Adaptive load-limiting steering column for vehicles

Abstract

The present disclosure relates to a steering column for a vehicle, comprising a telescopic structure that has a movable part and a reference part to be fixed to the vehicle. The steering column comprises a first actuator (30) for moving the movable part (10) in relation to the reference part (20), preferably in translation. A controllable and reversible coupling device (50) is arranged between the first actuator (30) and the movable part (10). A second actuator (40) controls the coupling device (50). A third actuator (60) is provided in order to brake the movable part (10) if the second actuator (40) has been actuated. The steering column enables adaptive load limiting and improves the safety of occupants in various collision scenarios.

Description

DESCRIPTION TITLE: LOAD-LIMITING ADAPTIVE STEERING COLUMN FOR VEHICLES Technical field of the invention

[0001] This disclosure relates to vehicle steering columns, and more specifically an adaptive steering column, a method of operation of such a steering column, and a vehicle incorporating the steering column, designed to improve occupant safety. State of the art

[0002] Steering columns are essential vehicle components, providing a mechanical link between the steering wheel and the steering mechanism. Traditional steering columns typically incorporate load-limiting features to improve occupant safety in collisions. These load-limiting mechanisms often utilize deformable elements within telescoping shafts, such as plastic deformation, bending, tearing, or shear elements, or separate mechanical modules like bending bars.

[0003] Current steering column designs face several challenges. The load-limiting methods employed are generally irreversible and typically activate during moderate to severe accidents. The minimum force required for activation is usually high, often exceeding 2 kN and reaching up to 8 kN. To prevent undesirable damage due to misuse, shear pins are commonly used, with breaking forces of approximately 3500 N. However, this high minimum force is undesirable in many situations, particularly in low-severity events where airbag deployment is not required.

[0004] On the other hand, the emergence of automated vehicles has introduced new requirements for steering columns. These include the need for increased longitudinal travel, from a common value of 100 mm to a new target of 250 mm, to accommodate designs with, for example, retractable steering wheels. This extended travel requirement poses challenges for existing plastic deformation load-limiting mechanisms, such as flex rods, which become cumbersome when adapted to longer travel distances.

[0005] Low-speed collisions, while frequent, present a significant challenge for current steering column designs. In these scenarios, airbag deployment may not occur, leaving the seat belt as the primary means of occupant restraint. However, the high initial forces required to activate current load-limiting mechanisms may not provide optimal protection in these low-severity impacts.

[0006] It has been recognized that an adaptive and dynamic steering column system is needed to overcome one or more of these problems. Description of the invention

[0007] A steering column for a vehicle may include a telescopic structure with a moving part and a reference part to be fixed to the vehicle. The steering column may include a first actuator to drive the moving part relative to the reference part, which may be in a translational manner. The telescopic structure could also be described as a sliding structure or a translational structure. In some applications, the first actuator may include an electric motor. The first actuator may be irreversible when a load is applied to the moving part in certain implementations.

[0008] The steering column may further include a controllable and reversible coupling device disposed between the first actuator and the part The column is mobile. Thus, it can be made retractable in the event of a collision or the detection of an imminent collision, even at low speeds and therefore with low stress on the column, without breaking any parts that would require subsequent replacement. A second actuator can be provided to control the coupling device, preferably reversibly. In some cases, the coupling device may include a clutch device, including a toothed clutch, and / or a load limiter (a force limiter, a torque limiter, etc.) incorporating elastic means or springs cooperating with a friction brake. The second actuator may include a solenoid to engage and disengage the toothed clutch and / or the load limiter.In all cases, the moving part can be translated more easily (generally when a force less than 1000 N is applied) after or during the actuation of the second actuator than without actuation of the second actuator. In other words, the coupling device is designed to withstand all driving conditions or requirements (including no translation of the moving part when a force of approximately 3500 N is applied) and to release the moving part when the second actuator is actuation so that it can be translated when a force less than 1000 N is applied.

[0009] In addition, the steering column may incorporate a third actuator to brake or restrain the moving part, especially if the second actuator has been actuated or is about to be actuated. In some implementations, the third actuator may include a brake caliper for clamping onto a rail (or guide rack) of a rail / gear system. The brake caliper may be actuated by various means, such as a pyrotechnic device, a pneumatic system including at least one pressure generator, or a spring-loaded mechanism released by a solenoid. In some aspects, the pyrotechnic device may include several independently controlled igniters to provide different levels of braking force and / or different actuation moments.

[0010] In other words, the steering column may include: a telescopic structure having a moving part and a reference part to be fixed to the vehicle; a first actuator to drive the moving part relative to the reference part, preferably by translation; a controllable and reversible coupling device disposed between the first actuator and the moving part; a second actuator to control the coupling device reversibly; and a controllable braking device to brake the moving part.

[0011] According to one embodiment, the braking device is controllable by the second actuator.

[0012] According to one embodiment, the braking device is controllable by the third actuator.

[0013] The steering column may also include a control unit configured to actuate the second actuator to disengage the coupling device in response to the detection of a collision or imminent collision, and optionally to actuate the third actuator to apply a braking force to the moving part. The braking force can be selected or adjusted based on factors such as the severity of the collision or imminent collision, occupant characteristics, and / or occupant position. The overall system may include sensors and detectors to assess factors such as the severity of the collision or imminent collision, occupant characteristics, and / or occupant position.

[0014] One method of operating the steering column may involve detecting a collision or an imminent collision, which may be of a severity not requiring airbag deployment. The method may include actuation of a second actuator to control the coupling device, which may involve energizing a solenoid. to disengage a clutch, a toothed clutch, and / or a load limiter between the first actuator and the moving part. The method may optionally include actuation of the third actuator to brake the moving part if the second actuator has been actuated, which may involve the activation of a pyrotechnic device to apply a braking force to the moving part. The method may further include selecting or adjusting a braking force to be applied by the third actuator based on factors such as the severity of the collision, the characteristics of the occupant, and the occupant's position.

[0015] The steering column as described can be incorporated into a vehicle, providing enhanced safety features and adaptable steering control in various driving conditions. Description of the figures

[0016] Other features and advantages of the present invention will become more apparent upon reading the following detailed description of embodiment(s) of the invention given by way of non-limiting example(s) and illustrated by the accompanying drawings, in which:

[0017] [fig. 1] illustrates a perspective view of a steering column for a vehicle, according to aspects of this disclosure;

[0018] [fig. 2] illustrates a cross-sectional view of a steering column assembly, according to one embodiment of the present disclosure;

[0019] [fig. 3] illustrates a cross-sectional view of a braking mechanism for a steering column, according to aspects of this disclosure.

[0020] Detailed description of implementation method(s)

[0021] A steering column 100 for a vehicle, as illustrated in Figure 1, is provided. The steering column 100 comprises a telescopic structure having a movable part 10 and a reference part 20. The reference part 20 is configured to be fixed to the vehicle.

[0022] The moving part 10 includes, in particular, a steering wheel 11, an outer shell 12, and a guide rack 13, the steering wheel 11 being rotatably mounted relative to the outer shell 12 (or around an axis that can be defined by the outer shell) to steer the vehicle. The reference part 20 includes, in particular, a mounting plate 21 and an outer housing 22 fixed together, as well as an articulated chain 23. The mounting plate 21 is configured to fix the steering column 100 to the vehicle structure. In the example shown, a mounting plate 21 with bolts is provided, but other solutions are possible.

[0023] The steering column 100 includes a first actuator 30 to drive the moving part 10 relative to the reference part 20. The first actuator 30 is configured to provide a translational movement of the moving part 10 relative to the reference part 20.

[0024] A controllable and reversible coupling device 50 is arranged between the first actuator 30 and the moving part 10. The steering column 100 further includes a second actuator 40 to control the coupling device 50.

[0025] A third actuator 60 is provided to brake the moving part 10, particularly if the second actuator 40 has been actuated or is about to be actuated. The third actuator 60 is positioned and fixed on the outer housing 22.

[0026] The telescopic structure of the 100 steering column allows for a longitudinal travel of up to 250 mm, for example (other ranges are possible). This extended travel range accommodates various driving positions, both manual and automatic, and improves the vehicle's safety features.

[0027] The guide rack 13 extends from the outer shell 12 and passes through the outer housing 22, including positioning rings or bearings, thus providing anti-rotation guidance and linear, facilitating the telescopic movement of the moving part 10. The articulated chain 23 is located inside the outer casing 22 and can be used to manage internal components such as wiring during the telescopic movement of the steering column 100.

[0028] The steering column 100 comprises several internal components arranged inside the outer housing 22, as illustrated in Figure 2. Figure 2 is a cross-sectional view through the first actuator 30. The outer shell 12 is positioned and guided inside the outer housing 22 and houses a central shaft 14. A guide rack 13 is located along one side of the assembly, providing a track for the telescopic movement of the moving part 10 of the steering column 100.

[0029] The first actuator 30 is positioned at the bottom left of the assembly shown in Figure 2. The first actuator 30 comprises an electric motor 31, a worm gear 32, and a toothed wheel 33. The first actuator 30 is connected to a shaft and to the coupling device 50, which has a freewheel 52 engaged with the guide rack 13. This arrangement forms a screw / wheel system that allows precise control of the telescopic movement of the moving part 10 relative to the reference part 20. The electric motor 31 drives the worm gear 32, which in turn cooperates with the toothed wheel 33 to convert the rotary motion into linear motion via the coupling device 50, which has the freewheel 52 engaged with the guide rack 13.

[0030] Adjacent to the first actuator 30 is the second actuator 40, which controls the coupling device 50. The coupling device 50 comprises an internal shaft 53 supporting a movable gear 51 and the freewheel 52. The coupling device 50 can therefore form a clutch assembly with a toothed clutch. The second actuator 40 may include a solenoid for engaging and disengaging the toothed clutch.

[0031] Indeed, the movable gear 51 translates along the internal shaft 53 under the action of the second actuator 40, so as to engage or disengage the freewheel 52. The coupling is therefore reversible depending on whether the second actuator 40 is activated or not. When the movable gear 51 is engaged with the freewheel 52, the moving part 10 cannot move relative to the reference part 20 because the system (screw / wheel system) is irreversible (unless the first actuator is actuated). When the movable gear 51 is disengaged from the freewheel 52, upon actuating the second actuator 40, the moving part 10 can move relative to the reference part 20 because the screw / wheel system is bypassed or the moving part is decoupled or disconnected from the reference part 20.Of course, an elastic return element allows the movable toothed wheel 51 to be returned to the engaged position with the free wheel 52 (especially when the actuator 40 is not powered).

[0032] In other words, the movable gear 51 and the freewheel 52 work together to engage or disengage the telescopic function of the steering column 100. When engaged, the movable gear 51 connects the first actuator 30 to the moving part 10, allowing controlled adjustment of the steering wheel position 11. When disengaged, upon actuating the second actuator 40, the moving part 10 can move freely relative to the reference part 20, subject to the braking action of the third actuator 60.

[0033] The coupling device 50 can also function as a load or torque (or force) limiter so as to limit in a controlled manner the displacement of the moving part 10 relative to the reference part 20.

[0034] The guide rack 13 and the screw / wheel system of the first actuator 30 together form a rail / gear system which allows the translation of the moving part 10. This system allows a precise and controlled telescopic movement of the steering column 100.

[0035] The arrangement of these components inside the outer casing 22 provides a compact and efficient design for the steering column 100. The integration of the first actuator 30, the second actuator 40 and the coupling device 50 allows both manually controlled adjustment and automated control of the steering column position, while incorporating safety features for use during collision events.

[0036] The steering column 100 includes a third actuator 60 for braking the moving part 10 when the movable gear 51 and the freewheel 52 are disengaged or if the movable gear 51 and the freewheel 52 are about to be disengaged. Figure 3 illustrates a cross-sectional view of the braking mechanism of the steering column 100 along the guide rack 13. The third actuator 60 includes a brake caliper for clamping onto a rail of the rail / gear system, in particular the guide rack 13.

[0037] The third actuator 60 comprises a caliper body 61 which houses several components. The guide rack 13 is positioned inside the outer housing 22 and serves as the surface on which the braking force is applied. A brake pad 62 is arranged to make contact with the guide rack 13. Springs 63 are incorporated to provide initial or residual tension and to prevent noise / rattling.

[0038] The brake caliper can be actuated by various mechanisms. In one example, the brake caliper is actuated by a pyrotechnic device. The pyrotechnic device may include several independently controlled detonators to provide different levels of braking force and / or different timings of actuation. As illustrated in Figure 3, a first pyrotechnic device 64 and a second pyrotechnic device 65 are included (which may be identical or different, particularly in terms of pressurization capacity). These devices, when activated, create pressure to push the brake pad 62 against the guide rack 13.

[0039] In another example, the brake caliper can be actuated by a pneumatic system comprising at least one pressure generator. The pneumatic system can use a pyrotechnic gas generator to function as an air brake. Alternatively, the brake caliper can be actuated by a spring-loaded mechanism released by a solenoid or a pyrotechnic device.

[0040] A pressure valve 66 is integrated into the system to regulate the pressure generated by the pyrotechnic devices and / or prevent overpressure. The pressure valve 66 limits the maximum pressure in the system.

[0041] The third actuator 60 can be designed to be reversible, allowing the braking force to be released after activation. Braking is achieved by friction between the brake pad 62 and the guide rack 13.

[0042] In some examples, the third actuator 60 may include a push-pin design with spring washers (spring washers or helical springs). This design may incorporate preloaded springs that can be released either by a pyrotechnic actuator or by a solenoid, depending on the specific configuration. In the examples above, the third actuator 60 is of the released-before-actuation type (i.e., prior to actuation, there is no or virtually no braking force). In some examples, the third actuator 60 may be of the "braked" or "activated"-before-actuation type (i.e., prior to actuation, the braking force is at its maximum), and upon actuation, the braking force is decreased or reduced to allow controlled sliding of the moving part 10.

[0043] The arrangement of these components allows for variable braking force, which can be adjusted by selectively activating one or both Pyrotechnic devices. Several pyrotechnic actuators can be individually controlled to provide different levels of braking force. This design allows the 100 steering column to provide adaptive load limiting based on various factors.

[0044] The steering column 100 may include a control unit (or the overall system or the vehicle may include the control unit) configured to manage the operation of various actuators and devices during normal use and collision scenarios. As mentioned, the control unit may be integrated into the steering column 100 or may be a separate unit communicating with the steering column 100.

[0045] During normal operation, the control unit can receive inputs from the vehicle or driver systems to adjust the position of the steering wheel 11. The control unit can activate the first actuator 30, which includes the electric motor 31, the worm gear 32 and the toothed wheel 33, to drive the moving part 10 relative to the reference part 20. This allows for precise adjustment of the position of the steering wheel 11 to adapt to different drivers or driving positions or situations.

[0046] In the event of a collision or imminent collision, the control unit can be configured to actuate the second actuator 40 to disengage the coupling device 50 in response to the detection of the collision or imminent collision. This action allows the moving part 10 to move freely relative to the reference part 20, subject to the braking action of the third actuator 60.

[0047] The control unit can also be configured to actuate the third actuator 60 to apply a braking force to the moving part 10. The braking force is selected and adjusted based on at least one of the following: collision severity, occupant characteristics, and occupant position. This adaptive load-limiting function improves the safety performance of the steering column 100 by adapting the behavior of the column to the specific circumstances of the collision.

[0048] In a scenario where a collision or imminent collision is detected with a severity not requiring the deployment of an airbag, the control unit can actuate the second actuator 40 to control the coupling device 50. This action may involve the disengagement of the movable toothed wheel 51 from the free wheel 52, allowing the movable part 10 to move independently of the first actuator 30.

[0049] The control unit can optionally actuate the third actuator 60 to brake the moving part 10 if the second actuator 40 has been actuated or is about to be actuated. The third actuator 60 comprises the caliper body 61 with brake pads 62 that can clamp or pinch a rail of the steering column 100 to provide controlled resistance to the movement of the moving part 10.

[0050] The braking force applied by the third actuator 60 can be selected based on at least one of the following: collision severity, occupant characteristics, and occupant position. For example, in the case of a minor collision and / or a short distance between the occupant and the steering wheel and / or an occupant in the 5th percentile (smaller build), the control unit can activate only the first pyrotechnic device 64 or only the second pyrotechnic device 65 to provide a lower braking force. In the case of a more serious collision and / or a large distance between the occupant and the steering wheel and / or an occupant in the 95th percentile (larger build), the control unit can activate both the first pyrotechnic device 64 and the second pyrotechnic device 65 to provide a higher braking force.

[0051] The pressure valve 66 in the third actuator 60 helps regulate the pressure generated by the pyrotechnic devices, ensuring that the braking force remains within a safe and effective range. This system Adaptive braking allows the 100 steering column to provide optimized occupant protection in a range of collision scenarios.

[0052] In one embodiment, the braking can be activated by the second actuator 40, which could, simultaneously with the disengagement of the coupling device 50, move a brake pad (or brake pads 62) to brake the moving part. This can be achieved through the movement of a lever or the action of a transmission between the second actuator 40 and the brake pad (or brake pads 62).

[0053] By integrating these control features, the 100 steering column offers enhanced safety performance while maintaining normal functionality for everyday use and allowing for reversible sliding. The ability to adapt the steering column's behavior based on collision characteristics and occupant-related factors represents a significant advancement in the design of steering columns and vehicle safety systems.

[0054] The features of all the examples or embodiments described above can be combined to create additional examples or embodiments without losing the desired effect. It should be understood that the description of any embodiment or example provided above is given by way of illustration only, and that various modifications could be made by a person competent in the field. Furthermore, a person competent in the field will recognize that many other modifications and combinations of various aspects are possible. Accordingly, the aspects described are intended to encompass all such alterations, modifications, and variations that fall within the scope of the invention. Industrial application

[0055] A steering column according to the present invention, and its manufacture, are capable of industrial application.

[0056] It will be understood that various modifications and / or improvements obvious to a person skilled in the art can be made to the different embodiments of the invention described in this description without departing from the scope of the invention.

[0057] In particular, the coupling device can be provided so as to couple or not the wheel 33 of the worm gear system with the internal shaft 53, the wheel 52 would then be mounted fixed (in anti-rotation) with the internal shaft 53.

Claims

DEMANDS

1. Steering column (100) for a vehicle, comprising: a telescopic structure having a movable part (10) and a reference part (20) to be fixed to the vehicle; a first actuator (30) for driving the movable part (10) relative to the reference part (20), preferably in a translation; a controllable and reversible coupling device (50) disposed between the first actuator (30) and the movable part (10); and a second actuator (40) for controlling the coupling device (50) in a reversible manner.

2. Steering column (100) according to claim 1, further comprising a third actuator (60) to brake the moving part (10) if the second actuator (40) has been actuated or if the second actuator (40) is about to be actuated.

3. Steering column (100) according to claim 1 or 2, wherein the coupling device (50) comprises a clutch device including a toothed clutch, and / or the coupling device (50) comprises a load limiter.

4. Steering column (100) according to claim 3, wherein the second actuator (40) comprises a solenoid for engaging and disengaging the toothed clutch and / or the load limiter.

5. Steering column (100) according to claim 2, wherein the third actuator (60) includes a brake caliper (61) for clamping onto a rail (13) of a rail / gear system.

6. Steering column (100) according to claim 5, wherein the brake caliper (61) is actuated by a pyrotechnic device (64, 65), or by a pneumatic system comprising at least one pressure generator, or by a spring mechanism releaseable by a solenoid.

7. Steering column (100) according to claim 6, wherein the pyrotechnic device (64, 65) comprises several independently controlled detonators to provide different levels of braking force.

8. Steering column (100) according to any one of the preceding claims, further comprising a control unit configured to: actuate the second actuator (40) to disengage the coupling device (50) in response to the detection of a collision or an impending collision; and optionally actuate the third actuator (60) to apply a braking force to the moving part (10), where the braking force is selected or adjusted according to at least one of the following: collision severity, occupant characteristics and occupant position.

9. Method of operating a steering column (100), the method comprising: supplying the steering column (100) according to claim 1; detecting a collision or imminent collision, the collision or imminent collision preferably having a severity not requiring the deployment of an airbag, actuation of the second actuator (40) to control the coupling device (50).

10. Vehicle comprising the steering column (100) according to any one of claims 1 to 8.

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