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EP-4532142-B1 - DEVICE AND METHOD FOR REMOVING A LOCK-UP PIN OF A TENSIONER FOR A BELT DRIVE

EP4532142B1EP 4532142 B1EP4532142 B1EP 4532142B1EP-4532142-B1

Inventors

  • ROCA FUMAGALLI, Flavio Alejandro
  • AQUILINO, Giuseppe

Dates

Publication Date
20260513
Application Date
20230424

Claims (11)

  1. Device for removing a lock-up pin (2) of a tensioner (3), comprising a main body (11) provided with a key (34) couplable to a loading element (35) integral with an arm (5) of the tensioner (3), a lever (12) rigidly coupled to the main body (11), a sliding element (13) prismatically coupled to the main body (11) and movable with respect to it along a first axis (C) parallel to an axis of the lock-up pin (2) when the key (34) is coupled to the loading element (35), at least one magnet (71) carried by the sliding element (13) and configured to interact with the lock-up pin (2) of the tensioner (3), the sliding element (13) being movable between a rearward rest position and a forward position of coupling with the lock-up pin (2), and elastic means (91) exerting on the sliding element (13) an elastic force parallel to said direction of relative motion between the main body (11) and the sliding element (13) to return the sliding element (13) from the forward position to the rest position.
  2. Device as claimed in claim 1, wherein the main body (11) comprises a coupling portion (21) provided with said key (34) and a guiding portion (22) configured to guide the sliding element (13).
  3. Device as claimed in claim 2, wherein the coupling portion (21) has a seat (31) configured to at least partially accommodate a pulley (6) of the tensioner (3), said key (34) being housed in the seat (31) and configured to cooperate with a prismatic end of a pin of the pulley (6) defining the loading element (35).
  4. Device as claimed in claim 2 or 3, wherein the guiding portion (22) has a cavity (53) configured to at least partially accommodate the lock-up pin (2).
  5. Device as claimed in any of claims 2 to 4, wherein the guiding portion (22) extends along an outer surface (23) of the coupling portion (21) and the sliding element (13) is shaped to at least partially envelop the guiding portion (22).
  6. Device as claimed in any of the preceding claims, wherein the lever (12) comprises a rod (36) orthogonal to the first axis (C).
  7. Device as claimed in any of claims 2 to 6, wherein the elastic means (91) are operatively interposed between the guiding portion (22) and the sliding element (13).
  8. Device as claimed in claim 7, wherein the elastic means (91) comprise at least one compression spring (91) having an axis parallel to the first axis (C) and wherein the at least one compression spring (91) has a maximum extension in the forward position of the sliding element (13) and a minimum extension in the rearward position of the sliding element (13).
  9. Device as claimed in any of the preceding claims, wherein the key (34) is interchangeable.
  10. Method for removing a lock-up pin (2) of a tensioner (3) via a device (1) as claimed in any of the preceding claims, the tensioner (3) comprising a base (4), an arm (5) hinged to the base (4), a spring exerting on the arm (5) a torque configured to cause a rotation of the arm (5) with respect to the base (4) in a first direction of rotation, a lock-up pin (2) configured to lock the arm (5) with respect to the base (4) in an installation position, a pulley (6) carried by the arm (5) and rotatable with respect to it about a second axis, and a loading element (35) integral with an arm (5) of the tensioner (3), the pulley (6) being configured to cooperate with a belt of a transmission, the method comprising the steps of: - coupling the device (1) to the tensioner (3) so that the key (34) engages the loading element (35); - displacing the sliding element (13) from the rearward rest position to the forward position of coupling with the lock-up pin (2), against the action of the elastic means (91), to magnetically couple the at least one magnet (71) to the lock-up pin (2); and - exerting on the lever (12) a torque opposite to the first direction of rotation so as to balance the torque exerted by the spring of the tensioner (3) on the arm (5), thus releasing the lock-up pin (2) at least from the base (4) via the displacement of the sliding element (13) from the forward position of coupling to the rearward rest position via the elastic means (91).
  11. Method as claimed in claim 10, comprising the further steps of: - guiding the rotation of the device (1) under the action of the spring of the tensioner (3) to a position where the pulley (6) cooperates with the belt and the force exerted by the contact between the belt and the pulley (6) balances the torque exerted by the spring of the tensioner (3) on the arm (5); - removing the device (1) from the tensioner (3) by decoupling the key (34) from the loading element (35); and - removing the lock-up pin (2) from the device (1).

Description

Technical field The present invention relates to a device and method for removing a lock-up pin of a tensioner for a belt drive. Such a device is known from US2015/101162A1. Background art As is known, a tensioner for a belt of a transmission comprises a base, an arm hinged to the base, a pulley carried by the arm and rotatable with respect to it, and a spring exerting on the arm a torque configured to maintain the pulley in contact with the belt. Generally, the tensioner further comprises a lock-up pin configured to lock the arm with respect to the base in an installation position. Conveniently, the tensioner is provided in the installation position, i.e. with the lock-up pin inserted so as to lock the arm with respect to the base. This facilitates the installation of the belt and of the tensioner, in particular the positioning and the fixing of the base, but makes it necessary to remove the lock-up pin so as to make the tensioner operational. Since the lock-up pin is subject to cutting forces exerted by the spring on the arm, its removal is possible only in an equilibrium condition where such forces are manually balanced by an operator who acts with a key on a loading element integral with the arm. Such action is carried out with one hand only because the other hand is engaged in manually extracting the lock-up pin. The manual effort required is thus very high. A purpose of the present invention is to provide a device which can overcome the above problems. Disclosure of the invention The aforementioned purpose is achieved by a device as claimed in claim 1. The present invention further relates to a method as claimed in claim 10. Brief description of the drawings For a better understanding of the present invention, a preferred embodiment is described below, by way of nonlimiting example and with reference to the accompanying drawings, wherein: Figure 1 is a front view of a device according to the present invention;Figure 2 is a rear view of the device of Figure 1;Figure 3 is a side view of the device of Figure 1;Figure 4 is a cross-sectional view along line IV-IV of Figure 1;Figure 5 is a cross-sectional view along line V-V of Figure 3;Figure 6 is a partial cross-sectional view along line VI-VI of Figure 1 in enlarged scale;Figure 7 is a partial side view, on an opposite side of Figure 3, and in enlarged scale of the device of Figure 1 in a different operational position; andFigure 8 is a partial exploded view of the device of Figure 1. Detailed description of the invention With reference to Figure 1, there is indicated by 1 a device for removing a lock-up pin 2 of a tensioner 3 according to the present invention. In particular, the tensioner 3 is of known type and comprises a base 4, an arm 5 hinged to the base 4, and a pulley 6 carried by the arm 5 and rotatable with respect to it. The tensioner 3 further comprises a spring (not illustrated) exerting on the arm 5 a torque configured to cause a rotation of the arm 5 with respect to the base 4 in a direction such as to maintain, in use, the pulley 6 in contact with a belt (not illustrated) of a transmission, for example an accessory transmission of an internal combustion engine. The lock-up pin 2 is configured to lock the arm 5 with respect to the base 4 in an installation position, and must be removed so as to make the tensioner 3 operational and to enable the rotation of the arm 5 under the action of the spring. The device 1 comprises a main body 11, a lever 12 rigidly coupled to the main body 11, and a sliding element 13 prismatically coupled to the main body 11. The main body 11 comprises a coupling portion 21, substantially shaped as a cylinder of axis A, and a guiding portion 22 extending along a lateral outer surface 23 of the coupling portion 21 and configured to guide the sliding element 13. The coupling portion 21 (Figure 2) of the main body 11 is configured to couple to the tensioner 3. In particular, the coupling portion 21 has a substantially cylindrical seat 31, defined by a substantially circular portion 32 of axis A and by a circumferential edge 33 extending axially from the lateral outer surface 23. The coupling portion 21 is provided with a key 34 of axis A, arranged in the portion 32, couplable to a loading element 35 integral with an arm 5 of the tensioner 3. In particular, the loading element 35 (Figure 4) is a prismatic end of a pin of the pulley 6 of the tensioner 3. Therefore, the seat 31 is configured to at least partially accommodate the pulley 6, and the key 34, of "female" type, is configured to prismatically cooperate with the loading element 35. Conveniently, the key 34 is interchangeable and can be chosen based on the prismatic end of the pin so as to couple thereto. The lever 12 comprises a rod 36 extending along an axis B, orthogonal to the axis A, and rigidly coupled to the coupling portion 21. The rod 36 (Figures 4 and 5) comprises a first end 41 which is free and constitutes a handle of the device 1, and a second end 42