shown, with the pilot pressure p_VS_22, wherein the actuator signal is present in energized transmission control unit such that the system pressure p_sys at the in 1 illustrated embodiment in the direction of the four-edge valve 7 in which in 2 illustrated embodiment of the device 1 towards the four-edge valve 7 as well as the four-edge valve 27 and in the execution of the front direction 1 according to 3 towards all four-edge valves 7 . 27 . 29 . 30 and 31 is forwarded.
Both at a restart of the vehicle as well as a failure of the transmission control unit, the actuator signal or the pilot pressure p_VS_22 of the further switching valve 22 Zero, leaving the valve spool 22_S the further switching valve 22 from a spring device 35 is completely shifted, whereby the forwarding of the system pressure p_sys in the range of the other switching valve 22 is interrupted.
Alternatively, the other switching valve 22 in a further development of the embodiment of the device 1 according to 3 is driven with a pilot pressure p_VS_22, which corresponds to an actuator signal, during the actuation of the piston 2C to 6C outputs a pressure signal. During the initialization phase of the device 1 becomes the further switching valve 22 however, it is not supplied with a pilot pressure value p_VS_22 which passes through the system pressure p_sys.
In this case, for example, it is possible to use the pressure signal of a proportional, electric pressure control valve, which is provided for controlling a dual clutch module of the present case designed as a dual clutch transmission device, wherein the pressure signals for controlling the two clutches via a so-called OR valve that designed as a ball valve may be, in each case in the direction of the other switching valve 22 be guided.
Alternatively, it is also possible to use a pressure signal of a proportional, electrical pressure control valve, which is provided for controlling the cooling oil quantity control, wherein the cooling oil valve provided for this purpose an inverse-proportional behavior to the drive signal of the other switching valve 22 having. Both the control signal provided for controlling the dual-clutch module and the signal provided for controlling the cooling oil quantity control are also present in the event of an electronic failure, since they are provided as information signals in the control unit of the dual-clutch transmission for a so-called emergency operation concept.
As a general rule
the use of a device according to the invention also offers the advantage
that used so-called open-end valves instead of so-called closed-end valves
which are cheaper to produce due to their lower functionality.
3, 4, 5, 6
- hydraulic cylinders
- piston chamber
- piston rod
- Four-edge valve
- valve slide
of the four-edge valve
- Pressure control valve
- spring means
- Supply control tongue
- Work control tongue
- Relief control tongue
- switching valve
- Pressure control valve
- magnetic valve
- valve slide
- Transfer Case
- Pressure relief valves
- Transfer case shift valve
- Four-edge valve
- valve slide
- Pressure control valve
- Four-edge valve
- Feedback control edge
- Pressure control valve
- Return line
- Pressure control valve
- connecting line
- spring means
- Pressure control valve
p_B, p_2A, p_2B
- working pressure
- pressure P_Red
- control pressure
- pilot pressure
- system pressure