DE10125172A1 - Hydraulic switching control device for a multispeed gear change box, especially a double clutch gear box, comprises a multi-way switching valve arranged between control valves and switching elements - Google Patents

Abstract

Hydraulic switching control device for a multispeed gear change box, especially a double clutch gear box, comprises at least two working lines (a pressure line (2) and a return line (3)), several double-acting switching elements (17a-17d) for loading/unloading the gang, and control valves for controlling the switching processes arranged between the working lines and the switching elements. Two control valves (4a, 4b) designed as solenoid valves are provided for controlling both sides of a switching element. A multi-way switching valve is arranged between the control valves and the switching elements for alternately connecting the control valves to the respective switching element.

Description

The invention relates to a hydraulic shift control device for a multi-speed gear change transmission, in particular a double clutch transmission, with at least two working lines, a pressure line and a return line, with several double-acting switching actuators for engaging and disengaging the gears, and arranged between the working lines and the switching actuators Control valves for controlling the circuit processes.

Hydraulic shift control devices are for different transmission types known and can both for the transmission of dialing and switching movements of a shift or selector lever on assigned selector and shift actuators, d. H. to the uncontrolled engagement and disengagement of the gears of a manual transmission or for activation and deactivating the gears of an automatic transmission, as well as for sequence control the switching operations, d. H. the control of the timing of the gears or Speed step change can be used.

DE 41 17 734 A1, for example, describes a shift control device Multi-speed gear change known in which each of the switching actuators a control valve controllable by means of control pressures is assigned. The activation and deactivation of the switching actuators takes place via a multi-way switching valve the control pressure lines of the control valves switched, d. H. pressurized or be depressurized. The multi-way switching valve is a rotary slide valve trained and adjustable via an electric stepper motor.

A disadvantage of this switching control device is the large number of required Control valves, which are predetermined by the design of the control valves Switching characteristics of the switching actuators, the high effort through the use of Control lines, and the complicated structure of the drum rotary slide valve trained multi-way switching valve.

There arises the problem of this generic shift control device to further develop such that their structure is simplified and their functionality is improved becomes.

The problem is inventively in connection with the preamble of the claim 1 solved in that two control valves designed as solenoid valves on both sides Control each one of the switching actuators are provided, and that between the Control valves and the switching actuators a multi-way switching valve for alternating Connection of the control valves is arranged with one of the switching actuators.

Advantageous embodiments of the control device according to the invention are in the Claims 2 to 14 specified.

By using two control valves that alternately control one the switching actuators via the multi-way switching valve with the relevant Switch actuator connected, is the total number of control valves required significantly reduced compared to the generic shift control device. In front the two connecting lines of the Control valves via the multi-way switching valve with the two supply lines of the concerned, preferably as an actuating cylinder with two opposing pressure chambers trained switching actuator and thus the two control valves this Switch actuator assigned. The switching of the multi-way switching valve thus takes place the dialing process, d. H. the selection of the shift rod or shift sleeve to be operated of the transmission. The actual switching process, i.e. H. inserting and removing one of the assigned gears, takes place via the control of the control valves, via which the Work lines, d. H. the pressure line and the return line with the Connection lines can be connected in a controlled manner. By using two Control valves will enter each pressure chamber of the activated switching actuator Control valve assigned, which optimal control of a circuit sequence allows. Due to the design of the control valves as solenoid valves Switching characteristics, d. H. the time course of the switching path and the switching force, not fixed, but variable. For example, this is an individual Regulation of the switching processes of each of the switching actuators or each of the Gear shift clutches possible. The gear shift clutches mostly differ the low and the high gears by using different Friction synchronization devices from each other, which by different, by which  Control of the control valves caused control processes can be taken into account. The use of solenoid valves also enables adaptive control of the Switch actuators, e.g. B. to compensate for wear of the friction components of the respective gear shift clutch, possible. Overall, the structure of the Switch control device according to the invention compared to the prior art greatly simplified and their functionality significantly improved.

The two control valves are each advantageous as a 3/3-way solenoid valve with two Inputs and an output, in which the inputs each with one of the Working lines and the output via a connecting line with the Multi-way switching valve are connected, and the two end positions, each in one of the inputs connected to the output without throttling and the other input is locked, and a middle position as a rest position, in which the entrances and the Output are blocked off. By avoiding an immediate Transition from the pressurized to the depressurized state between the End positions, the construction of the control valves can be kept relatively simple and inexpensive become. In addition, the closed rest position of the control valves enables largely pressure-free and therefore low-friction switching of the multi-way switching valve.

But it is also conceivable that both control valves in one Combination control valve are summarized. This allows a control valve can be saved, whereby the structure of the Shift control device is further simplified and its manufacturing cost be lowered.

A 4/5-way solenoid valve is preferred as the design of the combination control valve with two inputs and two outputs in question, in which the inputs each with one of the working lines and the outputs each via a connecting line the multi-way switching valve are connected, and the two end positions in which each of the Inputs are mutually unrestricted connected to one of the outputs, two intermediate positions, in which the inlet of the return line each with one of the Connected outputs and the input of the pressure line and the other Exit are blocked, and a middle position as the rest position, in which the entrance the return line connected to both outputs and the input of the pressure line is cordoned off.  

The multi-way switching valve can be designed as a rotary slide valve and by means of a controllable actuator can be switched in switch positions in which the Connection lines each connected to leads of one of the switching actuators are. This design of a multi-way switching valve, which is known in principle, is space-saving and functionally reliable with the appropriate design.

For the present application, the rotary slide valve advantageously has cylindrical housing with a circular disk-shaped input side Housing cover, a circular disk-shaped output-side housing cover, and one rotatably mounted between the housing covers around the cylinder axis circular disc-shaped rotary valve. The housing cover on the input side is included two radially spaced and largely axially extending input bores Mistake. The housing cover on the output side has several pairs accordingly radially spaced and largely axially extending output bores. The Rotary vane is covered with two, each with a pair of the output holes axial switch holes can be provided. And between the input side The lid and the rotary valve are two annular spaces for independent rotation angle Connect one of the input holes to one of the switch holes arranged. The rotary slide valve is thus relatively simple and inexpensive produced. The different switch positions, in each of which the two of the Control valves or coming from a combination control valve Connection lines with the two leads of the relevant switching actuator are connected by turning the rotary valve around the cylinder axis reached.

The annular spaces can each by one in the inner surface of the input side Housing cover or in the input circular area of the rotary valve arranged and easy to produce ring groove are formed. To be a special one large cross-sectional area and a correspondingly large volume of the annular spaces reach, the ring grooves are advantageous on both of the relevant one another arranged opposite surfaces.

Because of the low manufacturing costs, the actuator is preferred as a rotary motor and because of good controllability especially designed as an electric stepper motor.  

The rotary motor can be arranged coaxially to the axis of rotation of the rotary slide, a central shaft being used to transmit an actuating torque to the rotary valve is provided, with which the rotary valve is rotatably connected.

Alternatively, the rotary motor can be spaced radially parallel to the axis of rotation of the rotary valve can be arranged, wherein for transmitting an actuating torque the rotary valve is provided a gear transmission in which one of the gears is formed by the rotary valve itself having external teeth, and the other gear is rotatably connected to the output shaft of the rotary motor. Due to the reduction achieved by the gear transmission, the use is a smaller one, d. H. Less powerful and therefore cheaper rotary motor possible.

As a further alternative, the rotary motor can also be perpendicular to the axis of rotation of the Rotary slide valve can be arranged, wherein to transmit a control torque to the Rotary slide a worm gear is provided, in which the worm wheel is rotatably connected to the output shaft of the rotary motor, and the gear is formed by the rotary valve itself having external teeth.

In the construction of the rotary slide valve according to the invention results from the one-sided pressure load originating from the annular spaces is an automatic one Inhibition of the rotary valve against unwanted twisting. Still can Security a locking device for locking the rotary valve in the Switch positions are provided.

This locking device can at least one in the cylindrical inner wall of the Radially movable and spring-loaded locking body and several am Outer circumference of the rotary valve arranged and in accordance with the switching positions comprise circumferentially spaced depressions.

Alternatively or in addition, there are also a circular surface of the housing or the Rotary slide axially movable and spring-loaded locking body and several on the opposite circular surface (of the rotary valve or the housing) arranged and spaced according to the switching positions in the circumferential direction Wells possible as a locking device.  

Further details of the invention emerge from the following detailed Description and the accompanying drawings, which serve as examples to explain the serve switching control device according to the invention.

Show:

Fig. 1 shows a shift control device of the invention with two control valves in the form of a block diagram,

Fig. 2 shows a switching control device according to the invention with a single combination control valve in the form of a circuit diagram, and

Fig. 3a-3d designed as a rotary slide valve multipath switching valve of the shift control device of the invention in different sectional views.

Fig. 1 shows in schematic form the construction of a first embodiment of a hydraulic circuit control device 1 according to the invention. Two working lines 2 , 3 , a pressure line 2 connected to an oil pump (not shown ) and a return line 3 connected to an oil sump (not shown ) are connected to a first control valve 4 a and a second control valve 4 b. The control valves 4 a, 4 b are constructed largely identically and each as a 3/3-way solenoid valve with two inputs 5 a, 6 a; 5 b, 6 b and an output 7 a, 7 b, the inputs 5 a, 5 b; 6 a, 6 b are each connected to one of the working lines 2 , 3 and the output 7 a, 7 b via a connecting line 8 a, 8 b to a multi-way switching valve 9 . The control valves 4 a, 4 b each have two end positions 10 a, 10 b; 11 a, 11 b, in each of the inputs 5 a, 5 b; 6 a, 6 b is connected unthrottled to the relevant output 7 a, 7 b, and a central position 12 a, 12 b also effective as a rest position, in which the respective inputs 5 a, 6 a; 5 b, 6 b and the relevant output 7 a, 7 b are blocked. Via the multi-way switching valve 9 , which can be switched into four switching positions 14 a- 14 d by means of a controllable actuator 13 , the connecting lines 8 a, 8 b are each one of four double-acting with two supply lines 15 a, 16 a- 15 d, 16 d Switch actuators 17 a- 17 d connectable.

The shift actuators 17 a- 17 d 1 are shown in Fig. Exemplified as an actuating cylinder 18 disposed opposite to two, and accordingly in opposite directions on an adjusting piston 19 effective pressure spaces 20 a, 20 b formed, wherein each of the shift actuators 17 a- 17 d, at least one passage, usually however, two gears are assigned, each of which can be shifted, ie engaged and disengaged, by an axial displacement 21 of the actuating piston 19 . The illustrated shift control device 1 is provided for shift control of a multi-speed gear change transmission, in particular a double clutch transmission, with six forward gears and one reverse gear. Through the circuit 22 of the multi-way switching valve 9 in one of the switching positions 14 a- 14 d, the two control valves 4 a, 4 b via the connection of the connecting lines 8 a, 8 b with a pair of the supply lines 15 a, 16 a- 15 d, 16 d connected to the associated switching actuator 17 a- 17 d, which corresponds to a selection process. An electric stepper motor is preferably used as the controllable actuator 13 of the multi-way switching valve 9 because of its good controllability. The switching process following the selection process, ie engaging or disengaging a gear, takes place via the previously selected switching actuator 17 a- 17 d, the timing of the switching process being controlled via the control valves 4 a, 4 b. The design of the control valves 4 a, 4 b as solenoid valves enables individual control of each of the switching actuators 17 a - 17 d in both directions, whereas when using pressure-controlled control valves, a predetermined control characteristic determined by the structure of the control valves is disadvantageously given and consequently, as in the known shift control device according to DE 41 17 734 A1, a fixed assignment of the control valves to the shift actuators would be required. When switching from one switching actuator 17 a to 17 d to another, the two control valves 4 a, 4 b are preferably in their central position 12 a, 12 b, so that the multi-way switching valve 9 is largely depressurized during the switching and can be operated with correspondingly low friction can be brought d ie with low actuating force by means of the actuator 13 in another switching position 14 a- fourteenth The configuration of the switching control device 1 according to the invention drastically reduces the number of control valves required in comparison to the prior art and considerably simplifies the control structure with even improved functionality.

In FIG. 2, the structure 1 is provided as an alternative to the switch control apparatus 1 according to Fig. A second embodiment of a hydraulic shift control apparatus 1 according to the invention represented '. The difference from Fig. 1 is limited to that the two control valves 4a, 4b of the switching control device 1 b is now in a single combination of control valve 4 'are shown, which as a 4/5-way solenoid valve having two inputs 5', 6 ' and two outputs 7 ', 7 ". The inputs 5 ', 6 'are each connected to one of the working lines 2 , 3 and the outputs 7 ', 7 " are each connected to the multi-way switching valve 9 via one of the connecting lines 8 a, 8 b , The combination control valve 4 'has two end positions 23 , 24 , in which each of the inputs 5 ', 6 'is mutually unthrottled, each connected to one of the outputs 7 ', 7 ", two intermediate positions 25 , 26 , in which the input 6 'of the return line 3 are each connected to one of the outputs 7 ", 7 'and the input 5 ' of the pressure line 2 and the other output 7 ', 7 " are shut off, and a central position 27 , which is also effective as a rest position, in which the input 6 ' of the Return line 3 connected to both outputs 7 ', 7 "and the input 5 ' of the pressure line 2 is blocked. The remaining structure of the shift control device 1 ′ is identical to that of the shift control device 1 according to FIG. 1.

In the present case, the timing of a switching process, that is to say the engagement or disengagement of a gear, is carried out by means of the previously selected shift actuator 17 a- 17 d via the combination control valve 4 ', the design of the combination control valve 4 ' as a solenoid valve individually controlling each of the Switch actuators 17 a- 17 d in both directions. When switching from one switching actuator 17 a to 17 d to another, the combination control valve 4 'is preferably in its central position 27 , so that the multi-way switching valve 9 is largely depressurized during the switching and can be operated with corresponding low friction. In comparison with the shift control device 1 according to FIG. 1, a further control valve is saved in the present shift control device 1 ′ without having to accept a restriction in functionality. The combination control valve 4 'is in comparison to one of the control valves 4 a, 4 b of the shift control device 1 more complicated and therefore also more expensive to manufacture, due to the reduction in the number of control valves and the simplification of the shift control device 1 ' thereby achieved, nevertheless Cost savings with largely unlimited functionality.

In FIGS. 3a-3d, a rotary valve 1 3a 28 is shown, which is preferably a multi-way selector valve 9 of the hydraulic circuit control device 1 according to FIGS. And 1 'of FIG. 2 is used, in Fig. In the longitudinal central section, in Fig. 3b in the axial sectional view IIIB-IIIB according to FIG. 3a, in FIG. 3c in the axial sectional view IIIC -IIIC according to FIG. 3a, and in FIG. 3d in the axial sectional view IIID-IIID according to FIG. 3a. The rotary slide valve 28 has a cylindrical housing 29 with a circular disk-shaped inlet cover 30 , a circular disk-shaped outlet cover 31 , and a circular disk-shaped rotary slide 33 mounted rotatably about the cylinder axis 32 between the housing covers 30 , 31 . Are the input-side cover 30 is provided with two spaced radially and substantially axially extending inlet bores 34 a, b provided 34 for connecting the connection lines 8 a, 8 b of FIG. 1 and FIG. 2 are provided. The output-side housing cover 31 has four pairs of correspondingly radially spaced and largely axially extending output bores 35 a, 36 a- 35 d, 36 d, which are used to connect the supply lines 15 a, 16 a- 15 d, 16 d according to FIG. 1 and FIG . 2 are provided. The rotary valve 33 is provided with two axial switching bores 37 a, 37 b, each of which can be brought into congruence with a pair of the output bores 35 a, 36 a- 35 d, 36 d. In the inner surface 38 of the housing cover 30 on the input side, two annular grooves 39 a, 39 b are arranged for connection, independent of the angle of rotation, of one of the input bores 34 a, 34 b with one of the switching bores 37 a, 37 b. The rotary slide 33 is connected in a rotationally fixed manner to an axis 41 via a square connection 40 , which is rotatably mounted in the housing covers 30 , 31 . The axis 41 is connected to a controllable actuator 42 , which is preferably designed as an electrical stepper motor and by means of which a rotation 43 of the rotary slide 33 in four switching positions 44 a- 44 d is possible, which follows the switching positions 14 a- 14 d of the multi-way switching valve 9 Fig. 1 and Fig. 2 correspond. To seal the ring grooves 39 a, 39 b and the switching bores 37 a, 37 b on the input side, three large O-rings 45 a- 45 c are arranged around the ring grooves 39 a, 39 b and between the housing cover 30 on the input side and the rotary valve 33 . A total of eight small O-rings 46 a, 47 a- 46 d, 47 d, which are arranged around the output bores 35 a, 36 a- 35 d, 36 d and between the output-side housing cover 31 and the rotary valve, serve to seal the output bores 35 a, 36 a- 35 d, 36 d and the switching holes 37 a, 37 b on the output side.

Due to its constructive design, the dimensions of the rotary slide valve 28 are relatively compact and simple. The rotary slide valve 28 therefore represents an inexpensive to produce and reliably switchable multi-way switching valve 9 , which is particularly suitable for use in the hydraulic shift control device 1 according to FIG. 1 or 1 ′ according to FIG. 2.

LIST OF REFERENCE NUMBERS

1

Shift control device

1

'Shift control device

2

Working line, pressure line

3

Working line, return line

4

a control valve

4

b control valve

4

'' Combination control valve

5

a entrance

5

b entrance

5

' Entrance

6

a entrance

6

b entrance

6

' Entrance

7

a exit

7

b exit

7

' Exit

7

" Exit

8th

a connecting line

8th

b connecting line

9

Multipath switching valve

10

a end position

10

b end position

11

a end position

11

b end position

12

a middle position

12

b middle position

13

actuator

14

a switch position

14

b Switch position

14

c switch position

14

d switch position

15

a supply line

15

b supply line

15

c supply line

15

d supply line

16

a supply line

16

b supply line

16

c supply line

16

d supply line

17

a switching actuator

17

b switching actuator

17

c switching actuator

17

d switching actuator

18

actuating cylinder

19

actuating piston

20

a pressure room

20

b pressure room

21

axial displacement

22

circuit

23

end position

24

end position

25

intermediate position

26

intermediate position

27

center position

28

Rotary valve

29

casing

30

(input side) housing cover

31

(output side) housing cover

32

Cylinder axis, axis of rotation

33

rotary vane

34

a input hole

34

b Entry hole

35

a exit hole

35

b Exit hole

35

c Exit hole

35

d exit bore

36

a exit hole

36

b Exit hole

36

c Exit hole

36

d exit bore

37

a switch hole

37

b switch hole

38

Inner surface

39

a ring groove

39

b ring groove

40

Square head

41

axis

42

actuator

43

rotation

44

a switch position

44

b Switch position

44

c switch position

44

d switch position

45

a (large) O-ring

45

b (large) O-ring

45

c (large) O-ring

46

a (small) O-ring

46

b (small) O-ring

46

c (small) O-ring

46

d (small) O-ring

47

a (small) O-ring

47

b (small) O-ring

47

c (small) O-ring

47

d (small) O-ring

Claims (14)

1.Hydraulic shift control device for a multi-speed gear change transmission, in particular a double clutch transmission, with at least two working lines ( 2 , 3 ), a pressure line ( 2 ) and a return line ( 3 ), with a plurality of double-acting shift actuators ( 17 a - 17 d) for one - And lay out the gears, and with between the working lines ( 2 , 3 ) and the switching actuators ( 17 a - 17 d) arranged control valves for controlling the switching processes, characterized in that two control valves ( 4 a, 4 b) designed as solenoid valves for Control on both sides one of the switching actuators ( 17 a - 17 d) is provided, and that between the control valves ( 4 a, 4 b) and the switching actuators ( 17 a - 17 d) a multi-way switching valve ( 9 ) for alternating connection of the control valves ( 4 a, 4 b) with one of the switching actuators ( 17 a- 17 d) is arranged. 2. Switching control device according to claim 1, characterized in that a 3/3-way solenoid valve with two inputs ( 5 a, 6 a) and one output ( 7 a) is used as the control valve ( 4 a), the inputs ( 5 a, 6 a) are each connected to one of the working lines ( 2 , 3 ) and the outlet ( 7 a) via a connecting line ( 8 a) to the multi-way switching valve ( 9 ), and the control valves ( 4 a) each have two end positions ( 10 a, 11 a), in each of which one of the inputs ( 5 a, 6 a) is connected without restriction to the output ( 7 a) and the other input ( 6 a, 5 a) is shut off, and a middle position ( 12 a ) as the rest position, in which the inputs ( 5 a, 6 a) and the output ( 7 a) are closed off. 3. Switching control device according to claim 1, characterized in that the two control valves ( 4 a, 4 b) are combined in a single combination control valve ( 4 '). 4. Switching control device according to claim 3, characterized in that a 4/5-way solenoid valve with two inputs ( 5 ', 6 ') and two outputs ( 7 ', 7 ") is used as a combination control valve ( 4 '), the Inputs ( 5 ', 6 ') each with one of the working lines ( 2 , 3 ) and the outputs ( 7 ', 7 ") are each connected via a connecting line ( 8 a, 5 b) to the multi-way switching valve ( 9 ), and that Combination control valve ( 4 ') two end positions ( 23 , 24 ), in which each of the inputs ( 5 ', 6 ') is alternately unthrottled with one of the outputs ( 7 ', 7 "), two intermediate positions ( 25 , 26 ), in which the input ( 6 ') of the return line ( 3 ) is connected to one of the outputs ( 7 ', 7 ") and the input ( 5 ') of the pressure line ( 2 ) and the other output ( 7 ", 7 ') are shut off, and a middle position ( 27 ) as the rest position, in which the input ( 6 ') of the return line ( 3 ) with both outputs lengths ( 7 ', 7 ") and the inlet ( 5 ') of the pressure line ( 2 ) is shut off. 5. Switching control device according to one of claims 1 to 4, characterized in that the multi-way switching valve ( 9 ) is designed as a rotary slide valve ( 28 ), and that the rotary slide valve ( 28 ) by means of a controllable actuator ( 42 ) in switching positions ( 44 a- 44 d ) is switchable, in which the connecting lines ( 8 a, 8 b) are each connected to supply lines ( 15 a, 16 a - 15 d, 16 d) of one of the switching actuators ( 17 a - 17 d). 6. Switching control device according to claim 5, characterized in that the rotary slide valve ( 28 ) has a cylindrical housing ( 29 ) with a circular disk-shaped inlet-side housing cover ( 30 ), a circular disk-shaped outlet-side housing cover ( 31 ), and one between the housing covers ( 30 , 31 ) the cylinder axis ( 32 ) has rotatably mounted rotary disk slide valves ( 33 ), the housing cover ( 30 ) on the input side being provided with two radially spaced and largely axially extending input bores ( 34 a, 34 b), the housing cover ( 31 ) on the output side corresponding to a plurality of pairs has spaced and largely axially extending output bores ( 35 a, 36 a- 35 d, 36 d), the rotary valve ( 33 ) with two with a pair of the output bores ( 35 a, 36 a- 35 d, 36 d) can be brought into alignment axial switching bores ( 37 a, 37 b) is provided, and between the input-side cover ( 30 ) and the rotary slide valve ( 31 ) has two annular spaces for connecting one of the input bores ( 34 a, 34 b) to one of the switching bores ( 37 a, 37 b), independent of the angle of rotation. 7. Switching control device according to claim 6, characterized in that the annular spaces are each formed by an annular groove ( 39 a, 39 b) formed in the inner surface ( 38 ) of the input-side housing cover ( 30 ) and / or in the input-side circular surface of the rotary valve ( 33 ) become. 8. Switching control device according to claim 6 or 7, characterized in that the actuator ( 42 ) is designed as a rotary motor, in particular as an electric stepping motor. 9. Switching control device according to claim 8, characterized in that the rotary motor is arranged coaxially to the axis of rotation ( 32 ) of the rotary valve ( 33 ), and that a central shaft is provided for transmitting an actuating torque to the rotary valve ( 33 ). 10. Switching control device according to claim 8, characterized in that the rotary motor is arranged parallel to the axis of rotation ( 32 ) of the rotary valve ( 33 ), and that a gear transmission is provided for transmitting an actuating torque to the rotary valve ( 33 ), one of the gears by the rotary valve ( 33 ) having an external toothing is formed. 11. Shift control device according to claim 8, characterized in that the rotary motor is arranged at right angles to the axis of rotation ( 32 ) of the rotary valve ( 33 ), and that a worm gear is provided for transmitting a steep moment to the rotary valve ( 33 ), the worm wheel with the Output shaft of the rotary motor is connected, and the gear is formed by the rotary valve ( 33 ) having external teeth. 12. Switch control device according to one of claims 5 to 11, characterized in that the rotary slide valve ( 28 ) has a locking device for locking the rotary slide in the switching positions ( 44 a- 44 d). 13. Switching control device according to claim 12, characterized in that the locking device at least one in the cylindrical inner wall of the housing ( 29 ) radially movable and spring-loaded locking body and several on the outer circumference of the rotary valve ( 33 ) arranged and corresponding to the switching positions ( 44 a- 44 d ) comprises circumferentially spaced depressions. 14. Switching control device according to claim 12 or 13, characterized in that the locking device one in a circular surface of the housing ( 29 ) or the rotary valve ( 33 ) axially movable and spring-loaded locking body and several arranged on the opposite circular surface (the rotary valve or the housing) and corresponding to the switching positions ( 44 a- 44 d) comprises circumferentially spaced depressions.