DE102019205392B3 - Manual double clutch transmission for a motor vehicle - Google Patents

Abstract

Comprising dual clutch transmission (1) for a motor vehicle
- a first clutch (2) and a second clutch (3),
- A first transmission input shaft and a second transmission input shaft, the first transmission input shaft being connectable to a drive unit via the first clutch (2) and the second transmission input shaft via the second clutch (3),
- at least one gear output shaft,
- Several shiftable gears for connecting the transmission input shafts to the transmission output shaft, one gear being assigned to a transmission input shaft and thus one of the two clutches (2, 3) and
- An actuator system, the actuator system having a shift mechanism (4) for shifting a target gear and a clutch mechanism for actuating the clutch (2, 3) assigned to the target gear, both the shift mechanism (4) and the clutch mechanism being purely mechanical and by a motor vehicle driver , namely manually, are designed to be actuatable.

Description

Field of invention

The present invention relates to dual clutch transmissions for a motor vehicle comprising a first clutch and a second clutch, a first transmission input shaft and a second transmission input shaft, the first transmission input shaft being connectable to a drive unit via the first clutch and the second transmission input shaft via the second clutch, at least one transmission output shaft , several shiftable gears for connecting the transmission input shafts with the transmission output shaft, one gear being assigned to a transmission input shaft and thus one of the two clutches, and an actuator system, the actuator system having a shift mechanism for shifting a target gear and a clutch mechanism for actuating the clutch assigned to the target gear , both the switching mechanism and the clutch mechanism being purely mechanical.

State of the art

Double clutch transmissions have two sub-transmissions, one of which is used actively for power transmission and the other is inactive. In the inactive part, a target gear is then usually preselected, so that a gear change from a source gear to the target gear can take place by overlapping actuation of two friction clutches. The actuation of all of these processes usually takes place hydraulically, pneumatically and / or electrically and is automatically controlled by a control unit.

The document DE 10 2016 107 136 A1 describes, for example, a shift arrangement for a drive train of a motor vehicle with a plurality of shift clutch packs, each having one or two shift clutches, each shift clutch being designed to engage or disengage a gear stage of the drive train. Furthermore, the switching arrangement has a manual switching unit and an automated switching unit. The manual shift unit is designed to use a manually operable shift lever to perform a selection movement for selecting at least one of the shift clutch packs and a shift movement for engaging a gear of the selected shift clutch pack. The automated shift unit has at least one actuator and is designed to use the at least one actuator to execute a selection movement for selecting at least one of the clutch packs and a shift movement for engaging a gear of the selected clutch pack.

The document DE 10 2013 223 615 A1 discloses a motor vehicle transmission arrangement for a drive train of a motor vehicle, comprising a motor vehicle transmission and a starting element connected upstream of the motor vehicle transmission, the actuation of which can be automatically regulated. The motor vehicle transmission also has a selection device via which a shift in the motor vehicle transmission can be specified manually. In order to be able to carry out a gear change in addition to an automatic actuation of a gear change in a manner modeled on a manual transmission, a shift in the motor vehicle transmission is provided in addition to an automatic control and a manual specification via the selection device. Furthermore, a control device is assigned to the starting element, via which actuation of the starting element can be controlled manually in addition to the automatic regulation.

The document DE 10 2018 209 326 A1 describes a manual transmission for a hybrid drive train with a transmission input shaft and a transmission output shaft, the manual transmission having at least two countershafts.

Summary of the invention

It is an object of the invention to provide an alternatively designed dual clutch transmission which is characterized in particular by a low susceptibility to failure and an individual actuation system, namely that corresponds to the motor vehicle driver's wishes.

This need can be met by the subject matter of the present invention according to independent claim 1. Advantageous embodiments of the present invention are described in the dependent claims. Further developments of the invention are given in the dependent claims, the description and the accompanying drawings.

The dual clutch transmission according to the invention for a motor vehicle comprises a first clutch and a second clutch, a first transmission input shaft and a second transmission input shaft, wherein the first transmission input shaft can be connected to a drive unit via the first clutch and the second transmission input shaft via the second clutch, at least one transmission output shaft, several Shiftable gears for connecting the transmission input shafts with the transmission output shaft, one gear being assigned to a transmission input shaft and thus one of the two clutches and an actuator system.

According to the present invention, the actuator system has a shift mechanism for shifting or preselecting a target gear and a clutch mechanism for actuating the clutch assigned to the target gear. According to the invention, both the shift mechanism and the clutch mechanism are purely mechanical and can be actuated by a motor vehicle driver, namely manually.

The shift mechanism preferably has at least one shift drum for shifting a gear, the gears assigned to the shift stage, an adjustment element decoupled from the shift drum for adjusting the shift drum, which is preferably designed to be actuated by a motor vehicle driver, and a pretensioning mechanism for actuating the clutch assigned to the target gear, wherein the adjusting element is connected to the biasing mechanism.

The pretensioning mechanism preferably has a transmission unit with an eccentric element and a pretensioning lever, a pretensioning spring acting between the eccentric element and the pretensioning lever and the pretensioning lever being firmly connected to a piston rod.

The clutch mechanism preferably has a guide element, a piston rod lever and a piston, the guide element preferably being designed to be actuatable by the motor vehicle driver and being connected to the piston rod lever in an adjustable manner, which is fixedly connected to the piston rod and the piston is rotatably or fixedly arranged on the piston rod and at least partially protrudes into the area between the first clutch and the second clutch.

The guide element preferably has a guide groove into which the piston rod lever partially protrudes, the guide groove having a contour which is designed such that the guide element can be adjusted in three positions, namely in a first position, in a second position and in a neutral position between the first position and the second position.

A number of advantages result from the present invention. For example, it is not necessary to change the operating sequences for conventional sequential shifts, such as a conventional manual transmission. The shifting process takes place as with a manual sequential transmission with the advantage of completing the gear selection before the actual clutch change. The system also has a high level of safety, for example the piston cannot close both clutches at the same time and the guide grooves in the shift drum prevent two gears from being engaged in a partial transmission. In addition, highly dynamic gearshifts are possible without the gearshift mechanism experiencing a greatly increased load. The reduction of the engine torque is no longer necessary to the same extent. During the period of the interruption of the tractive effort, namely when the guide element is in the neutral position, the engine is accelerated. When the clutch is closed, this dynamic torque, which occurs when the engine decelerates, can be used to accelerate the vehicle. In conventional coupling processes, the piston has to be pushed away from the coupling and then moved back in the other direction towards the coupling to close, which in turn requires a time-consuming reversal of direction. In addition, the gear is already engaged. The fact that in the dual clutch transmission according to the invention the piston movement occurs only in one direction when changing gear and the target gear is already engaged, it is possible to optimize the shift times.

Figure list

• 1 zeigt eine schematische Darstellung eines beispielhaften Doppelkupplungsgetriebes.
• 2 zeigt eine schematische Schnittansicht einzelner Komponenten eines beispielhaften Doppelkupplungsgetriebes, insbesondere eines Vorspannmechanismus.
• 3a-3e zeigen schematisch einen Hochschaltvorgang eines erfindungsgemäßen Getriebes, wobei immer nur Ausschnitte einzelner Komponenten eines Doppelkupplungsgetriebes zu sehen sind.

The invention is described below by way of example with reference to the drawings.

• 1 shows a schematic representation of an exemplary dual clutch transmission.
• 2 shows a schematic sectional view of individual components of an exemplary dual clutch transmission, in particular a pretensioning mechanism.
• 3a-3e show schematically an upshift process of a transmission according to the invention, only sections of individual components of a double clutch transmission being shown.

Detailed description of the invention

In the following, the 1 and the 2 a possible embodiment of a dual clutch transmission according to the invention 1 described.

This in 1 double clutch transmission shown schematically 1 has a double clutch with a first clutch 2 and a second clutch 3 , a first transmission input shaft and a second transmission input shaft, the first transmission input shaft via the first clutch 2 and the second transmission input shaft via the second clutch 3 Can be connected to a drive unit, a transmission output shaft and several shiftable gears for connecting the transmission input shafts to the transmission output shaft.

The gears are designed as gear pairs between the transmission output shaft and the transmission input shafts, each consisting of an idler gear arranged around one of the shafts that can be connected to it in a rotationally fixed manner, and a fixed gear meshing with it and arranged in a rotationally fixed manner on a corresponding shaft to form gears with different gear ratios between the transmission output shaft and one of the transmission input shafts. A loose wheel is connected to the shaft on which it is located in a rotationally fixed manner via a clutch.

Each of the gears is assigned to a transmission input shaft and thus to one of the two clutches.

As is known, in motor vehicles with a dual clutch transmission, one of the gears is engaged during normal driving and the clutch connected to the corresponding transmission input shaft to which the relevant gear is assigned is closed. During a shift, a target gear assigned to the other, open clutch is first shifted. A transition from the selected active gear to the target gear then takes place by simultaneously opening the clutch of the active gear and closing the clutch of the target gear.

The dual clutch transmission also has an actuator system. The actuator system is purely mechanical and has a switching mechanism 4th and a clutch mechanism. The switching mechanism 4th is used for shifting or preselecting a target gear; the clutch mechanism is used to actuate the clutch concerned 2 , 3 . Both the switching mechanism 4th as well as the clutch mechanism are purely mechanical ( 1 , 2 ).

The switching mechanism 4th includes a shift drum 6th , an adjustment element 7th and a biasing mechanism 8th ( 1 , 2 ).

The shift drum 6th serves to operate the clutches. The shift drum 6th has a shift drum contour into which a driver connected to a shift fork engages in such a way that rotational movements of the shift drum 6th be implemented in axial movements of the shift fork. The shift fork is connected to the shift clutches for adjustment ( 1 ).

The adjustment element 7th is connected to an input device, namely a shift lever. The adjustment element 7th can be adjusted in this way by an input from the motor vehicle driver by means of the shift lever. Furthermore, the adjustment element 7th from the shift drum 6th executed decoupled, whereby a degree of freedom between the direct specification of the motor vehicle driver via the shift lever and the shift drum 6th results. The contact side of the shift drum is decisive here 6th to adjustment element 7th . If the shift direction is reversed (upshifting or downshifting), the system side is only changed due to the degree of freedom. As a result, the currently engaged gears remain engaged, only the one open clutch 2 , 3 is preloaded to change.

The preload mechanism 8th includes a translation unit 9 with an eccentric element 10 , a preload spring 12 , namely a push-pull spring and a preload lever 11 attached to a piston rod 13 is attached. The tension-compression spring acts between the eccentric element 10 and the preload lever 11 ( 1 , 2 ).

The adjustment element 7th is directly with the translation unit 9 the preload mechanism 8th connected. Each time the motor vehicle driver intervenes using the gearshift lever, the eccentric element is rotated 10 by preferably 180 °.

The design of the preload spring 12 can also use the radius of the eccentric element in addition to the force-displacement curve characteristic of the spring 10 and the lever arm length on the piston rod 13 respectively.

The clutch mechanism comprises a guide element 14th , a piston rod lever 15th as well as a piston 16 ( 1 , 2 ).

The guide element 14th is connected to an input device, namely a clutch lever, and is adjustable by means of an input from the motor vehicle driver by means of the clutch lever. In the present embodiment, the clutch lever is via a clutch cable 19th with the guide element 14th connected for adjustment ( 2 ). By pulling on the clutch lever, this is done with the clutch cable 19th connected guide element 14th pulled from a first position to a second position ( 2 , 3a-3e) . 3a , 3b and 3c show the guide element 14th in a first position. 3d shows the guide element in the neutral position and 3e shows the guide element 14th in a second position.

The guide element 14th has a guide groove 17th into which the piston rod lever 15th partially protrudes. The guide groove 17th has a contour 18th on, which is designed such that an adjustment of the guide element 14th in three positions, namely in a first position, in a second position and in a neutral position between the first Position and the second position, is actuatable. The first clutch is in the first position 2 actuated. The second clutch is in the second position 3 actuated. The neutral position is a third position between the first position and the second position in which neither the first clutch 2 still the second clutch 3 is actuated.

The piston rod lever 15th is thus adjustable with the guide element 14th connected. Furthermore is the piston rod lever 15th firmly to the piston rod 13 and thus indirectly with the preload lever 11 the preload mechanism 8th that is just as firmly attached to the piston rod 13 connected, connected.

The piston 16 is firmly on the piston rod 13 arranged and partially protrudes into the area between the first clutch 2 and the second clutch 3 . The piston is also conceivable 16 rotatable on the piston rod 13 to arrange.

The piston rod 13 thus forms the interface between the switching mechanism 4th and the clutch mechanism. During the motor vehicle driver the piston rod 13 directly over the guide element 14th actuated, acts simultaneously through the switching mechanism 4th a preload force on the piston rod 13 . Both the switching mechanism 4th just like the clutch mechanism, it applies a force to the piston rod 13 on that via the lever arms, namely the preload lever 11 and the piston rod lever 15th , into a torque of the piston rod 13 is converted and, for example, a worm gear (not shown) in turn into an axial force on the piston 16 , which is the contact pressure on the respective clutch to be closed 2 , 3 guaranteed ( 3a-3e) .

The following describes a shift sequence beginning with the motor vehicle driver's intervention in the shift mechanism 4th and the clutch mechanism by way of example 3a to 3e described. This is an upshift from a lower source gear to a higher target gear, for example from a third gear to a fourth gear.

The motor vehicle driver wishes to change gear and operates the gearshift lever. When the shift lever is operated, the adjustment element is rotated 7th that is directly connected to the gear lever. Depending on the relative position between the shift drum and the adjusting element, the shift drum is also rotated or remains in its position. The target gear is preselected and the currently active gear, the source gear, is still engaged. With the rotation of the adjustment element 7th becomes the pretensioning mechanism at the same time 8th activated. Due to the rigid coupling of the translation unit 9 to the adjustment element 7th this is rotated with each actuation of the motor vehicle driver on the shift lever.

Due to the eccentrically mounted preload spring 12 acts depending on the position of the eccentric element 10 , via the preload lever 11 a preload force on the piston rod 13 ( 3a-3c ). After this process, the contact pressure of the piston 16 on the currently closed clutch, namely the first clutch 2 , reduced by the biasing force in the direction of the other clutch, namely the second clutch 3 ( 3c ). When the clutch lever is actuated, the piston 16 starting from the first position in the neutral position, in which neither the first clutch 2 still the second clutch 3 is closed, moved ( 3d ). The piston 16 is between the first clutch 2 and the second clutch 3 and does not actuate the first clutch 2 still the second clutch 3 . On the piston rod 13 now acts through the pretensioning mechanism 8th resulting power. This biasing force of the biasing spring 12 has a directional effect on the piston rod 13 . With releasing clutch actuation, i.e. a transfer of the guide element from the neutral position to the second position ( 3d , 3e) , becomes the second clutch 3 closed and the shifting process or the gear change ended.

List of reference symbols

1

Double clutch

2

First clutch

3

Second clutch

4th

Switching mechanism

6th

Shift drum

7th

Adjustment element

8th

Pretensioning mechanism

9

Translation unit

10

Eccentric element

11

Preload lever

12

Preload spring

13

Piston rod

14th

Guide element

15th

Piston rod lever

16

piston

17th

Guide groove

18th

Contour (of the guide groove)

19th

Clutch cable

Claims (5)

Comprising dual clutch transmission (1) for a motor vehicle - a first clutch (2) and a second clutch (3), - A first transmission input shaft and a second transmission input shaft, the first transmission input shaft being connectable to a drive unit via the first clutch (2) and the second transmission input shaft via the second clutch (3), - at least one gear output shaft, - Several shiftable gears for connecting the transmission input shafts to the transmission output shaft, one gear being assigned to a transmission input shaft and thus one of the two clutches (2, 3) and - An actuator system, the actuator system having a shift mechanism (4) for shifting a target gear and a clutch mechanism for actuating the clutch (2, 3) assigned to the target gear, both the shift mechanism (4) and the clutch mechanism being purely mechanical and by a motor vehicle driver , namely manually, are designed to be actuatable. Dual clutch transmission (1) Claim 1 , characterized in that the shift mechanism (4) has at least one shift drum (6) for shifting the gears assigned to a shift stage, an adjusting element (7) decoupled from the shift drum (6) for adjusting the shift drum (6) and a pretensioning mechanism (8) for Actuation of the clutch (2, 3) assigned to the target gear, the adjusting element (7) being connected to the pretensioning mechanism (8). Dual clutch transmission (1) Claim 2 , characterized in that the pretensioning mechanism (8) has a transmission unit (9) with an eccentric element (10) and a pretensioning lever (11), a pretensioning spring (12) acting between the eccentric element (10) and the pretensioning lever (11) and wherein the pretensioning lever (11) is firmly connected to a piston rod (13). Dual clutch transmission (1) according to one of the Claims 1 to 3 , characterized in that the coupling mechanism has a guide element (14), a piston rod lever (15) and a piston (16), the guide element (14) being connected to the piston rod lever (15) in an adjustable manner, which in turn is fixed to a piston rod (13 ) is connected and wherein the piston (16) is rotatably or fixedly arranged on the piston rod (13) and at least partially protrudes into the area between the first coupling (2) and the second coupling (3). Dual clutch transmission (1) Claim 4 , characterized in that the guide element (14) has a guide groove (17) into which the piston rod lever (15) protrudes at least partially, the guide groove (17) having a contour (18) which is designed such that an adjustment of the Guide element (14) can be actuated in three positions, namely in a first position, in a second position and in a neutral position between the first position and the second position.

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