WO2019080961A1

WO2019080961A1 - Ratchet wheel, parking lock device and drive arrangement for a motor vehicle

Info

Publication number: WO2019080961A1
Application number: PCT/DE2018/100831
Authority: WO
Inventors: Peter Greb; Laszlo Man; Jose Alexander Lazo Zamalloa; Yilan HUANG
Original assignee: Schaeffler Technologies AG & Co. KG
Priority date: 2017-10-27
Filing date: 2018-10-08
Publication date: 2019-05-02
Also published as: DE102017125183B4; DE102017125183A1

Abstract

The invention relates to a ratchet wheel for a parking lock device, to the parking lock device itself, and to a drive arrangement for a motor vehicle having the parking lock device according to the invention. The ratchet wheel for the parking lock device serves to block a rotational movement in an output of a motor vehicle, and comprises an external toothing system (4) with a plurality of radially extending teeth (10), wherein, in the case of a respective tooth (10), the tooth tip (11) is configured in such a way that the centre of the tooth tip (12) is situated on a tip circle diameter (13). In the circumferential direction (2) of the ratchet wheel (1), a respective tooth (10) has a projection (20) at least on one side, which projection (20) is arranged on a projection diameter (21) which is greater than the tip circle diameter (13), with the result that, in the case of a rotation of the ratchet wheel (1), a locking pawl (50) which bears against the ratchet wheel (1) can be accelerated radially to the outside by way of the projection (20). The ratchet wheel according to the invention which is proposed here and the parking lock device which is equipped with it therefore provide a device which ensures that an engagement of the locking pawl and, accordingly, locking of the rotation take place reliably in a manner which is dependent on the realised rotational speed of the ratchet wheel, or else an engagement of the locking pawl is prevented cleanly, with the result that the wear on the ratchet wheel and on the locking pawl and corresponding noise emissions are reduced.

Description

Ratchet, parking lock and drive assembly for a motor vehicle

The invention relates to a ratchet wheel for a parking lock device for blocking a rotational movement in an output of a motor vehicle, the parking lock device itself and a drive arrangement for a motor vehicle with the parking lock device according to the invention. Devices for securing the position of a parked vehicle have long been known. Usually so-called hand brakes were used, which mechanically exerts a braking effect on the wheels of the motor vehicle to block them at a standstill and to secure the parked vehicle in the park position.

However, other known parking locks act on the drive axle of the vehicle for the purpose of blocking the driven wheels. The blocking effect should also occur when a clutch between the engine and transmission of the motor vehicle is opened and thus no engine brake acts on the vehicle. This means that when parking the motor vehicle, the braking effect of the engine can not be used to prevent unintentional rolling away of the vehicle. Accordingly, it is usually provided that the parking lock device acts on the output side of the transmission and thus on the drive train of the motor vehicle itself in order to block the rotational movement of wheels.

From WO 2001/09534 A1, a manual transmission for a vehicle is known, which has a parking lock device for blocking the output shaft. The

Parkperreinrichtung comprises a gear with an external toothing and a pivotally mounted pawl, which is adapted to engage in the toothing of the gear and to block its rotation. In this way, a vehicle equipped with the parking lock device can be secured in a parking situation.

With parking locks with pawls that are pressed by spring force on an external toothing of a locking rate, falls or presses a respective Locking element radially towards the center of the ratchet wheel, so that it abuts upon further rotation of the ratchet wheel against the next approached by the rotation tooth flank. However, the peripheral speed of the ratchet wheel plays an essential role. If this peripheral speed is relatively low and thus in the range of a so-called locking speed, the locking element enters the toothing and blocks the further rotation of the ratchet wheel. Is the

However, rotational speed is relatively high, such as in the region of a so-called repelling speed or Abhubgeschwindigkeit, the pawl receives through the teeth of the teeth constantly pulses in the radial direction, so that the locking element of the pawl can no longer engage in the toothing. The speed range between the locking speed and the

Abweisungsgeschwindigkeit or Abhubgeschwindigkeit is a so-called

Tolerance zone in which both the one situation, so the engagement of the locking element in the external teeth, as well as the other situation, ie the non-intervention in the teeth, may be present. The disadvantage of this, however, is that even at higher peripheral speeds of the ratchet the pawl against

Tooth flanks meets and these pulses in the with the parking lock device

equipped vehicle are audible and possibly also noticeable. Furthermore, this impulsive stress leads to wear on the toothing as well as on the pawl, which can have a reducing effect on the life of the system or can negatively influence the tooth geometry.

Proceeding from this, the present invention has the object to provide a ratchet wheel for a parking brake device and the parking lock device itself available, which ensure a low-wear operation and consequently an increased life.

This object is achieved by the ratchet wheel according to claim 1 and by the parking lock device according to the invention according to claim 6.

Advantageous embodiments of the ratchet wheel are given in the dependent claims 2-5. Advantageous embodiments of the parking brake device are specified in the dependent claims 7-9. In addition, a drive arrangement for a Motor vehicle provided, which is an inventive

Has parking lock.

The features of the claims may be combined in any technically meaningful manner, for which purpose the explanations of the following description as well as features of the figures may be consulted which comprise additional embodiments of the invention.

The invention relates to a ratchet wheel for a parking lock device for blocking a rotational movement in an output of a motor vehicle. This ratchet wheel comprises external teeth with a plurality of radially extending teeth, wherein in a respective tooth, the tooth head is designed such that the center of the tooth tip is on a tip diameter. A respective tooth has in the circumferential direction of the ratchet wheel at least on one side a projection which is arranged on a projection diameter which is larger than that

Tip diameter, so that a voltage applied to the ratchet pawl upon rotation of the ratchet wheel by the projection can be accelerated radially outward. The teeth of the external teeth are arranged as usual extending radially outward. A respective tooth head is the region of the tooth which is bounded by tooth flanks in the circumferential direction and has a larger diameter than the tooth root. The center of a respective tooth head is the area which is located centrally between the two tooth flanks delimiting the respective tooth head. At least this area is on the tip diameter.

The higher the angular velocity of the ratchet wheel, the higher the

Acceleration, which experiences the pawl applied to the external teeth, so that they receive - depending on the inertia or the mass moment of inertia of the pawl - a direction away from the ratchet trajectory and is lifted longer from the tip diameter.

In particular, it is provided that the tooth head has a projection on both sides in the circumferential direction. Such a blocking effect can be achieved independently of the direction of rotation of the ratchet wheel, so that the ratchet wheel at a Rotary movement for realizing a forward drive can be locked as well as during a rotational movement to realize a reverse drive.

To facilitate the radial movement of a voltage applied to the toothing pawl of the tooth head should have a ramp which is the radially outer

Surface of the area of the head circle diameter

Tooth head with the radially outer surface of the projection connects. This is intended to create the smoothest possible transition between the actual surface of the tooth head on the projection in order to avoid a shock load of the projection by the pawl and the angular acceleration of the

Tooth-mounted pawl to facilitate, according to the principle of a

Ski jump.

In particular, the ramp may have an increase of 5 ° to 45 °, in particular of 10 ° to 30 °, this increase being related to a tangent at

Head diameter at the point of transition of the tooth head into the ramp, in which the tooth head is still on the tip circle diameter.

The projection has a projection extent VE in the circumferential direction. A tooth space adjacent to the projection in the circumferential direction has a gap extension LE, wherein the projection extent VE to the gap extension LE is in the following ratio: VE / LE = 0, 1... That means the

Extension of the projection VE is significantly less than the extension of the gap, so that at sufficiently low rotational speed of the ratchet wheel immersion of the pawl is ensured in the tooth gap.

Furthermore, a parking lock device for blocking a

Having rotational movement in an output of a motor vehicle provided having an inventive ratchet wheel and a movably arranged pawl for engagement with the ratchet wheel for the purpose of its engagement in the toothing of the ratchet wheel at sufficiently low rotational speed. The parking lock device is configured to be activated when the vehicle is rolling so that the parking lock device receives a command "Close".

When engaging the pawl in the teeth of the ratchet engages the

Locking element of the pawl in a tooth gap.

Preferably, the pawl is rotatably mounted. Thus, the pawl performs a rotary pivoting movement.

In a further embodiment, the parking lock device may have a spring device for at least indirectly acting on the pawl with a force from which at least one component extends radially to the ratchet wheel. This means that the spring device preferably acts on the pawl in such a way that it presses radially onto the ratchet wheel and thus onto the toothing. In an alternative embodiment, it is provided that the pawl presses only by gravity on the toothing.

In a further advantageous embodiment of the parking lock device is provided that it has an output shaft of a transmission, wherein the ratchet wheel

torque-resistant connected to the output shaft or is formed of this as an integral part. In an alternative embodiment, the ratchet wheel is connected to a transmission element which is connected or connected torque-tight with the output shaft.

In addition, according to the invention a drive arrangement for a motor vehicle is provided, comprising a transmission and an inventive

Parking lock device, wherein the parking lock device with an element of the

Gear is connected fixed torque or is formed by this. Thus, the parking lock device is coupled to an output side of the drive assembly, so that when locking the ratchet wheel, the output is blocked and therefore the parking brake is activated.

The above-described invention will be explained in detail in the background of the relevant technical background with reference to the accompanying drawings, which show preferred embodiments. The invention is not limited by the purely schematic drawings in any way, it being noted that the embodiments shown in the drawings are not limited to the dimensions shown. Show it

FIG. 1 shows a partial area of a parking lock device according to the invention in a first situation,

FIG. 2 shows a partial area of a parking lock device according to the invention in a second situation,

FIG. 3 shows a partial area of a parking lock device according to the invention in a third situation,

Figure 4: the parking lock device according to the invention with lifted pawl, Figure 5: the parking lock device according to the invention with disengaged pawl, Figure 6: the parking lock device according to the invention with a latched pawl, and

Figure 7: the parking lock device according to the invention with representation

different trajectories of the pawl in response to the rotational speeds.

First, the general structure of the parking lock device according to the invention will be described with reference to FIG.

The parking lock comprises a ratchet wheel 1, which is rotatably mounted about a rotation axis, not shown here. The ratchet wheel 1 rotates in

Rotation direction 3 and thus in the direction of rotation shown here counterclockwise. Distributed in the circumferential direction 2 on the circumference of the ratchet wheel 1, an external toothing 4 is provided with a plurality of teeth 10. The tooth head 1 1 of a respective tooth 10 is formed as a cylindrical portion. At least the middle of the tooth head 12 is located on the tip circle diameter 13.

The tooth head 1 1 is thus located substantially on one

Tip diameter 13.

In the embodiment shown in Figure 1, the tooth head 1 1 in

Circumferential direction 2 on both sides arranged projections 20, wherein the invention is not limited to the arrangement of two-sided projections 20, but can also be provided only at a peripheral boundary of the Tooth head 1 1 to arrange such a projection 20. The projection 20 extends radially except for the projection diameter 21 which is larger than the tip circle diameter 13. Thereby, a respective projection 20 forms a ramp 30. From the tip diameter diameter portion 14, the ramp 30 extends radially outwardly from the point of transition 33 so as to be tangent with respect to a tangent 32 at the point of transition 33 at the circle

Tip diameter 13 abuts, a rise 31 has.

The projection 20 thus forms by its ramp 30 a kind of ski jump for the radially outwardly rotatably mounted pawl 50 and their on a

Swivel lever 52, which is rotatably mounted on a pivot bearing 51, arranged locking element 53 from.

In each case a tooth gap 40 connects to a respective projection 20 in the circumferential direction 2, wherein the transition between a projection 20 and the tooth gap 40 is realized by a substantially radially extending tooth flank 41. A respective tooth gap 41 is much longer in the circumferential direction 2 than a respective projection 20. This means that the projection extent VE in the circumferential direction 2 is much smaller than the gap extent LE in

Circumferential direction 2.

Figures 2 and 3 show situations in which due to the relative rotational movement between the ratchet wheel 1 and the pawl 50, the ratchet wheel 1 has rotated under the pawl 50, so that the locking element 53 of the pawl 50 on the ramp 30 of the projection 20th is moved. As a result, the pawl 50 receives an indicated in Figures 2 and 3 radial acceleration 54 to the outside.

Depending on the rotational speed of the ratchet wheel 1, it now happens that the pawl 50 relatively far away from the ratchet wheel 1 and does not engage in the respective projection 20 adjacent tooth gap 40, as shown in Figures 4 and 5; or it comes about that the pawl or its detent element 53 engages in this gap 20 adjacent the projection 20, as shown in Figure 6.

In Figures 4 and 5, the situation is shown that due to relatively high rotational speed of the ratchet wheel 1 and consequent relatively large radial Acceleration 54 of the pawl 50 it is so far lifted from the ratchet wheel 1 that it comes on further movement of the ratchet wheel 1 in the circumferential direction of the next projection 20 to the plant, as shown in Figure 5. This means that at a sufficiently high rotational speed of the ratchet wheel 1 through the ramp 30 of the projection 20, the pawl 50 is lifted so far from the ratchet wheel 1 that it does not engage in the toothing or in the tooth gaps 40 of the toothing 4.

FIG. 6 shows the situation in which the ratchet wheel 1 reduces one

Speed was such that the pawl 50, for example, through

Exposure to the force of gravity or the force of a not shown here

Spring device, was brought back to the ratchet wheel 1, so that the

Locking element 53 of the pawl 50 engages in the tooth gap 40 and consequently blocks a further rotational movement of the ratchet wheel 1.

In Figure 7, the parking brake device in connection with the

shown different speeds of the ratchet wheel 1 occurring flight trajectories. The lower the rotational speed of the ratchet wheel 1, the steeper the respective trajectory of the pawl or its detent element 53 falls. The parking lock device according to the invention is designed to be at a

Locking speed or a lower speed than that

Blocking speed to block the rotational movement of the ratchet wheel 1 and consequently to block a driving operation. In addition, the parking lock device is designed to be at a Abhubgeschwindigkeit or a larger

Speed as the Abhubgeschwindigkeit a blocking effect by the

To avoid pawl and therefore another turning operation too

enable. The locking speed is lower than that

Lift off speed. In a speed range between the

Blocking speed and the Abhubgeschwindigkeit the parking brake device should either also prevent the engagement of the pawl in the external teeth, or safely ensure engagement to reduce wear occurring at the parking brake device.

FIG. 7 illustrates the trajectory 60 at a lower speed than that of FIG

It can be seen that in the realization of this trajectory 60 the detent pawl 50 or its detent element 53 engages in the tooth gap 40.

The same situation occurs at a rotational speed of the ratchet wheel 1, which leads to the trajectory at blocking speed 61. Here, too, ends up

Locking element 53 of the pawl 50 in the tooth gap 40. When realizing a rotational speed of the ratchet wheel 1 between the locking speed and the

Abhubgeschwindigkeit a trajectory 62 is realized at medium speed. If the Abhubgeschwindigkeit realized by the ratchet wheel 1, there is a corresponding trajectory 63, which causes the pawl 50 is raised over the tooth gap 40 and the next in the circumferential direction 2 projection 20 so that this projection 20 is moved under the pawl 50 away and the pawl 50 does not engage in the toothing. The same situation occurs

of course, then also on when the ratchet wheel 1 is a higher

Rotation speed as the Abhubgeschwindigkeit performs, the trajectory 64 is performed in this situation and the pawl 50 also not in the

Interlocking intervenes.

Accordingly, the system is designed such that, depending on the realized rotational speed, either a clean intervention of the

Pawl comes in the external teeth 4, or a clean Abhub from the external teeth and consequently to a non-intervention in the

External toothing 4.

With the proposed here ratchet wheel and thus

equipped parking lock device is thus provided a device that ensures that depending on the realized rotational speed of the ratchet wheel sure engagement of the pawl and thus blocking the rotation takes place or clean intervention of the pawl is prevented, so that the wear on the ratchet wheel and the pawl and corresponding

Noise emissions are reduced. LIST OF REFERENCE NUMBERS

1 ratchet wheel

2 circumferential direction

3 direction of rotation

4 external toothing

10 tooth

1 1 tooth head

12 middle of the tooth head

13 tip diameter

14 on the tip diameter diameter range

20 advantage

21 projection diameter

VE projection extension

30 ramp

31 increase

32 tangent

33 point of transition

40 tooth gap

41 tooth flank

LE gap extension

50 pawl

51 pivot bearings

52 pivot lever

53 locking element

54 radial acceleration

60 trajectory at lower speed than locking speed

61 Trajectory at locking speed

62 trajectory at medium speed

63 trajectory at Abhubgeschwindigkeit

64 Trajectory at greater speed than Abhubgeschwindigkeit

Claims

claims

Ratchet wheel for a parking lock device for blocking a rotational movement in an output of a motor vehicle, comprising an external toothing (4) with a plurality of radially extending teeth (10), wherein at a respective tooth (10) of the tooth head (1 1) is designed such that the center of the tooth head (12) is on a tip circle diameter (13), and the tooth (10)

in the circumferential direction (2) of the ratchet wheel (1) at least on one side of a

Protrusion (20) disposed on a projection diameter (21) larger than the tip circle diameter (13), so that one on the

Ratchet (1) applied pawl (50) during rotation of the ratchet wheel (1) by the projection (20) can be accelerated radially outward.

Ratchet wheel according to claim 1, characterized in that the tooth head (1 1) on both sides in the circumferential direction (2) each have a projection (20).

Ratchet wheel according to one of the preceding claims, characterized in that the tooth head (1 1) has a ramp (30) which is the radially outer

Surface of the head circle diameter (13) located portion (14) of the tooth head (1 1) with the radially outer surface of the projection (20) connects.

Ratchet wheel according to claim 3, characterized in that the ramp (30) has a rise (31) of 5 ° to 45 °, in particular from 10 ° to 30 °.

Ratchet wheel according to one of the preceding claims, characterized in that the projection (30) in the circumferential direction (2) has a projection extent VE and one of the projection in the circumferential direction (2) adjoining

Tooth gap (40) has a gap extension LE, wherein the projection extent VE to the gap extension LE in the following ratio: VE / LE = 0, 1 ... 0.3.

6. parking lock device for blocking a rotational movement in an output of a motor vehicle, comprising a ratchet wheel (1) according to one of claims 1 to 5 and a movably arranged pawl (50) for engagement with the

Ratchet wheel (1) for the purpose of its engagement in the outer toothing (4) of the ratchet wheel at a sufficiently low rotational speed.

7. Parking lock device according to claim 6, characterized in that the

Pawl (50) rotatably mounted.

8. parking lock device according to one of claims 6 and 7, characterized

characterized in that the parking lock device comprises a spring device for at least indirectly acting on the pawl (50) with a force from which at least one component extends radially to the ratchet wheel (1).

9. parking lock device according to one of claims 6 to 8, characterized in that the parking lock device has an output shaft of a transmission, wherein the ratchet wheel (1) is fixedly connected to the output shaft torque output shaft or formed by this.

10. Drive arrangement for a motor vehicle, comprising a transmission and a

A parking brake device according to any of the claims, wherein the

Parkperreinrichtung with an element of the transmission is fixed torque or is formed by this.