DE102022104996A1 - Spindle assembly for a spindle drive device - Google Patents

Abstract

The invention relates to a spindle assembly for a spindle drive device, comprising a thrust tube (30) and a spindle nut (32) which is arranged in the thrust tube (30) in a torque-proof manner, the spindle nut (32) being threadably engageable with a spindle of the spindle drive device (10), wherein the push tube (30) has one or more contours (30a) in the area where it is connected to the spindle nut (32) and the spindle nut (32) is inserted into the push tube (30) in such a way that the contours (30a) prevent translational and/or or rotational movement is fixed in the thrust tube (30).

Description

The invention relates to a spindle assembly for a spindle drive device according to the preamble of patent claim 1.

In order to open and close doors, flaps or hoods of a motor vehicle automatically and in a controlled manner, electric drives in combination with passive components such as e.g. B. Gas springs used.

The electric drives often include spindle drive devices, which usually have an electric spindle drive, by means of which the associated vehicle flap can be opened and/or closed. A user of an associated vehicle no longer has to do the opening and closing manually, but only sends an opening or closing command to the spindle drive assembly, which he can do, for example, via a radio remote control or via a switch arranged in the vehicle.

In order to allow the spindle drive device to be changed in length, a spindle which is driven by a motor-gear unit and engages in a spindle nut is rotated. The spindle nut itself is fixed in translation and rotation by a thrust tube.

The type of connection technology between the spindle nut and the torque tube is the subject of this invention.

• Die Spindelmutter, die vorzugsweise aus Kunststoff besteht, ist an das Schubrohr gespritzt. Erst bei dieser Umspritzung entsteht das eigentliche Bauteil, die Spindelmutter. Schubrohr und Spindelmutter sind fest und unlösbar miteinander verbunden.

Various types of connection between the spindle nut and the thrust tube are known from the prior art, which are designed as follows:

• The spindle nut, which is preferably made of plastic, is injection molded onto the thrust tube. The actual component, the spindle nut, is only created during this overmoulding. Thrust tube and spindle nut are firmly and permanently connected to each other.

The problem with the overmoulded design is that due to the large variety of motor vehicle models, there is a correspondingly high number of different thrust tube lengths and different spindle nuts, in particular various sizes of the spindle nuts and different pitches of the spindle nut thread.

As a result, many different shaping tools, including long set-up times, are necessary in the injection molding process. Such prior art is for example in EP 2 037 067 B1 disclosed.

Another connection option is to screw the spindle nut and thrust tube together. The thrust tube usually has an internal thread into which an external thread of the spindle nut is screwed.

The spindle nut must be correctly aligned with the thrust tube and screwed into the thrust tube. Finally, the thrust tube must be partially pressed/crimped in order to finally fix both parts.

A problem here is the exact alignment between the spindle nut and the thrust tube in the automatic process. If the thread of the spindle nut is not correctly aligned during the joining process, it will not engage and can be damaged.

This connection method is for example in the DE 10 2018 108 277 A1 and DE 20 2021 100 014 U1 disclosed.

It is the object of the invention to firmly connect a spindle nut and a thrust tube of a spindle assembly. Translational and/or rotary movements relative to one another must not be possible. At least the axial play should be as small as possible.

The task is solved by a spindle assembly with the features of patent claim 1 .
Preferred developments of the invention and further advantageous features are specified in the dependent claims.

A spindle assembly for a spindle drive device is proposed, which comprises a torque tube and a spindle nut, the spindle nut being arranged in the torque tube in a rotationally fixed and translatory manner and being threadably engageable with a spindle of the spindle drive device.

According to the invention, the torque tube has one or more contours produced by stamping, embossing or laser cutting in the connection area with the spindle nut, and the spindle nut is inserted into the torque tube in such a way that it is fixed by the contours against translational and/or rotational movement in the torque tube.

The thrust tube and the spindle nut consist of two separate parts that are manufactured separately, with the spindle nut being inserted into the thrust tube, preferably being pressed. The push tube is made of metal, preferably aluminum or steel, and has the described contours in the connection area with the spindle nut, which after the insertion of the spindle nut ensure the required hold of the spindle nut in the thrust tube.

The contours are preferably designed as holding tongues which are distributed over the circumference of the thrust tube and whose free ends protrude into the interior of the thrust tube. A plurality of retaining tongues are preferably provided. The contours can include either one or more rows of retaining tongues distributed over the circumference of the thrust tube.

These stamped or embossed retaining tongues in the thrust tube for fixing the spindle nut are achieved by forming/stamping and preferably act like a leaf spring.

The spindle nut preferably has a cylindrical section that is inserted into the thrust tube. The spindle nut preferably has a collar at the end of the cylindrical section as a stop for the thrust tube.
The contours work according to the barb principle. The free ends of the retaining tongues of the contours, which protrude into the thrust tube, extend away from the end of the thrust tube into which the spindle nut is inserted. The force when pressing in/inserting the spindle nut is relatively low due to the retaining tongue running obliquely in the direction of insertion. On the other hand, the force when pulling out or rotating the spindle nut is relatively high.

The number and position of the contours can vary in order to change the pull-off strength between the spindle nut and the torque tube.

The spindle nut is pressed in up to the stop on the front side of the tube. Appropriate insertion aids, e.g. B. chamfers on the cylindrical portion of the spindle nut, etc., ensure easy introduction of the spindle nut into the thrust tube.

In another embodiment of the invention, one or more indentations can be distributed over the outer circumference of the cylindrical section of the spindle nut. After the spindle nut has been inserted into the thrust tube, the retaining tongues of the thrust tube engage in the associated indentations on the outer circumference of the spindle nut.

In yet another embodiment of the invention, provision can be made for the contours to be in the form of one or more complete punched-out portions in the thrust tube. In this case, one or more radial projections are distributed over the circumference of the cylindrical section of the spindle nut, which, after the cylindrical section has been inserted into the thrust tube, engage and snap into the punched-out portions of the thrust tube and ensure a firm and non-rotatable connection between the spindle nut and the provide thrust tube.

• • Es ist ein einfacher und robuster Füge-/Montageprozess realisierbar, der leicht zu überwachen ist.
• • Die Verbindung ist kostengünstig trotz/bei hoher Variantenvielfalt. Beispielsweise sind bei unterschiedlichen Schubrohrlängen und/oder verschiedenen Gewindesteigungen der Spindel und Spindelmutter keine ständigen Werkzeuganpassungen zur Umspritzung des Schubrohres mit der Spindelmutter nötig.
• • Die Spindelmutter kann als günstiges Spritzteil in beliebiger Varianz separat hergestellt werden.
• • Eine explizite rotatorische Ausrichtung der Spindelmutter vor dem Fügen mit dem Schubrohr ist in der Regel nicht nötig.
• • Es sind keine weiteren Arbeitsschritte nötig, außer dem Umformen des Rohrs und dem Verpressen beider Teile.

The main advantages of the connection techniques described are as follows:

• • A simple and robust joining/assembly process can be implemented that is easy to monitor.
• • The connection is inexpensive despite/with a large number of variants. For example, in the case of different thrust tube lengths and/or different thread pitches of the spindle and spindle nut, no constant tool adjustments are necessary for overmoulding the thrust tube with the spindle nut.
• • The spindle nut can be manufactured separately as an inexpensive molded part in any variation.
• • An explicit rotational alignment of the spindle nut before joining it with the thrust tube is usually not necessary.
• • No further work steps are necessary, apart from forming the tube and pressing both parts.

• 1 zeigt einen Schnitt durch eine Spindelantriebsvorrichtung, in welcher die erfindungsgemäße Spindelbaugruppe verwendet wird.
• 2A bis 2D zeigen ein erstes Ausführungsbeispiel der Erfindung.
• 3A bis 3D zeigen ein zweites Ausführungsbeispiel der Erfindung.
• 4A bis 4C zeigen ein drittes Ausführungsbeispiel der Erfindung.
• 5A bis 5D zeigen ein viertes Ausführungsbeispiel der Erfindung.
• 6A bis 6D zeigen ein fünftes Ausführungsbeispiel der Erfindung.

Several exemplary embodiments of the invention are explained in more detail below with reference to the drawings. This results in further features and advantages of the invention.

• 1 shows a section through a spindle drive device in which the spindle assembly according to the invention is used.
• 2A until 2D show a first embodiment of the invention.
• 3A until 3D show a second embodiment of the invention.
• 4A until 4C show a third embodiment of the invention.
• 5A until 5D show a fourth embodiment of the invention.
• 6A until 6D show a fifth embodiment of the invention.

1 shows a spindle drive device 10, preferably for motorized opening and closing of a vehicle flap (not shown).

The spindle drive device 10 includes a spindle housing 12 which extends along a spindle axis 14 . A motor gear unit 18 and a spindle unit 20 are arranged in the spindle housing 12 .

The spindle housing has a first end piece 16a which is fastened, for example, to the vehicle body. A second end piece 16b is arranged on the spindle unit 20 and is connected to the vehicle flap to be moved.

In the illustrated embodiment, the motor-gear unit 18 is mounted in the spindle housing 12 in a torque-proof manner via two damping elements 22a, 22b.

The spindle unit 20 includes a guide tube 24 in which a spindle 26 is rotatably mounted. At its end facing the motor gear unit 18 , the spindle 26 is preferably mounted in the guide tube 24 by means of a roller bearing 28 .

In the illustrated embodiment, the guide tube 24 is attached to the spindle housing 12 and, for example, glued or welded to the spindle housing.

Arranged between the guide tube 24 and the spindle 26 is a thrust tube 30 which is coupled to the spindle 26 by means of a spindle nut 32 arranged in a torque-proof manner in the thrust tube 30 .

The spindle 26 is rotatably mounted at its free end by means of a bearing arrangement in the thrust tube 30 and guided axially. The bearing arrangement also serves as a stop for the spindle nut 32, with which an axial movement of the spindle nut 32 on the spindle 26 is limited, so that the spindle nut 32 cannot move beyond the free end of the spindle 26.

The bearing arrangement preferably comprises a bearing element 34 which is arranged on the spindle and bears against the inner peripheral surface of the thrust tube 30 . A damping component 36 is arranged between the bearing element 34 and a thrust washer 38 . The arrangement consisting of the bearing element 34, the damping component 36 and the thrust washer 38 is fastened to the spindle 26 by a bearing washer 40.

The motor-gear unit 18 comprises a drive motor 42 with a motor shaft 44, which drives a gear shaft 48 via an epicyclic gear 46, at the output of which a ring gear 50 is provided. Ring gear 50 is rotatably coupled to spindle 26 via a clutch 52 . The ring gear 50 is rotatably mounted in the spindle housing 12 or a transmission housing not described in detail.

The spindle nut 32 is attached to one end of the thrust tube 30 . The other end of the thrust tube 30 is connected to a housing tube 54 via the end piece 16b.

When the spindle 26 is rotated by the motor gear unit 18 , the spindle nut 32 and the torque tube 30 connected thereto translate along the spindle 26 . Thus, the push tube 30 and the housing tube 54 connected thereto move telescopically relative to the spindle housing 12, so that a vehicle door coupled to the end piece 16b is moved.

A helical compression spring 56 is arranged in the housing tube 54 to assist the spindle unit 20 when the housing tube 54 is extended.

The helical compression spring 56 surrounds the guide tube 24 and is supported at one end against a stop on the guide tube 24 and at the other end on the thrust tube 30 .

The spindle nut 32 is preferably made of plastic and is non-rotatably connected to the metal thrust tube 30 .

According to the invention, the connection between the thrust tube 30 and the spindle nut 32 can take place in various ways.

How to get into the 2A until 2D recognizes, the spindle nut 32 includes in a first embodiment, a cylindrical portion 32a, which is connected to the push tube 30, and a nut head 32b.

In 2A is a perspective view of the connection between the push tube 30 and the spindle nut 32, wherein in 2 B the two components 30, 32 are shown before they are assembled.

2C shows a side view of the connection between the push tube 30 and the spindle motor 32, while 2D shows a longitudinal section of the connection between the thrust tube 30 and the spindle nut 32.

The threaded nut 32 has a continuous internal thread, into which the spindle 26 engages when the spindle drive is in the assembled state.

In the first embodiment of the invention shown, the thrust tube 30 has a plurality of contours 30a which consist of approximately U-shaped punched-out portions, resulting in retaining tongues whose free ends protrude into the interior of the thrust tube 30 . For example, 3 holding tongues 30a distributed over the circumference of the thrust tube 30 can be provided.

The cylindrical section 32a of the spindle nut 32 is inserted into the torque tube 30, preferably pressed in, with the outside diameter of the cylindrical section 32a being at least the same size as or slightly smaller than the inside diameter of the torque tube 30.

In the pressed-in state, according to 2C and 2D , the nut head 32b strikes with the collar 32e at the end of the thrust tube 30, and the retaining tongues 30a lie resiliently against the outer circumference of the cylindrical section 32a and claw firmly.

The free ends of the retaining tongues 30a protrude into the thrust tube 30 in the direction in which the spindle nut 32 is inserted, so that the cylindrical section 32a can be inserted into the thrust tube 30 with relatively little force, but the spindle nut 32a can be pulled out of the thrust tube due to the barb-like retaining tongues 30a requires a relatively large amount of force.

The retaining tongues 30a fix the spindle nut 32 against translational and rotational movement in the thrust tube 30 .

The nut head 32b can have sliding surfaces which slide on the inner circumference of the guide tube 24, so that the spindle nut 32 is guided axially in the guide tube 24.

The thrust tube 30 can have a constriction 30c at a short distance from the connection area with the spindle nut 32, which forms a stop for the thrust washer 38, which is arranged on the spindle 26, so that the spindle nut 32 cannot move beyond the free end of the spindle 26 .

The 3A until 3D show a modified embodiment of the invention, which is essentially the embodiment of 2A until 2D corresponds, but in the cylindrical portion 32a of the spindle nut 32 a plurality of depressions 32c are provided which correspond to the retaining tongues 30a of the push tube 30 in number and position.

In 3A a perspective view of the spindle nut 32 is shown and in FIGS 3B and 3C the torque tube 30 and the spindle nut 32 prior to their assembly. The 3D shows a cross section of the thrust tube 30 in the area of the punched-out areas 30a.

When the spindle nut 32 is inserted into the torque tube 30, the retaining tongues 30a of the torque tube 30 engage in the recesses 32c of the spindle nut 32 and form a snap-in connection, so that the spindle nut 32 cannot be pulled out of the torque tube 30 or the spindle nut can no longer be rotated relative to the torque tube 30 is possible.

The 4A until 4C show a further embodiment of the invention.

The 4A shows a perspective view of the thrust tube 30 with a double row of retaining tongues 30a. 4B shows a side view of the thrust tube 30 of FIG 4A and the 4C a longitudinal section through the thrust tube 30 of 4A .

In this embodiment of the invention, not only is one row of retaining tongues 30a distributed over the circumference of the thrust tube 30, but a second row of retaining tongues 30a is provided offset in the axial direction, so that both rows of retaining tongues 30a are embedded in the material of the cylindrical section 32a of the spindle nut 32 and thereby achieve a high pull-out force. This embodiment can additionally be combined with recesses 32c in the cylindrical section 32a of the spindle nut 32.

According to the 5A until 5D again only one row of holding tongues 30a distributed over the circumference of the thrust tube 30 can be provided.

The 5A shows a perspective view of the thrust tube 30. The 5B shows a side view of the thrust tube 30. The 5C shows a longitudinal section through the thrust tube 30 of FIG 5A . The 5D shows a cross section of the thrust tube 30 of FIG 5A in the area of the punchings 30a.

In this embodiment of the invention, the number of retaining tongues 30a compared to the embodiment of 2A until 2D increased and doubled, for example, so that not only three retaining tongues 30a, but for example six retaining tongues 30a distributed over the circumference are provided.

Here, too, the greater number of retaining tongues results in a greater pull-out force for the spindle nut 32. This embodiment can also be combined with indentations 32c in the cylindrical section 32a of the spindle nut 32.

The 6A until 6D show another embodiment of the invention.

The 6 A shows the thrust tube 30 and the spindle nut 32 before assembly. 6B shows the thrust tube 30 and the spindle nut after assembly. 6C shows a longitudinal section through the thrust tube 30 and the spindle nut 32 of 6B and the 6D shows a cross section of the assembled torque tube with the spindle nut 32 in the area of the punched-out portions 30b.

The thrust tube 30 has no retaining tongues 30a, but is provided with continuous punched-out portions 30b, for example with three punched-out portions 30b, which are distributed over the circumference of the thrust tube 30.

On its cylindrical section 32a, the spindle nut 32 has radially protruding projections 32d, which correspond in number and position to the punched-out portions 30b of the thrust tube 30.

When the spindle nut 32 is inserted into the thrust tube 30 , the radial projections 30d come to rest in the area of the punched-out portions 30b of the thrust tube 30 and engage in these recesses 30b and thus fix the spindle nut 32 in the thrust tube 30 .

As a result of the projections 32d of the spindle nut 32 engaging in the punched-out portions 30b of the push tube 30, the spindle nut 32 cannot be moved in relation to the push tube 30 either in translation or in rotation.

In all embodiments of the invention, the cylindrical section 32a of the spindle nut 32 can preferably have an insertion aid in the form of a chamfer at its free end, so that the cylindrical section 32a can be inserted into the push tube 30 more easily.

In the same way, the radial projections 32d of the spindle nut 32 according to 6A until 6D have insertion aids directed in the direction of the thrust tube 30 . At the other end, they can preferably have a right-angled transition to the cylindrical section 32a of the spindle nut 32, so that although it is easier to insert the spindle nut 32a into the push tube 30, it is no longer possible to pull the projections 32d out of the punched-out portions 20b after they have engaged.

List of References

10

spindle drive device

12

spindle housing

14

spindle axis

16a

tail

16b

tail

18

engine transmission unit

20

spindle unit

22a

damping element

22b

damping element

24

guide tube

26

spindle

28

roller bearing

30

thrust tube

30a

contour

30b

punch-outs

30c

constriction

32

spindle nut

32a

cylindrical section

32b

Head

32c

deepening

32d

head Start

32e

Federation

34

bearing element

36

damping component

38

thrust washer

40

bearing washer

42

drive motor

44

motor shaft

46

transmission

48

gear shaft

50

ring gear

52

coupling

54

housing tube

56

helical compression spring

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

• EP 2037067 B1 [0008]
• DE 102018108277 A1 [0012]
• DE 202021100014 U1 [0012]

Claims (10)

Spindle assembly for a spindle drive device (10) comprising a thrust tube (30) and a spindle nut (32) which is arranged in the thrust tube (30) in a torque-proof manner, wherein the spindle nut (32) can be brought into threaded engagement with a spindle (26) of the spindle drive device (10). is characterized in that the push tube (30) has one or more contours (30a, 30b) in the connection area with the spindle nut (32), and the spindle nut (32) is inserted into the push tube (30) in such a way that it passes through the Contours (30a, 30b) against translational and / or rotational movement in the push tube (30) is fixed. spindle assembly claim 1 , characterized in that the spindle nut (32) has a hollow-cylindrical section (32a) which is inserted into the thrust tube (30). Spindle assembly according to any of Claims 1 or 2 , characterized in that the spindle nut (32) at the end of the cylindrical portion (32a) has a collar (32e) as a stop for the thrust tube (30). Spindle assembly according to any of Claims 1 until 3 , characterized in that the contours comprise a plurality of retaining tongues (30a) distributed over the circumference of the thrust tube (30) and protruding into the interior of the thrust tube (30). Spindle assembly according to any of Claims 1 until 4 , characterized in that the contours comprise several rows of retaining tongues (30a) distributed over the circumference of the thrust tube (30) and protruding into the interior of the thrust tube (30). Spindle assembly according to any of Claims 1 until 5 , characterized in that distributed over the circumference of the hollow-cylindrical section (32a) of the spindle nut (32) are one or more recesses (32c) into which the retaining tongues (30a) of the thrust tube (30) engage. Spindle assembly according to any of Claims 1 until 3 , characterized in that the contours are formed as one or more complete punched-out portions (30b) in the thrust tube (30). Spindle assembly according to any of Claims 1 until 3 and 7 , characterized in that distributed over the circumference of the hollow-cylindrical section (32) of the spindle nut (32) are one or more radial projections (32d) which engage in the punched-out portions (30b) of the thrust tube (30). Spindle drive device (10) with a spindle assembly according to one of Claims 1 until 8th . Spindle drive device (10) after claim 9 for moving doors, flaps or hoods of a motor vehicle.

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