Reversible target for a 3-, 4- or 6-cylinder engine

1. A camshaft toothed wheel ( 1 ), forming a target for a camshaft position sensor ( 2 ), the toothed wheel comprising a circular body ( 10 ) comprising two opposite main faces ( 11 A, 11 B), and at least six teeth ( 12 ) distributed over the circumference of the circular body, each tooth comprising two edges ( 13 ), one corresponding to a rising edge and the other to a falling edge, as a function of a direction of rotation of the wheel, the toothed wheel having asymmetry of revolution,

wherein the six teeth ( 12 ) are shaped so that the toothed wheel ( 1 ) comprises, considering the same main face and the same direction of rotation of the wheel:

four edges ( 14 ) of the same first rising or falling type spaced 90° apart, respectively, and

six edges ( 15 ) of the same second falling or rising type, respectively, spaced 60° apart, respectively.

2. The camshaft toothed wheel ( 1 ) as claimed in claim 1 , comprising a marking element on one of the two opposite main faces.

3. The toothed wheel ( 1 ) as claimed in claim 2 , comprising on the circumference at least two zones ( 17 ) devoid of edges over an angle of at least 35°, the two zones being spaced 180° apart.

4. The toothed wheel ( 1 ) as claimed in claim 2 , in which two teeth ( 12 ) each comprise one of the six edges ( 15 ) spaced 60° apart and an edge ( 16 , 16 ′) of the same type as the four edges spaced 90° apart, but distinct from them, called the first ( 16 ) and second ( 16 ′) unassigned edges, respectively, and, with there being denoted by:

A the minimum angular difference between one of the four edges ( 14 ) spaced 90° apart and one of the six edges ( 15 ) spaced 60° apart, and by

B the minimum angular difference between one of the six edges ( 15 ) spaced 60° apart and the first unassigned edge ( 16 ), and by

C the minimum angular difference between one of the six edges ( 15 ) spaced 60° apart and the second unassigned edge ( 16 ), the angular positions of the edges of the teeth of the toothed wheel are [0, A, 60, 90+A, 120, 180−C, 180, 180+A, 240, 270+A, 300, 360−B].

5. An internal combustion engine (M) comprising three, four or six cylinders, a camshaft, and a toothed wheel ( 1 ) as claimed in claim 2 mounted securely fixed to the camshaft, in which each tooth ( 12 ) corresponds to a high level of the toothed wheel and each gap between two teeth corresponds to a low level of the toothed wheel, and the internal combustion engine (M) further comprises a position sensor ( 2 ) for the camshaft capable of detecting a high or low level of the tooth and of detecting a tooth edge from a variation in level, the sensor having a higher detection performance for one type of edge than for the other type of edge,

the toothed wheel ( 1 ) being mounted on the camshaft so that a main face ( 11 A, 11 B) is oriented toward the camshaft position sensor ( 2 ),

the main face oriented toward the position sensor being chosen so that:

if the engine has three or six cylinders, the six edges ( 15 ) spaced 60° apart are edges of the type for which the detection performance of the sensor is greater, and

if the engine has four cylinders, the four edges ( 14 ) spaced 90° apart are edges of the type for which the detection performance of the sensor is greater.

6. The toothed wheel ( 1 ) as claimed in claim 1 , comprising on the circumference at least two zones ( 17 ) devoid of edges over an angle of at least 35°, the two zones being spaced 180° apart.

7. The toothed wheel ( 1 ) as claimed in claim 6 , comprising on the circumference four zones ( 17 ) devoid of one of the four edges spaced 90° apart and devoid of one of the six edges spaced 60° apart, the four zones being spaced 90° apart.

8. The toothed wheel ( 1 ) as claimed in claim 7 , in which two teeth ( 12 ) each comprise one of the six edges ( 15 ) spaced 60° apart and an edge ( 16 , 16 ′) of the same type as the four edges spaced 90° apart, but distinct from them, called the first ( 16 ) and second ( 16 ′) unassigned edges, respectively, and, with there being denoted by:

A the minimum angular difference between one of the four edges ( 14 ) spaced 90° apart and one of the six edges ( 15 ) spaced 60° apart, and by

B the minimum angular difference between one of the six edges ( 15 ) spaced 60° apart and the first unassigned edge ( 16 ), and by

C the minimum angular difference between one of the six edges ( 15 ) spaced 60° apart and the second unassigned edge ( 16 ), the angular positions of the edges of the teeth of the toothed wheel are [0, A, 60, 90+A, 120, 180−C, 180, 180+A, 240, 270+A, 300, 360−B].

9. An internal combustion engine (M) comprising three, four or six cylinders, a camshaft, and a toothed wheel ( 1 ) as claimed in claim 7 mounted securely fixed to the camshaft, in which each tooth ( 12 ) corresponds to a high level of the toothed wheel and each gap between two teeth corresponds to a low level of the toothed wheel, and the internal combustion engine (M) further comprises a position sensor ( 2 ) for the camshaft capable of detecting a high or low level of the tooth and of detecting a tooth edge from a variation in level, the sensor having a higher detection performance for one type of edge than for the other type of edge,

the toothed wheel ( 1 ) being mounted on the camshaft so that a main face ( 11 A, 11 B) is oriented toward the camshaft position sensor ( 2 ),

the main face oriented toward the position sensor being chosen so that:

if the engine has three or six cylinders, the six edges ( 15 ) spaced 60° apart are edges of the type for which the detection performance of the sensor is greater, and

if the engine has four cylinders, the four edges ( 14 ) spaced 90° apart are edges of the type for which the detection performance of the sensor is greater.

10. The toothed wheel ( 1 ) as claimed in claim 6 , in which two teeth ( 12 ) each comprise one of the six edges ( 15 ) spaced 60° apart and an edge ( 16 , 16 ′) of the same type as the four edges spaced 90° apart, but distinct from them, called the first ( 16 ) and second ( 16 ′) unassigned edges, respectively, and, with there being denoted by:

A the minimum angular difference between one of the four edges ( 14 ) spaced 90° apart and one of the six edges ( 15 ) spaced 60° apart, and by

B the minimum angular difference between one of the six edges ( 15 ) spaced 60° apart and the first unassigned edge ( 16 ), and by

C the minimum angular difference between one of the six edges ( 15 ) spaced 60° apart and the second unassigned edge ( 16 ), the angular positions of the edges of the teeth of the toothed wheel are [0, A, 60, 90+A, 120, 180−C, 180, 180+A, 240, 270+A, 300, 360−B].

11. An internal combustion engine (M) comprising three, four or six cylinders, a camshaft, and a toothed wheel ( 1 ) as claimed in claim 6 mounted securely fixed to the camshaft, in which each tooth ( 12 ) corresponds to a high level of the toothed wheel and each gap between two teeth corresponds to a low level of the toothed wheel, and the internal combustion engine (M) further comprises a position sensor ( 2 ) for the camshaft capable of detecting a high or low level of the tooth and of detecting a tooth edge from a variation in level, the sensor having a higher detection performance for one type of edge than for the other type of edge,

the toothed wheel ( 1 ) being mounted on the camshaft so that a main face ( 11 A, 11 B) is oriented toward the camshaft position sensor ( 2 ),

the main face oriented toward the position sensor being chosen so that:

if the engine has three or six cylinders, the six edges ( 15 ) spaced 60° apart are edges of the type for which the detection performance of the sensor is greater, and

if the engine has four cylinders, the four edges ( 14 ) spaced 90 ° apart are edges of the type for which the detection performance of the sensor is greater.

12. The toothed wheel ( 1 ) as claimed in claim 1 , in which two teeth ( 12 ) each comprise one of the six edges ( 15 ) spaced 60° apart and an edge ( 16 , 16 ′) of the same type as the four edges spaced 90° apart, but distinct from them, called the first ( 16 ) and second ( 16 ′) unassigned edges, respectively, and, with there being denoted by:

A the minimum angular difference between one of the four edges ( 14 ) spaced 90° apart and one of the six edges ( 15 ) spaced 60° apart, and by

B the minimum angular difference between one of the six edges ( 15 ) spaced 60° apart and the first unassigned edge ( 16 ), and by

C the minimum angular difference between one of the six edges ( 15 ) spaced 60° apart and the second unassigned edge ( 16 ), the angular positions of the edges of the teeth of the toothed wheel [0, A, 60, 90+A, 120, 180−C, 180, 180+A, 240, 270+A, 300, 360−B].

13. The toothed wheel as claimed in claim 12 , in which each tooth ( 12 ) corresponds to a high level of the toothed wheel and each gap between two teeth corresponds to a low level of the toothed wheel, the toothed wheel being adapted to form a target for a camshaft position sensor of the type capable of detecting a high or low level of the tooth and of deducing from a variation in level the presence of a tooth edge,

and the minimum angular difference A corresponds to a high level of the toothed wheel, and is defined by the following relationships:

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where R is the radius of the toothed wheel including a height of the teeth relative to the circular body, r is the radius of the circular body, L high is the minimum distance between the edges of a tooth allowing the detection of the high level between the two edges by the sensor, and L low is the minimum distance between the edges of two consecutive teeth delimiting an gap allowing the detection of the low level between these edges by the sensor.

14. The toothed wheel as claimed in claim 13 , in which the angular differences B and C correspond to a low level of the toothed wheel, and are defined by the following relationships:

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with C and B showing different values.

15. An internal combustion engine (M) comprising three, four or six cylinders, a camshaft, and a toothed wheel ( 1 ) as claimed in claim 13 mounted securely fixed to the camshaft, in which each tooth ( 12 ) corresponds to a high level of the toothed wheel and each gap between two teeth corresponds to a low level of the toothed wheel, and the internal combustion engine (M) further comprises a position sensor ( 2 ) for the camshaft capable of detecting a high or low level of the tooth and of detecting a tooth edge from a variation in level, the sensor having a higher detection performance for one type of edge than for the other type of edge,

the toothed wheel ( 1 ) being mounted on the camshaft so that a main face ( 11 A, 11 B) is oriented toward the camshaft position sensor ( 2 ),

the main face oriented toward the position sensor being chosen so that:

if the engine has three or six cylinders, the six edges ( 15 ) spaced 60° apart are edges of the type for which the detection performance of the sensor is greater, and

if the engine has four cylinders, the four edges ( 14 ) spaced 90° apart are edges of the type for which the detection performance of the sensor is greater.

16. The toothed wheel as claimed in claim 12 , in which each tooth ( 12 ) corresponds to a high level of the toothed wheel and each gap between two teeth corresponds to a low level of the toothed wheel, the toothed wheel being adapted to form a target for a camshaft position sensor of the type capable of detecting a high or low level of the tooth and for deducing from a variation in level the presence of a tooth edge, and the minimum angular difference A corresponds to a low level of the toothed wheel, and is defined by the following relationships:

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where R is the radius of the toothed wheel including a height of the teeth relative to the circular body, r is the radius of the circular body, L high is the minimum distance between the edges of a tooth allowing the detection of the high level between the two edges by the sensor, and L low is the minimum distance between the edges of two consecutive teeth delimiting a gap allowing the detection of the low level between these edges by the sensor.

17. The toothed wheel as claimed in claim 16 , in which the angular differences B and C correspond to a high level of the toothed wheel, and are defined by the following relationships:

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with C and B showing different values.

18. An internal combustion engine (M) comprising three, four or six cylinders, a camshaft, and a toothed wheel ( 1 ) as claimed in claim 12 mounted securely fixed to the camshaft, in which each tooth ( 12 ) corresponds to a high level of the toothed wheel and each gap between two teeth corresponds to a low level of the toothed wheel, and the internal combustion engine (M) further comprises a position sensor ( 2 ) for the camshaft capable of detecting a high or low level of the tooth and of detecting a tooth edge from a variation in level, the sensor having a higher detection performance for one type of edge than for the other type of edge,

the toothed wheel ( 1 ) being mounted on the camshaft so that a main face ( 11 A, 11 B) is oriented toward the camshaft position sensor ( 2 ),

the main face oriented toward the position sensor being chosen so that:

if the engine has three or six cylinders, the six edges ( 15 ) spaced 60° apart are edges of the type for which the detection performance of the sensor is greater, and

if the engine has four cylinders, the four edges ( 14 ) spaced 90° apart are edges of the type for which the detection performance of the sensor is greater.

19. An internal combustion engine (M) comprising three, four or six cylinders, a camshaft, and a toothed wheel ( 1 ) as claimed in claim 1 mounted securely fixed to the camshaft, in which each tooth ( 12 ) corresponds to a high level of the toothed wheel and each gap between two teeth corresponds to a low level of the toothed wheel, and the internal combustion engine (M) further comprises a position sensor ( 2 ) for the camshaft capable of detecting a high or low level of the tooth and of detecting a tooth edge from a variation in level, the sensor having a higher detection performance for one type of edge than for the other type of edge,

the toothed wheel ( 1 ) being mounted on the camshaft so that a main face ( 11 A, 11 B) is oriented toward the camshaft position sensor ( 2 ),

the main face oriented toward the position sensor being chosen so that:

if the engine has three or six cylinders, the six edges ( 15 ) spaced 60° apart are edges of the type for which the detection performance of the sensor is greater, and

if the engine has four cylinders, the four edges ( 14 ) spaced 90° apart are edges of the type for which the detection performance of the sensor is greater.

20. A method for assembling an internal combustion engine (M), comprising a camshaft, a toothed wheel as claimed in claim 1 , and a camshaft position sensor ( 2 ) of the type capable of detecting a high or low level of the toothed wheel and of detecting a tooth edge from a variation in level, the sensor having a greater detection performance for one type of edge than for the other type of edge,

the assembly method comprising mounting the toothed wheel ( 1 ) on the camshaft so that a main face ( 11 A, 11 B) of the toothed wheel is oriented toward the camshaft position sensor, in which, if the engine has three or six cylinders, the main face oriented toward the position sensor is chosen so that the six edges ( 15 ) spaced 60° apart are of the type for which the sensor has the best detection performance, and

if the engine has four cylinders, the main face oriented toward the position sensor is the opposite face, so that the four edges ( 14 ) spaced 90° apart are of the type for which the sensor has the best detection performance.