Adjustable steering column for a steering system of a motor vehicle

Abstract

The invention relates to an adjustable steering column (10) for a steering system, in particular a steer-by-wire steering system, of a motor vehicle, having a stationary jacket tube (14) connected to a steering console (12), a movable jacket tube (18) guided in the stationary jacket tube (14), in particular by a ball guide (16), a crash tube (20) guided in the movable jacket tube (18), a steering spindle (22) arranged in the crash tube (20) and firmly connected to the crash tube (20), a drive unit (24) connected to the crash tube (20) and / or the steering spindle (22) and designed to axially move the crash tube (20) and the steering spindle (22) firmly connected to the crash tube (20);and a locking mechanism (26) which is designed to connect the movably guided jacket tube (18) to the crash tube (20) in a first locking position (P1) and to connect the movably guided jacket tube (18) to the stationary jacket tube (14) in a second locking position (P2);

Description

State of the art

[0001] Car steering columns are typically manually or electrically adjustable for height and reach. The fore / aft adjustment, in particular, is often implemented as a telescope between the housing, which performs the pivoting movement for height adjustment, and the telescopic tube, often referred to as the crash tube or guide tube.

[0002] Furthermore, some steering columns feature a so-called easy-entry function, which allows the steering column body to be retracted as far as the steering column's adjustment range allows. The steering column's adjustment range typically has a travel of 25 mm to 35 mm.

[0003] DE 10 2008 060 225 B4 discloses an adjustable steering column for a motor vehicle with a steering column body for supporting a rotatable steering shaft, a clamping mechanism for implementing a continuous adjustability of the steering shaft along the longitudinal direction of the steering column body and an energy absorption mechanism for energy-absorbing displacement of the steering shaft in the event of an accident.

[0004] However, in the context of the application of autonomous driving of the vehicle, it is desirable, on the one hand, to enable a larger adjustment range of the steering column so that the steering column and a steering device attached to it can be retracted as far as possible into a dashboard or interior paneling of the vehicle during autonomous driving of the vehicle.

[0005] Due to these requirements, these high axial adjustment ranges can only be achieved with a double telescope. The comfort range, i.e., individual adjustment of the steering wheel, should be achieved via the inner telescope, while movement via the outer telescope. To ensure correct movement and meet the strength requirements, the outer telescope must be lockable.

[0006] The invention is therefore based on the object of providing an improved steering column arrangement for a motor vehicle which is capable of enabling effective and safe adjustability of the double telescope.

[0007] The object is achieved with an adjustable steering column for a steering system, in particular a steer-by-wire steering system, of a motor vehicle having the features of patent claim 1. Disclosure of the invention

[0008] The present invention provides an adjustable steering column for a steering system, in particular a steer-by-wire steering system, of a motor vehicle.

[0009] The steering column comprises a stationary jacket tube connected to a steering console and a movable jacket tube guided in the stationary jacket tube, in particular by a ball guide.

[0010] Furthermore, the steering column comprises a crash tube guided in the movable casing tube and a steering spindle arranged in the crash tube and firmly connected to the crash tube.

[0011] The steering column further comprises a drive unit connected to the crash tube and / or the steering spindle, which is designed to axially move the crash tube and the steering spindle fixedly connected to the crash tube.

[0012] Furthermore, the steering column comprises a locking mechanism which is designed to connect the movably guided jacket tube to the crash tube in a first locking position and to connect the movably guided jacket tube to the stationary jacket tube in a second locking position.

[0013] The advantage of the ball / roller lock over other locking systems is a smaller installation space, fewer components, simple manufacturing, and easy assembly. Furthermore, the internal telescope is additionally guided.

[0014] The locking element, in the form of a movable element, is pressed into the corresponding locking notches via a locking contour during axial movement of the assemblies. The locking notches and movable elements thus create a positive locking connection.

[0015] Advantageous embodiments and further developments emerge from the subclaims and from the description with reference to the figures.

[0016] According to a preferred development, the locking mechanism is designed to positively connect the movably guided jacket tube to the crash tube in the first locking position, and to positively connect the movably guided jacket tube to the stationary jacket tube in the second locking position. Thus, a specific combination of tubes can be advantageously coupled to one another depending on the locking position.

[0017] According to a further preferred development, it is provided that the locking mechanism has a first recess formed in the stationary casing tube, a second recess formed in the movably guided casing tube, a guide slot formed in the crash tube and at least one movable object, wherein the at least one movable object is arranged in the first recess in the first locking position and at least partially in the second recess in the second locking position.

[0018] The first recess and the second recess thus advantageously serve to accommodate the at least one movable object in order to assume a respective locking position.

[0019] According to a further preferred development, the at least one movable object, in the first locking position, is arranged partially in the second recess formed in the movably guided casing tube and partially in the guide slot formed in the crash tube. The second recess and the guide slot thus combine to form a space for accommodating the respective object.

[0020] According to a further preferred development, the guide slot is designed such that, when the movable casing tube connected to the crash tube passes over the first recess, it moves the at least one movable object radially outward into the first recess. Thus, advantageously, no spring element is required to move the movable object into a respective recess.

[0021] According to a further preferred development, the at least one movable object is formed by at least one ball, disc, or roller. The specific design of the locking mechanism can thus be flexibly adapted to the respective structural requirements or space conditions.

[0022] According to a further preferred development, the guide slot is designed such that when the crash tube, which is decoupled from the movable casing tube, passes over the first recess, the at least one movable object can be moved radially inward in sections from the first recess into the second recess formed in the movably guided casing tube and in sections into the guide slot formed in the crash tube. The movable object can thus be moved radially inward or outward into a respective recess depending on the axial movement of the steering column.

[0023] According to a further preferred development, it is provided that the drive unit is designed to set an adjustment speed of the steering column in a first adjustment range, in particular a comfort adjustment range of the steering column, in which the locking mechanism has the first locking position, and in a second adjustment range, in particular a stowage range of the steering column, in which the locking mechanism has the second locking position.

[0024] This allows the adjustment speed to be adapted to the respective adjustment range. When adjusting the steering column to the stowage area, a higher adjustment speed is preferably required, which can therefore be adjusted.

[0025] According to a further preferred development, the drive unit is designed to detect a position of the steering column in the comfort adjustment range and the storage range by detecting a current consumption of the drive unit. Due to a different adjustment resistance in the various adjustment ranges, this can be detected by the current consumption of the drive unit.

[0026] According to a further preferred development, it is provided that a coefficient of friction of a connection of the movably guided jacket pipe with the crash pipe relative to the stationary jacket pipe is lower than a coefficient of friction of a connection of the stationary jacket pipe with the movably guided jacket pipe relative to the crash pipe.

[0027] The coefficient of friction is the parameter that influences the power consumption of the drive unit in different adjustment ranges of the steering column.

[0028] Further possible embodiments, developments and implementations of the invention also include combinations of features of the invention described previously or below with regard to the embodiments that are not explicitly mentioned. Short description of the drawings

[0029] The accompanying drawings are intended to provide a further understanding of embodiments of the invention. They illustrate embodiments and, in conjunction with the description, serve to explain principles and concepts of the invention.

[0030] Other embodiments and many of the aforementioned advantages will become apparent upon review of the drawings. The elements illustrated in the drawings are not necessarily drawn to scale.

[0031] They show: Fig. 1-6 a longitudinal sectional view of an adjustable steering column for a steering system, in particular a steer-by-wire steering system, of a motor vehicle according to a preferred embodiment of the invention; and Fig. 7-8 a cross-sectional view of the adjustable steering column for the steering system, in particular the steer-by-wire steering system, of the motor vehicle according to the preferred embodiment of the invention.

[0032] In the figures of the drawings, the same reference symbols designate the same or functionally equivalent elements, parts or components, unless otherwise stated.

[0033] Fig. 1 shows a longitudinal sectional view of an adjustable steering column 10 for a steering system, in particular a steer-by-wire steering system, of a motor vehicle according to a preferred embodiment of the invention.

[0034] The steering column 10 comprises a stationary jacket tube 14 connected to a steering console 12 and a movable jacket tube 18 guided in the stationary jacket tube 14, in particular by a ball guide 16.

[0035] Furthermore, the steering column 10 comprises a crash tube 20 guided in the movable casing tube 18 and a steering spindle 22 arranged in the crash tube 20 and firmly connected to the crash tube 20.

[0036] The steering column 10 further comprises a drive unit 24 connected to the crash tube 20 and / or the steering spindle 22, which is designed to axially move the crash tube 20 and the steering spindle 22, which is fixedly connected to the crash tube 20. The drive unit 24 comprises an axial adjustment motor 31 and a plunger spindle 32 axially adjustable by the motor. The plunger spindle 32 is connected to the crash tube 20 via a connecting element 33, so that an axial movement of the plunger spindle 32 causes an axial movement of the crash tube 20.

[0037] Furthermore, the steering column 10 comprises a locking mechanism 26 which is designed to connect the movably guided jacket tube 18 to the crash tube 20 in a first locking position P1 and to connect the movably guided jacket tube 18 to the stationary jacket tube 14 in a second locking position P2.

[0038] Fig. 2 shows a longitudinal sectional view of the adjustable steering column 10 for the steering system, in particular the steer-by-wire steering system, of the motor vehicle according to the preferred embodiment of the invention.

[0039] The movable jacket tube 18 is located in the stationary jacket tube 14 in the far left, inserted position. The crash tube 20, including the permanently mounted steering spindle 22, is also located in the movable jacket tube 18 in the far left, inserted position.

[0040] The movable objects formed by balls are located between the movable casing tube 18 and the crash tube 20. The balls are located in the guide slot 28 of the crash tube and the second recess 18a of the movable casing tube. This locks or couples the movable casing tube 18 and the crash tube 20. The axial adjustment motor 31 is de-energized.

[0041] Fig. 3 shows a longitudinal sectional view of the adjustable steering column 10 for the steering system, in particular the steer-by-wire steering system, of the motor vehicle according to the preferred embodiment of the invention.

[0042] The axial adjustment motor 31 rotates an internal nut, causing the plunger spindle 32 to move axially to the right. The plunger spindle 32 presses the entire assembly of steering spindle 22, crash tube 20, and movable jacket tube 18 against the vehicle connection or steering console 12 to the right, i.e., toward an extended position of the steering column 10.

[0043] A relative movement occurs between the stationary steering column and the assembly comprising the steering spindle 22, crash tube 20, and movable steering column. This movement is guided by a ball bearing 16. The steering wheel (not shown), which is attached to the steering wheel connector, now moves axially toward the driver.

[0044] Fig. 4 shows a longitudinal sectional view of the adjustable steering column 10 for the steering system, in particular the steer-by-wire steering system, of the motor vehicle according to the preferred embodiment of the invention.

[0045] The entire assembly of steering spindle 22, crash tube 20 and movable jacket tube moves to the right relative to the stationary jacket tube 14. The movable jacket tube 18 hits a (in Fig. 1) stop 34 of the stationary casing pipe and is thereby prevented from moving further to the right.

[0046] Fig. 5 shows a longitudinal sectional view of the adjustable steering column 10 for the steering system, in particular the steer-by-wire steering system, of the motor vehicle according to the preferred embodiment of the invention.

[0047] The replacement spindle continues to push the crash tube 20 and steering spindle 22 assembly to the right. The balls are pressed into the first recess 14a of the stationary casing tube via the guide slot 28 of the crash tube.

[0048] The locking between the crash tube 20 and the movable jacket tube 18 is released, the movable jacket tube 18 is locked to the stationary jacket tube 14.

[0049] The further movement to the right now occurs relative between the assembly of crash tube 20, steering spindle 22 and locked assembly of movable jacket tube 18, stationary jacket tube 14.

[0050] This movement is guided by a tube-to-tube guide 35. The movement of the crash tube 20 and steering spindle 22 assembly is automatically stopped in the selected position of the steering wheel.

[0051] Fig. 6 shows a longitudinal sectional view of the adjustable steering column 10 for the steering system, in particular the steer-by-wire steering system, of the motor vehicle according to the preferred embodiment of the invention.

[0052] Within the actual adjustment range of the steering wheel, the driver can adjust the axial position of the steering wheel. The plunger spindle 32 moves the steering spindle 22 and crash tube 20 assembly to the right or left. Guidance is provided by the tube-to-tube guide 35. The movable steering tube 18 is locked to the stationary steering tube 14.

[0053] Retraction into the stowed area occurs analogously to the extension of the steering column 10. The plunger spindle 32 pushes the crash tube 20 and steering spindle 22 assembly to the left until the locking contour of the crash tube lies below the ball.

[0054] The balls are then pushed out of the second recess 18a of the stationary jacket tube into the guide slot 28 of the crash tube. This releases the locking mechanism between the movable jacket tube 18 and the stationary jacket tube 14. The movable jacket tube 18 can now also be pushed to the left into the stowage area.

[0055] Fig. 7 shows a cross-sectional view of the adjustable steering column 10 for the steering system, in particular the steer-by-wire steering system, of the motor vehicle along the Fig. 1 shown section plane AA according to the preferred embodiment of the invention.

[0056] A system with three balls is shown as an example. The functional principle also applies when only one or more balls are used. Likewise, a ball can be replaced by a roller or disc. Fig. 7 shows the first locking position P1 of the locking mechanism 26, in which the movably guided jacket tube 18 is connected to the crash tube 20.

[0057] Fig. Figure 8 shows a cross-sectional view of the adjustable steering column 10 for the steering system, in particular the steer-by-wire steering system, of the motor vehicle along the Fig. 1 shown section plane BB according to the preferred embodiment of the invention.

[0058] In Fig. 8 also shows the first locking position P1 of the locking mechanism 26, in which the movably guided jacket tube 18 is connected to the crash tube 20. In the sectional plane BB shown, it can be seen that the respective first recess 14a of the stationary jacket tube 14 is empty, since the balls are in the first locking position P1 of the locking mechanism 26, in which the movably guided jacket tube 18 is connected to the crash tube 20. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2008 060 225 B4

[0003]

Claims

[1] Adjustable steering column (10) for a steering system, in particular a steer-by-wire steering system, of a motor vehicle, comprising: a stationary casing tube (14) connected to a steering console (12); a movable jacket tube (18) guided in the stationary jacket tube (14), in particular by a ball guide (16); a crash tube (20) guided in the movable casing tube (18); a steering spindle (22) arranged in the crash tube (20) and firmly connected to the crash tube (20); a drive unit (24) connected to the crash tube (20) and / or the steering spindle (22), which is designed to axially move the crash tube (20) and the steering spindle (22) fixedly connected to the crash tube (20); and a Locking mechanism (26) which is designed to connect the movably guided jacket tube (18) to the crash tube (20) in a first locking position (P1) and to connect the movably guided jacket tube (18) to the stationary jacket tube (14) in a second locking position (P2). [2] Adjustable steering column according to claim 1, wherein the locking mechanism (26) is designed to positively connect the movably guided jacket tube (18) to the crash tube (20) in the first locking position (P1) and to positively connect the movably guided jacket tube (18) to the stationary jacket tube (14) in the second locking position (P2). [3] Adjustable steering column according to claim 1 or 2, wherein the locking mechanism (26) has a first recess (14a) formed in the stationary casing tube (14), a second recess (18a) formed in the movably guided casing tube (18), a guide slot (28) formed in the crash tube (20) and at least one movable object (30), wherein the at least one movable object (30) is arranged in the first recess (14a) in the first locking position (P1) and at least partially in the second recess (18a) in the second locking position (P2). [4] Adjustable steering column according to claim 3, wherein the at least one movable object (30) in the first locking position (P1) is arranged in sections in the second recess (18a) formed in the movably guided casing tube (18) and in sections in the guide slot (28) formed in the crash tube (20). [5] Adjustable steering column according to claim 3 or 4, wherein the guide slot (28) is designed such that when the movable casing tube (18) connected to the crash tube (20) passes over the first recess (14a), the guide slot (28) moves the at least one movable object (30) radially outward into the first recess (14a). [6] Adjustable steering column according to one of the preceding claims, wherein the at least one movable object (30) is formed by at least one ball, disc or roller. [7] Adjustable steering column according to one of the preceding claims, wherein the guide slot (28) is designed such that when the crash tube (20) decoupled from the movable casing tube (18) passes over the first recess (14a), the at least one movable object (30) can be moved radially inwardly from the first recess (14a) in sections into the second recess (18a) formed in the movably guided casing tube (18) and in sections into the guide slot (28) formed in the crash tube (20). [8] Adjustable steering column according to one of the preceding claims, wherein the drive unit (24) is designed to set an adjustment speed of the steering column (10) in a first adjustment range, in particular a comfort adjustment range of the steering column (10), in which the locking mechanism (26) has the first locking position (P1), and in a second adjustment range, in particular a stowage range of the steering column (10), in which the locking mechanism (26) has the second locking position (P2). [9] Adjustable steering column according to claim 8, wherein the drive unit (24) is designed to detect a position of the steering column (10) in the comfort adjustment range and the storage range by detecting a current consumption of the drive unit (24). [10] Adjustable steering column according to claim 9, wherein a coefficient of friction of a connection of the movably guided jacket tube (18) with the crash tube (20) relative to the stationary jacket tube (14) is lower than a coefficient of friction of a connection of the stationary jacket tube (14) with the movably guided jacket tube (18) relative to the crash tube (20).

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