STEERING TEST BENCH

Description

[0001] The invention relates to a steering test bench.

[0002] A steering test bench allows for the testing of components within a vehicle's steering system. The chassis of the vehicle into which the steering system is to be installed is simulated by a substitute mechanism, such as replacement tie rods, which replicates the actual geometry of the chassis. The steering test bench thus simulates the real chassis kinematics as accurately as possible. This allows for testing the stress on steering components, such as steering gears and bearings, under conditions that closely resemble real kinematics. Ideally, testing should be performed in a lateral direction, i.e., along the path of a steering tie rod, and under real chassis kinematics during compression and rebound, i.e., in a vertical direction perpendicular to the lateral direction.

[0003] Devices are known from DE 102005057983A1 and CN 2684177 Y in which simulation is not performed in either the transverse or vertical direction.

[0004] CN 200941083 Y, CN 101975668 A, and CN 1877284 A disclose devices with which simulation is performed in the transverse and vertical directions. However, compared to the solution approach pursued there, it is desirable to provide a device with higher accuracy in the simulation quality, particularly with regard to the axis kinematics in the transverse and vertical directions.

[0005] DE 196 22 687 A1, US 4 672 844 A, JP S58 219434 A, JP S62 225923 A and KR 100 897 2780 B1 disclose further aspects of such devices. DE 196 22 687 A1 discloses a test rig for a steering system with a loading device for applying a load to the steering system in a direction in which a steering counterforce acts, and a loading device for applying a load to the steering system in a direction in which a road surface counterforce acts.

[0006] This problem is solved by the steering test stand according to claim 1. This test stand comprises at least one base plate extending in a longitudinal and a transverse direction, at least one spare control arm rotatably connected at a first end of the spare control arm to the at least one base plate about a first longitudinal axis by means of at least one fastening element, wherein the first longitudinal axis extends in the longitudinal direction, at least one spare wheel carrier for connecting the steering test stand to a steering gear tie rod of a steering system to be tested, wherein the spare wheel carrier is rotatably connected at a first end of the spare wheel carrier to a second end of the spare control arm about a second longitudinal axis by means of at least one connecting part, wherein the second longitudinal axis extends in the longitudinal direction, wherein at least one drive unit generates a force via at least one deflection lever.which acts on the spare wheel carrier in a vertical direction, where the vertical direction is perpendicular to both the longitudinal and transverse directions. This allows for a particularly precise simulation of the kinematics in both the transverse and vertical directions.

[0007] According to the invention, the steering test stand comprises at least one first replacement control arm rotatably connected at its first end to a first base plate about the first longitudinal axis by means of at least one first fastening element, at least one second replacement control arm rotatably connected at its first end to a second base plate about a third longitudinal axis by means of at least one second fastening element, wherein the third longitudinal axis extends in the longitudinal direction, wherein the first base plate and the second base plate are spaced apart from each other in the vertical direction, and wherein at least one first replacement control arm is rotatably connected at its second end to the first end of the spare wheel carrier about the second longitudinal axis by means of at least one first connecting part.and in which at least one of the second spare wishbones can be rotatably connected at its second end to a second end of the spare wheel carrier by means of at least one second connecting part about a fourth longitudinal axis. This further increases the accuracy of the simulation.

[0008] Preferably, the steering test stand comprises at least one first connecting element and at least one second connecting element, wherein the first connecting element is arranged on the first base plate and extends in a first direction between the first base plate and the second base plate, wherein the second connecting element is arranged on the second base plate and extends between the first base plate and the second base plate in the first direction, wherein the first connecting element has at least one first elongated hole extending in the first direction, wherein the second connecting element has at least one first fastening means, wherein the first connecting element and the second connecting element can be connected to the first fastening means, which can be guided through the at least one first elongated hole, for selecting a distance between the first base plate and the second base plate.The first base plate, the second base plate, the first connecting element, and the second connecting element form the basic framework of the steering test rig. Further chassis characteristics can be adjusted via the distance between the base plates, and thus via the distance between the substitute wishbones.

[0009] According to the invention, at least one substitute wishbone is designed as a double wishbone. This simplifies the representation of a substitute kinematic system.

[0010] According to the invention, the first base plate extends in the transverse direction from a first longitudinal edge to a second longitudinal edge, wherein a first double wishbone is arranged on two first connecting parts on the first base plate and projects beyond the first base plate at the first longitudinal edge in the transverse direction, wherein the second base plate extends in the transverse direction from a third longitudinal edge to a fourth longitudinal edge, wherein a second double wishbone is arranged on two second connecting parts on the second base plate and projects beyond the second base plate at the third longitudinal edge in the transverse direction. This enables a particularly precise simulation of one side of a steered axle of a chassis.

[0011] Preferably, the steering test rig comprises a third double wishbone, which is arranged on two third connection parts on the first base plate and projects beyond the first base plate at the second longitudinal edge in the transverse direction, wherein a fourth double wishbone is arranged on two fourth connection parts on the second base plate and projects beyond the second base plate at the fourth longitudinal edge in the transverse direction, wherein the first double wishbone and the second double wishbone carry a first spare wheel carrier for connection to a first side of the steering gear tie rod, and wherein the third double wishbone and the fourth double wishbone carry a second spare wheel carrier for connection to a second side of the steering gear tie rod. This makes it possible to simulate both sides of a steered axle of the chassis.

[0012] Preferably, the at least one replacement control arm comprises at least one leg extending between two ends of the replacement control arm, wherein the leg includes a threaded rod section extending between the two ends and a receptacle extending between the two ends for the threaded rod section, wherein the length of the at least one leg is adjustable by inserting at least a portion of the threaded rod section into the receptacle. This allows the component to be used for various kinematic models.

[0013] Preferably, the at least one base plate comprises a plurality of hole sections for the optional attachment of at least one fastening element to the base plate.

[0014] Preferably, the at least one spare wheel carrier comprises a first rail extending between two ends of the spare wheel carrier in a second direction, with at least one second elongated hole extending in the second direction, and a second rail extending between the two ends of the spare wheel carrier in the second direction, with at least one third elongated hole extending in the second direction, wherein the first rail and the second rail are connectable by a second fastening means, which can be guided through the at least one second elongated hole and through the at least one third elongated hole, at a length adjustable in the second direction. The two rails enable the simulation of a wheel carrier with an adjustable length, which is simulated by the two rails.

[0015] Preferably, the at least one spare wheel carrier comprises a third rail extending in a third direction, perpendicular to the second direction, with at least a fourth elongated hole extending in the third direction, wherein the third rail has a third connecting part for connecting the steering test stand to the steering gear tie rod, wherein the second rail and the third rail are connectable by a third fastening means that can be guided through the at least one third elongated hole and through the at least one fourth elongated hole, and wherein a distance between the third connecting part and the second rail is adjustable in the third direction. This allows for the simulation of an adjustable length of a tie rod, which is simulated by the third rail.

[0016] Preferably, the steering test bench comprises a control unit for controlling the at least one drive, which is designed to specify a substitute kinematics for a steering gear tie rod in the transverse and vertical directions.

[0017] Further advantageous embodiments will become apparent from the dependent claims, the following description, and the drawing. The drawing shows Fig. 1 schematically a front view of a schematically represented steering test bench, Fig. 2 schematically a top view of the schematically depicted steering test bench, Fig. 3 prospectively, a spare wheel carrier, Fig. 4 perspective, parts of a basic framework, Fig. 5 perspective, parts of a basic framework, Fig. 6 In perspective, a deflection lever.

[0018] In the following description, elements with the same or comparable function are designated with the same reference symbols.

[0019] Fig. 1 schematically shows a front view of a schematically represented steering test stand 100.

[0020] The steering test stand 100 serves to accommodate a steering gear tie rod 102 extending in a transverse direction 126 of a steering system to be tested.

[0021] The steering test stand 100 comprises a first spare wheel carrier 104 and a second spare wheel carrier 106, which are detachably connected to the steering gear tie rod 102 on opposite sides of the steering gear tie rod.

[0022] The steering test stand 100 comprises two first replacement wishbones 108, designed as double wishbones and connected to the first spare wheel carrier 104. The steering test stand comprises two second replacement wishbones 110, designed as double wishbones and connected to the second spare wheel carrier 106. Axles manufactured in this way are preferably used regardless of whether the actual vehicle is equipped with double wishbone axles or McPherson axles.

[0023] Optionally, on the steering test stand 100, a first shock absorber 112 is connected to the first spare wheel carrier 104 and a second shock absorber 114 is connected to the second spare wheel carrier 106.

[0024] The double wishbones 108, 110 and the optional shock absorbers 112, 114 are connected to a basic frame 116 of the steering test stand.

[0025] Fig. 2 schematically shows a top view of the schematically depicted steering test stand 100.

[0026] The basic frame 116 comprises a base plate extending in a longitudinal direction 130 perpendicular to the transverse direction 126 and in the transverse direction 126. The spare wishbones 108, 110 are rotatably connected at a first end to the base plate by means of fastening elements about a first longitudinal axis, the first longitudinal axis extending in the longitudinal direction 130. The spare wheel carriers 104, 106 are rotatably connected at a first end to a second end of the respective spare wishbones 108, 110 by means of a connecting part about a second longitudinal axis, the second longitudinal axis extending in the longitudinal direction 130.

[0027] The steering test stand 100 comprises a first drive 118 and a second drive 120, in particular linear actuators, arranged on opposite sides of the steering gear tie rod 102 in the transverse direction 126 on the steering test stand 100. The first drive 118 generates a first force via a first deflection lever 122, which acts on the first spare wheel carrier 104 in a vertical direction 128, wherein the vertical direction 128 is perpendicular to the longitudinal direction 130 and to the transverse direction 126. The second drive 120 generates a second force via a second deflection lever 124, which acts on the second spare wheel carrier 106 in the vertical direction 128.

[0028] The basic frame 116, the drives 118, 120 and the deflection levers 122, 124 are arranged, for example, on a base plate of the steering test stand 100.

[0029] A control unit uses drives 118 and 120 to define a substitute kinematics for the steering gear tie rod 102 in the transverse direction 126 and in the vertical direction 128. This arrangement allows for particularly precise simulation of the kinematics in the transverse direction 126 and in the vertical direction 128. The resulting change in the angle of the steering gear tie rod 102 causes the forces to act on the steering gear at a different angle. This, in turn, affects the frictional forces of the bearings in the steering gear.

[0030] To simulate the kinematics for testing the steering system, particularly the steering gear, as accurately as possible, the described components are designed and arranged geometrically to closely match the kinematic behavior of the actual components. A kinematic model is used for this purpose. A kinematic extension, derived from a CAD model, defines connection points where the described components are joined. Furthermore, the lengths of the components and their angles relative to each other are set to replicate the kinematics.

[0031] Details of the construction of an exemplary steering test stand 100, which enables this function, are described below.

[0032] In addition to screws, nuts, washers, etc., the following standard parts, for example, are used: Clevis head, DIN 71752 with external thread, size 8x16 (M8) Use: For connecting a front to a rear replacement control arm rod with replacement control arms 108, 110; Rod end, DIN 12240-4 with external thread, size M8 Use: For connecting replacement control arms 108, 110 to the steering test stand 100; Angle joint, DIN 71802, size M8 Use: For connecting replacement control arms 108, 110 to the spare wheel carriers 104, 106; Rod end, DIN 12240-4 with external thread, size M14 Use: For connecting the spare wheel carriers 104, 106 to the drives 118, 120 of the steering test stand 100, Shaft support, GW-1 Series 1, Diameter 30mm Use: For deflection, to hold the axle, needle bearing, with rings, without inner ring, NKS 30 Use: For deflection, shaft bearing, fitted bolts, ISO 7379, various sizes

[0033] Use: For replacement wishbones 108, 110 and bell cranks 122, 124.

[0034] The structure is built, for example, from various metal plates which are joined using cylinder head bolts and dowel pins. The adaptations used to connect the replacement control arms 108, 110, as well as the connection between the replacement control arms 108, 110 and the spare wheel carrier 104, 106, and the connection of the steering gear tie rod 102, are created anew for each kinematic model.

[0035] The replacement wishbones 108, 110 consist of four basic assemblies: the inner section, which is preferably the same at the front and rear; the outer section with the clevis; and the outer section with the connection to the spare wheel carrier. This assembly differs from top to bottom because a pushrod for the lifting movement is attached at the bottom.

[0036] These assemblies can be connected and adjusted using threaded rods of varying lengths. The combination of left- and right-hand threads allows for stepless adjustment of the threaded rods. For particularly short settings, shortened threaded sleeves can be used. For example, a threaded rod section and its receptacle are available with left- and right-hand threads. Alternatively, a threaded sleeve can be used to receptacle the threaded rod section.

[0037] The adaptations, i.e. the connecting elements, connection parts or fastening elements described below, for example for attaching the replacement wishbones 108, 110, are kept as simple as possible in order to avoid unnecessarily high manufacturing costs.

[0038] An adapter, for example, accommodates a rod end and can include a cone that is placed between the adapter and the rod end. This allows the full range of motion of the rod ends to be utilized.

[0039] The adaptations which connect the replacement wishbones 108, 110 with the spare wheel carrier 104, 106 differ in the example in an angle which the surface has to which an angle joint, which forms the adaptation, is screwed.

[0040] The adapter for connecting the steering gear tie rod 102 is adjusted in its angle and position to accommodate the corresponding bores. A sleeve, which receives a cone of the steering gear tie rod 102, is adapted to this cone.

[0041] The directions are defined below with respect to base plates that extend in a longitudinal and a transverse direction. The base plates are spaced apart from each other in a first direction, for example, in the vertical direction 128. A distance between the base plates can be adjusted via a connecting element with at least one first fastening element and a first elongated hole. The replacement control arms 108, 110 are rotatably connected at a first end of the respective replacement control arm 108, 110 to the respective base plate about a first longitudinal axis by means of appropriate adaptations. The first longitudinal axis extends in the longitudinal direction.

[0042] The spare wheel carriers 104, 106 are rotatably connected at one end to a second end of the spare wishbone 108, 110 by means of a suitable adapter about a second longitudinal axis. The second longitudinal axis extends in the longitudinal direction 130.

[0043] The drives 118, 120 generate a force via the respective deflection levers 122, 124 which acts on the respective spare wheel carrier 104, 106 in a vertical direction 128, wherein the vertical direction 128 is perpendicular to the longitudinal direction 130 and to the transverse direction 126.

[0044] Fig. 3 shows, in perspective, a spare wheel carrier 104, 106.

[0045] The spare wheel carriers 104 and 106 consist of three metal plates, which are also referred to as rails in the following. Two of these plates can be aligned relative to each other via elongated holes to create the different sizes of wheel carriers to be simulated. The third plate can also be variably positioned via elongated holes and serves to connect the steering gear tie rod 102 to the spare wheel carriers 104 and 106. The adapters for connecting the spare control arms 108 and 110 and the steering gear tie rod 102 are attached to the spare wheel carriers 108 and 110, respectively, using four socket head cap screws each.

[0046] The spare wheel carrier 104, 106 comprises a first rail 302 extending in a second direction between two ends of the spare wheel carrier 104, 106. The first rail 302 includes two second elongated slots 308, 310 extending parallel to each other in the second direction.

[0047] The spare wheel carrier 104, 106 comprises a second rail 304 extending between the two ends of the spare wheel carrier 104, 106 in the second direction. The second rail 304 includes two third elongated holes 312, 314 extending parallel to each other in the second direction.

[0048] The first rail 302 and the second rail 304 are connected to each other by a second fastening element 316. In this example, two dowel pins are guided through one of the second elongated holes 308, 310 and through one of the third elongated holes 312, 314 at two points spaced apart in the second direction. This allows the rails 302, 304 to be connected at a length adjustable in the second direction. The two rails 302, 304 enable the simulation of a wheel carrier with an adjustable length, which is simulated by the two rails 302, 304.

[0049] The spare wheel carrier 104, 106 can be rotatably connected at its first end by means of a first connecting part 317 to the first end of a first spare control arm and at its second end opposite in the second direction by means of a second connecting part 318 to the first end of a second spare control arm.

[0050] The spare wheel carrier 104, 106 includes a third rail 306 extending in a third direction, perpendicular to the second direction. The third rail 306 includes two fourth elongated holes extending in the third direction. The third rail 306 has a third connecting part for connecting the steering test stand to the steering gear tie rod 102, wherein the second rail 304 and the third rail 306 are connected by a third fastening element 316. The third fastening element consists, for example, of two dowel pins, each guided at two points spaced apart in the first direction through one of the third elongated holes 312, 314 and through one of the fourth elongated holes. This allows the distance between the third connecting part 320 and the second rail 304 to be adjusted in the third direction. This enables the simulation of an adjustable length of a tie rod, which is simulated by the third rail.

[0051] Fig. 4 Figure 1 shows parts of the basic framework 116 in perspective. A first base plate 400 extends in the transverse direction 126 and in the longitudinal direction 130. The first base plate 400 has a multitude of hole sections 402 for the optional attachment or positioning of fastening elements 404, 406 for replacement wishbones. In the example, the first replacement wishbone 108 is shown in its design as a double wishbone.

[0052] Fig. 5 Figure 1 shows further parts of the basic frame 116 in perspective. A second base plate 500 extends in the transverse direction 126 and in the longitudinal direction 130. The second base plate has a third fastening element 502 and a fourth fastening element 504 for replacement wishbones. In the example, the first replacement wishbone 108 is shown in its design as a double wishbone.

[0053] A first connecting element 408 and a second connecting element 506 are provided for connecting the first base plate 400 and the second base plate 500.

[0054] The first connecting element 408 is arranged on the first base plate 400 and extends in the first direction between the first base plate 400 and the second base plate 500. The second connecting element 506 is arranged on the second base plate 500 and extends between the first base plate 400 and the second base plate 500 in the first direction.

[0055] The first connecting element 408 has two first elongated holes 410, 412 which extend parallel to each other in the first direction.

[0056] The second connecting element 506 has a first fastening element 508, in this example four dowel pins, which can be guided in pairs through one of the first elongated holes. The second connecting element 506 can also have two fifth elongated holes that extend parallel to each other in the first direction and can be connected with dowel pins as described above.

[0057] The first connecting element 408 and the second connecting element 506 are connected by a first fastening element 508. The first fastening element 508 allows for a selection of the distance between the first base plate 400 and the second base plate 500.

[0058] Fig. 6 shows in perspective a deflection lever 122, 124, for deflecting a linear movement from the drives 118, 120.

[0059] The deflection lever 122, 124 has a third base plate 600 on which a first shaft support 616 and a second shaft support 618 are arranged, supporting a preferably hardened shaft 620. The shaft 620 is supported by needle bearings 602, which preferably run directly on the shaft without an inner ring. The shaft 620 has a first lever 604 and a second lever 606. The lever arms of the levers 604, 606 can be positioned at different angles on the shaft 620 via various bores.

[0060] A sixth elongated hole 608 and a seventh elongated hole 610 extend along one side of the third base plate 600. An eighth elongated hole 612 and a ninth elongated hole 612 extend along one of the opposite sides of the third base plate 600. These elongated holes serve for flexible attachment to the base plate.

[0061] An axial play can be adjusted via shims between the shaft supports 616, 618. The levers are preferably designed such that a movement between -75 mm and +75 mm, i.e. a corresponding wheel stroke, can be simulated in the vertical direction 128.

[0062] The aforementioned components can be manufactured in various shapes and lengths. This allows for easy replacement to adapt or adjust to the kinematics of the simulated chassis. The components are made of metal, particularly aluminum or an aluminum alloy, which reduces weight. Care is taken to ensure that moving parts are as lightweight as possible. Since the forces transmitted are not particularly high, it is recommended to use a cost-effective aluminum alloy, such as EN AW 5754 (AIMg3). For moving parts that must withstand higher forces or are not as generously dimensioned, such as a lower outer control arm that transmits the lifting motion, a stronger aluminum alloy, such as EN AW 5083 (AIMg4.5Mn), is used.For the stationary components, an aluminum alloy, for example EN AW 5754 (AIMg3), is also used for reasons of overall weight.

Claims

1. Steering test bench (100) for receiving a steering gear track rod (102) of a steering system to be tested, which extends in a transverse direction (126), comprising a first base plate (400) extending in a longitudinal direction (130) and in the transverse direction (126), and a second base plate (500) extending in a longitudinal direction (130) and in the transverse direction (126), a first substitute wishbone (108) and a second substitute wishbone (108), wherein the first substitute wishbone (108) is connected to a first end of the first substitute wishbone (108) by means of at least one fastening element (404, 406, 502, 504) at the first base plate (400) and the second substitute wishbone (108) at a first end of the second substitute wishbone (108) by means of at least one fastening element (404, 406, 502, 504) to the second base plate (500) so as to be rotatable about a respective first longitudinal axis, wherein the respective first longitudinal axis extends in the longitudinal direction (130), a spare wheel carrier (104) for connecting the steering test bench (100) to the steering gear track rod (102) of the steering system to be tested, wherein the spare wheel carrier (104) is connected at a first end of the spare wheel carrier (104) by means of at least one connecting part (317, 318) to a second end of the first substitute wishbone (108) by means of at least one connecting part (317, 318) and at a second end of the spare wheel carrier (104) by means of at least one connecting part (317, 318) with a second end of the second substitute wishbone (108) so as to be rotatable about a respective second longitudinal axis, wherein the respective second longitudinal axis extends in the longitudinal direction (130), wherein a drive (118) generates a force via at least one deflection lever (122) which acts on the spare wheel carrier (104) in a vertical direction (128), wherein the vertical direction (128) is perpendicular to the longitudinal direction (130) and to the transverse direction (126), wherein the first substitute wishbone (108) is designed as a first double wishbone and the second substitute wishbone (108) is designed as a second double wishbone, wherein the first base plate (400) extends in the transverse direction (126) from a first longitudinal edge to a second longitudinal edge, wherein the first base plate (400) and the second base plate (500) are spaced apart from each other in the vertical direction (128), wherein the first double wishbone is arranged on two first connecting parts on the first base plate (400) and the first base plate (400) protruding at the first longitudinal edge in the transverse direction (126), wherein the second base plate (500) extends in the transverse direction (126) from a third longitudinal edge to a fourth longitudinal edge, wherein the second double wishbone is arranged on two second connecting parts on the second base plate (500) and the second base plate (500) protrudes beyond the third longitudinal edge in the transverse direction (126).

2. Steering test bench (100) according to claim 1, characterized in that the first substitute wishbone (108) and the second substitute wishbone (108) each comprise at least one leg extending between two ends of the substitute wishbone (108), wherein the leg comprises a threaded rod section extending between the two ends and a receptacle for the threaded rod section extending between the two ends, wherein a length of the at least one leg can be adjusted by inserting at least a part of the threaded rod section into the receptacle.

3. Steering test bench (100) according to one of the preceding claims, characterized in that the first base plate (400) comprises a plurality of hole sections for selectively fastening at least one fastening element (404, 406) to the first base plate (400).

4. Steering test bench (100) according to one of the previous claims, characterized in that the spare wheel carrier (104) comprises a first rail (302) extending between two ends of the spare wheel carrier (104) in the longitudinal direction (130), with at least one second elongated hole (308, 310) extending in the longitudinal direction (130), and a second rail (304) extending between the two ends of the spare wheel carrier (104) in the longitudinal direction (130), with at least one third elongated hole (312, 314) extending in the longitudinal direction (130), and wherein the first rail (302) and the second rail (304) are connected by a second fastening means (316) which can be guided through the at least one second elongated hole (308, 310) and through at least one third elongated hole (312, 314) in a length that can be adjusted in the longitudinal direction (130).

5. Steering test bench (100) according to claim 4, characterized in that the spare wheel carrier (104) comprises a third rail (306) extending in the transverse direction (126) perpendicular to the longitudinal direction (130), wherein at least one fourth elongated hole extends in the transverse direction (126), the third rail (306) having a third connecting part (320) for connecting the steering test bench (100) to the steering gear track rod (102), wherein the second rail (304) and the third rail (302) are connected to a third fastening means (316) that can be guided through at least one third elongated hole (312, 314) and through at least one fourth elongated hole, and wherein a distance between the third connecting part (320) and the second rail (304) that can be adjusted in the transverse direction (126).

6. Steering test bench (100) according to one of the preceding claims, characterized by a control device for controlling the at least one drive (118, 120), which is designed to specify a substitute kinematics for a steering gear track rod (102) in the transverse direction (126) and in the vertical direction (128).