DE102021205942A1 - Parking lock wheel, a parking lock, a vehicle and a manufacturing method of a parking lock wheel - Google Patents

Abstract

Parking lock wheel (10), a parking lock with such a parking lock wheel (10), a vehicle with such a parking lock and a method for manufacturing a parking lock wheel (10) comprising an inner ring (12), the inner ring (12) being set up to be mounted on a shaft an outer ring (14), the outer ring (14) having a parking lock toothing (18), a damping body (22) made of metal foam being arranged in the radial intermediate space (20) between the inner ring (12) and the outer ring (14). which connects the inner ring (12) and the outer ring (14) to one another at least in sections, preferably completely, along the circumferential direction.

Description

State of the art

The invention relates to a parking lock wheel for a parking lock with features of claim 1, a parking lock with features of the first independent claim, a vehicle, in particular a motor vehicle, with features of the second independent claim, and a manufacturing method with features of the third independent claim.

The parking lock functionality has been known in automotive engineering for a long time. It prevents a driverless vehicle from rolling away unintentionally, e.g. B. when parking on a slope. For this purpose, a parking lock wheel is arranged in the vehicle's transmission on one of the existing shafts in a rotationally fixed manner. A pawl can enter the parking lock wheel. This is usually a radial movement. This pawl can in turn be rotated, but is stationary and also mechanically fixed in the gear housing.

Such a parking lock is, for example DE 10 2009 030 005 A1 and DE 10 2017 127 211 A1 disclosed. The disadvantage here is that, particularly when the parking lock wheel engages at low driving speeds of up to 3 km/h, as required by vehicle manufacturers, the transmission can be blocked by the parking lock wheel within a very short time. The abrupt blocking leads to a torque peak that has to be absorbed by the drive train, which requires a correspondingly larger dimensioning of the drive train. This results in weight and cost disadvantages.

Disclosure of Invention

The problem on which the invention is based is solved by a parking lock wheel for a parking lock having the features of claim 1, a parking lock having the features of the first independent claim, a vehicle, in particular a motor vehicle, having the features of the second independent claim, and a manufacturing method having the features of third independent claim solved. Advantageous developments of the invention are specified in the dependent claims.

According to the invention, a parking lock wheel for a parking lock is proposed, comprising an inner ring and an outer ring, with a damping body made of metal foam being arranged in the radial intermediate space between the inner ring and the outer ring, which at least partially, preferably completely, connects the inner ring and the outer ring to one another along the circumferential direction .

The inner ring is set up so that it can be mounted on a shaft (e.g. transmission shaft, intermediate shaft, input or output shaft of a transmission). For this purpose, the inner ring can have a central, axially aligned passage for receiving a shaft section. On its radial inner side (or on its inner circumference), the inner ring can have a recess for receiving a feather key or a key (shaft-hub connection), teeth and/or indentations.

The outer ring has parking lock teeth (external teeth) on its radial outside. This can be designed to be brought into engagement with a pawl of a parking lock, for example. This can prevent the parking lock gear from rotating. In other words, the parking lock gear can be blocked in this way.

The damping body bridges the radial space between the inner ring and the outer ring. The damping body thus extends between the radial outside of the inner ring and the radial inside of the outer ring.

The radial inside of the outer ring can be smooth. The radial outside of the inner ring can also be smooth. The connection between the inner ring, the outer ring and/or the damping body is in particular designed in such a way that the inner ring and the outer ring are connected to one another in a torque-proof manner by means of the damping body.

In the present case, the radial inside of the inner ring and/or the outer ring means a side (inner side) of the inner ring and/or the outer ring that points radially inwards. In the present case, the radial outside of the inner ring and/or the outer ring means a radially outward-facing side (outside) of the inner ring and/or the outer ring.

The metal foam can be aluminum, magnesium, zinc or steel foam. The damping body can be designed as a foam body or foamed metal body with open-pore or closed-pore metal foam. The damping body can be at least partially delimited at the axial end by an outer skin or plate elements or sandwich end plates.

Due to the inner structure of the damping body made of metal foam, the parking lock wheel remains mechanically and thermally high-strength and stable. There can be a reduction in load overshoot at all Insertion processes can be achieved, even if the parking lock is engaged when the vehicle is moving slowly. An undesired torque peak caused by an abrupt locking of a transmission can thus be dampened to a considerable extent. There is no need for mostly expensive devices for mechanical damping. In addition, weight can be saved by providing metal foam. This makes the parking lock lighter and cheaper overall.

According to a development, the inner ring can have at least one inner driver element on its radial outside (or its outer circumference), which extends from the inner ring in the, in particular radial, direction of the outer ring and engages with the damping body. Additionally or alternatively, the outer ring can have at least one outer driver element on its radial inside (or inner circumference), which extends from the outer ring in the, in particular radial, direction of the inner ring and engages with the damping body.

There is a positive connection between the inner and/or outer driver element and the damping body. It is conceivable that two or more inner driver elements are arranged on the inner ring. Additionally or alternatively, it is conceivable that two or more outer driver elements are arranged on the outer ring.

According to a development, the inner driver element and/or the outer driver element can be T-shaped (T-shaped cross section). This allows the injected metal foam to rest on the driver element over as large a surface as possible (large contact surface) and interlock. Other forms are also conceivable, in particular for form-fitting force transmission.

The inner ring, the outer ring, the inner driver element and/or the outer driver element can be made of metal (e.g. steel or another alloy, aluminum, etc.). The inner driver element and the inner ring can be made of the same material. The outer driver element and the outer ring can be made of the same material.

According to a further development, the inner ring can have several, in particular eight, inner driver elements which are arranged evenly distributed on the inner ring. In addition or as an alternative, the outer ring can have several, in particular eight, outer driver elements which are arranged evenly distributed on the outer ring. This enables a uniform transmission of force between the inner and/or outer driver elements and the damping body.

The inner driver elements and the outer driver elements can be arranged alternately along the circumferential direction. As a result, the inner and the outer driver elements can be offset from one another along the circumferential direction ("zigzag" pattern). A more uniform distribution of the metal foam in the radial intermediate space between the inner ring and the outer ring can hereby be achieved. An excessive material weakening in the space between the inner and/or the outer driver elements can be avoided by means of a staggered arrangement. In particular, the same number of inner driver elements and outer driver elements can be provided.

According to a development, the inner ring can have at least one inner lamella. The inner lamina can be arranged on the radial outside of the inner ring and/or protrude radially outwards or towards the outer ring. The inner ring can also have several inner laminations. Alternatively or additionally, the outer ring can have at least one outer lamella. The outer disk can be arranged on the radial inside of the outer ring and/or protrude radially inward or towards the inner ring. The outer ring can also have several outer laminations.

In particular, the inner slat and outer slat, preferably all slats, can be arranged parallel to one another. The central longitudinal planes of the individual or all slats can be arranged parallel to one another. This corresponds to an arrangement similar to a friction clutch. As a result, the largest possible contact surface can be achieved between the inner ring and the metal foam or the outer ring and the metal foam.

According to a development, the inner ring, the outer ring, the inner driver element, the outer driver element, the inner disk and/or the outer disk can be made of metal (e.g. steel or another alloy, aluminum, etc.).

In particular, the inner ring, the outer ring, the inner lamella, the outer lamella, the inner driver element and/or the outer driver element can be made of the same material.

According to the invention, a parking lock is proposed with at least one parking lock wheel according to the above statements. With regard to the advantages that can be achieved in this way, reference is made to the relevant Please refer to the comments on the parking lock wheel. The measures described in connection with the parking lock wheel can serve to further develop the parking lock.

According to the invention, a vehicle, in particular a motor vehicle, is proposed with a parking lock as described above. With regard to the advantages that can be achieved in this way, reference is made to the relevant statements on the parking lock. The measures described in connection with the parking lock can serve to further refine the vehicle.

According to the invention, a method for producing a parking lock wheel according to the above statements is proposed. The method comprises the steps: manufacturing and/or providing the inner ring made of metal, manufacturing and/or providing the outer ring made of metal, positioning the inner ring and the outer ring relative to one another, in particular by means of a positioning device, so that a radial gap is formed. In particular, the inner ring and the outer ring are positioned coaxially with one another.

The method further comprises the steps: filling the radial intermediate space with titanium hydride and metal powder, heating (e.g. by means of a heat source such as an oven) the parking lock wheel and in particular the positioning device to a temperature, in particular of approx. 700° C., such , that the titanium hydride can react with the metal powder and thus (porous) metal foam is formed.

The porous metal foam can connect to the two metal rings (inner ring and outer ring), in particular in a form-fitting manner via the T-shaped driver elements (if present).

It is also conceivable that the metal foam at least partially enters into a material connection with the inner ring and/or the outer ring.

According to a development, the method can further include the step: cooling the parking lock wheel and in particular the positioning device. The cooling can be implemented actively, for example by means of supplied cooling air, or passively by elapsing a dwell time.

In a further step, an outer skin or plate elements can be attached to the parking lock wheel on both sides at the axial ends of the parking lock wheel.

In a further step, particularly after the parking lock gear has cooled down, the parking lock gearing (outer gearing of the outer ring) can be ground.

The parking lock wheel can then be balanced in a further step.

• 1 eine Darstellung eines Parksperrenrads gemäß einer ersten Ausführungsform in einer Draufsicht;
• 2 eine perspektivische Darstellung des Parksperrenrads gemäß 1;
• 3 eine Darstellung des Parksperrenrads gemäß einer zweiten Ausführungsform in einer Draufsicht;
• 4 einen Ausschnitt eines Querschnitts des Parksperrenrads gemäß einer dritten Ausführungsform (Halbschnitt), und
• 5 einen Ausschnitt eines Querschnitts des Parksperrenrads gemäß einer vierten Ausführungsform (Halbschnitt).

Embodiments of the invention will be explained below with reference to the accompanying drawings. They show, each schematically:

• 1 a representation of a parking lock wheel according to a first embodiment in a plan view;
• 2 a perspective view of the parking lock wheel according to 1 ;
• 3 a representation of the parking lock wheel according to a second embodiment in a plan view;
• 4 a section of a cross section of the parking lock wheel according to a third embodiment (half section), and
• 5 a detail of a cross section of the parking lock gear according to a fourth embodiment (half section).

1 shows a schematic representation of a parking lock wheel 10 according to a first embodiment. The top view of the parking lock wheel 10 can be seen here. The parking lock wheel 10 has an inner ring 12 . The inner ring 12 is configured to be mounted on a shaft (not shown).

The inner ring 12 has a central, axially aligned passage 11 for receiving a shaft section (not shown). In order to connect the inner ring 12 to the shaft section, the inner ring 12 has internal teeth 15 on its radial inner side 13 .

The parking lock wheel 10 also has an outer ring 14 . The outer ring 14 has parking lock teeth 18 on its radial outside 16 .

A radial intermediate space 20 is arranged between the inner ring 12 and the outer ring 14 . A damping body 22 made of metal foam is arranged in the radial intermediate space 20 . In the present case, the damping body 22 completely connects the inner ring 12 and the outer ring 14 to one another along the circumferential direction.

In the present case, the parking lock wheel 10 has an outer skin 17 in the form of two metal plates. The outer skin 17 covers the damping body 22 and thus prevents, for example, oil from the Transmission can enter the pores of the metal foam.

The two metal plates of the outer skin 17 are arranged on the two axial ends of the parking lock gear 10 and each extend from the inner ring 12 to the outer ring 14. For the sake of clarity, the outer skin 17 has only been shown partially, so that the damping body arranged under the outer skin 17 22 is partially visible.

The inner ring 12 has a radial outer side 24 which is smooth in the present case. The outer ring 14 has a radial inner side 19, which is also smooth in the present case.

2 shows a perspective view of the parking lock wheel 10 according to FIG 1 .

3 shows a schematic representation of the parking lock wheel 10 according to a second embodiment. The second embodiment differs from the first embodiment in that the inner ring 12 has eight inner driver elements 26 on its radial outside 24 . These each extend from the inner ring 12, in particular radially, in the direction of the outer ring 14.

In addition, in the present case, the outer ring 14 has eight outer driver elements 28 on its radial inner side 19 . These each extend from the outer ring 14, in particular radially, in the direction of the inner ring 12.

In the present case, the inner and outer driver elements 26, 28 extend over the entire axial thickness of the parking lock wheel 10. In other words, the inner and outer driver elements 26, 28 each extend between the two axial ends of the parking lock wheel 10.

The inner and outer cam elements 26, 28 have a T-shape (T-shaped cross section) and are engaged with the damping body 22, respectively. In other words, the T-shaped driver elements 26, 28 are positively connected to the damping body 22.

The inner and outer driver elements 26, 28 are arranged alternately in the circumferential direction (staggered arrangement).

4 shows a detail of a cross section of the parking lock wheel 10 according to a third embodiment. A half-section of the parking lock gear 10 is shown. The illustrated embodiment differs from the first, in 1 shown embodiment in that the inner ring 12 has an inner lamella 30 . This is arranged on the radial outside 24 of the inner ring 12 and at least partially forms a first axial end 21 of the parking lock gear 10. The inner disk 30 extends from the radial outside 24 of the inner ring 12 in the direction of the outer ring 14 and in the circumferential direction.

In addition, the outer ring 14 has an outer lamella 32 . This is arranged on the radial inside 19 of the outer ring 14 and at least partially forms a second axial end 23 of the parking lock wheel 10. The outer disk 32 extends from the radial inside 19 of the outer ring 14 in the direction of the inner ring 12 and in the circumferential direction.

The inner and outer slats 30, 32 are arranged parallel to one another.

The parking lock wheel 10 according to the third embodiment can have an outer skin 17, not shown, analogously to the two embodiments described above. This can be arranged at least partially on the first axial and/or second axial end 21, 23 of the parking lock wheel 10. The outer skin 17 can cover the first and/or second axial end 21, 23 at least partially.

5 shows a detail of a cross section of the parking lock wheel 10 according to a fourth embodiment. The fourth embodiment differs from the third embodiment in that the inner ring 12 has a plurality of inner laminations 30 and the outer ring 14 has a plurality of outer laminations 32 . In the present case, the inner and outer disks 30, 32 are arranged alternately from the first axial end 21 to the second axial end 23 of the parking lock gear 10 (similar to a friction clutch).

In the example, the outer ring 14 has three outer lamellae 32 , the first axial end 21 and the second axial end 23 being formed at least partially by an outer lamella 32 . The inner ring 12 has two inner laminations 30 which are each arranged between the outer laminations 32 . In this way, the largest possible contact surface between the inner and/or outer lamellae 30, 32 and the damping body 22 can be achieved.

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• DE 102009030005 A1 [0003]
• DE 102017127211 A1 [0003]

Claims (10)

Parking lock wheel (10) for a parking lock comprising - an inner ring (12), the inner ring (12) being set up to be able to be mounted on a shaft, - an outer ring (14), the outer ring (14) having parking lock teeth (18) on its radial outside (16), - wherein a damping body (22) made of metal foam is arranged in the radial intermediate space (20) between the inner ring (12) and the outer ring (14), which dampens the inner ring (12) and the outer ring (14) along the circumferential direction at least in sections, preferably completely , connects with each other. Parking lock wheel (10). claim 1 , characterized in that the inner ring (12) has at least one inner driver element (26) on its radial outside (24), which extends from the inner ring (12) in the direction of the outer ring (14) and is connected to the damping body (22) in engagement and/or that the outer ring (14) has at least one outer driver element (28) on its radial inner side (19), which extends from the outer ring (14) in the direction of the inner ring (12) and is connected to the damping body (22). is engaged. Parking lock wheel (10). claim 2 , characterized in that the inner driver element (26) and / or the outer driver element (28) is T-shaped. Parking lock wheel (10). claim 2 or claim 3 , characterized in that the inner ring (12) has several, in particular eight, inner driver elements (26) which are arranged evenly distributed on the inner ring (12) and/or that the outer ring (14) has several, in particular eight, outer driver elements ( 28) which are evenly distributed on the outer ring (14). Parking lock wheel (10). claim 1 , characterized in that the inner ring (12) has at least one inner lamella (30), in particular a plurality of inner lamellae (30), and/or that the outer ring (14) has at least one outer lamella (32), in particular a plurality of outer lamellae (32 ), Has, in particular wherein the inner lamella (30) and outer lamella (32), in particular all lamellae (30, 32), are arranged parallel to one another. Parking lock wheel (10) according to one of the preceding claims, characterized in that the inner ring (12), the outer ring (14), the inner driver element (26), the outer driver element (28), the inner plate (30) and / or the outer lamella (32) consist of metal. Parking lock with at least one parking lock wheel (10) according to one of the preceding claims. Vehicle, in particular a motor vehicle, with a parking lock in accordance with claim 7 . Method for producing a parking lock wheel (10) according to one of Claims 1 until 6 comprising the steps of: - manufacturing and/or providing the inner ring (12) from metal, - manufacturing and/or providing the outer ring (14) from metal, - positioning the inner ring (12) and the outer ring (14), in particular by means of a positioning device , to each other, so that a radial space (20) is formed between the inner ring (12) and the outer ring (14), - filling the radial space (20) with titanium hydride and metal powder, - heating the parking lock wheel (10) and in particular the positioning device , to a temperature such, in particular of about 700 ° C, that the titanium hydride can react with the metal powder and metal foam is formed. procedure after claim 9 , characterized in that the method further comprises the step: - cooling the parking lock wheel (10) and in particular the positioning device.

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