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EP-4491465-B1 - LOCKING MECHANISM

EP4491465B1EP 4491465 B1EP4491465 B1EP 4491465B1EP-4491465-B1

Inventors

  • MOLLIER, CHRISTOPHE
  • LONGUENT, Stéphane
  • FAFET, OLIVIER
  • BARRY, Alain
  • MAURICE, BENOIT

Dates

Publication Date
20260513
Application Date
20240709

Claims (14)

  1. Locking mechanism capable of rotationally blocking a shaft of a vehicle equipped with at least one locking recess (45), the locking mechanism comprising: - a transmission housing (1) including a housing (2), the housing (2) having a first positioning face (23) and a second positioning face (24, 24'), the first positioning face (23) and the second positioning face (24, 24') forming a positioning slot; - a movable pawl (34) comprising a locking finger (35), the movable pawl (34) being pivotally mounted in a plane (P) around a pivot axis on the transmission housing (1) 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); - an actuator (37) that moves a pushing device (38), the pushing device (38) having a cam follower capable of moving on the cam surface (36) in order to move the movable pawl from the released position to the locking position; - a guide rail (27) having a guide wall (30) guiding the movement of the pushing device (38) and a positioning wall (300); the positioning wall (300) of the guide rail (27) being inserted into the positioning slot of the housing (2).
  2. Locking mechanism according to claim 1 wherein the positioning wall (300) and the guide wall (30) form a single wall (301), the positioning wall (300) comprising at least one protrusion (300, 300') extending substantially in a direction parallel to the movement of the pushing device (38) from the guide wall (30), the at least one protrusion (300, 300') facing the first positioning face (23) and/or the second positioning face (24, 24') of the housing (2).
  3. Locking mechanism according to claim 2, the positioning wall (300) comprising at least two protrusions (300, 300') extending substantially in a direction parallel to the movement of the pushing device (38), the at least two protrusions (300, 300') facing the first positioning face (23) and/or the second positioning face (24, 24') of the housing (2).
  4. Locking mechanism according to any one of the preceding claims wherein the first positioning face (23) of the housing (2) and the second positioning face (24, 24') of the housing (2) are parallel.
  5. Locking mechanism according to any one of the preceding claims wherein a width (L) of the positioning slot, a thickness (e) of the positioning wall (300), and an operating clearance equal to the difference between the width (L) and the thickness (e) are defined, the value of the operating clearance being between 0.05 and 1 mm, the value of the operating clearance being preferably between 0.2 and 0.6 mm.
  6. Locking mechanism according to any one of the preceding claims wherein the housing (2) has a first lateral face (21) facing and distant from a second lateral face (22) and a first longitudinal face (23) located between the first lateral face (21) and the second lateral face (22), wherein the guide rail (27) has, corresponding to the housing (2), a third lateral face (28) facing and distant from a fourth lateral face (29) and the guide wall (30) extending longitudinally between the third lateral face (28) and the fourth lateral face (29), and wherein the third lateral face (28), the fourth lateral face (29) and the guide wall (30) of the guide rail (27) are respectively facing the first lateral face (21), the second lateral face (22) and the first longitudinal face (23) of the housing (2) in order to limit movement of the guide rail (27) in all directions of the plane (P).
  7. Locking mechanism according to claim 6 wherein the first lateral face (21) of the housing and/or the second lateral face (22) of the housing do not have a common edge with the first longitudinal surface (23) of the housing, the first lateral face (21) of the housing, the second lateral face (22) of the housing and the first longitudinal surface (23) of the housing being obtained by a machining process and connected to each other by raw material walls.
  8. Locking mechanism according to any one of the preceding claims wherein the housing has a first notch (25) and, wherein the guide rail (27) has a second notch (32), the first notch (25) of the housing and the second notch (32) of the guide rail being through-holes and being intended to allow the passage of the actuator (37).
  9. Locking mechanism according to any one of the preceding claims wherein the guide rail (27) comprises an anti-return stop (28) and/or an end stop (29) preventing the movement of the pushing device (38) beyond said guide rail (27).
  10. Locking mechanism according to claim 9, wherein the anti-return stop is formed by the third lateral face (28) of the guide rail (27) and/or the end stop is formed by the fourth lateral face (29) of the guide rail (27).
  11. Locking mechanism according to any one of the preceding claims wherein the positioning slot of the housing (2) further comprises at least one bottom face (47, 47') parallel to the plane (P), and correspondingly, the positioning wall (300) of the guide rail (27) further comprises at least one lower face (31, 31') parallel to the plane P, the at least one lower face (31, 31') facing the at least one bottom face (47, 47') so as to limit the movement of the guide rail (27) in a direction perpendicular to the plane (P).
  12. Locking mechanism according to any one of the preceding claims, wherein a fastening means fixes the guide rail (27) to the transmission housing (1), the fastening means blocking a movement of the guide rail in a direction perpendicular to the plane (P).
  13. Locking mechanism according to any one of the preceding claims wherein the guide rail (27) is formed as a single piece in a bent metal material strip, particularly in a steel sheet.
  14. 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 13.

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 FR3128754 The locking mechanisms include a ratchet equipped with a locking pin and pivotally mounted on a transmission housing between a released position and a locked position. In the locked position, the locking pin is inserted into a locking recess that is rotationally fixed to the transmission shaft to be locked. The locking mechanism further includes an actuator that moves a movable carriage, which is guided in translation along the transmission housing by means of a guide rail. The movable carriage has a roller that engages with a cam surface of the ratchet, such that a translational movement of the movable carriage causes the ratchet to pivot. The guide rail is a stamped sheet metal part with several folded walls that allow it to be positioned by interlocking into a recess in the transmission housing. More specifically, the guide rail has four walls folded at a 90-degree angle to obtain an overall rectangular shape, and correspondingly, the recess has four machined faces opposite the four walls of the guide rail to ensure their positioning. Such a locking mechanism structure is simple in design, easy to assemble and robust enough to withstand the significant mechanical stresses that may occur during the transition from the released position to the locked position. FROM 10 2019 101467 A11 discloses a rear brake ratchet support fixed with screws. However, such a structure poses several technical problems: the guide rail, due to its large number of folded walls, has a complex shape that is difficult to manufacture; machining the surfaces of the guide rail housing in the casing requires a large amount of material removal; the positioning of the guide rail relative to its housing in the casing is not precise enough because it depends on the sum of the manufacturing tolerances of a large number of geometric dimensions. Therefore, it is necessary to propose a locking mechanism that is more economical, easier to implement and allows for more precise positioning of the guide rail. Summary Throughout this text, 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 feature. 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 capable of preventing the rotation of a shaft of a vehicle equipped with at least one locking recess, the locking mechanism comprising: a transmission housing comprising a housing, the housing comprising a first positioning face and a second face positioning, the first positioning face and the second positioning face forming a positioning slot; a movable ratchet comprising a locking finger, the movable ratchet being mounted pivotally in a plane about a pivot axis on the transmission housing 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; an actuator which moves a thrusting device, the 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; a guide rail comprising a guide wall guiding the movement of the pushing device and a positioning wall; the positioning wall of the guide rail being inserted into the positioning slot of the housing. Thanks to these features, precise positioning of the guide rail in a chosen direction of the plane is ensured, as this positioning depends solely and directly on two dimensions: that of the positioning wall and that of the slot. Furthermore, the slot can be created economically by simply passing a machining tool through it, thus significantly reducing the amount of machining required in the housing. According to a further feature of the invention, the housing is formed of material in the transmission casing. According to a further feature of the invention, the slot is made by a single machining operation using a cutting tool intended to machine the grooves, such as in particular a disc cutter, an end mill