Support beam and device for fixing an actuator of a steering by wire

Abstract

The utility model relates to a support beam for fixing an actuator of a steer-by-wire device on a vehicle structure of a motor vehicle. According to the invention, the support beam is designed as a one-piece forged part, said support beam having, in the region of the ends thereof, connection points for securely connecting to the actuator of the steering-by-wire device and at least one further connection point between said connection points for fixing to the vehicle structure.

Description

Technical Field

[0001] This utility model relates to a support beam for fixing an actuator of a steer-by-wire device according to the preamble of the independent claim, and a device and method for connecting the actuator to a vehicle structure. Background Technology

[0002] An actuator for a steer-by-wire system, serving as a rear axle steering system in a motor vehicle, is known from DE 10 2014 206 934 A1. This actuator is constructed as a so-called central controller, i.e., an actuator acting on the wheels of the axle on both sides. The actuator has a housing fixed to the side of the vehicle, preferably to the vehicle structure, and most preferably to the axle frame, within which are arranged main shaft drives acting on both sides. The main shaft drive has a longitudinally movable main shaft and a main shaft nut fixedly supported in position, which can be driven by an electric motor via a traction drive. A hinged connector, preferably a hinged fork, is arranged at the end of the main shaft, connecting to a linkage of the rear wheel. If possible, the actuator with a corresponding fixing point is directly connected to the rear axle bracket. However, in some installation cases, due to limited available installation space, it is necessary to use suitable components to indirectly fix the actuator to the vehicle structure. Such components are disclosed in DE 10 2017 215 140 A1 as sheet metal forming components. Utility Model Content

[0003] The purpose of this invention is to provide an improved alternative for fixing the actuator of the steer-by-wire device to a vehicle, particularly to the vehicle structure, in a manner that allows for reasonable installation space.

[0004] This utility model includes the features of the independent claims. Advantageous designs are derived from the dependent claims and the description.

[0005] According to a first aspect of this invention, a support beam is provided for securing the actuator of a steer-by-wire device to the vehicle structure of a motor vehicle. In a motor vehicle, the steering device guides the wheels in the chassis area. Despite the high lateral and retrograde forces present in the chassis, the wheel steering angle set by the steering device must be maintained on the corresponding axle. Therefore, the steering device must be securely connected or linked to the vehicle structure to absorb or support these forces. Due to the limited mounting space available in the axle, it is generally not possible to directly secure the steering device or actuator. For indirect mounting, a component capable of absorbing large forces or remaining undeformed under their influence must be selected. Deformation can lead to steering errors. It has been shown that a support beam constructed as a single-piece forged component advantageously meets these requirements. Compared to sheet metal components formed by deep drawing, this support beam occupies less mounting space and is better able to absorb the aforementioned forces. Forged components are more resistant to bending and torsion than sheet metal components of the same size. Furthermore, forged components are less expensive to manufacture. The support beam according to this invention can be designed as a forged component with a very slender profile, while still achieving a sufficiently rigid connection between the actuator and the vehicle structure. The support beam has connection points at its ends for a secure and direct connection to the actuator of the steer-by-wire device. At least one additional connection point is provided between these connection points for indirect fixation to the vehicle structure. With the aid of the support beam, an additional indirect connection between the actuator and the vehicle structure can be achieved.

[0006] The vehicle structure includes the body and any connecting components used to connect to the body. These include, for example, the axle frame or subframe. The axle frame or subframe is typically assembled into the axle or chassis so that the subframe can later be connected to the body along with the full axle or even the full chassis.

[0007] Support beams, which are forged components, are preferably made of alloy steel or light metal alloys. For example, quenched and tempered steel such as 30MnVS6(+P) is suitable for support beams. For support beams in variations made of light metal alloys, alloys made of aluminum or magnesium are suitable.

[0008] The shape of the support beam is designed accordingly based on the available installation space. However, in order to use the support beam to secure the actuator to the vehicle structure, it may be necessary to bridge the distance between the support beam and the vehicle structure because the shape of the forged component is limited. In a preferred embodiment, at least one additional connection point of the support beam is therefore at least partially constructed as a spacer block. In other words, the spacer block is integrated into the support beam and a separate spacer block is not required. The spacer block integrated into the support beam can bridge the installation-related distance between the actuator and the fixing point on the vehicle structure (e.g., the rear axle bracket) and allows for a threaded connection between the support beam and the rear axle bracket that is reasonable in terms of shape and load. To form the spacer block, the support beam may have, during its manufacturing process, provided, for example, a cylindrical structure or allowance in the area of ​​the corresponding connection point, which exceeds the material thickness of the support beam in the area of ​​the connection point. During manufacturing, this allowance can be reduced to the required size, for example by machining such as milling or sawing, depending on the distance to be bridged.

[0009] The connection point preferably has a through hole. Using this through hole, a force transmission connection and / or form-fit connection can be established, for example, via a threaded connection, not only with the actuator of the steering-by-wire device but also with the vehicle structure. The through hole can be created, for example, by drilling. Preferably, the through hole can have at least partially internal threads at at least one connection point. When threadedly connected to the actuator or vehicle structure, a more cost-effective force transmission connection can thus be achieved because the nut originally required for a threaded connection can be omitted. Here, "partially" means that the internal thread does not extend across the entire material thickness of the through hole. The length and configuration of the thread are constructed according to the tightening conditions and the expected forces at the other connection points. In one embodiment, the thread can be constructed as a fine thread to generate greater force when the components are tensioned together.

[0010] The positions and configurations of the through holes on the support beam are designed to match or align with fixing points on the actuator or vehicle structure. For example, if the actuator is fixed in a direction of travel parallel to the vehicle's longitudinal axis and orthogonal to the vehicle's lateral axis, the fixing points are spaced apart parallel to the vehicle's longitudinal axis. Therefore, the through holes are preferably aligned with the aforementioned fixing points. The fixing points also have through holes for fixing. A surface is arranged at the end of the through hole at the fixing point, which abuts against a suitable surface at the connection point of the support beam. Therefore, at least one through hole preferably has a connection surface that is substantially orthogonal to, and preferably orthogonal to, its longitudinal axis. This connection surface is preferably correspondingly constructed as an annular surface and abuts against the abutment surface formed therein during assembly to fix it to the vehicle structure and the actuator of the steer-by-wire device. Preferably, the longitudinal axes of the connection points extend almost parallel to each other, preferably parallel to each other. In this way, flush mounting between the support beam and the vehicle structure or actuator can be ensured.

[0011] According to another preferred embodiment, the support beam has a coating for corrosion protection. The support beam is part of the chassis of a motor vehicle. It is well known that the chassis is highly susceptible to external influences (water, dirt, salt, etc.). Therefore, corrosion protection of the support beam is beneficial for its service life.

[0012] According to another preferred embodiment, a metallic coating, particularly made of nickel and zinc, is provided, which is applied by electroplating. For this purpose, the support beam is coated, for example, in an electroplating bath.

[0013] According to another preferred embodiment, the coating is provided with an electrophoretic coating that can be cathodically deposited (on a cathode), which is applied, for example, in an electroplating bath and forms effective corrosion protection.

[0014] According to another aspect of the present invention, a device is provided for connecting the actuator of a steer-by-wire system to the vehicle structure of a motor vehicle, wherein a support beam according to the present invention is arranged between the actuator and the vehicle structure. The support beam is directly connected to both the actuator and the vehicle structure. Here, as mentioned above regarding the support beam, preferably, two outer connection points for direct fixation to the actuator and another connection point between these outer connection points for direct fixation to the vehicle structure are provided on the support beam. By means of the support beam and at least one spacer integrated into the support beam, a robust connection is thus achieved between the actuator and the vehicle structure, preferably the subframe or rear axle frame. Any distance between the support beam and the vehicle structure that may be caused by the installation space can be compensated by the spacer. Here, the length of the spacer is advantageous for threaded connections because it results in an increased clamping length. This allows for high preload, thereby achieving a safe threaded connection suitable for operational requirements.

[0015] According to a preferred embodiment, the support beam can be directly connected to the vehicle structure and / or actuator via a through-hole for force transmission. As described above, at least one through-hole may have at least partially internal threads. To secure the support beam to the actuator and / or vehicle structure, screws or bolts can be directly threaded onto the support beam via the internal threads. Therefore, an additional nut for force transmission connection to the support beam can be omitted.

[0016] Finally, another aspect of this invention is a method for manufacturing the aforementioned support beam, which is used to secure the actuator of a steer-by-wire device to the vehicle structure of a motor vehicle. The method steps listed below follow a certain order, but this order is not binding. Therefore, any order not mentioned herein is also part of this invention.

[0017] In the first step, a support beam is designed based on the available installation space and the forces introduced into the actuator of the steer-by-wire device at the axle in the motor vehicle. Here, not only the shape of the support beam is determined, but also its material thickness and the locations of necessary connection points and through holes. The material and thickness of the support beam are also determined based on a design scheme that considers the forces acting on the corresponding steer-by-wire device. According to this design scheme, the support beam is forged in the next step and given a predetermined shape. In the next step, through holes are created based on the locations of the fixing points of the actuator and the vehicle structure. In another step, connecting surfaces are created at the corresponding through holes. Connecting surfaces are created based on the mating surfaces at the corresponding fixing points on the actuator or vehicle structure, such that during assembly, the aforementioned surfaces form a flush mating. For example, through holes can be created by drilling, and mating surfaces can be created by milling. In another step, the support beam is coated to form a corrosion-resistant protection. In yet another step, internal threads are at least partially manufactured in at least one through hole. This is preferably done mechanically by thread cutting. Internal threads are created based on the force transmission connection required for reliable fixation of components to each other and the necessary support for the forces present in the corresponding vehicle.

[0018] This invention provides a cost-effective and feasible indirect connection solution for fixing the actuator of the steer-by-wire device to the vehicle structure when the installation space does not allow for direct fixation of the actuator to the vehicle structure. Attached Figure Description

[0019] Embodiments of this utility model are shown in the accompanying drawings and described in more detail below, wherein other features and / or advantages are set forth in the description and / or the drawings.

[0020] Figure 1 A top view of the axle is shown.

[0021] Figure 2 A steer-by-wire device according to the prior art is shown.

[0022] Figure 2a It shows that according to Figure 2 Detailed view,

[0023] Figure 3 A steer-by-wire device with a support beam according to the present invention is shown, along with a detailed view of the support beam. Detailed Implementation

[0024] Figure 1A steer-by-wire device 12 known in the prior art on an axle 1 is shown, illustrated here in top view as a rear axle with a subframe 2 fixed to or attributable to the vehicle structure and connected to the chassis of the motor vehicle body. However, the present invention is not limited to the rear axle. Wheels 5 and 6 are hinged to the subframe 2 via links 3 and 4. Links 3 and 4 are part of the wheel suspension of wheels 5 and 6. The actuator 10 of the steer-by-wire device 12 is arranged on the subframe 2. The actuator 10 is fixed to the subframe 2 via its housing 21. In this embodiment, the steer-by-wire device 12 is configured as a central steering device that acts on the two wheels 5 and 6 of the axle. It has a continuous steering rod 27 that is guided through the housing 21 of the actuator 10. A drive motor 22 is arranged axially parallel to the steering rod 27. Tie rods 23 and 24 are hinged at the ends of the steering rod 27, which is configured as a longitudinally movable main shaft. Each tie rod is hinged to a wheel carrier (not shown) of wheels 5 and 6, respectively, at its end away from actuator 10. Clearly, as the steering rod 27 is axially displaced—that is, displaced along the longitudinal axis s in one direction or the other—the wheel steering angles 8 and 9 change, because tie rods 23 and 24 represent a forced connection between wheels 5 and 6, or the wheel carrier, and actuator 10. For steering wheels 5 and 6, they are connected to the wheel carrier in a manner rotatable about their vertical axis.

[0025] Figure 2 A schematic rear view of the actuator 100 of the steer-by-wire device 112 is shown, the actuator having a steering rod 127 movable along the longitudinal axis s. The steering rod 127 has articulated forks 115 and 116 at its ends, which can be directly or indirectly connected to the wheel carrier via a linkage (not shown) to steer the wheels (towards...). Figure 1 (Comparison described in the text). The actuator 100 has fixing points 113, 114 at its two upper ends, which are configured for direct fixation to the subframe 102, which is part of the vehicle structure. The actuator 100 also has fixing points 110b, 111b at its two lower ends. Compared to direct fixation to the vehicle structure at the upper end, the two lower fixing points 110b, 111b can only be indirectly connected to the subframe 102 via a retaining plate 101 and using a spacer sleeve 104 due to the available mounting space. For this purpose, the retaining plate 101 has connection points 110, 111, at which the actuator 100 is directly threaded to the fixing points 110b, 111b. Figure 2aThe necessity of the spacer sleeve 104 can be seen from this. Due to the available mounting space, a direct threaded connection between the retaining plate 101 and the vehicle structure 102 in the form of a subframe is not possible. The spacer sleeve 104 is used to bridge the distance D. The spacer sleeve 104, like the vehicle structure 102, has a through hole 120. The screw 122 passes through the through hole 120, thereby forming a force-transmitting connection between the retaining plate 101 and the vehicle structure 102 through the nut 124 and the screw 122. This achieves indirect fixation between the actuator 100 and the vehicle structure 102.

[0026] Figure 3 It shows that it has the following characteristics: Figure 2 The actuator 200 of the steer-by-wire device 212 has the same structural form. Components with the same function and location are used with... Figure 2 The reference numeral 100 is used instead of the one used in the attached drawing and will not be described again here. The longitudinal axis s1 extends through the steering rod 227. In order to indirectly fix the actuator 200 to the vehicle structure 202 via an additional connection point 234, a support beam 201 constructed as a forged component is used instead of a retaining plate (according to...). Figure 2 (101). The support beam 201, adapted to the installation space, has an elongated shape in the side view, with two outer connection points 210, 211 and an additional connection point 234 located between the two outer connection points. The right end of the support beam 201 is shaped to adapt to the installation space by means of a bend pointing towards the actuator. Connection points 210, 211, and 234 have through holes 210d, 211d, and 234d, respectively, through which associated longitudinal axes d1, d2, and d3 extend. Perpendicular to the longitudinal axes d1, d2, and d3, the support beam 201 has opposing connection surfaces k1, k2, and k3, which are constructed as toroidal surfaces. The support beam 201 is connected to the actuator 200 at connection points 210 and 211. The connection between the actuator 200 and the vehicle structure 202 via the additional connection point 234 is indirectly achieved through the support beam 201. Therefore, connection point 234 is fixed to vehicle structure 202 by screw 222 in a force-transmitting connection manner, such as from Figure 3 See (the lower part). Figure 3 The support beam 201 is also shown in a top view. Furthermore, it can be seen that the distance D1 between the vehicle structure 202 and the support beam 201 is bridged by a spacer block 204 integrated into the support beam 201. Figure 3It can also be seen that the connecting surface k2 is flush with and abuts the vehicle structure 202. This ensures a flat contact between the support beam 201 and the vehicle structure 202 at this location. On the side away from the spacer block 204, the support beam 201 has an internal thread 226 in the through hole 234d at a distance G, with an adjacent distance D1. At the connection point 234, the support beam 201 is securely connected to the vehicle structure 202 by screws 222 in a force-transmitting connection. For this connection, a separate spacer sleeve (104, according to...) is not required at this location. Figure 1 ) and no nut (124, according to Figure 1 ).

[0027] This invention allows for a cost-effective and space-optimized indirect connection between the actuator 200 of the online steering device 212 and the vehicle structure 202 via the support beam 201. The elimination of the nut also simplifies assembly. Because of the clamping surfaces 232 near the connection points 210, 211, and 234, the support beam 201, forged to its final shape, can be easily clamped on a machining center for machining to produce through holes 210d, 211d, and 234d and connection surfaces k1, k2, and k3. In summary, this makes the production of the support beam as a forged component cost-effective.

[0028] Figure Labels

[0029] 1. Axle

[0030] 2 Subframe

[0031] 3-link

[0032] 4-link

[0033] 5 wheels

[0034] 6 wheels

[0035] 8. Wheel steering angle

[0036] 9. Wheel steering angle

[0037] 10 Actuators

[0038] 12. Steer-by-wire system

[0039] 21. Shell

[0040] 22 drive motors

[0041] 23. Tie rod

[0042] 24 tie rods

[0043] 27. Steering rod

[0044] 100 actuators

[0045] 101 Retention Plate

[0046] 102 Vehicle structure and subframe

[0047] 104 spacer sleeve

[0048] 110 Connection Point

[0049] 111 Connection Point

[0050] 110b Fixed point

[0051] 111b Fixed point

[0052] 112 Steer-by-wire device

[0053] 113 Fixed Points

[0054] 114 Fixed Points

[0055] 115 Articulated Fork

[0056] 116 Articulated Fork

[0057] 120 through hole

[0058] 122 screws

[0059] 124 nuts

[0060] 127 Steering rod

[0061] 200 actuators

[0062] 201 Support Beam

[0063] 202 Subframe

[0064] 204 spacer blocks

[0065] 210 Connection Point

[0066] 210b Fixed point

[0067] 210d through hole

[0068] 211 Connection Point

[0069] 211b Fixed point

[0070] 211d through hole

[0071] 212 Steer-by-wire device

[0072] 213 Fixed Points

[0073] 214 Fixed points

[0074] 215 Articulated Fork

[0075] 216 Articulated Fork

[0076] 220 through hole

[0077] 222 screws

[0078] 226 internal thread

[0079] 227 Steering rod

[0080] 232 Clamping surface

[0081] 234 Other connection points

[0082] 234d through hole

[0083] Longitudinal axes d1, d2, d3

[0084] k1, k2, k3 connection surfaces

[0085] s Longitudinal axis

[0086] s1 Longitudinal axis

[0087] D Distance

[0088] D1 Distance

[0089] G distance

Claims

1. A support beam (201) for securing the actuator (10) of a steer-by-wire device (12, 112, 212) to a vehicle structure (2, 102, 202) of a motor vehicle, said support beam (201) being constructed as a one-piece forged component, wherein, The support beam (201) has connection points (210, 211) in the region at its end for secure connection with the actuator of the steering-by-wire device and at least one additional connection point (234) between the connection points (210, 211) for fixing to the vehicle structure, characterized in that spacer blocks (204) are integrated in at least the additional connection points (234) of the support beam (201).

2. The support beam (201) according to claim 1, characterized in that, The support beam (201) is manufactured by forging alloy steel, aluminum alloy or magnesium alloy.

3. The support beam (201) according to claim 1 or 2, characterized in that, The connection points (210, 211, 234) each have a through hole (220), wherein the through hole of at least one connection point (234) has an internal thread (226).

4. The support beam (201) according to claim 1 or 2, characterized in that, At least one through hole (210d, 211d, 234d) has opposing faces (k1, k2, k3) that are generally orthogonal to its longitudinal axes (d1, d2, d3), said faces being configured for fixation to the actuator of the vehicle structure (202) and / or the steering-by-wire device (212).

5. The support beam (201) according to claim 4, characterized in that, The surface is constructed as an annular surface and configured for fixation to the vehicle structure (202) and / or the actuator of the steer-by-wire device (212).

6. The support beam (201) according to claim 1 or 2, characterized in that, The longitudinal axes (d1, d2, d3) of the connection points (210, 211, 234) extend almost parallel to each other.

7. The support beam (201) according to claim 1 or 2, characterized in that, The support beam (201) has a corrosion-resistant coating.

8. The support beam (201) according to claim 7, characterized in that, The coating is applied as a metallic coating by electroplating.

9. A device for connecting the actuator (10) of a steer-by-wire device (212) to the vehicle structure (202) of a motor vehicle via a support beam (201) according to any one of the preceding claims, characterized in that, The support beam (201) is arranged between the actuator (10) and the vehicle structure (202), and is directly connected to the actuator (10) on the one hand, and is firmly connected to the vehicle structure (202) on the other hand through a spacer block (204) integrated into the support beam.

10. The apparatus according to claim 9, characterized in that, The support beam (201) can be directly connected to the actuator and / or the vehicle structure (202) in a force-transmitting manner through through holes (210d, 211d, 234d).

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