Steering angle limiting mechanism, steering system and vehicle

Abstract

The invention relates to the field of automobiles, and discloses a steering angle limiting mechanism, a steering system and a vehicle, and the steering angle limiting mechanism comprises a driving element which is provided with a circle of outer teeth; an assembling hole is formed in the braking element, a circle of inner teeth are arranged on the inner wall of the assembling hole, the driving element is eccentrically arranged in the assembling hole, the outer teeth are meshed with the inner teeth so that the driving element can drive the inner teeth to rotate, and the rotating center of the driving element can move; the limiting mechanism shell is arranged outside the braking element in a sleeving manner; the limiting structure is arranged on the driving element and / or the braking element and used for limiting relative rest between the driving element and the braking element when the driving element rotates to a preset angle, and when the driving element rotates to the initial position, the distance d1 between the circle center of the outer teeth and the circle center of the inner teeth is larger than the distance d2 between the outer wall of the braking element and the inner wall of the limiting mechanism shell, and the distance d2 is larger than the distance d1 between the outer wall of the braking element and the inner wall of the limiting mechanism shell. The steering angle limiting mechanism is simple in structure, small in occupied space, convenient to disassemble and assemble and low in production cost.

Description

Technical Field

[0001] This application belongs to the automotive field, specifically relating to a steering angle limiting mechanism, a steering system, and a vehicle. Background Technology

[0002] The hand wheel actuator (HWA) is a component of current steer-by-wire technology solutions. Because the steer-by-wire system eliminates the intermediate shaft mechanical connection in the traditional steering system, the design and layout of the car chassis front suspension and engine compartment are more flexible. At the same time, the steering ratio of the system can be adjusted according to the driving intention, and the road excitation can be adjusted according to the driving intention, thereby improving the handling performance. When in autonomous driving mode, the steering wheel can cooperate with the autonomous driving system to achieve functions such as silent or folding and retracting.

[0003] Because the steer-by-wire system eliminates the intermediate shaft mechanical connection found in traditional steering systems, without a specially designed angle limiting mechanism, the steering wheel connected to the steering wheel control arm (HWA) can rotate without any angle limit. This rotation would damage components mounted on the HWA, such as the combination switch, clock spring, and airbag coil. Furthermore, excessive steering wheel rotation would disrupt the HWA's steering angle signal, making HWA control difficult. Therefore, an HWA with an angle limiting mechanism is needed to restrict the steering wheel rotation angle within a designed range. Existing angle limiting mechanisms include nut-screw type, threaded type, gear-rack type, and planetary gear assembly type, but these existing structures suffer from problems such as structural complexity and a large number of parts. Summary of the Invention

[0004] The purpose of this application is to provide a steering angle limiting mechanism, a steering system, and a vehicle to limit the steering wheel rotation angle. The limiting mechanism provided in this application has the advantages of simple structure, few parts, easy processing of parts, and low cost.

[0005] To achieve the above objectives, this application provides a steering angle limiting mechanism, comprising:

[0006] A driving element, on which a ring of external teeth is provided;

[0007] A braking element has a mounting hole inside, and a ring of internal teeth is provided on the inner wall of the mounting hole. The driving element is eccentrically disposed in the mounting hole. The external teeth mesh with the internal teeth, thereby causing the driving element to drive the internal teeth to rotate. The rotation center of the braking element is movable.

[0008] The housing of the limiting mechanism is sleeved outside the braking element;

[0009] A limiting mechanism is provided on the driving element and / or the braking element to limit the relative stationary between the driving element and the braking element after the driving element rotates to a predetermined angle. When the driving element is in the initial position, the distance d1 between the center of the outer tooth and the center of the inner tooth is greater than the distance d2 between the outer wall of the braking element and the inner wall of the limiting mechanism housing.

[0010] In the above technical solution, the driving element, as the active rotating component, maintains a constant rotation center. The driving element drives the braking element to rotate together through the meshing of its external and internal teeth. Each rotates around its own rotation center, and their circumferential linear velocities are different. The circumferential rotational speed of the driving element is greater than that of the braking element. When the rotation reaches a predetermined angle, the limiting structure restricts the driving element and the braking element to a relatively stationary state. Since the driving element and the braking element are eccentrically meshed, they form an integral eccentric structure. The continuously applied torque is then transmitted to the braking element. Because the distance d2 between the braking element and the limiting mechanism housing is smaller than the distance d1 between the centers of the driving element and the braking element, the braking element comes into contact with the limiting mechanism housing as it rotates around its axis with the driving element. The driving element, along with the power mechanism connected to it, is locked to the braking element, thereby achieving the purpose of limiting the rotation angle.

[0011] The limiting structure can take many forms. For example, it can be set on the driving element alone and form a limit by cooperating with a part of the braking element. It can also be set on the braking element alone and form a limit by cooperating with a part of the driving element. Alternatively, a limiting structure can be set on both and form a limit by cooperating with the limiting structures on both.

[0012] In some embodiments, the limiting structure includes a first limiting member and a second limiting member, wherein the first limiting member is disposed on the driving element, and the second limiting member is disposed on the braking element, and at least a portion of the running track of the second limiting member overlaps with the running track of the first limiting member. With this structure, when the driving element rotates, the first limiting structure on it rotates accordingly; when the driving element drives the braking element to rotate, the second limiting structure on it rotates together with the braking element. When the rotation reaches a predetermined angle, the first limiting structure and the second limiting structure abut against each other, thereby restricting the driving element and the braking element to a relatively stationary state.

[0013] In some embodiments, the first limiting member includes an annular base disposed on the driving element, the axis of the base coincides with the axis of the external tooth, and at least one first protrusion is provided on the outer circumferential surface of the base.

[0014] The second limiting member includes a number of second protrusions and / or second grooves equal to the number of the first protrusions, and all the second protrusions and / or second grooves are evenly distributed around the axis of the internal teeth;

[0015] When the driving element is in the initial position, the center of the outer tooth and the center of the inner tooth are connected to form a symmetrical center line, and the first limiting member and the second limiting member are respectively divided into two completely symmetrical parts by the symmetrical center line.

[0016] When the drive element rotates to a predetermined angle, the first protrusion abuts against the corresponding second protrusion or second groove.

[0017] With the above structure, the first limiting member is in the form of a protrusion, and the second limiting member is in the form of a matching protrusion or groove. The limiting effect is achieved by the abutment between the protrusions or between the protrusion and the groove wall. The structure is simple and the assembly accuracy is high.

[0018] In some embodiments, a first sectional surface is made along one side of the first protrusion, and a second sectional surface is made along the side of the second protrusion adjacent to the first sectional surface, wherein the first sectional surface and the second sectional surface intersect at the axis of the external tooth.

[0019] When the driving element is in the initial position, the included angle between the first and second tangential surfaces is α, where α = ×360° × β / 360°, n1 is the number of teeth of the external teeth, n2 is the number of teeth of the internal teeth, and β is the maximum angle of unidirectional rotation of the driving element.

[0020] Using the above structure, the gear ratio can be obtained according to the required maximum angle of unidirectional rotation and the acceptable α value. Generally speaking, the smaller the α value, the better. The maximum angle of unidirectional rotation refers to the maximum angle of rotation in either clockwise or counterclockwise directions.

[0021] In some embodiments, a third tangent is made along the other side of the first protrusion, and the first tangent and the third tangent intersect at the axis of the external tooth, with an included angle of γ1 between them;

[0022] A fourth tangent is made along the other side of the second protrusion. The second tangent and the fourth tangent intersect at the axis of the external tooth, and the included angle between them is γ2.

[0023] The γ1 and γ2 satisfy the following formula:

[0024] γ1 + γ2 = 360° - 2α × N

[0025] Where N is the sum of the number of the first protrusion and the number of the second protrusion divided by 2.

[0026] Using the above structure, the circumferential angle occupied by the first and second protrusions can be obtained by α. By reasonably selecting the values ​​of α and N, it can be ensured that the first and second protrusions have sufficient strength.

[0027] In some embodiments, the first protrusion includes a first step and a second step arranged radially along the base, wherein the first step is fixedly mounted on the outer circumferential surface of the base, the second step is fixedly connected to the first step, and the two are connected by a smooth curved surface, and the circumferential length of the first step along the base is less than the circumferential length of the second step along the base.

[0028] In some embodiments, the braking element includes an annular mounting portion, the circular hole of which forms the mounting hole;

[0029] The second protrusion includes a third step and a fourth step arranged sequentially along the radial direction of the assembly part. The third step and the fourth step are fixedly installed on the end face of the assembly part facing the first protrusion. The two are connected by a smooth curved surface. The circumferential length of the third step along the assembly part is greater than that of the fourth step along the circumferential length of the assembly part.

[0030] When the driving element rotates to a predetermined angle, the first step abuts against the third step, and the second step abuts against the fourth step.

[0031] With this structure, both the first and second protrusions adopt a stepped structure. When rotated to a predetermined angle, radial interlocking can be achieved through this stepped structure to prevent slippage and ensure that the rotation limit is always effective. In contrast, ordinary protrusions without a stepped structure are prone to rotation limit failure when rotated to the limit angle.

[0032] In some embodiments, the base has a first protrusion on its outer circumferential surface, and the second limiting member includes a second protrusion. When the driving element is in the initial position, the first protrusion and the second protrusion face each other.

[0033] Alternatively, two first protrusions are provided on the outer circumferential surface of the base, and the two first protrusions are arranged facing each other;

[0034] The second limiting member includes two second protrusions, which are symmetrically distributed around the center line of symmetry.

[0035] With the above structure, good angular limiting can be achieved by the cooperation of one set of first and second protrusions or two sets of first and second protrusions, and the first and second protrusions can be effectively guaranteed to have sufficient strength.

[0036] In some embodiments, three first protrusions are provided on the outer circumferential surface of the base, and the three first protrusions are evenly distributed along the circumference of the base;

[0037] The braking element includes an annular assembly portion, the circular hole in the assembly portion forming the assembly hole, and the assembly portion having a second groove corresponding to each of the three first protrusions on its end face facing the first protrusion. When rotating, the first protrusion rotates in the corresponding second groove.

[0038] With the above structure, when there are three first protrusions and three corresponding second grooves, when rotated counterclockwise to a predetermined angle, the force on each first protrusion is as follows: Figure 14 As shown, when the driving element is subjected to counterclockwise torque, FN1 is the reaction force on the contact point of one of the first protrusions, FN2 is the reaction force on the contact point of the other first protrusion, FN2H is the horizontal component of FN2, FN2V is the vertical component of FN2, FN3 is the reaction force on the contact point of the third first protrusion, FN3H is the horizontal component of FN3, and FN3V is the vertical component of FN3. The sum of FN2H and FN3H is close to FN1, and FN2V is close to FN3V. The radial forces on the three first protrusions are close. At this time, the radial forces on each first protrusion are very small. This structure reduces the strength requirements of the first protrusions and does not require the design of a step structure. Therefore, the first platform can be designed as an easy-to-process cylindrical shape.

[0039] In some embodiments, the drive element is connected to a power mechanism, which includes a reducer housing and an output shaft. A portion of the output shaft extends out of the reducer housing to form an output end, which passes through a circular hole in the base and is then connected to the drive element for transmission. With this structure, the output shaft of the power mechanism drives the drive element to rotate.

[0040] In some embodiments, the limiting mechanism housing is mounted on the reducer housing, and its end is covered with an end cap. The end cap has an annular mating portion formed on the side facing the assembly part. The mating portion extends into the limiting mechanism housing and is interference-fitted with it.

[0041] The assembly part has an annular fastening part on the side facing the end cap. The fastening part extends into the mating part, and the two are fitted together with a clearance in the circumferential direction. The end cap is pressed against the end face of the fastening part.

[0042] With the above structure, the end cap can axially limit the drive and braking components, while also providing a sealing function. Furthermore, the clearance fit between the end cap and the fastening part can reduce the noise of the entire structure.

[0043] A second aspect of this application provides a steering system including the steering angle limiting mechanism described in the first aspect of this application.

[0044] A third aspect of this application provides a vehicle including the steering angle limiting mechanism described in the first aspect of this application or the steering system described in the second aspect.

[0045] Through the above technical solution, the driving element and braking element of this application are eccentrically coupled. In the initial position, there is a certain angle difference between the first and second limiting members on them. During rotation, the circumferential linear velocities of the driving element and braking element are different. The driving element is smaller and located inside the braking element, so the driving element rotates faster. When the first limiting member on the driving element catches up with the second limiting member on the braking element, since the driving element and braking element adopt eccentric meshing, the driving element and braking element form an integral eccentric structure. Under the continuously applied torque, since the distance d2 between the braking element and the limiting mechanism housing is smaller than the distance d1 between the centers of the driving element and the braking element, the braking element abuts against the limiting mechanism housing during the rotation of the driving element around its axis. The driving element, together with the power mechanism connected to it, and the braking element achieve interlocking and limiting, thereby achieving the purpose of limiting the rotation angle. The steering angle limiting mechanism provided by this application has a simple structure, occupies little space, involves few parts, the parts are easy to process, disassemble and assemble conveniently, and the production cost is low.

[0046] Other features and advantages of the embodiments of this application will be described in detail in the following detailed description section. Attached Figure Description

[0047] The accompanying drawings are provided to further illustrate the embodiments of this application and form part of the specification. They are used together with the following detailed description to explain the embodiments of this application, but do not constitute a limitation on the embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without any inventive effort. In the drawings:

[0048] Figure 1 This is a schematic diagram of the HWA structure;

[0049] Figure 2 An exploded view of the angle-limiting mechanism;

[0050] Figure 3 This is a schematic diagram of the internal structure of the angle limiting mechanism;

[0051] Figure 4 This is a schematic diagram of the planar structure of an angle limiting mechanism;

[0052] Figure 5 for Figure 4A schematic diagram of the planar structure of the mechanism;

[0053] Figure 6 for Figure 4 A schematic diagram of the predetermined angle when the mechanism rotates counterclockwise;

[0054] Figure 7 for Figure 4 A schematic diagram of the predetermined angle when the mechanism rotates clockwise;

[0055] Figure 8 A schematic diagram of the planar structure of another angle-limiting mechanism;

[0056] Figure 9 for Figure 8 A schematic diagram of the predetermined angle when the mechanism rotates counterclockwise;

[0057] Figure 10 for Figure 8 A schematic diagram of the predetermined angle when the mechanism rotates clockwise;

[0058] Figure 11 A schematic diagram of the planar structure of another angle-limiting mechanism;

[0059] Figure 12 for Figure 11 A schematic diagram of the predetermined angle when the mechanism rotates counterclockwise;

[0060] Figure 13 for Figure 11 A schematic diagram of the predetermined angle when the mechanism rotates clockwise;

[0061] Figure 14 for Figure 11 Force analysis of the mechanism at a predetermined angle.

[0062] Explanation of reference numerals in the attached figures

[0063] Ⅰ Steering shaft Ⅱ Steering column

[0064] III. Reduction mechanism and torque sensor IV. Hand-feed motor

[0065] V. Controller VI. Angle limiting mechanism

[0066] 1. Drive element 2. Braking element

[0067] 2a Assembly part 2b Fastening part

[0068] 2c Assembly hole 3 External teeth

[0069] 4 Internal teeth 5 First limiting component

[0070] 5a Base 5b First convex part

[0071] 5b1 First step 5b2 Second step

[0072] 6 Second protrusion 6a Third step

[0073] 6b Fourth step 7 Second groove

[0074] 8. Gearbox housing 9. Output shaft

[0075] 10 Limiting mechanism housing 11 End cap

[0076] 12. Joint section 13. First cross section

[0077] 14 Second section 15 Third section

[0078] 16 Fourth cut surface 17 Snap-fit ​​part Detailed Implementation

[0079] The specific embodiments of this application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this application.

[0080] The following description is based on the accompanying drawings.

[0081] It should be noted that, in this application, unless otherwise stated, the directional terms such as "inner" and "outer" used indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this application.

[0082] The steer-by-wire hand wheel actuator (HWA) of this application is a steering subsystem that simulates the steering wheel feel of a traditional steering system by adding a hand wheel feel simulation motor to a traditional mechanical or electrically adjustable column. The hand wheel actuator transmits the road impact torque simulated by the hand wheel feel motor to the steering wheel. Angle limiting mechanism: This mechanical structure limits the rotation angle to a specific range, thus limiting the steering wheel angle.

[0083] A typical HWA (Hardware Controller) includes a steering shaft I, a steering column II, a reduction gear and torque sensor III, an ECU (Electronic Control Unit) V, a hand-feed motor IV, and an angle limiting mechanism VI. The steering shaft I is supported within the steering column II by a column bearing. The lower end of the steering column II is bolted to the reduction gear, and the steering shaft I is splined to the input shaft of the reduction gear. The structure of an HWA is well-known in the field and will not be elaborated upon further.

[0084] When the controller (ECU) V receives a tactile feedback request command from the vehicle, the controller (ECU) V controls the tactile feedback motor IV to output the requested torque. This torque is then applied to the steering shaft I after being reduced and amplified by the reduction mechanism. The steering wheel is connected to the upper end of the steering shaft I. The driver can feel the tactile force of the simulated road impact through the steering wheel. At the same time, the torque sensor installed between the speed mechanism and the steering shaft measures the torque of the steering shaft I and transmits the torque to the controller.

[0085] The maximum angle of unidirectional rotation refers to the maximum angle of rotation in a single direction, such as clockwise or counterclockwise.

[0086] The center of rotation refers to the point around which the element rotates. In this application, the center of rotation of the drive element 1 remains constant relative to the limiting structure housing 10. The center of rotation of the drive element 1 is generally its center. However, during the rotation of the brake element 2 with the drive element 1, the center of rotation of the brake element 2 relative to the limiting structure housing 10 is not fixed, but changes with the rotation. For example, before the first limiting member 5 and the second limiting member abut, the center of rotation of the brake element 2 is its center. When the first limiting member 5 and the second limiting member abut together, the brake element 2 and the drive element 1 become an eccentric structure as a whole. At this time, the center of rotation of the brake element 2 is the center of rotation of the drive element 1 (i.e., the center of the drive element). That is, the center of rotation of the brake element 2 has moved. After the two rotate synchronously at a certain angle, the brake element 2 abuts against the limiting structure housing 10.

[0087] The angle limiting mechanism VI provided in this application is installed at the end of the reducer housing 8 of the reduction mechanism, and its specific structure is as follows:

[0088] like Figure 1-5 As shown, a steering angle limiting mechanism includes:

[0089] Drive element 1 is used to connect to the power mechanism, and the drive element 1 is provided with a ring of external teeth 3;

[0090] The braking element 2 has a mounting hole 2c inside. A ring of internal teeth 4 is provided on the inner wall of the mounting hole 2c. The driving element 1 is eccentrically disposed in the mounting hole 2c. The external teeth 3 mesh with the internal teeth 4, thereby causing the driving element 1 to drive the internal teeth 4 to rotate. The rotation center of the braking element 2 is movable.

[0091] The housing of the limiting mechanism is sleeved outside the braking element;

[0092] A limiting structure is provided on the driving element and / or the braking element to limit the relative stationary position between the driving element 1 and the braking element 2 after the driving element rotates to a predetermined angle. When the driving element is in the initial position, the distance d1 between the center of the external tooth 3 and the center of the internal tooth 4 is greater than the distance d2 between the outer wall of the braking element 2 and the inner wall of the limiting mechanism housing 10 (see details). Figure 4 ).

[0093] The limiting structure includes a first limiting member 5 and a second limiting member. The first limiting member 5 is disposed on the driving element 1, and the second limiting member is disposed on the braking element 2. At least a portion of the running track of the second limiting member overlaps with the running track of the first limiting member 5. When the driving element rotates to a predetermined angle, the first limiting member 5 and the second limiting member abut against each other, and the braking element 2 abuts against the housing 10 of the limiting mechanism.

[0094] There are no specific requirements for the form of external teeth 3 and internal teeth 4. They can be involute spline gear transmission, cycloidal pinwheel transmission, linear conjugate internal meshing gear transmission, harmonic gear transmission, etc., which are known in this field and will not be elaborated here.

[0095] like Figure 2 and 3 As shown, the drive element 1 is connected to a power mechanism, which includes a reducer housing 8 and an output shaft 9. The output shaft 9 is mounted inside the reducer housing 8 via bearings. A portion of the output shaft 9 extends out of the reducer housing 8 to form an output end, and the drive element 1 is connected to this output end.

[0096] In this example, the driving element 1 is annular, with an internal circular hole forming a shaft hole, and a ring of external teeth 3 on its outer circumference. The limiting mechanism housing 10 is cylindrical and fixedly mounted on the reducer housing 8. The output end passes through the circular hole in the base 5a and extends into the shaft hole of the driving element 1, and is connected to the driving element 1 for transmission, driving it to rotate clockwise or counterclockwise. The output end and the driving element 1 can be connected and transmitted by spline, interference fit, snap-fit, adhesive, or shaft pin insertion. Of course, in addition to the above installation position, the steering angle limiting mechanism provided in this application can also be installed in other positions, such as inside a column, in which case the limiting mechanism housing 10 is connected to the column housing.

[0097] The first limiting member 5 includes an annular base 5a, which is disposed on the driving element 1. Specifically, it is mounted on the end face of the driving element 1 facing the reducer housing 8. The axis of the base 5a coincides with the axis of the external gear 3. At least one first protrusion 5b is provided on the outer circumferential surface of the base 5a. The outer diameter of the base 5a is substantially the same as the outer diameter of the driving element 1. The first protrusion 5b extends radially along the base 5a, and its end is higher than the outer circle of the driving element 1.

[0098] The second limiting member includes a second protrusion 6 and / or a second groove 7 in the same number as the first protrusion 5b, and all the second protrusions 6 and / or second grooves 7 are evenly distributed around the axis of the internal tooth 4;

[0099] When the drive element 1 rotates to a predetermined angle, the first protrusion 5b abuts against the corresponding second protrusion 6 or second groove 7.

[0100] like Figure 4 , 5 As shown in Figure 8, a first cross-section 13 is made along one side of the first protrusion 5b, and a second cross-section 14 is made along the side of the second protrusion 6 adjacent to the first cross-section 13. The first cross-section 13 and the second cross-section 14 intersect at the axis of the external tooth 3. When the driving element is in the initial position, the included angle between the first cross-section 13 and the second cross-section 14 is α, where α = 1 - n1 / n2 × 360° × β / 360°, where n1 is the number of teeth of the external tooth 3, n2 is the number of teeth of the internal tooth 4, and β is the maximum angle of unidirectional rotation of the driving element 1, i.e., the designed maximum rotation angle.

[0101] A third cut surface 15 is made along the other side of the first protrusion 5b. The first cut surface 13 and the third cut surface 15 intersect at the axis of the external tooth 3, and the included angle between them is γ1.

[0102] A fourth tangent 16 is made along the other side of the second protrusion 6. The second tangent 14 and the fourth tangent 16 intersect at the axis of the external tooth 3, and the included angle between them is γ2.

[0103] The γ1 and γ2 satisfy the following formula:

[0104] γ1 + γ2 = 360° - 2α × N

[0105] Wherein, N is the sum of the number of the first protrusion 5b and the number of the second protrusion 6 divided by 2.

[0106] The first protrusion 5b includes a first step 5b1 and a second step 5b2 arranged radially along the base 5a. The first step 5b1 is fixedly mounted on the outer circumferential surface of the base 5a, and the second step 5b2 is fixedly connected to the first step 5b1. The two are connected by a smooth curved surface. The circumferential length of the first step 5b1 along the base 5a is less than the circumferential length of the second step 5b2 along the base 5a. For ease of processing, the base 5a, the first step 5b1 and the second step 5b2 can be integrally formed.

[0107] The braking element 2 includes an annular assembly part 2a, and the inner circular hole of the assembly part 2a forms the assembly hole 2c. When the driving element is in the initial position, the axis of the assembly part 2a coincides with the axis of the limiting mechanism housing 10. The distance between the outer circumferential surface of the assembly part 2a and the inner wall of the limiting mechanism housing 10 is d2.

[0108] The second protrusion 6 includes a third step 6a and a fourth step 6b arranged sequentially along the radial direction of the assembly part 2a. The third step 6a and the fourth step 6b are fixedly mounted on the end face of the assembly part 2a facing the first protrusion 5b. The two are connected by a smooth curved surface. The circumferential length of the third step 6a along the assembly part 2a is greater than that of the fourth step 6b along the assembly part 2a. To facilitate processing, the assembly part 2a, the third step 6a and the fourth step 6b can be integrally formed. When the driving element 1 rotates to a predetermined angle, the first step 5b1 abuts against the third step 6a and the second step 5b2 abuts against the fourth step 6b.

[0109] like Figure 4-7 As shown, in some embodiments, a first protrusion 5b is provided on the outer circumferential surface of the base 5a, and the second limiting member includes a second protrusion 6. When the driving element is in the initial position, the first protrusion 5b and the second protrusion 6 face each other.

[0110] like Figure 6 As shown, when the first limiting member includes a first protrusion 5b and the second limiting member includes a second protrusion 6, the engagement relationship between the first protrusion 5b and the second protrusion 6 when rotated counterclockwise to a predetermined angle is as follows: Figure 7 As shown, when rotated clockwise to a predetermined angle, the first protrusion 5b and the second protrusion 6 are in a cooperative relationship.

[0111] like Figure 8-10As shown, in another embodiment, the outer circumferential surface of the base 5a is provided with two first protrusions 5b, which are arranged opposite each other. The second limiting member includes two second protrusions 6, which are symmetrically distributed about the center line of symmetry.

[0112] like Figure 9 As shown, when the first limiting member includes two first protrusions 5b and the second limiting member includes two second protrusions 6, the engagement relationship between the first protrusions 5b and the second protrusions 6 when the driving element rotates counterclockwise to a predetermined angle is as follows: Figure 10 As shown, when it rotates clockwise to a predetermined angle, the first protrusion 5b and the second protrusion 6 are in a matching relationship.

[0113] like Figure 11 In some other embodiments, three first protrusions 5b are provided on the outer circumferential surface of the base 5a. The three first protrusions 5b are evenly distributed along the circumference of the base 5a. The braking element 2 includes a circular mounting part 2a, in which the mounting part 2a is provided with the mounting hole 2c. The end face of the mounting part 2a facing the first protrusions 5b is provided with the second groove 7 corresponding to the three first protrusions 5b. When rotating, the first protrusions 5b rotate in the corresponding second groove 7. The first protrusions 5b are semi-cylindrical.

[0114] like Figure 12 As shown, when the driving element rotates counterclockwise to a predetermined angle, the engagement relationship between the first protrusion 5b and the second groove 7 is as follows: Figure 14 As shown, this is a force analysis diagram of each of the first protrusions 5b at this time, as follows: Figure 13 As shown, when it rotates clockwise to a predetermined angle, the first protrusion 5b and the second groove 7 are in a matching relationship.

[0115] In any of the above specific embodiments, at a predetermined angle of clockwise or counterclockwise rotation, the driving element 1 and the braking element 2 form an integral eccentric structure. When the braking element 2 continues to rotate, it will abut against the inner wall of the limiting mechanism housing 10, thereby achieving the function of limiting the angle.

[0116] The end of the housing 10 of the limiting mechanism is covered with an end cap 11. An annular mating part 12 is formed on the side of the end cap 11 facing the assembly part 2a. The mating part 12 extends into the housing 10 of the limiting mechanism and is interference-fitted with it.

[0117] The assembly part 2a has an annular fastening part 2b on its end face facing the end cover 11. The fastening part 2b extends into the mating part 12, and the two are fitted together with a clearance in the circumferential direction. The end cover 11 is pressed against the end face of the fastening part 2b.

[0118] To ensure proper fit between the drive element 1, braking element 2, reducer housing 8, and output shaft 9, and to reduce noise, a portion of the base 5a facing away from the external gear 3 extends axially to form a snap-fit ​​portion 17. The reducer housing 8 has a mounting hole, and the snap-fit ​​portion 17 is inserted into the mounting hole with a circumferential clearance fit. When the first protrusion 5b rotates, it has a circumferential clearance fit with the limiting mechanism housing 10. The first protrusion 5b has an axial clearance fit with the second protrusion 6, and the second protrusion 6 has an axial clearance fit with the reducer housing 8. Elastic components such as rubber pads can also be installed on the first protrusion 5b, the second protrusion 6, and the groove wall of the second groove 7 to reduce the impact between components when the steering wheel is rotated to a predetermined angle, reduce noise, reduce component deformation, and increase component lifespan.

[0119] from Figure 3 As can be seen, the output shaft 9 passes through the base 5a and enters the circular hole of the drive element 1, causing it to rotate. The base 5a and the first protrusion 5b rotate together with the drive element 1. The assembly part 2a meshes with the external tooth 3 of the drive element 1 through the internal tooth 4. The second protrusion 6 or the second groove 7 on the end face of the assembly part 2a facing the base 5a rotates together with the assembly part 2a. The second protrusion 6 or the second groove 7 is located on the running trajectory of the first protrusion 5b. Since the circumferential speed of the drive element 1 is greater than the circumferential speed of the brake element 2, after rotating a certain angle, the 5b will meet and abut against the second protrusion 6 or the second groove 7.

[0120] The working principle of the angle limiting mechanism provided in this application is as follows:

[0121] When the steering wheel is in the starting position (center position), both the first limiting member 5 and the second limiting member are symmetrical about the center line and have a certain angular difference. When the steering wheel is turned to the right, both the driving element 1 and the braking element 2 rotate clockwise. The circumferential linear velocity of the first limiting member 5 is greater than that of the second limiting member. When the angular difference between them becomes zero, the first protrusion 5b of the first limiting member 5 and the second protrusion 6 or second groove 7 of the second limiting member abut together. Due to the eccentricity of the driving element 1 and the braking element 2 in internal engagement... In this arrangement, the two components together form an integral eccentric structure. Under the applied torque, after the braking element 2 continues to rotate by a very small angle, a portion of the outer circumferential surface of its mounting portion 2a will abut against the inner wall of the limiting mechanism housing 10. At this time, the first protrusion 5b and the second protrusion 6 or second groove 7 of the second limiting member, the mounting portion 2a, and the limiting mechanism housing 10 mutually restrict each other. The output shaft 9, the driving element 1, and the braking element 2 are interlocked into one, forming an eccentric shaft structure, and the rotation of the driving element 1 and the output shaft 9 is restricted. When rotating counterclockwise, the above description is reversed.

[0122] This application can change the rotation angle limiting range of the steering angle limiting mechanism by changing the ratio of the number of teeth of the external teeth 3 and the internal teeth 4. It can also change the contact position between the first protrusion 5b and the second protrusion 6 or the second groove 7 by changing the length of the first protrusion 5b and the second protrusion 6 or the second groove 7 along the circumferential direction, thereby further adjusting the rotation angle limiting range of the steering angle limiting mechanism. The driving element 1 and the braking element 2 can be produced by powder metallurgy to achieve high working strength, and the manufacturing process is simple, the production efficiency is high, and the cost is low.

[0123] This application also provides a steering system, including the aforementioned steering angle limiting mechanism. The steering angle limiting mechanism provided by this invention can be installed at the end of the deceleration mechanism for easy assembly and disassembly.

[0124] This application also provides a vehicle including the aforementioned steering angle limiting mechanism or the aforementioned steering system.

[0125] In the description of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0126] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between components; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0127] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0128] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A steering angle limiting mechanism, characterized in that, include: A driving element, on which a ring of external teeth is provided; A braking element has a mounting hole inside, and a ring of internal teeth is provided on the inner wall of the mounting hole. The driving element is eccentrically disposed in the mounting hole. The external teeth mesh with the internal teeth, thereby causing the driving element to drive the braking element to rotate. The rotation center of the braking element is movable. The housing of the limiting mechanism is sleeved outside the braking element; A limiting structure is provided on the driving element and / or the braking element to limit the relative stationary between the driving element and the braking element after the driving element rotates to a predetermined angle. When the driving element is in the initial position, the distance d1 between the center of the outer tooth and the center of the inner tooth is greater than the distance d2 between the outer wall of the braking element and the inner wall of the limiting mechanism housing.

2. The steering angle limiting mechanism according to claim 1, characterized in that, The limiting structure includes a first limiting member and a second limiting member, wherein the first limiting member is disposed on the driving element, the second limiting member is disposed on the braking element, and at least a portion of the running track of the second limiting member overlaps with the running track of the first limiting member.

3. The steering angle limiting mechanism according to claim 2, characterized in that, The first limiting member includes an annular base, which is disposed on the driving element. The axis of the base coincides with the axis of the external tooth, and at least one first protrusion is provided on the outer circumferential surface of the base. The second limiting member includes a number of second protrusions and / or second grooves equal to the number of the first protrusions, and all the second protrusions and / or second grooves are evenly distributed around the axis of the internal teeth; When the driving element is in the initial position, the center of the outer tooth and the center of the inner tooth are connected to form a symmetrical center line, and the first limiting member and the second limiting member are respectively divided into two completely symmetrical parts by the symmetrical center line. When the drive element rotates to a predetermined angle, the first protrusion abuts against the corresponding second protrusion or second groove.

4. The steering angle limiting mechanism according to claim 3, characterized in that, A first sectional surface is made along one side of the first protrusion, and a second sectional surface is made along the side of the second protrusion adjacent to the first sectional surface. The first sectional surface and the second sectional surface intersect at the axis of the external tooth. When the driving element is in the initial position, the included angle between the first and second tangential surfaces is α, where α = ×360° × β / 360°, n1 is the number of teeth of the external teeth, n2 is the number of teeth of the internal teeth, and β is the maximum angle of unidirectional rotation of the driving element.

5. The steering angle limiting mechanism according to claim 4, characterized in that, A third tangent is made along the other side of the first protrusion. The first tangent and the third tangent intersect at the axis of the external tooth, and the included angle between them is γ1. A fourth tangent is made along the other side of the second protrusion. The second tangent and the fourth tangent intersect at the axis of the external tooth, and the included angle between them is γ2. The γ1 and γ2 satisfy the following formula: γ1 + γ2 = 360° - 2α × N Where N is the sum of the number of the first protrusion and the number of the second protrusion divided by 2.

6. The steering angle limiting mechanism according to any one of claims 3-5, characterized in that, The first protrusion includes a first step and a second step arranged radially along the base, wherein the first step is fixedly installed on the outer circumferential surface of the base, the second step is fixedly connected to the first step, and the two are connected by a smooth curved surface, and the circumferential length of the first step along the base is less than the circumferential length of the second step along the base.

7. The steering angle limiting mechanism according to claim 6, characterized in that, The braking element includes an annular assembly portion, and the assembly portion contains a circular hole that forms the assembly hole. The second protrusion includes a third step and a fourth step arranged sequentially along the radial direction of the assembly part. The third step and the fourth step are fixedly installed on the end face of the assembly part facing the first protrusion. The two are connected by a smooth curved surface. The circumferential length of the third step along the assembly part is greater than that of the fourth step along the circumferential length of the assembly part. When the driving element rotates to a predetermined angle, the first step abuts against the third step, and the second step abuts against the fourth step.

8. The steering angle limiting mechanism according to any one of claims 3-5, characterized in that, The base has a first protrusion on its outer circumferential surface, and the second limiting member includes a second protrusion. When the driving element is in the initial position, the first protrusion and the second protrusion face each other. Alternatively, two first protrusions are provided on the outer circumferential surface of the base, and the two first protrusions are arranged facing each other; The second limiting member includes two second protrusions, which are symmetrically distributed around the center line of symmetry.

9. The steering angle limiting mechanism according to any one of claims 3-5, characterized in that, Three first protrusions are provided on the outer circumferential surface of the base, and the three first protrusions are evenly distributed along the circumference of the base. The braking element includes an annular assembly portion, the circular hole in the assembly portion forming the assembly hole, and the assembly portion having a second groove corresponding to each of the three first protrusions on its end face facing the first protrusion. When rotating, the first protrusion rotates in the corresponding second groove.

10. The steering angle limiting mechanism according to claim 7, characterized in that, The drive element is connected to a power mechanism, which includes a reducer housing and an output shaft. A portion of the output shaft extends out of the reducer housing to form an output end, which passes through a circular hole in the base and is then connected to the drive element for transmission.

11. The steering angle limiting mechanism according to claim 10, characterized in that, The limiting mechanism housing is mounted on the reducer housing, and its end is covered with an end cap. The end cap has an annular mating part formed on the side facing the assembly part. The mating part extends into the limiting mechanism housing and is interference-fitted with it. The assembly part has an annular fastening part on the side facing the end cap. The fastening part extends into the mating part, and the two are fitted together with a clearance in the circumferential direction. The end cap is pressed against the end face of the fastening part.

12. A steering system, characterized in that, Includes the steering angle limiting mechanism as described in any one of claims 1-11.

13. A vehicle, characterized in that, Includes the steering angle limiting mechanism as described in any one of claims 1-11 or the steering system as described in claim 12.

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