EP1320673A1

EP1320673A1 - Drive unit for a vehicle

Info

Publication number: EP1320673A1
Application number: EP01978121A
Authority: EP
Inventors: Karl-Heinz Senger; Peter Baeuerle; Bram Veenhuizen; Engbert Spijker; Gert-Jan Van Spijk
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2000-09-15
Filing date: 2001-09-12
Publication date: 2003-06-25
Anticipated expiration: 2021-09-12
Also published as: US20030125162A1; US6852066B2; WO2002023030A1; JP2004509266A; DE10045759A1; EP1320673B1; DE50114005D1

Abstract

The invention relates to a drive unit for a vehicle, with at least one drive wheel, comprising an internal combustion engine, a clutch, arranged between the internal combustion engine and the at least one drive wheel, for the transfer of a torque between the internal combustion engine and the drive wheel and a vehicle controller for control or regulation of the internal combustion engine, depending upon the speed of the clutch on the internal combustion engine side and/or the speed of the clutch on the drive wheel side.

Description

description

Drive unit for a vehicle

The invention relates to a drive unit for a vehicle with at least one drive wheel, the drive unit having an internal combustion engine and a clutch arranged between the internal combustion engine and the at least one drive wheel for transmitting a torque between the internal combustion engine and the drive wheel. The invention further relates to a method and a control for operating such a drive unit.

It is an object of the invention to improve such a drive assembly or the operation of such a drive assembly.

The object is achieved by a method or a drive unit and a vehicle control according to claims 1 and 4 or according to claims 10, 11, 12 and 13. In this case, it is for operating a drive unit for a vehicle with at least one drive wheel, wherein the drive unit an engine and a ^'between the engine and the at least one drive wheel arranged coupling for transmitting a torque between the engine and the drive wheel of the internal combustion engine depending on the speed the clutch on the side of the engine and / or the rotational speed of the clutch on the side of the drive wheel and / or as a function of the time derivative of the rotational speed of the clutch on the side of the engine and / or the temporal ^• derivation of the rotational speed of the clutch on the side of the drive wheel controlled or regulated. In this way, a particularly advantageous limitation of torque surges in the drive unit is achieved. Particularly in connection with a belt transmission, a particularly good protection of this belt transmission is achieved in this way. Driving comfort is also increased.

In an advantageous embodiment of the invention, a setpoint for the torque of the internal combustion engine is determined as a function of the time derivative of the speed of the clutch on the side of the internal combustion engine and / or as a function of the time derivative of the speed of the clutch on the side of the drive wheel.

In a further advantageous embodiment of the invention, the internal combustion engine is controlled or regulated as a function of the setpoint.

In a further advantageous embodiment of the invention, the torque of the internal combustion engine is limited.

In a further advantageous embodiment of the invention, the target value is a maximum value that should not be exceeded.

In a further advantageous embodiment of the invention, the torque of the internal combustion engine is limited when

dn

> n Eliml German

where n _E de the speed of the clutch on the side of the internal combustion engine and n _{Eliml is} a predetermined limit value, and / or if

-> n

where n _{A is} the speed of the clutch on the side of the drive wheel and _A ιι _m ι is a predetermined limit.

d () / dt specifies the time derivative.

In a further advantageous embodiment of the invention, the limitation of the torque of the internal combustion engine is ended when

ⁿ E0 ^-n E < ^EL Elim2

where n _E i _άm 2 is a predetermined limit value and n _E o is the speed of the clutch on the side of the internal combustion engine at the point in time at which the limitation was started and / or if

ⁿ A0 ^—nn AHm2

where n _{Älim2 is} a predetermined limit value and n _A o is the speed of the clutch on the side of the drive wheel at the point in time at which the limitation was started.

Further details and advantages result from the following description of exemplary embodiments. In detail show:

Fig. 1 shows a drive unit for a motor vehicle. Fig. 2 shows a clutch Fig. 3 shows a clutch control

4 shows a flowchart for an engine torque setpoint generator. FIG. 5 shows a further sequence for an engine torque setpoint generator. FIG. 6 shows a slip regulator

1 shows a drive unit 16 for a motor vehicle. Reference numeral 1 denotes an internal combustion engine which is connected to an automatic transmission 2 via a shaft 4. The automatic transmission 2 is designed in a particularly advantageous manner as a continuously variable belt transmission. The automatic transmission 2 is connected via a clutch input shaft 5, a clutch 3, a clutch output shaft 6, a differential 7 to drive wheels 8, 9 for driving the motor vehicle. The torque transmitted via the clutch 3 can be adjusted by pressing the clutch 3 together with a contact pressure p. In order to set the torque transmitted via the clutch 3, a clutch control 12 is provided, which sets the contact pressure in the clutch 3 by presetting a target contact pressure p *. The contact pressure is synonymous with a contact pressure with which the clutch 3 is pressed together.

Input variables in the clutch control 12 are the speed n _{E of} the clutch input shaft 5, which is measured by means of a speed sensor 10, the speed n _{a of} the clutch output shaft 6, which is measured by a speed sensor 11, the transmission ratio i of the automatic transmission 2 and a Setpoint value Δn * for the clutch slip of clutch 3 (setpoint clutch slip) and optionally the torque T _{M of} the internal combustion engine 1 and information ΔT _M about the Inaccuracy of the information about the torque T _{M of} the internal combustion engine 1.

The clutch slip Δn is defined as

Δn = n, n

The torque T _{M of} the internal combustion engine 1 and the information ΔT _M about the inaccuracy of the information about the torque TM of the internal combustion engine 1 are provided by an engine controller 14, for example. A setpoint value T _M * and optionally a corrected engine torque T _MKr, which is a corrected value for the actual value of the torque TM of the internal combustion engine 1, is transmitted from the clutch controller 12 to the engine controller 14.

The internal combustion engine 1 is controlled or regulated by manipulated variables M * by means of the engine control 14. Actual engine values M are optionally transmitted from the internal combustion engine 1 to the engine control 14.

In an exemplary embodiment, the engine control 14 and the clutch control 12 are part of a vehicle control 15. This can also have a transmission control (not shown) for controlling and regulating the automatic transmission 2 and a higher-level control for coordinating the automatic transmission 2, internal combustion engine 1 and clutch 3. The higher-level control provides, for example, the ratio i of the automatic transmission 2 and the target slip Δn * for the clutch 3. Fig. 2 shows a clutch 3 in an exemplary embodiment. Reference numeral 83 designates a lubricating oil supply for hydraulic oil, reference numeral 84 an outer driver, reference numeral 85 an inner driver, reference numeral 86 an outer plate, reference number 87 an inner plate, reference number 88 a return spring, reference number 93 a cylinder, reference number 94 a piston, reference number 95 a pressure plate and reference numbers 96 a pressure medium supply. On the outer driver 84, which is connected to the clutch input shaft 5, outer plates 86, in an advantageous embodiment steel plates without a friction lining, are arranged. The inner driver 85 connected to the clutch output shaft 6 receives the inner disks 87, which are coated with a friction lining. When introducing hydraulic oil with a defined pressure level over the

■ Pressure medium supply 96 in the cylinder 93 moves

Piston 94 against the force of the return spring 88 in the direction of

Pressure plate 95 and presses the plate pack, which consists of inner and outer plates 87 and 86, together. To cool the plate pack, hydraulic oil is fed to the inner and outer plates 87 and 86 via the lubricating oil supply 83.

Fig. 3 shows the clutch control 12 in a detailed representation. It has a difference generator 20, a slip regulator 21 and an adapter 22. The slip regulator 21 is explained in more detail in FIG. 6. The difference former 20 determines the clutch slip Δn, which is the input variable in the slip regulator 21. Further input variables of the slip controller 21 include the target clutch slip Δn *, the engine torque T_ _M , the transmission ratio i of the automatic transmission 2 and the friction coefficient μ. The The coefficient of friction μ is formed by means of the adapter 22. Input variables in the adapter 22 are the desired clutch slip Δn *, the translation i of the automatic transmission 2, the torque T _{M of} the internal combustion engine 1, information ΔT _M about the inaccuracy of the information about the torque T _{M of} the internal combustion engine 1 and a differential torque T _R , which is formed by the slip controller 21. In addition to the coefficient of friction μ, a corrected engine torque T _{MK is} another output variable of the adapter 22. The slip regulator 21 also forms the target contact pressure p *.

The clutch control 12 also has a protective device 81 for protecting the drive unit 16, in particular the automatic transmission 2, against torque surges. The output variable of the protective device 81 is an impact torque T _s . In an advantageous embodiment, the impact torque T _{s is} calculated in accordance with

T.-T.-Vj, .---- * _-_-. ^{c Δ ll} Δt

Here, i is the moment of inertia of a 1st component of the drive unit on the side of the clutch 3 on which the internal combustion engine 1 is arranged. Δn _max the maximum permissible clutch slip T _c a constant torque Δt the length of time in which a torque surge leads to an increase in the slip. When so-called torque surges are introduced, in particular torque surges that are introduced into the drive unit by the drive wheels 8 and 9, the automatic transmission 2 can be damaged. The protection of, for example, a variator of a CVT (Continuously Variable Transmission) is particularly critical. Even a brief slipping of such a belt transmission due to a torque surge can lead to permanent damage in the belt transmission. Torque surges of this type occur, for example, when changing from a road surface with a low coefficient of friction to a road surface with a high coefficient of friction. Examples are, for example, the transition from an ice-covered road to a dry road or driving over railroad tracks.

If the slip duration Δt is of minor importance, the impact torque T _s can be _set equal to the constant torque T _c .

In an advantageous embodiment, the impact torque is provided

T _Ξ to be transmitted to a transmission control so that, for example, the

Contact pressure in a belt transmission can be increased accordingly. The required contact pressure in the belt transmission has to be increased depending on the impact torque T _s .

A protective device 81, as exemplified, is used particularly advantageously in combination with the invention. In an exemplary implementation of the invention, clutch controller 12 has an engine torque setpoint generator 91. The engine torque setpoint generator 91 gives a setpoint T _M * for the torque of the internal combustion engine 1, which is supplied to the engine control 14 in an exemplary embodiment. In addition to a torque specification, the target engine torque T _M * can also be specified by an ignition angle specification or a limit value for the engine speed. The value T _M * is advantageously a maximum value for limiting the torque of the internal combustion engine 1.

4 and 5 show flowcharts which are implemented individually or together on the engine torque setpoint generator 91 in an exemplary embodiment. Reference numerals 100 and 109 in FIG. 4 denote the beginning and the end of the process. The process begins with a step 101, in which the clutch input speed n _{E is} read. In a further step 102, the derivative dn _B / dt of the clutch input speed n _{E is} formed. Step 102 is followed by query 103, in which it is queried whether

dn _E ^ d, t, - ⁿ Eliml where n _Elim ι is a predetermined limit. If this condition is met, a value n _E0 becomes in a step 104

ⁿ E0 = ⁿ E

educated. In a further step 105, the engine torque T _{M of} the internal combustion engine 1 is limited. For this purpose, a corresponding target value T _M * is output, which can include a torque specification, an ignition angle specification or a limitation of the maximum engine speed of the internal combustion engine 1 (see above). In step 105, a new value n _{B is} read. Step 105 is also followed by query 106 as to whether ⁿ E0 ⁿ E < ⁿ Elim2

where n _E im2 is a predetermined limit. If the query is not fulfilled, step 105 follows again. If the query is fulfilled, step 107 follows in which the limitation of the engine torque is removed. That means there is no torque specification, ignition angle or the maximum engine speed is limited. Step 107 is followed by a query 108 asking whether the sequence should be ended. If the sequence is not to be ended, step 101 follows again, otherwise the sequence is ended.

Is the condition

dn

> n dt Eliml

of query 103 is not fulfilled, query 10E follows

Reference numerals 110 and 119 in Fig. 5 denote the beginning and the end of the process. The process begins with a step 111, in which the clutch output speed n _{A is} read. In a further step 112, the derivative dn _A / dt of the clutch output speed n _{A is} formed. Step 112 is followed by query 113, in which it is queried whether

- ^ —A- -> _^ j. - n ^xl AIiml where n _A ii _m i is a predetermined limit. If this condition is met, a value n _A o becomes in a step 114 ⁿ A0 ^-I1 A

educated. In a further step 115, the engine torque T _{M of} the internal combustion engine 1 is limited. For this purpose, a corresponding target value T _M * is output, which can include a torque specification, an ignition angle specification or a limitation of the maximum engine speed of the internal combustion engine 1 (see above). In step 113, a new value n _{A is also} read in. Step 115 is followed by query 116 as to whether

ⁿ A0 ⁿ A < ⁿ Alim_

where n _A ii _{ra2 is} a predetermined limit. If the query is not fulfilled, step 115 follows again. If the query is fulfilled, however, step 117 follows in that the limitation of the engine torque is canceled, ie there is no torque specification, ignition angle specification or limitation of the maximum engine speed. Step 117 is followed by a query 118 asking whether the sequence should be ended. If the process is not to be ended, step 111 follows again, otherwise the process is ended.

Is the condition

dt

query 113 is not fulfilled, query 118 follows. 6 shows the internal structure of the slip regulator 21. The slip regulator 21 has a filter 31 for filtering the clutch slip Δn. The difference between the target clutch slip Δn * and the clutch slip Δn filtered by the filter 31 is formed by means of a summer 36. This difference is negated by means of a negator 32 and is an input variable in a controller 33, which in an advantageous embodiment is designed as a PID controller. The output variable of the controller 33 is the differential torque T _R.

The engine torque T _{M is} filtered by means of a filter 34 and multiplied by the multiplier 90 by the gear ratio i of the automatic transmission 2. The product of engine torque T _M and translation of the automatic transmission 2 is added by means of a summer 37 to the output of a minimal generator 82, which compares the differential torque T _R and the impact torque T _s and outputs the smaller torque as an output value. The sum of the product of the engine torque T _M and the translation i of the automatic transmission 2 and the maximum of the differential torque T _R and the impact torque T _s is the clutch torque T _κ to be transmitted by the clutch 3, which together with the coefficient of friction μ is the input value in an inverse clutch model 35 is. In an exemplary embodiment, the following equation is implemented in the inverse clutch model 35:

, *. = - ^ + F ₀

A. -rZ _p

A _{R is} the piston surface of clutch 3, r is the effective friction radius of clutch 3, Z _{R is} the number of friction surfaces Clutch 3 and F ₀ the minimum force required for torque transmission by means of clutch 3.

LIST OF REFERENCE NUMBERS

1 engine 2 gearbox 3 clutch

4 wave

5 clutch input shaft

6 clutch output shaft 7 differential

8, 9 drive wheels

10, 11 speed sensors

12 clutch control

14 Engine control

15 Vehicle control

16 drive unit

20 difference formers

21 hatchlings

22 adapters

31, 34 filters

32 negators

33 controllers

35 inverse clutch model

36, 37 totalizers

100, 110 Start of the process

101, 102, step

104, 105,

107, 111,

112, 113

114, 115, 117

103, 106, query

108, 113, 116, 118,

109, 119 end of process

81 Protective device 82 Minimum value generator 83 Lube oil supply 84 Outer driver 85 Inner driver 86 Outer plate 87 Inner plate 88 Return spring 90 Multiplier 91 Motor torque setpoint device 93 Cylinder 94 Piston 95 Pressure plate 96 Pressure medium supply

n _E Speed of the clutch input shaft n _A Speed of the clutch output shaft T Information about the engine torque ΔT _M Inaccuracy of the information about the engine torque

Differential torque (controller output) τ _k clutch torque

Δn clutch slip

Δn * Desired clutch slip i transmission ratio

P contact pressure p * target contact pressure μ friction coefficient

Moment of inertia of the drive unit on the

Side of the clutch 1, on which the

Internal combustion engine is arranged.

Δn _ma χ maximum permissible clutch slip constant torque

A _R clutch piston area r effective clutch friction radius

ZR Number of friction surfaces of the clutch t Time Δt Time period in which a torque surge occurs

Leads to increased slip

TMK corrected engine torque Fo minimal force required

Torque transmission via the clutch

T _s impact torque T _M * Setpoint for the torque of the internal combustion engine d () / dt derivative

HEliml predefined limit value n _E l m2 predefined limit value n _A liml predefined limit value n _A lim2 predefined limit value n _E o value n _A o value

Claims

claims

1. Method for operating a drive unit (16) for a vehicle with at least one drive wheel (8, 9), the drive unit (16) having an internal combustion engine (1) and one between the internal combustion engine (1) and the at least one drive wheel (8, 9) arranged clutch (2) for transmitting a torque between the internal combustion engine (1) and the drive wheel (8, 9), characterized in that the internal combustion engine (1) depending on the speed of the clutch (2) on the side of the internal combustion engine ( 1) and / or the speed of the clutch (2) on the side of the drive wheel (8, 9) is controlled or regulated.

2. The method according to claim 1, characterized in that the internal combustion engine (1) as a function of the time derivative of the speed of the clutch (2) on the side of the internal combustion engine (1) and / or the time derivative of the speed of the clutch (2) on the Side of the drive wheel (8, 9) is controlled or regulated.

3. The method according to claim 1 or 2, characterized in that a setpoint for the torque of the internal combustion engine (1) as a function of the speed of the clutch (2) on the side of the internal combustion engine (1) and / or the speed of the clutch (2) the side of the drive wheel (8, 9) is determined.

4. Method for operating a drive unit (16) for a vehicle with at least one drive wheel (8, 9), the Drive unit an internal combustion engine (1) and one between the internal combustion engine (1) and the at least one drive wheel

(8, 9) arranged clutch (2) for transmitting a

Has moment between the internal combustion engine (1) and the drive wheel (8, 9), characterized in that the internal combustion engine (1) depending on the time derivative of the speed of the clutch (2) on the side of the internal combustion engine (1) and / or the time Deriving the speed of the clutch (2) on the side of the drive wheel (8, 9) is controlled or regulated.

5. The method of claim 2, 3 or 4, d a d u r c h g e k e n n z e i c h n e t that a setpoint for the torque of the internal combustion engine

(1) depending on the time derivative of the speed of the clutch (2) on the side of the internal combustion engine (1) and / or the time derivative of the speed of the clutch

(2) on the side of the drive wheel (8, 9) is determined.

6. The method according to claim 3 or 5, d a d u r c h g e k e n n z e i c h n e t that the internal combustion engine (1) is controlled or regulated depending on the target value.

7. The method according to any one of the preceding claims, d a d u r c h g e k e n n z e i c h n e t that the torque of the internal combustion engine (1) is limited and / or that the setpoint is a maximum value that should not be exceeded.

8. The method according to any one of claims 2 to 6, characterized in that the torque of the internal combustion engine (1) is limited when

dn

- ⁿ Eliml German

where n _{E is} the speed of the clutch (2) on the side of the internal combustion engine (1) and n _E ii _m ι is a predetermined limit value, and / or that the torque of the internal combustion engine (1) is limited if

dn, -> d jt, - - ^x n ⁱ Aliml

where n _{A is} the speed of the clutch (2) on the side of the drive wheel (8, 9) and n _A ii _m ι is a predetermined limit.

9. The method according to claim 8, characterized in that ^' the limitation of the torque of the internal combustion engine (1) is ended when

ⁿ E0 ~ ⁿ E ⁿ Elim ₂

where n _E ii _{m2 is} a predetermined limit value and n _E o is the speed of the clutch (2) on the side of the internal combustion engine (1) at the time at which the limitation was started and / or that the limitation of the torque of the internal combustion engine (1) is terminated if, in particular, ⁿ A0 ⁿ A ^<n AU 2

where n _A ii _{m2 is} a predetermined limit value and n _{A0 is} the speed of the clutch (2) on the side of the drive wheel (8, 9) at the time at which the limitation was started.

10. Drive unit (16) for a vehicle with at least one drive wheel (8, 9), in particular according to a method according to one of the preceding claims, operable drive unit (16), wherein the drive unit (16) one

Internal combustion engine (1) and one between the internal combustion engine

(1) and the at least one drive wheel (8, 9) arranged

Coupling (2) for transmitting a torque between the

Combustion engine (1) and the drive wheel (8, 9), characterized in that the drive unit (16) has a vehicle control (15) for controlling or regulating the internal combustion engine (1) depending on the speed of the clutch (2) on the side of the internal combustion engine (1) and / or the speed of the clutch (2) on the side of the drive wheel (8, 9).

11. Drive unit (16) for a vehicle with at least one drive wheel (8, 9), in particular according to a method according to one of the preceding claims, operable drive unit (16), the drive unit (16) having an internal combustion engine (1) and one between the internal combustion engine (1) and the at least one drive wheel (8, 9) arranged clutch (2) for transmitting a torque between the internal combustion engine (1) and the drive wheel (8, 9), characterized in that that the drive unit (16) a vehicle control (15) for

Control or regulation of the internal combustion engine (1) in

Dependence of the time derivative of the speed of the

Has clutch (2) on the side of the internal combustion engine (1) and / or the time derivative of the speed of the clutch (2) on the side of the drive wheel (8, 9).

12. Vehicle control (15) for a vehicle with at least one drive wheel (8, 9) and a drive unit (16), in particular according to a method according to one of claims 1 to 9, operable drive unit (16), wherein the drive unit (16) is an internal combustion engine (1) and a between the internal combustion engine (1) and the at least one drive wheel (8, 9) arranged clutch (2) for transmitting a torque between the internal combustion engine (1) and the drive wheel (8, 9), characterized in that the Vehicle control (15) for controlling or regulating the internal combustion engine (1) depending on the speed of the clutch (2) on the side of the internal combustion engine (1) and / or the speed of the clutch (2) on the side of the drive wheel (8, 9) is trained.

13. Vehicle control (15) for a vehicle with at least one drive wheel (8, 9) and a drive unit (16), in particular according to a method according to one of claims 1 to 9 operable drive unit (16), wherein the drive unit (16) is an internal combustion engine (1) and a clutch (2) arranged between the internal combustion engine (1) and the at least one drive wheel (8, 9) for transmitting a torque between the internal combustion engine (1) and the drive wheel (8, 9), characterized in that that the vehicle controller (15) for controlling or regulating the internal combustion engine (1) as a function of the time derivative of the speed of the clutch (2) on the side of the internal combustion engine (1) and / or as a function of the time derivative of the speed of the clutch (2) is formed on the side of the drive wheel (8, 9).