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EP-4553346-B1 - LOCKING MECHANISM

EP4553346B1EP 4553346 B1EP4553346 B1EP 4553346B1EP-4553346-B1

Inventors

  • NERRIERE, ADRIEN

Dates

Publication Date
20260513
Application Date
20241022

Claims (15)

  1. Locking mechanism capable of being mounted in a transmission housing (1) to block rotation of a shaft of a vehicle equipped with at least one locking recess (45), the locking mechanism comprising: - a movable pawl (34) comprising a locking finger (35), the movable pawl (34) being mounted pivoting around a pivot axis (Y1) between a locking position in which the locking finger (35) is engaged in the locking recess (45) and a released position in which the locking finger (35) is disengaged from said locking recess (45), the movable pawl (34) comprising a cam surface (36); - a pushing device (38) having a cam follower (42) capable of moving on the cam surface (36) in order to move the movable pawl (34) from the released position to the locking position; - an actuation lever (3) mounted pivoting around an actuation axis (Y2) and configured to move the pushing device (38), the actuation lever (3) comprising an external perimeter (300) having a first angular positioning notch (301) and a second angular positioning notch (302); and - a positioning member (2) cooperating with the external perimeter (300) of the actuation lever (3), the positioning member (2) having a support surface (204) configured to engage in the first angular positioning notch (301) when the movable pawl (34) is in the locking position and in the second angular positioning notch (302) when the movable pawl (34) is in the released position; characterized in that the positioning member includes a flexible blade (200) exerting a force, directly or indirectly, on the external perimeter (300) of the actuation lever (3), the flexible blade (200) comprising a form folded upon itself to constitute, in profile view, a V-shape.
  2. Locking mechanism according to claim 1, wherein the V-shape comprises a first flat wall (207) and a second flat wall (208), a folding angle (A) being established between the first flat wall (207) and the second flat wall (208), the folding angle (A) being between 0° and 80°, the folding angle (A) being preferably between 0° and 40°.
  3. Locking mechanism according to claim 2, wherein a curved wall (209) connects the first flat wall (207) and the second flat wall (208).
  4. Locking mechanism according to claim 3, wherein the curved wall (209) has a radius of curvature between 2 mm and 10 mm.
  5. Locking mechanism according to claim 3 or 4, wherein a radius of curvature of the curved wall, a thickness of the flexible blade, and a ratio equal to the ratio between the radius of curvature and the thickness of the flexible blade are established, the ratio being between 2 and 8.
  6. Locking mechanism according to any one of claims 2 to 5, wherein the first flat wall (207) and the second flat wall (208) are parallel to the actuation axis (Y2).
  7. Locking mechanism according to any one of the preceding claims, wherein the positioning member (2) includes a rolling element (203) arranged on the flexible blade (200), the rolling element (203) being configured to roll on the external perimeter (300) of the actuation lever (3).
  8. Locking mechanism according to any one of the preceding claims, wherein the flexible blade comprises a first folded mounting tab (201) and a second folded mounting tab (202), the first and second folded mounting tabs (201, 202) being folded at an angle of 90° from a first portion (210) of the flexible blade (200) and positioned axially on either side of said first portion (210) of the flexible blade (200).
  9. Locking mechanism according to claim 8, wherein the first folded mounting tab (201) is folded in a direction opposite to the second folded mounting tab (202).
  10. Locking mechanism according to claim 8 or 9, wherein the first folded mounting tab (201) and the second folded mounting tab (202) are offset from each other axially in a direction parallel to the actuation axis (Y2).
  11. Locking mechanism according to any one of claims 8 to 10, wherein: - a first fastening means (206), particularly a centering pin, cooperates with the first folded mounting tab (201) to limit the movement of the positioning member (2) in a plane perpendicular (P) to the actuation axis (Y2); and - a second fastening means (205), particularly a screw, cooperates with the second folded mounting tab (202) to block the movement of the positioning member (2) along an axis parallel to the actuation axis (Y2).
  12. Locking mechanism according to claim 11, wherein the flexible blade (200) has a shape configured to leave free a passage along an axis parallel to the actuation axis (Y2) allowing the assembly of the first and second fastening means (205, 206).
  13. Locking mechanism according to any one of the preceding claims, wherein the external perimeter (300) of the actuation lever (3) is constituted of surfaces parallel to the actuation axis (Y2).
  14. Locking mechanism according to any one of the preceding claims, wherein the flexible blade (200) is formed as a single piece from a strip of metallic material, particularly from a steel sheet.
  15. Transmission system comprising a shaft equipped with at least one locking recess (45) and a locking mechanism according to any one of claims 1 to 14.

Description

technical field The present invention relates to a locking mechanism for locking against rotation a shaft of a transmission chain of a mobility device, such as a motor vehicle for example. Technological background Locking mechanisms are used, for example, as parking brakes to secure a stationary vehicle. In such cases, they prevent the vehicle's drive shaft from rotating. These locking mechanisms are commonly used in vehicles with automatic transmissions, hybrid vehicles, and electric vehicles. It is known, in particular from the document US2018/0112774 Locking mechanisms include a movable pawl equipped with a locking finger and pivotally mounted on a transmission housing between a released position and a locked position, in which the locking finger is inserted into a locking recess that is rotationally fixed to the transmission shaft to be locked. The locking mechanism further includes a thrust device guided in translation on the transmission housing and comprising a cam follower that cooperates with a cam surface of the pawl such that a translational movement of the thrust device causes the pawl to pivot between the released position and the locked position. An actuating lever is used to control the movement of the thrusting device. The actuating lever is pivotally mounted on the transmission housing and driven in rotation, directly or indirectly, by the rotor shaft of an electric motor. Most often, the actuating lever has an outer rim with a first and second positioning notch. Angular. A positioning element fixed to the transmission housing includes an elastic device, for example in the form of a flexible blade, pressing against the outer edge of the actuating lever. The positioning element is configured to engage in the first angular positioning notch when the movable pawl is in the locked position, and in the second angular positioning notch when the movable pawl is in the released position. The positioning device thus makes it possible to maintain the position of the locking mechanism in a stable and precise manner in the released position and/or in the locked position. Such a structure for the blocking mechanism poses several technical problems: Firstly, compactness must be improved in order to be able to house the locking mechanism in the very restricted spaces allocated in recent transmissions, particularly transmissions for electric vehicles. Secondly, the assembly must be simplified. In particular, the various components of the locking mechanism can be fixed to the transmission housing along non-parallel fixing axes, which results in their assembly involving several complex operations. Finally, these improvements in compactness and assembly must be achievable while maintaining sufficient mechanical strength of the positioning element which is subjected to mechanical stresses occurring during the vehicle stopping phases ensured by the locking mechanism. Summary Throughout what follows, ordinal numeral adjectives are used to differentiate features. They do not define the position of a feature. Therefore, for example, a third feature of a product does not mean that the product has a first and/or a second characteristic. One idea behind the invention is a locking mechanism designed to prevent a vehicle's shaft from rotating. An idea underlying the invention is a blocking mechanism that makes it possible to solve one or more technical problems of the prior art, for example the aforementioned problems. The invention relates to a locking mechanism suitable for mounting in a transmission housing to prevent rotation of a shaft of a vehicle equipped with at least one locking recess, the locking mechanism comprising: a movable ratchet comprising a locking finger, the movable ratchet being mounted pivoting about a pivot axis between a locking position in which the locking finger is engaged in the locking recess and a released position in which the locking finger is disengaged from said locking recess, the movable ratchet comprising a cam surface; a thrusting device comprising a cam follower capable of moving on the cam surface in order to move the movable pawl from the released position to the locked position; an actuating lever mounted to pivot about an actuating axis configured to move the thrusting device, the actuating lever comprising an outer circumference having a first angular positioning notch and a second angular positioning notch; and a positioning member cooperating with the outer perimeter of the actuating lever, the positioning member having a bearing surface configured to engage in the first angular positioning notch when the movable pawl is in the locking position and in the second angular positioning notch when the movable pawl is in the released position; the positioning device comprising a flexible blade exerting a force, directly or indirectly, on the external periphery of the actuating lever, the flexible blade comprising a shape folded upon itself to constitute in profile view a V sha