TOOLING FOR ASSEMBLING A PULLEY WITH A SHAFT AND AN ASSEMBLY METHOD USING SUCH TOOLING

Abstract

The invention relates to a tool (10) for a vehicle for assembling a pulley and a shaft, the pulley having a first central axis, the shaft having a second central axis, the pulley comprising a belt configured to be tensioned, the tool (10) having a longitudinal axis (X), the tool (10) comprising a cam surface (13) configured to cooperate with the shaft, and the tool (10) being configured to form a predetermined angle between the longitudinal axis (X) and the first central axis causing a translation of the pulley towards the shaft in the direction of the first central axis when the cam surface (13) cooperates with a portion of the shaft. Abstract figure: Fig. 1

Description

Title of the invention: TOOLING FOR ASSEMBLING A PULLEY WITH A SHAFT AND METHOD ASSEMBLY USING SUCH TOOLING

[0001] The invention relates to vehicle maintenance tooling, in particular tooling for assembling a pulley and the shaft of a rotating machine, such as the drive shaft of an engine.

[0002] Patent application FR2813105A1 describes a screw-on assembly of a pulley with a vehicle shaft. The shaft has a threaded hole, while the pulley has a hole configured to be screwed onto the shaft using a threaded screw. The pulley also includes a periphery configured to cooperate with a belt.

[0003] However, to screw the shaft onto the pulley, the belt must first be relieved of tension on the pulley, for example, by adjusting a tensioner that applies tension to the belt. However, the tensioner is generally difficult to access. Thus, such an operation proves costly in terms of labor time.

[0004] The objective of the invention is to overcome this drawback by providing a simple and easy-to-use tool.

[0005] To achieve this objective, the invention proposes a tooling for assembling a pulley and a shaft, the pulley having a first central axis, the shaft having a second central axis, the pulley comprising a belt configured to be tensioned, the tooling having a longitudinal axis, the tooling comprising a cam surface configured to cooperate with the shaft, and the tooling being configured to form a predetermined angle between the longitudinal axis and the first central axis in a predetermined position causing a translation of the pulley towards the shaft in the direction of the first central axis when the cam surface cooperates with a part of the shaft.

[0006] The tooling facilitates the redirection of forces exerted by the tensioned belt, coupled with the tooling's inclination relative to the pulley, so that the tooling transmits a translational movement from the shaft to the pulley when the cam surface is in contact with a portion of the shaft. This makes it possible, in particular, to align the central axis of the pulley with that of the shaft while maintaining the tensioner's pressure on the belt during the assembly operation, thus avoiding the need to adjust the tensioner to perform the assembly. Furthermore, the tooling allows the translational movement to be performed with a force that ensures good assembly accuracy. while avoiding damage to mechanical components such as the pulley and shaft.

[0007] Advantageously, the tooling includes a stop having a first diameter greater than a second diameter of a shaft fixing hole extending along the direction of the second central axis.

[0008] Such a stop has a radial dimension, considered with respect to the longitudinal axis, small enough to be wedged against the shaft by passing through the pulley, without however inserting itself into such a fixing hole, thereby exerting a force, in particular in the fixing hole, for example, on the threading of the hole, risking damage to the latter.

[0009] Advantageously, the tooling includes a bearing surface configured to bear against the pulley when the pulley and shaft are assembled.

[0010] The bearing surface has a radial footprint, considered with respect to the longitudinal axis, small enough to pass through a hole through the bearing surface while having sufficient rigidity to accompany the tilting movement of the tooling while protecting it from wear stresses, particularly at the point of contact with the pulley.

[0011] Advantageously, the tooling features: - a first connecting surface extending between the bearing surface and the cam surface, the first connecting surface having a diameter strictly increasing along the longitudinal axis traversed from the bearing surface to the cam surface; - a second connecting surface extending between the cam surface and the stop, the second connecting surface having a diameter strictly decreasing along the longitudinal axis traversed from the cam surface to the stop.

[0012] Such connecting surfaces, due to their shape, facilitate the cooperation of the cam surface with the shaft.

[0013] Advantageously, the tooling includes a gripping surface and a shoulder between the bearing surface and the gripping surface.

[0014] This makes it possible in particular to reduce the concentrations of stresses on the tooling when the pulley and the shaft are assembled.

[0015] Advantageously, the gripping surface extends over a first distance along the longitudinal axis, the support surface extends over a second distance along the longitudinal axis, the ratio of the first distance to the second distance being between 1 and 10.

[0016] Such a distance ratio makes it possible to generate a lever arm, multiplying the forces exerted by the operator on the tooling, in particular to raise the pulley so as to align the central axis of the pulley with that of the shaft, thus facilitating the assembly of the pulley and the shaft.

[0017] Advantageously, the bearing surface and the gripping surface are cylindrical in shape, the bearing surface has a first diameter and the gripping surface has a second diameter, the ratio of the second diameter to the first diameter being between 1 and 10.

[0018] Such a diameter ratio gives the tooling sufficient rigidity to resist the stresses on the tooling in order to avoid any plastic deformation, while offering sufficient grip to easily handle the gripping surface.

[0019] Advantageously, the predetermined angle is substantially between 1° and 45°.

[0020] The invention also relates to a method for assembling a pulley with a shaft, using tooling defined as above, the method comprising the following steps: - a step of bringing the pulley and the shaft into contact; - a step of inserting the tooling into the pulley and the shaft, the tooling being in contact with the pulley and the shaft; - a step of actuation of the tooling so as to exert a torque on the gripping surface, the bearing surface being in contact with the pulley and the cam surface being in contact with the shaft; - an engagement step, so as to assemble the pulley and the shaft, by a translational movement of the pulley towards the shaft along the direction of the first central axis, the tooling being held in the predetermined position, when the first central axis and the second central axis are coaxial.

[0021] Advantageously, the method further includes a step of removing the tooling from the shaft and the pulley, a screw being inserted through a hole through the pulley and being screwed into a fixing hole in the shaft so as to keep the pulley and the shaft in contact.

[0022] The invention will be further detailed by describing an embodiment of the present invention, and based on the accompanying figures in which: - [Fig.1] schematically illustrates a front view along a longitudinal axis X of a tool for assembling a pulley and a shaft, according to an embodiment of the invention; - [Fig.2] schematically illustrates a cross-sectional view of a tool, illustrated in [Fig.1], in contact with the shaft and the pulley; - [Fig.3] schematically illustrates a cross-sectional view of the tooling, with the pulley and shaft in a predetermined relative position; - [Fig.4] schematically illustrates a cross-sectional view of the tooling in a predetermined position; - [Fig.5] schematically illustrates a front view of a pulley with a belt unloaded; - [Fig.6] schematically illustrates a front view of a pulley with a belt tensioned by a tensioner; - [Fig.7] illustrates a flowchart representing the steps of a process for assembling a pulley and a shaft, using tooling illustrated in [Fig.1], according to an embodiment of the present invention.

[0023] The tooling 10, illustrated in [Fig.1], has a longitudinal axis X and is configured to assemble a pulley 20 and a shaft 30 according to an embodiment of the present invention, the pulley 20 comprising a belt 40 configured to be tensioned, for example by a tensioner 50, the assembly being carried out without having to access the tensioner 50 to unload the belt 40.

[0024] In its general definition, the invention relates to the assembly of a pulley 20 and a shaft 30 of a vehicle, thus a specific use of the tooling 10 provides in particular for the assembly of the pulley 20 carrying the transmission belt 40 of a vehicle with the shaft 30 of the camshaft of the vehicle.

[0025] The pulley 20, illustrated in [Fig.2], has a first central axis XL. The pulley 20 includes a through hole 21 extending along the direction of the first central axis XL.

[0026] In [Fig.2], the pulley 20 has a housing 22 configured to receive the shaft 30, the housing 22 being connected to the through hole 21.

[0027] The pulley 20, illustrated in [Fig. 5], includes on its outer periphery a belt 40 configured to be tensioned. Indeed, a tensioner 50 exerts a pressure on the belt 40 that varies according to the extension of the tensioner 50, subjecting the belt 40 to a tensional stress.

[0028] In particular, at [Fig.5], the extension of the tensioner 50 is at its maximum, the belt 40 being unloaded and having so-called "soft" strands, these conditions allowing for the replacement of the pulley 20 or the shaft 30, or even of a component carrying the shaft 30, for example a camshaft carrier 30 of a thermal engine.

[0029] In [Fig.2], the shaft 30 has a second central axis X2. In addition, the shaft 30 includes a chamber 32 comprising a fixing hole 31 extending along the direction of the second central axis X2.

[0030] The tooling 10 includes a cam surface 13 configured to cooperate with the shaft 30, the tooling 10 being configured so that a predetermined angle between the longitudinal axis X and the first central axis XI in a predetermined position causes a translation of the pulley 20 towards the shaft 30 in the direction of the first central axis XI when the cam surface 13 cooperates with a part of the shaft 30.

[0031] In [Fig.1], the cam surface 13 has a ring shape extending circumferentially around the longitudinal axis X.

[0032] The tooling 10 advantageously includes a stop 15 having a first diameter dl, illustrated [Fig.1], greater than a second diameter d2, illustrated [Fig.3], of the fixing hole 31 of the shaft 30.

[0033] Thus, this prevents the tooling 10 from inserting into the fixing hole 31 when the cam surface 13 cooperates with the shaft 30, the stop 15 fitting into the chamber 32 of the shaft 30.

[0034] The tooling 10 advantageously includes a bearing surface 12 configured to bear against the pulley 20 when the pulley 20 and the shaft 30 are assembled.

[0035] A first connecting surface 16, included by the tooling 10, extends between the cam surface 13 and the stop 15.

[0036] The first connecting surface 16 has a diameter that is strictly increasing along the longitudinal axis X traversed from the support surface 12 to the cam surface 13.

[0037] A second connecting surface 17, included by the tooling 10, extends between the cam surface 13 and the stop 15.

[0038] The second connecting surface 17 has a diameter that is strictly decreasing along the longitudinal axis X traversed from the cam surface 13 to the stop 15.

[0039] The tooling 10, illustrated in [Fig.1], includes a gripping surface 11 represented by a cylinder having a first diameter and extending over a first distance Dl along the direction of the longitudinal axis X.

[0040] The support surface 12 is represented by a cylinder having a second diameter and extending over a second distance D2 along the direction of the longitudinal axis X.

[0041] In [Fig.1], the first distance is three times greater than the second distance and the first diameter is 1.5 times greater than the second diameter.

[0042] Advantageously, a shoulder 14 is provided between the gripping surface 11 and the support surface 12. The shoulder 14 having, in [Fig.1], a conical shape ensuring continuity between the support surface 12 and the gripping surface 11.

[0043] A flowchart of a method for assembling a pulley 20 and a shaft 30 is illustrated [Fig.7], the steps of the method being described below according to an embodiment of the present invention.

[0044] In a contact step El, the pulley 20 and the shaft 30 are brought into contact with each other.

[0045] In [Fig.2], the pulley 20 and the shaft 30 are brought into contact, the pulley 20 and the shaft 30 having a relative distance D3 between the first central axis XI and the second central axis X2.

[0046] In an insertion step E2, the tooling 10 is inserted into the pulley 20 and the shaft 30, as illustrated in [Fig.2], the tooling being in contact with the pulley 20 and the shaft 30.

[0047] Thus, on [Fig.2], the stop 15 is wedged against the chamber 32 of the shaft 30, while the bearing surface 12 is in contact with the through hole 21.

[0048] In an actuation step E3, the tooling 10 is actuated at the gripping surface 11 so as to exert a torque on the gripping surface 11, the bearing surface 12 being in contact with the pulley 20 and the cam surface 13 being in contact with the shaft 30.

[0049] Due to its actuation, the tooling 10 causes the pulley 20 to tension the belt 40 as illustrated in [Fig.6], requiring an effort and precision of movement incompatible with a manual operation which risks damaging the mechanical components or imposing unforeseen mechanical stresses on them.

[0050] The bearing surface 12 cooperates with the pulley 20 so as to create a lever arm reducing the relative distance D3 between the pulley 20 and the shaft 30. In [Fig.3], the first central axis XI is aligned with the second central axis X2, the shaft 30 and the pulley 20 being in a predetermined relative position.

[0051] In an engagement step E4, the pulley 20 is engaged on the shaft 30 by a translational movement of the pulley 20 along the direction of the first central axis XI, the tooling 10 being held in the predetermined position, when the first central axis XI and the second central axis X2 are aligned.

[0052] The difference in diameter between the bearing surface 12 and the radial clearance of the cam surface 13 with respect to the longitudinal axis X is provided so as to form the predetermined angle a between the longitudinal axis X and the first central axis XI, as illustrated in [Fig.4].

[0053] The predetermined angle a, coupled with the tension of the belt 40 on the pulley 20, allows the shaft 30 to slide towards the pulley 20 by a translational movement in the direction of the first central axis XI, the shaft 30 sliding in particular on the housing 22 of the pulley 20.

[0054] In a removal step E5, the tooling 10 is removed from the shaft 30 and the pulley 20, a screw 60 passing through the through hole 21 of the pulley 20 and being screwed into the fixing hole 31 of the shaft 30, as illustrated in [Fig.6], so as to keep the pulley 20 in contact with the shaft 30.

Claims

Demands

1. Tooling (10) for assembling a pulley (20) and a shaft (30), the pulley (20) having a first central axis (XI), the shaft (30) having a second central axis (X2), the pulley (20) comprising a belt (40) configured to be tensioned, the tooling (10) having a longitudinal axis (X), the tooling (10) comprising a cam surface (13) configured to cooperate with the shaft (30), and the tooling (10) being configured to form a predetermined angle (a) between the longitudinal axis (X) and the first central axis (XI) in a predetermined position causing a translation of the pulley (20) towards the shaft (30) in the direction of the first central axis (XI) when the cam surface (13) cooperates with a portion of the shaft (30).

2. Tooling (10) according to claim 1, characterized in that the tooling (10) comprises a stop (15) having a first diameter (dl) greater than a second diameter (d2) of a fixing hole (31) of the shaft (30) extending along the direction of the second central axis (X2).

3. Tooling (10) according to claim 1 or 2, characterized in that the tooling (10) comprises a bearing surface (12) configured to bear against the pulley (20) when the pulley (20) and the shaft (30) are assembled.

4. Tooling (10) according to claims 2 and 3, characterized in that the tooling has: - a first connecting surface (16) extending between the support surface (12) and the cam surface (13), the first connecting surface (16) having a diameter that is strictly increasing along the longitudinal axis (X) traversed from the support surface (12) to the cam surface (13); - a second connecting surface (17) extending between the cam surface (13) and the stop (15), the second connecting surface (17) having a diameter that is strictly decreasing along the longitudinal axis (X) traversed from the cam surface (13) to the stop (15).

5. Tooling (10) according to claim 3 or 4, characterized in that the tooling (10) comprises a gripping surface (11) and a shoulder (14) between the bearing surface (12) and the gripping surface (11).

6. Tooling (10) according to claim 5, characterized in that the gripping surface (11) extends over a first distance (D1) along the longitudinal axis (X), the support surface (12) extends over a second distance (D2) along the longitudinal axis (X), the ratio of the first distance (D2) to the second distance (D1) being between 1 and 10.

7. Tooling (10) according to claim 5 or 6, characterized in that the bearing surface (12) and the gripping surface (11) are cylindrical in shape, the bearing surface (12) having a first diameter and the gripping surface (11) having a second diameter, the ratio of the second diameter to the first diameter being between 1 and 10.

8. Tooling (10) according to any one of claims 1 to 7, characterized in that the predetermined angle (a) is substantially between 1° and 45°.

9. A method for assembling a pulley (20) with a shaft (30), employing a tool (10) according to any one of claims 1 to 8, the method comprising the following steps: - a step of bringing the pulley (20) and the shaft (30) into contact (E1); - a step of inserting the tool (10) into the pulley (20) and the shaft (30), the tool (10) being in contact with the pulley (20) and the shaft (30); - a step of actuating the tool (10) so as to exert a torque on the gripping surface (11), the bearing surface (12) being in contact with the pulley (20) and the cam surface (13) being in contact with the shaft (30);- an engagement step (E4) so ​​as to assemble the pulley (20) and the shaft (30) by a translational movement of the pulley (20) towards the shaft (30) along the direction of the first central axis (XI), the tooling (10) being held in the predetermined position, when the first central axis (XI) and the second central axis (X2) are coaxial.;

10. A method according to claim 9, characterized in that the method further comprises a step of removing the tooling (10) from the shaft (30) and the pulley (20), a screw (60) being inserted by a through hole (21) of the pulley (20) and being screwed into a fixing hole (31) of the shaft so as to keep the pulley (20) and the shaft (30) in contact.

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