DE102011016637A1 - Gearbox for motor vehicle, particularly passenger car, comprises shift device formed as cable-controlled gearshift, and four shift forks for operation of four synchronizing units, where shift device comprises shift shaft - Google Patents

Abstract

The gearbox comprises a shift device formed as a cable-controlled gearshift (10), and four shift forks (22) for operation of four synchronizing units. The shift device comprises a shift shaft (11) with three shift fingers (14,15,16) and three blocking portions. Each shift fork is operated by a shift finger during the blocking of the non-actuated shift forks by the blocking portions. Two shift fingers are provided for the actuation of two shift forks, and the other two shift fingers are provided for actuating a single shift fork.

Description

In a H-circuit of a motor vehicle, a rotary-sliding mechanism ensures that the movement of the gear lever, the shift pawl is operated, which shifts the responsible for the selected gear shift fork with the shift sleeve on a countershaft back and forth. By a movement of the gear lever in the switching direction (forward-back) through the idle lane or Wählgasse a rotational movement of a shift shaft is triggered in the transmission. The switching shaft engages via a shift finger in a shift mouth of a shift fork or shift claw, which can be moved in two directions. A shift sleeve, which is shifted by the shift fork on the shaft, is responsible for two gears or for reverse gear.

A forward-backward movement of the shift lever causes a shift of the shift fork, and a right-left movement selects another shift fork. This results in an H-shaped arrangement in a shift gate. By sliding the shift lever or shift knob in the shift gate of the selected gear a shift sleeve is pushed onto a countershaft. H-circuits allow for a free gear selection, where you can switch from one gear to another.

It is an object of the present application to provide an improved locking system for a manual transmission of a passenger car.

For this purpose, the present application discloses a switching device for a mechanical circuit of a motor vehicle transmission. Mechanical circuit means in this context, in particular a wire draw circuit, but also a rod circuit or the like, but in any case a manual circuit in contrast to about an automatic or mechatronics. The shift device has at least four shift forks for operating four synchronizers. Furthermore, the switching device has a switching shaft with at least three switching fingers and with at least three blocking regions. Each shift fork is operable by at least one shift finger, while the non-actuated shift forks are blocked by a blocking region. By blocking region is meant in particular a surface of at least one blocking cylinder. Further, one of the shift fingers for actuating two shift forks is provided and the other two shift fingers are each provided for operating a single shift fork. The selection of a shift fork is done by changing the shift gate, which causes a lifting or lowering of the shift shaft.

A switching device according to the application is particularly well suited for transmission with two countershafts or output shafts, because then it is easily possible to arrange the reverse gear in the circuit diagram with respect to the shift gate of the first and second gear. This is possible in particular for six gears, but also in other similar cases, such as eight gears, etc.

The application takes into account that the two provided for starting gears in the diagram can be easily arranged on different sides of the H-circuit diagram, so that a connection - as it might otherwise occur, is easily prevented. Furthermore, it can be achieved with a switching device according to the application that a reverse gear, which is provided on a separate shift gate, is blocked by lock cylinders when one of the other shift gates is selected. These favorable properties are achieved according to the application by a suitable design of components connected to a switching shaft, without it being necessary to make changes to the components located between a gear lever and the point of application of the cables or rods.

For this purpose, a shift finger is designed as a single-speed shift finger, which serves to actuate a single shift fork, which engages in a single-acting synchronizer. Another shift finger is designed so that it engages via a shift fork in a double-acting synchronizer. Another shift finger is designed as a four-speed shift finger, which selectively engages in one of two shift forks, which in turn engage in two double-sided synchronizers. The selection of the shift fork is done by selecting a shift gate.

According to a particular embodiment, the single-gear shift finger acts on a reverse gear, that is, a movement of the shift finger engages or disengages the reverse gear. Further, the two-speed shift finger acts on third and fourth gears, and the four-speed shift finger acts on first and second gears upon selection of a first shift gate and on fifth and sixth gears on selection of a second shift gate.

Specifically, the single-speed shift finger and the two-speed shift finger may be disposed in blocking regions of a first lock cylinder and the four-speed shift finger be arranged in a blocking region of a second blocking cylinder. According to another embodiment with three instead of two blocking cylinders, the single-speed shift finger is disposed in a blocking region of a first blocking cylinder, the two-speed shifting finger is disposed in a blocking region of a second blocking cylinder, and the four-speed shifting finger is disposed in a blocking region of a third blocking cylinder.

In a specific embodiment, furthermore, the single-speed shift finger and the two-speed shift finger are disposed above the four-speed shift finger. Depending on the transmission structure and vice versa, the single-gear shift finger and the two-speed shift finger can be arranged below the four-speed shift finger. Furthermore, the single-gear shift finger may be disposed above the two-speed shift finger.

To achieve the blocking effect of the four-speed shift finger may be arranged in particular in the lower region of a blocking cylinder, d. H. below the middle of the blocking cylinder.

The application relates in particular to a switching device in which the switching device is designed as a cable pull circuit in which a cable and a shift weight shifts a selector shaft along its axis and wherein the displacement of the selector shaft along its axis causes a displacement of the shift finger.

Further, the present application discloses a transmission having a shifting device according to the application, wherein fixed gears for a first, second, third, fourth and fifth and sixth gear are arranged on a main shaft, loose wheels for a first, second, fifth and sixth gear on one first countershaft are arranged. Idler gears for a third gear, a fourth gear and a reverse gear are arranged on a second countershaft.

In particular, it is advantageous to drive the reverse gear from the same fixed gear as the first gear. It follows that the reverse gear is arranged on a different output or countershaft as the first gear.

The single shift finger operates a shift fork of a one-way synchronizer, the two-speed shift finger operates a shift fork of a two-way synchronizer and the four-speed shift finger selectively operates a shift fork of a first two-way synchronizer or a shift fork of a second two-way synchronizer. Wherein in particular a second countershaft can be arranged above the first countershaft.

According to the application further discloses a motor vehicle, in particular a car, with a transmission according to the application.

The subject of the application will now be explained in more detail with reference to the following figures.

1 shows a partial perspective view of a cable pull circuit according to the application, and

2 shows a partial side view of a Seilzugschaltung according to the application, and

3 shows a transmission with a cable circuit according to the application.

1 shows a partial perspective view of a cable pull circuit 10 a vehicle transmission according to the application. The cable pull circuit 10 has a switching shaft 11 on. On the shift shaft 11 is an upper blocking cylinder 12 and a lower blocking cylinder 13 arranged. The upper locking cylinder 12 has two shift fingers 14 . 15 on, which are arranged one below the other. The lower blocking cylinder has a shift finger 16 on. There are recesses in the blocking cylinders 17 . 18 . 19 , which are each at the level of the shift finger and allow a lateral movement of Schaltmäulern. For each one shift gate of the cable pull circuit 10 Synchronizing unit is a switching jaw available, but is in 1 for the sake of clarity, only a switching mouth 20 shown.

Each of the shifters 20 is with a guide tube 21 connected, which is movable on a rod parallel to a transmission shaft. At one end of the guide tube 21 is a shift fork 22 provided, which engages in a sliding sleeve, not shown here. For clarity, the gear shaft and the rod are in 1 also omitted.

At an upper end of the stem 11 is a head 23 provided with a shift weight 24 is provided. Laterally on the head 23 there is a guide groove 25 engage in the roles of a bell crank, the in 1 not shown. The lever is in turn attached to a switch cover. The switch cover is in 1 omitted for the sake of clarity, but it is in 2 displayed.

At an approach of the shift weight 24 is an end of a shift cable 26 attached. One end of a selector cable, not shown here, is attached to the reversing lever, not shown here. Furthermore, on the upper blocking cylinder 12 a main contour 27 provided for guiding the shift shaft.

A selection movement for selecting a shift gate causes a translation of the shift shaft 11 by a double arrow 28 is indicated. By the translation of the switching shaft 11 Depending on the selected position, a different shift finger 14 . 15 . 16 With the corresponding shift fork engaged. A shift to select a gear causes the shift shaft 11 and thereby the shift fingers 14 . 15 . 16 perform a rotation by a defined switching angle, which in 1 by a double arrow 29 is marked. The shift finger 15 in the fork mouth 20 the shift fork 22 engages, shifts the shift fork 22 , which in turn engages in the sliding sleeve, not shown here. By the movement of the sliding sleeve a synchronizing unit for engaging or disengaging a loose wheel of a transmission is actuated. Synchronizer unit, idler gear and gearbox are in for simplicity 1 omitted. The locking cylinder 12 . 13 prevent inadvertent shifting of shift forks, which are not involved in the switching process.

2 shows a further view of the cable pull circuit 10 according to the application with attached switch cover 30 , Distances along the longitudinal axis of the switching shaft 11 are given in mm. On the switch cover 30 is the above-mentioned lever 31 attached to the guide groove 25 engages in 2 due to the switch cover is not recognizable.

In the inset of 2 below the switching shaft 11 the circuit diagram is shown by a cable switching circuit 10 realized according to the application. The wiring diagram has a selector gate 32 and four shift gates 33 on. From left to right these are: a 1-2 shift lane, a 3-4 shift lane, a 5-6 shift lane and an R shift lane. A neutral point is indicated by a black dot on the 3-4 shift gate.

When the reverse gear shift is selected, the top shift finger engages 14 in a shift jaw, which is connected to a shift fork, which serves to operate a one-sided synchronizer of a reverse gear. At the same time, the upper blocking cylinder blocks 12 Gear change of the other shift lanes 1-2, 3-4 and 5-6.

If the 3-4 shift gate is selected, the second upper shift finger engages 14 to a shift jaw connected to a shift fork for operating a two-way third and fourth speed synchronizer. At the same time, the upper blocking cylinder blocks 12 Gear change of the other shift lanes 1-2, 5-6 and R.

When selecting the 1-2 shift gate, the bottom shift finger engages 16 into a shift jaw connected to a shift fork which serves to operate a two-way synchronizer for a first and a second gear. At the same time the lower blocking cylinder blocks 13 Gear change of the shift gates 5-6 and the upper lock cylinder 12 Gear change of the shift lanes 3-4 and R.

When selecting the 5-6 shift gate, the lowest shift finger engages 16 into a shift jaw connected to a shift fork which serves to operate a two-way fifth and sixth speed synchronizer. At the same time the lower blocking cylinder blocks 13 Gear change of the shift lanes 1-2 and the upper lock cylinder 12 Gear change of the shift lanes 3-4 and R.

By a wire draw circuit according to the application, the engagement of the reverse gear is blocked when the shift gate for the reverse gear is not selected. Therefore, a separate device for blocking the reverse gear is not required. If desired, however, an additional mechanism may be provided to prevent manual misoperation that might arise when a driver attempts to engage a non-existent seventh gear. The risk of misoperation of the reverse gear is, however, lower in a shift arrangement according to the application than, for example, in a shift arrangement in which the reverse gear is located to the left of the 1-2 shift gate.

Further modifications and modifications are possible. For example, the operation can be replaced by a cable through a rod or rod circuit. In the cable pull circuit is advantageous that the vibrations of the transmission are not transmitted directly to the shift lever, whereas the rod circuit has the advantage that a more direct operation with less friction is possible in general. Furthermore, the blocking cylinder 12 . 13 be contoured to modify the switching force when engaging and disengaging the gears in a desired manner.

3 shows a gearbox 35 with a cable circuit according to the application. A main wave 36 is with an engine block 37 via a clutch 38 connected. A lower output shaft 39 has idler gears 40 . 41 . 42 . 43 for a first, second, fifth and sixth gear. An upper output shaft 44 has idler gears 45 . 46 . 47 for a reverse gear, a third gear and a fourth gear. The idler gears for the first to sixth gears are each equipped with a fixed gear on the main shaft 36 engaged. The idler wheel 45 the reverse gear is via a fixed gear 48 on a diversion shaft 49 with a fixed bike 50 on the main shaft 36 connected.

Between the idler gears of the first and second gears, between the idler gears of the fifth and sixth gears, and between the idler gears of the third and fourth gears, there is a double-acting synchronizer 51 . 52 . 53 intended. Side of the idler gear for the reverse gear is a one-sided acting synchronizer 54 intended. In the 1 shown shift fork 22 is located between the loose wheels 46 . 47 the third and fourth gear. Three more shift forks 55 . 56 . 57 , in the 1 not shown, engage in the double-sided synchronizers 51 . 52 . 53 and in the one-sided synchronizer 54 one.

In operation, the lower shift finger operates 16 the shift forks for the first and second gear as well as for the fifth and sixth gear. In contrast, the shift finger operates 15 only the shift fork for the third and fourth gear and the shift finger 14 only uses the shift fork for reverse gear. The shift finger and the cable circuit are in the schematic representation of 3 Not shown.

According to the application, it is also possible to design the construction so that the position of the upper countershaft with the position of the lower countershaft is reversed. In this case, the Seilzugschaltung is designed so that opposite the 2 the position of the upper blocking cylinder 12 with the shift fingers 14 and 15 with the position of the lower blocking cylinder 13 with the shift finger 16 is reversed.

LIST OF REFERENCE NUMBERS

10

cable shift

11

shift shaft

12

upper locking cylinder

13

lower locking cylinder

14

shift finger

15

shift finger

16

shift finger

17

recess

18

recess

19

recess

20

shift mouthpiece

21

guide tube

22

shift fork

23

head

24

switching weight

25

guide

26

Shifting

27

main contour

28

Translation

29

rotation

30

switch cover

31

Umlenkhebel

35

transmission

36

main shaft

37

block

38

clutch

39

lower countershaft

40

Idler first gear

41

Idler gear second gear

42

Losrad fifth gear

43

Idler gear sixth gear

44

upper countershaft

45

Idler gear reverse gear

46

Idler gear third gear

47

Losrad fourth gear

48

Fixed gear reverse

49

return shaft

50

Fixed gear reverse

51

double-sided synchronizer gear 1, 2

52

double-sided synchronizer gear 5, 6

53

double-sided synchronizer gear 3, 4

54

one-sided synchronizer reverse

Claims (13)

Motor vehicle transmission with a switching device, wherein the motor vehicle transmission has at least four shift forks for operating four synchronizers, wherein the switching device comprises a switching shaft with at least three switching fingers and at least three blocking regions, wherein each shift fork is operable by at least one shift finger, while the non-actuated shift forks are blockable by one of the blocking ranges, further comprising a shift finger for operating two shift forks, and wherein the other two shift fingers are each provided for operating a single shift fork, wherein one of the shift fingers provided for operating a single shift fork is designed as a single-speed shift finger, the other shift finger provided for operating a single shift fork being designed as a two-speed shift finger, and wherein the shift finger provided for actuating two shift forks is designed as a four-speed shift finger, wherein fixed wheels for a first, second, third, fourth, fifth and sixth gear are arranged on a main shaft, idler gears for a first, second, fifth and sixth gear are arranged on a first countershaft, and wherein idler gears for a third gear, for a Further, the single shift finger actuates a shift fork of a single-sided synchronizer, the two-speed shift finger actuates a shift fork of a two-sided synchronizer, and the four-speed shift ref ger in response to a selected shift gate a shift fork of a first two-sided synchronizer or a shift fork of a second two-sided synchronizer operated. Motor vehicle transmission according to claim 2, wherein the single-gear shift finger acts on a reverse gear. Motor vehicle transmission according to claim 1 or 2, wherein the two-speed shift finger acts on a third and a fourth gear. Motor vehicle transmission according to one of claims 1 to 3, wherein the four-speed shift finger acts on a first shift gate on a first and on a second gear and acts on selection of a second shift gate on a fifth and a sixth gear. A motor vehicle transmission according to any one of claims 1 to 4, wherein the single-speed shift finger and the two-speed shift finger are disposed in blocking regions of a first lock cylinder and the four-speed shift finger is disposed in a lock region of a second lock cylinder. The motor vehicle transmission according to claim 5, wherein the single-speed shift finger is disposed in a lock region of a first lock cylinder, the two-speed shift finger is disposed in a lock region of a second lock cylinder, and the four-speed shift finger is disposed in a lock region of a third lock cylinder. Motor vehicle transmission according to one of claims 1 to 6, wherein the single-speed shift finger and the two-speed shift finger is disposed above the four-speed shift finger. Motor vehicle transmission according to one of claims 1 to 7, wherein the single-speed shift finger and the two-speed shift finger is disposed below the four-speed shift finger. Motor vehicle transmission according to one of claims 1 to 8, wherein the single-gear shift finger is disposed above the two-speed shift finger. Motor vehicle transmission according to one of claims 1 to 9, wherein the four-speed shift finger is arranged in the lower region of a blocking cylinder. Motor vehicle transmission according to one of the preceding claims, wherein the switching device is designed as a cable pull circuit in which a cable shifts a switching shaft along its axis and wherein the displacement of the switching shaft along its axis causes a displacement of the shift finger. Motor vehicle transmission according to one of the preceding claims, wherein the second countershaft is arranged above the first countershaft. Motor vehicle with a motor vehicle transmission according to one of the preceding claims.

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