DE102015006196A1 - Device for actuating a clutch and a gearbox and method for controlling - Google Patents

Abstract

The invention relates to a device for actuating a clutch and a gearbox, with an electro-hydraulic unit (10) having an electric drive and a hydraulic pump and a plurality of hydraulic lines (19, 20, 21) with a slave cylinder (25) for actuating the Coupling and with one or more slave cylinders (26, 27) is connected to actuate the gearbox, wherein the lines (19, 20, 21) by valves (22, 23, 24) are shut off. According to the invention, a control is provided such that the position of the slave cylinders (25, 26, 27) can be calculated from the actuation of the electrohydraulic unit (10).

Description

The invention relates to a device according to the preamble of claim 1 and a method according to the preamble of claim 11 and a control device according to claim 15.

In a motor vehicle, a drive train typically includes, among other things, the engine, clutch, and transmission components. Coupling and transmission can be automated. The goals are a comfortable operation and / or gentle handling to increase the service life.

Known is a pneumatically controlled clutch and Getriebeaktuatorik that uses existing in medium and heavy trucks compressed air. For vehicles without compressor, this actuator is not usable.

Also known is a hydraulic actuator with electric motor, pump, accumulator (hydraulic accumulator), oil reservoir and with displacement sensors on each actuator. The combination of accumulator and oil tank is expensive, as is the use of displacement sensors on each actuator.

The object of the invention is to provide a device for carrying out switching operations, namely for actuating the clutch and the gearbox, in the most cost-effective design possible. The device should get along as far as possible without expensive components.

The electro-hydraulic unit has an electric drive and a hydraulic pump and is connected via a plurality of hydraulic lines with a slave cylinder for actuating the clutch and with one or more slave cylinders for actuating the gearbox. The hydraulic lines can be shut off by valves. Provided is a control such that the position of the slave cylinder can be calculated from the actuation of the electro-hydraulic unit. Preferably, the hydraulic pump pumps only when a slave cylinder is applied. There is an assignment, in particular a temporal relationship and an operative relationship between the actuation of the drive or hydraulic pump on the one hand and the movement or the loading of the slave cylinder on the other. The pumping volume always corresponds to the changed volume in the slave cylinders. An additional hydraulic accumulator is no longer required.

The electro-hydraulic unit acts on the slave cylinders of clutch and manual transmission. The loading of the individual slave cylinder is carried out sequentially and by controlling the electro-hydraulic unit in conjunction with the control of the valves provided in the lines. At any time, only one slave cylinder should be charged.

According to a further concept of the invention, a displacement sensor can be assigned to the electrohydraulic unit. Additionally or alternatively, a flow meter may be provided. Preferably, displacement sensor or flow meter are assigned exclusively to the electro-hydraulic unit, in particular the electric drive or the hydraulic pump. All other displacement sensors or flow meters can be omitted.

According to the invention, a hydraulic master cylinder can be provided as a hydraulic pump. As a result, a particularly accurate control and dosage of the subsidized in the slave cylinder liquid is possible. The master cylinder is preferably coupled to an electromotive spindle drive or a linear electric motor. Both master cylinder and linear motor contain linear moving parts and are particularly well suited for the functional connection with a position sensor. A spindle drive may be driven by a stepper motor, which typically includes a displacement sensor by the nature of its drive. A hydraulic pump of general type can also be coupled to a flow meter, which takes over the function of the displacement sensor. The flow measurement should be possible in both directions.

According to a further aspect of the invention, the volume of the master cylinder is as large as or greater than the sum of the volumes of the slave cylinder, which are at the same time filled during switching operations at the same time. Preferably, the volume of the master cylinder is as large as or greater than the sum of the total volumes of the slave cylinder which can be controlled by the master cylinder. The fewer slave cylinders are present, the more likely all the slave cylinders are involved in a shift. Even if not all slave cylinders must be involved in all switching operations, it may be useful to tune the volume of the master cylinder to the sum of the volumes of all slave cylinders, such as for carrying out tests.

Advantageously, the slave cylinders are assigned return springs. As a result, a master cylinder with a working chamber is sufficient on the part of the electrohydraulic unit. When reducing the working chamber in the master cylinder hydraulic fluid flows into the slave cylinder against the Pressure of the return springs. When enlarging the working chamber in the master cylinder, the hydraulic fluid passes under the pressure of the return springs from the slave cylinders back to the master cylinder.

For actuating the gearbox two or more slave cylinders are preferably provided, plus the slave cylinder for the actuation of the clutch. In a specific embodiment of the gearbox, in particular in the manner of a H-circuit, a slave cylinder is provided for selecting a shift gate and the other slave cylinder for engaging the gear of the selected shift gate. Depending on the gearbox and required action, the appropriate number of slave cylinders must be selected.

According to the invention, a control of the valves for blocking the lines may be provided such that always only one of the valves or only one line is open. This is at any time a precise relationship between the drive of the electro-hydraulic unit on the one hand and the currently acted upon slave cylinder on the other. This also applies to the acted upon by the slave cylinder component, such as a clutch lever, a shift lever or the like. The displacement sensor on the electrohydraulic unit or on the electric motor or on the hydraulic master cylinder indicates the position of the respective slave cylinder. For this purpose, it is only necessary to take into account which of the valves is currently open and which function this has. Analogously, this applies to signals of a flow meter.

Advantageously, the valves for blocking the lines are simple switching valves, at least one or more of the valves. "Simple" means preferably the use of 2/2-way valves, such as solenoid valves in the manner of poppet valves. The latter seal very well in the closed state, better than slide valves. Nevertheless, slide valves can also be used.

According to the invention, the hydraulic lines can be connected to the slave cylinders via a common star point to the electro-hydraulic unit. There are then no additional valves for the control of the branch provided, only the valves in the individual lines to the slave cylinders. From the neutral point, a common main line leads to the electrohydraulic unit. This simplifies the connection to the unit or to the master cylinder. In the main line preferably no valve is provided for shutting off. However, the neutral point can also be replaced by lines connected directly in parallel to the master cylinder. Also, the star point can represent a volume of the electro-hydraulic unit or the master cylinder.

For the inventive method for controlling the actuation of the clutch and the gearbox, the electro-hydraulic unit comprises an electric drive and a hydraulic pump, in particular a hydraulic master cylinder. In this case, the electro-hydraulic unit is connected via a hydraulic line with a slave cylinder for actuating the clutch and one or more hydraulic lines with one or more slave cylinders for actuating the gearbox. From the operation of the electro-hydraulic unit, the position of the slave cylinder is calculated. The hydraulic pump preferably pumps only when the slave cylinders are acted upon. The slave cylinders are acted upon directly by the hydraulic pump. There is no pressure storage by a hydraulic accumulator instead.

According to the invention, at the time of switching the transmission, at most one of the hydraulic lines connected to the slave cylinders is open, while the other lines (except for a main line with neutral point) are blocked. "Open" in this context means that a flow in the relevant line is possible.

According to the invention, the line to the slave cylinder of the clutch is opened to engage a gear and generates a volume flow from the electro-hydraulic unit until the clutch is opened. Then the volume flow from the electro-hydraulic unit is stopped and the line to the slave cylinder of the coupling is blocked. Subsequently, the line is opened to the slave cylinder of the transmission and the electro-hydraulic unit generates a volume flow until a piston of the slave cylinder of the transmission is in a desired position or a gear is engaged. Finally, the volume flow is stopped and the line to the slave cylinder of the transmission is blocked. If two slave cylinders are assigned to the transmission, then the total of three provided slave cylinders are controlled according to the scheme shown. This is the case, for example, if a shift gate must first be selected before engaging the gear. It is always opened only one line, the slave cylinder concerned acted upon with a flow rate, stopped the flow and then blocked the line in question again.

Advantageously, the opening and closing of the clutch and / or the insertion and removal of gears in the transmission by a displacement sensor on the electro-hydraulic unit and / or a flow meter is detected. From the operation of the valves on the one hand and the (the filling of the master cylinder representing) signals of the displacement sensor / flow meter On the other hand, the states of the individual slave cylinder can be determined. A monitoring of the switching operations with only one displacement sensor or flow meter is possible.

In the context of the invention is also a control device for the control of the device or for controlling the method. The control unit has an electronic switching unit for processing signals of the displacement sensor on the electro-hydraulic unit and / or signals of a flow meter, for controlling valves in the hydraulic lines and for controlling the electro-hydraulic unit. In the control unit, values can be stored which represent the paths in the electrohydraulic unit, in particular the master cylinder or a motor, upon actuation of each individual slave cylinder.

Further features of the invention will become apparent from the description, moreover, and from the claims.

Advantageous embodiments of the invention are explained below with reference to drawings. Show it:

1 a schematic representation of an electro-hydraulic unit, with control unit, hydraulic lines, valves in the lines and slave cylinders for actuating the clutch and transmission,

2 the scheme of a typical 4-speed H-circuit.

An electrohydraulic unit 10 has an electric motor 11 , a spindle fixed in the circumferential direction 12 , a hydraulic master cylinder 13 with working space fourteen and pistons 15 as well as a displacement sensor 16 on. The displacement sensor 16 detects here the way of the piston 15 , but may alternatively be realized by other measures, such as by training the electric motor 11 as stepper motor with position sensor. The electric motor 11 is a rotating motor, which drives a not shown, axially fixed spindle nut. Instead of a spindle drive with a rotating motor and a linear motor can be provided. On the aggregate 10 or in a subsequent main line 17 it is possible to provide a flow meter, not shown, whose signals are the signals of the displacement sensor 16 replace or supplement.

About the main line 17 and a star point 18 are three lines 19 . 20 . 21 to the workroom fourteen connected. In each of the lines 19 . 20 . 21 is a switching valve 22 . 23 . 24 intended to open or block the relevant line. Optionally, to the workroom fourteen or to the master cylinder 13 be connected to an oil reservoir.

To each of the lines 19 . 20 . 21 is a slave cylinder 25 . 26 . 27 connected. The slave cylinder each have a working space and are provided with return springs, not shown. Due to the action of the return springs are pistons 28 . 29 . 30 in the slave cylinders 25 . 26 . 27 in the direction of arrows 31 acted upon, namely in the opposite direction to that through the lines 19 . 20 . 21 introduced hydraulic pressure. The figure shows the pistons 28 . 29 . 30 in the maximum retracted by the return springs position, corresponding to the maximum extended position of the piston 15 for the formation of the maximum working space fourteen ,

Furthermore, part of the device is a control unit 32 with an electronic switching unit not shown in detail and with control lines 33 . 34 . 35 . 36 to the electric motor 11 and to the valves 22 . 23 . 24 , It also connects a signal line 37 the path sensor 16 with the control unit 32 , In the control unit 32 can give way values for each slave cylinder 25 . 26 . 27 and correlating values for the master cylinder 13 be deposited.

The slave cylinder 25 is associated with a clutch, not shown, in a motor vehicle. By movement of the piston 28 the clutch is acted upon to open, possibly with the interposition of a lever mechanism. Dashed lines 38 . 39 indicate the position of the piston 28 with the clutch closed (line 38 ) on the one hand and opened clutch (line 39 on the other hand.

The slave cylinder 26 . 27 are associated with a manual transmission, not shown, of the motor vehicle. It is assumed that a typical H-circuit with four gears I, II, III, IV plus reverse gear R, see 2 , An unillustrated shift lever must be along a main direction 40 in one of three shift lanes 41 . 42 . 43 to be moved. Then you have to cross the main direction 40 a gear are engaged, depending on the state in one or the other direction. Here is the slave cylinder 26 to select the shift gate 41 . 42 . 43 intended. By means of the slave cylinder 27 the insertion of the respective gear is transverse to the main direction 40 , Accordingly, the pistons 29 . 30 at least three different piston positions according to the dashed lines 44 . 45 . 46 can take.

The driver of the motor vehicle influences clutch and manual transmission only indirectly by starting the engine, selection of a selector lever between neutral, forward or reverse and position of the accelerator pedal. Everything else regulates that control unit 32 , also depending on speed and speed.

Starting from vehicle standstill, with the engine switched off before the start of the journey and from the position of the pistons 28 . 29 . 30 according to 1 , namely at the level of the positions 38 and 44 , the clutch are engaged, the shift gate 43 selected and the gear III inserted. When starting the internal combustion engine of the motor vehicle initially opens the valve automatically 22 and the electric motor 11 drives the piston 15 in the workroom fourteen so that over the line 19 hydraulic pressure on the piston 28 acts and the clutch disengages. Only then does the starter become effective for the internal combustion engine.

To open the clutch, the piston moves 28 to the position 39 , This correlates with a certain way of the piston 15 , This path is taken by the displacement sensor 16 detected, to the control unit 32 signaled and there compared with a stored setpoint. After reaching the setpoint, the drive stops for the piston 15 , The valve 22 is closed again, keeping the clutch open. In the control unit 32 the clutch is noted as open.

It will now be the valve 24 opened and through the electro-hydraulic unit 10 Pressure on the pipe 21 and the piston 30 given so that this in the position of the line 45 moves. This corresponds to the point A in 2 , Subsequently, the electro-hydraulic unit 10 stopped and the valve 24 closed. The piston 30 remains in its position of the line 45 , This is again detected by the displacement sensor 16 , In the control unit 32 It defines how big the paths have to be between the positions of the lines 44 . 45 and 46 switch.

Now the valve is 23 opened and through the electro-hydraulic unit 10 Pressure over the line 20 on the piston 29 given until this the middle shift gate 42 has reached. The total now existing switching position corresponds to point B in 2 , Again, the path covered by the displacement sensor 16 recorded and with the in the control unit 32 deposited, required path adjusted, so that the position B can be taken with pinpoint accuracy. This is now in the control unit 32 deposited. The valve 23 will be closed.

Then the valve 24 opened and the electro-hydraulic unit 10 moves the piston 15 to enlarge the workspace fourteen , By action of the return spring, the piston moves 30 now back from the position of the line 45 in the position of the line 44 , This will be the way of the piston 15 from the path sensor 16 detected and adjusted with the stored Sollweg until the piston 30 the position of the line 44 has reached. In 2 has the circuit then taken the point I, that is, the first gear is engaged. Subsequently, the valve 24 closed again. In the control unit 32 is noted that now the first gear is engaged.

Finally, depending on the operation of the accelerator pedal by the driver, the hitherto open clutch engaged again, so closed. This is done by opening the valve 22 and targeted retraction of the piston 15 so that too the piston 28 in the slave cylinder 25 under the pressure of the return spring from the position of the line 39 in the position of the line 38 can change. By targeted control of the electric motor 11 the speed of closing the clutch can be controlled. Subsequently, in the control unit 32 notes that the clutch is closed.

After completing the above operations, the vehicle drives in first gear. All other switching operations are carried out according to the above pattern, both shifting into higher gears and shifting into reverse gear R via shift point C.

LIST OF REFERENCE NUMBERS

10

electrohydraulic unit

11

electric motor

12

spindle

13

Master cylinder

14

working space

15

piston

16

displacement sensor

17

main

18

star point

19

management

20

management

21

management

22

switching valve

23

switching valve

24

switching valve

25

slave cylinder

26

slave cylinder

27

slave cylinder

28

piston

29

piston

30

piston

31

arrows

32

control unit

33

control lines

34

control lines

35

control lines

36

control lines

37

signal line

38

piston position

39

piston position

40

main direction

41

shift gate

42

shift gate

43

shift gate

44

piston position

45

piston position

46

piston position

A

switching point

B

switching point

C

switching point

Claims (16)

Device for actuating a clutch and a gearbox, with an electro-hydraulic unit ( 10 ), which has an electric drive and a hydraulic pump and via a plurality of hydraulic lines ( 19 . 20 . 21 ) with a slave cylinder ( 25 ) for actuating the clutch and with one or more slave cylinders ( 26 . 27 ) is connected to the actuation of the gearbox, wherein the lines ( 19 . 20 . 21 ) by valves ( 22 . 23 . 24 ) are characterized by a control such that from the actuation of the electro-hydraulic unit ( 10 ) the position of the slave cylinder ( 25 . 26 . 27 ) is calculable. Apparatus according to claim 1, characterized by a control such that at any one time only one slave cylinder ( 25 . 26 . 27 ) is applied. Apparatus according to claim 1 or 2, characterized in that the electro-hydraulic unit ( 10 ) a displacement sensor ( 16 ), in particular the electric drive or the hydraulic pump, and / or that a flow meter is provided. Apparatus according to claim 1 or one of the further claims, characterized in that as hydraulic pump, a hydraulic master cylinder ( 13 ) is provided. Apparatus according to claim 4, characterized in that the volume of the master cylinder ( 13 ) is as large as or greater than the sum of the volumes of slave cylinders ( 25 . 26 . 27 ), which are filled at the same time during switching operations at the same time. Apparatus according to claim 4 or 5, characterized in that the volume of the master cylinder ( 13 ) is as large as or greater than the sum of the total volumes of the master cylinder ( 13 ) controllable slave cylinder ( 25 . 26 . 27 ). Device according to claim 1 or one of the further claims, characterized in that the slave cylinders ( 25 . 26 . 27 ) Are associated with return springs. Device according to claim 1 or one of the further claims, characterized in that for the actuation of the gearbox two or more slave cylinders ( 26 . 27 ) are provided. Device according to claim 1 or one of the further claims, characterized by a control of the valves ( 22 . 23 . 24 ) to block the lines ( 19 . 20 . 21 ) such that always only one of the valves or only one of the lines is open. Device according to claim 1 or one of the further claims, characterized in that the valves for blocking the lines ( 19 . 20 . 21 ) are simple switching valves, at least one or more of the valves. Device according to claim 1 or one of the further claims, characterized in that the hydraulic lines ( 19 . 20 . 21 ) to the slave cylinders ( 25 . 26 . 27 ) via a common star point ( 18 ) to the electro-hydraulic unit ( 10 ) are connected. Method for controlling the actuation of a clutch and a gearbox, wherein an electro-hydraulic unit ( 10 ) an electric drive and a hydraulic pump, in particular a hydraulic master cylinder ( 13 ) and via a hydraulic line ( 19 ) with a slave cylinder ( 25 ) for actuating the coupling and via one or more hydraulic lines ( 20 . 21 ) with one or more slave cylinders ( 26 . 27 ) is connected to the actuation of the gearbox, characterized in that the position of the slave cylinder ( 25 . 26 . 27 ) from the operation of the electro-hydraulic unit ( 10 ) is calculated. A method according to claim 12, characterized in that when switching the transmission at any time at most one of the hydraulic cylinders connected to the slave cylinders ( 19 . 20 . 21 ) is open and the other lines are blocked. A method according to claim 12 or 13, characterized in that for inserting a gear, the line ( 19 ) to the slave cylinder ( 25 ) of the coupling is opened and the electro-hydraulic unit ( 10 ) generates a volume flow until the clutch is opened, that then the volume flow is stopped and the line ( 19 ) to the slave cylinder ( 25 ) of the coupling is blocked, that then the line ( 20 ) to the slave cylinder ( 26 ) of the transmission is opened and the electro-hydraulic unit ( 10 ) generates a volume flow until a piston ( 29 ) of the slave cylinder ( 26 ) of the transmission is in a desired position, and then that the volume flow is stopped and the line ( 20 ) to the slave cylinder ( 26 ) of the transmission is blocked. A method according to claim 12 or one of the further claims, characterized in that the opening and closing of the clutch and / or the insertion and removal of gears in the transmission by a displacement sensor ( 16 ) or flow meter is detected on the electro-hydraulic unit. Control device for the control of the device according to one of claims 1 to 11 and / or for controlling the method according to one of claims 12 to 15, with an electronic switching unit for processing signals of a displacement sensor ( 16 ) on the hydraulic unit ( 10 ) and / or signals of a flow meter, for controlling valves ( 22 . 23 . 24 ) in the hydraulic lines ( 19 . 20 . 21 ) and for controlling the electro-hydraulic unit ( 10 ).

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