DRIVE SHAFT REALIGNMENT TOOL FOR AN INTERNAL COMBUSTION ENGINE INTENDED FOR A MOTOR VEHICLE

Abstract

The invention relates to a realignment tool (1) for a drive shaft of an internal combustion engine intended for a motor vehicle, characterized in that the realignment tool (1) comprises a body (2) configured to be manipulated by a user and a head (3) configured to fit into a housing positioned at one end of the drive shaft, the body (2) and the head (3) each having a longitudinal shape, the body (2) being perpendicular to the head (3), said head (3) comprising a surface (5) and a bevel (6), the surface (5) and the bevel (6) each being configured to make partial or total contact with said housing. Furthermore, the invention relates to a method for realigning a drive shaft of an internal combustion engine intended for a motor vehicle by means of a realignment tool. Figure 1

Description

Title of the invention: DRIVE SHAFT REALIGNMENT TOOL FOR AN INTERNAL COMBUSTION ENGINE INTENDED FOR A MOTOR VEHICLE

[0001] The invention relates to means for realigning the transmission shafts of internal combustion engines in motor vehicles.

[0002] Prior art patent application FR3132658 is known, describing a tool for angularly setting the camshaft of an internal combustion engine. The camshaft has a flat face. The setting tool comprises a plate including a guide and a plurality of holes for mounting it on the internal combustion engine. Furthermore, the setting tool includes a setting stop that fits into the guide of the plate. The setting stop has a front surface intended to contact the flat face of the camshaft. In addition, the setting tool includes an axial clamping device for clamping the setting stop forward against the plate. By tightening the axial clamping device, the setting stop exerts pressure on the flat face of the camshaft to adjust its rotation. However, a drawback remains.The timing tool does not allow the camshaft to be locked in place and therefore cannot be correctly repositioned to correct a camshaft component such as a sprocket or pulley.

[0003] The objective of the present invention is to overcome these drawbacks and to to allow a realignment of a drive shaft without requiring it to be locked in a specific position beforehand.

[0004] To achieve this objective, the invention proposes a realignment tool for a transmission shaft of a thermal engine intended for a motor vehicle, remarkable in that the realignment tool comprises a body configured to be manipulated by a user and a head configured to fit into a housing positioned at one end of the transmission shaft, the body and the head each having a longitudinal shape, the body being perpendicular to the head, said head comprising a surface and a bevel, the surface and the bevel each being configured to make partial or total contact with said housing.

[0005] Thanks to the invention, stopping and holding the transmission shaft in a precise position is not required to perform the realignment. This therefore represents a time saving for technicians.

[0006] Advantageously, said realignment tool comprises a metallic material.

[0007] Metallic materials are sufficiently resistant to allow the exercise of force on the body without causing deformation, or even breakage, of the realignment tool.

[0008] Preferably, said metallic material comprises folded sheet metal.

[0009] The use of bent sheet metal facilitates the manufacture of the realignment tool.

[0010] Furthermore, the invention relates to a method for realigning a transmission shaft of a heat engine intended for a motor vehicle by means of a realignment tool described above, the transmission shaft having a first axis, the body of the realignment tool having a second axis, remarkable in that said method comprises the following steps: - a step of introducing the realignment tool into the housing, the realignment tool being introduced so that the bevel is entirely in contact with said housing, the surface being partially in contact with said housing, the second axis being inclined with respect to the first axis, the realignment tool being incapable of generating a rotation of the transmission shaft; - a step of tilting the realignment tool so that said bevel is partially in contact with said housing, said surface being entirely in contact with said housing, the first axis and the second axis being parallel to each other, the realignment tool being capable of generating a rotation of the transmission shaft to realign it when a first force is exerted on the body by the user, said first force being perpendicular to the second axis and directed from the bevel towards the body; - a step of removing the realignment tool by the user exerting a second force on the body, said second force being perpendicular to the second axis and directed from the body towards the bevel.

[0011] Thanks to the invention, the rotation of the transmission shaft in a single direction of rotation is permitted to realign the transmission shaft without risk of damaging the internal combustion engine.

[0012] Preferably, during the introduction step, the second axis is inclined with respect to the first axis at an angle between 130° and 170°.

[0013] Preferably, the transmission shaft is a module comprising two camshafts and a hydraulic tensioner.

[0014] In this case, when the mechanism is new, it prevents the two camshafts from becoming unsynchronized, and therefore prevents the internal combustion engine from becoming damaged.

[0015] The invention will be further detailed by describing non-limiting embodiments, and based on the accompanying figures illustrating variants of the invention, in which: - [Fig-1] schematically illustrates a tool for realigning a transmission shaft of a thermal engine intended for a motor vehicle according to an embodiment of the invention; - [Fig.2] schematically illustrates the transmission shaft during the introduction step of the process of realigning a transmission shaft of a thermal engine intended for a motor vehicle using the realignment tool; - [Fig.3] schematically illustrates the transmission shaft during the tilting step of the realignment process of a transmission shaft of a thermal engine intended for a motor vehicle using the realignment tool; - [Fig.4] schematically illustrates the transmission shaft during the removal step of the process of realigning a transmission shaft of a thermal engine intended for a motor vehicle using the realignment tool.

[0016] Figure 1 schematically illustrates a realignment tool 1 for a drive shaft 7 of an internal combustion engine intended for a motor vehicle. The realignment tool 1 comprises a longitudinal body 2 having a second axis Y (not shown in Figure 1). Furthermore, the realignment tool 1 comprises a head 3 positioned at one end of the body 2. The head 3 is configured to fit into a recess 4 positioned at the end of the drive shaft 7. The head 3 also has a longitudinal shape. The head 3 is perpendicular to the body 2. The head 3 has a surface 5 positioned opposite the body 2. The surface 5 is configured to make partial or full contact with said recess 4. In addition, the head 3 has a bevel 6 at its end. The bevel 6 is also configured to make partial or full contact with said recess 4.Preferably, the realignment tool 1 comprises a metallic material or any other material sufficiently rigid to allow forces to be exerted on said realignment tool 1 without causing it to break. Metal has the advantage of being readily available and inexpensive. Even more preferably, the metallic material is sheet metal bent to facilitate the manufacture of the realignment tool 1.

[0017] Furthermore, the invention relates to a method for realigning a drive shaft 7 of an internal combustion engine intended for a motor vehicle using the realignment tool described above. The drive shaft 7 has a first axis X. During the insertion step, the realignment tool 1 is inserted into the housing 4 positioned at the end of the drive shaft 7. The insertion is carried out so that the bevel 6 is fully in contact with said housing 4, that is to say with the walls forming said housing 4, and that the surface 5 is partially in contact with said housing 4. For this, the realignment tool 1 is introduced at an angle, such that the second axis Y is inclined with respect to the first axis X. Preferably, the second axis Y is inclined with respect to the first axis X at an angle between 130° and 170°. In this configuration illustrated in [Fig. 2], the realignment tool 1 is unable to generate a rotation of the transmission shaft 7. During a tilting step, the realignment tool 1 is tilted according to the arrow shown in [Fig. 2] so as to reach the position illustrated in [Fig. 3]. Specifically, the realignment tool 1 is tilted so that the chamfer 6 is partially in contact with the housing 4, unlike the insertion step during which the chamfer 6 was fully in contact with the housing 4. Similarly, the surface 5 comes into full contact with the housing 4, whereas previously, during the insertion step, the surface 5 was only partially in contact with the housing 4.In this configuration, the realignment tool 1 is capable of generating a rotation of the transmission shaft 7 in a single direction to realign it when a first force A, illustrated in [Fig. 3], is exerted by a user on the body 2 of the realignment tool 1. The first force A is perpendicular to the second Y-axis, that is, perpendicular to the body 2 of the realignment tool 1. Furthermore, the first force A is directed from the bevel 6 towards the body 2. Indeed, when the first force A is exerted by the user, the realignment tool 1 becomes wedged in the housing 4 thanks to a force transfer between the head 3 of the realignment tool 1 and the edge of the housing 4, so that the realignment tool 1 becomes fixed to the transmission shaft 7. Thus, it is possible to control the rotation of the transmission shaft 7 around the first X-axis in a single direction. During a withdrawal step illustrated in the [Fig.[4] The realignment tool 1 is withdrawn from the housing 4 by the application of a second force B. Like the first force A, the second force B is perpendicular to the body 2 of the realignment tool 1. However, the second force B is oriented inversely to the first force A, from the body 2 towards the bevel 6. The second force B is also applied by the user, at the level of the body 2 of the realignment tool 1. The application of the second force B causes the bevel 6 to move closer to the housing 4 and the surface 5 to detach from the housing 4. The surface 5 is therefore only partially in contact with the housing 4, while the bevel 6 is fully in contact with the housing 4. When the user applies the second force B to the realignment tool 1, this causes the realignment tool 1 to be withdrawn from the housing 4 as previously described.Therefore, it is impossible to generate a rotation of the transmission shaft 7 around the second axis Y when the second force B. is exerted by the user. As a result, the rotation of the transmission shaft 7 is only possible in the single direction permitted by the application of the first force A as illustrated in [Fig.3].

[0018] In a preferred embodiment, the drive shaft 7 is a module comprising two camshafts and a hydraulic tensioner. In an internal combustion engine, the two camshafts serve to better control the intake and exhaust of gases to improve the performance and efficiency of the internal combustion engine. The hydraulic tensioner ensures that the timing chain or belt remains properly tensioned and perfectly synchronizes the two camshafts with the crankshaft, so that the internal combustion engine operates smoothly and reliably. When such a mechanism is new, it is not primed with oil. This causes one of the camshafts to rotate in the opposite direction to the desired direction of rotation. This presents a risk of the two camshafts becoming unsynchronized during reassembly of the module, and consequently, damage to the internal combustion engine during its starting.

Claims

Demands

1. A realignment tool (1) for a drive shaft (7) of a heat engine intended for a motor vehicle, characterized in that the realignment tool (1) comprises a body (2) configured to be manipulated by a user and a head (3) configured to fit into a housing (4) positioned at one end of the drive shaft, the body (2) and the head (3) each having a longitudinal shape, the body (2) being perpendicular to the head (3), said head (3) comprising a surface (5) and a bevel (6), the surface (5) and the bevel (6) each being configured to make partial or total contact with said housing (4).

2. Realignment tool (1) according to claim 1 characterized in that said realignment tool (1) comprises a metallic material.

3. Realignment tool (1) according to claim 2 characterized in that said metallic material comprises bent sheet metal.

4. A method for realigning a drive shaft (7) of a heat engine intended for a motor vehicle by means of a realignment tool (1) according to any one of claims 1 to 3, the drive shaft (7) having a first axis (X), the body (2) of the realignment tool (1) having a second axis (Y), characterized in that said method comprises the following steps: - a step of introducing the realignment tool (1) into the housing (4), the realignment tool (1) being introduced so that the bevel (6) is entirely in contact with said housing (4), the surface (5) being partially in contact with said housing (4), the second axis (Y) being inclined with respect to the first axis (X), the realignment tool (1) being incapable of generating a rotation of the drive shaft (7);- a tilting step of the realignment tool (1) so that said bevel (6) is partially in contact with said housing (4), said surface (5) being entirely in contact with said housing (4), the first axis (X) and the second axis (Y) being parallel to each other, the realignment tool (1) being capable of generating a rotation of the transmission shaft (7) to realign it when a first force (A) is exerted on the body (2) by the user, said first force (A) being perpendicular to the second axis (Y) and directed from the bevel (6) towards the body (2); - a step of removing the realignment tool (1) by the exercise of a second force (B) on the body (2) by the user, said second force (B) being perpendicular to the second axis (Y) and oriented from the body (2) towards the bevel (6).

5. The method according to claim 4 characterized in that, during the introduction step, the second axis (Y) is inclined with respect to the first axis (X) at an angle between 130° and 170°.

6. Method according to claim 4 or 5 characterized in that the transmission shaft (7) is a module comprising two camshafts and a hydraulic tensioner.